全文获取类型
收费全文 | 2228199篇 |
免费 | 159385篇 |
国内免费 | 3311篇 |
专业分类
耳鼻咽喉 | 32173篇 |
儿科学 | 74056篇 |
妇产科学 | 60228篇 |
基础医学 | 315869篇 |
口腔科学 | 60834篇 |
临床医学 | 198618篇 |
内科学 | 432585篇 |
皮肤病学 | 49498篇 |
神经病学 | 172360篇 |
特种医学 | 88360篇 |
外国民族医学 | 869篇 |
外科学 | 339246篇 |
综合类 | 46126篇 |
现状与发展 | 2篇 |
一般理论 | 679篇 |
预防医学 | 165708篇 |
眼科学 | 50360篇 |
药学 | 171518篇 |
10篇 | |
中国医学 | 4735篇 |
肿瘤学 | 127061篇 |
出版年
2018年 | 23462篇 |
2017年 | 17938篇 |
2016年 | 19880篇 |
2015年 | 22359篇 |
2014年 | 30835篇 |
2013年 | 46500篇 |
2012年 | 63586篇 |
2011年 | 67405篇 |
2010年 | 39989篇 |
2009年 | 37733篇 |
2008年 | 63336篇 |
2007年 | 67927篇 |
2006年 | 68675篇 |
2005年 | 66507篇 |
2004年 | 64451篇 |
2003年 | 62222篇 |
2002年 | 60631篇 |
2001年 | 113044篇 |
2000年 | 117017篇 |
1999年 | 98636篇 |
1998年 | 26033篇 |
1997年 | 23249篇 |
1996年 | 23572篇 |
1995年 | 22162篇 |
1994年 | 20711篇 |
1993年 | 19360篇 |
1992年 | 76560篇 |
1991年 | 74116篇 |
1990年 | 72550篇 |
1989年 | 69505篇 |
1988年 | 63554篇 |
1987年 | 62203篇 |
1986年 | 58215篇 |
1985年 | 55532篇 |
1984年 | 41031篇 |
1983年 | 34563篇 |
1982年 | 19600篇 |
1981年 | 17581篇 |
1979年 | 36601篇 |
1978年 | 25065篇 |
1977年 | 21765篇 |
1976年 | 19684篇 |
1975年 | 21787篇 |
1974年 | 25366篇 |
1973年 | 24386篇 |
1972年 | 22889篇 |
1971年 | 21068篇 |
1970年 | 19735篇 |
1969年 | 18448篇 |
1968年 | 16613篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
C Edward Hoffler Kurt D Hankenson Joshua D Miller Sukhinderdeep K Bilkhu Steven A Goldstein 《Journal of orthopaedic research》2006,24(8):1687-1698
To understand in situ behavior of osteocytes, we characterized a model of osteocytes in their native bone matrix and demonstrated real-time biologic activity of osteocytes while bending the bone matrix. Using 43 male Sprague-Dawley rats, dumbbell-shaped explants were harvested from stainless steel femoral implants after 6-12 weeks and incubated in culture medium or fixed. Sixteen specimens were used to determine bone volume density (BV/TV), volumetric bone mineral density (BMD) and histology for different implantation periods. Osteocyte viability was evaluated by L-lactate dehydrogenase (LDH) activity in 12 cultured explants. Confocal microscopy was used to assess tracer diffusion in three explants and changes in osteocyte pH of a mechanically loaded explant. From 6 to 12 weeks, explant BV/TV and volumetric BMD trended up 92.5% and 101%, respectively. They were significantly and highly correlated. Tissues were uniformly intramembranous and all bone cell types were present. Explants maintained LDH activity through culture day 8. Diffusion at 200 microM was limited to 1,209 Da. Explants appeared capable of reproducing complex bone biology. This model may be useful in understanding osteocyte mechanotransduction in the context of a physiologically relevant bone matrix. 相似文献
102.
Surender Kumar Yachha Rakesh Aggarwal S Srinivas Anshu Srivastava Sanjay K Somani Srivenu Itha 《Indian journal of gastroenterology》2006,25(3):132-135
BACKGROUND: We prospectively evaluated the usefulness of IgA tissue transglutaminase antibodies (IgA tTG) in the initial diagnosis of celiac disease (CD) and compared its diagnostic potential with that of IgA anti-endomysial antibodies (IgA EMA) and anti-IgA and IgG gliadin antibodies (AGA and AGG, respectively). METHODS: Sera of 23 untreated children fulfilling the revised ESPGHAN criteria for diagnosis of CD (Group I; mean age 10.8 y); 19 disease controls (Group II; mean age 8.5 y) presenting with chronic diarrhea, short stature or both; and 22 healthy children (Group III; mean age 8.8 y) were studied. These were tested in a blinded manner for AGA, AGG, IgA tTG (guinea pig as antigen) and IgA EMA. RESULTS: In Group I, IgA EMA was positive in 19, IgA tTG in 17, AGA in 14 and AGG in 17 patients. In Group II, these tests were positive in 1, 0, 2 and 14 patients, respectively and in Group III, in 0, 0, 0 and 1 child, respectively. Analyzing data from Group I and II, IgA EMA, IgA tTG, AGA and AGG had sensitivity rates of 83%, 74%, 61% and 74%, respectively; the specificity rates were 95%, 100%, 89% and 26%; positive predictive values were 95%, 100%, 88% and 55% and negative predictive values were 82%, 74%, 65% and 45%, respectively. CONCLUSION: IgA tTG is useful for the diagnosis of CD, with sensitivity and specificity rates comparable to those of EMA and this test is well suited for use in tropical countries like India. 相似文献
103.
P Avalos-Peralta† A Herrera† JJ Ríos-Martín‡ AM Pérez-Bernal† D Moreno-Ramírez† F Camacho† 《Journal of the European Academy of Dermatology and Venereology》2006,20(1):79-83
We report the case of a patient with a 13-year history of pemphigus vulgaris (PV) treated with immunosuppressive agents, prednisone and mycophenolate mofetil who had developed lesions of Kaposi's sarcoma (KS) on a sole plaque of PV that had been previously treated with intralesional injections of steroids. The lesions were surgically removed and polymerase chain reaction (PCR) demonstrated human herpesvirus-8 (HHV-8) DNA. There were neither recurrences nor later dissemination of KS following gradual decrease of the immunosuppressive therapy. We suggest that the treatment with intralesional steroids may have influenced the local reactivation of a latent infection of the virus, determining the appearance of this localized KS. 相似文献
104.
Kevin L Taylor Rhonda K Oates Ron Grane Douglas W Leaman Ernest C Borden Daniel J Lindner 《Journal of interferon & cytokine research》2006,26(5):353-361
Interferon-alpha (IFN-alpha) has proved effective in the treatment of hemangiomas, hemangioblastomas, and Kaposi's sarcoma. To investigate the ability of IFNs to inhibit angiosarcoma, we used two transformed murine endothelial cell lines that form angiosarcomas in vivo. SVR and MS1-VEGF cell lines express oncogenic H-ras or vascular endothelial growth factor (VEGF), respectively. IFN-alpha1,8, which is active against murine and human cells, inhibited SVR and MS1-VEGF proliferation in vitro by 40% at 10(3) U/mL (p = 0.028). In vivo, IFN-alpha1,8 inhibited SVR tumor volume by 71% (p = 0.047) and MS1-VEGF volume by 79% (p = 0.003). Tumor-induced angiogenesis was decreased in SVR tumors by 52% (p = 0.005) and in MS1-VEGF tumors by 58% (p = 0.001). Sera from IFN-alpha1,8-treated mice bearing either SVR or MS1-VEGF tumors demonstrated a 5-fold increase in IP-10/CXCL10 (p = 0.001), an IFN-induced antiangiogenic protein. Both recombinant IP-10 and IFN-alpha1,8 inhibited human umbilical vein endothelial cell (HUVEC) vessel formation in the fibrin gel assay, a three-dimensional culture model of angiogenesis, by 56% at 25 ng/mL and 50% at 1.2 ng/mL, respectively (p < 0.001). An IP-10 blocking antibody restored vessel formation to 80% of untreated controls (p = 0.001). Given the magnitude of the in vivo response, these data suggested that the antitumor effects of IFN-alpha1,8 were likely mediated through angiogenesis inhibition rather than solely by direct inhibition of tumor cell proliferation. 相似文献
105.
106.
Successful efforts in improving breastfeeding initiation rates at an urban teaching hospital prompted the hospital to create a lactation consultant (LC) position in the outpatient setting to focus on breastfeeding duration. This article reviews the complexity of the clinic setting, with the challenges and benefits of the consultant's first year in one of the hospital's outpatient clinics. Preliminary data collected by the consultant suggest that patients counseled by the LC in the outpatient clinic setting have longer breastfeeding duration rates. 相似文献
107.
108.
Abstract: Background: Few studies have examined in depth the labor progression of multiparas to determine if there is any additional impact of being parous beyond the first birth. The objective of this study was to determine the effect of parity on labor progression in contemporary obstetric practice. Methods: Our sample consisted of all low‐risk women who delivered a term, live‐born infant from January 2002 to March 2004 at a single institution in Delaware, United States (n = 5,589). The median duration of labor by each centimeter of cervical dilation was computed for parity = 0 (n = 2,645); parity = 1 (n = 1,839); parity = 2 (n = 750); and parity = 3 + (n = 355). Results: Multiparas had a significantly faster labor progression from 4 to 10 cm (293, 300, and 313 min, respectively, for parity = 1, parity = 2, and parity = 3 +), compared with nulliparas (383 min for parity = 0), as well as a shorter second stage of labor. However, no significant differences were found in duration of the active phase or the second stage of labor among multiparas. Conclusions: Additional childbearing appears to have no effect of on the progression of labor among multiparous subgroups. The difference in duration of the active phase between nulliparas and multiparas is substantially smaller in a contemporary population. (BIRTH 33:1 March 2006) 相似文献
109.
Andrea R Genazzani Hermann P G Schneider Nick Panay Esme A Nijland 《Gynecological endocrinology》2006,22(7):369-375
OBJECTIVES: To identify and describe current women's thoughts about the menopause, hormone treatment (HT) and perceptions about breast cancer. METHODS: Between December 2004 and January 2005, 4201 postmenopausal women in seven European countries were interviewed via a standardized computer-aided telephone interview protocol. RESULTS: Almost all women reported to have experienced climacteric symptoms, and 63% of the women rated them as being severe. Only 52% of women were aware of the benefits of HT for relief of climacteric symptoms. Although 84% felt that severe symptoms should be treated, only 40% had used HT at some point in time. Thirty-four percent of the women preferring treatment with natural products did so because of the risk of breast cancer associated with HT. HT was recognized by 59% of the women as one of the most important contributors to an increased breast cancer risk. Most women received their information about HT and breast cancer risk from the media. CONCLUSIONS: This European survey reveals that the majority of women experience climacteric symptoms but that their decision whether or not to use HT is highly dependent on their concern about breast cancer risk. An increase in knowledge of the benefits and risks of HT is required for women to make appropriate decisions about hormone use. 相似文献
110.
Elhaji Youssef A.; Stoica Ileana; Dennis Sheldon; Purisima Enrico O.; Lumbroso Rose; Beitel Lenore K.; Trifiro Mark A. 《Human molecular genetics》2006,15(9):1561
Human Molecular Genetics (2006) 15, 921931; 相似文献