Antioxidant and Moisture-preserving Activities of Polysaccharides Obtained from Hericium erinaceus

[Objectives]The paper was to determine the physicochemical characteristics and antioxidant activity of three polysaccharide fractions(HP1,HP2 and HP3)obtained by ethanol precipitation from cold water,hot water and hot aqueous NaOH extracts of the fruiting body of Hericium erinaceus.[Methods]The chemical components,antioxidant and moisture-preserving activities of the three polysaccharides were determined.[Results]All the three polysaccharide extracts showed similar physicochemical characteristics and FT-IR spectra.HP1,which had the highest sugar content and lowest molecular weight,exhibited the best antioxidant activities against DPPH and hydroxyl radicals.HP3 exhibited the greatest ability to absorb and retain moisture.[Conclusions]These data demonstrate the potential utility of polysaccharides extracted form H.erinaceus in the cosmetics,food and pharmaceutical industries.

Analysis of ultrasound clinical early warning system in hyper-coiling umbilical cord

To the Editor:The umbilical cord is the vital link between the fetus and the placenta.The proper spiral state of the umbilical cord plays a key role in maintaining its function.The umbilical coiling index(UCI)is the number of spiral cycles per 1 cm of length and is normally 0.17,with UCI>0.30 considered hyper-coiling.^([1])Previous studies have identified hyper-coiling umbilical cord significantly associated with adverse pregnancy outcomes.^([2])However,many other studies have failed to find a strong correlation between abnormal coiling and adverse outcomes.^([3])Whether there are other abnormal ultrasound indicators in the hyper-coiling cord(HC)that can give early warning of adverse pregnancy still needs to be further explored.

The next-generation sequencing technology and application

As one of the key technologies in biomedical research,DNA sequencing has not only improved its productivity with an exponential growth rate but also been applied to new areas of application over the past few years.This is largely due to the advent of newer generations of sequencing platforms,offering ever-faster and cheaper ways to analyze sequences.In our previous review,we looked into technical characteristics of the nextgeneration sequencers and provided prospective insights into their future development.In this article,we present a brief overview of the advantages and shortcomings of key commercially available platforms with a focus on their suitability for a broad range of applications.

Synthesis and application of near-infrared substituted rhodamines

Near infrared(NIR) fluorescent probes are highly attractive in the field of fluorescent imaging of living organisms for their outstanding signal-to-noise ratio, strong tissue penetration and low biotoxicity.Herein, we summarized some recent progress in the synthesis and application of NIR rhodamines by replacing the bridging oxygen atom with main group elements such as silicon and phosphorus.

连续横向扫查结合连续冠状扫查对胎儿双主动脉弓的诊断价值

目的探讨连续横向扫查(CTS)结合连续冠状扫查(CCS)方法在胎儿右位主动脉弓合并镜像分支(MB-RAA)与胎儿双主动脉弓(DAA)鉴别诊断中的价值。方法采用队列研究方法,对2017年1月至2020年2月北京大学人民医院经产前超声CTS方法诊断的42例MB-RAA及DAA胎儿,利用CTS结合CCS方法复核上述诊断。随访至胎儿引产或出生后。采用McNemar检验比较CTS与CTS结合CCS方法对胎儿DAA的诊断准确率差异。结果采用CTS方法诊断MB-RAA胎儿39例(孤立性22例,合并心内畸形者15例,合并心外畸形者6例,其中合并心内、外畸形病例存在重叠),DAA胎儿3例(均未发现心内心外其他结构异常);采用CTS结合CCS方法复核,最终诊断MB-RAA胎儿32例,DAA胎儿10例(包括7例CTS方法诊断为孤立性MB-RAA者)。引产13例,足月分娩29例(包括10例产前诊断为DAA,17例产前诊断为孤立性MB-RAA,1例MB-RAA合并法洛四联症,1例MB-RAA合并轻度脑室增宽)。随访至胎儿出生后:1例MB-RAA合并法洛四联症胎儿出生后手术治疗,术中证实诊断;1例MB-RAA合并轻度脑室增宽及16例孤立性MB-RAA均无压迫症状;另1例孤立性MB-RAA出生后6个月出现喘鸣,行CT检查诊断为DAA,并行手术治疗;10例产前诊断为DAA的新生儿,2例出生后出现压迫症状行手术治疗,8例复查超声或CT均证实DAA,无压迫症状暂时观察。CTS结合CCS方法产前诊断DAA的诊断准确率高于CTS方法(10/42 vs 3/42),且差异具有统计学意义(P=0.016)。结论CTS结合CCS方法能提高产前超声诊断DAA的准确率,有助于DAA与MB-RAA的鉴别诊断。

江苏某校专本一体化“3+2”全科医学生心理健康状况调查

采用症状自评量表(SCL-90)及自制量表,于2021年10月至2022年1月对江苏某校2017—2021级在校的全体专本一体化“3+2”全科医学生进行心理健康状况调查,并与全国常模、医师常模及江苏省医学生常模进行比较。共回收有效问卷125份,SCL-90量表阳性检出率为17.6%(22/176)。调查对象的强迫(t=-2.47)、人际关系敏感(t=-2.00)、敌对(t=-2.65)、偏执(t=-3.14)和精神病性因子(t=-2.45)得分低于2015年全国常模,差异有统计学意义(P<0.05);与全国医师常模和江苏省医学生常模相比,除恐怖因子外,调查对象其余各因子得分均低于这两个常模,差异有统计学意义(均P<0.05);不同性别、不同培养阶段、不同生源的全科医学生之间总分和各因子差异均无统计学意义。SCL-90量表总分与全科相关理论及技能掌握情况(r=-0.18)、成就感获得(r=-0.23)呈负相关(P<0.05)。结果提示专本一体化“3+2”全科医学生心理健康水平总体优于各常模,并与全科相关理论及技能的掌握和成就感的获得情况等因素有关。

A biogeographic map of soil bacterial communities in wheats field of the North China Plain

The vast diversity of soil bacteria provides essential ecosystem services that support agricultural production.Variation in the diversity and composition of soil biota may have predictive values for soil nutrient cycling and resilience of ecosystem services,thus providing valuable insights to improve food production.The North China Plain(NCP)is one of the world’s key agricultural regions,supplying more than 50% of the cereal consumed in Asia.However,it is unknown whether soil microbial diversity is predictable across the NCP.Using the MiSeq Illumina platform,we examined bacterial community variation in relation to spatial and environmental factors from 243 soils in wheat-maize double cropping rotation fields across the NCP,which cover nearly 0.3 million km^(2).Based on observed bacterial communities and their relationships with environmental factors,we generated a map of bacterial communities across the NCP.The highest bacterial diversity was found in the middle part of the NCP,with most of the variation in diversity attributable to differences in the community similarity of Actinobacteria and Alphaproteobacteria.These findings provide important baseline information for analyzing the relationships between microbial community,soil functionality and crop yields.

Prenatal ultrasonographic characteristics and prognosis of isolated redundant foramen ovale flap

Objective:To analyze the prenatal ultrasonographic characteristics and prognosis of the isolated redundant foramen ovale flap(RFOF).Methods:From January 2014 to December 2021,we collected data on fetal echocardiography analyses and perinatal outcomes for fetuses with isolated RFOF in Peking University People's Hospital.Results:We found that 0.31%(87/28308)of participants have RFOF.The four-chamber results of the foramen ovale flap(FOF)showed that it was stiff and extended>50%or reached the lateral wall of the left atrium(LA)in diastole.As seen from the foramen ovale(FO)channel and four-chamber views,the hypermobile and redundant flap were observed shrinking and stretching with the fetal cardiac cycle,which is similar to jellyfish.The lateral displacement of flow from LA to the left ventricle(LV)around the FOF on color doppler demonstrated thin linear blood flow from the right to left and a reversal of flow across FO.A uniphasic,but not biphasic,pattern of FOF displacement was observed on M-mode.Stages I(23/87)and II(51/87)had a higher ratio of ventricular disproportion than Stage 0(11/87)and III(2/87).We observed the RA/LA(right/left atrium)>1.2 in 53 cases(60.9%),RV/LV(right/left ventricle)>1.2 in 53 cases(60.9%),PA/AO(pulmonary/aortic artery)>1.2 in 53 cases(60.9%),and moderate or severe tricuspid regurgitation in 10 cases and moderate pericardial effusion in 2 cases(2.2%).Seventy-four RFOF cases had follow-up data.Neonatal death occurred in 2 cases;72 fetuses survived with normal or minor heart defects.Conclusion:RFOF should be considered if the left side of the heart of a fetus is smaller and related to hypermobile FOF.For isolated RFOF cases,a monthly follow-up is recommended to monitor arrhythmia or fetal hydrop status.Prompt treatment is recommended for those with adequate gestational age and lung maturity.

Lowered water table causes species substitution while nitrogen amendment causes species loss in alpine wetland microbial communities

Alpine wetlands are hotspots of carbon(C)storage and methane emission,and they could be key contributors to global warming.In recent years,rapid warming has lowered the water table in alpine wetlands on the Tibetan Plateau,concurrent with intensified nitrogen(N)deposition via anthropogenic activities.We carried out a field experiment to investigate the ecological impacts of these two factors on soil bacterial and functional communities,which are essential drivers of greenhouse gas emissions.Nitrogen amendment alone decreased the phylogenetic alpha-diversity of bacterial communities which could be offset by lowered water table.In contrast,microbial functional alpha-diversity,revealed by a high-throughput microarray,remained unchanged.Both bacterial and functional beta-diversity responded to lowered water table,but only bacterial community responded to N amendment.The alpha-Proteobacteria,beta-Proteobacteria,and Bacteroidetes were the major responsive bacterial lineages,and C degradation,methanogenesis,alkaline shock,and phosphorus oxidation were the major responsive functional processes.Partitioning analysis revealed that N amendment changed bacterial community structure mainly via species loss processes but did not affect bacterial functional communities,with soil pH and ammonium as the key factors influencing changes in bacterial community structure.Conversely,lowered water table altered bacterial and functional communities through species substitution processes linked to soil pH and soil moisture.According to our results,the response mechanisms of microbial communities to lowered water table and N amendment are fundamentally different in alpine wetlands.

High-performance fiber strain sensor of carbon nanotube/thermoplastic polyurethane@styrene butadiene styrene with a double percolated structure

In this work,a high-performance fiber strain sensor is fabricated by constructing a double percolated structure,consisting of carbon nanotube(CNT)/thermoplastic polyurethane(TPU)continuous phase and styrene butadiene styrene(SBS)phase,incompatible with TPU(CNT/TPU@SBS).Compared with other similar fiber strain sensor systems without double percolated structure,the CNT/TPU@SBS sensor achieves a lower percolation threshold(0.38 wt.%)and higher electrical conductivity.The conductivity of 1%-CNT/TPU@SBS(4.12×10^(-3) S·m^(-1))is two orders of magnitude higher than that of 1%-CNT/TPU(3.17×10^(-5) S·m^(-1))at the same CNT loading of 1 wt.%.Due to double percolated structure,the 1%-CNT/TPU@SBS sensor exhibits a wide strain detection range(0.2%-100%)and an ultra-high sensitivity(maximum gauge factor(GF)is 32411 at 100%strain).Besides,the 1%-CNT/TPU@SBS sensor shows a high linearity(R^(2)=0.97)at 0%-20%strain,relatively fast response time(214 ms),and stability(500 loading/unloading cycles).The designed sensor can efficiently monitor physiological signals and movements and identify load distribution after being woven into a sensor array,showing broad application prospects in wearable electronics.