首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   85076篇
  免费   3972篇
  国内免费   342篇
耳鼻咽喉   2304篇
儿科学   2764篇
妇产科学   2632篇
基础医学   10862篇
口腔科学   2514篇
临床医学   5558篇
内科学   20220篇
皮肤病学   2533篇
神经病学   7300篇
特种医学   1734篇
外国民族医学   1篇
外科学   9462篇
综合类   500篇
一般理论   22篇
预防医学   8206篇
眼科学   1785篇
药学   7023篇
中国医学   501篇
肿瘤学   3469篇
  2024年   132篇
  2023年   584篇
  2022年   1412篇
  2021年   2808篇
  2020年   1372篇
  2019年   2550篇
  2018年   3220篇
  2017年   1960篇
  2016年   1921篇
  2015年   2032篇
  2014年   3178篇
  2013年   4436篇
  2012年   5982篇
  2011年   6570篇
  2010年   3648篇
  2009年   2807篇
  2008年   4577篇
  2007年   5054篇
  2006年   4818篇
  2005年   4814篇
  2004年   4528篇
  2003年   4243篇
  2002年   3754篇
  2001年   2018篇
  2000年   2188篇
  1999年   1704篇
  1998年   552篇
  1997年   433篇
  1996年   324篇
  1995年   301篇
  1994年   250篇
  1993年   192篇
  1992年   541篇
  1991年   443篇
  1990年   440篇
  1989年   317篇
  1988年   326篇
  1987年   297篇
  1986年   265篇
  1985年   255篇
  1984年   163篇
  1983年   162篇
  1982年   135篇
  1981年   156篇
  1980年   114篇
  1979年   161篇
  1978年   130篇
  1974年   114篇
  1971年   91篇
  1969年   88篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Objectives: Understanding inhaler preferences may contribute to improving adherence in COPD patients and improving long-term outcomes. This study aims to identify and quantify preferences for convenience-related inhaler attributes in French moderate-to-severe COPD patients, with discrete choice experiment (DCE) methodology.

Methods: Attributes were defined from a literature search, clinician and patient interviews: shape, dose insertion, dose preparation, dose release, dose confirmation, dose counter and reusability. An online DCE was conducted in respondents with self-reported COPD stage 2–4 recruited through a panel. The study questionnaire included twelve choice scenarios per respondent and questions on patient characteristics, treatment and disease severity. Statistical analyses used a mixed logit regression model with random effects. Utility scores were estimated for four types of inhalers: Inhaler A – soft mist inhaler; Inhaler B – reusable soft mist inhaler; Inhaler C – multi-dose dry powder inhaler; and Inhaler D – single dose dry powder inhaler.

Results: The study was completed by 153 patients (50 females); respondents were 50.4?years old on average; 13 different inhaler devices were reported. The most preferred inhaler is L-shaped, has dose preparation with capsule insertion and a dose counter, and is reusable. Inhaler profiles A and B had the highest utilities (mean of 1.2533 and 0.9578 respectively) compared to inhaler C (0.6315) and D (0.2200).

Conclusions: This study showed statistically significant results that the strongest drivers of preference in French users of inhalation devices for COPD are shape, dose counter and reusability. Convenience-related characteristics are important to patients and should be taken into account by clinicians prescribing these devices.  相似文献   

12.
Abstract

Objectives: This study examined word use as an indicator of interpersonal positive reframing in daily conversations of couples coping with breast cancer and as a predictor of stress.

Design: The Electronically Activated Recorder (EAR) and Linguistic Inquiry and Word Count (LIWC) were used to examine naturally occurring word use conceptually linked to positive reframing (positive emotion, negative emotion, and cognitive processing words).

Sample: Fifty-two couples coping with breast cancer.

Methods: Couples wore the EAR, a device participants wear, that audio-recorded over one weekend (>16,000 sound files), and completed self-reports of positive reframing (COPE) and stress (Perceived Stress Scale). LIWC, a software program, measured word use.

Findings: Both partners’ word use (i.e., positive emotion and cognitive processing words) was associated with their own reported positive reframing, and spouses’ word use was also indicative of patients’ positive reframing. Results also revealed that, in general, words indicating positive reframing predicted lower levels of stress.

Conclusions: Findings supported the hypothesis that partners—and particularly spouses of breast cancer patients—may assist each other’s coping by positively reframing the cancer experience and other negative experiences in conversation.  相似文献   
13.
ObjetivoAdaptar y validar el instrumento Informed Choice (IC) para la decisión de mamografía al contexto chileno.DiseñoEstudio transversal, analítico, de adaptación y validación psicométrica.EmplazamientoCentro de atención primaria del sector sur oriente de Santiago de Chile.Métodos1) traducir y contra-traducir IC; 2) realizar un grupo focal para la relevancia cultural/lingüística; 3) examinar la validez del contenido; 4) pilotar el instrumento; 5) aplicar para validación. Para la consistencia interna se usó el alfa de Cronbach, prueba de esfericidad de Bartlett y la medida de Kaiser-Meyer-Olkin para determinar correlaciones entre las variables y análisis factorial.ResultadosSe construyeron 3 versiones del IC, modificándose según la opinión de usuarios y expertos. La validación se llevó a cabo en una muestra de 70 mujeres. La edad media fue de 54,4 años, el 47,1% de educación secundaria completa y el 92,9% al menos se había realizado alguna vez una mamografía. Se realizó análisis factorial del IC y se eliminó uno de sus ítems. El alfa de Cronbach final fue 0,79.ConclusiónEl uso de instrumentos de medición requiere de su validación previa ya que la versión original puede variar de acuerdo al contexto cultural donde será aplicado y las necesidades locales particulares. El proceso de validación del IC permite contar con un instrumento confiable para medir la decisión de las mujeres que deben realizarse la mamografía en la dimensión conocimiento, actitud e intención hacia el examen.Palabras clave: Toma de decisiones en salud, Cáncer de mama, Mamografía  相似文献   
14.
Loxoprofen is an anti‐inflammatory drug that requires bioactivation into the trans‐OH metabolite to exert pharmacological activity. Evidence suggests that carbonyl reductase 1 (CBR1) is important during the bioactivation of loxoprofen. This study examined the impact of the functional single nucleotide polymorphism CBR1 rs9024 on the bioactivation of loxoprofen in a collection of human liver samples. The synthesis ratios of trans‐OH loxoprofen/cis‐OH loxoprofen were 33% higher in liver cytosols from donors homozygous for the CBR1 rs9024 G allele in comparison with the ratios in samples from donors with heterozygous GA genotypes. Complementary studies examined the impact of CBR1 rs9024 on the bioactivation of loxoprofen in lymphoblastoid cell lines. CBR1 rs9024 genotype status impacts the synthesis of the bioactive trans‐OH metabolite of loxoprofen in human liver.  相似文献   
15.

Background

Patients with Diabetic Foot Ulcer (DFU) show high levels of depression and anxiety symptoms. The loss of a limb is undoubtedly a devastating experience and several studies have shown that anxiety and depression symptoms are a common reaction after a lower limb amputation (LLA). However, no study has focused on the immediate emotional reactions to LLA as a personal factor based on the ICF Model.

Objective

This study focused on the characterization of anxiety and depression levels, before and after surgery, differences in levels of depression and anxiety before and after surgery and the predictors of anxiety and depression one month after surgery, in a sample of patients with DFU.

Methods

This was a longitudinal study with 179 patients with Diabetes Mellitus Type 2 and DFU indicated for amputation, screened for the presence of anxiety and depression symptoms during the hospitalization that preceded amputation and one month after surgery, during a follow-up consultation.

Results

The results showed a significant effect of anxiety and depression symptoms at pre-surgery in the prediction of anxiety and depression symptoms one month after LLA. Patients showed higher levels of anxiety than depression symptoms at pre-surgery, although anxiety significantly decreased on month after surgery. Both anxiety and depression symptoms contributed to depression after LLA, although anxiety at pre-surgery was the only predictor of anxiety at post-surgery.

Conclusions

Tailored multidisciplinary interventions need to be developed providing support before and after an amputation surgery, in order to reduce anxiety and depression symptoms and promote psychological adjustment to limb loss.  相似文献   
16.
Administration of local anesthetics is one of the most effective pain control techniques for postoperative analgesia. However, anesthetic agents easily diffuse into the injection site, limiting the time of anesthesia. One approach to prolong analgesia is to entrap local anesthetic agents in nanostructured carriers (e.g., liposomes). Here, we report that using an ammonium sulphate gradient was the best strategy to improve the encapsulation (62.6%) of dibucaine (DBC) into liposomes. Light scattering and nanotracking analyses were used to characterize vesicle properties, such as, size, polydispersity, zeta potentials, and number. In vitro kinetic experiments revealed the sustained release of DBC (50% in 7 h) from the liposomes. In addition, in vitro (3T3 cells in culture) and in vivo (zebrafish) toxicity assays revealed that ionic-gradient liposomes were able to reduce DBC cyto/cardiotoxicity and morphological changes in zebrafish larvae. Moreover, the anesthesia time attained after infiltrative administration in mice was longer with encapsulated DBC (27 h) than that with free DBC (11 h), at 320 μM (0.012%), confirming it as a promising long-acting liposome formulation for parenteral drug administration of DBC.  相似文献   
17.
A growing health concern, due to poor air quality, recently led to an increased number of studies regarding air pollution effects on public health. Consequently, close attention is paid to estimation methods of exposure to atmospheric pollutants. This paper aims to meet a specific requirement of epidemiological researchers, that is providing annual air pollution maps at municipality scale for health impact assessment purposes on national basis. Firstly, data fusion through kriging with external drift is implemented, combining pollution data from two different sources, models and measurements, in order to improve the spatial distribution of surface concentrations at grid level. Then, the assimilated data of air pollution are upscaled, so as to obtain concentrations at municipality level. This methodology was applied to Italy and Spain (in Spain, only the second step was carried out since the modeled concentration already included an assimilation procedure). In both countries, for each municipality, an estimate of the concentration value for atmospheric pollutants of major concern for human health (PM10 and NO2) was provided, offering more relevant information from a surveillance point of view.  相似文献   
18.
One of the side-effects of ketamine abuse is genito-urinary damage. This report describes a case of a former ketamine user who presented with urinary symptoms associated with ketamine years after stopping consumption. This was a 26-year-old male with a history of ketamine abuse. He started treatment for alcohol dependence at age 19. He smoked marijuana daily and denied any other drug use. During the follow-up, urinary symptoms were evidenced (dysuria, frequency, urgency, incontinence, nocturia, hematuria, and suprapubic pain). Urinary symptoms started two years ago and worsened over time. The patient was referred to a urologist. A cystoscopy revealed lesions compatible with interstitial cystitis like the ones that appear in some ketamine abusers. Given the medical history, the urologist asked him about ketamine consumption and the patient declared a daily use of 50 milligrams intranasally from age 15 to age 17. Given these findings, not reported previously in the medical literature, future research should follow up patients who at some point in their life made an abusive consumption of ketamine in order to understand the pathogenesis and to be able to intervene before clinical disease manifests itself.  相似文献   
19.
20.
In this study, we applied various assays to reveal new activities of phenylcyanomethylenequinone oxime-4-(hydroxyimino) cyclohexa-2,5-dien-1-ylidene](phenyl)ethanenitrile (4-AN) for potential anti-microbial applications. These assays demonstrated (a) the antimicrobial effect on bacterial and fungal cultures, (b) the effect on the in vitro activity of the kinase CK2, (c) toxicity towards human erythrocytes, the Caco-2 cancer cell line, and embryonic development of Zebrafish. We demonstrated the activity of 4-AN against selected bacteria and Candida spp. The MIC ranging from 4?µg/ml to 125?µg/ml proved effective in inhibition of formation of hyphae and cell aggregation in Candida, which was demonstrated at the cytological level. Noteworthy, 4-AN was found to inhibit the CK2 kinase with moderate potency. Moreover, at low concentrations, it did not exert any evident toxic effects on human erythrocytes, Caco-2 cells, or Zebrafish embryos. 4-AN can be a potential candidate as a novel drug against Candida infections.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号