全文获取类型
收费全文 | 11204篇 |
免费 | 885篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 111篇 |
儿科学 | 608篇 |
妇产科学 | 300篇 |
基础医学 | 1719篇 |
口腔科学 | 226篇 |
临床医学 | 1032篇 |
内科学 | 2510篇 |
皮肤病学 | 118篇 |
神经病学 | 990篇 |
特种医学 | 374篇 |
外科学 | 1960篇 |
综合类 | 144篇 |
一般理论 | 3篇 |
预防医学 | 772篇 |
眼科学 | 218篇 |
药学 | 467篇 |
中国医学 | 11篇 |
肿瘤学 | 547篇 |
出版年
2021年 | 106篇 |
2019年 | 106篇 |
2018年 | 136篇 |
2017年 | 114篇 |
2016年 | 112篇 |
2015年 | 133篇 |
2014年 | 223篇 |
2013年 | 307篇 |
2012年 | 400篇 |
2011年 | 419篇 |
2010年 | 236篇 |
2009年 | 215篇 |
2008年 | 422篇 |
2007年 | 384篇 |
2006年 | 378篇 |
2005年 | 456篇 |
2004年 | 427篇 |
2003年 | 365篇 |
2002年 | 384篇 |
2001年 | 368篇 |
2000年 | 354篇 |
1999年 | 304篇 |
1998年 | 122篇 |
1997年 | 115篇 |
1996年 | 112篇 |
1995年 | 105篇 |
1992年 | 289篇 |
1991年 | 274篇 |
1990年 | 286篇 |
1989年 | 299篇 |
1988年 | 277篇 |
1987年 | 284篇 |
1986年 | 268篇 |
1985年 | 253篇 |
1984年 | 174篇 |
1983年 | 193篇 |
1982年 | 124篇 |
1981年 | 125篇 |
1980年 | 117篇 |
1979年 | 221篇 |
1978年 | 194篇 |
1977年 | 149篇 |
1976年 | 163篇 |
1975年 | 142篇 |
1974年 | 144篇 |
1973年 | 146篇 |
1972年 | 150篇 |
1971年 | 108篇 |
1970年 | 103篇 |
1969年 | 116篇 |
排序方式: 共有10000条查询结果,搜索用时 7 毫秒
131.
Forty-eight children with short stature, growth rate less than 4 cm/yr, and normal growth hormone response to secretagogues were given exogenous human growth hormone (hGH) for 6 months to determine its effect on the short-term growth rate in these children. All except three had an increase in growth rate with hGH therapy. The mean +/- SD pretreatment growth rate (3.4 +/- 0.8 cm/yr) was significantly less than either the growth rate during 6 months of hGH therapy (6.9 +/- 2.6 cm/yr) or after therapy (4.1 +/- 1.8 cm/yr). Several patterns of response were observed after treatment was stopped: the mean growth rate in 22 children decreased after treatment but remained above basal rates, the mean growth rate in seven children was similar to the rates during treatment, and the mean growth rate in 16 children was less than basal rates. Twenty children received therapy for an additional 6 months and had a mean increase in growth rate from 3.6 +/- 1.3 to 6.7 +/- 2.4 cm/yr. The decreased growth rate after discontinuation of treatment and increased rate with resumption of therapy indicates that maintenance of the increased growth rate might be dependent on continuation of hGH therapy. 相似文献
132.
We determined the effect of pituitary human growth hormone treatment on the growth rate of 52 children with Turner syndrome. The pretreatment growth rate was 3.2 +/- 0.8 cm/yr. Growth hormone treatment (0.2 IU/kg three times per week) resulted in enhancement of the growth rate to 5.9 +/- 1.4 cm/yr for the first year of therapy. The bone age advanced approximately 1 year during the year of therapy. The growth hormone therapy was discontinued at 12 months, and the mean growth rate decreased to pretreatment levels, 3.1 +/- 1.9 cm/yr; 26 of 41 patients actually had post-treatment growth rates that were less than the pretreatment rate. Glucose tolerance tests at 6-month intervals did not indicate an effect of hGH treatment on glucose intolerance. Several patients had glucose intolerance that preceded hGH treatment, but this remained stable during treatment; glucose intolerance likely was related to obesity in this group of patients. Basal and hGH-stimulated somatomedin C levels (32 patients) correlated with age of the patient but not with growth rate during therapy. We conclude that hGH therapy can accelerate the growth rate of patients with Turner syndrome. The growth rate increased to "normal" levels and was dependent on continued treatment with hGH. If the response continues, long-term treatment of Turner syndrome may result in increased adult height. 相似文献
133.
Brenda Waning Warren Kaplan Alexis C King Danielle A Lawrence Hubert G Leufkens Matthew P Fox 《Bulletin of the World Health Organization》2009,87(7):520-528
Objective
To estimate the impact of global strategies, such as pooled procurement arrangements, third-party price negotiation and differential pricing, on reducing the price of antiretrovirals (ARVs), which currently hinders universal access to HIV/AIDS treatment.Methods
We estimated the impact of global strategies to reduce ARV prices using data on 7253 procurement transactions (July 2002–October 2007) from databases hosted by WHO and the Global Fund to Fight AIDS, Tuberculosis and Malaria.Findings
For 19 of 24 ARV dosage forms, we detected no association between price and volume purchased. For the other five ARVs, high-volume purchases were 4–21% less expensive than medium- or low-volume purchases. Nine of 13 generic ARVs were priced 6–36% lower when purchased under the Clinton Foundation HIV/AIDS Initiative (CHAI). Fifteen of 18 branded ARVs were priced 23–498% higher for differentially priced purchases compared with non-CHAI generic purchases. However, two branded, differentially priced ARVs were priced 63% and 73% lower, respectively, than generic non-CHAI equivalents.Conclusion
Large purchase volumes did not necessarily result in lower ARV prices. Although current plans for pooled procurement will further increase purchase volumes, savings are uncertain and should be balanced against programmatic costs. Third-party negotiation by CHAI resulted in lower generic ARV prices. Generics were less expensive than differentially priced branded ARVs, except where little generic competition exists. Alternative strategies for reducing ARV prices, such as streamlining financial management systems, improving demand forecasting and removing barriers to generics, should be explored. 相似文献134.
Allon N. Friedman Lee M. Kaplan Carel W. le Roux Philip R. Schauer 《Journal of the American Society of Nephrology : JASN》2021,32(4):777
Obesity is a leading public health problem that currently affects over 650 million individuals worldwide. Although interest in the adverse effects of obesity has grown exponentially in recent years, less attention has been given to studying its management in individuals with CKD. This relatively unexplored area should be considered a high priority because of the rapid growth and high prevalence of obesity in the CKD population, its broad impact on health and outcomes, and its modifiable nature. This article begins to lay the groundwork in this field by providing a comprehensive overview that critically evaluates the available evidence related to obesity and kidney disease, identifies important gaps in our knowledge base, and integrates recent insights in the pathophysiology of obesity to help provide a way forward in establishing guidelines as a basis for managing obesity in CKD. Finally, the article includes a kidney-centric algorithm for management of obesity that can be used in clinical practice. 相似文献
135.
Maria Guttadauria Herman Ellman George Emmanuel David Kaplan Herbert Diamond 《Arthritis \u0026amp; Rheumatology》1977,20(5):1071-1079
Pulmonary function tests were performed in 45 patients with scleroderma. Thirteen patients (29%) were found to have restrictive disease, 12 patients (27%) were found to have obstructive disease, and 19 patients (42%) had small airway disease (SAD). Smoking did not seem to be a factor underlying either obstructive or small airway disease in these patients. A low diffusing capacity was most common in patients with restrictive disease and rarely the only abnormality in pulmonary function. SAD was usually found in patients who had normal chest radiographs and no pulmonary symptoms and was often the only abnormality. SAD is therefore an early and sensitive indicator of pulmonary involvement in scleroderma. 相似文献
136.
L Wetstein R Mark E Kaplinsky H Mitamura A Kaplan C Sauermelch E L Michelson 《Surgery》1985,98(3):532-539
Ventricular tachyarrhythmia is the leading cause of sudden cardiac death. Determination of the substrates conducive to the initiation of this arrhythmia remains an important clinical goal. The purpose of this study was to correlate histopathologic findings, specifically: pattern (heterogeneous versus homogeneous infarct morphology), distribution (viable epicardial and/or endocardial rim), and infarct size, with susceptibility to the initiation of sustained ventricular tachycardia employing programmed electrical stimulation in two canine models of experimental myocardial infarction. Twenty-one adult dogs were randomly divided into two groups: 12 dogs underwent two-stage, 2-hour occlusion of the proximal left anterior descending coronary artery and nine animals underwent permanent, complete occlusion of the left anterior descending coronary artery with latex embolization. With programmed ventricular pacing with two premature ventricular extrastimuli, initiation of ventricular tachycardia was attempted, open chest, two weeks after infarction. Electrophysiologic evaluation of the infarct type correlated significantly with the histologic morphology of the infarction (p less than 0.001). The presence of a viable epicardial rim was an extremely important variable for ability to induce sustained ventricular tachycardia (p = 0.04). The presence of an endocardial rim was not significant (p = 1.0). Infarct size alone was only marginally related to ventricular tachycardia inducibility (p = 0.08). Nonuniform infarcts were more conducive to the initiation of sustained ventricular tachycardia than were homogeneous infarcts (p = 0.025). The presence of a large, nonuniform infarct correlated best with inducibility (p = 0.0002). Thus in these experimental models, specific infarct morphologies correlate significantly with susceptibility to inducible sustained ventricular tachyarrhythmias. 相似文献
137.
Treatment of superior mesenteric and portal vein thrombosis with direct thrombolytic infusion via an operatively placed mesenteric catheter 总被引:4,自引:0,他引:4
Kaplan JL Weintraub SL Hunt JP Gonzalez A Lopera J Brazzini A 《The American surgeon》2004,70(7):600-604
Acute superior mesenteric vein (SMV) and portal vein (PV) thrombosis can be a complication of hypercoagulable, inflammatory, or infectious states. It can also occur as a complication of medical or surgical intervention. Management of mesenteric and portal vein thrombosis includes both operative and nonoperative approaches. Operative interventions include thrombectomy with thrombolysis; this is often employed for patients who present with signs of peritoneal irritation. Nonoperative approaches can be either noninvasive or invasive. Treatment with anticoagulation has been shown to be efficacious, though its rate of recanalization is not as high as with intravascular infusion of thrombolytics. Intravenous catheterization and thrombolytic infusion has the advantage of direct pharmacologic thrombolysis of clot, with decreased infusion required and the possibility to carry out dilation or thrombectomy concurrently. We report the use of recombinant tissue-plasminogen activator (rt-PA) infusion via an operatively placed multi side-hole catheter/5-Fr introducer sheath into the right portal and superior mesenteric vein clot, inserted through a small jejunal vein, in a patient who presented with acute gangrenous appendicitis and thrombosis of the main portal trunk and superior mesenteric vein. A temporary abdominal closure was maintained until 36 hours after the start of infusion of the rt-PA. At this time venous system had normal flow, with complete recanalization of the right portal and superior mesenteric veins. 相似文献
138.
PurposeLife course models suggest that socioeconomic mobility is associated with decreased cardiovascular disease (CVD) mortality risk. We examined adult socioeconomic mobility measured by household income in relation to CVD mortality risk among older adults.MethodsData from 2691 (nmen = 1157; nwomen = 1534) Alameda County Study respondents in 1994 were used in these analyses. Latent growth curve models were used to identify income patterns from 1965 to 1994.ResultsIncome patterns were categorized as consistently low, moderately low, increasing, and high. Bivariate models showed that membership in the increasing compared with high pattern was associated with decreased hazards of CVD mortality (hazard ratio, 0.15; 95% confidence interval [CI], 0.04–0.53). Controlling for age, race/ethnicity, marital status, and gender, respondents in the consistently low (HR, 2.1; 95% CI, 1.5–3.1) and high pattern (HR, 2.2; 95% CI, 1.1–4.2) had increased hazards of CVD mortality than those in the moderately low income group.ConclusionsPatterns of association were consistent with social mobility models of socioeconomic position, indicating lower CVD mortality risk for those with increasing or higher incomes. Future work should continue to investigate measures that capture the variation in social mobility over the life course, and how these patterns shape chronic disease risk in later life. 相似文献
139.
Phyllis D. Kaplan PhD Morris Blackstone 《Archives of environmental & occupational health》2013,68(6):387-389
An atomic absorption method for the direct determination of metals in mammalian tissues has been developed. The procedure, which involves digestion of the sample with a quaternary ammonium hydroxide, allows one to measure metals normally present in low concentrations, such as cadmium and nickel, with a great degree of sensitivity and a minimal amount of sample handling. 相似文献
140.
An enzyme-linked immunosorbent assay has been developed for the quantitation of activated Hageman factor-C1 inactivator (HF-C1 INH) complexes. Addition of increasing quantities of either of the major forms of activated Hageman factor (HFa or HFf) to normal plasma or to Hageman factor-deficient plasma leads to a dose-dependent increase in activated HF-C1 INH complexes. As little as 0.5 micrograms/mL of activated HF added to plasma can be detected, corresponding to activation of approximately 2% of plasma HF. The sensitivity of the assay is increased at least tenfold when complexes are formed in HF- deficient plasma, indicating competition between unactivated HF and activated HF-C1 INH complexes for binding to the antibody. Specificity is demonstrated in that addition of activated HF to hereditary angioedema plasma yields less than 1% of the activated HF-C1 INH complex formation obtained with normal plasma. Kaolin activation of HF- deficient plasma yields no detectable complex formation. Kaolin activation of prekallikrein-deficient plasma demonstrates a time- dependent increase in formation of activated HF-C1 INH complex consistent with the ability of HF in this plasma to autoactivate as the time of incubation with the surface is increased. Kaolin treatment of high-molecular weight (HMW) kininogen-deficient plasma yields an even more profound abnormality in the rate of formation of activated HF-C1 INH complexes reflecting the complex role of HMW kininogen in the initiation of contact activation. Although addition of corn inhibitor to plasma prevents activated HF-C1 INH complex formation, it does not inhibit activated HF sufficiently fast to prevent prekallikrein activation. 相似文献