全文获取类型
收费全文 | 2399篇 |
免费 | 292篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 31篇 |
儿科学 | 129篇 |
妇产科学 | 73篇 |
基础医学 | 380篇 |
口腔科学 | 39篇 |
临床医学 | 257篇 |
内科学 | 510篇 |
皮肤病学 | 22篇 |
神经病学 | 234篇 |
特种医学 | 39篇 |
外科学 | 244篇 |
综合类 | 64篇 |
一般理论 | 9篇 |
预防医学 | 358篇 |
眼科学 | 54篇 |
药学 | 181篇 |
中国医学 | 4篇 |
肿瘤学 | 68篇 |
出版年
2022年 | 22篇 |
2021年 | 50篇 |
2020年 | 31篇 |
2019年 | 47篇 |
2018年 | 41篇 |
2017年 | 43篇 |
2016年 | 49篇 |
2015年 | 42篇 |
2014年 | 64篇 |
2013年 | 90篇 |
2012年 | 145篇 |
2011年 | 124篇 |
2010年 | 70篇 |
2009年 | 81篇 |
2008年 | 125篇 |
2007年 | 122篇 |
2006年 | 104篇 |
2005年 | 128篇 |
2004年 | 114篇 |
2003年 | 85篇 |
2002年 | 92篇 |
2001年 | 56篇 |
2000年 | 60篇 |
1999年 | 33篇 |
1998年 | 29篇 |
1997年 | 26篇 |
1996年 | 17篇 |
1994年 | 20篇 |
1993年 | 16篇 |
1992年 | 36篇 |
1991年 | 42篇 |
1990年 | 28篇 |
1989年 | 34篇 |
1988年 | 38篇 |
1987年 | 33篇 |
1986年 | 30篇 |
1985年 | 37篇 |
1984年 | 30篇 |
1983年 | 40篇 |
1982年 | 16篇 |
1981年 | 31篇 |
1979年 | 25篇 |
1978年 | 24篇 |
1977年 | 21篇 |
1975年 | 16篇 |
1974年 | 19篇 |
1973年 | 20篇 |
1972年 | 23篇 |
1970年 | 17篇 |
1969年 | 16篇 |
排序方式: 共有2696条查询结果,搜索用时 986 毫秒
991.
Raphael J. Landovitz Thuy Tien T. Tran Susan E. Cohn Ighovwhera Ofotokun Catherine Godfrey Daniel R. Kuritzkes Jeffrey L. Lennox Judith S. Currier Heather J. Ribaudo 《AIDS and behavior》2016,20(12):2983-2995
Antiretroviral therapy (ART) can minimize HIV transmission. Prevention benefits may be compromised by barriers to virologic suppression, and by increased condomless sex among those initiating ART. We evaluated condomless sex in a cohort of HIVinfected US individuals poised to initiate ART in a clinical trial. We assessed partner and sex act type, condom use, and perception of infectiousness. Six percent of participants reported as not infectious; men who have sex with men were more likely to perceive high infectivity. Prevalence of condomless sex was 44 %; 74 % of those also reported homosexual acquisition of HIV. Predictors of increased risk of condomless sex included greater numbers of lifetime partners, recent stimulant drug use and an HIV-positive or unknown serostatus partner. In the context of serodifferent partners, lower perception of infectiousness was also associated with a higher risk of condomless sex. Results highlight opportunities for prevention education for HIV infected individuals at ART initiation. 相似文献
992.
Melissa Carroll Nick Mellick Godfrey Wagner 《The Australasian journal of dermatology》2015,56(3):224-226
Dermatomyositis‐related panniculitis is a rare cutaneous manifestation of dermatomyositis. There are few reported cases in the medical literature. We present the case of a 60‐year‐old woman with a 2‐year history of dermatomyositis and recent biopsy‐confirmed panniculitis treated with prednisone, cyclophosphamide and i.v. immunoglobulin. 相似文献
993.
Malamba SS Mermin J Reingold A Lule JR Downing R Ransom R Kigozi A Hunt BM Hubbard A Rosenthal PJ Dorsey G 《The American journal of tropical medicine and hygiene》2006,75(3):375-380
The purpose of this prospective cohort study was to assess the effect of cotrimoxazole prophylaxis taken by human immunodeficiency virus (HIV)-infected persons on the selection of sulfadoxine-pyrimethamine (SP)-resistant malaria parasites among HIV-uninfected household members. A total of 2,567 HIV-uninfected persons from 605 households were followed and blood specimens were collected each time an episode of Plasmodium falciparum malaria was diagnosed. Study participants were living in households where HIV-infected persons were either taking (exposed) or not taking (unexposed) cotrimoxazole prophylaxis. From all malaria episodes diagnosed, 50% of the specimens were randomly selected and tested for the presence of five key mutations known to mediate resistance to SP (dihydrofolate reductase [dhfr] Asn-108, Ile-51, and Arg-59, and dihydropteroate synthase [dhps] Gly-437 and Glu-540). Plasmodium falciparum isolates were recovered from 163 specimens in the exposed households and 113 specimens in the unexposed households, with similar proportions containing the dhfr triple mutant (37% versus 45%; P = 0.18), the dhps double mutant (64% versus 62%; P = 0.81), and the dhfr/dhps quintuple mutant (30% versus 32%; P = 0.74). The HIV-uninfected persons living with HIV-infected household members taking cotrimoxazole prophylaxis had a lower incidence of malaria (incidence rate ratio [IRR] = 0.64, 95% confidence interval [CI] = 0.50-0.83, P = 0.001) and fewer malaria episodes due to parasites containing the dhfr/dhps quintuple mutant (IRR = 0.61, 95% CI = 0.41-0.91, P = 0.014). Cotrimoxazole prophylaxis taken by HIV-infected persons did not select for SP-resistant malaria parasites among HIV-uninfected household members, and was associated with a lower overall incidence of SP-resistant malaria among household members. 相似文献
994.
Mujuzi G Magambo B Okech B Egwang TG 《The American journal of tropical medicine and hygiene》2006,74(5):724-729
Pigmented leukocytes are reported to be associated with severe malaria (SM). Blood smears from a case-control study of SM conducted in Apac Hospital in Northern Uganda were examined for pigmented leukocytes to investigate their association with measures of disease and clinical immunity in children less than 5 years old. Pigmented leukocytes, predominated by monocytes, were significantly greater in number in SM by comparison with uncomplicated malaria (UM). SM children with no pigmented leukocytes had significantly elevated hemoglobin, packed cell volumes, and titers of IgG anti-SERA5 by comparison with SM children with pigmented leukocytes. These differences were not observed in UM. A Spearman rank correlation analysis showed, in addition, a negative but weak correlation between pigmented monocytes and titers of IgG anti-Plasmodium falciparum lysate and IgG anti-EBA-175 in both SM and UM children. Thus, numbers of pigmented monocytes might be negative correlates of clinical immunity in a region of holoendemic malaria. 相似文献
995.
Traditional risk factor assessment does not capture the extent of cardiovascular risk in systemic lupus erythematosus 总被引:3,自引:0,他引:3
Lee AB Godfrey T Rowley KG Karschimkus CS Dragicevic G Romas E Clemens L Wilson AM Nikpour M Prior DL Best JD Jenkins AJ 《Internal medicine journal》2006,36(4):237-243
Background: Systemic lupus erythematosus (SLE) is associated with accelerated atherosclerosis. However, the degree of endothelial dysfunction and its relationship to traditional and novel cardiovascular risk factors have not been examined in SLE. Methods: In a case–control design, 35 patients with clinically stable SLE and 35 control subjects matched for age, sex, body mass index and smoking status were studied. Arterial elasticity, lipid profile, homocysteine, measures of inflammation and oxidative stress were determined. Results: Among traditional vascular risk factors, there was a nonsignificant trend towards lower blood pressure in the control subjects, whereas low‐density lipoprotein (LDL) cholesterol levels were significantly lower in the SLE group (2.5 vs 3.3 mmol/L, P < 0.001). Patients with SLE had significantly lower small artery elasticity (SAE; 4.9 vs 7.0 ml/mmHg × 100, P < 0.001) and higher plasma homocysteine (11.4 vs 8.3 mmol/L, P = 0.002) than control subjects. Levels of serum sVCAM‐1 (614 vs 494 ng/mL, P = 0.002), oxidized LDL (144 vs 97, P < 0.001) and CD40 ligand (4385 vs 1373 pg/ml, P = 0.001) were significantly higher in SLE. Oxidized LDL levels, older age at SLE diagnosis and higher disease damage scores correlated inversely with SAE but not traditional risk factors. Conclusion: Impaired endothelial function as shown by decreased SAE, and an adverse profile of novel proatherogenic and prothrombotic vascular disease risk factors were prevalent in clinically quiescent SLE. These findings show the vulnerability of patients with SLE for atherosclerosis, and emphasize that assessments based on traditional risk factors alone may be inadequate. 相似文献
996.
Polyunsaturated fatty acids (PUFA) are thought to influence plasma lipid levels, atherosclerosis, and the immune system. In this study, we fed male LDL receptor deficient (LDLR(-/-)) mice and immune incompetent LDLR(-/-) RAG2(-/-) mice diets containing predominantly saturated fats (milk fat) or PUFA (safflower oil) to determine if the response to diet was influenced by immune status. Relative to milk fat diet, plasma lipid and VLDL levels in both the LDLR(-/-) and LDLR(-/-) RAG2(-/-) mice fed safflower oil diet were lower, suggesting that the primary effect of PUFA on plasma lipids was not due to its inhibition of the immune system. Neither diet nor immune status influenced hepatic triglyceride production and post-heparin lipase activity, suggesting that the differences in triglyceride levels are due to differences in rates of catabolism of triglyceride-rich lipoproteins. While both diets promoted atherogenesis, both aortic root and innominate artery atherosclerosis in LDLR(-/-) mice was less in safflower oil fed animals. In contrast, a site-specific effect of PUFA was observed in the immune incompetent LDLR(-/-) RAG2(-/-). In these mice, aortic root atherosclerosis, but not innominate artery atherosclerosis, was less in PUFA fed animal. These results suggest that PUFA and the immune system may influence innominate artery atherosclerosis by some overlapping mechanisms. 相似文献
997.
Jones A Godfrey KM Wood P Osmond C Goulden P Phillips DI 《The Journal of clinical endocrinology and metabolism》2006,91(5):1868-1871
CONTEXT: Experimental studies in animals show that adverse prenatal environments lead to lifelong alterations in the activity of the hypothalamic-pituitary-adrenal axis, which mediates the stress response through secretion of glucocorticoid hormones. The extent to which such prenatal hypothalamic-pituitary-adrenal axis adaptations occur in humans is unknown. OBJECTIVE: The objective of the study was to determine whether smaller but otherwise healthy term babies are more likely to demonstrate increased glucocorticoid responses to psychological stress in childhood. DESIGN AND PARTICIPANTS: This was a cross-sectional study of 68 boys and 72 girls (aged 7-9 yr) who have been followed up since 12 wk gestation when their mothers took part in a study of healthy children born in Southampton, United Kingdom. MAIN OUTCOME MEASURE: Salivary cortisol responses to psychological stress were measured. RESULTS: In boys, birth weight was inversely related to salivary cortisol responses to stress (r = -0.56, P < 0.001) but not morning cortisol levels, whereas in girls, morning peak cortisol was inversely related to birth weight (r = -0.36, P < 0.05). These associations were independent of gestational age and potential confounding factors including obesity, social class, and educational achievement. CONCLUSIONS: This study suggests that processes occurring during fetal life, resulting in smaller newborns, have a lasting effect on adrenocortical responses to stress in boys and on basal adrenocortical activity in girls. Given the known associations between small alterations in adrenocortical activity and features of the metabolic syndrome such as raised blood pressure and glucose intolerance, these effects warrant further investigation of their potential impact on the future health of prepubertal children. 相似文献
998.
Berkowitz RB McCafferty F Lutz C Bazelmans D Godfrey P Meeves S Liao Y Georges G 《Clinical therapeutics》2006,28(10):1658-1669
BACKGROUND: The onset of action of antihistamine-decongestant combinations is an important factor in the treatment of subjects with seasonal allergic rhinitis (SAR). OBJECTIVE: This was a pooled analysis of 2 published studies with identical designs investigating the onset of action of the combination of fexofenadine hydrochloride 60 mg/pseudoephedrine hydrochloride 120 mg (FEX60/PSE120) in subjects with moderate to severe SAR. METHODS: Subjects aged 12 years received single doses of FEX60/PSE120 or placebo in 2 randomized, double-blind, placebo-controlled, parallel-group, allergen exposure unit studies and recorded their SAR symptoms on diary cards before dosing, at 15-minute intervals for 2 hours after dosing, and at 30-minute intervals for the next 4 hours. The primary efficacy end point was onset of action, assessed in terms of absolute change in the major symptom complex (MSC) score, which was the sum of scores for the individual symptoms of stuffy nose, itchy nose, runny nose, watery eyes, itchy eyes, itchy ears/throat, and sneezing. Secondary end points included the absolute and percent change in the total symptom complex (TSC) score (the sum of the MSC score plus the scores for nose blowing, sniffles, postnasal drip, and cough) and individual symptom scores. Treatment-emergent adverse events (TEAEs) were recorded. Analyses were performed on the modified intention-to-treat (mITT) population, which included all subjects who were randomized to treatment and took the single dose of study medication according to the protocol. RESULTS: A total of 1693 subjects were screened in the 2 studies, and 786 were randomized (298 in study 1, 488 in study 2). Two subjects withdrew from study 2; therefore, the mITT population consisted of 784 subjects. Subjects' mean age was 33.4 years, and 64.4% were female. The onset of action of FEX60/PSE120 was 45 minutes; the least squares mean (SD) treatment difference in the change from baseline in absolute MSC score was 0.8 (0.31) (95% CI, 0.2-1.4; P = 0.008). All subsequent changes from baseline in MSC scores were statistically significant for FEX60/PSE120 compared with placebo (P < 0.001). The absolute and percent change in TSC score and the percent change in MSC score were significantly decreased at all time points from 45 minutes after dosing for FEX60/PSE120 compared with placebo (all, P < 0.05). Individual symptoms (mean of hours 1 to 5) also were significantly improved with FEX60/PSE120 compared with placebo (all, P < 0.05). TEAEs were reported by 2.3% (9/391) and 4.3% (17/393) of subjects receiving FEX60/PSE120 and placebo, respectively. The most commonly occurring TEAS in the FEX60/PSE120 and placebo groups was somnolence (n = 4 and n = 6, respectively). CONCLUSION: In this pooled analysis of 2 allergen exposure unit studies, FEX60/PSE120 had an onset of action of 45 minutes and a sustained effect throughout the 6-hour study period in subjects with moderate to severe SAR. 相似文献
999.
Garcia-Contreras L Sethuraman V Kazantseva M Godfrey V Hickey AJ 《The Journal of antimicrobial chemotherapy》2006,58(5):980-986
OBJECTIVES: The efficacy of rifampicin-loaded polymeric microspheres (RPLGA) delivered to guinea pigs infected with Mycobacterium tuberculosis (H37Rv) was compared with a daily dose of nebulized rifampicin suspension. METHODS: Aerosol-infected animals were subjected to multiple dose or single dose treatment with RPLGA, PLGA microspheres or micronized rifampicin suspension aerosols. For comparison with treatment with suspensions of microspheres, additional groups received daily doses of rifampicin-only suspensions for 20 (20-RIF) and 10 (10-RIF) days. RESULTS: Drug and polymer treated multiple dose groups exhibited significantly lower wet lung weights than untreated animals. Spleen wet weights and viable bacterial counts (VBCs) were much lower for drug microsphere treated animals than for all other groups. In multiple dose studies with rifampicin-only suspensions, wet lung weights for 10-RIF and 20-RIF treated animals were much smaller than controls. Likewise, wet spleen weights of 10-RIF and 20-RIF treated animals were much smaller than controls, consistent with reduced inflammation. Spleen VBC of 20-RIF treated animals was much smaller than controls. No statistical differences were observed in the lung VBC among single dose groups. However, a trend similar to that of the wet weights was observed. CONCLUSIONS: Aerosolized RPLGA reduced most measures of tuberculosis (TB) infection. These studies are further evidence for the potential of inhaled aerosol therapy for the treatment of TB. However, additional studies are required to elucidate underlying mechanisms of action and optimize this route of drug delivery. 相似文献
1000.