全文获取类型
收费全文 | 130354篇 |
免费 | 11372篇 |
国内免费 | 6699篇 |
专业分类
耳鼻咽喉 | 1238篇 |
儿科学 | 1962篇 |
妇产科学 | 2938篇 |
基础医学 | 13578篇 |
口腔科学 | 2690篇 |
临床医学 | 16151篇 |
内科学 | 20327篇 |
皮肤病学 | 1598篇 |
神经病学 | 6453篇 |
特种医学 | 4259篇 |
外国民族医学 | 41篇 |
外科学 | 13456篇 |
综合类 | 19678篇 |
现状与发展 | 23篇 |
一般理论 | 18篇 |
预防医学 | 9518篇 |
眼科学 | 3497篇 |
药学 | 13617篇 |
121篇 | |
中国医学 | 6687篇 |
肿瘤学 | 10575篇 |
出版年
2024年 | 356篇 |
2023年 | 1733篇 |
2022年 | 4069篇 |
2021年 | 5524篇 |
2020年 | 4113篇 |
2019年 | 3736篇 |
2018年 | 3969篇 |
2017年 | 3742篇 |
2016年 | 3349篇 |
2015年 | 5307篇 |
2014年 | 6818篇 |
2013年 | 7033篇 |
2012年 | 10231篇 |
2011年 | 10985篇 |
2010年 | 7561篇 |
2009年 | 6229篇 |
2008年 | 7867篇 |
2007年 | 7829篇 |
2006年 | 7388篇 |
2005年 | 6737篇 |
2004年 | 4891篇 |
2003年 | 4441篇 |
2002年 | 3705篇 |
2001年 | 3135篇 |
2000年 | 2888篇 |
1999年 | 2690篇 |
1998年 | 1332篇 |
1997年 | 1245篇 |
1996年 | 1008篇 |
1995年 | 972篇 |
1994年 | 895篇 |
1993年 | 516篇 |
1992年 | 896篇 |
1991年 | 806篇 |
1990年 | 670篇 |
1989年 | 570篇 |
1988年 | 527篇 |
1987年 | 457篇 |
1986年 | 357篇 |
1985年 | 284篇 |
1984年 | 184篇 |
1983年 | 167篇 |
1982年 | 95篇 |
1981年 | 93篇 |
1979年 | 140篇 |
1978年 | 111篇 |
1977年 | 83篇 |
1974年 | 94篇 |
1973年 | 72篇 |
1972年 | 87篇 |
排序方式: 共有10000条查询结果,搜索用时 20 毫秒
991.
Telomerase Activity in Tumor and Remnant Liver as Predictor of Recurrence and Survival in Hepatocellular Carcinoma after Resection 总被引:1,自引:0,他引:1
Background and Aim Results after curative liver resection in hepatocellular carcinoma are unsatisfactory with regard to high postoperative intrahepatic
recurrence and liver failure. This study evaluates telomerase activity in liver with and without tumor as a predictor of recurrence
and survival.
Materials and Methods Liver tissue with and without tumor from 53 hepatocellular carcinoma patients receiving curative resection during the period
of 1998–2000 was used for detecting telomerase activity by PCR-ELISA. Clinicopathological data were compared to identify predictors
of recurrence and survival.
Results Telomerase activity was detected in 98% of liver tissue with tumor and 70% liver tissue without. Telomerase activity in cancerous
liver correlated significantly with HCV infection (P = 0.012) and cirrhotic change in liver parenchyma (P = 0.006). Telomerase activity in non-cancerous liver correlated with high serum AFP level (P = 0.002). The telomerase activity of liver tissue with and without tumor is significant higher in patients with recurrence
than in those without recurrence, 413.7 ± 100.5 versus 110.8 ± 32.7, P = 0.006, and 34.7 ± 14.2 versus 4.2 ± 1.4, P = 0.039. Recurrence could be predicted by abnormally high tumor telomerase activity (P = 0.026) or by advanced TNM stage (P = 0.001). TNM stage or high serum ALT level could predict multinodular intrahepatic recurrence (P = 0.028 and P = 0.030). High serum AFP combined with high telomerase activity in liver without tumor had a significant ability to predict
poor survival (OR: 11.19, CI: 1.95–64.12, P = 0.007).
Conclusion Tumor telomerase is an independent predictor of recurrence. Simultaneous high remnant liver telomerase and high serum AFP
is a strong negative predictor of survival. 相似文献
992.
Surgical Treatment of Solitary Thyroid Nodules Via Fine-Needle Aspiration Biopsy and Frozen-Section Analysis 总被引:4,自引:0,他引:4
Background Fine-needle aspiration biopsy (FNAB) and frozen-section analysis of managing solitary thyroid nodules continue to generate
considerable controversy.
Methods This study was a retrospective review of 619 patients with solitary thyroid nodules who underwent thyroidectomy.
Results Of 540 FNABs, 35 (6.5%) were positive for malignancy, 276 (51.1%) were benign, and 229 (42.4%) were suspicious. Only 5.1%
were false negative, and 11.4% were false positive. Diagnostic FNAB sensitivity, specificity, positive predictive value (PPV),
negative predictive value (NPV), and accuracy for malignancy were 86.1%, 59.7%, 33.0%, 94.9%, and 64.6%, respectively. Of
569 patients analyzed by frozen section, diagnosis was deferred in 86 (15.1%) patients, and results were positive for malignancy
in 92 (16.2%) and benign in 391 (68.7%). No false-positive results were noted, but 2.3% (391) were false negative. Of 86 deferred
frozen sections, 11 (12.8%) patients had malignant tumors confirmed by permanent section. Diagnostic frozen-section sensitivity,
specificity, PPV, NPV, and accuracy for carcinoma were 82.1%, 100%, 100%, 95.8%, and 96.5%, respectively. Sensitivity, specificity,
PPV, NPV, and accuracy for frozen-section analysis for diagnosis of carcinoma in patients with suspicious FNAB were 83.9%,
100%, 100%, 94.9%, and 96.0%, respectively.
Conclusions FNAB is a sensitive diagnostic modality in selecting patients who require surgery. Routine use of frozen-section analysis
is unwarranted for benign FNAB results. Frozen section is specific and cost-effective in determining the extent of surgery
in patients with suspicious or malignant FNABs. 相似文献
993.
994.
美托康注射液与都可喜联合治疗椎基底动脉供血不足的疗效观察 总被引:1,自引:0,他引:1
目的观察美托康注射液与都可喜联合治疗椎基底动脉供血不足的临床疗效。方法随机将87例病人分为治疗组(45例)和对照组(42例),治疗组应用美托康注射液250ml静滴,1a/d,同时加服都可喜1片,2次/d;对照组应用复方丹参注射液30m1加入5%葡萄糖注射液500ml静滴,1次/d;两组均连用10d,其余常规治疗相同。结果治疗组痊愈26例,有效18例,总有效率98%;对照组痊愈15例,有效24例,总有效率93%。治疗组疗效优于对照组(P〈0.05)。结论美托康注射液与都可喜联合治疗椎基底动脉供血不足有良好临床疗效,可于临床广泛应用。 相似文献
995.
Lin ZHANG Zhong-Xin ZHAO Department of Neurology Changzheng Hospital Shanghai China 《中国神经科学杂志》2006,(1)
Synapsins are a family of phosphoproteins specifically associated with the cytoplasmic surface of the synaptic vesicle membrane, appearing to regulate neurotransmitter release, the formation and maintenance of synaptic contacts. They could induce the change of the synaptic plasticity to regulate various adaptation reactions, and change the cognitive behaviors. So we presume that if some cognitive behavior are damaged, synapsins would be changed as well. This gives us a new recognition of better diagnosis and therapy of cognitive disorder desease. 相似文献
996.
中成药天智颗粒对血管性痴呆大鼠脑内神经细胞增殖的影响 总被引:1,自引:0,他引:1
目的观察中成药天智颗粒对血管性痴呆大鼠学习记忆能力和神经前体细胞与星形胶质细胞增殖水平的影响。方法老年雄性SD大鼠192只,随机分为治疗组、模型组、假手术组和正常对照组,每组48只。治疗组、模型组采用双侧颈总动脉结扎方法建立血管性痴呆大鼠模型,于造模60d后治疗组大鼠应用天智颗粒5g/(kg·d)治疗30d。采用三等分Y型电迷宫测试各组大鼠的学习记忆能力,应用免疫组织化学尿嘧啶脱氧核苷(BrdU)和胶质纤维酸性蛋白(GFAP)染色方法标记并观察神经细胞增殖变化,以比较各组大鼠学习记忆能力和神经细胞增殖的变化规律和差异。结果与正常对照组相比,假手术组大鼠的学习记忆能力和免疫组织化学检测结果无明显变化。经天智颗粒治疗30d后,治疗组大鼠学习记忆能力明显改善,与模型组相比差异有统计学意义(P<0.05),BrdU阳性细胞显著增加(P<0.05),而星形胶质细胞明显减少(P<0.05);但与正常对照组相比,其学习记忆能力、BrdU阳性细胞和星形胶质细胞数量仍未恢复至正常水平(P<0.05)。结论天智颗粒可通过促进神经前体细胞的增殖而抑制星形胶质细胞的增殖,从而改善血管性痴呆大鼠的学习记忆能力。 相似文献
997.
PURPOSE: Neuropeptide Y (NPY) has been shown to modulate seizure activities. To provide further understanding of the involvement of two of the most abundantly expressed NPY receptors, Y1 and Y2, we assessed the effect of Y1 and Y2 gene deletion on systemic kainic acid-induced seizures. We also examined the effect of rAAV-mediated hippocampal NPY overexpression on seizure susceptibility in these receptor knockout mice. METHODS: Recombinant adeno-associated viral vector overexpressing NPY (rAAV-NPY) or an empty vector control (rAAV-Empty) was injected into the hippocampus of adult C57BL/6-129/SvJ wild-type male mice and mice deficient of Y1 or Y2 receptors on the same background. Four weeks after vector injection, mice were subjected to systemic kainic acid-induced seizures, and the seizure behaviors were scored. RESULTS: The rAAV-mediated hippocampal overexpression of NPY led to a twofold reduction in seizures induced by systemic kainic acid in wild-type mice and Y1 receptor knockout mice but not in mice deficient of Y2 receptors. A differential action by the receptors was observed in the seizure-induced mortality rate, with increased fatality in Y2-/- mice. In addition, although NPY overexpression did not significantly affect the mortality rate in Y2-/- and wild-type mice, it abolished KA-induced mortality in Y1-/-mice. CONCLUSIONS: This study shows for the first time an altered susceptibility to chemically induced seizures in Y1 and Y2 knockout mice and demonstrates a differential seizure modulation mediated by these receptors via a genetic approach. 相似文献
998.
微创切取长屈肌腱重建慢性跟腱断裂 总被引:1,自引:0,他引:1
目的探讨微创切取长屈肌腱转移重建慢性跟腱断裂的临床效果。方法 2006年7月-2009年12月,收治22例22足慢性跟腱断裂患者。男16例,女6例;年龄28~65岁,中位年龄48岁。21例有患足用力蹬地史,1例无明显诱因。患者出现症状至手术时间为27~1 025 d,中位时间51 d。均有走路无力症状,Thompson试验呈阳性。根据美国矫形足踝协会(AOFAS)踝与后足疗效评价标准评分为(53.04±6.75)分。MRI示跟腱缺损长度为4.2~8.0 cm。术中作中足足底内侧切口和趾间关节跖侧平行横纹的小切口分步切取长屈肌腱,切取长度为超过跟骨结节10.5~13.5 cm,作3束反折编织缝合。界面螺钉或锚钉于跟骨后结节固定肌腱。结果术后患者切口均Ⅰ期愈合,无早期并发症发生。22例均获随访,随访时间12~42个月,平均16.7个月。术后12个月根据AOFAS踝与后足疗效评价标准评分为(92.98±5.72)分,与术前比较差异有统计学意义(t=—40.903,P=0.000);获优18例,良2例,可2例,优良率90.9%。随访期间均未见胫、腓肠神经损伤、跖底部痛性瘢痕、足底内外侧神经损伤。结论微创切取长屈肌腱转移重建慢性跟腱断裂具有切口小、术后恢复快、肌腱固定强度高以及并发症少的优点。 相似文献
999.
目的 建立2型糖尿病大鼠动物模型,探讨晚期糖基化终末产物及其受体在实验性2型糖尿病大鼠种植体骨整合过程中的变化及表达.方法 45只3个月龄SD健康雄性大鼠,将大鼠随机分为糖尿病模型组25只和正常对照组20只.首先建立2型糖尿病大鼠模型,建模成功后将模型大鼠随机分为DM组和DM种植组,每组10只.将20只正常组大鼠随机分为正常对照组和正常种植组,每组10只.分别于正常种植组和DM种植组的胫骨近骺端植入纯钛种植体,植入10周后于下腔静脉采血,保存所采集标本,用RF-5301PC型荧光分光光度计测定血清中AGEs含量的变化.硬组织标本采用不带种植体脱钙切片,以正常组为对照,HE染色后用免疫组织化学方法检测种植体周围RAGE的表达.结果 10周后,DM种植组和DM组与正常对照组和正常种植组相比,血清中AGEs的变化差异有统计学意义(P <0.05),正常种植组和DM种植组与正常对照组的种植体周围骨组织RAGE表达比较,差异均有统计学意义(P <0.05);DM种植组与DM组比较,差异亦有统计学意义(P <0.05).结论 种植体骨组织愈合过程中AGEs和RAGE相互作用是影响2型糖尿病种植体骨结合的机制之一. 相似文献
1000.
Shun Cui Fei Xiong Yan Hong Ji‐Ung Jung Xing‐Sheng Li Jian‐Zhong Liu Riqiang Yan Lin Mei Xu Feng Wen‐Cheng Xiong 《Journal of bone and mineral research》2011,26(5):1084-1098
Alzheimer's disease (AD), one of the most dreaded neurodegenerative disorders, is characterized by cortical and cerebrovascular amyloid β peptide (Aβ) deposits, neurofibrillary tangles, chronic inflammation, and neuronal loss. Increased bone fracture rates and reduced bone density are commonly observed in patients with AD, suggesting one or more common denominators between both disorders. However, very few studies are available that have addressed this issue. Here, we present evidence for a function of amyloid precursor protein (APP) and Aβ in regulating osteoclast (OC) differentiation in vitro and in vivo. Tg2576 mice, which express the Swedish mutation of APP (APPswe) under the control of a prion promoter, 1 exhibit biphasic effects on OC activation, with an increase of OCs in younger mice (< 4 months old), but a decrease in older Tg2576 mice (> 4 months old). The increase of OCs in young Tg2576 mice appears to be mediated by Aβ oligomers and receptor for advanced glycation end products (RAGE) expression in bone marrow macrophages (BMMs). However, the decrease of OC formation and activity in older Tg2576 mice may be due to the increase of soluble rage (sRAGE) in aged Tg2576 mice, an inhibitor of RANKL‐induced osteoclastogenesis. These results suggest an unexpected function of APPswe/Aβ, reveal a mechanism underlying altered bone remodeling in AD patients, and implicate APP/Aβ and RAGE as common denominators for both AD and osteoporosis. © 2011 American Society for Bone and Mineral Research. 相似文献