Search

Introduction: The relationship between oscillatory activity in hippocampus and cognitive impairment in traumatic brain injury (TBI) remains unclear. Although TBI decreases gamma oscillations and 40 Hz light flicker improves TBI prognosis, the effects and mechanism of rhythmic flicker on TBI remain unclear. Aims: In this study, we aimed to explore whether light flicker could reverse cognitive deficits, and further explore its potential mechanisms in TBI mouse model. Methods: The Morris water maze test (MWM), step-down test (SDT), and novel object recognition test (NOR) were applied to evaluate the cognitive ability. The local field potential (LFP) recording was applied to measure low gamma reduction of CA1 in hippocampus after TBI. And electrophysiological experiments were applied to explore effects of the gamma frequency entrainment on long-term potentiation (LTP), postsynaptic transmission, and intrinsic excitability of CA1 pyramidal cells (PCs) in TBI mice. Immunofluorescence staining and western blotting were applied to explore the effects of 40 Hz light flicker on the expression of PSD95 in hippocampus of TBI mice. Results: We found that 40 Hz light flicker restored low gamma reduction of CA1 in hippocampus after TBI. And 40 Hz, but not random or 80 Hz light flicker, reversed cognitive impairment after TBI in behavioral tests. Moreover, 40 Hz light flicker improved N-methyl-D-aspartate (NMDA) receptor-dependent LTP (LTPNMDAR) and Ltype voltage-gated calcium channel-dependent LTP (LTPL-VGCC) after TBI treatment. And gamma frequency entrainment decreased excitatory postsynaptic currents (EPSCs) of CA1 PCs in TBI mice. Our results have illustrated that 40 Hz light flicker could decrease intrinsic excitability of PCs after TBI treatment in mice. Furthermore, 40 Hz light flicker decreased the expression of PSD95 in hippocampus of TBI mice. Conclusion: These results demonstrated that 40 Hz light flicker rescues cognitive impairment by decreasing postsynaptic transmission in PCs after TBI treatment in mice. [ABSTRACT FROM AUTHOR]

This work reports the second-harmonic generation (SHG) in a z-cut thin-film lithium niobate (LN) under nearly normal-incident linearly-polarized pumping. To utilize the largest nonlinear term which is along the out-of-plane direction in the z-cut LN film, the film is patterned with a 2D periodic array to support symmetry-protected bound states in the continuum (BICs) bearing strong out-of-plane electric field component. Enabled by such optical resonances near the BIC condition at the pumping wavelength, significant enhancement in SHG compared to an unpatterned film is observed. This approach, combining transparent thin-film nonlinear materials with tailored BICs, offers prospects for engineering compact coherent light sources in a broad wavelength range. [ABSTRACT FROM AUTHOR]

Carbon nano-onions (CNOs) are fullerene-like structures which consist of quasi-spherical closed carbon shells. These structures have become a subject of great interest thanks to their characteristic absorption feature of interstellar origin (at 217.5 nm, 4.6 μm-1). An additional extinction peak at 3.8 μm-1 has also been reported and attributed to absorption by graphitic residues between the asgrown CNOs. Here, we report the ultraviolet absorption properties of ultra-thick CNOs filled with FePt3 crystals, which also exhibit two main absorption peaks--features located at 4.58 μm-1 and 3.44 μm-1. The presence of this additional feature is surprising and is attributed to nonmagnetic graphite flakes produced as a by-product in the pyrolysis experiment (as confirmed by magnetic separation methods). Instead, the feature at 4.58 μm-1 is associated with the p-plasmonic resonance of the CNOs structures. The FePt3 filled CNOs were fabricated in situ by an advanced one-step fast process consisting in the direct sublimation and pyrolysis of two molecular precursors, namely, ferrocene and dichloro-cyclooctadiene-platinum in a chemical vapour deposition system. The morphological, structural, and magnetic properties of the as-grown filled CNOs were characterized by a means of scanning and transmission electron microscopy, X-ray diffraction, and magnetometry. [ABSTRACT FROM AUTHOR]

Many studies have shown that patients with Coronavirus disease 2019 (COVID-19) have different degrees of liver injury. However, the mechanisms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) invasion into the liver are still not fully understood. This review mainly summarizes the recently published works on the abnormal liver biochemical indicators and the mechanism of viral invasion with liver injury in COVID-19 patients. Generally, SARSCoV-2 infection of the liver was caused by blood circulation or retrograde infection of the digestive tract, which led to the liver injury through direct cytopathic effect induced by virus or immunopathological effect caused by excessive inflammation. Besides these, hypoxia, endothelial injury and drug-induced jury were also the main reasons of liver injury in COVID-19 patients. In the liver function indicators, elevated alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyl transpeptidase, and lactate dehydrogenase levels with reduced albumin levels were observed in COVID-19 patients. [ABSTRACT FROM AUTHOR]

The integration of muscle cells with soft robotics in recent years has led to the development of biohybrid machines capable of untethered locomotion. A major frontier that currently remains unexplored is neuronal actuation and control of such muscle-powered biohybrid machines. As a step toward this goal, we present here a biohybrid swimmer driven by on-board neuromuscular units. The body of the swimmer consists of a free-standing soft scaffold, skeletal muscle tissue, and optogenetic stem cell-derived neural cluster containing motor neurons. Myoblasts embedded in extracellular matrix self-organize into a muscle tissue guided by the geometry of the scaffold, and the resulting muscle tissue is cocultured in situ with a neural cluster. Motor neurons then extend neurites selectively toward the muscle and innervate it, developing functional neuromuscular units. Based on this initial construct, we computationally designed, optimized, and implemented light-sensitive flagellar swimmers actuated by these neuromuscular units. Cyclic muscle contractions, induced by neural stimulation, drive time-irreversible flagellar dynamics, thereby providing thrust for untethered forward locomotion of the swimmer. Overall, this work demonstrates an example of a biohybrid robot implementing neuromuscular actuation and illustrates a path toward the forward design and control of neuron-enabled biohybrid machines. [ABSTRACT FROM AUTHOR]

A multistep diffusion-mediated process was developed to control the nucleation density, size, and lateral growth rate of WSe2 domains on c-plane sapphire for the epitaxial growth of large area monolayer films by gas source chemical vapor deposition (CVD). The process consists of an initial nucleation step followed by an annealing period in H2Se to promote surface diffusion of tungsten-containing species to form oriented WSe2 islands with uniform size and controlled density. The growth conditions were then adjusted to suppress further nucleation and laterally grow the WSe2 islands to form a fully coalesced monolayer film in less than 1 h. Postgrowth structural characterization demonstrates that the WSe2 monolayers are single crystal and epitaxially oriented with respect to the sapphire and contain antiphase grain boundaries due to coalescence of 0° and 60° oriented WSe2 domains. The process also provides fundamental insights into the two-dimensional (2D) growth mechanism. For example, the evolution of domain size and cluster density with annealing time follows a 2D ripening process, enabling an estimate of the tungsten-species surface diffusivity. The lateral growth rate of domains was found to be relatively independent of substrate temperature over the range of 700-900 °C suggesting a mass transport limited process, however, the domain shape (triangular versus truncated triangular) varied with temperature over this same range due to local variations in the Se/W adatom ratio. The results provide an important step toward atomic level control of the epitaxial growth of WSe2 monolayers in a scalable process that is suitable for large area device fabrication. [ABSTRACT FROM AUTHOR]

Background: Type 2 diabetes is a persistent inflammatory response that impairs the healing process. We hypothesized that stimulation with high glucose following a pro-inflammatory signal would lead to autophagy inhibition, reactive oxygen species (ROS) production and eventually to the activation of the Nod-like receptor protein (NLRP) -3. Methods: Macrophages were isolated from human diabetic wound. We measured the expression of NLRP3, caspase1 and interleukin-1 beta (IL-1β) by western blot and real-time PCR, and the surface markers on cells by flow cytometry. THP-1-derived macrophages exposed to high glucose were applied to study the link between autophagy, ROS and NLRP3 activation. LC3-II, P62, NLRP3 inflammation and IL-1β expression were measured by western blot and real-time PCR. ROS production was measured with a Cellular Reactive Oxygen Species Detection Assay Kit. Results: Macrophages isolated from diabetic wounds exhibited a pro-inflammatory phenotype, including sustained NLRP3 inflammasome activity associated with IL-1β secretion. Our data showed that high glucose inhibited autophagy, induced ROS production, and activated NLRP3 inflammasome and cytokine secretion in THP-1-derived macrophages. To study high glucose-induced NLRP3 inflammasome signalling, we performed studies using an autophagy inducer, a ROS inhibitor and a NLRP3 inhibitor and found that all reduced the NLRP3 inflammasome activation and cytokine secretion. Conclusion: Sustained NLRP3 inflammasome activity in wound-derived macrophages contributes to the hyper-inflammation in human diabetic wounds. Autophagy inhibition and ROS generation play an essential role in high glucose-induced NLRP3 inflammasome activation and cytokine secretion in macrophages. [ABSTRACT FROM AUTHOR]

Background: Type 2 diabetes is a persistent inflammatory response that impairs the healing process. We hypothesized that stimulation with high glucose following a pro-inflammatory signal would lead to autophagy inhibition, reactive oxygen species (ROS) production and eventually to the activation of the Nod-like receptor protein (NLRP)-3. Methods: Macrophages were isolated from human diabetic wound. We measured the expression of NLRP3, caspase1 and interleukin-1 beta (IL-1β) by western blot and real-time PCR and the surface markers on cells by flow cytometry. THP-1-derived macrophages exposed to high glucose were applied to study the link between autophagy, ROS and NLRP3 activation. LC3-II, P62, NLRP3 inflammation and IL-1β expression were measured by western blot and real-time PCR. ROS production was measured with a Cellular Reactive Oxygen Species Detection Assay Kit. Results: Macrophages isolated from diabetic wounds exhibited a pro-nflammatory phenotype, including sustained NLRP3 inflammasome activity associated with IL-1β secretion. Our data showed that high glucose inhibited autophagy, induced ROS production and activated NLRP3 inflammasome and cytokine secretion in THP-1-derived macrophages. To study high glucose-induced NLRP3 inflammasome signalling, we performed studies using an autophagy inducer, a ROS inhibitor and a NLRP3 inhibitor and found that all reduced the NLRP3 inflammasome activation and cytokine secretion. Conclusion: Sustained NLRP3 inflammasome activity in wound-derived macrophages contributes to the hyper-inflammation in human diabetic wounds. Autophagy inhibition and ROS generation play an essential role in high glucose-induced NLRP3 inflammasome activation and cytokine secretion in macrophages. [ABSTRACT FROM AUTHOR]

Autotaxin (ATX) is a key enzyme that converts lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA), a lysophospholipid mediator that regulates cellular activities through its specific G protein-coupled receptors. The ATX-LPA axis plays an important role in various physiological and pathological processes, especially in inflammation and cancer development. Although the transcriptional regulation of ATX has been widely studied, the post-transcriptional regulation of ATX is largely unknown. In this study, we identified conserved adenylate-uridylate (AU)-rich elements in the ATX mRNA 3'-untranslated region (3UTR). The RNA-binding proteins HuR and AUF1 directly bound to the ATX mRNA 3UTR and had antagonistic functions inATXexpression. HuRenhancedATXexpression by increasing ATX mRNA stability, whereas AUF1 suppressed ATX expression by promoting ATX mRNA decay. HuR and AUF1were involved inATXregulation in Colo320 human colon cancer cells and the LPS-stimulated human monocytic THP-1 cells. HuR knockdown suppressed ATX expression in B16 mouse melanoma cells, leading to inhibition of cell migration. This effect was reversed by AUF1 knockdown to recover ATX expression or by the addition of LPA. These results suggest that the post-transcriptional regulation of ATX expression by HuR and AUF1 modulates cancer cell migration. In summary, we identified HuR and AUF1 as novel post-transcriptional regulators of ATX expression, thereby elucidating a novel mechanism regulating the ATX-LPA axis. [ABSTRACT FROM AUTHOR]

Hematologic malignancies are frequently associated with cardiac pathologies. Mutations of isocitrate dehydrogenase 1 and 2 (IDH1/2) occur in a subset of acute myeloid leukemia patients, causing metabolic and epigenetic derangements. We have now discovered that altered metabolism in leukemic cells has a profound effect on cardiac metabolism. Combining mathematical modeling and in vivo as well as ex vivo studies, we found that increased amounts of the oncometabolite D-2-hydroxyglutarate (D2-HG), produced by IDH2 mutant leukemic cells, cause contractile dysfunction in the heart. This contractile dysfunction is associated with impaired oxidative decarboxylation of α-ketoglutarate, a redirection of Krebs cycle intermediates, and increased ATP citrate lyase (ACL) activity. Increased availability of D2-HG also leads to altered histone methylation and acetylation in the heart. We propose that D2-HG promotes cardiac dysfunction by impairing α-ketoglutarate dehydrogenase and induces histone modifications in an ACL-dependent manner. Collectively, our results highlight the impact of cancer cell metabolism on function and metabolism of the heart. [ABSTRACT FROM AUTHOR]

Suspended sediment (SPS) is widely present in rivers around the world. However, the bioavailability of hydrophobic organic compounds (HOCs) associated with SPS is not well understood. In this work, the influence of SPS grain size on the bioavailability of SPS-associated pyrene to Daphnia magna was studied using a passive dosing device, which maintained a constant freely dissolved pyrene concentration (Cfree) in the exposure systems. The immobilization and protein as well as enzymatic activities of Daphnia magna were investigated to study the bioavailability of SPS-associated pyrene. With Cfree of pyrene ranging from 20.0 to 60.0 μg L-1, the immobilization of Daphnia magna in the presence of 1 g L-1 SPS was 1.11-2.89 times that in the absence of SPS. The immobilization caused by pyrene associated with different grain size SPS was on the order of 50-100 μm > 0-50 μm > 100-150 μm. When pyrene Cfree was 20.0 μg L-1, the immobilization caused by pyrene associated with 50-100 μm SPS was 1.42 and 2.43 times that with 0-50 and 100-150 μm SPS, respectively. The protein and enzymatic activities of Daphnia magna also varied with the SPS grain size. The effect of SPS grain size on the bioavailability of SPS-associated pyrene was mainly due to the difference in SPS ingestion by Daphnia magna and SPS composition, especially the organic carbon type, among the three size fractions. This study suggests that not only the concentration but also the size distribution of SPS should be considered for the development of a biological effect database and establishment of water quality criteria for HOCs in natural waters. [ABSTRACT FROM AUTHOR]

Xueshuan Xinmaining Tablet (XXT), the Chinese formula, has long been administered in clinical practice for the treatment of cerebral thrombosis and coronary heart disease. In this study, we aimed to study the effect and the molecular mechanism of activating blood circulation and removing blood stasis. Rat models of cold coagulation blood stasis were induced with ice-water bath and epinephrine to assess the amelioration of blood stasis by XXT. Microarray technique was used to identify gene expression from the model and XXT-treated rats. In addition, Quantitative Real-Time PCR (qPCR) was performed to verify the microarray results. The results showed that XXT had a good therapeutic effect on blood stasis by reducing the whole blood viscosity (WBV), plasma viscosity (PV), increasing PT, APTT and TT, and by inhibiting platelet aggregation. Genes were differentially expressed in rats among the model group and the XXT-pretreated groups. XXT ameliorated blood stasis by regulating the expressions of F13a1, Car1, and Tbxa2r. [ABSTRACT FROM AUTHOR]

Modular multilevel converters (MMCs) have become increasingly interesting in dc-dc applications, as there is a growing demand for dc-dc converters in high-voltage applications. Power electronics transformers can be used for high step-down ratio dc-dc power conversion, with high power rating and efficiency achieved. However, this arrangement requires a large number of high isolation voltage transformers and a complicated balancing control scheme. To provide a simple solution with inherent voltage balancing, this paper presents a new resonant MMC topology for dc-dc conversion. The proposed converter achieves high-voltage step-down ratio depending on the number of submodules. The converter also exhibits simplicity and scalability with no necessary requirement of high-voltage isolation transformers. By using phase-shift control, a much higher converter operating frequency is achieved compared to the switching frequency. Resonant conversion is achieved between the series inductor and submodule capacitors. The operation principle and theoretical analysis are presented in this paper, which have been verified by experimental results based on a bench-scale prototype. [ABSTRACT FROM AUTHOR]

The potential to remove boron and arsenic from petrochemical wastewater by using aquatic booster was investigated in batch experiment process and the results were measured by inductively coupled plasma mass spectrometry (ICPMS). The main parameters influencing arsenic and boron adsorption onto the aquatic booster were contact time, size of particle, agitation speed, and dosage. The initial concentration of boron and arsenic was fixed by changing contact time (120-480 minutes), agitation speed (0-120 rpm), aquatic booster dosage (0-55 g/L), and size of particle (2 mm, 1 mm, and 0.60 mm). The adsorption efficiency of arsenic and boron increases with longer contact time as well as more aquatic booster dosage and higher agitation speed. However, it tends to achieve equilibrium once the active sites of the adsorbent are fully occupied. On the other hand, adsorption efficiency decreases with larger adsorbent particle size. The equilibrium time for both boron and arsenic is 390 minutes. The removal efficiency for boron is around 60.36% by 35g/L dosage, 80 rpm and a particle size of 0.60 mm at of 390 minutes. As for the arsenic, the condition where it gives the removal percentage around 71.83% is that particle size of 0.6 mm, 300 minutes contact time, agitation speed of 80 rpm and dosage of 45g/L. The modeling study shows that the adsorption isotherms for both metals onto aquatic booster are Freundlich type. [ABSTRACT FROM AUTHOR]

As power factor correction (PFC) converters for low-power applications usually operate in the discontinuous conduction mode (DCM), operating in continuous conduction mode (CCM) will produce input current distortion. This distortion can be observed in a few switching cycles of one line cycle. Asynchronous switching maps are derived to obtain the time-domain waveforms of input current and output voltage. It can be seen that the cause of the distortion is the change in the current conduction mode. A model for PFC converters operating in DCM with fixed switching frequency and duty-ratio is developed, which can predict the converter operation mode under practical circumstances. Analysis of the output voltage and power limitations is provided based on the proposed model. Simulation and experimental results are presented to verify the proposed method. [ABSTRACT FROM AUTHOR]

When a classical digital controller is applied to parallel inverters, there is a tradeoff with respect to the stability, dynamic response, and control accuracy. In a practical design, the stability of the system should be considered first. To ensure sufficient margin in stability in a digitally controlled system, the proportional gains in the feedback path are limited. To solve these problems, a linear voltage-control scheme with duty-ratio feedforward is proposed. The control parameters are chosen according to the stable operating condition derived in the z-domain. In this paper, the closed-loop transfer function and output impedance for both the classical controller and the proposed controller are derived theoretically. A comparison reveals the advantages of the proposed control scheme, i.e., a unity closed-loop gain, no phase shift, good current sharing, and low total harmonic distortion of the output voltage. The theoretical results are verified by the experimental setup of a system with two digitally controlled inverters connected in parallel. [ABSTRACT FROM AUTHOR]

A microscopic model Hamiltonian for the ferroelectric field effect is introduced for the study of oxide heterostructures with ferroelectric components. The long-range Coulomb interaction is incorporated as an electrostatic potential, solved self-consistently together with the charge distribution. A generic double-exchange system is used as the conducting channel, epitaxially attached to the ferroelectric gate. The observed ferroelectric screening effect, namely, the charge accumulation/depletion near the interface, is shown to drive interfacial phase transitions that give rise to robust magnetoelectric responses and bipolar resistive switching, in qualitative agreement with previous density functional theory calculations. The model can be easily adapted to other materials by modifying the Hamiltonian of the conducting channel, and it is useful in simulating ferroelectric field effect devices particularly those involving strongly correlated electronic components where ab initio techniques are difficult to apply. [ABSTRACT FROM AUTHOR]

The resistivity anisotropy unveiled in the study of detwinned single crystals of the undoped 122 pnictides is here studied using the two-dimensional, three-orbital Hubbard model in the mean-field approximation. Calculating the Drude weight in the x and y directions at zero temperature for a Q = (π,0) magnetically ordered state, the conductance along the antiferromagnetic direction is shown to be larger than along the ferromagnetic direction. This effect is caused by the suppression of the dyz orbital at the Fermi surface, but additional insight based on the momentum dependence of the transitions induced by the current operator is provided. It is shown that the effective suppression of the interorbital hopping dxy and dyz along the y direction is the main cause of the anisotropy. [ABSTRACT FROM AUTHOR]

Oxytocin is a neuropeptide produced primarily in the hypothalamus and plays an important role in the regulation of mammalian birth and lactation. It has been shown that oxytocin has important cardiovascular protective effects. Here we investigated the effects of oxytocin on vascular reactivity and underlying the mechanisms in human umbilical vein endothelial cells (HUVECs) in vitro and in rat aorta ex vivo. Oxytocin increased phospho-eNOS (Ser 1177) and phospho-Akt (Ser 473) expression in HUVECs in vitro and the aorta of rat ex vivo. Wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K), inhibited oxytocin-induced Akt and eNOS phosphorylation. In the rat aortic rings, oxytocin induced a biphasic vascular reactivity: oxytocin at low dose (10-9-10-8 M) initiated a vasorelaxation followed by a vasoconstriction at high dose (10-7 M). L-NAME (a nitric oxide synthase inhibitor), endothelium removal or wortmannin abolished oxytocin-induced vasorelaxation, and slightly enhanced oxytocin-induced vasoconstriction. Atosiban, an oxytocin/ vasopressin 1a receptor inhibitor, totally blocked oxytocin-induced relaxation and vasoconstriction. PD98059 (ERK1/2 inhibitor) partially inhibited oxytocin-induced vasoconstriction. Oxytocin also increased aortic phospho-ERK1/2 expression, which was reduced by either atosiban or PD98059, suggesting that oxytocin-induced vasoconstriction was partially mediated by oxytocin/V1aR activation of ERK1/2. The present study demonstrates that oxytocin can activate different signaling pathways to cause vasorelaxation or vasoconstriction. Oxytocin stimulation of PI3K/eNOS-derived nitric oxide may participate in maintenance of cardiovascular homeostasis, and different vascular reactivities to low or high dose of oxytocin suggest that oxytocin may have different regulatory effects on vascular tone under physiological or pathophysiological conditions. [ABSTRACT FROM AUTHOR]

At present, safe and effective treatment drugs are urgently needed for diabetic kidney disease (DKD). Circulating protein biomarkers with causal genetic evidence represent promising drug targets, which provides an opportunity to identify new therapeutic targets. Summary data from two protein quantitative trait loci studies are presented, one involving 4,907 plasma proteins data from 35,559 individuals and the other encompassing 4,657 plasma proteins among 7,213 European Americans. Summary statistics for DKD were obtained from a large genome-wide association study (3,345 cases and 2,372 controls) and the FinnGen study (3,676 cases and 283,456 controls). Mendelian randomization (MR) analysis was conducted to examine the potential targets for DKD. The colocalization analysis was used to detect whether the potential proteins exist in the shared causal variants. To enhance the credibility of the results, external validation was conducted. Additionally, enrichment analysis, assessment of protein druggability, and the protein-protein interaction networks were used to further enrich the research findings. The proteome-wide MR analyses identified 21 blood proteins that may causally be associated with DKD. Colocalization analysis further supported a causal relationship between 12 proteins and DKD, with external validation confirming 4 of these proteins, and TGFBI was affirmed through two separate group data sets. These results indicate that targeting these four proteins could be a promising approach for treating DKD, andwarrant further clinical investigations. [ABSTRACT FROM AUTHOR]

This article provides an overview of gastrointestinal (GI) cancer screening in China, focusing on the past 30 years. It discusses the prevalence of GI cancers in China and their impact on global new cases and deaths. The article emphasizes the importance of early screening and diagnosis in reducing incidence and mortality rates. It also highlights the national population-based cancer screening programs implemented in China and the progress made in reducing the burden of GI cancers. The article concludes by discussing future strategies for cancer screening in China and other developing countries. [Extracted from the article]

Objective Assess whether local health facilities can adequately support the performance of general practitioners (GPs) trained by China's national compulsory services programme (CSP). Design Prospective cohort study. Setting Health facilities in middle and western rural areas in China, 2015-2022. Participants Cohorts of CSP graduates from 2015 to 2019 in four major medical universities. Main outcomes Job performance measured by a 12-item Job Performance Scale; productivity measured by outpatient volume per day; turnover measured by ever changing jobs within the past year. Results 91.2%, 92.0% and 90.5% GPs working in township health centres reported inadequate medication, equipment and external assistance from higher level hospitals, while CSP graduates working in secondary or tertiary hospitals reported a lower rate of less than 60%. The top three tests reported as lacking were blood gases (67.7%), microbiology (61.6%) and cancer biomarkers (49.7%); the top three lacked procedures were CT scan (64.8%), MRI scan (58.1%) and ambulatory BP monitoring (55.8%); and the top three lacked drugs were drugs for cardiovascular diseases (23.3%), systematic hormonal preparations (17.7%) and traditional Chinese medicines (13.0%). Multivariable analysis showed that facility support was positively associated with job performance--adequate medication increased job performance by 2.2 points (95% CI 0.7 to 3.8), and adequate external assistance increased job performance by 3.3 points (95% CI 1.8 to 4.8). Facility support was also positively associated with productivity--adequate medication increased outpatients seen per day by 20% (95% CI 0.1 to 0.3), and adequate equipment increased outpatients seen per day by 12% (95% CI 0.0 to 0.2). Facility support did not have significant impact on turnover, but GPs who changed jobs in the past year were 1.9-2.3 times more likely to report adequate facility support. Conclusion GPs in township health centres experienced a high prevalence of shortage in facility support. The identification of a positive association between facility support and performance and productivity has implications for future research and resources deployment in primary healthcare. [ABSTRACT FROM AUTHOR]

A propensity for rewiring genetic and epigenetic regulatory networks, thus enabling sustained cell proliferation, suppression of apoptosis, and the ability to evade the immune system, is vital to cancer cell propagation. An increased understanding of how this is achieved is critical for identifying or improving therapeutic interventions. In this study, using acute myeloid leukemia (AML) human cell lines and a custom CRI SPR/Cas9 screening platform, we identify the H3K9 methyltransferase SET DB1 as a novel, negative regulator of innate immunity. SET DB1 is overexpressed in many cancers, and loss of this gene in AML cells triggers desilencing of retrotransposable elements that leads to the production of double-stranded RNAs (dsRNAs). This is coincident with induction of a type I interferon response and apoptosis through the dsRNA-sensing pathway. Collectively, our findings establish a unique gene regulatory axis that cancer cells can exploit to circumvent the immune system. [ABSTRACT FROM AUTHOR]

Purpose The human epidermal growth factor receptor 2 (HER2) is an established therapeutic target for various kinds of solid tumors. HER2 amplification occurs in approximately 1% to 6% of colorectal cancer. In this study, we aimed to assess the efficacy and safety of trastuzumab in combination with chemotherapy in HER2-positive metastatic colorectal cancer (mCRC). Materials and Methods An open-label, phase II trial (Clinicaltrials.gov: NCT03185988) was designed to evaluate the antitumor activity of trastuzumab and chemotherapy in HER2-positive digestive cancers excluding gastric cancer in 2017. Patients from this trial with HER2-positive, KRAS/BRAF wild-type, unresectable mCRC were analyzed in this manuscript. Eligible patients were treated with trastuzumab (8 mg/kg loading dose and then 6 mg/kg every 3 weeks) and irinotecan (120 mg/m2 days 1 and 8 every 3 weeks). The primary endpoint was the objective response rate. Results Twenty-one HER2-positive mCRC patients were enrolled in this study. Seven patients (33.3%) achieved an objective response, and 11 patients (52.4%) had stable disease as their best response. The median progression-free survival (PFS) was 4.3 months (95% confidence interval, 2.7 to 5.9). Four of the 21 patients (19.0%) had grade 3 adverse events, including leukopenia, neutropenia, urinary tract infection, and diarrhea. No treatment-related death was reported. Exploratory analyses revealed that high tumor tissue HER2 copy number was associated with better therapeutic response and PFS. Alterations in the mitogen-activated protein kinase pathway, HER2 gene, phosphoinositide 3-kinase/AKT pathway, and cell cycle control genes were potential drivers of trastuzumab resistance in mCRC. Conclusion Trastuzumab combined with chemotherapy is a potentially effective and well-tolerated therapeutic regimen in mCRC with a high HER2 copy number. [ABSTRACT FROM AUTHOR]

Objective: Immune checkpoint inhibitors (ICIs) have achieved remarkable results in cancer treatments. However, there is no effective predictive biomarker for gastrointestinal (GI) cancer. Methods: We conducted integrative analyses of the genomic and survival data of ICI-treated GI cancer patients from the Memorial Sloan Kettering Cancer Center cohort (MSK-GI, n = 227), the Janjigian cohort (n = 40), and the Peking University Cancer Hospital & Institute cohort (PUCH, n = 80) to determine the possible associations between DNA damage response and repair (DDR) gene mutations and clinical outcomes. Data from The Cancer Genome Atlas database were analyzed to determine the possible correlations between DDR gene mutations and the tumor microenvironment. Results: In the MSK cohort, the presence of ≥ 2 DDR gene mutations was correlated with prolonged overall survival (OS). The Janjigian and PUCH cohorts further confirmed that subgroups with ≥ 2 DDR gene mutations displayed a prolonged OS and a higher durable clinical benefit. Furthermore, the DDR gene mutation load could be considered as an independent prognostic factor, and exhibited a potential predictive value for survival in GI cancer patients treated with ICIs. Mechanistically, we showed that the presence of ≥ 2 DDR gene mutations was correlated with higher levels of tumor mutation burden, neoantigen, and T cell infiltration. Conclusions: The DDR gene mutation status was correlated with favorable clinical outcomes in GI cancer patients receiving ICIs, which could serve as a potential biomarker to guide patient selection for immunotherapy. [ABSTRACT FROM AUTHOR]

Identification of drug-target interactions is an important process in drug discovery. Although high-throughput screening and other biological assays are becoming available, experimental methods for drug-target interaction identification remain to be extremely costly, time-consuming and challenging even nowadays. Therefore, various computational models have been developed to predict potential drug-target associations on a large scale. In this review, databases and web servers involved in drug-target identification and drug discovery are summarized. In addition, we mainly introduced some stateof- the-art computational models for drug-target interactions prediction, including network-based method, machine learning-based method and so on. Specially, for the machine learning-based method, much attention was paid to supervised and semi-supervised models, which have essential difference in the adoption of negative samples. Although significant improvements for drug-target interaction prediction have been obtained by many effective computational models, both network-based and machine learning-based methods have their disadvantages, respectively. Furthermore, we discuss the future directions of the network-based drug discovery and network approach for personalized drug discovery based on personalized medicine, genome sequencing, tumor clone-based network and cancer hallmark-based network. Finally, we discussed the new evaluation validation framework and the formulation of drug-target interactions prediction problem by more realistic regression formulation based on quantitative bioactivity data. [ABSTRACT FROM AUTHOR]

Background: Mounting evidence has indicated that high-mobility group box 1 (HMGB1) is involved in cell activation and migration. Our previous study demonstrated that methamphetamine mediates activation of astrocytes via sigma-1 receptor (σ-1R). However, the elements downstream of σ-1R in this process remain poorly understood. Thus, we examined the molecular mechanisms involved in astrocyte activation and migration induced by methamphetamine. Methods: The expression of HMGB1, σ-1R, and glial fibrillary acidic protein (GFAP) was examined by western blot and immunofluorescent staining. The phosphorylation of cell signaling pathways was detected by western blot, and cell migration was examined using a wound-healing assay in rat C6 astroglia-like cells transfected with lentivirus containing red fluorescent protein (LV-RFP) as well as in primary human astrocytes. The role of HMGB1 in astrocyte activation and migration was validated using a siRNA approach. Results: Exposure of C6 cells to methamphetamine increased the expression of HMGB1 via the activation of σ-1R, Src, ERK mitogen-activated protein kinase, and downstream NF-κB p65 pathways. Moreover, methamphetamine treatment resulted in increased cell activation and migration in C6 cells and primary human astrocytes. Knockdown of HMGB1 in astrocytes transfected with HMGB1 siRNA attenuated the increased cell activation and migration induced by methamphetamine, thereby implicating the role of HMGB1 in the activation and migration of C6 cells and primary human astrocytes. Conclusions: This study demonstrated that methamphetamine-mediated activation and migration of astrocytes involved HMGB1 up-regulation through an autocrine mechanism. Targeting HMGB1 could provide insights into the development of a potential therapeutic approach for alleviation of cell activation and migration of astrocytes induced by methamphetamine. [ABSTRACT FROM AUTHOR]

Rye (Secale cereale genome RR), a close relative of common wheat, possesses valuable resistance genes for wheat improvement. Due to the co-evolution of pathogen virulence and host resistance, some resistance genes derived from rye have lost effectiveness. Development and identification of new, effective resistance genes from rye is thus required. In the current study, wheat-rye line WR56 was produced through distant hybridization, embryo rescue culture, chromosome doubling and backcrossing. WR56 was then proved to be a wheat-rye 2RL ditelosomic addition line using GISH (genomic in situ hybridization), mc-FISH (multicolor fluorescence in situ hybridization), ND-FISH (non-denaturing FISH), mc-GISH (multicolor GISH) and rye chromosome arm-specific marker analysis. WR56 exhibited a high level of adult plant resistance to powdery mildew caused by Blumeria graminis f. sp. tritici (Bgt). This resistance was carried by the added 2RL telosomes and presumed to be different from Pm7 which is also located on chromosome arm 2RL but confers resistance at the seedling and adult stages. WR56 will be a promising bridging parent for transfer of the resistance to a more stable wheat breeding line. A newly developed 2RL-specific KASP (kompetitive allele specific PCR) marker should expedite that work. [ABSTRACT FROM AUTHOR]

A one-pot synthesis of indolo[2,3-c]quinolin-6(7H)-ones was achieved by sequential photocyclizations of 3-(2-azidophenyl)- N-phenylacrylamides in moderate to high yields. The reactions proceeded via photochemical cyclization of aryl azides to form N-phenylindol- 2-carbamides and subsequent 6π-electrocyclic reaction and oxidative aromatization to afford the corresponding indolo[2,3- c]quinolin-6(7H)-ones. [ABSTRACT FROM AUTHOR]

Mutations in the adult β-globin gene can lead to a variety of hemoglobinopathies, including sickle cell disease and β-thalassemia. An increase in fetal hemoglobin expression throughout adulthood, a condition named hereditary persistence of fetal hemoglobin (HPFH), has been found to ameliorate hemoglobinopathies. Deletional HPFH occurs through the excision of a significant portion of the 3′ end of the β-globin locus, including a CTCF binding site termed 3′HS1. Here, we show that the deletion of this CTCF site alone induces fetal hemoglobin expression in both adult CD34+ hematopoietic stem and progenitor cells and HUDEP-2 erythroid progenitor cells. This induction is driven by the ectopic access of a previously postulated distal enhancer located in the OR52A1 gene downstream of the locus, which can also be insulated by the inversion of the 3′HS1 CTCF site. This suggests that genetic editing of this binding site can have therapeutic implications to treat hemoglobinopathies. [ABSTRACT FROM AUTHOR]

NSun2 is an RNA methyltransferase introducing 5-methylcytosine into tRNAs, mRNAs, and noncoding RNAs, thereby influencing the levels or function of these RNAs. Autotaxin (ATX) is a secreted glycoprotein and is recognized as a key factor in converting lysophosphatidylcholine into lysophosphatidic acid (LPA). The ATX-LPA axis exerts multiple biological effects in cell survival, migration, proliferation, and differentiation. Here, we show that NSun2 is involved in the regulation of cell migration through methylating ATX mRNA. In the human glioma cell line U87, knockdown of NSun2 decreased ATX protein levels, whereas overexpression of NSun2 elevated ATX protein levels. However, neither overexpression nor knockdown of NSun2 altered ATX mRNA levels. Further studies revealed that NSun2 methylated the 39-UTR of ATX mRNA at cytosine 2756 in vitro and in vivo. Methylation by NSun2 enhanced ATX mRNA translation. In addition, NSun2-mediated 5-methylcytosine methylation promoted the export of ATX mRNA from nucleus to cytoplasmin an ALYREF-dependent manner. Knockdown of NSun2 suppressed the migration of U87 cells, which was rescued by the addition of LPA. In summary, we identify NSun2-mediated methylation of ATX mRNA as a novel mechanismin the regulation of ATX. [ABSTRACT FROM AUTHOR]

There is significant interest in the growth of single crystal monolayer and few-layer films of transition metal dichalcogenides (TMD) and other 2D materials for scientific exploration and potential applications in optics, electronics, sensing, catalysis and others. The characterization of these materials is crucial in determining the properties and hence the applications. The ultra-thin nature of 2D layers presents a challenge to the use of x-ray diffraction (XRD) analysis with conventional Bragg–Brentano geometry in analyzing the crystallinity and epitaxial orientation of 2D films. To circumvent this problem, we demonstrate the use of in-plane XRD employing lab scale equipment which uses a standard Cu x-ray tube for the analysis of the crystallinity of TMD monolayer and few-layer films. The applicability of this technique is demonstrated in several examples for WSe2 and WS2 films grown by chemical vapor deposition on single crystal substrates. In-plane XRD was used to determine the epitaxial relation of WSe2 grown on c-plane sapphire and on SiC with an epitaxial graphene interlayer. The evolution of the crystal structure orientation of WS2 films on sapphire as a function of growth temperature was also examined. Finally, the epitaxial relation of a WS2/WSe2 vertical heterostructure deposited on sapphire substrate was determined. We observed that WSe2 grows epitaxially on both substrates employed in this work under all conditions studied while WS2 exhibits various preferred orientations on sapphire substrate which are temperature dependent. In contrast to the sapphire substrate, WS2 deposited on WSe2 exhibits only one preferred orientation which may provide a route to better control the orientation and crystal quality of WS2. In the case of epitaxial graphene on SiC, no graphene-related peaks were observed in in-plane XRD while its presence was confirmed using Raman spectroscopy. This demonstrates the limitation of the in-plane XRD technique for characterizing low electron density materials. [ABSTRACT FROM AUTHOR]

Powdery mildew, caused by Blumeria graminis f. sp. tritici, is a serious disease of wheat (Triticum aestivum L.) throughout the world. Host resistance is the most effective and preferred means for managing this disease. Line 10V-2, a wheat breeding line with superior agronomic performance, shows broad-spectrum seedling resistance to powdery mildew. Genetic analysis demonstrated that its resistance was controlled by a single dominant gene, tentatively designated Pm10V-2. This gene was localized near the documented Pm2 locus on chromosome 5DS using the simple sequence repeat (SSR) marker Cfd81. To saturate the marker map of Pm10V-2, more markers were developed using bulked segregant RNA-Seq. Two single-nucleotide polymorphism (SNP) markers (Swgi047 and Swgi064), three expressed sequence tag markers (Swgi007, Swgi029, and Swgi038), and one SSR marker (Swgi066) were polymorphic between the resistant and susceptible bulks and showed tightly linked to the Pm10V-2 gene. Pm10V-2 was flanked by the new developed markers Swgi064 and Swgi066 at genetic distances of 0.4 and 1.2 centimorgans (cM), respectively, and cosegregated with Swgi007 and Swgi038. The homologous sequence of Pm2a was cloned from 10V-2 based on a recent study. Although the sequence cloned from 10V-2 was completely identical to that of the reported Pm2a-related gene, they did not cosegregate but were separated at a genetic distance of 1.6 cM, indicating that Pm10V-2 was different from the reported of Pm2a-related gene. When inoculated with multiple B. graminis f. sp. tritici isolates, Pm10V-2 had a significantly different resistance spectrum from Pm2a and other powdery mildew (Pm) resistance genes at or near the Pm2 locus. Therefore, Pm10V-2 may be a new Pm2 allele or Pm2-linked gene. To use Pm10V-2 in marker-assisted selection (MAS) breeding, seven markers applicable for MAS were confirmed, including three newly developed markers (Swgi029, Swgi038, and Swgi064) in the present work. Using these markers, a great number of resistant lines with desirable agronomic performance were selected from crosses involving 10V-2, including the breeding line KM5016, which has been entered in the Regional trials in Hebei Province, China. [ABSTRACT FROM AUTHOR]

Introduction In addition to diffuse brain oedema, diabetic ketoacidosis (DKA) can lead to ischaemic or haemorrhagic stroke, extrapontine myelinolysis, and sinovenous thrombosis. However, posterior reversible encephalopathy syndrome (PRES) and spinal cord oedema are rarely reported in patients with DKA. Methods We present a case of a 17-year-old-girl who developed headache, blurred vision, and paraplegia after her DKA was controlled. Sequential magnetic resonance (MR) scans of the brain and spinal cord were performed. Results Brain MR showed large patchy lesions in the bilateral white matter of the parieto-occipital lobes, which had high T2 signal intensity and low T1 signal intensity. MR scanning of the spinal cord showed longitudinal confluent central spinal cord T2 hyperintensity spanning seven thoracic spinal segments. With symptomatic treatment, the patient’s headache and vision disturbance subsided within 1 week. Subsequent MR scans demonstrated that the lesion in the spinal cord had decreased significantly in 10 days, and the large patchy lesions in the brain disappeared completely in 2 months. Her paraplegia improved gradually without obvious sequela 3 months later. The evolution of the disease and radiological findings supported the diagnosis of PRES with spinal cord involvement. Conclusion To the best of our knowledge, this is the first case report describing PRES with spinal cord involvement as a complication of DKA. PRES is a rare complication that should be considered along with other neurological complications of DKA when focal deficits appear. [ABSTRACT FROM AUTHOR]

Serum α-fetoprotein- (AFP-) elevated gastric cancer is a rare tumor that has a poor prognosis due to high incidence of liver metastasis. This study sought to investigate the optimal treatment modality. A total of 319 gastric cancer patients with liver metastasis (GCLM) whose serum AFP levels were tested before treatment were enrolled in this study. They were classified as the serum AFP ≥ 20 ng/ml group (n = 74) and the AFP < 20 ng/ml group (n = 245). Median OS of the AFP < 20 ng/ml group was significantly longer than that of the AFP ≥ 20 ng/ml group (15.7m versus 10.9 m, P = 0 004). ORR of first-line chemotherapy was 43.3% and 56.1% of the two groups, respectively (P = 0 024). Of patients who received doublet regimen, ORR of the AFP ≥ 20 ng/ml group was significantly lower (38.2 versus 56.9%, P = 0 013), while in those received triplet regimens, ORR between two groups was similar (66.7% versus 66.7%, P = 0 676). Moreover, for patients of the AFP ≥ 20 ng/ml group, those who reached PR had a longer survival period (15.4m versus 9.4 m, P = 0 017), and combined with local treatment for liver metastasis also seemed to improve prognosis (19.2m versus 8.4 m, P = 0 003). In conclusion, serum AFP-elevated GCLM had a poorer prognosis. Multimodality treatment including aggressive first-line chemotherapy with triplet regimen may be needed when treating them. [ABSTRACT FROM AUTHOR]

Solanum nigrum fruits have been conventionally used in beverages due to their nutritional substances such as minerals, vitamins, amino acids, proteins, sugars, polyphenols, and anthocyanins. The characterization of components and regulatory mechanism of anthocyanins in S. nigrum fruits have rarely been reported. In this study, we determined that the peel and flesh of S. nigrum fruits shared similar HPLC profiles but different contents and total antioxidant activities for anthocyanins. After an efficient purification method, mainly including extraction with pH 1.0 distilled water and then desorption with pH 1.0 95% ethanol after a DM-130 resin adsorption step to obtain more pure anthocyanin extracts, the purity of anthocyanins extracted from S. nigrum fruits reached 56.1%. Moreover, eight anthocyanins from S. nigrum fruit were identified with HPLC-MS/MS for the first time. A typical R2R3-MYB transcription factor gene, SnMYB, was also cloned for the first time by rapid amplification of cDNA ends (RACE)-PCR from S. nigrum. Moreover, the contents of anthocyanins were shown to correlate well (r = 0.93) with the expression levels of SnMYB gene during the fruit's developmental stages. Most significantly, SnMYB gene successfully produced high anthocyanin content (1.03 mg/g) when SnMYB gene was transiently expressed in tobacco leaves. Taken together, S. nigrum fruits are a promising resource for anthocyanin extraction, and SnMYB gene is an activator that positively regulates anthocyanin biosynthesis in S. nigrum. [ABSTRACT FROM AUTHOR]

Autotaxin (ATX) or ectonucleotide pyrophosphatase/phosphodiesterase 2 (ENPP2) is a secretory glycoprotein and functions as the key enzyme for lysophosphatidic acid generation. The mechanism of ATX protein trafficking is largely unknown. Here, we demonstrated that p23, a member of the p24 protein family, was the protein-sorting receptor required for endoplasmic reticulum (ER) export of ATX. A di-phenylalanine (Phe-838/Phe-839) motif in the human ATX C-terminal region was identified as a transport signal essential for the ATX-p23 interaction. Knockdown of individual Sec24 isoforms by siRNA revealed that ER export of ATX was impaired only if Sec24C was down-regulated. These results suggest that ATX is selectively exported from the ER through a p23, Sec24C-dependent pathway. In addition, it was found that AKT signaling played a role in ATX secretion regulation to facilitate ATX ER export by enhancing the nuclear factor of activated T cell-mediated p23 expression. Furthermore, the di-hydrophobic amino acid motifs (FY) also existed in the C-terminal regions of human ENPP1 and ENPP3. Such a p23, Sec24C-dependent selective ER export mechanism is conserved among these ENPP family members. [ABSTRACT FROM AUTHOR]

Exploitation of host resistance is important for controlling powdery mildew of wheat (Triticum aestivum L.). In this study, a wheat-Thinopyrum intermedium introgression line, designated WE99, conferred seedling resistance to 47 of 49 Blumeria graminis f. sp. tritici isolates. Genetic analysis demonstrated that the resistance segregation deviated significantly from a single gene Mendelian ratio. However, marker analysis indicated that only a single recessive resistance gene, temporarily designated PmWE99, conferred powdery mildew resistance (Pm). PmWE99 was mapped to chromosome arm 2BS and linked to the three simple-sequence repeat markers Cwml48, Gwm271, and Barc55. Using race spectrum analysis, PmWE99 was shown to be significantly different from the documented genes Pm42 and MIIW170 located on chromosome arm 2BS and, thus, appeared to be a new Pm gene. Examination of the genotype frequencies in the F2:3 families showed that a genetic variation in the PmWE99 interval that favored the transmission of the WE99 allele could be the cause of the deviated segregation. Further investigation revealed that the abnormal segregation only occurred at the PmWE99 interval and was not common at other loci in this population. Identification of PmWE99 will increase the diversity of the Pm genes for wheat improvement. [ABSTRACT FROM AUTHOR]

α-fetoprotein (AFP)-producing esophageal carcinoma is a rare type of esophageal cancer, with its characteristics not yet fully clarified. In the present study, a case of esophageal carcinoma was misdiagnosed as an AFP-producing esophageal carcinoma. The patient was a 50-year-old woman who was referred to Qianfoshan Hospital Affiliated to Shandong University in November 2014 with a 3-month history of progressive dysphagia. A chest computed tomography (CT) scan showed thickening of the wall of the esophagus, corresponding regions of luminal stenosis and massive lymph node swelling around the lesser curvature of the esophagus. A laboratory investigation showed that the serum AFP levels of the patient were elevated to 18.97 ng/ml (normal range <12 ng/ml). These laboratory investigation findings combined with the aforementioned pathological diagnosis supported a diagnosis of AFP-producing esophageal carcinoma. An abdominal ultrasound was performed and a cystic low-density measuring 5x4 mm was identified. No metastases were revealed in the liver. The boundary of the focal low density was clear, which indicated a clinical diagnosis of liver cyst. A radical esophagectomy was performed on December 5, 2014. Microscopically, the tumor was a moderately differentiated squamous cell carcinoma invading the serous layer, with no hepatoid features. Immunohistochemistry showed that the cells were diffusely negative for AFP expression. Histopathological examination revealed the absence of hepatoid features. According to these findings, the tumor was diagnosed as a moderately differentiated squamous cell carcinoma. In the present study, the case of a patient with squamous cell carcinoma that was misdiagnosed as an α-fetoprotein-producing esophageal carcinoma was reported, with a review of the literature. [ABSTRACT FROM AUTHOR]

The tRNA methytransferase NSun2 promotes cell proliferation, but the molecular mechanism has not been elucidated. Here, we report that NSun2 regulates cyclin-dependent kinase 1 (CDK1) expression in a cell cycle-dependent manner. Knockdown of NSun2 decreased the CDK1 protein level, while overexpression of NSun2 elevated it without altering CDK1 mRNA levels. Further studies revealed that NSun2 methylated CDK1 mRNA in vitro and in cells and that methylation by NSun2 enhanced CDK1 translation. Importantly, NSun2-mediated regulation of CDK1 expression had an impact on the cell division cycle. These results provide new insight into the regulation of CDK1 during the cell division cycle [ABSTRACT FROM AUTHOR]

It is well-known that the body burden of hydrophobic organic compounds (HOCs) increases with the trophic level of aquatic organisms. However, the mechanism of HOC biomagnification is not fully understood. To fill this gap, this study investigated the effect of predation on the bioaccumulation of polycyclic aromatic hydrocarbons (PAHs), one type of HOC, in low-to-high aquatic trophic levels under constant freely dissolved PAH concentrations (1, 5, or 10 μg L-1) maintained by passive dosing systems. The tested PAHs included phenanthrene, anthracene, fluoranthene, and pyrene. The test organisms included zebrafish, which prey on Daphnia magna, and cichlids, which prey on zebrafish. The results revealed that for both zebrafish and cichlids, predation elevated the uptake and elimination rates of PAHs. The increase of uptake rate constant ranged from 20.8% to 39.4% in zebrafish with the amount of predation of 5 daphnids per fish per day, and the PAH uptake rate constant increased with the amount of predation. However, predation did not change the final bioaccumulation equilibrium; the equilibrium concentrations of PAHs in fish only depended on the freely dissolved concentration in water. Furthermore, the lipid-normalized water-based bioaccumulation factor of each PAH was constant for fish at different trophic levels. These findings infer that the final bioaccumulation equilibrium of PAHs is related to a partition between water and lipids in aquatic organisms, and predation between trophic levels does not change bioaccumulation equilibrium but bioaccumulation kinetics at stable freely dissolved PAH concentrations. This study suggests that if HOCs have not reached bioaccumulation equilibrium, biomagnification occurs due to enhanced uptake rates caused by predation in addition to higher lipid contents in higher trophic organisms. Otherwise, it is only due to the higher lipid contents in higher trophic organisms. [ABSTRACT FROM AUTHOR]

We study the normal-state and superconducting properties of the NaFe1-xCoxAs system by specific heat measurements. Both the normal-state Sommerfeld coefficient and superconducting condensation energy are strongly suppressed in the underdoped and heavily overdoped samples. The low-temperature electronic specific heat can be well fitted by either a one-gap or a two-gap BCS-type function for all the superconducting samples. The ratio γNTc2/Hc2(0) can nicely associate the neutron spin resonance as the bosons in the standard Eliashberg model. However, the value of ΔC/TcγN near optimal doping is larger than the maximum value the model can obtain. Our results suggest that the high-Tc superconductivity in the Fe-based superconductors may be understood within the framework of boson-exchange mechanism but significant modification may be needed to account for the finite-temperature properties. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum) genotypes with rye (Secale cereale) 1RS chromosomal translocations are widely used in wheat breeding programs because 1RS carries genes for resistance to several diseases. However, some of the pathogens have evolved into new races that overcome the resistance due to extensive use of cultivars with the resistance genes from rye. Therefore, identification and deployment of new resistance sources with desirable agronomic characteristics are important and urgent. We have used winter rye cultivar German White as a source of genes for desirable traits in wheat improvement. A new genotype named WR04-32 was produced through hybridization and chromosome manipulation between common winter wheat cultivar Xiaoyan 6 and German White. This genotype was highly resistant to a wide spectrum of the wheat stripe rust (Puccinia striiformis f. sp. tritici) and powdery mildew (Blumeria graminis f. sp. tritici) pathotypes prevalent in China. The polymerase chain reaction (PCR) result using EST-STS (expressed sequence tag-site tagged sequence) marker STSWE126 specific to 1RS confirmed 1RS in WR04-32, and it was further proved to be a wheat-rye T2BL·1RS translocation line using sequential genomic in situ hybridization (GISH) and multicolor fluorescence in situ hybridization (FISH) with probes pAs1 and pSc119.2 (or pHvG38). In addition to its resistance to stripe rust and powdery mildew, WR04-32 was genetically stable and had desirable agronomic traits, making it a desirable germplasm for wheat breeding. [ABSTRACT FROM AUTHOR]

The effective use of the van der Waals 2D materials relies on their successful transfer from the growth substrate onto other target substrates in the form of large films or flakes. In particular, it is important to transfer such atomically thin samples to various substrates with minimal sample damage and exposure to etchants and chemicals to realize their applications. Here we develop a universal transfer method that not only is free of reactive etchants, but also can maintain the film morphology intact with no tears and cracks. We show a variety of different 2D crystals and thin films with various sizes and thicknesses transferred from different substrates, i.e. metal-organic chemical vapor deposition-grown WSe2 coalesced thin films on sapphire and mechanically exfoliated 2D crystalline flakes on titanium nitride. Further examination by transmission electron microscopy indicates successful transfer of all the samples. This study presents a universal and etchant-free transfer method that can be used to transfer a variety of 2D crystals and other nanostructures from/to various substrates. [ABSTRACT FROM AUTHOR]

We have systematically studied the nematic fluctuations in the electron-doped iron-based superconductor BaFe2-xNixAs2 by measuring the in-plane resistance change under uniaxial pressure. While the nematic quantum critical point can be identified through the measurements along the (110) direction, as studied previously, quantum and thermal critical fluctuations cannot be distinguished due to similar Curie-Weiss-like behaviors. Here we find that a sizable pressure-dependent resistivity along the (100) direction is present in all doping levels, which is against the simple picture of an Ising-type nematic model. The signal along the (100) direction becomes maximum at optimal doping, suggesting that it is associated with nematic quantum critical fluctuations. Our results indicate that thermal fluctuations from striped antiferromagnetic order dominate the underdoped regime along the (110) direction. We argue that either there is a strong coupling between the quantum critical fluctuations and the fermions, or more exotically, a higher symmetry may be present around optimal doping.. [ABSTRACT FROM AUTHOR]

We have studied the angular magnetoresistance of iron pnictides BaFe2−xNixAs2, which shows clear 180 degree periodicity as fitted by a cosine function. In the x = 0.065 sample, the phase of the two-fold symmetry changes 90 degrees above the tetragonal-to-orthorhombic structural transition temperature Ts. Since the phase at low temperature is associated with the rotation of orthorhombic domains by magnetic field, we show that even vacuum grease can push the presence of orthorhombic domains at temperatures much higher than Ts. Our results suggest that residual stress may have significant effects in studying the nematic orders and its fluctuations in iron pnictides. [ABSTRACT FROM AUTHOR]