全文获取类型
收费全文 | 532篇 |
免费 | 27篇 |
出版年
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2018年 | 13篇 |
2017年 | 10篇 |
2016年 | 15篇 |
2015年 | 14篇 |
2014年 | 16篇 |
2013年 | 41篇 |
2012年 | 25篇 |
2011年 | 30篇 |
2010年 | 30篇 |
2009年 | 26篇 |
2008年 | 25篇 |
2007年 | 32篇 |
2006年 | 22篇 |
2005年 | 34篇 |
2004年 | 29篇 |
2003年 | 23篇 |
2002年 | 22篇 |
2001年 | 9篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1974年 | 3篇 |
1973年 | 5篇 |
1971年 | 2篇 |
1969年 | 2篇 |
1968年 | 4篇 |
1966年 | 2篇 |
排序方式: 共有559条查询结果,搜索用时 265 毫秒
551.
Abstract It was previously reported that spleen cells of rabbits infected with Treponema pallidum produced anti-treponemal lymphotoxins (ATL). This ability was distinctly disturbed when circulating immune complexes (CIC) and autolymphocytotoxins (AL) were present in the sera of cell donors. ATL liberated from cells of donors without CIC and AL displayed a marked ability to immobilize treponemes. The percentage of immobilized treponemes varied according to the type of cells used for ATL liberation and their density. The most active was ATL from T cells (density 4 × 108 ml−1 ) and the weakest was the one from B lymphocytes. In the presence of CIC in sera of cell donors the weakest ATL was from macrophages and in the presence of AL from T lymphocytes. When both factors (CIC and AL) were present ATL from T lymphocytes did not immobilize treponemes. This seems to suggest that the impairment of the cells' ability to produce ATL may facilitate the survival of treponemes in the host despite the presence of immunologically competent cells. 相似文献
552.
Porcine luteal cells were obtained from corpora lutea on the 5th, 13th and 17th days of the estrous cycle. The cells were suspended at a concentration of 5 × 104 cells/ml in Eagle's medium with 2% human serum albumin. These cells were incubated with or without 0.01, 0.1, 1 or 10 μg/ml porcine prolactin. The amount of progesterone in cultures was estimated by a radio-immunological method after 30 min, 3 h and 6 h of culturing.Luteal cells obtained on the 5th day of the estrous cycle and incubated without prolactin secreted 71.24 ± 21.91 ng progesterone/ml of medium, whereas under the influence of prolactin at 0.01, 0.1, 1 and 10 μg/ml, 39.06 ± 13.33, 44.31 ± 12.69, 44.88 ± 16.85 and 51.62 ± 15.01 ng progesterone/ml (P<0.01) were secreted. Luteal cells from the 13th day of the estrous cycle incubated without prolactin secreted on average 70.72 ± 9.21 ng progesterone/ml of medium, whereas under the influence of different prolactin doses 50.75 ± 8.52, 46.54 ± 7.13, 43.30 ± 6.78 and 41.68 ± 7.21 ng progesterone/ml (P<0.01) were secreted.Prolactin did not change progesterone secretion by luteal cells obtained on the 17th day of the estrous cycle. An influence of the incubation time on progesterone secretion by these cells was observed: after 30 min of incubation the cells secreted 8.83 ± 2.95 ng/ml, after 3 h 8.12 ± 2.57 ng/ml and after 6 h 6.86 ± 1.91 ng/ml, irrespective of the amount of PRL added.The results suggest that prolactin plays a role in the luteolysis of the corpus luteum. 相似文献
553.
Plich Jarosław Zimnoch-Guzowska Ewa Tatarowska Beata Śliwka Jadwiga 《Molecular biology reports》2020,47(3):1713-1722
Molecular Biology Reports - A conversion of amyloplasts into chloroplasts in the potato tuber after light exposure is known as tuber greening and is one of the major causes of tuber loss. We report... 相似文献
554.
Magdalena Wiecek Marcin Maciejczyk Jadwiga Szymura Malgorzata Kantorowicz Zbigniew Szygula 《Redox report : communications in free radical research》2017,22(6):367-376
Objectives: The aim of the study was to evaluate the activity of xanthine oxidase (XO) in the blood of men and women during the first hour following a single anaerobic exercise (AN-EX), and after 24 hours of recovery, and to determine whether the changes in XO activity in the blood after AN-EX are dependent on anaerobic performance.Methods: Ten men and ten women performed a single AN-EX. Blood was collected before and five times after completion of the AN-EX. The activity of XO was determined.Results: In both groups, a significant (P?0.05) increase in blood XO activity was found only 24 hours after the AN-EX. The increased activity of XO in men was significantly lower than in women (P?0.05). Negative correlations were found between the increase in XO activity in the blood plasma 24 hours after the AN-EX and anaerobic power, the total work performed during the AN-EX and the power decrease.Discussion: In the first hour after the single AN-EX, XO activity in the blood of women and men did not change, but after 24 hours of recovery, it was significantly higher compared to baseline levels in both sexes. Single AN-EX causes a smaller increase in XO activity in people with higher anaerobic performance. 相似文献
555.
556.
557.
On the multiplicity of neuronal pathways from muscle spindles and tendon organs and their selection in the cat 总被引:1,自引:0,他引:1
E Jankowska 《Journal de physiologie》1982,78(8):772-774
A short review is presented of the results of recent studies of spinal reflex pathways from muscle spindles and tendon organs. The observations on the existence of parallel neuronal pathways from these receptors to motoneurones and the mechanisms of selection of these pathways are briefly summarized. 相似文献
558.
559.
J Zubowska J Jankowska K Kula I Owczarczyk A Garbowska-Górska 《Endokrynologia Polska》1979,30(6):565-573
Examination of 16 adult men operated in childhood for hypospadias revealed signs of moderate injury of the male genital system. It appears that accessory sexual glands were mainly responsible for the observed abnormalities. Since testicular position and size, serum testosterone and FSH levels were normal it seems that hypospadias and the accompanied disturbances are connected with reduction of responsiveness of target tissues to androgen stimuli rather, than with lesion of the testicle. The coexistence of normal serum testosterone and elevation of serum LH suggests the decrease of sensitivity of hypothalamic or pituitary receptors to negative feedback influence of androgens. The consciousness of sexual inadequacy noted in some cases was mainly of emotional character. 相似文献