The gap-free genome of mulberry elucidates the architecture and evolution of polycentric chromosomes

Mulberry is a fundamental component of the global sericulture industry,and its positive impact on our health and the environment cannot be overstated.However,the mulberry reference genomes reported previously remained unassembled or unplaced sequences.Here,we report the assembly and analysis of the telomere-to-telomere gap-free reference genome of the mulberry species,Morus notabilis,which has emerged as an important reference in mulberry gene function research and genetic improvement.The mulberry gap-free reference genome produced here provides an unprecedented opportunity for us to study the structure and function of centromeres.Our results revealed that all mulberry centromeric regions share conserved centromeric satellite repeats with different copies.Strikingly,we found that M.notabilis is a species with polycentric chromosomes and the only reported polycentric chromosome species up to now.We propose a compelling model that explains the formation mechanism of new centromeres and addresses the unsolved scientific question of the chromosome fusion-fission cycle in mulberry species.Our study sheds light on the functional genomics,chromosome evolution,and genetic improvement of mulberry species.

Molten salt synthesis,morphology modulation,and lithiation mechanism of high entropy oxide for robust lithium storage

High entropy oxides(HEOs)with ideal element tunability and enticing entropy-driven stability have exhibited unprecedented application potential in electrochemical lithium storage.However,the general control of dimension and morphology remains a major challenge.Here,scalable HEO morphology modulation is implemented through a salt-assisted strategy,which is achieved by regulating the solubility of reactants and the selective adsorption of salt ions on specific crystal planes.The electrochemical properties,lithiation mechanism,and structure evolution of composition-and morphology-dependent HEO anode are examined in detail.More importantly,the potential advantages of HEOs as electrode materials are evaluated from both theoretical and experimental aspects.Benefiting from the high oxygen vacancy concentration,narrow band gap,and structure durability induced by the multi-element synergy,HEO anode delivers desirable reversible capacity and reaction kinetics.In particular,Mg is evidenced to serve as a structural sustainer that significantly inhibits the volume expansion and retains the rock salt lattice.These new perspectives are expected to open a window of opportunity to compositionally/morphologi cally engineer high-performance HEO electrodes.

Application of Wavelength Selection Combined with DS Algorithm for Model Transfer between NIR Instruments

This study aims to realize the sharing of near-infrared analysis models of lignin and holocellulose content in pulp wood on two different batches of spectrometers and proposes a combined algorithm of SPA-DS,MCUVE-DS and SiPLS-DS.The Successive Projection Algorithm(SPA),the Monte-Carlo of Uninformative Variable Elimination(MCUVE)and the Synergy Interval Partial Least Squares(SiPLS)algorithms are respectively used to reduce the adverse effects of redundant information in the transmission process of the full spectrum DS algorithm model.These three algorithms can improve model transfer accuracy and efficiency and reduce the manpower and material consumption required for modeling.These results show that the modeling effects of the characteristic wavelengths screened by the SPA,MCUVE and SiPLS algorithms are all greatly improved compared with the full-spectrum modeling,in which the SPA-PLS result in the best prediction with RPDs above 6.5 for both components.The three wavelength selection methods combined with the DS algorithm are used to transfer the models of the two instruments.Among them,the MCUVE combined with the DS algorithm has the best transfer effect.After the model transfer,the RMSEP of lignin is 0.701,and the RMSEP of holocellulose is 0.839,which was improved significantly than the full-spectrum model transfer of 0.759 and 0.918.

Self reported adherence to antiretroviral treatment and correlates in Hunan province,the Peoples Republic of China

Aims:This study aimed to describe the adherence level to antiretroviral therapy and its associated factors among people living with HIV in Hunan province,China.Methods:Across-sectional survey study was done at two major HIV treatment sites within Hunan province in China from July 2011 to Oct 2012 through face-to-face interviews.Adherence measures were captured using a 30-day visual analog scale(VAS).Results:A total of 418 participants consented and completed the questionnaires with the mean age being 38 years old.Based on VAS,28%of the participants had lower than 90%ART adherence level.The main reasons for missing drugs were;forgetting,being away from home,being busy and feeling worse after taking drugs.Logistic regression results showed that drug use(B=0.68,OR=2.11),time on ART(B=0.31,OR=0.72)and side effects(B=0.64,OR=1.82)were significantly associated with adherence to ART.Conclusion:Patients on ARVs in Hunan province are faced with adherence challenges notably drug abuse,drug regime scheduling challenges at the initial stages of therapy and drug side effects.It is therefore necessary to institute specific adherence interventions that target those who abuse drugs,ART naïve patients,and those experiencing side effects in order to achieve optimal ART adherence.

Psychometric properties of the Chinese Version of the Readiness for Hospital Discharge Scale for people living with HIV

Objective:The study was conducted to validate the reliability and factor structure of the Chinese version of the Readiness for Hospital Discharge Scale(RHDS-CH)for people living with HIV(PLWH).Methods:From May 2017 to November 2017,a cross-sectional survey was performed in two AIDS inpatient departments located in two cities in Hunan,China.Reliability was evaluated by examining the internal consistency and split-half reliability of the items.A confirmatory factor analysis was performed to assess the factor structure of the RHDS-CH,and the model was revised according to the modification index.Results:Cronbach'sαfor the RHDS-CH was 0.912,and the split-half reliability of the total scale was 0.831.Initially,the results of the confirmatory factor analysis indicated that the sample did not fit this four-factor model and its 23 items well(x2/df=3,GFI=0.772,TLI=0.823,CFI=0.844,RMSEA=0.100).To improve the model fit indices,we performed model modification with the guidance of modification indices.Finally,the model fit indices showed an acceptable fit to the data(x2/df=2.141,GFI=0.844,TLI=0.899,CFI=0.915,RMSEA=0.075).Coefficients of corrected item-total correlation of the RHDS-CH ranged from 0.435 to 0.726.Conclusion:This study is the first to examine the psychometric properties of the RHDS-CH for PLWH.Our findings showed good reliability and confirmed the four-factor structure model for PLWH.

Antiretroviral therapy improves neurocognitive impairment in people living with HIV? A meta-analysis

Objectives:Although effective antiretroviral therapy(ART)has been used for more than two decades,HIV-associated neurocognitive disorder remains prevalent.Thus,whether ART can improve neurocognitive impairment is controversial.This review aims to explore the effects of ART on cognitive impairment in people living with HIV(PLWH).Methods:A systematic literature search was conducted in eight databases(PubMed,Embase,Web of Science,Cochrane Library,CNKI,VIP,China Biology Medicine disc,and WanFang)to identify studies that compare cognitive function between study groups who are administered and not administered ART.We searched for articles published up to April 2019.Article evaluation and data extraction were independently conducted by two reviewers.Results:Sixteen articles(6,694 participants)-14 cross-sectional studies and 2 cohort studies—were included in this meta-analysis.The cross-sectional studies demonstrated that ART group did not perform better than the non-ART group(OR=1.16;95%CI,1.03-1.30).However,the cohort studies reported a significant improvement in cognitive function at three months(OR=4.01;95%CI,2.35-6.85)and six months(OR=9.24;95%CI,1.71-49.96)after ART initiation compared with the baseline data.No significant cognitive improvement was found in participants younger than 55 years old,but the two crosssectional studies showed that ART may improve cognitive function in PLWH under 65 years old with poor physical condition and immune status.Conclusions:ART could improve cognitive function in PLWH with poor physical condition and immune status,but it does not considerably improve cognition in the entire PLWH population.

Transmission risk of asymptomatic SARS-CoV-2 infection:a systematic review and meta-analysis

Background:Global evidence on the transmission of asymptomatic SARS-CoV-2 infection needs to be synthesized.Methods:A search of 4 electronic databases(PubMed,EMBASE,Cochrane Library,and Web of Science databases)as of January 24,2021 was performed.Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines were followed.Studies which reported the transmission rate among close contacts with asymptomatic SARS-CoV-2 cases were included,and transmission activities occurred were considered.The trans-mission rates were pooled by zero-inflated beta distribution.The risk ratios(RRs)were calculated using random-effects models.Results:Of 4923 records retrieved and reviewed,15 studies including 3917 close contacts with asymptomatic indexes were eligible.The pooled transmission rates were 1.79 per 100 person-days(or 1.79%,95%confidence interval[CI]0.41%-3.16%)by asymptomatic index,which is significantly lower than by presymptomatic(5.02%,95%CI 2.37%-7.66%;p<0.001),and by symptomatic(5.27%,95%CI 2.40%-8.15%;p<0.001).Subgroup anal-yses showed that the household transmission rate of asymptomatic index was(4.22%,95%CI 0.91%-7.52%),four times significantly higher than non-household transmission(1.03%,95%CI 0.73%-1.33%;p=0.03),and the asymptomatic transmission rate in China(1.82%,95%CI 0.11%-3.53%)was lower than in other countries(2.22%,95%CI 0.67%-3.77%;p=0.01).Conclusions:People with asymptomatic SARS-CoV-2 infection are at risk of transmitting the virus to their close contacts,particularly in household settings.The transmission potential of asymptomatic infection is lower than symptomatic and presymptomatic infections.This meta-analysis provides evidence for predict-ing the epidemic trend and promulgating vaccination and other control measures.Registered with PROS-PERO International Prospective Register of Systematic Reviews,CRD42021269446;https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=269446.

催化还原降解Cr(Ⅵ)

工业化的快速发展导致含有六价铬(Cr(Ⅵ))的废水排放量日益增加,Cr(Ⅵ)的毒性和高流动性造成极大的环境污染问题。将Cr(Ⅵ)还原成低毒性和低流动性三价铬(Cr(Ⅲ))是当前的有效处理方式之一。与传统方法相比,利用太阳光、电和微波等驱动氧化还原反应进行Cr(Ⅵ)降解,无催化剂消耗,还原剂用量少,且不会造成二次污染和有限资源损耗,成为处理Cr(Ⅵ)污染的有效解决方案。基于此,本文综述了光催化剂、电催化剂及微波催化剂等在还原Cr(Ⅵ)领域的应用现状,在总结分析前人研究成果的基础上,对今后Cr(Ⅵ)催化还原技术的研究方向和重点进行了展望。

Nano-sized Ag rather than single-atom Ag determines CO oxidation activity and stability

Single-atom catalysis recently attracts great attentions,however,whether single atom or their nanoparticle(NP)has the advantage in its intrinsic activity remains under heated debate.Ag/Al_(2)O_(3) is a widely used catalyst for many catalytic reactions,while the effect of Ag particle size on the actity is seldom investigated due to the great difficulty in synthesizing single atom Ag and Ag clusters/particles with different sizes.Herein,we firstly prepared an atomically dispersed Ag/Al_(2)O_(3) catalyst using a nano-sized y-Al_(2)O_(3) as the support,subsequently obtained a series of Ag/Al_(2)O_(3) catalysts with different Ag particle sizes by H_(2) reducing single-atom Ag/Al_(2)O_(3) catalyst at various temperatures.The Ag/Al_(2)O_(3) treated at 600℃demonstrated superior CO oxidation performance over single-atom Ag/Al_(2)O_(3) and the Ag/Al_(2)O_(3) treated at 400 and 800℃.Based on experimental data and dpnsity functional theory(DFT)calculation results,we reveal that the larger Ag°particle is beneficial to oxygen activation and improves the valence stability during oxidation reaction,while the aggregation of Ag°particle also accordingly decreases the concentration of surface active sites,hence,there is an optimum Ag0 particle size.Our findings clearly confirm that Ag0nanoparticle has the advantage over single-atom Ag species in its intrinsic activity for CO oxidation.

Synthesis of sulfur doped C_(3)N_(4) with enhanced photocatalytic activity in molten salt

In this paper,sulfur doped g-C_(3)N_(4)(S-g-C_(3)N_(4))was successfully prepared at 500℃ for 3 h via a modified molten salt method using dicyandiamide as the main raw material,trithiocyanuric acid as the sulfur source and LiBreKCl as the reaction medium.The as-prepared SeCN5.0% sample(the mass ratio of trithiocyanuric acid to dicyandiamide was 5.0%)composed of irregular flakes showed a band gap of 1.83 eV,which was narrower than that(2.55 eV)of pristine g-C_(3)N_(4).The SeCN5.0% sample also exhibited an outstanding absorption capacity of visible light.Moreover,the photodegradation rate toward methylene blue and tetracycline were respectively 10 and 20 times as high as that of bulk g-C_(3)N_(4) prepared by conventional heating methods,confirming its superior photocatalytic performance.These results can be attributed to that the replacement of lattice nitrogen with sulfur atom tuned the electronic structure of g-C_(3)N_(4),improved the absorption of visible light,optimized the separation of photogenerated electron-hole pairs,and consequently enhanced the photocatalytic activity of g-C_(3)N_(4).Moreover,the trapping experiments implied that hole(ht)and superoxide radical($O2)were the main active species in the process of photodegradation.

Transcriptional addiction in mixed lineage leukemia: new avenues for target therapies

Mixed lineage leukemia(MLL)is an aggressive and refractory blood cancer that predominantly occurs in pediatric patients and is often associated with poor prognosis and dismal outcomes.Thus far,no effective target therapy for the treatment of MLL leukemia is available.MLL leukemia is caused by the rearrangement of MLL genes at 11q23,which generates various MLL chimeric proteins that promote leukemogenesis through transcriptional misregulation of MLL target genes.Biochemical studies on MLL chimeras have identified that the most common partners exist in the superelongation complex(SEC)and DOT1L complex,which activate or sustain MLL target gene expression through processive transcription elongation.The results of these studies indicate a transcription-related mechanism for MLL leukemogenesis and maintenance.In this study,we first review the history of MLL leukemia and its related clinical features.Then,we discuss the biological functions of MLL and MLL chimeras,significant cooperating events,and transcriptional addiction mechanisms in MLL leukemia with an emphasis on potential and rational therapy development.Collectively,we believe that targeting the transcriptional addiction mediated by SEC and the DOT1L complex will provide new avenues for target therapies in MLL leukemia and serve as a novel paradigm for targeting transcriptional addiction in other cancers.

Enzyme-free and multiplexed micro RNA detection using micro RNA-initiated DNA molecular motor

In this work,we have developed a sensitive,simple,and enzyme-free assay for detection of micro RNAs(mi RNAs)by means of a DNA molecular motor consisting of two stem-loop DNAs with identical stems and complementary loop domains.In the presence of mi RNA target,it can hybridize with one of the stem-loop DNA to open the stem and to produce a mi RNA/DNA hybrid and a single strand(ss)DNA,the ss DNA will in turn hybridize with another stem-loop DNA and finally form a double strand(ds)DNA to release the mi RNA.One of the stem-loop DNA is double-labeled by a fluorophore/quencher pair with efficiently quenched fluorescence.The formation of ds DNA can produced specific fluorescence signal for mi RNA detection.The released mi RNA will continuously initiate the next hybridization of the two stem-loop DNAs to form a cycle-running DNA molecular motor,which results in great fluorescence amplification.With the efficient signal amplification,as low as 1 pmol/L mi RNA target can be detected and a wide dynamic range from 1 pmol/L to 2 nmol/L is also obtained.Moreover,by designing different stem-loop DNAs specific to different mi RNA targets and labeling them with different fluorophores,multiplexed mi RNAs can be simultaneously detected in one-tube reaction with the synchronous fluorescence spectrum(SFS)technique.

Quantum phase transition and destruction of Kondo effect in pressurized SmB6

SmB_6 has been a well-known Kondo insulator for decades, but recently attracts extensive new attention as a candidate topological system. Studying SmB_6 under pressure provides an opportunity to acquire the much-needed understanding about the effect of electron correlations on both the metallic surface state and bulk insulating state. Here we do so by studying the evolution of two transport gaps(low temperature gap E_l and high temperature gap E_h) associated with the Kondo effect by measuring the electrical resistivity under high pressure and low temperature(0.3 K) conditions. We associate the gaps with the bulk Kondo hybridization, and from their evolution with pressure we demonstrate an insulator-tometal transition at ~4 GPa. At the transition pressure, a large change in the Hall number and a divergence tendency of the electron-electron scattering coefficient provide evidence for a destruction of the Kondo entanglement in the ground state. Our results raise the new prospect for studying topological electronic states in quantum critical materials settings.