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   1567篇
  免费   117篇
  国内免费   2篇
耳鼻咽喉   128篇
儿科学   45篇
妇产科学   26篇
基础医学   224篇
口腔科学   91篇
临床医学   178篇
内科学   271篇
皮肤病学   22篇
神经病学   175篇
特种医学   98篇
外科学   130篇
综合类   20篇
预防医学   91篇
眼科学   24篇
药学   62篇
肿瘤学   101篇
  2021年   19篇
  2020年   18篇
  2019年   28篇
  2018年   31篇
  2017年   20篇
  2016年   16篇
  2015年   31篇
  2014年   34篇
  2013年   47篇
  2012年   65篇
  2011年   70篇
  2010年   42篇
  2009年   31篇
  2008年   48篇
  2007年   54篇
  2006年   63篇
  2005年   56篇
  2004年   57篇
  2003年   71篇
  2002年   47篇
  2001年   50篇
  2000年   45篇
  1999年   57篇
  1998年   32篇
  1997年   30篇
  1996年   24篇
  1995年   21篇
  1994年   23篇
  1993年   17篇
  1992年   27篇
  1991年   31篇
  1990年   33篇
  1989年   34篇
  1988年   27篇
  1987年   31篇
  1986年   32篇
  1985年   28篇
  1984年   22篇
  1983年   24篇
  1982年   17篇
  1981年   22篇
  1980年   14篇
  1979年   30篇
  1978年   19篇
  1977年   19篇
  1976年   16篇
  1975年   16篇
  1974年   14篇
  1970年   10篇
  1968年   10篇
排序方式: 共有1686条查询结果,搜索用时 25 毫秒
31.
A domestic swine model was developed to examine the interaction of chemical warfare agents with anesthetics and other drugs used during general anesthesia. Animals were fully instrumented, and clinically relevant physiological parameters were monitored throughout the experimental procedures. Exposure of animals under halothane anesthesia to the chemical warfare agent sulfur mustard (HD; 1 mg/kg intravenous) produced mild signs of systemic intoxication during the subsequent 5 hours. Induction doses of ketamine 1 hour after HD exposure resulted in periods of profound apnea, with continued respiratory distress for the next 2 hours. When animals were treated with HD 1 hour after the initiation of ketamine anesthesia, severe and persistent convulsion-like muscular activity was observed within 45 minutes of HD administration. This nonpurposeful activity was not ameliorated by diazepam but was dramatically reduced or eliminated by resumption of halothane anesthesia. Treatment of HD-intoxicated pigs with succinylcholine produced a prolonged apnea resulting in death. In these apparently mildly HD-intoxicated animals, the introduction of ketamine or succinylcholine can rapidly induce potentially life-threatening situations.  相似文献   
32.
Thyroid dysfunction can develop in patients with Hodgkin's disease who are treated with mantle irradiation. During the period 1970-89, the records of 320 patients who received mantle irradiation and who had thyroid function tests (TFT) were retrospectively reviewed. The median age was 30 years (range, 7-69 years). The median mantle and thyroid dose was 36 Gy (range, 30-40 Gy) and 39.8 Gy (range, 32-65 Gy), respectively. Overall thyroid dysfunction was present in 39% of the patients. Clinical hypothyroidism was seen in 10% and biochemical hypothyroidism was noted in 25%. Hyperthyroidism was found in 4% of patients. Thyroid nodules had developed in six patients (2%), of which those in four patients were malignant. Age, sex, histological subtype, stage of disease, dose, lymphangiogram and treatment with chemotherapy were not significant factors in the development of thyroid dysfunction. The narrow dose range prevented adequate analysis of dose effect. The results indicate that the incidence of thyroid abnormalities is high enough to warrant regular TFT assessment with pre-irradiation levels and follow-up testing for life because the development of abnormalities can occur many years later. Thyroid examination should form part of the routine follow-up examination and any abnormality should be promptly investigated.  相似文献   
33.
Determination of obstructive site in obstructive sleep apnoea (OSA) is of paramount importance is planning the management. Cephalometric evaluation of lateral X-rays when combined with clinical assessment and fibreoptic examination of the airway helps in locating the site of obstruction. The usual technique of cephalometry has been modified so as to give a better delineation of the soft tissues. Holding a 2mm card board in the mouth and using barium paste helped in more accurate calculations. Using our technique, various parameters have been quantified and a number of controls were studied and normal range derived. Further improvement in cephalometry has been done by using C.T. cephlometry topogram technique. A topogram is a scan done on a running table top cranio-caudally. Using the topogram technique 38 OSA patients were evaluated for all the parameters. The technique, its advantages over traditional cephalometry and the values obtained in the study are discussed in this paper.  相似文献   
34.
35.
Puppa G, Senore C, Sheahan K, Vieth M, Lugli A, Zlobec I, Pecori S, Wang L M, Langner C, Mitomi H, Nakamura T, Watanabe M, Ueno H, Chasle J, Conley S A, Herlin P, Lauwers G Y & Risio M
(2012) Histopathology  61, 562–575 Diagnostic reproducibility of tumour budding in colorectal cancer: a multicentre, multinational study using virtual microscopy Aims: Despite the established prognostic relevance of tumour budding in colorectal cancer, the reproducibility of the methods reported for its assessment has not yet been determined, limiting its use and reporting in routine pathology practice. Methods and results: A morphometric system within telepathology was devised to evaluate the reproducibility of the various methods published for the assessment of tumour budding in colorectal cancer. Five methods were selected to evaluate the diagnostic reproducibility among 10 investigators, using haematoxylin and eosin (H&E) and AE1‐3 cytokeratin‐immunostained, whole‐slide digital scans from 50 pT1–pT4 colorectal cancers. The overall interobserver agreement was fair for all methods, and increased to moderate for pT1 cancers. The intraobserver agreement was also fair for all methods and moderate for pT1 cancers. Agreement was dependent on the participants’ experience with tumour budding reporting and performance time. Cytokeratin immunohistochemistry detected a higher percentage of tumour budding‐positive cases with all methods compared to H&E‐stained slides, but did not influence agreement levels. Conclusions: An overall fair level of diagnostic agreement for tumour budding in colorectal cancer was demonstrated, which was significantly higher in early cancer and among experienced gastrointestinal pathologists. Cytokeratin immunostaining facilitated detection of budding cancer cells, but did not result in improved interobserver agreement.  相似文献   
36.
We determined whether clinically relevant phosphodiesterase 5 (PDE5) inhibitors interacted with clinically relevant chemotherapies to kill medulloblastoma cells. In medulloblastoma cells PDE5 inhibitors interacted in a greater than additive fashion with vincristine/etoposide/cisplatin to cause cell death. Knockdown of PDE5 expression recapitulated the combination effects of PDE5 inhibitor drugs with chemotherapy drugs. Expression of dominant negative caspase 9 did not significantly inhibit chemotherapy lethality but did significantly reduce enhanced killing in combination with the PDE5 inhibitor sildenafil. Overexpression of BCL-XL and c-FLIP-s suppressed individual and combination drug toxicities. Knockdown of CD95 or FADD suppressed drug combination toxicity. Treatment with PDE5 inhibitors and chemotherapy drugs promoted autophagy which was maximal at ~12 h post-treatment, and in a cell type-dependent manner knockdown of Beclin1 or ATG5 either suppressed or enhanced drug combination lethality. PDE5 inhibitors enhanced the induction of chemotherapy-induced DNA damage in a nitric oxide synthase-dependent fashion. In conclusion, our data demonstrate that the combination of PDE5 inhibitors with standard of care chemotherapy agents for medulloblastoma represents a possible novel modality for future treatment of this disease.  相似文献   
37.

Aim

The 5:2 diet (two non‐consecutive days of 2460 KJ (600 calories) and 5 days of ad libitum eating per week) is becoming increasingly popular. This pilot study aimed to determine whether the 5:2 diet can achieve ≥5% weight loss and greater improvements in weight and biochemical markers than a standard energy‐restricted diet (SERD) in obese male war veterans.

Methods

A total of 24 participants were randomised to consume either the 5:2 diet or a SERD (2050 KJ (500 calorie) reduction per day) for 6 months. Weight, waist circumference (WC), fasting blood glucose, blood lipids, blood pressure and dietary intake were measured at baseline, 3 and 6 months by a blinded investigator.

Results

After 6 months, participants in both groups significantly reduced body weight (P = <0.001), WC (P = <0.001) and systolic blood pressure (P = 0.001). Mean weight loss was 5.3 ± 3.0 kg (5.5 ± 3.2%) for the 5:2 group and 5.5 ± 4.3 kg (5.4 ± 4.2%) for the SERD group. Mean WC reduction for the 5:2 group was 8.0 ± 4.5 and 6.4 ± 5.8 cm for the SERD group. There was no significant difference in the amount of weight loss or WC reduction between diet groups. There was no significant change in diastolic blood pressure, fasting blood glucose or blood lipids in either dietary group.

Conclusions

Results suggest that the 5:2 diet is a successful but not superior weight loss approach in male war veterans when compared to a SERD. Future research is needed to determine the long‐term effectiveness of the 5:2 diet and its effectiveness in other population groups.  相似文献   
38.
The aims of the study were to investigate the alteration of temporomandibular disorders (TMD) after correction of dentofacial deformities by orthodontic treatment in conjunction with orthognathic surgery; and to compare the frequency of TMD in patients with dentofacial deformities with an age and gender matched control group. TMD were evaluated in 121 consecutive patients (treatment group), referred for orthognathic surgery, by a questionnaire and a clinical examination. 18 months after treatment, 81% of the patients completed a follow-up examination. The control group comprised 56 age and gender matched subjects, of whom 68% presented for follow-up examination. TMD were diagnosed according to research diagnostic criteria for TMD. At baseline examination, the treatment group had a higher frequency of myofascial pain (P = .035) and arthralgia (P = .040) than the control group. At follow-up, the frequencies of myofascial pain, arthralgia and disc displacement had decreased in the treatment group (P = .050, P = .004, P = .041, respectively). The frequency of TMD was comparable in the two groups at follow-up. Patients with dentofacial deformities, corrected by orthodontic treatment in conjunction with orthognathic surgery, seem to have a positive treatment outcome in respect of TMD pain.  相似文献   
39.
40.
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