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   23204篇
  免费   1309篇
  国内免费   170篇
耳鼻咽喉   325篇
儿科学   422篇
妇产科学   539篇
基础医学   2758篇
口腔科学   750篇
临床医学   1866篇
内科学   6278篇
皮肤病学   406篇
神经病学   2299篇
特种医学   748篇
外科学   3449篇
综合类   83篇
一般理论   9篇
预防医学   1094篇
眼科学   309篇
药学   1537篇
  1篇
中国医学   42篇
肿瘤学   1768篇
  2023年   141篇
  2022年   293篇
  2021年   662篇
  2020年   384篇
  2019年   552篇
  2018年   638篇
  2017年   474篇
  2016年   563篇
  2015年   603篇
  2014年   915篇
  2013年   1166篇
  2012年   1804篇
  2011年   1790篇
  2010年   1063篇
  2009年   944篇
  2008年   1632篇
  2007年   1561篇
  2006年   1473篇
  2005年   1479篇
  2004年   1371篇
  2003年   1251篇
  2002年   1149篇
  2001年   159篇
  2000年   156篇
  1999年   178篇
  1998年   195篇
  1997年   185篇
  1996年   178篇
  1995年   162篇
  1994年   131篇
  1993年   122篇
  1992年   106篇
  1991年   68篇
  1990年   87篇
  1989年   70篇
  1988年   80篇
  1987年   80篇
  1986年   60篇
  1985年   66篇
  1984年   81篇
  1983年   72篇
  1982年   70篇
  1981年   61篇
  1980年   57篇
  1979年   32篇
  1978年   41篇
  1977年   26篇
  1976年   21篇
  1975年   19篇
  1971年   14篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.

Background

Cystic fibrosis per se can sometimes lead to hyponatremia, hypokalemia, hypochloremia or hyperbicarbonatemia. This tendency was first documented 60 years ago and has subsequently been confirmed in single case reports or small case series, most of which were retrospective. However, this issue has not been addressed analytically. We have therefore systematically reviewed and analyzed the available literature on this subject.

Methods

This was a systematic review of the literature.

Results

The reports included in this review cover 172 subacute and 90 chronic cases of electrolyte imbalances in patients with cystic fibrosis. The male:female ratio was 1.57. Electrolyte abnormalities were mostly associated with clinically inapparent fluid volume depletion, mainly affected patients aged ≤2.5 years, frequently tended to recur and often were found before the diagnosis of cystic fibrosis was established. Subacute presentation often included an history of heat exposure, vomiting, excessive sweating and pulmonary infection. History of chronic presentation, in contrast, was often inconspicuous. The tendency to hypochloremia, hypokalemia and metabolic alkalosis was similar between subacute and chronic patients, with hyponatremia being more pronounced (P?<?0.02) in subacute compared to chronic presentations. Subacute cases were treated parenterally; chronic ones were usually managed with oral salt supplementation. Retention of urea and creatinine was documented in 38 % of subacute cases.

Conclusions

The findings of our review suggest that physicians should be aware that electrolyte abnormalities can occur both as a presenting and a recurring feature of cystic fibrosis.  相似文献   
992.
Nonsyndromic congenital heart defects (CHDs) develop during embryogenesis as a result of a complex interplay between environmental exposures, genetics, and epigenetic causes. Genetic factors associated with CHDs may be attributed to either independent effects of maternal or fetal genes, or the intergenerational interactions between maternal and fetal genes. Detecting gene‐by‐gene interactions underlying complex diseases is a major challenge in genetic research. Detecting maternal‐fetal genotype (MFG) interactions and differentiating them from the maternal/fetal main effects has presented additional statistical challenges due to correlations between maternal and fetal genomes. Traditionally, genetic variants are tested separately for maternal/fetal main effects and MFG interactions on a single‐locus basis. We conducted a haplotype‐based analysis with a penalized logistic regression framework to dissect the genetic effect associated with the development of nonsyndromic conotruncal heart defects (CTD). Our method allows simultaneous model selection and effect estimation, providing a unified framework to differentiate maternal/fetal main effect from the MFG interaction effect. In addition, the method is able to test multiple highly linked SNPs simultaneously with a configuration of haplotypes, which reduces the data dimensionality and the burden of multiple testing. By analyzing a dataset from the National Birth Defects Prevention Study (NBDPS), we identified seven genes (GSTA1, SOD2, MTRR, AHCYL2, GCLC, GSTM3, and RFC1) associated with the development of CTDs. Our findings suggest that MFG interactions between haplotypes in three of seven genes, GCLC, GSTM3, and RFC1, are associated with nonsyndromic conotruncal heart defects.  相似文献   
993.
994.
This study was aimed at increasing the clinical usefulness of clinical pharmacological advice (CPA) for personalized drug dosing based on therapeutic drug monitoring (TDM). Educational and organizational interventions focused on improving the knowledge of clinical pharmacology among hospital healthcare workers and reducing the incidence of errors throughout the process were planned. After a pre‐interventional period of risk assessment, different list forms of the types of error occurring in the various phases of the process (Phase 1, request for CPA and blood sampling for TDM; Phase 2, sample delivery to and check in at the CPU; Phase 3, TDM execution and CPA production) were created. In the interventional period, the errors were collected daily and educational programmes were carried out. The pre‐intervention error rate was 19.5%, and resulted significantly higher for the requests coming from the medical wards compared with those from the surgical wards or the ICUs (26.0% versus 10.5% versus 13.7%, < 0.001). The educational programme trained 303 nurses and 145 physicians. Afterwards, the error percentage progressively dropped (15.5% in the 2nd trimester; 12.3% in the 3rd one; 10.5% in the 4th one). The adopted strategy resulted in significant improvements which may be useful both to improve quality of patient care and to reduce waste in healthcare costs.  相似文献   
995.
996.
A physician affected by amyotrophic lateral sclerosis (ALS) explores the meaning of his disease. The deterioration of his physical health and of his independence provided a new and deeper view of healing, as well as a new mission for his medical profession. He has become at the same time a “voice for the voiceless” and a source of hope and inspiration for patients and health professionals alike. Espousing the principle that healing is always possible even when the disease is incurable, the author proposes a three-prong approach to healing: symptom management, allegiance to the patient up to the ends, and common search of meaning. He emphasizes that both patients and health care workers need to be healed.  相似文献   
997.
Studies on the interactions between SARS-CoV-2 and humoral immunity are fundamental to elaborate effective therapies including vaccines. We used polychromatic flow cytometry, coupled with unsupervised data analysis and principal component analysis (PCA), to interrogate B cells in untreated patients with COVID-19 pneumonia. COVID-19 patients displayed normal plasma levels of the main immunoglobulin classes, of antibodies against common antigens or against antigens present in common vaccines. However, we found a decreased number of total and naïve B cells, along with decreased percentages and numbers of memory switched and unswitched B cells. On the contrary, IgM+ and IgM plasmablasts were significantly increased. In vitro cell activation revealed that B lymphocytes showed a normal proliferation index and number of dividing cells per cycle. PCA indicated that B-cell number, naive and memory B cells but not plasmablasts clustered with patients who were discharged, while plasma IgM level, C-reactive protein, D-dimer, and SOFA score with those who died. In patients with pneumonia, the derangement of the B-cell compartment could be one of the causes of the immunological failure to control SARS-Cov2, have a relevant influence on several pathways, organs and systems, and must be considered to develop vaccine strategies.  相似文献   
998.
Punishment in economic games has been interpreted as “altruistic.” However, it was shown that punishment is related to trait anger instead of trait altruism in a third-party dictator game if compensation is also available. Here, we investigated the influence of state anger on punishment and compensation in the third-party dictator game. Therefore, we used movie sequences for emotional priming, including the target states anger, happy, and neutral. We measured the Feedback-Related Negativity (FRN) and midfrontal theta band activation, to investigate an electro-cortical correlate of the processing of fair and unfair offers. Also, we assessed single-trial FRN and midfrontal theta band activation as a predictor for punishment and compensation. We found that punishment was linked to state anger. Midfrontal theta band activation, which has previously been linked to altruistic acts and cognitive control, predicted less punishment. Additionally, trait anger led to enhanced FRN for unfair offers. This led to the interpretation that the FRN depicts the evaluation of fairness, while midfrontal theta band activation captures an aspect of cognitive control and altruistic motivation. We conclude that we need to redefine “altruistic punishment” into “costly punishment,” as no direct link of altruism and punishment is given. Additionally, midfrontal theta band activation complements the FRN and offers additional insights into complex responses and decision processes, especially as a single trial predictor.   相似文献   
999.
This study analysed the association between discrimination and satisfaction with life (SWL) in migrant groups by investigating whether different types of social support (SS; emotional, instrumental, and informational) and networks (family, immigrant and native friends, neighbours, and the community) buffer the negative effects of discrimination on SWL among migrant men and women from different backgrounds. Participants were 631 migrants from Latin America and China residing in Malaga (Spain). We identified behaviour patterns that suggest that SS has different effects on men and women from the same place of origin and similar effects on women and men from different places of origin. In conclusion, the main differences in the effects of SS as a buffer mechanism are not determined by cultural factors. It is more likely that they are determined by differential gender-role socialization, which would lead women to positively value social support.  相似文献   
1000.
It is well-established that food proteins, such as egg, soya, cow's milk and wheat, are detectable in breastmilk for many hours or days after ingestion. Exposure to these proteins is important to the process of developing tolerance but can also sometimes elicit IgE-mediated and non–IgE-mediated allergic symptoms in breastfed infants. Non–IgE-mediated allergy, outside of food protein-induced allergic proctocolitis and eosinophilic oesophagitis, is not well understood, leading to variations in the diagnosis and management thereof. A primary objective of the European Academy for Allergy and Clinical Immunology is to support breastfeeding in all infants, including those with food allergies. A Task Force was established, to explore the clinical spectrum of non–IgE-mediated allergies, and part of its objectives was to establish diagnosis and management of non–IgE-mediated allergies in breastfed infants. Eight questions were formulated using the Patient, Intervention, Comparison, Outcome (PICO) system and Scottish Intercollegiate Guideline Network (SIGN) criteria for data inclusion, and consensus was achieved on practice points through the Delphi method. This publication aims to provide a comprehensive overview on this topic with practice points for healthcare professionals.  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