The biological functions and metabolic pathways of valine in swine

Valine is an essential amino acid and a type of branched-chain amino acid. Due to the involvement of branchedchain amino acids in various metabolic pathways, there has been a surge of interests in valine nutrition and its role in animal physiology. In pigs, the interactions between valine and other branched-chain amino acids or aromatic amino acids are complex. In this review, we delve into the interaction mechanism, metabolic pathways, and biological functions of valine. Appropriate valine supplementation not only enhances growth and reproductive performances, but also modulates gut microbiota and immune functions. Based on past observations and interpretations, we provide recommended feed levels of valine for weaned piglets, growing pigs, gilts, lactating sows, barrows and entire males. The summarized valine nutrient requirements for pigs at different stages offer valuable insights for future research and practical applications in animal husbandry.

Application of a jigsaw puzzle flap based on free-style perforator to repair large scalp defects after tumor resection:A case series

Background:Reconstruction of large scalp defects after tumor resection is common and challenging.Free skin grafting or free flap transfer is always performed.However,these techniques can result in poor functional and cosmetic outcomes.Methods:In the Second Affiliated Hospital of Soochow University and the Second Affiliated Hospital of Chengdu Medical College,35 patients underwent jigsaw puzzle flap procedures based on a free-style perforator to repair large scalp defects after tumor resection from May 2013 to November 2022.The key to this procedure was to divide a large defect into several smaller parts that correspond to adjacent free-style perforators around the scalp defect.The free-style perforator flaps were designed in different ways,such as propeller flaps,rotation flaps,and V-Y advancement flaps,which were pedicled with free-style perforators.All of the small flaps were then mobilized to the defect and sutured to each other to create a new,large jigsaw puzzle-like flap to cover the large scalp defect.Finally,all the donor sites were closed directly.Results:Overall,35 patients were treated.The average defect size was 72 cm^(2)(range,25-91 cm^(2)).All flaps had a satisfactory appearance after follow-up periods of 6 months-10 years.Local tumor recurrence occurred in one case.Conclusion:The application of a jigsaw puzzle flap based on a free-style perforator is a suitable option for the reconstruction of large scalp defects after resection,yielding satisfactory functional and cosmetic results.

外周血管介入治疗大咯血的临床疗效探讨

目的:探讨外周血管介入治疗大咯血的临床疗效。方法:收治大咯血患者40例,随机分为两组,各20例。对照组采用常规治疗;观察组采用外周血管介入治疗。比较两组临床疗效、不良反应情况及生活质量。结果:观察组治疗总有效率高于对照组,差异有统计学意义(P<0.05);观察组不良反应发生率低于对照组,生活质量评分高于对照组,差异均有统计学意义(P<0.05)。结论:采用外周血管介入疗法治疗大咯血,疗效显著。

不同能量电子辐照下星用瑞侃导线性能退化研究

目的研究卫星上外露导线在空间辐射环境下的耐受能力。方法通过分析GEO轨道下在轨10年航天器外露瑞侃导线的辐照环境,研究低能和高能电子对导线性能的影响,地面模拟试验参数选择能量分别为45 keV和1 MeV,注量率均为8.3×10^10 e/(cm^2·s),总注量均为2×10^16 e/cm^2。考察瑞侃导线力学性能(断裂伸长率、拉伸强度)和电性能(击穿电压)的退化情况,并用XPS和SEM测试分析手段,对其电子辐照损伤机理进行研究。结果在不同能量电子辐照下,瑞侃导线的力学性能均略有下降,没有显著区别,而电学性能严重退化,且低能电子较高能电子对其电学性能影响更为严重,其击穿电压分别下降了100%和50%。结论通过剂量-深度分布计算,45 keV入射电子能量全部沉积在样品表层下数微米的深度范围内,完全被导线外皮吸收,对样品的损伤较大;而1 MeV入射电子能量绝大部分穿透表皮沉积在样品铜芯中,因而其性能退化情况相对低能电子较小。进一步的,通过SEM和XPS测试和分析发现,电子辐照造成瑞侃导线分子链降解,形成自由基以及气体,自由基的再交联是造成瑞侃导线损伤的重要机理。

温度对石墨平面吸附水环境中甲烷分子过程的影响

为研究温度对甲烷分子在水-石墨界面上吸附的影响,利用分子动力学模拟,分析了不同温度下多层石墨平面对水环境中甲烷分子的吸附情况.结果表明:石墨平面片层吸附甲烷分子时呈现出特定的吸附位点,甲烷分子沿这些吸附位点呈六边形状态聚集,且吸附在石墨平面上的甲烷分子有序分层,第1层吸附饱和后将在吸附位点附近继续第2层吸附.进一步分析发现,在等容体系中,石墨平面吸附甲烷量与温度呈近似线性关系,且温度越高吸附总量反而越大.这些研究结果对理解疏水固体表面吸附水环境中气体分子的微观机制有所帮助.

基于三角形光栅结构的薄膜晶硅/PEDOT:PSS异质结太阳电池的陷光设计

针对薄膜硅的光学管理问题,通过有限元方法求解麦克斯韦基本方程组,研究基于一维三角形光栅结构对电池的光吸收率、光电流密度(Jph)和电场强度分布的影响,设计并优化适合2μm硅/PEDOT:PSS系统的双面一维三角形光栅结构,有效提升薄膜硅的光学吸收,并能与PEDOT:PSS形成优异的异质结,基于此结构的薄膜硅/PEDOT:PSS异质结太阳电池的效率可超过15%,展现了高效柔性薄膜硅/PEDOT:PSS HSCs的可行性。

基于代价敏感方法的智能制造故障诊断

在设备故障诊断过程中,数据集中正负分类样本数量相差较为悬殊等数据不平衡问题会导致诊断准确率降低。为减少由于正负类样本不均衡而导致的误判,提高设备故障诊断准确率,提出一种代价敏感方法。该方法借助Boosting方法,通过多次概率采样生成多个模型,并确定每个模型的权重。其中采样的概率取决于代价调整值,所提方法在每一个迭代过程中根据上一次迭代的结果对代价调整值进行调整。通过实验,并与其他方法进行对比,结果表明与采用固定的代价敏感值及非代价敏感方法相比,提出的方法具有更好的表现。

国有企业融资性贸易审计方法与实务

近几年以商品贸易为平台夸大贸易背景或虚构贸易背景的融资行为暴露出的各种风险问题,已引起有关方面的高度重视,管理层对国企融资性贸易进行风险提醒并做出越来越严格的规定要求。作为国有企业内部审计部门,应通过研究、掌握融资性贸易的实质,以便在审计实务中能够敏锐地识别出融资性贸易,更好地贯彻国有资产管理部门的要求并帮助企业实现规范管理。为此,通过归纳融资性贸易的风险特点,找到融资性贸易审计的切入点和突破口,并通过审计实务案例对融资性贸易的审计方法进行了探索与思考。研究结果表明:①近年来国有企业融资性贸易迅速扩张是由银行收紧信贷规模和国际环境下国有企业考核指标完成压力过大两方面因素促成;②融资性贸易审计中不仅存在对大宗商品贸易审计的难点问题,还因为比自偿性贸易融资更具灵活性、多样性、复杂性等特点导致其识别难度较大;③国有企业融资性贸易存在的风险包括资金损失风险、法律和税收风险以及经营风险;④结合融资性贸易的特点,通过加强对贸易链条中关联关系、现场监盘存货、合同和发票、大额无动态应收款项挂账、交易货物的来源和去向等的审查力度,可有效辨认是否存在融资性贸易。

Activation of autophagy in the retina after optic nerve crush injury in rats

AIM: To investigate the activation of autophagy in rat retina after optic nerve crush(ONC) and evaluate its relationship with apoptosis of retinal ganglion cells(RGCs).METHODS: The ONC model was established. Western blots were performed to investigate expression of p62, LC3 and Beclin-1. Transmission electron microscopy was performed to discover the autophagosomes in the retina after ONC. Immunohistochemistry was used to confirm the distribution of LC3. TUNEL was performed to confirm the relationship between autophagy and RGC apoptosis. RESULTS: p62/Beclin-1 ratio was declined shortly after ONC until to day 7 after ONC and then restored to a normal level at day 21. There was an opposite change in the LC3-II/LC3 I ratio in the retina compared to the p62/Beclin-1 ratio. Increased autophagosomes were found after ONC using transmission electron microscopy, and most of the LC3-stained cells were colocalized with RGCs and Müller cells. More LC3-immunoreactive cells and apoptotic RGCs were found on day 7 following ONC. CONCLUSION: Possible activation of autophagy in RGCs after ONC;autophagy mainly occurred in RGCs and Müller cells, and the apoptosis of RGCs after ONC may be partly associated with autophagic activation.

Direct Growth of Graphene on Silicon by Metal-Free Chemical Vapor Deposition

The metal-free synthesis of graphene on singlecrystal silicon substrates, the most common commercial semiconductor, is of paramount significance for many technological applications. In this work, we report the growth of graphene directly on an upside-down placed,single-crystal silicon substrate using metal-free, ambientpressure chemical vapor deposition. By controlling the growth temperature, in-plane propagation, edge-propagation, and core-propagation, the process of graphene growth on silicon can be identified. This process produces atomically flat monolayer or bilayer graphene domains, concave bilayer graphene domains, and bulging few-layer graphene domains. This work would be a significant step toward the synthesis of large-area and layer-controlled, high-quality graphene on single-crystal silicon substrates.

SOX2-dependent expression of dihydroorotate dehydrogenase regulates oral squamous cell carcinoma cell proliferation

Oral squamous cell carcinoma(OSCC)become a heavy burden of public health,with approximately 300000 newly diagnosed cases and 145000 deaths worldwide per year.Nucleotide metabolism fuel DNA replication and RNA synthesis,which is indispensable for cell proliferation.But how tumor cells orchestrate nucleotide metabolic enzymes to support their rapid growth is largely unknown.Here we show that expression of pyrimidine metabolic enzyme dihydroorotate dehydrogenase(DHODH)is upregulated in OSCC tissues,compared to non-cancerous adjacent tissues.Enhanced expression of DHODH is correlated with a shortened patient survival time.Inhibition of DHODH by either shRNA or selective inhibitors impairs proliferation of OSCC cells and growth of tumor xenograft.Further,loss of functional DHODH imped de novo pyrimidine synthesis,and disrupt mitochondrial respiration probably through destabilizing the MICOS complex.Mechanistic study shows that transcriptional factor SOX2 plays an important role in the upregulation of DHODH in OSCC.Our findings add to the knowledge of how cancer cells co-opt nucleotide metabolism to support their rapid growth,and thereby highlight DHODH as a potential prognostic and therapeutic target for OSCC treatment.

Effects of Organic Fertilizers Made from Distiller＇s Grains on the Growth and Development of Flue-cured Tobacco

Pot experiments were conducted to study the effects of different organic fertilizers made from distiller＇s grains on the physiological characteristics and growth of flue-cured tobacco. The results showed that the agronomic traits and biomass of flue-cured tobacco in the three treatments were higher than that of the control group,and the mixed application of different organic fertilizers made from distiller＇s grains and compound fertilizer could promote the growth and development of flue-cured tobacco significantly.

分析利用超选择性动脉栓塞对上消化道出血的临床治疗效果

目的:探讨超选择性动脉栓塞治疗上消化道出血的临床价值。方法:收治上消化道出血患者116例,随机分为观察组(超选择性动脉栓塞治疗)和对照组(常规药物治疗),各58例。比较两组患者输血量及止血时间情况。结果:与对照组相比,观察组输血量较少,且止血时间较短(P<0.05)。结论:超选择性动脉栓塞治疗上消化道出血,能够使输血量减少,止血时间缩短。

High-Pressure Phase Transitions of Cubic Y_2O_3 under High Pressures by In-situ Synchrotron X-Ray Diffraction

High-pressure phase transitions of cubic Y_2O_3 are investigated using in situ synchrotron x-ray diffraction in a diamond anvil cell up to 36.3 GPa. The pressure-induced phase transitions of cubic Y_2O_3, which display apparent inconsistencies in previous studies, are verified to be from a cubic phase to a monoclinic phase and further to a hexagonal phase at 11.7 and 21.6 GPa, respectively. The hexagonal Y_2O_3 displays noticeable anisotropic compressibility due to its layered structure and it is stable up to the highest pressure in the present study. A third-order Birch–Murnaghan fit based on the observed pressure-volume data yields zero pressure bulk moduli of180(3), 196(7) and 177(7) GPa for cubic, monoclinic and hexagonal phases, respectively.

A New Approach for Residual Stress Analysis of GH3535 Alloy by Using Two-Dimensional Synchrotron X-Ray Diffraction

We propose a new method to evaluate residual stress based on the analysis of a portion of a Debye ring with two-dimensional synchrotron x-ray diffraction.The residual stress of a nickel-based alloy GH3535 evaluated by the proposed method is determined to be-1149 ± 34 MPa based on the quantitative analysis of the deformation of the(200) reflection,and the residual stress obtained by analyzing THE(111) plane is-933 ± 68 MPa.The results demonstrate that the GH3535 alloy surface is highly compressive,as expected for a polishing surface treatment.The proposed method provides insight into the field of residual stress measurement and quantitative understanding of the residual stress states in GH3535.

Effects of Distiller's Grain Substrate with Acid Regulation on the Growth of Tobacco Seedlings in Floating Breeding System

In order to reduce the use of peat resources and realize the sustainable development of tobacco, the pH of distiller s grain substrate was adjusted with humic acid, and the effects of various distiller s grain substrates on the growth of tobacco seedlings were studied to find out the method of cultivating high-quality tobacco seedlings by using distiller s grain substrate. The results showed that when 60% of humic acid was added to the distiller s grain substrate made from coarse distiller s grains, fine distiller s grains, perlite and vermiculite, both the pH and electrical conductivity decreased significantly and were similar to that of the conventional substrate. Moreover, the emergence rate of tobacco seedlings, the rate of strong tobacco seedlings, leaf number, stem height, root growth and quality of tobacco seedlings were good.

附设式多层变电所在精细化工项目中的应用

本文通过对精细化工项目中现有的两种不同附设式变电所的优缺点进行分析,创新地提出了第三种变电所布置形式.布置两层半的结构形式,有效地利用了动力车间的高度差,优化了变电所结构,节约了电气投资,降低了变电所的占地面积,提高了动力车间的土地利用率,节省了土地资源.

Intercomparison of multi-model ensemble-processing strategies within a consistent framework for climate projection in China

Climate change adaptation and relevant policy-making need reliable projections of future climate.Methods based on multi-model ensemble are generally considered as the most efficient way to achieve the goal.However,their efficiency varies and inter-comparison is a challenging task,as they use a variety of target variables,geographic regions,time periods,or model pools.Here,we construct and use a consistent framework to evaluate the performance of five ensemble-processing methods,i.e.,multimodel ensemble mean(MME),rank-based weighting(RANK),reliability ensemble averaging(REA),climate model weighting by independence and performance(ClimWIP),and Bayesian model averaging(BMA).We investigate the annual mean temperature(Tav)and total precipitation(Prcptot)changes(relative to 1995–2014)over China and its seven subregions at 1.5 and 2℃warming levels(relative to pre-industrial).All ensemble-processing methods perform better than MME,and achieve generally consistent results in terms of median values.But they show different results in terms of inter-model spread,served as a measure of uncertainty,and signal-to-noise ratio(SNR).ClimWIP is the most optimal method with its good performance in simulating current climate and in providing credible future projections.The uncertainty,measured by the range of 10th–90th percentiles,is reduced by about 30%for Tav,and 15%for Prcptot in China,with a certain variation among subregions.Based on ClimWIP,and averaged over whole China under 1.5/2℃global warming levels,Tav increases by about 1.1/1.8℃(relative to 1995–2014),while Prcptot increases by about 5.4%/11.2%,respectively.Reliability of projections is found dependent on investigated regions and indices.The projection for Tav is credible across all regions,as its SNR is generally larger than 2,while the SNR is lower than 1 for Prcptot over most regions under 1.5℃warming.The largest warming is found in northeastern China,with increase of 1.3(0.6–1.7)/2.0(1.4–2.6)℃(ensemble’s median and range of the 10th–90th percentiles)under 1.5/2℃warming,followed by northern and northwestern China.The smallest but the most robust warming is in southwestern China,with values exceeding 0.9(0.6–1.1)/1.5(1.1–1.7)℃.The most robust projection and largest increase is achieved in northwestern China for Prcptot,with increase of 9.1%(–1.6–24.7%)/17.9%(0.5–36.4%)under 1.5/2℃warming.Followed by northern China,where the increase is 6.0%(–2.6–17.8%)/11.8%(2.4–25.1%),respectively.The precipitation projection is of large uncertainty in southwestern China,even with uncertain sign of variation.For the additional half-degree warming,Tav increases more than 0.5℃throughout China.Almost all regions witness an increase of Prcptot,with the largest increase in northwestern China.

Numerical investigations of the failure mechanism evolution of rock-like disc specimens containing unfilled or filled flaws

The mechanical responses and ultimate failure patterns of rocks are associated with the failure mechanism evolution.In this study,smoothed particle hydrodynamics(SPH)method with the mixed-mode failure model is proposed to probe into failure mechanism evolutions for disc specimens upon loading.The tensile damage model and the Drucker-Prager model are used to calculate the tensile failure and shear failure of the material,respectively.It is concluded that for flaw-unfilled disc specimens,the crack coalescence mechanism in the rock bridge area is affected by the flaw inclination angle and the material property.Considering disc specimens with filled flaws,the incremental rate of tensile damage grows more rapidly when the disc and filling material have a closer ratio of tensile strength to cohesion,which makes the entire specimen response greater brittleness.Furthermore,with the increasing non-uniformity of filling distribution,the incremental rate of tensile-activated damage decreases and the disc specimen performs more ductile.Besides,the influence of the fillings is greater when the flaw inclination angle is approaching 45°.It is proved that the proposed SPH method can be used to simulate the failure mechanism evolution of rocks,which lays a foundation for the study of more complex rock failure.

Adsorption of Eu(Ⅲ) on titanate nanotubes studied by a combination of batch and EXAFS technique

The effects of pH,contact time and natural organic ligands on radionuclide Eu(Ⅲ) adsorption and mechanism on titanate nanotubes(TNTs) are studied by a combination of batch and extended X-ray absorption fine structure(EXAFS) techniques.Macroscopic measurements show that the adsorption is ionic strength dependent at pH < 6.0,but ionic strength independent at pH > 6.0.The presence of humic acid(HA) /fulvic acid(FA) increases Eu(Ⅲ) adsorption on TNTs at low pH,but reduces Eu(Ⅲ) adsorption at high pH.The results of EXAFS analysis indicate that Eu(Ⅲ) adsorption on TNTs is dominated by outer-sphere surface complexation at pH < 6.0,whereas by inner-sphere surface complexation at pH > 6.0.At pH < 6.0,Eu(Ⅲ) consists of ～ 9 O atoms at REu?O ≈ 2.40  in the first coordination sphere,and a decrease in NEu-O with increasing pH indicates the introduction of more asymmetry in the first sphere of adsorbed Eu(Ⅲ).At long contact time or high pH values,the Eu(Ⅲ) consists of ～2 Eu at REu-Eu ≈ 3.60  and ～ 1 Ti at REu-Ti ≈ 4.40 ,indicating the formation of inner-sphere surface complexation,surface precipitation or surface polymers.Surface adsorbed HA/FA on TNTs modifies the species of adsorbed Eu(Ⅲ) as well as the local atomic structures of adsorbed Eu(Ⅲ) on HA/FA-TNT hybrids.Adsorbed Eu(Ⅲ) on HA/FA-TNT hybrids forms both ligand-bridging ternary surface complexes(Eu-HA/FA-TNTs) as well as surface complexes in which Eu(Ⅲ) remains directly bound to TNT surface hydroxyl groups(i.e.,binary Eu-TNTs or Eu-bridging ternary surface complexes(HA/FA-Eu-TNTs)).The findings in this work are important to describe Eu(Ⅲ) interaction with nanomaterials at molecular level and will help to improve the understanding of Eu(Ⅲ) physicochemical behavior in the natural environment.