AUV-Aided Data Collection Considering Adaptive Ocean Currents for Underwater Wireless Sensor Networks

Autonomous underwater vehicle(AUV)-assisted data collection is an efficient approach to implementing smart ocean.However,the data collection in time-varying ocean currents is plagued by two critical issues:AUV yaw and sensor node movement.We propose an adaptive AUV-assisted data collection strategy for ocean currents to address these issues.First,we consider the energy consumption of an AUV in conjunction with the value of information(VoI)over the sensor nodes and formulate an optimization problem to maximize the VoI-energy ratio.The AUV yaw problem is then solved by deriving the AUV's reachable region in different ocean current environments and the optimal cruising direction to the target nodes.Finally,using the predicted VoI-energy ratio,we sequentially design a distributed path planning algorithm to select the next target node for AUV.The simulation results indicate that the proposed strategy can utilize ocean currents to aid AUV navigation,thereby reducing the AUV's energy consumption and ensuring timely data collection.

A Quorum Sensing Active Matter in a Confined Geometry

Inspired by the problem of biofilm growth,we numerically investigate clustering in a two-dimensional suspension of active(Janus)particles of finite size confined in a circular cavity.Their dynamics is regulated by a non-reciprocal mechanism that causes them to switch from active to passive above a certain threshold of the perceived near-neighbor density(quorum sensing).A variety of cluster phases,i.e.,glassy,solid(hexatic)and liquid,are observed,depending on the particle dynamics at the boundary,the quorum sensing range,and the level of noise.

膀胱癌精准化新辅助化疗研究进展

根治性膀胱切除术(radical cystectomy,RC)是肌层浸润性膀胱癌(muscular invasive bladder cancer,MIBC)患者的标准治疗,术后5年总生存率仅约50%,而术前新辅助化疗(neoadjuvant chemotherapy,NAC)提高了患者的总生存率。虽各指南均推荐行NAC,但部分患者对NAC无治疗反应,不能从中获益。采用NAC治疗反应的筛选方法对行NAC的患者是否受益进行识别,是实现个体化、精准化治疗的关键所在,但在临床实践中目前尚无一种可靠的筛选方法。本文将对膀胱癌精准化NAC及NAC反应的筛选方法进行综述。

铜催化苯硼酸与苯并呋咱-1-氧化物的胺化反应（英文）

C-N键普遍存在于药物和有机功能分子中,传统构建C-N键的方法包括Goldberg反应、Buchwald-Hartwig偶联、Chan-Lam偶联和C-H键活化胺化.虽然这些方法都可以高效构建C-N键,但它们需要使用官能化的芳基底物、官能化的胺化试剂或在氧化条件下进行.理想的胺化反应应在氧化还原中性条件下进行,更为理想的则是在引入氨基的同时引入另外一个官能团.实现这个目标最直接的策略就是使用氮杂环,通过N-E(E=N或O)键的断裂,N原子和E原子可同时被引入.最近我们课题组利用氨茴内酐和氮杂苯并降冰片烯的C-H键活化反应成功实现了这种双官能团化.尽管该法很有吸引力,但是要通过氮杂环的断裂实现双官能团化,需要发生非张力环的开环,这在热力学上是非常不利的.苯并呋咱-1-氧化物可以开环得到邻二硝基苯中间体.基于对胺化反应的兴趣,我们推测苯并呋咱1-氧化物可以作为一个胺化试剂实现苯硼酸的胺化.尽管亚硝基苯对芳基硼酸进行简单的胺化已经被报道,但需要化学计量的铜盐,或是引入还原剂.因此本文报道铜催化的苯硼酸的胺化反应,该反应以苯并呋咱1-氧化物为胺化试剂,在温和及氧化还原中性条件下成功实现了双官能团化.本文共完成了31个不同官能团取代的硝基苯胺骨架结构的合成,反应均以中等到良好的收率得到目标产物,最高收率可达99%.为了增加反应的实用性,我们还进行了放大实验,实验表明,当苯并呋咱-1-氧化物的量由0.2 mmol放大至4 mmol时,反应仍能以较高的收率得到目标产物.此外,目标产物通过进一步的衍生化反应还可方便地转化为其他杂环类化合物.例如,在PPh_3作用下,通过还原环化作用可生成吩嗪.在钯催化下可发生分子内碳氢键氧化反应得到咔唑类化合物.通过还原及重氮化反应还可方便地转化为苯并三唑.总之,我们以苯并呋咱-1-氧化物为胺化试剂,在铜催化下成功实现了苯硼酸的胺化反应,合成了一系列双官能团化产物.该催化体系反应条件温和,底物适用范围广,对各种官能团具有很好的兼容性.

Methylenetrahydrofolate Reductase Gene C677T Polymorphism and Diabetic Retinopathy: a Meta-Analysis

Objective To investigate the association between the methylenetetrahydrofolate reductase gene C677T(MTHFR C677T)polymorphism and diabetic retinopathy(DR).Methods A total of 6971 subjects including 2707 DR patients and 4264 controls from 23 studies were enrolled in the study.A random-effects model was applied to estimate the overall effects and the stratified effects of the MTHFR C677T polymorphism on the risk of DR,and study quality was also assessed.Results Strong associations were observed between the MTHFR C677T polymorphism and DR.The carries of MTHFR C677T were more likely to be found in the DR group in relative to the healthy control group with odds ratio 1.6&2.55,and 2.31 respectively in allele contrast model(T vs.C,95%CZ:1.29-2.18,P<0.001,f=7&4%),homozygous model(TT vs.CC,95%CZ:1.70-3.83,P=0.008,72=54.4%)and dominant model(TT+CT vs.CC,95%CZ:1.62-3.29,P<0.001,12=74.7%).This association can also be found in contrast to the Ned(non-complicated diabetic mellitus)group(allele contrast,OR—1.50,95%Ch 1.07-2.11,P=0.032,I2=62.1%;homozygous,OR—2.39,9S%CZ:1.06-5.38,P=0.017,Z2=66.7%;dominant,OR=1.59,95%CZ:0.97-2.62,P=0.056,I2=56.5%).For the heterozygous model(CT vs.CC),the association was significant in contrast to the healthy control group(OR=1.46,95%CZ:1.64-3.69,P=0,P=77.3%),while in contrast to the Ned control group the association was not statistically meaningful(OR=1.38,95%CZ:0.87-2.18,P=0.131,Z2=43.7%).For the recessive model,1.92-fold increased risk was found only in contrast to the Ned control group(95%C1:1.07-3.43,P=0.064,P=55.0%).There was no significant association found in the models in contrast to the DM control group.Conclusion In this meta-analysis,we found an association between the MTHFR C677T polymorphism and DR,especially in contrast to the Ned control group.Further studies are required to establish more definite relationship.

Excess Diffusion of a Driven Colloidal Particle in a Convection Array

We numerically investigate the transport of a passive colloidal particle in a periodic array of planar counterrotating convection rolls,at high Peclet numbers.It is shown that an external bias,oriented parallel to the array,produces a huge excess diffusion peak,in cases where bias and advection drag become comparable.This effect is not restricted to one-dimensional convection geometries,and occurs independently of the array’s boundary conditions.

Clustering of quorum sensing colloidal particles

We propose a simple model of colloidal suspension,whereby individual particles change their diffusivity from high(hot)to low(cold),as the local concentration of their closest peers grows larger than a certain threshold.Such a non-reciprocal interactive mechanism is known in biology as quorum sensing.Upon tuning the parameters of the adopted quorum sensing protocol,the suspension is numerically shown to go through a variety of two-phase(hot and cold)configurations.This is an archetypal model with potential applications in robotics and social studies.

MIL-101(Cr)-decorated Ti/TiO_(2) anode for electrochemical oxidation of aromatic pollutants from water

Hydroxyl radicals(·OH) generated on anode play a vital role in electrochemical oxidation(EO) of organic pollutants for water treatment. Inspired by the four-electron oxygen evolution reaction(OER), we supposed an anode-selection strategy to stabilize deeply oxidized states(*O and*OOH) which are beneficial to generating·OH. To verify the hypothesis, a candidate anode component(MIL-101(Cr), a well-known metal-organic framework with active variable-valence transition metal centers) was used to coat Ti/TiO_(2)plate to fabricate anodes. Compared to TiO_(2)(101) plane on undecorated anode surface, fast and complete removal of aniline and phenol, and improved energy utilization were achieved on MIL-101(Cr)-coatedTi/TiO_(2)anode. Mechanism investigation, including pollutant degradation pathways, showed the predominate contribution(69.60%–75.13%) of·OH in pollutant mineralization. Density functional theory(DFT)computations indicated Cr site in MIL-101(Cr) was more conducive to stabilizing*O and*OOH, leading to thermodynamical spontaneous generation of·OH. This work opens up an exciting avenue to explore·OH production, and supplies a useful guidance to the development of anode materials for EO process.

Molecular characterization of organic matter transformation mediated by microorganisms under anoxic/hypoxic conditions

Dissolved organic matter(DOM) in the ocean is one of the largest carbon pools on Earth. Microbial metabolism is an important process that shapes the marine DOM pool. Current studies on the interactions between microorganisms and DOM focus mainly on oxic environments. Few studies have addressed the molecular characteristics of DOM in microbial-mediated transformation under anoxic/hypoxic conditions. As a result of deteriorating water quality due to eutrophication and global warming, anoxia occurs frequently in coastal waters. In this study, we performed an experiment to investigate changes in microbial community responses and the molecular characteristics of DOM in microbial-mediated transformation under hypoxic conditions. We compared microbial-mediated DOM transformation at different dissolved oxygen levels(7, 5, and 2 mg L^(-1)) and in different media(natural and artificial seawater with and without laminarin). We also investigated differences in DOM composition between groups using spectroscopic analysis and ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry. The results showed decreased microbial metabolic activity and delayed community succession at low oxygen(≤2 mg L^(-1)) in natural seawater supplemented with laminarin. The growth of strictly aerobic bacteria such as Pseudomonadaceae and Sphingomonadaceae was inhibited and the total organic carbon utilization rate was reduced by 36.9–46.7% from 4 to 32days. Moreover, tyrosine-like and tryptophan-like components were preserved, while DOM humification and modified aromaticity indices were significantly reduced under low oxygen conditions. This experiment provides justification for further study of the processes and mechanisms of improved labile DOM preservation in anoxic estuarine and coastal waters.

全球铝土矿贸易格局演化及中国贸易特征

我国铝土矿资源供给长期难以满足需求,需要从海外进口大量的优质铝土矿来满足国内需求。为了研究经济政策等要素对铝土矿国际贸易格局的影响,以2012—2022年全球铝土矿贸易额作为数据来源,运用复杂网络分析方法,构建了铝土矿贸易随机网络和加权网络,对全球铝土矿贸易格局演变、主要贸易国地位演变和中国铝土矿贸易网络特征进行研究。结果表明:(1)全球铝土矿贸易网络规模具有稳健性,但其贸易网络结构具有不对称性,国家之间的贸易联系较为分散,全球铝土矿贸易呈碎片化特征。(2)全球铝土矿贸易国家中,澳大利亚与中国分别为出入强度最大的国家,但二者中介控制能力均有待加强,印度的中介控制能力较强,起到“桥梁”的作用。(3)中国是全球第一大铝土矿进口国,出口贸易额排名也不断上升,且进出口市场格局均较为集中。未来中国扩大铝土矿进口市场格局,潜在可选范围较为广泛:一方面中国仍然可以继续对澳大利亚、印度尼西亚、巴西和圭亚那等传统贸易国家加大进口份额;另一方面,中国可以利用地缘优势加强对土耳其、印度等“一带一路”沿线国家的铝土矿进口。

Non-Gaussian normal diffusion in low dimensional systems

Brownian particles suspended in disordered crowded environments often exhibit non-Gaussian normal diffusion(NGND),whereby their displacements grow with mean square proportional to the observation time and non-Gaussian statistics.Their distributions appear to decay almost exponentially according to“universal”laws largely insensitive to the observation time.This effect is generically attributed to slow environmental fluctuations,which perturb the local configuration of the suspension medium.To investigate the microscopic mechanisms responsible for the NGND phenomenon,we study Brownian diffusion in low dimensional systems,like the free diffusion of ellipsoidal and active particles,the diffusion of colloidal particles in fluctuating corrugated channels and Brownian motion in arrays of planar convective rolls.NGND appears to be a transient effect related to the time modulation of the instantaneous particle’s diffusivity,which can occur even under equilibrium conditions.Consequently,we propose to generalize the definition of NGND to include transient displacement distributions which vary continuously with the observation time.To this purpose,we provide a heuristic one-parameter function,which fits all time-dependent transient displacement distributions corresponding to the same diffusion constant.Moreover,we reveal the existence of low dimensional systems where the NGND distributions are not leptokurtic(fat exponential tails),as often reported in the literature,but platykurtic(thin sub-Gaussian tails),i.e.,with negative excess kurtosis.The actual nature of the NGND transients is related to the specific microscopic dynamics of the diffusing particle.