NEA 迎来转折

过去的三年，我们95％的案子都是成长期的企业，未来我们仍然会在这个方向努力，希望在其中找到更多更好的投资机会。

纤维、掺合料和外加剂材料在面板混凝土防裂抗冻作用中的研究综述

在高寒、高海拔等气候复杂地区,面板混凝土的防裂和抗冻耐久性能是影响面板工程的关键技术问题,甚至影响整个面板坝的运行安全。在国家大力发展抽水蓄能电站的大背景下,总结了面板混凝土裂缝的成因,以及纤维材料在部分高寒和寒冷地区面板堆石坝中的运用及发展情况,并从面板混凝土防裂抗冻技术角度,对纤维材料品种、材料特性,混杂纤维技术,以及纤维复合材料等3个层面影响面板混凝土防裂抗冻性能进行了研究分析,同时对外加剂、掺合料等其他原材料,以及表面涂层防护材料等对面板混凝土防裂抗冻性能的影响进行了分析。从材料角度提出了今后在面板混凝土防裂抗冻技术需求方面建议开展的研究工作。

Diabetic foot ulcer:A comprehensive review of pathophysiology and management modalities

Diabetic foot ulcer (DFU) is a debilitating and severe manifestation ofuncontrolled and prolonged diabetes that presents as ulceration, usually locatedon the plantar aspect of the foot. Approximately 15% of individuals with diabeteswill eventually develop DFU, and 14%-24% of them will require amputation ofthe ulcerated foot due to bone infection or other ulcer-related complications. Thepathologic mechanisms underlying DFU are comprise a triad: Neuropathy,vascular insufficiency, and secondary infection due to trauma of the foot.Standard local and invasive care along with novel approaches like stem celltherapy pave the way to reduce morbidity, decrease amputations, and preventmortality from DFU. In this manuscript, we review the current literature withfocus on the pathophysiology, preventive options, and definitive management ofDFU.

CRISPR/Cas9 editing of the polygalacturonase FaPG1 gene improves strawberry fruit firmness

Firmness is one of the most important fruit quality traits in strawberries.The postharvest shelf life of this soft fruit is highly limited by the loss of firmness,where cell wall disassembly plays an important role.Previous studies demonstrated that the polygalacturonase FaPG1 has a key role in remodelling pectins during strawberry softening.In this study,FaPG1 knockout strawberry plants have been generated using the CRISPR/Cas9 system delivered via Agrobacterium tumefaciens.Ten independent lines,cv.“Chandler”,were obtained,and all of them were successfully edited as determined by PCR amplification and T7 endonuclease assay.The targeted mutagenesis insertion and deletion rates were analyzed using targeted deep sequencing.The percentage of edited sequences varied from 47%up to almost 100%,being higher than 95%for seven of the selected lines.Phenotypic analyses showed that 7 out of the eight lines analyzed produced fruits significantly firmer than the control,ranging from 33 to 70%increase in firmness.There was a positive relationship between the degree of FaPG1 editing and the rise in fruit firmness.Minor changes were observed in other fruit quality traits,such as colour,soluble solids,titratable acidity or anthocyanin content.Edited fruits showed a reduced softening rate during postharvest,displayed a reduced transpirational water loss,and were less damaged by Botrytis cinerea inoculation.The analysis of four potential off-target sites revealed no mutation events.In conclusion,editing the FaPG1 gene using the CRISPR/Cas9 system is an efficient method for improving strawberry fruit firmness and shelf life.

朱敏:搭建科学家创业服务平台,赋能硬科技企业加速成长

曾经的硅谷创业传奇人物回国搭建科学家创业服务平台,帮助中国的硬科技创业者走向更远的未来。75岁的朱敏与时代共命运,下乡插队,公派留学,硅谷创业,公司上市……他的人生堪称传奇。经历了波澜壮阔的岁月,现在的投资人朱敏仍旧激情十足,干劲满满。从创业者到投资人从插队知青到硅谷英雄,朱敏在美国高科技产业中攻关闯荡20多年,以创新创业成就和奋斗精神享有很高的知名度和声望。

Functional diversity in an Andean subparamo affected by wildfire in Colombia

Recently,the Andean subparamo in Colombia has experienced severe wildfires,but little is known about the functional composition of recovering or not after a wildfire.Therefore,we examined the functional community composition subparamo affected byfire in 2016.We documented how functional traits changed 31 months after the disturbance and compared them with an unburned site.We sampled from one to two years after the fire every four months,then registered all recruits in 1655m plots.New individuals were classified into strategy functional groups based on the traits of persistence and dispersal.The first group was stem type and regeneration mechanism(seedling and resprout),and the second was fruit type and dispersal mode.We investigated the degree to which functional diversity changes plant communities over time(woody and non-woody),and we compared it with an unburned site.The most relevant results showed that resprouts and seed regenerated increased post-fire time and significant differences between sampling periods.The anemochory is the most relevant dispersal mode that indicates the community capacity to colonize the new gaps opened by the fire rapidly.We discuss how wildfire appears to be a triggering factor for persistence and dispersal strategy groups in subparamo burned given their characteristics of tolerance to stress.For this reason,a greater functional divergence between the ecosystems studied post-fire recovery has been related to higher levels of biodiversity at the landscape scale due to the high degree of endemism and significant differences in species composition between paramos.

A Review of the Impact of Covid-19 on the Male Genito-Urinary Tract

Introduction and Objectives: Since its advent in 2019, Corona Virus Disease 19 (Covid-19) has changed everyday life in many unprecedented ways. With the availability of Covid-19 vaccines, clinical practice has stepped gradually towards its everyday routine. The clinician, however, needs to address such concerns as “Can Covid-19 present with urinary tract symptoms predominantly?”, “Can the urinary tract develop long-term Covid-19 symptoms?”, “Can Covid-19 vaccines/drug therapy cause male infertility?” Methods: This mini-review of the current literature has been carried out by searching the Pubmed database. Results and Conclusions: Our literature review suggests that there is insufficient evidence to conclude a significant impact on the urinary tract from Covid-19 infection. There is supporting evidence that mRNA anti-SARS-CoV-2 vaccines are safe for male gonads. Research to further support these conclusions is required.

QTL analysis for ascorbic acid content in strawberry fruit reveals a complex genetic architecture and association with GDP-L-galactose phosphorylase

Strawberry(Fragaria×ananassa)fruits are an excellent source of L-ascorbic acid(AsA),a powerful antioxidant for plants and humans.Identifying the genetic components underlying AsA accumulation is crucial for enhancing strawberry nutritional quality.Here,we unravel the genetic architecture of AsA accumulation using an F1 population derived from parental lines‘Candonga’and‘Senga Sengana’,adapted to distinct Southern and Northern European areas.To account for environmental effects,the F1 and parental lines were grown and phenotyped in five locations across Europe(France,Germany,Italy,Poland and Spain).Fruit AsA content displayed normal distribution typical of quantitative traits and ranged five-fold,with significant differences among genotypes and environments.AsA content in each country and the average in all of them was used in combination with 6,974 markers for quantitative trait locus(QTL)analysis.Environmentally stable QTLs for AsA content were detected in linkage group(LG)3A,LG 5A,LG 5B,LG 6B and LG 7C.Candidate genes were identified within stable QTL intervals and expression analysis in lines with contrasting AsA content suggested that GDP-L-Galactose Phosphorylase FaGGP(3A),and the chloroplast-located AsA transporter gene FaPHT4;4(7C)might be the underlying genetic factors for QTLs on LG 3A and 7C,respectively.We show that recessive alleles of FaGGP(3A)inherited from both parental lines increase fruit AsA content.Furthermore,expression of FaGGP(3A)was two-fold higher in lines with high AsA.Markers here identified represent a useful resource for efficient selection of new strawberry cultivars with increased AsA content.

The complete reference genome for grapevine (Vitis vinifera L.) genetics and breeding

Grapevine is one of the most economically important crops worldwide.However,the previous versions of the grapevine reference genome tipically consist of thousands of fragments with missing centromeres and telomeres,limiting the accessibility of the repetitive sequences,the centromeric and telomeric regions,and the study of inheritance of important agronomic traits in these regions.Here,we assembled a telomere-to-telomere(T2T)gap-free reference genome for the cultivar PN40024 using PacBio HiFi long reads.The T2T reference genome(PN_T2T)is 69 Mb longer with 9018 more genes identified than the 12X.v0 version.We annotated 67%repetitive sequences,19 centromeres and 36 telomeres,and incorporated gene annotations of previous versions into the PN_T2T assembly.We detected a total of 377 gene clusters,which showed associations with complex traits,such as aroma and disease resistance.Even though PN40024 derives from nine generations of selfing,we still found nine genomic hotspots of heterozygous sites associated with biological processes,such as the oxidation–reduction process and protein phosphorylation.The fully annotated complete reference genome therefore constitutes an important resource for grapevine genetic studies and breeding programs.

刚性抗滑桩的桩土相互作用机理与极限阻滑力研究

采用新的无量纲参数锚固比作为控制参量,在滑动面从桩顶到桩底逐步变化的过程中,研究不同滑动面位置对土体抗滑桩阻滑工作机理与破坏模式的影响及其演变规律,建议了4种土体抗滑桩阻滑与破坏模式。基于塑性力学极限平衡理论,得到了4种模式的极限阻滑力理论解,给出了它们的界限判别条件。通过试验证明,抗滑桩存在4种阻滑破坏模式,而不是Viggiani假定的3种。建议的桩土相互作用机理模型及其解析解更为合理地描述了任意滑动面位置条件下抗滑桩的阻滑机理与破坏模式。研究表明,滑动面的相对位置决定抗滑桩的工作阻滑模式和极限阻滑力的大小,同一根抗滑桩对沿不同滑动面的滑动所产生的极限阻滑力会有很大的不同。建议的极限阻滑力计算方法可用于常规的滑坡稳定分析计算,对于地下连续墙、嵌岩桩等地下结构亦有重要的借鉴意义,与依靠经验公式与图表计算极限阻滑力的方法相比,所得计算公式在理论上更加完整合理,使用上也更为准确方便。

面向新型电力系统的水电发展战略研究

践行双碳战略,能源是主战场,电力是主力军,构建以新能源为主体的新型电力系统是实现碳中和的必由之路。在分析碳中和背景下电力行业减排目标、电力结构及其占比的基础上,针对构建新型电力系统面临的问题与挑战,提出加快常规水电和抽水蓄能电站建设是新型电力系统可靠性和长周期调节能力的重要基础。结合我国能源资源禀赋和开发利用现状,提出强化水电与新能源协同发展战略思路,依托流域梯级水电建设更大规模清洁能源基地,并加快抽水蓄能电站和储能工厂建设的发展路径,重新定义了水电在新型电力系统中既提供基础电量又发挥容量功能的新定位,进而提出促进清洁能源大基地和储能工厂建设的政策建议。研究成果可为清洁能源基地规划设计和相关政策文件的编制与修订提供一定参考。

掺聚合物纤维面板混凝土的防裂抗冻性能

严寒区面板混凝土的抗裂防冻性能对大坝的耐久性具有较大影响,本文采用平板法研究了不同聚丙烯腈纤维掺量对掺粉煤灰面板混凝土的早期抗裂性;采用冻融试验、气泡参数试验方法研究了掺聚丙烯腈纤维面板混凝土的质量损失、相对动弹性模量变化、气泡参数变化特征。研究结果表明:细短型聚丙烯腈纤维在面板混凝土内分布的平均间距约为5.98 mm,聚丙烯腈纤维的增强阻裂效果提高了面板混凝土的强度和早期抗裂性;掺入聚丙烯腈纤维后,面板混凝土的引气效果更好,且引入气泡的间距系数小于200μm,聚丙烯腈纤维弹性模量随温度降低而增大的特点,可以提高面板混凝土的抗冻性能。

胶凝砂砾石过水围堰填筑材料特性研究

大华桥水电站上游过水围堰采用坝址区附近河床天然砂砾石及工程开挖弃渣料作为骨料配制胶凝砂砾石材料,骨料最大粒径250mm。针对河床天然砂砾料含砂量波动大、含泥量较高的特点,系统研究了20%~35%含砂量范围内,胶凝砂砾石材料水胶比、单位用水量、砂率、28d抗压强度之间的关系,并提出了满足材料性能设计要求的水胶比、单位用水量等关键配合比参数控制范围。基于现场碾压工艺试验,提出了250mm大粒径胶凝砂砾石材料碾压施工关键工艺参数。

纤维高性能混凝土力学及耐久性能

结合某隧道工程跨海区间衬砌结构混凝土所处环境类别和作用等级,对不同纤维长度的聚丙烯纤维混凝土抗压性能及抗氯离子侵蚀耐久性能开展对比试验研究,提出掺加聚丙烯纤维的高性能混凝土方案,针对该方案配合比开展了轴心抗压试验、轴心抗拉试验、抗渗试验及干缩试验。结果表明:在早龄期(3~7 d),纤维混凝土的抗压强度略低于基准组抗压强度,而在后期(7~90 d),纤维混凝土抗压强度逐渐超过基准组抗压强度;28 d龄期混凝土抗压强度随纤维掺量的增加呈现增长的趋势;另外,当纤维掺量在1.5%以内时,随着纤维掺量的增加,28 d和90 d氯离子扩散系数皆随纤维掺量的增加而增加;纤维长度为6 mm的混凝土氯离子扩散系数略大于纤维长度为12 mm的混凝土氯离子扩散系数。

我国流域梯级水电开发的回顾与展望

水电在我国电力供应中一直占据不可替代的重要作用。本文回顾了我国流域梯级水电开发的历程与成就,阐述了当前流域水电梯级开发格局和最新进展,系统总结了70多年来我国流域梯级水电开发的主要经验与特点,分析了在“双碳”目标和能源安全新战略的引领下流域梯级水电开发面临的新挑战。放眼未来,我国流域水电开发前景依然光明,流域水电将在新能源为主体的新型电力系统中占据更加重要的位置,为“双碳”目标的实现作出更大的新贡献。

高坝水库放空要求及设施设计研究

高坝水库调节能力强,在流域梯级开发和防灾减灾中发挥重要作用,但其面临的风险也客观存在,一旦失事后果不堪设想。水库放空或降水位能力是经济社会发展新阶段对大坝风险防控和应急管理提出的新要求。本文给出水库放空的定义、目的及分类,系统阐述了放空水头比、放空库容比、库水位降速等水库放空能力评价指标,梳理了国内外对水库放空的要求,选取我国25座典型高坝水库进行放空能力分析。结果表明:高坝水库放空水头比介于17.5%~71.8%,均值为42.7%;放空库容比介于47.2%~99.2%,均值为81.7%;放空时间介于7.2~123 d,均值为42.7 d;库水降速介于0.71~9.03 m/d,均值为3.0 m/d。从实践来看,高坝水库放空能力受总库容、放空水位、坝型等工程特性参数影响,也受河流形态、河谷形状和库盆特点等因素影响。据此对水库放空设施设计中的入库流量、放空指标、启动条件和分级决策模式等关键问题进行了分析,对我国水利水电工程行业水库放空设施设计和应急管理有一定参考意义。

白格堰塞湖抢险处置应急管理与经验启示

基于2018年金沙江白格堰塞湖应急处置工作,全面总结了部际联合会商、央地协同联动等应急抢险工作机制,深入分析了金沙江中游梯级水库群联合调度削峰对防灾减灾所发挥的重要作用。研究表明,若无梨园水库拦蓄,将可能新增淹没面积约160 km^(2),必对沿江两岸造成更大的损失。据此认识到,迅速获取堰塞湖信息是抢险处置的前提,快速研判堰塞湖风险是重要支撑,精准分析溃决洪水是核心技术,协同联动工作机制是基本保证,动态抢险工程管理是科学方法,完善的高坝水库群是应对洪灾的根本手段。进而提出加强乏信息条件下堰塞湖多源信息快速获取与处理技术、乏信息条件下风险快速研判技术能力、抢险处置专用装备研发、抢险工程统筹管理和协同联动体系完善、高坝水库群开发建设和风险防控与应急调度体系建设等建议,为堰塞湖应急管理水平提升和流域综合防灾减灾提供借鉴。

Diabetes treatment in patients with renal disease: Is the landscape clear enough?

Diabetes is the most important risk factors for chronic kidney disease(CKD). The risk of CKD attributable to diabetes continues to rise worldwide. Diabetic patients with CKD need complicated treatment for their metabolic disorders as well as for related comorbidities. They have to treat, often intensively, hypertension, dyslipidaemia, bone disease, anaemia, and frequently established cardiovascular disease. The treatment of hypoglycaemia in diabetic persons with CKD must tie their individual goals of glycaemia(usually less tight glycaemic control) and knowledge on the pharmacokinetics and pharmacodynamics of drugs available to a person with kidney disease. The problem is complicated from the fact that in many efficacy studies patients with CKD are excluded so data of safety and efficacy for these patients are missing. This results in fear of use by lack of evidence. Metformin is globally accepted as the first choice in practically all therapeutic algorithms for diabetic subjects. The advantages of metformin are low risk of hypoglycaemia, modest weight loss, effectiveness and low cost. Data of UKPDS indicate that treatment based on metformin results in less total as well cardiovascular mortality. Metformin remains the drug of choice for patients with diabetes and CKD provided that their estimate Glomerular Filtration Rate(eGFR) remains above 30 mL/min per square meter. For diabetic patients with eGFR between 30-60 mL/min per square meter more frequent monitoring of renal function and dose reduction of metformin is needed. The use of sulfonylureas, glinides and insulin carry a higher risk of hypoglycemia in these patients and must be very careful. Lower doses and slower titration of the dose is needed. Is better to avoid sulfonylureas with active hepatic metabolites, which are renally excreted. Very useful drugs for this group of patients emerge dipeptidyl peptidase 4 inhibitors. These drugs do not cause hypoglycemia and most of them(linagliptin is an exception) require dose reduction in various stages of renal disease.

Management bone loss of the proximal femur in revision hip arthroplasty: Update on reconstructive options

The number of revision total hip arthroplasties is expected to rise as the indications for arthroplasty will expand due to the aging population. The prevalence of extensive proximal femoral bone loss is expected to increase subsequently. The etiology of bone loss from the proximal femur after total hip arthroplasty is multifactorial. Stress shielding, massive osteolysis, extensive loosening and history of multiple surgeries consist the most common etiologies. Reconstruction of extensive bone loss of the proximal femur during a revision hip arthroplasty is a major challenge for even the most experienced orthopaedic surgeon. The amount of femoral bone loss and the bone quality of the remaining metaphyseal and diaphyseal bone dictate the selection of appropriate reconstructive option. These include the use of impaction allografting, distal press-fit fixation, allograft-prosthesis composites and tumor megaprostheses. This review article is a concise review of the current literature and provides an algorithmic approachfor reconstruction of different types of proximal femoral bone defects.

Respiratory mechanics in brain injury: A review

Several clinical and experimental studies have shown that lung injury occurs shortly after brain damage. The responsible mechanisms involve neurogenic pulmonary edema, inflammation, the harmful action of neurotransmitters, or autonomic system dysfunction. Mechanical ventilation, an essential component of life support in brain-damaged patients(BD), may be an additional traumatic factor to the already injured or susceptible to injury lungs of these patients thus worsening lung injury, in case that non lung protective ventilator settings are applied. Measurement of respiratory mechanics in BD patients, as well as assessment of their evolution during mechanical ventilation, may lead to preclinical lung injury detection early enough, allowing thus the selection of the appropriate ventilator settings to avoid ventilatorinduced lung injury. The aim of this review is to explore the mechanical properties of the respiratory system in BD patients along with the underlying mechanisms, and to translate the evidence of animal and clinical studies into therapeutic implications regarding the mechanical ventilation of these critically ill patients.