全文获取类型
收费全文 | 655篇 |
免费 | 24篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 35篇 |
妇产科学 | 7篇 |
基础医学 | 70篇 |
口腔科学 | 59篇 |
临床医学 | 54篇 |
内科学 | 117篇 |
皮肤病学 | 9篇 |
神经病学 | 12篇 |
特种医学 | 97篇 |
外科学 | 109篇 |
综合类 | 5篇 |
预防医学 | 32篇 |
眼科学 | 13篇 |
药学 | 29篇 |
中国医学 | 1篇 |
肿瘤学 | 42篇 |
出版年
2023年 | 2篇 |
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 6篇 |
2019年 | 6篇 |
2018年 | 10篇 |
2017年 | 16篇 |
2016年 | 6篇 |
2015年 | 21篇 |
2014年 | 15篇 |
2013年 | 21篇 |
2012年 | 26篇 |
2011年 | 23篇 |
2010年 | 29篇 |
2009年 | 19篇 |
2008年 | 28篇 |
2007年 | 25篇 |
2006年 | 29篇 |
2005年 | 27篇 |
2004年 | 19篇 |
2003年 | 18篇 |
2002年 | 19篇 |
2001年 | 10篇 |
2000年 | 27篇 |
1999年 | 14篇 |
1998年 | 28篇 |
1997年 | 40篇 |
1996年 | 29篇 |
1995年 | 22篇 |
1994年 | 14篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 9篇 |
1989年 | 12篇 |
1988年 | 12篇 |
1987年 | 4篇 |
1986年 | 8篇 |
1985年 | 7篇 |
1984年 | 7篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1977年 | 7篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1973年 | 1篇 |
排序方式: 共有692条查询结果,搜索用时 15 毫秒
1.
2.
Intra-abdominal surgery in patients with advanced cirrhosis 总被引:3,自引:0,他引:3
Between 1971 and 1984, intra-abdominal surgical procedures were required in 51 patients with cirrhosis who had advanced liver dysfunction and/or ascites. These included the following types of surgery: gastric, 17 patients; small bowel, two patients; colon, five patients; hepatic, nine patients; and pancreas, nine patients. Twelve patients also underwent exploratory celiotomy for an acute condition of the abdomen (six patients) and jaundice (six patients). Patients fell into two groups: (1) those with prothrombin time (PT) greater than 2.5 s over control (24 patients), and (2) those with PT within 2.5 s of control (27 patients). The 30-day mortality rate was 34 (67%) of 51 patients. Nineteen (83%) of 23 patients who had ascites died. Twenty-two (91%) of 24 patients with elevated PT greater than 2.5 s of control died. Twenty-five (86%) of 29 patients who underwent surgery under emergency conditions died. Intraabdominal surgery in decompensated patients with cirrhosis must be undertaken with great caution. 相似文献
3.
4.
5.
Michael B. Farnell Gerard V. Aranha Yuji Nimura Fabrizio Michelassi 《Journal of gastrointestinal surgery》2008,12(4):651-656
With improvements in the safety of Whipple resection in recent decades, surgeons have continued to explore the role of more
extensive lymphadenectomy in hope of improving long-term survival. A systematic literature search of level I evidence addressing
the role of the extent of lymphadenectomy was undertaken. Only reports of prospective, randomized controlled trials comparing
pancreaticoduodenectomy with standard lymphadenectomy to pancreaticoduodenectomy with extended lymphadenectomy where information
regarding survival, morbidity, mortality, the number of resected lymph nodes in each group and detailed operative technique
were included. Four prospective, randomized trials comprising some 424 patients and one meta-analysis were identified. In
aggregate, these studies confirmed that the number of resected lymph nodes was significantly higher in the pancreaticoduodenectomy
with extended lymphadenectomy group. Morbidity and mortality rates were comparable. Postoperative diarrhea in the early months
after operation was problematic in patients undergoing extended lymphadenectomy. In none of the studies was a benefit in long-term
survival demonstrated. Standard pancreaticoduodenectomy continues to be the operation of choice for adenocarcinoma of the
head of the pancreas.
Presented at The Society for Surgery of the Alimentary Tract Postgraduate Course “Systematic Reviews of Pancreaticobiliary
Disease Customized for the Gastroenterologist and Gastrointestinal Surgeon” on May 20, 2007, Washington, D.C. 相似文献
6.
7.
A comparison of Skirrow's, Butzler's, Blaser's, Campy-BAP and Preston media for Campylobacter spp was made using human, animal and environmental specimens. Butzler's medium gave the lowest isolation rate and Preston medium, which was the most selective, the highest isolation rate. Enrichment culture using Preston enrichment broth gave a higher isolation rate than direct plating onto Preston medium. 相似文献
8.
Pfeifer JD Ashley Hill D Ramos CV Wippold FJ II Dehner LP 《Archives of pathology & laboratory medicine》2000,124(6):898-901
A 77-year-old woman with neurofibromatosis type 1 presented with ill-fitting dentures due to intraoral extension of a right temporal fossa mass. Computed tomographic scanning demonstrated that the masticator space mass bowed the zygomatic arch and remodeled the lateral orbit and maxillary sinus walls, findings that were consistent with the clinical diagnosis of a neurofibroma with possible malignant transformation. However, light microscopic, immunohistochemical, and ultrastructural examination of tissue from an incisional biopsy specimen were diagnostic of meningioma. This case illustrates that the clinicopathologic differential diagnosis of an enlarging mass in patient with neurofibromatosis should include sporadic, unrelated neoplasms as well as tumors known to be associated with the syndrome. 相似文献
9.
Frataxin is reduced in Friedreich ataxia patients and is associated with mitochondrial membranes 总被引:17,自引:8,他引:17
Campuzano V; Montermini L; Lutz Y; Cova L; Hindelang C; Jiralerspong S; Trottier Y; Kish SJ; Faucheux B; Trouillas P; Authier FJ; Durr A; Mandel JL; Vescovi A; Pandolfo M; Koenig M 《Human molecular genetics》1997,6(11):1771-1780
Friedreich ataxia is a progressive neurodegenerative disorder caused by
loss of function mutations in the frataxin gene. In order to unravel
frataxin function we developed monoclonal antibodies raised against
different regions of the protein. These antibodies detect a processed 18
kDa protein in various human and mouse tissues and cell lines that is
severely reduced in Friedreich ataxia patients. By immunocytofluorescence
and immunocytoelectron microscopy we show that frataxin is located in
mitochondria, associated with the mitochondrial membranes and crests.
Analysis of cellular localization of various truncated forms of frataxin
expressed in cultured cells and evidence of removal of an N-terminal
epitope during protein maturation demonstrated that the mitochondrial
targetting sequence is encoded by the first 20 amino acids. Given the
shared clinical features between Friedreich ataxia, vitamin E deficiency
and some mitochondriopathies, our data suggest that a reduction in frataxin
results in oxidative damage.
相似文献
10.
Dithiothreitol prevents age-associated decrease in oocyte/conceptus viability in vitro 总被引:2,自引:0,他引:2
The present study was designed to ascertain whether the negative effects on
reproductive potential of post-ovulatory ageing in vitro of oocytes can be
prevented by antioxidant therapy. Mouse metaphase II (MII) oocytes were
aged in vitro for 12 h prior to insemination in the presence of varying
concentrations of L-ascorbic acid, 6-methoxy-
2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), L-cystine
dihydrochloride, ethylenediaminetetraacetic acid (EDTA), beta-
mercaptoethanol and DL-dithiothreitol (DTT). In-vitro ageing of oocytes was
associated with lower fertilization rate, higher proportion of concepti
exhibiting cellular fragmentation at 24 h post-insemination and lower
percentage of concepti reaching the blastocyst stage. Ascorbic acid, Trolox
and EDTA had no effect on cellular fragmentation or potential of oocytes
for development. However, the probability of an oocyte reaching the
blastocyst stage was decreased (P < or = or = 0.05) in oocytes incubated
in the presence of L-cystine (50 and 500 microM) and beta-mercaptoethanol
(5, 50 and 500 microM) when compared to control aged oocytes.
Age-associated cellular fragmentation at 24 h post-insemination was
partially prevented (P < or = 0.05) by incubating oocytes in the
presence of beta-mercaptoethanol (500 microM). DTT (50 and 500 microM)
increased (P < or = 0.05) fertilization rate and number of cells at 81 h
post-insemination to levels similar to those exhibited by control oocytes.
Furthermore, both age-associated fragmentation at 24 h post-insemination (P
< or = 0.05) and decreased potential of oocytes for development to the
blastocyst stage (P < or = 0.05) were prevented, at least in part, by
culturing oocytes in the presence of DTT (50 microM). Although the
mechanism by which DTT exerts its beneficial effects on aged oocytes
remains to be elucidated, it may protect oocytes by preventing oxidation of
free thiol groups and/or altering a redox-independent signalling pathway
that mediates cellular fragmentation and death.
相似文献