TS-254型拖拉机转向机下垂臂轴锻造工艺

此文对TS-254型拖拉机转向机下垂臂轴的制坯工艺、模具结构设计作了介绍,同时对锻造过程容易出现的典型问题和锻造缺陷进行了分析,并提出了解决问题和避免缺陷的措施。

更换主轴瓦的简便方法

一台6130ZD型柴油发电机组,主轴瓦磨损较重需更换。按常规方法需要卸掉机体的大部分零部件,把曲轴取下来才行,是相当费工的。在不需要修磨,更换曲轴的情况下,笔者采用了不卸曲轴前后端的零件,也不取下曲轴而换主轴瓦的简便方法,证明可行。 将油底壳内的机油放出,并卸下油底壳。打开飞轮检视窗,以便拨动飞轮,使曲轴转动。

EFFECTS OF ACUPUNCTURE ON THE HYPOTHALAMUS-PITUITARY-OVARY AXIS IN RATS WITH DYSMENORRHEA

Objective To observe the influence of acupuncture on hypothalamus-pituitary-ovary axis （HPOA） in rats with primary dysmenorrhea, and to explore its mechanisms. Methods Effects of acupuncture on the concentration level of β-endorphin （β-EP）, hypothalamic hormone （gonadotropin-releasing hormone, GnRH）, pituitary hormone （GnRH receptor GnRH-R, follicle stimulating hormone FSH, luteinizing hormone LH） and ovarian hormone （estrodiol E2, estrodiol receptor ER, progesterone P and progesterone receptor PR） were observed in dysmenorrheic rats. Results After receiving acupuncture treatment, the levels of 13- EP, GnRH, GnRH-R, FSH, LH, E2, ER, P and PR were changed, and this suggested that acupuncture had a regulative action on HPOA in dysmenorrheic rats. Conclusion The mechanism of acupuncture acting on the HPOA with primary dysmenorrhea might be its regulating role to the gonadal hormone of HPOA and its corresponding receptor expression.

Distribution of Oxytocin Hypothamic-Picuitary-Ovary Axis in Guangxi Local Buffalo

To study the association of oxytocin (OT)'s distribution in hypothalamatic,pituitary and ovary,and understand how the OT secrete releasing in hypothalamus,pituitary and ovaries,the paraffin section immunohistochemistry SuperPicTureTM two step method was used to detect the distribution of OT in hypothalamatic-pituitary-ovary axis of five femal Guangxi local buffalo. The test results could provide morphology according to study the OT's synthesis and mechanism of action,and could play reference and directions part in breeding Guangxi local buffalo. The test results display:oxytocin immuno reactive (OT-IR) neuronsw eremainly distributed arcuate nucleus,supraoptic nucleus and paraventricular nucleus,and OT-IR neurons was also found in ventromedial nucleus,ventrolateralis nucleus,suprachiasmaticus nucleus,dorsomedial nucleus,mamillary body,anterior hypothalamic nucleus and so on. The OT immunoactive production was found in pituitary and few OT-IR nerve fibers extended to post pituitary from hypophyseal stalk and medium eminence. In ovaries,OT immunoactive productions were only distributed in germinal epithelium cells,granulosa cells and lutein cells. The OT was first discovered in singulorum link of hypothalamatic-pituitary-ovary axis of Guangxi local buffalo. The OT immunoactive neurons were first discovered in every main nucleus of Guangxi local buffalo hypothalamus,especially distributed in arcuate nucleus,supraoptic nucleus and paraventricular nucleus.

Sini Powder extract produces antidepressant-like effects in a chronic social defeat stress model of depression in tree shrews

Sini Power（SP） is a famed traditional Chinese formula that has long been used to treat depression. Here, we investigated the effects and possible mechanisms of SP extract on an established model of depression： chronic stressed tree shrew, which mimics the human condition of social stress. The animals were divided into 4 groups. Except for the na？ve group, the other animals were subjected to daily social defeat stress for 5 weeks, and during the last 4 weeks treated with SP extract（3.6 g/kg/d）, fluoxetine（15 mg/kg/d）, and vehicle, respectively. The results showed that SP extract could reverse body weight loss to a certain extent and reduce the levels of urine/serum cortisol that were initially increased by chronic social defeat. In addition, SP extract increased hippocampus norepinephrine concentrations. Our data suggested that SP extract had positive effects on the main depression symptoms in the chronic stressed tree shrew model and that it may be used to help control hypothalamic-pituitary-adrenal axis hyperactivity.

Increased expression level of corticotropin-releasing hormone in the amygdala and in the hypothalamus in rats exposed to chronic unpredictable mild stress

Objective Corticotropin-releasing hormone（CRH）plays an important role in neuroendocrine,autonomic and behavioral responses to stressors.In the present study,the effect of chronic unpredictable mild stress（CUMS）on CRH neurons was investigated in rat brain.Methods The rats were exposed to one of the stressors each day for 21 d.Immunostaining was performed to detect the CRH-positive neurons in the paraventricular nucleus（PVN）of the hypothalamus and in amygdala.Results After the stress protocol,the animals showed a reduction in body weight gain as well as reduced sucrose preference and locomotor activity.Interestingly,the CRH neurons in both PVN and central nucleus of the amygdala（CeA）were stimulated by CUMS.The densities of CRH-containing neurons in both PVN and CeA were significantly higher than those in control group.Conclusion The CRH systems in PVN and CeA may both contribute to depression-like behaviors during CUMS.

Effects of neuro-immuno-modulation on healing of wound combined with local radiation injury in rats

Purpose： To investigate effects of neuro-immuno-modulation on wound healing by observing changes of cytokines and hypothalamic-pituitary-adrenal （HPA） axis hormones in acute stress reaction in rats with wound and combined local radiation injury. Methods： Sixty female Wistar rats （weighting 200 ± 20 g） were randomly divided into normal control group, wound group and combined wound-local radiation （CWR） group （25 Gy local radiation post wound）, 20 rats in each group. Contents of IL-1β, IL-6 and IFN-γ and IL-4 in serum were measured and changes of adrenocorticotropic hormone （ACTH） and glucocorticoid （GC） in serum were analyzed by using enzyme-linked immunosorbent assay and radioimmunologic assay, respectively at different time points post wound and radiation. Results： （1） The level of IFN-γ, one of the Thl cell cytokines increased significantly at 14 d post CWIL which was markedly higher than that in control group and wound group. However, the level of IL-4, IL-1β and IL-6, one of the Th2 cell cytokines, did not show obvious change. （2） Ratio of Thl/Th2 （IFN-γ/IL-4） in wound group and CWR group increased significantly at 7 d after wound and radiation, which suggested that Thl/Th2 balance drifted to Thl immune response. The ratio of Thl/Th2 in wound group returned to the normal level up to 14 d after the wound and radiation, while the Thl/Th2 ratio in CWR group increased persistently and was much higher than that in control and wound groups. （3） Level of serous ACTH and CC in CWR group increased at 3 d post wound and radiation, and among them, level of CC showed statistically significant increase, which was much higher than that in control and wound groups. Conclusion： Level of serous neurohormone CC in rats increased significantly immediately after wound and radiation; while the level of IFN-γ showed significant increase only up to 14 d after wound and radiation, and the Th1/Th2 imbalance sustained till 28 d post wound and radiation. In order to reduce acute damage caused by CWR, organic immune system and nerve system showed up a marked regulate effects simultaneously and mutually. Nonetheless, the excessive stress induced by CWR causes distur- bance of immunoregulation, which is one of the key reasons for delayed wound healing in CWR.