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   10385篇
  免费   710篇
  国内免费   177篇
耳鼻咽喉   82篇
儿科学   166篇
妇产科学   163篇
基础医学   396篇
口腔科学   221篇
临床医学   1577篇
内科学   658篇
皮肤病学   102篇
神经病学   289篇
特种医学   618篇
外科学   654篇
综合类   2514篇
一般理论   1篇
预防医学   1715篇
眼科学   242篇
药学   717篇
  51篇
中国医学   829篇
肿瘤学   277篇
  2024年   18篇
  2023年   123篇
  2022年   298篇
  2021年   408篇
  2020年   409篇
  2019年   247篇
  2018年   264篇
  2017年   345篇
  2016年   363篇
  2015年   355篇
  2014年   886篇
  2013年   731篇
  2012年   824篇
  2011年   797篇
  2010年   616篇
  2009年   560篇
  2008年   578篇
  2007年   552篇
  2006年   486篇
  2005年   380篇
  2004年   306篇
  2003年   268篇
  2002年   193篇
  2001年   150篇
  2000年   141篇
  1999年   141篇
  1998年   93篇
  1997年   108篇
  1996年   80篇
  1995年   74篇
  1994年   64篇
  1993年   68篇
  1992年   48篇
  1991年   45篇
  1990年   33篇
  1989年   29篇
  1988年   25篇
  1987年   19篇
  1986年   18篇
  1985年   21篇
  1984年   9篇
  1983年   11篇
  1982年   22篇
  1981年   12篇
  1980年   12篇
  1979年   15篇
  1978年   6篇
  1977年   7篇
  1976年   4篇
  1975年   3篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
This study attempts to point out the importance of the anatomo-clinical finding of an "hour-glass" shape to the uterus in the diagnosis and treatment of cervical pregnancy. From 1973 to 2001, four cases of cervical pregnancy were treated in the 2nd Obstetrical and Gynecological Clinic of the Aristotelion University of Salonica. The incidence was 1:13,111 pregnancies (4 cervical in 52,446 pregnancies). Three of the patients underwent bilateral ligation of the anterior trunk of the internal iliac artery using absorbable ligatures. The fourth patient (a 42-year-old), elected to have a hysterectomy. All patients were well and discharged from hospital on the seventh postoperative day. Two of the three patients treated by ligation of the anterior trunk of the internal iliac arteries subsequently had normal pregnancies and deliveries. We lost contact with the third patient. The finding of an "hour-glass" uterine shape was very helpful in the diagnosis of cervical pregnancy. The Aristotelion University of Salonica has found that treatment by ligation of the anterior trunk of the internal iliac arteries is effective, causes no complications, never ends in hysterectomy, and maintains the normal menstrual cycles and reproductive ability of the woman.  相似文献   
62.
1049例育龄妇女下生殖道感染情况调查   总被引:2,自引:0,他引:2  
目的了解育龄妇女下生殖道感染情况,为育龄女性生殖健康提供进一步的数据资料。方法对1049例来自健康体检中心的21~40岁育龄妇女的阴道后穹窿及宫颈分泌物标本进行检测,阴道清洁度、滴虫采用显微镜镜检法,淋球菌、解脲支原体、人型支原体、真菌采用培养法,沙眼衣原体则采用免疫层析法。检测结果进行统计学分析。结果女性生殖道感染的感染率为53.3%,其中混合感染率为9.8%,而清洁度异常率仅为28.4%;前三位病原体感染依次为解脲支原体(35.9%)、衣原体(18.1%)、真菌(6.7%)。结论女性生殖道感染情况严重,具有隐匿性,应加强对无症状感染的育龄妇女的监测。  相似文献   
63.
A unique case of duodenal stromal tumor In a 51-year-old man is reported. The tumor histologically showed spindle cell proliferation and numerous eosinophilic globules. Most globules were composed of tangled 45 nm thick fibrils, which were ultrastructurally Identical to 'skelnoid fibers'. The presence of glycogen granules in the tumor cells and the Immunoreactivity for α-smooth muscle actin suggested smooth muscle differentiation. Focal ultrastructural findings also supported the smooth muscle nature of this tumor. There were no immunohistochemical and ultra-structural features indicating neural differentiation. In previous studies, the presence of such 'skeinoid fibers' was suggested to be a histological marker for neural differentiation in gastrointestinal stromal tumor. However, the findings In the present case suggest that numerous 'skeinoid fibers' can be Identified in duodenal stromal tumor with smooth muscle differentiation, although this condition may be rare.  相似文献   
64.
本研究取材于人的皮肤,电镜常规方法处理。发现人皮肤内有两种类型的神经肥大细胞联接。提示可能分别为传出性和传入性的,或暂称为A型和B型联接,分别报告于上篇和本篇中。 B型联接的构造特点是,脱开薛旺鞘样长带包被的轴突来到肥大细胞近旁,突进细胞体中。轴突终末的一部分被胞质唇封盖起来,终末周围的轴膜与细胞质膜形成联接的双层膜。无肥大细胞表面皱褶参与其形成,无线粒体和显明的囊泡存在终末之内,无薛旺细胞包被轴突终末。薛旺细胞伴同A型联接出现,可与肥大细胞紧密接触。胞质内有狭缝系统和粗面内质网片断,能拖出长尾,估计将过渡为鞘膜。薛旺细胞不是间织细胞,这里的间织细胞应是成纤维细胞。  相似文献   
65.
BACKGROUND: This study in humans was undertaken to evaluate earlier results from animal research showing a retrograde migration of glove powder from the vagina into the intra-abdominal cavity. METHODS: One study group was gynaecologically examined with powdered gloves the day before an abdominal hysterectomy and another group 4 days pre-operatively. There were two control groups similarly examined with powder-free gloves. Cell smears were taken from the peritoneal fluid and during the operation further smears were taken from the Fallopian tubes, uterine cavity and cervical canal. RESULTS: Statistically significant differences were found for large starch particles at all locations between the study and control groups examined 1 day pre-operatively. Considering small starch particles, there were significant differences in cervix (P < 0.001), uterus (P < 0.01) and the Fallopian tubes (P < 0.01). The combined results also show significant differences between both large and small starch particles in cervix, uterus and the Fallopian tubes. There were also differences between the study and control groups examined 4 days pre-operatively, but these were not statistically significant except for small and large starch particles in uterus (P < 0.01, P < 0.05) and cervix (P < 0.05, P < 0.05). CONCLUSIONS: This study has pointed out a retrograde migration of starch also in humans after a gynaecological examination with powdered gloves. Consequently, powder or any other potentially harmful substance that can migrate from the vagina should be avoided.  相似文献   
66.
琼脂石蜡双包埋切片在胸水细胞学诊断中的应用   总被引:1,自引:0,他引:1  
目的探讨胸水琼脂石蜡双包埋切片在肿瘤细胞学诊断中的意义。方法对44例胸水沉淀物分别进行常规涂片和琼脂石蜡双包埋切片,并对琼脂石蜡双包埋切片进行免疫组织化学染色。结果在确诊的21例恶性胸水中,琼脂石蜡双包埋切片法检测癌细胞的阳性率为90.48%,显著高于涂片法52.38%。11例涂片法阳性的标本中,只有5例做出了病理分类诊断,而19例琼脂石蜡双包埋切片阳性的标本均做出了病理分类诊断。琼脂石蜡双包埋切片的免疫组织化学染色阳性结果定位准确,图象背景清晰。结论琼脂石蜡双包埋切片细胞集中,可以提高恶性胸水癌细胞的检出率和做出分型的病理诊断,利于以及进行免疫组织化学检测。  相似文献   
67.
We evaluated a novel method of computed tomography (CT) analysis using formalin-fixed lungs of autopsy cases with mild emphysema. Eight formalin-inflated lungs (FILs) obtained at autopsy were examined using CT after draining off the formalin and air inflation with an air pump, and subjected to pathological study including pathological scoring of emphysema and microscopic image analysis (MIA). Satisfactory CT examination was carried out within 5 h of lung fixation. The mean alveolar area determined by MIA correlated highly with the lung volume (r=0.845) and CT score (r=0.722). This method is simple compared with conventional polyethylene glycol fixation for CT and enables CT examination of resected lungs without anxiety about biohazards. Mild emphysema can be detected by MIA.  相似文献   
68.
The purpose of this study was to evaluate the cellular composition of the bone marrow of cynomolgus monkeys (Macaca fascicularis). Femoral bone marrow smears from 23 healthy, adult animals (11 males and 12 females) were examined. For each animal, three femoral bone marrow smears were prepared immediately after euthanasia and stained with May-Grünwald-Giemsa. On two of the three smears available, and for each of these smears, a 500-cell differential count was performed and the myeloid: erythroid (M:E) ratio established. The M:E ratio for males varied from 0.67∶1.00 to 1.85∶1.00 with a mean of 1.03∶1.00 and for females from 0.67∶1.00 to 1.63∶1.00 with a mean of 1.02∶1.00. The mean percentage of granulocytic, lymphocytic, plasmacytic and erythroid series was 47.60, 5.44, 1.45 and 46.05% for males and 47.28, 5.12, 1.49 and 46.28% for females. No significant differences were noted between males and females. All cell lines were well represented and showed normal maturation in both sexes. Megakaryocytes were adequate in number and morphology in all animals. Cynomolgus monkeys showed a bone marrow composition similar to rhesus monkeys (Macaca mulatta). Cytological examination of bone marrow was found to be a simple and rapid procedure, well suited to the toxicological research environment. It provided excellent information on cell distribution, morphology and maturation of the haematopoietic system.  相似文献   
69.
Biological markers play an evolving role in the diagnosis of Alzheimer disease (AD). We compare conventional measurements of cerebrospinal fluid (CSF) tau and β-amyloid1–42 proteins to a novel approach – Fourier transformed infrared (FT-IR) spectroscopy – a simple technique derived from chemical and physical sciences that characterizes intramolecular bonds. For automatic diagnostic analysis, we developed an artificial neural network (ANN). We examined 71 patients with a clinical diagnosis of AD and 66 controls. β-Amyloid1–42 was decreased (sensitivity 80% and specificity 78%); tau was elevated (sensitivity 76% and specificity 88%) in CSF of AD patients. The combined tau/β-amyloid1–42 quotient was able to distinguish healthy from diseased subjects with 99% sensitivity and 86% specificity. The ANN could separate FT-IR spectroscopy data with 88.5% sensitivity and 80% specificity. FT-IR spectroscopy proved to be cost-effective and simple to perform. Diagnostic sensitivity and specificity is in the range of CSF tau and β-amyloid1–42 protein analysis. Larger sample numbers for ANN training and validation could increase diagnostic accuracy and thus prove to be a useful screening tool.  相似文献   
70.
Summary This is a review of 1,000 consecutive cases of severe head injury admitted to our Neurosurgical Department between January 1973 and August 1976, before the advent of CT scanning. All patients were comatose following head injury (GCS8) and were treated homogeneously by the same neurosurgical team by a protocol that included immediate resuscitation on arrival, diagnosis of intracranial lesions by angiography, early surgery when needed, mechanical ventilation, steroids, and mannitol. Extracranial lesions, even if preponderant, were treated by various specialists in the Neurosurgical Department, which for all practical purposes operated as an Emergency Department. Admission criteria were very broad with no preadmission selection. The overall mortality for this series was 45%. A little less than half the patients made good recoveries or remained moderately disabled (47%); 6% were severely disabled, and 2% survived in a persistent vegetative state. More than two-thirds of the patients were brought to our Neurosurgical Department after a short stay at a general hospital; 72% were admitted within 6 hours of injury; 71% were traffic accident victims; and 34% had significant associated extracranial injuries. Carotid angiography was performed in 78% of the patients and indicated the presence of an intracranial haematoma requiring surgery in 36% of the whole series. Mortality was significantly higher in operated than in unoperated patients (56% versus 39%); those treated surgically, however, were older, in worse clinical condition, and showed a higher incidence of acute subdural haematomas associated with brain contusion. Carotid angiography proved very effective in revealing the presence of an expansive lesion but failed to reflect the severity of brain damage, since the group with negative angiograms showed a high mortality (52%). Patients with a lucid interval had a higher percentage of surgical lesions than those with immediate coma (58% versus 26%); but fully 42% of them did not require surgery, and 25% had negative angiograms. From the prognostic point of view the clinical data elicited after initial resuscitation were highly predictive of the outcome: some individual neurological signs, such as mydriasis, posturing and eye movements, were not inferior to the GCS score in that respect. Age also proved a strong predictor, since elderly patients are more likely to have severe subdural and parenchymal lesions and their clinical severity is accordingly greater.Our series amounts to a data bank of cases both contemporary to and in good agreement with that collected by Jennett and his associates in their 1977 multinational study; and it affords a useful reference in the assessment of epidemiological variations and alternative management in relation to outcome.  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