视剥夺及视剥夺学习后Jun样蛋白在雏鸡两侧半球中不同表达的研究

该实验利用免疫组化技术,在已有实验的基础上进一步观察比较了左眼视剥夺及单眼学习后,Ｊｕｎ样蛋白在雏鸡两侧半球ＨＶ和ＬＰＯ中表达的差异。实验结果表明：１．视剥夺２、２４、４８、７２小时后观测到Ｊｕｎ样蛋白在左、右半球ＨＶ和ＬＰＯ中的表达逐渐增高,并且于视剥夺４８小时表达到达峰值。同时仅在视剥夺２小时后观测到两半球ＬＰＯ中Ｊｕｎ样蛋白的表达存在差异,在其余各视剥夺时程中两侧半球的ＬＰＯ、ＨＶ中Ｊｕｎ样蛋白的表达均无显著差异。２．视剥夺２小时和２４小时后均在学习后７０分钟组中观测到Ｊｕｎ样蛋白在左、右半球的ＨＶ和ＬＰＯ中表达的显著升高,而在视剥夺２小时学习后１０分钟只观测到左半球ＨＶ和ＬＰＯ中Ｊｕｎ样蛋白表达的显著升高,在视剥夺２４小时学习后１０分钟中仅观测到左半球ＬＰＯ中Ｊｕｎ样蛋白的显著升高。同时也仅在视剥夺２小时学习后１０分钟观测到两侧半球ＨＶ、ＬＰＯ中Ｊｕｎ样蛋白表达的显著性差异。３．无论单纯视剥夺组还是单眼学习组,各组同侧半球中ＬＰＯＪｕｎ样蛋白的表达显著高于ＨＶ的Ｊｕｎ样蛋白的表达现象在视剥夺４８小时后消失。     

Partial body weight support treadmill training speed influences paretic and non-paretic leg muscle activation,stride characteristics,and ratings of perceived exertion during acute stroke rehabilitation

BackgroundIntensive task-specific training is promoted as one approach for facilitating neural plastic brain changes and associated motor behavior gains following neurologic injury. Partial body weight support treadmill training (PBWSTT), is one task-specific approach frequently used to improve walking during the acute period of stroke recovery (<1 month post infarct). However, only limited data have been published regarding the relationship between training parameters and physiologic demands during this early recovery phase.ObjectiveTo examine the impact of four walking speeds on stride characteristics, lower extremity muscle demands (both paretic and non-paretic), Borg ratings of perceived exertion (RPE), and blood pressure.DesignA prospective, repeated measures design was used.MethodsTen inpatients post unilateral stroke participated. Following three familiarization sessions, participants engaged in PBWSTT at four predetermined speeds (0.5, 1.0, 1.5 and 2.0 mph) while bilateral electromyographic and stride characteristic data were recorded. RPE was evaluated immediately following each trial.ResultsStride length, cadence, and paretic single limb support increased with faster walking speeds (p ⩽ 0.001), while non-paretic single limb support remained nearly constant. Faster walking resulted in greater peak and mean muscle activation in the paretic medial hamstrings, vastus lateralis and medial gastrocnemius, and non-paretic medial gastrocnemius (p ⩽ 0.001). RPE also was greatest at the fastest compared to two slowest speeds (p < 0.05).ConclusionsDuring the acute phase of stroke recovery, PBWSTT at the fastest speed (2.0 mph) promoted practice of a more optimal gait pattern with greater intensity of effort as evidenced by the longer stride length, increased between-limb symmetry, greater muscle activation, and higher RPE compared to training at the slowest speeds.     

Cascade effects on the irradiation stability of amorphous SiOC

We studied the heavy ion radiation tolerance of amorphous silicon oxycarbide (SiOC) alloys by in situ Kr ion irradiation within a transmission electron microscopy. The amorphous SiOC thin films were grown via co-sputtering from SiO₂ and SiC targets on a surface-oxidized Si (100) substrate. These films were irradiated by 1 MeV Kr ions at both room temperature and 300 °C with damage levels up to 5 displacements per atom (dpa). TEM characterization shows no sign of crystallization, void formation or segregation in all irradiated samples. Our findings suggest that SiOC alloys are a class of promising radiation tolerant materials.     

Hydrogen-assisted damage in austenite/martensite dual-phase steel

For understanding the underlying hydrogen embrittlement mechanism in transformation-induced plasticity steels, the process of damage evolution in a model austenite/martensite dual-phase microstructure following hydrogenation was investigated through multi-scale electron channelling contrast imaging and in situ optical microscopy. Localized diffusible hydrogen in martensite causes cracking through two mechanisms: (1) interaction between {1?1?0}_M localized slip and {1?1?2}_M twin and (2) cracking of martensite–martensite grain interfaces. The former resulted in nanovoids along the {1?1?2}_M twin. The coalescence of the nanovoids generated plate-like microvoids. The latter caused shear localization on the specific plane where the crack along the martensite/martensite boundary exists, which led to additional martensite/martensite boundary cracking.     

Hemispheric connectivity and the visual–spatial divergent-thinking component of creativity

Background/hypothesis

Divergent thinking is an important measurable component of creativity. This study tested the postulate that divergent thinking depends on large distributed inter- and intra-hemispheric networks. Although preliminary evidence supports increased brain connectivity during divergent thinking, the neural correlates of this characteristic have not been entirely specified. It was predicted that visuospatial divergent thinking would correlate with right hemisphere white matter volume (WMV) and with the size of the corpus callosum (CC).

Methods

Volumetric magnetic resonance imaging (MRI) analyses and the Torrance Tests of Creative Thinking (TTCT) were completed among 21 normal right-handed adult males.

Results

TTCT scores correlated negatively with the size of the CC and were not correlated with right or, incidentally, left WMV.

Conclusions

Although these results were not predicted, perhaps, as suggested by Bogen and Bogen (1988), decreased callosal connectivity enhances hemispheric specialization, which benefits the incubation of ideas that are critical for the divergent-thinking component of creativity, and it is the momentary inhibition of this hemispheric independence that accounts for the illumination that is part of the innovative stage of creativity. Alternatively, decreased CC size may reflect more selective developmental pruning, thereby facilitating efficient functional connectivity.     

Socrates on How Wrongdoing Damages the Soul

There has been little scholarly attention given to explaining exactly how and why Socrates thinks that wrongdoing damages the soul. But there is more than a simple gap in the literature here, we shall argue. The most widely accepted view of Socratic moral psychology, we claim, actually leaves this well-known feature of Socrates’ philosophy absolutely inexplicable. In the first section of this paper, we rehearse this view of Socratic moral psychology, and explain its inadequacy on the issue of the damaging consequences of wrongdoing. We then go on to provide our own account of the way in which injustice damages the soul, and then draw conclusions about how Socratic moral psychology should be understood.     

心理应激与DNA损害

心理应激不仅能使人的行为特征发生变化,而且也能使人的生理状况发生改变,因此,被认为是某些身心疾病的诱因。在此过程中,DNA损害是心理应激造成的最终结果之一。有关DNA损害,虽然以往的研究者以人或动物为对象进行了一系列急性应激和慢性应激的实验研究,但是,心理应激是如何造成DNA损害的过程还不清楚,具体的生理心理机制还未阐明。该文利用健康心理学提出的理论模型对此进行了分析,阐述了心理应激与DNA损害之间联系的可能的机制,强调了氧化应激在这一过程中的重要作用。同时,为临床制订预防疾病的干预措施提供了思路     

中美医疗损害责任制度改革之比较研究

医疗损害责任已成为现代社会普遍的医疗法律问题。中美两国医疗损害责任制度改革正朝着相反的方向发展。诉讼机制在美国医疗损害责任中的作用由强变弱，医疗诉讼起诉由易变难，医疗损害赔偿由不限制到相对限制，行政管理式的医疗过错责任制度由无到逐渐提议。我国医疗损害责任制度改革恰恰相反，即诉讼制度的作用由弱变强、医疗损害起诉由难到易，医疗损害赔偿由相对限制到不限制、行政管理式的医疗过错责任制度从有到无。我国医疗损害责任制度的改革趋势值得反思。建议借鉴美国医疗损害责任制度改革的经验。     

Does exercise-induced muscle damage impair subsequent motor skill learning?

Motor skill learning is a fundamental aspect of human behavior based on the calibration of internal models via sensory information such as proprioception. Some conditions, as exercise-induced muscle damage (EIMD), disrupt proprioceptive information, and may cause learning impairment. Such possible relation between EIMD and motor skill learning has not yet been investigated and it is the aim of this study. For this purpose, thirty male university students (19.3 ± 1.8 years) were equally assigned to two groups: EIMD and CON group. The EIMD group received a treatment to induce muscle damage consisting of a weight lifting protocol directed to the agonist muscles related to the task prior to the pretest and to the learning sessions. EIMD was verified and compared between groups and along the process (0–168 h) by means of the degree of delayed onset muscle soreness (DOMS), perceived total quality recovery and maximal isometric strength (MIS). To investigate motor skill learning, both groups practiced a dart throwing task for four sessions with 150 trials in each session. Recovery status and DOMS were recovered at 96 h in the EIMD group, and MIS was not recovered throughout 168 h. In contrast, muscle damage parameters were not altered across 168 h in the CON group. Accuracy and consistency were compared within and between groups in a pretest posttest design. The EIMD group showed less accurate and consistent results on the long term (delayed posttest). Results confirmed our hypothesis that EIMD, a common condition in sports and in rehab practices, may hinder motor skill learning, possibly due to neurological aspects such as proprioceptive information, its relation to central nervous system reorganization and internal model consolidation.     

The effects of stress on dna repair capacity

Abstract

Research has shown that lymphocytes of high-distress patients have reduced DNA repair relative to that of low-distress patients and healthy controls. Furthermore, deficits in repair are associated with an increased risk of cancer. Using and academic stress model, we hypothesized that students would exhibit lower levels of Nucleotide Excision Repair (NER) during a stressful exam period when compared to a lower stress period. Participants were 19 healthy graduate level students. NER was measured in lymphocytes using the unscheduled DNA synthesis (UDS) assay with slide autoradiography. Contrary to prediction, mean values for NER significantly increased during the higher stress period relative to the lower stress period controlling for background differences in repair. Furthermore, lymphocytes had significantly increased repair of endogenous damage during the higher stress period. Stress appears to directly increase DNA repair. Additionally, stress may increase DNA repair indirectly by increasing damage to DNA.