全文获取类型
收费全文 | 22227篇 |
免费 | 1154篇 |
国内免费 | 228篇 |
专业分类
耳鼻咽喉 | 283篇 |
儿科学 | 561篇 |
妇产科学 | 518篇 |
基础医学 | 2402篇 |
口腔科学 | 646篇 |
临床医学 | 1844篇 |
内科学 | 6111篇 |
皮肤病学 | 362篇 |
神经病学 | 2339篇 |
特种医学 | 924篇 |
外科学 | 3426篇 |
综合类 | 62篇 |
一般理论 | 4篇 |
预防医学 | 825篇 |
眼科学 | 289篇 |
药学 | 1289篇 |
中国医学 | 36篇 |
肿瘤学 | 1688篇 |
出版年
2023年 | 231篇 |
2022年 | 479篇 |
2021年 | 854篇 |
2020年 | 501篇 |
2019年 | 635篇 |
2018年 | 772篇 |
2017年 | 592篇 |
2016年 | 620篇 |
2015年 | 716篇 |
2014年 | 882篇 |
2013年 | 1147篇 |
2012年 | 1761篇 |
2011年 | 1714篇 |
2010年 | 956篇 |
2009年 | 916篇 |
2008年 | 1444篇 |
2007年 | 1364篇 |
2006年 | 1300篇 |
2005年 | 1223篇 |
2004年 | 1081篇 |
2003年 | 890篇 |
2002年 | 852篇 |
2001年 | 271篇 |
2000年 | 249篇 |
1999年 | 243篇 |
1998年 | 165篇 |
1997年 | 134篇 |
1996年 | 130篇 |
1995年 | 112篇 |
1994年 | 77篇 |
1993年 | 90篇 |
1992年 | 131篇 |
1991年 | 105篇 |
1990年 | 100篇 |
1989年 | 80篇 |
1988年 | 86篇 |
1987年 | 85篇 |
1986年 | 57篇 |
1985年 | 65篇 |
1984年 | 57篇 |
1983年 | 44篇 |
1982年 | 27篇 |
1981年 | 25篇 |
1980年 | 20篇 |
1979年 | 45篇 |
1978年 | 25篇 |
1977年 | 25篇 |
1976年 | 25篇 |
1975年 | 30篇 |
1974年 | 28篇 |
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
81.
Andrea Bonetti Marta Zaninelli Stefania Rodella Annamaria Molino Loris Sperotto Quirino Piubello Franco Bonetti Rolando Nortilli Monica Turazza Gian Luigi Cetto 《Breast cancer research and treatment》1996,38(3):289-297
Summary The relationship between tumor proliferative activity and response to first-line chemotherapy and survival was investigated in 76 advanced breast cancer patients. Proliferative activity was determined by means of Ki-67 immunohistologic staining on primary tumors (55 patients) or at the relapse site (21 patients), and was classified as low ( 25% of stained cells) or high (> 25% of stained cells). The usual WHO response criteria were used. The median duration of follow-up was 18 months (range 3–58).Forty-seven patients (62%) had tumors with low, and 29 (38%) had tumors with a high rate of proliferative activity. The two groups were well balanced in terms of important variables such as disease-free survival, performance status, age, menopausal status, and the type of first-line chemotherapy (anthracycline-based regimens versus cyclophosphamide-methotrexate-5-fluorouracil). The estrogen receptor (ER) content, measured by means of immunohistochemical assay, was markedly different in the two groups, with 27/47 tumors with low proliferative activity (57%) and 6/29 with high-proliferative activity (21%) being ER positive ( 45% of stained cells) (p = 0.003). Moreover, a significant difference in the metastatic pattern was also evident, with a higher incidence of bone and a lower incidence of soft tissue metastases in the group of patients with tumors with low proliferative activity (p = 0.004). Overall, 10/47 responses (21%: PR = 7, and CR = 3) were observed in the group with a low rate of proliferative activity, versus 14/29 (48%: PR = 9, and CR = 5) in the group with highly proliferative tumors, the difference being statistically significant (p = 0.03). When a multivariate analy-sis was performed, the only factor that retained independent prognostic significance was the predominant site of disease, particularly soft tissues (p = 0.003). Despite the difference in response rate, when survival analysis was performed according to the Kaplan-Meier method, no significant difference was observed in the two groups, but when the analysis was limited to responsive patients, the median survival observed in those with a low and those with a high rate of proliferation was 35 and 19 months respectively (p = 0.02). The same results were obtained when multivariate survival analysis was carried out using Cox's regression model. These data suggest that there is a link between tumor proliferative activity and response to chemotherapy in advanced breast cancer, and may indicate the need to use more intensive treatments in selected patients with highly proliferative tumors.Presented in part at the Annual Meeting of the American Society of Clinical Oncology, May 14–17, 1994, Dallas, TX, USA 相似文献
82.
Ayan I Luca JW Jaffe N Yazici H Ekmekçioğlu S Hansen MF 《Journal of experimental & clinical cancer research : CR》1998,17(4):497-502
Although somatic mutations of p53 are the most common genetic changes observed to date, the frequency of germline p53 mutations is found to be very low in sporadic malignant tumors. It has been postulated that de novo germline p53 mutations may occur in a substantial population of patients in pediatric age group, who die of their disease and do not propagate the mutation. To determine the frequency and type of p53 germline mutations in pediatric patients, we screened 65 children who were consecutively admitted with primary malignant solid tumors. 相似文献
83.
Luciano De Carlis Ernesto Del Favero Gianfranco Rondinara Luca S. Belli Cosimo V. Sansalone Bruno Zani Alberto Cazzulani Giorgio Brambilla Antonio Rampoldi Lino Belli 《Transplant international》1992,5(1):9-14
Spontaneous portosystemic shunts are commonly found in cirrhotic patients. Not yet established is their role after orthotopic liver transplantation (OLTx), especially when an increase in portal pressure develops, as during early acute rejection. In this study, 34 cirrhotic patients in a series of 70 OLTx are considered. Each patient had preoperative angiographic assessment, and, in 21 (62%), large spontaneous portosystemic shunts were evident. In 12 cases the shunts were not affected by the surgical procedure and were present during the postoperative period; in 9 the hepatectomy itself involved interruption of the shunts. The patient population was divided into two groups: patients with postoperative shunts (n=12) and those without (n=22). The two groups were similar in age, sex, Child's stage, transplantation variables, and number and grade of rejection episodes. However, mean transaminases (AST) values in the first 2 weeks were significantly higher levels in shunt versus nonshunt patients (421±335 vs 183±126; P<0.025), and this was even more evident when rejection occurred (626±375 vs 195±129; P<0.001). Furthermore, during an acute rejection reaction, three cases showed a true steal phenomenon through the large reopened shunts with ischemic damage to the grafts. The data indicate a possible detrimental effect of the spontaneous shunts on graft perfusion and suggest the prophylactic surgical interruption of the residual shunts during the transplantation. 相似文献
84.
Rhombencephalosynapsis is an unusual disorder characterised by maldevelopment of the rhombencephalon, sometimes with supratentorial
midline anomalies. We report MRI findings in a 39-year-old woman, the oldest in the literature. MRI demonstrated hypoplasia
of the cerebellar vermis, with fusion of the cerebellar hemispheres and abnormally oriented folia. Supratentorial anomalies
were also seen.
Received: 26 April 1999 Accepted: 13 July 1999 相似文献
85.
BACKGROUND AND OBJECTIVE: Nd:YAG laser photothermal ablation has been accepted as a treatment modality for hemorrhoidal disease. There is little reported on its use in treating pilonidal disease. We hypothesized that laser would be an excellent tool for pilonidal cystectomy, facilitating improved outcome and patient satisfaction. STUDY DESIGN/MATERIALS AND METHODS: A 5-year retrospective study was performed comparing Nd:YAG laser to the standard surgical technique. A telephone questionnaire addressing the length of time the cyst was debilitating both preoperatively and postoperatively as well as length of convalescent time before return to work was administered. Pain was assessed by using an analog pain scale. RESULTS: Operative time for the traditional pilonidal cystectomy was 20 minutes longer than Nd:YAG laser cystectomy. Postoperative hospital stay was similar. Laser patients returned to work an average of 2.4 days earlier, and their postoperative pain was less than those treated traditionally. CONCLUSION: In an era when the medical consumer makes decisions based on the efficacy of treatment by using criteria such as pain, length of hospitalization, and speed of return to work, Nd:YAG lasers have emerged as a surgical tool that can fulfill these criteria for certain procedures. Patient postoperative satisfaction after laser excision was greater when compared with those who had traditional excisions. Postoperative pain was less, as was the pain experienced during the first week of recovery. Cost for both was comparable. 相似文献
86.
Neumann CP Tatarciuc MS Viţalariu A Diaconu D Luca O 《Revista medico-chirurgical?? a Societ????ii de Medici ??i Naturali??ti din Ia??i》2000,104(2):161-163
In modern CAD/CAM technology of dental prosthetics, the "optical impression" taken by special video cameras deploying 3D-recording of the oral situation (Cerec 1, Cerec 2) initiates the computer-generated production of a digital model. The computer receives and renders the digital data obtained through "optical impression" i.e. data acquisition not as a "negative" of the oral situation but as a "positive" copy of it, namely as a digital model in a virtual environment which can be displayed on the screen and be further used in the fabrication of dental prostheses by means of a computer-assisted device (CAM or CIM). 相似文献
87.
Miftode E Luca V Dănilă F Corcaci C 《Revista medico-chirurgical?? a Societ????ii de Medici ??i Naturali??ti din Ia??i》2000,104(4):153-155
We report the case of an infant with cytomegalovirus (CMV) infection who developed a nosocomial sepsis of mixed etiology. Fever failed to decrease despite long-time and sustained antibiotic therapy. Treatment with an antiviral agent following the detection of CMV antibody of the IgM class resulted in clinical improvement and subsequent full recovery. We suggest that the diagnosis of CMV infection should be considered even in immunocompetent patients in whom antibiotic therapy fails. 相似文献
88.
Santarossa Sandra Vaccher Emanuela Balestreri Luca Volpe Rachele Tirelli Umberto 《Journal of neuro-oncology》1997,35(2):141-143
Patients with locally advanced transitional cell carcinoma (TCC)of the bladder are at high risk forsystemic relapse, with liver, bone and lung beingthe commonest sites of metastases.We report the case of a 52-year-old womanwith a solitary meningeal relapse, a rare siteof recurrence, after 8 months of complete remissionobtained with M-VEC for locally advanced TCC ofthe bladder. We speculate on the likely riskfactors related to this unusual site of recurrence. 相似文献
89.
Antonio Macciò M.D. Paola Lai M.D. Maria Cristina Santona M.D. Loredana Pagliara M.D. Gian Benedetto Melis M.D. Giovanni Mantovani M.D. 《Gynecologic oncology》1998,69(3):248-252
The serum levels of interleukin-(IL-)1α, IL-1β, IL-2, IL-6, TNFα, and sIL-2R and the proliferative response of peripheral blood mononuclear cells (PBMC) to phytohemagglutinin (PHA), anti-CD3 monoclonal antibody (mAb), recombinant IL-2 (rIL-2), and the combination of PHA or anti-CD3 mAb with rIL-2 were studied and correlated with serum levels of C-reactive protein (CRP) in women with advanced epithelial ovarian cancer. The expression of CD25 and CD122 subunities of membrane-bound IL-2R on PHA- or anti-CD3 mAb-stimulated PBMC was also studied. In comparisons with the controls, PBMC response to PHA, anti-CD3 mAb, and rIL-2 was significantly lower in the cancer patients. The addition of exogenous rIL-2 to the PBMC cultures increased response in both controls and patients but did not modify the significance of the differences. After stimulation with PHA or anti-CD3 mAb, the percentage of PBMC CD25+or CD122+was significantly lower in patients. The serum levels of IL-1α, IL-1β, IL-6, TNFα, sIL-2R, and CRP were significantly increased in patients compared to the controls. Instead, no differences were observed for serum levels of IL-2. A strong association was found between high serum levels of the above-mentioned cytokines, sIL-2R, and CRP. The results of our study on advanced stage (IIIb–IV) ovarian cancer patients are consistent with the previously reported hypothesis that high IL-6 and/or CRP serum levels may represent an important and independent prognostic factor of the likely outcome in cancer patients. 相似文献
90.