全文获取类型
收费全文 | 2959102篇 |
免费 | 212691篇 |
国内免费 | 7973篇 |
专业分类
耳鼻咽喉 | 39510篇 |
儿科学 | 97397篇 |
妇产科学 | 81097篇 |
基础医学 | 424186篇 |
口腔科学 | 81422篇 |
临床医学 | 268330篇 |
内科学 | 580187篇 |
皮肤病学 | 70691篇 |
神经病学 | 241402篇 |
特种医学 | 113404篇 |
外国民族医学 | 795篇 |
外科学 | 441093篇 |
综合类 | 56252篇 |
现状与发展 | 6篇 |
一般理论 | 1121篇 |
预防医学 | 229564篇 |
眼科学 | 66354篇 |
药学 | 217072篇 |
8篇 | |
中国医学 | 6022篇 |
肿瘤学 | 163853篇 |
出版年
2019年 | 23470篇 |
2018年 | 33034篇 |
2017年 | 25513篇 |
2016年 | 29532篇 |
2015年 | 33114篇 |
2014年 | 45641篇 |
2013年 | 68239篇 |
2012年 | 91025篇 |
2011年 | 96351篇 |
2010年 | 57939篇 |
2009年 | 55533篇 |
2008年 | 89954篇 |
2007年 | 95620篇 |
2006年 | 97296篇 |
2005年 | 93083篇 |
2004年 | 89464篇 |
2003年 | 86198篇 |
2002年 | 83220篇 |
2001年 | 142208篇 |
2000年 | 145918篇 |
1999年 | 122798篇 |
1998年 | 35230篇 |
1997年 | 31165篇 |
1996年 | 31617篇 |
1995年 | 30511篇 |
1994年 | 27947篇 |
1993年 | 26228篇 |
1992年 | 95396篇 |
1991年 | 92297篇 |
1990年 | 89606篇 |
1989年 | 86647篇 |
1988年 | 79332篇 |
1987年 | 77825篇 |
1986年 | 72804篇 |
1985年 | 69618篇 |
1984年 | 51692篇 |
1983年 | 43775篇 |
1982年 | 25678篇 |
1981年 | 22997篇 |
1979年 | 45883篇 |
1978年 | 32412篇 |
1977年 | 27598篇 |
1976年 | 25517篇 |
1975年 | 27563篇 |
1974年 | 32602篇 |
1973年 | 30829篇 |
1972年 | 29101篇 |
1971年 | 27135篇 |
1970年 | 25036篇 |
1969年 | 24023篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Yaprak Engin-Ustün Yusuf Ustün M Mutlu Meydanli Ay?e Kafkasli 《Gynecological endocrinology》2006,22(12):676-679
AIM: To compare the effects of 17beta-estradiol given intranasally (intranasal E2) and raloxifene on serum lipid profile and fibrinogen in hypercholesterolemic postmenopausal women. METHODS: The study population consisted of 46 women after menopause. The placebo group (n = 11) was given calcium, while the intervention groups were given intranasal E2 (Aerodiol; Servier, Chambray-les-Tours, France) (n = 16) or raloxifene (Evista; Lilly SA, Madrid, Spain) (n = 19). Blood lipids and fibrinogen were compared between groups at baseline and after 3 months of treatment. RESULTS: The group receiving intranasal E2 showed a significant decrease in triglyceride levels (p<0.05) and a marked increase in high-density lipoprotein cholesterol levels (p<0.05). No changes in lipid profile were observed in the raloxifene and placebo groups. Raloxifene caused a significant decrease in fibrinogen levels (p<0.05). CONCLUSION: Intranasal E2 exerts significant effects on lipid profile in hypercholesterolemic postmenopausal women. Raloxifene has a greater impact on fibrinogen than intranasal E2 application. 相似文献
992.
OBJECTIVE: To compare infants' discomfort, nursing-time and caregiver preference, and assess the clinical efficiency (as a secondary outcome) of hood versus facemask nebulization in infants with evolving bronchopulmonary dysplasia (BPD) in the neonatal intensive care unit. STUDY DESIGN: A prospective, open, randomized, controlled crossover clinical trial. In total, 10 infants with BPD who were on inhaled beta-agonist bronchodilators and corticosteroids were randomly assigned to receive their nebulized treatments either by a facemask, or by a hood for 2-3 days, and then crossover to receive the same treatments with the other technique for another 2-3 days. Infants' discomfort, nursing-time, caregiver preference and clinical efficiency were compared. RESULTS: At baseline there was no significant clinical difference between the groups. Nurse-time required for administering the hood nebulization (mean+/-s.e.m.: 1.9+/-0.1 min) was significantly shorter than the time for mask nebulization (12.0+/-0.6 min, P<0.0001). Infants' discomfort score was significantly lower (0.1+/-0.04) for hood versus mask nebulization (2.5+/-0.2, P<0.0001). Nurses and parents unequivocally preferred the hood treatment. During both mask and hood nebulization therapies (2-3 days) clinical efficiency was comparable. While both methods caused an immediate (20 min post) clinical improvement, the immediate respiratory assessment change score was significantly greater for the hood versus the mask nebulization (0.62+/-0.27 versus 0.13+/-0.14, P<0.05). CONCLUSIONS: Nebulization of aerosolized medications in infants with evolving BPD by hood was less time-consuming for caregivers and was much better tolerated by the infants while being at least as effective as the conventional facemask nebulization. 相似文献
993.
J. M. Troyano M. T. Clavijo A. Gonzalez-Lorenzo I. Martí nez-Wallin O. Y. Marco P. S. Casas L. Martí nez-Cort s L. T. Merc J. Bajo-Arenas N. Hernandez D. Castro 《The Ultrasound Review of Obstetrics & Gynecology》2006,6(1):79-99
In order to assess the state and pathology of the woman's pelvis minor, a number of methods are commonly used among practitioners, encompassing clinical exploration, radiology, MRN, urodynamics, endoscopy and echography.
Echography has been poorly used in clinical pelvic exploration and its reliability is actually a matter of controversy 1. However, echographic surveys can provide us with valuable gynecological data on the state and pathologies of the soft pelvis, within the genital regions or even going beyond them, i.e. the rectal channel, bladder, urethra, anus, vascular plexuses, and all of their supporting tissues.
At our research unit, we have been employing Transvaginal Ultrasound echography (TVU) for a long time in conjunction with other pelvis-focused methods in order to study different kinds of pelvic alterations. TVU has proven to be friendly to use, fast, harmless and inexpensive, allowing serial explorations and producing high-quality dynamic images (loop-cinema, video-tape). Furthermore, this method is fairly aseptic in that the occurrence of faeces in the rectal ampolla is not a nuisance but a bonus in tracking the contours of the rectum walls and other topographical features which would be otherwise difficult to survey.
A complete pelvic floor TVU may add no longer than 5-8 minutes to a routine gynecological examination, can be implemented by the general gynecologist and generates data that can be further studied by the appropriate specialist for a more insightful evaluation 2. 相似文献
Echography has been poorly used in clinical pelvic exploration and its reliability is actually a matter of controversy 1. However, echographic surveys can provide us with valuable gynecological data on the state and pathologies of the soft pelvis, within the genital regions or even going beyond them, i.e. the rectal channel, bladder, urethra, anus, vascular plexuses, and all of their supporting tissues.
At our research unit, we have been employing Transvaginal Ultrasound echography (TVU) for a long time in conjunction with other pelvis-focused methods in order to study different kinds of pelvic alterations. TVU has proven to be friendly to use, fast, harmless and inexpensive, allowing serial explorations and producing high-quality dynamic images (loop-cinema, video-tape). Furthermore, this method is fairly aseptic in that the occurrence of faeces in the rectal ampolla is not a nuisance but a bonus in tracking the contours of the rectum walls and other topographical features which would be otherwise difficult to survey.
A complete pelvic floor TVU may add no longer than 5-8 minutes to a routine gynecological examination, can be implemented by the general gynecologist and generates data that can be further studied by the appropriate specialist for a more insightful evaluation 2. 相似文献
994.
K. HELLMAN M. LUNDELL† C. SILFVERSWÄRD‡ B. NILSSON§ A.-C. HELLSTRÖM & B. FRANKENDAL 《International journal of gynecological cancer》2006,16(3):1201-1211
The goal of this retrospective study concerning primary carcinoma of the vagina (PCV) was to analyze clinical and histopathologic prognostic factors in one of the largest known material, which comprised 314 patients. PCV is a rare disease, and the majority of published studies are based on small materials; therefore, the established knowledge concerning prognostic factors is insufficient. Routine treatment is based on irradiation with risk for undertreatment or overtreatment, which leads to unnecessary complications in the absence of prognostic factors. The overall 5-year disease-specific survival rate in this study was 45% and in stage I 75%. In the univariate statistical analysis, several factors correlated significantly with disease-specific survival. However, in the multivariate analysis, there were only three factors that independently could predict poor survival-high age at diagnosis, large tumors (> or =4 cm), and advanced stage. Common background factors with no prognostic significance were prior hysterectomy, other gynecological malignancies, and pelvic irradiation. In conclusion, this study has elucidated three strong prognostic factors that might be considered in the choice of therapy and also for modification of the FIGO guidelines. Increased knowledge concerning complementary biologic markers to discriminate between low- and high malignant tumors is however of great importance. 相似文献
995.
Frederieke M Brouwers Graeme Eisenhofer Jacques W M Lenders Karel Pacak 《Endocrinology & Metabolism Clinics of North America》2006,35(4):699-724, viii
Pheochromocytoma may lead to important emergency situations, ranging from cardiovascular emergencies to acute abdomen and multiorgan failure. It is vital to think about this disease in any emergency situation when conventional therapy fails to achieve control or symptoms occur that do not fit the initial diagnosis. The importance of keeping this diagnosis in minds is underscored by the fact that, in 50% of pheochromocytoma patients, the diagnosis is initially overlooked. Two other tumors of the sympathetic nervous system, neuroblastoma and ganglioneuroma, are less commonly associated with emergency conditions. If they occur, they are often linked to catecholamine excess, paraneoplastic phenomena, or local tumor mass effect. 相似文献
996.
Dr. D. Süsskind S. Aisenbrey J. M. Rohrbach 《Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft》2006,103(5):421-424
Ohne Zusammenfassung 相似文献
997.
Gonadotropins mediate DNA synthesis and protection from spontaneous cell death in human ovarian surface epithelium 总被引:2,自引:0,他引:2
R.J. EDMONDSON J.M. MONAGHAN & B.R. DAVIES† 《International journal of gynecological cancer》2006,16(1):171-177
Gonadotropins have been implicated in the development of epithelial ovarian cancers. These tumors are derived from ovarian surface epithelium (OSE). The purpose of this study was to determine the effects of these hormones on DNA synthesis and spontaneous cell death in primary cultures of OSE and three immortalized OSE cultures. Primary cultures of OSE cells were generated from the ovaries of women with benign disease. The effects of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) on DNA synthesis and cell death were determined using [(3)H]thymidine incorporation and JAM assays. Significant inductions of DNA synthesis were demonstrated with LH in 4/12 (33%) primary cultures of OSE and 2/3 OSE cell lines and with FSH in 4/11 (36%) primary cultures of OSE and 2/3 OSE cell lines. A significant protection from cell death was also observed in the presence of FSH in 2/4 primary cultures of OSE and 1/3 OSE cell lines and in the presence of LH in 1/4 primary cultures of OSE and 2/3 OSE cell lines. The results indicate that while gonadotropins have the potential to induce cell proliferation and protect from cell death in OSE cells in vitro, their effects are variable in OSE cells from different women. 相似文献
998.
999.
C.A. AMEZCUA H.R. MACDONALD† C.A. LUM W. YI‡ L.I. MUDERSPACH† L.D. ROMAN† & J.C. FELIX† 《International journal of gynecological cancer》2006,16(3):1336-1341
In this study, we examine the prevalence of finding isolated tumor cells (ITCs) in negative lymph nodes of endometrial cancer patients using immunohistochemistry. Seventy-six endometrial cancer patients with lymph nodes histologically negative for metastatic disease were examined. Nodal tissue sections were stained with anticytokeratin antibodies AE-1 and CAM 5.2. Nodes with single or groups of cells (two to four cells) < or =0.2 mm and showing cytokeratin reactivity were positive for ITCs. Findings were compared to features of the primary tumor and patient outcome. ITCs were present in 31 of 1712 lymph nodes. Fifteen (19.7%) patients had ITC-positive nodes. ITCs involved only pelvic nodes in nine cases, only para-aortic nodes in five cases, and pelvic and para-aortic in one case. Tumor in adnexa was the only pathologic feature associated with nodal ITCs (P= 0.0485). All 15 patients with nodal ITCs were alive at follow-up. One (6.7%) patient suffered recurrent disease but was alive at last encounter. Disease recurred in 5 (8.8%) of 57 patients without nodal ITCs. Two are alive without disease, two alive with disease, and one died from her cancer. In summary, a significant proportion of endometrial cancer patients have ITCs detected by immunohistochemistry in histologically negative regional lymph nodes. 相似文献
1000.
Matthew J Matasar Ellen K Ritchie Nathan Consedine Carol Magai Alfred I Neugut 《European journal of cancer prevention》2006,15(4):367-370
Despite significant improvements in the prognosis of acute promyelocytic leukemia brought about by therapeutic advances, understanding of the epidemiology of acute promyelocytic leukemia remains limited. Earlier reports have suggested that Hispanics may have an increased incidence of acute promyelocytic leukemia, but no systematic analysis of national data has yet been reported. We performed a retrospective cohort study, using data from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute from 1992-2001 in order to compare leukemia incidence rates as a function of race and ethnicity. We identified 709 cases of acute promyelocytic leukemia and analyzed incidence rates by race and sex. Hispanics were not found to have greater lifetime incidence rates than whites, with an incidence relative rate (IRR) of 0.86 that of whites (P=0.17). The age distribution among Hispanics was significantly different from non-Hispanic whites, with greater incidence rates for children ages 1-19 years (IRR=1.9, P=0.02) and adult ages 20-44 years (IRR=1.6, P=0.004). Blacks had lower lifetime incidence rates than non-Hispanic whites (IRR=0.75, P=0.04), Hispanics (IRR=0.64, P=0.007), and Asians (IRR=0.67, P=0.03). Asians did not differ from non-Hispanic whites in lifetime or age-specific incidence rates. These results indicate that while US Hispanics do not have greater lifetime incidence rates of acute promyelocytic leukemia, blacks have lower incidence rates of acute promyelocytic leukemia than Hispanics, non-Hispanic whites, and Asians. 相似文献