Comparison of microscopic features of bone false starts produced by reciprocating saw blades and handsaws of the same class

In cases of criminal dismemberment, the analysis of saw marks helps to determine the class of the saw used. The present study compared the microscopic features of experimental false starts performed on three freshly defleshed human femurs. 150 lesions were produced using three reciprocating blades and two hand saws of similar class. Two groups of tools were created according to the class of the blades: group 1 (teeth per inch = 6, alternating set) and group 2 (teeth per inch = 24, wavy set).The minimum width of the kerf was always thicker with reciprocating blades than that of the handsaw of the same class. This fact is linked to the thickness of the blades and not necessarily to the fast forth and back motion of the blades. Shape kerf profiles and shape of the walls were very confusing, with a lot of variation of the false starts caused by the reciprocating blades and the risk of misclassification (rip teeth versus crosscut teeth, alternating set versus wavy set). Striae on the kerf floor and bone islands were more consistent.The main conclusions are, first, that usual features of false starts achieved by reciprocating saw blades used in this work vary a great deal and may lead to misclassification of the saw class, and second, that no criterion has been found to differentiate reciprocating blades and handsaws. These results demonstrate that we have to be very prudent while estimating the possible saw from a false start in a real forensic case.     

Alternating Skew Deviation from Traumatic Intracranial Hypotension

A 56-year-old woman developed progressive headache, mental status changes, and diplopia after trauma. She was diagnosed with alternating skew deviation caused by intracranial hypotension. This is the first case of alternating skew deviation reported from intracranial hypotension and perhaps a differential pressure between intracranial and intraspinal spaces plays a role in the development of these findings.     

儿童交替性偏瘫一例

目的了解儿童交替性偏瘫(AHC)的诊断及治疗方法的合理选择。方法介绍我院收治的1例难治的儿童交替性偏瘫患儿的临床特点,检索国内外10年内的相关文献。结果本病的临床特点为反复发作性的偏瘫,睡眠后缓解,可有其他发作性症状,如发作性肌张力障碍、眼球运动异常和认知障碍等。氟桂利嗪是最常用的药物,托吡酯片、阿立哌唑也可用于治疗本病。结论本病是一种罕见的神经系统发作性疾病,临床表现多样,容易误诊,目前没有标准的治疗方法。     

低频重复经颅磁刺激治疗老年人失眠症的疗效观察

目的 观察低频重复经颅磁刺激（rTMS）对失眠症老年人睡眠和情绪的影响。 方法 选取34例失眠症老年患者,按照随机数字表法将其分为试验组（18例）和对照组（16例）。试验组采用低频rTMS刺激右背外侧前额叶皮质（DLPFC)治疗,对照组给予交变磁场治疗。治疗前及治疗4周后（治疗后）,使用匹兹堡睡眠质量指数(PSQI)、汉密尔顿焦虑量表(HAMA)和汉密尔顿抑郁量表(HAMD)对患者进行评估。为了消除睡眠变化对患者HAMA和HAMD评分的影响,对此两项评分去除睡眠相关项得分后的分值（标记为HAMA-A、HAMD-A）进行评估。 结果 治疗前,2组患者的PSQI、HAMA和HAMD评分比较,差异无统计学意义（P>0.05）。治疗后,试验组与对照组患者的PSQI、HAMA、HAMD评分均明显下降（P<0.05）,且试验组PSQI［(8.44±1.82)分］、HAMA［(10.66±2.59)分］、HAMD［(11.78±3.64)分］较对照组低,差异有统计学意义（P<0.05）。除去HAMA与HAMD的睡眠相关选项得分后,试验组患者治疗后HAMA-A、HAMD-A较组内治疗前低（P<0.05）,对照组患者治疗后HAMA-A、HAMD-A虽较组内治疗前低,但差异无统计学意义（P>0.05）。试验组患者治疗后HAMA-A［(11.11±2.72)分］、HAMD-A［(10.17±3.28)分］较对照组低（P<0.05）。 结论 rTMS治疗老年失眠症的疗效优于交变磁场,能显著改善患者睡眠和情绪。     

Fe_3O_4磁纳米介导磁感应治疗Wistar大鼠Walker-256肿瘤

目的探讨Fe3O4磁性纳米微球磁感应对Wistar大鼠Walker-256肿瘤的治疗作用。方法荷瘤鼠随机分为NS组（注入生理盐水而不接受磁场处理）、MF组（注入磁流体而不接受磁场处理）、MFH1组（注入磁流体在交变磁场中治疗1次）、MFH2组（治疗2次）和MFH3组（治疗3次）,共5组。治疗温度控制在50～55℃,分别观察肿瘤体积抑制率和生存期,以及肿瘤的病理改变。结果MFH2组和MFH3组的肿瘤在2周内有明显的肿瘤体积抑制作用,肿瘤体积抑制率分别为（65.0±3.5）%、（71.6±4.2）%。与NS组（35.5±5.6）d比较,MFH3组（41.9±6.5）d和MFH2组（42.1±5.0）d的生存期延长,差异有统计学意义（q=4.386,P〈0.05;q=4.558,P〈0.05）;MFH1组（39.0±5.3）d和MF组（36.1±6.6）d的生存期差异无统计学意义（q=2.406,P〉0.05）。NS、MF组肿瘤表面光滑,小灶性坏死区;癌细胞密度大,核仁明显,易见核分裂相。MFH2和MFH3组瘤内大片坏死残留的无结构红染物质,或空洞,部分胞核有固缩、碎裂及崩解。结论Fe3O4纳米磁流体介导的磁热疗能抑制大鼠Walker-256皮下肿瘤增殖。     

磁流体肿瘤热疗的研究进展

肿瘤治疗的方法层出不穷,手术、放疗与化疗依然是当前治疗的主要手段。随着科技的进步,尤其是物理医学与医学影像学的发展,物理治疗逐渐成为医学与工程界的研究热点,其中热疗是目前国内外学者研究的热点之一。针对磁流体热疗,从工程学角度和临床实验两方面详细介绍了磁流体材料的制作、交变磁场发生设备的开发以及磁流体热疗实验、动物试验和...     

Safety of 5 kHz tACS

BackgroundSinusoidal transcranial alternating current stimulation (tACS) at 5 kHz applied for 10 min at 1 mA intensity over the hand area of the primary motor cortex (M1) results in sustained changes in cortical excitability as previously demonstrated.ObjectiveHere we have assessed safety aspects of this stimulation method by measuring neuron-specific enolase (NSE) levels, examining electroencephalogram (EEG) traces and analyzing anatomical data by using magnetic resonance imaging (MRI).MethodsAltogether 18 healthy volunteers participated in the study. tACS was applied at 5 kHz for a duration of 10 min over the left M1 at an intensity of 1 mA.ResultsAfter stimulation no significant changes were detected in NSE levels, no structural alterations were observed in the anatomical scans and no pathological changes were found in the EEG recordings.ConclusionsOur data imply that the application of tACS is safe at least within these parameters and with these applied protocols.     

Effects of scopolamine on variable intertrial interval spatial alternation and memory in the rat

A repeated measures procedure, variable intertrial interval (ITI) spatial alternation, was used to assess scopolamine effects on memory, and to compare effects of the drug on discrimination processes with effects on storage. Rats learned in two stages to press left and right levers in alternation on discrete trials separated by 5 different ITI's ranging from 2.5 to 40 s and presented in random order during the experimental session. In the first stage, alternating discrimination, alternation was controlled by a light on over the correct lever at the time of the trial; in the second stage, variable ITI spatial alternation, a centrally located panel light signalled all trials and alternation was controlled by stimuli from prior trials (memory). Alternation response occurrence declined moderately (but significantly) with increasing ITI duration in both the alternating discrimination and variable ITI spatial alternation stages; response occurrence was also significantly decreased by scopolamine treatment in both stages. Accuracy of alternating discrimination performance was not significantly altered by either ITI duration or scopolamine treatment. Accuracy of variable ITI spatial alternation performance on a trial varied inversely with the duration of the ITI that preceded the trial. Scopolamine treatment significantly reduced accuracy of lever pressing in variable ITI spatial alternation but did not alter the slope of the curves relating accuracy to ITI duration. These effects indicate that the drug impaired discrimination processes but did not alter memory storage.