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   5363篇
  免费   377篇
  国内免费   19篇
耳鼻咽喉   89篇
儿科学   211篇
妇产科学   63篇
基础医学   540篇
口腔科学   103篇
临床医学   414篇
内科学   1012篇
皮肤病学   146篇
神经病学   322篇
特种医学   301篇
外国民族医学   1篇
外科学   894篇
综合类   163篇
一般理论   6篇
预防医学   306篇
眼科学   145篇
药学   624篇
中国医学   41篇
肿瘤学   378篇
  2023年   38篇
  2022年   78篇
  2021年   203篇
  2020年   110篇
  2019年   143篇
  2018年   176篇
  2017年   104篇
  2016年   147篇
  2015年   147篇
  2014年   192篇
  2013年   259篇
  2012年   385篇
  2011年   355篇
  2010年   216篇
  2009年   187篇
  2008年   298篇
  2007年   296篇
  2006年   274篇
  2005年   249篇
  2004年   217篇
  2003年   209篇
  2002年   165篇
  2001年   129篇
  2000年   112篇
  1999年   103篇
  1998年   44篇
  1997年   44篇
  1996年   44篇
  1995年   38篇
  1994年   40篇
  1993年   35篇
  1992年   73篇
  1991年   68篇
  1990年   51篇
  1989年   51篇
  1988年   63篇
  1987年   50篇
  1986年   53篇
  1985年   56篇
  1984年   42篇
  1983年   27篇
  1982年   15篇
  1981年   17篇
  1980年   12篇
  1979年   22篇
  1978年   14篇
  1974年   9篇
  1972年   10篇
  1971年   12篇
  1968年   9篇
排序方式: 共有5759条查询结果,搜索用时 265 毫秒
21.
Buserelin, a luteinizing hormone releasing hormone agonist was administered nasally in doses of 900 micrograms daily to inhibit the ovarian cycle. Of 16 patients recruited, ten completed the treatment. Daily symptoms were measured on the Visual Analogue Scale and Trigg's trend analysis utilized for the analysis. The peak severity of symptoms (ESAmax) and the maximum global scores (Gmax) reduced on buserelin treatment. The minimum global scores (Gmin) and the minimum score for each symptom (ESAmin) increased, suggesting worsening of underlying symptoms. The difference between ESAmax and ESAmin (ESAdelta) and Gmax and Gmin (Gdelta) were calculated to determine the degree of symptom change. The delta scores for symptoms of depression, bloatedness and breast symptoms, and Gdelta were significantly reduced (p less than 0.05) on buserelin, whilst the latter significantly worsened in the follow-up months. Side-effects may limit the place of buserelin in the long-term treatment of premenstrual syndrome, although combination of additional hormonal treatment may facilitate long-term treatment.  相似文献   
22.
A double-blind placebo-controlled study in children showed codergocrine mesylate to be effective in improving cognitive functions and behavioural symptoms associated with learning disorders. Forty randomly grouped children of either sex were given an increasing dosage of codergocrine mesylate and followed up for 12 weeks. A significant improvement was noted in speech (acquisition of new words, comprehensibility/meaningfulness of speech), sociability, attention/concentration, comprehension and memory. Improvement in behaviour (emotional lability and cooperativeness) was also noted. Problems of assessing cognitive progress in very young children with culturally appropriate methods were encountered.  相似文献   
23.
Calcineurin inhibitor (CNI) withdrawal has been used as a strategy to improve renal allograft function, however, it also carries risk of acute rejection. We conducted a systematic review of randomized trials that involved CNI withdrawal from a sirolimus-based immunosuppressive regimen. The search strategy yielded six trials (n = 1047 patients) reported in eight publications. CNI withdrawal from sirolimus-based therapy, was associated with an increased risk of acute rejection (risk difference, 6%; 95% CI 2-10%, p = 0.002) but a higher creatinine clearance (mean difference, 7.49 mL/min; 95% CI 5.08-9.89 mL/min, p < 0.00001) at 1 year compared to continued CNI and sirolimus therapy. Graft loss (relative risk, 0.87; 95% CI 0.46-1.64, p = 0.66) and death (relative risk, 0.88; CI 0.40-1.96, p = 0.76) were similar in both groups at 1 year. Hypertension was significantly reduced in the CNI withdrawal group (relative risk, 0.56; 95% CI 0.40-0.78, p = 0.0006). CNI withdrawal from sirolimus-based therapy is associated with an increased risk of acute rejection in the short term with a significant improvement in renal function and a reduction in hypertension. Longer follow-up is needed to determine if these changes will result in a significant improvement in patient and graft survival.  相似文献   
24.
Spillage of gallstones may occur in the course of laparoscopic cholecystectomy. The incidence of this mishap and its consequences are variable. Ignored by many surgeons, stone spillage may be the source of significant morbidity many years after surgery. In this report, we describe the clinical course of a patient who presented with upper abdominal pain and swelling. The past history was positive for laparoscopic cholecystectomy 15 years earlier. After excision, the swelling was found to be a pseudocyst formed around spilled gallstones during a previous cholecystectomy. Apart from postoperative wound infection, the patient recovered well and remains so. Here, we discuss the problem and provide suggestions for spillage prevention and stone retrieval once spillage occurs.  相似文献   
25.
26.
Birthweight is an important indicator of child survival. Appropriate and timely care of a newborn specially if he is born with low birthweight is important but this is difficult in developing countries since most of the deliveries are conducted at home where adequate facilities to weigh a new born does not exist. This study was conducted to find out a surrogate which could efficiently be used for detecting low birthweight babies at birth when no weighing machine is around. In this study 41% of the newborn babies were found to weigh less than 2,500 gm at birth. Out of this about 52% were females. The mean chest, thigh and mid-arm circumference at birth for males were 30.89 cm, 15.06 cm and 9.27 cm respectively with standard deviations of 1.83 cm, 1.30 cm and 1.04 cm. Corresponding figures for female babies were 30.69 cm, 15.14 cm and 9.25 cm respectively with standard deviations of 2.08 cm, 1.70 cm and 1.16 cm. Correlation co-efficient between normal birthweight and the chest, thigh and mid-arm circumference were 0.867, 0.845 and 0.842 respectively. A liner regression analysis showed that a chest circumference of 30.14 cm, a thigh circumference of 14.56 cm and a mid-arm circumference of 8.90 cm corresponded well with a birthweight of 2,500 gm. On this basis sensitivity, specificity and predictive values of the chest circumference was better than the other two measurements. However, the mid-arm circumference was observed to be more reliable than the other two measurements for detecting birthweight less than 2,000 gm. A home made measuring tape has been devised on this basis to detect brithweights with cut-off values for 2,500 gm, 2,000 gm to 2,500 gm and 2,000 gm in different shades of colour for illiterate birth attendants.  相似文献   
27.
A case of bilateral vocal cord palsy caused by relapsing polychondritis is presented. The diagnosis was not suspected preoperatively and was made solely on histopathology. A case is made for histological examination of cartilage removed during routine tracheostomy.  相似文献   
28.
1. In the present study we have evaluated whether alpha 2-adrenoceptor binding sites on bovine cerebral cortex membranes labelled by [3H]-clonidine, [3H]-idazoxan and [3H]-RX-821002 can distinguish between known agonists and antagonists. This model has then been used to compare the binding profiles of the putative non-catecholamine, clonidine-displacing substance (CDS), agmatine and crude methanolic extracts of bovine lung and brain. 2. Saturation studies carried out in the presence and absence of noradrenaline, 10 mumol 1(-1), revealed that the maximum number of binding sites on bovine cerebral cortex membranes for [3H]-idazoxan and [3H]-RX-821002 were approximately 60-80% greater than those for [3H]-clonidine (62.6 fmol mg-1 protein). Rauwolscine, the selective alpha 2-adrenoceptor antagonist, was approximately 100 fold more potent against each of the ligands than the selective alpha 1-adrenoceptor diastereoisomer, corynanthine. Also, the pKi value for the selective alpha 1-adrenoceptor prazosin against each ligand was less than 6. 3. Adrenaline, UK-14034, rauwolscine, corynanthine, RX-811059 and prazosin produced concentration-dependent inhibition of binding of all three 3H-ligands. The agonists, adrenaline and UK-14304, were approximately 5 and 10 fold less potent against [3H]-idazoxan and [3H]-RX-821002, respectively, than against [3H]-clonidine. In marked contrast, the antagonists, rauwolscine, corynanthine, RX-811059 and prazosin exhibited a different profile, being approximately 2-3 fold more potent against sites labelled by [3H]-RX-821002 and [3H]-idazoxan compared to sites labelled by [3H]-clonidine.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
29.
BACKGROUND: Spironolactone is useful in heart failure, but is not given to dialysis patients for fear of hyperkalaemia. This study evaluated the safety of spironolactone administration in haemodialysis patients. METHODS: Fifteen haemodialysis outpatients with mean serum potassium <5.6 mEq/l over the preceding 4 months were treated with spironolactone 25 mg daily for 28 days. Serum potassium was measured before every haemodialysis during the study. Aldosterone and renin were measured at the beginning and end of the study. Patients were monitored for side effects. Data were examined with a paired t-test, with patients serving as their own controls and P < 0.05 considered significant. A sample size of 14 was required to achieve a power of 0.8 and a P = 0.05 to detect a potassium difference of 0.5 +/- 0.6 mEq/l. All patients were analysed as intention-to-treat. RESULTS: The mean potassium level was 4.6 +/- 0.6 mEq/l at baseline and 4.9 +/- 0.9 mEq/l at study completion (P = 0.14). Thirteen patients completed the trial with no potassium levels >6.0 mEq/l. Four patients had potassium levels between 5.5 and 6.0 mEq/l. One patient was withdrawn at day 20 after developing hyperkalaemia (7.6 mEq/l). Another patient was withdrawn at day 25 after missing a dialysis treatment. There were no differences in either baseline or 28 day aldosterone or renin levels (16.8 +/- 28.8 vs 11.7 +/- 6.1 ng/dl and 3.5 +/- 3.9 vs 3.5 +/- 3.5 ng/ml/h, respectively). Infrequent side effects included dry mouth, nosebleed, pruritis, gynecomastia and diarrhoea. No significant leukopenia or anaemia was noted. CONCLUSIONS: Spironolactone may be considered as a treatment option for selected chronic haemodialysis patients with heart disease.  相似文献   
30.
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