全文获取类型
收费全文 | 10529篇 |
免费 | 767篇 |
国内免费 | 146篇 |
专业分类
耳鼻咽喉 | 90篇 |
儿科学 | 174篇 |
妇产科学 | 176篇 |
基础医学 | 547篇 |
口腔科学 | 238篇 |
临床医学 | 1692篇 |
内科学 | 693篇 |
皮肤病学 | 105篇 |
神经病学 | 349篇 |
特种医学 | 643篇 |
外科学 | 727篇 |
综合类 | 2442篇 |
一般理论 | 2篇 |
预防医学 | 1890篇 |
眼科学 | 241篇 |
药学 | 805篇 |
55篇 | |
中国医学 | 272篇 |
肿瘤学 | 301篇 |
出版年
2024年 | 32篇 |
2023年 | 181篇 |
2022年 | 367篇 |
2021年 | 481篇 |
2020年 | 453篇 |
2019年 | 275篇 |
2018年 | 293篇 |
2017年 | 351篇 |
2016年 | 365篇 |
2015年 | 360篇 |
2014年 | 853篇 |
2013年 | 742篇 |
2012年 | 805篇 |
2011年 | 792篇 |
2010年 | 600篇 |
2009年 | 558篇 |
2008年 | 574篇 |
2007年 | 544篇 |
2006年 | 472篇 |
2005年 | 371篇 |
2004年 | 299篇 |
2003年 | 261篇 |
2002年 | 184篇 |
2001年 | 143篇 |
2000年 | 131篇 |
1999年 | 133篇 |
1998年 | 90篇 |
1997年 | 105篇 |
1996年 | 78篇 |
1995年 | 69篇 |
1994年 | 61篇 |
1993年 | 64篇 |
1992年 | 44篇 |
1991年 | 44篇 |
1990年 | 32篇 |
1989年 | 29篇 |
1988年 | 27篇 |
1987年 | 22篇 |
1986年 | 20篇 |
1985年 | 22篇 |
1984年 | 9篇 |
1983年 | 13篇 |
1982年 | 24篇 |
1981年 | 13篇 |
1980年 | 11篇 |
1979年 | 16篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1976年 | 5篇 |
1975年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
41.
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
42.
Martin Griebe Michael Daffertshofer Mark Stroick Magdalena Syren Parviz Ahmad-Nejad Michael Neumaier Juergen Backhaus Michael G. Hennerici Marc Fatar 《Neuroscience letters》2007
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
43.
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
44.
目的探讨聚合酶链反应检验法在阴道炎患者阴道细菌检查中的应用价值。方法选取2019年6月~2020年6月于我院行细菌检查的58例阴道炎患者为研究对象,所有患者均采用阴道分泌物细菌培养、聚合酶链式反应(PCR)检验,比较两种检验方法阳性检出率。结果PCR检验阳性检出率(89.66%)高于细菌培养法(70.69%),差异有统计学意义(P<0.05)。结论PCR检验法应于阴道炎患者阴道细菌检查中,阳性检出率高,可为阴道炎的诊断及治疗提供较准确的科学依据,具有较高的临床应用价值。 相似文献
45.
《Health & place》2021
The distribution of food outlets within towns and cities and the provision of active travel infrastructure have been associated with health behaviours that can contribute to obesity risk. Decision-makers describe a lack of local data and research evidence as a barrier to policy adoption to improve the public's health. Online spatial data visualisation tools created by researchers can help to bridge this gap. We explored stakeholder experiences of using such tools for decision-support, with a focus on facilitators and barriers to use. We conducted 16 qualitative interviews with Public Health, Planning and Transport Planning professionals, who had used two recently-developed tools. Participants described the importance of tools being open access; their use in “story-telling”, particularly to non-experts; and more broadly their use even when imperfect. They expressed that ‘robustness’ of underpinning data was important, however this was not easily defined. Participants employed personal heuristics, principally based on endorsement and developer credibility, to determine suitability for use. We present key learning points for future developers to maximise engagement and impact. 相似文献
46.
重点高中生的心理状态与高考成绩的相关性研究 总被引:5,自引:1,他引:4
目的;了解重点高中学生的心理状态与高考成绩之间的关系。方法:以398例应届生为对象,应用16PF人格测验,气质测量工具(STI,TTI)及焦虑自评量表(SAS),对考生进行测试分析,结果:文理科学生的16PF的人格特质有明显的差别,判别分析和多因素回归分析显示16PF人格特质中的Q1因素(实验性F=8.76,P<0.01),Q2因素(独立性F=8.23,P<0.01),与高考成绩呈正相关,与M因素(幻想性F=4.88,P<0.01),呈负相关;气质中的神经过程灵活性(F=8.15,P<0.01)和时间特质中的灵活性(F=12.36,P<0.01)与高才成绩呈正相关。结论:高考生的实验性,独立性高分及幻想性低分的个性特质和气质上的灵活性有助于高考成绩的发挥,学生文理科分班宜参考学生人格特质这一特点,。 相似文献
47.
目的 了解胎儿脐带绕颈时对胎儿安危及窘迫和缺氧的影响程度。方法 采用日本Aloka-630型超声诊断仪,孕妇孕周为28-42周。结果 二维超声诊断胎儿脐带绕颈136例,经分娩证实129例。符合率94.85%。结论 二维超声诊断与分娩后证实比较,超声是诊断脐带绕颈的可靠方法之一。为分娩方式提供依据。 相似文献
48.
49.
50.