Sawtooth and dune auroras simultaneously driven by waves around the plasmapause

The dune aurora,at a scale of~30 kilometers,was reported recently using ground camera.The small-scale dune aurora occurs on the duskside and exhibits a monochromatic oscillation in the auroral emission,implying fundamental energy conversions.However,whether the dune auroras correspond to atmospheric waves or are associated with magnetospheric dynamics should be determined.This paper reports a dune aurora that occurred during a storm;further,we demonstrate that it was the substructure of the sawtooth aurora that was generated by plasmapause surface waves.Conjugate observations in the magnetospheric source region suggest that the exohiss waves,which are periodically modulated by the plasmapause surface wave-excited ultralow frequency wave,might be responsible for the generation of the dune aurora.Most reported dune aurora events have occurred simultaneously with sawtooth auroras,suggesting that both are plasmapause-driven cross-scale auroral structures.

Acute high-altitude hypoxic brain injury Identification of ten differential proteins

Hypobaric hypoxia can cause severe brain damage and mitochondrial dysfunction, and is involved in hypoxic brain injury. However, little is currently known about the mechanisms responsible for mi- tochondrial dysfunction in hypobaric hypoxic brain damage. In this study, a rat model of hypobaric hypoxic brain injury was established to investigate the molecular mechanisms associated with mi- tochondrial dysfunction. As revealed by two-dimensional electrophoresis analysis, 16, 21, and 36 differential protein spots in cerebral mitochondria were observed at 6, 12, and 24 hours post-hypobaric hypoxia, respectively. Furthermore, ten protein spots selected from each hypobaric hypoxia subgroup were similarly regulated and were identified by mass spectrometry. These de- tected proteins included dihydropyrimidinase-related protein 2, creatine kinase B-type, is- ovaleryI-CoA dehydrogenase, elongation factor Ts, ATP synthase beta-subunit, 3-mercaptopyruvate sulfurtransferase, electron transfer flavoprotein alpha-subunit, Chain A of 2-enoyI-CoA hydratase, NADH dehydrogenase iron-sulfur protein 8 and tropomyosin beta chain. These ten proteins are all involved in the electron transport chain and the function of ATP synthase. Our findings indicate that hypobaric hypoxia can induce the differential expression of several cerebral mitochondrial proteins, which are involved in the regulation of mitochondrial energy production.

发泡碱式硫酸氧镁胶凝材料的动态力学性能试验研究

随着固废再生利用研究的迅速发展,研究固废再生复合材料的性能势在必行。本文对比分析了有无添加固废再生料的发泡碱式硫酸氧镁胶凝材料(FMOCM)的内部结构、准静态和动态力学性能。实验结果表明,由于添加了固废再生料和木粉,FMOCM内部结构的孔径显著变小,这大幅度提高了FMOCM的准静态抗压强度。同时,FMOCM表现出明显的应变率效应,通过比较动态强度因子可知,常规FMOCM的动态增强效果几乎翻倍,而固废再生料的添加减弱了应变率效应。仅当应变速率较低时,相比于常规FMOCM的粉碎性破坏,含固废再生料的FMOCM表现出较好的韧性。总之,本研究表明固废再生料在轻质碱式硫酸氧镁胶凝材料领域中具有广阔的应用前景。

Two-dimensional gel electrophoresis and surface-enhanced laser desorption ionization-time of flight-mass spectrometry for detection of protein expression profiles in the hippocampus following closed brain injury

Gene expression profile changes in brain regions following traumatic brain injury at the gene level cannot sufficiently elucidate gene expression time, expression amount, protein post-translational processing or modification. Therefore, it is necessary to quantitatively analyze the gene expression profile using proteomic techniques. In the present study, we established a rat model of closed brain injury using Marmarou＇s weight-drop device, and investigated hippocampal differential protein expression using two-dimensional gel electrophoresis and surface-enhanced laser desorption ionization-time of flight-mass spectrometry. A total of 364 protein peaks were detected on weak cation exchange-2 protein chips, including 37 differential protein peaks. 345 protein peaks were detected on immobilized metal affinity capture arrays-Cu, including 12 differential protein peaks Further examination of these differential proteins revealed that glucose-regulated protein and proteasome subunit alpha type 3 expression were significantly upregulated post-injury. These results indicate that brain injury can alter protein expression in the hippocampus, and that glucose-regulated protein and proteasome subunit alpha type 3 are closely associated with the occurrence and development of traumatic brain injury.

Distinct proteins in cortex of rats with closed traumatic brain injury detected by a WCX-2 protein chip

BACKGROUND： Mechanical injury can cause the changes of polygene expression spectrum in rat cerebral cortical nerve cells, and then result in the changes of intracellular protein expression. At present, dielectrophoresis is combined with mass spectrum technique to detect the expression of different proteins in rat cortex after brain injury, but the protein chip technique requires further investigation. OBJECTIVE： To analyze the differences of protein expression spectrum in rat cerebral cortex before and after closed traumatic brain injury using WCX-2 protein chip technique. DESIGN： A randomized controlled animal experiment. SETTING： Training Division of the Medical College of Chinese People＇s Armed Police Force. MATERIALS： Seventy-two male SD rats of clean degree, 350 - 450 g, were provided by the Experimental Animal Center, Academy of Military Medical Sciences of Chinese PLA. Urea, trifluoroacetic acid, CHAPS and Tris （Sigma, USA）; WCX-2 （Ciphergen, USA）. Ultra-high speed hypothermia centrifuger （Bechman, USA）; Rotary tissue microtome （Keuca, Germany）; Biochip processor and PBS II-C protein chip reader （Ciphergen, USA）. METHODS： The experiments were carried out in the Institute of Molecular Pathology, Central Laboratory, and Department of Pathology, Medical College of Chinese People＇s Armed Police Force from June 2005 to March 2006. ① Grouping and treatment： The experiments were completed in molecular pathological institute, central laboratory and pathological department. ② The rats were randomly divided into control group （n =12） and brain injury group （n =60）. Marmarou＇s weight-dropping models were duplicated at different time points in the brain injury group. In the control group, the rats were only treated by incising the skin of head top, without fixing the stainless steel hitting backup plate at the vault of skull, and obtain brain cortex for pathological and protein chip research, and they were killed after 24 hours. The rats in the brain injury group were killed at 4, 8, 12, 24 and 48 hours after model establishment. ③ Pathological observation： Longitudinal section was made on cerebral cortex, and sections of 5 μm were prepared, then stained with hematoxylin and eosin （HE）. ④Protein chip analysis： 100 mg cerebral cortex was collected from each rat, and the protein content in sample was detected with Bradford method, meanwhile, WCX-2 protein chip was used to analyze the protein spectrum. The data were automatically collected with Ciphergen proteinchip 3.0 software, and the results were analyzed using Biomarker Wizard software to compare the differences of protein spectrum in rat cortex between the groups. MAIN OUTCOME MEASURES： Results of the pathological observation of cerebral cortex and the protein spectrum analysis. RESULTS：①Pathological changes of cerebral cortex： In the control group, no necrosis and edema was observed. In the brain injury group, injures of different severity occurred at different time points; After 4 hours, focal or scattered red nerve cells could be observed, the size of some cells was increased, cytoplasm was lightly stained, and only nuclear fragments were seen; After 8 hours, the necrotic nerve cells were increased, and the number of nerve cells was reduced, astrocytes （neuronophagia） could be seen in partial cytoplasm; there was small vascular dilatation, and endothelial cell proliferation; interstitial edema, regional rarefaction lightly stained. After 12- 48 hours, the necrotic nerve cells were reduced, and astrocytes proliferated. ② Results of protein spectrum analysis： The WCX-2 experiment found that the expressions of 5 639, 3 212 and 7 536 u proteins in cerebral cortex changed after injury in the brain injury group. The peak intensity of 5 639 u protein in the brain injury group at 8 hours after injury was higher than that in the control group （P 〈 0.05）; The peak intensity of 3 212 u protein in the brain injury group at 48 hours after injury was higher than that in the control group （P 〈 0.05）; The peak intensity of 7 536 u protein at 24 hours after injury was higher than that in the control group （P 〈 0.05）. CONCLUSION： Brain injury can cause the changes of protein expression spectrum in cerebral cortex, it is suggested that brain injury can induce the expression of protein.

Underlying mechanism of protection from hypoxic injury seen with n-butanol extract of Potentilla anserine L. in hippocampal neurons

The alcohol and n-butanol extract of Potentilla anserine L. significantly protects myocardium from acute ischemic injury. However, its effects on rat hippocampal neurons and the mechanism of protection remain unclear. In this study, primary cultured hippocampal neurons from neonatal rats were incubated in 95% N2 and 5% CO2 for 4 hours. Results indicated that hypoxic injury decreased the viability of neurons, increased the expression levels of caspase-9 and caspase-3 mRNA, as well as cytochrome c, Caspase-9, and Caspase-3 protein. Pretreatment with 0.25, 0.062 5, 0.015 6 mg/mL n-butanol extract of Potentilla anserine L. led to a significant increase in cell viability. Expression levels of caspase-9 and caspase-3 mRNA, as well as cytochrome c, Caspase-9, and Caspase-3 protein, were attenuated. The neuroprotective effect of n-butanol extract of Potentilla anserine L. was equivalent to tanshinone IIA. Our data suggest that the n-butanol extract of Potentilla anserine L. could protect primary hippocampal neurons from hypoxic injury by deactivating mitochondrial cell death.

Sequential expression of cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor in rat hippocampal neurons after fluid percussion injury

Traumatic brain injury causes gene expression changes in different brain regions. Occurrence and development of traumatic brain injury are closely related, involving expression of three factors, namely cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor. However, little is known about the correlation of these three factors and brain neuronal injury. In this study, primary cultured rat hippocampal neurons were subjected to fluid percussion injury according to Scott’s method, with some modifications. RT-PCR and semi-quantitative immunocytochemical staining was used to measure the expression levels of cyclooxygenase-2, glutamate receptor-2, and platelet activating factor receptor. Our results found that cyclooxygenase-2 expression were firstly increased post-injury, and then decreased. Both mRNA and protein expression levels reached peaks at 8 and 12 hours post-injury, respectively. Similar sequential changes in glutamate receptor 2 were observed, with highest levels mRNA and protein expression at 8 and 12 hours post-injury respectively. On the contrary, the expressions of platelet activating factor receptor were firstly decreased post-injury, and then increased. Both mRNA and protein expression levels reached the lowest levels at 8 and 12 hours post-injury, respectively. Totally, our findings suggest that these three factors are involved in occurrence and development of hippocampal neuronal injury.

Effects of “Bioactive” amino acids leucine, glutamate, arginine and tryptophan on feed intake and mRNA expression of relative neuropeptides in broiler chicks

Feed intake control is vital to ensuring optimal nutrition and achieving full potential for growth and development in poultry. The aim of the present study was to investigate the effects of L-leucine, L-glutamate, L-tryptophan and L-arginine on feed intake and the mRNA expression levels of hypothalamic Neuropeptide involved in feed intake regulation in broiler chicks. Leucine, glutamate, tryptophan or arginine was intra-cerebroventricularly （ICV） administrated to 4d-old broiler chicks respectively and the feed intake were recorded at various time points. Quantitative PCR was performed to determine the hypothalamic mRNA expression levels of Neuropeptide Y （NPY）, agouti related protein （AgRP）, pro-opiomelanocortin （POMC）, melanocortin receptor 4 （MC4R） and corticotrophin releasing factor （CRF）. Our results showed that ICV administration of L-leucine （0.15 or 1.5 μmol） significantly （P〈0.05） increased feed intake up to 2 h post-administration period and elevated both hypothalamic NPY and AgRP mRNA expression levels. In contrast, ICV administration of L-glutamate （1.6 μmol） significantly （P 〈 0.05） decreased feed intake 0.25, 0.5 and 2 h post-injection, and increased hypothalamic CRF and MC4R mRNA expression levels. Meanwhile, both L-tryptophan （10 or 100 μg） and L-arginine （20 or 200 μg） had no significant effect on feed intake. These findings suggested that L-leucine and L-glutamate could act within the hypothalamus to influence food intake, and that both orexigenic and anorexigenic Neuropeptide genes might contribute directly to these effects.

Travel time prediction with viscoelastic traffic model

Travel time through a ring road with a total length of 80 km has been predicted by a viscoelastic traffic model(VEM), which is developed in analogous to the non-Newtonian fluid flow. The VEM expresses a traffic pressure for the unfree flow case by space headway, ensuring that the pressure can be determined by the assumption that the relevant second critical sound speed is exactly equal to the disturbance propagation speed determined by the free flow speed and the braking distance measured by the average vehicular length. The VEM assumes that the sound speed for the free flow case depends on the traffic density in some specific aspects, which ensures that it is exactly identical to the free flow speed on an empty road. To make a comparison, the open Navier-Stokes type model developed by Zhang(ZHANG, H. M. Driver memory, traffic viscosity and a viscous vehicular traffic flow model. Transp. Res. Part B, 37, 27–41(2003)) is adopted to predict the travel time through the ring road for providing the counterpart results.When the traffic free flow speed is 80 km/h, the braking distance is supposed to be 45 m,with the jam density uniquely determined by the average length of vehicles l ≈ 5.8 m. To avoid possible singular points in travel time prediction, a distinguishing period for time averaging is pre-assigned to be 7.5 minutes. It is found that the travel time increases monotonically with the initial traffic density on the ring road. Without ramp effects, for the ring road with the initial density less than the second critical density, the travel time can be simply predicted by using the equilibrium speed. However, this simpler approach is unavailable for scenarios over the second critical.

Effect of diacylglycerol acyltransferase 2overexpression in 3T3-L1 is associated to an increase in mono-unsaturated fatty acid accumulation

Background：Fatty acid（FA） composition is the most important parameter affecting the flavor and nutritional value of the meat.The final and the only committed step in the biosynthesis of triglycerides is catalyzed by diacylglycerol acyltransferase 2（DGAT2）.The role of DGAT2 in lipid accumulation has been demonstrated in adipocytes,However,little is known about the effect of DGAT2 on the FA composition of these cells.Methods：To investigate the role of DGAT2 in regulating lipid accumulation,FA composition and the expression of adipogenic genes,we cloned the open reading frame of the porcine DGAT2 gene and established 3T3-L1 cells that overexpressed DGAT2.Cells were then cultured in differentiation medium（DM） without FA,with a mixture of FAs（FA-DM）,or containing a ^（13）C stable isotope-labeled FA mixture（IFA-DM）.The FA composition of adipocytes was analyzed by gas chromatography-mass spectrometry and gas chromatography-isotope ratio mass spectrometry.Quantitative PCR and western blotting were employed to detect expression of adipogenic genes in 3T3-L1 adipocytes cultured with FA-DM for 12 d.Results：The triacylglyceride（TAG） content was significantly higher in 3T3-L1 adipocytes overexpressing DGAT2 than in control cells.When cultured in DM or FA-DM for 12 d,cells overexpressing DGAT2 showed a higher proportion of unsaturated FAs（C16：1 and C18：1）.However,when cells overexpressing DGAT2 were cultured with FA-DM for30 min,the FA composition was almost identical to that of controls.Further,the proportion of stable isotope-labeled FAs were similar in 3T3-L1 adipocytes overexpressing DGAT2 and control cells cultured in IFA-DM for 12 d.These results collectively indicate that the higher proportion of mono-unsaturated FAs,C16：1 and C18：1,may originate from de novo FA synthesis but not from the uptake of specific FAs from the medium.This hypothesis is further supported by evidence that both mRNA and protein expression of genes involved in FA synthesis（ACACA,FASN,SCD1,and A-FABP）were significantly higher in cells overexpressing DGAT2 than in control cells.Conclusions：In conclusion,our study revealed that TAG accumulation,the proportion of MUFAs,and the expression of adipogenic genes were higher in 3T3-L1 cells overexpressing DGAT2 than in control cells.

Inlet flow disturbance effects on direct numerical simulation of incompressible round jet at Reynolds number 2500

This letter reports inlet flow disturbance effects on direct numerical simulation of incompressible round jet at Reynolds number 2500.The simulation employs an accurate projection method in which a sixth order biased upwind difference scheme is used for spatial discretization of nonlinear convective terms,with a fourth order central difference scheme used in the discretization of the divergence of intermediate velocity.Carefully identifying reveals that the inlet flow disturbance has some influences on the distribution pattern of mean factor of swirling strength intermittency.With the increase of inlet disturbance magnitude jet core cone slightly shortens,observable differences occur in the centerline velocity and its fluctuations,despite the negligible impacts on the least square fitted centerline velocity decay constant(B_u)and distribution parameter(K_u)for velocity profile in self-similar region.

Differential protein expression in rat cortical astrocytes following fluid percussion injury Two-dimensional gel electrophoresis and mass-spectrum detection

BACKGROUND： The Glasgow Coma Scale, computer tomography, and nuclear magnetic resonance imaging have been frequently used to diagnose brain injury. However, these methods do not accurately and quantitatively evaluate injury degree. However, proteomics displays some advantages. To date, there are few proteomics studies based on primary astrocyte cultures from a fluid percussion injury model. OBJECTIVE： To detect differential protein expression in rat cerebral cortical astrocytes following fluid percussion injury using two-dimensional gel electrophoresis and mass spectrum and to determine specific biological markers of brain injury. DESIGN, TIME AND SETTING： Complete, randomized grouping and proteomics experiments were performed at the Molecular Pathological Laboratory, Central Laboratory and Tianjin Key Laboratory for Biomarkers of Occupational and Environmental Hazard of Medical College of Chinese People＇s Armed Police Force from October 2007 to May 2008. MATERIALS： Inverted phase-contrast microscope was purchased from Olympus, Japan. PROTEAN IEF Cell isoelectric focusing electrophoresis system and PROTEAN II Xi-Cell vertical electrophoresis system were purchased from Bio-Rad, USA. Autofiex MALDI-TOF mass spectrometer was purchased from Bruker, Germany. METHODS： A total of 90 culture dishes, fully coated with Sprague Dawley rat cortical astrocytes, were randomly divided into control （n = 30） and injury （n = 60） groups. Astrocytes in the injury group were subjected to fluid percussion and subdivided into 4-hour （n = 30） and 48-hour injury （n = 30） groups. MAIN OUTCOME MEASURES： Cell morphology was observed using inverted phase-contrast microscopy. Cell total protein was extracted from each group, followed by two-dimensional gel electrophoresis and silver staining, and the differential protein expression was analyzed using PDQuest 7.0 software. Protein peptide mass fingerprinting of differential protein spots was obtained by matrix assisted laser desorption/ionization-time of flight mass spectrometry. The National Center for Biotechnology Information （NCBI） protein database was retrieved by Mascot to primarily identify protein type, Finally, differential protein expression was detected by Western blot analysis. RESULTS： Following fluid percussion injury, astrocytes displayed obvious swelling and increased intercellular space, with some cell detachment; the number of dead cells was significantly greater than the control group （P 〈 0.05）. Expression intensity of 114 protein spots was significantly greater in the injury group compared with the control group （P〈 0.05）; 9 of the 114 protein spots were identified and peptJde matching scores of 8 spots were 〉 61 （P 〈 0.05）. Protein types were identified and included cellular retinol binding protein, brain fatty acid binding protein 7, $100 calcium binding protein All, 60S acidic ribosomal protein P2, calponin 3, breast carcinoma amplified sequence 2 homolog, eukaryotic translation initiation factor 1A, and hypothetical protein LOC685814. Western blot detection revealed brain fatty acid binding protein 7 expression in cortical astrocytes, which increased with injury time compared with the control group （P 〈 0.05）. CONCLUSION： Results from this study showed morphological and proteomic changes in cortical astrocytes following fluid percussion injury. Brain fatty acid binding protein 7 was expressed in astrocytes and possibly played an important role in injury repair. Mass-spectrum identified differentially expressed proteins that correlated with cell metabolism regulation, signal transduction, and translation initiation, and could serve as specific biological markers of brain injury.

Weak cation exchange 2 protein chip for detecting differentially expressed brainstem proteins in a rat model of closed traumatic brain injury

BACKGROUND： Studies have reported the combined use of two-dimensional gel electrophoresis and mass spectrometry to detect differentially expressed proteins in the rat brainstem following brain injury. However, the detected differential proteins often exhibit low sensitivity and high relative molecular weight. Although protein chip technology is thought to compensate for these inadequacies, no related studies or results have been reported. OBJECTIVE： To propose the application of weak cation exchange protein chips in combination with mass spectrometry for determining protein expression profiles and characteristics in the brainstem following closed brain injury. DESIGN, TIME AND SETTING： Randomized, controlled, animal experiments utilizing proteomics were performed from June 2007 to December 2008 in the Proteomics Laboratory, Medical College of Chinese People＇s Armed Police Force. MATERIALS： Weak cation exchange 2 protein chip, Ciphergen Proteinchip System （PBS-IIC）. METHODS： A total of 72 rats were randomly assigned to two groups： sham-surgery （n = 12） and injury （n = 60）. A closed traumatic brain injury model caused by falling object was replicated in the injury group, which was then subdivided into five subgroups according to different time points after injury： 4, 8, 12, 24, and 48 hours, with 12 rats in each subgroup. In the sham-surgery group, only the skin was removed and the stainless steel pad was fixed to the skull. MAIN OUTCOME MEASURES： The brain injury rats were sacrificed at 4, 8, 12, 24, and 48 hours after injury, respectively, and the control rats were sacrificed at 24 hours. Pathological changes in the brainstem were determined using hematoxylin-eosin staining, and differential protein expression in the brainstem was detected using a weak cation exchange 2 protein chip and protein chip reader. RESULTS： In the sham-surgery group, cells appeared normal. However, in the brain injury group, some brainstem neurons exhibited pyknosis, with reduced numbers of Nissl bodies in the cytoplasm swollen cell bodies and nuclei, irregular staining in the cytoplasm, and decreased numbers of neurons. Results from weak cation exchange 2 protein chip detection demonstrated that, compared with the sham-surgery group, the expression profiles of 2 proteins were altered in the brainstem of the injury group. At 12, 24, and 48 hours after injury, expression was increased （P 〈 0.01 ）. The mass charge ratio （M/Z） of 7 862 differentially expressed proteins was greater in the sham-surgery group compared with 12 and 24 hours after injury （P 〈 0.05）. CONCLUSION： The combined method of weak cation exchange 2 protein chip and mass spectrometry detected differential protein expression in the brainstem following closed brain injury in the rats, which suggested that closed brain injury induced altered protein expression profiles in the brainstem.

Tunnel effects on ring road traffic flow based on an urgent-gentle class traffic model

To explore tunnel effects on ring road traffic flow,a macroscopic urgent-gentle class traffic model is put forward.The model identifies vehicles with urgent and gentle classes,chooses the tunnel speed limit as free flow speed to express the fundamental diagram in the tunnel,and adopts algebraic expressions to describe traffic pressure and sound speed.With two speed trajectories at the Kobotoke tunnel in Japan,the model is validated,with good agreement with observed data.Numerical results indicate that in the case of having no ramp effects,tunnel mean travel time is almost constant dependent on tunnel length.When initial density normalized by jam density is above a threshold of about 0.21,a traffic shock wave originates at the tunnel entrance and propagates backward.Such a threshold drops slightly as a result of on-ramp merging effect,the mean travel time drops as off-ramp diversion effect intensifies gradually.These findings deepen the understanding of tunnel effects on traffic flow in reality.

A Morphological Classification Method of ECG ST-Segment Based on Curvature Scale Space

Aomalous changes in the ST segment, including ST level deviation and ST shape change, are the major parameters in clinical electrocardiogram (ECG) diagnosis of myocardial ischemia. Automatic detection of ST segment morphology can provide a more accurate evidence for clinical diagnosis of myocardial ischemia. In this paper, we proposed a method for classifying the shape of the ST-segment based on the curvature scale space (CSS) technique. First, we established a reference ST set and preprocessed the ECG signal by using the CSS technique. Then, the corner points in the ST-segment were detected at a high scale of the CSS and tracked through multiple lower scales, in order to improve its localization. Finally, the current beat of ST morphology can be distinguished by the corner points. We applied the developed algorithm to the ECG recordings in European ST-T database and QT database to validate the accuracy of the algorithm. The experimental results showed that the average detection accuracy of our algorithm was 91.60%. We could conclude that the proposed method is able to provide a new way for the automatic detection of myocardial ischemia.

Maternal Administration of GHRP-6-loaded PLGA-PEG-PLGA Thermosensitive Hydrogel Increases Growth and Vitality of Piglets

Both growth hormone-releasing peptide 6 （GHRP-6） and growth hormone-releasing hormone （GHRH） have potent GH-releasing activity in animals. We have previously demonstrated that the administration of a plasmid encoding the GHRH gene to pregnant mice and pig augmented long-term growth in first generation progeny,and that the administration of GHRP-6 results in growth augmentation in mice and rabbits. However,it has not yet been reported if GHRP-6 induces intergenerational growth effects in pigs. Ploy lactic-co-glycolic acid （PLGA） microsphere adsorption of treatment proteins enhances gene expression,genetic immunization and the ability to protect plasmid DNA and peptides from degradation. The cur-rent study was conducted to determine the growth performance of piglets born to gilts treated with GHRP-6 incorporated into thermosensitive PLGA-PEG-PLGA triblock copolymers. Gilts were injected intra-muscularly once at day 85 of gestation with 30 mg of GHRP6-loaded thermosensitive PLGA-PEG-PLGA triblock copolymers. Piglets were weighed periodically between birth and 28 days. Mean body weights of piglets born to GHRP-6-treated gilts were 6. 58% to 18. 89% （P 〈 0. 05 ） greater than those of piglets born to control gilts. This study confirms that enhanced maternal GHRP-6 mediated by thermosensitive PLGA-PEG-PLGA can augment growth of piglets.

Seismic response of the long-span steel truss arch bridge with the thrust under multidimensional excitation

Purpose–Under different ground motion excitation modes,the spatial coupling effect of seismic response for the arch bridge with thrust,seismic weak parts and the internal force components of the control section of main arch ribs are analyzed.Design/methodology/approach–Taking a 490 m deck type railway steel truss arch bridge as the background,the dynamic calculation model of the whole bridge was established by SAP2000 software.The seismic response analyses under one-,two-and three-dimension(1D,2D and 3D)uniform ground motion excitations were carried out.Findings–For the steel truss arch bridge composed of multiple arch ribs,any single direction ground motion excitation will cause large axial force in the chord of arch rib.The axial force caused by transverse and vertical ground motion excitation in the chord of arch crown area is 1.4–3.6 times of the corresponding axial force under longitudinal seismic excitation.The in-plane bending moment caused by the lower chord at the vault is 4.2–5.5 times of the corresponding bending moment under the longitudinal seismic excitation.For the bottom chord of arch rib,the arch foot is the weak part of earthquake resistance,but for the upper chord of arch rib,the arch foot,arch crown and the intersection of column and upper chord can all be the potential earthquake-resistant weak parts.The normal stress of the bottom chord of the arch rib under multidimensional excitation is mainly caused by the axial force,but the normal stress of the upper chord of the arch rib is caused by the axial force,in-plane and out of plane bending moment.Originality/value–The research provides specific suggestions for ground motion excitation mode and also provides reference information for the earthquake-resistant weak part and seismic design of long-span deck type railway steel truss arch bridges.

Plant virology in the 21st century in China:Recent advances and future directions

Plant viruses are a group of intracellular pathogens that persistently threaten global food security.Significant advances in plant virology have been achieved by Chinese scientists over the last 20 years,including basic research and technologies for preventing and controlling plant viral diseases.Here,we review these milestones and advances,including the identification of new crop-infecting viruses,dissection of pathogenic mechanisms of multiple viruses,examination of multilayered interactions among viruses,their host plants,and virus-transmitting arthropod vectors,and in-depth interrogation of plantencoded resistance and susceptibility determinants.Notably,various plant virus-based vectors have also been successfully developed for gene function studies and target gene expression in plants.We also recommend future plant virology studies in China.

基于半导体纳米材料的偏振光发射:从材料到发光二极管

由于偏光片、彩色滤光片和液晶层等结构的损耗,基于背光源技术的液晶显示器的整体效率不足5%.自发射发光二极管(LED)不但具有巨大的市场潜力,而且能够满足未来显示的需求,迎来了巨大的发展机遇.更重要的是,由于避免了偏光片造成的光损失,偏振LED可以提高背景光利用效率.因此,亟需寻找有效的方法组装高质量的各向异性纳米材料薄膜,从而制备出具有高偏振度和高外量子效率的偏振LED.本文介绍了一些半导体纳米材料的光电特性及其在偏振LED中的潜在应用.综述了在偏振光发射领域从材料到薄膜,再到LED的研究进展;总结和比较了构建偏振光发射薄膜和LED的不同组装策略;最后,讨论了当前面临的挑战,并对偏振LED的潜在商业应用价值进行了展望.我们希望这篇综述能够对偏振LED当前研究进展进行有价值的总结,并对其未来发展激发一些新的、切实可行的想法.

Impacts of Down-Up Hill Segment on the Threshold of Shock Formation of Ring Road Vehicular Flow

The study of impacts of down-up hill road segment on the density threshold of traffic shock formation in ring road vehicular flow is helpful to the deep understanding of sags’bottleneck effect.Sags are freeway segments along which the gradient increases gradually in the traffic direction.The main aim of this paper is to seek the density threshold of shock formation of vehicular flow in ring road with down-up hill segment,because down-up hill roadway segment is a source to cause capacity reduction that is an attractive topic in vehicular traffic science.To seek the density threshold numerically,a viscoelastic continuum model[1]is extended and used.To solve the model equations,a fifth-order weighted essentially non-oscillatory scheme for spatial discretization,and a 3rd order Runge-Kutta scheme for time partial derivative term are used.Validation by existing observation data and the Navier-Stokes like model[2]extended as EZM is done before conducting extensive numerical simulations.For ring road vehicular flow with three separated down-up hill segments,it is found that the density threshold of shock formation decreases monotonically with the relative difference of free flow speed,this variation can be simply fitted by a third order polynomial.