The Research on Identification of Gene Splice Sites by Support Vector Machine

The recognition of splicing sites is a very important step in the eukaryotic DNA se-quence analysis. Many scholars are working hard to improve the accuracy of identifi-cation. Our team carried out research on this issue based on support vector machine, which is one famous algorithm in data mining. The training and testing data is from the HS3D dataset, and excellent accuracy rate is achieved by nucleic acid sequence orthogonal coding and RBF core function, and the cross validation experiment hints that base pattern information is mainly located within 20 nucleotides upstream and downstream splice sites.

Dexamethasone does not affect endolymphatic hydrops(EH)in patients with Meniere's disease within 24 h,and intratympanic administration of gadolinium plus dexamethasone simplifies high-quality imaging of EH using a novel protocol of 7 min

Background:Intratympanic administration of gadolinium chelate allows for a better visualization of endolymphatic hydrops(EH)using MRI than intravenous injection and was recently further improved to facilitate high-quality imaging of EH in 7 min.The aim of the present study was to simplify the intratympanic administration protocol by mixing gadolinium chelate with therapeutic dexamethasone and to evaluate the effects of this mixture on the visualization of EH in MRI.Materials and methods:In an in vitro study,the potential impact of gadolinium-diethylenetriamine pentaacetic acid(Gd-DTPA)on the stability of dexamethasone was evaluated by analyzing dynamic changes in dexamethasone with high-performance liquid chromatography(HPLC)after mixing with GdDTPA.Ten patients with definite Meniere's disease(MD)were recruited to study the potential interference of dexamethasone on MRI visualization of EH,and 49 patients with MD were recruited to evaluate the effect of intratympanic injection of Gd-DTPA mixed with dexamethasone on MRI of EH using a 3T MR machine and a novel heavily T2-weighted 3-dimensional fluid-attenuated inversion recovery reconstructed using a magnitude plus zero-filled interpolation(hT2FLAIR-MZFI)sequence.Results:The retention times and peak area of dexamethasone in HPLC were not modified by the addition of Gd-DTPA.EH grading in the cochlea and vestibule was not influenced in any ear by intratympanic injection of dexamethasone.Excellent inner ear images were obtained from all patients,and EHs with various grades were displayed.There were significant correlations between diagnosis and cochlear EH(p<0.01,Spearman's Rho),between diagnosis and vestibular EH(p<0.01,Spearman's Rho),and between cochlear and vestibular EH(p<0.01,Spearman's Rho).The distribution of Gd-DTPA plus dexamethasone negatively correlated with the grade of vestibular EH.Injury of the endolymph-perilymph barrier was detected in one cochlea and three vestibules of 59 inner ears with MD.Conclusions:Intratympanic administration of Gd-DTPA plus dexamethasone yielded high-quality MRI images of EH in patients with MD using a novel 7-min protocol and simplified the clinical application.Intratympanic administration of Gd-DTPA plus dexamethasone might be used to test its therapeutic effect in future work.

3D human nonalcoholic hepatic steatosis and fibrosis models

This study presents a simple and robust three-dimensional human hepatic tissue model to emulate steatotic and fibrotic conditions and provide an in vitro model for drug testing and mechanistic studies.Using a photolithographic biofabrication method with a photomask featuring hexagonal units,liver cells,including a human hepatic cell line(HepG2-C3A)and a human hepatic stellate cell line(LX-2)were embedded in gelatin methacryloyl hydrogel.Hepatic steatosis was induced by supraphysiological concentration of free fatty acids;hepatic fibrosis was induced by transforming growth factor-β1.Induction of steatosis was confirmed by Oil Red O and BODIPY staining and was inhibited with toyocamycin and obeticholic acid.Induction of fibrosis was confirmed by immunostaining for collagen type I and alpha smooth muscle actin and inhibited by rapamycin and curcumin treatment.This model was further preliminarily validated using primary human hepatocytes in a similar setup.These constructs provide a viable,biologically relevant,and higher throughput model of hepatic steatosis and fibrosis and may facilitate the study of the mechanisms of disease and testing of liver-directed drugs.

Fabrication of paper-based devices for in vitro tissue modeling

Paper devices have recently attracted considerable attention as a class of cost-effective cell culture substrates for various biomedical applications.The paper biomaterial can be used to partially mimic the in vivo cell microenvironments mainly due to its natural three-dimensional characteristic.The paper-based devices provide precise control over their structures as well as cell distributions,allowing recapitulation of certain interactions between the cells and the extracellular matrix.These features have shown great potential for the development of normal and diseased human tissue models.In this review,we discuss the fabrication of paper-based devices for in vitro tissue modeling,as well as the applications of these devices toward drug screening and personalized medicine.It is believed that paper as a biomaterial will play an essential role in the field of tissue model engineering due to its unique performances,such as good biocompatibility,eco-friendliness,cost-effectiveness,and amenability to various biodesign and manufacturing needs.

Cyclical helping hands: seasonal tailwinds differentially affect migrating Oriental Storks (Ciconia boyciana) travel speed

Background:The Oriental Stork(Ciconia boyciana)breeds in southeastern Siberia and parts of northeast China,and winters mainly in southeast China.Although the autumn migration pattern of Oriental Storks has been previ-ously described,differences between spring and autumn migration travel speed in relation to wind assistance were unknown.Methods:Using GPS/GSM transmitters,we tracked the full migrations of 18 Oriental Storks during 2015-2018 to compare differences in autumn and spring migration patterns,and combined the satellite telemetry data with the National Center for Environmental Prediction Reanalysis data to explain the relationship between 850 mbar wind vec-tors and seasonal differences in travel speed.Results:Differences in tailwinds contributed to significant differences in daily average Oriental Storks travel speed in spring(258.11±64.8 km/day)compared to autumn(172.23±49.7 km/day,p<0.001).Storks stopped significantly more often in autumn than spring(1.78±1.1 versus 1.06±0.9,p<0.05),but stopover duration(15.52±12.4 versus 16.30±15.1 days,respectively,p=0.3)did not differ significantly.Tailwinds at 850 mbar pressure level(extracted from the National Center of Environmental Prediction Reanalysis data archive)significantly affected daily flying speed dur-ing spring and autumn migration.Tailwind conditions in spring(mean 4.40±5.6 m/s)were always more favourable than in autumn when they received no net benefit(0.48±5.6 m/s,p<0.001).Despite mean spring migration dura-tion being less than autumn(27.52±15.9 versus 32.77±13.4 days,p=0.17),large individual variation meant that this duration did not differ significantly from each other.Conclusions:For long distance migratory soaring birds(such as storks),relative duration of spring and autumn migration likely relates to the interaction between imperative for earliest arrival to breeding grounds and seasonal meteorological conditions experienced en route.

Identification of microsatellites in cattle unigenes

To identify EST-SSR molecular markers, 41,986 cattle UniGene sequences from NCBI were mined for analyzing SSRs. A total of 1,831 SSRs were identified from 1,666 ESTs, which represented an average density of 19.88 kb per SSR. The frequency of EST-SSRs was 4.0%. The dinucleotide repeat motif was the most abundant SSR, accounting for 54%, followed by 22%, 13%, 7% and 4%, respectively, for tri-, hexa-, penta- and tetra-nucleotide repeats. Depending upon the length of the repeat unit, the length of microsatellites varied from 14 to 86 bp. Among the di- and tri-nucleotide repeats, AC/TG （57%） and AGC （12%） were the most abundant type. Annotation of EST-SSRs was also carried out. Three hundred primer pairs were randomly designed using Prime Premier 5.0 program and Oligo 5.0 for further experimental validation.

Application of geophysical well logs in solving geologic issues:Past,present and future prospect

Geophysical well logs are widely used in geological fields,however,there are considerable incompatibilities existing in solving geological issues using well log data.This review critically fills the gaps between geology and geophysical well logs,as assessed from peer reviewed papers and from the authors’personal experiences,in the particular goal of solving geological issues using geophysical well logs.The origin and history of geophysical logging are summarized.Next follows a review of the state of knowledge for geophysical well logs in terms of type of specifications,vertical resolution,depth of investigations and demonstrated applications.Then the current status and advances in applications of geophysical well logs in fields of structural geology,sedimentary geology and petroleum geology are discussed.Well logs are used in structural and sedimentary geology in terms of structure detection,in situ stress evaluation,sedimentary characterization,sequence stratigraphy division and fracture prediction.Well logs can also be applied in petroleum geology fields of optimizing sweet spots for hydraulic fracturing in unconventional oil and gas resource.Geophysical well logs are extending their application in other fields of geosciences,and geological issues will be efficiently solved via well logs with the improvements of advanced well log suits.Further work is required in order to improve accuracy and diminish uncertainties by introducing artificial intelligence.This review provides a systematic and clear descriptions of the applications of geophysical well log data along with examples of how the data is displayed and processed for solving geologic problems.

Location of the AICA influences the severity but not occurrence of ISSNHL:A reappraisal using high-resolution 3 T MRI

Objective:To investigate the potential influence of anatomical variation in the anterior inferior cerebellar artery(AICA)on the occurrence and severity of idiopathic sudden sensorineural hearing loss(ISSNHL).Methods:Ninety ISSNHL patients were enrolled.The anatomical location of the AICA was exhibited using high-resolution magnetic resonance imaging(MRI),and the various AICA types classified by previously reported Chavda and Gorrie methods were analyzed.The severity of hearing loss in the ipsilateral ear among different AICA types was compared.Results:Approximately 85.6%of subjects had unilateral ISSNHL(uISSNHL),and the others had bilateral ISSNHL(bISSNHL).In the uISSNHL group,the ratios of different AICA types were similar between the ipsilateral and contralateral ears.The ratios of the different AICA types in the bISSNHL group were similar to those in the uISSNHL group.In the uISSNHL group,pure tone audiometry(PTA)thresholds at 2 kHz,4 kHz and 8 kHz of patients with Chavda type II AICA were higher than those of patients with Chavda type I and type III,with a significant difference at 4 kHz between type I and type II.There was a tendency of the PTA threshold in patients with Chavda type II or Gorrie type C to gradually increase from low to high frequency zones.Conclusion:When the AICA enters the IAC(Chavda type II)or crosses between the 7th and 8th cranial nerves(Gorrie type C),the severity and frequency of hearing impairment in ISSNHL but not the occurrence of ISSNHL will be affected.

Cotton BLH1 and KNOX6 antagonistically modulate fiber elongation via regulation of linolenic acid biosynthesis

BEL1-LIKE HOMEODOMAIN(BLH)proteins are known to function in various plant developmental processes.However,the role of BLHs in regulating plant cell elongation is still unknown.Here,we identify a BLH gene,GhBLH1,that positively regulates fiber cell elongation.Combined transcriptomic and biochemical analyses reveal that GhBLH1 enhances linolenic acid accumulation to promote cotton fiber cell elongation by activating the transcription of GhFAD7A-1 via binding of the POX domain of GhBLH1 to the TGGA cis-element in the GhFAD7A-1 promoter.Knockout of GhFAD7A-1 in cotton significantly reduces fiber length,whereas overexpression of GhFAD7A-1 results in longer fibers.The K2 domain of GhKNOX6 directly interacts with the POX domain of GhBLH1 to form a functional heterodimer,which interferes with the transcriptional activation of GhFAD7A-1 via the POX domain of GhBLH1.Overexpression of GhKNOX6 leads to a significant reduction in cotton fiber length,whereas knockout of GhKNOX6 results in longer cotton fibers.An examination of the hybrid progeny of GhBLH1 and GhKNOX6 transgenic cotton lines provides evidence that GhKNOX6 negatively regulates GhBLH1-mediated cotton fiber elongation.Our results show that the interplay between GhBLH1 and GhKNOX6 modulates regulation of linolenic acid synthesis and thus contributes to plant cell elongation.

Modeling and prediction of tribological properties of copper/aluminum-graphite self-lubricating composites using machine learning algorithms

The tribological properties of self-lubricating composites are influenced by many variables and complex mechanisms.Data-driven methods,including machine learning(ML)algorithms,can yield a better comprehensive understanding of complex problems under the influence of multiple parameters,typically for how tribological performances and material properties correlate.Correlation of friction coefficients and wear rates of copper/aluminum-graphite(Cu/Al-graphite)self-lubricating composites with their inherent material properties(composition,lubricant content,particle size,processing process,and interfacial bonding strength)and the variables related to the testing method(normal load,sliding speed,and sliding distance)were analyzed using traditional approaches,followed by modeling and prediction of tribological properties through five different ML algorithms,namely support vector machine(SVM),K-Nearest neighbor(KNN),random forest(RF),eXtreme gradient boosting(XGBoost),and least-squares boosting(LSBoost),based on the tribology experimental data.Results demonstrated that ML models could satisfactorily predict friction coefficient and wear rate from the material properties and testing method variables data.Herein,the LSBoost model based on the integrated learning algorithm presented the best prediction performance for friction coefficients and wear rates,with R^(2) of 0.9219 and 0.9243,respectively.Feature importance analysis also revealed that the content of graphite and the hardness of the matrix have the greatest influence on the friction coefficients,and the normal load,the content of graphite,and the hardness of the matrix influence the wear rates the most.

Spatial structure regulation towards armor-clad five-membered pyrroline nitroxides catholyte for long-life aqueous organic redox flow batteries

Five-membered pyrroline nitroxides with high-potential is fascinating as catholyte for aqueous organic redox flow batteries(AORFBs),however,it suffers from a primary deficiency of insufficient stability due to ring-opening side reaction.Herein we report a spatial structure regulation strategy by host-guest chemistry,encapsulating 3-carbamoyl-2,2,5,5-tetramethylpyrroline-1-oxyl(CPL)into hydrosoluble cyclodextrins(CDs)with an inclusion structure of N–O⋅head towards cavity bottom,to boost the solubility and cyclability of pyrroline nitroxides significantly.The armor-clad CPL(CPL⊂HP-β-CD)catholyte in 0.05–0.5 M presents a battery capacity fade rate as low as 0.002%/cycle(0.233%/day)compared to the sole CPL in 0.05 M(0.039%/cycle or 5.23%/day)over 500 cycles in assembled AORFBs.The optimized reclining spatial structure with N–O⋅head towards CD cavity bottom effectively inhibits the attack of Lewis base species on the hydrogen abstraction site in pyrroline ring,and thus avoids the ring-opening side reaction of pyrroline nitroxides.

膜蒸馏用中空纤维膜制备技术的研究进展

作为一种热驱动的膜分离技术,膜蒸馏以其较低的操作要求及极高的截留率而成为极具开发潜力的膜分离技术之一。然而,较低的渗透通量和抗润湿性限制了膜蒸馏技术的广泛发展和应用。除了优化设计膜蒸馏工艺,疏水性多孔分离膜的研究成为关键解决途径。具有高比表面积的疏水性中空纤维膜以其自支撑结构及其组件的设计灵活性而成为膜蒸馏技术中应用较广的一种分离膜。文中从中空纤维膜材料的选择和开发、常规和新型纺丝方法及后处理等方面对近些年膜蒸馏用中空纤维膜制备技术进行综述,并对其制备方法中亟待深入研究的内容和应用前景进行了展望。

HOXD3在乳腺癌细胞干性和化疗耐药性中的作用及机制研究

目的:探讨HOXD3表达对乳腺癌细胞干性的影响,并研究HOXD3表达与乳腺癌细胞化疗耐药的关系。方法:收集2006年1月至2008年12月哈尔滨医科大学附属肿瘤医院87例乳腺癌患者组织标本。采用免疫组织化学染色法检测乳腺癌细胞和组织中HOXD3表达;采用RT-PCR、Western blot和免疫荧光染色法检测HOXD3在顺铂或阿霉素耐药细胞系MDA-MB-231和MDA-MB-435中的表达水平,分析HOXD3过表达对乳腺癌细胞系MDA-MB-231和MDA-MB-435的干细胞生物标志物表达水平的影响;采用MTT法和集落形成实验分析HOXD3在乳腺癌细胞化疗耐药中的作用。结果:乳腺癌组织中HOXD3 m RNA相对表达量显著高于癌旁正常组织,乳腺癌细胞系MDA-MB-231、MDA-MB-435和MCF-7的HOXD3 m RNA相对表达量均高于正常乳腺上皮细胞系MCF-10A(均P<0.05)。顺铂或阿霉素耐药的细胞系MDA-MB-231和MDA-MB-435的半抑制浓度(half maximal inhibi-tory concentration,IC50)分别为(20.82±0.05)μmol/L和(19.69±0.47)μmol/L,或(32.26±0.23)mmol/L和(26.08±0.55)mmol/L,均高于对应原始细胞系(均P<0.05);耐药倍数分别为2.47和3.10倍,或1.86和2.08倍。HOXD3过表达MDA-MB-231、MDA-MB-435的肿瘤球体数目、干细胞生物标志物的表达水平均明显增加(均P<0.05)。结论:HOXD3过表达对乳腺癌细胞干性的维持及化疗耐药性的发生发挥重要的作用,为制定针对肿瘤干细胞的分子靶向治疗提供理论参考。

Size matters: wintering ducks stay longer and use fewer habitats on largest Chinese lakes

Background:Evidence suggests that wintering waterbirds have become conspicuously more concentrated at two largest lakes of the Yangtze River Floodplain,East Dong Ting Lake(Hunan Province,29°20′N,113°E)and Poyang Lake(Jiangxi Province,29°N,116°20′E),relative to other lakes,despite the establishment of reserves elsewhere.While this relationship is likely due to greater extent of undisturbed habitats in larger lakes,we understand little of the drivers affecting individual behaviours behind this tendency.Methods:We tracked wintering movements of three duck species(Eurasian Wigeon Mareca penelope,Falcated Duck M.falcata and Northern Pintail Anas acuta)using GPS transmitters,examining differences between the two largest lakes and other smaller lakes in ducks’habitat use,duration of stay at each lake and the daily distances moved by the tagged birds while at these sites.Results:The Eurasian Wigeon and Falcated Duck stayed five times longer and almost exclusively used natural habitat types at the two large lakes(91‒95%of positions)compared to length of stay time at smaller lakes,where they spent 28‒33 days on average(excluding the capture site)and exploited many more different habitats(including c.50%outside lakes).Conclusions:Our study is the first to show that shorter length of stay and more varied habitat use by ducks at small lakes may contribute to explaining the apparent regional concentration of numbers present of these and other species at the largest lakes in recent years.This compares with their declining abundance at smaller lakes,where habitat loss and degradation has been more manifest than on the larger lakes.

Simultaneous, hybrid single-molecule method by optical tweezers and fluorescence

As studies on life sciences progress toward the single-molecule level,new experiments have put forward more requirements for simultaneously displaying the mechanical properties and conformational changes of biomolecules.Optical tweezers and fluorescence microscopy have been combined to solve this problem.The combination of instruments forms a new generation of hybrid single-molecule technology that breaks through the limitations of traditional biochemical analysis.Powerfulmanipulation and fluorescence visualization have beenwidely used,and these techniques provide new possibilities for studying complex biochemical reactions at the singlemolecule level.This paper explains the features of this combined technique,including the application characteristics of single-trap and dual-traps,the anti-bleaching method,and optical tweezers combined with epifluorescence,confocal fluorescence,total internal reflection fluorescence,and other fluorescence methods.Using typical experiments,we analyze technical solutions and explain the factors and principles that instrument designers should consider.This review aims to give an introduction to this novel fusion technology process and describe important biological results.

中华民族现代文明的内涵及意义

中华民族现代文明是指现代性塑造下的以中国为范围的文明体系,是中华文明的现代形态,是中国式现代化创造的人类文明新形态。中华文明含括着古典与现代两个层面的要素,是经过现代性改造和升华的现代文明,具有古今结合之特质。中华民族现代文明的根基是中国自身的传统资源,包括中国古代文明最重要的两个核心要素:强调人伦,即人与人之间的关系;强调集体和国家,形成了典型的国家主义理念。中华民族现代文明的核心要素,也包括当今被世界普遍认可并践行的要素,它为全人类所共享。强化中华民族现代文明意识,不仅赋予我们生活以价值,对中华民族共同体建设起到催生和促进的作用,而且能从人类命运共同体的角度,理解中华文明如何与其他国家和地区的文明共同相处。

Digital light processing (DLP)-based (bio)printing strategies for tissue modeling and regeneration

Digital light processing(DLP)-based bioprinting technology has recently aroused considerable concerns as a strategy to deliver biomedical materials and/or specific cells to create sophisticated structures for various tissue modeling and regeneration.In this review,we display a concise introduction of DLP bioprinting,and a further discussion on the design and manufacture of DLP(bio)printer with varied bioinks and their biomedical applications toward drug screening,disease modeling,tissue repair,and regenerative medicine.Finally,the advantages,challenges,and perspectives of the DLP printing platforms are detailed.It is believed that DLP bioprinting will play a decisive role in the field of tissue model and regenerative medicine,mainly due to its time-efficient,higher resolution,and amenability to automation for various tissue needs.

Ablation resistance of ZrC coating modified by polymer-derived SiHfOC ceramic microspheres at ultrahigh temperature

Polymer-derived ceramics(PDCs)method opens up new possibilities for the preparation of novel multi-phase ceramic nanocomposites owing to the molecular design of the precursors at the nanoscale level.In the current work,ZrC coatings incorporated with polymer-derived ceramic microspheres(CMS),SiH-fOC_CMS,were deposited to enhance the ablation resistance by supersonic atmosphere plasma spraying.Upon 10.0 MW·m^(-2) plasma ablation at above 3000℃,the linear ablation rate of ZrC-SiHfOC_CMS coat-ing was reduced to 0.20μm·s^(-1),62%lower than that of the pristine ZrC coating.The improvement was ascribed to the presentence of viscous SiO_(2)/HfO_(2) molten mixed phase,rather than HfSiO4,which can ef-fectively seal pinholes and cracks.Moreover,the in-situ generated crystalline SiO_(2) had a lower oxygen diffusion rate than amorphous SiO_(2),meanwhile,m-HfO_(2) could improve the stability of SiO_(2) glassy film,thus further enhancing the ablation resistance.

Analyses on an electronic voltage transformer's failure by its resonance with very fast transient overvoltage and suppression

As voltage measuring devices are widely used in the high voltage power system with a primary-secondary-fusion structure,electronic voltage transformers are directly connected to the primary conductor and would face much more serious electromagnetic environments than general secondary equipment.As a result,they would still experience failures even when general protection measures are adopted to suppress overvoltages'amplitudes.To address this issue,an innovative method is proposed after analyses are conducted on the resonance between a transformer and an overvoltage.Within this method,an air-cored coil is installed in a transformer to artificially shift its natural frequency and to dodge the high-frequency dominant component of a transient overvoltage,avoiding the aforementioned resonance and suppressing the secondary overvoltage.In addition,simulations and laboratory tests are conducted to prove this method's validity.

Investigation of hot jet on active control of oblique detonation waves

The hot jet injection is utilized to actively control the oblique detonation wave,such as initiating and stabilizing an oblique detonation wave at a desired position that is shorter than the length of induction zone,and adjust the height of the oblique detonation wave at the exit of combustor when the oblique detonation wave engine is working on off-design flight conditions.The fifth order Weighted Essentially Non-Oscillatory(WENO)scheme and a two-step reversible reaction mechanism of the stoichiometric H_2/Air are adopted in the simulations.With the help of hot jet injection,the transition from inert oblique shock wave to the oblique detonation wave immediately occurs near the position of hot jet injection,and consequently the length of combustor can be reduced.The angle of oblique detonation wave also decreases as the hot jet injection approaches the nose of wedge.Additionally,the height of the oblique detonation wave at the exit of combustor can be flexibly adjusted,and also depends on the injection position and the strength of the hot jet.If the velocity of the hot jet is too weak to directly trigger the overall oblique detonation wave at the position of injection,increasing the injection pressure will improve the strength of the hot jet and results in a successful transition.