Nd~(3 ):YAG倍频激光对眼损伤阈值的研究

实验用Nd~(3 ):YAG倍频激光照射青紫蓝灰兔眼及恒河猴眼.求得视网膜损伤阈值ED_(50),兔眼和猴眼的角膜入射能量密度分别为39.2μJ/cm~2及187μJ/cm~2.两ED_(50)之比为1:4.7.     

308nm紫外激光对兔眼角膜的光化学损伤反应的研究

近来,紫外激光和近紫外激光对生物组织的损伤作用研究引起世界众多学者的关注。本实验采用308nm XeCl准分子激光器作为照射源,以免眼角膜为动物模型,研究角膜受308nm紫外激光照射瞬时反应的损伤阈,并对角膜损伤延迟反应作一探讨,为制订我国激光防护标准提供依据。     

CO_2激光对角膜损伤阈值的研究

用连续CO_2激光器,照射青紫蓝灰兔眼142只.求得平均照射时间1.03秒,角膜损伤阈值ED_(50)(?)5.72W/cm~2(95%可信限5.58～5.85W/cm~2);平均照射0.12秒,ED_(50)(?)10.7W/cm~2(95%可信限10.4～10.9W/cm~2).     

Nd：YAG三倍频,四倍频激光对兔角膜损伤阈值研究

本文报导了Nd:YAG三倍频(355nm)及四倍频(266nm)紫外激光的兔角膜损伤阈值,其ED_(50)分别为404.8mJ/cm~2和43.7mJ/cm~2。     

连续波Nd:YAG激光对人皮肤损伤阈值的研究

连续波1.06μm激光的损伤阈值经过动物实验及人皮肤实验.最后结果:中国人皮肤偏白者MRD_(50)为65.519J/cm~2,黄皮肤为60.989J/cm~2,偏黑者52.321J/cm~2.实验证明,皮肤色素的多少对Nd:YAG激光的吸收有明显的差异.     

CO_2激光对兔眼角膜损伤阈值的研究

本文介绍连续CO_2激光对青紫蓝灰兔角膜损伤阈值研究的材料、方法和结果.辐照1秒,ED_(50)为3.62W/cm~2;辐照125ms,ED_(50)为4.01W/cm~2.     

CO_2激光对黄种人皮肤急性损伤阈值的研究

本文主要叙述了CO_2激光照射系统的监测工作.对8只小白猪皮肤受CO_2激光照射的急性损伤阈值(MRD_(50))进行了测定.在此基础上,对6位志愿者的前臂屈侧皮肤进行了受CO_2激光照射后的急性损伤阈值测定,其值为2.3J/cm~2.用该能量密度照射后皮肤的组织学检查,发现其所引起的反应是最小反应,是可逆的.     

连续Nd~(3 ):YAG激光对视网膜损伤阈值的研究

连续Nd~(3 ):YAG激光照射青紫蓝灰兔眼100只,1000个照射点,求得照射时间平均1.02s及0.12s,检眼镜可见视网膜损伤阈值,其ED_(50)分别为角膜平均入射2.52W/cm~2及5.42W/cm~2.     

265毫微米脉冲激光辐照皮肤的损伤阈研究

本文探讨了265nm脉冲辐照皮肤所引起的紫外红斑.实验中明显地观察到紫外红斑的两相反应——延迟和瞬时红斑.概率统计分析表明,本实验所获得的猪皮肤最小红斑剂量(22.00mJ/cm~2)是可信的.     

Nd~(3 ):YAG调Q倍频激光对视网膜损伤阈值的研究

本文介绍Nd~(3 ):YAG调Q倍频激光对青紫蓝灰兔视网膜损伤阈值研究的材料、方法和结果.曝光时间8×10~(-9)s,ED_(50)为232.05μJ/cm~2.     

Epidermal and endosteal sources of endogenous electricity ininjured canine limbs

Endogenous electricity associated with musculoskeletal injuries was investigated in injured forelegs of anesthetized adult dogs to identify the endogenous sources and to understand their possible role in healing. Voltages and currents in the injury were measured in progressive stages ranging from a skin incision to an osteotomy of the radius. A circuit model was then developed for the injured limb, and the injury potentials and injury currents were deduced from the measured results. The skin injury activated an epidermal battery (17-42 mV) and bone injury activated an endosteal battery (15-56 mV), both of which drove currents into the injury. The return flow of these currents away from the injury site were along the subdermal soft-tissue surface (10-32 μA) and periosteal bone surface (8-23 μA) and through the medullary canal (2-7 μA); there was also a net outward flow of 10-17 μA through the osteotomy. The epidermal battery was identified as the primary source of the injury currents on the periosteal surface of bone. The currents in the medullary canal and through the osteotomy were primarily due to the endosteal battery     

Charge density and charge per phase as cofactors in neural injuryinduced by electrical stimulation

The possibility of neural injury during prolonged electrical stimulation of the brain imposes some constraints on the use of this technique for therapeutic and experimental applications. Stimulating electrodes of various sizes were used to investigate the interactions of two stimulus parameters, charge density and charge per phase, in determining the threshold of neural injury induced by electrical stimulation. Platinum electrodes ranging in size from 0.002 to 0.5 cm2 were implanted over the parietal cortex of adult cats. Penetrating microelectrodes fabricated from iridium, with surface areas of 65 +/- 3 x 10(-6) cm2 were inserted into the parietal cortex. Ten days after implantation, the electrodes were pulsed continuously for 7h using charge balanced, current regulated, symmetric pulse pairs, 400 microseconds per phase in duration, at a repetition rate of 50 Hz. The animals were perfused immediately after the stimulation for histologic evaluation of the brain tissue subjacent to the electrode sites. The results show that charge density (as measured at the surface of the stimulating electrode), and charge per phase, interact in a synergistic manner to determine the threshold of stimulation-induced neural injury. This interaction occurs over a wide range of both parameters; for charge density from at least 10 to 800 microC/cm2 and, for charge per phase, from at least 0.05 to 5.0 microC per phase. The significance of these findings in elucidating the mechanisms underlying stimulation-induced injury is discussed.     

A comparative study of human skin thermal response to sapphirecontact and cryogen spray cooling

Surface cooling, in conjunction with various thermally mediated therapeutic procedures, can provide a means to protect superficial tissues from injury while achieving destruction of deeper targeted structures. We have investigated the thermal response of in-vivo human skin to: (1) contact cooling with a sapphire window (6-12°C); and (2) spray cooling with a freon substitute cryogen [tetrafluoroethane; boiling point ≈-26°C at 1 atmospheric pressure (atm)]. Measurements utilizing infrared radiometry show surface temperature reductions from 30°C to 14-19°C are obtained within approximately is in response to sapphire contact cooling. Surface temperature reductions to values between 5°C and -9°C are obtained in response to 20-100-ms cryogen spurts. Computational results, based on fitting the measured radiometric surface temperature to estimate heat transfer parameters, show: (1) temperature reductions remain localized to approximately 200 μm of superficial tissue; and (2) values of heat flux and total energy removed per unit skin surface area at least doubled when using cryogen spray cooling     

氩激光照射视网膜损伤阈值的研究

本文介绍氩激光照射兔眼、猴眼及人眼视网膜损伤阈值研究的材料、方法与结果.     

Platelet‐Inspired Nanocells for Targeted Heart Repair After Ischemia/Reperfusion Injury

Cardiovascular disease is the leading cause of mortality worldwide. While reperfusion therapy is vital for patient survival post‐heart attack, it also causes further tissue injury, known as myocardial ischemia/reperfusion (I/R) injury in clinical practice. Exploring ways to attenuate I/R injury is of clinical interest for improving post‐ischemic recovery. A platelet‐inspired nanocell (PINC) that incorporates both prostaglandin E2 (PGE₂)‐modified platelet membrane and cardiac stromal cell‐secreted factors to target the heart after I/R injury is introduced. By taking advantage of the natural infarct‐homing ability of platelet membrane and the overexpression of PGE₂ receptors (EPs) in the pathological cardiac microenvironment after I/R injury, the PINCs can achieve targeted delivery of therapeutic payload to the injured heart. Furthermore, a synergistic treatment efficacy can be achieved by PINC, which combines the paracrine mechanism of cell therapy with the PGE₂/EP receptor signaling that is involved in the repair and regeneration of multiple tissues. In a mouse model of myocardial I/R injury, intravenous injection of PINCs results in augmented cardiac function and mitigated heart remodeling, which is accompanied by the increase in cycling cardiomyocytes, activation of endogenous stem/progenitor cells, and promotion of angiogenesis. This approach represents a promising therapeutic delivery platform for treating I/R injury.     

电针足三里对脓毒症大鼠促炎症因子所致心肌损伤的保护作用

目的研究电针足三里穴(ST36)对脓毒症大鼠促炎症因子所致心肌损伤的保护作用。方法雄性SD大鼠32只,采用盲肠结扎穿孔术(CLP)制备大鼠脓毒症模型,随机分为电针(Electro-Acupuncture,EA)足三里组(EA组)、CLP+假电针(ShameEA)组(SEA组)、迷走神经切断(Vagotomy,VA)+CLP组(VA组)和迷切后CLP再电针组(VA/EA组)4组,每组8只。EA组持续针刺双侧足三里穴1h(2mA,2-100Hz);SEA组采用相同频率和强度刺激非经非穴(足三里穴外侧旁开0.5cm)。VA组先切断腹腔迷走神经再施行CLP术。各组大鼠于CLP术后6h,取血检测血浆肌酸激酶同工酶(CK-MB)活性;然后处死动物,取心肌组织,测定肿瘤坏死因子-α(TNF-α)水平、一氧化氮(NO)含量、随过氧化物酶(MPO)活性以及组织含水率。结果CLP术后6h,EA组心肌组织促炎症因子TNF-α、NO、MPO水平、CK-MB活性以及组织含水率均显著低于其余3组(P<0.05);VA/EA组和VA组TNF-α、NO、MPO水平、CK-MB活性及组织含水率均高于SEA组(P<0.05);VA/EA组与VA...     

半导体绿色激光穴位照射对大鼠神经损伤后神经再生的影响

周围神经损伤后提高神经功能恢复是临床治疗的目的.本实验利用大鼠坐骨神经钳夹损伤模型,用半导体绿色激光533nm(A组)、He-Ne激光632.8nm(B组)对穴位照射.观察对神经损伤后神经再生的影响.结果:(1)术后18d,A组可引出短潜伏期(45～150ms)及长潜伏期(125～525ms)神经传入纤维反应高于B组;(2)术后18d脊神经节的标记细胞百分率分别为12.9%(A组)、10.2%B(组).上述结果表明:半导体绿色激光在抑制神经损伤后促进周围神经再生等方面具有更显著的生理功效.     

Functional electrical stimulation [bioengineering]

Functional electrical stimulation (FES) or functional neuromuscular stimulation (FNS) is the name that has been given to the controlled stimulation of muscles in order to return some function. After a spinal injury, muscle wastes very rapidly, particularly in the large muscles of the thigh. The author shows that routine stimulation of muscles with an exercise stimulator over many weeks or months, often for 1-2 hours a day, is needed to bring the muscle bulk back to the level where it can support the person when standing. It is only at this point that any kind of ambulation can be attempted     

输尿管镜气压弹道碎石术严重并发症的防治

目的探讨输尿管镜气压弹道碎石严重并发症与预防措施。方法总结分析输尿管镜气压弹道碎石治疗患者的资料,统计并发症的发生和处理情况。结果输尿管穿孔3例,输尿管口损伤2例,输尿管黏膜下假道形成3例,输尿管断裂1例,输尿管全层黏膜撕脱1例。结论输尿管镜下取石术并发症的发生与手术者的技术操作密切相关,正确熟练地操作可有效减少并发症。