全文获取类型
收费全文 | 8199篇 |
免费 | 704篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 83篇 |
儿科学 | 320篇 |
妇产科学 | 101篇 |
基础医学 | 1078篇 |
口腔科学 | 139篇 |
临床医学 | 945篇 |
内科学 | 1383篇 |
皮肤病学 | 100篇 |
神经病学 | 693篇 |
特种医学 | 559篇 |
外科学 | 1122篇 |
综合类 | 219篇 |
现状与发展 | 1篇 |
一般理论 | 3篇 |
预防医学 | 836篇 |
眼科学 | 172篇 |
药学 | 668篇 |
1篇 | |
中国医学 | 32篇 |
肿瘤学 | 477篇 |
出版年
2023年 | 38篇 |
2022年 | 46篇 |
2021年 | 111篇 |
2020年 | 79篇 |
2019年 | 110篇 |
2018年 | 129篇 |
2017年 | 107篇 |
2016年 | 101篇 |
2015年 | 146篇 |
2014年 | 199篇 |
2013年 | 280篇 |
2012年 | 392篇 |
2011年 | 408篇 |
2010年 | 302篇 |
2009年 | 267篇 |
2008年 | 391篇 |
2007年 | 434篇 |
2006年 | 360篇 |
2005年 | 348篇 |
2004年 | 340篇 |
2003年 | 319篇 |
2002年 | 314篇 |
2001年 | 272篇 |
2000年 | 239篇 |
1999年 | 223篇 |
1998年 | 172篇 |
1997年 | 144篇 |
1996年 | 134篇 |
1995年 | 141篇 |
1994年 | 85篇 |
1993年 | 92篇 |
1992年 | 179篇 |
1991年 | 174篇 |
1990年 | 143篇 |
1989年 | 147篇 |
1988年 | 142篇 |
1987年 | 134篇 |
1986年 | 105篇 |
1985年 | 133篇 |
1984年 | 106篇 |
1983年 | 89篇 |
1982年 | 61篇 |
1981年 | 65篇 |
1980年 | 58篇 |
1979年 | 75篇 |
1978年 | 62篇 |
1977年 | 54篇 |
1976年 | 37篇 |
1974年 | 46篇 |
1972年 | 33篇 |
排序方式: 共有8932条查询结果,搜索用时 0 毫秒
101.
Oh BR Sasaki M Perinchery G Ryu SB Park YI Carroll P Dahiya R 《The Journal of urology》2000,163(5):1584-1587
PURPOSE: Tumor necrosis factor-alpha (TNF-alpha) is involved in oncogenesis of several cancers. The purpose of this study was to investigate whether genotype changes of TNF-alpha promoter regions (-238, -308) and at the 488 region are associated with human prostate cancer. MATERIALS AND METHODS: The DNA from 73 cases of human prostate cancer was analyzed by allele-specific polymerase chain reaction to characterize the genotype changes of three regions of the TNF-alpha gene in prostate cancer patients. We also determined the genotype frequency in these patients. The relative risk of variant genotype was calculated by comparing with our previous data from healthy controls. RESULTS: Genetic changes were detected in 15.1% (11/73) of prostate cancer samples at 488 region of TNF-alpha. Seventy-three percent (53/73) of the patients showed genotype GA at -308 region of TNF-alpha. Genotype GA at 488 region in TNF-alpha was observed in 73% (53/73) of the cancer and 71% (52/73) of the normal tissue. The relative risks of incidence for prostate cancer was 14-fold higher in people with genotype GA at -308 region of TNF-alpha. The relative incidence for prostate cancer was a 17-fold higher in-patient with genotype GA at 488 region of TNF-alpha. Genotype GA at -308 of TNF-alpha was related to higher clinical tumor stage of prostate cancer than genotype G (p <0.05). CONCLUSIONS: The present study demonstrates, for the first time, that the genotype changes in -308 and 488 regions of TNF-alpha are associated with prostate cancer. 相似文献
102.
W D Carroll W Lenney F Child R C Strange P W Jones M K Whyte R A Primhak A A Fryer 《Archives of disease in childhood》2006,91(5):405-409
BACKGROUND: The relationship between asthma severity and atopy is complex. Many studies have failed to show significant relationships between clinical severity or lung function and markers of atopic sensitisation. AIM: To determine whether increasing asthma severity is related to atopic sensitisation in a population of children with asthma. METHODS: A total of 400 children (7-18 years) with asthma were recruited as part of a multicentre study of the genetics of asthma. Detailed phenotypic data were collected on all participants. Associations between measures of asthma severity and atopic sensitisation were sought using multilevel models allowing variation at the individual and family level. RESULTS: Children recruited to the study had a range of asthma severities, with just over a third having mild persistent asthma. The logarithm of total serum IgE was associated with increased asthma severity score, decreased FEV1, increased airways obstruction, risk of hospital admission, and inhaled steroid use. Increasing skin prick test reactivity to a panel of seven aeroallergens was associated with increased risk of hospital admission, use of an inhaled steroid, and airways obstruction. The results remained highly significant after corrections for age, gender, and birth order. CONCLUSIONS: In children with asthma, increasing atopy is associated with increasing asthma severity. However, the relationships between asthma severity and skin prick tests, and asthma severity and total serum IgE values, appear subtly different. 相似文献
103.
Christopher L Carroll Anita Bhandari Aaron R Zucker Craig M Schramm 《Pediatric critical care medicine》2006,7(6):527-531
OBJECTIVES: Childhood obesity contributes to a wide array of medical conditions, including asthma. There is also increasing evidence in adult patients admitted to the intensive care unit (ICU) that obesity contributes to increased morbidity and to a prolonged length of stay. We hypothesized that obesity is associated with the need for increased duration of therapy in children admitted to the ICU with status asthmaticus. DESIGN: Retrospective cohort study. SETTING: A tertiary pediatric ICU in a university-affiliated children's hospital. PATIENTS: We retrospectively examined data from all children older than 2 yrs admitted to the ICU with status asthmaticus between April 1997 and June 2004. Children were classified as normal weight (<95% weight-for-age percentile) or obese (>95% weight-for-age). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 209 children admitted to the ICU with asthma, 45 (22%) were obese. Compared with children of normal weight, the obese children were older (9.7 +/- 4.4 vs. 8.0 +/- 4.3 yrs, p = .02), more likely to be female (60% vs. 37%, p < .01), and more likely to have been admitted to the ICU previously (40% vs. 20%, p = .01). The obese children also had a statistically significant difference in race (more likely to be Hispanic) and in baseline asthma classification (more likely to have persistent asthma). Despite similar severity of illness at ICU admission, obese children had a significantly longer ICU length of stay (116 +/- 125 hrs vs. 69 +/- 57 hrs, p = .02) and hospital length of stay (9.8 +/- 7.0 vs. 6.5 +/- 3.4 days, p < .01). Obese children also received longer courses of supplemental oxygen, continuous albuterol, and intravenous steroids. CONCLUSIONS: Childhood obesity significantly affects the health of children with asthma. Obese children with status asthmaticus recovered more slowly from an acute exacerbation, even after adjustment for baseline asthma severity and admission severity of illness. 相似文献
104.
Carroll S Cooper C Brown D Sormann G Flood S Denison M 《The Australian and New Zealand journal of surgery》2000,70(8):563-568
BACKGROUND: The purpose of the present study was to document the value of an implanted multichannel neuroprosthesis (Freehand System) for restoring hand grasp in the first Australians to receive this device. METHODS: Hand function in C5 quadriplegic patients was assessed via measurement of pinch forces, a grasp release test and tests of activities of daily living (ADL). Comparisons were made between presurgery scores and scores recorded after rehabilitation when the neuroprosthesis was and was not in use. RESULTS: A significant difference for both lateral pinch (P = 0.003) and palmar grasp (P = 0.003) was found between forces recorded with and without the use of the neuroprosthesis after rehabilitation, but not between forces recorded presurgery and during rehabilitation without the neuroprosthesis. All subjects were able to grasp, move and release more objects within the 30-s test period with the neuroprosthesis than without it. Collective results for the eight ADL tests for all six subjects show that, in 35 of the 48 (73%) occasions, less physical assistance and/or adaptive equipment was required when the Freehand system was employed compared to when it was not used. In 41 of the 48 (85%) occasions, the six subjects expressed a preference for using the neuroprosthesis to perform these activities of daily living. Twelve months after rehabilitation, five of the six subjects still used the neuroprosthesis daily or every second day. CONCLUSION: The Freehand neuroprosthesis has provided useful hand function with few surgical and technical difficulties in these patients. Regular ongoing use of the device indicates user satisfaction. 相似文献
105.
Matthias Kirsch Patrick Weigel Thomas Pinzer Rona S Carroll Peter McL Black Hans-Konrad Schackert Gabriele Schackert 《Clinical cancer research》2005,11(3):1259-1267
PURPOSE: Cerebral metastases represent the most common type of brain tumors. This study investigated the effects of endogenous endostatin on hematogenous cerebral melanoma metastases. EXPERIMENTAL DESIGN: Murine K1735 melanoma cells were transfected with the mouse endostatin cDNA. Experimental tumors were induced either by s.c. injection, intracerebral implantation, or via injection into the internal carotid artery to simulate hematogenous metastatic spread. The effects of endostatin expression on tumor incidence, growth pattern, and vascularity were analyzed. RESULTS: In vitro secretion of endostatin by 2.5 x 10(5) cells within 24 hours was 0.12 +/- 0.03 ng, 4.35 +/- 0.4, and 1.18 +/- 0.7 ng/mL for wild type and two endostatin-transfected K1735 clones termed K1735-endo/2 and K1735-endo/8, respectively. Tumor inhibition in vivo correlated with endogenous endostatin production. Within 25 days, growth of s.c. K1735-endo/2 tumors was <20% compared with wild-type controls. Following intracerebral implantation the average survival time of mice was 27.8 +/- 2.6 versus 13.3 +/- 3.7 days in the K1735-endo/2 versus the wild-type group, respectively. Intracarotid injection of 1 x 10(5) wild-type cells killed the mice within 24 +/- 1.8 days. In contrast, endostatin expression prevented macroscopic metastatic tumor growth in 11 of 12 mice, although viable microscopic tumor pockets were detectable in all animals. CONCLUSION: Endostatin inhibits tumor progression of multiple cerebral metastases in vivo. Hematogenous micrometastases are more efficiently suppressed than tumors resulting from high focal cell numbers which may be due to a higher angiogenic signaling exerted by massive cell deposits. Endostatin may prevent solid tumor growth more effectively by inhibition of early angiogenesis. 相似文献
106.
M J Sutcliffe J J Shuster H N Sather B M Camitta J Pullen K R Schultz M J Borowitz P S Gaynon A J Carroll N A Heerema 《Leukemia》2005,19(5):734-740
Chromosome aberrations have a major role in pediatric acute lymphoblastic leukemia (ALL) risk assignment. The Children's Cancer Group (CCG) and the Pediatric Oncology Group (POG) independently assessed the significance of trisomy for chromosomes 4, 10, and 17 in National Cancer Institute (NCI) Standard- and High-Risk ALL. Data from 1582 (CCG) and 3902 (POG) patients were analyzed. Eight-year event-free survivals (EFS) of 91% (CCG) and 89% (POG) (P < 0.001) were achieved in patients assigned to NCI Standard Risk whose leukemic cells had simultaneous trisomies 4, 10, and 17. Both groups showed the degree of favorable prognostic importance increased with the actual number of favorable trisomies. POG analyses also demonstrated hyperdiploidy (> or =53 chromosomes) was less of an independently significant prognostic factor in the absence of these key trisomies. This finding supported conclusions from previous CCG and POG studies that specific trisomies are more important than chromosome number in predicting outcome in pediatric B-precursor ALL. In NCI Higher Risk patients, the number of favorable trisomies was not prognostically significant, but showed the same trend. Moreover, specific trisomies 4, 10, and 17 remain associated with favorable prognosis in Standard-Risk B-precursor ALL, even in the context of very different treatment approaches between the groups. 相似文献
107.
The changing face of prostate cancer. 总被引:4,自引:0,他引:4
Matthew R Cooperberg Judd W Moul Peter R Carroll 《Journal of clinical oncology》2005,23(32):8146-8151
Prostate cancer remains the most common noncutaneous human malignancy, and the second most lethal tumor among men. However, the natural history of the disease is often prolonged, and the survival benefits of local therapy for men with low-risk tumors may not be realized for a decade or more, as is increasingly well demonstrated in long-term observational cohorts in both the United States and Europe. A significant proportion of men with prostate cancer may be overdiagnosed, in the sense that diagnosis may not improve their lifespan or quality of life. However, the extent to which overdiagnosis represents a true problem relates to the consistency with which diagnosis leads invariably to active treatment. Prostate cancer is diagnosed at progressively earlier stages and with lower risk features; despite these trends, patients are less likely now than a decade ago to undergo a trial of active surveillance. Rates of brachytherapy and hormonal therapy use, in particular, have risen markedly. Important progress has been made in recent years in prostate cancer risk assessment. These advances, in combination with biomarkers in later stages of development, should be expected in the coming years to yield further improvements in clinicians' ability to diagnose prostate cancer early, and guide appropriately selected patients toward increasingly tailored treatment. 相似文献
108.
109.
Carroll PV Christ ER Umpleby AM Gowrie I Jackson N Bowes SB Hovorka R Croos P Sönksen PH Russell-Jones DL 《Diabetes》2000,49(5):789-796
Type 1 diabetes is associated with abnormalities of the growth hormone (GH)-IGF-I axis. Such abnormalities include decreased circulating levels of IGF-I. We studied the effects of IGF-I therapy (40 microg x kg(-1) x day(-1)) on protein and glucose metabolism in adults with type 1 diabetes in a randomized placebo-controlled trial. A total of 12 subjects participated, and each subject was studied at baseline and after 7 days of treatment, both in the fasting state and during a hyperinsulinemic-euglycemic amino acid clamp. Protein and glucose metabolism were assessed using infusions of [1-13C]leucine and [6-6-2H2]glucose. IGF-I administration resulted in a 51% rise in circulating IGF-I levels (P < 0.005) and a 56% decrease in the mean overnight GH concentration (P < 0.05). After IGF-I treatment, a decrease in the overnight insulin requirement (0.26+/-0.07 vs. 0.17+/-0.06 U/kg, P < 0.05) and an increase in the glucose infusion requirement were observed during the hyperinsulinemic clamp (approximately 67%, P < 0.05). Basal glucose kinetics were unchanged, but an increase in insulin-stimulated peripheral glucose disposal was observed after IGF-I therapy (37+/-6 vs. 52+/-10 micromol x kg(-1) x min(-1), P < 0.05). IGF-I administration increased the basal metabolic clearance rate for leucine (approximately 28%, P < 0.05) and resulted in a net increase in leucine balance, both in the basal state and during the hyperinsulinemic amino acid clamp (-0.17+/-0.03 vs. -0.10+/-0.02, P < 0.01, and 0.25+/-0.08 vs. 0.40+/-0.06, P < 0.05, respectively). No changes in these variables were recorded in the subjects after administration of placebo. These findings demonstrated that IGF-I replacement resulted in significant alterations in glucose and protein metabolism in the basal and insulin-stimulated states. These effects were associated with increased insulin sensitivity, and they underline the major role of IGF-I in protein and glucose metabolism in type 1 diabetes. 相似文献