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   823篇
  免费   112篇
耳鼻咽喉   19篇
儿科学   11篇
妇产科学   3篇
基础医学   32篇
口腔科学   6篇
临床医学   39篇
内科学   282篇
皮肤病学   12篇
神经病学   44篇
特种医学   21篇
外国民族医学   1篇
外科学   156篇
综合类   11篇
一般理论   1篇
预防医学   21篇
眼科学   30篇
药学   32篇
肿瘤学   214篇
  2023年   16篇
  2022年   11篇
  2021年   42篇
  2020年   33篇
  2019年   40篇
  2018年   52篇
  2017年   38篇
  2016年   30篇
  2015年   36篇
  2014年   39篇
  2013年   48篇
  2012年   79篇
  2011年   82篇
  2010年   33篇
  2009年   22篇
  2008年   35篇
  2007年   42篇
  2006年   34篇
  2005年   34篇
  2004年   29篇
  2003年   22篇
  2002年   25篇
  2001年   18篇
  2000年   16篇
  1999年   11篇
  1998年   3篇
  1996年   2篇
  1995年   1篇
  1993年   2篇
  1992年   4篇
  1991年   5篇
  1990年   2篇
  1989年   2篇
  1988年   4篇
  1987年   7篇
  1986年   4篇
  1985年   5篇
  1984年   4篇
  1983年   1篇
  1982年   1篇
  1979年   4篇
  1977年   1篇
  1974年   2篇
  1973年   4篇
  1972年   3篇
  1969年   1篇
  1968年   1篇
  1966年   1篇
  1965年   2篇
  1963年   1篇
排序方式: 共有935条查询结果,搜索用时 15 毫秒
1.
Progress in the understanding of the biology and therapy of acute myeloid leukemia (AML) is occurring rapidly. Since 2017, nine agents have been approved for various indications in AML. These included several targeted therapies like venetoclax, FLT3 inhibitors, IDH inhibitors, and others. The management of AML is complicated, highlighting the need for expertise in order to deliver optimal therapy and achieve optimal outcomes. The multiple subentities in AML require very different therapies. In this review, we summarize the important pathophysiologies driving AML, review current therapies in standard practice, and address present and future research directions.Subject terms: Prognosis, Health services  相似文献   
2.
A quantitative competitive PCR (QC-PCR) assay for Epstein-Barr virus (EBV) has been developed to provide accurate measurement of EBV genome load in pediatric transplant recipients at risk for developing posttransplant lymphoproliferative disorder (PTLD). The assay quantifies between 8 and 5,000 copies of the EBV genome in 10(5) lymphocytes after a 30-cycle amplification reaction. For 14 pediatric patients diagnosed with PTLD, the median EBV genome load was 4,000, and 13 of the 14 patients had values of >500 copies per 10(5) lymphocytes. Only 3 of 12 control transplant recipients not diagnosed with PTLD had detectable viral genome loads (median value, 40). This median was calculated by using the highest value obtained by PCR testing on each of these patients posttransplantation. PCR values of >500 copies per 10(5) lymphocytes appear to correlate with a diagnosis of PTLD. By a modified protocol, the EBV genome copy number in latently infected adults was estimated to be <0.1 copy per 10(5) lymphocytes.  相似文献   
3.
The Eastern Mediterranean Region (EMR) is experiencing a nutrition transition, characterized by the emergence of overnutrition and micro-nutrient deficiencies. No previous study has comparatively examined nutrient intake in adults across countries in the EMR. This review examined the adequacy of nutrients in adults living in the EMR. Moreover, it analyzed the food balance sheets (FBS) for 1961–2018 to identify the trajectory of energy supply from macro-nutrients in the EMR. A systematic search was conducted from January 2012 to September 2020. Only observational studies were retained with a random sampling design. An assessment of the methodological quality was conducted. Levels of nutrient daily intake and their adequacy compared to the daily reference intake of the Institute of Medicine were reported across the region. No studies were identified for half of the region’s countries. Although nutrient energy intake was satisfactory overall, fat and carbohydrate intake were high. Intake of vitamin D, calcium, potassium, zinc, and magnesium were below that recommended. The analysis of the FBS data allowed for the identification of four linear patterns of trajectories, with countries in the EMR best fitting the ‘high-energy-supply from carbohydrate’ group. This systematic review warrants multi-sectorial commitment to optimize nutrient intake.  相似文献   
4.
The optimal approach to upper tract TCC remains to be redefined. A routine nephroureterectomy for every filling defect in the upper urinary system, even in the case of a normal contralateral kidney, constitutes an unnecessary mutilation in more than two thirds of the cases. Nephroureterectomy does not reduce the need for a long-term cystoscopic follow-up because of the high rate of bladder tumor recurrence that may happen years later after nephroureterectomy. Relying solely on radiography and cytology, lacking sensitivity and specificity, to recommend a nephroureterectomy is against the principles of oncologic surgery, especially now that preoperative histologic proof is easy to obtain endoscopically without compromising cancer control. Ureteroscopy, rigid and flexible, provides a complete assessment of the upper urinary system. Biopsy specimens taken with ureteroscopy may be sufficient for grading but less adequate for staging of the tumor. The authors reserve ureteroscopy for ureteral tumors and small (< 1.5 cm) single tumors of the renal pelvis. They approach large or multiple tumors of the renal pelvis percutaneously, in which a full histologic assessment is possible along with a complete resection of the tumor. The decision on the therapeutic approach is made only after the final pathologic report is reviewed. Grade I and grade II superficial disease (Ta, T1) can be treated endoscopically with minimal morbidity and with an efficiency comparable with the standard more invasive nephroureterectomy (Table 5). The indications for endourologic treatment in these cases can be extended safely beyond a solitary kidney or a high surgical risk to include any healthy individual with a normal contralateral kidney who is willing to commit to a rigorous lifelong follow-up. Patients with grade II T1 lesions require a more vigilant follow-up. For grade III Ta disease, more caution should be exercised in selecting these patients for elective endourologic management. When criteria of good prognosis are found, such as absence of carcinoma in situ, presence of diploidy, low p53 expression and a single-tumor, endoscopic management can be offered [table: see text] with a closer follow-up and resorting always to immediate nephroureterectomy at the first evidence of upstaging. Because of the high incidence of recurrence and progression, elective endourologic management for grade III T1 tumors is not recommended. Endoscopic conservative surgery still can be offered in the cases of a solitary kidney or chronic renal insufficiency or for poor surgical candidates. Patients with localized stages (T2, T3) TCC should be offered immediate nephroureterectomy. The authors do not expect adequate endoscopic extirpation with muscle invasive tumors. Although the tissue removed may include deep layers, deep resection is precluded by the thin renal pelvic wall and the associated risk for perforation. Patients with more extensive disease (T3, T4) have a bad prognosis regardless of the form of therapy. Achieving local control percutaneously while preserving as many nephrons as possible for the future chemotherapy can be a reasonable option.  相似文献   
5.
PURPOSE: Cloretazine (VNP40101M) is a novel sulfonylhydrazine alkylating agent with significant antileukemia activity. A phase I study of cloretazine combined with cytarabine (1-beta-d-arabinofuranosylcytosine, ara-C) was conducted in patients with refractory disease. DESIGN: Ara-C was given i.v. at a fixed dose of 1.5 gm/m(2)/d by continuous infusion for 4 days (patients ages <65 years at time of diagnosis) or 3 days (patients ages > or =65 years). Cloretazine was given i.v. over 15 to 60 minutes on day 2 at a starting dose of 200 mg/m(2), with escalation in 100 mg/m(2) increments in cohorts of three to six patients until a maximum tolerated dose was established. The DNA repair enzyme O(6)-alkylguanine DNA alkyltransferase (AGT) was measured at baseline. RESULTS: Forty patients, including 32 with acute myeloid leukemia, received 47 courses of treatment. Complete responses were seen at cloretazine dose levels of > or =400 mg/m(2) in 10 of 37 (27%) evaluable patients, and in this patient subset, AGT activity was significantly lower in patients that responded to treatment than in patients who did not (P < or = 0.027). Dose-limiting toxicities (gastrointestinal and myelosuppression) were seen with 500 and 600 mg/m(2) of cloretazine combined with the 4-day ara-C schedule but not seen with the 3-day schedule. CONCLUSION: The recommended cloretazine dose schedule for future studies is 600 mg/m(2) combined with 1.5 gm/m(2)/d continuous infusion of ara-C for 3 days. The cloretazine and ara-C regimen has significant antileukemic activity. AGT activity may be a predictor of response to cloretazine.  相似文献   
6.
7.
8.
Historically treated with surgery, current practice recommends anal carcinoma to be treated with a combination of chemotherapy and radiation. This review will examine the anatomy, modes of disease spread and recurrence, and evaluate the existing evidence for treatment options for these tumors. An in-depth examination of specific radiation therapy (RT) techniques—such as conventional 3D-conformal RT and intensity-modulated RT—will be discussed along with modern dose constraints. RT field arrangement, patient setup, and recommended gross and clinical target volume (CTV) contours will be considered. Areas in need of further investigation, such as the role in treatment for positron emission tomography (PET) will be explored.  相似文献   
9.

Background

Transplantation of hearts retrieved from donation after circulatory death (DCD) donors is an evolving clinical practice.

Objectives

The purpose of this study is to provide an update on the authors’ Australian clinical program and discuss lessons learned since performing the world’s first series of distantly procured DCD heart transplants.

Methods

The authors report their experience of 23 DCD heart transplants from 45 DCD donor referrals since 2014. Donor details were collected using electronic donor records (Donate Life, Australia) and all recipient details were collected from clinical notes and electronic databases at St. Vincent’s Hospital.

Results

Hearts were retrieved from 33 of 45 DCD donors. A total of 12 donors did not progress to circulatory arrest within the pre-specified timeframe. Eight hearts failed to meet viability criteria during normothermic machine perfusion, and 2 hearts were declined due to machine malfunction. A total of 23 hearts were transplanted between July 2014 and April 2018. All recipients had successful implantation, with mechanical circulatory support utilized in 9 cases. One case requiring extracorporeal membrane oxygenation subsequently died on the sixth post-operative day, representing a mortality of 4.4% over 4 years with a total follow-up period of 15,500 days for the entire cohort. All surviving recipients had normal cardiac function on echocardiogram and no evidence of acute rejection on discharge. All surviving patients remain in New York Heart Association functional class I with normal biventricular function.

Conclusions

DCD heart transplant outcomes are excellent. Despite a higher requirement for mechanical circulatory support for delayed graft function, primarily in recipients with ventricular assist device support, overall survival and rejection episodes are comparable to outcomes from contemporary brain-dead donors.  相似文献   
10.
The progress with intensive chemotherapy and supportive care measures has improved survival in patients with newly diagnosed acute myeloid leukemia (AML). Given the recent development of effective low intensity therapies, an optimal decision on the therapy intensity may improve survival through the avoidance of early mortality. We reviewed the outcome of 3728 patients with newly diagnosed AML who received intensive chemotherapy between August 1980 and May 2020. Intensive chemotherapy was defined as a cumulative cytarabine dose ≥ 700 mg/m2 during induction therapy. We divided the whole cohort into a training and validation group at a 3:1 ratio. The population was divided into a training (2790 patients) and a validation cohort (938 patients). The median age was 55 years (range, 15-99). Among them, 442 patients (12%) had core-binding factor AML. Binary logistic regression identified older age, worse performance status, hyperbilirubinemia, elevated creatinine, hyperuricemia, cytogenetic abnormalities other than CBF and -Y, and pneumonia as adverse prognostic factors for an early 4-week mortality. This risk classification for early mortality was verified in the validation cohort of patients. In the validation cohort of more recently treated patients from 2000 to 2017, the 4-week mortality rates with intensive chemotherapy were 2%, 14%, and 50% in the low-, high-, and very high-risk group, respectively. The mortality rates with low intensity therapies were 3%, 9%, and 20%, respectively. The risk classification guides treatment intensity by the assessment of age, frailty, organ dysfunction, cytogenetic abnormality, and infection to avoid early mortality.  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