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   1375篇
  免费   129篇
  国内免费   6篇
耳鼻咽喉   16篇
儿科学   52篇
妇产科学   30篇
基础医学   217篇
口腔科学   40篇
临床医学   70篇
内科学   314篇
皮肤病学   12篇
神经病学   153篇
特种医学   61篇
外科学   232篇
综合类   37篇
一般理论   1篇
预防医学   54篇
眼科学   31篇
药学   94篇
中国医学   4篇
肿瘤学   92篇
  2023年   16篇
  2022年   10篇
  2021年   46篇
  2020年   24篇
  2019年   42篇
  2018年   40篇
  2017年   33篇
  2016年   59篇
  2015年   56篇
  2014年   60篇
  2013年   72篇
  2012年   113篇
  2011年   108篇
  2010年   55篇
  2009年   60篇
  2008年   89篇
  2007年   98篇
  2006年   75篇
  2005年   76篇
  2004年   62篇
  2003年   46篇
  2002年   39篇
  2001年   31篇
  2000年   23篇
  1999年   19篇
  1998年   11篇
  1997年   10篇
  1996年   9篇
  1995年   12篇
  1994年   6篇
  1992年   5篇
  1991年   16篇
  1990年   8篇
  1989年   4篇
  1988年   3篇
  1987年   9篇
  1986年   5篇
  1985年   3篇
  1984年   9篇
  1983年   3篇
  1982年   3篇
  1979年   4篇
  1975年   3篇
  1974年   3篇
  1968年   3篇
  1967年   2篇
  1966年   2篇
  1965年   3篇
  1946年   3篇
  1945年   2篇
排序方式: 共有1510条查询结果,搜索用时 18 毫秒
1.
2.
According to the eighth edition of the AJCC Cancer Staging Manual (AJCC8), a depth of invasion (DOI) >10 mm is classified as pT3, representing a locally advanced tumour requiring postoperative radiotherapy (PORT). When node-negative, however, evidence regarding whether PORT improves loco-regional control or survival is unclear. To clarify this, two cohorts of patients were studied: (1) patients classified as pT3N0 by the seventh edition of the AJCC manual (AJCC7), with DOI >10 mm and a tumour diameter >4 cm (17 patients who received PORT), and (2) patients classified as pT1N0 and pT2N0 by AJCC7, with DOI >10 mm and a tumour diameter <4 cm (55 patients who did not receive PORT). Loco-regional control and survival were analysed. PORT was found not to impact overall survival or disease-free survival. It was also found not to impact local, regional, or distant recurrence. Although the two subsets of patients considered here (DOI >10 mm with tumour diameter below or above 4 cm) were previously distinct, they are both considered pT3 in AJCC8. Data from this study indicate that the routine administration of PORT to patients with a DOI >10 mm may not be warranted in the absence of other risk features such as nodal disease or close margins.  相似文献   
3.
4.
BackgroundCirculating cell-free deoxyribonucleic acid (cfDNA) is promptly materializing as a highly useful tool for the surveillance of solid-organ transplant rejection. Donor-specific fraction (DF) cfDNA is a potential marker of selective donor organ injury. It is emerging as a promising analytical target in the near future. The aim of this systematic review is to throw light on the importance of cfDNA and future perspective in detecting acute rejection in heart transplantation.MethodsAn exhaustive search was carried out for this review article on the basis of literature available including scientific databases of PubMed, Embase, and ClinicalTrials.gov. The search engines were systematically explored using the search terms “cell free DNA,” “Heart transplant,” and “Rejection” from inception until August 2020, and narrative analysis was accomplished. Majority of the studies described endomyocardial biopsy-proven acute rejection as reference standard.ResultsAfter initial screening of 331 articles, 11 studies were included and discussed in detail in the present review article. Majority of the studies showed prospective designs. A firm correlation was noted between acute rejection (identified on endomyocardial biopsy) and cfDNA levels by most of the studies.ConclusionscfDNA is a promising tool to replace repeated biopsies to detect rejection. The development in the area of digital droplet polymerase chain reaction and massive parallel sequencing, along with the overall reduction in cost of sequencing with its automation, has helped establish its role in the transplant population.  相似文献   
5.
Objectives: To evaluate the effect of different pathways for developing a life story book (LSB) for people with dementia.

Method: Preliminary randomised control trial; 23 people with dementia in care homes (mean age 86) randomly assigned to receive either 12 individual life review sessions and co-creating a LSB or a personal LSB created by their relatives as a ‘gift’

Results: No difference in quality of life (quality of life–Alzheimer's disease (QOL–AD)) was observed between the two groups, six weeks after having received the LSB (F(1,20) = 0.08, p = 0.77). At this point, QOL–AD had improved for both groups, but there was a significant between-group difference at an intermediate assessment immediately after the life review sessions had been completed, before the LSBs were received (F(1, 20) = 5.11, p = 0.035), in favour of life review. A similar pattern was observed on autobiographical memory (extended autobiographical memory interview), with the life review group improving significantly more than the gift group during the life review sessions, but no difference was observed once all participants had had their LSB for six weeks. After the LSBs were produced – by either pathway – quality of relationship as rated by relatives improved significantly (F(2, 39) = 19.37, p < 0.001) and staff knowledge regarding the resident and attitudes to dementia improved.

Conclusion: The creation of LSBs – either through a life review process or by relatives without involving the person with dementia – has benefits for people with dementia, relatives and staff in care homes. However, undertaking a life review requires training and supervision.  相似文献   

6.
7.
The impairment of protein degradation via the ubiquitin‐proteasome system (UPS) is present in sporadic Parkinson's disease (PD), and might play a key role in selective degeneration of vulnerable dopamine (DA) neurons in the substantia nigra pars compacta (SN). Further evidence for a causal role of dysfunctional UPS in familial PD comes from mutations in parkin, which results in a loss of function of an E3‐ubiquitin‐ligase. In a mouse model, genetic inactivation of an essential component of the 26S proteasome lead to widespread neuronal degeneration including DA midbrain neurons and the formation of alpha‐synuclein‐positive inclusion bodies, another hallmark of PD. Studies using pharmacological UPS inhibition in vivo had more mixed results, varying from extensive degeneration to no loss of DA SN neurons. However, it is currently unknown whether UPS impairment will affect the neurophysiological functions of DA midbrain neurons. To answer this question, we infused a selective proteasome inhibitor into the ventral midbrain in vivo and recorded single DA midbrain neurons 2 weeks after the proteasome challenge. We found a selective increase in the mean in vivo firing frequencies of identified DA SN neurons in anesthetized mice, while those in the ventral tegmental area (VTA) were unaffected. Our results demonstrate that a single‐hit UPS inhibition is sufficient to induce a stable and selective hyperexcitability phenotype in surviving DA SN neurons in vivo. This might imply that UPS dysfunction sensitizes DA SN neurons by enhancing ‘stressful pacemaking’.  相似文献   
8.
Gluteal abscess commonly follows intramuscular injections with contaminated needles. Carcinoma cecum is known to present with pericolic abscess due to microperforations and may rupture intraperitoneally. Gluteal abscess secondary to perforated carcinoma cecum with pericolic abscess is extremely uncommon. A 50-year-old woman who was receiving intramuscular iron injections for anemia presented with a 10 × 10-cm abscess in the right gluteal region and a vague mass in the right iliac fossa. After investigations, a diagnosis of perforated carcinoma cecum with pericolic abscess tracking into the right gluteal region was made, and incision and drainage were done. Fine-needle aspiration cytology from the cecal growth revealed adenocarcinoma. Unfortunately, the patient was not willing to undergo definitive treatment. This case is being reported for its rarity and as an uncommon etiology for a common condition.Key words: Gluteal abscess, Carcinoma cecum, Inferior lumbar triangleGluteal abscess is a common condition and most commonly follows intramuscular injections with contaminated needles.1,2 Carcinoma cecum is known to present with pericolic abscess due to microperforations and may rupture intraperitoneally. Retroperitoneal abscess is rare with carcinoma cecum. Gluteal abscess secondary to perforated carcinoma cecum with pericolic abscess is extremely uncommon. Here we report a case of carcinoma cecum presenting as right gluteal abscess for its rarity and diagnostic challenge and to review its pathogenesis.  相似文献   
9.
The term gossypiboma is used to describe a mass of cotton matrix left behind in a body cavity intraoperatively. The most common site reported is the abdominal cavity. It can present with abscess, intestinal obstruction, malabsorption, gastrointestinal hemorrhage, and fistulas. A 37-year-old woman presented with pain in the right hypochondrium for 2 months following open cholecystectomy. As she did not improve with proton pump inhibitors, an esophagogastroduodenoscopy (EGD) was done, which showed a possible gauze piece stained with bile in the first part of the duodenum. Contrast-enhanced computed tomography (CECT) of the abdomen revealed an abnormal fistulous communication of the first part of duodenum with proximal transverse colon, with a hypodense, mottled lesion within the lumen of the proximal transverse colon plugging the fistula, suggestive of a gossypiboma. Excision of the coloduodenal fistula, primary duodenal repair, and feeding jejunostomy was done. The patient recovered well and is now tolerating normal diet. Coloduodenal fistula is usually caused by Crohn''s disease, malignancy, right-sided diverticulitis, and gall stone disease. Isolated coloduodenal fistula due to gossypiboma has not been reported in the literature so far to the best of our knowledge. We report this case of coloduodenal fistula secondary to gossypiboma for its rarity and diagnostic challenge.Key words: Surgical sponges, Intestinal fistula, Multidetector computed tomographyThe first report of a coloduodenal fistula was by Haldane in 1862, and it was malignant from the hepatic flexure.1 Coloduodenal fistula is caused by Crohn''s disease, malignancy, right-sided diverticulitis, and gall stone disease, but isolated coloduodenal fistula due to gossypiboma has not been reported in the literature to the best of our knowledge. Gossypiboma is known to present as intra-abdominal abscess, intestinal obstruction, and fistulization, but coloduodenal fistula has not been reported as a mode of presentation. We report this case of coloduodenal fistula secondary to gossypiboma for its rarity and diagnostic challenge.  相似文献   
10.
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