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   7044篇
  免费   465篇
  国内免费   57篇
耳鼻咽喉   20篇
儿科学   162篇
妇产科学   54篇
基础医学   377篇
口腔科学   36篇
临床医学   355篇
内科学   2783篇
皮肤病学   14篇
神经病学   72篇
特种医学   297篇
外科学   2106篇
综合类   50篇
现状与发展   1篇
预防医学   194篇
眼科学   18篇
药学   160篇
中国医学   9篇
肿瘤学   858篇
  2024年   5篇
  2023年   531篇
  2022年   862篇
  2021年   710篇
  2020年   665篇
  2019年   467篇
  2018年   380篇
  2017年   397篇
  2016年   315篇
  2015年   341篇
  2014年   729篇
  2013年   521篇
  2012年   251篇
  2011年   93篇
  2010年   255篇
  2009年   229篇
  2008年   58篇
  2007年   90篇
  2006年   80篇
  2005年   75篇
  2004年   30篇
  2003年   49篇
  2002年   46篇
  2001年   44篇
  2000年   43篇
  1999年   37篇
  1998年   49篇
  1997年   38篇
  1996年   39篇
  1995年   45篇
  1994年   26篇
  1993年   19篇
  1992年   13篇
  1991年   10篇
  1990年   1篇
  1989年   8篇
  1988年   9篇
  1983年   2篇
  1980年   1篇
  1979年   1篇
  1978年   2篇
排序方式: 共有7566条查询结果,搜索用时 36 毫秒
991.
Cataloguing the effects of different types of stress on behaviour and physiology in rodent models has not been comprehensively attempted. Here, we systematically review whether chronic exposure to physical stress, psychosocial stress, or both types of stress can induce different behavioural and neurobiological outcomes in male and female rodents. We found that physical stress consistently increased depressive-like behaviour, impaired social interaction and decreased body weight, while psychosocial stress consistently increased both anxiety- and depressive-like behaviour, impaired social interaction and learning and memory, increased HPA axis activity, peripheral inflammation and microglial activation, and decreased hippocampal neurogenesis in male rodents. Moreover, we found that the combined effect of both stress types resulted in a more severe pathological state defined by increased anxiety- and depressive-like behaviour, impaired social interaction and learning and memory, increased HPA axis activity and central inflammation, and reduced hippocampal neurogenesis and neural plasticity in male rodents. Phenotypes for females were less consistent, irrespective of the type of stress exposure, on account of the limited number of studies using females. This review highlights that the type of stress may indeed matter and will help animal researchers to more appropriately choose a stress/depression model that fits their research purposes.  相似文献   
992.
993.
994.
《Pancreatology》2022,22(5):547-552
Abdominal pain is considered a cardinal feature of acute pancreatitis (AP), and abdominal imaging is only required to diagnose AP when the pain is atypical, or serum enzyme elevation does not match the clinical picture. While painless lipase elevation is being increasingly associated with worse outcomes in various diseases, the diagnostic approach to such elevation is so-far unclear. We thus aimed to learn the impact of pain on the diagnosis of AP.MethodsAll patients presenting to the Mayo Clinic Arizona Hospital emergency department with a serum lipase ≥3x upper limit of normal between April 2016 and January 2020 were prospectively followed. Their charts were reviewed for the nature of pain, serum lipase levels on presentation, abdominal imaging, and whether a diagnosis of AP was made. Chronic pancreatitis was excluded.ResultsAmong 320 patients, 85 (26.5%) had painless lipase elevation. These patients had abdominal imaging less often (56/85, 66%) than in those with abdominal pain (201/235, 83%; p = 0.001). The diagnosis of AP increased overall from 31/63 (49%) without imaging to 198/257 (77%) with imaging (P < 0.001). Imaging increased the diagnosis of AP in patients with painless lipase elevation from 2/29 (7%) without imaging to 16/56 (29%; p = 0.025) among those who were imaged.ConclusionsPainless lipase elevation >3-fold the upper limit of normal is common in emergency department patients. 1/3 to 1/4 of these may have AP. Abdominal imaging increases the diagnosis of AP in patients with painless lipase elevation. Therefore, abdominal imaging in such patients may help detect AP that otherwise eludes diagnosis.  相似文献   
995.
BackgroundSelection of liver grafts suitable for transplantation (LT) mainly depends on a surgeon's subjective assessment. This study aimed to investigate the role of radiomic analysis of donor-liver CTs after brain death (DBD) to predict the occurrence of early posttransplant allograft dysfunction (EAD).MethodsWe retrospectively extracted and analyzed the left lobe radiomic features from CT scans of DBD livers in training and validation cohorts. Multivariate analysis was performed to identify predictors of EAD.ResultsFrom 126 LTs included in the study in the training cohort, 27 (21.4%) had an EAD. For each patient, 279 radiomic features were extracted of which 5 were associated with EAD (AUC = 0.81) (95% CI 0.72–0.89). Among donor and recipient clinical characteristics, cardiac arrest, steatosis on donor's CT, cold ischemic time and age of recipient were also identified as independent risk factors for EAD. Combined radiomic signature and clinical risk factors showed a strong predictive performance for EAD with a C-index of 0.90 (95% CI 0.84–0.96). A validation cohort of 23 patients confirmed these results.ConclusionRadiomic signatures extracted from donor CT scan, independently or combined with clinical risk factors is an objective and accurate biomarker for prediction of EAD after LT.  相似文献   
996.
997.
BackgroundSome patients remain deemed unsuitable for resection after portal vein embolization (PVE) because of insufficient hypertrophy of the future remnant liver (FRL). Hepatic and portal vein embolization (HPVE) has been shown to induce hypertrophy of the FRL. The aim of this study was to provide a systematic review of the available literature on HPVE as preparation for major hepatectomy.MethodsThe literature search was performed on online databases. Studies including patients who underwent preoperative HPVE were retrieved for evaluation.ResultsSix articles including 68 patients were published between 2003 and 2017. HPVE was performed successfully in all patients with no mortality and morbidity-related procedures. The degree of hypertrophy of the FRL after HPVE ranged from 33% to 63.3%. Surgical resection after preoperative HPVE could be performed in 85.3% of patients, but 14.7% remained unsuitable for resection because of insufficient hypertrophy of the FRL or tumor progression. Posthepatectomy morbidity and mortality rates were 10.3% and 5.1%, respectively. The postoperative liver failure rate was nil.ConclusionHPVE as a preparation for major hepatectomy appears to be feasible and safe and could increase the resectability of patients initially deemed unsuitable for resection because of absent or insufficient hypertrophy of the FRL after PVE alone.  相似文献   
998.
目的比较腹腔镜经腹腹膜前疝修补术(TAPP)与开放式腹膜前疝修补术治疗股疝的手术结果和对生活质量的影响。 方法回顾性分析2014年1月至2019年12月新疆医科大学第一附属医院收治的58例股疝患者的临床资料,根据手术方式不同分为TAPP组和开放式腹膜前疝修补术组(开放组),TAPP组31例,开放组27例。比较两组手术指标,采用卡罗来纳舒适量表(CCS)评估并比较两组患者术前及术后1、6、12和24个月的生活质量。 结果TAPP组在手术时间、术中出血量、术后住院天数及术后并发症发生率等方面和开放组相比差异无统计学意义(P>0.05);TAPP组在术后24 h疼痛视觉模拟评分及术后镇痛药使用率方面明显优于开放组(P<0.05);TAPP组术后离床时间及术后首次进食时间长于开放组(P<0.05);2组患者术后随访24个月,均无复发病例。两种术式均能有效改善患者术前的疼痛、运动受限及总体生活质量(P<0.05);TAPP组患者术后1个月疼痛及总体生活质量优于开放组(P<0.05)。 结论TAPP与开放式腹膜前疝修补术均可有效治疗股疝。TAPP可作为无全身麻醉禁忌股疝患者的首选治疗方法。股疝的治疗应依据患者的自身情况和手术医师的技术掌握程度制定个体化治疗方案。  相似文献   
999.
The pituitary tumor-transforming gene 1 (PTTG1), also known as Securin, is considered an oncogene. This study aimed to investigate the role of PTTG1 in clear cell renal cell carcinoma (ccRCC) using in silico bioinformatics approaches. A pan-cancer analysis using The Cancer Genome Atlas (TCGA) data indicated that among all cancer types copy number amplification of PTTG1 gene was most frequently found in ccRCC. However, amplification of PTTG1 gene copy number did not correlate with the increase of mRNA level in ccRCC, and did not predict the patients' overall survival. Instead, ccRCC was correlated with overexpression of PTTG1 mRNA, and its expression level was stage-dependent increased in cancer patients. An outlier analysis using the Oncomine database suggested that PTTG1 mRNA expression served as a good biomarker for ccRCC. Pathway analysis for upregulated genes enriched in PTTG1-high expressing ccRCC patients found that PTTG1 overexpression was associated with mitotic defects. Mining drug sensitivity data using the Cancer Therapeutics Response Portal (CTRP) discovered that PTTG1-high expressing ccRCC cell lines were susceptible to a Rac1 (Ras-related C3 botulinum toxin substrate 1) inhibitor NSC23766. Therefore, this study provides an in silico insight into the role of PTTG1 in ccRCC, and repurposes the Rac1 inhibitor NSC23766 for treating PTTG1-high expressing ccRCC.  相似文献   
1000.

Background

In colorectal cancer liver metastases (CRCLM), bevacizumab-based neoadjuvant strategies provide increased pathologic response. We aimed at assessing the activity of perioperative capecitabine, oxaliplatin, irinotecan, and bevacizumab (COI-B regimen) in patients with potentially resectable CRCLM, and investigating biomarkers for early prediction of pathologic response.

Patients and Methods

This was a single-center phase II study enrolling patients with liver-limited, borderline resectable disease and/or high-risk features. Patients received 5 preoperative and 4 postoperative cycles of biweekly COI-B (irinotecan 180 mg/m2 and bevacizumab 5 mg/Kg on day 1, oxaliplatin 85 mg/m2 on day 2, and capecitabine 1000 mg/m2 twice a day on days 2 to 6). The primary endpoint was pathologic response rate in the intention-to-treat population. A Simon 2-stage design was adopted to detect an increase from 30% to 50% with a power of 90%. Dynamic imaging biomarkers (early tumor shrinkage [ETS], deepness of response, maximum standardized uptake volume [SUVmax]/regression index) and next generation sequencing data were explored as surrogates.

Results

From June 2013 to March 2017, 46 patients were enrolled. Pathologic response was achieved in 63% patients (endpoint met), and responders achieved significantly better survival outcomes with respect to non-responders. The most frequent grade 3/4 adverse events were diarrhea and neutropenia (8.7%) in the preoperative phase and thromboembolic events (5.9%) in the postoperative phase. ETS and lower SUV-2 were significantly associated with pathologic response.

Conclusion

The COI-B regimen is a feasible and highly active perioperative strategy in patients with molecularly unselected, potentially resectable CRCLM. ETS and SUV-2 have a promising role as imaging-based biomarkers for pathologic response.  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