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Simple Summary: Blood clots are formed when blood vessels are injured. They help stop bleeding and heal wounds, but can also cause serious problems if they block blood flow or break off and travel to other organs. This study investigates how blood clots differ in people with cancer compared to healthy or non-cancerous individuals. This study found that cancer patients have higher levels of histones in their blood, which make their clots stiffer and resistant to lysis. Further, clots formed in cancer patients have higher viscoelastic properties, and hence are harder to break down. These findings suggest that cancer patients have abnormal clotting properties that may increase their risk of developing thrombosis, and evaluating these properties can be helpful in detecting cancer. Background: Blood viscoelasticity and plasma protein levels can play an important role in the diagnosis and prognosis of cancer. However, the role of histones and DNA in modulating blood clot properties remains to be investigated. This study investigates the differences in blood viscoelasticity and plasma protein levels among cancer patients, individuals with other diseases, and healthy individuals. Methods: Blood samples were collected from 101 participants, including 45 cancer patients, 22 healthy individuals, and 34 individuals with other diseases. Rheological properties of clots formed in vitro by reconstituted elements of fibrinogen or plasma were analyzed with an Anton Paar Rheometer, USA. Plasma protein levels of D-dimer, TPA, EPCR, fibrinogen, and histone H3 were measured through ELISA. Blood clots were formed with or without DNA and histones (H3) by adding thrombin and calcium to plasma samples, and were evaluated for viscoelasticity, permeability, and degradation. Results: Cancer patients show higher blood viscoelasticity and plasma D-dimer levels compared to healthy individuals and individuals with other diseases. Our in vitro analysis showed that the addition of histone to the plasma results in a significant decrease in viscoelasticity and mean fiber thickness of the clot formed thereafter. In parallel studies, using plasma from patients, DNA and histones were detected in fibrin clots and were associated with less degradation by t-PA. Moreover, our results show that the presence of DNA and histones not only increases clots' permeability, but also makes them more prone to degradation. Conclusions: Plasma histones and DNA affect the structure of the clot formed and induce defective fibrinolysis. Moreover, the increased viscoelastic properties of plasma from cancer patients can be used as potential biomarkers in cancer prognosis. [ABSTRACT FROM AUTHOR]

The Chinese-Russian Workshop on Biophotonics and Biomedical Optics 2023 brought together scientists, engineers, and clinical researchers from Russia and China to discuss the application of optical science, photonics, and imaging technologies in biology and medicine. The workshop featured two plenary lectures and twenty invited presentations, and this special issue of the Journal of Innovative Optical Health Sciences includes selected papers from the workshop. The papers cover a range of topics, including optical imaging techniques, monitoring cell behavior, diffuse reflectance spectroscopy, photodynamic therapy, and neural networks for biomedical applications. The issue provides readers with the latest developments in biophotonics and biomedical optics. [Extracted from the article]

In this paper, we have provided a mathematical analysis of an empirical result, namely, the Fahraeus–Lindqvist effect, a phenomenon that occurs in capillary tubes with a diameter lower than 0.3 mm. According to this effect, in capillary tubes under 0.3 mm in diameter, the apparent viscosity of blood decreases as the diameter of the tube decreases, making flow possible in these vessels. A two-phase blood flow mathematical model for human capillaries has been presented here. According to Haynes' theory, blood is separated into two layers when it flows from the capillary. It is assumed that the first layer is plasma, and the second layer is the core layer. The plasma layer flows near the wall of the capillary, and the core layer flows along the axis of the capillary. Further, the core layer is assumed to be a mixture of two phases: one is the plasma, and the other is that of RBCs. For mathematical modeling purposes, a curvilinear coordinate system has been adopted, with physical quantities used in tensorial form. Derived equations are solved to find the effective viscosity, which depends upon the radius of the capillary; that is, it reduces viscosity to make blood flow possible. A comparative study was conducted with the experimental result of this effect, and it was observed that the proposed two-phase blood flow model is much closer to the experimental data than the single-phase blood flow model, and both have the same trends. After validation of the model with the experimental result, this model was applied to human capillaries (diameter lower than 10 μ m ) to show the F-L effect, and the impact of various physiological quantities that are relevant to the flow of blood into human capillaries are also discussed here. The impact of hematocrit on various parameters has been demonstrated explicitly. [ABSTRACT FROM AUTHOR]

"The viscosity of the blood in narrow capillary tubes" by Robin Fåhraeus and Torsten Lindqvist (Am J Physiol 96: 562-568, 1931) can be a valuable opportunity for teaching basic hemorheological principles in undergraduate cardiovascular physiology. This classic paper demonstrates that a progressive decline in apparent viscosity occurs when blood flows through glass capillary tubes of diminishing radius, which was later designated the "Fåhraeus-Lindqvist effect." Subsequent studies have shown that apparent viscosity continues to decline at diameters that correspond to the arteriolar segments of the systemic vascular tree, where the majority of the total peripheral resistance resides and is actively regulated in vivo. The Fåhraeus-Lindqvist effect thus reduces microvascular resistance, thereby maintaining local tissue perfusion at a relatively lower blood pressure. The paper by Fåhraeus and Lindqvist can be used as a platform for a plenary discussion of these concepts as well as of the relationships among hematocrit, vessel diameter, red blood cell deformability, and resistance to blood flow, and how these factors may affect the work of the heart. [ABSTRACT FROM AUTHOR]

This paper discusses the fully developed electromagnetic hydrodynamic flow and heat transfer of a Casson nanofluid Fe3O4-blood in a porous medium. The flow takes place in a horizontal channel with walls at different temperatures. The channel is influenced by an externally applied magnetic field that is perpendicular to the walls of the channel and an externally applied electric field that is perpendicular to the longitudinal vertical plane of the channel. Both of these fields are homogeneous. The induced magnetic field is considered weak and can be neglected. The described problem is represented by differential equations which are analytically solved after the transformation into a dimensionless form. The obtained velocity and temperature distributions of the Casson fluid Fe3O4- blood are graphically represented and the influences of the Hartmann number, the Brinkman number, the power factor, the porosity factor, and the volume fraction of nanoparticles are examined. The Nusselt number and dimensionless friction voltages are given in a table. [ABSTRACT FROM AUTHOR]

Blood viscosity is the defining health indicator for hyperviscosity syndrome patients. This paper introduces an alternative approach for the real-time monitoring of blood viscosity by employing a surface-horizontal surface acoustic wave (SH-SAW) device at room temperature. A novel bi-layer waveguide is constructed on top of the SAW device. This device enables the SAW sensing of liquid droplets utilizing a bi-layer waveguide, consisting of a zinc oxide (ZnO) enhancement layer and Parlyene C, that facilitates the promotion of the surface horizontal mode. The ZnO piezoelectric thin-film layer enhanced the local particle displacement and dielectric coupling while the Parylene C layer constrained the wave mode at the interface of the piezoelectric material and polymer material. The device was tested with a liquid drop on the SAW delay-line path. Both experimental and finite element analysis results demonstrated the benefits of the bi-layer waveguide. The simulation results confirmed that the displacement field of local particles increased 9 times from 1.261 nm to 11.353 nm with the Parylene C/ZnO bi-layer waveguide structure. The device demonstrated a sensitivity of 3.57 ± 0.3125 kHz shift per centipoise enabling the potential for high precision blood viscosity monitoring. [ABSTRACT FROM AUTHOR]

Platelet–endothelial interactions have a critical role in microcirculatory function, which maintains tissue homeostasis. The subtle equilibrium between platelets and the vessel wall is disturbed by the coronavirus disease 2019 (COVID-19), which affects all three components of Virchow's triad (endothelial injury, stasis and a hypercoagulable state). Endotheliitis, vasculitis, glycocalyx degradation, alterations in blood flow and viscosity, neutrophil extracellular trap formation and microparticle shedding are only few pathomechanisms contributing to endothelial damage and microthrombosis resulting in capillary plugging and tissue ischemia. In the following opinion paper, we discuss major pathological processes leading to microvascular endothelial activation and thrombosis formation as a possible major adverse factor driving the deterioration of patient disease course in severe COVID-19. [ABSTRACT FROM AUTHOR]

Following recent works on the sonochemical degradation of butyl ethyl piperidinium bis-(trifluoromethylsulfonyl)imide ([BEPip][NTf2]), monitoring of sonoluminescence (SL) spectra in the first tens of seconds of sonolysis was needed to better characterize the formed plasma and to question the correlation of the SL spectra with the viscosity. A very dry [BEPip][NTf2] ionic liquid (IL) and a water-saturated liquid are studied in this paper. In both cases, IL degradation is observed as soon as SL emission appears. It is confirmed that the initial evolution of the SL intensity is closely linked to the liquid viscosity that impacts the number of bubbles; however, other parameters can also play a role, such as the presence of water. The water-saturated IL shows more intense SL and faster degradation. In addition to the expected bands, new emission bands are detected and attributed to the S2 B-X emission, which is favored in the water-saturated ionic liquid. [ABSTRACT FROM AUTHOR]

Backgrounds. Chuanxiong Chatiao san (CXCT) is a famous Chinese classical prescription. It has a favorable effect in treating migraine. It is reported that CXCT combined with Western conventional medicine (WCM) could increase the therapeutic efficacy on migraine. The purpose of this paper is to systematically assess the clinical efficacy, safety, and some indexes of CXCT for migraine. Methods. PubMed, Embase Database, China National Knowledge Infrastructure (CNKI), Wanfang Database, the Cochrane Library, and the CBM were searched from January 2000 to February 2019. We made a detailed record of outcome measurements. Meta-analysis was performed using RevMan 5.3 software. Results. A total of 3307 patients were included in the 37 articles. Meta-analysis showed that CXCT significantly increased the total efficiency rate (TER), compared with Western medicine treatment (WMC) (P < 0.00001). When CXCT is combined with WMC, the result showed that P < 0.00001. CXCT was significantly reduced the adverse events (AEs) compared with WMC (P < 0.00001). The levels of VAS, number of migraine episodes (NE), and time of headache duration (TD) were significantly reduced (P < 0.00001). Platelet function and blood rheology level were improved via a significantly decrease in 5-HT and β-EP (P < 0.00001). Other indicators such as substance P, CGRP high-cut viscosity, low-cut viscosity, plasma viscosity, and fibrinogen were significantly reduced (P < 0.00001). Conclusion. Our findings provide evidence that CXCT and CXCT combined with WMC have higher efficacy in the treatment of migraine compared with WCM alone. Methodological quality was generally low, so the conclusion of this paper has some limitations and it has to be carefully evaluated. [ABSTRACT FROM AUTHOR]

Blood flow in a double aneurysmatic artery of the normal tissue is studied. A Finite element method is used to analyze numerical simulation of blood flow through aneurysmatic arteries and Comsol multiphysics software is used for blood flow simulation. The Newtonian, generalized Newtonian, Oldroyd-B, and generalized Oldroyd-B models are considered due to the behavior of blood viscosity. In this paper, the effect of aneurysmatic artery on blood flow with permeability in human organs has been investigated. The non-Newtonian models have been applied to study the blood velocity, pressure, and wall shear stress in an aneurysmatic artery. A set of partial differential equations are transformed into dimensionless equations using non-dimensional variables and solved numerically. The novelty of this work is to identify the cardiovascular diseases in case of double aneurysmatic artery conditions for all models. The effect of wall shear stress is a vital factor to determine fatal arterial diseases which may be reported in the research center. The findings of this study can be used to know the atherosclerosis diseases and increase the understanding level of the double aneurysmal artery with the presence of permeability for which may help to enhance the knowledge of medical science. We have focused our consideration on the simulation of blood velocity and pressure in terms of blood flow rate for various Weissenberg numbers (Wi) and Peclet numbers (Pe). In this study, significant changes in blood velocity, pressure, and wall shear stress for all cases due to the presence of permeability at aneurysm in the artery are found. The effect of the Peclet number and Weissenberg number have played a key role in the blood flow at the porous area. The important effects on blood flow of aneurysmatic artery for blood velocity, pressure, and wall stress profiles are presented graphically for Newtonian and non-Newtonian models. [ABSTRACT FROM AUTHOR]

The Fåhræus-Lindqvist effect is usually explained from a physical point of view with the so-called Haynes' marginal zone theory, i.e., migration of red blood cells (RBCs) to a core layer surrounded by an annular RBCs-free plasma layer. In this paper we show that the marginal layer, though causing a substantial reduction in flow resistance and increasing discharge, does not reduce the rate of energy dissipation. This fact is not surprising if one considers the electric analog of the flow in a vessel: a resistance reduction increases both the current intensity (i.e., the discharge) and the energy dissipation. This result is obtained by considering six rheological models that relate the blood viscosity to hematocrit (volume fraction occupied by erythrocytes). Some physiological implications are discussed. [ABSTRACT FROM AUTHOR]

Abstract Marine resources are limited and optimal utilisation of all the available material is essential to ensure sustainability. This brings two main challenges: the first is to get the maximum quantity and quality out of the catch of high value-added raw material. The second is to upgrade low value-added raw material such as blood-waters. The volume of blood-waters generated from pelagic processing industries and their organic load varies from species to species but volumes are large and costs associated with disposal are substantial. However, pelagic blood-water waste streams contain proteins, lipids and small molecules with potential for use in food and feed. The dog and cat feed and food industry is a lucrative sector which is currently valued at $42 billion and is considerably larger than the worldwide baby food market. Furthermore, blood-water from processing is a substantial environmental and economic cost for pelagic processors. To date, the utilisation of blood-waters as food and feed ingredients has not been intensively reviewed. The central focus of this paper is to provide a comprehensive and critical review of recent progress in the recovery of proteins and other molecules from pelagic fish derived blood-waters using filtration and other methods which have potential for use by food and feed industries. The current and potential applications of blood-waters are discussed and the review confirms that blood-water recovery technologies are viable and environmentally beneficial but production efficiency and costs should be improved. The review also provides analysis of challenges that exist concerning the development of ingredients from this resource including the relevant legislation and regulation governing access/use of blood-water and limitations that can be encountered in the development of products. Recent research indicates that proteins derived from blood-waters which are obtained in properly managed processing plants can be considered safe if handled correctly and have potential to replace proteins from other sources in fish and feed manufacture. It is recommended that the safety of recovered pelagic blood-waters in terms of the microbial and heavy metal load is assessed prior to use and that further research should be carried out in conjunction with industry to reduce costs associated with implementation of successful filtration methods. This review provides scientific value for marine and food scientists concerning recovery and utilisation strategies of pelagic processing blood-waters and this may be used to inform industry and environmental policy makers in the future. Graphical abstract Image 1 Highlights • Review collates the current state-of-the-art concerning treatment of blood-water prior to release at sea. • Details potential markets and challenges associated with these markets for proteins recovered from bloodwaters. • Details potential health and technofunctional properties of recovered blood-water proteins. [ABSTRACT FROM AUTHOR]

Blood is one of the most important biofluids used for clinical diagnostics. Cells and proteins in the blood can provide a rich source of information for the evaluation of human health. Efficient separation of blood components is a necessary process in order to minimize the interference of unwanted components during sensing, separation, and detection. In this paper, an insulator-based gradient dielectrophoretic device has been applied to separate red blood cells from model protein biomarkers for myocardial infarction in buffer. Within one min, red blood cells are largely depleted regardless of the minimum adherence on the channel wall. Considering the adhered red blood cells will not be transported further, a purified protein solution can be delivered for potential downstream processing or detection. [ABSTRACT FROM AUTHOR]

This paper proposes a new index for evaluating the stiffness-based deformability of a cell using a microchannel. In conventional approaches, the transit time of a cell through a microchannel is often utilized for the evaluation of cell deformability. However, such time includes both the information of cell stiffness and viscosity. In this paper, we eliminate the effect from cell viscosity, and focus on the cell stiffness only. We find that the velocity of a cell varies when it enters a channel, and eventually reaches to equilibrium where the velocity becomes constant. The constant velocity is defined as the equilibrium velocity of the cell, and it is utilized to define the observability of stiffness-based deformability. The necessary and sufficient numbers of sensing points for evaluating stiffness-based deformability are discussed. Through the dimensional analysis on the microchannel system, three dimensionless parameters determining stiffness-based deformability are derived, and a new index is introduced based on these parameters. The experimental study is conducted on the red blood cells from a healthy subject and a diabetes patient. With the proposed index, we showed that the experimental data can be nicely arranged. [ABSTRACT FROM PUBLISHER]

This paper proposes an algorithm that estimates blood viscosity during cardiopulmonary bypass (CPB) and validates its application in clinical cases. The proposed algorithm involves adjustable parameters based on the oxygenator and fluid types and estimates blood viscosity based on pressure-flow characteristics of the fluid perfusing through the oxygenator. This novel nonlinear model requires four parameters that were derived by in vitro experiments. The results estimated by the proposed method were then compared with a conventional linear model to demonstrate the former's optimal curve fitting. The viscosity (\eta e) estimated using the proposed algorithm and the viscosity (\eta) measured using a viscometer were compared for 20 patients who underwent mildly hypothermic CPB. The developed system was applied to ten patients, and \eta _{e} was recorded for comparisons with hematocrit and blood temperature. The residual sum of squares between the two curve fittings confirmed the significant difference, with p < 0.001. \eta _{e} and \eta showed a very strong correlation with R^{2} = 0.9537 and p < 0.001. Regarding the mean coefficient of determination for all cases, the hematocrit and temperature showed weak correlations at 0.33 ± 0.14 and 0.22 ± 0.21, respectively. For CPB measurements of all cases, \eta _{e}$ was more than 98% distributed in the range from 1 to 3 mPa⋅s. This new system for estimating viscosity may be useful for detecting various viscosity-related effects that may occur during CPB. [ABSTRACT FROM AUTHOR]

Background: A normal number of T-cell receptor excision circles (TRECs) and K-deleting recombination excision circles (KRECs) is considered a biomarker for adequate new T- and B-cell production. In newborns, detection of TRECs and KRECs by real time PCR from dried blood spotted on filter paper is used for the screening of severe immunodeficiency. In adults, elderly and during diseases, where the number of TRECs is lower than in newborns and children, a large amount of DNA and a sensitive method of amplification are necessary to identify newly produced lymphocytes.Methods: DNA was prepared from blood of 203 healthy adults (range: 18-91 years old) absorbed for 10 s on flocked swabs and let to dry, or from peripheral blood mononuclear cells. DNA was subjected to digital PCR and to well established conventional real time PCR-based method using TREC- and KREC-specific primers and probes. The number of TRECs and KRECs was expressed per mL of blood. Statistical analysis was performed by nested ANOVA, Pearson coefficient of determination, and by linear regression tests.Results: The novel method for the storage of dried blood on nylon flocked swabs and the use of digital PCR allow quantification of TRECs and KRECs with high degree of sensitivity, specificity, accuracy, and precision. TRECs and KRECs were amplified by digital PCR in all tested blood samples, including those obtained from elderly individuals (>70 years old) and that were negative by real time PCR. Furthermore, values of TRECs and KRECs obtained by digital PCR were in the range of those acquired by real time PCR.Conclusions: Our findings demonstrate that DNA isolation from dried blood on flocked swabs followed by digital PCR-based analysis represents a useful tool for studying new lymphocyte production in adults and elderly individuals. This suggests the potential use of the methodology when monitoring of clinical variables is limited by the number of molecules that can be amplified and detected, such as in patients with immunodeficiency or under immunosuppressive therapies. [ABSTRACT FROM AUTHOR]

Introduction Information on the prevalence of lead exposure is essential to formulate efficient public health policies. Developed countries have implemented successful public policies for the prevention and control of lead poisoning. In the United States, Canada, Japan and the European Union, for instance, periodically repeated prevalence studies show that blood lead levels (BLLs) in children have decreased overall. Although BLL of Latino children in the U.S. have also dropped in recent years, the geometric mean remains higher than that of white children. Little is known about lead exposure in children in Latin America and the Caribbean (LAC). In this review, we responded to two questions: What is currently known about lead sources and levels in children in LAC? Are there public policies to prevent children's exposure to lead in LAC? Method We conducted a literature review covering the period from January 2000 to March 2014 in the PubMed and Lilacs databases to obtain English, Portuguese and Spanish language studies reporting the prevalence of BLLs in children aged 0–18 years living in LAC countries. No specific analytical method was selected, and given the scarcity of data, the study was highly inclusive. Results Fifty-six papers were selected from 16 different LAC countries. The children's BLLs found in this review are high (≥ 10 μg/dL) compared to BLLs for the same age group in the U. S. However, most studies reported an association with some type of “lead hot spot”, in which children can be exposed to lead levels similar to those of occupational settings. Only Peru and Mexico reported BLLs in children from population-based studies. Conclusions Most BLLs prevalence studies carried out in LAC were in areas with known emission sources. The percentage of children at risk of lead poisoning in LAC is unknown, and probably underestimated. Thus, there is an urgent need to establish public health policies to quantify and prevent lead poisoning, specifically by prioritizing the identification and control of “hot spots”. [ABSTRACT FROM AUTHOR]

Advanced personalized medical diagnostics depend on the availability of high-quality biological samples. These are typically biofluids, such as blood, saliva, or urine; and their collection and storage is critical to obtain reliable results. Without proper temperature regulation, protein biomarkers in particular can degrade rapidly in blood samples, an effect that ultimately compromises the quality and reliability of laboratory tests. Here, we present the use of silk fibroin as a solid matrix to encapsulate blood analytes, protecting themfrom thermally induced damage that could be encountered during nonrefrigerated transportation or freeze-thaw cycles. Blood samples are recovered by simple dissolution of the silk matrix in water. This process is demonstrated to be compatible with a number of immunoassays and provides enhanced sample preservation in comparison with traditional air-drying paper approaches. Additional processing can remediate interactions with conformational structures of the silk protein to further enhance blood stabilization and recovery. This approach can provide expanded utility for remote collection of blood and other biospecimens empowering new modalities of temperature- independent remote diagnostics. [ABSTRACT FROM AUTHOR]

Background: The following article describes the concept of optical measurement of blood volume in ventricular assist devices (VAD's) of the pulsatile type. The paper presents the current state of art in blood volume measurements of such devices and introduces a newly developed solution in the optic domain. The objective of the research is to overcome the disadvantages of the previously developed acoustic method-the requirement of additional sensor chamber.Methods: The idea of a compact measurement system has been introduced, followed by laboratory measurements. Static tests of the system have been presented, followed by dynamic measurements on a physical model of the human ventricular system. The results involving the measurements of blood chamber volume acquired by means of an optical system have been compared with the results acquired by means of the Transonic T410 ultrasound flow rate sensor (11PLX transducer, uncertainty ±5 %).Results: Preliminary dynamic measurements conducted on the physical model of the human cardiovascular system show that the proposed optical measurement system may be used to measure the transient blood chamber volumes of pulsatile VAD's with the uncertainties (standard mean deviation) lower than 10 %.Conclusions: The results show that the noninvasive measurements of the temporary blood chamber volume in the POLVAD prosthesis with the use of the developed optical system allows us to carry out accurate static and dynamic measurements. [ABSTRACT FROM AUTHOR]

Objectives In 1981, Peter A. Stewart published a paper describing his concept for employing Strong Ion Difference. In this study we compared the HCO3 levels and Anion Gap (AG) calculated using the classic method and the Stewart method. Methods Four hundred nine (409) arterial blood gases of 90 patients were collected retrospectively. Some were obtained from the same patients in different times and conditions. All blood samples were evaluated using the same device (ABL 800 Blood Gas Analyzer). HCO3 level and AG were calculated using the Stewart method via the website AcidBase.org. HCO3 levels, AG and strong ion difference (SID) were calculated using the Stewart method, incorporating the parameters of age, serum lactate, glucose, sodium, and pH, etc. Results According to classic method, the levels of HCO3 and AG were 22.4± 7.2 mEq/L and 20.1± 4.1 mEq/L respectively. According to Stewart method, the levels of HCO3 and AG were 22.6±7.4 and 19.9±4.5 mEq/L respectively. Conclusions There was strong correlation between the classic method and the Stewart method for calculating HCO3 and AG. The Stewart method may be more effective in the evaluation of complex metabolic acidosis. [ABSTRACT FROM AUTHOR]

Improved understanding of how vortices develop and propagate under pulsatile ow can shed important light on the mixing and transport processes occurring in such systems, in- cluding the transition to turbulent regime. For example, the characterization of pulsatile ows in obstructed artery models serves to encourage research into ow-induced phenom- ena associated with changes in morphology, blood viscosity, wall elasticity and ow rate. In this work, an axisymmetric rigid model was used to study the behaviour of the ow pattern with varying degrees of constriction (d0) and mean Reynolds (R-e) and Womersley numbers (α). Velocity fields were obtained experimentally using Digital Particle Image Velocimetry, and generated numerically. For the acquisition of data, R-e was varied from 385 to 2044, d0 was 1.0 cm and 1.6 cm, and was varied from 17 to 33 in the experi- ments and from 24 to 50 in the numerical simulations. Results for the Reynolds numbers considered showed that the ow pattern consisted of two main structures: a central jet around the tube axis and a recirculation zone adjacent to the inner wall of the tube, where vortices shed. Using the vorticity fields, the trajectory of vortices was tracked and their displacement over their lifetime calculated. The analysis led to a scaling law equation for maximum vortex displacement as a function of a dimensionless variable dependent on the system parameters Re and α. [ABSTRACT FROM AUTHOR]

The viscosity of fluids has an essential role in blood circulation through veins and arteries. So, this paper focuses on the influences of dependent-viscosity on the peristaltic flow of Powell-Eyring fluid in a divergent-convergent channel. Viscosity is supposed to vary with the temperature and concentration fluid. A theoretical relation to the concentration-dependent viscosity is introduced mathematically for the Powell-Eyring nanofluid for the first time in our literature. The formulation of the model contains a highly nonlinear system of PDEs that converted to ODEs by physical assumptions to low Reynolds number and long wavelength. A semi-analytical solution was obtained in different theoretical cases of the divergent-convergent channel using the generalized differential transform method (GDTM). Results for velocity profile, temperature distribution, and concentration distribution as well as extra stress tensor profile versus various values flow parameters have been constructed. Results show that the variation parameters of viscosity α , and β can control with flow velocity at each part of channel wall making them improve/get better the blood circulation in veins (Circulatory system). Furthermore, the concentration-dependent viscosity parameter increases the temperature distribution of fluid while it declines the nanoparticle diameter of fluid. [ABSTRACT FROM AUTHOR]

A new experimental model developed to simulate arterial pulsatile flow is presented in this paper. As a representative example, the flow characteristics and the properties of brachial artery were adopted for the purpose of this study. With the physiological flow of the human brachial artery as the input, the pressure and pressure gradient waves under healthy and different scenarios mimicking diseased conditions were simulated. The diseased conditions include the increase in blood viscosity (reflecting the elevation of hematocrit), stiffening of the arterial wall, and stiffening of the aortic root as the coupling between the heart and arterial tree, presented by the Windkessel element in the setup. Each of these conditions resulted in certain effects on the propagation of the pressure and pressure gradient waves, as well as their patterns and values, investigated experimentally. The results suggest that the pressure wave dampens at arterial sites with higher hematocrit, while the stiffening of the Windkessel element elevated the diastolic pressure, and lowered the pressure drop, similar to the results observed by stiffening the arterial wall. Based on these results, it is hypothesised that the cardiovascular system may not function within the minimum energy consumption criterion, contrary to some other physiological functions. [ABSTRACT FROM AUTHOR]

Wall shear rate (WSR) is the derivative of blood velocity with respect to vessel radius at the endothelial cell (EC) surface. The product of WSR and blood viscosity is the wall shear stress (WSS) that has been identified as an important factor for atherosclerosis development. High echo signal-to-noise ratio (eSNR) and high spatial resolution are crucial for minimizing the errors in WSR estimates. By transmitting coded pulses with time-bandwidth product greater than one, high eSNR from weak blood scatter can be achieved without increasing instantaneous power or sacrificing spatial resolution. This paper summarizes a series of measurements in a straight tube (5-mm diameter), constant velocity flow phantom using a 10 MHz transducer (60% bandwidth, f/1.5) imaged with a 72° Doppler angle, 125 MHz sampling frequency and 1 kHz pulse repetition frequency. Measurements were made using a frequency-modulated (FM) code, phase-modulated (PM) codes, and uncoded broadband and narrow band pulse transmissions. Both simulation and experimental results show that coded-pulse excitation increases accuracy and precision in WSR estimation for laminar flow over a broad range of peak velocity values when compared to standard pulsing techniques in noise-limited conditions (eSNR < 30 dB). The code sequence and its length are selected to balance range lobe suppression with eSNR and echo coherence enhancements to minimize WSR errors. In our study, the combination of an eight bit Optimal coded pulse with a Wiener compression filter yielded the highest WSR estimation performance. [ABSTRACT FROM AUTHOR]

The peristaltic flow of blood in small vessels is investigated in the paper by developing a mathematical model in which blood has been treated as a two-layer fluid where the core region is described by Casson model and the peripheral region is taken to be Newtonian viscous. Wave frame steady solutions for channel flow as well as axisymmetric flow are presented. Due care has been taken to consider the conservation of mass separately in the two layers. It is found that the higher the viscosity of the peripheral layer, the greater is the flow rate. Moreover, a thinner peripheral layer enhances the flow rate, whereas the flow rate reduces when the yield stress increases. It is further observed that the flow-rate in the case of a single layer is more than the two layer flow-rate when the peripheral layer is more viscous than the core layer. Besides, the flow-rate in the case of axisymmetric flow is always found to be much greater than that of channel flow under identical conditions. [Copyright &y& Elsevier]

Acute myeloid leukemia (AML) is a hematologic malignancy that can present with central nervous system (CNS) symptoms. Neurological symptoms may result from the local accumulation of malignant cells in or near the brain (chloroma), infection, hemorrhage, or infarcts from leukostasis. Leukostasisis a syndrome that can include brain infarction due hyperviscosity of blood with vascular occlusion but CNS involvement is rarely encountered in adults. We report an unusual case of leukostasis in an adult who presented with multiple high attenuation intracranial masses on CT. While initially thought to represent chloromasthey proved to be hemorrhagic infarcts secondary toleukostasis on open brain biopsy. This condition is under-reported in the radiology literature and only rarely biopsy proven. We review in this paper the pathological, CT and MRI findings of leukostasis in order to increase awareness of this uncommon entity and facilitate diagnosis. [ABSTRACT FROM AUTHOR]

The aim of this paper is to compare the results of kinematic viscosity of lubricating oils measurements at 40 °C, obtained with three different rapid evaluation devices, and the standardized method using an Ubbelohde Capillary viscometer. The following instruments were selected to measure: a mid-FTIR spectrophotometer, a microchannel viscometer, and a Stabinger viscometer. The study material comprised 42 fresh engine oils, all of which are commercially available. The main data analysis tools used in the study were multiple regression, Mahala Nobis distance, post-hoc analysis, and the Wilcoxon signed-rank test with the Bonferroni correction. Consistent outcomes were obtained for the Stabinger viscometer only, whereas the microchannel viscometer and the mid-FTIR spectrophotometer were not as precise as the reference method. It was also found that the results obtained with the use of the mid-FTIR spectrophotometer were burdened with a very large measurement error. Therefore, a very careful approach is suggested when choosing these instruments. The study fills an important gap in empirical research in the context of the reliability of measurement results obtained using various research techniques. [ABSTRACT FROM AUTHOR]

In this paper, we numerically simulate the flow of blood in two benchmark problems: the flow in a sudden expansion channel and the flow through an idealized curved coronary artery with pulsatile inlet velocity. Blood is modeled as a suspension (a non-linear complex fluid) and the movement of the red blood cell (RBCs) is modeled by using a concentration flux equation. The viscosity of blood is obtained from experimental data. In the sudden expansion flow, the predicted velocity profiles for two different Reynolds numbers (based on the inlet velocity) agree well with the available experiments; furthermore, the numerical results also show that after the sudden expansion there exists a RBCs depletion region. For the second problem, the idealized curved coronary artery, it is found that the RBCs move towards and concentrate near the inner surface where the viscosity is higher and the shear stress is lower; this phenomenon may be related to the atherosclerotic plaque formation which usually occurs on the inside surface of the arteries. [ABSTRACT FROM AUTHOR]

Schefflera heptaphylla (L.) Frodin, are commonly used in anti-inflammatory, analgesic, traumatic bleeding and hemostasisas. In this paper, the coagulation effect of the ethanol extract (Set), ethyl acetate phase (Sea) and n-butanol phase (Sbu) was evaluated by prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen content (FIB) assays in vitro. Then, Three main lupanine triterpenes (compounds A–C) were isolated and identified from Sea and Sbu by a bioassay-guided method and their structure were identified as 3α-Hydroxy-lup-20(29)-ene-23, 28-dioic acid, betulinic acid 3-O-sulfate and 3α-Hydroxy-lup-20(29)-ene-23, 28-dioic acid 28-O-(α-l-rhamnopyranosyl(1→4)-O-β-d-glucopyranosyl(1→6))-β-d-glucopyranoside) by spectroscopic data analysis. Among of them, compound B was confirmed to have significant coagulant effect in vitro. Furthermore, the pro-coagulation mechanism of S. heptaphylla extracts and compound B were investigated by measuring whole blood viscosity (WBV), plasma viscosity (PV), erythrocyte sedimentetion rate (ESR), pack cell volume (PCV), APTT, PT, TT, and FIB in vivo. Meanwhile, the levels of thromboxane B2 (TXB2), 6-keto prostaglandin F1α (6-keto-PGF1α), endothelial nitric oxide synthase (eNOS) and (endothelin-1) ET-1 were detected. The bleeding time (BT) was tested by tail bleeding method, which proved the traumatic bleeding and hemostasis activities of S. heptaphylla. The pharmacology experiments showed that the Set, Sea, Sbu and compound B has significant pro-coagulation effect. In addition, compound B might be the main constituent of pro-coagulation in S. heptaphylla These results could support the fact that S. heptaphylla could be used traditionally to cure traumatic bleeding, and the pro-coagulation effects were associated with the regulation of vascular endothelium active substance and hemorheology parameters. [ABSTRACT FROM AUTHOR]

The blackberry seed was typically removed as a byproduct and waste from blackberry fruits for juices. Developing value-added utilization of berry seeds will significantly expand the market for berry products as well as improve benefit to berry producers. However, the research on blackberry seed is limited. The objective of this paper was to research antithrombotic mechanism of polysaccharides in blackberry seeds. Polysaccharides in blackberry seeds were extracted, purified and identified by high-performance gel permeation chromatography (HPSEC), gas chromatography (GC), fourier transform infrared (FT-IR) spectrometer and nuclear magnetic resonance spectra (NMR). Anticoagulant activities were evaluated in vivo by measuring activated partial thromboplastin time (APTT), thrombin time (TT), prothrombin time (PT), fibrinogen (FIB) and plasma recalcification time (RRT). Four polysaccharides named BSP-1a, BSP-1b, BSP-2 and BSP-3 were isolated from Blackberry (Rubus spp.) seeds. The results indicated that BSP-1b, BSP-2 and BSP-3 exhibited the anticoagulant activity. Therefore, the anti-thrombosis effects of BSP-1b, BSP-2 and BSP-3 were investigated in vivo by 6-Keto-PGF1α, thromboxane B2 (TXB2), endothelial nitric oxide synthase (eNOS), endothelin-1 (ET-1), whole blood viscosity (WBV), plasma viscosity (PV), hematocrit (Hct), erythrocyte sedimentation rate (ESR), APTT, TT, PT and FIB. The results suggested that BSP-1b, BSP-2 and BSP-3 had the inhibition effect on thrombus formation, and the antithrombotic effects were associated with the regulation of vascular endothelium active substance, activating blood flow and anticoagulation effect. [ABSTRACT FROM AUTHOR]