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   5196篇
  免费   327篇
  国内免费   37篇
耳鼻咽喉   82篇
儿科学   132篇
妇产科学   154篇
基础医学   695篇
口腔科学   212篇
临床医学   491篇
内科学   992篇
皮肤病学   185篇
神经病学   214篇
特种医学   153篇
外科学   900篇
综合类   83篇
一般理论   3篇
预防医学   381篇
眼科学   85篇
药学   514篇
中国医学   35篇
肿瘤学   249篇
  2024年   7篇
  2023年   53篇
  2022年   150篇
  2021年   206篇
  2020年   144篇
  2019年   199篇
  2018年   248篇
  2017年   184篇
  2016年   198篇
  2015年   206篇
  2014年   285篇
  2013年   332篇
  2012年   474篇
  2011年   477篇
  2010年   267篇
  2009年   210篇
  2008年   284篇
  2007年   256篇
  2006年   229篇
  2005年   205篇
  2004年   165篇
  2003年   149篇
  2002年   126篇
  2001年   38篇
  2000年   45篇
  1999年   38篇
  1998年   23篇
  1997年   23篇
  1996年   26篇
  1995年   22篇
  1994年   16篇
  1993年   18篇
  1992年   18篇
  1991年   24篇
  1990年   24篇
  1989年   18篇
  1988年   15篇
  1987年   26篇
  1986年   24篇
  1985年   13篇
  1984年   8篇
  1983年   10篇
  1982年   9篇
  1981年   8篇
  1980年   12篇
  1979年   5篇
  1978年   5篇
  1971年   8篇
  1970年   4篇
  1966年   4篇
排序方式: 共有5560条查询结果,搜索用时 0 毫秒
991.

Background

Diaphragmatic paralysis in newborns is related to brachial plexus palsy. It can cause respiratory failure necessitating prolonged mechanical ventilation and subsequent extubation failure.

Case Presentation

We present a two-hour-old male newborn with a birth weight of 4500 grams who had a right-sided brachial plexus palsy and right diaphragmatic paralysis due to shoulder dystocia. He developed respiratory distress due to isolated paralysis of the right hemi diaphragm. The clinical course was progressive, his condition worsening despite oxygen application. Physical examination, chest X-rays and M-mode ultrasonography of the diaphragm confirmed the diagnosis diaphragmatic paralysis. Surgical plication of diaphragm was done earlier than the usual time because of recurrent extubation failure. Diaphragmatic plication led to rapid improvement of pulmonary function and allowed discontinuation of mechanical ventilation in less than 3 days.

Conclusion

Early diaphragmatic plication enhances weaning process and may prevent or minimize the morbidity associated with long-term mechanical ventilation in a neonate with diaphragmatic paralysis.  相似文献   
992.
Chemokines are involved in both the negative and positive regulation of inflammatory processes, angiogenesis and cancer/cancer stem cell proliferation as well as the chemoattraction of tumor cells to metastatic sites. The aim of this study was to measure the mRNA expression levels of three chemokines, CCL2, CCL7 and CX3CL1, in soft tissue sarcomas (STSs) and to assess the correlations between these levels as well as their correlations with clinicopathological data and the disease‐specific survival of STS patients. The mRNA levels of CCL2, CCL7 and CX3CL1 were analyzed in tumor tissues from 126 STS patients using qPCR. Low mRNA expression of CCL2 and CX3CL1 was significantly correlated with a worse prognosis (RR = 1.98; p = 0.019 and RR = 2.10; p = 0.014; multivariate Cox's regression analysis). A combined low expression of CCL2 and CX3CL1 was associated with a significantly increased risk of tumor‐related death as compared to patients with high expression levels of both chemokines (RR = 3.08; p = 0.003). A gender‐specific multivariate analysis revealed that female STS patients with low CX3CL1 mRNA expression had a 3.46‐fold increased risk of death (p = 0.004). Low expression of both CCL2 and CX3CL1 mRNAs resulted in an additive 5.37‐fold increased risk of tumor‐related death (p = 0.003) as compared to those with high expression of both parameters in female patients. In conclusion, this is the first study to show a significant correlation between combined low expression of CCL2 and CX3CL1 and a poor prognosis for STS patients, particularly in female patients.  相似文献   
993.
994.
Hepatoblastoma (HB) is the most common primary liver tumor in children and accounts for two-thirds of all malignant liver neoplasms in the pediatric population. For patients with advanced HB (unresectable or unresponsive to chemotherapy), combined treatment with chemotherapy and liver transplantation is an excellent option. The etiology of HB is mostly obscure because of its extreme rarity although some inherited syndromes and very low birth weight have been associated with it. The prognosis for children with HB has significantly improved in the past three decades thanks to advancements in chemotherapy, surgical resection and postoperative care. In 2002 a surgical staging system called pretreatment extent of disease (PRETEXT) was designed to allow a universal, multidisciplinary approach to patients with HB. Between one-third to two-thirds of patients initially present with unresectable tumors or distant metastases, but up to 85% of these tumors become operable after neoadjuvant chemotherapy. Patients with PRETEXT categories 1, 2, and some 3 are referred for neoadjuvant chemotherapy followed by surgical resection with the goal of complete tumor removal. Classic treatments regimens include a combination of cisplatin, fluorouracil, and vincristine or cisplatin and doxorubicin. Liver transplantation is the only treatment option for unresectable HB. In 2010 the pediatric end-stage liver disease, a pediatric-specific scoring system that determines a patient’s ranking on the liver transplant list, began to award additional “exception” points for patients with HB. We analyzed the Standard Transplant Analysis and Research dataset to assess the impact of changes in exception point criteria for HB on outcomes after liver transplantation at Texas Children’s Hospital in Houston, Texas. We found that patients who were listed for transplantation with current HB exception criteria experienced a shorter waitlist time but survival was similar between the two eras.  相似文献   
995.
996.
997.
998.
Neurophysiological processes underlying auditory memory and attention are impaired in habitually short sleepers. The aim of this study was to use dynamic causal modeling (DCM) to study the mechanisms of these impairments in short sleepers. Eight normal sleepers (total sleep time (TST)=7-8h) and nine habitual short sleepers (TST≤6h) participated. The time in bed was increased from habitual (≤6h) to extended (~8.5h) for one week in the short sleep group. Event related potentials (ERPs) were collected using an auditory novelty task in "IGNORE" and "ATTEND" conditions. Fourteen DCM models were considered using different configurations of connections among the following six areas: left and right primary auditory cortices, superior temporal gyri (STG), and inferior temporal gyri (IFG). After fitting the ERPs to the 14 models (separately for the IGNORE and ATTEND conditions), the best model (across subjects) was chosen using the Bayesian model comparison. For both conditions, the connection from right-STG to right-IFG for normal sleepers was significantly greater than habitual short sleepers. This connection did not differ in habitual short sleepers before and after one week of extended sleep time. This connection for normal sleepers was not significantly greater than the habitual short sleepers after one week of extended sleep. These results show that the deficiency of novelty processing, seen in short sleepers, can be explained by the differences in connectivity of the pathway between frontal and temporal brain areas as compared to the normal sleepers. In addition, one week of extended time in bed was not enough to fully normalize this neuronal pathway between STG and IFG in short sleepers.  相似文献   
999.
1000.
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