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   973篇
  免费   66篇
  国内免费   3篇
耳鼻咽喉   7篇
儿科学   15篇
妇产科学   19篇
基础医学   184篇
口腔科学   19篇
临床医学   105篇
内科学   163篇
皮肤病学   33篇
神经病学   86篇
特种医学   30篇
外科学   91篇
综合类   3篇
预防医学   102篇
眼科学   11篇
药学   78篇
中国医学   3篇
肿瘤学   93篇
  2023年   12篇
  2022年   43篇
  2021年   40篇
  2020年   19篇
  2019年   38篇
  2018年   31篇
  2017年   33篇
  2016年   34篇
  2015年   34篇
  2014年   46篇
  2013年   51篇
  2012年   121篇
  2011年   65篇
  2010年   46篇
  2009年   39篇
  2008年   61篇
  2007年   47篇
  2006年   48篇
  2005年   40篇
  2004年   47篇
  2003年   33篇
  2002年   24篇
  2001年   3篇
  1999年   7篇
  1998年   4篇
  1997年   5篇
  1996年   5篇
  1995年   2篇
  1994年   2篇
  1993年   5篇
  1992年   2篇
  1988年   3篇
  1987年   2篇
  1983年   2篇
  1982年   2篇
  1980年   2篇
  1979年   3篇
  1978年   5篇
  1977年   4篇
  1976年   5篇
  1974年   8篇
  1973年   2篇
  1971年   2篇
  1970年   3篇
  1969年   2篇
  1967年   2篇
  1965年   2篇
  1964年   1篇
  1963年   1篇
  1960年   1篇
排序方式: 共有1042条查询结果,搜索用时 31 毫秒
31.
AIM: To investigate whether selected single nucleotide polymorphisms (SNPs) in miR-196a2, miR-27a and miR-146a genes are associated with sporadic colorectal cancer (CRC).METHODS: In order to investigate the effect of these SNPs in CRC, we performed a case-control study of 197 cases of sporadic CRC and 212 cancer-free controls originating from the Central-European Caucasian population using TaqMan Real-Time polymerase chain reaction and allelic discrimination analysis.RESULTS: The genotype and allele frequencies of SNPs were compared between the cases and the controls. None of the performed analysis showed any statistically significant results.CONCLUSION: Our data suggest a lack of association between rs11614913, rs895819 and rs2910164 and colorectal cancer risk in the Central-European Caucasian population, a population with an extremely high incidence of sporadic colorectal cancer.  相似文献   
32.
BackgroundGrasses belong to major sources of inhaled allergens. The knowledge of particular molecules responsible for hypersensitivity is of crucial importance for better understanding of individual differences among single allergic subjects and allergic populations living in various world-areas.MethodsSpecific-IgE-antibodies against Phl p 1, Phl p 5, Phl p 7, Phl p 12 were detected in a group of 130 Phleum-allergic-subjects (82 children, 48 adults).ResultsPhl p 1 antibodies were detected in most pediatric and adult patients, however, the children were associated with higher RAST classes more often. Anti-Phl p 5-antibodies were found more frequently in adults. An increase was observed in the number of pediatric patients reacting to Phl p 7 and Phl p 12. There were no differences in concentrations of specific-IgE against Phl p 5, Phl p 7 and Phl p 12 depending on age. Almost 10% of allergic children produced antibodies directed exclusively against minor allergens or did not produce specific-IgE-antibodies against tested molecules. Part of the patients reacted to profilin and calcium-binding protein originating from only one source (Phl p 12/Bet v 2 and Phl p 7/Bet v 4).ConclusionsAntibodies against Phl p 1 and Phl p 5 can be used as a marker of allergy to grasses in adult patients. Children reacted exclusively to minor allergens more frequently than adults. Prolonged allergen exposure is evidently necessary to induce sensitization to Phl p 5. A high level of homology between profilins and calcium-binding proteins enables only one allergen to be used for diagnostic purposes but a possibility of a reaction to species-bound epitopes should be taken into account.  相似文献   
33.
Extremely acidic soils (pH?<?3) harbour mycobiota that are different from less acidic habitats and are dominated by a small number of fungal species. During investigation of the mycobiota of highly acidic soils in the Czech Republic and Iceland, a group of melanised fungal isolates was obtained. Based on phenotype and nuclear ribosomal DNA sequences (ITS region, SSU, LSU), the isolates were accommodated by three phylogenetic lineages within the family Teratosphaeriaceae (Capnodiales, Dothideomycetes). The first lineage is here described as a new acidotolerant genus and species Acidiella bohemica gen. nov. et sp. nov. The most closely related species to this new clade are other extremotolerant fungi isolated from rocks and lichens collected in the Alps and Antarctica as well as leaf-spotting species and opportunistic human pathogens. The isolates belonging to the second and the third lineages were identified as the recently described acidophilic fungi Acidomyces acidophilus and Teratosphaeria acidotherma, respectively. The taxonomic status of both sister species is discussed and the latter species is ascribed here to the genus Acidomyces.  相似文献   
34.
A hippocampal‐prominent event‐related potential (ERP) with a peak latency at around 450 ms is consistently observed as a correlate of hippocampal activity during various cognitive tasks. Some intracranial EEG studies demonstrated that the amplitude of this hippocampal potential was greater in response to stimuli requiring an overt motor response, in comparison with stimuli for which no motor response is required. These findings could indicate that hippocampal‐evoked activity is related to movement execution as well as stimulus evaluation and associated memory processes. The aim of the present study was to investigate the temporal relationship between the hippocampal negative potential latency and motor responses. We analyzed ERPs recorded with 22 depth electrodes implanted into the hippocampi of 11 epileptic patients. Subjects were instructed to press a button after the presentation of a tone. All investigated hippocampi generated a prominent negative ERP peaking at ~420 ms. In 16 from 22 cases, we found that the ERP latency did not correlate with the reaction time; in different subjects, this potential could either precede or follow the motor response. Our results indicate that the hippocampal negative ERP occurs independently of motor execution. We suggest that hippocampal‐evoked activity, recorded in a simple sensorimotor task, is related to the evaluation of stimulus meaning within the context of situation. © 2013 Wiley Periodicals, Inc.  相似文献   
35.
B cells play an important role in the immune responses which affect the outcomes of kidney allografts. Dynamic changes of B‐cell compartments in clinical kidney transplantation are still poorly understood. B‐cell subsets were prospectively monitored using flow cytometry for 1 year in 98 kidney transplant recipients. Data were correlated with immunosuppression and clinical outcomes. An increase in the total population of B lymphocytes was observed during the first week after transplantation. The level of IgMhighCD38highCD24high transitional B cells reduced significantly up until the third month, with partial repopulation in the first year. Lower numbers of transitional B cells in the third month were associated with higher risk of graft rejection. IgM+IgD+CD27? naive B cells did not change within follow‐up. IgM+CD27+ nonswitched memory B cells and IgM?CD27+ switched memory B cells increased on post‐operative day 7. IgM?CD38highCD27high plasmablasts showed similar kinetics during the first post‐transplant year, similar to transitional B cells. In conclusion, sensitized kidney transplant recipients as well as those with either acute or chronic rejection within the first post‐transplant year exhibited lower levels of transitional B cells. Therefore, these data further support the hypothesis that transitional B cells have a protective role in kidney transplantation.  相似文献   
36.
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Antibiotikaresistenz stellt eine der größten Herausforderungen für die Gesundheitsversorgung des...  相似文献   
37.
AIM: The aim of this article is to present a case of Paracoccidioidomycosis with involvement of the oral cavity but without pulmonary manifestations. BACKGROUND: Paracoccidioidomycosis is a fungal infection caused by Paracoccidioides brasiliensis. It is an endemic disease representing a serious health problem for Latin American countries, especially Brazil. This infection primarily affects the lungs of adult men and is acquired through inhalation or accidental inoculation of the fungus. It can spread to other organs and tissues, mainly the oral cavity. Administration of antifungal medication always resolves the disease. REPORT: A 58-year-old black male presented with three painless, ulcerated, mulberry-like granulomatous lesions located in the floor of the mouth, on the superior alveolar ridge, and on the hard palate, which had evolved over a period of two years. Facial asymmetry was observed due to edema in the lower lip and lymphadenopathy. He had smoked for more than six years but showed no evidence of lung alterations, productive cough, or fever. Panoramic radiography showed no signs of a bone lesion in the jaws. Both a radiograph and a CT scan of the thorax showed no areas of nodular infiltration. Fibrobronchoscopic examination of the entire respiratory tract was normal. Biopsies of the oral lesions were performed, and tissue sections exhibited oral mucosa coated with non-keratinized stratified squamous epithelium with acanthosis and focal areas of exocytosis. The underlying connective tissue showed an intense lymphocytic and polymorphonuclear infiltrate in addition to multinuclear giant cells and coagulation necrosis. A special stain used for fungus (the Grocott-Gomori method) was positive. Pulmonary biopsy exhibited aerial spaces containing macrophages, dark granular hemossiderin, and absence of fungus. This was considered normal. In agreement with the recommendation of pneumologists 400 mg/day of ketoconazole was prescribed for the patient. After two months of treatment, even though the oral lesions had resolved completely, the therapy was maintained for six months more. One year after following treatment the patient was in good health and free of any signs of a recurrent infection. SUMMARY: Based on clinical, radiographic, and histologic findings the differential diagnosis included paracoccidioidomycosis and squamous cell carcinoma. Following clinical and biopsy examinations of the oral lesions and the lungs a final diagnosis of paracoccidioidomycosis was made. This is a prime example of oral manifestations of a systemic disease in which the dentist is the initial health care professional to evaluate the patient due to the location of the lesions.  相似文献   
38.
Introduction

Millions of patients worldwide suffer disability and death due to complications related to surgery. Many of these complications can be reduced by the use of the World Health Organization (WHO) Surgical Safety Checklist (SSC), a simple tool that can enhance teamwork and communication and improve patient safety. Despite the evidence on benefits of its use, introducing and sustaining the use of the checklist are challenging. We present a team-based approach employed in a low-resource setting in Tanzania, which resulted in high checklist utilization and compliance rates.

Methods

We reviewed reported data from facility registers supplemented by direct observation data by mentors to evaluate the use of the WHO SSC across 40 health facilities in two regions of Tanzania between January and December 2018. We analyzed the self-reported monthly data on total number of major surgeries performed and proportion of surgeries where the checklist was used. We also analyzed the use of the SSC during direct observation by external mentors and completion rates of the SSC in a random selection of patient files during two mentorship visits between June and December 2018.

Results

During the review period, the average self-reported checklist utilization rate was 79.3% (11,564 out of 14,580 major surgeries). SSC utilization increased from 0% at baseline in January 2018 to 98% in December 2018. The proportion of checklists that were completely and correctly filled out increased between the two mentor visits from 82.1 to 92.8%, but the gain was significantly greater at health centers than at hospitals (p < 0.05). Health centers (which had one or two surgical teams) self-reported a higher checklist utilization rate than hospitals (which had multiple surgical teams), i.e., 99.4% vs 68.8% (p < 0.05).

Conclusion and recommendations

Our findings suggest that Surgical Safety Checklist implementation is feasible even in lower-resource settings. The self-reported SSC utilization rate is higher than reported in other similar settings. We attribute this finding to the team-based approach employed and the ongoing regular mentorship. We recommend use of this approach to scale-up checklist use in other regions in the country as recommended in the Ministry of Health of Tanzania’s National Surgical, Obstetric, and Anesthesia Plan (NSOAP).

  相似文献   
39.

Background

The anti-androgen withdrawal syndrome (AAWS) can be seen in one-third of patients after discontinuation of first-generation non-steroidal anti-androgen therapy. With the introduction of new agents for anti-androgen therapy as well as alternate mechanisms of action, new therapeutic options before and after docetaxel chemotherapy have arisen (Ohlmann et al. in World J Urol 30(4):495–503, 2012). The question regarding the occurrence of an enzalutamide withdrawal syndrome (EWS) has not been evaluated yet. In this study, we assess prostate-specific antigen (PSA) response after discontinuation of enzalutamide.

Methods

In total 31 patients with metastatic castration-resistant prostate cancer (mCRPC) underwent an enzalutamide withdrawal and were evaluated. Data were gathered from 6 centres in Germany. Patients with continuous oral administration of enzalutamide with rising serum PSA levels were evaluated, starting from enzalutamide withdrawal until subsequent therapy was initiated, follow-up ended or death of the patient occurred. Statistical evaluation was performed applying one-sided binomial testing using R-statistical software, version 3.0.1.

Results

Mean withdrawal follow-up was 6.5 weeks (range 1–26.1 weeks). None of the 31 patients showed a PSA decline. Mean relative PSA rise over all patients was 73.9 % (range 0.5–440.7 %) with a median of 44.9 %.

Conclusions

If existent, an AAWS is at least very rare for enzalutamide in patients with mCRPC after taxane-based chemotherapy and does not play a clinical role in this setting. This may be attributed to the different pharmacodynamics of enzalutamide. Longer duration of therapy or a longer withdrawal interval may reveal a rare EWS in the future.  相似文献   
40.
The literature has shown that low-level laser therapy accelerates the repair of cutaneous wounds. However, there is a scarcity of scientific studies that characterise the possible systemic interference of laser photobiomodulation. The aim of this research was to quantitatively evaluate blood corticosterone levels and tissue cytokine expression in cutaneous wounds of rats treated with low-level laser therapy (semiconductor diode AsGaAl, continuous emission, 9 mW, 670 nm, 0.031 W/cm2, beam with an output area of 0.28 cm2) and normal controls. A total of 36 male Wistar rats were used and randomly divided into two groups of 18 rats each. A standardised circular 6-mm-diameter wound was made in the dorsal skin region of each rat, and they were euthanised at 1, 6 and 12 h after cutaneous surgery. The blood was collected, and portions of cutaneous tissue and subcutaneous muscle were removed and cryopreserved. Corticosterone levels in the blood were measured by a radioimmunoassay technique; histological sections were submitted to the ELISA technique for analysis of tissue cytokine expression levels. At 6 h after surgery, a significant increase in corticosterone and a significant reduction in the levels of IL-1β and IL-6 in tissues of irradiated wounds were observed when compared to controls (p?<?0.05). The levels of TNF-α and IL-10 expression were not significantly different between the groups at different time intervals. Thus, this study strongly suggests a systemic and local biomodulation of low-level laser therapy as indicated by the blood levels of corticosterone and the tissue expression of IL-1β and IL-6, respectively.  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