全文获取类型
收费全文 | 562篇 |
免费 | 57篇 |
国内免费 | 21篇 |
出版年
2024年 | 2篇 |
2023年 | 11篇 |
2022年 | 15篇 |
2021年 | 20篇 |
2020年 | 19篇 |
2019年 | 33篇 |
2018年 | 18篇 |
2017年 | 22篇 |
2016年 | 25篇 |
2015年 | 17篇 |
2014年 | 36篇 |
2013年 | 50篇 |
2012年 | 23篇 |
2011年 | 36篇 |
2010年 | 14篇 |
2009年 | 21篇 |
2008年 | 19篇 |
2007年 | 27篇 |
2006年 | 18篇 |
2005年 | 15篇 |
2004年 | 22篇 |
2003年 | 13篇 |
2002年 | 16篇 |
2001年 | 17篇 |
2000年 | 11篇 |
1999年 | 6篇 |
1998年 | 2篇 |
1997年 | 8篇 |
1996年 | 8篇 |
1995年 | 7篇 |
1994年 | 3篇 |
1993年 | 10篇 |
1992年 | 9篇 |
1991年 | 8篇 |
1990年 | 9篇 |
1989年 | 8篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 13篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1978年 | 4篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1972年 | 1篇 |
1971年 | 2篇 |
排序方式: 共有640条查询结果,搜索用时 46 毫秒
11.
H. DOORNEWAARD J. M. C. WOUDT P. STRUBBE H. VAN DE SEIJP J. G. VAN DEN TWEEL 《Cytopathology》1997,8(5):313-321
Evaluation of PAPNET-assisted cervical rescreening
We have compared the results of targeted manual rescreening of 1211 randomly selected smears with the results of PAPNET-assisted rescreening of 1613 cervical smears, containing at least 6.3% low-grade squamous intraepithelial lesion (SIL). PAPNET diagnosis and the targeted rescreening diagnosis were compared with the initial report, issued on the corresponding smear. Reproducibility scores for inadequacy, presence of endocervical and endometrial cells, specific infections and squamous cell abnormalities were determined. The reproducibility scores for the diagnosis of inadequate smears and specific infections were lower with the PAPNET-assisted rescreening. The detection of squamous cell abnormalities was excellent for both methods (>0.95), with a higher detection rate for false-negative smears with the PAPNET testing system. 相似文献
We have compared the results of targeted manual rescreening of 1211 randomly selected smears with the results of PAPNET-assisted rescreening of 1613 cervical smears, containing at least 6.3% low-grade squamous intraepithelial lesion (SIL). PAPNET diagnosis and the targeted rescreening diagnosis were compared with the initial report, issued on the corresponding smear. Reproducibility scores for inadequacy, presence of endocervical and endometrial cells, specific infections and squamous cell abnormalities were determined. The reproducibility scores for the diagnosis of inadequate smears and specific infections were lower with the PAPNET-assisted rescreening. The detection of squamous cell abnormalities was excellent for both methods (>0.95), with a higher detection rate for false-negative smears with the PAPNET testing system. 相似文献
12.
Pro-enkephalin gene derived peptides in the porcine stomach: cellular distribution and molecular forms 总被引:2,自引:0,他引:2
Antisera to the enkephalin variants Met-enk Arg6Phe7 and Met-enk Arg6Gly7Leu8 have been used in immunohistochemistry and radioimmunoassay studies of hog stomach. In the mucosa of the antrum, but not fundus, there was identified a population of immunoreactive endocrine-like cells. When extracts of antral mucosa were fractionated by gel filtration on Sephadex G50 the predominant immunoreactive forms of Met-enk Arg6Phe7 and Met-enk Arg6Gly7Leu8 were found to elute before the standards, and were compatible with N-terminally extended variants. In the muscle layers of both antrum and fundus, immunoreactive nerve fibers were found, these were especially numerous in the myenteric plexus. In extracts of the antral muscle, 50-60% of both Met-enk Arg6Phe7 and Met-enk Arg6Gly7Leu8 immunoreactivity eluted in the position of the standards and the remainder had the properties of N-terminally extended variants. In the fundus muscle the variants accounted for 70-80% of total activity. The results indicate that the proenkephalin gene is expressed in neurones and endocrine cells of the hog stomach. The different patterns of molecular forms found in different regions of the stomach suggest that the precursor is processed by different pathways in different populations of endocrine cells and neurones. 相似文献
13.
Epidermal growth factor (EGF) or saline was administered intraperitonally to hypophysectomized adult male CD2F1 mice or intact controls at 0700 hr. Subgroups of mice were killed at 4, 8, or 12 hr after injection. EGF was shown to stimulate [3H]TdR incorporation into DNA into several organs as previously reported. The response to EGF was found to be enhanced in both hypophysectomized and fasted mice. Differences in [3H]TdR incorporation into DNA, corneal epithelium mitotic index, RNA in pancreas and kidney of hypophysectomized and intact mice are reported. EGF was shown to result in stomach enlargement due to increased luminal contents in both hypophysectomized and intact mice. 相似文献
14.
Taenia taeniaeformis: characterization of larval metabolic products and growth of host gastric cells in vitro 总被引:1,自引:0,他引:1
Development of larvae of the cestode parasite Taenia taeniaeformis in the liver of rats induces gross hyperplasia of the gastric mucosa and excessive mucus production in the stomach without any direct contact with the stomach. Because the taeniid larvae are known to elaborate excretory-secretory (E-S) product in vivo and in vitro, the product was analyzed further, and its effects on cultured rat and dog stomach cells were investigated. In vitro E-S product contained less negatively charged glycosaminoglycan than either heparin or chondroitin sulfate, and proteins of various molecular weights. It stimulated the growth of both rat and dog stomach cells at concentrations of 3-9 micrograms protein/ml culture medium. At a concentration of 30 micrograms protein/ml culture medium, it stimulated hexosamine production in the cells up to 20 times, and multiple intracytoplasmic granules were found in both rat and dog cultured cells by light and electron microscopy. These results suggest that larval E-S product may be involved in the induction of gastric hyperplasia and hypermucus secretion. 相似文献
15.
John E. Randall Stephen M. Head Adrian P. L. Sanders 《Environmental Biology of Fishes》1978,3(2):235-238
Synopsis The giant humphead wrasse (Cheilinus undulatus), an inhabitant of coral reefs, is widely distributed in the tropical Indo-Pacific region. Stomach and intestinal contents of 72 specimens from the Pacific and the Red Sea revealed that this fish feeds primarily on mollusks, fishes, echinoids, and crustaceans.This article is one of several presented at the Second European Ichthyological Congress, Paris, 8-15 September 1976, to be published by Environmental Biology of Fishes. 相似文献
16.
用胃壁标本评估中国狍和欧洲狍(Capreolus capreolus)的营养状况(英文) 总被引:2,自引:0,他引:2
通过测量12只中国狍(Capreolus capreolus bedfordi)瘤胃壁粘膜标本,作者测定了12只狍胃壁粘膜的表面扩张系数(SEF)。结果表明,中国狍胃壁粘膜的表面扩张系数与德国和波兰狍基本一致,说明中国狍的营养状况和生境的食物条件良好。 相似文献
17.
About ScienceDirect 《Biochimica et Biophysica Acta (BBA)/General Subjects》1982,719(3):453-456
The photoaffinity ligand 8-azidoadenosine 3′,5-monophosphate was employed to label cAMP binding proteins in both fractionated and freeze-thawed rabbit gastric glands. Fractionated glands incorporated the azido-cAMP label primarily into two cytosolic proteins with apparent molecular weights of 58 000 and 48 000. No enrichment of label was found in fractions containing basolateral or apical membranes. DEAE-cellulose chromatography of the cytosolic proteins resulted in the separation of two cAMP-dependent protein kinase peaks. Azido cAMP labelling of each peak suggested the initial peak contained type I cAMP-dependent protein kinase while the second peak contained the type II kinase. Labelling of ‘resting’ gastric glands resulted in radioactive proteins of apparent molecular weights of 58 000.and 48 000. When gastric glands were stimulated to produce acid by the addition of 10?4 M histamine or 1 mM dibutyryl cAMP there was 32–44% dimunition of ligand incorporation compared to control glands. The results strongly suggest that histamine- mediated stimulus-secretion coupling in gastric glands involves activation of parietal cell cAMP-dependent protein kinases. 相似文献
18.
Summary Gastric parietal cells of rats maintained under standardized conditions and fed ad libitum were examined by electron microscopy at 6 time points of the 24-h day. Morphometric determinations were made on 4 cell characteristics. The volume density of secretory canaliculi was maximal at the mid-dark sampling point and decreased during the light phase; a secondary peak was seen 1 h before the onset of darkness. The surface density of microvesicles and RER fluctuated inversely with the pattern displayed by secretory canaliculi. The number of multivesicular bodies per cytoplasmic area exhibited a single peak, 1 h after the onset of darkness. It was further noted that parietal cells in the necks and bases of glands differed morphologically and that their organelle populations varied at individual circadian rates. 相似文献
19.
目的:比较血小板生成素与白介素-11治疗胃癌患者术后化疗血小板减少症的时效和安全性。方法:术后辅助化疗出现血小板计数低于75×109/L的进展期胃癌患者68例,将其分为TPO组与IL-11组,分别为35例和33例。分别皮下注射rhTPO 15000U,每日1次;rhIL-11 1.5 mg,每日1次,当血小板计数125×109/L或比用药前上升50×109/L,即停止给药,疗程最长为14天。每3天抽取外周静脉血2 m L,通过全自动血液分析仪测定血小板计数,密切观察出现的不良反应并记录。比较两组患者不同临床病理资料、血小板计数、血小板计数升至75×109/L和125×109/L的时程、药物不良反应。结果:两组患者年龄、性别、化疗方案、血小板最低值出现的化疗周期及临床病理分期的比较均没有统计学差异(P值均0.05)。TPO组与IL-11组血小板动态值的比较,第9天出现显著差异(P=0.032)。TPO组与IL-11组血小板计数恢复至75×109/L和125×109/L所需的时间,有显著差异(P=0.041,P=0.013)。TPO组中,有3例(8.6%)患者发生不良反应,IL-11组中,有13例(39.4%)患者发生不良反应,TPO组患者出现的不良反应少且较轻微(P=0.006)。结论:rhTPO治疗胃癌患者术后化疗血小板减少症时效快,安全性好。 相似文献
20.