首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   28083篇
  免费   3132篇
  国内免费   1890篇
耳鼻咽喉   309篇
儿科学   504篇
妇产科学   554篇
基础医学   2653篇
口腔科学   432篇
临床医学   3275篇
内科学   3742篇
皮肤病学   318篇
神经病学   1364篇
特种医学   987篇
外国民族医学   11篇
外科学   3390篇
综合类   5380篇
现状与发展   6篇
一般理论   2篇
预防医学   2420篇
眼科学   482篇
药学   3012篇
  33篇
中国医学   1975篇
肿瘤学   2256篇
  2024年   142篇
  2023年   551篇
  2022年   1314篇
  2021年   1713篇
  2020年   1309篇
  2019年   1036篇
  2018年   1065篇
  2017年   1088篇
  2016年   961篇
  2015年   1498篇
  2014年   1763篇
  2013年   1914篇
  2012年   2516篇
  2011年   2533篇
  2010年   1812篇
  2009年   1419篇
  2008年   1593篇
  2007年   1445篇
  2006年   1294篇
  2005年   1139篇
  2004年   785篇
  2003年   770篇
  2002年   670篇
  2001年   522篇
  2000年   417篇
  1999年   326篇
  1998年   139篇
  1997年   170篇
  1996年   118篇
  1995年   107篇
  1994年   106篇
  1993年   55篇
  1992年   110篇
  1991年   105篇
  1990年   90篇
  1989年   75篇
  1988年   80篇
  1987年   65篇
  1986年   54篇
  1985年   37篇
  1984年   25篇
  1983年   20篇
  1982年   11篇
  1981年   10篇
  1980年   18篇
  1979年   16篇
  1978年   13篇
  1977年   10篇
  1971年   8篇
  1970年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
目的比较前列腺动脉栓塞术(PAE)与经尿道前列腺电切术(TURP)治疗良性前列腺增生的疗效与安全性,为前列腺增生症适宜治疗方案的选择提供理论依据。方法通过检索PubMed、EMBASE、Cochrane Library、CNKI、CBM、维普和万方等数据库,筛选出符合要求的PAE和TURP对比研究,并对所有纳入文献进行质量评价和资料提取,最后应用统计学软件Rev Man 5.3进行Meta分析,比较PAE与TURP治疗良性前列腺增生的优劣势。结果本研究最终共纳入9篇文献,共计675例患者。Meta分析结果显示:①临床疗效方面,术后3个月,TURP组优于PAE组,疗效指标IPSS、QOL、Qmax、PVR、PV的改善差异有统计学意义;术后12个月,TURP组改善情况优于PAE组,虽然指标IPSS、PVR的改善差异无统计学意义,但其余指标QOL、Qmax、PV的改善差异具有统计学意义;术后24个月,PAE组与TURP组治疗效果相近,指标IPSS、QOL、Qmax、PVR、PV的改善差异无统计学意义;PAE组失败率(4.4%)大于TURP组(0.5%);②安全性方面,PAE组比TURP组术中出血量少[MD=-98.25,95%CI:-105.51^-91.00,P<0.00001]、留置导尿时间短[MD=-1.61,95%CI:-2.31^-0.90,P<0.0006]、住院时间短[MD=-3.07,95%CI:-4.40^-1.74,P<0.00001];两组手术时间差异无统计学意义[MD=17.28,95%CI:-15.92~50.48,P=0.31];PAE组并发症(21.6%)少于TURP组(33.7%)。结论PAE治疗良性前列腺增生短期疗效(3个月)不及TURP;但中长期疗效(24个月)与TURP相近。总体来说,PAE较TUPR安全性高,具有术中出血量少,留置导尿时间短、住院时间短、并发症少的优点,对于不能耐受麻醉及TURP者可选择PAE治疗良性前列腺增生。但PAE手术失败率相对较高,其疗效的稳健性相对较差,目前尚没有足够的证据认定PAE优于TURP。未来随着更大样本、更多中心以及设计精良的随机对照试验出现,PAE用于治疗前列腺增生的疗效可以得到进一步的论证。  相似文献   
992.
目的探讨平行重叠吻合法在3D腹腔镜右半结肠癌根治术中的应用价值。方法采用回顾性横断面研究方法。收集2016年7月至2019年7月河南省人民医院收治的138例行3D腹腔镜右半结肠癌根治术患者的临床病理资料;男83例,女55例;中位年龄为64岁,年龄范围为30~76岁。138例患者术前右半结肠肿瘤均经肠镜及病理学检查确诊为恶性肿瘤;所有患者按日本大肠癌协会第9版《大肠癌规约》进行淋巴结清扫,严格遵循无瘤原则行右半结肠切除术。观察指标:(1)手术情况。(2)术后情况。(3)随访情况。采用门诊或电话方式进行随访,了解患者生存和肿瘤复发转移情况。随访时间截至2019年9月。正态分布的计量资料以±s表示。偏态分布的计量资料以M(范围)表示。计数资料以绝对数或百分比表示。结果(1)手术情况:138例患者均行3D腹腔镜右半结肠癌根治术,消化道重建采用平行重叠吻合法,无1例中转开腹。138例患者手术时间为(151.0±54.0)min,平行重叠吻合时间为(20.1±2.0)min,术中出血量为(60±21)mL。(2)术后情况:138例患者术后首次肛门排气时间为(2.5±0.4)d,术后进食半流质食物时间为(4.0±1.3)d,手术辅助切口长度为(3.0±0.2)cm,术后并发症发生率为3.62%(5/138)。5例术后发生并发症的患者中,1例肠梗阻经胃肠减压、营养支持等保守治疗后痊愈;1例吻合口漏,经胃肠减压、局部通畅引流、控制感染、营养支持等保守治疗后痊愈;1例腹腔积液伴感染行CT引导下置管引流后痊愈;1例切口感染给予控制感染,加强换药,局部冲洗引流后痊愈;1例肺部感染,经抗感染治疗后痊愈。138例患者术后清扫淋巴结数目为(19±8)枚,术后住院时间为(7.2±4.1)d,治疗费用为(4.8±1.4)万元。138例患者术后病理学检查结果示结肠腺癌,其中低分化腺癌27例,中分化腺癌92例,高分化腺癌10例,黏液腺癌9例。(3)随访情况:138例患者中,133例获得随访,随访时间为2~38个月,中位随访时间为18个月。随访期间,2例患者死亡(1例术后16个月发现多发肝转移,术后21个月死亡;1例术后20个月发现多发肝转移,术后24个月死亡),8例出现肿瘤远处转移,其中肝转移5例,肺转移1例,腹腔转移2例,死亡及转移患者的术后病理学分期均为Ⅲ期。其余123例患者一般情况良好。结论平行重叠吻合法应用于3D腹腔镜右半结肠癌根治术中安全、有效。  相似文献   
993.
目的评价腹腔镜下膀胱腰大肌悬吊输尿管膀胱再植术治疗输尿管远端缺损的有效性及安全性。方法回顾性分析本院2014年4月至2018年3月期间行腹腔镜下膀胱腰大肌悬吊法处理的输尿管下段较长缺损患者15例。其中男性患者6例,女性患者9例,年龄23~68岁,平均42岁。病变位于左侧10例,右侧5例。彩超提示肾盂分离平均2.7(1.4~5.2)cm,患者平均体重指数(BMI)为23.8(19.8~28.5)kg/m^2。术前评估缺损段长度平均4.8(3.0~8.0)cm。结果所有患者手术均经腹腔镜顺利完成,无中转开放。患者平均手术时间为125(90~210)min,平均手术失血量是75(30~150)mL。术后平均尿管拔除时间为7.2(5.0~11.0)d,术后平均住院8.7(5.0~14.0)d,术后输尿管支架管平均拔除时间为46(28~90)d,平均随访时间19.2(4.0~34.0)个月。围手术期无重大并发症,所有患者均出现症状缓解,排尿良好。结论腹腔镜下膀胱腰大肌悬吊输尿管膀胱再植术治疗输尿管下段较长缺损安全、有效,具有学习曲线短,手术创伤小,出血少,术后恢复快,并且可以完全保证输尿管无张力及连续性等优点,短期随访效果满意。  相似文献   
994.
目的探讨腹腔镜袖状胃切除术(LSG)胃切缘出血的相关因素与处理措施。 方法回顾性分析2017年1月至2018年12月82例行LSG术患者资料,采用SSPS20.0软件统计分析,统计术中胃切缘出血与切缘血管处理及术中血压的关系,采用χ2检验,P<0.05差异具有统计学意义。 结果患者BMI≥40、高血压、有阻塞性睡眠呼吸暂停(OSA)与胃切缘出血率的关系密切(P<0.01);切割胃壁后胃切缘出血60例(73.2%),胃切缘无出血22例(26.8%)。术中胃壁切割闭合前,进行切缘血管预夹闭28例,切割后发生出血10例;未进行切缘血管预夹闭54例,切割后发生出血50例(χ2=30.39,P=0.000)。切割胃壁过程中26例患者血压大于130 mmHg,其中14例切缘出血需要处理;56例患者血压小于等于130 mmHg,其中15例切缘出血需要处理(χ2=5.69,P=0.017)。 结论LSG中预夹闭切缘血管可有效减少胃切缘出血,控制术中血压130 mmHg以下可减少胃切缘出血,且胃切缘出血后通过夹闭切缘血管和降低血压至130 mmHg以下可以有效控制出血。  相似文献   
995.
The experience of using pediatric donors in split liver transplant is exceedingly rare. We aim to investigate the outcomes of recipients receiving split pediatric grafts. Sixteen pediatric recipients receiving split liver grafts from 8 pediatric donors < 7 years were enrolled. The donor and recipient characteristics, perioperative course, postoperative complications, and graft and recipient survival rates were evaluated. The mean follow‐up time was 8.0 ± 2.3 months. The graft and recipient survival rates were 100%. The liver function remained in the normal range at the end of the follow‐up time in all recipients. No life‐threatening complications were seen in these recipients, and the only surgery‐related complication was portal vein stenosis in 1 recipient. Cytomegalovirus infection was the most common complication (62.5%). The transaminase level was significant higher in extended right lobe recipients in the early postoperative days, but the difference vanished at the end of first week; postoperative complications and graft and recipient survival rates did not differ between left and right graft recipients. Notably, the youngest split donor graft (2.7 years old) was associated with ideal recipient outcomes. Split liver transplant using well‐selected pediatric donors is a promising strategy to expand pediatric donor source in well‐matched recipients.  相似文献   
996.
Treating chronic skin wounds in patients with diabetes, bed sores, or stasis dermatitis is typically a time‐consuming and costly process, and the outcome is not always promising. Concentrated growth factor (CGF) obtained from the autologous venous blood of patients via fractional centrifugation is employed for producing a CGF gel or membrane that can be applied to expedite self‐regeneration of skin wounds. In this case report, we presented the results from 18 patients with chronic skin wounds treated with a CGF gel or membrane produced from autologous venous blood. Noticeable granulation tissue and regenerated epidermal coverage were observed in 16 patients who received CGF treatment over various time courses, thereby demonstrating the significant therapeutic effects of CGF treatment in overall wound healing. The other two patients with stasis ulcers in their calves failed to respond to the treatment because of the comorbidity of iliac vein thrombosis. In addition, by culturing HaCaT keratinocytes using CGF membrane as the foundation, we observed that HaCaT cells attached to the CGF membrane migrated and proliferated to form an epithelium‐like structure. Comprehensively, the clinical results infer that CGF gel can expedite the regeneration of the soft tissue at the wound, whereas CGF membrane may facilitate its marginal re‐epithelialisation. The combination of the two can promote autologous regeneration of both deep and superficial wounds effectively and safely.  相似文献   
997.
The objective of this study is to investigate the mechanism whereby innate immune molecule surfactant protein D (SP‐D) attenuates sepsis‐induced acute kidney injury (AKI) through modulating apoptosis and nuclear factor kappa‐B (NFκB)‐mediated inflammation. In the present study, a mouse sepsis model was established by cecal ligation and puncture in SP‐D knockout (KO) mice and wild‐type (WT) mice. A sham‐operated group was included as the control. The experimental materials were extracted 6 and 24 hours postoperatively. The plasma levels of tumour necrosis factor alpha (TNF‐α) and MCP‐1 were determined by enzyme‐linked immunosorbent assay (ELISA). Apoptosis was measured by double staining with Annexin V/propidium iodide and flow cytometry. The levels of NFκB in renal tissues were measured by ELISA and Western blotting assay. Apoptosis was detected by TUNEL assays. There were no significant differences in plasma TNF‐α levels between the WT sham group and the KO sham group at 6 and 24 hours postoperatively (P < .05), but the levels of TNF‐α in the WT sepsis and KO sepsis groups were significantly higher than those in controls (P < .05). The levels of TNF‐α in the KO sepsis group were significantly higher than those of the WT sepsis group (P < .05). TNF‐α levels in the WT sepsis group and the KO sepsis group at 24 hours postoperatively were significantly higher than those at 6 hours postoperatively (P < .05). The levels of MCP‐1 in the WT sepsis group and the KO sepsis group at 6 and 24 hours postoperatively were significantly higher than those in the control group (P < .05), and MCP‐1 levels in the KO sepsis group were significantly higher than those in the WT sepsis group (P < .05). MCP‐1 levels in the WT sepsis group and the KO sepsis group at 24 hours postoperatively were significantly higher than those at 6 hours postoperatively (P < .05). The expression of SP‐D in WT kidneys was significantly lower at 6 and 24 hours postoperatively (P < .05). The number of TUNEL‐positive cells in the kidneys from septic SP‐D KO mice was significantly higher (P < .05). The levels of NFκB in septic mice were significantly increased at 6 and 24 hours after induction of sepsis compared with the sham‐operated group compared with those of septic SP‐D KO mice and WT mice (P < .05). Innate immune molecule SP‐D significantly decreased plasma levels of inflammatory cytokines in mice and attenuated sepsis‐induced AKI by inhibiting NFκB activity and apoptosis.  相似文献   
998.
999.
1000.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号