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   148篇
  免费   9篇
  157篇
  2023年   1篇
  2021年   1篇
  2020年   3篇
  2019年   3篇
  2018年   1篇
  2017年   5篇
  2016年   4篇
  2015年   4篇
  2014年   5篇
  2013年   13篇
  2012年   6篇
  2011年   3篇
  2010年   8篇
  2009年   6篇
  2008年   8篇
  2007年   3篇
  2006年   7篇
  2005年   3篇
  2004年   6篇
  2003年   4篇
  2002年   3篇
  2001年   3篇
  2000年   3篇
  1999年   2篇
  1998年   9篇
  1997年   2篇
  1996年   1篇
  1995年   2篇
  1994年   1篇
  1992年   2篇
  1991年   3篇
  1990年   1篇
  1989年   5篇
  1985年   3篇
  1984年   3篇
  1983年   1篇
  1982年   1篇
  1981年   3篇
  1980年   1篇
  1979年   3篇
  1978年   4篇
  1977年   1篇
  1976年   1篇
  1974年   1篇
  1968年   2篇
  1951年   1篇
  1939年   1篇
排序方式: 共有157条查询结果,搜索用时 0 毫秒
71.
The clinical records of 563 patients undergoing either abdominoplasty alone or in combination with other major surgical procedures were reviewed in order to determine the relative safety of combined procedures. One-hundred-seventeen patients had abdominoplasty alone; 230 had abdominoplasty with either an intraabdominal or major pelvic procedure with or without an additional major aesthetic procedure; 216 had abdominoplasty with one or more major aesthetic procedures (without intraabdominal or pelvic procedures). The rates of occurrence of major complications, including death, pulmonary embolus, and infection, among the three groups were examined. Also examined were morbidity factors such as length of hospital stay and the need for blood transfusion. In this study, the only risk factor identified in predicting major morbidity, specifically the occurrence of pulmonary embolus, was obesity, not the complexity of the surgical procedure.  相似文献   
72.

Background  

High-throughput experiments, such as with DNA microarrays, typically result in hundreds of genes potentially relevant to the process under study, rendering the interpretation of these experiments problematic. Here, we propose and evaluate an approach to find functional associations between large numbers of genes and other biomedical concepts from free-text literature. For each gene, a profile of related concepts is constructed that summarizes the context in which the gene is mentioned in literature. We assign a weight to each concept in the profile based on a likelihood ratio measure. Gene concept profiles can then be clustered to find related genes and other concepts.  相似文献   
73.

Background

Children with neuromuscular disorders with a progressive muscle weakness such as Duchenne Muscular Dystrophy and Spinal Muscular Atrophy frequently develop a progressive scoliosis. A severe scoliosis compromises respiratory function and makes sitting more difficult. Spinal surgery is considered the primary treatment option for correcting severe scoliosis in neuromuscular disorders. Surgery in this population requires a multidisciplinary approach, careful planning, dedicated surgical procedures, and specialized after care.

Methods

The guideline is based on scientific evidence and expert opinions. A multidisciplinary working group representing experts from all relevant specialties performed the research. A literature search was conducted to collect scientific evidence in answer to specific questions posed by the working group. Literature was classified according to the level of evidence.

Results

For most aspects of the treatment scientific evidence is scarce and only low level cohort studies were found. Nevertheless, a high degree of consensus was reached about the management of patients with scoliosis in neuromuscular disorders. This was translated into a set of recommendations, which are now officially accepted as a general guideline in the Netherlands.

Conclusion

In order to optimize the treatment for scoliosis in neuromuscular disorders a Dutch guideline has been composed. This evidence-based, multidisciplinary guideline addresses conservative treatment, the preoperative, perioperative, and postoperative care of scoliosis in neuromuscular disorders.  相似文献   
74.
Polyploidization frequently precedes tumorigenesis but also occurs during normal development in several tissues. Hepatocyte ploidy is controlled by the PIDDosome during development and regeneration. This multi‐protein complex is activated by supernumerary centrosomes to induce p53 and restrict proliferation of polyploid cells, otherwise prone for chromosomal instability. PIDDosome deficiency in the liver results in drastically increased polyploidy. To investigate PIDDosome‐induced p53‐activation in the pathogenesis of liver cancer, we chemically induced hepatocellular carcinoma (HCC) in mice. Strikingly, PIDDosome deficiency reduced tumor number and burden, despite the inability to activate p53 in polyploid cells. Liver tumors arise primarily from cells with low ploidy, indicating an intrinsic pro‐tumorigenic effect of PIDDosome‐mediated ploidy restriction. These data suggest that hyperpolyploidization caused by PIDDosome deficiency protects from HCC. Moreover, high tumor cell density, as a surrogate marker of low ploidy, predicts poor survival of HCC patients receiving liver transplantation. Together, we show that the PIDDosome is a potential therapeutic target to manipulate hepatocyte polyploidization for HCC prevention and that tumor cell density may serve as a novel prognostic marker for recurrence‐free survival in HCC patients.  相似文献   
75.
Anni 2.0 is an online tool () to aid the biomedical researcher with a broad range of information needs. Anni provides an ontology-based interface to MEDLINE and retrieves documents and associations for several classes of biomedical concepts, including genes, drugs and diseases, with established text-mining technology. In this article we illustrate Anni's usability by applying the tool to two use cases: interpretation of a set of differentially expressed genes, and literature-based knowledge discovery.  相似文献   
76.
This article assesses the positive biopsy rate and core sampling pattern in patients undergoing needle biopsy of the prostate in the United States at a national reference laboratory (NRL) and anatomic pathology laboratories integrated into urology group practices, and analyzes the relationship between positive biopsy rates and the number of specimen vials per biopsy. For the years 2005 to 2011 we collected pathology data from an NRL, including number of urologists and urology practices referring samples, total specimen vials submitted for prostate biopsies, and final pathologic diagnosis for each case. The diagnoses were categorized as benign, malignant, prostatic intraepithelial neoplasia, or atypical small acinar proliferation. Over the same period, similar data were gathered from urology practices with in-house laboratories performing global pathology services (urology practice laboratories; UPLs) as identified by a survey of members of the Large Urology Group Practice Association. For each year studied, positive biopsy rate and number of specimen vials per biopsy were calculated in aggregate and separately for each site of service. From 2005 to 2011, 437,937 biopsies were submitted in > 4.23 million vials (9.4 specimen vials/biopsy); overall positive biopsy rate was 40.3%-this was identical at both the NRL and UPL (P = .97). Nationally, the number of specimen vials per biopsy increased sharply from a mean of 8.8 during 2005 to 2008 to a mean of 10.3 from 2009 to 2011 (difference, 1.5 specimen vials/biopsy; P = .03). For the most recent 3-year period (2009–2011), the difference of 0.6 specimen vials per biopsy between the NRL (10.0) and UPL (10.6) was not significant (P = 0.08). Positive biopsy rate correlated strongly (P < .01) with number of specimen vials per biopsy. The positive prostate biopsy rate is 40.3% and is identical across sites of service. Although there was a national trend toward increased specimen vials per biopsy from 2005 to 2011, from 2009 to 2011 there was no significant difference in specimen vials per biopsy across sites of service. Increased cancer detection rate correlated significantly with increased number of specimens examined. Segregation of prostate biopsy cores into 10 to 12 unique specimen vials has been widely adopted by urologists across sites of service.Key Words: Prostate cancer, Prostate biopsy, Utilization trends, National reference laboratory, Urology practice laboratoriesPublished data over the past decade suggesting that prostate cancer detection rates are enhanced with additional sampling of the prostate have resulted in modifications to the traditional 6-core (sextant) biopsy regimen1,2 such that recent clinical guidelines recommend that extended biopsy schemes with 10 to 12 specimens be obtained.35 There are also data that suggest that segregation of prostate biopsy tissue specimens into individual vials improves specimen handling, enhances tissue representation, and improves diagnostic accuracy.68 Furthermore, focal prostate cancer treatment strategies gaining recent popularity are dependent on more precise tumor mapping, requiring even greater tissue sampling.9Over approximately the same time frame, there has been an increase in consolidation of medical practices into larger single- or multispecialty group practices. By incorporating efficiencies of scale, these groups afford physicians the opportunity to retain the characteristics of traditional medical practices while improving their ability to adapt to changing health care circumstances.10 These groups often integrate additional capabilities beyond professional services, including anatomic and clinical pathology, diagnostic imaging, and radiation therapy. Proponents of these arrangements argue that integration of medical services facilitates the development of coordinated clinical pathways, improves communication between specialists, offers better quality control of ancillary services, and enhances data collection—all of which can improve patient care and lead to lower costs.1113 Specifically with regard to anatomic pathology, recent data suggest that certain specimen handling errors are significantly lower (P = .018) at urology practices with integrated in-house pathology laboratories (urology practice laboratories [UPLs]) than at other sites of service14; however, some contend that group practice integration creates conflicts of interest and self-referral issues, which ultimately leads to increased utilization of services.1519 A recent study based on analysis of Medicare claims data purported that positive prostate biopsy rates and the number of samples submitted per biopsy are significantly different across sites of service20; however, this study has been criticized as both methodologically flawed and scientifically inaccurate.21 Also problematic is the fact that calculation of prostate cancer incidence has been identified as particularly susceptible to error when determined by analysis of outpatient claims data alone.22We sought to determine positive biopsy rates and utilization trends in the United States via direct analysis of laboratory records from both a national reference laboratory (NRL) and UPLs, and to determine if there was a correlation between positive biopsy rates and number of specimen vials submitted.  相似文献   
77.
This study aims to establish the antiproliferative effects of PK11195, a peripheral benzodiazepine receptor antagonist (PBR) in rat mammary tumor cells. Breast tumors were induced by administration of a carcinogen, dimethylbenz[a]anthracene to 50-day-old female rats maintained on a standard AIN-76A diet with casein as the protein source. The tumors were developed approximately after 120 days. The tumors were of grade I (20%), grade II (60%), and grade III (20%). The tumors were isolated and cultured in DMEM/F12 media with supplements. We characterized the properties of the isolated cells and study the effect of PK11195 on those cells. We were successful in growing breast tumor cells up to 30 passages for cellular characterization. These cells had high reactivity with Ki-67 and PCNA antibodies suggesting high proliferation rate. These cells were highly invasive as evident by matrigel invading ability. Furthermore, these cells acquired a positive response for CD-31 and VEGF antibodies suggesting angiogenic potential, and also possessed migrating ability/motility as evident by the wound healing properties. These cells expressed elevated levels of PBR, a cancer promoting gene. The proliferation, invasion and migration appear to decrease when treated with PK11195, a PBR antagonist. Furthermore, PK11195 treatment caused an increase in apoptosis as evident by increase in the levels of annexin V. However, the inhibition of cell proliferation by PK11195 was counteracted by Ro5-4864, a PBR agonist. Thus, PBR antagonist may be a potential therapeutic agent for the control of aggressiveness of breast cancer.  相似文献   
78.
79.
80.

Background

Sustainable DNA resources and reliable high-throughput genotyping methods are required for large-scale, long-term genetic association studies. In the genetic dissection of common disease it is now recognised that thousands of samples and hundreds of thousands of markers, mostly single nucleotide polymorphisms (SNPs), will have to be analysed. In order to achieve these aims, both an ability to boost quantities of archived DNA and to genotype at low costs are highly desirable. We have investigated Φ29 polymerase Multiple Displacement Amplification (MDA)-generated DNA product (MDA product), in combination with highly multiplexed BeadArray? genotyping technology. As part of a large-scale BeadArray genotyping experiment we made a direct comparison of genotyping data generated from MDA product with that from genomic DNA (gDNA) templates.

Results

Eighty-six MDA product and the corresponding 86 gDNA samples were genotyped at 345 SNPs and a concordance rate of 98.8% was achieved. The BeadArray sample exclusion rate, blind to sample type, was 10.5% for MDA product compared to 5.8% for gDNA.

Conclusions

We conclude that the BeadArray technology successfully produces high quality genotyping data from MDA product. The combination of these technologies improves the feasibility and efficiency of mapping common disease susceptibility genes despite limited stocks of gDNA samples.  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