查看更多>>摘要：Understanding the structure and function of life requires the study of its basic constituent unit—ells.Cell bio-function depends largely on the coordinated expression of different genes.Traditional sequencing methods (such as DNA sequencing,and bulk RNA-seq) are performed on cell populations or tissue samples,in which biological differences between cells can be easily obscured by sample averaging and technical noises.Single-cell sequencing,an emerging technique in recent years,contributes extensively to understanding biological phenomena and studying the mechanism of diseases.Sequencing the genome of individual cells could reveal gene mutations,while single-cell transcriptome sequencing helps uncover the expression variability of genes,and most importantly,heterogeneous cells from the same samples.In this review,we will give an overview of the single-cell sequencing technique and its current applications in one of the most popular research fields: neuroscience research.
查看更多>>摘要：Cancer is a major public health problem worldwide and its overall morbidity and mortality have been increasing every year.The growth,invasion and metastasis of cancer are vital traits of malignancy causing extreme difficulties in therapeutic management.These behavioral characteristics of cancer are closely related to tumor angiogenesis.The argument was put forward that tumorigenesis depended on the formation of new blood vessels,which gained insight into a promising treatment strategy for cancer based on the inhibition of tumor angiogenesis.To date,many new therapeutic strategies targeting tumor vessels are universally accepted and become a hotspot in oncology research.Angiomotin (Amot),encoded by Amot gene,is expressed predominantly in endothelial cells of capillaries as well as larger vessels of the placenta.During the formation of new blood vessels,Amot may play an inhibitory effect of angiostatin on tube formation and the migration of endothelial cells toward growth factors.In this review,we summarized the structure and function of Amot,and its mechanism and research progress in cancer.
查看更多>>摘要：Leptospirosis,a major zoonotic disease widespread in the world,would infect humans and other animals by direct contacting with the soil or water contaminated by the pathogenic leptospires.This report analyzes the accuracy of polymerase chain reaction (PCR) assay used in the detection of leptospira specific genes in humans.Seventeen published articles which included 2 526 samples satisfied all inclusion standards and were applied to meta-analysis.Pooled sensitivity and specificity were 0.73 (95％ CI 0.70-0.76) and 0.94 (95％ CI 0.93-0.95),respectively.Heterogeneity was statistically significant among studies,but none of the sources for heterogeneity (disease stage,PCR type,targeted genes) could adequately interpret this finding.Meta-regression advised that real-time PCR (qPCR) targeted 16s rRNA would be the best choice for early detection of cases during the acute stage of the disease and was accounted as a good screening tool in all stages of the disease.
查看更多>>摘要：We retrospectively investigated 68 parturients with or without COVID-19 undergone emergency cesarean section with combined spinal-epidural anesthesia (CSEA) from a single tertiary university hospital in Wuhan,China.The cases were divided into 2 groups: patients with COVID-19 pneumonia (Group 1) and cases without COVID-19 pneumonia (Group 2).The patients in Group 1 were later divided into 2 groups: patients with low-angiotensin converting enzyme (ACE) (Group 3) and patients with normal-ACE (Group 4).The ACE levels,blood pressure and anesthesia management between the patients of Group 1 and Group 2,Group 3 and Group 4 were recorded as the primary outcome.The secondary outcome included perioperative symptoms,laboratory parameters and vital signs.Compared with Group 2,the patients in Group 1 had different ACE level and lower blood pressure after CSEA.Compared with Group 4,the patients in Group 3 showed lower SBP after CSEA (127 vs.130 mmHg,p=0.028),accompanied with more partus matures and younger age (28 vs.32 years,p=0.007).ACE may be a possible biomarker to predict the anesthesia effects on patients with COVID-19 infections undergoing emergency cesarean delivery.
查看更多>>摘要：The purpose of this study was to primarily culture human periodontal ligament cells (hPDLCs) and to reprogram hPDLCs with exogenous genes via a lentivirus-mediated transfection system.Then induced pluripotent stem cells derived from hPDLCs (hPDLC-iPSCs) were identified.Alizarin red staining was used to observe the formation of mineralized nodules and real-time Polymerase Chain Reaction (PCR) was used to detect the expression of osteogenic genes.For the in vivo experiment,nude mouse skull defect models were established and cell sheets were made to repair the bone defect.The reprogrammed cells were positive for alkaline phosphatase (ALP) staining and embryonic stem cells (ESCs)-specific proteins,and could form teratomas.After osteogenic induction,alizarin red staining showed that the number of mineralized nodules in the hPDLC-iPSCs group was more and the osteogenic related factors ALP,osteocalcin (OCN),CoM and Runx2 were also expressed higher in hPDLC-iPSCs.The hPDLC-iPSC cell sheets were all successfully made.Histological analysis showed that the hPDLC-iPSC cell sheet got new bone formation.These results demonstrated that hPDLC-iPSCs were successfully generated from human periodontal ligament fibroblasts and hPDLC-iPSC cell sheets provided new options for bone tissue engineering.
查看更多>>摘要：Anxiety is a common reaction of men undergoing assisted reproductive treatment.Our study aims to explore the risk factors of anxiety among men receiving assisted reproductive treatment.We found that the men who have primary school education were more anxious than those who have higher level education including junior middle school (X2=13.01,P＜0.01),senior middle school (X2=5.63,P=0.02),junior college (X2=6.94,P=0.01)and higher education (X2=13.78,P＜0.01).Moreover,the men who have severe financial burden were more anxious than the men who have mild (X2=9.54,P＜0.01) or moderate (X2=6.30,P=0.01)burden.For trait anxiety,the independent risk factor was financial burden of treatment.Therefore,we suggest that for men who prepare to receive assisted reproductive treatment,especially for men who had financial burden for treatment or only received primary education,pre-treatment counseling or psychological intervention should be provided.
查看更多>>摘要：A novel 4-tert-butyl-N'-(4-(1,2,2-triphenylvinyl) benzylidene) benzohydrazide (TBB) was successfully synthesized in simple one-step process.It was characterized by FT-IR,1H NMR,13C NMR and HRMS.Its fluorescence sensing ability to 15 metal ions was investigated.Weak emission from TBB could be efficiently increased by trace Hg2+,through coordination reaction between TBB and Hg2+ with "turn on" character.The fluorescence intensity of TBB/Hg2+ ([TBB]=3.0× 10-6 mol/L,[Hg2+]=1.3 × 10-4 mol/L) was 7.5 times higher than that of TBB.This TBB sensor exhibited high selectivity for Hg2+ and other metal ions did not interfere in this determination.The limit of detection was 0.566 μmol/L (S/N=3).The experimental results showed that this TBB sensor could sensitively respond to Hg2+ within concentration range (from 5 × 10-6 mol/L to 1.3 × 10-4 mol/L).
查看更多>>摘要：In this paper,we reported a facile additive-free route for synthesizing calcium carbonate (CaCO3) with different morphologies and polymorphs by a precipitation reaction method between Ca(CH3COO)2 and NaHCO3 in water and ethylene glycol (H2O/EG) mixed solvent.It has been found that the concentration of Ca2+ and HCO3-,the volume ratio of H2O/EG and the reaction temperature are turned out to be important parameters for the morphology and polymorph of CaCO3.Various interesting morphologies,such as the spherical,elliptoid,spindle-like,petal-like,cricoid,cubic,plate-like and rod-like can be easily obtained.Pure polymorphs of vaterite,calcite and aragonite can also be tuned by adjusting experimental conditions.The studies might be helpful to provide new insights into the morphosynthesis and crystalline phase control of other inorganic materials.O 611.4;O 643.1
查看更多>>摘要：In this work,an original Sallen-Key second-order low-pass filter is first turned into a current-mode one by means of the adjoint network theorem.Two nodal admittance matrices (NAM) of the filter are then educed.Furthermore,these two matrices are expanded through NAM expansion approach,generating one current-mode Sallen-Key filter,which uses two compact voltage differential trans-conductance amplifiers (VDTAs) and two grounded capacitors,implements not only one low-pass transfer function but two band-pass transfer functions,and provides the non-interrelated control between the natural frequency and quality factor.As an example of the synthesized filter,a second-order VDTA filter withf0=1 MHz,Q=1,HLp=-HBP1=HBP2=1 is designed.The used synthesis approach has been confirmed with the help of circuit and computer analysis.
查看更多>>摘要：Chaotic sequence has been applied in Cognitive Radio (CR) to exert the enormous potential spectral utilization and enhance the transmission security.However,since there is not strict orthogonality between chaotic signals,intra-signal interference (ISI) will be introduced into the demodulation.Here,an anti-interference orthogonal-frequency-division-multiplexing (OFDM) chaotic modulation named Walsh-sequence chaotic CR (WS-CCR) is proposed for cognitive radio.By constructing the strictly orthogonal chaotic signal based on Walsh sequence,the ISI component,which is produced by frequency offset in previous CR,can be eliminated during the demodulation.Moreover,the chaotic sequence can also be applied to scramble subcarriers to relieve the interference caused by malicious attacks.Gaussian approximation method is adopted to obtain the exact performance analysis of WS-CCR over Additive White Gaussian Noise (AWGN) channel and Rayleigh multipath fading channel.Results show that,with subcarriers scrambling by chaotic sequence,anti-interference performance and transmitting security can be significantly improved in WS-CCR.Importantly,due to the absence of ISI component,the bit-error ratio (BER) performance of WS-CCR is better than that of the previous CR system.
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