407 research outputs found
Visualizing topological edge states of single and double bilayer Bi supported on multibilayer Bi(111) films
Freestanding single-bilayer Bi(111) is a two-dimensional topological
insulator with edge states propagating along its perimeter. Given the
interlayer coupling experimentally, the topological nature of Bi(111) thin
films and the impact of the supporting substrate on the topmost Bi bilayer are
still under debate. Here, combined with scanning tunneling microscopy and
first-principles calculations, we systematically study the electronic
properties of Bi(111) thin films grown on a NbSe2 substrate. Two types of
non-magnetic edge structures, i.e., a conventional zigzag edge and a 2x1
reconstructed edge, coexist alternately at the boundaries of single bilayer
islands, the topological edge states of which exhibit remarkably different
energy and spatial distributions. Prominent edge states are persistently
visualized at the edges of both single and double bilayer Bi islands,
regardless of the underlying thickness of Bi(111) thin films. We provide an
explanation for the topological origin of the observed edge states that is
verified with first-principles calculations. Our paper clarifies the
long-standing controversy regarding the topology of Bi(111) thin films and
reveals the tunability of topological edge states via edge modifications.Comment: 36 pages, 10 figure
Effect of Acorus tatarinowii extract on hyperprolactinemia in rats
Purpose: To determine the mechanism underlying the anti-hyperprolactinemia effect of Acorus tatarinowii extract (ATE) in rats.
Methods: Rats were divided into six groups (n =10 each group), viz, healthy control, untreated hyperprolactinemic rats, hyperprolactinemic rats treated with bromocriptine (0.6 mg/kg), and hyperprolactinemic rats treated with ATE (3.2, 6.4, or 12.8 g/kg). After 30 days, the hypothalamic protein levels of dopamine D2 receptor, protein kinase A (PKA), and cyclic adenosine monophosphate (cAMP) were determined.
Results: Dopamine D2 receptor levels were lower in untreated hyperprolactinemic rats than in healthy control (p < 0.01), but this decrease was attenuated by ATE (p < 0.05). Elevated PKA levels in untreated hyperprolactinemic rats (0.78 ± 0.03”g/mL, p < 0.01) were decreased by ATE (3.2 g/kg, 0.51 ± 0.02 ”g/mL, p < 0.05; 6.4 g/kg, 0.39 ± 0.03 ”g/mL, p < 0.01; 12.8 g/kg, 0.24 ± 0.04 ”g/mL, p < 0.01). Similarly, elevated cAMP levels in hyperprolactinemic rats (3.1 ± 0.3 ng/mL) were lowered by ATE (3.2 g/kg, 2.2 ± 0.4 ng/mL, p < 0.05; 6.4 g/kg, 1.8 ± 0.3 ng/mL, p < 0.01; 12.8 g/kg, 1.4 ± 0.3 ng/mL, p < 0.01).
Conclusion: ATE anti-hyperprolactinemia activity is mediated by dopamine D2 receptor signaling via cAMP/PKA pathway
Elevation Estimation-Driven Building 3D Reconstruction from Single-View Remote Sensing Imagery
Building 3D reconstruction from remote sensing images has a wide range of
applications in smart cities, photogrammetry and other fields. Methods for
automatic 3D urban building modeling typically employ multi-view images as
input to algorithms to recover point clouds and 3D models of buildings.
However, such models rely heavily on multi-view images of buildings, which are
time-intensive and limit the applicability and practicality of the models. To
solve these issues, we focus on designing an efficient DSM estimation-driven
reconstruction framework (Building3D), which aims to reconstruct 3D building
models from the input single-view remote sensing image. First, we propose a
Semantic Flow Field-guided DSM Estimation (SFFDE) network, which utilizes the
proposed concept of elevation semantic flow to achieve the registration of
local and global features. Specifically, in order to make the network semantics
globally aware, we propose an Elevation Semantic Globalization (ESG) module to
realize the semantic globalization of instances. Further, in order to alleviate
the semantic span of global features and original local features, we propose a
Local-to-Global Elevation Semantic Registration (L2G-ESR) module based on
elevation semantic flow. Our Building3D is rooted in the SFFDE network for
building elevation prediction, synchronized with a building extraction network
for building masks, and then sequentially performs point cloud reconstruction,
surface reconstruction (or CityGML model reconstruction). On this basis, our
Building3D can optionally generate CityGML models or surface mesh models of the
buildings. Extensive experiments on ISPRS Vaihingen and DFC2019 datasets on the
DSM estimation task show that our SFFDE significantly improves upon
state-of-the-arts. Furthermore, our Building3D achieves impressive results in
the 3D point cloud and 3D model reconstruction process
The Effect of Rice Cultivars on Methane Emission From Irrigated Rice Field
Rice plants have been reported to affect methane (CH4) emission from rice fields. The objectives of this study were to determine the effect of rice cultivars on CH4 emission from flooded rice and to develop crop management strategies with low emitting rice cultivars while sustaining high yield. The four rice cultivars studied were Memberamo, Cisadane, IR64, and Way Apoburu. The CH4 emissions were determined in the wet season of 2001/2002 (November-February) using an automated closed chamber technique in an irrigated field condition. Farmyard manure at the rate of 5 t ha-1 was given to the plots to ensure carbon was not limited. Root weight, root length, biomass, and number of tillers were determined at 17, 36, and 57 days after transplanting (DAT). The results showed that the mean CH4 emission was highest in the plot planted with Cisadane (94.8 kg CH4 ha-1), and the lowest with IR64 (37.7 kg CH4 ha-1). The plots treated with emberamo and Way Apoburu resulted an intermediate CH4 emission at the average of 61.1 and 58.9 kg CH4 ha-1, respectively. There was no significant difference in yield between the cultivars tested. The yield of Memberamo, Cisadane, IR64, and Way Apoburu were 5.882, 5.764, 5.873 and 6.065 t ha-1, respectively. Statistical analysis showed that there were no significant differences in the root weight and root length among cultivars. However, Cisadane gave the highest dry matter weight (222 g hill-1) at 57 DAT compared to the other cultivars (175-190 g hill-1). Plant tillers did not show significant differences between the cultivars. Regression analysis showed that CH4 flux was significantly related with root weight, root length, aboveground biomass, and number of plant tillers. This finding shows that the use of selected cultivars, such as IR64, can potentially lower CH4 emission without scarifying yield
Electroacupuncture Ameliorates Acute Lung Injury through Promoting Gastrointestinal Motility in Rats with Acute Pancreatitis
Objective. Gastrointestinal disfunction and acute lung injury (ALI) were common in acute pancreatitis (AP). The effect of electro-acupuncture (EA) on gastrointestinal motility and ALI in rats with AP was investigated to verify the theory of âlung and large intestine are interior exteriorly relatedâ in traditional Chinese medicine. Methods. Male Sprague-Dawley rats were randomly divided into the normal group, model group, and EA group. AP model was established by three injections of 20% L-arginine at 1âh intervals. EA were applied to bilateral ST-25 and ST-36 for 30 minutes twice a day after modeling for 3 days. Arterial blood, pancreas, lung, and intestinal tissues were collected for detecting the inflammatory factors and histopathology. Intestinal propulsion rate (IPR) was also measured at 72âh. Results. EA treatment improved IPR and increased CCK-8 level compared with model group (P < 0.05). It lowered the serum levels of TNF-α and IL-6 and increased the level of IL-4 with no effect on IL-10. EA treatment reduced serum vasoactive intestinal peptide (VIP) and myeloperoxidase (MPO) level in the lung and the pathologic scores of pancreas, lung and intestine were decreased (P < 0.05). Conclusion. EA treatment could promote gastrointestinal motility through inhibiting VIP, and promoting CCK expression and regulate pro- and anti-inflammatory mediators to ameliorate ALI in AP
Prevalence and genotyping of Toxoplasma gondii in naturally-infected synanthropic rats (Rattus norvegicus) and mice (Mus musculus) in eastern China
Stray dogs as indicators of Toxoplasma gondii distributed in the environment: the first report across an urban-rural gradient in China
<p>Abstract</p> <p>Background</p> <p>Toxoplasmosis is an important parasitic zoonosis caused by the protozoan <it>Toxoplasma gondii </it>that is distributed world-wide and infects a variety of hosts. However, the prevalence of <it>T. gondii </it>in the environment (such as soil, water and food) is largely unknown. Due to the technical difficulty in oocyst counting directly, an alternative assay using the serologic status of <it>T. gondii </it>in free-living animals, such as stray or free-living dogs, as an indicator, can be used to evaluate environmental contamination indirectly, as they are exposed to the same risk of infection as humans and other animals.</p> <p>Results</p> <p>In the present study, 231 stray or free-living dogs across an urban-rural gradient were examined to assess the frequency of <it>T. gondii </it>in the environment. Specific antibodies to <it>T. gondii </it>were found in 93 dogs (40.3%) by enzyme-linked immunosorbent assay (ELISA), and no statistically significant differences were observed in seroprevalences of <it>T. gondii </it>between urban dogs (38.7%) and rural dogs (41%) (<it>p </it>> 0.05).</p> <p>Conclusions</p> <p>A high seroprevalence of <it>T. gondii </it>in stray or free-living dogs in the present study indicates that there would be a wide distribution and a constant infection pressure of <it>T. gondii </it>across an urban-rural gradient, and the oocysts of <it>T. gondii </it>in the environment would be an important source of infection for humans and other animals both in urban and rural areas in China.</p
Cardioprotective effect of Shenxiong glucose injection on acute myocardial infarction in rats via reduction in myocardial intracellular calcium ion overload
Purpose: To explore the cardioprotective effects and potential mechanisms of Shenxiong Glucose Injection (SGI) in rat acute myocardial infarction (AMI).Methods: AMI model was created by ligating left anterior descending coronary artery. After 7 daysâ consecutive intravenous administration of SGI, serum samples were used to conduct biochemical analysis while hearts were excised and processed for infraction size, enzyme activity, histopathology and qPCR studies. Intracellular Ca2+ {(Ca2+)i} overload in H9c2 cells was measured by laser scanning confocal microscope (LSCM).Results: In AMI rats, pretreatment with SGI significantly ameliorated myocardial histopathologic damage. It exerted cardioprotective effect by decreasing myocardial infarct size, electrocardiogram (ECG) ST segment elevation, and CK, cTnI, BNP levels in serum. In addition, SGI significantly decreased calmodulin (CaM) and calmodulin-dependent protein kinase II (CaMK II) mRNA expression, but increased Ca2+-Mg2+-ATPase and Na+-K+-ATPase activities in myocardium. In doxorubicin (DOX)- induced H9c2 cells injury model, SGI reversed (Ca2+)i overload to protect cells.Conclusion: The results demonstrate SGI exerts cardioprotective effect by decreasing myocardial infarct size, restoring ST segment and reversing (Ca2+)i overload. It suggests that SGI may be a new clinical candidate to treat myocardial infarction.Keywords: Shenxiong glucose injection, Tanshinol, Ligustrazine, Myocardial infarction, Intracellular Ca2+ overload, Calmodulin, Calmodulin-dependent protein kinase I
Alkynyl-Protected Au-23 Nanocluster: A 12-Electron System
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ć°ć: Jiang, DEA 23-gold-atom nanocluster was prepared by NaBH4-mediated reduction of a solution of PhC equivalent to CAu and Ph3PAuSbF6 in CH2Cl2. The cluster composition was determined to be [Au-23(PhC equivalent to C)(9)(Ph3P)(6)](2+) and single-crystal X-ray diffraction revealed that the cluster has an unprecedented Au-17 kernel protected by three PhC2-Au-C-2(Ph)-Au-C2Ph motifs and six Ph3P groups. The Au-17 core can be viewed as the fusion of two Au-10 units sharing a Au-3 triangle. Electronic structure analysis from DFT calculations suggests that the stability of this unusual 12-electron cluster is a result of the splitting of the superatomic 1D orbitals under D-3h symmetry of the Au-17 kernel. The discovery and determination of the structure of the Au-23 cluster demonstrates the versatility of the alkynyl ligand in leading to the formation of new cluster compounds.973 program
2014CB845603
Natural Science Foundation of China
21125102
21390390
21473139
University of California, Riversid
Ultrasound measurement of vastus lateralis and vastus medialis muscle parameters to identify chronic thyrotoxic myopathy
Introduction: Chronic thyrotoxic myopathy (CTM) is a common, easily neglected complication of hyperthyroidism. There are currently no standard diagnostic criteria for CTM, and the ultrasonic characteristics of CTM-affected skeletal muscle remain unclear. Herein, we aimed to evaluate hyperthyroid patients for CTM by ultrasound and identify ultrasonic muscle parameter cutoffs for CTM diagnosis.
Materials and methods: Each participant underwent ultrasonography. The original (muscle thickness (MT), pennation angle (PA), and cross-sectional area (CSA)) and corrected (MT/height (HT), MT/body mass index (BMI), CSA/HT, and CSA/BMI) parameters of the vastus lateralis and vastus medialis (VM) were evaluated. The diagnostic effectiveness of ultrasound for predicting CTM was determined using receiver operating characteristic (ROC) curve analysis. Our study included 203 participants: 67 CTM patients (18 males, 49 females), 67 non-CTM patients (28 males, 39 females) and 69 healthy controls (20 males, 49 females).
Results: The CTM group had lower muscular ultrasonic and anthropometric parameters, higher thyroid hormone and thyroid-stimulating hormone receptor antibody (TRAb) levels, and a longer duration of hyperthyroidism than the non-CTM group (P < 0.05). The VM-PA, VM-CSA, VM-CSA/HT, and VM-CSA/BMI were lower in females than in males (P < 0.05). Free thyroxine (FT4) and TRAb both showed significant negative correlations with VM-MT, VM-MT/HT, VM-CSA, and VM-CSA/HT (P < 0.05). VM-MT/BMI and VM-CSA/HT, respectively, best predicted male and female CTM (AUC = 0.84, 0.85; cutoff †0.07, < 4.01).
Conclusion: Ultrasound measurement of muscular parameters, especially in the VM, is a valid and feasible way of diagnosing and characterizing possible CTM in hyperthyroidism
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