嗜热毛壳菌端粒酶的表达纯化及酶学特性分析

为进一步探究端粒酶的酶学特性,以嗜热毛壳菌(Chaetomium thermophilum, Thermo)端粒酶为研究对象,通过生物化学、生物信息学等方法得到4种不同长度的Thermo端粒酶蛋白,分别与体外转录得到的Thermo端粒酶RNA进行组装。通过端粒酶体外延伸试验检测组装体的反转录活性,进一步分析影响其反转录活性的各种因素。结果表明,4种不同长度的Thermo端粒酶蛋白重组质粒经大肠杆菌表达系统诱导表达后均可得到相应的Thermo端粒酶蛋白,且纯度均在90%以上;体外孵育试验表明,在10 mmol/L HEPES-KOH(pH 8.0)、1 mmol/L MgCl2、100 mmol/L NaCl、3 mmol/L KCl、体积分数25%Glycerol、10units/μL Rnasin的条件下,端粒酶蛋白与RNA的摩尔浓度比达到1∶1及以上时,两者能有效复合;端粒酶体外延伸试验发现,结构完整的Thermo端粒酶组装体具有很强的反转录活性,可使18nt-DNA引物反复延伸。TEN结构域不完整并未减弱Thermo端粒酶组装体的反转录活性,说明其在反转录过程中未发挥显著作用。T-PK区或TWJ区缺失的组装体均不能使18nt-DNA引物发生延伸,表明RNA结构的完整性是端粒酶发挥反转录功能的必要条件。

超深井溢漏监测装备、压井技术进展及思考

随着勘探开发走向超深层,工程作业面临的井控风险日益突出,钻井过程中溢漏风险、压井难度增大,如何及时发现溢漏和提高压井的成功率是急需解决的现场问题。文章调研了超深井钻井溢漏监测装备、压井技术的研究进展,阐述了大排量出口流量精确监测技术、起下钻自动灌浆及溢漏监测技术、环空液面连续监测技术、循环罐体积数字化监测技术等溢漏监测井控装备的研发现状,以及压井理论、压井工艺技术在超深井的研究进展情况。分析了人工智能钻井溢漏预警系统、井下溢漏早期精确监测技术、自动及智能化压井技术等领域的未来发展趋势。总结了井下—地面的钻井全过程溢漏监测装备、基于多源数据融合的溢漏预警软件和复杂井况压井模拟系统技术发展情况,提升了溢漏监测的及时性和准确性,提高了复杂井况压井成功率,为超深井井控安全提供技术保障。

多UUV集群协同作业技术研究现状及发展趋势分析

与单体UUV相比,多UUV集群具有低成本、高容错、高效率和可重构等优点,将会是未来海洋作业任务的趋势。针对多UUV集群协同作业技术梳理了国内外的研究成果,重点对编队控制、任务规划、协调路径规划和目标搜索等领域的协同作业技术进行分析介绍,最后对多UUV集群协同作业的现状进行总结和展望,为今后的UUV集群协同作业技术的发展提供参考和思路。

高含硫气井钻完井技术新进展与发展展望

我国高含硫天然气资源丰富,但普遍具有高温高压和高含腐蚀性气体的特点,在开采过程中容易发生气侵、井涌、管材腐蚀等安全隐患,其安全高效钻完井对保障我国高含硫天然气稳产、增产目标具有重要意义。为此,开展了高含硫天然气气井钻井过程的流体相态特征及井筒压力分析,从井筒压力控制的角度,总结分析了近年来国内外高含硫气井在钻井工艺、钻井液技术以及井筒完整性等方面取得的关键技术突破和新进展,并展望了万米特深井钻完井技术的发展趋势。研究结果表明:①气体溶解度对井筒流动压力影响较大,高含硫气井钻井过程中必须考虑酸性气体溶解特性对井筒多相流动的影响;②精细控压钻井及控压固井技术能精确控制井筒压力在安全密度窗口内,防止钻井过程酸性气体侵入井筒,实现了固井过程压稳不漏;③适用于H2S地层的钻井液技术不但可以稳定井壁、保护储层,还能提高钻井速度;④从井下管柱结构优化设计开始,研究完整性风险定量评价方法和低成本防腐技术,可以实现全生命周期井筒完整性,降低高含硫气井钻完井安全生产风险。结论认为,高含硫气井钻完井技术新进展的系统梳理不仅对推动高含硫天然气藏的安全高效开发具有重要的现实意义,同时也为高含硫气藏深井超深井安全高效钻完井技术发展提供了研究思路和攻关方向。

Extracellular vesicles from human urine-derived stem cells prevent osteoporosis by transferring CTHRC1 and OPG

Osteoporosis is a debilitating bone disease affecting millions of people. Here, we used human urine-derived stem cells(USCs),which were noninvasively harvested from unlimited and easily available urine, as a "factory" to obtain extracellular vesicles(USCEVs) and demonstrated that the systemic injection of USC-EVs effectively alleviates bone loss and maintains bone strength in osteoporotic mice by enhancing osteoblastic bone formation and suppressing osteoclastic bone resorption. More importantly, the anti-osteoporotic properties of USC-EVs are not notably disrupted by the age, gender, or health condition(with or without osteoporosis) of the USC donor. Mechanistic studies determined that collagen triple-helix repeat containing 1(CTHRC1) and osteoprotegerin(OPG) proteins are enriched in USC-EVs and required for USC-EV-induced pro-osteogenic and anti-osteoclastic effects. Our results suggest that autologous USC-EVs represent a promising novel therapeutic agent for osteoporosis by promoting osteogenesis and inhibiting osteoclastogenesis by transferring CTHRC1 and OPG.

Mechanism and prevention method of drill string uplift during shut-in after overflow in an ultra-deep well

Drill string will sustain large uplift force during the shut-in period after gas overflow in an ultra-deep well, and in serious case, it will run out of the wellhead. A calculation model of uplift force was established to analyze dynamic change characteristics of the uplift force of drill string during the shut-in period, and then a management procedure for the uplift risk during the shut-in period after gas overflow in the ultra-deep well was formed. Cross section method and pressure area method were used to analyze the force on drill string after shut-in of well, it was found that the source of uplift force was the "fictitious force" caused by the hydrostatic pressure in the well. When the fictitious force is in the opposite direction to the gravity, it is the uplift force. By adopting the theory of annular multiphase flow, considering the effects of wellbore afterflow and gas slippage, the dynamic change of the pressure and fluid in the wellbore and the uplift force of drill string during the shut-in period were analyzed. The magnitude and direction of uplift force are related to the length of drill string in the wellbore and shut-in time, and there is the risk of uplift of drill string when the length of drill string in the wellbore is smaller than the critical drill string length or the shut in time exceeds the critical shut in time. A set of treatment method and process to prevent the uplift of drill string is advanced during the shut-in period after overflow in the ultra-deep well, which makes the risk management of the drill string uplift in the ultra-deep well more rigorous and scientific.

可变形天然裂缝动态宽度流-固耦合计算模型

针对当前的天然裂缝宽度预测模型没有考虑裂缝在缝内流动净压力作用下变形的问题,开展了可变形天然裂缝动态宽度流-固耦合计算模型研究。首先,根据天然裂缝的变形控制方程和缝内流动净压力方程建立流-固耦合漏失动力学模型,得到漏失速率和漏失前端侵入速度的控制方程;然后,运用自适应搜索法求取天然裂缝等效平均宽度,结合体积等效原则求得天然裂缝初始宽度,联合初始宽度和漏失速率的几何控制方程建立天然裂缝形态系数的求解方法;最后,基于漏失前端侵入速度的几何控制方程进行天然裂缝形态约束求解得到法向刚度,进而得到天然裂缝动态宽度流-固耦合计算模型。建立的可变形天然裂缝动态宽度流-固耦合计算模型,经验证其计算结果与现场测量数据吻合较好,仅需钻井液性能、井漏现场测量的漏失速率序列及漏失体积序列,就能进行天然裂缝动态宽度预测,便于现场应用。

跌倒防护机器人的用户接受度模型

跌倒防护机器人解决了老年群体由于跌倒造成伤亡的社会问题,为探究老年用户对其接受度问题,以基础技术接受模型为基础,将感知易用性、感知有用性、使用态度、行为意向、技术信任度、社会规范、个人创新意识、面子文化、舒适度9个变量纳入分析,提出12项假设,构建了跌倒防护机器人的接受度模型。通过李克特5点量表测量变量,并结合结构方程模型进行数学分析,探究变量间的相互作用关系。结果表明:9个变量之间的作用具有显著性,12项假设全部成立,跌倒防护机器人接受度模型具有较好的拟合性。可见,研究结果可以为进一步探讨跌倒防护机器人的设计、开发、推广和普及提供有效参考。

Metformin accelerates bone fracture healing by promoting type H vessel formation through inhibition of YAP1/TAZ expression

Due to increasing morbidity worldwide,fractures are becoming an emerging public health concern.This study aimed to investigate the effect of metformin on the healing of osteoporotic as well as normal fractures.Type H vessels have recently been identified as a bone-specific vascular subtype that supports osteogenesis.Here,we show that metformin accelerated fracture healing in both osteoporotic and normal mice.Moreover,metformin promoted angiogenesis in vitro under hypoxia as well as type H vessel formation throughout fracture healing.Mechanistically,metformin increased the expression of HIF-1α,an important positive regulator of type H vessel formation,by inhibiting the expression of YAP1/TAZ in calluses and hypoxia-cultured human microvascular endothelial cells(HMECs).The results of HIF-1αor YAP1/TAZ interference in hypoxia-cultured HMECs using si RNA further suggested that the enhancement of HIF-1αand its target genes by metformin is primarily through YAP1/TAZ inhibition.Finally,overexpression of YAP1/TAZ partially counteracted the effect of metformin in promoting type H vessel-induced angiogenesis-osteogenesis coupling during fracture repair.In summary,our findings suggest that metformin has the potential to be a therapeutic agent for fractures by promoting type H vessel formation through YAP1/TAZ inhibition.

半导体制冷服设计方法研究进展

为提高半导体制冷服的制冷效率和穿着热舒适度,梳理了近年来国内外相关研究成果,将半导体制冷服的制冷系统分为冷源模块(包括制冷部分和热端散热部分)和冷端传热模块进行讨论。针对冷源模块,提高冷源制冷效率的方法有改善电源输入和提高热端散热性能。热端散热方式有强制风冷、液冷和热管散热,可通过改变不同散热方式下的各种参数来提高热端散热性能。针对冷端传热模块,传热方式有液冷传热、风冷传热和接触传热,可根据不同工况选择合适的传热方式。与传热部分的结构、介质相关的各项参数是影响传热效率和穿着者热舒适度的重要因素。热舒适度实验是评价和优化制冷服的重要方式,实验时需考虑装置、环境、人体等各项因素,建立人体-制冷服-环境的热舒适度模型是一种高效的分析和处理方法。综合各方面研究总结出影响半导体制冷服制冷效率和穿着热舒适度的因素,可为半导体制冷服各部分选型、设计优化和实验评估提供思路。最后提出:轻量便携、智能可控、高舒适性、适用于多场景的半导体制冷服以及利用半导体双制特性研发的空调服将成为未来的研究方向。

Axial length shortening in myopic children with Stickler syndrome after repeated low-level red-light therapy

AIM:To report the myopia-controlling effect of repeated low-level red-light(RLRL)therapy in patients with Stickler syndrome(STL),an inherited collagenic disease typically presenting with early onset myopia.METHODS:Three STL children,aged 3,7,and 11y,received RLRL therapy throughout the follow-up period of 17,3,and 6mo,respectively after exclusion of fundus anomalies.Data on best-corrected visual acuity(BCVA),intraocular pressure,cycloplegic subjective refraction,ocular biometrics,scanning laser ophthalmoscope,optical coherence tomography,genetic testing,systemic disease history,and family history were recorded.RESULTS:At the initiation of the RLRL therapy,the spherical equivalent(SE)of 6 eyes from 3 patients ranged from-3.75 to-20.38 D,axial length(AL)were from 23.88 to 30.68 mm,and BCVA were from 0.4 to 1.0(decimal notation).Myopia progression of all six eyes slowed down after RLRL therapy.AL in five out of the six eyes shortened-0.07 to-0.63 mm.No side effects were observed.CONCLUSION:Three cases of STL whose progression of myopic shift and AL elongation are successfully reduced and even reversed after RLRL therapy.

水平井大规模压裂固井水泥石性能设计方法

水平井大规模压裂对固井水泥石性能提出了更高的要求,不仅要求水泥石有一定的抗压强度,还需要具备一定变形能力。目前普遍采用的标准已不能满足水平井大规模压裂对水泥环密封性的要求。基于压裂工况条件下水泥环受力分析模型,综合考虑水泥环拉伸破坏和界面剥离破坏两种失效形式,提出了一种能满足大规模压裂密封要求的固井水泥石性能设计方法,建立了包含弹性模量、泊松比以及抗拉强度(或屈服强度)的固井水泥石性能指标控制图版,量化了水泥石的杨氏模量、泊松比、抗拉强度(或屈服强度)之间的关系。根据该指标控制图版进行水泥石性能设计,可以有效减少水泥环破坏的风险。建立了玛湖油田大规模压裂水平井固井指标控制图版,并根据该控制图版优选了弹韧性水泥浆体系,该体系现场应用10余口井,顺利完成了井口压力增量90 MPa的储层压裂改造,效果良好,达到了预期产量。

基于机器视觉的插件式元器件插装后自动检测系统在PCBA过程中的应用

本文提出了一种基于视觉检测的自动化系统,旨在快速、准确地检测和分类插件式电子元器件插装后的错、漏、反、多、歪斜等缺陷。该系统利用高分辨率图像采集设备和先进的图像处理算法,实时检测和定位PCB板上的插件式电子元器件,并通过分析图像中的特征和模式,自动识别与分类缺陷,对不同缺陷开展针对性处理,大大提高了生产效率和产品质量。

无电解电容变频驱动系统设计与实现

在无电解电容变频驱动系统中,采用薄膜电容取代传统的电解电容,可以有效提高系统的可靠性。本文设计了一种基于逆变器等效转矩控制的单相无电解电容高功率因数驱动系统,通过计算逆变器等效输入输出转矩,并采用IR转矩调节器,以实现对网侧功率因数的控制。实验结果表明:所设计的驱动系统输入功率因数高达0.980,输入电流谐波满足IEC61000-3-2谐波标准。

致密油藏水平井前置增能体积压裂高效开发技术研究及应用——以延长油田FL121平2井为例

延长油田南部油区下组合多为致密油藏,孔隙度不大于15%,渗透率不大于0.5×10^(-3)μm^(2),主要以水平井开发为主。为了进一步补充地层能量,延缓产量递减,提高单井采收率,通过岩心实验模拟了裂缝对岩心的动态渗吸影响,采用水平井前置增能体积压裂工艺,促进了蓄能增能和油水渗吸置换作用,实现了水平井单井产量是常规井产量的5~6倍,是优化前水平井产量的1~2倍。FL121平2井应用该工艺压裂改造后,试油期间,最高产油量达93.5 t/d,稳产约9.0 t/d,取得了比较理想的开发效果。

旋转导向工具环空掉块运移规律数值模拟

页岩气水平井钻井使用旋转导向工具后,井壁掉块卡钻事故时有发生。为此,结合现场井壁掉块形状和大小,利用球面填充法建立掉块模型,借助计算流体力学软件Fluent和离散单元法软件EDEM,研究了掉块运移的影响因素。数值模拟结果表明:在现场施工排量条件下,遇阻掉块运移离开旋转导向环空时间为5~15 min,当钻井液排量大于35 L/s时可显著提高掉块的运移速度;增加钻井液密度会使掉块摆脱遇阻,为预防卡钻建议将钻井液密度维持在1.9 g/cm^(3)以上;当钻井液黏度为20~60 mPa·s时,其对环空中可活动掉块的运移有一定促进作用,但不影响已经遇阻和遇卡掉块。所得结论对预防水平井钻井中,旋转导向工具井壁掉块卡钻和钻井液安全循环时间制定具有一定的理论指导作用。

基于复杂网络的国际石油贸易关系定量研究

针对如何更加准确地评价国际石油贸易关系问题,开展了将该贸易关系进行网络化和结构化的特征指标量化分析研究。研究中以复杂网络理论进行网络化建模,以结构平衡理论进行定量分析,采用了计算聚类系数、平衡度等关键指标进行年度基准对比。获得了国际石油贸易关系网络随着贸易者数量的增加尤其是进口国数量增加,网络的聚类系数变大,平衡度值增加,整个贸易网络平衡性变差,贸易关系变得更加紧张这一结论。本研究采用网络化和结构化的方式进行关系评价,是将石油贸易关系的研究从定性推进至定量的有益尝试。

Omentin-1 prevents inflammation-induced osteoporosis by downregulating the pro-inflammatory cytokines

Osteoporosis is a frequent complication of chronic inflammatory diseases and increases in the pro-inflammatory cytokines make an important contribution to bone loss by promoting bone resorption and impairing bone formation. Omentin-1 is a newly identified adipocytokine that has anti-inflammatory effects, but little is known about the role of omentin-1 in inflammatory osteoporosis. Here we generated global omentin-1 knockout（omentin-1^-/-） mice and demonstrated that depletion of omentin-1 induces inflammatory bone loss-like phenotypes in mice, as defined by abnormally elevated pro-inflammatory cytokines, increased osteoclast formation and bone tissue destruction, as well as impaired osteogenic activities. Using an inflammatory cell model induced by tumor necrosis factor-α（TNF-α）, we determined that recombinant omentin-1 reduces the production of proinflammatory factors in the TNF-α-activated macrophages, and suppresses their anti-osteoblastic and pro-osteoclastic abilities. In the magnesium silicate-induced inflammatory osteoporosis mouse model, the systemic administration of adenoviral-delivered omentin-1 significantly protects from osteoporotic bone loss and inflammation. Our study suggests that omentin-1 can be used as a promising therapeutic agent for the prevention or treatment of inflammatory bone diseases by downregulating the proinflammatory cytokines.

致密油藏水平井分段压裂集成开采实践

为了提高致密油藏水平井开发储量动用程度,运用油藏数值模拟方法对水平井分段压裂集成开采的开发效果进行了对比分析,结合现场实际地质模型进行开发效果预测。研究表明:采用水平井分段压裂集成开采方法,第一生产阶段日产油量低于常规开采(全井段压裂)的,但第二生产阶段日产油量高达24t,是常规开采(全井段压裂)的2.5倍,共增油2477t。应用实际地质模型模拟20年,可增大油藏开发中压力波及范围,累计增油963t。研究结果可为致密油藏水平井开采提供理论支持。

鄂尔多斯盆地H8井区长6油层组砂岩储层特征

综合应用储层露头、岩心观察、铸体薄片、扫描电镜、压汞实验等分析资料,对鄂尔多斯盆地H8井区长6油层组储层岩石学、物性、孔隙类型及结构特征等进行综合分析。结果表明:长6油层组储层岩性主要为细粒长石砂岩,成分成熟度较低,结构成熟度属于中等-差;储层物性较差,为典型的特低孔、超低渗透储层;发育粒间孔及溶蚀孔,喉道类型主要以片状和弯片状喉道为主;长6储层可划分为三类,Ⅰ类为低门槛压力-高进汞饱和度型,物性最好,Ⅱ类为中门槛压力-中进汞饱和度型,物性次之,Ⅲ类为高门槛压力-低进汞饱和度型,物性最差。压实作用、碳酸盐岩矿物胶结是造成储层物性变差的主要原因,溶蚀作用对储层物性起改善作用。以上研究成果为H8井区下步勘探开发提供了地质依据。