2,205 results on '"Absorption (Physiology)"'
Search Results
2. Development of UV Spectrophotometric Method for Estimation of Barberin in Bulk and Pharmaceutical Dosage Form.
- Author
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Dhere, Mohan D. and Bhavya, E.
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DOSAGE forms of drugs ,SPECTROPHOTOMETRY ,STRESS management ,ABSORPTION (Physiology) ,ACCURACY - Abstract
A simple, accurate, precise spectrophotometric method was developed for the estimation of barberin (BRN). The optimum condition for the analysis of the BRN was studied. BRN was subjected to stress degradation under different conditions like acidic, alkali, neutral, oxidation, photolytic, and thermal degradation as per recommended by the International Conference on Harmonization (ICH). The samples thus prepared were used for degradation studies by with the developed method. The lambda max i.e. absorption maxima found at 348 nm and calibration curve linear over the range of 0-40 µg/ml. The standard regression equation and correlation coefficient fond to be y = 0.02x - 0.0189 R² = 0.9982 respectively. % RSD found to be less than one. The accepted limits of accuracy (recovery) were found to be 97.75% and all observed data are within required range which indicates good recovery value. LOD and LOQ found to be 0.0529 µg/ml and 0.2167 µg/ml respectively by developed UV spectroscopic method. [ABSTRACT FROM AUTHOR]
- Published
- 2023
3. Texture and terahertz analysis of YBa2Cu3O7 grown onto LaAlO3 by the chemical solution deposition technique.
- Author
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Sanchez Cornejo, H., De Los Santos Valladares, L., Kamboj, V. S., Bustamante Dominguez, A., González, J. C., Osorio Anaya, A. M., Moreno, N. O., Beere, H. E., Ritchie, D. A., Newton, P. J., and Barnes, C. H. W.
- Subjects
CHEMICAL solution deposition ,X-ray diffraction ,MAGNETIZATION ,SUPERCONDUCTORS ,ABSORPTION (Physiology) - Abstract
We analyze in-plane and out-of-plane texture and terahertz analysis of a YBa
2 Cu3 O7-δ (YBCO) film deposited by chemical solution deposition technique onto LaAlO3 (100) substrate. X-ray diffraction reveals the presence of (00l) reflections for the YBCO phase. The out-of-plane texture, measured by a rocking curve, shows two sub-layers with Δω = 0.45° and 1.8°. The value of the c-axis fraction of the crystallites is 81%. Also, the in-plane texture was studied by ϕ-scan measurements of the (102) reflection, displaying mostly a colony of c-axis oriented grains, and two colonies of a-axis oriented grains onto the YBCO surface. In addition, the temperature dependence of the magnetization measurement revealed a critical temperature of 90 K, typical for YBCO superconductor material. From the temperature-dependent optical conductivity of YBCO, we observe an absorption feature at ≈1.57 THz, which redshifts with increasing temperature. [ABSTRACT FROM AUTHOR]- Published
- 2021
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4. FENTANYL FEAR AND FACTS.
- Author
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Erich, John
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FENTANYL ,HEALTH risk assessment ,COMMON misconceptions ,HAZARDOUS substance exposure ,ABSORPTION (Physiology) ,FIRST responders - Abstract
The article discusses the spread of misinformation about the health risks of fentanyl exposure. Topics explored include the myths regarding fentanyl absorption into the body according to medical toxologist Ryan Marino, the perception of some first responders on incidental exposure to fentanyl, and the criticisms received by the 2021 video released by the San Diego County Sheriff's Department about the alleged fentanyl intoxication experienced by Deputy David Faiivae.
- Published
- 2022
5. Development of a predictive tool for estimating occupational inadvertent ingestion exposure
- Author
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Gorman Ng, Melanie
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610 ,Occupational safety ,Absorption (Physiology) - Abstract
There are three primary routes by which occupational exposure to hazardous substances occurs: inhalation, dermal absorption, and ingestion. Of these, ingestion has been the least studied. Ingestion exposure is typically controlled in workplaces by the provision of clean eating areas that are separated from the work areas, and by encouraging hand-washing prior to eating. However, this control strategy does not affect ingestion exposure that can occur when contaminated hands or objects contact the mouth; these sorts of exposures can occur during work tasks in the general work area. For example, these sorts of contacts can occur when workers wipe their mouths or noses, chew pens or glasses, or bite their nails. Exposure by this pathway is called inadvertent ingestion exposure. In addition to the insertion of contaminated hands and objects directly into the oral cavity, contact can occur with the perioral area (the area surrounding the mouth) and transferred substances can subsequently transfer to the mouth. The aim of this thesis was to study inadvertent ingestion exposure in order to develop a generic predictive screening model to allow occupational hygienists and risk assessors to estimate exposure by inadvertent ingestion for a range of exposure scenarios. The thesis project was carried out in a series of steps, all of which are described below. The steps were carried out in the order presented and the findings from the work on earlier steps influenced the work carried out in later steps.
- Published
- 2013
6. A novel educational tool helps teach intestinal absorption in physiology.
- Author
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Lin-Lin Wang, Lingyue Liu, Aohan Zu, Xiaoning Lv, Zixuan Mei, Zhouhan Wang, and Ying-Ying Chen
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ABSORPTION (Physiology) , *INTESTINAL physiology , *INTESTINAL absorption , *BIOMEDICAL engineering , *PHYSIOLOGY education , *GROUP reading - Abstract
A novel educational tool helps teach intestinal absorption in physiology--We have designed an interesting educational tool to help sophomores learn intestinal absorption in physiology course. In the study group (2019), 51 sophomores from biomedical engineering were encouraged to learn the intestinal absorption knowledge through reading materials and group discussion. Then, using the form of flipped class, they stepped on the podium and simulated and explained the absorption processes with designed paper props as educational tool. In contrast, the control group (2018), 52 sophomores from the same specialty had taken the same professional courses before. The result of theoretical test showed the average score in the study group was higher than that in the control group. The questionnaire analysis showed the positive role of the education tool in their learning efficacy. To sum up, using our tool has achieved better teaching effects than the traditional lecture. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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7. A novel experimental technique for the fabrication of the vitamin B12 nucleus using quartz crystal microbalance: Statistical physics modeling and new microscopic properties.
- Author
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Ben Yahia, Manel and Ben Yahia, Mohamed
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QUARTZ crystal microbalances , *STATISTICAL physics , *VITAMIN B12 , *STATISTICAL models , *ADSORPTION isotherms , *COBALT porphyrins , *ABSORPTION (Physiology) - Abstract
A novel adsorption model for the description of adsorption isotherms of cobalt nitrate on porphyrins H2TPP and H2TTPP is developed in the present paper. Experimental data were measured at five temperatures using the quartz crystal microbalance technique and were discussed to choose the most reproductive adsorbent for the achievement of the vitamin B12 nucleus. Then, the modeling treatment was established based on the grand canonical formalism in statistical physics by taking into account the lateral interaction between the adsorbate particles. This leads to a six parameter equation describing the complexation process at the molecular level. Actually, there is a good correlation between experimental data and those calculated by using the double-layer L.B.L. model. It was found that cobalt ions were adsorbed via a multi-docking mechanism onto the two adsorbents. The study of the density of receptor sites (PM) confirmed the endothermic nature of the two complexation processes. The van der Waals parameters indicated that the disturbances following the lateral interactions between the adsorbates are the highest in the case of tetraphenylporphyrin. The magnitude of the calculated adsorption energies reveals that cobalt is physisorbed onto tetraphenylporphyrin, whereas chemical forces were found in the case of porphyrins (H2TTPP). In addition, the proposed model allows the prediction of some adsorption thermodynamic functions, which govern the adsorption mechanism, such as entropy, Gibbs free enthalpy, and internal energy. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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8. Cadmium removal using potato peels as adsorbent: kinetic studies.
- Author
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Palabıyık, Basak Berna, Selcuk, Huseyin, and Oktem, Yalcin Askin
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POTATO waste ,CADMIUM ,ADSORPTION capacity ,BOUNDARY layer (Aerodynamics) ,AQUEOUS solutions ,ABSORPTION (Physiology) - Abstract
In this study, untreated waste potato peels were used as adsorbents for treatment and cadmium removal mechanisms were investigated. Maximum removal efficiency was 76% at an initial concentration of 100 mg L
-1 of Cd(II) at pH 5.8 in an aqueous solutions at room temperature; 7.61 mg of cadmium was removed per gram of adsorbent. However, as the initial concentration increased, the removal efficiency decreased. Under optimum conditions, two parameters equilibrium isotherms (Langmuir, Freundlich, Temkin etc.) were applied. The Freundlich isotherm has the highest correlation (99.9%) in isotherms. Isothermal adsorption capacity (KF) has 19.94 mg g-1 and heterogeneity factor (1/n) 1.0 were determined. In adsorption, it was found that both the boundary layer diffusion and the intra-particle diffusion steps were effective, and the determination of the adsorption rate showed that the Type I pseudo-second-order equation had a high correlation (99%) at all concentrations. [ABSTRACT FROM AUTHOR]- Published
- 2019
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9. Performance and mechanism of estrone (E1) and 17β-estradiol (17β-E2) removal from aqueous solution using hexadecyltrimethylammonium (HDTMA) modified zeolites.
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Zhong, Shuang, Zhang, Shengyu, Zhang, Yixin, and Li, Chenyang
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ABSORPTION (Physiology) ,GENTIAN violet ,SEX hormones ,AQUEOUS solutions ,ORGANIC compounds ,LANGMUIR isotherms ,ADSORPTION capacity ,ZETA potential - Abstract
Modified zeolites (MZs) were prepared by loading different concentrations of hexadecyltrimethylammonium (HDTMA) solution: 0.5, 1.0 and 2.5 mmol/L onto raw zeolites (RZ) that were then used as adsorbents to remove estrogen contaminants from water. The RZ and MZs were characterized by FTIR, BET, SEM and Zeta potential tests, which proved that the HDTMA had been successfully loaded into the zeolites and did not alter the structure of the mineral. Loading the HDTMA into the zeolites changed their surface properties from hydrophilic to hydrophobic, which increased their adsorption capacity for the estrogens E1 and E2. The adsorption equilibrium data of the MZs were found to conform to the Langmuir isotherm. The adsorption kinetic data were found to obey a pseudo-second-order model. The adsorption mechanism was dominated by distribution effects, combined with surface adsorption. Batch experiments were conducted using the MZs as a function of contact time, initial estrogen concentration, temperature, pH and natural organic matter. The experimental results indicated that low initial concentration, low temperature, and low pH in the range of 5.0–7.0 were favorable for adsorption of E1 and E2. As a result, MZs were concluded to be effective adsorbents for the removal of estrogen contaminants from wastewater. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
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10. Intravenous Enoxaparin in Pediatric Burn Patients: A Case Series.
- Author
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Streetz, Vonya N. and Patatanian, Leslie K.
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ENOXAPARIN , *BURN patients , *ANTICOAGULANTS , *ABSORPTION (Physiology) , *BODY surface area - Abstract
Patients with acute burns experience a hypercoagulable state that may necessitate the use of anticoagulants to prevent the complications of venous thromboembolism (VTE). Enoxaparin is a low molecular weight heparin that is commonly used for this purpose; however, the traditional SC route of administration poses potential limitations in the pediatric burn population. These include pain upon injection, increased anxiety, erroneous absorption and distribution, and difficulty in finding an administration site when burns encompass a large percentage of body surface area. As a result, the IV route of administration may be preferable in these patients. To date, a limited number of studies in critically ill pediatric patients have been performed. In this report, we present a case series of 3 pediatric burn patients who initially received SC enoxaparin and were transitioned to IV enoxaparin for VTE prophylaxis. The patients were 2, 8, and 10 years old. Burn involvement ranged from 8% to 75% total body surface area, and all patients had central line access. Adequate prophylactic low molecular weight heparin anti-Xa peak concentrations (0.1-0.3 international units/mL) were achieved with IV doses ranging from 0.35 to 0.5 mg/kg administered every 12 hours. No adverse effects, major bleeding events, or treatment failures occurred. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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11. Antimicrobial peptide KR-32 alleviates Escherichia coli K88–induced fatty acid malabsorption by improving expression of fatty acid transporter protein 4 (FATP4) 1.
- Author
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Liu, Heyuan, Cao, Xiaoxuan, Wang, Hong, Zhao, Jian, Wang, Xinxia, and Wang, Yizhen
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ANTIMICROBIAL peptides , *ESCHERICHIA coli diseases , *GENE expression in bacteria , *PIGLET physiology , *ABSORPTION (Physiology) , *FATTY acid-binding proteins - Abstract
Bacterial infection causes nutrient malabsorption in small intestine. KR-32, a kind of synthetic antimicrobial peptide, has the bacteriostatic effect. In the present study, 2 experiments were designed to analyze the effects of KR-32 on fat absorption of piglets with or without Escherichia coli infection. In Exp. 1, 12 weaning piglets (21 d old) were allocated to 2 groups: piglets with an intraperitoneal (i.p.) injection of antimicrobial peptide KR-32 (APK) and piglets with an i.p. injection of an equivalent volume (1 mL) of phosphate-buffered saline (PBS) (CON-1). Results showed that after 7 d of growth, KR-32 did not significantly change growth performance and apparent total tract digestibility (ATTD) of feed nutrients of normal pigs. To confirm whether KR-32 affects those of enterotoxigenic Escherichia coli (ETEC) K88–challenged pigs, we performed Exp. 2, in which 18 piglets (28 d old) were divided into the following 3 groups: 1) piglets orally challenged with 1 × 1010 cfu ETEC K88 on day 1 followed by an i.p. injection of 0.6 mg/kg KR-32 (K88 + APK); 2) piglets orally challenged with 1 × 1010 cfu ETEC K88 on day 1 followed by an i.p. injection of an equivalent volume (1 mL) of PBS (K88); and 3) piglets with an oral administration of fresh Luria–Bertani broth (50 mL) followed by an i.p. injection of an equivalent volume of PBS (CON-2). Results showed that ETEC K88 challenge led to poor ADFI, ADG, and G:F in piglets; decreased ATTD of feed nutrients, especially CP and ether extract (EE); and intestinal morphology disorder. After i.p. injection of KR-32, ADG and ATTD of CP and EE were greatly increased, G:F was significantly reduced (P < 0.05), and, especially, ATTD of EE returned to a normal level compared with group CON-2. Fatty acid absorption also highly increased after KR-32 injection. Then we focused on fat digestion and fatty acid uptake. The pH in the intestine and pancreas lipase showed no difference among the 3 treatment groups, whereas fatty acid transporter protein 4 (FATP4) expression was remarkably improved (P < 0.05) and the epithelial barrier was recovered after i.p. injection of KR-32. In conclusion, KR-32, given to ETEC K88–challenged piglets, improved growth performance, ATTD of EE, fatty acid absorption, and intestinal morphology, which indicated that KR-32 was likely to improve the expression of FATP4 and by repairing the epithelial barrier, thereby alleviating fatty acid malabsorption. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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12. Removal of Estrogen Hormones (17β-Estradiol and Estrone) from Aqueous Solutions Using Rice Husk Silica.
- Author
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Zarghi, M. H., Roudbari, A., Jorfi, S., and Jaafarzadeh, N.
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ABSORPTION (Physiology) , *RICE hulls , *ESTRONE , *AQUEOUS solutions , *LANGMUIR isotherms , *ADSORPTION isotherms - Abstract
The aim of this study was to investigate the removal of estrogen hormones (17β-estradiol and estrone) from aqueous solutions using rice husk extracted silica. Rice husk was collected from rice factories in Mazandaran province (Iran) and the adsorbent was prepared in a furnace at 800 °C for 4 h, after acid leaching with hydrochloric and sulfuric acid mixture. Optimal operating parameters for estrogen removal were determined, including initial pH values (4-9), adsorbent dosages (0.5, 1, 1.5, and 2 g L-1), contact times (30, 60, 90, and 120 min), and initial concentrations of 17β-estradiol and estrone (10, 40, 70 and 100 ng L-1); one-factor-at-a-time method was used. The method of electrochemiluminescence was used to measure the concentration of hormones. Kinetic adsorption models and adsorption isotherms were also studied. The maximum removal efficiency (%) of 17β-estradiol (E2) and estrone (E1) hormones of 95.5 and 93.1 %, respectively, was obtained at optimal conditions of pH 4, 1.5 g L-1 of adsorbent dosage, 60 min of contact time and 10 ng L-1 initial concentrations of E2 and E1. Pseudo first-order kinetic model and Langmuir adsorption isotherm had the best fit with experimental data for both estrogen hormones, following nonlinear regression procedure. Rice husk silica could be considered as effective and accessible adsorbent for removal of estrogenic hormones. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
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13. Probing fouling mechanism of naphthenic acids on forward osmosis polymer membranes in oil sands process water treatment.
- Author
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Xiang, Li, Zhu, Shu, Li, Mingyu, Zhang, Jiawen, Gamal El-Din, Mohamed, and Zeng, Hongbo
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PENETRANTS (Chemicals) , *SOLUTION (Chemistry) , *ABSORPTION (Physiology) , *BIOLOGICAL transport , *AQUEOUS solutions - Abstract
Abstract Forward osmosis (FO) polymer membrane filtration is an effective approach for the reclamation of oil sands process water (OSPW). Naphthenic acid (NAs), the major organic component in OSPW, can severely foul the FO membrane during wastewater treatment. Although much effort has been devoted to reducing the fouling of FO membrane, the fundamental understanding of fouling mechanism of NAs on membrane still remains incomplete. In this work, for the first time, the interaction forces between common FO membranes and major functional groups in NAs in aqueous solutions were directly measured using a surface forces apparatus (SFA) at nanoscale. The experimental force results could be well described by the classical Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, indicating that the electrical double layer (EDL) repulsion plays a dominant role in inhibiting membrane fouling, and the adhesion leading to the membrane fouling is mainly driven by hydrophobic interaction. Addition of Ca2+ was found to induce the attractive bridging effect between the membranes and –COOH groups, thus aggravating the membrane fouling. Moreover, macroscale adsorption tests and OSPW fouling experiment results demonstrate that both surface potential and hydrophobicity significantly affect the membrane fouling/anti-fouling performance, in agreement with the nanoscale surface force results. Graphical abstract fx1 Highlights • Surface force measurements were conducted to investigate the fouling mechanism of the NAs. • Electrostatic interaction plays an important role in preventing the membrane fouling. • Hydrophobic interaction could induce adhesion between NAs and FO membrane. • The presence of Ca2+ ions would strengthen the adhesion between NAs and FO membrane. • The macroscale fouling tests agree with the surface force results at nanoscale. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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14. Division of Gastroenterology Hepatology and Nutrition Researcher Publishes New Studies and Findings in the Area of Diagnostics and Screening (Fat digestion and absorption: Normal physiology and pathophysiology of malabsorption, including...).
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ABSORPTION (Physiology) ,MEDICAL screening ,RESEARCH personnel ,DIGESTION ,PATHOLOGICAL physiology - Abstract
A recent report published by researchers from the Division of Gastroenterology Hepatology and Nutrition explores the process of fat digestion and absorption in the human body. The study emphasizes the importance of effective fat digestion for overall health, as it allows for the absorption of essential nutrients and provides energy to the body. The researchers discuss various pathophysiological conditions that can lead to fat malabsorption, such as exocrine pancreatic insufficiency, bile acid disorders, and intestinal diseases. Diagnostic approaches for fat malabsorption include assessing fecal fat levels, imaging studies, and functional tests. This article provides a concise overview of the physiological process of fat digestion and absorption, as well as current diagnostic testing methods. [Extracted from the article]
- Published
- 2024
15. Reliability and validity of assessing energy and nutrient intake with the Vienna food record: a cross-over randomised study.
- Author
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Putz, Peter, Kogler, Birgit, and Bersenkowitsch, Isabel
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INGESTION , *ABSORPTION (Physiology) , *GEOPHAGY , *DIET , *RANDOMIZED controlled trials - Abstract
Background: The Vienna Food Record was developed as a simple paper-based pre-coded food record for use in Austrian adults, which can be completed over a flexible period of time. The present study aimed at evaluating test-retest reliability of the Vienna Food Record and its concurrent validity against a weighed food record.Methods: A randomised cross-over study served to compare outcomes of the Vienna Food Record with those of the weighed food record. The Vienna Food Record was completed for a second time, in order to assess test-retest reliability. Three assessment phases were interrupted by two-week wash-out phases. Sixty-seven free living Austrians aged 18-64 years, without (self-) diagnosed food allergies or intolerances, not at any medication, and not nutrition experts, were randomly assigned to one of two study arms. After drop-outs and exclusion of under-reporters, data of 35 participants has been analysed. Paired t-tests were performed for comparisons, regarding test-retest reliability and criterion validity, where mean differences were calculated as effect sizes. Consistency between repeated assessments with the Vienna Food Record was expressed by intra-class-correlation coefficients (ICC), while Pearson's r was used for agreement regarding validity. Bland-Altman Plots with 95% limits of agreement were created for energy and macronutrients. Validity metrics for macronutrients were analysed additionally separated by gender, taking an adjustment of energy intake into account. Total energy intakes as well as intakes of macro- and selected micronutrients, expressed as daily means, were defined as 34 primary outcomes.Results: ICCs for energy and intake of preselected nutrients, expressing the consistency of the Vienna Food Record, ranged from not significant to 0.95. Pearson's correlation coefficients, expressing the agreement of the Vienna Food Record with the weighed food record ranged from not significant to 0.80.Conclusions: This study demonstrates acceptable reliability and validity of the Vienna Food Record as an instrument for the assessment of energy and nutrient intake, comparable to the results of similar studies. [ABSTRACT FROM AUTHOR]- Published
- 2019
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16. Construction of a Quantitative Structure Activity Relationship (QSAR) Model to Predict the Absorption of Cephalosporins in Zebrafish for Toxicity Study.
- Author
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Liu, Ying, Zhang, Xia, Zhang, Jingpu, and Hu, Changqin
- Subjects
CEPHALOSPORIN analysis ,QSAR models ,ZEBRA danio ,TOXICITY testing ,DRUG development ,ABSORPTION (Physiology) - Abstract
Cephalosporins are beta-lactam antibiotics that are widely used in China. Five generations of cephalosporins have been introduced in clinical practice to date; moreover, some new candidates are also undergoing clinical evaluations. To improve the success rates of new drug development, we need to have a comprehensive understanding about the relationship between the structure of cephalosporins and the toxicity that it induces at an early stage. In the cephalosporins toxicity study using zebrafish, the drug absorption is a key point. In this study, we determined the absorption of cephalosporins in zebrafish during toxicity test. The internal concentrations of 19 cephalosporins in zebrafish were determined using a developed liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Furthermore, a quantitative structure-activity relationship (QSAR) model was established by multilinear regression; moreover, it was used to predict the absorption of cephalosporins in zebrafish. During leave-one-out cross-validation, a satisfactory performance was obtained with a predictive ability (q
2 ) of 0.839. The prediction ability of the model was further confirmed when the predictive ability (q2 ) was 0.859 in external prediction. The best QSAR model, which was based on five molecular descriptors, exhibited a promising predictive performance and robustness. In experiments involving drug toxicity, the developed QSAR model was used to estimate internal concentrations of cephalosporins. Thus, the toxicity results were correlated with the internal concentration of the drug within the larvae. The developed model served as a new powerful tool in zebrafish toxicity tests. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
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17. Could vesicular transport of Na + and Cl – be a feature of salt tolerance in halophytes?
- Author
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Flowers, Timothy J, Glenn, Edward P, and Volkov, Vadim
- Subjects
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HALOPHYTES , *ENDOCYTOSIS , *EXOCYTOSIS , *PINOCYTOSIS , *ABSORPTION (Physiology) , *PLANT roots , *TONOPLASTS , *PLANT vacuoles , *PLANTS - Abstract
Background Halophytes tolerate external salt concentrations of 200 mm and more, accumulating salt concentrations of 500 mm and more in their shoots; some, recretohalophytes, excrete salt through glands on their leaves. Ions are accumulated in central vacuoles, but the pathway taken by these ions from the outside of the roots to the vacuoles inside the cells is poorly understood. Do the ions cross membranes through ion channels and transporters or move in vesicles, or both? Vesicular transport from the plasma membrane to the vacuole would explain how halophytes avoid the toxicity of high salt concentrations on metabolism. There is also a role for vesicles in the export of ions via salt glands. Scope and Methods We have collected data on the fluxes of sodium and chloride ions in halophytes, based on the weight of the transporting organs and on the membrane area across which the flux occurs; the latter range from 17 nmol m–2 s–1 to 4.2 μmol m–2 s–1 and values up to 1 μmol m–2 s–1 need to be consistent with whatever transport system is in operation. We have summarized the sizes and rates of turnover of vesicles in plants, where clathrin-independent vesicles are 100 nm or more in diameter and can merge with the plasma membrane at rates of 100 s–1. We gathered evidence for vesicular transport of ions in halophytes and evaluated whether vesicular transport could account for the observable fluxes. Conclusions There is strong evidence in favour of vesicular transport in plants and circumstantial evidence in favour of the movement of ions in vesicles. Estimated rates of vesicle turnover could account for ion transport at the lower reported fluxes (around 20 nmol m–2 s–1), but the higher fluxes may require vesicles of the order of 1 μm or more in diameter. The very high fluxes reported in some salt glands might be an artefact of the way they were measured. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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18. Absorption of foliar-applied Zn in sunflower (Helianthus annuus): importance of the cuticle, stomata and trichomes.
- Author
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Li, Cui, Wang, Peng, van der Ent, Antony, Cheng, Miaomiao, Jiang, Haibo, Read, Thea Lund, Lombi, Enzo, Tang, Caixian, Jonge, Martin D de, Menzies, Neal W, and Kopittke, Peter M
- Subjects
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ABSORPTION (Physiology) , *SUNFLOWERS , *PLANT cuticle , *PLANT nutrients , *STOMATA , *TRICHOMES , *MASS spectrometry , *PLANTS - Abstract
Background and Aims The pathways whereby foliar-applied nutrients move across the leaf surface remain unclear. The aim of the present study was to examine the pathways by which foliar-applied Zn moves across the sunflower (Helianthus annuus) leaf surface, considering the potential importance of the cuticle, stomata and trichomes. Methods Using synchrotron-based X-ray florescence microscopy and nanoscale secondary ion mass spectrometry (NanoSIMS), the absorption of foliar-applied ZnSO4 and nano-ZnO were studied in sunflower. The speciation of Zn was also examined using synchrotron-based X-ray absorption spectroscopy. Key Results Non-glandular trichomes (NGTs) were particularly important for foliar Zn absorption, with Zn preferentially accumulating within trichomes in ≤15 min. The cuticle was also found to have a role, with Zn appearing to move across the cuticle before accumulating in the walls of the epidermal cells. After 6 h, the total Zn that accumulated in the NGTs was approx. 1.9 times higher than in the cuticular tissues. No marked accumulation of Zn was found within the stomatal cavity, probably indicating a limited contribution of the stomatal pathway. Once absorbed, the Zn accumulated in the walls of the epidermal and the vascular cells, and trichome bases of both leaf sides, with the bundle sheath extensions that connected to the trichomes seemingly facilitating this translocation. Finally, the absorption of nano-ZnO was substantially lower than for ZnSO4, with Zn probably moving across the leaf surface as soluble Zn rather than nanoparticles. Conclusions In sunflower, both the trichomes and cuticle appear to be important for foliar Zn absorption. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
19. Nutrient absorption in Tithonia Diversifolia.
- Author
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Londoño, Julián Mauricio Botero, Carabali, Arnulfo Gómez, and Londoño, Mónica Andrea Botero
- Subjects
TITHONIA diversifolia ,ABSORPTION (Physiology) ,PLANT nutrients ,SOIL remediation ,GRASSLAND soils ,FOLIAR feeding ,PLANTS - Abstract
Copyright of Universitas Scientiarum is the property of Pontificia Universidad Javeriana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
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20. CCN activation properties at a tropical hill station in Western Ghats during south-west summer monsoon: Vertical heterogeneity.
- Author
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Jayachandran, V., Nair, Vijayakumar S., and Babu, S. Suresh
- Subjects
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CLOUD condensation nuclei , *ATMOSPHERIC aerosols , *ABSORPTION (Physiology) , *CARBONACEOUS aerosols , *MONSOONS - Abstract
Abstract Cloud Condensation Nuclei (CCN) concentrations, aerosol number concentrations larger than about 3 nm (CN), and aerosol scattering and absorption coefficient measurements carried out at a hill station (Ponmudi, 8.8°N, 77.1°E, ~960 m amsl) located on Western Ghats and at a nearby coastal location (Thumba, 8.5°N, 76.9°E, ~3 m amsl) in the peninsular India during summer monsoon period are used to investigate the vertical heterogeneity in the activation properties and its association with the aerosol optical properties. CCN concentration over the hill station depicted high values during daytime and low values during nighttime, whereas an opposite pattern in CCN is observed over the coastal site. The intrinsic properties like CCN activation fraction and Twomey's empirical fit (k value) show insignificant diurnal variation over the hill station in contrast to the coastal location where the land-sea breeze circulation modify the prevailing airmasses over the sampling site. The percentage of CN acting as CCN at 0.4% supersaturation is about 25% at Ponmudi and is about 46% at Thumba. The higher scattering angstrom exponent observed at Ponmudi indicates the consistent presence of fine mode particles. CCN concentration at both Ponmudi and Thumba show a good linear correlation with scattering aerosol index. The association between CCN number concentrations and BC mass concentrations suggest that carbonaceous combustion sources influence CCN at Ponmudi. Even though marine airmass prevails over both locations due to the onset of the summer monsoon, CCN activation properties are distinct at the mean sea level and at an altitude of 1 km above the coastal region. Highlights • High CCN concentration during daytime at the hill station • Low CCN activation fraction at the high altitude compared to the surface level • CCN concentration linearly increases with scattering index of aerosols. • High CCN concentration at the hill station is associated with carbonaceous aerosols. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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21. Comparing two classes of biological distribution systems using network analysis.
- Author
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Papadopoulos, Lia, Blinder, Pablo, Ronellenfitsch, Henrik, Klimm, Florian, Katifori, Eleni, Kleinfeld, David, and Bassett, Danielle S.
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PLANAR motion , *BIOLOGICAL transport , *ABSORPTION (Physiology) , *AGONOMYCETALES - Abstract
Distribution networks—from vasculature to urban transportation pathways—are spatially embedded networks that must route resources efficiently in the face of pressures induced by the costs of building and maintaining network infrastructure. Such requirements are thought to constrain the topological and spatial organization of these systems, but at the same time, different kinds of distribution networks may exhibit variable architectural features within those general constraints. In this study, we use methods from network science to compare and contrast two classes of biological transport networks: mycelial fungi and vasculature from the surface of rodent brains. These systems differ in terms of their growth and transport mechanisms, as well as the environments in which they typically exist. Though both types of networks have been studied independently, the goal of this study is to quantify similarities and differences in their network designs. We begin by characterizing the structural backbone of these systems with a collection of measures that assess various kinds of network organization across topological and spatial scales, ranging from measures of loop density, to those that quantify connected pathways between different network regions, and hierarchical organization. Most importantly, we next carry out a network analysis that directly considers the spatial embedding and properties especially relevant to the function of distribution systems. We find that although both the vasculature and mycelia are highly constrained planar networks, there are clear distinctions in how they balance tradeoffs in network measures of wiring length, efficiency, and robustness. While the vasculature appears well organized for low cost, but relatively high efficiency, the mycelia tend to form more expensive but in turn more robust networks. As a whole, this work demonstrates the utility of network-based methods to identify both common features and variations in the network structure of different classes of biological transport systems. [ABSTRACT FROM AUTHOR]
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- 2018
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22. Investigation of optical properties of dissected and homogenized biological tissue.
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Eisel, Maximilian, Ströbl, Stephan, Pongratz, Thomas, Stepp, Herbert, Rühm, Adrian, and Sroka, Ronald
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OPTICAL properties of tissues , *ABSORPTION (Physiology) , *DEHYDRATION , *BIOPSY , *PHOTODYNAMIC therapy - Abstract
Knowledge of tissue optical properties, in particular the absorption μa and the reduced scattering coefficient μs , is required for diagnostic and therapeutic applications in which the light distribution during treatment has to be known. As it is generally very difficult to obtain this information with sufficient accuracy in vivo, optical properties are often approximately determined on ex vivo tissue samples. In this case, the obtained optical properties may strongly depend on the sample preparation. The extent of the expectable preparationdependent differences was systematically investigated in comparative measurements on dissected and homogenized porcine tissue samples (liver, lung, brain, and muscle). These measurements were performed at wavelengths 520, 635, 660, and 785 nm, using a dual-step reflectance device and at a spectral range of 515 to 800 nm with an integrating sphere setup. In a third experiment, the density of tissue samples (dissected and homogenized) was investigated, as the characteristic of the packaging of internal tissue structures strongly influences the absorption and scattering. The standard errors of the obtained absorption and reduced scattering coefficients were found to be reduced in case of homogenized tissue. Homogenizing the tissues also allows a much easier and faster sample preparation, as macroscopic internal tissue structures are destroyed in the homogenized tissue so that a planar tissue sample with well-defined thickness can easily and accurately be prepared by filling the tissue paste into a cuvette. Consequently, a better reproducibility result was obtained when using homogenized samples. According to the density measurements accomplished for dissected and homogenized tissue samples, all types of tissues, except lung, showed a decrease in the density due to the homogenization process. The presented results are in good agreement for μs regardless of the preparation procedure, whereas μa differs, probably influenced by blood content and dehydration. Because of faster and easier preparation and easier sample positioning, homogenization prior to measurement seems to be suitable for investigating the optical properties ex vivo. Additionally, by means of using the homogenization process, the sample size and thickness do not need to be particularly large, as is the case for most biopsies from the OR. [ABSTRACT FROM AUTHOR]
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- 2018
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23. How Old Is Your Brain? Slow-Wave Activity in Non-rapid-eye-movement Sleep as a Marker of Brain Rejuvenation After Long-Term Exercise in Mice.
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Panagiotou, Maria, Papagiannopoulos, Kostas, Rohling, Jos H. T., Meijer, Johanna H., and Deboer, Tom
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PHYSICAL activity ,BRAIN function localization ,ELECTROENCEPHALOGRAPHY ,PHYSIOLOGY ,ABSORPTION (Physiology) - Abstract
Physical activity is beneficial for health. It has been shown to improve brain functioning and cognition, reduce severity of mood disorders, as well as facilitate healthy sleep and healthy aging. Sleep has been studied in healthy aged mice and absolute slow-wave-activity levels (SWA, electroencephalogram power between 0.75 and 4.0 Hz) in non-rapid-eye-movement sleep (NREM) were elevated, suggesting changes in brain connectivity. To investigate whether physical activity can diminish this aging-induced effect, mice of three age groups were provided with a running wheel (RW) for 1–3 months (6-months-old, n = 9; 18-months-old, n = 9; 24–months-old, n = 8) and were compared with control sedentary mice (n = 11, n = 8 and n = 9 respectively). Two weeks before the sleep-wake recordings the running wheels were removed. The electroencephalogram (EEG) and electromyogram were continuously recorded during undisturbed 24 h baseline (BL) and a sleep-deprivation was conducted during the first 6 h of the second day. Increased waking and decreased NREM sleep was found in the young RW mice, compared to young controls. These effects were not evident in the 18 and 24 months old mice. Unlike sleep architecture, we found that SWA was altered throughout the whole age spectrum. Notably, SWA was increased with aging and attenuated with exercise, exhibiting the lowest levels in the young RW mice. To utilize the cross-age revealing features of SWA, we applied machine learning techniques and found that characteristic information regarding age and exercise was enclosed in SWA. In addition, with cluster analysis, we could classify and accurately distinguish the different groups based solely on their SWA. Therefore, our study comprises a three-fold contribution: (a) effects of exercise on sleep are sustained following 2 weeks after removal of the wheel, (b) we show that EEG SWA can be used as a physiological marker of brain age in the mouse, (c) long-term voluntary regular age-matched exercise leads to a younger phenotype. [ABSTRACT FROM AUTHOR]
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- 2018
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24. Fat encapsulation enhances dietary nutrients utilization and growth performance of nursery pigs.
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Yang, Fei, Zhang, Shihai, Kim, Sung Woo, Ren, Chunxiao, Tian, Min, Cheng, Lin, Song, Junjie, Chen, Jun, Chen, Fang, and Guan, Wutai
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FATS & oils in animal nutrition , *ENCAPSULATION (Catalysis) , *SWINE nutrition , *SWINE growth , *DIGESTION , *ABSORPTION (Physiology) , *FAT content of food , *DIGESTIVE enzymes , *SWINE - Abstract
Encapsulation of fat may facilitate digestion and absorption of fat in nursery pigs. Two experiments were conducted to evaluate 1) effects of encapsulation of palm oil (PO) and coconut oil (CO) on growth performance, feed intake, feed efficiency, and blood parameters, and 2) effects of encapsulation of PO and CO on apparent total tract digestibility (ATTD) of nutrients, and the activity of digestive enzymes in nursery pigs. In Exp. 1, 540 pigs (28 d of age, 8.23 ± 0.22 kg BW) were allotted to five treatments based on a randomized complete block design (as-fed basis). Pigs were fed basal diets with five different fat sources: 6.0% soybean oil (SBO), 6.0% PO, 6.0% PO from encapsulated fat (EPO), 6.0% CO, and 6.0% CO from encapsulated fat (ECO), respectively, with six pens per treatment and 18 pigs per pen for a 4-wk feeding trial. Dried casein and whey powder used for encapsulation were included at identical levels in all diets. Pigs fed EPO had increased (P < 0.05) ADG during days 0 to 14 and overall compared to pigs fed SBO and PO, whereas ADG of pigs fed ECO was not different from pigs fed EPO and CO. There were no differences in ADFI among treatments. Pigs fed EPO had increased G:F (P < 0.05) during days 0 to 14 compared to SBO, PO, and CO. Serum urea nitrogen concentrations in pigs fed EPO, CO, and ECO were lower (P < 0.05) than that of pigs fed SBO and PO. In Exp. 2, 30 pigs (28 d of age, 8.13 ± 0.10 kg BW) were housed individually (n = 6 per treatment) and allotted to five treatments as described in Exp.1. Pigs were fed ad libitum for 4 wk to measure ATTD of diets weekly and digestive enzyme activity at week 4. Pigs fed EPO, CO, and ECO had increased (P < 0.05) ATTD of DM and GE compared to pigs fed SBO and PO. Pigs fed SBO had reduced (P < 0.05) ATTD of CP compared to other treatments. Pigs fed PO had reduced (P < 0.05) ATTD of ether extracts (EE) compared to other treatments. Pigs fed PO had greater (P < 0.05) trypsin activity in the pancreas than pigs fed SBO and CO. Pigs fed PO tended to have lower (P = 0.073) pancreatic lipase activity compared to other treatments, whereas dietary treatments had no effect on pancreatic amylase activity. In conclusion, this study indicates that encapsulation of PO improved growth performance and ATTD of diets in nursery pigs, whereas the limited effects of encapsulated CO were likely due to the high digestibility of the medium-chain triglycerides abundant in CO. [ABSTRACT FROM AUTHOR]
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- 2018
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25. Sarcopenia is associated with the risk of significant liver fibrosis in metabolically unhealthy subjects with chronic hepatitis B.
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Han, E., Lee, Y.‐h., Kim, B. K., Park, J. Y., Kim, D. Y., Ahn, S. H., Lee, B.‐W., Kang, E. S., Cha, B.‐S., Han, K.‐H., and Kim, S. U.
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SARCOPENIA , *CHRONIC hepatitis B , *FIBROSIS , *FATTY liver , *ABSORPTION (Physiology) , *PATIENTS - Abstract
Summary: Background: Sarcopenia is significantly associated with the degree of liver fibrosis. This study investigated the influence of sarcopenia on liver fibrosis in individuals with chronic hepatitis B. Methods: Data from the Korean National Health and Nutrition Examination Surveys 2008‐2011 were analysed. The sarcopenia index (total appendicular skeletal muscle mass [kg]/body mass index [kg/m2]) was calculated using dual‐energy X‐ray absorptiometry. Sarcopenia was defined as the lowest quintile sarcopenia index value (cut‐offs: 0.89 for men and 0.58 for women). The fibrotic burden was assessed using the nonalcoholic fatty liver disease fibrosis score and fibrosis‐4 index. Significant fibrosis was defined as the highest nonalcoholic fatty liver disease fibrosis score quartile and a fibrosis‐4 index ≥2.67. Results: Among the 506 respondents with chronic hepatitis B (258 men and 248 women), the nonalcoholic fatty liver disease fibrosis score and fibrosis‐4 index identified sarcopenia and significant fibrosis in 126 (24.9%) and 217 (42.9%), respectively. Sarcopenia was significantly associated with significant fibrosis, regardless of the fibrosis prediction model used (all P < 0.05). When the study population was stratified according to metabolic factors, sarcopenia was specifically associated with an increased risk of significant fibrosis among subgroups with obesity, insulin resistance, metabolic syndrome and liver steatosis (odds ratio 2.37‐3.57; all P < 0.05). An independent association between sarcopenia and significant fibrosis was identified after adjusting for other confounders (odds ratio 2.67‐3.62 by the nonalcoholic fatty liver disease fibrosis score and 2.04‐2.62 by the fibrosis‐4 index; all P < 0.05). Conclusions: Sarcopenia is associated with significant fibrosis in subjects with chronic hepatitis B, specifically those with obesity, insulin resistance, metabolic syndrome and liver steatosis. [ABSTRACT FROM AUTHOR]
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- 2018
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26. Absorption of arsenic from soil and water by two chard (Beta vulgaris L.) varieties: A potential risk to human health.
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Yañez, L.M., Alfaro, J.A., and Bovi Mitre, G.
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ARSENIC , *SOIL composition , *ARSENIC in water , *ABSORPTION (Physiology) , *HEALTH risk assessment , *FOOD chains ,BEET varieties - Abstract
The accumulation of arsenic (As) in vegetables poses a risk of contamination to humans via the food chain. Two chard (var. cicla and var. d'ampuis ) crops were grown for 60 days in greenhouses on Aridisol soil, and irrigated with water from Pastos Chicos, Jujuy (Argentina). The soil and water used in the trial presented 49 and 1.44 mg/L As concentration levels, respectively. Total dry biomass (TDB) and total As were determined in soils, roots and leaves. The latter was quantified by atomic absorption spectrometry with hydride generation, and bioconcentration and translocation factors were determined. TDB in var. cicla showed statistically significant differences when the plant was cultivated in control soil and watered with the toxicant (2.04 g), as compared with the treatment without exposure (2.8 g). TDB in var. d'ampuis presented statistically significant differences with respect to that of the control when the plants were grown in soils with As and watered with the toxicant (3.3 g). This variety increased its biomass in the presence of As. In the two Swiss chard varieties evaluated, the largest As accumulation in root and leaves was found when they were cultivated in contaminated soil and watered with distilled water. The presence of the toxicant in the leaves exceeded the limits established by Código Alimentario Argentino, i.e. 0.30 mg/kg. Total target hazard quotient (THQ) values for As were higher than 1, suggesting that consumers would run significant risks when consuming these chard varieties. Furthermore, it was determined that the carcinogenic risk (CR) posed by this type of exposure to As exceeded the acceptable risk level of 1 × 10 −6 . Based on this evidence, we may conclude that consuming chard cultivated on the evaluated site brings about considerable risks to local residents' health. [ABSTRACT FROM AUTHOR]
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- 2018
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27. Nail Analysis for Drugs: A Role in Workplace Testing?
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Hill, Virginia A., Stowe, G. Neil, Paulsen, Ryan B., and Schaffer, Michael
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INGESTION , *MORPHINE , *HAIR analysis , *MICROBIAL contamination , *ABSORPTION (Physiology) - Abstract
Analysis of nail clippings may be a useful back-up for hair analysis when hair is unavailable. One aspect of using nails or hair is the ability to analyze whether drug present is from ingestion or from contamination. A common method of three 15-s rinses in methanol failed to remove drug from nails that had been soaked in either 5 or 50 µg/mL cocaine, methamphetamine or morphine for 1 h. While methanol rinsing did not remove contaminating drug, washing the nails soaked with 5 and 50 µg/mL of these drugs with an extended wash, a method developed for hair analysis and consisting of a 15-min isopropanol wash, and three 30-min and two 60-min phosphate buffer-0.1% albumin washes, when applied to nails did remove most of the contaminating drug. The drug left in the nails after extended washing could be interpreted as contamination by applying a wash criterion that is routinely applied in hair analysis. Successful decontamination of the soaked contaminated nail model was followed by applying this extended wash method to presumptive positive nail samples identified in workplace testing. While the extended buffer wash and wash criterion distinguish contamination from ingestion with hair, we failed to demonstrate that the method effectively differentiates contamination from ingestion with nails. [ABSTRACT FROM AUTHOR]
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- 2018
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28. Experimental estimation of energy absorption during heel strike in human barefoot walking.
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Baines, Patricia M., Schwab, A. L., and van Soest, A. J.
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HUMAN bioenergetics , *ENERGY metabolism , *WALKING , *HUMAN locomotion , *ABSORPTION (Physiology) - Abstract
Metabolic energy expenditure during human gait is poorly understood. Mechanical energy loss during heel strike contributes to this energy expenditure. Previous work has estimated the energy absorption during heel strike as 0.8 J using an effective foot mass model. The aim of our study is to investigate the possibility of determining the energy absorption by more directly estimating the work done by the ground reaction force, the force-integral method. Concurrently another aim is to compare this method of direct determination of work to the method of an effective foot mass model. Participants of our experimental study were asked to walk barefoot at preferred speed. Ground reaction force and lower leg kinematics were collected at high sampling frequency (3000 Hz; 1295 Hz), with tight synchronization. The work done by the ground reaction force is 3.8 J, estimated by integrating this force over the foot-ankle deformation. The effective mass model is improved by dropping the assumption that foot-ankle deformation is maximal at the instant of the impact force peak. On theoretical grounds it is clear that in the presence of substantial damping that peak force and peak deformation do not occur simultaneously. The energy absorption results, due the vertical force only, corresponding to the force-integral method is similar to the results of the improved application of the effective mass model (2.7 J; 2.5 J). However the total work done by the ground reaction force calculated by the force-integral method is significantly higher than that of the vertical component alone. We conclude that direct estimation of the work done by the ground reaction force is possible and preferable over the use of the effective foot mass model. Assuming that energy absorbed is lost, the mechanical energy loss of heel strike is around 3.8 J for preferred walking speeds (≈ 1.3 m/s), which contributes to about 15–20% of the overall metabolic cost of transport. [ABSTRACT FROM AUTHOR]
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- 2018
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29. A hierarchical model of metabolic machinery based on the kcore decomposition of plant metabolic networks.
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Filho, Humberto A., Machicao, Jeaneth, and Bruno, Odemir M.
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PLANT metabolism , *PLANT physiology , *BIOLOGY , *ABSORPTION (Physiology) , *CELL proliferation , *PLANTS - Abstract
Modeling the basic structure of metabolic machinery is a challenge for modern biology. Some models based on complex networks have provided important information regarding this machinery. In this paper, we constructed metabolic networks of 17 plants covering unicellular organisms to more complex dicotyledonous plants. The metabolic networks were built based on the substrate-product model and a topological percolation was performed using the kcore decomposition. The distribution of metabolites across the percolation layers showed correlations between the metabolic integration hierarchy and the network topology. We show that metabolites concentrated in the internal network (maximum kcore) only comprise molecules of the primary basal metabolism. Moreover, we found a high proportion of a set of common metabolites, among the 17 plants, centered at the inner kcore layers. Meanwhile, the metabolites recognized as participants in the secondary metabolism of plants are concentrated in the outermost layers of the network. This data suggests that the metabolites in the central layer form a basic molecular module in which the whole plant metabolism is anchored. The elements from this central core participate in almost all plant metabolic reactions, which suggests that plant metabolic networks follows a centralized topology. [ABSTRACT FROM AUTHOR]
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- 2018
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30. Living on a trophic subsidy: Algal quality drives an upper-shore herbivore’s consumption, preference and absorption but not growth rates.
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Quintanilla-Ahumada, Diego, Quijón, Pedro A., Navarro, Jorge M., Pulgar, José, and Duarte, Cristian
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ALGAE , *PROSOBRANCHIA , *HERBIVORES , *FOOD consumption , *MOLLUSK growth , *ABSORPTION (Physiology) , *PHYSIOLOGY - Abstract
The transfer of seaweeds from subtidal bottoms to nearby intertidal rocky shores is a common but often overlooked phenomenon. Freshly detached seaweeds often represent critical trophic subsidies for herbivores living in upper-shore rocky intertidal areas, such as the marine snail Diloma nigerrima. This species relies on three species of seaweeds for food and displays feeding strategies to deal with a resource that is scarce and at times unpredictable. This study focused on the nutritional quality of freshly detached algae (Durvillaea antarctica, Lessonia spicata and Lessonia trabeculata) and measured Diloma nigerrima’s algal consumption rates in trials with and without choice. Absorption efficiency and growth of individual snails fed on each alga were also measured. Durvillaea antarctica had the highest nutritional quality and was the most consumed algae in both single and multiple-choice trials. Absorption efficiency was also highest for D. antarctica but growth rates of snails fed with this species were similar to those fed with the other algae. Combined, these results suggest that D. nigerrima has the ability to discriminate among seaweeds based on their nutritional quality. A potential increase in oxygen uptake when D. nigerrima is consuming the preferred food item is also proposed as a plausible hypothesis to explain the mismatch between snails’ preference and growth rate. These results aim to guide further studies on trophic subsidies and their role in coastal systems. [ABSTRACT FROM AUTHOR]
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- 2018
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31. A noncanonical role for dynamin-1 in regulating early stages of clathrin-mediated endocytosis in non-neuronal cells.
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Srinivasan, Saipraveen, Burckhardt, Christoph J., Bhave, Madhura, Chen, Zhiming, Chen, Ping-Hung, Wang, Xinxin, Danuser, Gaudenz, and Schmid, Sandra L.
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GUANOSINE triphosphatase , *PHOSPHATASES , *ENDOCYTOSIS , *ABSORPTION (Physiology) , *CLATHRIN - Abstract
Dynamin Guanosine Triphosphate hydrolases (GTPases) are best studied for their role in the terminal membrane fission process of clathrin-mediated endocytosis (CME), but they have also been proposed to regulate earlier stages of CME. Although highly enriched in neurons, dynamin-1 (Dyn1) is, in fact, widely expressed along with Dyn2 but inactivated in non-neuronal cells via phosphorylation by glycogen synthase kinase-3 beta (GSK3β) kinase. Here, we study the differential, isoform-specific functions of Dyn1 and Dyn2 as regulators of CME. Endogenously expressed Dyn1 and Dyn2 were fluorescently tagged either separately or together in two cell lines with contrasting Dyn1 expression levels. By quantitative live cell dual- and triple-channel total internal reflection fluorescence microscopy, we find that Dyn2 is more efficiently recruited to clathrin-coated pits (CCPs) than Dyn1, and that Dyn2 but not Dyn1 exhibits a pronounced burst of assembly, presumably into supramolecular collar-like structures that drive membrane scission and clathrin-coated vesicle (CCV) formation. Activation of Dyn1 by acute inhibition of GSK3β results in more rapid endocytosis of transferrin receptors, increased rates of CCP initiation, and decreased CCP lifetimes but did not significantly affect the extent of Dyn1 recruitment to CCPs. Thus, activated Dyn1 can regulate early stages of CME that occur well upstream of fission, even when present at low, substoichiometric levels relative to Dyn2. Under physiological conditions, Dyn1 is activated downstream of epidermal growth factor receptor (EGFR) signaling to alter CCP dynamics. We identify sorting nexin 9 (SNX9) as a preferred binding partner to activated Dyn1 that is partially required for Dyn1-dependent effects on early stages of CCP maturation. Together, we decouple regulatory and scission functions of dynamins and report a scission-independent, isoform-specific regulatory role for Dyn1 in CME. [ABSTRACT FROM AUTHOR]
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- 2018
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32. Regulation of Bicarbonate Secretion in Marine Fish Intestine by the Calcium-Sensing Receptor.
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Gregório, Sílvia F. and Fuentes, Juan
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MARINE fishes , *EPITHELIAL cells , *BICARBONATE ions , *CALCIUM-sensing receptors , *ABSORPTION (Physiology) - Abstract
In marine fish, high epithelial intestinal HCO3- secretion generates luminal carbonate precipitates of divalent cations that play a key role in water and ion homeostasis. The present study was designed to expose the putative role for calcium and the calcium-sensing receptor (CaSR) in the regulation of HCO3- secretion in the intestine of the sea bream (Sparus aurata L.). Effects on the expression of the CaSR in the intestine were evaluated by qPCR and an increase was observed in the anterior intestine in fed fish compared with unfed fish and with different regions of intestine. CaSR expression reflected intestinal fluid calcium concentration. In addition, anterior intestine tissue was mounted in Ussing chambers to test the putative regulation of HCO3- secretion in vitro using the anterior intestine. HCO3- secretion was sensitive to varying calcium levels in luminal saline and to calcimimetic compounds known to activate/block the CaSR i.e., R 568 and NPS-2143. Subsequent experiments were performed in intestinal sacs to measure water absorption and the sensitivity of water absorption to varying luminal levels of calcium and calcimimetics were exposed as well. It appears, that CaSR mediates HCO3- secretion and water absorption in marine fish as shown by responsiveness to calcium levels and calcimimetic compounds. [ABSTRACT FROM AUTHOR]
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- 2018
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33. The effects of exercise and passive heating on the sweat glands ion reabsorption rates.
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Gerrett, Nicola, Amano, Tatsuro, Inoue, Yoshimitsu, Havenith, George, and Kondo, Narihiko
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EXERCISE physiology , *SWEAT glands , *ABSORPTION (Physiology) , *SKIN temperature , *GALVANIC skin response , *PHYSIOLOGY - Abstract
The sweat glands maximum ion reabsorption rates were investigated (n = 12, 21.7 ± 3.0 years, 59.4 ± 9.8 kg, 166.9 ± 10.4 cm and 47.1 ± 7.5 mL/kg/min) during two separate endogenous protocols; cycling at 30% (LEX) and 60% VO2max (MEX) and one exogenous trial; passive heating (PH) (43°C water lower leg immersion) in 27°C, 50%RH. Oesophageal temperature (Tes), skin temperature (Tsk), and forearm, chest and lower back sweat rate (SR) and galvanic skin conductance (GSC) were measured. Salivary aldosterone was measured pre-and postheating (n = 3). Using the ØSR threshold for an increasing ΔGSC to identify maximum sweat ion reabsorption rate revealed higher reabsorption rates during MEX compared to PH (mean of all regions: 0.63 ± 0.28 vs. 0.44 ± 0.3 mg/cm²/min, P < 0.05). It was not possible to identify the ion reabsorption rate during LEX for some participants. Tes and mean Tsk were different between conditions but mean body temperature (Tb) and local Tsk (forearm, chest and back) were similar (P > 0.05). Aldosterone increased more during MEX (72.8 ± 36.6 pg/mL) compared to PH (39.2 ± 17.5 pg/mL) and LEX (1.8 ± 9.7 pg/mL). The back had a higher threshold than the forearm (P < 0.05) but it was similar to the chest (P > 0.05) (mean of all conditions; 0.64 ± 0.33, 0.42 ± 0.25, 0.54 ± 0.3 mg/cm²/min, respectively). Although the differences between conditions may be influenced by thermal or nonthermal mechanism, our results indicate a possibility that the sweat glands maximum ion reabsorption rates may be different between exercise and passive heating without mediating skin regional differences. [ABSTRACT FROM AUTHOR]
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- 2018
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34. Enhanced photocatalytic activity of Au-doped Au@ZnO core-shell flower-like nanocomposites.
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Jung, Hyeon Jin, Koutavarapu, Ravindranadh, Lee, Seulki, Kim, Ju Hyun, Choi, Hyun Chul, and Choi, Myong Yong
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ZINC oxide , *CATALYTIC activity , *ABSORPTION (Physiology) , *PHOTOCATALYTIC oxidation , *NANOSTRUCTURED materials , *NANOCOMPOSITE materials - Abstract
We introduce a simple and low-cost three-step hydrothermal and pulsed laser ablation technique for the fabrication of flower-like pure ZnO nanostructures, Au@ZnO core-shell nanocomposites, and Au@ZnO/Au core-shell nanocomposites doped with various concentrations (5, 10, and 15 wt%) of Au nanoparticles without using surfactants or catalysts to enhance the catalytic performance of ZnO under UV–visible irradiation. The decoration of Au nanoparticles on the surface of ZnO promoted the absorption of visible light due to the surface plasmon resonance of Au. Further, we evaluated the photocatalytic performance of the nanocomposites in the degradation of methylene blue (MB). Our findings revealed that the Au@ZnO/Au core-shell nanocomposites with 5 wt% of doped Au NPs demonstrated the highest photocatalytic activity. In addition, radical-scavenging experiments were conducted to determine the main reactive species formed in the reaction mixture, and accordingly, a plausible photocatalytic reaction mechanism for the enhanced photodegradation of MB is presented. [ABSTRACT FROM AUTHOR]
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- 2018
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35. Conditional Mediation of Absorptive Capacity and Environment in International Entrepreneurial Orientation of Family Businesses.
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Hernández-Perlines, Felipe and Xu, Wenkai
- Subjects
ABSORPTION (Physiology) ,FAMILY-owned business enterprises ,MEDIATION ,GLOBALIZATION ,STRUCTURAL equation modeling - Abstract
This study analyzes the effect of conditional mediation of environment-absorptive capacity in international entrepreneurial orientation of family businesses. Results involve data from 218 Spanish family businesses, analyzed with SmartPLS 3.2.7 software. This paper presents a relevant contribution both to the academic field and the performance of family firms, helping to understand the process of transforming international entrepreneurial orientation into a better international performance through absorptive capacity while family businesses invest their efforts in aligning international entrepreneurial orientation and absorptive capacity with international results, bearing in mind the positive moderator effect of environment. The most relevant contribution of this work is to integrate in the same model the mediating effect of the absorption capacity and the moderating effect of the environment: the effect of the international entrepreneurial orientation on the international performance of family businesses improves with the mediation of the absorptive capacity (the variability of international performance goes from 32.5 to 40.6%) and the moderation of the environment (to variability of international performance goes from 40.6 to 45.3%). [ABSTRACT FROM AUTHOR]
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- 2018
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36. MHD mixed convective stagnation point flow along a vertical stretching sheet with heat source/sink.
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Sharma, P.R., Sinha, Sharad, Yadav, R.S., and Filippov, Anatoly N.
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STAGNATION flow , *HEAT sinks , *ABSORPTION (Physiology) , *ORDINARY differential equations , *MAGNETIC field effects - Abstract
Aim of the paper is to investigate the effects of heat generation/absorption on MHD mixed convective stagnation point flow along a vertical stretching sheet in the presence of external magnetic field. The governing boundary layer equations are formulated and transformed into nonlinear ordinary coupled differential equations using similarity transformation and numerical solution is obtained by using Runge-Kutta fourth order scheme with shooting technique. The effects of various physical parameters such as velocity ratio parameter, mixed convection parameter, Hartmann number, Prandtl number and heat source/sink on velocity and temperature distributions are presented through graphs and discussed numerically. The skin friction coefficientand Nusselt number at the sheet are derived, discussed numerically and their numerical values are presented through tables. [ABSTRACT FROM AUTHOR]
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- 2018
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37. Renal and colonic potassium transporters in the pregnant rat.
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West, Crystal A., Welling, Paul A., West Jr., David A., Coleman, Richard A., Kit-Yan Cheng, Chao Chen, DuBose Jr., Thomas D., Verlander, Jill W., Baylis, Chris, and Gumz, Michelle L.
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POTASSIUM in the body , *POTASSIUM channels , *ABSORPTION (Physiology) - Abstract
Gestational potassium retention, most of which occurs during late pregnancy, is essential for fetal development. The purpose of this study was to examine mechanisms underlying changes in potassium handling by the kidney and colon in pregnancy. We found that potassium intake and renal excretion increased in late pregnancy while fecal potassium excretion remained unchanged and that pregnant rats exhibited net potassium retention. By quantitative PCR we found markedly increased H+-K+- ATPase type 2 (HKA2) mRNA expression in the cortex and outer medullary of late pregnant vs. virgin. Renal outer medullary potassium channel (ROMK) mRNA was unchanged in the cortex, but apical ROMK abundance (by immunofluorescence) was decreased in pregnant vs. virgin in the distal convoluted tubule (DCT) and connecting tubule (CNT). Big potassium-α (BKα) channel-α protein abundance in intercalated cells in the cortex and outer medullary collecting ducts (by immunohistochemistry) fell in late pregnancy. In the distal colon we found increased HKA2 mRNA and protein abundance (Western blot) and decreased BKα protein with no observed changes in mRNA. Therefore, the potassium retention of pregnancy is likely to be due to increased collecting duct potassium reabsorption (via increased HKA2), decreased potassium secretion (via decreased ROMK and BK), as well as increased colonic reabsorption via HKA2. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
38. Tubular maximum phosphate reabsorption capacity in living kidney donors is independently associated with one-year recipient GFR.
- Author
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van Londen, Marco, Aarts, Brigitte M., Sanders, Jan-Stephan F., Hillebrands, Jan-Luuk, Bakker, Stephan J. L., Navis, Gerjan, and de Borst, Martin H.
- Subjects
- *
GLOMERULAR filtration rate , *PHOSPHATES , *ABSORPTION (Physiology) - Abstract
The donor glomerular filtration rate (GFR) measured before kidney donation is a strong determinant of recipient graft outcome. No tubular function markers have been identified that can similarly be used in donors to predict recipient outcomes. In the present study we investigated whether the pre-donation tubular maximum reabsorption capacity of phosphate (TmP-GFR), which may be considered a functional tubular marker in healthy kidney donors, is associated with recipient GFR at 1 yr after transplantation, a key determinant of long-term outcome. We calculated the pre-donation TmP-GFR from serum and 24-h urine phosphate and creatinine levels in 165 kidney donors, and recipient 125I-iothalamate GFR and eGFR (CKD-EPI) at 12 mo after transplantation. Kidney donors were 51 γ 10 yr old, 47% were men, and mean GFR was 118 γ 26 ml/min. The donor TmP-GFR was associated with recipient GFR 12 mo after transplantation (GFR 6.0 ml/min lower per 1 mg/dl decrement of TmP-GFR), which persisted after multivariable adjustment for donor age, sex, pre-donation GFR, and blood pressure and other potential confounders. Results were highly similar when eGFR at 12 mo was taken as the outcome. Tubular damage markers kidney injury molecule- 1 and neutrophil gelatinase-associated lipocalin were low and not associated with recipient GFR. A lower donor TmP-GFR before donation, which may be considered to represent a functional measure of tubular phosphate reabsorption capacity, is independently associated with a lower recipient GFR 1 yr after transplantation. These data are the first to link donor tubular phosphate reabsorption with recipient GFR post-transplantation. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
39. The Balance of HCOL3- Secretion vs. Reabsorption in the Endometrial Epithelium Regulates Uterine Fluid pH.
- Author
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Xie, Zhang-Dong, Guo, Yi-Min, Ren, Mei-Juan, Yang, Jichun, Wang, Shao-Fang, Xu, Tong-Hui, Chen, Li-Ming, and Liu, Ying
- Subjects
BICARBONATE ions ,ION transport (Biology) ,ABSORPTION (Physiology) ,SECRETION ,EPITHELIUM ,ENDOMETRIUM - Abstract
Uterine fluid contains a high concentration of HCO
3 - which plays an essential role in sperm capacitation and fertilization. In addition, the HCO3 - concentration in uterine fluid changes periodically during the estrous cycle. It is well-known that the endometrial epithelium contains machineries involving the apical SLC26 family anion exchangers for secreting HCO3 - into the uterine fluid. In the present study, we find for the first time that the electroneutral Na+ /HCO3 - cotransporter NBCn1 is expressed at the apical membrane of the endometrial epithelium. The protein abundance of the apical NBCn1 and that of the apical SLC26A4 and SLC26A6 are reciprocally regulated during the estrous cycle in the uterus. NBCn1 is most abundant at diestrus, whereas SLC26A4/A6 are most abundant at proestrus/estrus. In the ovariectomized mice, the expression of uterine NBCn1 is inhibited by β-estradiol, but stimulated by progesterone, whereas that of uterine SLC26A4/A6 is stimulated by β-estradiol. In vivo perfusion studies show that the endometrial epithelium is capable of both secreting and reabsorbing HCO3 - . Moreover, the activity for HCO3 - secretion by the endometrial epithelium is significantly higher at estrus than it is at diestrus. The opposite is true for HCO3 - reabsorption. We conclude that the endometrial epithelium simultaneously contains the activity for HCO3 - secretion involving the apical SLC26A4/A6 and the activity for HCO3 - reabsorption involving the apical NBCn1, and that the acid-base homeostasis in the uterine fluid is regulated by the finely-tuned balance of the two activities. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
40. Feasibility of spatial frequency-domain imaging for monitoring palpable breast lesions.
- Author
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Robbins, Constance M., Raghavan, Guruprasad, Antaki, James F., and Kainerstorfer, Jana M.
- Subjects
- *
DIAGNOSTIC imaging , *MEDICAL imaging systems , *BREAST cancer , *CANCER treatment , *ABSORPTION (Physiology) - Abstract
In breast cancer diagnosis and therapy monitoring, there is a need for frequent, noninvasive disease progression evaluation. Breast tumors differ from healthy tissue in mechanical stiffness as well as optical properties, which allows optical methods to detect and monitor breast lesions noninvasively. Spatial frequency-domain imaging (SFDI) is a reflectance-based diffuse optical method that can yield two-dimensional images of absolute optical properties of tissue with an inexpensive and portable system, although depth penetration is limited. Since the absorption coefficient of breast tissue is relatively low and the tissue is quite flexible, there is an opportunity for compression of tissue to bring stiff, palpable breast lesions within the detection range of SFDI. Sixteen breast tissue-mimicking phantoms were fabricated containing stiffer, more highly absorbing tumor-mimicking inclusions of varying absorption contrast and depth. These phantoms were imaged with an SFDI system at five levels of compression. An increase in absorption contrast was observed with compression, and reliable detection of each inclusion was achieved when compression was sufficient to bring the inclusion center within ∼12 mm of the phantom surface. At highest compression level, contrasts achieved with this system were comparable to those measured with single source–detector near-infrared spectroscopy. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
41. Discriminating modes of toxic action in mice using toxicity in BALB/c mouse fibroblast (3T3) cells.
- Author
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Huang, Tao, Yan, Lichen, Zheng, Shanshan, Wang, Yue, Fan, Lingyun, Li, Chao, Zhao, Yuanhui, Wang, Xiaohong, and Martyniuk, Christopher J.
- Subjects
- *
FIBROBLASTS , *TOXICITY testing , *LABORATORY mice , *BIOCHEMICAL mechanism of action , *ABSORPTION (Physiology) , *ANIMAL models of toxicology , *CELL-mediated cytotoxicity , *CHEMICAL kinetics - Abstract
The objective of this study was to determine whether toxicity in mouse fibroblast cells (3T3 cells) could predict toxicity in mice. Synthesized data on toxicity was subjected to regression analysis and it was observed that relationship of toxicities between mice and 3T3 cells was not strong (R 2 = 0.41). Inclusion of molecular descriptors (e.g. ionization, pKa) improved the regression to R 2 = 0.56, indicating that this relationship is influenced by kinetic processes of chemicals or specific toxic mechanisms associated to the compounds. However, to determine if we were able to discriminate modes of action (MOAs) in mice using the toxicities generated from 3T3 cells, compounds were first classified into “baseline” and “reactive” guided by the toxic ratio (TR) for each compound in mice. Sequence, binomial and recursive partitioning analyses provided strong predictions of MOAs in mice based upon toxicities in 3T3 cells. The correct classification of MOAs based on these methods was 86%. Nearly all the baseline compounds predicted from toxicities in 3T3 cells were identified as baseline compounds from the TR in mice. The incorrect assignment of MOAs for some compounds is hypothesized to be due to experimental uncertainty that exists in toxicity assays for both mice and 3T3 cells. Conversely, lack of assignment can also arise because some reactive compounds have MOAs that are different in mice compared to 3T3 cells. The methods developed here are novel and contribute to efforts to reduce animal numbers in toxicity tests that are used to evaluate risks associated with organic pollutants in the environment. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
42. Bioenergetic adaptations of the human liver in the ALPPS procedure – how liver regeneration correlates with mitochondrial energy status.
- Author
-
Alexandrino, Henrique, Rolo, Anabela, Teodoro, João S., Donato, Henrique, Martins, Ricardo, Serôdio, Marco, Martins, Mónica, Tralhão, José G., Caseiro Alves, Filipe, Palmeira, Carlos, and Castro e Sousa, Francisco
- Subjects
- *
LIVER transplantation , *BIOENERGETICS , *ABSORPTION (Physiology) , *TUMOR growth , *TUMOR budding - Abstract
Background The Associating Liver Partition and Portal Ligation for Staged Hepatectomy (ALPPS) depends on a significant inter-stages kinetic growth rate (KGR). Liver regeneration is highly energy-dependent. The metabolic adaptations in ALPPS are unknown. Aims: i) Assess bioenergetics in both stages of ALPPS (T1 and T2) and compare them with control patients undergoing minor (miHp) and major hepatectomy (MaHp), respectively; ii) Correlate findings in ALPPS with volumetric data; iii) Investigate expression of genes involved in liver regeneration and energy metabolism. Methods Five patients undergoing ALPPS, five controls undergoing miHp and five undergoing MaHp. Assessment of remnant liver bioenergetics in T1, T2 and controls. Analysis of gene expression and protein content in ALPPS. Results Mitochondrial function was worsened in T1 versus miHp; and in T2 versus MaHp (p < 0.05); but improved from T1 to T2 (p < 0.05). Liver bioenergetics in T1 strongly correlated with KGR (p < 0.01). An increased expression of genes associated with liver regeneration (STAT3, ALR) and energy metabolism (PGC-1α, COX, Nampt) was found in T2 (p < 0.05). Conclusion Metabolic capacity in ALPPS is worse than in controls, improves between stages and correlates with volumetric growth. Bioenergetic adaptations in ALPPS could serve as surrogate markers of liver reserve and as target for energetic conditioning. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
43. Determination of cepharanthine in rat plasma by LC–MS/MS and its application to a pharmacokinetic study.
- Author
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Deng, Yingbin, Wu, Weijun, Ye, Sunzhi, Wang, Wei, and Wang, Zhiyi
- Subjects
- *
BIOAVAILABILITY , *PHARMACOKINETICS , *INTRAVENOUS therapy , *LABORATORY rats , *ABSORPTION (Physiology) - Abstract
Context:Cepharanthine (CPA) has been reported to possess a wide range of pharmacological activities. Objective:This study investigates the pharmacokinetic characteristics after oral or intravenous administration of CPA by using a sensitive and rapid LC–MS/MS method. Materials and methods:A sensitive and rapid LC–MS/MS method was developed for the determination of CPA in Sprague–Dawley rat plasma. Twelve rats were equally randomized into two groups, including the intravenous group (1 mg/kg) and the oral group (10 mg/kg). Blood samples (250 μL) were collected at designated time points and determined using this method. The pharmacokinetic parameters were calculated. Results:The calibration curve was linear within the range of 0.1–200 ng/mL (r = 0.999) with the lower limit of quantification at 0.1 ng/mL. After 1 mg/kg intravenous injection, the concentration of CPA reached a maximum of 153.17 ± 16.18 ng/mL and thet1/2was 6.76 ± 1.21 h. After oral administration of 10 mg/kg of CPA, CPA was not readily absorbed and reachedCmax46.89 ± 5.25 ng/mL at approximately 2.67 h. Thet1/2was 11.02 ± 1.32 h. The absolute bioavailability of CPA by oral route was 5.65 ± 0.35%, and the bioavailability was poor. Discussion and conclusions:The results indicate that the bioavailability of CPA was poor in rats, and further research should be conducted to investigate the reason for its poor bioavailability and address this problem. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
44. Current understanding of iron homeostasis.
- Author
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Anderson, Gregory J. and Frazer, David M.
- Subjects
PHYSIOLOGICAL effects of iron ,HOMEOSTASIS ,IRON metabolism ,ABSORPTION (Physiology) ,BLOOD transfusion ,IRON in the blood ,MAMMALS ,HEMOCHROMATOSIS ,ANEMIA ,FERRITIN ,IRON ,TRANSFERRIN - Abstract
Iron is an essential trace element, but it is also toxic in excess, and thus mammals have developed elegant mechanisms for keeping both cellular and whole-body iron concentrations within the optimal physiologic range. In the diet, iron is either sequestered within heme or in various nonheme forms. Although the absorption of heme iron is poorly understood, nonheme iron is transported across the apical membrane of the intestinal enterocyte by divalent metal-ion transporter 1 (DMT1) and is exported into the circulation via ferroportin 1 (FPN1). Newly absorbed iron binds to plasma transferrin and is distributed around the body to sites of utilization with the erythroid marrow having particularly high iron requirements. Iron-loaded transferrin binds to transferrin receptor 1 on the surface of most body cells, and after endocytosis of the complex, iron enters the cytoplasm via DMT1 in the endosomal membrane. This iron can be used for metabolic functions, stored within cytosolic ferritin, or exported from the cell via FPN1. Cellular iron concentrations are modulated by the iron regulatory proteins (IRPs) IRP1 and IRP2. At the whole-body level, dietary iron absorption and iron export from the tissues into the plasma are regulated by the liver-derived peptide hepcidin. When tissue iron demands are high, hepcidin concentrations are low and vice versa. Too little or too much iron can have important clinical consequences. Most iron deficiency reflects an inadequate supply of iron in the diet, whereas iron excess is usually associated with hereditary disorders. These disorders include various forms of hemochromatosis, which are characterized by inadequate hepcidin production and, thus, increased dietary iron intake, and iron-loading anemias whereby both increased iron absorption and transfusion therapy contribute to the iron overload. Despite major recent advances, much remains to be learned about iron physiology and pathophysiology. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
45. Use of pineapple waste for production of decomposable pots.
- Author
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Jirapornvaree, I., Suppadit, T., and Popan, A.
- Subjects
PINEAPPLE ,WASTE management ,PLANT nurseries ,POTS ,ABSORPTION (Physiology) ,PLANTS - Abstract
Purpose: The aim of this research was to evaluate the suitability of pineapple waste for production of decomposable nursery pots. Methods: The experiment was completely randomized, with three replicates and eighteen formula treatments. Treatments consisted of varying ratios of pineapple waste to binder, including 2:1, 1:0 (fresh pineapple waste), 1:1, 1:1.5, and 1:2; the textures tested were coarse, medium, and fine, and the pot thicknesses were 0.5, 1.0 and 1.5 cm. Results: The results revealed that the physical and chemical properties of pineapple waste were suitable for use in nursery pots on an experimental scale. The optimal physical and chemical properties for a decomposable pot included a 1:0 ratio of pineapple waste to binder, a coarse structure, and a pot thickness of 1 cm. With these properties, the pot degraded in more than 45 days, N and P release rates were 0.49% and 7.97 mg-P/kg, respectively, and the average absorption rate was 258.43%. Saturation occurred in 45 min, and the water evaporated in 444 h. Conclusion: In terms of cost production per pot, fresh pineapple waste cost 0.0075 USD for a three-and-a-half inch diameter decomposable pot (excluding logistical costs). Therefore, this study provides a possible method for waste management. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
46. The Effects of Different Isocaloric Oral Nutrient Solutions on Psychophysical, Metabolic, Cognitive, and Olfactory Function in Young Male Subjects.
- Author
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Bachlechner, Stephan, Denzer-Lippmann, Melanie Y., Wielopolski, Jan, Fischer, Marie, Buettner, Andrea, Doerfler, Arndt, Schöfl, Christof, Münch, Gerald, Kornhuber, Johannes, and Thürauf, Norbert
- Subjects
INGESTION ,PHAGOCYTOSIS ,ABSORPTION (Physiology) ,DIETARY supplements ,ANTIOXIDANTS ,METABOLISM - Published
- 2017
- Full Text
- View/download PDF
47. Feeding behaviour of a new worm (Priapulida) from the Sirius Passet Lagerstätte (Cambrian Series 2, Stage 3) of North Greenland (Laurentia).
- Author
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Peel, John S. and Rahman, Imran
- Subjects
- *
PRIAPULIDA , *ANIMAL nutrition , *INGESTION , *ABSORPTION (Physiology) ,LAURENTIA (Continent) - Abstract
Singuuriqia simoni gen. et sp. nov. represents the first record of a priapulid worm from the Sirius Passet Lagerstätte (Cambrian Series 2, Stage 3) of North Greenland (Laurentia). It is defined by an unusually broad, longitudinally folded, foregut which tapers through the pharynx towards the anterior mouth; posteriorly, the same longitudinal folding is evident in the narrow gut. The slender, smooth, trunk in the unique specimen passes anteriorly into an oval proboscis which culminates in a smooth, extensible, pharynx with pharyngeal teeth. The capacity for substantial expansion of the foregut permitted rapid ingestion of food prior to digestion at leisure. Cololites suggest both carnivorous and deposit feeding behaviour, indicating that Singuuriqia, like the present day Priapulus, was probably omnivorous. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
48. Removal of Brilliant Green Dye from Aqueous Medium by Untreated Acid treated and Magnetite Impregnated Bentonite Adsorbents.
- Author
-
Ishaq, Mohammad, Sultan, Siraj, Ahmad, Imtiaz, and Saeed, Khalid
- Subjects
- *
ADSORPTION kinetics , *ABSORPTION (Physiology) , *SCANNING electron microscopy , *ENERGY dispersive X-ray spectroscopy , *LANGMUIR isotherms - Abstract
The untreated bentonite (UB), acid treated bentonite (ATB) and magnetite impregnated bentonite (MIB) has been examined as adsorbents for the removal of Brilliant green (BG) dye from aqueous medium. The batch adsorption experiments were conducted at different pH, contact time, adsorbent dosage, dye concentration and temperature. The adsorption of BG was dependent on pH of the solutions and the optimized pH value for their adsorption is 8. The adsorption data were fitted to Freundlich and Langmuir adsorption models, which were best fitted to Langmuir isotherm model. The monolayer adsorption capacity of UB, ATB and MIB was 689.6, 785, 877 mg/g, respectively. The kinetic study was analyzed by pseudo first, second and intraparticle diffusion models. It was found that adsorption of BG onto all three adsorbents followed pseudo second order kinetic model. The prepared adsorbents were also characterized by scanning electron microscopy (SEM), energy dispersive X-rays (EDX) and XRD. [ABSTRACT FROM AUTHOR]
- Published
- 2017
49. Assessment of veterinary drugs in plants using pharmacokinetic approaches: The absorption, distribution and elimination of tetracycline and sulfamethoxazole in ephemeral vegetables.
- Author
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Chen, Hui-Ru, Rairat, Tirawat, Loh, Shih-Hurng, Wu, Yu-Chieh, Vickroy, Thomas W., and Chou, Chi-Chung
- Subjects
- *
BOK choy , *TETRACYCLINE , *SULFAMETHOXAZOLE , *PHARMACOKINETICS , *ANTIBACTERIAL agents , *ABSORPTION (Physiology) - Abstract
The present study was carried out to demonstrate novel use of pharmacokinetic approaches to characterize drug behaviors/movements in the vegetables with implications to food safety. The absorption, distribution, metabolism and most importantly, the elimination of tetracycline (TC) and sulfamethoxazole (SMX) in edible plants Brassica rapa chinensis and Ipomoea aquatica grown hydroponically were demonstrated and studied using non-compartmental pharmacokinetic analysis. The results revealed drug-dependent and vegetable-dependent pharmacokinetic differences and indicated that ephemeral vegetables could have high capacity accumulating antibiotics (up to 160 μg g-1 for TC and 38 μg g-1 for SMX) within hours. TC concentration in the root (Cmax) could reach 11 times higher than that in the cultivation fluid and 3–28 times higher than the petioles/stems. Based on the volume of distribution (Vss), SMX was 3–6 times more extensively distributed than TC. Both antibiotics showed evident, albeit slow elimination phase with elimination half-lives ranging from 22 to 88 hours. For the first time drug elimination through the roots of a plant was demonstrated, and by viewing the root as a central compartment and continuous infusion without a loading dose as drug administration mode, it is possible to pharmacokinetically monitor the movement of antibiotics and their fate in the vegetables with more detailed information not previously available. Phyto-pharmacokinetic could be a new area worth developing new models for the assessment of veterinary drugs in edible plants. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
50. Amino Acid Absorption in the Large Intestine of Humans and Porcine Models.
- Author
-
van der Wielen, Nikkie, Moughan, Paul J., and Mensink, Marco
- Subjects
- *
AMINO acid analysis , *LARGE intestine , *NUTRITION , *LOW-protein diet , *ABSORPTION (Physiology) - Abstract
Dietary protein quality has been recognized as a critical issue by international authorities because it can affect important functions of the body. To predict protein quality, the FAO introduced the Digestible Indispensable Amino Acid Score. This score depends on ileal amino acid (AA) digestibility; therefore, the assumption is made that AAs are not absorbed in nutritionally relevant amounts from the large intestine. This article reviews the evidence for this assumption by considering the role of the mammalian large intestine in dietary protein and AA digestion and absorption, with particular reference to adult humans. Although most dietary AAs and peptides are absorbed in the small intestine, substantial amounts can enter the large intestine. Nitrogen is absorbed in the large intestine, and a series of animal experiments indicate a potential small degree of AA absorption. In humans, colonocytes have the capacity for AA absorption because AA transporters are present in the large intestine. The absorption of nutritionally relevant amounts of dietary indispensable AAs and peptides in the human large intestine has not been convincingly demonstrated, however. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
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