全文获取类型
收费全文 | 406432篇 |
免费 | 288496篇 |
国内免费 | 45280篇 |
专业分类
耳鼻咽喉 | 3619篇 |
儿科学 | 7179篇 |
妇产科学 | 3911篇 |
基础医学 | 100308篇 |
口腔科学 | 6312篇 |
临床医学 | 77172篇 |
内科学 | 112568篇 |
皮肤病学 | 6204篇 |
神经病学 | 26773篇 |
特种医学 | 15845篇 |
外国民族医学 | 27篇 |
外科学 | 55155篇 |
综合类 | 90500篇 |
现状与发展 | 29篇 |
一般理论 | 12篇 |
预防医学 | 57725篇 |
眼科学 | 21254篇 |
药学 | 73763篇 |
104篇 | |
中国医学 | 58625篇 |
肿瘤学 | 23123篇 |
出版年
2022年 | 7099篇 |
2021年 | 8376篇 |
2020年 | 10287篇 |
2019年 | 15687篇 |
2018年 | 16433篇 |
2017年 | 17374篇 |
2016年 | 15718篇 |
2015年 | 17169篇 |
2014年 | 18626篇 |
2013年 | 19573篇 |
2012年 | 22833篇 |
2011年 | 27392篇 |
2010年 | 27165篇 |
2009年 | 33249篇 |
2008年 | 21590篇 |
2007年 | 17749篇 |
2006年 | 16808篇 |
2005年 | 16100篇 |
2004年 | 20423篇 |
2003年 | 19073篇 |
2002年 | 17411篇 |
2001年 | 17883篇 |
2000年 | 11263篇 |
1999年 | 16016篇 |
1998年 | 16054篇 |
1997年 | 15765篇 |
1996年 | 16107篇 |
1995年 | 16160篇 |
1994年 | 15889篇 |
1993年 | 15030篇 |
1992年 | 14065篇 |
1991年 | 13271篇 |
1990年 | 11986篇 |
1989年 | 11643篇 |
1988年 | 11060篇 |
1987年 | 10342篇 |
1986年 | 9842篇 |
1985年 | 8670篇 |
1984年 | 6660篇 |
1983年 | 6616篇 |
1982年 | 7648篇 |
1981年 | 7190篇 |
1980年 | 6847篇 |
1979年 | 6693篇 |
1978年 | 5854篇 |
1977年 | 6168篇 |
1976年 | 5778篇 |
1975年 | 5530篇 |
1974年 | 5076篇 |
1973年 | 4775篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
11.
12.
Bi-Hua BIE Yong CHEN Zhi-Qi ZHAO Institute of Neurobiology Fu-Dan University Shanghai China Institute of Shanghai Physiology Chinese Academy of Sciences Shanghai China 《中国神经科学杂志》2006,(2)
Objective Ligustrazine, also named as tetramethylpyrazine, is a compound purified from Ligusticum chuanxiong hort and has ever been testified to be a calcium antagonist. The present investigation was to determine the antinoci-ceptive effect of ligustrazine and, if any, the peripheral ionic mechanism involved. Methods Paw withdrawal Latency ( PWL) to noxious heating was measured in vivo and whole-cell patch recording was performed on small dorsal root ganglion (DRG) neurons. Results Intraplantar injection of ligustrazine (0.5 mg in 25μl) significantly prolonged the withdrawal latency of ipsilateral hindpaw to noxious heating in the rat. Ligustrazine not only reversibly inhibited high-voltage gated calcium current of dorsal root ganglion (DRG) neuron in dose-dependent manner with IC50 of 1.89 mmol/L, but also decreased tetrodotoxin (TTX) -resistant sodium current in relatively selective and dose-dependent manner with IC50 of 2.49 mmol/L. Conclusion The results suggested that ligustrazine could elevate the threshold of thermal nociception through inhibiting the high-voltage gated calcium current and TTX-resistant sodium current of DRG neuron in the rat. 相似文献
13.
BACKGROUND: Ankle brachial index(ABI)is widely involved in researches and clinical application of peripheral vascular injury of patients with diabetes (DM);however ,the application in cerebral infarction(CI)is rare.OBJECTIVE: To investigate the possible risk factor of cerebral infarction plus peripheral arterial disease(PAD),compare metabolic characteristics of patients who having CI plus PAD or only having CI,and understand the significance of ABI on screening and diagnosing CI plus PAD of lower limb.DESIGN: Contrast observation based on CI patients.SETTING: Deparment of Neurology,Nanxishan Hospital of Guangxi Zhang Autonomous Region.PARTICIPANTS:A total of 124 CI patients were selected from Department of Neurology.Nanxishan Hospital of Guangxi Zhuang Autonomous Region from July 2005 to April 2006,including 72 males and 52 females aged from 45 to 88 years.All patients met the diagnostic criteria of cerebrovascular disease established by National Academic Conference of Cerebrovascular Diseases in 1995 and determined as cerebral infarction with MRI or CT examination.All patients provided informed consent.There were 46 cases(37.2%)with CI plus PAD and 78 cases(62.8%)only with CI.METHODS: Blood pressure of bilateral ankles and upper extremities was measured at plain clinostatism with DINAMAP blood pressure monitor(GE Company).The ratio between average systolic pressure of lateral ankle and average systolic pressure of both upper extremities was regarded as ABI.The normal ABI was equal to or more than 0.9.If ABI<0.9 occurred at one side,patients were diagnosed as PAD.On the second morning after hospitalization,blood was collected to measure fasting blood glucose(FBG),2-hour postprandial blood glucose(PBG2h),glycosylated hemoglobin(HbAlc),triglycerides(TG),total cholesterol(TC),high-density lipoprotein cholesterol(HDL-C)and low-density lipoprotein cholesterol(LDL-C).Among them,blood glucose.lipid and other biochemical markers were measured with enzyme chemistry assay and HbA1c was measured with HbA1c meter based on high liquid phase.Measurement data and enumeration data were compared with t test and Chi-square test.and multiple factors were deat with Logistic regression analysis and multivariate linear regression analysis.MAIN OUTCOME MEASURES: Results of correlation between ABI and metabolic markers with multivariate linear regression analysis;risk factors of CI plus PAD with Logistic regression analysis;comparisons of metabolic markers between PAD and non-PAD patients.RESULTS:All 124 patients with acute CI were involved in the final analysis.①Comparisons of metabolic markers:Levels of serum LDL-C and uric acid(UA)were higher of PAD patients than those of non-PAD patients(t=2.051 9,3.339 1,P<0.05);however,there were no significant differences among other metabolic markers(P>0.05).②Results of multivariate linear regression analysis:PBG2h,LDL.C and UA were obvious correlation with ABI of posterior tibial artery of lower limb and dorsal pedis artery rpartial regression coefficient:-0.231 to-1.010,P<0.05).③Risk factors of CI plus PAD with Logistic regression analysis:Age.Smoking history,sum of CI focus(≥3)and LDL-C were independent risk factor of CI plus PAD(OR=1.524-5.422,P<0.05-0.01 ).CONCLUSION:①Levels of serum LDL-C and UA of patients with CI plus PAD are high.②ABI of lower limbs is correlation with PBG2h,LDL-C and UA.In addition,measuring ABI is beneficial for early diagnosing PAD of lower limbs of patients who have poorly controlled blood glucose,abnormal lipid and poor renal function.③Age,LDL-C and sum of CI focus(≥3)are independent risk factors of CI plus PAD.It is of significance for screening non-PAD patients to evaluate risk degrees and prognosis and select therapeutic methods based on ABI measurement. 相似文献
14.
BACKGROUND/PURPOSE: Sensitive skin is a condition associated with reduced tolerance to environmental factors and/or the application of topical products, such as cosmetics. Its pathophysiology has not been fully elucidated and few data are available on its prevalence. The aim of this study was to investigate possible correlation between objective sensitivity and skin surface microrelief. METHODS: During an epidemiological survey conducted for a campaign promoted by International Society of Plastic Dermatology in Italy, 243 adult healthy subjects of both sexes with no evident dermatological disorder but positive to the lactic acid stinging test, were submitted to cyanoacrylate stratum corneum stripping from the volar forearm for the determination of the irregularity of the skin surface microrelief (irregularity skin index (ISI)). RESULTS: A significant correlation was found between intensity of symptoms in stingers and ISI (r(s)=-0.47; P<0.001). CONCLUSION: Sensitive skin is common in the healthy population. ISI can contribute towards the identification of subjects with sensitive skin and the development of more specific skin treatments for this prevalent condition. 相似文献
15.
16.
17.
GIUSEPPE BORIANI MAURO BIFFI MAURIZIO RUSSO† MAURIZIO LUNATI‡ GIANLUCA BOTTO¶ ALESSANDRO PROCLEMER§ GIUSEPPE VERGARA WERNER RAHUE†† CRISTIAN MARTIGNANI RENATO RICCI† MASSIMO SANTINI† On Behalf of the SEARCH MI Registry Italian Investigators 《Pacing and clinical electrophysiology : PACE》2006,29(S2):S29-S34
Background: Large randomized trials show that in appropriately selected patients with left ventricular dysfunction, implantable cardioverter-defibrillators (ICDs) can improve overall survival at 2–5 years. Since direct implementation of the criteria used in the MADIT II and SCD-HeFT will lead to a marked rise in ICD implants, there is a growing fear that increased use of ICDs may cause a dramatic burden to health care systems. The ICD has traditionally been seen as an expensive form of treatment, which is difficult to accept at the first look. This is mainly due to the nonlinear character of the ICD investment, characterized by high initial expenditure, followed by a deferred pay-off in terms of clinical benefits. Cost-effectiveness analysis may help provide a different perspective on the problem of ICD cost, as may estimation of the daily cost of ICD treatment, assuming a time horizon of 5–7 years—a particularly interesting subject for further registry studies.
Methods and Results: Based on real expenditure data from 2002 to 2005, as recorded in the Search-MI Registry-Italian Sub-study of patients implanted on MADIT II indications, we estimated the daily costs associated with the device and leads. Over a 5–7 year time horizon, the average daily cost was estimated to be €4.60–€6.70. Translation of these figures into U.S. market conditions suggests a daily cost of around $7.90–$11.40.
Conclusions: These findings appear useful to help evaluate the affordability of ICD in comparison with other therapeutic options in a context of limited available economic resources. 相似文献
Methods and Results: Based on real expenditure data from 2002 to 2005, as recorded in the Search-MI Registry-Italian Sub-study of patients implanted on MADIT II indications, we estimated the daily costs associated with the device and leads. Over a 5–7 year time horizon, the average daily cost was estimated to be €4.60–€6.70. Translation of these figures into U.S. market conditions suggests a daily cost of around $7.90–$11.40.
Conclusions: These findings appear useful to help evaluate the affordability of ICD in comparison with other therapeutic options in a context of limited available economic resources. 相似文献
18.
Abstract It is well established that thrombolytic therapy increases the risk of secondary intracerebral hemorrhage in ischemic stroke
patients. However, the term “intracerebral hemorrhage” (ICH) covers a wide spectrum from tiny spots of blood to massive space-occupying
hematoma. We will review the etiology and clinical consequences of secondary hemorrhage after thrombolysis in ischemic stroke
patients and discuss the ability of magnetic resonance imaging (MRI) to predict this phenomenon. MRI is a highly sensitive
tool for detection of hemorrhagic transformation after ischemic stroke. The definitions of a so-called symptomatic hemorrhage
after ischemic infarction differ considerably and will also be described. Attributing a causal relationship of a clinical
deterioration to a secondary hemorrhage is not easy and should be only addressed when it exceeds at least 30% of the infarct
volume. In other patients, secondary hemorrhage might be regarded as side effect of reperfusion within the region with the
most severe perfusion deficit. Cerebral microbleeds (CMBs) are a frequent finding in patients with leukoaraiosis and appear
to be a general marker of various types of bleeding- prone small vessel disease and a predictor of recurrent vascular events.
Current data do not support the hypothesis that the detection of CMBs is a useful diagnostic criterion for the exclusion of
patients with CMBs from thrombolytic therapy. However, an increased risk for the rare patients with numerous CMBs can not
be ruled out.
相似文献
19.
20.
Access to good-quality health services is crucial for the improvement of many health outcomes, such as those targeted by the
Millennium Development Goals (MDGs) adopted by the international community in 2000. The health-related MDGs cannot be achieved
if vulnerable populations do not have access to skilled personnel and to other necessary inputs. This paper focuses on the
geographical dimension of access and on one of its critical determinants: the availability of qualified personnel. The objective
of this paper is to offer a better understanding of the determinants of geographical imbalances in the distribution of health
personnel, and to identify and assess the strategies developed to correct them. It reviews the recent literature on determinants,
barriers and the effects of strategies that attempted to correct geographical imbalances, with a focus on empirical studies
from developing and developed countries. An analysis of determinants of success and failures of strategies implemented, and
a summary of lessons learnt, is included. 相似文献