Assessment of Knowledge, Attitude and Practices among Healthcare Workers in a Tertiary Care Hospital on Needle Stick Injury

Purpose: Needle-stick injury (NSI) is one of the most potential occupational hazards for healthcare workers because of the transmission of blood-borne pathogens. As per recent data, around 30 lakh healthcare workers sustain Needle stick injuries each year. This study was conducted to assess healthcare workers’ knowledge, attitude and practices regarding needle stick injury. Materials & Methods: A cross-sectional study was conducted in a Tertiary Care Hospital over the period of 3 months. The study population consisted of Intern Doctors, Post Graduate resident Doctors, Staff Nurses, laboratory technicians of Government Medical College and New Civil Hospital, Surat (n = 300). The data were collected using a self-administered questionnaire via the means of Google Forms. Questionnaire was made with prior review literature. The data obtained were entered and analysed in Microsoft Excel. Results: The prevalence of NSI in our study was 46%, with a higher prevalence among the PG residents (72%). Overall scores regarding knowledge and attitude were better in PG residents (knowledge score > 7 in 71% and Attitude Score > 7 in 68% of PG Residents). Even though the PG residents scored highest in the knowledge category, the majority of them suffered needle stick injuries as a result of poor practice scores. Among those who had NSI (n = 139/300), 70% of study participants had superficial injuries, only 9% reported the incident, 18% got medical attention within 2 hours of the incident, and 7% followed up to recheck their viral markers status. Most incidents of NSI were due to hypodermic needles while recapping needles. Conclusion: Exposure to needle stick injuries and their underreporting remains a common problem. It is imperative that healthcare workers receive regular training on the proper handling of sharp objects. We can also draw the conclusion that preventing NSIs requires putting knowledge into practice.

Effect of titanium on the sticking of pellets based on hydrogen metallurgy shaft furnace:Behavior analysis and mechanism evolution

Direct reduction based on hydrogen metallurgical gas-based shaft furnace is a promising technology for the efficient and low-carbon smelting of vanadium-titanium magnetite.However,in this process,the sticking of pellets occurs due to the aggregation of metal-lic iron between the contact surfaces of adjacent pellets and has a serious negative effect on the continuous operation.This paper presents a detailed experimental study of the effect of TiO2 on the sticking behavior of pellets during direct reduction under different conditions.Results showed that the sticking index(SI)decreased linearly with the increasing TiO2 addition.This phenomenon can be attributed to the increase in unreduced FeTiO3 during reduction,leading to a decrease in the number and strength of metallic iron interconnections at the sticking interface.When the TiO2 addition amount was raised from 0 to 15wt%at 1100°C,the SI also increased from 0.71%to 59.91%.The connection of the slag phase could be attributed to the sticking at a low reduction temperature,corresponding to the low sticking strength.Moreover,the interconnection of metallic iron became the dominant factor,and the SI increased sharply with the increase in re-duction temperature.TiO2 had a greater effect on SI at a high reduction temperature than at a low reduction temperature.

Effect of Mouth Opening Training Stick Combined with Oral Massage on Mouth Opening Difficulty in Head and Neck Cancer Patients after Treatment

Objective: To study the application effect of mouth-opening training sticks combined with oral massage on patients with mouth-opening difficulty after treatment for head and neck cancer. Methods: Using convenient sampling, 60 patients with mouth-opening difficulty after treatment for head and neck cancer admitted to the Oncology Department from February 2022 to October 2023 were selected for a 2-week exercise and nursing program. The patients were divided into a control group (February 1, 2022 to November 30, 2022) and an observation group (December 1, 2022 to October 31, 2023), with 30 patients in each group. The control group underwent routine mouth-opening functional exercises combined with cork for oral support training, while the observation group underwent routine mouth-opening functional exercises combined with oral massage and mouth-opening training sticks for oral support training. The mouth-opening degree, mouth-opening difficulty level, comfort level, compliance, and quality of life were observed in both groups. Results: Before the intervention, there were no statistically significant differences in mouth-opening degree and mouth-opening difficulty level between the two groups (P > 0.05). After the intervention, the mouth-opening degree, mouth-opening difficulty level, oral comfort level, compliance, and QLICP-HN scores in the observation group were all better than those in the control group, with statistically significant differences (P < 0.05). Conclusion: The combination of mouth-opening training sticks and oral massage with mouth-opening functional exercises can effectively improve the degree of mouth-opening difficulty, enhance oral comfort, increase compliance with mouth-opening exercises, and improve quality of life.

Charactering the spoilage mechanism of"three sticks"of Jinhua ham

To investigate the spoilage characteristics of Jinhua ham,sensory scores,volatile compounds,biogenic amine,physicochemical parameters and microbial counts were evaluated between normal and spoiled hams.The results showed that off-odors of spoiled hams were dominated by rancid,sour,sulfide and ammonia odors derived from these compounds including butanoic acid,methanethiol and dimethyl disulfide.Total content of biogenic amine in spoiled hams was significantly higher(more than 10-fold)compared with normal hams,and putrescine,cadaverine and histamine were the key components of biogenic amine of spoiled hams.Lower salt content,and higher moisture,TVB-N and thiobarbituric acid reactive substances(TBARS)values were observed in spoiled hams compared with normal hams.The populations of Enterobacteriaceae and Enterococcus of spoiled hams were obviously higher than that of normal hams.High moisture and low salt content caused the abnormal growth of Enterobacteriaceae and Enterococcus in spoiled hams,which contributed to the spoilage of Jinhua ham.

闭合复位内固定联合joy stick操纵杆技术治疗儿童难复性肱骨髁上骨折效果观察

目的观察闭合复位内固定联合joy stick操纵杆技术治疗儿童难复性肱骨髁上骨折的临床效果。方法选择因“肘关节外伤后肿痛伴活动受限”入院患儿4例,均诊断为GartlandⅢ型肱骨髁上骨折,均采用闭合复位内固定联合joy stick操纵杆技术治疗。结果4例患儿均获得满意复位,无一例转为切开复位,平均手术时间66 min,住院时间均<5 d。出院后规律复查换药,1月后均恢复良好,骨折线对位满意,未出现感染等短期并发症,拔除克氏针。结论Joy stick操纵杆技术不仅可以更加准确地控制肱骨轴的旋转,还能更快地获得复位和维持复位,进针顺利,手术时间短,减少转为切开复位,降低手术难度,且未增加围手术期并发症。

Antibacterial Activities of <i>Psidium guajava</i>(Guava) and <i>Velvet tamarin</i>(Icheku) Local Chewing Sticks on <i>Streptococcus mutans</i>Isolated from Human Mouth

Globally dental diseases are mainly caused by Streptococcus mutans, it is one of the leading causative agents of dental caries worldwide, because of its resistance to conventional antibacterial agents, alternative therapies are used to control resistance of oral pathogens. This research was done to determine the antibacterial activities of Psidium guajava (guava) and Velvet tamarin (Icheku) chewing sticks on Streptococcus mutans isolated from the oral cavity. The study was conducted in Owerri Imo State Nigeria during November-December period. Phytochemical analysis of the plant extracts was done using appropriate techniques. The procedure used for antimicrobial susceptibility test was disk diffusion method. Serial dilutions of Psidium guajava (guava) and Velvet tamarind (Icheku) extracts were prepared, Muller-Hinton media was used to put together the extract of serial dilutions of Psidium guajava (guava) and Velvet tamarin (Icheku) and a microbiological procedure were used for visually determining the minimum inhibitory concentration as well as minimum bactericidal concentration. Phytochemical evaluation of the plants’ extracts revealed that it contains saponins, tannins, alkaloid, steriods, glycosides and phenol. The results obtained from the antibacterial susceptibility testing of the extracts against Streptococcus mutans showed that the zones of inhibition recorded ranged from 18 mm to 27 mm. Ethanol (Soxhlet) extract of Icheku twig showed no zone of inhibition on the isolated organism. The ethanol (soxhlet) extract of the individual Psidium guajava (guava) and Velvet tamarin (Icheku) has a better antibacterial effect when compared to their aqueous extracts and combined forms. Psidium guajava (Guava) and Velvet tamarin (Icheku) twigs are made up of composite that is active against S. mutans and can be used in oral hygiene. There is a need for further investigation on the plant extracts as the rural poor make use of it because it is cheap, readily available and the rich also use it once they are in the village mostly in Eastern Nigeria. Similarly chewing sticks has been reported to be practiced by 90 of rural population in Nigeria.

Chemical control of Apriona germari(Hope) larvae with zinc phosphide sticks

Larvae of Apriona germari （Hope）, found widely in China, cause serious damage to trees and are difficult to control. Since some biological control methods have not been applied effectively in the field, chemical control methods are used widely. Because of low cost, no poisonous residues and relatively safe application, zinc phosphide sticks have been tested to control the larvae as a matter of urgency. However, there were no criteria about the dosage and use. Given the characteristics of larvae tunnels on triploid Populus tomentosa trees and the one-on-one way of using poison-fumigated sticks, the larvae were treated by three treatments with zinc phosphide sticks. The treatments are as follows： inserting one stick into the first hole of the tunnel from bottom to top （T1）, inserting a stick into each of the lowest two holes （T2） and inserting one stick into the first and third hole from bottom to top separately （T3）. We cleared the frass around the holes and on the ground before inserting the sticks and blocking every hole with mud for each treatment. After the fourth investigation was carried out, the larvae of CK were still active, and had caused serious damage and emanated fresh fi＇ass from old and new holes. Some larvae treated with T1 and T2 were in an intermediate state, but all of the larvae treated with T3 died completely and their old holes had healed. The results show that inserting zinc phosphide sticks （the extent of dispersion of the sticks was 20%） is a feasible method to control A. germari （Hope） larvae in triploid P. tomentosa of pulpwood trees. Because there were no statistically significant differences （p 〉 0.05） among the three treatments, we recommend that T1 should be used for economic efficacy.

Modeling and simulation of solvent behavior and temperature distribution within long stick propellants with large web thickness undergoing drying

Drying is a complicated physical process which involves simultaneous heat and mass transfer in the removal of solvents inside propellants.Inappropriate drying techniques may result in the formation of a hard skin layer near the surface to block the free access of most solvent through for long stick propellants with large web thickness,which lead to lower drying efficiency and worse drying quality.This study aims to gain a comprehensive understanding of drying process and clarify the mechanism of the blocked layer near the propellant surface.A new three-dimensional coupled heat and mass transfer(3D-CHMT)model was successfully developed under transient conditions.The drying experiment results show that the 3DCHMT model could be applied to describe the drying process well since the relative error of the content of solvent between simulation and experiment values is only 5.5%.The solvent behavior simulation demonstrates that the mass transfer process can be divided into super-fast(SF)and subsequent minorfast(MF)stages,and the SF stage is vital to the prevention of the blocked layer against the free access for solvent molecules inside propellant grains.The effective solvent diffusion coefficient(Deff)of the propellant surface initially increases from 3.4×10^(-6)to 5.3×10^(-6)m^(2)/s as the temperature increases,and then decreases to 4.1×10^(-8)m^(2)/s at 60-100 min.The value of Deffof surface between 0-1.4 mm has a unique trend of change compared with other regions,and it is much lower than that of the internal at100 min under simulation conditions.Meanwhile,the temperature of the propellant surface increases rapidly at the SF stage(0-100 min)and then very slowly thereafter.Both the evolution of Deffand temperature distribution demonstrate that the blocked layer near the propellant surface has been formed in the time period of approximately 0-100 min and its thickness is about 1.4 mm.To mitigate the formation of blocked layer and improve its drying quality of finial propellant products effectively,it should be initially dried at lower drying temperature(30-40℃)in 0-100 min and then dried at higher drying temperature(50-60℃)to reduce drying time for later drying process in double base gun propellants.The present results can provide theoretical guidance for drying process and optimization of drying parameters for long stick propellants with large web thickness.

An Artificial Intelligence Algorithm for the Real-Time Early Detection of Sticking Phenomena in Horizontal Shale Gas Wells

Sticking is the most serious cause of failure in complex drilling operations.In the present work a novel“early warning”method based on an artificial intelligence algorithm is proposed to overcome some of the known pro-blems associated with existing sticking-identification technologies.The method is tested against a practical case study(Southern Sichuan shale gas drilling operations).It is shown that the twelve sets of sticking fault diagnostic results obtained from a simulation are all consistent with the actual downhole state;furthermore,the results from four groups of verification samples are also consistent with the actual downhole state.This shows that the pro-posed training-based model can effectively be applied to practical situations.

蜜环菌人工菌棒基质碳氮比对乌天麻产量及营养品质的影响

目的分析蜜环菌人工菌棒基质碳氮比对乌天麻产量及基本营养成分含量的影响,并对乌天麻氨基酸品质进行评价。方法通过大棚内随机区组实验,测定不同种植模式下乌天麻的基本营养成分含量,对其进行单因素方差分析和多重比较,通过氨基酸评分法对乌天麻中氨基酸营养价值进行评价。结果蜜环菌人工菌棒基质碳氮比对乌天麻的产量、基本营养成分含量及氨基酸的营养品质均有显著影响;蜜环菌人工菌棒基质碳氮比为75.94时种植的乌天麻,其各项营养指标接近对照种植的乌天麻的各项营养指标,显著大于蜜环菌人工菌棒基质碳氮比为60.69、126.39时种植的乌天麻的各项营养指标。蜜环菌人工菌棒基质碳氮比为75.94时种植的乌天麻,其必需氨基酸含量与总氨基酸含量的比值为37.03%,接近40%;必需氨基酸含量与非必需氨基酸含量的比值为58.79%,接近60%;必需氨基酸的氨基酸比值、必需氨基酸的比值系数分、必需氨基酸比值系数与联合国粮食及农业组织/世界卫生组织提出的氨基酸理想模式较接近。结论利用蜜环菌人工菌棒种植乌天麻可以获得基本营养成分含量高、氨基酸丰富、必需氨基酸的组成比例相对合理、符合人体吸收利用需求、具有较高营养价值的乌天麻。

考虑桩土间黏滑机制的桩基沉降动态特性研究

基于桩基运动控制方程,对荷载作用下的桩基沉降动态特性进行了研究。首先,考虑桩土间黏滞与滑动两种接触状态,建立了一种考虑侧阻软化及侧阻恢复的桩土相互作用模型;然后采用该模型及修正三折线模型分别模拟桩与桩侧土以及桩端土间的相互作用,结合有限差分法建立了考虑桩土间黏滑机制的桩基沉降分析方法;最后,基于建立的桩基受荷沉降分析方法,研究了桩基沉降的黏滑动态特性以及桩身的力学特性,并讨论了桩土相互作用模型中的参数对桩基沉降动态特性的影响。结果表明:当桩顶荷载接近桩基单级加载极限值,桩基沉降表现出黏滞位移与快速滑动位移交替的动态特性;桩身力学响应表现出加载路径相关性,与单级加载相比,分级加载时桩侧摩阻力能得到更好发挥,桩基极限承载力更高;提出的分析方法能够较好地模拟桩基静载试验沉降过程。

“三把半香”与袍哥精神世界的塑造

敬拜“三把半香”是袍哥精神和仪式的重要组成部分。关于“三把半香”的文字与口头传播,吸取了中国历史、传说和民间文化中的诸多元素。“三把半香”的信仰仪式、其中的故事人物及其传达的伦理信息,既继承了从墨子到游侠的文化传统,也显示了人们对游侠风骨的精神寄托,构成了袍哥伦理说教的组成部分,是稳固袍哥组织、加强袍哥身份认同以及进行袍哥内部控制的行之有效的工具。这种工具从中国的历史传说中得到了养料,使得他们团结一心。这种共同的信仰,成为这个组织的粘黏合剂,将袍哥的信仰与仪式规范结合了起来。袍哥之开山立堂,行走江湖,敬拜“三把半香”,成为袍哥的精神支柱和共同教条。

中药离子导入联合穴位贴敷对膝骨关节炎患者步态行走及致痛因子表达的影响

目的观察中药离子导入联合穴位贴敷对膝骨关节炎康复效果和步态行走及致痛因子表达的影响。方法将80例膝骨关节炎患者按照随机数字表法分为2组,治疗组40例予中药离子导入联合穴位贴敷治疗,对照组40例予艾瑞昔布片口服。2组均治疗4周。比较2组治疗前后可溶性白细胞介素2受体(sIL-2R)、降钙素基因相关肽(CGRP)、可溶性细胞间黏附分子1(sICAM-1)、肿瘤坏死因子α(TNF-α)、骨碱性磷酸酶(BALP)、核转录因子κB受体活化因子配体(RANKL)、甲壳质酶蛋白40(YKL-40)、神经肽Y(NPY)、6-酮前列腺素E_(1α)(6-keto-PGE_(1α))、过氧化脂质(LPO)、总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)水平,以及膝关节运动功能Lysholm量表(LKSS)、Berg平衡量表(BBS)、西安大略和麦克马斯特大学(WOMAC)骨关节炎指数、关节炎生活质量测量量表(AIMS2-SF)评分,并统计2组疗效。结果治疗组总有效率95.00%(38/40),对照组总有效率82.50%(33/40),治疗组临床疗效优于对照组(P<0.05)。2组治疗后sICAM-1、sIL-2R、TNF-α水平均较本组治疗前降低(P<0.05),且治疗组治疗后均低于对照组(P<0.05)。2组治疗后T-AOC、SOD水平均较本组治疗前升高(P<0.05),且治疗组治疗后均高于对照组(P<0.05),2组治疗后LPO水平均较本组治疗前降低(P<0.05),且治疗组治疗后低于对照组(P<0.05)。2组治疗后CGRP、NPY、6-keto-PGE_(1α)水平均较本组治疗前降低(P<0.05),且治疗组治疗后均低于对照组(P<0.05)。2组治疗后RANKL、YKL-40水平均较本组治疗前降低(P<0.05),且治疗组治疗后均低于对照组(P<0.05),2组治疗后BALP水平均较本组治疗前升高(P<0.05),且治疗组治疗后高于对照组(P<0.05)。2组治疗后BBS、LKSS、AIMS2-SF评分均较本组治疗前升高(P<0.05),且治疗组治疗后均高于对照组(P<0.05),2组治疗后WOMAC评分均较本组治疗前降低(P<0.05),且治疗组治疗后低于对照组(P<0.05)。结论中药离子导入联合穴位贴敷治疗膝骨关节炎患者,可改善炎症,减少氧化反应,降低致痛因子水平,改善RANKL、YKL-40、BALP水平,改善膝关节功能及步态行走,提升临床疗效及生活质量。

基于反相高效液相色谱法的面团黏性与小麦醇溶蛋白组成关系研究

以74份不同黏性等级的小麦品种(系)为研究材料,采用反相高效液相色谱(RP-HPLC)法分离不同黏性小麦品种的醇溶蛋白特征图谱,并进行面团黏性、醇溶蛋白组分含量与小麦面粉品质性状的相关性分析,以期建立采用少样本量快速准确识别面团黏性的方法。结果表明,经RP-HPLC分离后,ω-、α/β-和γ-醇溶蛋白3个组分在图谱上清晰可见;不同黏性等级小麦材料的醇溶蛋白得到了不同的特征图谱,黏性较大的小麦ω-醇溶蛋白的组分峰数较多,总峰面积较大;ω-醇溶蛋白在不同黏性等级小麦材料间存在显著差异。相关性分析结果表明,面团黏性与ω-醇溶蛋白相对含量呈极显著正相关,与α/β-和γ-醇溶蛋白相对含量相关性不显著;ω-醇溶蛋白相对含量与沉淀值、形成时间、稳定时间、能量、拉伸阻力和最大拉伸阻力均呈极显著负相关,与蛋白质、湿面筋含量均呈显著正相关,与弱化度呈极显著正相关;ɑ/β-醇溶蛋白相对含量与蛋白质、湿面筋含量均呈极显著正相关;γ-醇溶蛋白相对含量与小麦各品质性状均无显著相关性。可见,面团黏性主要与ω-醇溶蛋白相对含量有关,ω-醇溶蛋白对面团质量有弱化作用。

亚欧传播链上中国古代马球的器材与打法考论

马球运动是一项由人、马、球杆、球等要素组合起来的复杂竞技运动,自公元7世纪开始在亚欧大陆广大区域流行。考证分析中国历史文献和考古出土文物,并对比古代波斯、朝鲜、日本等国的文献、文物资料,在亚欧传播链上考察中国古代马球器材和打法的历史演变。认为:马球比赛中对阻挡“球路”的规则限制是自唐代以来马球竞赛和谐进行的核心条款,其最大限度地避免了双方马匹迎头相撞的伤亡事件,在中国古代出土壁画中也呈现出马头朝向同一方向的竞赛场景;马球能够在亚洲多地流行得益于公元5世纪马镫技术的发明,马镫使“人马合一”,能够完成马球运动所需要的各种高难度技术动作;唐代已降至明代,马球的球杆迭次发生标志性变化,折射出亚洲各地马球运动发展的“同”与“异”,充分说明古代马球运动的跨文化交互影响。

考虑深井井下动力钻具影响的钻柱粘滑振动规律

油气勘探开发统计数据显示,深井钻井过程中粘滑振动频发,占钻进时长的50%以上,严重影响了钻井井下安全,延长了钻井周期,增加了钻井成本。由于深井钻柱结构较为复杂,井下动力钻具应用普遍,但动力钻具对井底钻头粘滑振动的影响规律缺乏深入研究,目前尚未有学者提出深井动力钻具下的钻柱全尺寸动力学模型。为此,基于弹簧集中质量原理,建立了包含井下动力钻具的粘滑振动仿真模型和螺杆钻具输出参数的计算模型,研究了螺杆钻具、扭力冲击器及两种工具复合使用对钻头粘滑振动的影响,并基于模型分析了现场实钻案例。研究结果表明:(1)使用螺杆钻具复合钻进时,转盘转速与螺杆转速对粘滑振动影响较大,复合转速越大,越有利于消除粘滑振动;(2)钻压和钻头尺寸越大,需要消除粘滑振动的转速就越大;(3)在保证水力参数的情况下,螺杆输出较高的扭矩和转速,能够有效地抑制钻头粘滑;(4)扭力冲击器和螺杆钻具复合使用情况下,当螺杆钻具的输出参数不足以抑制粘滑振动时,提高扭力冲击器的冲击扭矩和冲击频率,可降低螺杆钻具的临界转速,抑制井底粘滑振动。结论认为,该动力学模型可以为深井合理使用动力钻具、避免粘滑振动和提高机械钻速提供有效的技术支撑,该理论新认识在指导钻井现场钻进,提高钻井效率和降低钻井成本等方面具有重要的现实意义。

泥蚶提取物抗氧化及抗运动性疲劳作用研究

为开发利用泥蚶资源,探究泥蚶水提物和醇提物的抗氧化及抗运动性疲劳作用效果,以1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除能力、超氧阴离子(O_(2)^(-))自由基清除能力、抑制β-胡萝卜素褪色能力为指标评价泥蚶提取物的体外抗氧化作用。通过测定小鼠转棒停留时间、负重力竭游泳时间及小鼠运动后体内相关血清生化指标变化情况,分析泥蚶提取物的抗运动性疲劳作用效果。实验结果表明,泥蚶醇提物对DPPH、O_(2)^(-)自由基的清除能力及抑制β-胡萝卜素-亚油酸体系的褪色能力较强,其半抑制浓度(half maximal inhibitory concentration,IC_(50))分别为1.38、1.87、2.07 mg/mL。泥蚶水提物高剂量组对应的小鼠转棒停留时间为64.10±1.86 s、负重力竭游泳时间为102.55±2.49 min,并呈剂量-效应关系;另外,高剂量泥蚶水提物还可提高小鼠运动后体内肝糖原和肌糖原含量,降低尿素氮和血乳酸水平,其结果分别为16.36±0.42 mg/g、2.56±0.22 mg/g、7.84±0.31 mmol/L、3.44±0.25 mmol/L,与泥蚶醇提物各组差异显著(P<0.05)。该研究可为泥蚶的深度开发与利用提供理论依据。

温和灸足三里穴对自然衰老大鼠肾组织p16 DNA甲基化的影响

目的 观察温和灸足三里穴对自然衰老大鼠肾组织p16 DNA甲基化的调控作用及潜在机制。方法 将Sprague-Dawley(SD)大鼠随机分为12月龄组、24月龄组和艾灸组。24月龄组和艾灸组制备自然衰老模型。12月龄组和24月龄组大鼠不予治疗,待相应时间取材;艾灸组采用温和灸足三里穴至24月龄取材。采用免疫荧光法观察3组大鼠肾组织衰老相关标志物β-半乳糖苷酶的表达。采用酶联免疫吸附法和免疫组织化学法检测3组大鼠肾组织衰老相关p16蛋白及甲基转移酶[甲基转移酶3a(DNA methyltransferase 3a,Dnmt3a)和甲基转移酶3b(DNA methyltransferase 3b,Dnmt3b)]蛋白的表达。采用定量反转录聚合酶连锁反应(quantitative real time-polymerase chain reaction,qRT-PCR)法检测3组大鼠肾组织端粒长度、肾组织衰老相关p16 mRNA及甲基转移酶(Dnmt3a和Dnmt3b) mRNA表达。采用重亚硫酸盐测序技术检测3组大鼠肾组织p16 DNA CpG岛甲基化程度。结果 与12月龄组比较,24月龄组大鼠肾组织β-半乳糖苷酶表达、端粒长度的损耗及衰老相关p16蛋白和mRNA表达水平升高(P<0.05),24月龄组大鼠肾组织Dnmt3a和Dnmt3b蛋白及mRNA表达水平降低(P<0.05)。与24月龄组比较,艾灸组大鼠肾组织β-半乳糖苷酶表达、端粒长度的损耗及肾组织衰老相关p16蛋白和mRNA表达显著降低(P<0.05),艾灸组大鼠肾组织Dnmt3a和Dnmt3b蛋白及mRNA表达显著升高(P<0.05)。结论温和灸可通过影响自然衰老大鼠肾组织衰老相关甲基转移酶的表达调控p16 DNA CpG岛整体甲基化水平,降低肾组织p16蛋白及mRNA在衰老机体肾组织的表达,延缓肾组织衰老进程。

断层接触非均匀性对米尺度断层黏滑失稳成核过程的控制

非均匀性是野外断层的重要特征,我们利用预制的具备接触非均匀性的米尺度岩石断层开展黏滑实验,模拟野外地震失稳过程.通过观测预制岩石断层发生的多个黏滑事件的应变时空演化,并对比断层接触非均匀性测定结果发现:(1)断层的接触弱段是成核最先启动,即最早发生预滑的区域,随失稳临近,预滑区域扩展且滑动速率增加,与厘米尺度均匀断层相比,准静态过程的预滑扩展不明显,向准动态过程转变突然且迅速;(2)断层的接触强段在成核期间一直处于闭锁状态,应力升高,且随失稳临近增幅加强,强段的屈服是断层从缓慢破裂到快速破裂的转折点,接触强段的持续闭锁在以往的厘米尺度均匀断层黏滑实验中较为少见;(3)加载速率以及加载历史是影响米尺度断层成核持续时间的重要因素,随加载速率变慢,成核持续时间变长,随加载历史变长,断层趋于均匀化,成核持续时间变短.上述研究结果明确提供断层接触非均匀性控制成核过程的直接证据.这不仅有助于将实验结果向可操作的地震预测实践转化,也有助于促进(大陆浅源)地震前兆机理的探索及理解.

Power-V诱导的钻柱黏滑振动特征分析

黏滑是石油钻井过程中影响钻井效率和井下钻柱安全的一种振动形式.垂直钻井系统Power-V在提供有效控斜力的同时,还会诱导钻柱黏滑振动.通过研究垂直钻井系统Power-V与井壁的接触作用及钻头与地层的相互作用模型,基于钻柱动力学有限元方法,深入分析Power-V的作用机理,研究其对扭转振动的影响,指出Power-V和井壁间的相互作用会导致钻柱与井壁的摩阻显著增加,进而引起摩阻扭矩的增大,诱导井下黏滑振动.实测振动数据证实,Power-V与井壁间的相互作用是引起钻柱黏滑振动的关键因素.这对于揭示黏滑振动的成因和更好地发挥Power-V的作用具有重要意义.