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   1784篇
  免费   176篇
  国内免费   18篇
耳鼻咽喉   80篇
儿科学   90篇
妇产科学   13篇
基础医学   313篇
口腔科学   52篇
临床医学   120篇
内科学   239篇
皮肤病学   32篇
神经病学   75篇
特种医学   143篇
外科学   147篇
综合类   141篇
预防医学   144篇
眼科学   5篇
药学   112篇
中国医学   39篇
肿瘤学   233篇
  2022年   23篇
  2021年   33篇
  2020年   25篇
  2019年   23篇
  2018年   26篇
  2017年   20篇
  2016年   27篇
  2015年   38篇
  2014年   53篇
  2013年   50篇
  2012年   78篇
  2011年   82篇
  2010年   93篇
  2009年   81篇
  2008年   60篇
  2007年   60篇
  2006年   86篇
  2005年   55篇
  2004年   48篇
  2003年   58篇
  2002年   37篇
  2001年   47篇
  2000年   42篇
  1999年   49篇
  1998年   68篇
  1997年   68篇
  1996年   68篇
  1995年   45篇
  1994年   37篇
  1993年   40篇
  1992年   27篇
  1991年   12篇
  1990年   19篇
  1989年   35篇
  1988年   27篇
  1987年   24篇
  1986年   22篇
  1985年   16篇
  1984年   14篇
  1983年   13篇
  1982年   18篇
  1981年   11篇
  1980年   14篇
  1977年   13篇
  1976年   15篇
  1975年   11篇
  1974年   13篇
  1971年   14篇
  1966年   9篇
  1961年   9篇
排序方式: 共有1978条查询结果,搜索用时 15 毫秒
61.
The kidneys in paroxysmal nocturnal hemoglobinuria   总被引:6,自引:0,他引:6  
Long-term study of 21 PNH patients revealed an unexpectedly high incidence of functional and anatomic renal abnormalities. Most patients demonstrated varying degrees of hematuria and proteinuria distinct from hemoglobinuria. Evaluation of renal function revealed hyposthenuria, abnormal tubular function, and declining creatinine clearance. Radiologically these patients had enlarged kidneys, cortical infarcts, cortical thinning, and papillary necrosis which were confirmed by autopsy studies. Hypertension developed in eight patients. Urinary tract infection was uncommon. The renal findings bear striking similarity to those of sickle cell anemia. Contrary to the usual opinion, out studies clearly showed evidence of widespread renal pathology in PNH most likely due to repeated microvascular thrombosis similar to the venous thrombosis involving other organs in this disorder.  相似文献   
62.
63.
A phase I clinical trial was initiated to treat patients with stage IV B-derived chronic lymphocytic leukemia (CLL) with the IgG2a murine monoclonal antibody T101. This antibody binds to a 65,000-mol wt (T65) antigen found on normal T lymphocytes, malignant T lymphocytes, and B- derived CLL cells. All of the patients had a histologically confirmed diagnosis of advanced B-derived CLL and were refractory to standard therapy, and more than 50% of their leukemia cells reacted with the T101 antibody in vitro. The patients received T101 antibody two times per week, over two to 50 hours by intravenous administration in 100 mL of normal saline containing 5% human albumin. Twelve patients were treated with a fixed dosage of 1, 10, 50, or 100 mg, and one patient was treated with 140 mg of antibody. It was demonstrated that patients given two-hour infusions of 50 mg developed pulmonary toxicity, with shortness of breath and chest tightness. This toxicity was eliminated when infusions of 50 or 100 mg of T101 were prolonged to 50 hours. All dose levels caused a rapid but transient decrease in circulating leukemia cell counts. In vivo binding to circulating and bone marrow leukemia cells was demonstrated at all dose levels with increased binding at higher dosages. Antimurine antibody responses were not demonstrated in any patients at any time during treatment. Circulating free murine antibody was demonstrated in the serum of only the two patients treated with 100 mg of antibody as a 50-hour infusion and the patient treated with 140 mg of antibody over 30 hours. Antigenic modulation was demonstrated in patients treated at all dose levels but was particularly apparent in patients treated with prolonged infusions of 50 and 100 mg of antibody. We were also able to demonstrate antigenic modulation in lymph node cells, which strongly suggests in vivo labeling of these cells. Overall, T101 antibody alone appears to have a very limited therapeutic value for patients with CLL. The observations of in vivo labeling of tumor cells, antigenic modulation, antibody pharmacokinetics, toxicity, and antimurine antibody formation may be used in the future for more effective therapy when drugs or toxins are conjugated to the antibody.  相似文献   
64.
本文详细介绍了在新疆发现的花蠕形蚤、叶氏蠕形蚤、北山羊蠕形蚤、羊长喙蚤和狍长喙蚤的形态学特点、地理分布和某些生物学特性。  相似文献   
65.
带蒂腹直肌包绕阴茎增强犬尿道压力的研究   总被引:1,自引:0,他引:1  
目的探讨采用带蒂腹直肌包绕球部尿道治疗男性尿失禁的可行性。方法成年雄性比格犬10条,游离阴茎周围组织,建立类似尿失禁模型。取长8.0cm,宽2.5cm全层带蒂的腹直肌。包绕球部尿道处阴茎1周。术前,术中,术后1个月、2个月分别测定尿道压力变化。结果术前平均最大尿道压力为(48.9±11.0)cm H_2O,使用带蒂腹直肌包绕阴茎后,平均最大尿道压力为(78.3±20.5)cmH_2O,与术前相比,差异有统计学意义(t=4.995,P<0.01)。术后1个月和术后2个月复查时,平均最大尿道最大压力分别为(92.2±31.6)cm H_2O和(88.3±22.4)cm H_2O,与术前相比差异均有统计学意义(t=4.011,P<0.01和t=6.058,P<0.01)。结论采用带蒂腹直肌包绕球部尿道能明显提高尿道压力,为采用此法治疗男性尿失禁提供了实验依据。  相似文献   
66.
Sclerosing cholangitis: CT findings   总被引:5,自引:0,他引:5  
The value of computed tomography (CT) in the detection of primary sclerosing cholangitis (PSC) in the intrahepatic and extrahepatic biliary systems was assessed by comparing CT scans of 20 cases of PSC with cholangiographic findings. In 16 of 19 cases of extrahepatic duct disease demonstrated with cholangiography, CT demonstrated abnormalities of the common hepatic duct, or bile duct, including duct stenosis, mural nodularity, duct dilatation, wall thickening, and mural enhancement. CT demonstrated intrahepatic disease in all 20 cases, including duct dilatation, duct stenosis, pruning, and beading. CT was superior to cholangiography in characterization of the status of the intrahepatic duct system in 11 of 20 cases. In addition, CT demonstrated extrabiliary complications of PSC in 12 cases and superimposed cholangiocarcinoma in three cases. While cholangiography remains the standard for diagnosis and follow-up of PSC, CT can provide valuable information about the extent and complications of the disease.  相似文献   
67.
目的 总结直视下尿道内切开术(direct vision internal urethrotomy,DVIU)治疗尿道狭窄的经验.方法 回顾性分析1990年6月至2010年6月20年间DVIU治疗尿道狭窄或闭锁患者361的临床资料.年龄16~72岁,平均38岁.病程3~78个月,平均16个月.狭窄或闭锁长度0.2~2.0 cm,平均1.1 cm.狭窄长度≤1.0 cm 238例,其中≤0.5 cm 63例(组1),0.6~1.0 cm 175例(组2),瘢痕厚度≤1.0 cm 148例,>1.0 cm 90例;狭窄长度1.1~2.0 cm 123例,其中1.1~1.5cm 85例(组3),1.6~2.0 cm 38例(组4),瘢痕厚度≤1.0 cm 44例,>1.0 cm 79例.结果 361例中手术失败3例.320例获随访,随访时间12~120个月,平均42个月.因狭窄复发而接受开放手术174例(54.4%),4组中转开放手术率分别为3.3%、49.7%、83.3%和97.1%.狭窄长度≤1.0cm者获随访207例,其中瘢痕厚度≤1.0 cm转开放手术27.2%(37/136),瘢痕厚度>1.0 cm转开放手术60.6%(43/71).狭窄长度>1.0 cm者获随访113例,其中瘢痕厚度≤1.0 cm转开放手术78.6%(33/42),瘢痕厚度>1.0 cm转开放手术84.5%(60/71).结论 当尿道狭窄长度≤0.5 cm时,DVIU术后转开放手术的比例明显减少;狭窄长度≤1.0 cm,瘢痕厚度≤1.0 cm者,DVIU也可获较好疗效.
Abstract:
Objective To summarize the experience and evaluate the efficacy of treatment of urethral stricture using direct visual internal urethrotomy (DVIU).Methods The clinical data of 361 patients (age range 16 -72 years, mean age 38 years) with urethral stricture who underwent urethrotomy from 1990 to 2010 was retrospectively analyzed.The disease course ranged from three months to 78 months with a mean of 16 months.The stricture length ranged from 0.2 to 2.0 cm (mean 1.1 cm).Stricture length was split into four main groups:stricture length≤0.5 cm in 63 (group 1 ), stricture length ranging between 0.6 and 1.0 cm in 175 ( group 2), stricture length ranging between 1.0 and 1.5 cm in 85 ( group 3 ) , and stricture length ranging between 1.6 and 2.0 cm in 38 ( Group 4).Of the 238 patients with length less than 1.0 cm there were 148 who's scar thickness were less than 1.0 cm, and 90 who's scar thickness were greater than 1.0 cm.Of the 123 patients with length less than 2.0 cm there were 69 who's scar thickness was less than 1.0 cm, and 54 who's scar thickness was greater than 1.0 cm.Results Three patients with DVIU failed because of long occlusion and false passage.Three hundred and twenty patients were followed-up from 12 to 120 months (mean:42).Re-openiag procedures were performed on 174 patients (54.4%) due to recurrence.The re-openiag procedure rate was 3.3%, 49.7%, 83.3% and 97.1% in Group1, Group2,Group3 and Group4, respectively.On the basis of scar thickness, of the 207 patients with stricture length less than 1.0 cm, 38 of 136 patients (27.9%) with scar thickness less than 1.0 cm underwent opening operation, and 43 of 71 patients (60.6%) with scar thickness more than 1.0 cm underwent opening operation.One hundred and thirteen patients with stricture length more than 1.0 cm, 33 of 42 patients (78.6%) with scar thickness less than 1.0 cm underwent opening operation, and 60 of 71 patients (84.5%) with scar thickness more than 1.0 cm underwent opening operation.Conclusions Good efficacy can be achieved in patients whose urethral stricture length is less than 0.5cm or whose stricture length and scar thickness is less than 1.0 cm using DVIU.  相似文献   
68.
 目的 分析超声各特征性影像表现在乳腺浸润性导管癌中的诊断价值。方法 选取解放军总医院第六医学中心 2018-01至2019-12两年内收治的 135例乳腺浸润性导管癌患者纳入本研究,分析乳腺浸润性导管癌的超声影像特征、体检自检发现率以及淋巴结转移与病变大小、位置的相关性。结果 (1)单因素分析显示:形态不规则(91.11%)、边界不清楚(64.44%)、血流信号(44.44%)、微钙化(37.78%)、纵横比>1(17.78%)、后方回声衰减(15.56%)超声诊断指标,与浸润性导管癌的诊断具有相关性;(2)与其他三个象限相比较,内上象限浸润性导管癌更容易被患者自检发现,占自检发现病例的34.93%;(3)内上象限及外上象限的浸润性导管癌更容易发生淋巴结转移(转移率为:内上:25.53%,内下:0.00%,外上:64.70%,外下:11.76%);(4)对<3 cm的浸润性导管癌,其大小与腋窝淋巴结的转移没有相关性。结论 超声表现以形态不规则在乳腺浸润性导管癌中的发生率最高,且在早期病变中即表现出来;乳腺病变的自检检出率、乳腺癌淋巴转移率均与乳腺病变的大小和位置密切相关。  相似文献   
69.
70.

Introduction

The retrojugular approach for carotid endarterectomy (CEA) has been reported to have the advantages of shorter operative time and ease of dissection, especially in high carotid lesions. Controversial opinion exists with regard to its safety and benefits over the conventional antejugular approach.

Methods

A systematic review of electronic information sources was conducted to identify studies comparing outcomes of CEA performed with the retrojugular and antejugular approach. Synthesis of summary statistics was undertaken and fixed or random effects models were applied to combine outcome data.

Findings

A total of 6 studies reporting on a total of 740 CEAs (retrojugular approach: 333 patients; antejugular approach: 407 patients) entered our meta-analysis models. The retrojugular approach was found to be associated with a higher incidence of laryngeal nerve damage (odds ratio [OR]: 3.21, 95% confidence interval [CI]: 1.46–7.07). No significant differences in the incidence of hypoglossal or accessory nerve damage were identified between the retrojugular and antejugular approach groups (OR: 1.09 and 11.51, 95% CI: 0.31–3.80 and 0.59–225.43). Cranial nerve damage persisting during the follow-up period was similar between the groups (OR: 2.96, 95% CI: 0.79–11.13). Perioperative stroke and mortality rates did not differ in patients treated with the retrojugular or antejugular approach (OR: 1.26 and 1.28, 95% CI: 0.31–5.21 and 0.25–6.50).

Conclusions

Currently, there is no conclusive evidence to favour one approach over the other. Proof from a well designed randomised trial would help determine the role and benefits of the retrojugular approach in CEA.  相似文献   
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