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   2450篇
  免费   170篇
  国内免费   39篇
耳鼻咽喉   44篇
儿科学   113篇
妇产科学   45篇
基础医学   272篇
口腔科学   14篇
临床医学   315篇
内科学   283篇
皮肤病学   9篇
神经病学   72篇
特种医学   87篇
外科学   364篇
综合类   319篇
预防医学   311篇
眼科学   7篇
药学   156篇
  3篇
中国医学   17篇
肿瘤学   228篇
  2024年   5篇
  2023年   49篇
  2022年   122篇
  2021年   150篇
  2020年   119篇
  2019年   133篇
  2018年   130篇
  2017年   100篇
  2016年   102篇
  2015年   145篇
  2014年   229篇
  2013年   182篇
  2012年   162篇
  2011年   197篇
  2010年   130篇
  2009年   135篇
  2008年   110篇
  2007年   96篇
  2006年   64篇
  2005年   57篇
  2004年   55篇
  2003年   37篇
  2002年   25篇
  2001年   16篇
  2000年   14篇
  1999年   11篇
  1998年   10篇
  1997年   21篇
  1996年   7篇
  1995年   7篇
  1994年   6篇
  1993年   5篇
  1992年   3篇
  1991年   4篇
  1990年   4篇
  1989年   3篇
  1988年   2篇
  1987年   2篇
  1986年   2篇
  1985年   3篇
  1984年   2篇
  1982年   1篇
  1980年   1篇
  1976年   1篇
排序方式: 共有2659条查询结果,搜索用时 15 毫秒
1.
ObjectivesOur aim was to evaluate the effect of the updated European Organization for Research and Treatment of Cancer (EORTC) and Mycoses Study Group 2019 definitions for invasive pulmonary aspergillosis (IPA) on patient classification and the related all-cause 12-week mortality.MethodsIn this retrospective cohort study from our tertiary care centre, we reclassified patients with haematological malignancy who underwent bronchoalveolar lavage between 2014 and 2019 for suspected IPA using the novel EORTC 2019 criteria. We performed receiver operating characteristic curve analysis to define the optimal cut-off for positive PCR and galactomannan and present survival analyses and their possible association with these diagnostic criteria through post hoc comparisons with log rank and Cox regression.ResultsFrom 323 episodes of suspected IPA in 282 patients, 73 were reclassified: 31 (42.5%) from possible to probable IPA, 5 (6.8%) from EORTC criteria not met to probable IPA, and 37 (50.7%) from EORTC criteria not met to possible IPA. Probable IPA increased therefore 11.1% (64/323, 19.8% to 100/323, 30.9%), mostly due to positive PCR (31/36, 86.1%). There was no difference in mortality between newly defined possible and probable IPA (log rank p = 0.950). Mortality was higher in probable cases with lower cycle thresholds (Ct values) versus higher Ct values (p = 0.004). Receiver operating characteristic curve analysis showed an optimal Ct value cut-off of 36.8 with a sensitivity of 75% (95% CI 64.9%–85.1%) and a specificity of 61.7% (95% CI 53.5–69.9) for 12-week mortality.DiscussionThe new EORTC criteria led to 11.1% more probable IPA diagnoses, mostly due to Aspergillus PCR. Restricting positive PCR to below a certain threshold might improve the discrimination of the new EORTC IPA categories for mortality.  相似文献   
2.

Background

Laparoscopic Roux-en-Y gastric bypass, laparoscopic sleeve gastrectomy, and laparoscopic adjustable gastric banding all lead to substantial weight loss in obese patients. Long-term weight loss can be highly variable beyond 1-year postsurgery. This study examines and compares the frequency distribution of weight loss and lack of treatment effect rates after laparoscopic Roux-en-Y gastric bypass, laparoscopic sleeve gastrectomy, and laparoscopic adjustable gastric banding.

Methods

A total of 1,331 consecutive patients at a single academic institution were reviewed from a prospectively collected database. Preoperative data collected included demographics, body mass index, and percent excess weight loss. Postoperative BMI and %EWL were collected at 12, 24, and 36 months. Percent excess weight loss was analyzed by the percentiles of excess weight lost, and the distribution of percent excess weight loss was evaluated in 10% increments. Lack of a successful treatment effect was defined as <25% excess weight loss.

Results

Of the 1,331 patients, 72.4% (963) underwent laparoscopic Roux-en-Y gastric bypass, 18.3% (243) laparoscopic sleeve gastrectomy, and 9.4%(125) laparoscopic adjustable gastric banding. Mean percent excess weight loss was greatest for laparoscopic Roux-en-Y gastric bypass, followed by laparoscopic sleeve gastrectomy, and then by laparoscopic adjustable gastric banding at every time point: at 2 years mean percent excess weight loss was 77.9± 24.4 for laparoscopic Roux-en-Y gastric bypass, 50.8 ± 25.8 for laparoscopic sleeve gastrectomy, and 40.8± 25.9 for laparoscopic adjustable gastric banding (P < .0001). The rates of a successful treatment effect s for laparoscopic Roux-en-Y gastric bypass, laparoscopic sleeve gastrectomy, and laparoscopic adjustable gastric banding were 0.9%, 5.2%, and 24.3% at 1 year; 0.3%, 11.1%, and 26.0% at 2 years; and 1.0%, 25.3%, and 30.2% at 3 years. At 1 year, the odds ratio of lack of a successful treatment effect of laparoscopic sleeve gastrectomy versus laparoscopic Roux-en-Y gastric bypass was 6.305 (2.125–19.08; P?=?.0004), the odds ratio for laparoscopic adjustable gastric banding versus laparoscopic Roux-en-Y gastric bypass was 36.552 (15.64–95.71; P < .0001), and the odds ratio for laparoscopic adjustable gastric banding versus laparoscopic sleeve gastrectomy was 5.791 (2.519–14.599; P < .0001). At 2 years, the odds ratio for laparoscopic sleeve gastrectomy versus laparoscopic Roux-en-Y gastric bypass increased to 70.7 (9.4–531.7; P < .0001), the odds ratio for laparoscopic adjustable gastric banding versus laparoscopic Roux-en-Y gastric bypass increased to 128.1 (16.8–974.3; P < .0001), and the odds ratio for laparoscopic adjustable gastric banding versus laparoscopic sleeve gastrectomy decreased to 1.8 (0.9–3.6; P?=?.09).

Conclusion

This study emphasizes the existing variability in weight loss across bariatric procedures as well as in the lack of a treatment effect for each procedure. Although laparoscopic adjustable gastric banding has the greatest rate of a lack of a successful treatment effect, the rate remained stable over 3 years postoperatively. Laparoscopic sleeve gastrectomy showed a doubling in the rate of a lack of a successful treatment effect every year reaching 25% at year 3. The rates for lack of a successful treatment effect for laparoscopic Roux-en-Y gastric bypass remained stable at about 1% for the first 3 years postoperatively.  相似文献   
3.
4.
BackgroundIn the last decade, many novel minimally invasive surgical techniques within benign prostatic hyperplasia (BPH) surgery were developed to reduce postoperative complications that often discourage patients from pursuing BPH surgery.AimTo assess perspective of future and past international BPH surgery patients regarding their postoperative complications, namely erectile and ejaculatory function.MethodsA survey was distributed randomly to 2 groups of BPH patients: one with 149 patients having undergone surgery in the last 2 years (group A), and the other cohort of 151 men seriously considering BPH surgery in the next year (group B). This survey consisted of 20 questions that assessed patients' motivating factors for undergoing elective BPH surgery and their perspectives regarding the potential postoperative complications attributed to BPH surgery.OutcomesThe perspective of future and past international BPH surgical patients towards the preservation of their erectile and ejaculatory functions was assessed with the help of a survey.ResultsResults indicated that in general BPH surgery patients considered the maintenance of erectile (95%, n = 284) and ejaculatory function (92%, n = 276) to be important preoperative considerations, regardless of their age. Patients aged 50–59 years were most concerned with the permanent impact on sexual function and patients aged >60 years were most concerned with urinary incontinence. In patients aged >70 years, 66% (n = 43) and 62% (n = 40) of the respondents indicated that maintaining erectile and ejaculatory function was important, respectively.Clinical ImplicationsPatient-centered care needs to be implemented in order to address the importance that past and future BPH surgery patients hold toward the maintenance of their postoperative sexual function.Strengths & LimitationsIn the group of patients having previously undergone BPH surgery, the possibility of recall bias should be taken into account when interpreting the study's findings. However, maintaining sexual function was also important for the group of patients seriously considering surgery in the next year suggesting that these considerations are not solely due to recall bias. Additionally, the results were limited by the small sample size of participants in groups A (n = 149) and B (n = 151).ConclusionIt was found that past and future BPH surgery patients attribute a significant importance toward the maintenance of their sexual function. Although novel approaches with better sexual outcomes such as Rezum and UroLift for prostates <80 mL, and Aquablation for any size prostate are available, more research is needed to investigate their long-term effects on sexual function before they can be recommended to patients.Bouhadana D, Nguyen D-D, Zorn KC, et al. Patient Perspectives on Benign Prostatic Hyperplasia Surgery: A Focus on Sexual Health. J Sex Med 2020;17:2108–2112.  相似文献   
5.
A series of 8 rat and 16 mouse invasive bladder carcinomas were investigated for the presence of silverstained nucleolar organizer regions (AgNORs) to clarify whether this parameter is applicable to the estimation of their invasive character. With regard to number of AgNORs per cell, neither rat nor mouse carcinomas showed any difference between invasive and noninvasive sites within the same tumor. However, the frequency of cancer cells bearing bizarre dots, irregular in size and shape, was significantly higher at sites of actual invasion. Quantitative data generated using an image analyzer revealed significantly lower values for NOR roundness and significantly larger NOR size in invasive sites than in noninvasive sites in all groups. Double staining for the proliferation marker proliferating cell nuclear antigen (PCNA) and AgNORs was performed on eight rat carcinomas and a close correlation between the two was confirmed. Thus the number of AgNORs in PCNA-positive cells was significantly greater than in PCNA-negative cells. Furthermore, a particularly strong correlation was observed for incidences of PCNA-positive cells and bizarre dots (P<0.01). The quantitative data also demonstrated significant differences in size and shape of dots. It is concluded that AgNORs have diagnostic value for the invasive character of bladder carcinomas.  相似文献   
6.
微创内固定系统在膝关节周围复杂骨折治疗中的应用   总被引:3,自引:1,他引:2  
目的探讨AO微创内固定系统(less invasive stab ilization system,LISS)治疗膝关节周围复杂骨折的效果。方法2004年4月~2005年6月对15例干骺端闭合性膝关节周围复杂骨折(左侧9例,右侧6例),分别应用股骨远端LISS或胫骨近端LISS行内固定治疗。结果15例随访5~26个月,平均13.2月。完全负重时间为12~26周,X线骨愈合时间11~24周,无延迟愈合及骨不连。浅表感染1例,皮肤水疱2例,经换药后愈合。无深部感染及皮肤坏死,无骨筋膜室综合征。Johner-W ruhs方法评价功能优11例、良3例、中1例,以优良为满意标准,本组满意率为93.3%(14/15)。1例C3型胫骨平台骨折在术后2周出现胫骨内侧骨块明显移位伴髁间分离,二次手术在胫骨平台内侧加以支撑钢板固定,术后20周骨折愈合,功能评价为良;1例C3型胫骨平台骨折在术后8周出现膝内翻(胫骨平台内翻角为82°),术后20周骨折愈合,功能评价为中。结论LISS适用于单处股骨远端、胫骨近端骨折及骨质疏松性股骨干远端骨折的治疗;对于胫骨平台C3型骨折内侧平台粉碎严重时,不能过分依赖LISS系统,或将接骨板置于内侧,而应该考虑在内侧辅助支撑钢板。  相似文献   
7.
Summary A 40-year-old, HIV-infected female patient received antibiotic treatment for a urinary tract infection. After the initial success of therapy and a symptom-free period, she developed pneumonia with septic shock and adult respiratory distress syndrome (ARDS). In spite of intensive care and respirator therapy with positive end-expiratory pressure (PEEP), she died of infectious toxic shock. Autopsy findings showed relapsing, gramnegative, bacterial pneumonia (morphologically compatible with Klebsiella pneumonia) and secondary, invasive aspergillosis. The pathogenesis and epidemiology of these unusual complications of AIDS are discussed.Abbreviations AIDS acquired immunodeficiency syndrome - ARDS adult respiratory distress syndrome - CDC Centers for Disease Control - HIV human immunodeficiency virus - PEEP positive end-expiratory pressure  相似文献   
8.
目的 探讨急性心肌梗死(AMI)溶栓治疗后无创法评价心肌再灌注的可行性。方法选择AMI溶栓治疗后行冠状动脉造影的患者,溶栓后90min血浆肌红蛋白(Mb)浓度与溶栓前血浆Mb浓度比值≥2.4或心电图ST段回落≥50%定义为成功再灌注(阳性)。上述两项指标均阳性为完全再灌注,仅一项阳性为部分再灌注,两项均阴性为无再灌注。再根据冠状动脉造影结果将患者分为完全再灌注(TIMI3级)、部分再灌注(TIMI2级)、无再灌注(TIMI0~1级)。对无创法和介入法进行一致性检验。共入选45例患者。结果无创法和介入法评价心肌再灌注经一致性检验,符合率为84.4%,Kappa=0.75(P〈0.01)。结论.心电图ST段回落和血浆Mb浓度变化两项指标合用可提高评价心肌再灌注准确性,和介入法有很高的符合率,简便易行,且结果可靠。  相似文献   
9.
李枫  刘德敏  侯伟光 《西部医学》2023,35(8):1167-1172
研究经皮内镜下可视化置钉在经皮内镜下后路腰椎融合术(End-PLIF)椎弓根螺钉置钉中的应用价值。方法 纳入2020年10月—2021年4月我院有腰椎融合手术指征的腰椎间盘源性腰痛、腰椎管狭窄症伴腰椎不稳、腰椎间盘突出症伴腰椎不稳、腰椎滑脱症(Meyerding分级I、II)患者共50例。50例患者随机分为甲、乙两组,每组25例。甲组的手术方式为经皮内镜下后路腰椎融合术+经皮脊柱内镜下可视化椎弓根螺钉置钉,乙组的手术方式为经皮内镜下后路腰椎融合术+传统X线透视下经皮椎弓根螺钉置钉。比较两组X线透视总次数、导丝置入时间、手术时间、术后住院时间;采用Gertzbein-Robbins标准评价置钉优良率;术前及术后24 h VAS评分和ODI指数、改良Macnab标准及术后并发症的发生率评价疗效。同时对经皮内镜下改进的置钉器械进行3D打印制造并验证其可行性、实用性。通过上述指标观察其医患X线辐射情况、微创性、置钉的优良率及手术效果。结果 全部患者均完成了手术和随访。甲组患者X线透视总次数、手术时间、导丝置入时间,均少于乙组(P<0.05),两组术后住院时间比较差异无统计学意义(P>0.05)。两组术前、术后24 h VAS、ODI比较差异无统计学意义(P>0.05),但两组术后24 hVAS、ODI均较术前改善(P<0.05)。末次随访时,两组患者改良Macnab标准的优良率比较差异无统计学意义(P>0.05)。甲组经皮内镜置钉优良率优于乙组(P<0.05)。两组患者术后并发症发生率比较差异无统计学意义(P>0.05)。结论 经皮内镜下置钉能减少医患X线辐射次数,降低医患辐射暴露风险,且置钉的优良率较高;同时,3D打印的经皮内镜下置钉器械具有可行性和实用性  相似文献   
10.
Human contact with fungi does not usually lead to pathological consequences, as the immune system manages to defeat the invader pathogens. Nevertheless, under immune suppression, fungi overcome immune defenses and cause diseases that range from nonserious colonizations of keratinizated tissue (Dermatophytosis) to life threatening disseminated infections (Aspergillosis). Host defenses against fungi rely on innate and adaptative responses, with dendritic cell (DC) and macrophage surface receptors having a major role in the recognition of fungal pathogens and in the orchestration of an effective immune response. DC-SIGN is a C-type lectin involved in the recognition of bacterial, viral and parasitic pathogens, as well as in interactions between cells of the immune system. Its expression is restricted to DCs and subsets of macrophages. Here we show that DC-SIGN mediates the binding and capture of Aspergillus fumigatus and keratinophylic fungi, including Chrysosporium tropicum, by human DCs, describe the requirements of these interactions and discuss their potential involvement in the onset and persistence of pulmonary fungal 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