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Due to the density contrast between the hydrate and methane gas, the pore pressure is accumulated in the sediment during the decomposition process of methane hydrate. This accumulation of pore pressure decreases the magnitude of effective stress, further triggering potential geological disasters such as landslide. This paper establishes a theoretical framework to investigate the evolution of fluid pressure in the hydrate-bearing sediments during the decomposition process. This model consists of two parts: an unsaturated thermo-poromechanical constitutive law as well as a phase equilibrium equation. Compared with the existing studies, the present work incorporates the effect of pore volume change into the pressure built-up model. In addition, the capillary effect is considered, which plays a nontrivial role in fine-grained sediments. Based on this model, the evolution of fluid pressure is investigated in undrained conditions. It is shown that four mechanisms mainly contribute to the pressure built-up: the density contrast between decomposing hydrate and producing fluid, the variation of pore volume, the compaction of hydrate due to variation of capillary pressure, and the thermal deformation of pore constituents induced by temperature change. Among these mechanisms, the density contrast dominates the pore pressure accumulation. Under the combined effect of these contributions, the evolution of fluid pressure exhibits a strong nonlinearity during the decomposition process and can reach up to dozens of mega Pascal. Nevertheless, this high-level pressure built-up results in a significant tensile strain, yielding potential fracturing of the sediment. [ABSTRACT FROM AUTHOR]

A novel educational tool helps teach intestinal absorption in physiology--We have designed an interesting educational tool to help sophomores learn intestinal absorption in physiology course. In the study group (2019), 51 sophomores from biomedical engineering were encouraged to learn the intestinal absorption knowledge through reading materials and group discussion. Then, using the form of flipped class, they stepped on the podium and simulated and explained the absorption processes with designed paper props as educational tool. In contrast, the control group (2018), 52 sophomores from the same specialty had taken the same professional courses before. The result of theoretical test showed the average score in the study group was higher than that in the control group. The questionnaire analysis showed the positive role of the education tool in their learning efficacy. To sum up, using our tool has achieved better teaching effects than the traditional lecture. [ABSTRACT FROM AUTHOR]

Strain describes the deformation of a material as a result of applied stress. It has been widely employed to probe transport properties of materials, ranging from semiconductors to correlated materials. In order to understand, and eventually control, transport behavior under strain, it is important to quantify the effects of strain on the electronic bandstructure, carrier density, and mobility. Here, we demonstrate that much information can be obtained by exploring magnetoelastoresistance (MER), which refers to magnetic field-driven changes of the elastoresistance. We use this powerful approach to study the combined effect of strain and magnetic fields on the semimetallic transition metal dichalcogenide WTe2. We discover that WTe2 shows a large and temperature-nonmonotonic elastoresistance, driven by uniaxial stress, that can be tuned by magnetic field. Using first-principle and analytical low-energy model calculations, we provide a semiquantitative understanding of our experimental observations. We show that in WTe2, the strain-induced change of the carrier density dominates the observed elastoresistance. In addition, the change of the mobilities can be directly accessed by using MER. Our analysis also reveals the importance of a heavy-hole band near the Fermi level on the elastoresistance at intermediate temperatures. Systematic understanding of strain effects in single crystals of correlated materials is important for future applications, such as strain tuning of bulk phases and fabrication of devices controlled by strain. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the effect of resveratrol on inflammatory pain. Mice were injected intraperitoneally with lipopolysaccharide (LPS) for 5 consecutive days to induce subacute systemic inflammation. Acetic acid-induced writhing tests and tail-flick tests were performed following the final LPS injection. Glial fibrillary acidic protein (GFAP; an astrocyte-specific activation marker), ionized calcium binding adapter molecule 1 (Iba-1; a microglia-specific activation marker) and sirtuin 1 (SIRT1) protein expression levels were detected using immunohistochemistry analysis or western blotting. Following administration of LPS for 5 days, the number of writhes increased and the tail-flick latency decreased. Resveratrol (10 or 20 mg/kg) partly inhibited LPS-induced hyperalgesia and prevented the increase in tumor necrosis factor-a and interleukin 6 levels induced by LPS. LPS injection reduced the SIRT1 protein expression and increased the number of GFAP-positive and Iba-1-positive cells in the spinal cord. Resveratrol increased the SIRT1 protein expression levels and decreased the number of GFAP-positive and Iba-1-positive cells in LPS-treated mice. The protective effect of resveratrol was partly blocked by a selective SIRT1 inhibitor, EX-257. Results from the present study suggest that subacute treatment with LPS induced the activation of glial cells and hyperalgesia. Resveratrol was demonstrated to inhibit the activation of glial cells and attenuate inflammatory hyperalgesia in a SIRT1-dependent manner. [ABSTRACT FROM AUTHOR]

Studies have shown that cannabinoid CB2 receptors are involved in wound repair, however, its physiological roles in fibrogenesis remain to be elucidated. In the present study, the capacity of cannabinoid CB2 receptors in the regulation of skin fibrogenesis during skin wound healing was investigated. To assess the function of cannabinoid CB2 receptors, skin excisional BALB/c mice were treated with either the cannabinoid CB2 receptor selective agonist, GP1a, or antagonist, AM630. Skin fibrosis was assessed by histological analysis and profibrotic cytokines were determined by immunohistochemistry, immunofluorescence staining, reverse transcription-quantitative polymerase chain reaction and immunoblotting in these animals. GP1a decreased collagen deposition, reduced the levels of transforming growth factor (TGF)-β1, TGF-β receptor I (TβRI) and phosphorylated small mothers against decapentaplegic homolog 3 (P-Smad3), but elevated the expression of its inhibitor, Smad7. By contrast, AM630 increased collagen deposition and the expression levels of TGF-β1, TβRI and P-Smad3. These results indicated that cannabinoid CB2 receptors modulate fibrogenesis and the TGF-β/Smad profibrotic signaling pathway during skin wound repair in the mouse. [ABSTRACT FROM AUTHOR]

Density functional theory is used to study structural energetics of Pb vacancy cluster formation on C60/Pb/Si(l11) to explain the unusually fast and error-free transformations between the "Devil's Staircase" (DS) phases on the Pb/Si(l11) wetting layer at low temperature (~110 K). The formation energies of vacancy clusters are calculated in C60/Pb/Si(l11) as Pb atoms are progressively ejected from the initial dense Pb wetting layer. Vacancy clusters larger than five Pb atoms are found to be stable with seven being the most stable, while vacancy clusters smaller than five are highly unstable, which agrees well with the observed ejection rate of ~5 Pb atoms per C60- The high energy cost (~0.8 eV) for the small vacancy clusters to form indicates convincingly that the unusually fast transformation observed experimentally between the DS phases, upon C6o adsorption at low temperature, cannot be the result of single-atom random walk diffusion but of correlated multi-atom processes. [ABSTRACT FROM AUTHOR]

To explore uncertain aspects of the processes that maintain species boundaries, we evaluated contributions of pre- and postpollination reproductive isolation mechanisms in sympatric populations of Arnebia guttata and A. szechenyi. For this, we investigated their phylogenetic relationships, traits, microenvironments, pollinator visits, action of natural selection on floral traits, and the outcome of hand pollination between the two species. Phylogenetic analysis indicates that A. szechenyi is a derived species that could be closely related to A. guttata, and both could be diploid species. Arnebia guttata flowers have larger parts than A. szechenyi flowers, but smaller nectar guides. Soil supporting A. szechenyi had higher water contents than soil supporting neighboring populations of A. guttata (in accordance with their geographical distributions). The pollinators shared by the two species preferred A. szechenyi flowers, but interspecific visitations were frequent. We found evidence of conflicting selection pressures on floral tube length, flower diameter and nectar guide size mediated via male fitness, and on flower diameter and floral tube diameter via female fitness. Handpollination experiments indicate complete pollen incompatibility between the two species. Our results suggest that postpollination prezygotic mechanisms are largely responsible for reproductive isolation of sympatric populations of the two Arnebia species. [ABSTRACT FROM AUTHOR]

"Zhu She Yong Xue Shuan Tong" lyophilized powder (ZSYXST), consists of a series of saponins extracted from Panax notoginseng, which has been widely used in China for the treatment of strokes. In this study, an ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) combined with preparative high performance liquid chromatography (PHPLC) method was developed to rapidly identify both major and minor saponins in ZSYXST. Some high content components were removed through PHPLC in order to increase the sensitivity of the trace saponins. Then, specific characteristic fragment ions in both positive and negative mode were utilized to determine the types of aglycone, saccharide, as well as the saccharide chain linkages. As a result, 94 saponins, including 20 pairs of isomers and ten new compounds, which could represent higher than 98% components in ZSYXST, were identified or tentatively identified in commercial ZSYXST samples. [ABSTRACT FROM AUTHOR]

X-linked hyper-IgM syndrome (XHIGM) is one type of primary immunodeficiency diseases, resulting from defects in the CD40 ligand/CD40 signaling pathways. We retrospectively analyzed the clinical and molecular features of 20 Chinese patients diagnosed and followed up in hospitals affiliated to Shanghai Jiao Tong University School of Medicine from 1999 to 2013. The median onset age of these patients was 8.5 months (range: 20 days-21 months). Half of them had positive family histories, with a shorter diagnosis lag. The most common symptoms were recurrent sinopulmonary infections (18 patients, 90%), neutropenia (14 patients, 70%), oral ulcer (13 patients, 65%), and protracted diarrhea (13 patients, 65%). Six patients had BCGitis. Six patients received hematopoietic stem cell transplantations and four of them had immune reconstructions and clinical remissions. Eighteen unique mutations in CD40L gene were identified in these 20 patients from 19 unrelated families, with 12 novel mutations. We compared with reported mutation results and used bioinformatics software to predict the effects of mutations on the target protein. These mutations reflected the heterogeneity of CD40L gene and expanded our understanding of XHIGM. [ABSTRACT FROM AUTHOR]

The ectoenzyme CD39 hydrolyzes extracellular adenosine 5'-triphosphate (ATP), which possesses pro-inflammatory properties. However, the role of CD39 in allergic asthma has not been fully elucidated. A total of 18 patients with persistent asthma who were allergic to house dust mites and 19 healthy volunteers were enrolled in this study. The expression of CD39, GATA3, RAR-related orphan receptor γ (ROR-γt) and forkhead box P3 (FoxP3) mRNA in peripheral blood mononuclear cells (PBMCs) was determined by SYBR-Green I quantitative polymerase chain reaction (qPCR). The cytokines interleukin (IL)-4, IL-17A, transforming growth factor β (TGF-β) and DP.sIgE were detected by enzyme-linked immunosorbent assay. Our data demonstrated that the expression of CD39 mRNA in PBMCs from asthmatic patients was significantly lower compared to that in normal controls [(1.49±0.59)x10-3 vs. (2.17±0.77)x10-3, respectively; P<0.01]. CD39 mRNA was negatively correlated with serum IL-4, IL-17A and GATA3 expression (r=-0.468, P<0.05; r=-0.550, P<0.05; and r=-0.424, P<0.01, respectively) and positively correlated with FoxP3 and TGF-β expression (r=0.373, P<0.05; and r=0.425, P<0.05, respectively). There was no obvious correlation between CD39 and ROR-γt expression (r=-0.259, P=0.122). These data suggested that CD39 mRNA expression was downregulated in allergic asthma, which was positively correlated with serum IL-4, IL-17A and GATA3 expression and negatively correlated with serum TGF-β and FoxP3 expression, whereas there was no correlation with ROR-γt. Therefore, it was hypothesized that CD39 may participate in the occurrence and progression of allergic asthma. [ABSTRACT FROM AUTHOR]

A delayed predator-prey diffusion system with homogeneous Neumann boundary condition is considered. In order to study the impact of the time delay on the stability of the model, the delay τ is taken as the bifurcation parameter, the results show that when the time delay across some critical values, the Hopf bifurcations may occur. In particular, by using the normal form theory and the center manifold reduction for partial functional differential equations, the direction of the Hopf bifurcation and the stability of the bifurcated periodic solution have been established. The effect of the diffusion on the bifurcated periodic solution is also considered. A numerical example is given to support the main result. [ABSTRACT FROM AUTHOR]

We show that the noncrystalline-to-crystalline transition of supported Pt nanoparticles (NPs) in the subnanometer to nanometer size range is statistical in nature, and strongly affected by particle size, support, and adsorbates (here we use H2). Unlike in the bulk, a noncrystalline phase exists and is stable in small NPs, reflecting a general mesoscopic feature. Observations of >3000 particles by high-resolution transmission electron microscopy show a noncrystalline-to-crystalline transition zone that is nonabrupt; there is a size regime where disordered and ordered NPs coexist. The NP size at which this transition occurs is strongly dependent on both the adsorbate and the support, and this effect is general for late 5d transition metals. All results are reconciled via a statistical description of particle-support-adsorbate interactions. [ABSTRACT FROM AUTHOR]

In the immune system, CD4+CD25+Foxp3+ regulatory T cells (Tregs) maintain self-tolerance and Th17 cells mediate inflammatory responses. CD39 is expressed on the surface of a subset of naturally occurring human Tregs that are important in constraining pathogenic Th17 cells. Additional studies have shown that Tregs differentiate into interleukin-17 (IL-17)+Foxp3+ T cells. Our previous study indicated an imbalance of Th17 and Tregs in allergic asthma; however, the underlying mechanisms remain poorly understood. Using quantitative PCR (qPCR), CD39 and CD73 mRNA levels in CD4+ T cells were investigated. Flow cytometry was used to analyze the proportion of IL-17+Foxp3+ T cells, and CD39 and CD73 expressed by CD4+ T cells and Tregs in the peripheral blood of the subjects. The results of the present study demonstrated an increased frequency of CD4+Foxp3+IL-17+ T cells in moderate to severe asthma. A deficiency in CD39 expressed on the surface of CD4+ T cells and Tregs was observed in asthma patients. The expression of CD39 and CD73 on the surface of CD4+ T cells and Tregs was negatively correlated with the number of Th17 cells. These results indicated that the plasticity of Tregs transforming to IL-17+Foxp3+CD4+ T cells, the reduced frequency of CD39+ Tregs and less effective suppression of IL-17 production by residual CD39+ Tregs leads to an imbalance of Th17 and Tregs in asthma. Therefore, enhanced CD39 activity is hypothesized to prevent the progression of asthma. [ABSTRACT FROM AUTHOR]

The enhanced stability and modified electronic structure of intermetallic compounds provide discovery of superior catalysts for chemical conversions with high activity, selectivity, and stability. We find that the intermetallic NaAu2 is an active catalyst for CO oxidation at low temperatures. From density functional theory calculations, a reaction mechanism is suggested to explain the observed low reaction barrier of CO oxidation by NaAu2, in which a CO molecule reacts directly with an adsorbed O2 to form an OOCO* intermediate. The presence of surface Na increases the binding energy of O2 and decreases the energy barrier of the transition states. [ABSTRACT FROM AUTHOR]

Formation energies of native defects in Bi2(TexSe3?x), with comparison to ideal Bi2Te2S, are calculated in density-functional theory to assess transport properties. Bi2Se3 is found to be n type for both Bi- and Se -rich growth conditions, while Bi2Te3 changes from n to p type going from Te- to Bi-rich conditions, as observed. Bi2Te2Se and Bi2Te2S are generally n type, explaining observed heavily doped n-type behavior in most samples. A (0/?) transition level at 16 meV above valence-band maximum for Bi on Te antisites in Bi2Te2Se is related to the observed thermally active transport gap causing a p-to-n transition at low temperature. Bi2(TexSe3?x) with x>2 are predicted to have high bulk resistivity due to effective carrier compensation when approaching the n-to-p crossover. Predicted behaviors are confirmed from characterization of our grown single crystals. [ABSTRACT FROM AUTHOR]

Average conditions are obtained for the permanence of a discrete bounded system with Holling type II functional response u(n+1) = u(n)exp{a(n)-b(n)u(n)-c(n)v(n)/(u(n)+m(n)v(n))}, v(n+1) = v(n)exp{-d(n) + e(n)u(n)l(u(n) + m(n)v(n))}. The method involves the application of estimates of uniform upper and lower bounds of solutions. When these results are applied to some special delay population models with multiple delays, some new results are obtained and some known results are generalized. [ABSTRACT FROM AUTHOR]

By coupling a cluster expansion with density functional theory (DFT) calculations, we determine the configurational thermodynamics (site preferences and occupations) for alloyed nanoparticles (NPs) as functions of composition (c) and temperature (T), exemplified using a 55-atom Ag-Au truncated cuboctahedron NP The c-T phase diagram for site occupations gives detailed design information for alloyed NP, especially the thermodynamically stable active sites for catalysis and how they change with stoichiometry and processing temperature. Generally, Ag prefers core and Au prefers shell, agreeing with our universal core-shell preference assessed from DFT impurity segregation energies but with interesting multishell configurations having specific active sites. [ABSTRACT FROM AUTHOR]

A large number of non-synonymous single-nucleotide polymorphisms (nsSNPs) have been found in human genome, but there is poor knowledge on the relationship between the genotype and phenotype of these nsSNPs. Human ATP-binding cassette (ABC) transporters are able to transport a number of important substrates including endogenous and exogenous compounds. This study aimed to predict the phenotypical impact of nsSNPs of human ABC transporter genes, and the predicted results were further validated by reported phenotypical data from site-directed mutagenesis and clinical genetic studies. One thousand and six hundred thirty-two nsSNPs were found from 49 human ABC transporter genes. Using the PolyPhen and SIFT algorithms, 41.8-53.6% of nsSNPs in ABC transporter genes were predicted to have an impact on protein function. The prediction accuracy was up to 63-85% when compared with known phenotypical data from in vivo and in vitro studies. There was a significant concordance between the prediction results using SIFT and PolyPhen. Of nsSNPs predicted as deleterious, the prediction scores by SIFT and PolyPhen were significantly related to the number of nsSNPs with known phenotypes confirmed by experimental and human studies. The amino acid substitution variants are supposed to be the pathogenetic basis of increased susceptibility to certain diseases with Mendelian or complex inheritance, altered drug resistance and altered drug clearance and response. Predicting the phenotypic consequence of nsSNPs using computational algorithms may provide a better understanding of genetic differences in susceptibility to diseases and drug response. The prediction of nsSNPs in human ABC transporter genes would be useful hints for further genotype-phenotype studies. [ABSTRACT FROM AUTHOR]

Transition-metal alloyed nanoparticles with core--shell features (shell enrichment by one of the metals) are becoming ubiquitous, from (electro-)catalysis to biomedical applications, due to their size control, performance, biocompatibility, and cost. We investigate 132 binary-alloyed nanoparticle systems (groups 8 to 11 in the Periodic Table) using density functional theory (DFT) and systematically explore their segregation energies to determine core--shell preferences. We find that core--shell preferences are generally described by two independent factors: (1) cohesive energy (related to vapor pressure) and (2) atomic size (quantified by the Wigner--Seitz radius), and the interplay between them. These independent factors are shown to provide general trends for the surface segregation preference for atoms in nanoparticles, as well as semi-infinite surfaces, and give a simple correlation (a "design map") for the alloying and catalytic behavior. Finally, we provide a universal description of core-shell preference via tight-binding theory (band-energy differences) that (i) quantitatively reproduces the DFT segregation energies and (ii) confirms the electronic origins and correlations for core--shell behavior. [ABSTRACT FROM AUTHOR]

Verifiable criteria are established for the permanence and existence of positive periodic solutions of a delayed discrete predator-prey model with monotonic functional response. It is shown that the conditions that ensure the permanence of this system are similar to those of its corresponding continuous system. And the investigations generalize some well-known results. In particular, a more acceptant method is given to study the bounded discrete systems rather than the comparison theorem. [ABSTRACT FROM AUTHOR]

The permanence of a single-species population discrete model with feedback control is considered.We found that if we use the method of comparison theorem, then the additional condition, to someextent, is necessary. But for the system itself, this condition may not be necessary. Here, we use new methods instead of the comparison theorem to get the permanence of the system in consideration; the additional condition in Chen’s paper (2007) is deleted.

Using density functional theory calculations, we have studied the morphology of a Pt37 nanoparticle supported on carbon with and without hydrogen (H) passivation that arises with postprocessing of nanoparticles before characterization. Upon heating in an anneal cycle, we find that without H (e.g., in a helium atmosphere or evacuation at high temperature), the morphology change of a truncated cuboctahedral Pt37 is driven by the shearing of (100) to (111 ) facets to lower the surface energy, a remnant shear instability that drives surface reconstruction in semi-infinite Pt(100). With H passivation from a postprocessing anneal, we show that the sheared structure automatically reverts to the observed truncated cuboctahedral structure and the average first nearest-neighbor PtPt bond length increases by 3%, agreeing well with experiment. We explain the stabilization of the truncated cuboctahedral structure due to H passivation via adsorption energetics of hydrogen on Pt(100) and (111) facets, specifically, the preference for H adsorption at bridge sites on (100) facets, which should be considered in a realistic model for H adsorption on Pt nanoparticles. We find that dramatic morphological change of a nanoparticle can occur even with small changes to first-shell Pt-Pt coordination number. The implications of our findings when comparing to experimental data are discussed. [ABSTRACT FROM AUTHOR]

We describe a theoretical analysis of the structures of self-organizing nanoparticles formed by Pt and Ru–Pt on carbon support. The calculations provide insights into the nature of these metal particle systems—ones of current interest for use as the electrocatalytic materials of direct oxidation fuel cells—and clarify complex behaviors noted in earlier experimental studies. With clusters deposited via metalloorganic Pt or PtRu5 complexes, previous experiments [Nashner et al. J. Am. Chem. Soc. 1997, 119, 7760; Nashner et at J Am. Chem. Soc. 1998, 120, 8093; Frenkel et at J. Phys. Chem. B 2001, 105, 126891 showed that the Pt and Pt–Ru based clusters are formed with fcc(111)-stacked cuboctahedral geometry and essentially bulklike metal—metal bond lengths, even for the smallest (few atom) nanoparticles for which the average coordination number is much smaller than that in the bulk, and that Pt in bimetallic [PtRu5] clusters segregates to the ambient surface of the supported nanoparticles. We explain these observations and characterize the cluster structures and bond length distributions using density functional theory calculations with graphite as a model for the support. The present study reveals the origin of the observed metal-metal bond length disorder, distinctively different for each system, and demonstrates the profound consequences that result from the cluster/carbon-support interactions and their key role in the structure and electronic properties of supported metallic nanoparticles. [ABSTRACT FROM AUTHOR]

1 We evaluated in Sprague-Dawley rats anaesthetized with propofol the engagement of soluble guanylyl cyclase (sGC)/cGMP cascade, glutamatergic and GABAergic neurotransmission in the cardiovascular actions of endogenous nitric oxide (NO) at the rostral ventrolateral medulla (RVLM). 2 Microinjection bilaterally into the RVLM of a selective iNOS inhibitor, S-methylisothiourea (SMT, 250 pmoles), or a selective nNOS inhibitor, 7-nitroindazole (7-NI, 5 pmoles), induced respectively an enhancement or a reduction in systemic arterial pressure, heart rate and power density of the vasomotor components in the spectrum of arterial blood pressure signals, our experimental index for sympathetic neurogenic vasomotor tone. 3 The cardiovascular actions of SMT or 7-NI in the RVLM were significantly antagonized by coadministration into the RVLM of the sGC inhibitor, 1H-[1,2,4]Oxadiazole[4,3-α]quinoxalin-l-one (ODQ, 250 or 500 pmoles). 4 The cardiovascular excitatory effects after blockade of endogenous iNOS activity were significantly attenuated when N-methyl-D-aspartate (NMDA) receptor antagonist, dizocilpine (20 or 50 pmoles), or non-NMDA receptor antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione (250 or 500 pmoles), was co-microinjected bilaterally into the RVLM. 5 On the other hand, the cardiovascular depressive responses to blockade of endogenous nNOS activity were significantly antagonized on co-administration of GABA[sub A] receptor antagonist, bicuculline methiodine (5 or 10 pmoles), but not GABA[sub B] receptor antagonist, 2-hydroxy saclofen (50 or 100 pmoles). 6 We conclude that the cardiovascular actions of endogenous NO in the RVLM engage the sGC/ cGMP pathway. In addition, whereas NO derived from nNOS induced sympathoexcitation via both NMDA and non-NMDA receptors in the RVLM, NO generated by iNOS elicited sympathoinhibition via GABA[sub A] receptors. [ABSTRACT FROM AUTHOR]

This paper describes a technical improvement of a synthesis algorithm for relational database scheme design, which was proposed by Yang et al. in 1988 [6]. The improvement is based on the observation that the original algorithm may lose attributes in a decomposition in special cases, due to an insufficient handling of representatives of equivalence classes formed over a given set of functional dependencies. The paper then proposes a correction of the original algorithm in which this problem disappears. [ABSTRACT FROM AUTHOR]

Given the importance of crystal symmetry for the emergence of topological quantum states, we have studied, as exemplified in NbNiTe2, the interplay of crystal symmetry, atomic displacements (lattice vibration), band degeneracy, and band topology. For the NbNiTe2 structure in space-group 53 (Pmna)--having an inversion center arising from two glide planes and one mirror plane with a twofold rotation and screw axis--a full gap opening exists between two band manifolds near the Fermi energy. Upon atomic displacements by optical phonons, the symmetry lowers to space-group 28(Pma2), eliminating one glide plane along c, the associated rotation and screw axis, and the inversion center. As a result, 20 Weyl points emerge, including four type-II Weyl points in the G-X direction at the boundary between a pair of adjacent electron and hole bands. Thus, optical phonons may offer control of the transition to a Weyl fermion state. [ABSTRACT FROM AUTHOR]

A physiology laboratory course plays an important role in improving the scientific abilities of medical students. This study involved a teaching reform based on problem-based self-designed experiments in a physiology laboratory course. The study subjects were divided into two groups, i.e., students enrolled in 2019 were assigned to the traditional course control group (n = 146) and students enrolled in 2021 were assigned to the improved course test group (n = 128). Students in the test group were required to conduct self-designed experiments based on the questions for each experimental theme, in addition to completing the specified experimental items. At the end of the course, the differences in academic achievements between the two groups were compared. The results showed that compared to the control group, the students in the test group spent less time finishing the specified experimental items (P < 0.05). More students in the test group obtained good results in the operation assessment for the specified experiments (P < 0.05), and a significant increase in the number of winners in discipline-wise competitions, participants in scientific research projects, and academic publications was observed in the test group. Most of the students in the test group agreed that the self-designed experiment promoted their scientific thinking, helped them better understand theoretical knowledge, and improved their hands-on operation and team cooperation abilities. Our research showed that our teaching reform promoted students' self-directed learning and problem-solving abilities, stimulated their enthusiasm for scientific research, and was conducive to the cultivation of innovative medical talents. [ABSTRACT FROM AUTHOR]

Background: Jiangtang decoction (JTD) is a China patented drug which contains Euphorbia humifusa Willd, Salvia miltiorrhiza Bunge, Astragalus mongholicus Bunge, Anemarrhena asphodeloides Bunge, and Coptis chinensis Franch. For decades, it has also been used clinically to treat diabetic nephropathy (DN) effectively; however, the associated mechanisms remain unknown. Thus, the present study aimed to examine the protective efficacy of JTD in DN and elucidate the underlying molecular mechanisms. Methods: A diabetic model using KK-Ay mice received a daily administration of JTD for 12 weeks. Body weight, blood glucose, triglycerides (TGs), total cholesterol (TC), urea nitrogen (UN), creatinine (Cr), and microalbumin/urine creatinine (MA/UCREA) was measured every 4 weeks. Furthermore, on the day of the sacrifice, blood, urine, and kidneys were collected to assess renal function according to general parameters. Pathological staining was performed to evaluate the protective renal effect of JTD. In addition, the levels of inflammatory cytokines (tumor necrosis factor-α [TNF-α], interleukin [IL]-6 and intercellular adhesion molecule [ICAM]-1), insulin receptor substrate [IRS]-1, advanced glycation end products [AGEs], and receptor of glycation end products [RAGE] were assessed. Finally, the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway and involvement of nuclear factor-κB (NF-κB) was further analyzed. Results: After 12 weeks of metformin and JTD administration, the mice exhibited a significant amelioration in glucose and lipid metabolism dysfunction, reduced morphological changes in the renal tissue, decreased urinary albumin excretion, and normalized creatinine clearance. JTD treatment also reduced the accumulation of AGEs and RAGE, up-regulated IRS-1, and increased the phosphorylation of both PI3K (p85) and Akt, indicating that the activation of the PI3K/Akt signaling pathway was involved. Additionally, JTD administration reduced the elevated levels of renal inflammatory mediators and decreased the phosphorylation of NF-κB p65. Conclusions: These results demonstrate that JTD might reduce inflammation in DN through the PI3K/Akt and NF-κB signaling pathways. [ABSTRACT FROM AUTHOR]

Amyloid-&3946; peptides (Aβ) exist in several forms and are known as key modulators of Alzheimer's disease (AD). Fibrillary Aβ (fAβ) has been found to disrupt the blood-brain barrier (BBB) by triggering and promoting inflammation. In this study, luteolin, a naturally occurring flavonoid that has shown beneficial properties in the central nervous system, was evaluated as a potential agent to preserve barrier function and inhibit inflammatory responses at the BBB that was injured by fAβ1-40. We established an in vitro BBB model by co-culturing human brain microvascular endothelial cells (hBMECs) and human astrocytes (hAs) under fAβ1-40-damaged conditions and investigated the effect of luteolin by analyzing cellular toxicity, barrier function, cytokine production and inflammation-related intracellular signaling pathways. Our results demonstrated that, in cells injured by fAβ1-40, luteolin increased cell viability of hBMECs and hAs. The cytoprotection of the co-culture against the damage induced by fAβ1-40 was also increased at both the apical and basolateral sides. Luteolin protected the barrier function by preserving transendothelial electrical resistance and relieving aggravated permeability in the human BBB model after being exposed to fAβ1-40. Moreover, in both the apical and basolateral sides of the co-culture, luteolin reduced fAβ1-40-induced inflammatory mediator and cytokine production, including cyclooxygenase-2 (COX-2), tumor necrosis factor (TNF-α ), interleukin 1 β (IL-1β), interleukin 6 (IL-6), and interleukin 8 (IL-8), however it did not show sufficient effects on scavenging intracellular reactive oxygen species (ROS) in hBMECs and hAs. The mechanism of BBB protection against fAβ1-40-induced injury may be related to the regulation of inflammatory signal transduction, which involves inhibition of p38 mitogen-activated protein kinase (MAPK) activation, downregulation of phosphorylated inhibitory кB kinase (phosphor-IKK) levels, relief of inhibitory кB (IкB ) degradation, blockage of nuclear factor кB (NF-кB) p65 nuclear translocation, and reduction of the release of inflammatory cytokines. Moreover, the employment of p38 MAPK and NF-кB inhibitors reversed luteolin-mediated barrier function and cytokine release. Taken together, luteolin may serve as a potential therapeutic agent for BBB protection by inhibiting inflammation following fAβ1-40-induced injury. [ABSTRACT FROM AUTHOR]

In this paper, the influence of the second-order slowly varying loads on the estimation of deckwetness is studied. A series of experiments related to classic cylindrical and new sandglass-type Floating Production, Storage, and Offloading Unit (FPSO) models are conducted. Due to the distinctive configuration design, the sandglasstype FPSO model exhibits more excellent deckwetness performance than the cylindrical one in irregular waves. Based on wave potential theory, the first-order wave loads and the full quadratic transfer functions of second-order slowly varying loads are obtained by the frequency-domain numerical boundary element method. On this basis, the traditional spectral analysis only accounting for the first-order wave loads and time-domain numerical simulation considering both the first-order wave loads and nonlinear second-order slowly varying wave loads are employed to predict the numbers of occurrence of deckwetness per hour of the two floating models, respectively. By comparing the results of the two methods with experimental data, the shortcomings of traditional method based on linear response theory emerge and it is of great significance to consider the second-order slowly drift motion response in the analysis of deckwetness of the new sandglass-type FPSO. [ABSTRACT FROM AUTHOR]

We use angle-resolved photoemission spectroscopy to study a nontrivial surface state in a pseudobinary Bi2Te2.8Se0.2 topological insulator. We show that, unlike previously studied binaries, this is an intrinsic topological insulator with the conduction bulk band residing well above the chemical potential. Our data indicate that under a good vacuum condition there are no significant aging effects for more than two weeks after cleaving. We also demonstrate that the shift of the Kramers point at low temperature is caused by UV-assisted absorption of molecular hydrogen. Our findings pave the way for applications of these materials in devices and present an easy scheme to tune their properties. [ABSTRACT FROM AUTHOR]

MicroRNAs have been implicated in the regulation of several cellular signaling pathways of colorectal cancer (CRC) cells. Although emerging evidence proves that microRNA (miR)-106a is expressed highly in primary tumor and stool samples of CRC patients; whether or not miR-106a mediates cancer metastasis is unknown. We show here that miR-106a is highly expressed in metastatic CRC cells, and regulates cancer cell migration and invasion positively in vitro and in vivo. These phenotypes do not involve confounding influences on cancer cell proliferation. MiR-106a inhibits the expression of transforming growth factor-b receptor 2 (TGFBR2), leading to increased CRC cell migration and invasion. Importantly, miR-106a expression levels in primary CRCs are correlated with clinical cancer progression. These observations indicate that miR-106a inhibits the anti-metastatic target directly and results in CRC cell migration and invasion. [ABSTRACT FROM AUTHOR]

The exact mechanism associated with inflammation and atrial fibrillation (AF) remains unknown. The aim of the present study was to investigate the roles of connexin 43 (Cx43) and a1‑adrenergic receptor (α1‑AR) activation in the pathogenesis of system inflammation‑induced AF. A canine model of chronic low‑grade system inflammation was established by administrating a low dose of lipopolysaccharide (LPS; 0.1 μg/kg) for 2 weeks. Programmed stimulation was applied on the right atrial appendage to determine the effective refractory periods (ERP) and the window of vulnerability (WOV). Tumor necrosis factor α (TNF‑α) and interleukin 6 (IL‑6) levels in plasma and atrial tissue were measured by ELISA. Cx43, Toll‑like receptor 4 (TLR4) and nuclear factor κB (NF‑κB) proteins were analyzed using western blotting or immunohistochemistry. Administration of LPS for 2 weeks increased the concentration of TNF‑α and IL‑6 in the plasma and right atrium. ERP was markedly shortened and cumulative WOV was significantly widened in the LPS group. Following treatment with LPS, the amount of Cx43 protein in the area of intercalated disk increased. In addition, a high‑density of Cx43 in the lateral connection was identified. LPS also induced the activation of NF‑κB in the canine atrium. Administration with the α1‑AR blocker doxazosin prevented the production of LPS‑induced inflammatory cytokine and reversed the enhanced vulnerability to atrial fibrillation. Doxazosin inhibited the LPS‑induced increase in Cx43 protein and heterogeneous distribution, and prevented the activation of NF‑κB. These results indicated that chronic low‑grade system inflammation may increase the inducibility of AF in a canine model. The underlying mechanism may be involved in the LPS‑induced activation of NF‑κB, and the increase in Cx43 expression and lateral distribution via an α1‑AR‑dependent pathway. [ABSTRACT FROM AUTHOR]

The characterization of nanometer-scale interactions between carbon-containing substrates and alumina surfaces is of paramount importance to industrial and academic catalysis applications, but it is also very challenging. Here, we demonstrate that dynamic nuclear polarization surface-enhanced NMR spectroscopy (DNP SENS) allows the unambiguous description of the coordination geometries and conformations of the substrates at the alumina surface through high-resolution measurements of 13C-27Al distances. We apply this new technique to elucidate the molecular-level geometry of 13C-enriched methionine and natural abundance poly(vinyl alcohol) adsorbed on γ -Al2O3-supported Pd catalysts, and we support these results with element-specific X-ray absorption near-edge measurements. This work clearly demonstrates a surprising bimodal coordination of methionine at the Pd-Al2O3 interface. [ABSTRACT FROM AUTHOR]

The recently discovered material PtSn4 is known to exhibit extremely large magnetoresistance (XMR) that also manifests Dirac arc nodes on the surface. PdSn4 is isostructural to PtSn4 with the same electron count. We report on the physical properties of high-quality single crystals of PdSn4 including specific heat, temperature- and magnetic-field-dependent resistivity and magnetization, and electronic band-structure properties obtained from angle-resolved photoemission spectroscopy (ARPES). We observe that PdSn4 has physical properties that are qualitatively similar to those of PtSn4, but find also pronounced differences. Importantly, the Dirac arc node surface state of PtSn4 is gapped out for PdSn4. By comparing these similar compounds, we address the origin of the extremely large magnetoresistance in PdSn4 and PtSn4; based on detailed analysis of the magnetoresistivity ρ(H, T), we conclude that neither the carrier compensation nor the Dirac arc node surface state are the primary reason for the extremely large magnetoresistance. On the other hand, we find that, surprisingly, Kohler's rule scaling of the magnetoresistance, which describes a self-similarity of the field-induced orbital electronic motion across different length scales and is derived for a simple electronic response of metals to an applied magnetic field is obeyed over the full range of temperatures and field strengths that we explore. [ABSTRACT FROM AUTHOR]

Myocardial dysfunction in sepsis is associated with an increased risk of mortality. The mitochondrial aldehyde dehydrogenase (ALDH2) enzyme is crucial for protecting the heart from ischemic injury. The aim of the present study was to determine the role of ALDH2 in cardiac dysfunction induced by lipopolysaccharide (LPS). Male rats were treated intraperitoneally with LPS, and their stroke volume and cardiac output were evaluated using an M-mode echocardiograph. The expression levels and activity of ALDH2, nitric oxide content and inducible nitric oxide synthase (iNOS) activity, and the opening of the mitochondrial permeability transition pore (MPTP) were also evaluated. Treatment with LPS (5, 10, or 20 mg/kg) resulted in a steady decrease in cardiac output and stroke volume. The ALDH2 activity was decreased in a dose-dependent manner; however, the ALDH2 protein expression levels remained unchanged. Alda-1, a specific activator of ALDH2, increased the activity of ALDH2 and lessened LPS-induced cardiac dysfunction. A marked opening of the MPTP was observed 12 h following treatment with LPS, which was prevented by Alda-1. The improvement in cardiac function in response to treatment with Alda-1, was partially prevented by treatment with the MPTP inhibitor atractyloside. LPS treatment induced an increase in iNOS activation and inhibition of ALDH2 activity. The iNOS selective inhibitor, aminoguanidine, partially reversed the LPS-induced ALDH2 activity decrease and MPTP opening. These results indicate that ALDH2 activity may have a role in protecting against LPS-induced cardiac dysfunction. The potential mechanism may involve inhibition of MPTP opening and iNOS expression. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants, and have been reported to be a risk factor for human neural tube defects (NTDs). We investigated the relationship between PAH concentrations in maternal serum and NTD risk in offspring using a case-control study design, and explored the link between PAH concentrations to household energy usage characteristics and life styles. One hundred and seventeen women who had NTD-affected pregnancies (cases) and 121 women who delivered healthy infants (controls) were recruited in Northern China. Maternal blood samples were collected at pregnancy termination or at delivery. Twenty-seven PAHs were measured by gas chromatography-mass spectrometry. The concentrations of 13 individual PAHs detected were significantly higher in the cases than in the controls. Clear dose-response relationships between concentrations of most individual PAHs and the risk of total NTDs or subtypes were observed, even when potential covariates were adjusted for. High-molecular-weight PAHs (H-PAHs) showed higher risk than low-molecular-weight PAHs (L-PAHs). No associations between PAH concentrations and indoor life styles and energy usage characteristics were observed. It was concluded that maternal exposure to PAHs was associated with an increased risk of NTDs, and H-PAHs overall posed a higher risk for NTDs than L-PAHs. [ABSTRACT FROM AUTHOR]

We use our high resolution He-lamp-based, tunable laser-based angle-resolved photoemission spectroscopy measurements and density functional theory calculations to study the electronic properties of LaBi, a binary system that was proposed to be a member of a new family of topological semimetals. Both bulk and surface bands are present in the spectra. The dispersion of the surface state is highly unusual. It resembles a Dirac cone, but upon closer inspection we can clearly detect an energy gap. The bottom band follows roughly a parabolic dispersion. The dispersion of the top band remains very linear, "V" -shape like, with the tip approaching very closely to the extrapolated location of Dirac point. Such asymmetric mass acquisition is highly unusual and opens a possibility of a new topological phenomenon that has yet to be understood. [ABSTRACT FROM AUTHOR]

Aims. To determine whether multiple daily injections (MDIs) or continuous subcutaneous insulin infusion (CSII) contributes to better glucose control in children with different type 1 diabetes duration. Methods. Subjects were grouped according to early (≤1 year after disease onset; 1A) or late (1-3 years after onset; 2A) MDIs/CSII treatment initiation. Corresponding control groups (1B, 2B) received insulin injections twice daily. Results. HbA1c levels were consistently lower in group 1A than in group 1B (6 months (T2): 7.37% versus 8.21%; 12 months (T3): 7.61% versus 8.41%; 24/36 months (T4/T5): 7.61% versus 8.72%; all P < 0.05), but were lower in group 2A than in group 2B only at T2 (8.36% versus 9.19%; P = 0.04). Levels were lower in group 1A than in group 2A when disease duration was matched (7.61% versus 8.49%; P < 0.05). Logistic regression revealed no correlation between HbA1c level and MDIs/CSII therapy. HbA1c levels were only negatively related to insulin dosage. Conclusions. Blood glucose control was better in patients receiving MDIs/CSII than in those receiving conventional treatment. Early MDIs/CSII initiation resulted in prolonged maintenance of low HbA1c levels compared with late initiation. MDIs/CSII therapy should be combined with comprehensive management. [ABSTRACT FROM AUTHOR]

The presence of uniformly small collagen fibrils in tendon repair is believed to play a major role in suboptimal tendon healing. Collagen V is significantly elevated in healing tendons and plays an important role in fibrillogenesis. The objective of this study was to investigate the effect of a particular chain of collagen V on the fibrillogenesis of Sprague-Dawley rat tenocytes, as well as the efficacy of Col V siRNA engineered tenocytes for tendon tissue engineering. RNA interference gene therapy and a scaffold free tissue engineered tendon model were employed. The results showed that scaffold free tissue engineered tendon had tissue-specific tendon structure. Down regulation of collagen V &agr;1 or &agr;2 chains by siRNAs (Col5&agr;1 siRNA, Col5&agr;2 siRNA) had different effects on collagen I and decorin gene expressions. Col5&agr;1 siRNA treated tenocytes had smaller collagen fibrils with abnormal morphology; while those Col5&agr;2 siRNA treated tenocytes had the same morphology as normal tenocytes. Furthermore, it was found that tendons formed by coculture of Col5&agr;1 siRNA treated tenocytes with normal tenocytes at a proper ratio had larger collagen fibrils and relative normal contour. Conclusively, it was demonstrated that Col V siRNA engineered tenocytes improved tendon tissue regeneration. And an optimal level of collagen V is vital in regulating collagen fibrillogenesis. This may provide a basis for future development of novel cellular- and molecular biologybased therapeutics for tendon diseases. [ABSTRACT FROM AUTHOR]

Objective: To investigate whether pretreatment with single low loading dose of Tongxinluo (TXL), a traditional Chinese medicine, 1 hour before myocardial ischemia can attenuate the no-reflow and ischemia-reperfusion injury by regulating endothelial nitric oxide synthase (eNOS) via the protein kinase A (PKA) pathway. Methods and Results: In a 90-minute ischemia and 3-hour reperfusion model, Minipigs were randomly assigned to sham, control, TXL (0.05g/kg, gavaged 1 hour prior to ischemia), TXL+H-89 (a PKA inhibitor, intravenously infused at a dose of 1.0 μg·kg-1·min-1 per minute 30 minutes before ischemia), and TXL+Nω-nitro-L-arginine (L-NNA, an eNOS inhibitor, intravenously administered at a dose of 10 mg/kg 30 minutes prior to ischemia) groups. TXL decreased creatine kinase (CK) activity (P<0.05), reduced the no-reflow area from 48.6% to 9.5% and infarct size from 78.5% to 59.2% (P<0.05), whereas these effects of TXL were partially abolished by H-89 and completely reversed by L-NNA. TXL elevated the PKA activity and the expression of PKA, Thr 198 phosphorated-PKA, Ser 1179 phosphorated-eNOS (p-eNOS), and Ser 635 p-eNOS in the ischemic myocardium. H-89 repressed the TXL-induced enhancement of PKA activity and the phosphorylation of Ser 635 p-eNOS, and L-NNA counteracted the phosphorylation of eNOS at Ser 1179 and Ser 635 without apparent influence on the PKA activity. Conclusion: Pretreatment with single low loading dose of TXL 1 hour before ischemia reduces the myocardial no-reflow and ischemia-reperfusion injury by up-regulating the phosphorylation of eNOS at Ser 1179 and Ser 635, and this effect is partially mediated by the PKA pathway. [ABSTRACT FROM AUTHOR]

Background: Autophagy is an evolutionarily conserved protein degradation pathway. A defect in autophagy may contribute to tumorigenesis. Autophagy inducers could have a potential function in tumor prevention and treatment. Methodology/Principal Findings: Our results showed that Rhabdastrellic acid-A, an isomalabaricane triterpenoid isolated from the sponge Rhabdastrella globostellata, inhibited proliferation of human cancer cell lines Hep3B and A549 and induced caspase-independent cell death in both the cell lines. Further investigation showed that Rhabdastrellic acid-A induced autophagy of cancer cells determined by YFP-LC3 punctation and increased LC3-II. The pretreatment with autophagy inhibitor 3-MA inhibited Rhabdastrellic acid-A-induced cell death. Knockdown of autophagy-related gene Atg5 inhibited Rhabdastrellic acid-A-induced cell death in A549 cells. Also, phospho-Akt and its downstream targets significantly decreased after treatment with Rhabdastrellic acid-A in both cancer cell lines. Transfection of constitutive active Akt plasmid abrogated autophagy and cell death induced by Rhabdastrellic acid-A. Conclusions/Significance: These results suggest that Rhabdastrellic acid-A could induce autophagy-associated cell death through blocking Akt pathway in cancer cells. It also provides the evidence that Rhabdastrellic acid-A deserves further investigation as a potential anticancer or cancer preventive agent. [ABSTRACT FROM AUTHOR]

Background: Root avulsion of the brachial plexus causes an oxidative stress reaction in the spinal cord and induces dramatic spinal motoneuron death, while EGb761 is a natural free radical cleaning agent. This study was designed to investigate the protective effects of intraperitoneally injected EGb761 against neural damage following brachial root avulsion. Methods: The effect of EGb761 on avulsion-induced motoneuron injury was studied in 26 total groups of (n) rats, treated as follows. Animals in singular number groups received EGb761(50 mg/kg.d) and those in complex number groups received normal saline solution (i.p.), serving as controls. Groups 1-8 were used for the determination of nitric oxide (NO) levels in the serum and injured spinal cord at the 5 d, 2 w, 4 w, and 6 w time points. Groups 9-16 were used for determination of constitutive nitric oxide synthase (cNOS) and inducible nitric oxide synthase (iNOS) levels in injured spinal cord at the 5 d, 2 w, 4 w, and 6 w time points. Groups 17-26 were used for determination of the number of neuronal nitric oxide synthase (nNOS)-positive and surviving motoneurons in injured C7 ventral horn at the 5 d, 2 w, 4 w, 6 w and 8 w time points. Results: Compared to control groups, the EGb761 treatment group not only had significant decreased levels of NO in serum at 2 w and 6 w after avulsion, but also had reduced levels of NO specifically in the spinal cord at 2 w, 4 w and 6 w. The cNOS activity in the spinal cord was also significant decreased at 2 w and 4 w, while the iNOS activity in injured C6- T1 spinal segments was reduced at 2 w, 4 w and 6 w. All together, the percentages of NADPH-d positive motoneurons in an injured C7 segment were down-regulated and the number of surviving motoneurons in injured C7 ventral horn was increased at 2 w, 4 w, 6 w and 8 w in treated versus untreated animals. Conclusions: Intraperitoneal administration of EGb761 after root avulsion of the brachial plexus exerted protective effects by decreasing the level of NO in spinal cord and serum and the activity of cNOS and iNOS, easing the delayed motoneurons death. EGb761 should be considered in the treatment of brachial plexus nerve injuries. [ABSTRACT FROM AUTHOR]

Introduction: Spinal subdural hematoma is rare and can cause serious neurological symptoms. Sometimes, idiopathic spinal subdural hematoma can spontaneously occur without any identifiable underlying etiologies. In this report, we present such an uncommon case of paraplegia caused by idiopathic spinal subdural hematoma that was successfully managed by laminectomy. Case presentation: A 45-year-old Chinese woman presented with sudden onset of progressive asthenia and numbness in both lower extremities, accompanied by difficulty in micturition. An initial non-contrast spinal magnetic resonance imaging at a local hospital suggested a spinal subdural tumoral hematoma at the T9 level. She was referred to our hospital and an emergency laminectomy from T8 to T10 was performed 22 hours after onset of her initial symptoms. However, nothing but a hematoma was identified during the operation, and a final diagnosis of spontaneous acute spinal subdural hematoma was concluded. She had partial return of sensations and voluntary movement after the operation. Conclusions: On imaging findings, spinal subdural hematoma could manifest as focal and independent from the dura matter, and, therefore, it should be included in the differential diagnosis of medullary compressive lesions. [ABSTRACT FROM AUTHOR]

We use high resolution angle resolved photoemission spectroscopy and density functional theory with measured crystal structure parameters to study the electronic properties of CaKFe4As4. In contrast to the related CaKFe2As2 compounds, CaKFe4As4 has a high Tc of 35 K at stochiometric composition. This presents a unique opportunity to study the properties of high temperature superconductivity in the iron arsenides in the absence of doping or substitution. The Fermi surface consists of several hole and electron pockets that have a range of diameters. We find that the values of the superconducting gap are nearly isotropic (within the explored portions of the Brillouin zone), but are significantly different for each of the Fermi surface (FS) sheets. Most importantly, we find that the momentum dependence of the gap magnitude plotted across the entire Brillouin zone displays a strong deviation from the simple cos(kx) cos(ky) functional form of the gap function, proposed by the scenario of Cooper pairing driven by a short range antiferromagnetic exchange interaction. Instead, the maximum value of the gap is observed on FS sheets that are closest to the ideal nesting condition, in contrast to previous observations in other ferropnictides. These results provide strong support for the multiband character of superconductivity in CaKFe4As4, in which Cooper pairing forms on the electron and the hole bands interacting via a dominant interband repulsive interaction, enhanced by band nesting. [ABSTRACT FROM AUTHOR]