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   758篇
  免费   44篇
  国内免费   2篇
耳鼻咽喉   12篇
儿科学   14篇
妇产科学   18篇
基础医学   95篇
口腔科学   14篇
临床医学   26篇
内科学   256篇
皮肤病学   14篇
神经病学   58篇
特种医学   14篇
外科学   53篇
综合类   12篇
预防医学   51篇
眼科学   9篇
药学   26篇
中国医学   1篇
肿瘤学   131篇
  2023年   4篇
  2022年   5篇
  2021年   16篇
  2020年   12篇
  2019年   17篇
  2018年   21篇
  2017年   15篇
  2016年   16篇
  2015年   18篇
  2014年   30篇
  2013年   44篇
  2012年   44篇
  2011年   60篇
  2010年   24篇
  2009年   25篇
  2008年   23篇
  2007年   47篇
  2006年   26篇
  2005年   30篇
  2004年   28篇
  2003年   27篇
  2002年   27篇
  2001年   22篇
  2000年   22篇
  1999年   13篇
  1998年   9篇
  1997年   5篇
  1996年   5篇
  1995年   5篇
  1994年   7篇
  1992年   17篇
  1991年   11篇
  1990年   10篇
  1989年   16篇
  1988年   11篇
  1987年   5篇
  1986年   8篇
  1985年   11篇
  1984年   5篇
  1982年   4篇
  1981年   5篇
  1980年   4篇
  1979年   9篇
  1976年   5篇
  1975年   3篇
  1973年   6篇
  1970年   3篇
  1969年   3篇
  1968年   4篇
  1967年   3篇
排序方式: 共有804条查询结果,搜索用时 15 毫秒
81.
The highest mortality due to cancer worldwide for both genders corresponds to lung cancer (1,179,000 deaths). In Mexico, the crude mortality rate due to lung cancer was of 5.01 per 10(5) inhabitants in 1979. The most important risk factor is smoking. The present study was aimed at analyzing the mortality due to lung cancer in Mexico, assessing data from each of the states constituting the Mexican Republic during the 1998-2004 period. Data were obtained from the National Institute of Statistics, Geography and Informatics (INEGI, for its initials in Spanish) corresponding to deaths due to lung cancer (1998-2004). We estimated the mean annual mortality rate (MAMR) for each of the 32 states of Mexico. We used the "World Population Standard". The MAMR was standardized according to age (ARS) direct method, and the standard error was determined by Poisson's approximation at a 95% confidence interval. To know the excess risk due to mortality, we calculated the standardized mortality ratios (SMRs) of ARS for each federal state, using the national rate as reference. In this period, 397,400 deaths due to malignant neoplasms were recorded, corresponding 45,578 (11.5%) to lung cancer; for men, 31,025 (68.1%) with MAMR of 8.9 and the respective ARS of 13.2 both x10(5) inhabitants. For women, results were 4553 (31.9%) deaths with MAMR of 4.1 and ARS of 5.4 both x10(5) inhabitants. The highest mortality rates due to lung cancer in both genders were observed in the north of Mexico, whereas for women this was observed in the central states. Although smoking is the main risk for lung cancer, there are other factors such as environmental pollution or exposure to toxicants that could be associated to this cancer. The years potentially lost due to lung cancer were 258,550 for men and 133,315 for women, with a total of 391,865 according to histopathology registry neoplasm malignant RHNM (1985-1995). Studies focused on the characterization and measurement of polluting agents would be a good start to determine the level of participation of air pollution in the development of lung cancer.  相似文献   
82.
We studied 490 women aged 35 to 55 years randomly selected from the urban population of León, México. The mean age for the onset of menopause, calculated with a probit regression was 48.5 years. The median of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) increased with the rate of menopause women, but the 10th percentile for both hormones did not increase above 15 IU/L in older groups. Meanwhile, prolactin did not change. In menopause women FSH correlated positively with cigarette smoking, and negatively with body mass index. Luteinizing hormone had negative correlation with the number of pregnancies. Most symptoms studied were not associated with menopause or gonadotropins levels, except hot flushes, and the empty nest syndrome. It was concluded that during menopause, FSH increases with the smoking habit, and decreases with overweight.  相似文献   
83.
Minimally invasive heart surgery encompasses a variety of techniques, each with its own objective (minimal incisions, absence of cardiopulmonary bypass and cost reduction). Postoperative care after such procedures are simpler, with early extubation and shortened hospital stays. A period of close observation in a postoperative intensive care recovery ward is still required.  相似文献   
84.
85.
Hydrochlorothiazide-induced pulmonary edema is an unusual but life-threatening adverse reaction. It causes hypoxemia, hypotension, tachycardia, fever, and occasionally electrocardiographic and echocardiographic abnormalities. The mechanism of production is, probably, idiosyncratic. Received: 26 May 1997 Accepted: 13 January 1998  相似文献   
86.
Controversy exists regarding whether gastrointestinal (GI) issues play a role in the symptomatology of autism spectrum disorder (ASD). While some studies have found GI problems to be more prevalent in individuals with ASD, others have reported no such difference. Studies looking at the relationship between GI issues and ASD symptom severity have also had mixed results. The current study examined 112 participants between the age of 17 to 37 months. Participants comprised four groups of 28 children: an ASD and no GI issues group, an ASD with GI problems group, an atypical development and no GI issues group, and an atypical development with GI issues group. The results of the current study suggest that although the prevalence of GI symptoms was higher in participants with ASD than those without, this difference was not significant. The study also found that GI issues were not related to ASD symptom severity or developmental functioning.  相似文献   
87.
The conventional treatment of myelofibrosis involves a wait-and-see approach for asymptomatic patients, oral chemotherapy for the hyperproliferative forms of the disease, androgens or erythropoietin for the anaemia, and splenectomy in selected patients. Low-dose thalidomide plus prednisone is a well-tolerated therapy for the anaemia and the thrombocytopenia of myelofibrosis, whereas imatinib has shown little efficacy. Allogeneic stem cell transplantation (allo-SCT) is the only curative therapy for myelofibrosis. Its standard modality has an associated mortality of about 30% and can be applied to younger patients with high-risk disease or resistant to conventional treatment. Reduced-intensity conditioning allo-SCT involves a low mortality and is a promising therapy for patients aged 45-70 years old with the above characteristics. Autologous SCT is a palliative therapy for patients resistant to conventional treatment who lack a suitable donor. The next candidates for the treatment of myelofibrosis are the thalidomide derivatives, the proteasome inhibitors, and vascular endothelial growth factor neutralizing antibodies.  相似文献   
88.
BACKGROUND AND OBJECTIVE: Although there are indications that the profile of chronic myeloid leukemia (CML) at presentation has changed in recent years, information is scarce. The objective of the present study was to ascertain whether the initial features of CML have changed over time, as well as the possible impact on survival. DESIGN AND METHODS: The initial features of 167 patients diagnosed with chronic phase Ph-positive CML from 1972 to 1985 were compared with those of 174 such patients diagnosed at the same institution from 1985 to 1998. The survival of the two groups was also compared. RESULTS: CML patients diagnosed since 1985 were significantly older at presentation (mean age 47+17 vs 43+17 years, p = 0.04), were more often asymptomatic (36% vs 19%, p = 0.0003), less often had constitutional symptoms (30% vs 45%, p = 0.004), less frequently had splenomegaly (59% vs 75%, p = 0.0008) and hepatomegaly (35% vs 49%, p = 0.01), had less marked leukocytosis (mean WBC count 139+/-124x10(9)/L vs 179+/-132x10(9)/L, p = 0.007), with 30% of them showing an initial WBC count below 50x10(9)/L (vs 19%, p = 0.02), and showed less marrow blast cell infiltration (p = 0.0003). No significant differences were observed in the distribution by Sokal's risk groups. Median survival of patients diagnosed since 1985 was 5. 33 years (95% CI: 4.3-6.36), vs 4.06 years (95% CI: 3.28-4.84) for patients diagnosed before (p = 0.07). Finally, patients asymptomatic at diagnosis had a longer survival (median survival 5.7 years, 95% CI: 4.5-6.9, vs 4.1 years, 95% CI: 3.4-4.7, p = 0.03). INTERPRETATION AND CONCLUSIONS: A substantial proportion of CML patients are currently diagnosed early in the course of the disease. The effect of earlier diagnosis on survival prolongation in such patients should be taken into account.  相似文献   
89.
Pantothenate kinase‐associated neurodegeneration (PKAN) is an autosomal recessive disorder characterized by iron accumulation in the brain, because of mutations in the PANK2 gene. Phenotypic and genotypic characteristics of 11 patients from five Mexican families with PKAN disease are reported. Sequencing of PANK2 confirmed the diagnosis. The 11 patients had dysarthria associated with dystonia and Parkinsonism in six. Brain magnetic resonance imaging (MRI) showed the ‘eye‐of‐the‐tiger’ sign in all patients. Three different mutations were identified, a novel one (p.A469P) and two (p.G219V and p.N404I) very rare. Homozygous sibs for the p.G219V mutation had a severe disease progression with early death. Dystonia predominated in the p.A469P/p.N404I compound heterozygous patients. Homozygous for p.N404I showed Parkinsonism, tics and personality and speech disorders. Early and late disease onset and variable expression was present in carriers of the different identified mutations. The ‘eye‐of‐the‐tiger’ is an excellent neuroimaging hallmark to predict PANK2 mutations. We detected a ‘cluster’ of patients harboring the p.N404I mutation, strongly suggesting a founder effect for this mutation. This is the first familial clinical‐genetic PKAN disease study accomplished in Mexico.  相似文献   
90.
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