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   4809篇
  免费   233篇
  国内免费   37篇
耳鼻咽喉   90篇
儿科学   145篇
妇产科学   242篇
基础医学   404篇
口腔科学   183篇
临床医学   425篇
内科学   1067篇
皮肤病学   157篇
神经病学   253篇
特种医学   182篇
外科学   832篇
综合类   71篇
一般理论   1篇
预防医学   188篇
眼科学   202篇
药学   277篇
中国医学   7篇
肿瘤学   353篇
  2024年   5篇
  2023年   47篇
  2022年   94篇
  2021年   126篇
  2020年   87篇
  2019年   117篇
  2018年   162篇
  2017年   104篇
  2016年   156篇
  2015年   178篇
  2014年   209篇
  2013年   266篇
  2012年   369篇
  2011年   352篇
  2010年   158篇
  2009年   151篇
  2008年   326篇
  2007年   363篇
  2006年   343篇
  2005年   340篇
  2004年   281篇
  2003年   207篇
  2002年   175篇
  2001年   93篇
  2000年   74篇
  1999年   68篇
  1998年   16篇
  1997年   16篇
  1996年   19篇
  1995年   16篇
  1993年   6篇
  1992年   23篇
  1991年   25篇
  1990年   21篇
  1989年   15篇
  1988年   11篇
  1987年   6篇
  1986年   5篇
  1984年   3篇
  1983年   3篇
  1979年   7篇
  1978年   5篇
  1977年   2篇
  1974年   4篇
  1972年   2篇
  1971年   2篇
  1968年   2篇
  1967年   2篇
  1966年   3篇
  1934年   2篇
排序方式: 共有5079条查询结果,搜索用时 15 毫秒
51.
AIM: To evaluate the intraocular pressure (IOP) measurements by Icare rebound tonometer over a contact lens in comparison with Goldmann applanation tonometry (GAT).METHODS: Fifty patients using contact lens were included in this study. One of the eyes of the patients was selected randomly and their IOP were measured by rebound tonometer with and without contact lens (RTCL, RT respectively) and by GAT, as well as their central corneal thickness (CCT) by optical pachymeter. The results of both methods were compared by correlation analysis, general linear method repeated measure and Bland-Altman analysis.RESULTS: Mean IOP values measured by RTCL, RT and GAT were 15.68±3.7, 14.50±3.4 and 14.16±2.8 (P<0.001), respectively. Mean IOP by RTCL was significantly higher than the measurements implemented by RT and GAT (P<0.001), while there was no difference between the measurements by GAT and RT (P=0.629). There was a good level of positive correlation between GAT and RTCL as well as RT (r=0.786 P<0.001, r=0.833 P<0.001, respectively). We have observed that CCT increase did not show any correlation with the differences of the measurements between RTCL and RT (P=0.329), RTCL and GAT (P=0.07) as well as RT and GAT (P=0.189) in linear regression model.CONCLUSION: The average of the measurements over contact lens by rebound tonometer was found to be higher than what was measured by GAT. Although this difference is statistically significant, it may be clinically negligible in the normal population.  相似文献   
52.
Pachydermoperiostosis (PDP), also known as primary hypertrophic osteoarthropathy, is a rare genetic disorder characterized by pachyderma and periostosis. Acromegaly is a condition caused by excessive secretion of growth hormone (GH) leading to elevated insulin-like growth factor 1 levels, and is characterised by somatic overgrowth and physical disfigurement, notably affecting hands and feet. We present two cases referred with an initial diagnosis of acromegaly that were ultimately diagnosed as PDP. Case 1: A 17 year-old boy presented with enlargement in both feet and hands, finger clubbing, swelling in knee joints, knee pain, coarsening of facial skin lines and forehead skin, and excessive sweating which increased gradually over five years. There were prominent skin folds on the forehead, face, and eyelids. Also, there was an enlargement in both hands and clubbing of the fingers. There was marked swelling in the knee joints and ankles. Genetic analysis revealed a novel homozygous variant NM_005630: c.31C>T (p.Q11*) in the SLCO2A1 gene. Case 2: A 16 year-old boy presented with coarsening of forehead skin and scalp, excessive sweating, and pain in the elbow and knee over three years. Skin folds were prominent on the forehead and scalp. Genetic analysis revealed a homozygous variant NM_005630.2:c.86delG (p.G29Afs*48) in the SLCO2A1 gene. Such clinical presentation contemporaneous with normal GH level and prominent radiological abnormalities prompted the diagnosis of PDP. In conclusion, PDP is a very rare osteoarthrodermopathic disorder with clinical and radiographic presentation that may mimic acromegaly. In the evaluation of patients with acromegaloid appearance, PDP should be considered as a differential diagnosis.  相似文献   
53.
Objective:Diabetic ketoacidosis (DKA) - a potentially preventable complication of type 1 diabetes mellitus (T1D) - is one of the most common chronic childhood diseases, and is associated with a significant risk of morbidity and mortality. The limited use of healthcare services due to fear of Coronavirus disease-2019 (COVID-19) transmission during the pandemic has raised concerns of delays in T1D diagnosis, among other diseases. This study investigated the presenting characteristics of newly diagnosed T1D patients assessed in a single clinic during the pandemic and compares them with the pre-pandemic period.Methods:For the purpose of this study, the first year of the pandemic is referred to as the “pandemic period”, and the previous three years as the “pre-pandemic period”. Patient files were reviewed retrospectively, the demographic and clinical characteristics and laboratory findings of the patients were recorded, and the findings from both periods were compared.Results:The number of patients diagnosed with T1D in the pandemic period was 44, and in the pre-pandemic period 39 in 2017, 22 in 2018 and 18 in 2019. The two groups had similar age, sex, pubertal stage and anthropometric characteristics (p>0.05). Regarding the type of presentation, the frequency of DKA was significantly higher in the pandemic period (68.2%) than in the pre-pandemic period (40.5%) (p=0.006), and this difference was also observed in the comparison by years (p=0.016). The duration of symptoms (16.5±10.7 vs. 23.5±17.6 days) and the length of hospital stay (10±3.9 vs. 15.2±5.5 days) were significantly shorter in the pandemic period (p=0.032, and p<0.001, respectively). There was no difference in the frequency of severe DKA between the pandemic (46.7%) and the pre-pandemic (37.5%) periods (p>0.05). However, pH (7.17±0.16 vs. 7.26±0.14) and bicarbonate (12.8±6.3 vs. 16.6±6.3) levels were significantly lower in the pandemic period (p<0.005). Additional signs of infection on admission were less frequent in the pandemic period (9.1%) than in the pre-pandemic period (27.8%) (p=0.027). The groups did not differ in terms of hemoglobin A1c, C-peptide, concurrent thyroid autoantibodies and tissue transglutaminase antibodies (p>0.05). The rate of anti-glutamic acid decarboxylase positivity was higher in the pandemic period (73.8% vs. 39.2%) (p=0.001) while the frequency of other diabetes-associated autoantibodies was similar between the groups (p>0.05). The polymerase chain reaction test for COVID-19 was negative in six patients with a history of contact.Conclusion:There was an increased frequency and severity of DKA in children with newly diagnosed T1D in the pandemic period, and these findings justify concerns related to the diagnosis of other diseases during the pandemic. Studies to raise awareness of diabetes symptoms during the pandemic should be continued regularly to reach all segments of society. Our study provides an additional contribution to the literature in its coverage of the one-year period during the pandemic and its comparison with the previous three years.  相似文献   
54.
COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS CoV-2), is estimated to have caused over 6.5 million deaths worldwide. The emergence of fast-evolving SARS-CoV-2 variants of concern alongside increased transmissibility and/or virulence, as well as immune and vaccine escape capabilities, highlight the urgent need for more effective antivirals to combat the disease in the long run along with regularly updated vaccine boosters. One of the early risk factors identified during the COVID-19 pandemic was that men are more likely to become infected by the virus, more likely to develop severe disease and exhibit a higher likelihood of hospitalisation and mortality rates compared to women. An association exists between SARS-CoV-2 infectiveness and disease severity with sex steroid hormones and, in particular, androgens. Several studies underlined the importance of the androgen-mediated regulation of the host protease TMPRSS2 and the cell entry protein ACE2, as well as the key role of these factors in the entry of the virus into target cells. In this context, modulating androgen signalling is a promising strategy to block viral infection, and antiandrogens could be used as a preventative measure at the pre- or early hospitalisation stage of COVID-19 disease. Different antiandrogens, including commercial drugs used to treat metastatic castration-sensitive prostate cancer and other conditions, have been tested as antivirals with varying success. In this review, we summarise the most recent updates concerning the use of antiandrogens as prophylactic and therapeutic options for COVID-19.  相似文献   
55.
Suffering comes in many ways for patients confronting cancer. One of these is an unspecifiable fear about death, which is an existential issue. The aim of this study was to investigate the relationship between death anxiety and its correlates in cancer patients. Seventy cancer patients were assessed using SCID-I, Templer's Death Anxiety Scale, the Hospital Anxiety (A) and Depression (D) Scale, the Distress Thermometer, the Visual Analogue Scale for pain (VAS), the Global Assessment of Functioning, and Glock and Stark's Dimensions of Religious Commitment scales, and these assessments were compared between cancer patients with and without death anxiety. Multiple regression analysis was conducted after correlation analysis between death anxiety and sociodemographic and clinical variables. Axis I psychiatric diagnosis, pain scores, and negative believes about what will happen after death were found to be higher in patients having death anxiety than patients not having death anxiety. Also life expectancy was perceived as shortened in patients with death anxiety. Death anxiety was associated with anxiety, depressive symptoms, and beliefs about what will happen after death. In conclusion, death anxiety could not be regarded as a natural consequence of having cancer; it is associated with the unresolved psychological and physical distress.  相似文献   
56.
Methods:We retrospectively analyzed the patients who underwent RALRP for localized prostate cancer by a single surgeon in our clinic from January 1, 2009–February 1, 2016. Continence was defined as no leakage or use of a safety pad for minimal leakage. The main outcome measure was continence at postoperative week 1 and months 1, 6, and 12.Results:Between 2009 and 2016, 239 patients underwent RALRP for localized prostate disease. Seventy-four patients underwent a standard approach (group 1), 88 had posterior reconstruction (group 2), and 77 had posterior reconstruction with total anatomic restoration (group 3). After 1 week, 24.3% of the patients in group 1 (18/74), 31.8% in group 2 (28/88), and 45.8% in group 3 (33/72) were continent (P = .02). One month after the surgery, continence rates for groups 1, 2, and 3 were 56.7, 67, and 75%, respectively (0.065). After 6 and 12 months, continence rates for groups 1, 2, and 3 were 72.9 and 87.8%, 81.8 and 89.7%, and 84.7 and 91.6%, respectively (P = .178 and .7484).Conclusion:Anatomic restoration improves continence rates in the early period after RALRP. Even though other parameters were higher in the total restoration group, immediate continence (at 1 week) was significantly better.  相似文献   
57.
58.
PURPOSEWe aimed to show the effects of long-term screening on clinical, pathologic, and survival outcomes in patients with screen-detected breast cancer and compare these findings with breast cancer patients registered in the National Breast Cancer Registry Data (NBCRD).METHODSWomen aged 40–69 years, living in Bahcesehir county, Istanbul, Turkey, were screened every 2 years using bilateral mammography. The Bahcesehir National Breast Cancer Registry Data (BMSP) data were collected during a 10-year screening period (five rounds of screening). BMSP data were compared with the NBCRD regarding age, cancer stage, types of surgery, tumor size, lymph node status, molecular subtypes, and survival rates.RESULTSDuring the 10-year screening period, 8758 women were screened with 22621 mammograms. Breast cancer was detected in 130 patients; 51 (39.2%) were aged 40–49 years. The comparison of breast cancer patients in the two programs revealed that BMSP patients had earlier stages, higher breast-conserving surgery rates, smaller tumor size, more frequent negative axillary nodal status, lower histologic grade, and higher ductal carcinoma in situ rates than NBCRD patients (p = 0.001, for all).CONCLUSIONThese results indicate the feasibility of successful population-based screening in middle-income countries.

Breast cancer is the most frequent cancer and cause of cancer-related deaths among Turkish women, as well as globally (15). Although the incidence of breast cancer increases every year, mortality rates are decreasing in developed countries because of nationwide screening programs and modern treatment options (5, 6). An invited mammography screening program for women aged between 40 and 69 years revealed a 60% reduction in cancer-related 10-year mortality in a landmark study (7). A systematic review of Myers et al. (8) showed that breast cancer screening reduced mortality by 20% in average-risk women of all age groups. However, this review did not evaluate the differences between annual and biannual mammographic screening.In 2004, the Cancer Control Department of Turkey recommended biannual mammographic screening for women aged 50–69 years, based on European Guidelines. The population of Turkey is relatively young, and almost half of all breast cancer patients in Turkey are younger than 50 years. According to and National Breast Cancer Registry Data (NBCRD) reports, the starting age for mammography screening was set as 40 years. The Bahcesehir Mammographic Screening Program (BMSP) was the first organized population-based 10-year (2009–2019) mammography screening program in Turkey, a middle-income country.Turkish Federation of Breast Diseases Societies started a voluntary data registry program that was provided by breast surgeons working in secondary or tertiary hospitals. This program aimed to collect detailed information of breast cancer patients and to pool comprehensive country-specific breast cancer data. This registry, namely the NBCRD, was the first specified database on breast cancer in the country and was started in 2005, before the BMSP (9). Data from 36 centers were collected for 10 years. However, the cancer registry is a standard database containing general information as defined by the International Agency for Research on Cancer standards.The aim of this study was to show the feasibility of a population-based breast cancer screening program in an emerging, middle-income country, Turkey. The objective of our study was to evaluate the effectiveness of a population-based breast cancer screening program by comparing it with NBCRD data.  相似文献   
59.
60.
Cancer is a major worldwide health problem and one of the leading causes of death either in developed or developing countries. Plant extracts and derivatives have always been used for various disease treatments and many anticancer agents issued from plants and vegetables are clinically recognized and used all over the world. Lycium europaeum (Solanaceae) also called “wolfberry” was known since ancient times in the Mediterranean area as a medicinal plant and used in several traditional remedies. The Lycium species capacity of reducing the incidence of cancer and also of halting or reserving the growth of cancer was reported by traditional healers. In this study, the antiproliferative capacity, protective properties, and antioxidant activity of the hydro-alcoholic fruit extract of Lycium europaeum were investigated. Results showed that Lycium extract exhibits the ability to reduce cancer cell viability, inhibits proliferation, and induces apoptosis in A549 human lung cancer cells and PC12 rat adrenal medulla cancer cells, in a concentration- and time-dependent manner. Cytotoxic effect on normal rat cerebellum granule cells was assessed to be nonsignificant. Results also showed that Lycium fruit extract protected lipids, proteins, and DNA against oxidative stress damages induced by H2O2 via scavenging reactive oxygen species.  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