Search

Background: The Twin-arginine translocation (Tat) system serves to translocate folded proteins, including periplasmic enzymes that bind redox cofactors in bacteria. The Tat system is also a determinant of virulence in some pathogenic bacteria, related to pleiotropic effects including growth, motility, and the secretion of some virulent factors. The contribution of the Tat pathway to Vibrio cholerae has not been explored. Here we investigated the functionality of the Tat system in V. cholerae, the etiologic agent of cholera. Results: In V. cholerae, the tatABC genes function in the translocation of TMAO reductase. Deletion of the tatABC genes led to a significant decrease in biofilm formation, the ability to attach to HT-29 cells, and the ability to colonize suckling mouse intestines. In addition, we observed a reduction in the output of cholera toxin, which may be due to the decreased transcription level of the toxin gene in tatABC mutants, suggesting an indirect effect of the mutation on toxin production. No obvious differences in flagellum biosynthesis and motility were found between the tatABC mutant and the parental strain, showing a variable effect of Tat in different bacteria. Conclusion: The Tat system contributes to the survival of V. cholerae in the environment and in vivo, and it may be associated with its virulence. [ABSTRACT FROM AUTHOR]

ABSTRACTAtherosclerosis, a progressive disease characterized by the accumulation of lipids and fibrous elements in the arteries, is a most important contributor to cardiovascular diseases. Resveratrol is a naturally occurring phytopolyphenol compound and shows the ability to reduce the risk of cardiovascular diseases. In this review, beneficial effects of resveratrol on the initiation and progression of atherosclerosis, including regulation of vasodilator and vasoconstrictor production, inhibition of oxidative stress/reactive oxygen species generation, anti-inflammation, inhibition of modification of low-density lipoproteins, anti-platelet aggregation, and its abilities to impede progression and modulate complications of atherosclerosis, are discussed. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the origin and nosocomial transmission of human granulocytic anaplasmosis (HGA) in the Anhui Provence in China. The authors explain that HGA is a tick-borne infectious disease. A laboratory diagnosis to test for serum IgG to A phagocytophium was performed on patients who were suspected of HGA exposure to an index patient. A discussion of the epidemiological investigation is included. Results of the serological and molecular diagnosis are also included. Researchers found HGA in China and likely nosocomial transmission of HGA from direct contact with respiratory secretions or blood. A discussion of the contact investigation and risk factors for the disease are included.

A nearly 100% yield peptide carboxy group derivatization method was offered to largely enhance phosphopeptide ionization efficiency. This method, adopting 1-(2-pyrimidyl) piperazine (PP) as the derivatization reagent, shows several advantages such as good reproducibility, ease of handling, rapid reaction time, and no side reaction. PP derivatization improves the hydrophobicities, pI values, and gas-phase basicities of peptides especially those of phosphopeptides. In the matrix assisted laser desorption ionization (MALDI) source, the ionization efficiencies of four synthetic phosphopeptides were increased by 50-101 times while that of three nonphosphopeptides were 10-40-fold. In the electrospray ionization (ESI) source, PP-derivatized phosphopeptides also gave much higher ionization efficiency improvements than nonphosphopeptides. When this method was applied to much more complex mixtures, tryptic BSA digests spiked with one single phosphopeptide in different molar ratios, the signal intensity of this phosphopeptide always had the largest increment among all those peptides. Obviously, this easily manipulated as well as highly specific method provides a promising tool for high-throughput phosphoproteome research. [ABSTRACT FROM AUTHOR]

Bilayer nanostructured poly(3,4-ethylenedioxythiophene) (PEDOT) and polyaniline (PANI) conducting polymer composites have been successfully prepared by oxidative polymerization of the parent monomers, aniline (An) and 3,4-ethylenedioxythiophene (EDOT), in aqueous solutions of p-toluenesulfonic acid ( p-TSA). As the first step, PANI nanofibers were obtained in the p-TSA solution using ammonium persulfate (APS) as the oxidant. Subsequently, PEDOT was coated onto the PANI nanofibers by the oxidative polymerization of EDOT to form PEDOT/PANI bilayer nanofibers. The resulting nanostructured material was characterized by SEM and a range of spectroscopic methods, which confirmed that the surface layer of the synthesized materials had features typical of chemically synthesized PEDOT. The presence of the PEDOT layer increased the room temperature electrical conductivity of the PEDOT/PANI nanocomposites by 2 orders of magnitude in comparison with the parent PANI nanofibers. Moreover, PEDOT/PANI nanocomposites on a glassy carbon electrode showed stronger electrocatalytic activity for the oxidation of ascorbic acid than PANI nanofibers. [ABSTRACT FROM AUTHOR]

A systematic procedure is presented for selecting the carrier material and stabilizer for drug-loaded solid lipid microparticles (SLMs). Heuristics criteria as well as investigation methods are proposed. The proposed procedure is based on the summaries of the authors’ investigation and the accumulated heuristics derived from the available literature works. The physical properties of carrier materials, drug distribution in the carrier matrix, the compatibility between drugs and carrier materials, and the crystal structures of carrier matrices are taken into account in the selection of the carrier materials. In stabilizer selection, the coverage of stabilizer molecules on particle surfaces and the electrostatic repulsion and steric repulsion of stabilizers should be considered. The presented heuristics and criteria are to assist with decision making in new SLM development. This is demonstrated with an application case, in which a clozapine-loaded SLM formulation is designed, to illustrate the selection of carrier materials and stabilizers. Experiments and testing have confirmed the effectiveness of the proposed procedure and heuristics. [ABSTRACT FROM AUTHOR]

Abstract  A new reduced ferrous molybdophosphate composite solid of the formula, [(C10H14N2)H]4[FeII 10MoV 24(H2PO4)4(HPO4)12(PO4)4(H2O)16(OH)16O44]?12H2O, has been synthesized from a reaction mixture of MoO3, FeSO4?7H2O, C2H2O4?2H2O, nicotine, H3PO4, and H2O under hydrothermal conditions. The crystal data: monoclinic, space group C2/m, a = 24.4349(124), b = 12.9935(66), c = 14.7281(74) ?, ß = 104.87(1) ?, V = 4520(4) ?3, Z = 2, R 1  = 0.0874, wR 2  = 0.2179. The structure is built from the building blocks of the formula, {FeII[Mo6P4O31]2}, consisting of a network of MO6 (M = Fe, Mo) octahedral and PO4 tetrahedral linked through their vertices. The connectivity of the building blocks with two pairs of face-sharing dinuclear Fe(II) clusters of the formula of [FeII 2(H2O)4O5] on which a phosphate group is hanging gives rise to one-dimensional chains with eight-membered apertures. The remarkable hydrogen bonded interactions between the chains form a unique and interesting framework with three-dimensional intersecting tunnels where the protonated nicotine molecules as structuring templates and crystallization water molecules are situated. [ABSTRACT FROM AUTHOR]

Dengue virus (DENV) nonstructural protein-1 (NS1) is a secreted glycoprotein that is absent from viral particles but accumulates in the supernatant and on the plasma membrane of cells during infection. Immune recognition of cell surface NS1 on endothelial cells has been hypothesized as a mechanism for the vascular leakage that occurs during severe DENV infection. However, it has remained unclear how NS1 becomes associated with the plasma membrane, as it contains no membrane-spanning sequence motif. Using flow cytometric and ELISA-based binding assays and mutant cell lines lacking selective glycosaminoglycans, we show that soluble NS1 binds back to the surface of uninfected cells primarily via interactions with heparan sulfate and chondroitin sulfate E. DENV NS1 binds directly to the surface of many types of epithelial and mesenchymal cells yet attaches poorly to most peripheral blood cells. Moreover, DENV NS1 preferentially binds to cultured human microvascular compared to aortic or umbilical cord vein endothelial cells. This binding specificity was confirmed in situ as DENV NS1 bound to lung and liver but not intestine or brain endothelium of mouse tissues. Differential binding of soluble NS1 by tissue endothelium and subsequent recognition by anti-NS1 antibodies could contribute to the selective vascular leakage syndrome that occurs during severe secondary DENV infection. [ABSTRACT FROM AUTHOR]

Polyaniline (PANI) micro/nanofibers (190–450 nm in diameter) doped with saturation fatty acids such as acetic acid (CH3COOH, AA), hexanoic acid (CH3(CH2)4COOH, HA), lauric acid (CH3(CH2)10COOH, LA) and stearic acid (CH3(CH2)16COOH, SA) as the dopant were prepared by template-free method in the presence of ammonium per-sulfate (NH4)2S2O8, APS) as an oxidant. It was found that the crystalline, morphology and diameter as well as room-temperature conductivity of the PANI fibers were affected by the number of 一CH2一 group of the fatty acids. [Copyright &y& Elsevier]

Explores the involvement of heparan sulfate (HS) in FGF1/HS/FGFR1 signaling complex. Size and molar ratio of HS in the complex; Evidence that both FGF1 and FGFR1 simultaneously interact with HS; Use of genetic and biochemical methods in the study; Observation of the ternary complex of FGF1, HS, and FGFR1.

Investigates the antimicrobial and hemolytic activities of microbial peptide polyphemusin I and its ability to bind lipopolysaccharide, to permeabilize bacterial membranes and to interact with model membrane systems. Membrane permeabilization activity; Interaction of peptides with liposomes; Interaction of peptides with lipid monolayers.

Examines the influence of proline residues on the antibacterial and synergistic activities of alpha-helical peptides. Variant synthesis with insertions of proline residues; Utilization of circular dichroism spectroscopy; Effects of proline-induced bends to helicity, antibacterial activity, hemolyticity and synergistic activity.

High seroprevalence rates for Anaplasma phagocytophilum (8.8%), Coxiella burnetii (6.4%), Bartonella henselae (9.6%), and Rickettsia typhi (4.1%) in 365 farm workers near Tianjin, People's Republic of China, suggest that human infections with these zoonotic bacteria are frequent and largely unrecognized. Demographic features of seropositive persons suggest distinct epidemiology, ecology, and risks. [ABSTRACT FROM AUTHOR]

• A variable coefficient constitutive model for chloride ion transport under coupled bending and drying–wetting conditions is proposed. • The model considers the key factors such as the porosity, tortuosity and saturation changes during the transport of chloride ions in concrete. • The two-dimensional variable coefficient constitutive equations of water and chloride ion transport are solved by the alternating implicit finite difference method. The transport of chloride ions in concrete under the coupled effects of a bending load and drying–wetting cycles accelerates the degradation of marine concrete. Based on the microstructure characteristics of concrete, the models of the tortuosity of concrete under a bending load were built. Considering the interaction between the transport of water and the tortuosity in the concrete microstructure, a nonlinear diffusion-convection model of the water and chloride ions transport in unsaturated conditions were also proposed in this paper. Finally, a two-dimensional variable coefficient model of chloride ion transport in concrete under the coupled effects of a bending load and drying–wetting cycles was also established based on Fick′s second law, which was numerically solved using the alternating direction implicit (ADI) method. The results show that the values predicted agree with those of experiments and those reported in the literatures. [ABSTRACT FROM AUTHOR]

Partial oxidation of methane (CH4) to value-added products is significantly challenging due to the highly inert chemical property of CH4 at ambient conditions and easy over-oxidation into carbon dioxide (CO2) or carbon monoxide (CO) at elevated temperatures and pressures. Targeting this challenge, the efficient photocatalytic coupling of CO2 and CH4 into ethanol is demonstrated, using a cerium (Ce)-doped zinc oxide (ZnO) photocatalyst with abundant Ce--O--Zn units. Under light illumination, CO2 is adsorbed on the Ce atoms and photo-reduced to CO, and CH4 is captured by the Zn atoms and photo-oxidized to hydroperoxymethane (CH3OOH). The close proximity of Ce and Zn atoms on the Ce--O--Zn units allowed to further efficiently couple the as-formed CO and CH3OOH into ethanol. Without additional Oxygen (O2) oxidant or sacrificial regent, the ethanol production rate reached 580 µmol g-1 h-1, substantially exceeding previously reports on photocatalytic CH4 oxidation. This work features to convert two greenhouse gases into value-added chemicals with adjacent and asymmetric reaction sites, suggesting attractive potentials for CH4 and CO2 utilization. [ABSTRACT FROM AUTHOR]

Objectives: Patients with IgG4-related disease (IgG4-RD) suffer high relapse rates during long-term treatment, but factors that predict relapse outcomes are not well established. In the present study, we aimed to identify predictive factors for treatment resistance and disease relapse in a Chinese IgG4-RD cohort. Methods: This study enrolled 102 patients newly diagnosed with IgG4-RD. Disease prognosis was determined by evaluating disease activity and dosage of glucocorticoids. Predictive factors for refractory and relapsed disease were identified by univariate analysis and Cox regression. Results: Among the 102 patients, 78 cases received medical treatment with regular follow-up (21 [6-111] months). During the follow-up period, 55 (70.5%) patients sustained clinical remission, and 23 (29.5%) patients suffered refractory or relapsed disease. The relapse rate of the patients with IgG4-RD was significantly higher among patients who stopped taking medicine than among those who continued treatment with glucocorticoids (GC) + immunosuppressor (IM). Serum TNF-α ≥ 13 pg/mL, sIL-2R ≥ 1010 U/mL, total cholesterol < 3.55 mmol/L, low-density lipoprotein < 2.0 mmol/L, IgG ≥ 20.2 g/L, and drug withdrawal were predictive factors for refractory and relapsed IgG4-RD. Multivariate Cox regression revealed that both sIL-2R and TNF-α were independent risk factors for refractory and relapsed disease. The combination of GC and IM treatment was an independent protective factor against refractory and relapsed IgG4-RD. Conclusions: High serum levels of sIL-2R and TNF-α may be informative risk factors for refractory and relapsed IgG4-RD. Our data suggest that a combination treatment of GC along with IM may be protective against refractory and relapsed IgG4-RD. Key Points • High sIL-2R and TNF-α levels are informative risk factors for refractory and relapsed IgG4-related disease. • Combination treatment of GC with IM protects against refractory and relapsed IgG4-related disease [ABSTRACT FROM AUTHOR]

The article presents a study on the role of microglia in hippocampal neurogenesis and stress resilience. It discusses the roles of microglia in immune surveillance and maintenance of brain homeostasis, the link between vulnerability to stress and a reduction in interleukin 4 (IL4) signaling in the hippocampus, and enhancement of neurogenesis by IL4-driven microglia.

• Coupled transport model of sulfate–chloride salts in concrete is established. • Chloride ions' adsorption and desorption capacities are considered in model. • The effect of interaction concentration of SO 4 2− and Cl− is quantified. The transport of sulfate–chloride salts in concrete is the main cause of its structural deterioration. Traditional numerical simulation assumes that the diffusion coefficients of sulfate ions and chloride ions are both constant leading to large deviations in the predicted results. Based on the mass conservation law, Fick's second law, and the theory of porous media, a variable coefficient transport model of sulfate–chloride salts in concrete is established in this paper. The model fully reflects the adsorption and desorption of chloride ions in the transport process, the reaction-filling process of sulfate ions and hydration products, as well as the most important porosity and tortuosity affecting ion transport. Results show that the prediction results of the two-dimensional variable coefficient model are consistent with experimental and literature results, with maximum error of 23.49%. The analysis of influencing factors shows that the interaction between sulfate ions and chloride ions does not change the transport law of ions in concrete, but delays the rate of ion corrosion within about 700 days. The ability of chloride ions to be adsorbed decreases by about 20% when sulfate ions are present, and the desorption rate is about 40% to 60%. The tortuosity decreases with the increase of water-binder ratio, and increasing the initial porosity from 5% to 12% leads to an early appearance of cracks by about 1400 days. [ABSTRACT FROM AUTHOR]

Janus adhesive hydrogels have one-sided adhesive properties and hold promising applications in the health care field. However, a simple method for synthesizing Janus hydrogels is still lacking. In this study, we introduce an innovative method to prepare Janus hydrogels by harnessing a fundamental phenomenon: the self-aggregation of surfactants at high concentrations at the water-air interface. By combining a small amount [0.8 to 3.2 weight %, relative to mass of acrylamide (AM)] of sodium a-linoleate (LAS) with AM through free radical polymerization, we have synthesized Janus adhesive hydrogels. The Janus hydrogels exhibit remarkable adhesive strength and adhesive differences, with the top side (84 J m-2) being 21 times stronger than the bottom side, also an excellent elongation rate. Through comprehensive experiments, including chemical composition, surface morphology, and molecular dynamics (MD) simulations, we thoroughly investigate the mechanisms of the hydrogel's heterogeneous adhesion. This study presents an easy, efficient, and innovative method for preparing one-sided adhesive hydrogels. [ABSTRACT FROM AUTHOR]

Using a combination of photoelectron spectroscopy measurements and quantum chemistry calculations, we have identified competing electron emission processes that contribute to the 350-315 nm photoelectron spectra of the deprotonated green fluorescent protein chromophore anion, phydroxybenzylidene- 2,3-dimethylimidazolinone. As well as direct electron detachment from S0, we observe resonant excitation of the 21ππ* state of the anion followed by autodetachment. The experimental photoelectron spectra are found to be significantly broader than photoelectron spectrum calculated using the Franck-Condon method and we attribute this to rapid (∼10 fs) vibrational decoherence, or intramolecular vibrational energy redistribution, within the neutral radical. [ABSTRACT FROM AUTHOR]

The streaming potential in porous media is one of the main constituents of the self-potential. It has attracted special attention in environmental and engineering geophysics. Forward modeling of streaming potentials could be the foundation of corresponding data inversion and interpretation, and improving the application effect of the self-potential method. The traditional finite element method has a large subdivision area and computational quantity, and the artificial boundary condition is not suitable for complex models. The Helmholtz-Smoluchowski equation is introduced for evaluating the streaming potential. Then three new shape functions of the multidirectional mapping infinite elements are proposed and the finite-infinite element coupling method is deduced for reducing the subdivision scale and improving both the calculation efficiency and accuracy. The correctness and validity of the new coupled method are verified by a resistive model in homogeneous half-space. Besides, a seepage model with complex terrain and a landfill model with dynamic leakages are modeled using the improved coupled method. The results show that the accuracy of the improved coupled method is superior to the unimproved coupled method, and is better than the finite element method. Also, the coupled method has better adaptability to complex models and is suitable for the accurate simulation of dynamic multi-source seepage models. [ABSTRACT FROM AUTHOR]

The chest X-ray is routinely requested by pediatricians for children with suspected pneumonia, but has been demonstrated to be an insensitive method with relatively low accuracy. Computed tomography (CT) allows for the characterization of the consolidation in pneumonia but has a high risk of radiation exposure in children. Lung ultrasonography can identify subpleural lung consolidation in adults, but it is not accepted in routine clinical practice and is also not used for the diagnosis of children with pneumonia. The objective of the present study was to compare diagnostic parameters of lung ultrasound with chest X-ray in children with suspected pneumonia, using CT as a reference standard. Medical records of 949 children, aged ≤16 years, with suspected pneumonia were reviewed. Data regarding the chest radiograph, lung ultrasound and chest CT were collected and analyzed. Beneficial score analysis for each diagnostic modality was evaluated according to the pneumonia severity index. The chest radiograph successfully detected subpleural lung consolidation and dense lung opacity. The lung ultrasound successfully detected pleural effusion and perilesional inflammatory edema. The chest CT successfully detected a liquefied area, enhancement and necrosis of the lungs. Compared with the chest CT, the lung ultrasound displayed 0.906 sensitivity and 0.661 accuracy, while the chest radiograph displayed 0.793 sensitivity and 0.559 accuracy. For a pneumonia severity index of <3, the chest CT displayed a good beneficial score, followed by the lung ultrasound and chest radiograph. In conclusion, lung ultrasound is a non-invasive and simple method that could be used for the diagnosis of suspected pneumonia in children. [ABSTRACT FROM AUTHOR]

A new type of plane strain apparatus is developed to study the mechanical properties and shear band failure of soil, which possesses the advantages of flexible loading for lateral confining pressure and noncontact measurement and high measurement accuracy for surface deformation. In addition, the whole deformation procedure of the specimen can be recorded with images, which can be used to describe the development of strain localization and the shear band. It can be seen that the deformation process has three obvious stages, that is, the hardening stage, the softening stage, and the residual stage. The measured inclination angles of shear bands decrease as confining pressure or the mean size increases. In addition, it can be observed that the sand presents continuing growth of the unrecoverable plastic deformation inside the shear band and exhibits almost elastic deformation outside. From the detection results for local points in the specimen, the stress-strain relationships are different for different parts, and the sand sample behaves like an uneven structure instead of an even element, which means that the usual method of measuring the stress-strain relationship of the soil sample is only a macroscopic approximation. [ABSTRACT FROM AUTHOR]

The article presents a study which identifies the detection of DNA hybridization with blue luminescent quantum dots and dye-labeled single-stranded DNA. It has been noted that quantum dots are important photonic tool due to their unique properties. Homogenous DNA fluorescence essays are a particularly versatile way to detect hybridization.

The article focuses on the interplay between autophagy and glycolysis and reveals that ULK1 activation leads to the phosphorylation of lactate dehydrogenase A (LDHA), promoting lactate production. It mentions the Lactate then mediates the lactylation of Vps34, enhancing its association with key autophagy proteins and increasing its lipid kinase activity, thereby promoting autophagy and endolysosomal trafficking.

The Poincaré plot emerges as an effective tool for assessing cardiovascular autonomic regulation. It displays nonlinear characteristics of heart rate variability (HRV) from electrocardiographic (ECG) recordings and gives a global view of the long range of ECG signals. In the telemedicine or computer-aided diagnosis system, it would offer significant auxiliary information for diagnosis if the patterns of the Poincaré plots can be automatically classified. Therefore, we developed an automatic classification system to distinguish five geometric patterns of the Poincaré plots from four types of cardiac arrhythmias. The statistics features are designed on measurements and an ensemble classifier of three types of neural networks is proposed. Aiming at the difficulty to set a proper threshold for classifying the multiple categories, the threshold selection strategy is analyzed. 24 h ECG monitoring recordings from 674 patients, which have four types of cardiac arrhythmias, are adopted for recognition. For comparison, Support Vector Machine (SVM) classifiers with linear and Gaussian kernels are also applied. The experiment results demonstrate the effectiveness of the extracted features and the better performance of the designed classifier. Our study can be applied to diagnose the corresponding sinus rhythm and arrhythmia substrates disease automatically in the telemedicine and computer-aided diagnosis system. [ABSTRACT FROM AUTHOR]

The oxygen states (O-states) of carbon quantum dots (CDs) play ail important rule, with regard to their optical properties and analytical applications. However, the rapid screening of O-states in CDs is still a great challenge, because of the complicated surface composition. In this study, it is found that the chemiluminescence (CL) intensity of prepared CDs in the presence of peroxynitrite (ONOO-) is proportional to the content of C—O group-related O-states. The related mechanism discloses that the O-state-dependent CL is due to the fact that abundant C—O functional groups in CDs with high O-states could facilitate the electron transfer of the produced smaller energy gaps for strong CL emission. Hence, ONOO--induced CL can be utilized as a facile probe for the rapid screening of O-states in CDs with some advantages, such as rapid response, low cost, and easy operation. Its practicability is verified by detecting the CL of phosphorus-doped CDs with variable phosphorus-doping contents. The content of C—O group-related O-states in sulfur-/ phosphorus-doped CDs measured by the proposed CL probe is consistent with X-ray photoelectron spectroscopy (XPS) characterization. This strategy can also be extended to distinguish O-states in different types of nanoparticles by tuning the CL probe molecules. [ABSTRACT FROM AUTHOR]

The effect of vegetation on temperature is an emerging topic in the climate science community. Existing studies have mostly examined the effects of vegetation on daytime temperature (Tmax), whereas this study investigates the effects on nighttime temperature (Tmin). Ground measurements from 53 sites across northeastern China (NEC) from 1982 to 2006 show that early summer (June) Tmax and Tmin increased at mean rates of approximately 0.61 °C/10 year and 0.67 °C/10 year, respectively. Over the same period, the satellite-based Normalized Difference Vegetation Index (NDVI) decreased by approximately 0.10 (accounting for 18% of the climatological NDVI for 1982–1991). It is highlighted that a larger increase in Tmax (Tmin) co-occurred spatially with a larger (smaller) decrease in NDVI. Deriving from such spatial co-occurrences, we found that the spatial variability of changes in Tmax (i.e., ΔTmax) is negatively correlated with the spatial variability of changes in NDVI (i.e., ΔNDVI),while the spatial variability of changes in Tmin (i.e., ΔTmin) is positively correlated (r2 = 0.10; p < 0.05) with that of ΔNDVI. Similarly, we detected significant positive correlations between the spatial variability of ΔNDVI and the change in surface latent heat flux (r2 = 0.16; p < 0.01) and in surface air specific humidity (r2 = 0.28; p < 0.001). These findings on the spatial co-occurrences suggest that the vegetation growth intensifies the atmospheric water vapor through evapotranspiration, which enhances the atmospheric downward longwave radiation and strengthens the greenhouse warming effects at night. Thereby, the positive correlation between ΔNDVI and ΔTmin is better understood. These results indicate that vegetation growth may not only exert effects on daytime temperature but also exert warming effects on nighttime temperature by increasing atmospheric water vapor and thus intensifying the local greenhouse effect. This study presents new observation evidence of the effects of vegetation on local temperature. [ABSTRACT FROM AUTHOR]

Self-assembled poly(o-methoxyaniline) (POMA) hollow nanospheres were prepared in a solution of poly(methyl vinyl ether-alt-maleic acid) (PMVEA) by oxidative polymerization using ammonium persulfate as the oxidant. The weight ratio of PMVEA to o-methoxyaniline in the solution had a significant effect on the morphology of the poly(o-methoxyaniline) nanospheres as determined by scanning electron microscopy. The diameter of the hollow nanospheres decreased from 440 to 210 nm with an increase in the PMVEA concentration from 1% to 5%. Freeze-fracture transmission electron microscopy results showed the presence of spherical micelles composed of PMVEA/ o-methoxyaniline prior to polymerization, which also decreased in size as more PMVEA was added to the solution, and can act as soft templates for the formation of the hollow POMA nanospheres. The POMA/PMVEA hollow nanospheres were characterized by means of Fourier transform infrared, UV-visible, x-ray photoelectron spectroscopy, elemental analysis and conductivity measurements. [ABSTRACT FROM AUTHOR]

We examined the effects of an herbal formula, WL2, on weight loss, lipid metabolism, and associated angiogenesis status. Male SD rats were pre-fed a high-calorie-diet (HCD) for 6 wks to prior establish obesity. Obese rats were randomized to receive vehicle or WL2 (1.5 g/kg) by gavage for 10 wks. Reduced BW was seen with WL2 at Wk 2 and later weeks (p<0.05∼0.01). At Wk 10, BW and weight of abdominal fat pad and the liver were reduced with WL2 by 5.6%, 38% & 13% (p<0.01). Size and total number of adipocytes were reduced with WL2, represented by increased adipocyte number per microscopic view field and reduced total DNA in fat pad (p<0.05). Plasma LDL-c, VEGF, leptin, and adiponectin was decreased with WL2 by 39%, 33%, 35% & 27%, while HDL-c and glucagon increased by 18% & 17% (all p<0.01). Reduced liver weight associates with improvement of hepatic fatty degeneration and steatohepatitis (p=0.006). Gene expression array displays multiple changes in gene expression in many tissues, suggesting enhanced thermogenesis and adipocyte apoptosis, optimized glucose-lipid-protein metabolism, and improved muscle cell survival. In conclusion, WL2 intervention reduces BW and improves energy-glucose-lipid metabolism in DIO through multiple metabolic pathways. The reduced mass of adipose tissue associates with reduction of circulating leptin and adiponectin, inhibition of angiogenesis and optimization of multiple metabolic systems. [ABSTRACT FROM AUTHOR]

Background: Semaphorin 4D (Sema4D) belongs to the class IV semaphorins, and accumulating evidence has indicated that its elevated level may be one strategy by which tumors evade current antiangiogenic therapies. The biological roles of Sema4D in colorectal cancer (CRC), however, remain largely undefined. This study was designed to investigate the effects of Sema4D on tumor angiogenesis and growth in CRC, especially in different vascular endothelial growth factor (VEGF) backgrounds. Methods: The expression of Sema4D in human CRC was evaluated by immunohistochemical analysis of tumors and their matching normal control tissues. The expression level of Sema4D and VEGF was investigated in different CRC cell lines. To evaluate the contributions of Sema4D to tumor-induced angiogenesis, two CRC cell lines with opposite VEGF backgrounds were infected with lentiviruses expressing Sema4D or Sema4D short hairpin RNA, followed by in vitro migration and in vivo tumor angiogenic assays. Results: Immunohistochemical analysis of human CRC revealed high levels of Sema4D in a cell surface pattern. In all, 84.85% of CRC samples analyzed exhibited moderate to strong Sema4D expression. The positive ratios of Sema4D staining for well, moderately, and poorly differentiated cancers were 71.43%, 96.67%, and 77.27%, respectively. Sema4D is highly expressed in five different CRC cell lines, while VEGF expression level varies among these cell lines. HCT- 116 showed the lowest VEGF level, while Caco-2 showed the maximum VEGF level. In vitro migration results show that regardless of cell type and VEGF background, Sema4D showed an enhanced in vitro proangiogenic effect to induce the migration of human umbilical vein endothelial cells. Finally, in vivo tumor angiogenic assays demonstrated that Sema4D alone can elicit a significant angiogenic response to promote tumor growth independently of VEGF. Conclusion: Targeting Sema4D might serve as a parallel option for antiangiogenic therapy for CRC, particularly when traditional anti-VEGF therapies fail or tumors develop resistance to strategies targeting a single angiogenic signaling pathway. [ABSTRACT FROM AUTHOR]

The Hedgehog (Hh) signaling pathway not only plays important roles in embryogenesis and adult tissue homeostasis, but also in tumorigenesis. Aberrant Hh pathway activation has been reported in a variety of malignant tumors including colon carcinoma. Here, we sought to investigate the regulation of the Hh pathway transcription factor Gli1 by arsenic trioxide and phosphoinositide 3-kinase (PI3K) inhibitor LY294002 in colon carcinoma cells. We transfected cells with siGli1 and observed a significant reduction of Gli1 expression in HCT116 and HT29 cells, which was confirmed by quantitative real-time polymerase chain reaction and Western blots. Knocking down endogenous Gli1 reduced colon carcinoma cell viability through inducing cell apoptosis. Similarly, knocking down Gli2 using short interfering RNA impaired colon carcinoma cell growth in vitro. To elucidate the regulation of Gli1 expression, we found that both Gli inhibitor arsenic trioxide and PI3K inhibitor LY294002 significantly reduced Gli1 protein expression and colon carcinoma cell proliferation. Arsenic trioxide treatment also reduced Gli1 downstream target gene expression, such as Bcl2 and CCND1. More importantly, the inhibition of Hedgehog-Gli1 by arsenic trioxide showed synergistic anticancer effect with the PI3K inhibitor LY294002 in colon carcinoma cells. Our findings suggest that the Hh pathway transcription factor Gli1 is involved in the regulation of colon carcinoma cell viability. Inhibition of Hedgehog-Gli1 expression by arsenic trioxide and PI3K inhibitor synergistically reduces colon cancer cell proliferation, indicating that they could be used as an effective anticolon cancer combination therapy. [ABSTRACT FROM AUTHOR]

With the wide application of chiral ionic liquids (CILs) as green solvents, their threats to the aquatic environment cannot be ignored. Thus, risk assessment and the prospective design of inherently safe CILs have become more urgent. However, whether enantioselectivity is a feature of the aquatic toxicity of CILs is poorly understood. Herein, we describe the first investigation into the ecotoxicities of CILs toward green algae Scenedesmus obliquus and Euglena gracilis. A series of methylimidazolium lactic ionic liquids, which cation parts with different alkyl chains and anion part is enantiomers of lactate, are used as representative CILs. The results of S. obliquus showed that the EC50 value of l-(+)-1-ethyl-3-methylimidazolium lactate (l-(+)-EMIM L) was more than 5000μM, while the EC50 value of d-(-)-1-ethyl-3-methylimidazolium lactate (d-(-)-EMIM L) was 2255.21μM. Such a distinct difference indicates the enantioselective toxicity of CILs to algae. This enantioselectivity initially persisted with increasing carbon chain length, but no longer exhibited when with greater carbon chain lengths, due to changes in the toxicity weightings of the cation parts. Further research showed that the enantioselective effects of CILs resulted from the differences in the production of reactive oxygen species, the damage to cell membrane integrity and cell wall after exposure to CILs. Results from this study showed that monitoring for the racemate CILs will give an inadequate or misleading environmental risk assessment. Thus, we should improve our ability to predict their effects in natural environments. In the meantime, non-selective use of CILs will do harm to aquatic organisms. Therefore, to minimize their potential for environmental impact, the enantioselective toxicities of CILs with short alkyl chains should be taken into consideration. [ABSTRACT FROM AUTHOR]

Single crystals of a metal organic complex (CsH12N)CuBr3 (C5H12N = piperidinium, pipH for short) have been synthesized, and the structure was determined by single-crystal X-ray diffraction. (pipH)CuBr3 crystallizes in the monoclinic group C2/c. Edging-sharing CuBr5 units link to form zigzag chains along the c axis, and the neighboring Cu(II) ions with spin-1/2 are bridged by bibromide ions. Magnetic susceptibility data down to 1.8 K can be well fitted by the Fisher-Bonner formula for the antiferromagnetic spin-1/2 chain, giving the intrachain magnetic coupling constant J ≈ -17 K. At zero field, (pipH)CuBr3 shows three-dimensional (3D) order below TN = 1.68 K. Calculated by the mean-field theory, die interchain coupling constant J' = -0.91 K is obtained and the ordered magnetic moment mQ is about 0.23µB. This value of mn makes (pipH)CuBr3 a rare compound suitable to study the 1D-3D dimensional cross-over problem in magnetism, since both 3D order and one-dimensional (ID) quantum fluctuations are prominent In addition, specific heat measurements reveal two successive magnetic transitions with lowering temperature when external field µ0H ≥ 3 T is applied along the a' axis. The µ0H-T phase diagram of (pipH)CuBr3 is roughly constructed. [ABSTRACT FROM AUTHOR]

A new family of silver(I)-lanthanide(III) heterometallic-organic frameworks having the formula [AgLn(bpdc)2] (Ln = Eu (1), Tb (2), Sm (3), Dy (4), Y (5), Yb (6), Er (7), Ho (8); H2bpdc = 2,2'- bipyridine-3,3'-dicarboxylic acid), each of which crystallizes in the monoclinic space group C2/c with Z = 4, has been hydrothermally synthesized. The compounds were characterized by means of IR, elemental analysis, thermogravimetric-differential thermal analysis, and powder X-ray diffraction (XRD), wherein compounds 1, 2, and 4-8 were structurally characterized. The powder XRD and single-crystal structures of the title compounds indicate that all the compounds are isostructural and feature a three-dimensional (3-D) open framework. In the structures of the compounds, bpdc2- ligands link Ln3+ through their carboxylic groups, resulting in the formation of a one-dimensional {Ln(bpdc)2}n infinite chain along the c direction. The adjacent chains are then connected to each other through the coordination interaction between Ag+ and the pyridyl N atoms of bpdc2- ligands from the chains, resulting in a 3-D (2,4,6)-connected open framework with (411̣64)(4³̣8²̣10)(8)2 topology. The compounds show remarkable good thermally stability up to 370 °C because neither aquo ligands nor lattice water molecules exist in the composition of the compounds. The photoluminescent properties of compounds I and 2 were studied in detail. The energy level of the triplet states of the ligand H2bpdc 21 505 cm-1 (465 ran) was determined based on the 77 K emission spectrum of the compound [Gd2(bpdc)3(phen)2(H2O)2]̣6H2O 9. The 5D0 and 5D4 emission lifetimes (1.58 and 1.76 ms) and the overall quantum yields (21% and 22%) were determined for the compounds 1 and 2, respectively. [ABSTRACT FROM AUTHOR]

Micro sensors have large potential to measure soil nitrous oxide (N2O) emissions. However, because of its low sensitivity to get the electrical signals on soil with low moisture content, little research has been conducted in semi-arid agro-ecosystem. Moreover, the use of N2O microelectrode studies were largely focused on the marshy fields, paddy fields and waste waters with high soil moisture content. In order to characterize the boundary of the sensor signal (upper and lower), purified water without N2O is usually used as the calibration medium to calibrate the electrode. However, the physical and chemical properties of purified water and soil leaching solutions are very different. In this study, we improved and verified a microelectrode calibration method based on selecting appropriate media and optimal electrolyte concentration. In addition, we applied the improved microelectrode calibration method to continuously observe N2O flux from the soil column in a 30-day-long incubation experiment. The results pointed to noteworthy improvement of the microelectrode calibration compared to the current method, with soil solution validated as a calibration medium at optimal electrolytic concentration of 7:1-8:1, expressed as water/soil ratio. The emission of N2O from soil with different soil fertility were also significantly different. Our research is beneficial to establish the microelectrode calibration method of N2O emission under low moisture conditions from soil microenvironment, and also points on management practices of agro-ecosystem for N2O mitigation strategies. [ABSTRACT FROM AUTHOR]

In light of the significance of glycosylation for wealthy biological events, it is important to prefractionate glycoproteins/glycopeptides from complex biological samples. Herein, we reported a novel protocol of solid-phase extraction of glycopeptides through a reductive amination reaction by employing the easily accessible 3-aminopropyltriethoxysilane (APTES)-functionalized magnetic nanoparticles. The amino groups from APTES, which were assembled onto the surface of the nanoparticles through a one-step silanization reaction, could conjugate with the aldehydes from oxidized glycopeptides and, therefore, completed the extraction. To the best of our knowledge, this is the first example of applying the reductive amination reaction into the isolation of glycopeptides. Due to the elimination of the desalting step, the detection limit of glycopeptides was improved by 2 orders of magnitude, compared to the traditional hydrazide chemistry-based solid phase extraction, while the extraction time was shortened to 4 h, suggesting the high sensitivity, specificity, and efficiency for the extraction of N-linked glycopeptides by this method. In the meantime, high selectivity toward glycoproteins was also observed in the separation of Ribonuclease B from the mixtures contaminated with bovine serum albumin. What’s more, this technique required significantly less sample volume, as demonstrated in the successful mapping of glycosylation of human colorectal cancer serum with the sample volume as little as 5 μL. Because of all these attractive features, we believe that the innovative protocol proposed here will shed new light on the research of glycosylation profiling. [ABSTRACT FROM AUTHOR]

Using the base forces as fundamental variables to describe the stress state and the displacement gradients that are the conjugate variables of the base forces to describe the deformation state for the two-dimensional elasticity problems, a 4-mid-node planemodel of base force element method (BFEM) based on complementary energy principle is proposed. In this paper, the complementary energy of an element of the BFEM is constructed by using the base forces. The equilibrium conditions are released by the Lagrange multiplier method, and amodified complementary energy principle described by the base forces is obtained. The formulation of the 4-mid-node plane element of the BFEM is derived by assuming that the stress is uniformly distributed on each edge of the plane elements. A procedure of the BFEM on complementary energy principle is developed using MATLAB language. The numerical results of examples show that this model of the BFEM has high precision and is free from mesh sensitivity. This model shows good performances. [ABSTRACT FROM AUTHOR]

In this work, we systematically investigated the morphologies of polymers prepared by chemical oxidation of aniline and methyl-, methoxy-, or ethoxy-substituted aniline under the same experimental conditions. No matter the presence or absence of 10-camphorsulfonic acid (CSA), the oxidation of aniline produces nanotubes, while the oxidation of most aniline derivatives produce hollow microspheres under the same experimental conditions. These results illustrate the oligomers with phenazine-like structures produced at the initial oxidation of aniline are crucial for the formation of PANI nanotubes. The formation mechanism of the hollow microspheres of PANI derivatives is discussed. The main factors to control the polymer morphology are stability of droplets of aniline and its derivatives formed in an aqueous solution and the rate of exothermal reaction. The fast exothermal reaction benefits the formation of uniform microspheres. We also suggest that the hole on the surface of microspheres forms at the initial oxidation stage and is maintained by the flux of water and water-soluble components in the course of polymerization. [ABSTRACT FROM AUTHOR]

Coaxially aligned polyaniline (PANI) nanofibers doped with 3-thiopheneacetic acid (TAA) were chemically synthesized by the interfacial polymerization of aniline in the presence of TAA, using iron (III) chloride hexahydrate (FeCl3·6H2O) as the oxidant. The morphology, crystallinity, room temperature conductivity, and coaxial alignment of the PANI-TAA nanofibers were highly dependent on the organic solvent used for the interfacial polymerization, the oxidant, and also the molar ratio of the aniline to TAA. Hexane, diethyl ether, dichloromethane, chloroform, and acetone were used as the organic solvents, and chloroform proved to be the best solvent for the formation of PANI-TAA nanofibers. The redox potential of the oxidant is the key to controlling the morphology and diameter of the PANI-TAA nanofibers. The use of FeCl3 as the oxidant leads to the formation of thin (~50 nm) PANI-TAA nanofibers, which increased in length, crystallinity, conductivity, and coaxial alignment as the molar ratio of TAA to aniline was increased from 0.1 : 1 to 1 : 1. By comparison, only granular PANI was obtained when ammonium persulfate (APS), which has a higher redox potential, was used as the oxidant. The doping function of TAA in the PANI-TAA nanofibers was confirmed by means of FTIR and UV-Visible spectroscopy. [ABSTRACT FROM AUTHOR]

Wang, Jinxia, Jikun Huang, Lijuan Zhang, Qiuqiong Huang, and Scott Rozelle, 2010. Water Governance and Water Use Efficiency: The Five Principles of WUA Management and Performance in China. Journal of the American Water Resources Association (JAWRA) 46(4): 665-685. DOI: 10.1111/j.1752-1688.2010.00439.x In recent years China has attempted to reform water management by decentralizing water management responsibilities. The overall goal of our paper is to better understand the emergence of water user associations (WUAs) in China and assess if they are adhering to the practices spelled out by the Five Principles, a set of recommended practices that are supposed to lead to successful WUA operation. Using four sets of different types of villages to examine implementation and performance, we find that World Bank-supported WUA villages (“Bank villages”) can be thought of as operating mostly according to the Five Principles. For example, the Bank villages were endowed with a more reliable water supply; were set up and were operating with a relatively high degree of farmer participation; and leaders were more consultative and the process more formal. When WUAs are run according to the Five Principals, we show that WUAs increase water use efficiency. The study also provides evidence that there is a perception in the Bank villages that water management is improving in general and that there is less conflict both within the village and among villages. Perhaps more importantly, we find that the Bank’s effort to promote WUAs extended beyond their own project villages. The openness, consultative nature, and transparency found in the Bank WUAs are also found (albeit at a somewhat lower level) in the non-Bank WUA villages. [ABSTRACT FROM AUTHOR]

Density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations were carried out to comparatively study the molecular structures, atomic charges, molecular orbitals, and electronic absorption spectra of fluoroboron−subtriazaporphyrin (SubTAP) and fluoroboron−subphthalocyanine (SubPc) as well as their benzo-fused low-symmetrical derivatives AaBbCc(3 ≥ a, b, c≥ 0). The peripherally fused benzene rings are revealed to have a significant effect on the structure and charge density distribution of the inner nitrogen atoms of subtriazaporphyrin core, while the charge of the central fluoroboron group changes very little. The effect of peripherally fused benzene rings on the frontier molecular orbitals of different compounds is comparatively discussed. The nature of the electron excitation between the frontier molecular orbitals of the 20 compounds is assigned according to the calculation results. The benzene rings fused directly onto pyrrole rings have been revealed to show more effect on the inner nitrogen atom than the outer benzene rings fused onto the periphery of isoindole rings. The present work will be helpful toward systematically understanding the effect of ring enlargement through asymmetrically fusing benzene ring(s) onto the subtriazaporphyrin skeleton on the structures and properties of fluoroboron−subtriazaporphyrin and fluoroboron−subphthalocyanine analogues. [ABSTRACT FROM AUTHOR]

A novel boronic acid functionalized mesoporous silica, which holds the attractive features of high surface area and large accessible porosity, was developed to enrich glycopeptides. This is the first time that mesoporous material has been introduced into glycoproteome. In comparison to direct (traditional) analysis, this novel method enabled 2 orders of magnitude improvement in the detection limit of glycopeptides. The unbiased nature of organo-boronic acid groups also made this method applicable to all kinds of glycopeptides regardless of their sizes, structures, and hydrophilicities. [ABSTRACT FROM AUTHOR]

The chemical oxidation of polyaniline is carried out at constant acidity, investigating six separate pH levels (pH = 1, 2, 3, 4, 5, and 6). All prior studies on polyaniline self-assembly used a falling-pH or a temporarily buffered falling-pH method, making this the first application of pH-stat techniques to the study of polymer nanostructure formation. This allows us to isolate with improved precision the various nanostructures formed at different stages of polyaniline self-assembly, which include spheres, flakes and ribbons at neutral pH, fibers and tubes at mildly acidic pH, and grains at highly acidic pH. The evolution of these structures is investigated as a function of both pH and time. This approach results in the observation of two previously unnoticed phenomena: the morphology is found to evolve as a function of time even when pH is kept constant, and polyaniline nanotubes are formed at a constant acidity. Both of these results have important implications for existing self-assembly theories. Fourier transform infrared spectroscopy is used to investigate the polyaniline compositional and structural evolution underlying the visible morphological changes and shows that as pH falls there is increased protonation, decreased ortho-coupling, lower phenazine presence, and less sulfonation. The time evolution, on the other hand, shows increased sulfonation and decreased oxidation. Ultraviolet−visible spectroscopy shows a mixture of delocalized and localized polaron behavior for the pH-1-stat to pH-3-stat products, and insulating characteristics for the higher pH structures. This is confirmed by four-point conductivity measurements. [ABSTRACT FROM AUTHOR]

A novel boronic acid functionalized mesoporous silica, which holds the attractive features of high surface area and large accessible porosity, was developed to enrich glycopeptides. This is the first time that mesoporous material has been introduced into glycoproteome. In comparison to direct (traditional) analysis, this novel method enabled 2 orders of magnitude improvement in the detection limit of glycopeptides. The unbiased nature of organo-boronic acid groups also made this method applicable to all kinds of glycopeptides regardless of their sizes, structures, and hydrophilicities. [ABSTRACT FROM AUTHOR]

Apoptotic cells must be rapidly eliminated to avoid harmful inflammatory and autoimmune reactions. Innate immunity is designed/poised to identify dying cells by their unique surface-associated molecular patterns. Here we demonstrate for the first time, to our knowledge, that the human complement protein properdin binds to early apoptotic I cells and initiates complement activation, leading to C3b opsonization and ingestion by phagocytic cells. Properdin binding was facilitated by the glycosaminoglycan chains of surface proteoglycans. Properdin released by activated neutrophils was particularly effective at recognition of apoptotic T cells, whereas the binding activity of properdin in the serum appeared to be inhibited. "Properdin tagging" of apoptotic T cells also induced their uptake by phagocytes independent of complement activation or other complement proteins. Although our findings were made primarily with apoptotic T cells, they suggest that properdin could play a similar role during apoptosis of other cell types. [ABSTRACT FROM AUTHOR]

The structure and oxidation state of self-assembled nanostructures formed by oxidation of aniline with ammonium persulfate in the presence of alanine have been investigated by solid-state 13C and 15N NMR, FTIR, GPC, elemental, UV−vis, and SEM methods. These techniques have been applied to samples obtained 1 and 20 h after the beginning of the reaction in their doped as-synthesized form or after reduction with hydrazine or dedoping with NH 4OH or LiOH. Peaks at 66 and 72 ppm and a peak at 241 ppm in the 15N NMR spectra are shifted downfield by about 1−6 ppm and upfield by about 80 ppm, respectively, relative to the positions expected for the amine and imine N atoms in polyaniline. This indicates a difference in molecular structure between the nanotube material and standard polyaniline. This may be attributed to the presence of either strong H-bonding or a fundamentally different bonding connectivity in the nanotube material. Despite the significant difference in morphology of the samples after 1 and 20 h as shown by SEM, the 13C and 15N spectra show resonances at very similar chemical shifts for the two reaction times. The differences in line width and intensity of the peaks in these spectra are attributed to an increased number of positive charges and to longer polymer chains for the longer reaction time. The previously postulated presence of phenazine-like units in the molecular structure within the nanotubes cannot be excluded due to possible overlapping of resonances from amine and tertiary nitrogens in the 15N NMR spectra. The carbon and nitrogen NMR spectra show that the alanine is not incorporated into the aniline oxidation products. Chemical structures whose presence is consistent with the data obtained from solid-state NMR and the other methods applied in this work are proposed. [ABSTRACT FROM AUTHOR]