全文获取类型
收费全文 | 5079篇 |
免费 | 296篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 161篇 |
妇产科学 | 148篇 |
基础医学 | 631篇 |
口腔科学 | 106篇 |
临床医学 | 509篇 |
内科学 | 1112篇 |
皮肤病学 | 115篇 |
神经病学 | 448篇 |
特种医学 | 66篇 |
外科学 | 559篇 |
综合类 | 25篇 |
一般理论 | 1篇 |
预防医学 | 445篇 |
眼科学 | 209篇 |
药学 | 318篇 |
中国医学 | 38篇 |
肿瘤学 | 478篇 |
出版年
2024年 | 6篇 |
2023年 | 52篇 |
2022年 | 128篇 |
2021年 | 283篇 |
2020年 | 131篇 |
2019年 | 228篇 |
2018年 | 239篇 |
2017年 | 149篇 |
2016年 | 143篇 |
2015年 | 152篇 |
2014年 | 235篇 |
2013年 | 236篇 |
2012年 | 380篇 |
2011年 | 411篇 |
2010年 | 262篇 |
2009年 | 167篇 |
2008年 | 267篇 |
2007年 | 283篇 |
2006年 | 243篇 |
2005年 | 266篇 |
2004年 | 237篇 |
2003年 | 229篇 |
2002年 | 219篇 |
2001年 | 38篇 |
2000年 | 51篇 |
1999年 | 46篇 |
1998年 | 33篇 |
1997年 | 24篇 |
1996年 | 28篇 |
1995年 | 17篇 |
1994年 | 15篇 |
1993年 | 12篇 |
1992年 | 21篇 |
1991年 | 18篇 |
1990年 | 26篇 |
1989年 | 17篇 |
1988年 | 10篇 |
1987年 | 18篇 |
1986年 | 7篇 |
1985年 | 9篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1972年 | 3篇 |
排序方式: 共有5412条查询结果,搜索用时 15 毫秒
31.
BACKGROUND: The purpose of this study is that of assessing the validity of the computerized diagnoses of hospital discharges of congenital defects by comparing them with the information included in the medical history. METHODS: Based on the discharge records generated over a one-year period at 7 hospitals in the Autonomous Region of Valencia, 100 children were selected at random from each hospital. As a standard, the diagnoses stated in the medical histories were indexed and coded. Solely those discharges having taken place during the first year of life were considered. A study was also made of the type, seriousness and individual or combinations of congenital defects. A calculation was made of the sensitivity, specificity, predictive values and the 95% confidence intervals thereof by the exact binomial method for the case studies (children) and the positive predictive value and sensitivity for the study of diagnoses. RESULTS: 126 children were detected as having congenital defects, and 201 diagnoses in medical records, and 83 children with congenital defects and 108 diagnoses on record. For the detection of cases, the records showed a 64% sensitivity, a 99.1% specificity and some positive and negative predictive values of over 90%. With regard to the detection of diagnoses, the sensitivity was 46% and the positive predictive value 83%. The sensitivity varied a great deal depending upon the diagnoses. CONCLUSIONS: The hospital discharge records revealed a high degree of specificity and high predictive values, but a low degree of sensitivity. These facts must be considered when these records are used as a source of cases for the epidemiological studies of congenital defects. 相似文献
32.
33.
Maximiano Vásquez R Roca Suárez A Ramírez Chamorro F de Alba López JR Gordón Laporte R 《Actas urologicas espa?olas》1999,23(9):814-817
Presentation of one case of scrotal hernia in a man of 64 years old patient. Diagnosed by cistography and ultrasound and treated by herniorraphy and posterior transuretral litolaplaxy of a vesical litiasis and RTU of prostate. Postoperative urography showed normal vesical morphology. 相似文献
34.
Corsonello A Pedone C Corica F Malara A Carosella L Sgadari A Mauro VN Ceruso D Pahor M Carbonin P 《European journal of epidemiology》1999,15(10):893-901
We performed this case–control study to evaluate the risk of hypoglycemia associated with the use of antihypertensive drugs in older hospitalized diabetic patients treated with sulfonylureas and/or insulin. All diabetic patients admitted during 4 months in 1988, 1 month in 1991, 4 months in 1993 and 4 months in 1995 (n = 3477, mean age 71.4 ± 0.2 years, 1542 males and 1935 females) were enrolled in the study. During the four annual surveys 86 patients (mean age 71.1 ± 1.4 years, 33 males and 53 females) presented hypoglycemia during hospital stay. The patients who presented hypoglycemia were less frequently users of sulfonylureas and more frequently users of a combination of insulin and sulfonylureas. Use of antihypertensive drugs was similar in the two groups studied, and among potentially interacting drugs considered in the analysis, sulfonamides were more frequently used in patients who experienced hypoglycemia. Moreover, patients with hypoglycemia used a higher number of drugs, had a longer length of stay and had a greater prevalence of hypoglycemia as admission problem. Finally, although not significant, liver and renal diseases were more frequent among patients with hypoglycemia. In the multivariate analysis, contemporary use of insulin and sulfonylureas, liver disease and length of stay were significantly associated with hypoglycemia, while none of the antihypertensive drugs showed a significant association with the occurrence of hypoglycemia during hospital stay. Our results indicate that antihypertensive drugs do not increase the risk of hypoglycemia in elderly diabetic patients. 相似文献
35.
Lorenzo Alonso Carrión Francisco Jesús González Sánchez Emilio Alba Conejo Esperanza Torres Sánchez 《Clinical & translational oncology》2004,6(8):462-467
Advanced stage ovarian cancer has a high rate of recurrence even after surgery followed by chemotherapy combining carboplatin
and a taxane. New strategies are currently under way to combat this situation and one of the most promising ones is based
on the knowledge that angiogenesis, the mechanism of formation of new blood vessels coupled with the degradation of the extracellular
matrix for metalloproteinases, could be crucial in the development of this tumor. The principal molecule implicated in angiogenesis
process of ovarian cancer is the vascular endothelial growth factor (VEGF). Several studies are now in progress to clarify
its role as a diagnostic tool or its therapeutic implication. Presently, there is no indication for the use of VEGF in a preliminary
diagnosis seeing that an increase in levels can be seen in both benign and malignant ovarian conditions. VEGF is also responsible
for an increase in vascular permeability and is directly related to symptoms such as ascites and pleural effusion, both of
which are frequent in ovarian cancer. Several papers have analised the role of VEGF as a prognostic factor and some of them
do confirm VEGF as an independent prognostic factor in ovarian cancer. VEGF and the metalloproteinase system coupled with
angiogenesis are currently being evaluated as therapeutic targets but no positive results have yet to be seen in this field.
相似文献
36.
Loss of beta-catenin expression in metastatic gastric cancer. 总被引:10,自引:0,他引:10
Matthias P A Ebert Jun Yu Juliane Hoffmann Alba Rocco Christoph R?cken Sabine Kahmann Oliver Müller Murray Korc Joseph J Sung Peter Malfertheiner 《Journal of clinical oncology》2003,21(9):1708-1714
PURPOSE: Beta-catenin (beta-catenin) participates in intercellular adhesion and is an integral part of the Wnt signaling pathway. The role of beta-catenin in the pathogenesis of gastric cancer and its metastasis is largely unknown. PATIENTS AND METHODS: Immunohistochemistry and Western blot analysis were used to analyze the expression of beta-catenin in 87 human gastric cancers, in metastasis and cancer cell lines. The beta-catenin and the adenomatous polyposis coli (APC) genes were analyzed for gene mutations. Furthermore, methylation of the beta-catenin promoter in cell lines was assessed by treatment with 5'-azadeoxycytidine and sodium bisulfite genomic sequencing. RESULTS: beta-Catenin expression was present at either the cell membrane or the cytoplasm in 34 of 75 primary gastric cancers. Expression of beta-catenin was significantly more frequent in intestinal-type (P =.0049) and well-differentiated gastric cancers (P <.001). There were no quantitative differences between gastric cancers and the nonmalignant gastric tissues, as determined by Western blot analysis. One of 18 metastatic cancer lesions and four of five gastric cancer cell lines expressed beta-catenin protein. N87 cells, derived from the liver metastasis of a gastric cancer, did not express beta-catenin. Treatment with 5'-azadeoxycytidine restored beta-catenin protein levels in this cell line, which exhibited significantly more 5-methylcytosines in the beta-catenin promoter compared with the other cell lines. CONCLUSION: beta-Catenin expression is lost in a subgroup of primary gastric cancers, is frequently absent in metastases, and exhibits nuclear localization in cancers with either beta-catenin or APC gene mutations. Interestingly, the loss of beta-catenin expression in metastatic gastric cancers may result from hypermethylation of the beta-catenin promoter. 相似文献
37.
Liliana Ala Andrade Renato Z Torres An José Fs Sales Regina Vicentini Gustavo A De Souza 《Pathology oncology research : POR》1998,4(1):44-47
Three cases of intravenous leiomyomatosis (IVL) of the uterus, a rare benign smooth-muscle tumor, are described. A preoperative
diagnosis of IVL was not made in any of the patients, all of which presented with a pelvic mass with the presumptive diagnosis
of leiomyoma. Surgical exploration confirmed the presence of uterine mass and two of the three cases showed extra-uterine
extension into the ovarian or uterine veins. Histological examination demonstrated a fascicular pattern of bland spindle-shaped
smooth-muscle cells, which extended to veins inside the myometrium or to extrauterine veins. This was confirmed by immunohistochemical
stain for desmin and factor VIII. Despite their histological benignity, these lesions have a tendency to metastasize and are
closely related to the conditions called “benign metastasizing leiomyoma” and “intracaval mass and cardiac extension”. The
primary treatment of IVL is hysterectomy and excision of any extrauterine tumor, when technically feasible. Anti-estrogenic
therapy has been suggested as potentially useful in controlling of unresectable tumor. According to the literature, the follow-up
must be long and periodic postoperative ultrasonic or magnetic nuclear resonance imaging studies may be useful in detecting
growth of residual intravascular tumor. 相似文献
38.
Purpose: To test the influence of nerve growth factor (NGF) on striatal glutathione (GSH) content and the activities of GSH-related enzymes from quinolinic acid-lesioned rats. Methods: Rats were intrastriatally injected with QA and NGF. Enzymatic and GSH assays were performed one week later. Results: NGF prevented the QA-induced decline in glutathione reductase activity and GSH content. Conclusions: NGF is able to prevent some of the disturbances induced by the excitotoxic insult in the striatal GSH metabolism. 相似文献
39.
40.
Ignacio Escobar-Munguía Ricardo Berea-Baltierra ngel Morales-Gonzlez Eduardo Madrigal-Santilln Liliana Anguiano-Robledo Jos A Morales-Gonzlez 《American journal of cancer research》2022,12(7):3294
Colorectal cancer (CRC) is found among those with greatest frequency and exponential increase worldwide, with high mortality rates, which are observed as increasing due to the postsurgical complications that come to present. Systemic inflammation participates in the development and progression of cancer; therefore, inflammatory and/or immunological response markers such as the neutrophil/lymphocyte index (NLI) can aid us in predicting the poor results of our interventions. The purpose of our study was to determine the impact of an NLI of ≥2.6 as a predictor of early postsurgical complications. By means of a prospective cohort, we analyzed 158 patients with CRC who were submitted to elective surgery with a later 30-day follow-up. We found that the preoperatory NLI of ≥2.6 obtained an odds ratio (OR) = 2.24 (95% confidence interval [CI], 1.15-4.36) as a prognostic factor of early postsurgical complications according to the Clavien-Dindo classification scale, which represents a low prognostic impact due to its predictive yield with low accuracy, which is the opposite of what other reports have previously published. The use of chemotherapy before the surgical procedure was also determined to be a risk factor for post-surgical complications. 相似文献