洗衣废水影响纳米银团聚及溶解行为的关键因素研究进展

纳米银因卓越的抗菌性能被广泛用于纺织品生产中。然而,在纺织品洗涤过程中,大量的纳米银会释放并进入到洗衣废水中。不同的洗涤条件决定了释放出的纳米银的团聚及溶解行为,进而影响后续环境过程并对水生生物及生态系统产生负面影响。为探究不同洗涤条件对纳米银团聚及溶解行为的具体影响,降低纳米银所带来的环境风险,文章归纳了国内外相关研究文献,在分析洗衣废水特点的基础上,讨论了废水中洗涤剂种类、光照、pH值、离子强度等条件对纳米银团聚及溶解行为的单独或联合作用与影响机理,并根据机理提出了减小纳米银生物毒性的建议,包括减少洗涤过程中纳米银的释放及洗衣废水处理方法的改善,最后对洗衣废水中纳米银未来的研究方向进行展望,提出了后续研究建议。

Application of real-time shear wave elastography to Achilles tendon hardness evaluation in older adults

BACKGROUND Real-time shear wave elastography(SWE)is a non-invasive imaging technique used to measure tissue stiffness by generating and tracking shear waves in real time.This advanced ultrasound-based method provides quantitative information regarding tissue elasticity,offering valuable insights into the mechanical properties of biological tissues.However,the application of real-time SWE in the musculoskeletal system and sports medicine has not been extensively studied.AIM To explore the practical value of real-time SWE for assessing Achilles tendon hardness in older adults.METHODS A total of 60 participants were enrolled in the present study,and differences in the elastic moduli of the bilateral Achilles tendons were compared among the following categories:(1)Age:55-60,60-65,and 65-70-years-old;(2)Sex:Male and female;(3)Laterality:Left and right sides;(4)Tendon state:Relaxed and tense state;and(5)Tendon segment:Proximal,middle,and distal.RESULTS There were no significant differences in the elastic moduli of the bilateral Achilles tendons when comparing by age or sex(P>0.05).There were,however,significant differences when comparing by tendon side,state,or segment(P<0.05).CONCLUSION Real-time SWE plays a significant role compared to other examination methods in the evaluation of Achilles tendon hardness in older adults.

GrCol-PPFL:User-Based Group Collaborative Federated Learning Privacy Protection Framework

With the increasing number of smart devices and the development of machine learning technology,the value of users’personal data is becoming more and more important.Based on the premise of protecting users’personal privacy data,federated learning(FL)uses data stored on edge devices to realize training tasks by contributing training model parameters without revealing the original data.However,since FL can still leak the user’s original data by exchanging gradient information.The existing privacy protection strategy will increase the uplink time due to encryption measures.It is a huge challenge in terms of communication.When there are a large number of devices,the privacy protection cost of the system is higher.Based on these issues,we propose a privacy-preserving scheme of user-based group collaborative federated learning(GrCol-PPFL).Our scheme primarily divides participants into several groups and each group communicates in a chained transmission mechanism.All groups work in parallel at the same time.The server distributes a random parameter with the same dimension as the model parameter for each participant as a mask for the model parameter.We use the public datasets of modified national institute of standards and technology database(MNIST)to test the model accuracy.The experimental results show that GrCol-PPFL not only ensures the accuracy of themodel,but also ensures the security of the user’s original data when users collude with each other.Finally,through numerical experiments,we show that by changing the number of groups,we can find the optimal number of groups that reduces the uplink consumption time.

Genomic prediction of yield performance among single-cross maize hybrids using a partial diallel cross design

Genomic prediction(GP)in plant breeding has the potential to predict and identify the best-performing hybrids based on the genotypes of their parental lines.In a GP experiment,34 elite inbred lines were selected to make 285 single-cross hybrids in a partial-diallel cross design.These lines represented a mini-core collection of Chinese maize germplasm and comprised 18 inbred lines from the Stiff Stalk heterotic group and 16 inbred lines from the Non-Stiff Stalk heterotic group.The parents were genotyped by sequencing and the 285 hybrids were phenotyped for nine yield and yield-related traits at two locations in the summer sowing area(SUS)and three locations in the spring sowing area(SPS)in the main maizeproducing regions of China.Multiple GP models were employed to assess the accuracy of trait prediction in the hybrids.By ten-fold cross-validation,the prediction accuracies of yield performance of the hybrids estimated by the genomic best linear unbiased prediction(GBLUP)model in SUS and SPS were 0.51 and 0.46,respectively.The prediction accuracies of the remaining yield-related traits estimated with GBLUP ranged from 0.49 to 0.86 and from 0.53 to 0.89 in SUS and SPS,respectively.When additive,dominance,epistasis effects,genotype-by-environment interaction,and multi-trait effects were incorporated into the prediction model,the prediction accuracy of hybrid yield performance was improved.The ratio of training to testing population and size of training population optimal for yield prediction were determined.Multiple prediction models can improve prediction accuracy in hybrid breeding.

MPFracNet:A Deep Learning Algorithm for Metacarpophalangeal Fracture Detection with Varied Difficulties

Due to small size and high occult,metacarpophalangeal fracturediagnosis displays a low accuracy in terms of fracture detection and locationin X-ray images.To efficiently detect metacarpophalangeal fractures on Xrayimages as the second opinion for radiologists,we proposed a novel onestageneural network namedMPFracNet based onRetinaNet.InMPFracNet,a deformable bottleneck block(DBB)was integrated into the bottleneckto better adapt to the geometric variation of the fractures.Furthermore,an integrated feature fusion module(IFFM)was employed to obtain morein-depth semantic and shallow detail features.Specifically,Focal Loss andBalanced L1 Loss were introduced to respectively attenuate the imbalancebetween positive and negative classes and the imbalance between detectionand location tasks.We assessed the proposed model on the test set andachieved an AP of 80.4%for the metacarpophalangeal fracture detection.To estimate the detection performance for fractures with different difficulties,the proposed model was tested on the subsets of metacarpal,phalangeal andtiny fracture test sets and achieved APs of 82.7%,78.5%and 74.9%,respectively.Our proposed framework has state-of-the-art performance for detectingmetacarpophalangeal fractures,which has a strong potential application valuein practical clinical environments.

Comparison of clinical features and outcomes in peritoneal dialysisassociated peritonitis patients with and without diabetes:A multicenter retrospective cohort study

BACKGROUND The number of end-stage renal disease patients with diabetes mellitus(DM)who are undergoing peritoneal dialysis is increasing.Peritoneal dialysis-associated peritonitis(PDAP)is a serious complication of peritoneal dialysis leading to technical failure and increased mortality in patients undergoing peritoneal dialysis.The profile of clinical symptoms,distribution of pathogenic organisms,and response of PDAP to medical management in the subset of end-stage renal disease patients with DM have not been reported previously.Discrepant results have been found in long-term prognostic outcomes of PDAP in patients with DM.We inferred that DM is associated with bad outcomes in PDAP patients.AIM To compare the clinical features and outcomes of PDAP between patients with DM and those without.METHODS In this multicenter retrospective cohort study,we enrolled patients who had at least one episode of PDAP during the study period.The patients were followed for a median of 31.1 mo.They were divided into a DM group and a non-DM group.Clinical features,therapeutic outcomes,and long-term prognostic outcomes were compared between the two groups.Risk factors associated with therapeutic outcomes of PDAP were analyzed using multivariable logistic regression.A Cox proportional hazards model was constructed to examine the influence of DM on patient survival and incidence of technical failure.RESULTS Overall,373 episodes occurred in the DM group(n=214)and 692 episodes occurred in the non-DM group(n=395).The rates of abdominal pain and fever were similar in the two groups(P>0.05).The DM group had more infections with coagulase-negative Staphylococcus and less infections with Escherichia coli(E.coli)as compared to the non-DM group(P<0.05).Multivariate logistic regression analysis revealed no association between the presence of diabetes and rates of complete cure,catheter removal,PDAP-related death,or relapse of PDAP(P>0.05).Patients in the DM group were older and had a higher burden of cardiovascular disease,with lower level of serum albumin,but a higher estimated glomerular filtration rate(P<0.05).Cox proportional hazards model confirmed that the presence of diabetes was a significant predictor of all-cause mortality(hazard ratio=1.531,95%confidence interval:1.091-2.148,P<0.05),but did not predict the occurrence of technical failure(P>0.05).CONCLUSION PDAP patients with diabetes have similar symptomology and are predisposed to coagulase-negative Staphylococcus but not E.coli infection compared those without.Diabetes is associated with higher all-cause mortality but not therapeutic outcomes of PDAP.

表面活性剂——超声提取莲子心总生物碱工艺研究

对超声辅助乙醇提取莲子心总生物碱的工艺进行了研究。考察超声功率、超声时间、浸泡时间、乙醇体积分数、料液比对生物碱提取率的影响,在此基础上用正交试验进行条件优化。并在优化的工艺条件下,考察吐温20、吐温60、吐温80、司盘80、APG0810、APG1214表面活性剂对提取率的影响。结果表明,在超声功率105 W、超声时间40 min、浸泡时间30 min、乙醇体积分数70%、料液比1:30、APG08103加入量0.02 g/mL的条件下,生物碱提取率为157.268 mg/g,比单纯超声提取(138.231 mg/g)提高13.8%,证明表面活性剂可显著提高超声提取莲子心生物碱的效果。

10 kV配电线路单相接地故障暂态特征分析

配电网作为我国电力系统的重要组成部分,其安全稳定的运行对整个电力系统的安全稳定运行起着重要的作用。在我国,配电系统主要采用中性点不接地系统。在中性点不接地系统中发生单相接地故障后,故障电流比较小,系统可以继续正常运行一段时间,不影响对用户供电。但是,长时间的运行会引起其它更严重的故障,破坏系统的安全运行。因此,必须及时找到故障线路并且切除。而应用故障线路暂态信息进行选线是目前研究的热点,本文在分析国内外10 kV配网单相接地故障原因及危害的基础上,分析了10 kV配网发生单相接地故障时系统暂态电流的变化规律。

Characterization of Fundamental Logics for the Sub-Threshold Digital Design

Digital circuits operating in the sub-threshold regime consume the least energy. The strict energy constraints are desired in the applications which work at the lowest possible supply voltage. On the other hand, the conventional design flow utilizes the technology library provided by the foundry with a fixed voltage boundary, which causes problems when the supply scales down to the sub-threshold regime. In this paper, we present a design methodology to characterize the existing cell library with Liberty NCX to facilitate the standard design flow. It is demonstrated in 0.13 μm complementary metal-oxide-semiconductor （CMOS） technology with the supply voltage of 300 mV.

Efficient Slew-Rate Enhanced Operational Transconductance Amplifier

Today, along with the prevalent use of portable equipment, wireless, and other battery powered systems, the demand for amplifiers with a high gain-bandwidth product（GBW）, slew rate（SR）, and at the same time very low static power dissipation is growing. In this work, an operational transconductance amplifier（OTA） with an enhanced SR is proposed. By inserting a sensing resistor in the input port of the current mirror in the OTA, the voltage drop across the resistor is converted into an output current containing a term in proportion to the square of the voltage, and then the SR of the proposed OTA is significantly enhanced and the current dissipation can be reduced. The proposed OTA is designed and simulated with a 0.5μm complementary metal oxide semiconductor（CMOS） process. The simulation results show that the SR is 4.54V/μs, increased by 8.25 times than that of the conventional design, while the current dissipation is only 87.3%.

Ultra-Low Power Pipeline Structure Exploiting Noncritical Stage with Circuit-Level Timing Speculation

With the increase of the clock frequency and silicon integration, power aware computing has become a critical concern in the design of the embedded processor and system-on-chip （SoC）. Dynamic voltage scaling （DVS） is an effective method for low-power designs. However, traditional DVS methods have two deficiencies. First, they have a conservative safety margin which is not necessary for most of the time. Second, they are exclusively concerned with the critical stage and ignore the significant potential free slack time of the noncritical stage. These factors lead to a large amount of power waste. In this paper, a novel pipeline structure with ultra-low power consumption is proposed. It cuts off the safety margin and takes use of the noncritical stages at the same time. A prototype pipeline is designed in 0.13 μm technology and analyzed. The result shows that a large amount of energy can be saved by using this structure. Compared with the fixed voltage case, 50% of the energy can be saved, and with respect to the traditional adaptive voltage scaling design, 37.8% of the energy can be saved.

Risk factors for mortality within 6 mo in patients with diabetes undergoing urgent-start peritoneal dialysis:A multicenter retrospective cohort study

BACKGROUND The risk of early mortality of patients who start dialysis urgently is high;however,in patients with diabetes undergoing urgent-start peritoneal dialysis(USPD),the risk of,and risk factors for,early mortality are unknown.AIM To identify risk factors for mortality during high-risk periods in patients with diabetes undergoing USPD.METHODS This retrospective cohort study enrolled 568 patients with diabetes,aged≥18 years,who underwent USPD at one of five Chinese centers between 2013 and 2019.We divided the follow-up period into two survival phases:The first 6 mo of USPD therapy and the months thereafter.We compared demographic and baseline clinical data of living and deceased patients during each period.Kaplan-Meier survival curves were generated for all-cause mortality according to the New York Heart Association(NYHA)classification.A multivariate Cox proportional hazard regression model was used to identify risk factors for mortality within the first 6 mo and after 6 mo of USPD.RESULTS Forty-one patients died within the first 6 mo,accounting for the highest proportion of mortalities(26.62%)during the entire follow-up period.Cardiovascular disease was the leading cause of mortality within 6 mo(26.83%)and after 6 mo(31.86%).The risk of mortality not only within the first 6 mo but also after the first 6 mo was higher for patients with obvious baseline heart failure symptoms than for those with mild or no heart failure symptoms.Independent risk factors for mortality within the first 6 mo were advanced age hazard ratio(HR:1.908;95%CI:1.400-2.600;P<0.001),lower baseline serum creatinine level(HR:0.727;95%CI:0.614-0.860;P<0.001),higher baseline serum phosphorus level(HR:3.162;95%CI:1.848-5.409;P<0.001),and baseline NYHA class III-IV(HR:2.148;95%CI:1.063-4.340;P=0.033).Independent risk factors for mortality after 6 mo were advanced age(HR:1.246;95%CI:1.033-1.504;P=0.022)and baseline NYHA class III-IV(HR:2.015;95%CI:1.298-3.130;P=0.002).CONCLUSION To reduce the risk of mortality within the first 6 mo of USPD in patients with diabetes,controlling the serum phosphorus level and improving cardiac function are recommended。

Construction and prokaryotic expression of the fusion protein Stx2B-IntiminC300 of EHEC O157: H7 and its immunoprophylactic potential

To construct and express the fusion protein Stx2B-IntiminC300 of EHEC O157 ： H7, and to further investigate its immunoprophylactic potential, the gene of Stx2B （stx2b） from EHEC O157：H7 chromosome was cloned into pMD18-T vector. Thereafter, the amplified gene was cloned into prokary- otic expression plasmid pET-28a （ ＋ ）-eaeC300, which was constructed previously. The recombinant pasmid pET-28a（ ＋ ）-stx2b-eaeC300 was transformed into E. coli BL21 （DE3）. After inducement, the protein Stx2B-IntiminC300 was successfully expressed and analyzed with sodium dodecyl sulfate polyacrylamide gel electrophoresis （SDS-PAGE）, Western blotting and N-terminal amino acid residual sequencing. To evaluate its immunoprophylactic potential, it was primarily purified by ion-exchange chromatography and injected into 30 BALB/c mice with AI（OH）3 in the subscapular region. Ten days after the last booster vaccination, 20 mice were attacked with EHEC O157：H7 lysate and the protective efficacy was observed. In the present study, the gene of Stx2B-intiminC300 was successfully cloned into pET-28a （ ＋ ） vector. The results of SDS-PAGE and Western blotting assay showed that the fusion protein was successfully expressed in the inclusion body form, accounting for 25 % of total expression products, and its molecular weight was about 43 kDa. The result of the N-terminal amino acid residual sequencing showed that it was identical to that of the molecular designed. The purity was about 75 % after primary purification. Animal tests revealed that the fusion protein Stx2B-intiminC300 has elicited high titer of protective antibody relatively. These results demonstrate that the fusion protein Stx2B-IntiminC300 is successfully expressed in prokaryotic expression system and shows certain immunoprophylactic potential.

Cooperative Detection Method for DDoS Attacks Based on Blockchain

Distributed Denial of Service(DDoS)attacks is always one of the major problems for service providers.Using blockchain to detect DDoS attacks is one of the current popular methods.However,the problems of high time overhead and cost exist in the most of the blockchain methods for detecting DDoS attacks.This paper proposes a blockchain-based collaborative detection method for DDoS attacks.First,the trained DDoS attack detection model is encrypted by the Intel Software Guard Extensions(SGX),which provides high security for uploading the DDoS attack detection model to the blockchain.Secondly,the service provider uploads the encrypted model to Inter Planetary File System(IPFS)and then a corresponding Content-ID(CID)is generated by IPFS which greatly saves the cost of uploading encrypted models to the blockchain.In addition,due to the small amount of model data,the time cost of uploading the DDoS attack detection model is greatly reduced.Finally,through the blockchain and smart contracts,the CID is distributed to other service providers,who can use the CID to download the corresponding DDoS attack detection model from IPFS.Blockchain provides a decentralized,trusted and tamper-proof environment for service providers.Besides,smart contracts and IPFS greatly improve the distribution efficiency of the model,while the distribution of CID greatly improves the efficiency of the transmission on the blockchain.In this way,the purpose of collaborative detection can be achieved,and the time cost of transmission on blockchain and IPFS can be considerably saved.We designed a blockchain-based DDoS attack collaborative detection framework to improve the data transmission efficiency on the blockchain,and use IPFS to greatly reduce the cost of the distribution model.In the experiment,compared with most blockchain-based method for DDoS attack detection,the proposed model using blockchain distribution shows the advantages of low cost and latency.The remote authentication mechanism of Intel SGX provides high security and integrity,and ensures the availability of distributed models.

The Infeasibility of Establishing Land Development Rights in China Based on the Path of Real Rights

Using comparative analysis and documentation method,this paper reveals infeasibility of establishing land development rights in China based on the path of real rights,in the hope of providing recommendations for improving the research route on localization of land development rights. Results indicate that at the level of legislative techniques,the land development rights rooted from property right paradigm do not contain possess the elements of object of real rights and conflict with the principle of statutory real rights and single ownership. At the level of legal logic,individual case of TDR conflicts with real right in rem. In conclusion,it is infeasible to introduce land development rights based on the path of real rights. In future,it is required to discard the concept of mechanical transplantation and explore feasible path and seek feasible way for establishing land development rights along with the direction of quasi-property and improving regulation efficiency.

Positive Periodic Solutions of Nonautonomous Delayed Predator-Prey System with Pulse Controls

In this paper, a biological model for two predators and one prey with impulses and periodic delays is considered. By assuming that one predator consumes prey according to Holling II functional response while the other predators consume prey according to the Beddington-DeAngelis functional response, based on the coincidence degree theory, the existence of positive periodic solutions of nonautonomous predator-prey system with impulses and periodic delays is obtained under suitable conditions.

被子植物花朵重瓣化分子调控机制

重瓣花表现为花瓣数目增加、花瓣褶皱或面积增大,具有较高的观赏价值和经济价值。该文针对重瓣性状中花瓣或花瓣类似器官数目增多的特点,综述了模式植物和观赏植物中重瓣花形成的分子机理,包括参与花瓣数量调控的重要转录因子,以及miRNAs、DNA甲基化、组蛋白修饰和染色质重塑等表观遗传调控方式,并在此基础上展望未来的研究方向。

Improving discharge voltage and ion storage dynamic in polyaniline via modulation of carrier charge density for magnesiummetal batteries

Rechargeable magnesium-metal batteries(RMBs)have gained much attention due to their abundant resources as well as high safety.However,the high charge density of Mg^(2+)is one of the main reasons for the slow kinetics performance of RMBs,and modulation of the charge density is an important strategy to improve the kinetics and electrochemical performance of RMBs.Herein,we report on the conductive polymer polyaniline(PANI)for RMBs,which is found to have excellent kinetics and high discharge voltage when storing MgCl^(+).In the storage of MgCl^(+),PANI exhibits a high average discharge voltage platform is 2.3 V vs.Mg^(2+)/Mg,which is higher than that in storage of Mg^(2+).We demonstrated the reversible intercalation/de-intercalation of MgCl^(+)in PANI accompanying with the reversible transformation between the quinone ring(C–C,–N=)and the benzene ring(C=C,–NH–)during charging and discharging.Density functional theory calculation reveals that PANI exhibit higher voltages(2.25 V vs.1.82 V)along with lower diffusion energy barriers(1.27 eV vs.1.55 eV)for MgCl^(+)storage compared to Mg^(2+)storage.This work refines the storage mechanism of PANI in RMBs and provides new guidelines for the application of PANI in RMBs.

Accelerated ion/electron transport kinetics and increased active sites via local internal electric fields in heterostructured VO_(2)–carbon cloth for enhanced zinc-ion storage

Although the performance of the self-standing electrode has been enhanced for aqueous zinc-ion batteries(AZIBs),it is necessary to explore and analyse the deep modification mechanism(especially interface effects).Herein,density functional theory(DFT)calculations are applied to investigate the high-performance cathode based on the VO_(2)/carbon cloth composites with heterostructures interface(H-VO_(2)@CC).The adsorption energy comparisons and electron structure analyses verify that HVO_(2)@CC has extra activated sites at the interface,enhanced electrical conductivity,and structural stability for achieving highperformance AZIBs due to the presence of built-in electric field at the interfaces.Accordingly,the designed self-standing HVO_(2)@CC cathode delivers higher rate capacity,longer-life cyclability,and faster electronic/ion transmission kinetics benefiting from the synergistic effects.The risks of active material shedding and dissolution during the dis/charge process of two cathodes were evaluated via ex-situ ultraviolet–visible(UV–vis)spectrum and inductively coupled plasma-atomic emission spectroscopy(ICP-AES)technique.Finally,this investigation also explores the charge storage mechanism of H-VO_(2)@CC through various exsitu and in-situ characterization techniques.This finding can shed light on the significant potential of heterostructures interface engineering in practical applications and provide a valuable direction for the development of cathode materials for AZIBs and other metal-ion batteries.

Animal models for testing biomaterials in periodontal regeneration

Periodontitis is a prevalent oral disease. It can cause tooth loss and has a significant impact on patients’ quality of life. While existing treatments can only slow the progression of periodontitis, they are unable to achieve complete regeneration and functional reconstruction of periodontal tissues. As a result, regenerative therapies based on biomaterials have become a focal point of research in the field of periodontology. Despite numerous studies reporting the superiority of new materials in periodontal regeneration, limited progress has been made in translating these findings into clinical practice. This may be due to the lack of appropriate animal models to simulate the tissue defects caused by human periodontitis. This review aims to provide an overview of established animal models for periodontal regeneration, examine their advantages and limitations, and outline the steps for model construction. The objective is to determine the most relevant animal models for periodontal regeneration based on the hypothesis and expected outcomes.