Spatiotemporal hemodynamic monitoring via configurable skin-like microfiber Bragg grating group

Systemic blood circulation is one of life activity’s most important physiological functions.Continuous noninvasive hemodynamicmonitoring is essential for the management of cardiovascular status.However,it is difficult to achieve systemichemodynamic monitoring with the daily use of current devices due to the lack of multichannel and time-synchronized operationcapability over the whole body.Here,we utilize a soft microfiber Bragg grating group to monitor spatiotemporalhemodynamics by taking advantage of the high sensitivity,electromagnetic immunity,and great temporal synchronizationbetween multiple remote sensor nodes.A continuous systemic hemodynamic measurement technique is developedusing all-mechanical physiological signals,such as ballistocardiogram signals and pulse waves,to illustrate the actualmechanical process of blood circulation.Multiple hemodynamic parameters,such as systemic pulse transit time,heartrate,blood pressure,and peripheral resistance,are monitored using skin-like microfiber Bragg grating patches conformallyattached at different body locations.Relying on the soft microfiber Bragg grating group,the spatiotemporal hemodynamicmonitoring technique opens up new possibilities in clinical medical diagnosis and daily health management.

手术治疗高度近视合并白内障的研究进展

高度近视的全球发病率逐年上升,高度近视与白内障密切相关,而高度近视合并特殊病理变化,使得高度近视合并白内障的手术难度及术后并发症远高于普通白内障手术,而随着屈光性白内障时代的到来,患者术后的视觉质量要求更高,对眼科医生的挑战也更大,因此对于高度近视合并白内障手术患者的管理需要得到我们的重视。本文对高度近视合并白内障的手术方式、术前生物学测量、术中术后常见的并发症做一综述。

Hepatitis C virus infections and genotypes in China

Objective: To define the conditions of hepatitis C vi- rus (HCV) infections, and geographic and demo- graphic distributions of genotypes in China. Methods: HCV infected patients were selected from individuals with different patterns of liver diseases and high risk populations in different parts of China. Genotypes of HCV in some isolates were further ana- lyzed, based on the data from our laboratory studies and some carefully selected published literatures. Results: The anti-HCV positive rates were 9.7% in patients with acute hepatitis, 13.3% in patients with chronic hepatitis, 18.3% in patients with hepatocel- lular carcinoma, 33.0% in patients with liver cirrho- sis, and 43.2% in patients with posttransfusional hepatitis (average, 16.2% in patients with liver di- seases). The anti-HCV positive rates in the high risk populations were 36.4% in leukemic patients, 43.0% in hemodialysis patients, 12.7% in blood do- nors, 64.1% in drug abusers, 13.1% in prostitutes, and 2.57% in naturally healthy people. At least 4 clades (clades 1, 2, 3 and 6) of HCV were found in China with different geographic and demographic distributions. Genotype 1b was the most widely dis- tributed genotype, and genotype 3 was mainly found in Yunnan Province, Southwest China. Conclusion: China has a high incidence of HCV in- fection. Our results will provide a strategic basis for diagnosis, treatment and possibly prophylaxis of he- patitis C virus diseases.

An efficiency algorithm on Gaussian mixture UKF for BDS/INS navigation system

To further improve the performance of UKF(Unscented Kalman Filter) algorithm used in BDS/SINS(BeiDou Navigation Satellite System/Strap down Inertial Navigation System), an improved GM-UKF(Gaussian Mixture Unscented Kalman Filter) considering non-Gaussian distribution is discussed in this paper. This new algorithm using SVD(Singular Value Decomposition) is proposed to alternative covariance square root calculation in UKF sigma point production. And to end the rapidly increasing number of Gaussian distributions, PDF(Probability Density Function) re-approximation is conducted. In principle this efficiency algorithm proposed here can achieve higher computational speed compared with traditional GM-UKF. And simulation experiment result show that, compared with UKF and GM-UKF algorithm, new algorithm implemented in BDS/SINS tightly integrated navigation system is suitable for handling nonlinear/non-Gaussian integrated navigation position calculation, for its lower computational complexity with high accuracy.

Sequence variability of the 5, UTR in isolates of hepatitis C virus in China

Background: Hepatitis C virus infection is a great is- sue in China; however, there is very little informa- tion on genotyping investigations based on sequence variability in the 5' untranslated (5'UTR) reported. The present study was to define the sequence varia- bility based on the sequence divergences of the 5' UTR of the virus. Methods: Sequences of 91 isolates from patients with chronic hepatitis C from Yunnan, southwest China, were sequenced and genotypes were defined accord- ing to the sequence divergences of the 5' UTR of the virus. Results: Eighty-six isolates were classified into 3 clades (previously termed groups or major types) by the methods proposed by Chan et al in 1992 and phy- logenetic analysis based on nucleotide sequence diver- gences within the 5' UTR. Fifty-six percent of the i- solates were classified into clade 3, 35% into clade 1, and 34.9% into clade 2. New genotypes 1f, 2h, 3h and 3i were defined. In addition, 3 novel sequences were discovered, respectively with an 18-nt sequence deletion (corresponding to nucleotide position -173 to -156), a 28-nt sequence insertion, and a 40-nt se- quence insertion, between -56 and -55. Of these i- solates, 56% possessed a 'G' at position -66 in place of the 'T' that is present in all previously re- ported sequences. Conclusions: These HCV variants, evolved or re- mained in this area, may be of great significance in diagnosis and treatment of hepatitis C patients.

Monolayer MoS_(2)of high mobility grown on SiO_(2)substrate by two-step chemical vapor deposition

We report a novel two-step ambient pressure chemical vapor deposition(CVD)pathway to grow high-quality Mo S_(2)monolayer on the Si O_(2)substrate with large crystal size up to 110μm.The large specific surface area of the pre-synthesized Mo O_(3)flakes on the mica substrate compared to Mo O_(3)powder could dramatically reduce the consumption of the Mo source.The electronic information inferred from the four-probe scanning tunneling microscope(4P-STM)image explains the threshold voltage variations and the n-type behavior observed in the two-terminal transport measurements.Furthermore,the direct van der Pauw transport also confirms its relatively high carrier mobility.Our study provides a reliable method to synthesize high-quality Mo S_(2)monolayer,which is confirmed by the direct 4P-STM measurement results.Such methodology is a key step toward the large-scale growth of transition metal dichalcogenides(TMDs)on the Si O_(2)substrate and is essential to further development of the TMDs-related integrated devices.

Effect of Templates on the Structure and Stability of Ti-TMS

Pure Mesoporous TiO2 molecular sieves (Ti-TMS) were synthesized with different templates for the first time and the templates can be successfully removed by refluxing the samples in the EtOH/H2O/KOH solution. The XRD pattern and TEM confirm that the uniformity and stability of Ti-TMS2 synthesized with dodecylamine as template is obviously inferior to that of Ti-TMS1 prepared with dodecylphosphate and hexadecylphosphate as templates. Furthermore, after the templates were removed, the mesostructure of Ti-TMS1 was preserved to a great degree than that of Ti-TMS2.

Local Density of States Modulated by Strain in Marginally Twisted Bilayer Graphene

In marginally twisted bilayer graphene,the Moirépattern consists of the maximized AB(BA)stacking regions,minimized AA stacking regions and triangular networks of domain walls.Here we realize the strain-modulated electronic structures of marginally twisted bilayer graphene by scanning tunneling microscopy/spectroscopy and density functional theory(DFT)calculations.The experimental data show four peaks near the Fermi energy at the AA regions.DFT calculations indicate that the two new peaks closer to the Fermi level may originate from the intrinsic heterostrain and the electric field implemented by back gate is likely to account for the observed shift of the four peaks.Furthermore,the d I/d V map across Moirépatterns with different strain strengths exhibits a distinct appearance of the helical edge states.

A Facile Synthesis of N-Substituted Spirocyclic Diester of α-Aminophosphonic Acid

A simple and direct method for preparation of N-substituted spirocyclic dieSter of □-amino phosphonic acid (4) in high yield is introduced. The reaction consists of the threecomponent reachon of phenylurea (1), an aromatic aldehyde (2), and 3,9-dichloro-2,4,8,10-tetraoxa- 3, 9 -diphosphaspiro [5,5] undecane (3) in anhydrous benzene.

Highly stable side-chain-type cardo poly(aryl ether ketone)s membranes for vanadium flow battery

Vanadium flow batteries(VFBs)have drawn considerable attention as an emerging technology for largescale energy storage systems(ESSs).One of the pivotal challenges is the availability of eligible ion exchange membranes(ICMs)that provide high ion selectivity,proton conductivity,and stability under rigorous condition.Herein,a‘side-chain-type’strategy has been employed to fabricate highly stable phenolphthalein-based cardo poly(arylene ether ketone)s(PAEKs)membrane with low area resistance(0.058Ωcm^(2)),in which flexible alkyl spacers effectively alleviated inductive withdrawing effect from terminal ion exchange groups thus enabling a stable backbone.The assembled VFBs based on PAEKs bearing pendent alkyl chain terminated with quaternary ammonium(Q-PPhEK)demonstrated an energy efficiency above 80%over 700 cycles at 160 mA/cm^(2).Such a remarkable results revealed that the side-chain-type strategy contributed to enhancing the ICMs stability in strong oxidizing environment,meanwhile,more interesting backbones would be woken with this design engaging in stable ICMs for VFBs.

Modeling Morning Commute with Different Kinds of Activities Based on Bottleneck Model

Morning commute problem has always been concerned by researchers in transportation research field.For the bottleneck existing in the road network between home and school,this paper studies the household travel with different kinds of activities,i.e.,home-school-home trip and home-school-workplace trip.Individuals just send their children to school and then go home,which is named school travel.Individuals need to send their children to school firstly and then go to work,which is named household travel.Firstly,according to the proportions of two types of travelers and school-work start time difference,the possible equilibrium cases are solved and the conditions for the occurrence of each case are revealed.Different from the traditional bottleneck model with a unique equilibrium traffic pattern,the mixed travel case has six possible equilibrium traffic patterns.Secondly,the cost of traveler is analyzed for all possible equilibrium traffic patterns.Result shows that equilibrium trip costs of two types of travelers are more sensitive to the number of travelers in that class than the number in another class in all possible equilibrium cases.Finally,the influence of school-work start time difference on the total travel cost is discussed.Result shows that the total system travel cost can be reduced by appropriately adjusting the difference of school-work start time.

A special issue for the 20^(th) anniversary of National Center for Nanoscience and Technology

National Center for Nanoscience and Technology(NCNST),China,established in December 2003,is co-founded by the Chinese Academy of Sciences(CAS)and the Ministry of Education as an institution dedicated to fundamental and applied researches in the field of nanoscience and technology,especially those with important potential applications.NCNST is operated under the supervision of the Governing Board and aims to become a world-class research center,as well as public technological platform and young talents training center in the field,and to act as an important bridge for international academic exchange and collaboration.The NCNST currently has three CAS Key Laboratories:the CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety,the CAS Key Laboratory for Standardization and Measurement for Nanotechnology and the CAS Key Laboratory for Nanosystem and Hierarchical Fabrication.In 2020,the CAS Key Laboratory of Nanophotonic Materials and Devices started construction.Besides,there are Division of Nanotechnology Development,Nanofabrication Laboratory,Intelligent Nanosensing Laboratory and Theoretical Laboratory.

Association between large artery stenosis,cerebral small vessel disease and risk of ischemic stroke

We aimed to assess the associations of large artery stenosis(LAS)and cerebral small vessel disease(CSVD)with the risk of ischemic stroke and to investigate their respective and combined contributions.In the prospective population-based Shunyi Study,1,082 stroke-free participants aged 55.9±9.1 years were included.Participants were followed for incident stroke throughout the study period(2013-2019).Total small vessel disease score was used to measure CSVD burden.Cervico-cerebral large artery stenosis was evaluated via brain magnetic resonance angiography and carotid ultrasound.We estimated the risk of ischemic stroke in relation to LAS and CSVD with Cox regression models.During a mean follow-up of 4.2 years,34 participants(3.1%)experienced at least one ischemic stroke.Severe LAS(≥50% stenosis versus no stenosis:HR=3.27(95%CI:1.31-8.18))and high CSVD burden(total small vessel disease score 2-4 versus 0 point:HR=12.73(4.83-33.53))were associated with increased stroke risk independently.In multivariate models,CSVD burden(7.72%)explained a larger portion of the variation in stroke risk than severity of LAS(3.49%).Our findings identified that both LAS and CSVD were associated with future ischemic stroke in asymptomatic subjects,while those with high CSVD burden deserve more attention in primary prevention of stroke.

Comparison of nonhuman primates identified the suitable model for COVID-19

Identification of a suitable nonhuman primate(NHP)model of COVID-19 remains challenging.Here,we characterized severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection in three NHP species:Old World monkeys Macaca mulatta(M.mulatta)and Macaca fascicularis(M.fascicularis)and New World monkey Callithrix jacchus(C.jacchus).Infected M.mulatta and M.fascicularis showed abnormal chest radiographs,an increased body temperature and a decreased body weight.Viral genomes were detected in swab and blood samples from all animals.Viral load was detected in the pulmonary tissues of M.mulatta and M.fascicularis but not C.jacchus.Furthermore,among the three animal species,M.mulatta showed the strongest response to SARS-CoV-2,including increased inflammatory cytokine expression and pathological changes in the pulmonary tissues.Collectively,these data revealed the different susceptibilities of Old World and New World monkeys to SARS-CoV-2 and identified M.mulatta as the most suitable for modeling COVID-19.

基于线上自主学习和考核的标准切面强化培训在产科超声教学中的应用

目的探讨基于线上自主学习和考核的产科超声教学模式对规范化培训学员识别产科超声标准切面能力的效果。方法2021年3月纳入21名在北京协和医院超声医学科参加住院医师规范化培训的学员,应用调查问卷收集学员对产科超声的教学需求,以胎儿颅脑、胸腹腔和心脏3个部位的标准切面及标志性结构为培训内容录制讲课视频。学员通过线上自主学习形式,完成标准切面强化培训及考核。应用χ^(2)检验对比培训前后学员答题正确率的差异。结果大部分学员(95.2%,20/21)认为产科超声培训非常重要并且非常愿意参加;考核题目包含胎儿颅脑、胸腹腔、心脏3个部位标准切面的标志性结构识别共22题。培训前学员答题总正确率为79.9%(369/462),培训后学员答题总正确率提高为88.7%(410/462),其中,学员对心脏标志性结构识别的正确率提高11.5%(87.7%vs76.2%),培训前后答题正确率比较,差异具有统计学意义(χ^(2)=11.28,P=0.001)。结论基于线上自主学习和考核的标准切面强化培训,提高了规范化培训学员对胎儿颅脑、胸腹腔和心脏系统标准切面中标志性结构的识别能力,可作为产科超声培训的有效手段。

Detecting molecular vibrational modes of side chains and endpoints in nanoscale proteins with graphene plasmon

Monitoring the chemical and structural changes in protein side chains and endpoints by infrared(IR)spectroscopy is important for studying the chemical reaction and physical adsorption process of proteins.However,the detection of side chains and endpoints in nanoscale proteins is still challenging due to its weak IR response.Here,by designing a double layered graphene plasmon sensor on MgF2/Si substrate in the IR fingerprint region,we detect the vibrational modes in side chains and endpoints(1397 cm^-1 and 1458 cm^-1)of monolayer protein.The sensor could be applied on biochemistry to investigate the physical and chemical reaction of biomolecules.

Saliva-based point-of-care testing techniques for COVID-19 detection

Saliva has recently attracted increasing interest for disease diagnosis since it presents a rich pool of biological markers such as proteins,DNA,RNA,hormones,microorganisms.Notably,saliva collection is convenient and safe,making it a perfect candidate for point-of-care testing(POCT)techniques.Several saliva-based POCT devices have been developed for large-scale pandemic screening,self-diagnosis,daily health monitoring.

原子制造的物质科学基础

近年来,原子制造技术备受关注,已成为各国积极追求的前沿制造技术领域.一代物质科学,一代制造革新,原子制造技术的发展不仅仰赖于深厚的物质科学底蕴,还需要解决高效的原子精准操控与测量、原子尺度结构的物性设计等多个方面的基础科学问题.2023年3月,国家自然科学基金委员会交叉科学部在武汉召开了主题为“原子制造的物质科学基础”的战略研讨会.本文基于会议研讨的相关内容,对原子制造技术的发展背景、概念内涵以及面临的挑战进行了凝练,并提出如何利用该技术推动物质科学的快速发展,同时也就国家自然科学基金委员会对该领域的顶层设计和战略规划提出了政策建议.