全文获取类型
收费全文 | 613篇 |
免费 | 21篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 46篇 |
妇产科学 | 4篇 |
基础医学 | 56篇 |
口腔科学 | 15篇 |
临床医学 | 110篇 |
内科学 | 93篇 |
皮肤病学 | 14篇 |
神经病学 | 18篇 |
特种医学 | 113篇 |
外科学 | 44篇 |
综合类 | 50篇 |
预防医学 | 26篇 |
眼科学 | 8篇 |
药学 | 24篇 |
1篇 | |
中国医学 | 2篇 |
肿瘤学 | 14篇 |
出版年
2021年 | 4篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2015年 | 31篇 |
2014年 | 43篇 |
2013年 | 24篇 |
2012年 | 11篇 |
2011年 | 26篇 |
2010年 | 20篇 |
2009年 | 25篇 |
2008年 | 20篇 |
2007年 | 31篇 |
2006年 | 28篇 |
2005年 | 14篇 |
2004年 | 14篇 |
2003年 | 11篇 |
2002年 | 13篇 |
2001年 | 11篇 |
2000年 | 11篇 |
1999年 | 20篇 |
1998年 | 14篇 |
1997年 | 15篇 |
1996年 | 18篇 |
1995年 | 24篇 |
1994年 | 25篇 |
1993年 | 12篇 |
1992年 | 5篇 |
1991年 | 9篇 |
1990年 | 4篇 |
1989年 | 11篇 |
1988年 | 10篇 |
1987年 | 8篇 |
1986年 | 11篇 |
1985年 | 22篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1982年 | 3篇 |
1981年 | 11篇 |
1980年 | 8篇 |
1979年 | 3篇 |
1978年 | 9篇 |
1977年 | 8篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1968年 | 2篇 |
1966年 | 4篇 |
1964年 | 3篇 |
排序方式: 共有639条查询结果,搜索用时 468 毫秒
71.
目的 探讨采用da Vinci S机器人系统完成机器人辅助腹腔镜下根治性膀胱切除(robotic-assisted laparoscopic radical cystectomy,RARC)加尿流改道术的临床可行性,并总结技术特点和临床效果. 方法 2007年12月至2012年3月膀胱尿路上皮癌患者22例,男20例,女2例.年龄37~ 72岁,平均62岁.体质指数22.5 ~ 30.1 kg/m2,平均26.1 kg/m2.麻醉评分1~2分.术前肿瘤活检病理诊断为浸润性或高危的非肌层浸润性膀胱尿路上皮痛,术前检查均未发现有其他邻近脏器浸润、盆腔淋巴结转移或远处转移,临床分期均低于T2N0M0.全麻下行RARC加尿流改道术,其中行体外尿流改道术15例(原位新膀胱2例,回肠膀胱术13例),行完全腹腔镜下尿流改道术7例(回肠膀胱术2例,原位新膀胱5例). 结果 本组22例手术均获得成功.手术时间300 ~ 667 min,平均480 min;出血量100 ~ 1200 ml,平均550 ml;淋巴结清扫数目6~ 25枚,平均15枚.术后2~3d下地活动,3~4d肠功能恢复,术后住院时间8~35 d,平均16d.行原位新膀胱的患者术后1个月行膀胱造影确定无吻合口漏后拔除尿管和双侧输尿管支架管.术后随访4 ~ 49个月,平均32个月,复发2例,死亡1例,出现肾积水2例,其余病例肾功能均正常,尿控较满意. 结论 根据初期的手术操作过程和随访结果,RARC加尿流改道术在临床上是可行的.更多的操作经验、长期和随机的对照研究将有助于对这一技术进行评估和推广. 相似文献
72.
Eight brains from patients with a mean age of 82 years showing clinical and neuropathological manifestations of senile dementia of the Alzheimer type (SDAT) and 6 control brains from individuals with a mean age of 89 years who were mentally normal or who had minimal senile impairment of memory, were selected by a rigorous elimination procedure for final evaluation from a total of 26 brains. Using an optical electronic image-analysis system, stereological measurements were made of the size and number of senile plaques, and of nerve cell area, capillary diameter, capillary length and intercapillary distance in the medial frontal gyrus, medial temporal gyrus and precentral gyrus. The number and size of senile plaques did not correlate with any of the other parameters measured, whereas Mountjoy et al. (1983) found a correlation between neuronal count and plaque count. In SDAT the cerebral cortex displayed significant atrophy of the neuronal perikarya (mean decrease approximately 50%). The greatest decrease in nerve cell area (55%) was seen in layers III and IV of the medial temporal cortex. Stereological measurements on the capillary network revealed only moderate neuropil shrinkage. Capillary volume was on average 30% greater in SDAT as a result of a decrease in intercapillary distance. These findings indicate that nerve cell shrinkage is a characteristic indicator of senile dementia. Neuropil atrophy may be of secondary importance. 相似文献
73.
Shpall EJ; Stemmer SM; Hami L; Franklin WA; Shaw L; Bonner HS; Bearman SI; Peters WP; Bast RC Jr; McCulloch W 《Blood》1994,83(11):3132-3137
4-Hydroperoxycyclophosphamide (4-HC), a commonly used marrow-purging agent, is active against many tumors, but is also toxic to normal marrow progenitors. Amifostine (WR-2721) is a sulfhydryl compound with chemoprotectant activity. Preclinical studies using suspensions of bone marrow and breast cancer cells demonstrated that ex vivo treatment with amifostine followed by 4-HC resulted in protection of marrow progenitors, with no compromise in the antitumor effect of 4-HC. This fact stimulated the development of a clinical trial. Bone marrow was harvested from 15 poor-prognosis breast cancer patients and randomly assigned to ex vivo treatment with amifostine followed by 4-HC (amifostine + 4-HC), or treatment with 4-HC alone. High-dose chemotherapy was then administered followed by infusion of the purged autologous bone marrow support (ABMS). Leukocyte engraftment, defined as a white blood cell count > or = 1 x 10(9)/L, was achieved in an average of 26 days for patients whose marrow was purged with amifostine + 4-HC versus 36 days for patients whose marrow was purged with 4-HC alone (P = .032). The average number of platelet transfusions (12 v 29; P = .017) and days of antibiotic therapy (28 v 40; P = .012) were significantly less for patients whose marrow was exposed to amifostine + 4-HC, compared with 4-HC alone. Unpurged backup marrow fractions were infused into three patients whose marrow was purged with 4-HC alone, because of inadequate marrow recovery. None of the patients who received amifostine + 4-HC-purged marrow required a backup marrow fraction. Complete remissions were achieved in 83% of patients with measurable disease, with no difference between the two cohorts. Forty- three percent of patients remained alive and progression-free at a mean of 13 months posttransplant. There was no significant difference in the rate or pattern of relapse for patients whose marrow was purged with amifostine + 4-HC compared with those whose marrow was purged with 4-HC alone. Ex vivo treatment of marrow with amifostine significantly shortens the time to marrow recovery, thereby reducing the risk of myelosuppressive complications in breast cancer patients receiving high- dose chemotherapy and 4-HC-purged ABMS. Since supportive care requirements are also significantly decreased, amifostine may reduce the cost of such therapy. 相似文献
74.
Weinberg JB; Misukonis MA; Shami PJ; Mason SN; Sauls DL; Dittman WA; Wood ER; Smith GK; McDonald B; Bachus KE 《Blood》1995,86(3):1184-1195
75.
76.
77.
Inactivation of factor XIa in human plasma assessed by measuring factor XIa-protease inhibitor complexes: major role for C1-inhibitor 总被引:3,自引:1,他引:2
Wuillemin WA; Minnema M; Meijers JC; Roem D; Eerenberg AJ; Nuijens JH; ten Cate H; Hack CE 《Blood》1995,85(6):1517-1526
From experiments with purified proteins, it has been concluded that factor XIa (FXIa) is inhibited in plasma mainly by alpha 1-antitrypsin (a1AT), followed by antithrombin III (ATIII), C1-inhibitor (C1Inh), and alpha 2-antiplasmin (a2AP). However, the validity of this concept has never been studied in plasma. We established the relative contribution of different inhibitors to the inactivation of FXIa in human plasma, using enzyme-linked immunosorbent assays (ELISAs) for the quantification of complexes of FXIa with a1AT, C1Inh, a2AP, and ATIII. We found that 47% of FXIa added to plasma formed complexes with C1Inh, 24.5% with a2AP, 23.5% with a1AT, and 5% with ATIII. The distribution of FXIa between these inhibitors in plasma was independent of whether FXIa was added to plasma, or was activated endogenously by kaolin, celite, or glass. However, in the presence of heparin (1 or 50 U/mL), C1Inh appeared to be the major inhibitor of FXIa, followed by ATIII. Furthermore, at lower temperatures, less FXIa-C1Inh and FXIa-a1AT complexes but more FXIa-a2AP complexes were formed. These data demonstrate that the contribution of the different inhibitors to inactivation of FXIa in plasma may vary, but C1Inh is the principal inhibitor under most conditions. 相似文献
78.
79.
BACKGROUND: The effect of prestorage filtration on the quality of apheresis platelet concentrates stored for transfusion is undetermined. STUDY DESIGN AND METHODS: Investigation of 11 plateletpheresis components used a concurrent paired-study design. On the day of collection, each component was equally divided into two suspensions; one half was filtered, and the other half was not. Each suspension was stored for 5 days. In vitro testing was performed on the day of collection (Day 0) for cell counts and on Day 5 for measurements of lactate, glucose, blood gases, pH, platelet ATP, hypotonic stress ratio, extent of shape change in response to ADP, tissue necrosis factor alpha, interleukin 8, interleukin 1 alpha, interleukin 1 beta, interleukin 6, and platelet surface glycoproteins by flow cytometry. At the end of the 5-day period, a sample was taken from each of the two suspensions, radiolabeled with either 51Cr or 111In, and transfused concurrently. Posttransfusion samples were drawn for measurements of recovery and platelet survival and for functional assessment of the ex vivo ability of the circulating radiolabeled platelets to aggregate in response to ADP. RESULTS: The apheresis component had a mean platelet yield of 3.2 +/? 0.4 × 10(11) and a white cell yield ranging from 1 × 10(5) to 1 × 10(8), with a median of 2 × 10(7). Filtration resulted in a platelet loss of approximately 10 percent and a variable 2 to 3 log10 reduction in white cell content. No significant differences between filtered and unfiltered suspensions in paired t tests that would likely have an impact on platelet quality were observed in the in vitro tests. The in vivo recovery and survival were highly similar and not statistically different in filtered and unfiltered paired suspensions: the mean difference was 1.2 +/? 4.0 percent for recovery and 7.0 +/? 15 hours for survival. The functional assessment by aggregation to ADP showed no difference between filtered and unfiltered suspensions. A small decrease in tumor necrosis factor alpha and interleukin 8 was evident in the filtered suspension as compared to levels in the unfiltered suspensions. CONCLUSION: Prestorage white cell reduction in apheresis components resulted in WBC reduction by several log10 with no evident adverse effect on platelet viability or function. 相似文献
80.
Induction of IL-5 expression by IL-2 is resistant to the immunosuppressive agents cyclosporin A and rapamycin 总被引:1,自引:0,他引:1
T cell cytokine expression may be induced by the cytokine IL-2 or via the
TCR complex. The comparative effects of cytokine- and TCR-mediated
signalling on the induction of human IL-5 mRNA were examined. Cytokine mRNA
expression was analysed by RT-PCR in fresh peripheral blood mononuclear
cells (PBMC) from normal individuals and in populations of activated T
lymphocytes, derived from phytohaemagglutinin (PHA)- stimulated PBMC. rIL-2
induced IL-5 expression in PBMC, the kinetics of which were similar to the
effects of PHA. rIL-4 induced IL-5 mRNA expression in activated T
lymphocytes. IL-5 expression induced by either IL-2 or PHA was completely
abolished by the protein synthesis inhibitor cycloheximide. rIL-2-induced
IL-5 expression was resistant to cyclosporin A (CsA), whereas IL-5
expression elicited by PHA was inhibited by CsA, at doses as low as 10
ng/ml. Rapamycin (RAP) had no effect on rIL-2-stimulated IL-5 expression,
but suppressed IL-5 expression induced by PHA. The inhibitory effect of RAP
on PHA-induced IL-5 expression was more apparent at 12 and 24 h after
stimulation than at earlier times. The resistance of IL-2 receptor (IL-2R)
signalling to CsA and RAP indicates that the IL-2R and the TCR are
associated with different pathways regulating IL-5 expression.
相似文献