全文获取类型
收费全文 | 996篇 |
免费 | 88篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 81篇 |
妇产科学 | 23篇 |
基础医学 | 155篇 |
口腔科学 | 27篇 |
临床医学 | 113篇 |
内科学 | 156篇 |
皮肤病学 | 7篇 |
神经病学 | 130篇 |
特种医学 | 30篇 |
外科学 | 74篇 |
综合类 | 1篇 |
预防医学 | 112篇 |
眼科学 | 10篇 |
药学 | 69篇 |
中国医学 | 1篇 |
肿瘤学 | 83篇 |
出版年
2024年 | 3篇 |
2023年 | 10篇 |
2022年 | 18篇 |
2021年 | 24篇 |
2020年 | 20篇 |
2019年 | 23篇 |
2018年 | 43篇 |
2017年 | 23篇 |
2016年 | 30篇 |
2015年 | 34篇 |
2014年 | 42篇 |
2013年 | 63篇 |
2012年 | 71篇 |
2011年 | 85篇 |
2010年 | 41篇 |
2009年 | 34篇 |
2008年 | 79篇 |
2007年 | 65篇 |
2006年 | 67篇 |
2005年 | 68篇 |
2004年 | 62篇 |
2003年 | 52篇 |
2002年 | 54篇 |
2001年 | 11篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 9篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 5篇 |
1978年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有1085条查询结果,搜索用时 15 毫秒
51.
52.
Kysti Nuorva Ylermi Soini Dia Kamel Raimo Pllnen Risto Bloigu Kirsi Vhkangas Paavo Pkk 《International journal of cancer. Journal international du cancer》1995,64(6):424-429
Accumulation of the tumour suppressor gene p53 product due to a gene mutation is frequently seen in human carcinomas, including lung carcinoma. Another indirect mechanism involving p53 in malignant growth relates to the E6 protein of the human papillomavirus (HPV), which is able to bind and degrade wild-type p53 protein, thus eliminating its tumour suppressor activities. Bronchiolo-alveolar carcinoma (BAC) is a rare type of lung carcinoma. The aim of our study was to examine the occurrence of p53 accumulation and the presence of HPV DNA in BAC. Sections of 22 BACs were immunohistochemically stained using a p53 antibody, CM-1. The presence of HPV DNA in BACs was verified by in situ hybridisation for HPV types 6, 11, 16, 18, 31 and 33 and confirmed by PCR. Thirty-six percent of the tumours showed abnormal p53 nuclear accumulation, and HPV DNA, revealed by in situ hybridisation, was found in 36%. Unexpectedly, only 13% of the type 1 BACs were positive for p53, whereas 45% of the type 2 BACs were positive. During a follow-up of 12-176 months, only 10% of the patients with BACs negative for both p53 and HPV died of the disease, compared with 42% of the patients with either p53 or HPV positivity. No inverse relationship between abnormal p53 protein accumulation and the presence of HPV DNA was found. © 1995 Wiley-Liss, Inc. 相似文献
53.
Healing of subcapital femoral osteotomies fixed with self-reinforced poly-L-lactide screws: an experimental long-term study in sheep 总被引:3,自引:0,他引:3
Jukkala-Partio K Laitinen O Vasenius J Partio EK Toivonen T Tervahartiala P Kinnunen J Rokkanen P 《Archives of orthopaedic and trauma surgery》2002,122(6):360-364
Subcapital femoral osteotomies of ten young adult sheep were fixed with two bioabsorbable, self-reinforced, poly- L-lactide (SR-PLLA) lag screws of 4.5 mm in diameter. At 3 weeks radiographs were taken to check the reduction and fixation achieved. After follow-up periods of 12 weeks, 1 year and 3 years with three sheep in each group, and of 7 years and 4 months with one sheep, the sheep were killed, and the healing of the osteotomies, degradation and tissue response of the implants were examined radiographically, histologically and microradiographically. All osteotomies healed with a firm bony union. There was no dislocation or wound infection. Histologically, there was no marked tissue response in the bone tissue. At 12 weeks the implants were grossly intact, at 1 year granulation tissue and new bone formation had started to penetrate into the implant, and at 3 years the implant area was mostly replaced by connective tissue and new bone, but implant material was still seen as little islands surrounded by some lymphocytes. At 7 years and 4 months, the implant material had been degraded and replaced by tight bone. Self-reinforced poly- L-lactide lag screws seem to possess adequate mechanical properties and good biocompatibility for this demanding fixation. 相似文献
54.
Genetic and environmental influences on the tracking of body size from birth to early adulthood 总被引:2,自引:0,他引:2
OBJECTIVE: This study identified genetic and environmental influences on the tracking of body size from birth to 16 to 18.5 years of age. RESEARCH METHODS AND PROCEDURES: Longitudinal information was collected from a nationally representative sample of Finnish twin adolescents (birth cohorts 1975 to 1979) and their parents through questionnaires mailed when the twins were ages 16 and 18.5 years old. The sample included 702 monozygotic, 724 same-sex dizygotic, and 762 opposite-sex dizygotic sets of twins. The measures used were length, weight, ponderal index (kilograms per cubic meters), and gestational age at birth, and height, weight, and body mass index (kilograms per square meters) at 16 to 18.5 years of age. The changes in genetic and environmental influences on body size from birth to early adulthood were analyzed by quantitative genetic modeling. RESULTS: The twins who had a higher weight or ponderal index at birth were taller and heavier in early adulthood, whereas those who were longer at birth were taller, but not heavier, later in life. Adult height was affected more by the birth size than body mass index. In the genetic modeling analyses, the genetic factors accounting for the variation of body size became more apparent with age, and both genetic and environmental influences on stature had a sizable carry-over effect from birth to late adolescence, whereas for relative weight, the influences were more age-specific. DISCUSSION: The genetic and environmental architecture of body size changes from birth to adulthood. Even in monozygotic twins who share their genetic background, the initially larger twin tended to remain larger, demonstrating the long-lasting effects of fetal environment on final body size. 相似文献
55.
In addition to visual loss, methanol intoxication can cause brain damage that is revealed by neuroimaging. We report on a 34-year-old man whose visual acuity deteriorated dramatically during his journey round the world, shortly after an evening with excessive alcohol consumption. Two months after the start of visual disturbances he returned to Finland. At examination, poor visual acuity and glaucomatously cupped pale optic discs were detected. The history and clinical findings indicated possible methanol intoxication, which was supported by both CT and MRI. The MRI findings are discussed in the light of the MRI appearance of the pallidum nuclei among patients of different age groups. 相似文献
56.
The fact that our brain is continuously shaped by the environment and experience presents many challenges. It was noted several decades ago that exposure of a laboratory rat to a complex environment alters its brain and improves problem solving in complex tasks. Rats that are housed in an enriched environment can better compensate for brain lesion-induced deficits and resist neurodegeneration. In this article, the role of an enriched environment on brain plasticity following experimentally-induced lesions is discussed. 相似文献
57.
Utilization of health care services has been found to differ between psychiatric disorders. However, the pattern of health care contacts among suicide attempters with mental disorders is not known. This study systematically investigated the pattern of health care contacts among suicide attempters with schizophrenia spectrum versus mood disorders with or without comorbid substance use disorders both before and after attempted suicide. All consecutive medically treated suicide attempters in Helsinki from January 15, 1997, to January 14, 1998, were identified (n = 1,198). Data were gathered on all their health care contacts within the 12 months before and after the index attempt. Whereas the clear majority of all suicide attempters with schizophrenia spectrum or mood disorders had a treatment contact during the 30 days following the attempt, half of those with pure substance use disorders were without any contact with health care. Comorbid substance use made treatment less likely after attempted suicide among both psychiatric disorder groups; those with schizophrenia spectrum and comorbid substance use disorders were seven times more often left without aftercare recommendation than those without substance use comorbidity. Comorbid substance use disorders among suicide attempters with schizophrenia spectrum disorders decrease the likelihood of active aftercare, despite high suicide risk. 相似文献
58.
The cellular components present in chlamydial preparations may contribute to the course of the experimental infection. NIH/S mice were inoculated and reinoculated intranasally with Chlamydia pneumoniae or a cellular preparation. The mock inoculation induced only mild histological changes in the lungs, which possibly induced partial protection against subsequent C. pneumoniae infection and, when given as reinoculation, possibly reactivated the culture-negative infection as culture-positive. In addition, serum antibodies against mouse heat shock protein 60 (Hsp60) were found in a few mice. In conclusion, the main immunopathogenic factors in a C. pneumoniae mouse model are chlamydial components. However, a cellular preparation may participate in an inflammatory reaction. Autoimmunity against Hsp60 may also play a role in the pathogenesis of C. pneumoniae infection. 相似文献
59.
Erika Isolauri Arthur C Ouwehand Kirsi Laitinen 《Acta paediatrica (Oslo, Norway : 1992)》2005,94(S449):110-114
The increased prevalence of atopic diseases, i.e. atopic eczema, allergic rhinitis and asthma, has been described as the epidemic of the 21st century in Western societies. New approaches in the fight against allergic diseases are clearly called for, the target being the persistence of the allergic responder pattern beyond infancy. The advantage afforded by elimination diets lies in the silencing of specific allergic inflammation induced by an offending food. Novel nutritional approaches, beyond the treatment of food allergies, have recently attracted research interest subsequent to the identification of the immunomodulatory potential of specific dietary compounds. Dietary lipids as immunomodulators may prevent allergic sensitization by down-regulating inflammatory response whilst protecting the epithelial barrier. Probiotic bacteria have been shown to reinforce the different lines of gut defence: immune exclusion, immune elimination and immune regulation. On this basis, the strategy against allergic disease proposed here is based on the administration of tolerogenic gut-processed peptide fragments of a specific protein, in addition to the use of specific dietary compounds such as fatty acids and antioxidants, and introducing a microbial stimulus for the immature immune system by means of cultures of beneficial live micro-organisms characteristic of the healthy infant gut microbiota. 相似文献
60.
Randomized, placebo-controlled trial of clodronate in patients with primary operable breast cancer. 总被引:17,自引:0,他引:17
Trevor Powles Sandy Paterson John A Kanis Eugene McCloskey Sue Ashley Alwynne Tidy Kirsi Rosenqvist Ian Smith Lars Ottestad Sandra Legault Marjo Pajunen Auli Nevantaus Esa M?nnist? Anne Suovuori Sari Atula Jaakko Nevalainen Liisa Pylkk?nen 《Journal of clinical oncology》2002,20(15):3219-3224
PURPOSE: The development of bone metastases depends on tumor-induced osteoclastic resorption of bone, which may be inhibited by the antiosteolytic bisphosphonate clodronate. Given to patients with primary breast cancer, clodronate might reduce the subsequent incidence of bone metastases. PATIENTS AND METHODS: This double-blind, multicenter trial accrued 1,069 assessable patients with operable breast cancer between 1989 and 1995. All patients received surgery, radiotherapy, chemotherapy, and tamoxifen as required. Patients were randomized to receive oral clodronate 1,600 mg/d or a placebo for 2 years starting within 6 months of primary treatment. The primary end point was relapse in bone, analyzed on an intent-to-treat basis, during the medication period and during the total follow-up period (median follow-up, 2,007 days). Secondary end points were relapse in other sites, mortality, and toxicity. RESULTS: During the total follow-up period, there was a nonsignificant reduction in occurrence of bone metastases (clodronate, n = 63; placebo, n = 80; hazards ratio [HR], 0.77; 95% confidence interval [CI], 0.56 to 1.08; P =.127). During the medication period there was a significant reduction in the occurrence of bone metastases (clodronate, n = 12; placebo, n = 28; HR, 0.44; 95% CI, 0.22 to 0.86; P =.016). The occurrence of nonosseous metastases was similar (clodronate, n = 112; placebo, n = 128; P =.257), but there was a significant reduction in mortality (clodronate, n = 98; placebo, n = 129; P =.047) during the total follow-up period. CONCLUSION: Clodronate, given to patients with primary operable breast cancer, may reduce the occurrence of bone metastases, although this reduction was only significant during this medication period. There was a significant reduction in mortality. 相似文献