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   2986篇
  免费   170篇
  国内免费   2篇
耳鼻咽喉   50篇
儿科学   125篇
妇产科学   85篇
基础医学   426篇
口腔科学   26篇
临床医学   229篇
内科学   492篇
皮肤病学   64篇
神经病学   108篇
特种医学   47篇
外科学   307篇
综合类   207篇
一般理论   4篇
预防医学   212篇
眼科学   354篇
药学   184篇
中国医学   15篇
肿瘤学   223篇
  2023年   14篇
  2022年   49篇
  2021年   103篇
  2020年   70篇
  2019年   53篇
  2018年   77篇
  2017年   40篇
  2016年   63篇
  2015年   84篇
  2014年   105篇
  2013年   144篇
  2012年   191篇
  2011年   193篇
  2010年   128篇
  2009年   79篇
  2008年   165篇
  2007年   163篇
  2006年   125篇
  2005年   131篇
  2004年   140篇
  2003年   148篇
  2002年   130篇
  2001年   89篇
  2000年   102篇
  1999年   85篇
  1998年   35篇
  1997年   16篇
  1996年   19篇
  1995年   19篇
  1994年   21篇
  1993年   11篇
  1992年   27篇
  1991年   31篇
  1990年   32篇
  1989年   20篇
  1988年   24篇
  1987年   17篇
  1986年   15篇
  1985年   14篇
  1984年   11篇
  1981年   14篇
  1980年   10篇
  1978年   8篇
  1977年   11篇
  1976年   10篇
  1975年   11篇
  1973年   11篇
  1972年   9篇
  1970年   8篇
  1968年   11篇
排序方式: 共有3158条查询结果,搜索用时 15 毫秒
91.
92.
Purpose:The aim of this study was to formulate a methodological approach for resuming eye bank services during COVID-19 pandemic.Methods:Eye bank operations were temporarily halted in March after the government-mandated “Lockdown” in response to COVID-19 pandemic. Before restarting eye bank operations in May, we studied sources of exposure, performed risk assessment, instituted additional process validations and redefined the Standard Operating Procedures (SOPs) in consultation with the guidelines published by the Eye bank Association of India and All India Ophthalmological Society. The eye bank staff were rigorously trained before and after operations were restarted. We conducted a survey at the end of July to gauge staff attitude and reaction.Results:Eye banks services resumed on 20th May 2020. Since reopening till the end of July total 41 keratoplasties have been done. 91.75% of all keratoplasties done were therapeutic surgeries and 17% of the surgeries were done using glycerine preserved tissues. No staff had COVID-19 symptoms when the operations restarted and none developed symptoms up to the end of July. All eye bank staff were aware of COVID-19 pandemic and 86% said they felt safe working at the eye bank. 86% of the staff said that they received adequate training and 66% of the staff expressed that they always received proper PPE and kits. Overall, 93% of the staff expressed that the measures taken by the eye bank ensured their safety.Conclusion:Based on our experience we suggest the following activities for planned resumption of eye bank services during the pandemic: Exposure Risk Analysis, Personal Protective Equipment usage training, SOP Revision and staff training on modified SOPs. Criteria based selection of donor sources, participatory planning involving the staff and double-checking at critical process junctions helped us in managing a smooth transition.  相似文献   
93.
Recent myocardial infarction is a recognized risk factor for ischemic stroke. Patients who have a stroke in the peri-infarct period are usually in hospital and therefore well placed to access early cerebral reperfusion therapy. However, due to the risk of myocardial rupture, recent myocardial infarction is considered a contraindication to intravenous thrombolysis, which is usually the first-line therapy for the treatment of ischemic stroke. We report a case in which intravenous thrombolysis was safely and effectively used to treat acute ischemic stroke in a patient who had suffered an acute myocardial infarct within the previous 48 h. We also highlight the lack of evidence-based guidelines for the treatment of stroke in this important subgroup of patients.  相似文献   
94.
95.
In this study, eight Escherichia coli isolates were obtained from milk samples of dairy cattle suffering from clinical/subclinical mastitis. Isolates were characterized for antimicrobial resistance traits and virulence genes. Results revealed that one isolate was harbouring New Delhi metallo‐beta‐lactamase gene (blaNDM). Cloning and sequencing of the PCR amplicon confirmed the identity of the gene (GenBank accession no. KC769583 ) having 100% homology with blaNDM‐5 (GenBank accession no. JN104597.1 ), and this isolate was susceptible to colistin, chloramphenicol and tetracycline only. Moreover, another isolate carried extended‐spectrum beta‐lactamase (ESBL) gene – blaCTX‐M, and all isolates possessed blaTEM gene. Of the eight isolates, only one isolate was positive for shiga toxin gene (stx2), and none were harbouring stx1 gene. Occurrence of New Delhi metallo‐beta‐lactamase (blaNDM) in one E. coli isolate and ESBL genes in other isolates poses a potential threat to human health following possible entry and spread through food chain.  相似文献   
96.

Introduction:

Our present observational study attempted to evaluate the clinical profiles, diagnosis, treatment and follow-up results of 51 pediatric neurocysticercosis patients over a mean duration of five years (from January 2006 to December 2010).

Materials and Methods:

Diagnosis was mainly based on clinical features, computed tomography (CT)/magnetic resonance imaging scan and exclusion of other causes. Patients with active, transitional cysts and seizure were treated with albendazole for 28 days, steroids and anticonvulsants.

Results:

A total of 38 patients completed this study. Mean age of the presentation was 8.47 ± 3.19 years 52.6% of the patients were female. Overall patients presented with generalized seizure in 55.3%, focal in 31.6%, headache ± vomiting in 63.2%, focal neurodeficit in 10.5% and combination of symptoms in 60.5% cases. Contrast CT brain showed a solitary lesion in 27 (71.1%) and multiple in the rest. At presentation lesions were transitional in 58.2%, inactive in 20% and mixed in 14.6%. After a mean of 2 years, seizure persisted in 9 (23.7%) and headache in 8 (21.1%) of whom six had normal electroencephalography (EEG) while one each showed focal slowing, generalized slowing and epileptiform discharges. During the follow-up, CT scan brain 44.7% lesions calcified, 31.6% disappeared, 10.5% regressed and the rest persisted.

Conclusion:

Solitary ring enhancing lesions (transitional stage) involving the parietal lobe was the commonest CT picture at presentation. Generalized tonic-clonic seizure was the most common type of seizure. Number of lesions, persistence of lesion, number of seizures, EEG abnormality at presentation were not found to be prognostically significant (P > 0.05).Key Words: Brain, epilepsy, lesion, neurocysticercosis, parenchyma, solitary  相似文献   
97.
98.
Craniopagus conjoined twins are rare, and the chance that an anesthesiologist might face the challenge of providing anesthesia for this condition is very rare. The incidence of conjoined twins ranges from 1 : 50 000 to 1 : 200 000 births. We describe the anesthetic management of a pair of premature craniopagus conjoined twins posted for emergency surgery prior to their separation.  相似文献   
99.
The concept proposed is that transient bacteraemia occurring in otherwise healthy individuals can cause acute life threatening events due to bacterial toxaemia even though the bacteraemia is rapidly cleared (<20 min). This is most likely to occur in infancy at around two to three months of age when anti-toxin IgG reaches its nadir. Sudden unexpected death in infancy, acute life threatening events, haemorrhagic shock and encephalopathy, and the triad of retinal haemorrhage, encephalopathy and bilateral thin film subdural haematomata are conditions which could be caused by this mechanism. Investigations need to be directed to measuring bacterial toxins in blood, CSF and urine; anti-toxin IgG in blood; and bacterial specific nucleic acid sequences in blood, CSF and urine using polymerase chain reaction in order to confirm recent bacteraemia. Furthermore the upper respiratory tract bacterial flora should be mapped in cases and appropriately matched live healthy community controls. Sudden onset, profound life threatening physiological dysfunction occurring in later life could also be caused by a similar mechanism and should be investigated in a similar way; candidate conditions include epilepsy, migraine, stroke and cardiac arrhythmias.  相似文献   
100.
The DNA replication machinery of the Plasmodium falciparum apicoplast is a validated drug target. Nuclear-encoded gyrase subunits are predicted to play a critical role in maintaining DNA topology during the D-loop/bi-directional ori replication process of the parasite. We show the presence of P. falciparum gyrase subunits in parasite lysates by using antibodies generated against recombinant gyrase A and B. The ATPase activity of PfGyrB was inhibited by novobiocin that also caused parasite death in culture. Reduction of apicoplast/nuclear DNA ratio in the presence of novobiocin indicated that the drug targets apicoplast DNA replication. Molecular modeling of gyrase A and B subunits revealed extensive fold conservation with the Escherichia coli counterparts as well as the presence of a long disordered loop adjacent to the ATPase domain of PfGyrB. Our results have implications for development of PfGyrB as a drug target against malaria.  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