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排序方式: 共有229条查询结果,搜索用时 15 毫秒
81.
Neal Gutterson 《Acta Botanica Sinica》2011,(3)
Selection of energy crops is the first priority for large-scale biofuel production in China. As a major topic, it was extensively discussed in the Second International Symposium on Bioen- 相似文献
82.
Claus C Chey S Heinrich S Reins M Richardt B Pinkert S Fechner H Gaunitz F Schäfer I Seibel P Liebert UG 《Journal of virology》2011,85(8):3881-3892
The interaction of the rubella virus (RV) capsid (C) protein and the mitochondrial p32 protein is believed to participate in virus replication. In this study, the physiological significance of the association of RV with mitochondria was investigated by silencing p32 through RNA interference. It was demonstrated that downregulation of p32 interferes with microtubule-directed redistribution of mitochondria in RV-infected cells. However, the association of the viral C protein with mitochondria was not affected. When cell lines either pretreated with respiratory chain inhibitors or cultivated under (mild) hypoxic conditions were infected with RV, viral replication was reduced in a time-dependent fashion. Additionally, RV infection induces increased activity of mitochondrial electron transport chain complex III, which was associated with an increase in the mitochondrial membrane potential. These effects are outstanding among the examples of mitochondrial alterations caused by viruses. In contrast to the preferential localization of p32 to the mitochondrial matrix in most cell lines, RV-permissive cell lines were characterized by an almost exclusive membrane association of p32. Conceivably, this contributes to p32 function(s) during RV replication. The data presented suggest that p32 fulfills an essential function for RV replication in directing trafficking of mitochondria near sites of viral replication to meet the energy demands of the virus. 相似文献
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AA Bozzo CA Soñez I Monedero Cobeta A Rolando MC Romanini D Cots 《Biotechnic & histochemistry》2014,89(4):296-303
The model of chronic intermittent stress by immobilization during pregnancy may produce alterations in the mechanisms that maintain adrenal gland homeostasis. In earlier investigations using this model, significant variations in plasma prolactin and corticosterone levels, and adrenal gland weights were observed. We hypothesized that chronic stress causes changes in apoptosis in the adrenal glands of pregnant rats. We identified and quantified apoptotic cells in the adrenal cortex and examined their ultrastructural characteristics using transmission electron microscopy. Adrenal glands of pregnant rats at gestation days 12, 17 and 21 were studied for control and experimental (stressed) rats. Immunolabelling techniques, stereological analysis and image quantification of adrenal gland sections were combined to determine differences in apoptosis in the different cell populations of the adrenal cortex. The apoptotic index of the experimental rats showed a significant reduction at gestation day 17, while at days 12 and 21 there were no differences from controls. Moreover, the apoptotic index of the reticular zones in control and experimental animals showed a significant increase compared to the glomerular and fascicular zones at the three gestation times studied. Chronic stress by immobilization reduced the caspase-dependent apoptotic index at gestation day 17, which may be related to variations in plasma concentrations of estrogens and prolactin. 相似文献
85.
Dorota Jezierska Krystyna Adamska W?odzimierz Liebert 《Reports of Practical Oncology and Radiotherapy》2014,19(1):19-29
Aim
The purpose of our review was to evaluate results of radiosurgery for patients with brain metastases from lung cancer.Background
Lung cancer is the leading cause of death from cancer and the most common source of brain metastases. Radiosurgery allows the precise focal delivery of a high single radiation dose to brain metastases and results in high rates of local control.Materials and methods
83 patients were treated between 2006 and 2008. We evaluated local control and outcome after radiosurgery and identified prognostic factors.Results
Median survival in the whole group was 7.8 months from radiosurgery and 11 months from diagnosis. Median survival in classes I, II and III was 13.2, 8.2 and 2.2 months. For 94% of patients symptoms improved or stabilised at the first follow-up visit and this status did not change during 7.1 months. According to the univariate analysis, factors associated with improved survival included: RPA class 1 compared with RPA 2 and 3, RPA class 2 compared with RPA 3, KPS > 70, control of the primary disease, radiosurgery performed more than once, level of haemoglobin >7 mmol/1, absence of extracranial metastases, volume of the biggest lesion <11 cm3. The multivariate analysis confirmed a significant influence on survival for the following factors: RPA class 1 as compared with RPA 3, KPS > 70, absence of extracranial metastases, multiplicity of radiosurgery.Conclusions
Stereotactic radiosurgery is a safe and effective treatment. It proved to be effective and safe in older patients. Selection of patients who are likely to benefit most should be based on prognostic factors. KPS proved to be the most important prognostic factor. In the RPA III group (patients with KPS < 70) survival time was similar to that achieved after symptomatic medical management. 相似文献86.
BACKGROUND: Current knowledge about the optimal energy and nutrient supply for common marmoset monkeys (Callithrix jacchus) is scarce, and more information is needed for establishing the underlying nutritional concepts for facilitating longevity of this species as laboratory animals for biomedical research. Methods: Two feeding experiments were conducted to yield fundamental data about feed acceptance, real feed intake, and feed preferences under laboratory conditions. Newly developed feeding concepts for marmoset monkeys were also examined in preliminary investigations to compare the outcomes with those of a commercial pelletized mixed feed. RESULTS: The first experiments showed preferences for main protein sources in the diets studied, specifically that plant proteins are more accepted than fish meal or egg protein as the main protein source. Several aroma supplements did not modify the acceptance and feed intake markedly. Conclusions: The newly developed feeding concept yielded promising preliminary data for long-term studies of energy and nutrient supply under laboratory conditions. However, studies of the fundamental requirements are still needed. 相似文献
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角果碱蓬(Suaeda corniculata)是藜科一年生盐生植物, 在我国分布于北方盐碱滩涂和盐碱荒漠地区。角果碱蓬具有棕色和黑色两种异型体种子(简称棕色和黑色种子)。对采自内蒙古鄂托克前旗盐渍化生境的角果碱蓬二型种子的形态、休眠和萌发特性开展对比研究, 测定了二型种子休眠和萌发行为对温度、光照和盐分(NaCl)的响应, 以揭示盐生植物异型种子对温带盐漠生境的适应对策。结果表明: (1)二型性种子在大小、种皮特性和结实比例方面有显著差异。与黑色种子相比, 棕色种子个体较大, 种皮透水性强。黑色种子与棕色种子的结实比例约为5.6 : 1。(2)新成熟的棕色种子的萌发对各温度梯度和光照条件不敏感, 萌发率较高(84%-100%); 而新成熟的黑色种子萌发率较低(8%-78%), 萌发对光照敏感。(3)黑色种子具有浅度生理休眠, 种皮划破、赤霉素处理和低温层积均可有效地提高种子的萌发率。(4)二型种子萌发对土壤盐分的胁迫具有不同的响应。与黑色种子相比, 棕色种子对盐分胁迫不敏感, 在较高的盐分浓度下仍有较高的萌发率, 低温层积处理能够降低黑色种子对盐胁迫的敏感性, 有效地提高种子的初始萌发率、萌发恢复率和最终萌发率。角果碱蓬二型种子不同的形态、休眠和萌发特性, 提高了该物种在高度异质性生境中的适合度, 对种群成功地适应温带盐漠环境具有重要的意义。 相似文献
90.