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   14610篇
  免费   1225篇
  国内免费   417篇
耳鼻咽喉   282篇
儿科学   429篇
妇产科学   971篇
基础医学   996篇
口腔科学   534篇
临床医学   1656篇
内科学   3368篇
皮肤病学   131篇
神经病学   370篇
特种医学   352篇
外国民族医学   5篇
外科学   1592篇
综合类   2089篇
现状与发展   1篇
预防医学   750篇
眼科学   189篇
药学   1206篇
  27篇
中国医学   683篇
肿瘤学   621篇
  2024年   28篇
  2023年   287篇
  2022年   448篇
  2021年   687篇
  2020年   665篇
  2019年   649篇
  2018年   555篇
  2017年   632篇
  2016年   644篇
  2015年   590篇
  2014年   1029篇
  2013年   1161篇
  2012年   886篇
  2011年   901篇
  2010年   741篇
  2009年   689篇
  2008年   649篇
  2007年   651篇
  2006年   606篇
  2005年   548篇
  2004年   415篇
  2003年   357篇
  2002年   310篇
  2001年   271篇
  2000年   228篇
  1999年   186篇
  1998年   172篇
  1997年   134篇
  1996年   143篇
  1995年   128篇
  1994年   103篇
  1993年   81篇
  1992年   84篇
  1991年   78篇
  1990年   57篇
  1989年   52篇
  1988年   51篇
  1987年   30篇
  1986年   26篇
  1985年   46篇
  1984年   48篇
  1983年   39篇
  1982年   45篇
  1981年   30篇
  1980年   27篇
  1979年   10篇
  1978年   20篇
  1977年   13篇
  1976年   9篇
  1968年   2篇
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
51.
目的研究重型颅脑损伤后早期鼻饲生大黄粉对防治上消化道出血的作用.方法选择GCS3~8分重型颅脑损伤患者90例,随机选45例(实验组)伤后早期(24~48h)鼻饲生大黄粉,另45例(对照组)未予生大黄粉治疗.所有患者其他治疗措施均基本相同.结果39例患者出现上消化道出血.其中实验组14例,有13例上消化道出血治愈,治愈时间(7.6±2.5)d;对照组25例,有16例上消化道出血治愈,治愈时间(13.4±3.3)d.实验组上消化道出血率和上消化道出血治愈平均时间均显著低于对照组(P<0.05),而上消化道出血治愈率显著高于对照组(P<0.05).结论早期鼻饲生大黄粉能有效防治重型颅脑损伤后并发上消化道出血,值得临床推广应用.  相似文献   
52.
新式非脱垂子宫阴式全子宫切除术45例报告   总被引:3,自引:1,他引:2  
目的探讨非脱垂子宫经阴道改良切除的可行性及方法。方法将103例子宫肌瘤、子宫腺肌瘤、功能性子宫出血等需行全子宫切除术的患者随机分为两组,常规经腹式全子宫切除术(腹式组)58例,经阴道全子宫切除术(阴式组)45例,比较两种手术方法的优劣。结果阴式组较腹式组手术时间短,术中出血少,术后痛苦少;48h内肛门排气阴式组40例(88.9%),腹式组31例(53.4%);平均住院天数阴式组5.1d,腹式组7.1d。结论新式非脱垂子宫的阴式全子宫切除术相对于经腹式全子宫切除术有一定的优势,但要严格选择其手术适应证。  相似文献   
53.
A retrospective multicentre study of 341 children with persistent/recurrent, isolated haematuria is described. The haematuria was isolated for at least 6 months at the beginning of observation. The duration of follow-up was 2–5 years in 201, 5–10 years in 119, 10–15 years in 19, and over 15 years in 2 cases. Of these patients 47.8% became symptom-free. In 18.4% the haematuria remained isolated; in 13.8% it was combined with proteinuria over 250 mg/day more than 2 years later. The occurrence of associated proteinuria increased progressively with time. It was 8.6% between the 3rd and 5th years, and 37.0% after the 5th year. Renal biopsy was performed because of the symptoms of glomerular disease in 47 cases at an average time of 12 months following the appearance of proteinuria. Proteinuria appeared after a 2–5, 5–10, 10–15 and more than 15 years follow-up period in 16, 23, 6, and 2 patients respectively; 14 of them had Alport's nephropathy. The percentage of more serious azotaemia was 1.7 (creatinine clearance: 10–50 ml/min per 1.73 m2) and 0.3 (creatinine clearance: < 10 ml/min per 1.73 m2). Mortality was 0.58%. Most of the patients who developed severe azotaemia had persistent microscopic haematuria at the beginning. The prevalence of hypertension was only 1.2%. The time of its appearance was above 5 years in 2 and below 5 years in 2 cases. All these patients had chronic glomerulonephritis. The haematuria was associated with hypercalciuria in 19.9%. In 14.3% of the overall group of patients urolithiasis developed 2–15 years after onset. All of these had hypercalciuria. Our findings suggest that symptoms of isolated haematuria may last for a longterm period and need systematic control. When proteinuria and/or hypertension is associated with haematuria a worse prognosis can be expected.Participating paediatric hospitals and university departments: Second Department of Paediatrics, I. Semmelweis Medical University of Budapest (M. Visy); Department of Paediatrics, University Medical School of Pécs (V. Jászai); Department of Paediatrics, A. Szent-Györgyi Medical University of Szeged (I. Haszon, S. Túri); County Children's Hospital, Miskolc (Á. Vissy); P. Heim Children's Hospital, Budapest (Z. Czirbesz); County Children's Hospital, Györ (Zs. Szelid); Buda-Children's Hospital, Budapest (I. Ferkis); I. Apáthy Hospital, Budapest (J. Kisbán); János Hospital, Budapest (I. Marosváry); Hospital of Hungarian State Railway, Budapest (J. Fehér); L. Madarász Hospital, Budapest (F. Kalmár); South Pest Hospital, Budapest (G. Halász); County Children's Hospital, Pécs (E. Kolman); County Children's Hospital, Gyula (P. Sipos); County Children's Hospital, Szolnok (I. Jaksics); County Children's Hospital, Debrecen (Á. Miskolczi); County Children's Hospital, Tatabánya (I. Kiss); County Children's Hospital, Eger (M. Frank, E. Ladányi); County Children's Hospital, Nyíregyháza (E. Bujdosó); County Children's Hospital, Szombathely (M. Andics); Kerepestarcsa Hospital, Budapest (M. Marcell); Komárom Hospital, Komárom (J. Kecskés)  相似文献   
54.
The usefulness of carcinoembryonic antigen (CEA) as an indicator for recurrence and a guide to the treatment was evaluated from a retrospective analysis of 88 patients with recurrent gastric cancer. Sixty-two of these patients (70.5 per cent), 25 of whom had a preoperative positive assay, and 37 a negative assay, had elevated levels of CEA after disease progression. Averaged CEA level in patients with liver metastasis was significantly higher (872 ng/ml) than in those with peritoneal metastasis (68 ng/ml), with lymph node metastasis (103 ng/ml) or with local metastasis (93 ng/ml) (p<0.01). An elevation of CEA was found prior to the clinical manifestation of recurrence, and the average lead time was 4 months. In 25 patients with a lead time of more than 4 months, survival time after CEA elevation was 13.3 months, which was longer than the 6.5 months of 28 patients with less than 4 months. Thirty-seven of the 88 patients were treated after recurrence. The average survival period after the detection of recurrence was 9.4 months in patients with surgical treatments followed by chemotherapy, 5.9 months in those with chemotherapy alone and 3.8 months in those with surgery alone. The average survival period of 26 patients with positive CEA assays in recurrence was 5.1 months longer than of patients with negative assays. This fact suggested that early detection of recurrence followed by various treatments, in the elevated CEA group, contributes to favorable results.  相似文献   
55.
A 66-year-old man died of massive gastrointestinal hemorrhage caused by a fistula between the third portion of the duodenum and the abdominal aorta. An autopsy revealed that duodenal tuberculosis had resulted in the development of a fistula into the aorta with no pathological changes, and no active pulmonary tuberculosis was found. Duodenal tuberculosis and primary aortoduodenal fistula (ADF) without an aneurysm are both extremely rare. Thus, we report herein a unique case of primary aortoduodenal fistula without an abdominal aortic aneurysm, but associated with duodenal tuberculosis, and review the current literature.  相似文献   
56.
ABSTRACT. Two atypical cases of colitis due to cow's milk protein intolerance (CMPI) are reported, affecting preterm infants. One developed a toxic dilatation of the colon and responded well to a casein hydrolysate based feed. The second presented insidiously and failed to tolerate a casein hydrolysate, but responded well to a chicken-based modular feed.  相似文献   
57.
Hemoglobin-heme is variably converted to porphyrin during enterocolic transit. This intestinal converted fraction, as measured by HemoQuant, was elevated as a predictor of the occult bleeding site in 152 patients with discrete lesions. The intestinal converted fraction, expressed as the percentage of total fecal hemoglobin, was similar with upper gastrointestinal and proximal colon lesions. Within the colon, values trended downward with more distal location: means ± standard deviations were 18±14 proximal colon, 16 ±15 sigmoid, and 10±10 rectum. The amount of fecal blood also affected the intestinal converted fraction; correcting for hemoglobin concentration improved separation by site. Corrected intestinal converted fraction values were significantly lower with rectal (P< 0.0005) and sigmoid (P<0.02) lesions than with proximal colon lesions. Unfortunately, large within-site variation caused considerable overlap between sites. We conclude that the intestinal converted fraction is influenced by the site and amount of bleeding. However, its clinical utility is compromised by substantial individual differences in luminal hemoglobin metabolism.Presented in part at the Annual meeting of the American Gastroenterological Association in San Francisco in May of 1986 (Gastroenterology 90:1431, 1986).Supported by the Mayo Foundation.  相似文献   
58.
上消化道出血798例分析   总被引:33,自引:0,他引:33  
目的 探讨上消化道出血的病因和相关因素。方法 回顾性分析我院 8年来 798例上消化道出血病人的临床资料。结果 男性并发上消化道出血占 80 .2 0 %、女性占 19.80 % ,男性明显高于女性 (χ2 =6 .5 6 ,P <0 .0 5 ) ;青年人、中年人及老年人各占 2 7.82 %、5 7.6 1%和 14 .5 7% (P <0 .0 1) ,老年人合并重度上消化道出血多见 ;不同性别、年龄者出血的原因不尽相同。结论 上消化道出血的病人以消化性溃疡、胃癌、急性胃粘膜损害、食道胃底静脉曲张为最常见的病因 ,性别、年龄等均为上消化道出血的相关因素  相似文献   
59.
Objective: To investigate the clinical efficacy of estrogen or contraceptives in the treatment of acute bleeding of dysfunctional uterine bleeding (DUB) in adolescent patients and the optimal starting dosage of drugs.Methods: The clinical records of 106 girls who with DUB and moderate or severe anemia from February 1990 to July 2005 were analyzed retrospectively.Results: All 106 patients received hormonal therapy. 56 patients were treated with estradiol benzoate(E2), 30 patients with conjugated equine estrogen(CEE) and 20 patients with combined oral contraceptives (COCs). The rates for rapidly controlling bleeding and for rapidly stopping bleeding in E2 group were higher than those in CEE group ,but similar to those in COCs group. The days for controlling and completely stopping bleeding were not significantly different between the starting dosages (≤8 mg/d and >8 mg/d) of E2 groups, and also there were no statistical difference between the starting dosages (<7.5 mg/d and ≥7.5 mg/d) of CEE groups, but during the treatment the rate of increasing the dosage in <7.5 mg/d group was higher than that of ≥7.5 mg/d group(40% vs. 5%),while there were no statistical difference between the starting dosages (≤3 pills/d and >3 pills/d) of COCs groups. Conclusions: The clinical efficiency of E2 treatment on DUB in adolescent patients is similar to that of COCs. And the efficacies of treatment of DUB with E2, CEE and COCs in the different dosages are similar.  相似文献   
60.
CHIP (325 mg/M2), a second generation cisplatin derivative, was administered intravenously every 3 weeks to 85 pediatric patients with recurrent sarcomas (19), osteosarcomas (20), neuroblastoma (23), germ cell tumors (10), and other malignant tumors (7). Thirty-eight of them had been previously exposed to cisplatin. Partial remissions were only observed in 3 of 23 (13% SE=7%) patients having neuroblastoma. Severe thrombocytopenia (65%) and neutropenia (35%) were the dose limiting factors.  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