Miracle-dz/UniFAR-FTUs huggingface dataset:
Electrospinning of Poly(Hydroxybutyrate-co-hydroxyvalerate) Fibrous Scaffolds for Tissue Engineering Applications: Effects of Electrospinning Parameters and Solution Properties

Electrospinning, a technology capable of fabricating ultrafine fibers (microfibers and nanofibers), has been investigated by various research groups for the production of fibrous biopolymer membranes for potential medical applications. In this study, poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), a natural, biocompatible, and biodegradable polymer, was successfully electrospun to form nonwoven fibrous mats. The effects of different electrospinning parameters (solution feeding rate, applied voltage, working distance and needle size) and polymer solution properties (concentration, viscosity and conductivity) on fiber diameter and morphology were systematically studied and causes for these effects are discussed. The formation of beaded fibers was investigated and the mechanism presented. It was shown that by varying electrospinning parameters within the processing window that was determined in this study, the diameter of electrospun PHBV fibers could be adjusted from a few hundred nanometers to a few microns, which are in the desirable range for constructing “biomimicking” fibrous scaffolds for tissue engineering applications.
Hemoglobin Scavenger Receptor CD163 Mediates Interleukin-10 Release and Heme Oxygenase-1 Synthesis: Antiinflammatory Monocyte-Macrophage Responses In Vitro, in Resolving Skin Blisters In Vivo, and After Cardiopulmonary Bypass Surgery

Abstract— The recently described hemoglobin scavenger receptor CD163 mediates the endocytosis of hemoglobin:haptoglobin (Hb:Hp) complexes and thereby counters Hb-induced oxidative tissue damage after hemolysis. Although CD163 has been indirectly associated with antiinflammatory and atheroprotective activity, no ligand-receptor-effector pathway has yet been described for this receptor. To understand the significance of CD163 and more clearly define downstream pathways linked to inflammatory resolution, we studied the expression and function of CD163 in human monocytes/macrophages using both in vitro and in vivo models. Differentiation of human blood monocytes into macrophages either by in vitro culture or in resolving cantharidin-induced skin blisters led to an equivalent increase (>15×) in CD163 expression. Elevated CD163 levels were also noted on circulating monocytes in cardiac surgical patients during the resolution phase of the systemic inflammatory response to cardiopulmonary bypass surgery. In each case, binding of Hb:Hp to CD163-bearing cells elicited potent interleukin-10 secretion, and this was inhibited by the anti-CD163 antibody RM3/1. Release of interleukin-10, in turn, induced heme oxygenase-1 stress protein synthesis via an autocrine mechanism. Such induction of heme oxygenase-1 was observed in vivo 24 to 48 hours after the onset of cardiopulmonary bypass surgery. These results identify novel antiinflammatory and cytoprotective effector pathways in human monocytes/macrophages related to Hb scavenging and metabolism, which may have relevance in atheroprotection, wound healing, and patient recovery postoperatively.
Who Leaves? Teacher Attrition and Student Achievement

Almost a quarter of entering public-school teachers leave teaching within their first three years. High attrition would be particularly problematic if those leaving were the more able teachers. The goal of this paper is estimate the extent to which there is differential attrition based on teachers' value-added to student achievement. Using data for New York City schools from 2000-2005, we find that first-year teachers whom we identify as less effective at improving student test scores have higher attrition rates than do more effective teachers in both low-achieving and high-achieving schools. The first-year differences are meaningful in size; however, the pattern is not consistent for teachers in their second and third years. For teachers leaving low-performing schools, the more effective transfers tend to move to higher achieving schools, while less effective transfers stay in lower-performing schools, likely exacerbating the differences across students in the opportunities they have to learn.
Experimental and Theoretical Challenges in the Search for the Quark Gluon Plasma: The STAR Collaboration’s Critical Assessment of the Evidence from RHIC Collisions

We review the most important experimental results from the first three years of nucleus-nucleus collision studies at RHIC, with emphasis on results from the STAR experiment, and we assess their interpretation and comparison to theory. The theory-experiment comparison suggests that central Au+Au collisions at RHIC produce dense, rapidly thermalizing matter characterized by: (1) initial energy densities above the critical values predicted by lattice QCD for establishment of a Quark-Gluon Plasma (QGP); (2) nearly ideal fluid flow, marked by constituent interactions of very short mean free path, established most probably at a stage preceding hadron formation; and (3) opacity to jets. Many of the observations are consistent with models incorporating QGP formation in the early collision stages, and have not found ready explanation in a hadronic framework. However, the measurements themselves do not yet establish unequivocal evidence for a transition to this new form of matter. The theoretical treatment of the collision evolution, despite impressive successes, invokes a suite of distinct models, degrees of freedom and assumptions of as yet unknown quantitative consequence. We pose a set of important open questions, and suggest additional measurements, at least some of which should be addressed in order to establish a compelling basis to conclude definitively that thermalized, deconfined quark-gluon matter has been produced at RHIC.
Cardiac Myocyte Dysfunction Induced by Streptolysin O Is Membrane Pore and Calcium Dependent

ABSTRACT Septic cardiomyopathy is a severe complication among some patients who develop group A streptococcal toxic shock syndrome. Despite the importance of cardiac dysfunction in determining prognosis, very little is known about mechanisms that reduce cardiac output in association with streptococcal infection. Here, we investigated the effects of streptococcal extracellular toxins on mechanical contractility of electrically paced primary murine cardiomyocytes. Our data demonstrate that streptolysin O (SLO) is the major streptococcal toxin responsible for cardiomyocyte contractile dysfunction. Streptolysin O dose-dependently affected cardiac myocyte function in discrete stages. Exposure to SLO caused a failure of cardiac cells to respond to electrical pacing, followed by spontaneous dysregulated contractions and augmented strength of contraction. Central to these SLO-mediated effects is a marked influx of calcium into the cytosol through SLO-mediated pores in the cytoplasmic membrane. Such calcium mobilization in response to SLO correlated temporally with hypercontractility and unpaced contractions. During continued exposure to SLO, cardiomyocytes exhibited periods of reversion to normal electrical pacing suggestive of membrane lesion repair and restoration of calcium handling. Together, these observations are consistent with the clinical observation that septic cardiomyopathy is a reversible condition in patients who survive streptococcal toxic shock syndrome. These data provide strong evidence that streptococcal exotoxins, specifically SLO, can directly impact cardiac mechanical function.
GIANT VACUOLES OBSERVED IN DICTYOSTELIUM DISCOIDEUM

Large intracellular vacuoles, >4μm in diameter and either round or oval‐shaped, were observed infrequently in Dictyostelium discoideum amoebae of axenically‐grown strain AX2 (only 1 in 106–108cells). These previously unreported single or multiple ‘giant’ vacuoles were more common, however, in newly germinated KAX3 cells (0.55% of the population) and AT‐Kneg, a strain that lacks an esterase (0.47% of the population). A vacuolar H+‐ATPase was enriched in their membranes of intracellular giant vacuoles, indicating that the vacuoles were related possibly to both endosomes and the contractile vacuole compartment. When monitored over time, giant vacuoles protruded from, and retracted back into cells under hyperosmotic conditions, suggesting an osmoregulatory role for these vacuoles. Some of the intracellular and protruded giant vacuoles harbored a fluid‐phase marker, fluorescein‐labeled dextran, implying a pinocytotic origin for the vacuoles.
An Achievable Rate Region for the Broadcast Channel With Feedback

A single-letter achievable rate region is proposed for the two-receiver discrete memoryless broadcast channel with generalized feedback. The coding strategy involves block-Markov superposition coding using Marton's coding scheme for the broadcast channel without feedback as the starting point. If the message rates in the Marton scheme are too high to be decoded at the end of a block, each receiver is left with a list of messages compatible with its output. Resolution information is sent in the following block to enable each receiver to resolve its list. The key observation is that the resolution information of the first receiver is correlated with that of the second. This correlated information is efficiently transmitted via joint source-channel coding, using ideas similar to the Han-Costa coding scheme. Using the result, we obtain an achievable rate region for the stochastically degraded additive white Gaussian noise broadcast channel with noisy feedback from only one receiver. It is shown that this region is strictly larger than the no-feedback capacity region.
Embryonic Morphogen Nodal Is Associated with Progression and Poor Prognosis of Hepatocellular Carcinoma

Background Nodal, a TGF-β-related embryonic morphogen, is involved in multiple biologic processes. However, the expression of Nodal in hepatocellular carcinoma (HCC) and its correlation with tumor angiogenesis, epithelial-mesenchymal transition, and prognosis is unclear. Methods We used real-time PCR and Western blotting to investigate Nodal expression in 6 HCC cell lines and 1 normal liver cell line, 16 pairs of tumor and corresponding paracarcinomatous tissues from HCC patients. Immunohistochemistry was performed to examine Nodal expression in HCC and corresponding paracarcinomatous tissues from 96 patients. CD34 and Vimentin were only examined in HCC tissues of patients mentioned above. Nodal gene was silenced by shRNA in MHCC97H and HCCLM3 cell lines, and cell migration and invasion were detected. Statistical analyses were applied to evaluate the prognostic value and associations of Nodal expression with clinical parameters. Results Nodal expression was detected in HCC cell lines with high metastatic potential alone. Nodal expression is up-regulated in HCC tissues compared with paracarcinomatous and normal liver tissues. Nodal protein was expressed in 70 of the 96 (72.9%) HCC tumors, and was associated with vascular invasion (P = 0.000), status of metastasis (P = 0.004), AFP (P = 0.049), ICGR15 (indocyanine green retention rate at 15 min) (P = 0.010) and tumor size (P = 0.000). High Nodal expression was positively correlated with high MVD (microvessal density) (P = 0.006), but not with Vimentin expression (P = 0.053). Significantly fewer migrated and invaded cells were seen in shRNA group compared with blank group and negative control group (P<0.05). High Nodal expression was found to be an independent factor for predicting overall survival of HCC. Conclusions Our study demonstrated that Nodal expression is associated with aggressive characteristics of HCC. Its aberrant expression may be a predictive factor of unfavorable prognosis for HCC after surgery.
Molecular characterization of immunoglobulin D in mammals: immunoglobulin heavy constant delta genes in dogs, chimpanzees and four old world monkey species

Antibodies are adaptor molecules that neutralize pathogens and link humoral and cellular defence mechanisms. Immunoglobulin D (IgD), one of the five antibody classes present in mammals, is expressed as an antigen receptor on naïve B cells. The functional role that IgD plays in the immune response is still poorly understood, but the recent characterization of immunoglobulin heavy constant delta genes (IGHD) in a variety of species challenges the view that IgD is of minor importance and is not present in many animals. On the basis of serological studies, IgD appears to be expressed in the majority of mammalian species examined. To confirm, at the molecular level, that IgD is present in different species, we cloned and sequenced IGHD cDNA from dogs and five non‐human primate species (chimpanzee, rhesus macaque, cynomolgus macaque, baboon and sooty mangabey). Our results show that in all six species, IgD heavy chains possess three immunoglobulin domains and a long hinge region encoded by two exons. Only the hinge region of non‐human primates is similar to the human hinge region, with conservation of O‐glycosylation sites and multiple charged residues at opposing ends. The preservation of IgD in primates, dogs and previously characterized species suggests an important functional role for IgD, possibly involving binding to a receptor. The high degree of similarity existing between the structural features of human and non‐human primate IgD suggests that non‐human primates are suitable for in vivo studies designed to define the role that IgD plays in the immune response.
Metal Artifact Reduction in Computed Tomography After Deep Brain Stimulation Electrode Placement Using Iterative Reconstructions

Objectives Diagnostic accuracy of intraoperative computed tomography (CT) after deep brain stimulation (DBS) electrode placement is limited due to artifacts induced by the metallic hardware, which can potentially mask intracranial postoperative complications. Different metal artifact reduction (MAR) techniques have been introduced to reduce artifacts from metal hardware in CT. The purpose of this study was to assess the impact of a novel iterative MAR technique on image quality and diagnostic performance in the follow-up of patients with DBS electrode implementation surgery. Materials and Methods Seventeen patients who had received routine intraoperative CT of the head after implantation of DBS electrodes between March 2015 and June 2015 were retrospectively included. Raw data of all patients were reconstructed with standard weighted filtered back projection (WFBP) and additionally with a novel iterative MAR algorithm. We quantified frequencies of density changes to assess quantitative artifact reduction. For evaluation of qualitative image quality, the visibility of numerous cerebral anatomic landmarks and the detectability of intracranial electrodes were scored according to a 4-point scale. Furthermore, artifact strength overall and adjacent to the electrodes was rated. Results Our results of quantitative artifact reduction showed that images reconstructed with iterative MAR (iMAR) contained significantly lower metal artifacts (overall low frequency values, 1608.6 ± 545.5; range, 375.5–3417.2) compared with the WFBP (overall low frequency values, 4487.3 ± 875.4; range, 2218.3–5783.5) reconstructed images (P < 0.004). Qualitative image analysis showed a significantly improved image quality for iMAR (overall anatomical landmarks, 2.49 ± 0.15; median, 3; range, 0–3; overall electrode characteristics, 2.35 ± 0.16; median, 2; range, 0–3; artifact characteristics, 2.16 ± 0.08; median, 2.5; range, 0–3) compared with WFBP (overall anatomical landmarks, 1.21 ± 0.64; median, 1; range, 0–3; overall electrode characteristics, 0.74 ± 0.37; median, 1; range, 0–2; artifact characteristics, 0.51 ± 0.15; median, 0.5; range, 0–2; P < 0.002). Conclusions Reconstructions of cranial CT images with the novel iMAR algorithm in patients after DBS implantation allows an efficient reduction of metal artifacts near DBS electrodes compared with WFBP reconstructions. We demonstrated an improvement of quantitative and qualitative image quality of iMAR compared with WFBP in patients with DBS electrodes.
Bone marrow mesenchymal stem cells transplantation promotes the release of endogenous erythropoietin after ischemic stroke

This study investigated whether bone marrow mesenchymal stem cell (BMSC) transplantation protected ischemic cerebral injury by stimulating endogenous erythropoietin. The model of ischemic stroke was established in rats through transient middle cerebral artery occlusion. Twenty-four hours later, 1 × 10 6 human BMSCs (hBMSCs) were injected into the tail vein. Fourteen days later, we found that hBMSCs promoted the release of endogenous erythropoietin in the ischemic region of rats. Simultaneously, 3 μg/d soluble erythropoietin receptor (sEPOR) was injected into the lateral ventricle, and on the next 13 consecutive days. sEPOR blocked the release of endogenous erythropoietin. The neurogenesis in the subventricular zone was less in the hBMSCs + sEPOR group than in the hBMSCs + heat-denatured sEPOR group. The adhesive-removal test result and the modified Neurological Severity Scores (mNSS) were lower in the hBMSCs + sEPOR group than in the heat-denatured sEPOR group. The adhesive-removal test result and mNSS were similar between the hBMSCs + heat-denatured sEPOR group and the hBMSCs + sEPOR group. These findings confirm that BMSCs contribute to neurogenesis and improve neurological function by promoting the release of endogenous erythropoietin following ischemic stroke.
ESAT-6/CFP10 Skin Test Predicts Disease in M. tuberculosis-Infected Guinea Pigs

Background Targeted preventive chemotherapy of individuals with progressive subclinical (incipient) disease before it becomes contagious would break the chain of tuberculosis transmission in high endemic regions. We have studied the ability of a skin test response to ESAT-6 and CFP10 (E6/C10) to predict later development of tuberculosis disease in the guinea pig model. Methods and Findings Guinea pigs, either vaccinated with BCG or unvaccinated, were infected with a low dose of Mycobacterium tuberculosis by the aerosol route and the development of delayed type hypersensitivity responses to E6/C10 and to purified protein derivative (PPD) were followed until the onset of clinical disease. We demonstrated a negative correlation between the size of the skin test response and the time to the onset of clinical disease; a large E6/C10 skin test response correlated to a shorter survival time post skin testing, while a small E6/C10 skin test reaction correlated with a longer survival time (r = −0.6 and P<0.0001). No correlation was found using PPD. Conclusions Our data suggest that it may be possible to develop a prognostic skin test based on E6/C10 that will allow the identification of individuals with incipient disease, who have the highest risk of developing active tuberculosis in the near future.
Improving automatic writer identification

State-of-the-art systems for automatic writer identification from handwritten text are based on two approaches: a statistical approach or a model-based approach. Both approaches have limitations. The main limitation of the statistical approach is that it relies on single-scale statistical features. The main limitation of the model-based approach is that the codebook generation is time-consuming. We attempt to improve automatic writer identification by overcoming the limitations of both approaches. For the statistical approach we evaluate multi-scale statistical features and find one of them to improve the identification performance of singlescale features. For the model-based approach we show that the usage of Kohonen maps for codebook generation is unnecessary, and that a randomly generated codebook is more efficient. We conclude that multi-scale features may enhance identification performances and that random codebooks are to be preferred over Kohonen-based codebooks.
Load balancing combining fractional frequency reuse with unrestricted user association

Maximizing system throughput and bandwidth utilization while guaranteeing fairness among users is a core technical challenge in the design of next generation cellular networks. In this context, fractional frequency reuse (FFR) is a helpful tool if it is flexible in terms of resource and power allocation as well as scheduling. Complementary to this tool, a well-chosen association of users to base station sectors can yet be another important factor, particularly when users are distributed unevenly in space. Here we propose a load balancing scheme that combines flexible FFR with an unrestricted association of users to sectors or base stations, thereby effectively increasing the user data rates in the dense regions of the network. In a first step, we perform virtual joint power allocation and scheduling so as to determine the best sectors for maximizing the throughput for a given user. In a second step, users are actually associated to the best sectors, which are not necessarily the ones providing the strongest signal. Simulation results show that our proposed mechanism provides fairness by load balancing while still maintaining the throughput over all users.
ABRASION RESISTANCE OF CONCRETE

The abrasion resistance of 12 concretes is compared with the ASTM C779-82 (procedure C) testing method. Four different types of aggregates were used; their source rocks are completely characterized in terms of compressive strength, modulus of elasticity, Los Angeles loss, and abrasion resistance. The first series of air-entrained concretes show that while silica fume can slightly improve concrete abrasion resistance, coarse aggregate nature is more significant. The second series, focusing on the effect of water/cementitious ratio (\IW\N/\IC\N) on abrasion resistance, reveal that as long as \IW\N/\IC\N is maintained at about 0.30, the concrete’s abrasion resistance almost equals that of the coarse-aggregate source rock. The third series demonstrates that abrasion resistance in high-strength concretes with very low \IW\N/\IC\N is largely determined by that of the coarse aggregate. It is noted, however, that when the wet-sieved concrete (mortar) and aggregate are of roughly equal abrasion resistance, the concrete itself exhibits slightly higher resistance than either of them alone.
Viscosity studies of poly(DL‐lactic acid) in supercritical CO2

The effect of supercritical CO2 on the viscosity and activation energy to viscous flow of PDLLA is investigated, using a high pressure parallel plate rheometer, over a range of temperatures (50–140 °C) and pressures (5–12 MPa). The Cross model is fitted to the data to enable calculation of the zero shear viscosity and critical shear rate. A significant decrease in the viscosity is observed on increasing both variables; however, at high temperatures, the pressure effect becomes negligible. An increase in the critical shear rate is also observed on raising the pressure, indicative of a reduction in the relaxation time of the polymer. Manipulation of the Arrhenius equation shows a reduction in the activation energy to viscous flow as the pressure is increased. Together, these results show that the melt processing temperature of PDLLA can be reduced in the presence of supercritical and high pressure CO2. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012