Simultaneous determination of human plasma protein binding of bioactive favonoids in Polygonum orientale by equilibrium dialysis combined with UPLC–MS/MS

A simple and selective ultra performance liquid chromatography--electrospray ionization tandem mass spectrometry （UPLC-ESI-MS/MS） assay was developed for the determination of the human plasma protein binding of four bioactive ftavonoids （such as orientin and vitexin） in Polygonum orientale. Protein precipitation was used for sample preparation. Equilibrium dialysis technique was applied to determine the plasma protein binding under physiological conditions. The separation was achieved through a Waters C i s column with a mobile phase composed of 0.1% formic acid in acetonitrile and 0.1% aqueous formic acid using step gradient elution at a flow rate of 0.35 mL/min. A Waters ACQUITYTM TQD system was operated under the multiple reaction monitoring （MRM） mode of positive electrospray ionization. All of the recovery, precision, accuracy and stability of the method met the requirements. Good correlations （r 〉 0.99） of the four compounds were found, which suggested that these compounds can be simultaneously determined with acceptable accuracy. Results showed that the plasma protein bindings of the four bioactive flavonoids were in the range of 74-89% over the six concentrations studied. The binding parameters containing protein binding affinity, protein binding dissociation constant, and protein binding site were studied. The maximum ability to bind with protein was also determined in the assay in order to understand the drug-protein binding of each compound better.

Zinc Finger Protein-activating Transcription Factor Up-regulates Vascular Endothelial Growth Factor-A Expression in Vitro

Objective To construct the zinc finger protein-activating transcription factor (ZFP-ATF) plasmid and evaluate its efficacy in inducing vascular endothelial growth factor (VEGF) expression in EY.HY926 endothelial cells. Methods Firstly, we constructed the ZFP-ATF plasmid, then testified the quantity of VEGF protein in EY.HY926 endothelial cells after transfected with ZFP-ATP plasmid by Western blot, finally, we used the RT-PCR to testify whether the ZFP-ATF can stimulate expression of VEGF splice variants. Results The ZFP-ATF DNA sequences were located the multiclone sites of PVAX1 vector between the site of BamH Ⅰ and Xhol. Western blot result showed VEGF expression in EY.HY926 endothelial cells transfected with ZFP-ATF plasmid was significantly higher than that in cells transfected with VEGF165 (19.95±3.95 vs. 12.15±1.55 μg/μL, P<0.01). RT-PCR result showed VEGF-A mRNA expression level induced by ZFP-ATF was high than that induced by VEGF165. Conclusion ZFP-ATF can up-regulate the VEGF-A expression in comparison with VEGF165, which might have beneficial effects in angiogenesis process.

IMPAIRED ANGIOGENESIS FOLLOWING HIND-LIMB ISCHEMIA IN DIABETES MELLITUS MICE

Objective To investigate vascular endothelial growth factor(VEGF) and its signaling pathway spontaneous response in type 2 diabetes mellitus(T2DM) mice to surgery-induced hind-limb ischemia.Methods Sixty mice were randomly divided into two groups,one was fed with normal chow as control,and another was fed with high fat diet to induce T2DM.Fourteen weeks later,mice were surgically induced to hind-limb ischemia.Blood flow restoration was monitored with laser Doppler perfusion imaging.Tibialis anterior muscle was collected after 3 days of hind-limb ischemia.VEGF mRNA and protein expressions were analyzed using real-time PCR and ELISA;expressions of VEGF downstream signal molecules and receptors were analyzed using Western blotting and RT-PCR,respectively.Results Perfusion recovery 10,20,30 days after ischemia was significantly attenuated in T2DM compared with control group(P<0.05).T2DM impaired VEGF signaling pathway although VEGF levels increased in T2DM group.After ischemia,T2DM group had a comparable increase in VEGF expression compared with control group,but still had an impaired VEGF signaling pathway.Conclusion VEGF signaling pathway is abnormal in T2DM mice,although VEGF had a response to the ischemic stimulation.

Vacuum joints of dispersion-strengthened copper and its applications in synchrotron radiation front end

Masks are critical elements of synchrotron radiation front end that are exposed to high temperature and stress.The absorber material is typically comprised of dispersion-strengthened copper,which can retain high performance at elevated temperature.Joining processes under vacuum,including brazing and electron beam welding,are novel approaches for prolonging the absorber and for reducing power densities.The mechanical properties of brazed joints and electron beam welded joints of dispersion-strengthened copper workpieces are evaluated by tensile testing at 20,100,and 200 C.The testing results indicate that the tensile strength and elongation of both vacuum joints decrease with increasing temperature.Compared to brazed joints,electron beam welded joints have higher tensile strength,better ductility,and more stable performance.A novel welded mask with a total length of 600 mm is presented and shown to be practical for use in the highest heat load front end in the Shanghai synchrotron radiation facility phase-Ⅱ beamline project.

Lower Extremity Arterial Occlusive Disease As a Rare Complication of Crohn’s Disease

Objective To investigate the clinical characteristics and treatment strategy of lower extremity arterial occlusive disease in patients with Crohn's disease (CD). Methods Clinical information of 9 cases suffering from lower extremity arterial occlusion and CD was investigated retrospectively. Results All the cases were less than 50 years old and the most were females (8/9). Arterial occlusions occurred in either active (5/9) or inactive (4/9) stage of CD. Besides the arteries of lower extremities, other arteries could also be involved such as aorta, iliac artery, renal artery or mesentery artery. Seven cases had atherosclerotic imaging findings (4 had aortic plaques and 6 had iliac artery stenoses). Embolectomy or thromboendarterectomy were mostly performed. Four (44.4%) cases had recurrent lower limb ischemia. Conclusions Arterial occlusive disease is a rare extraintestinal manifestation of CD. A thorough inspection of aorta is necessary. Embolectomy is mostly preferred. Anticoagulation treatment is highly recommended after the operation.

Mg-6Zn-3Sn合金的均匀化热处理及其对显微组织和力学性能的影响

利用DSC、OM、XRD、SEM、TEM、维氏硬度计和万能试验机,研究Mg-6Zn-3Sn合金均匀化过程中的显微组织和力学性能演变,分析合金过烧的原因和扩散动力学,确定合金的均匀化制度。结果表明,单级均匀化处理后,Mg_(2)Zn_(3)相分解,同时伴随着Mg_(2)Sn相的析出。当均匀化温度上升到350℃时,Mg_(2)Zn_(3)相导致合金的过烧。合金合适的均匀化制度为(335℃,24 h)+(400℃,6 h)。在双级均匀化过程中,合金的硬度持续下降,力学性能呈现先升后降的趋势,这与Zn和Sn原子的固溶和Mg_(2)Sn相的析出有关。

Dislocation configuration evolution during extension twinning and its influence on precipitation behavior in AZ80 wrought magnesium alloy

Thermomechanical treatment T10(extension twinning+aging treatment)can largely enhance the precipitation strengthening effect of magnesium alloys.In this study,dislocation structure evolution and precipitation behavior during T10 treatment of an AZ80 extruded bar were analyzed mainly by two-beam diffraction in TEM.At a compressive strain of 1%in the extrusion direction(ED),a typical dislocation configuration,including basal I1 stacking faults(SFs)and<c+a>dislocations,has been established in extension twins.As the strain reaches 7%,the volume fraction of extension twins increases to more than 90%at which point high dense I1 SFs and<c+a>dislocations occur.After aging for 2 h at 150℃for the 7%strained sample,masses of basal I1 SFs and<c+a>dislocations remain in the extension twins and can act as effective nucleation sites and solute fast-diffusion channels for continuous precipitates.Consequently,the precipitates in extension twins become highly dense.

Mg-2Zn-xCu合金的显微组织和热物性能

通过显微组织和热物性能表征、热处理及第一性原理计算,研究Mg-2Zn-xCu (x=0.5, 1.0, 1.5,摩尔分数,%)合金的显微组织和热物性能。结果表明,添加Cu元素对合金显微组织和热物性能有影响。随着Cu含量增加,铸态合金中MgCuZn相含量增加,铸态合金电导率和热导率增大。固溶处理后,合金中共晶组织部分溶解,Zn原子回溶进入基体,导致合金的电导率和热导率均降低。时效处理前期,溶质原子从基体中沉淀析出,合金电导率增大,时效24 h后,Mg-2Zn-1.5Cu合金的热导率最高达到147.1 W/(m·K)。合金中形成的热稳定MgCuZn相对合金的电导率和热导率起促进作用。Zn元素在基体中含量越低,晶格畸变程度越低,导热性能则越好。另外,第一性原理计算结果也表明MgCuZn三元相具有很好的导电和导热性能。

含14H-LPSO结构的Mg-7Gd-3Y-1Nd-1Zn-0.5Zr合金在240℃时效过程中析出相的演化

通过TEM与HAADF-STEM技术分析含14H-LPSO结构的Mg-7Gd-3Y-1Nd-1Zn-0.5Zr (质量分数,%)合金在240℃时效过程中析出相的形貌和晶体学特征。薄片状14H-LPSO结构在500℃、2 h热处理过程中析出,而β型析出相在240℃时效过程中析出。14H-LPSO结构沿[0001]α方向的原子堆垛顺序为ABABCACACACBABA。240℃时效2 h时,β型析出相为有序固溶团簇、之字形GP区和少量的β′相。240℃时效18 h达到峰值,相应的布氏硬度值为112,β型析出相为β′相和局部富RE结构。240℃时效100 h时,β型析出相为β′、β1和β’F。β′相不经过β″相直接从之字形GP区形核,然后通过β′→β’F→β1转变成β1相。Zn的添加不仅可以形成LPSO结构,而且参与β1相的形成。LPSO结构阻碍β’和β1相沿<0001>α的生长。

胃食管反流病患者食管动力及酸暴露特点分析

目的通过对胃食管反流病(gastroesophageal reflux disease,GERD)患者食管高分辨率测压及24 h食管p H-阻抗联合监测结果分析,以探讨GERD患者食管动力及酸暴露特点.方法选取2017-07/2018-07就诊于石河子大学第一附属医院消化内科门诊及住院部具有典型症状(反酸、烧心)、根据蒙特利尔共识意见可诊断为GERD的患者59例,行胃镜、食管高分辨率测压及24 h食管p H-阻抗联合监测等检查;根据胃镜是否诊断反流性食管炎(reflux esophagitis, RE)组(27例,男/女:12/15)和非糜烂性反流病(nonerosive reflux disease, NERD)组(32例,男/女:14/18),比较两组患者食管高分辨测压及24 h食管pH-阻抗监测结果的差异.结果食管高分辨率测压结果中, RE组患者下食管括约肌静息压明显低于NERD组(P<0.05),上食管括约肌静息压及上下食管括约肌残余压比较差异无统计学意义(P>0.05), RE组患者远端波波幅低于NERD组(P <0.05),蠕动波持续时间、起始速度、远端收缩延迟时间两组间差异无统计学意义(P>0.05);分析24 h食管pH-Z监测结果, RE组DeMeester评分明显高于NERD组(P<0.05),总计酸反流时间低于NERD组(P <0.05),立卧位反流次数、总计反流次数、不同物理性质之间差异无统计学意义(P>0.05).结论不同GERD患者食管动力及酸反流存在一定的差异,RE患者食管动力障碍及酸反流较NERD更明显.

PREVALENCE AND RISK FACTORS OF PERIPHERAL ARTERIAL DISEASE IN DIABETIC PATIENTS OVER 50 YEARS OLD IN CHINA

Objective To investigate the prevalence of peripheral arterial disease (PAD) in China type 2 diabetic patients and to demonstrate the relationships between putative risk factors and PAD. Methods In total 1 397 type 2 diabetic patients aged 50 years and older were enrolled and determined ankle-brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) in 15 Class III Grade A hospitals in 7 major cities of China. Results Mean patient age was 63.7±8.2 years and mean duration of diabetes mellitus was 9.39±7.4 years. Two hundreds and seventy-two (19.47%) patients were diagnosed as PAD by ABI <0.9, 122 (18.37%) in male and 150 (20.46%) in female. PAD patients had a significantly longer duration of diabetes mellitus, higher hemoglobin Alc, and a significantly lower mean body mass index than non-PAD ones. Aging, smoking, and systolic blood pressure were found to be positively related with the prevalence of PAD. In terms of lipid profiles, no variable was found to relate with PAD. Notably, baPWV showed as the same significant guiding index for PAD, almost matched with ABI. Conclusions PAD is a common complication in China type 2 diabetic patients. Therefore, PAD screening and treatment should be emphasized for diabetic patients with high risk factors.

Effects of nicorandil on myocardial infarct size in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention:study design and protocol for the randomized controlled trial

Previous studies have shown that nicorandil has a protective effect on cardiomyocytes.However,there is no study to investigate whether perioperative intravenous nicorandil can further reduce the myocardial infarct size in patients with ST-segment elevation myocardial infarction(STEMI)compared to the current standard of percutaneous coronary intervention(PCI)regimen.The CHANGE(China-Administration of Nicorandil Group)study is a multicenter,prospective,randomized,double-blind and parallel-controlled clinical study of STEMI patients undergoing primary PCI in China,aiming to evaluate the efficacy and safety of intravenous nicorandil in ameliorating the myocardial infarct size in STEMI patients undergoing primary PCI and provide evidence-based support for myocardial protection strategies of STEMI patients.

Simulation of stray grain formation at the platform during Ni-base single crystal superalloy DD403 casting

The mechanism of stray grain formation at the platform of turbine blade simulator and the effect of withdrawal rate(V) on the stray grain phenomenon have been investigated using a macro-scale Pro CAST coupled with a 3D Cellular Automaton Finite Element(CAFE) model. The results indicate that the stray grains nucleate at the edges of platform at V =150 μm·s^(-1) and 200 μm·s^(-1). Using Pro CAST computer simulation software, it was proven that the stray grain formation is signifi cantly dependent on the undercooling and the temperature fi eld distribution in the platform. The macroscopic curvature of the liquidus isotherm becomes markedly concave with an increase in the withdrawal rate. The probability of stray grain formation at the edges of platform can be increased by increasing the withdrawal rate in the range of 70 μm·s^(-1) to 200 μm·s^(-1).

Regulation of the EGFR pathway by visfatin and its effect on cardiac hypertrophy

Objective:To investigate the regulation of the epidermal growth factor receptor(EGFR)pathway by visfatin and its effect on cardiac hypertrophy.Methods:60 Wistar male rats were randomly divided into control group,visfatin group and visfatin+AG1478 group,with 20 rats in each group.The cardiac mass index,left ventricular mass index and cardiomyocyte volume of rats in each group were calculated.The total protein content of each group of cardiomyocytes was detected by coomassie bright blue staining,and the protein expression was detected by Western blotting.Results:Compared with the control group,the cardiac mass index,left ventricular mass index,cardiomyocyte volume,protein content,and relative expressions of ANP and BNP were significantly increased in the visfatin group(P<0.05).The relative expression levels of EGFR,p-AKT,p-ERK1/2,p-STAT3,ANP and BNP in cardiac myocytes in the visfatin group were significantly higher than those in the control group and the visfatin+AG1478 group(P<0.05).Conclusion:Visfatin induces hypertrophy in cardiomyocytes by activating the EGFR signaling pathway.

Nerve Growth Factor Promotes Angiogenesis and Skeletal Muscle Fiber Remodeling in a Murine Model of Hindlimb Ischemia

Background： Therapeutic angiogenesis has been shown to promote blood vessel growth and improve tissue perfusion.Nerve growth factor （NGF） has been reported to play an important role in both physiological and pathological angiogenesis.This study aimed to investigate the effects of NGF on angiogenesis and skeletal muscle fiber remodeling in a murine model of hindlimb ischemia and study the relationship between NGF and vascular endothelial growth factor （VEGF） in angiogenesis.Methods： Twenty-four mice were randomly allocated to normal control group （n =6）, blank control group （n =6）, VEGF gene transfection group （n =6）, and NGF gene transfection group （n =6）.The model of left hindlimb ischemia model was established by ligating the femoral artery.VEGF165 plasmid （125 μg） and NGF plasmid （125 μg） was injected into the ischemic gastrocnemius of mice from VEGF group and NGF group, respectively.Left hindlimb function and ischemic damage were assessed with terminal points at 21th day postischemia induction.The gastrocnemius of four groups was tested by hematoxylin-eosin staining, proliferating cell nuclear antigen and CD34 immunohistochemistry staining, and myosin ATPase staining.NGF and VEGF protein expression was detected by enzyme-linked immunosorbent assay.Results： On the 21th day after surgery, the functional assessment score and skeletal muscle atrophy degree of VEGF group and NGF group were significantly lower than those of normal control group and blank control group.The endothelial cell proliferation index and the capillary density of VEGF group and NGF group were significantly increased compared with normal control group and blank control group （P 〈 0.05）.The NGF and VEGF protein expression of NGF group showed a significant rise when compared with blank control group （P 〈 0.05）.Similarly, the VEGF protein expression of VEGF group was significantly higher than that of blank control group （P 〈 0.05）, but there was no significant difference of the NGF protein expression between VEGF group and blank control group （P 〉 0.05）.The type Ⅰ skeletal muscle fiber proportion in gastrocnemius of NGF group and VEGF group was significantly higher than that of blank control group （P 〈 0.05）.Conclusions： NGF transfection can promote NGF and VEGF protein expression which not only can induce angiogenesis but also induce type Ⅰ muscle fiber expression in ischemic limbs.

Microstructure and corrosion resistance of bone-implanted Mg-Zn-Ca-Sr alloy under different cooling methods

The cooling gradient of Mg-3 Zn-1 Ca-0.5 Sr alloy in cast ingots under different cooling methods(air cooling,warm-water cooling and ice-water-mixture cooling) was examined and the effect of cooling rate on the structure and corrosion properties was studied.The microstructure of the alloy was composed of α-Mg,Ca_(2) Mg_(6) Zn_(3) and Mg_(17)Sr_(2) phases.As the solidification cooling rate increased,the grain was refined,Zn and Sr were less segregated,the distributions of Zn and Sr were more uniform,and corrosion rate was found to first increase and then decrease;this contradicts the findings of recent research.With cooling rate increasing,the number of corroded microcouples comprising second phase and α-Mg increases.More α-Mg participates in corrosion,leading to a layered and deep corrosion pit and an increased corrosion rate.However,as the microstructure became sufficiently dense,the corroded structure protected the deep α-Mg from participating in corrosion,thus reducing the corrosion rate.

Microstructure and texture evolution of Mg–7Y–1Nd–0.5Zr alloy sheets with different rolling temperatures

The extruded Mg-7Y-1Nd-0.5Zr(wt%)alloy were performed to the same strain hot rolling with different temperatures.The microstructure and texture evolution of the sheets were investigated by optical microscopy(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD),and electron back-scattered diffraction(EBSD).The results indicate that the microstructure becomes homogeneous after hot rolling process and precipitated phase distributes at grain boundaries along rolling direction.With the increase in rolling temperature,the grains of sheet grow up.The sheet rolling at 400℃is composed of recrystallization grains,the necklace of the precipitated phase in the grain boundaries and excessive dislocations.The structure of necklace of the precipitated phase is fcc structure with lattice constant of a=0.75 nm.With rolling temperatures increasing from 400 to 450℃,the content of recrystallized grains in volume fraction with relatively random orientations increases significantly.Compared with the rolling process at 400℃,the amount of precipitated phases is reduced at the grain boundary,and the precipitated phase begins to appear in the grain interior when rolling at 450℃.The structure of the precipitated phase is fcc with lattice constant of a=2.22 nm.The recrystallization grains begin to grow in the rolling process at 500℃.The basal texture is obviously produced during the rolling process at 400 and 450℃;however,the basal texture is weak in the rolling process at 500℃.

Identification of a novel coronavirus causing severe pneumonia in human:a descriptive study

Background:Human infections with zoonotic coronaviruses(CoVs),including severe acute respiratory syndrome(SARS)-CoV and Middle East respiratory syndrome(MERS)-CoV,have raised great public health concern globally.Here,we report a novel batorigin CoV causing severe and fatal pneumonia in humans.Methods:We collected clinical data and bronchoalveolar lavage(BAL)specimens from five patients with severe pneumonia from Wuhan Jinyintan Hospital,Hubei province,China.Nucleic acids of the BAL were extracted and subjected to next-generation sequencing.Virus isolation was carried out,and maximum-likelihood phylogenetic trees were constructed.Results:Five patients hospitalized from December 18 to December 29,2019 presented with fever,cough,and dyspnea accompanied by complications of acute respiratory distress syndrome.Chest radiography revealed diffuse opacities and consolidation.One of these patients died.Sequence results revealed the presence of a previously unknownβ-CoV strain in all five patients,with 99.8%to 99.9%nucleotide identities among the isolates.These isolates showed 79.0%nucleotide identity with the sequence of SARS-CoV(GenBank NC_004718)and 51.8%identity with the sequence of MERS-CoV(GenBank NC_019843).The virus is phylogenetically closest to a bat SARS-like CoV(SL-ZC45,GenBank MG772933)with 87.6%to 87.7%nucleotide identity,but is in a separate clade.Moreover,these viruses have a single intact open reading frame gene 8,as a further indicator of bat-origin CoVs.However,the amino acid sequence of the tentative receptor-binding domain resembles that of SARS-CoV,indicating that these viruses might use the same receptor.Conclusion:A novel bat-borne CoV was identified that is associated with severe and fatal respiratory disease in humans.

Rationale and study design for one-stop assessment of renal artery stenosis and renal microvascular perfusion with contrast-enhanced ultrasound for patients with suspected renovascular hypertension

Background:Renal artery stenosis (RAS) is always associated with abnormalities in renal microvascular perfusion (RMP).However,few imaging methods can simultaneously evaluate the degree of luminal stenosis and RMP.Thus,this study will aim to evaluate the feasibility of using contrast-enhanced ultrasound (CEUS) for assessing both RAS and RMP to achieve a one-stop assessment of patients with suspected renovascular hypertension. Methods:This will be a single-center diagnostic study with a sample size of 440.Patients with chronic kidney disease (CKD) and suspected of having resistant hypertension will be eligible.Patients with Stages 1–3 CKD will undergo CEUS and computed tomography (CT) angiography (CTA).Values obtained by CEUS and CTA for diagnosing low-grade (lumen reduced by <60%) and high-grade (lumen reduced by ≥60%) RAS will be compared.Moreover,all patients will also undergo radionuclide imaging.The diagnostic value for RAS will be assessed by the receiver operating characteristic curve,including the accuracy,sensitivity,specificity,positive predictive values,negative predictive values,and area under the ROC.Pearson correlation analysis will be performed to assess the association between CEUS findings for RMP and glomerular filtration rate measured by a radionuclide imaging method. Conclusion:The data gathered from this study will be used to evaluate the feasibility of expanding clinical applications of CEUS for evaluation of patients with suspected renovascular hypertension.

Microstructure and phase transformation of as-cast and annealed Mg–4Zn–1Y alloy containing quasi-crystal phase

By means of optical microscope （OM）, X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM） analyses, the microstructures of as-cast and heat-treated Mg--4Zn-IY （wt%） alloy containing quasi-crystal phase were studied. The microstructure of the as-cast alloy consists of a-Mg solid solution grains, intermetallic particles and eutectic phases （W-phase and 1-phase）, and huge grains with seri- ous dendritic segregation are clearly observed. After heat treatment, phase transformation and dissolution occur in the alloy and many phases remain. When the alloy was treated above 410 ~C, the eutectic phases transform into spherical shape as the I-phase turns to W-phase. After heat treatment for long time, the alloy is over burnt and the W-phase decomposes to Mg-Y binary phase.