Miracle-dz/UniFAR-FTUs huggingface dataset:
Effects of partial substitution of pre-clinical skills training by attachments to primary health care centers: An experimental study

Background: Recent studies indicate that students may encounter problems when they have to apply clinical skills learned in a skills laboratory to patients. To facilitate this transition, it has been advised to include patient contacts early in the pre-clinical curriculum. Objective: To compare clinical skills performance and level of preparedness for entering the clerkships between students who were prepared exclusively in a skills laboratory and peers for whom part of their skills training program was substituted by training in a primary health care (PHC) center. Methods: Pre-clinical students either trained clinical skills exclusively in a skills laboratory while their peers attended a mixed program of laboratory trainings and practice in PHC centers. Students’ perception of preparedness for the clerkships was explored through the Preparation for Hospital Practice Questionnaire. Students’ clinical skills were assessed by an Objective Structured Clinical Examination (OSCE) and by supervisors in PHC centers. Results: Students following the mixed program felt better prepared for their clerkships than skills lab-trained peers. Students’ perceptions were supported by assessments by their supervisors. However, mean OSCE scores of both groups did not differ significantly. Conclusion: PHC centers can be involved to better prepare pre-clinical students for their clerkships.
Hydrothermal Scheduling Using Benders Decomposition: Accelerating Techniques

A new decomposition method is presented that includes the network through ac modeling within the hydrothermal scheduling optimization process including the losses. In short-term hydrothermal scheduling, the transmission network is typically modeled with dc power flow techniques. Such modeling, however, can lead to impractical solutions when it is verified with ac power flow. Another proposal considers in thermal systems the ac network modeling but not the optimization of losses. The approach presented here addresses issues such as congestion management and control of service quality that often arise in large and weakly meshed networks - the typical pattern of power systems in Latin America. Generalized Benders decomposition and traditional, well-known optimization techniques are used to solve this problem. The master problem stage defines the generation levels by regarding the inter-temporal constraints, whereas the subproblem stage determines both the active and the reactive economical dispatches for each time interval of the load curve. It meets the electrical constraints through a modified ac optimal power flow (OPF). Another important contribution is the inclusion of accelerating techniques aimed at reducing the number of iterations and CPU time. The methodology was proven in a real system and test systems. Results are discussed in this paper.
Has Financial Development Worsened Income Inequality in China? Evidence from Threshold Regression Model

As a central variable of modern economy,the effect of financial development on income distribution is an emerging issue in macroeconomic field.This paper makes a systematic review of related studies,and summarizes the function mechanism of the effect of financial development on income inequality.Using China's provincial-level panel data from 1996 to 2009,it employs the threshold model proposed by Hansen in 1999 to estimate the effect of financial development on income inequality.The results show that financial development significantly intensifies income inequality in China and the effect of financial development on income inequality is featured by the threshold effect.Especially,in provinces whose economic variable cross a certain threshold value,the effect of financial development on income inequality is greater.
An amino acid code to define a protein's tertiary packing surface

One difficult aspect of the protein‐folding problem is characterizing the nonspecific interactions that define packing in protein tertiary structure. To better understand tertiary structure, this work extends the knob‐socket model by classifying the interactions of a single knob residue packed into a set of contiguous sockets, or a pocket made up of 4 or more residues. The knob‐socket construct allows for a symbolic two‐dimensional mapping of pockets. The two‐dimensional mapping of pockets provides a simple method to investigate the variety of pocket shapes to understand the geometry of protein tertiary surfaces. The diversity of pocket geometries can be organized into groups of pockets that share a common core, which suggests that some interactions in pockets are ancillary to packing. Further analysis of pocket geometries displays a preferred configuration that is right‐handed in α‐helices and left‐handed in β‐sheets. The amino acid composition of pockets illustrates the importance of nonpolar amino acids in packing as well as position specificity. As expected, all pocket shapes prefer to pack with hydrophobic knobs; however, knobs are not selective for the pockets they pack. Investigating side‐chain rotamer preferences for certain pocket shapes uncovers no strong correlations. These findings allow a simple vocabulary based on knobs and sockets to describe protein tertiary packing that supports improved analysis, design, and prediction of protein structure. Proteins 2016; 84:201–216. © 2015 Wiley Periodicals, Inc.
Atrophic Gastritis Is Associated with Increased Sucrose Permeability Related to Chronic Inflammation

Background: Different theories have been presented to explain how atrophic gastritis may lead to gastric cancer development. One contributing factor could be impaired function of the gastric mucosal barrier. The aim of this study was to investigate if there are changes in gastric mucosal permeability to sucrose in atrophic gastritis.Methods: The study comprised 22 patients with atrophic gastritis and 21 normal controls. Gastritis was classified according to the Sydney system from endoscopic biopsies of the gastric corpus and antrum. All subjects were exposed to oral sucrose load (100 g), and the fraction of sucrose excreted in urine was measured by gas chromatography-mass spectrometry. Results: The fraction of sucrose excreted in urine after oral load was significantly increased in atrophic gastritis compared with controls (median 0.08 vs. 0.04%; p = 0.003). Sucrose excretion was positively related to the degree of chronic inflammation (median fraction excreted: mild inflammation 0.06%, moderate inflammation 0.08%, severe inflammation 0.18%; p = 0.04) rather than to the degree of atrophy in the gastric mucosa. Occurrence of intestinal metaplasia was also associated with significantly higher sucrose excretion. However, in multivariate analysis, including intestinal metaplasia, only the degree of inflammation was positively related to sucrose excretion. Conclusion: Atrophic gastritis is associated with increased sucrose permeability, suggesting paracellular leakage of the gastric mucosa. This leakage seems to be related to the degree of inflammation rather than the degree of atrophy. The findings may have implications for the diseases and complications associated with atrophic gastritis.
Relationships Between Conductor Damage, Quenching and Electromechanical Behavior in YBCO Coated Conductors

The implementation of emerging superconducting materials into magnet systems with long service lifetimes requires a thorough understanding of their engineering properties, including their quench and electromechanical behaviors. Furthermore, it is essential to understand the role of defects in the conductor, whether they be pre-existing defects from the conductor manufacturing process that locally reduce Jc, or local defects that result from a non-destructive quench (i.e., a quench that may reduce Jc locally but does not significantly affect the end-to-end behavior). This paper reports results on both of these types of defects and the interplay between quenching and electromechanical behavior. Quench studies investigate the initiation and propagation of quenches in coated conductors. Disturbances in homogeneous conductors are initiated by a pulsed heater attached to the conductor. Disturbances in locally damaged conductors are initiated by increasing the transport current above the Ic at the local defect but below the end-to-end Ic. Samples are quenched to determine the minimum quench energy and the quench propagation velocity. Homogeneous samples are also quenched to the point of initiating local damage, thereby identifying the maximum allowable hot-spot temperature or hot-spot temperature gradient. Samples used in quench studies are subsequently used in Ic-strain measurements to determine how quenching affects subsequent performance. Samples that exhibit reduced Ic from quenching, and samples from regions adjacent to such damaged samples, are studied. It is found that quenching can reduce the electromechanical performance of conductors that do not initially show a reduction in their electrical performance.
The Logic of Joint Research and Development

Recently, joint R&D involving horizontal collaboration among three or more competing firms has emerged in a variety of industrial sectors. This article views the evolution of the R&D collaborative as an innovative and efficient institutional form for the development of "leaky" intellectual property. The authors argue that private firms underinvest in the development of "leaky" intellectual property due to difficulties in appropriability. Three U.S. case histories and one Japanese example of horizontal R&D collaboration illustrate differences in organizational design, goal formation, and management. The authors conclude that an insufficiency of institutional support for U.S. collaboratives may lead to underinvestment in "leaky" technologies.
Research on optimal model based on multiple flood disaster evaluation results

Different results are caused by a great diversity of flood disaster evaluation methods.And this bring difficulty to decision-making.Based on the problem and take the multiple results of evaluation methods as analyze objects,analytic hierarchy process(AHP) is introduced into weight value distribute for the results and an optimal model based on multiple evaluation methods is established.The analyses about flood disaster data in every district in 1998 show the synthetically optimal result includes more information and contains all the virtues of multiple evaluation results.The simple and reliable model provides effectively support for scientific decision.Meanwhile,the model is prevalent applicable for rank evaluate.
Problems of sperm fertility: A reproductive biologist's view

For natural fertilization to occur successfully, millions of spermatozoa must be deposited in the lower end of the female genital tract during mating. Considerably fewer spermatozoa are required for fertilization when spermatozoa are deposited in the upper region of the female tract. The extreme case of assisted fertilization is the direct injection of a single spermatozoon into an oocyte in vitro, which is referred to as intracytoplasmic sperm injection or ICSI. All that is required to fertilize an oocyte is a single spermatozoon with a genetically and epigenetically normal nucleus. Even spermatozoa with grossly misshapen heads and no motility at all are able to produce normal offspring by ICSI as long as their nuclei are normal. There is a distinct difference between natural and ICSI fertilization. In ICSI the sperm plasma membrane and the acrosome, which never enter the oocyte's cytoplasm during natural fertilization, are injected into an oocyte. There are reports that the oocytes injected with acrosome-less spermatozoa develop better than those injected with acrosome-intact spermatozoa. At least in the mouse, pre-spermatozoal cells (e.g., round spermatids) are able to produce fertile offspring by injection into oocytes. Whether ‘spermatozoa’ produced from embryonic stem (ES) or induced pluri-potent stem (iPS) cells are functional remains to be determined. Will assisted reproduction increase overall male infertility by spreading genes involved in infertility? This is most unlikely in view of the widespread propagation of spontaneous mutation in the general population. When assisted reproduction technologies are perfected, pregnancy through assisted reproduction will become as safe as pregnancy through natural conception.
An Energy-Based Controller for HVDC Modular Multilevel Converter in Decoupled Double Synchronous Reference Frame for Voltage Oscillation Reduction

This paper consists of the presentation of a regulation strategy capable of controlling the energy stored in the modular multilevel converter (MMC) in an HVDC configuration. This is achieved by regulating the positive, negative, and zero sequences in dqo coordinates of the differential current using two rotating reference frames: at once and at twice the fundamental grid frequency value. The active and reactive negative sequence components of the differential current at twice the fundamental frequency are used to eliminate the oscillations of the three-phased leg energy, reducing significantly the capacitor voltage oscillations, while the zero-sequence component is used to regulate the total energy stored at a given reference. Meanwhile, active and reactive positive sequence components of the circulating current are used for eliminating the average energy difference between the upper and lower arms in a three-phase MMC. In order to decouple efficiently the differential current components, the decoupled-double-synchronous-reference-frame current control strategy is used. Finally, simulation results validate the performance of the MMC in an HVDC configuration with the proposed control. Control equations are demonstrated, and cross-coupled leg-energy terms are introduced.
The Crystallographic Structure of the Mannitol 2-Dehydrogenase NADP+ Binary Complex from Agaricus bisporus *

Mannitol, an acyclic six-carbon polyol, is one of the most abundant sugar alcohols occurring in nature. In the button mushroom, Agaricus bisporus, it is synthesized from fructose by the enzyme mannitol 2-dehydrogenase (MtDH; EC 1.1.1.138) using NADPH as a cofactor. Mannitol serves as the main storage carbon (up to 50% of the fruit body dry weight) and plays a critical role in growth, fruit body development, osmoregulation, and salt tolerance. Furthermore, mannitol dehydrogenases are being evaluated for commercial mannitol production as alternatives to the less efficient chemical reduction of fructose. Given the importance of mannitol metabolism and mannitol dehydrogenases, MtDH was cloned into the pET28 expression system and overexpressed in Escherichia coli. Kinetic and physicochemical properties of the recombinant enzyme are indistinguishable from the natural enzyme. The crystal structure of its binary complex with NADP was solved at 1.5-Å resolution and refined to an R value of 19.3%. It shows MtDH to be a tetramer and a member of the short chain dehydrogenase/reductase family of enzymes. The catalytic residues forming the so-called catalytic triad can be assigned to Ser149, Tyr169, and Lys173.
Galectin-3: A Positive Regulator of Leukocyte Recruitment in the Inflamed Microcirculation

In vivo and ex vivo imaging were used to investigate the function of galectin-3 (Gal-3) during the process of leukocyte recruitment to the inflamed microcirculation. The cremasteric microcirculation of wild-type (C57BL/6), Gal-3−/−, and CX3CR1gfp/+ mice were assessed by intravital microscopy after PBS, IL-1β, TNF-α, or recombinant Gal-3 treatment. These cellular responses were investigated further using flow-chamber assays, confocal microscopy, flow cytometry, PCR analysis, and proteome array. We show that mechanisms mediating leukocyte slow rolling and emigration are impaired in Gal-3−/− mice, which could be because of impaired expression of cell adhesion molecules and an altered cell surface glycoproteome. Local (intrascrotal) administration of recombinant Gal-3 to wild-type mice resulted in a dose-dependent reduction in rolling velocity associated with increased numbers of adherent and emigrated leukocytes, ∼50% of which were Ly6G+ neutrophils. Intrascrotal administration of Gal-3 to CX3CR1gfp/+ mice confirmed that approximately equal numbers of monocytes are also recruited in response to this lectin. Exogenous Gal-3 treatment was accompanied by increased proinflammatory cytokines and chemokines within the local tissue. In conclusion, this study unveils novel biology for both exogenous and endogenous Gal-3 in promoting leukocyte recruitment during acute inflammation.
The hitchhiker's guide to the galaxy of mathematical tools for shape analysis

A practical guide for researchers who are exploring the new frontiers of 3D shape analysis and managing the complex mathematical tools that most methods rely on. Many research solutions come from advances in pure and applied mathematics, as well as from re-reading classical mathematical theories. Managing these math tools is critical to understanding and solving current problems in 3D shape analysis. This course is designed to help mathematicians and scientists communicate in a world where boundaries between disciplines are (fortunately) blurred, so they can quickly find the right mathematical tools for a bright intuitive idea and strike a balance between theoretical rigor and computationally feasible solutions. The course presents basic concepts in differential geometry and proceeds to advanced topics in algebraic topology, always keeping an eye on their computational counterparts. It includes examples of applications to shape correspondence, symmetry detection, and shape retrieval that show how these mathematical concepts can be translated into practical solutions.
Bi-directional active-filter-integrated AC/DC converter without electrolytic capacitor and extra power switches

In this paper, a cost-effective single-phase bidirectional active-filter-integrated AC/DC converter is proposed. It provides simultaneous functions of power factor correction (PFC), DC voltage regulation and active power decoupling for mitigating the low-frequency DC voltage ripple, without an electrolytic capacitor and extra power switches. Such a converter is readily available from a conventional H-bridge converter with minor hardware modification. Detailed principles of operation, controller design of the converter are provided in the paper. The feasibility of the converter is then confirmed experimentally through a 210 W rectification system. A stable DC output with merely 1.9% ripple is realized with two 50 μF film capacitors. In contrast, for the same ripple performance, a 514 μF capacitor is required in conventional converters without an active filter. Additionally, the uncompromised or even improved efficiency performance is another unique feature of the proposed converter.
The Primary Photophysics of the Avena sativa Phototropin 1 LOV2 Domain Observed with Time‐resolved Emission Spectroscopy †

The phototropins are blue‐light receptors that base their light‐dependent action on the reversible formation of a covalent bond between a flavin mononucleotide (FMN) cofactor and a conserved cysteine in light, oxygen or voltage (LOV) domains. The primary reactions of the Avena sativa phototropin 1 LOV2 domain were investigated by means of time‐resolved and low‐temperature fluorescence spectroscopy. Synchroscan streak camera experiments revealed a fluorescence lifetime of 2.2 ns in LOV2. A weak long‐lived component with emission intensity from 600 to 650 nm was assigned to phosphorescence from the reactive FMN triplet state. This observation allowed determination of the LOV2 triplet state energy level at physiological temperature at 16600 cm−1. FMN dissolved in aqueous solution showed pH‐dependent fluorescence lifetimes of 2.7 ns at pH 2 and 3.9−4.1 ns at pH 3–8. Here, too, a weak phosphorescence band was observed. The fluorescence quantum yield of LOV2 increased from 0.13 to 0.41 upon cooling the sample from 293 to 77 K. A pronounced phosphorescence emission around 600 nm was observed in the LOV2 domain between 77 and 120 K in the steady‐state emission.
A highly efficient hybrid CdS-GaAs solar cell

A novel design of hybrid solar cell combining traditional GaAs-based solar cell with colloidal CdS quantum dots (QDs) is demonstrated. By applying CdS QDs on the surface of GaAs device, we can obtain an effective anti-reflection coating at long wavelength. Moreover, due to its strong absorption at ultraviolet range and efficient light emission at blue photon, CdS quantum dots can down-convert the high-energy UV photons into visible ones, which are more easily to be collected in GaAs solar cell. The short circuit current and power conversion efficiency of this new device increases by 21% and 18.9%, respectively, when we compare them to the uncoated GaAs solar cell. An increase of the surface photoconductivity was also detected due to UV presence, and the fill factor of the CdS QDs solar cell can be improved accordingly.
Primary macrophages infected by human immunodeficiency virus trigger CD95‐mediated apoptosis of uninfected astrocytes

Infection of macrophages (M/M) by human immunodeficiency virus (HIV) is a main pathogenetic event leading to neuronal dysfunction and death in patients with AIDS dementia complex. Alteration of viability of neurons and astrocytes occurs in vivo even without their infection, thus it is conceivable that HIV‐infected M/M may affect viability of such cells even without direct infection. To assess this hypothesis, we studied the effects of HIV‐infected M/M on an astrocytic cell‐line lacking CD4‐receptor expression. Exposure to supernatants of HIV‐infected M/M triggers complete disruption and apoptotic death of astrocytic cells. This effect is not related to HIV transmission from infected M/M, because HIV‐DNA and p24 production in astrocytic cells remained negative. Apoptotic death of astrocytes is mainly mediated by Fas ligand released in supernatants of HIV‐infected M/M (as demonstrated by complete reversal of such phenomenon by adding neutralizing antibodies against CD95 receptor). Treatment of astrocytic cells with recombinant (biologically active) Tat induces <10% apoptosis, and gp120 was totally ineffective. Treatment of HIV‐infected M/M with AZT completely reverses the proapoptotic effect of their supernatants on astrocytes, thus demonstrating that productive virus replication within M/M is required for the induction of astrocytic cell death.