基于Y-SNP和Y-STR揭示汉族人群父系遗传关系

汉族是中国人口最多的民族,现有研究多集中于汉族人群的起源、迁徙、融合等遗传历史,以及局部地区汉族人群的父系遗传关系,鲜有全局视角下的汉族人群父系遗传结构研究。本研究检测了362份青海、四川和辽宁的汉族无关男性样本,整合已发表文献相关数据,最终获得了国内15个省份16个汉族人群1830人份样本,覆盖89个Y-SNP、16个Y-STR的数据。通过统计Y-SNP单倍群频率、Y-STR单倍型多样性,使用主成分分析(principal component analysis,PCA)、系统发育树、单倍型网络等分析,综合Y-SNP和Y-STR两个反映不同时间尺度的遗传标记,研究不同地区汉族人群之间的遗传分化、汉族人群与其周边少数民族的遗传关系。单倍群频率统计结果显示单倍群O-M175是汉族人群主体单倍群(青海汉族60.53%~广东汉族92.7%),其下游亚单倍群呈现地域差异化分布。单倍群O2-M122高频分布于各地汉族,总体分布趋势北高南低;单倍群O1b-M268分布频率由南向北递减,尤其在岭南地区汉族人群中分布显著;单倍群O1a-M119在中部汉族人群中分布频率较高。汉族人群遗传结构研究表明,其主要分为北部、中部及南部三个聚类簇,其中青海汉族与其他地区汉族存在一定的遗传分化。在合并少数民族的遗传关系研究中,汉族人群彼此之间遗传关系更紧密,但北部汉族与回族遗传关系更近,而南部汉族则与仡佬族、黎族遗传关系更近。总之,本文基于89个Y-SNP和16个Y-STR,系统地研究了中国不同地域的汉族人群的单倍群分布、遗传亚结构及其与周边少数民族的遗传关系,为群体遗传学、法医遗传学补充理论依据,为Y染色体的法医学应用提供数据支撑。Y-SNP单倍群结合Y-STR单倍型对于分析汉族人群遗传亚结构以及法医学应用具有重要作用。

Single-cell RNA sequencing analysis of the retina under acute high intraocular pressure

High intraocular pressure causes retinal ganglion cell injury in primary and secondary glaucoma diseases,yet the molecular landscape characteristics of retinal cells under high intraocular pressure remain unknown.Rat models of acute hypertension ocular pressure were established by injection of cross-linked hyaluronic acid hydrogel(Healaflow■).Single-cell RNA sequencing was then used to describe the cellular composition and molecular profile of the retina following high intraocular pressure.Our results identified a total of 12 cell types,namely retinal pigment epithelial cells,rod-photoreceptor cells,bipolar cells,Müller cells,microglia,cone-photoreceptor cells,retinal ganglion cells,endothelial cells,retinal progenitor cells,oligodendrocytes,pericytes,and fibroblasts.The single-cell RNA sequencing analysis of the retina under acute high intraocular pressure revealed obvious changes in the proportions of various retinal cells,with ganglion cells decreased by 23%.Hematoxylin and eosin staining and TUNEL staining confirmed the damage to retinal ganglion cells under high intraocular pressure.We extracted data from retinal ganglion cells and analyzed the retinal ganglion cell cluster with the most distinct expression.We found upregulation of the B3gat2 gene,which is associated with neuronal migration and adhesion,and downregulation of the Tsc22d gene,which participates in inhibition of inflammation.This study is the first to reveal molecular changes and intercellular interactions in the retina under high intraocular pressure.These data contribute to understanding of the molecular mechanism of retinal injury induced by high intraocular pressure and will benefit the development of novel therapies.

Depositional model of the Member Deng-2 marginal microbial mound-bank complex of the Dengying Formation in the southwestern Sichuan Basin, SW China: Implications for the Ediacaran microbial mound construction and hydrocarbon exploration

Recent advances in hydrocarbon exploration have been made in the Member Deng-2 marginal microbial mound-bank complex reservoirs of the Dengying Formation in the western Sichuan Basin, SW China,where the depositional process is regarded confusing. The microfacies, construction types, and depositional model of the Member Deng-2 marginal microbial mound-bank complex have been investigated using unmanned aerial vehicle photography, outcrop section investigation, thin section identification,and seismic reflections in the southwestern Sichuan Basin. The microbialite lithologic textures in this region include thrombolite, dendrolite, stromatolite, fenestral stromatolite, spongiostromata stone,oncolite, aggregated grainstone, and botryoidal grapestone. Based on the comprehensive analysis of“depositional fabrics-lithology-microfacies”, an association between a fore mound, mound framework,and back mound subfacies has been proposed based on water depth, current direction, energy level and lithologic assemblages. The microfacies of the mound base, mound core, mound flank, mound cap, and mound flat could be recognized among the mound framework subfacies. Two construction types of marginal microbial mound-bank complex have been determined based on deposition location, mound scale, migration direction, and sedimentary facies association. Type Jinkouhe microbial mound constructions(TJMMCs) develop along the windward margin owing to their proximity to the seaward subfacies fore mound, with a northeastwardly migrated microbial mound on top of the mud mound,exhibiting the characteristics of large-sized mounds and small-sized banks in the surrounding area. Type E'bian microbial mound constructions(TEMMCs) primarily occur on the leeward margin, resulting from the presence of onshore back mound subfacies, with the smaller southwestward migrated microbial mounds existing on a thicker microbial flat. The platform margin microbial mound depositional model can be correlated with certain lateral comparison profile and seismic reflection structures in the 2D seismic section, which can provide references for future worldwide exploration. Microbial mounds with larger buildups and thicker vertical reservoirs are typically targeted on the windward margin, while small-sized microbial mounds and flats with better lateral connections are typically focused on the leeward margin.

Bile acids inhibit ferroptosis sensitivity through activating farnesoid X receptor in gastric cancer cells

BACKGROUND Gastric cancer(GC)is associated with high mortality rates.Bile acids(BAs)reflux is a well-known risk factor for GC,but the specific mechanism remains unclear.During GC development in both humans and animals,BAs serve as signaling molecules that induce metabolic reprogramming.This confers additional cancer phenotypes,including ferroptosis sensitivity.Ferroptosis is a novel mode of cell death characterized by lipid peroxidation that contributes universally to malignant progression.However,it is not fully defined if BAs can influence GC progression by modulating ferroptosis.AIM To reveal the mechanism of BAs regulation in ferroptosis of GC cells.METHODS In this study,we treated GC cells with various stimuli and evaluated the effect of BAs on the sensitivity to ferroptosis.We used gain and loss of function assays to examine the impacts of farnesoid X receptor(FXR)and BTB and CNC homology 1(BACH1)overexpression and knockdown to obtain further insights into the molecular mechanism involved.RESULTS Our data suggested that BAs could reverse erastin-induced ferroptosis in GC cells.This effect correlated with increased glutathione(GSH)concentrations,a reduced GSH to oxidized GSH ratio,and higher GSH peroxidase 4(GPX4)expression levels.Subsequently,we confirmed that BAs exerted these effects by activating FXR,which markedly increased the expression of GSH synthetase and GPX4.Notably,BACH1 was detected as an essential intermediate molecule in the promotion of GSH synthesis by BAs and FXR.Finally,our results suggested that FXR could significantly promote GC cell proliferation,which may be closely related to its anti-ferroptosis effect.CONCLUSION This study revealed for the first time that BAs could inhibit ferroptosis sensitivity through the FXR-BACH1-GSHGPX4 axis in GC cells.This work provided new insights into the mechanism associated with BA-mediated promotion of GC and may help identify potential therapeutic targets for GC patients with BAs reflux.

Synthesizing active and durable cubic ceria catalysts(<6 nm)for fast dehydrogenation of bio-polyols to carboxylic acids coproducing green H_(2)

Dehydrogenation is considered as one of the most important industrial applications for renewable energy.Cubic ceria-based catalysts are known to display promising dehydrogenation performances in this area.Large particle size(>20 nm)and less surface defects,however,hinder further application of ceria materials.Herein,an alternative strategy involving lactic acid(LA)assisted hydrothermal method was developed to synthesize active,selective and durable cubic ceria of<6 nm for dehydrogenation reactions.Detailed studies of growth mechanism revealed that,the carboxyl and hydroxyl groups in LA molecule synergistically manipulate the morphological evolution of ceria precursors.Carboxyl groups determine the cubic shape and particle size,while hydroxyl groups promote compositional transformation of ceria precursors into CeO_(2) phases.Moreover,enhanced oxygen vacancies(Vo)on the surface of CeO_(2) were obtained owing to continuous removal of O species under reductive atmosphere.Cubic CeO_(2) catalysts synthesized by the LA-assisted method,immobilized with bimetallic PtCo clusters,exhibit a record high activity(TOF:29,241 h^(-1))and Vo-dependent synergism for dehydrogenation of bio-derived polyols at 200℃.We also found that quenching Vo defects at air atmosphere causes activity loss of PtCo/CeO_(2) catalysts.To regenerate Vo defects,a simple strategy was developed by irradiating deactivated catalysts using hernia lamp.The outcome of this work will provide new insights into manufacturing durable catalyst materials for aqueous phase dehydrogenation applications.

Detection of Novel BEST1 Variations in Autosomal Recessive Bestrophinopathy Using Third-generation Sequencing

Objective:Autosomal recessive bestrophinopathy(ARB),a retinal degenerative disease,is characterized by central visual loss,yellowish multifocal diffuse subretinal deposits,and a dramatic decrease in the light peak on electrooculogram.The potential pathogenic mechanism involves mutations in the BEST1 gene,which encodes Ca2+-activated Cl−channels in the retinal pigment epithelium(RPE),resulting in degeneration of RPE and photoreceptor.In this study,the complete clinical characteristics of two Chinese ARB families were summarized.Methods:Pacific Biosciences(PacBio)single-molecule real-time(SMRT)sequencing was performed on the probands to screen for disease-causing gene mutations,and Sanger sequencing was applied to validate variants in the patients and their family members.Results:Two novel mutations,c.202T>C(chr11:61722628,p.Y68H)and c.867+97G>A,in the BEST1 gene were identified in the two Chinese ARB families.The novel missense mutation BEST1 c.202T>C(p.Y68H)resulted in the substitution of tyrosine with histidine in the N-terminal region of transmembrane domain 2 of bestrophin-1.Another novel variant,BEST1 c.867+97G>A(chr11:61725867),located in intron 7,might be considered a regulatory variant that changes allele-specific binding affinity based on motifs of important transcriptional regulators.Conclusion:Our findings represent the first use of third-generation sequencing(TGS)to identify novel BEST1 mutations in patients with ARB,indicating that TGS can be a more accurate and efficient tool for identifying mutations in specific genes.The novel variants identified further broaden the mutation spectrum of BEST1 in the Chinese population.

海南卫星地面站综合防雷措施的研究

海南地区雷暴天气发生频繁,采取有效的防雷措施是确保海南卫星地面站安全稳定运行的前提。利用Matlab对近30年的雷暴数据进行可视化处理,对海南年平均雷暴日数和月平均雷暴百分率进行统计分析。根据雷暴数据、天线高度、电源和信号线缆布设方式等信息,计算了海南卫星地面站年预计雷击次数,按照防雷装置的拦截效率确定了雷电防护等级。结合海南雷暴发生规律和地面站电子设备,从接闪针防护面积、天线塔基避雷措施、机房等电位连接、浪涌保护器选型安装、屏蔽保护和光纤传输、防雷装置检测维护等方面,研究提出了海南卫星地面站综合防雷的措施。

Non-use value assessment for wetland ecosystem service of Hongxing National Nature Reserve in northeast China

By the contingent value method, we studied the non-use value of wetland ecosystem service of Hongxing National Nature Reserve （HNNR） in Heilongjiang Pro- vince, northeast China. The proportion of respondents willing to pay （WTP） for protection of HNNR was 63 %. The WTP ratio was affected by geographical area, contact nature, personal preferences, and familiar degree of the respondents. The WTP value was affected by age, education level and career of the respondents. The mainly reasons for people rejecting to pay for protecting HNNR were ＂I am not familiar to HNNR＂ and ＂I had no capacity for additional spending because of low income＂. Weighted average individual WTP value was CNY 59.26 Yuan ind.^-1 year^-1 for all the respondents with WTP. The total non-use ecosystem service value of HNNR was CNY 1430 million Yuan in 2013. The heritage value was highest followed by existence value and option value. From the high ecosystem service value in HNNR, it is very important to construct nature reserve for protecting natural ecosystems and human sustainable use of natural resources.

Antioxidative effect of peroxiredoxin-3 in the rat myocardium exposed to renal ischemia-reperfusion injury

Background:Peroxiredoxin-3(Prx-3)is known to be involved in the clearance of cellular hydrogen peroxide and plays an important role in protecting the myocardial tissue against damage of oxidative stress.However,the role of Prx-3 in protecting the myocardial tissue against renal ischemia/reperfusion(I/R)-induced myocardial injury(RI/RMI)remains unknown.We aimed to examine the antioxidative effect of Prx-3 using a rat RI/RMI model in an attempt to find a new approach to the prevention and treatment of myocardial injury induced by renal I/R.Methods:A RI/RMI rat model was established to detect the renal histopathology and renal functions by hematoxylin-eosin staining staining and commercially available assay kits.The myocardial antioxidant activity and the expressions of mRNA and protein of Prx-3 in the myocardial tissue were measured by real-time polymerase chain reaction and Western blotting assay,respectively.Results:Compared with the normal and control groups,the serum level of blood urea nitrogen and serum creatinine was significantly increased in the I/R group(P<0.05).Histopathological changes in the kidneys were also more obvious,including glomerular cystic and renal interstitial hemorrhage,renal tubular epithelial cell edema,and tubular type formation.The mRNA and protein expressions of Prx-3 were increased significantly in the RI/MRI rat model as compared with those in the normal and control groups.Conclusion:Oxidative damage occurred in the remote myocardium after renal I/R and Prx-3 was able to enhance the self-regulatory ability of the myocardium against damage from oxidative stress after RI/MRI.

曲克芦丁联合丁苯酞治疗脑梗死的临床疗效评价

目的 探讨曲克芦丁联合丁苯酞治疗脑梗死患者的临床疗效。方法 选取2020年2月至2022年4月南阳市中心医院收治的98例脑梗死患者作为研究对象,按照治疗方式差异将其分为观察组(51例)和对照组(47例),对照组予以丁苯酞治疗,观察组在此基础上联合曲克芦丁治疗。比较两组在疗效、不良反应发生率、治疗前后神经功能、日常生活能力、凝血功能(D-二聚体,D-D)、凝血酶原时间(PT)、纤维蛋白原(FIB)及一氧化氮(NO)、内皮素-1(ET-1)和血管性假血友病因子(vWF)水平的差异。结果 观察组总有效率较对照组高(98.04%vs. 76.60%,P<0.001);在神经功能方面,治疗后两组NIHSS评分下降,观察组较对照组低(7.38±2.33vs. 12.78±2.75,P <0.001),两组BI评分升高,观察组较对照组高(58.01±10.72vs. 46.45±8.35,P <0.001);在凝血功能方面,两组治疗后D-D、PT、FIB、NO、ET-1、vWF水平均改善,观察组优于对照组(P <0.05)。结论 曲克芦丁联合丁苯酞可能有助于调节脑梗死患者的NO、ET-1、vWF水平,改善神经功能、日常生活能力与凝血功能,对于治疗脑梗死具有一定的价值。

重复抗VEGF治疗对DME患者玻璃体黄斑界面的影响及其危险因素

目的:探讨糖尿病性黄斑水肿(DME)患者重复接受玻璃体腔注射抗血管内皮生长因子(VEGF)治疗对玻璃体黄斑界面(VMI)的影响及其相关危险因素。方法:回顾性分析2018-01/2021-12于遵义市第一人民医院眼科接受玻璃体腔注射康柏西普治疗(3+PRN)的DME患者31例55眼的临床资料。比较发生VMI改变(VMI改变组,9例13眼)和未发生VMI改变(VMI无改变组,22例42眼)的患者治疗前后最佳矫正视力(BCVA)、中央视网膜厚度(CRT)、中心凹下脉络膜厚度(CCT)情况,并分析发生VMI改变的危险因素。结果:纳入患者平均随访9.58±8.32mo,平均接受抗VEGF治疗4.07±2.17次,且VMI改变组患者玻璃体腔注射次数多于VMI无改变组(5.77±2.09次vs 3.55±1.93次,P=0.001)。末次随访时,与治疗前相比,两组患者治疗后BCVA均显著改善(均P<0.05),而CCT均无明显变化(均P>0.05),VMI无改变组患者CRT显著减小(P=0.039),但VMI改变组患者CRT未见明显变化(P=0.627)。Logistic回归分析结果显示,治疗前BCVA是VMI改变的危险因素(P=0.049,OR=6.210,95%CI 1.006~38.346)。结论:DME患者反复玻璃体腔注射抗VEGF药物过程中可能发生VMI改变,治疗前BCVA越差的患者VMI发生改变的风险越高,且VMI改变的患者对抗VEGF治疗反应欠佳。

Outcomes of ABO-incompatible liver transplantation in end-stage liver disease patients co-infected with hepatitis B and human immunodeficiency virus

BACKGROUND Human immunodeficiency virus(HIV)-positive patients coinfected with hepatitis B virus(HBV)are eligible for liver transplantation(LT)in Africa and Southeast Asia,particularly China.However,the outcome of HIV-HBV coinfected patients referred for ABO-incompatible LT(ABOi-LT)is unknown.AIM To clarify the outcome of ABOi-LT for HIV-HBV coinfected patients with endstage liver disease(ESLD).METHODS We report on two Chinese HIV-HBV coinfected patients with ESLD who underwent A to O brain-dead donor LT and reviewed the literature on HIV-HBV coinfected patients treated with ABO-compatible LT.The pretransplantation HIV viral load was undetectable,with no active opportunistic infections.Induction therapy consisted of two sessions of plasmapheresis and a single dose of rituximab in two split doses,followed by an intraoperative regimen of intravenous immunoglobulin,methylprednisolone,and basiliximab.Post-transplant maintenance immunosuppressive agents consisted of tacrolimus and mycophenolate mofetil,and prednisone.RESULTS At the intermediate-term follow-up,patients showed undetectable HIV viral load,CD4(+)T cell counts greater than 150 cells/μL,no HBV recurrence,and stable liver function.A liver allograft biopsy showed no evidence of acute cellular rejection.Both patients survived at 36-42 mo of follow-up.CONCLUSION This is the first report of ABOi-LT in HIV-HBV recipients with good intermediate-term outcomes,suggesting that ABOi-LT may be feasible and safe for HIV-HBV coinfected patients with ESLD.

Preparation of TiO_(2) Supported Mxene Catalyst for High Efficiency Hydrogen Production

We studied a method to prepare a novel titanium dioxide(TiO_(2))composite photocatalyst,starting from improving the separation efficiency of photogenerated electrons and holes.Regular TiO_(2)microspheres were prepared by sol-gel method and loaded onto Ti3C2Tx(Mxene).The high electrical conductivity of Mxene was utilized to transfer photogenerated electrons quickly and effectively prevent their recombination.By adjusting the addition amount of Mxene,the hydrogen production efficiency of the sample was greatly improved,and the maximum efficiency reached 135.2μmol·g^(-1)·h^(-1),which was twice that of pure TiO_(2).The nanocomposites were characterized by XRD,PL,TEM and SEM analysis and electrochemical methods,and the test proved that the improvement of hydrogen production efficiency was caused by the improvement of the separation efficiency of photogenerated electrons and holes.This work demonstrates the application of Mxene as a catalyst to improve efficiency and broadens the application prospects of Mxene.

Identifying a novel frameshift pathogenic variant in a Chinese family with neurofibromatosis type 1 and review of literature

AIM:To detect the pathogenic gene variant in a family with neurofibromatosis type 1(NF1).METHODS:This patient with NF1 was sequenced using target sequence capture and high-throughput sequencing technology.After detecting the suspicious pathogenic variant type,the pathogenic variant sites of the patient and the patient’s family members were verified by multiple ligation dependent probe amplification and Sanger sequencing.Sift,polyphen-2,Mutation Taster and GERP++software were used to predict the pathogenicity of the unknown loci.The clinical data,diagnosis and treatment process of the patients were reviewed.Using the keyword“NF1;frameshift pathogenic variant”,relevant literature was gathered for analysis from Chinese and international databases,with articles dating from the establishment of each database to April 2022.RESULTS:A heterozygous frameshift pathogenic variant of NF1 in exon 33 was detected in the patient.The insertion of adenine in coding region 4486 resulted in the replacement of isoleucine with asparagine in protein 1497.Sanger sequencing validation and segregation analysis were performed,which demonstrated that the NF1 gene was cosegregated with the disease phenotype in this family.This study identified a novel NF1 heterozygous frameshift mutation c.4486dupA(p.I1497Nfs*12).Relevant literature retrieval found 7 Chinese articles and 12 foreign articles.With NF1 gene mutation,mutation types are diverse,including point mutation,frameshift mutation,splice site mutation,exon mutation,chimeric mutation and de novo mutation.Foreign reports are based on autosomal dominant inheritance.CONCLUSION:This study’s results demonstrate that a novel deletion in exon 33 caused NF1 in this Chinese family,expanding the mutational spectrum of the NF1 gene.

Wettability alteration of organo-vermiculites induced by layer charge and tailored bis-N-heterocyclic quaternary ammonium salts

Wettability is an important surface property that deserves to further explore the factors on its alteration.Series of bis-N-heterocyclic quaternary ammonium salts with different spacer length and N-heterocyclic headgroups(morpholinium(BMMB,BMMD and BMMH),piperidinium(BPMH)and piperazinium(BMPMH))have been synthesized and employed for altering the wettability of vermiculite and its derivates(Vts)treated by Li^(+)-saturated heating method.The results of X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),thermogravimetric analysis(TG-DTG),scanning electron microscopy(SEM)and N_(2)adsorption/desorption isotherms indicate that all of the bis-N-heterocyclic quaternary ammonium salts have been successfully inserted into the vermiculite layers,leading to the organic monolayer.The results of capillary rise tests combined with Lipophilic to Hydrophilic Ratio(LHR)values unveil the wettability alteration of the organo-Vts.As the layer charge decreases,the hydrophilicity of the organo-Vts gradually increases,which is probably caused by the decline in binding sites.As the result of the change in spacer length of modifier,the wetting properties of morpholinium-based organo-Vts change in order of BMMD-Vts>BMMH-Vts>BMMB-Vts,and difference in N-heterocyclic headgroups leads to the sequence of wettability:BMPMH-Vts>BPMH-Vts>BMMH-Vts.Layer charge of Vt,spacer length and the type of the N-heterocyclic headgroup of modifier have the synergistic effect on the regulation of the wettability.

Selective capture of silver ions from aqueous solution by series of azole derivatives-functionalized silica nanosheets

The introduction of bifunctional groups into low-cost adsorbents for selective adsorption of Ag(I) through synergistic effect will have a profound impact on the recovery of precious metals. Organo silica nanosheets(organo-Si NSs) functionalized by series of azole derivatives(2-mercaptoimidazole(MI), 2-mercaptobenzimidazole(MBT) and 1H-1,2,4-triazole-3-thiol(MTT)), are fabricated and employed for selective removal of Ag(I). The structures of the organo-Si NSs are investigated using several characterization methods. The results of batch adsorption experiments display that the maximum adsorption amounts are 70.3, 103.2 and 139.5 mg·g^(-1) on MI-Si NSs, MBI-Si NSs and MTT-Si NSs for Ag(I) ions, and reach rapid equilibrium within 10–30 min. The adsorption processes are chemisorption and fit pseudo-second-order kinetic model and Langmuir adsorption isotherm model. Notably, MTT-Si NSs is greatly selective for Ag(I) in multicomponent system, and the distribution coefficient value of Ag(I) ions reaches 2331.26 ml·g^(-1). The reusability of organo-Si NSs is verified by four cycles of regeneration tests with 0.1 mol·L^(-1) HNO_(3) as the eluent. A combination of experimental, structural along with theoretical analysis is conducted to proclaim the structure-adsorptivity relationship:(i) The adsorption mechanisms are attributed to complexation.(ii) The amino group and sulfhydryl group of MTT-Si NSs as well as MBISi NSs may have synergistic impacts on Ag(I) capture.(iii) The differences in adsorption behavior and selectivity of the three organo-Si NSs are mainly related to the form of function groups, charge density and steric hindrance of adsorbent. This work not only sheds light on the promise of functionalized organo-Si NSs for the rapid and selective removal/enrichment of Ag(I) ions in complex water systems,but also provides new insights for designing cost-effective Si NSs-based adsorbents.

Hydrothermal conversion of fructose to lactic acid and derivatives:Synergies of metal and acid/base catalysts

With increasing strict regulation on single-use plastics,lactic acid(LA)and alkyl lactates,as essential monomers for bio-degradable polylactic acid(PLA)plastic products,have gained worldwide attention in both academia and industry.While LA is still dominantly produced through fermentation processes from start,chemical synthesis from cellulosic biomass remains a grand challenge,owing to poor selectivity in activating CAH and CAC bonds in sugar molecules.To our best knowledge,recent publications have been focused on hydrothermal conversion of glucose to LA,while this review summarizes the highlights on direct thermal conversion of fructose as starting material to LA and derivatives.In particular,the synergies of metal/metal cations and acid/base catalysts will be critically revised on retro-aldol and dehydration reactions.This work will provide insights into rational design of active and selective catalysts for the production of carboxylic acids from biomass feedstocks.

Engineered nitrogen doping on VO_(2)(B)enables fast and reversible zinc-ion storage capability for aqueous zinc-ion batteries

Vanadium-based compounds with high theoretical capacities and relatively stable crystal structures are potential cathodes for aqueous zinc-ion batteries(AZIBs).Nevertheless,their low electronic conductivity and sluggish zinc-ion diffusion kinetics in the crystal lattice are greatly obstructing their practical application.Herein,a general and simple nitrogen doping strategy is proposed to construct nitrogen-doped VO_(2)(B)nanobelts(denoted as VO_(2)-N)by the ammonia heat treatment.Compared with pure VO_(2)(B),VO_(2)-N shows an expanded lattice,reduced grain size,and disordered structure,which facilitates ion transport,provides additional ion storage sites,and improves structural durability,thus presenting much-enhanced zinc-ion storage performance.Density functional theory calculations demonstrate that nitrogen doping in VO_(2)(B)improves its electronic properties and reduces the zinc-ion diffusion barrier.The optimal VO_(2)-N400 electrode exhibits a high specific capacity of 373.7 mA h g^(-1)after 100 cycles at 0.1 A g^(-1)and stable cycling performance after 2000 cycles at 5 A g^(-1).The zinc-ion storage mechanism of VO_(2)-N is identified as a typical intercalation/de-intercalation process.

Polar motion prediction using the combination of SSA and ARMA

High-precision polar motion(PM) prediction is of important significance in astronomy, geodesy, aviation,hydrographic mapping, interstellar navigation, and so on. SSA can effectively extract the trend and period terms of PM,in the process of achieving high-precision medium-and long-term polar motion prediction,it is necessary to solve the end effect problem and overfitting problem of SSA forecasting method;therefore, ARMA was applied to decreasethe end effect, and a suitable combination of reconstructed components was determined to avoid the high variance reaction of SSA overfitting. Based on the decomposition and reconstruction of the PM by SSA, the reconstructed components are determined to participate in the SSA iterative fitting model according to the variance contribution rate. The combination of the reconstructed components representing the polar motion period term and the trend term is determined according to the correlation analysis of the selected reconstructed components. After the above work, the principal component prediction sequence is obtained by fitting the period term and the trend term to convergence, respectively, and then, the SSA end effect is modified, and the residual term is predicted based on ARMA. The test results show that he prediction accuracy of SSA + ARMA at the front of the X and Y directions are improved by 96.90% and 97.53% compared with those of SSA, respectively,and the forecast accuracy of 365 days are improved by 37.93% and 19.53% in the X and Y directions compared with those of Bulletin A, respectively.

关于丙酮碘化反应实验的方法误差的讨论

用简单的方法估算了丙酮碘化反应实验中用平均速率代替瞬时速率产生的方法误差,相对误差的绝对值为10-4数量级,并分析了产生误差的原因。