全文获取类型
收费全文 | 35865篇 |
免费 | 2855篇 |
国内免费 | 366篇 |
专业分类
耳鼻咽喉 | 390篇 |
儿科学 | 978篇 |
妇产科学 | 960篇 |
基础医学 | 4595篇 |
口腔科学 | 593篇 |
临床医学 | 3728篇 |
内科学 | 7693篇 |
皮肤病学 | 834篇 |
神经病学 | 2417篇 |
特种医学 | 1242篇 |
外科学 | 4899篇 |
综合类 | 1172篇 |
一般理论 | 32篇 |
预防医学 | 1976篇 |
眼科学 | 1585篇 |
药学 | 2713篇 |
中国医学 | 309篇 |
肿瘤学 | 2970篇 |
出版年
2023年 | 240篇 |
2022年 | 498篇 |
2021年 | 957篇 |
2020年 | 617篇 |
2019年 | 783篇 |
2018年 | 1002篇 |
2017年 | 768篇 |
2016年 | 873篇 |
2015年 | 1049篇 |
2014年 | 1380篇 |
2013年 | 1650篇 |
2012年 | 2347篇 |
2011年 | 2463篇 |
2010年 | 1424篇 |
2009年 | 1250篇 |
2008年 | 1919篇 |
2007年 | 2008篇 |
2006年 | 2000篇 |
2005年 | 1930篇 |
2004年 | 1703篇 |
2003年 | 1587篇 |
2002年 | 1416篇 |
2001年 | 1123篇 |
2000年 | 1056篇 |
1999年 | 907篇 |
1998年 | 369篇 |
1997年 | 276篇 |
1996年 | 253篇 |
1995年 | 206篇 |
1994年 | 201篇 |
1993年 | 204篇 |
1992年 | 457篇 |
1991年 | 442篇 |
1990年 | 428篇 |
1989年 | 410篇 |
1988年 | 365篇 |
1987年 | 382篇 |
1986年 | 329篇 |
1985年 | 282篇 |
1984年 | 208篇 |
1983年 | 155篇 |
1982年 | 99篇 |
1981年 | 89篇 |
1980年 | 95篇 |
1979年 | 140篇 |
1978年 | 90篇 |
1977年 | 79篇 |
1976年 | 81篇 |
1975年 | 78篇 |
1972年 | 69篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
OBJECTIVE: To assess changes in sociodemographic characteristics of mothers, their obstetric management and perinatal outcomes in the 1980s. DESIGN: A survey of data recorded in the South Australian perinatal data collection. For singleton births, we compared risks of stillbirth, neonatal death and perinatal death by year of birth, after adjusting for risk factors. SUBJECTS: There were 176,637 births of at least 400 g birthweight (or at least 20 weeks' gestation) notified to the perinatal data collection between 1981 and 1989. MAIN OUTCOME MEASURES: Frequency of risk factors and relative risks of stillbirth, neonatal death and perinatal death by year of birth. RESULTS: There have been changes in the sociodemographic characteristics of mothers, their obstetric management and perinatal outcomes during the 1980s. Crude perinatal mortality rates have not increased, despite increases in the frequency of low birthweight, preterm births, mothers aged 35 years and over, and some other risk factors. After adjusting for risk factors, the risks of stillbirth, neonatal death and perinatal death were lower among singletons in 1987-1989 than in the 1981-1982 reference period. CONCLUSION: Advances in clinical management may be preventing increases in stillbirths, neonatal deaths and perinatal deaths in response to increased numbers of births with low birthweight, preterm delivery and some other risk factors in South Australia. 相似文献
102.
In a group of patients with breast lumps, diagnosis made by pre-operative aspiration cytology was compared with that obtained by histological section of excised specimens. Results showed that aspiration cytology correctly diagnosed 89% of malignant lesions and 92.6% of benign lesions based upon histological diagnosis. Cytological diagnosis of benign disease had a false negative rate of 6% while cytological diagnosis of malignant disease had a 2.7% false positive rate. Only 3.5% of cytologies returned an inadequate diagnosis. This study shows that aspiration cytology should be useful in allowing a better psychological preparation of patients before surgery as well as better utilization of operation theatre facilities. 相似文献
103.
104.
Regional anaesthesia provides many advantages and can be practised safely in ambulatory surgery. It provides better postoperative pain control, avoids many complications associated with general anaesthesia and shortens recovery time. However, extra time required, associated complications and acceptance of patients are the factors of concern in practising regional anaesthesia in an ambulatory setting. This review will discuss various regional anaesthesia techniques suitable for outpatients. 相似文献
105.
R F Lai A Fat M Harboe J C Chan Pin Jin M M Diesselhoff-den Dulk R van Furth 《International journal of leprosy and other mycobacterial diseases : official organ of the International Leprosy Association》1988,56(4):552-558
For the detection of the synthesis in vitro of anti-Mycobacterium leprae antibodies in various tissues of leprosy patients, biopsy specimens of skin lesions, nasal mucosa, larynx, lymph nodes, and bone marrow were cultured in a medium containing 14C-labeled lysine and isoleucine. The culture fluids were analyzed by crossed immunoelectrophoresis with intermediate gel and autoradiography. The results show that synthesis of anti-M. leprae antibodies occurs at the investigated sites of leprosy patients and that the specificities of the synthesized antibodies differ between sites in individual patients. It is conceivable that these antibodies play a role in the local defense against M. leprae. 相似文献
106.
107.
One hundred eighty-two fine needle aspirations (FNAs) of head and neck masses performed between the years 1981 and 1987 were studied retrospectively. Seventeen FNAs were unsatisfactory. Of the remaining 165, 148 (90%) were followed up with either surgery or clinical follow-up of at least 12 months' duration. Seventy-one of these aspirates were malignant. Fifty-six cases of metastatic carcinoma and 13 cases of lymphoma were diagnosed. The positive predictive value for metastatic carcinoma and lymphoma was 100%, and the sensitivities were 92% and 100%, respectively. For benign salivary gland lesions, the positive predictive value was 94%, whereas for malignant lesions it was 100%. One case of carcinoma ex-pleomorphic adenoma was missed by FNA. No complications were associated with FNA. We conclude that FNA is a safe and accurate technique, well suited to the in-office evaluation of neck masses of differing causes. 相似文献
108.
RAMASWAMY MANIKANDAN MAGDA KUJAWA EVELYN PEARSON PATRICK H O''REILLY STEPHEN CW BROWN 《International journal of urology》2004,11(4):206-212
BACKGROUND: To evaluate the results of the tension-free vaginal tape procedure (TVT) from a patient's perspective. METHODS: Between May 1999 and January 2002, 90 patients underwent a TVT for genuine stress incontinence (GSI) and mixed incontinence. Prior to the procedure, GSI was confirmed by clinical examination and urodynamic studies. Results were then audited from patient notes and the same patients were sent questionnaires to examine results from a patient perspective. RESULTS: Overall response rate to the questionnaire was 70 (77%). The mean age of the patients was 50.4 years (range 31-83 years). Sixty-one patients had spinal anesthesia, seven had general anesthesia and two had local anesthesia. Mean hospital stay was 3.36 days (range 2-14 days) and mean period from the operation to the time of the survey and audit was 16.34 months (range 3-28; SD 6.92). Thirty-nine (56%) of the 70 patients who answered said that the operation had cured their incontinence, 16 (23%) had an improvement in their symptoms, 7 (10%) had worsening of their symptoms and 8 (11%) felt that the operation did not make any difference. The overall success rate according to the patients' perspective was 79%, whereas our audit showed an overall success rate of 86% (77% and 82%, respectively, when we compared only the 66 patients who had both notes and replies available for analysis). CONCLUSION: Although a patient's perception regarding the success of TVT tends to differ from that of a clinician, it was not found to be statistically significant (P = 0.22, McNemar test). The TVT is a very successful operation, but realistic cure rates should be offered to patients. 相似文献
109.
Hidenori Endo Chikako Nito Hiroshi Kamada Tatsuro Nishi Pak H Chan 《Journal of cerebral blood flow and metabolism》2006,26(12):1479-1489
Recent studies have revealed that the phosphatidylinositol 3-kinase (PI3-K) pathway is involved in apoptotic cell death after experimental cerebral ischemia. The serine-threonine kinase, Akt, functions in the PI3-K pathway and prevents apoptosis by phosphorylation at Ser473 after a variety of cell death stimuli. After phosphorylation, activated Akt inactivates other apoptogenic factors, including glycogen synthase kinase-3beta (GSK3beta), thereby inhibiting cell death. However, the role of Akt/GSK3beta signaling in the delayed death of hippocampal neurons in the CA1 subregion after transient global cerebral ischemia (tGCI) has not been clarified. Transient global cerebral ischemia for 5 mins was induced by bilateral common carotid artery occlusion combined with hypotension. Western blot analysis showed a significant increase in phospho-Akt (Ser473) and phospho-GSK3beta (Ser9) in the hippocampal CA1 subregion after tGCI. Immunohistochemistry showed that expression of phospho-Akt (Ser473) and phospho-GSK3beta (Ser9) was markedly increased in the vulnerable CA1 subregion, but not in the ischemic-tolerant CA3 subregion. Double staining with phospho-GSK3beta (Ser9) and terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end labeling showed different cellular distributions in the CA1 subregion 3 days after tGCI. Phosphorylation of Akt and GSK3beta was prevented by LY294002, a PI3-K inhibitor, which facilitated subsequent DNA fragmentation 3 days after tGCI. Moreover, transgenic rats that overexpress copper/zinc-superoxide dismutase, which is known to be neuroprotective against delayed hippocampal CA1 injury after tGCI, had enhanced and persistent phosphorylation of both Akt and GSK3beta after tGCI. These findings suggest that activation of the Akt/GSK3beta signaling pathway may mediate survival of vulnerable hippocampal CA1 neurons after tGCI. 相似文献
110.