全文获取类型
收费全文 | 1187篇 |
免费 | 66篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 32篇 |
妇产科学 | 31篇 |
基础医学 | 156篇 |
口腔科学 | 28篇 |
临床医学 | 204篇 |
内科学 | 345篇 |
皮肤病学 | 3篇 |
神经病学 | 18篇 |
特种医学 | 164篇 |
外科学 | 76篇 |
综合类 | 41篇 |
预防医学 | 75篇 |
眼科学 | 6篇 |
药学 | 37篇 |
肿瘤学 | 55篇 |
出版年
2023年 | 7篇 |
2021年 | 15篇 |
2019年 | 11篇 |
2018年 | 11篇 |
2017年 | 10篇 |
2016年 | 13篇 |
2015年 | 7篇 |
2014年 | 24篇 |
2013年 | 33篇 |
2012年 | 40篇 |
2011年 | 37篇 |
2010年 | 39篇 |
2009年 | 65篇 |
2008年 | 32篇 |
2007年 | 45篇 |
2006年 | 39篇 |
2005年 | 48篇 |
2004年 | 41篇 |
2003年 | 31篇 |
2002年 | 48篇 |
2001年 | 27篇 |
2000年 | 35篇 |
1999年 | 32篇 |
1998年 | 45篇 |
1997年 | 41篇 |
1996年 | 39篇 |
1995年 | 41篇 |
1994年 | 25篇 |
1993年 | 26篇 |
1992年 | 18篇 |
1991年 | 19篇 |
1990年 | 16篇 |
1989年 | 31篇 |
1988年 | 28篇 |
1987年 | 16篇 |
1986年 | 19篇 |
1985年 | 26篇 |
1984年 | 16篇 |
1983年 | 11篇 |
1982年 | 23篇 |
1981年 | 13篇 |
1980年 | 18篇 |
1979年 | 9篇 |
1978年 | 18篇 |
1977年 | 13篇 |
1976年 | 12篇 |
1973年 | 6篇 |
1971年 | 7篇 |
1970年 | 8篇 |
1966年 | 6篇 |
排序方式: 共有1275条查询结果,搜索用时 15 毫秒
41.
Phylogenetic analysis of human G9P[8] rotavirus strains circulating in Jiangsu,China between 2010 and 2016 下载免费PDF全文
Cheng Xu MD Jianguang Fu DC Jing Ai MD Jun Zhang MD Cheng Liu BD Xiang Huo MD Changjun Bao MD Yefei Zhu DM 《Journal of medical virology》2018,90(9):1461-1470
Rotavirus A (RVA) is the leading cause of acute viral gastroenteritis in children under 5 years of age worldwide. G9P[8] is a common RVA genotype that has been persistently prevalent in Jiangsu, China. To determine the genetic diversity of G9P[8] RVAs, 7 representative G9P[8] strains collected from Suzhou Children’s Hospital between 2010 and 2016 (named JS2010‐JS2016) were analyzed through whole‐genome sequencing. All evaluated strains showed the Wa‐like constellation G9‐P[8]‐I1‐R1‐C1‐M1‐A1‐N1‐T1‐E1‐H1. Furthermore, phylogenetic analysis revealed that the VP7 genes of all strains clustered into lineage G9‐III and G9‐VI. With the exception of strain JS2012 (P[8]‐4), the VP4 sequences of all strains belonged to the P[8]‐3 lineage. Sequencing further revealed that amino acid substitutions were present in the antigenic regions of the VP7 and VP4 genes of all strains. Moreover, there were multiple substitutions in antigenic sites I and II of the nonstructural protein 4 (NSP4) genes, whereas the other NSP genes were relatively conserved. In conclusion, our phylogenetic analysis of these 7 G9P[8] strains suggests that RVA varied across regions and time. Therefore, our findings suggest that continued surveillance is necessary to explore the molecular evolutionary characteristics of RVA for better prevention and treatment of acute viral gastroenteritis. 相似文献
42.
Follicular density in ovarian biopsy of infertile women: a novel method to assess ovarian reserve 总被引:4,自引:15,他引:4
Lass A; Silye R; Abrams DC; Krausz T; Hovatta O; Margara R; Winston RM 《Human reproduction (Oxford, England)》1997,12(5):1028-1031
The ageing ovary appears to be characterized by depletion of primordial
follicles. The relationship between infertility and the number of follicles
in the ovarian cortex is not known. Moreover, there are no accurate markers
or clinical methods to predict the decline in ovarian reserve. This study
investigates the correlation between early follicular follicle stimulating
hormone, ovarian size and follicular density in 60 infertile women aged
19-45 years (mean = 34.4 +/- 5.5). An ovarian biopsy was taken from each
patient while performing diagnostic laparoscopy (n = 28) or laparotomy for
tubal surgery or myomectomy (n = 32). The median number of follicles was
similar in tubal and unexplained infertility patients (9.5 versus 5.5).
Increasing age showed a significant negative correlation with follicular
density and ovarian volume (r = -0.46, P = 0.0003;. r = -0.43, P = 0.0016,
respectively). In women > or = 35 years of age the ovarian volume showed
a strong correlation with follicular density (r = 0.71, P < 0.0001). Our
results indicate that infertile women in their late thirties and over have
a decreased ovarian reserve which could possibly be predicted by ovarian
volume measurement. Ovarian biopsy may have a place as part of infertility
evaluation in older women.
相似文献
43.
44.
DC Wilson MJ Cunningham MMcC Reid SS Johnston TF Fannin 《Acta paediatrica (Oslo, Norway : 1992)》1992,81(1):84-85
A baby with unilateral cleft lip, midline cleft palate and hypertelorism developed meningitis in the first 48 h of life. Examination of the nasopharynx showed a soft tissue mass, which was confirmed as a basal encephalocele by computed tomography. There was also congenital hydrocephalus and the corpus callosum was absent. Surgical treatment included repair of the anterior basal skull defect, repair of the lip and palate, and ventriculo-peritoneal shunt. There is currently evidence of developmental delay and right-sided visual impairment due to Morning Glory syndrome. This case demonstrates that basal encephalocele should be considered in any baby with midline facial deformity who develops meningitis. 相似文献
45.
The clinical relevance of non-nucleoside reverse transcriptase inhibitor hypersusceptibility: a prospective cohort analysis 总被引:5,自引:0,他引:5
46.
Utter AC Whitcomb DC Nieman DC Butterworth DE Vermillion SS 《Medicine and science in sports and exercise》2000,32(1):41-45
PURPOSE: Aerobic exercise may influence gallstone disease pathogenesis through its effect on gallbladder motility. The purpose of this investigation was to examine the effects of exercise training on gallbladder emptying in obese women. METHODS: Twenty-seven obese subjects were randomized into one of two groups: exercise (E) (five 45-min brisk walking sessions per week at 75.2 +/- 0.5% of maximum heart rate) and controls (C). Gallbladder function via cholescintigraphy, cardiorespiratory fitness, and body composition were measured in all subjects before and after a 12-wk intervention period. In each cholescintigraphy trial subjects ingested an 8-oz liquid meal 45 min after injection of 99mTc disofenin to promote gallbladder emptying. Gallbladder areas were then scanned for 60 s and then every 5 min for 60 min. RESULTS: VO2max increased significantly by 9% for E when compared with that for C (P < 0.001). Within E postprandial gallbladder ejection fraction (EF) increased significantly after training (39.5 +/- 4.9% to 54.7 +/- 6.5%, P < 0.05); however, this 15.2% increase in EF was not significantly greater than the change reported in the controls. CONCLUSIONS: Results indicate that 12 wk of moderate exercise training does improve cardiorespiratory fitness but does not significantly effect gallbladder emptying in obese women. 相似文献
47.
Circulating PP binds to specific receptors in the DVC through the AP, but the mechanism through which these brain receptors affect pancreatic secretion is not clear. We hypothesize that the removal of the AP (APX) will alter the effects of PP on pancreatic secretion. APX or sham procedures were performed in anesthetized male Wistar rats. After a 1-month recovery, one group of rats were infused with either PP (30 or 100 pmol/kg per h) or vehicle under basal or 2-DG-stimulated (75 mg/kg, i.v. bolus) conditions for studying pancreatic exocrine secretion. A second parallel group was sacrificed for examination of PP receptor binding in the brain stem. A third group received an intraperitoneal injection of PP at the dose of 4.15x10(4) pmol/kg (200 microg/kg) and c-fos expression in the brain stem was examined. APX eliminated PP binding sites in the DVC as assessed by autoradiography. PP infusion caused a dose-dependent decrease in basal protein secretion. APX partially reversed PP inhibition of basal protein secretion when infused at 30 pmol/kg per h, and at 100 pmol/kg per h stimulated pancreatic fluid secretion and reversed the inhibition of protein secretion. During 2-DG stimulation the effects of PP and 2-DG on pancreatic fluid and protein secretion were parallel. PP dose-dependently inhibited 2-DG-stimulated secretion in sham rats. APX reduced the pancreatic fluid (54%) and protein (46%) secretory response to 2-DG. However, PP at 30 pmol/kg per h remained a potent inhibitor of 2-DG-stimulated pancreatic secretion in APX rats. This effect was blunted with PP at 100 pmol/kg per h in APX rats, possibly related to the stimulatory effect of high-dose PP in APX rats without 2-DG. Furthermore, i.p. PP induced significantly greater c-fos activation of NTS neurons in APX rats than sham rats, despite the apparent absence of PP binding sites in the DVC. We conclude that in awake rats, PP inhibits basal secretion, in part, through the AP. Furthermore, and unlike PYY, PP inhibits 2-DG-stimulated pancreatic secretion, and it does so through an AP-independent mechanism. The possibility that the mechanism may involve the DVC cannot be excluded since i.p. injection of PP activates c-fos expression in DVC neurons. Thus, PP and PYY may regulate different components of the pancreatic secretory control system through unique pathways. 相似文献
48.
Loss of tumor-promoting activity of unleaded gasoline in N- nitrosodiethylamine-initiated ovariectomized B6C3F1 mouse liver 总被引:1,自引:0,他引:1
Unleaded gasoline (UG) vapor (2056 ppm) increased the incidence of liver
tumors in a chronic bioassay and exhibited tumor-promoting activity in
N-nitrosodiethylamine (DEN)-initiated female mouse liver. Estrogen
inhibited mouse liver tumor development and the hepatocarcinogenic and
tumor-promoting dose of UG produced uterine changes suggestive of estrogen
antagonism. To directly test the hypothesis that UG-induced tumor-promoting
ability is secondary to its interaction with the mouse liver tumor
inhibitor, estrogen, we compared the tumor-promoting ability of UG in
ovariectomized (Ovex) mice with the hepatic tumor-promoting ability of UG
in intact mice. Ovaries were surgically removed at 4 weeks of age. Exposure
to wholly vaporized UG (2018 ppm) under bioassay and tumor-promoting
conditions began at 8 weeks of age. After 4 months of exposure, UG
increased relative liver weight and hepatic microsomal cytochrome P450
pentoxyresourfin-O- dealkylase and ethoxyresorufin-O-deethylase activity to
a similar extent in intact and Ovex mice. Non-focal hepatocyte
proliferation, as measured by the incorporation of bromo-deoxyuridine, was
not changed by UG exposure and was similar in all treatment groups. After 4
months of exposure to DEN-initiated mice, UG significantly increased the
volume fraction of liver occupied by foci (three-fold) as compared to
control intact mice. As expected, volume of foci was elevated in
DEN/Ovex/control mice as compared to DEN/intact/control mice. In DEN/Ovex
mice UG did not significantly increase the focal volume fraction. Thus, the
tumor promoting activity of UG, as demonstrated by increased volume
fraction of liver occupied by hepatic foci in intact mice, is greatly
attenuated in Ovex mice. The volume fraction data in Ovex mice support the
hypothesis that the tumor promoting activity of UG is dependent upon the
interaction of UG with ovarian hormones. These data also indicate that
hepatic microsomal cytochrome P450 PROD and EROD induction, hepatomegaly
and non-focal hepatic LI are not specific markers of hepatic tumor
promoting activity of UG.
相似文献
49.
Perkins SN; Hursting SD; Haines DC; James SJ; Miller BJ; Phang JM 《Carcinogenesis》1997,18(5):989-994
Transgenic mice with both alleles of the p53 tumor suppressor gene product
'knocked out' by gene targeting are susceptible to early development of
tumors, chiefly lymphomas and sarcomas. Compared with the control group,
administration of dehydroepiandrosterone (DHEA) at 0.3% of the diet to male
p53-deficient mice extended their lifespan by delaying death due to
neoplasms (from 105 to 166 days on study, P = 0.002), primarily by
suppressing lymphoblastic lymphoma (from 45 to 6% of neoplastic deaths, P =
0.010). Treatment with a synthetic DHEA analog,
16alpha-fluoro-5-androsten-17-one (compound 8354), at 0.15% of the diet
also increased lifespan, to 140 days for mice that developed tumors (P =
0.037). The effects of these steroids on lifespan and tumor development did
not appear to be strongly related to inhibition of food consumption and
weight gain, in that a group pair-fed with control diet to the reduced food
consumption of the DHEA-treated group developed and died of the same types
of neoplasms at the same rate as the controls fed ad libitum. The
chemopreventive effect of these steroids has been proposed to be due to
suppression of DNA synthesis by inhibition of glucose 6-phosphate
dehydrogenase, the rate-limiting enzyme of the pentose phosphate pathway.
Although DHEA and its analog are strong non- competitive inhibitors of this
enzyme in vitro, treatment with DHEA did not deplete cellular nucleotide
pools in the liver, as would have been predicted. The chemopreventive
effect of DHEA in this model may be due to steroid-induced thymic atrophy
and suppression of T cell lymphoma, permitting these mice to survive long
enough to develop tumors with longer latency.
相似文献
50.
Wu DC; Liu JM; Chen YM; Yang S; Liu SM; Chen LT; Whang-Peng J 《Japanese journal of clinical oncology》1997,27(2):115-118
Hemolytic uremic syndrome spontaneously arises in a few patients with
advanced cancer, but it is more commonly related to the use of certain
chemotherapeutic agents. Mitomycin-C is, etiologically, the most common
causative agent inducing hemolytic uremic syndrome, in a dose dependent
manner. We report this syndrome, attributable to mitomycin-C at a
cumulative dose of 40 mg/m2, in a gastric cancer patient. A 42-year-old
female with stage III gastric cancer underwent radical gastrectomy and was
given mitomycin-C at 10 mg/m2 intravenously every four weeks as adjuvant
therapy. Hemolytic uremic syndrome was diagnosed three months after the
last dose of mitomycin-C administration. The most prominent symptoms
included pallor, hypertension and anasarca, with laboratory evidence of
microangiopathic hemolytic anemia, azotemia and hyperkalemia. Her disease
was progressive, but fortunately stabilized after staphylococcus column A
dialysis. Her disease remained in remission for 24 months from the time of
diagnosis, and then relapsed in the form of peritoneal carcinomatosis with
partial intestinal obstruction.
相似文献