缉“毒”除污的微纳米机器人

现代社会中,化学和相关工业的快速发展导致水环境污染问题日益严重,这对水质检测以及水资源的处理技术提出了更高的要求,然而目前尚难以快速、高效地实现对低浓度、痕量的污染物的检测和处理。为此,科学家们设计出一类新型的智能材料——微纳米机器人。基于微纳米机器人的可控运动性能、精准识别能力、高效吸附效果和原位降解能力,可以对痕量污染物建立高灵敏度的响应,从而实现水中污染物的有效检测与处理。为了能够让广大读者深入理解微纳米机器人在水污染检测和处理领域的发展前沿和未来研究趋势,本文以微纳米机器人组织“污染刺客联盟”为背景,简单有趣地介绍了微纳米机器人在水环境检测、监测和处理方面的应用及其科学机理。

Effects of Spring Biomass Burning in the Indochina Peninsula on May Precipitation in South China

Each year, during the dry season that precedes the summer wind and rainfall Indo-China Peninsula (ICP), significant biomass burning occurs and reaches its peak from March to April. This biomass burning generates large amounts of aerosols that impact East Asia and surrounding areas through the Asian monsoon. This study aims to investigate the potential connection between biomass burning over the ICP and precipitation in South China during May, along with the physical processes involved. The analysis is based on GLDAS soil moisture reanalysis data and CPC (NOAA) precipitation data covering the period from 1980 to 2021. The research findings indicate a negative (positive) correlation between biomass burning in the ICP region during spring and precipitation in the same region (South China) during May. The circulation patterns corresponding to years with biomass-burning emission anomalies are further investigated, and the impact of biomass-burning emissions in spring on soil moisture and temperature is examined. The results suggest that biomass-burning emissions can significantly affect atmospheric circulation and precipitation, ultimately leading to anomalous precipitation in South China.

Determination of Meclofenoxate Content in Meclofenoxate Hydrochloride for Injection by DSC and 1H-NMR

Two simple and rapid analytical methods (DSC and 1H-NMR), are proposed for determination of meclofenoxate in meclofenoxate hydrochloride for injection. DSC thermogram is recorded without any sample pretreatment. The response linearity is ensured by linear determination factors R2, which is 0.9982. The recoveries of meclofenoxate hydrochloride in sterile powder for injection are from 98.3% to 102.3% (n = 3). The quantitative 1H-NMR is quick and simple to use. The quantitation of meclofenoxate is reproducible and the relative standard deviation is 1.0%. The accuracy of two methods is validated by comparison with the results obtained by HPLC. The results show that the two methods are capable of quantifying the content of meclofenoxate in meclofenoxate hydrochloride for injection.

Analysis of atmospheric effects on the continuous variable quantum key distribution

Atmospheric effects have significant influence on the performance of a free-space optical continuous variable quantum key distribution(CVQKD)system.In this paper,we investigate how the transmittance,excess noise and interruption probability caused by atmospheric effects affect the secret-key rate(SKR)of the CVQKD.Three signal wavelengths,two weather conditions,two detection schemes,and two types of attacks are considered in our investigation.An expression aims at calculating the interruption probability is proposed based on the Kolmogorov spectrum model.The results show that a signal using long working wavelength can propagate much further than that of using short wavelength.Moreover,as the wavelength increases,the influence of interruption probability on the SKR becomes more significant,especially within a certain transmission distance.Therefore,interruption probability must be considered for CVQKD by using long-signal wavelengths.Furthermore,different detection schemes used by the receiver will result in different transmission distances when subjected to individual attacks and collective attacks,respectively.

Optimization of a High-pressure Water-Powder Mixing Prototype for Offshore Platforms

A new device is designed to promote the mixing of high-pressure water jets and powders in typical industrial applications.The water and powder mixing devices traditionally used on offshore platforms are detrimentally affected by the geometrical configuration of the water nozzle and the powder spraying pipe,which are parallel,resulting in small intersecting volumes of liquid and powder.By allowing the related jets to intersect,in the present work the optimal horizontal distance,vertical distance and intersection angle are determined through a parametric investigation.It is also shown that such values change if the number of water layers is increased from one to two.In such a case,the water and powder intersection volume can be greatly increased because the trajectory of the dry powder particles becomes more chaotic.

Solvent Effects on the UV Absorption Spectrum of Carmofur

In this article, we reported that carmofur could be induced by some solvent to produce conformational alteration. Ultraviolet (UV) spectra were used to study the conformation alteration of carmofur. Upon the addition of acid in the some solvent, UV spectroscopy of carmofur could change gradually. When base was added to this system, UV spectroscopy of carmofur could return to the original state, and the change process was reversible. The variable temperature 1H and 13C-NMR spectrum were used to testify that temperature did not have any effect on the conformation alteration of carmofur in Acetonitrile: Trifluoroacetic-acid (9:1). These two conformers of carmofur were structurally stable in Acetonitrile: Trifluoroacetic-acid (9:1).

微分定义的演变及其内蕴的逻辑错误

本文认真梳理了微分概念产生、发展与演变的历史,搜集整理了各国数学分析相关教材中微分的定义并将其归纳为三类;详细分析了三类微分定义中内蕴的逻辑错误,在此基础上呼吁学界重新审视现行微积分体系,揭示真正的微积分原理并发展微积分方法。

The super-pangenome of Populus unveils genomic facets for its adaptation and diversification in widespread forest trees

Understanding the underlying mechanisms and links between genome evolution and adaptive innovations stands as a key goal in evolutionary studies.Poplars,among the world’s most widely distributed and cultivated trees,exhibit extensive phenotypic diversity and environmental adaptability.In this study,we present a genus-level super-pangenome comprising 19 Populus genomes,revealing the likely pivotal role of private genes in facilitating local environmental and climate adaptation.Through the integration of pangenomes with transcriptomes,methylomes,and chromatin accessibility mapping,we unveil that the evolutionary trajectories of pangenes and duplicated genes are closely linked to local genomic landscapes of regulatory and epigenetic architectures,notably CG methylation in gene-body regions.Further comparative genomic analyses have enabled the identification of 142202 structural variants across species that intersect with a significant number of genes and contribute substantially to both phenotypic and adaptive divergence.We have experimentally validated a∼180-bp presence/absence variant affecting the expression of the CUC2 gene,crucial for leaf serration formation.Finally,we developed a user-friendly web-based tool encompassing the multi-omics resources associated with the Populus super-pangenome(http://www.populus-superpangenome.com).Together,the present pioneering super-pangenome resource in forest trees not only aids in the advancement of breeding efforts of this globally important tree genus but also offers valuable insights into potential avenues for comprehending tree biology.

Discovery of first-in-class DOT1L inhibitors against the R231Q gain-of-function mutation in the catalytic domain with therapeutic potential of lung cancer

Recent research certified that DOT1L and its mutations represented by R231Q were potential targets for the treatment of lung cancer.Herein,a series of adenosine-containing derivatives were identified with DOT1LR231Q inhibition through antiproliferation assay and Western blot analysis in the H460R231Q cell.The most promising compound 37 significantly reduced DOT1LR231Q mediated H3K79 methylation and effectively inhibited the proliferation,self-renewal,migration,and invasion of lung cancer cell lines at low micromolar concentrations.The cell permeability and cellular target engagement of 37 were verified by both CETSA and DARTS assays.In the H460R231Q OE cell-derived xenograft(CDX)model,37 displayed pronounced tumor growth inhibition after intraperitoneal administration at 20 mg/kg dose for 3 weeks(TGI=54.38%),without obvious toxicities.A pharmacokinetic study revealed that 37 possessed tolerable properties(t_(1/2)=1.93±0.91 h,F=97.2%)after intraperitoneal administration in rats.Mechanism study confirmed that 37 suppressed malignant phenotypes of lung cancer carrying R231Q gain-of-function mutation via the MAPK/ERK signaling pathway.Moreover,analysis of the binding modes between molecules and DOT1LWT/R231Q proteins put forward the“Induced-fit”allosteric model in favor to the discovery of potent DOT1L candidates.

Evoking immune system to potentiate nanocatalytic therapy through activation of cGAS-STING pathway

Nanocatalytic therapy shows great potential for therapeutic interventions.However,therapeutic efficiency is often limited by unsatisfactory enzyme activity and lack of the coordination of immune system.Therefore,engineering nanozymes activity enhancement while activating immune system will be an effective strategy to achieve efficient tumor therapy.Herein,we synthesize a DSPE-PEG-FA modified manganese dioxide-based dual-atom nanozyme(MDF),on which iridium and platinum atoms are anchored.The obtained MDF can simultaneously mimic four enzyme activities of catalase,oxidase,peroxidase,and glutathione oxidase,set off a reactive oxygen species(ROS)storm,cause tumor cell death.The enzyme activity of MDF can be enhanced by its own photothermal effect.Meanwhile,MDF can consume intracellular glutathione and release Mn^(2+),which can prevent generated ROS from consumption and further activate cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes(cGAS-STING)pathway and promote the secretion of type I interferon,which will help promote dendritic cells maturation,present antigens to T lymphocytes to help kill tumor cells.Ultimately,MDF shows excellent tumor suppressive effects.This work provides a new paradigm for the field of nanozymes and offers a new reference for involvement of cGAS-STING pathway activation in tumor catalytic therapy.

Fabrication of a 3D bioprinting model for posterior capsule opacification using GelMA and PLMA hydrogel-coated resin

Posterior capsule opacification(PCO)remains the predominant complication following cataract surgery,significantly impairing visual function restoration.In this study,we developed a PCO model that closely mimics the anatomical structure of the crystalline lens capsule post-surgery.The model incorporated a threaded structure for accurate positioning and observation,allowing for opening and closing.Utilizing 3D printing technology,a stable external support system was created using resin material consisting of a rigid,hollow base and cover.To replicate the lens capsule structure,a thin hydrogel coating was applied to the resin scaffold.The biocompatibility and impact on cellular functionality of various hydrogel compositions were assessed through an array of staining techniques,including calcein-AM/PI staining,rhodamine staining,BODIPY-C11 staining and EdU staining in conjunction with transwell assays.Additionally,the PCO model was utilized to investigate the effects of eight drugs with anti-inflammatory and anti-proliferative properties,including 5-aminoimidazole-4-carboxamide ribonucleotide(AICAR),THZ1,sorbinil,4-octyl itaconate(4-OI),xanthohumol,zebularine,rapamycin and caffeic acid phenethyl ester,on human lens epithelial cells(HLECs).Confocal microscopy facilitated comprehensive imaging of the PCO model.The results demonstrated that the GelMA 605%þPLMA 2%composite hydrogel exhibited superior biocompatibility and minimal lipid peroxidation levels among the tested hydrogels.Moreover,compared to using hydrogel as the material for 3D printing the entire model,applying surface hydrogel spin coating with parameters of 2000 rpm�2 on the resin-based 3D printed base yielded a more uniform cell distribution and reduced apoptosis.Furthermore,rapamycin,4-OI and AICAR demonstrated potent antiproliferative effects in the drug intervention study.Confocal microscopy imaging revealed a uniform distribution of HLECs along the anatomical structure of the crystalline lens capsule within the PCO model,showcasing robust cell viability and regular morphology.In conclusion,the PCO model provides a valuable experimental platform for studying PCO pathogenesis and exploring potential therapeutic interventions.

Endogenous/exogenous dual stimulation“ROS engineering”amplification combined with autophagy-augmented for efficient ferroptosis therapy

“Reactive oxygen species(ROS)engineering”is one of the most promising anti-tumor treatments developed in recent years.Massive explosion of ROS will cause oxidative stress,thereby inducing tumor cell death.However,ROS accumulation in tumor cells is eliminated by endogenous cellular self-regulation strategies.In this work,a kind of endogenous/exogenous dual stimulation nanoagent noted as UMZC is developed.Fenton reaction occurs between NH_(2)-MIL-88B(Fe)contained in UMZC and the overexpression of endogenous H_(2)O_(2)to generate ROS,amplified by endogenous H_(2)S of colon tumor cells.In addition,NH_(2)-MIL-88B(Fe)also functions to deplete glutathione(GSH)for stopping it from consuming ROS.Upconversion nanoparticles at the core of UMZC convert near-infrared into visible light,which excites zinc phthalocyanine to initiate the photochemical reaction that generates more ROS,thus alleviating the lack of tissue penetration depth for visible light.Autophagy agonist chitosan oligosaccharides induce enhancement of cellular autophagy for disrupting cellular metabolic stress and the resistance to oxidative stress of tumor cells,allowing“ROS engineering”to fully exert anti-tumor effects.All of ROS generation,GSH depletion,and induced cellular autophagy caused by nanoagents have promoting effects on the occurrence of ferroptosis.Finally,the nanoagents show the ability to effectively treat colon tumors.

悟空巧饰磷脂膜,囊泡大败癌细胞

“我们能人工合成一个细胞吗?Can a cell be artificially synthesized?”——这是2021年《科学》期刊新发布的世界最前沿的125个重大科学问题之一。科学家为了揭示“生命起源”的奥秘以及解决世界关注的重大基础科学问题,设计出人造细胞这类仿生材料。它们最明显的特点就是具有与生物细胞类似的结构与功能。因此,深入研究人造细胞,不仅有利于研究真实细胞的结构与功能机制,还有助于建立非生物物质与真实细胞之间的联系,从而搭建非生命系统与生命系统之间的桥梁,为生命起源等相关研究提供实验与理论依据。而磷脂囊泡作为目前应用最为广泛的人造细胞更是有着广阔的应用前景。为了使“磷脂囊泡”这类材料以及相关研究技术得到更广泛的认识,本文基于耳熟能详的四大名著之一——《西游记》,讲述了孙悟空凭借火眼金睛帮助磷脂囊泡战胜癌细胞的故事,介绍了磷脂囊泡的设计和制备、代表功能以及体内治疗案例,以期促进广大读者对该技术的理解,并激发更多该技术潜在的应用可能。

The short-chain perfluorinated compounds PFBS,PFHxS, PFBA and PFHxA, disrupt human mesenchymal stem cell self-renewal and adipogenic differentiation

Per-and polyfluorinated alkyl substances(PFASs) are commonly used in industrial processes and daily life products.Because they are persistent, they accumulate in the environment, wildlife and humans.Although many studies have focused on two of the most representative PFASs, PFOS and PFOA, the potential toxicity of short-chain PFASs has not yet been given sufficient attention.We used a battery of assays to evaluate the toxicity of several four-carbon and six-carbon perfluorinated sulfonates and carboxyl acids(PFBS,PFHxS, PFBA and PFHxA), with a human mesenchymal stem cell(hMSC) system.Our results demonstrate significant cyto-and potential developmental toxicity for all the compounds analyzed, with shared but also distinct mechanisms of toxicity.Moreover, the effects of PFBS and PFHxS were stronger than those of PFBA and PFHxA, but occurred at higher doses compared to PFOS or PFOA.

前交叉韧带重建术后评估何时重返运动指标的研究进展

前交叉韧带重建术(ACLR)是前交叉韧带(ACL)损伤最常用的治疗手段。术后重返运动(RTS)是医生和患者共同关注的问题。在现有文献中,评估患者RTS时机的标准尚未达成一致。常用的评价指标包括术后时间、下肢肌力、功能评分和单腿跳跃测试。近年来,研究学者开始更多地关注单腿跳跃测试。本文将就以上评价指标和单腿跳跃测试进行归纳总结,旨为临床医生评估重返运动时机提供参考。

RhizoVision Crown:An Integrated Hardware and Software Platform for Root Crown Phenotyping

Root crown phenotyping measures the top portion of crop root systems and can be used for marker-assisted breeding,genetic mapping,and understanding how roots influence soil resource acquisition.Several imaging protocols and image analysis programs exist,but they are not optimized for high-throughput,repeatable,and robust root crown phenotyping.The RhizoVision Crown platform integrates an imaging unit,image capture software,and image analysis software that are optimized for reliable extraction of measurements from large numbers of root crowns.The hardware platform utilizes a backlight and a monochrome machine vision camera to capture root crown silhouettes.The RhizoVision Imager and RhizoVision Analyzer are free,open-source software that streamline image capture and image analysis with intuitive graphical user interfaces.The RhizoVision Analyzer was physically validated using copper wire,and features were extensively validated using 10,464 groundtruth simulated images of dicot and monocot root systems.This platform was then used to phenotype soybean and wheat root crowns.A total of 2,799 soybean(Glycine max)root crowns of 187 lines and 1,753 wheat(Triticum aestivum)root crowns of 186 lines were phenotyped.Principal component analysis indicated similar correlations among features in both species.The maximum heritability was 0.74 in soybean and 0.22 in wheat,indicating that differences in species and populations need to be considered.The integrated RhizoVision Crown platform facilitates high-throughput phenotyping of crop root crowns and sets a standard by which open plant phenotyping platforms can be benchmarked.

关节镜下前交叉韧带重建术后急性骨筋膜室综合征

急性骨筋膜室综合征(acute osteofasical compartment syndrome,AOCS)是指骨、骨间膜、肌间膜和深筋膜形成的骨筋膜室内,由于各种原因导致室内压力升高,造成室内血流灌注减少而引起急性严重缺血缺氧的一种外科急症,如未早期诊断和干预,将引起截肢残废,甚至危及生命[1-3]。

Copper-Catalyzed Asymmetric Hydroamination:A Unified Strategy for the Synthesis of Chiralβ-Amino Acid and Its Derivatives

Catalytic asymmetric aza-Michael represents one of the most convenient and atom-economical approaches for the rapid construction of biologically active chiralβ-amino acid frameworks.However,the direct enantioselective addition of nitrogen-based nucleophiles to intrinsically low reactivity ofα,β-unsaturated carboxylic acid,ester,and amide,as well as simpleα,β-unsaturated nitrile,remains a long-standing challenge.

Distributed Nash equilibrium seeking with order-reduced dynamics based on consensus exact penalty

In this paper,we consider a networked game with coupled constraints and focus on variational Nash equilibrium seeking.For distributed algorithm design,we eliminate the coupled constraints by employing local Lagrangian functions and construct exact penalty terms to attain multipliers'optimal consensus,which yields a set of equilibrium conditions without any coupled constraint and consensus constraint.Moreover,these conditions are only based on strategy and multiplier variables,without auxiliary variables.Then,we present a distributed order-reduced dynamics that updates the strategy and multiplier variables with guaranteed convergence.Compared with many other distributed algorithms,our algorithm contains no auxiliary variable,and therefore,it can save computation and communication.