全文获取类型
收费全文 | 1339篇 |
免费 | 107篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 98篇 |
妇产科学 | 11篇 |
基础医学 | 121篇 |
口腔科学 | 26篇 |
临床医学 | 97篇 |
内科学 | 212篇 |
皮肤病学 | 28篇 |
神经病学 | 31篇 |
特种医学 | 147篇 |
外科学 | 161篇 |
综合类 | 140篇 |
预防医学 | 108篇 |
眼科学 | 4篇 |
药学 | 102篇 |
中国医学 | 40篇 |
肿瘤学 | 134篇 |
出版年
2023年 | 8篇 |
2022年 | 17篇 |
2021年 | 26篇 |
2020年 | 23篇 |
2019年 | 15篇 |
2018年 | 23篇 |
2017年 | 18篇 |
2016年 | 28篇 |
2015年 | 33篇 |
2014年 | 49篇 |
2013年 | 42篇 |
2012年 | 60篇 |
2011年 | 61篇 |
2010年 | 79篇 |
2009年 | 70篇 |
2008年 | 35篇 |
2007年 | 53篇 |
2006年 | 53篇 |
2005年 | 43篇 |
2004年 | 21篇 |
2003年 | 28篇 |
2002年 | 20篇 |
2001年 | 26篇 |
2000年 | 29篇 |
1999年 | 25篇 |
1998年 | 47篇 |
1997年 | 63篇 |
1996年 | 54篇 |
1995年 | 42篇 |
1994年 | 32篇 |
1993年 | 34篇 |
1992年 | 13篇 |
1991年 | 15篇 |
1990年 | 11篇 |
1989年 | 29篇 |
1988年 | 24篇 |
1987年 | 20篇 |
1986年 | 19篇 |
1985年 | 15篇 |
1984年 | 13篇 |
1982年 | 11篇 |
1981年 | 10篇 |
1980年 | 15篇 |
1978年 | 11篇 |
1977年 | 8篇 |
1976年 | 9篇 |
1975年 | 9篇 |
1974年 | 7篇 |
1972年 | 7篇 |
1970年 | 8篇 |
排序方式: 共有1464条查询结果,搜索用时 0 毫秒
11.
Fatty acid balance studies in term infants fed formula milk containing long-chain polyunsaturated fatty acids 总被引:1,自引:0,他引:1
C Morgan L Davies F Corcoran J Stammers J Colley SA Spencer D Hull 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(2):136-142
Long-chain polyunsaturated fatty acids (LCP) are thought to be required for optimal nervous system development in the newborn. A commercial milk formula containing LCP (Aptamil-LCP) with a fatty acid profile closely resembling breast milk, has recently been introduced for term infants. The absorption of fatty acids in term infants was examined in a double-blind randomized controlled trial comparing Aptamil-LCP ( n = 20) and standard Aptamil ( n = 20). Formula-fed newborn infants were studied from birth for 14 d. Fat balances (3 d) were performed from d 10. A 3-d stool collection was performed from d 10 in a parallel breastfed group ( n = 21). Plasma samples were taken on d 6. Median fat excretion (mg kg−1 ) was 897.1, 615.0 and 355.2 with Aptamil, Aptamil-LCP and breastfeeding, respectively. The median total fat absorption coefficient in Aptamil-LCP-fed infants was higher than in those fed standard Aptamil ( p < 0:01). These findings were accounted for by differences in the excretion and absorption of long-chain saturated fatty acids (C14:0, C16:0 and C18:0). Higher fat excretion was associated with bulkier and firmer stools. Only trace amounts of LCP were detected in the stools of all groups. This accounted for less than 4% of dietary intake in Aptamil-LCP-fed infants. No differences in the utilization of LCP from Aptamil-LCP and breast milk feeding were apparent. Plasma phospholipid fatty acid composition data reflected differences in dietary LCP intake. Thus, PL LCP levels were highest in the breastfed infants and lowest in the Aptamil-fed infants, with values for the Aptamil-LCP-fed group falling in between. 相似文献
12.
Characterization of the insulin-like growth factor axis in a human hepatoma cell line (PLC) 总被引:4,自引:0,他引:4
Scharf JG; Schmidt-Sandte W; Pahernik SA; Ramadori G; Braulke T; Hartmann H 《Carcinogenesis》1998,19(12):2121-2128
13.
14.
Samuel M Boddy SA Nicholls E Capps S 《The Australian and New Zealand journal of surgery》2000,70(4):258-262
BACKGROUND: Large bowel volvulus is extremely uncommon in children. The probable pathogenesis, predisposing factors and management of large bowel volvulus in children are debatable. METHODS: Seven consecutive cases of large bowel volvulus occurring over a 6-year period are reported. RESULTS: Two patients with caecal volvulus, one with transverse and subsequent sigmoid volvulus, one with transverse colon volvulus and three children with sigmoid volvulus are reported. Four girls and one boy with cerebral palsy, one female with Moya Moya disease and spastic paraplegia and an otherwise healthy boy presented at a mean age of 8.3 years (range: 3-15 years). The common presentation was abdominal distension (n = 6), tenderness (n = 6), constipation (n = 7) and bloody mucoid discharge per rectum (n = 6). Plain abdominal X-ray and barium enema were diagnostic. Resection with primary ileocolic, colocolic or colorectal anastomosis was performed in all cases. The mean follow-up was 3.4 years (range: 1-6 years) and there was no mortality. CONCLUSIONS: Large bowel volvulus in children may be due to congenital anomalous or absent ligamentous fixation of the large bowel, and abnormal mesocolon or a common ileocolo-mesentery. Large bowel obstruction due to volvulus must be considered in the differential diagnosis in a child presenting with constipation associated with bloody mucoid discharge per rectum. Resection of the involved segment and primary anastomosis is the definitive treatment for large bowel volvulus in children. 相似文献
15.
E Ruth Plummer Mark R Middleton Christopher Jones Anna Olsen Ian Hickson Peter McHugh Geoffrey P Margison Gail McGown Mary Thorncroft Amanda J Watson Alan V Boddy A Hilary Calvert Adrian L Harris David R Newell Nicola J Curtin 《Clinical cancer research》2005,11(9):3402-3409
PURPOSE: Temozolomide, a DNA methylating agent used to treat melanoma, induces DNA damage, which is repaired by O6-alkylguanine alkyltransferase (ATase) and poly(ADP-ribose) polymerase-1 (PARP-1)-dependent base excision repair. The current study was done to define the effect of temozolomide on DNA integrity and relevant repair enzymes as a prelude to a phase I trial of the combination of temozolomide with a PARP inhibitor. EXPERIMENTAL DESIGN: Temozolomide (200 mg/m2 oral administration) was given to 12 patients with metastatic malignant melanoma. Peripheral blood lymphocytes (PBL) were analyzed for PARP activity, DNA single-strand breakage, ATase levels, and DNA methylation. PARP activity was also measured in tumor biopsies from 9 of 12 patients and in PBLs from healthy volunteers. RESULTS: Temozolomide pharmacokinetics were consistent with previous reports. Temozolomide therapy caused a substantial and sustained elevation of N7-methylguanine levels, a modest and sustained reduction in ATase activity, and a modest and transient increase in DNA strand breaks and PARP activity in PBLs. PARP-1 activity in tumor homogenates was variable (828 +/- 599 pmol PAR monomer/mg protein) and was not consistently affected by temozolomide treatment. CONCLUSIONS: The effect of temozolomide reported here are consistent with those documented in previous studies with temozolomide and similar drug, dacarbazine, demonstrating that a representative patient population was investigated. Furthermore, PARP activity was not inhibited by temozolomide treatment and this newly validated pharmacodynamic assay is therefore suitable for use in a proof-of-principle phase I trial a PARP-1 inhibitor in combination with temozolomide. 相似文献
16.
Alan V Boddy E Ruth Plummer Radha Todd Julieann Sludden Melanie Griffin Lesley Robson James Cassidy Donald Bissett Alberto Bernareggi Mark W Verrill A Hilary Calvert 《Clinical cancer research》2005,11(21):7834-7840
PURPOSE: To determine the safety, maximum tolerated dose, pharmacokinetics, and toxicities associated with administration of paclitaxel poliglumex (PPX, XYOTAX, Cell Therapeutics, Inc., Bresso, Italy) given on either 3-weekly or 2-weekly schedule. EXPERIMENTAL DESIGN: Nineteen patients were investigated on the 3-weekly phase Ia study and 11 patients on the 2-weekly phase Ib study. Dose escalation starting with 100% increments and one patient per dose level was modulated in accordance with the observed toxicities. Conjugated and unconjugated paclitaxel were measured in plasma. RESULTS: Dose-limiting toxicity of neutropenia was encountered at 266 mg/m(2) (paclitaxel equivalents) in phase Ia and the maximum tolerated dose was 233 mg/m(2). Neuropathy was dose-limiting in phase Ib with a maximum tolerated dose of 177 mg/m(2). Pharmacokinetic investigations indicated a prolonged half-life of >100 hours for conjugated taxanes. Plasma concentrations of unconjugated paclitaxel were similar to those following administration of an equivalent dose of Taxol. Two partial responses were observed, one in a patient with mesothelioma at 177 mg/m(2) in phase Ia and one in a patient with gastric carcinoma at 175 mg/m(2) in phase Ib. CONCLUSION: PPX is a water-soluble paclitaxel-polymer conjugate with a prolonged half-life and limited volume of distribution. Dose-limiting toxicities were neutropenia and neuropathy. PPX showed activity in this patient population. 相似文献
17.
舌黏膜尿道成形治疗尿道狭窄的初步报告 总被引:3,自引:0,他引:3
目的:探讨舌黏膜补片法尿道成形治疗尿道狭窄的疗效。方法:采用舌黏膜尿道成形治疗尿道狭窄14例。尿道狭窄段3.5~14cm,平均6.2cm;术前耻骨上膀胱造瘘8例,余6例排尿均较为困难,最大尿流率2.5~5.5ml/s,平均3.8ml/s。结果:术后随访2~8个月,1例因伤口感染致尿道皮肤瘘,余患者均排尿通畅,最大尿流率增至22~51ml/s,平均29.6ml/s。结论:舌黏膜具有取材方便、对患者创伤小、抗感染力强等特点,是一种较好的尿道替代物,尤其适合尿道狭窄段<6cm的患者。 相似文献
18.
[目的]评价蒙药胃舒安对束缚-水浸应激所致大鼠胃溃疡的预防作用。[方法]将Wistar实验大鼠,分正常组、给药组和对照组3组,正常组不给药,无束缚-水浸应激压力,对照组给淀粉,给药组灌胃给蒙药胃舒安,给药剂量为0.9~1.3mL/只(82.5g/L),连续给胃舒安7d后,停食24h,建立3h束缚-水浸应激性胃溃疡模型,取胃,肉眼观察胃黏膜损伤,用Image J图像分析法测定胃黏膜溃疡面积,并进行比较。用酶联免疫吸附测定法检测胃溃疡大鼠血清转化生长因子(TGF-β1)含量并进行比较。[结果]蒙药胃舒安对3h束缚-水浸应激所致大鼠胃溃疡形成有抑制作用。胃舒安组大鼠血清TGF-β1含量明显低于对照组。[结论]蒙药胃舒安对实验大鼠束缚-水浸应激3h所致胃溃疡的形成有显著抑制作用。 相似文献
19.
目的 分析未净化Z:ZCLA长爪沙鼠封闭群繁育和生长指标,并利用直接测序法分析其遗传稳定性.方法 随机选择40对Z:ZCLA长爪沙鼠,记录其繁殖胎次、产子数等指标,分析其仔鼠的生长发育情况.遗传稳定性分析选择Z:ZCLA长爪沙鼠非同胞、非亲代个体33只,提取肝脏基因组DNA,PCR扩增D-Loop序列,产物纯化后双向测序,测序结果与Z:ZCLA长爪沙鼠标准序列比对.结果 Z:ZCLA长爪沙鼠每胎产仔7只,胎间隔多在20~60d间,雄性体重高于雌性.遗传稳定性分析检测发现33只Z:ZCLA长爪沙鼠序列与标准序列完全一致.结论 Z:ZCLA长爪沙鼠群体内未发现遗传多态性,说明该群体具有较好的遗传稳定性. 相似文献
20.
目的了解安徽省志贺氏菌的流行菌型,并建立脉冲场凝胶电泳(PFGE)分子分型方法,为菌痢防控提供理论基础。方法对22株志贺氏菌进行血清分型、药物敏感试验和PFGE试验。结果22株志贺氏菌血清分型:B群19株,占总数86.5%;C群1株,占总数的4.5%;D群2株,占总数的9.0%。成功建立了菌痢的PFGE分子分型方法,并将我省22株流行株分为若干带型。试验结果进一步作聚类分析。结论安徽省菌痢流行株以福氏为主;安徽省PFGE分子分型方法和初步带型数据库对提高细菌检测水平有一定意义。 相似文献