全文获取类型
收费全文 | 18486篇 |
免费 | 1311篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 171篇 |
儿科学 | 690篇 |
妇产科学 | 698篇 |
基础医学 | 2264篇 |
口腔科学 | 307篇 |
临床医学 | 2963篇 |
内科学 | 3276篇 |
皮肤病学 | 352篇 |
神经病学 | 1490篇 |
特种医学 | 339篇 |
外科学 | 1819篇 |
综合类 | 336篇 |
一般理论 | 19篇 |
预防医学 | 2304篇 |
眼科学 | 379篇 |
药学 | 1093篇 |
中国医学 | 22篇 |
肿瘤学 | 1297篇 |
出版年
2023年 | 118篇 |
2022年 | 200篇 |
2021年 | 447篇 |
2020年 | 330篇 |
2019年 | 443篇 |
2018年 | 461篇 |
2017年 | 346篇 |
2016年 | 394篇 |
2015年 | 449篇 |
2014年 | 597篇 |
2013年 | 894篇 |
2012年 | 1394篇 |
2011年 | 1484篇 |
2010年 | 773篇 |
2009年 | 638篇 |
2008年 | 1250篇 |
2007年 | 1290篇 |
2006年 | 1202篇 |
2005年 | 1222篇 |
2004年 | 1148篇 |
2003年 | 1108篇 |
2002年 | 897篇 |
2001年 | 155篇 |
2000年 | 156篇 |
1999年 | 148篇 |
1998年 | 194篇 |
1997年 | 183篇 |
1996年 | 138篇 |
1995年 | 107篇 |
1994年 | 109篇 |
1993年 | 104篇 |
1992年 | 117篇 |
1991年 | 89篇 |
1990年 | 89篇 |
1989年 | 88篇 |
1988年 | 66篇 |
1987年 | 62篇 |
1986年 | 73篇 |
1985年 | 67篇 |
1984年 | 98篇 |
1983年 | 66篇 |
1982年 | 69篇 |
1981年 | 53篇 |
1980年 | 61篇 |
1979年 | 50篇 |
1978年 | 43篇 |
1977年 | 29篇 |
1976年 | 31篇 |
1975年 | 30篇 |
1974年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Antibiotic-resistant infections in primary care are symptomatic for longer and increase workload: outcomes for patients with E.coli UTIs 下载免费PDF全文
Christopher C Butler Sharon Hillier Zoë Roberts Frank Dunstan Anthony Howard Stephen Palmer 《The British journal of general practice》2006,56(530):686-692
BACKGROUND: Antimicrobial resistance is considered to be one of the major threats to public health. However, the practical implications for patients and workload in primary care are largely unknown. AIM: To determine outcomes for patients managed in primary care with an antibiotic resistant compared to an antibiotic sensitive Escherichia coli (E. coli) urinary tract infection (UTI). DESIGN: Nested case control study with prospective measurement of outcomes. SETTING: Ten general practices in South Wales. METHOD: Patients consulting with symptoms suggestive of UTI identified through systematic sampling, and with a laboratory proven E. coli infection, were followed up by interview 1 month after their consultations and by searching of their medical records. RESULTS: Nine hundred and thirty-two patients were interviewed and had their medical records reviewed. The risk of patients reporting 'feeling poorly', 'frequency or pain on urinating' and being 'out of action' for more than 5 days after consulting was significantly increased for patients with resistant compared to sensitive infections. After adjusting for risk factors, there was an increased risk of 'frequency or pain on urinating' and 'being out of action' for those infected with a resistant E. coli. The median number of maximum reported days with at least one symptom was 12 days for patients with E. coli infections resistant to trimethoprim, 7 days for infections resistant to ampicillin, 7 days for infections resistant to any antibiotic, and 5 days for infections sensitive to all tested antibiotics. Even if treated with an appropriate antibiotic, infections caused by a resistant strain were symptomatic for longer. For those infected with an organism resistant to at least one antibiotic, the odds ratio (OR) for re-visiting their GP within the next 30 days for the UTI was 1.47 (95% confidence interval [CI] = 1.10 to 1.95). The OR was 1.49 (95% CI = 1.11 to 2.00) for ampicillin resistance and 2.48 (95% CI = 1.70 to 3.59) for trimethoprim resistance. CONCLUSIONS: Resistant E. coli UTIs are symptomatic for longer and cause increased work load in general practice. 相似文献
83.
Chaim Brautbar Marian Moscovitz Tatyana Livshits Salim Haim Shoshana Hacham-Zadeh Haim A. Cohen Rafi Sharon David Nelken Tirza Cohen 《Tissue antigens》1980,16(3):238-243
Pemphigus vulgaris (PV) is relatively common in Jews. Three HLA antigens were significantly more frequent in 39 Israeli Jewish PV patients than in controls: A26 – 59% vs 20%; Bw38 – 61% vs 20%; and DRw4 – 90% vs 38%. The joint occurrence of A26–Bw38–DRw4 was observed in 46% of PV patients and in 10% of controls. Similar results were recently reported for Jews in the Los Angeles area. Yet, when our patient sample was grouped into Ashkenazi and non-Ashkenazi Jews, it was evident that each of the three antigens had a higher frequency both in Ashkenazi patients and controls as compared to non-Ashkenazim. The relative risk for DRw4 in Ashkenazim was 33.8 as compared to 14.4 in the total sample of Israeli PV patients. The phenotype A26–Bw38–DRw4 was present in 57% of Ashkenazi patients and in 13% of controls. Ashkenazi Jews have the highest prevalence of PV, and HLA associations were strongest with Ashkenazi PV patients. These associations were with three antigens, all of high frequency in that group. 相似文献
84.
The current study examined how individuals deal with genital herpes, a recurrent, incurable disease with a great psychological impact. An assessment battery composed of cognitive and problem-focused coping, attribution, and social support mechanisms was employed. These coping mechanisms were correlated with measures of psychological adjustment: self-esteem, depression, sexual adjustment, and amount upset by herpes. Subjects were 152 people with herpes recruited from self-help groups and people from the community who volunteered to participate in the study. Results supported several hypotheses derived from previous research on coping with life stressors. Cognitive coping mechanisms, especially negative thoughts, along with wishful thinking and characterological self-blame, were significant predictors of poor psychological adjustment. Social support was correlated with better psychological adjustment. In addition, the repeated use of disease management strategies was found to correlate with poor psychological adjustment. Further research in the area of coping with chronic illness is suggested. 相似文献
85.
Ghazi Kayali Sharon F. Setterquist Ana W. Capuano Kendall P. Myers James S. Gill Gregory C. Gray 《Journal of clinical virology》2008,43(1):73-78
BACKGROUND: The hemagglutination inhibition (HI) assay is a frequently used method to screen human sera for antibodies against influenza A viruses. Because HI has relatively poor sensitivity in detecting antibodies against avian influenza A strains, a more complicated microneutralization (MN) assay is often preferred. Recent research suggests that the sensitivity of the HI assay can be improved by switching from the traditionally used turkey, guinea pig, human, or chicken RBCs to horse RBCs. OBJECTIVE: To evaluate the performance of the horse RBC HI when screening for human antibodies against avian influenza types H3, H4, H5, H6, H7, H9, H11, and H12. STUDY DESIGN: We evaluated the reproducibility of horse RBC HI and its agreement with MN results using sera from people exposed or not exposed to wild and domestic birds. RESULTS: The horse RBC HI assay had high reliability (90%-100%) and good agreement with MN assay results (52%-100%). CONCLUSION: The horse RBC HI assay is reliable, less expensive, less complex, and faster than the MN assay. While MN will likely remain the gold standard serologic assay for avian viruses, the horse RBC HI assay may be very useful as a screening assay in large-scale epidemiologic studies. 相似文献
86.
Isolated central nervous system (CNS) vasculitis is rare medium- sized vessel disease limited to intracerebral vessels. The two most common symptoms of this inflammatory disorder observed at entry to a hospital are headaches and mild memory deficits. Further progression of this disease may result in focal neurologic alterations and seizures. Currently, the most common laboratory abnormality noted is an elevated erythrocyte sedimentation rate. The complement (C) system is known to play a role in many inflammatory processes; it may also be involved in CNS vasculitis. In this longitudinal study of patients with CNS vasculitis, we detected C activation by highly sensitive and specific assays that are capable of identifying breakdown products formed after C activation: C3a des arg, C4a des arg, C5a des arg, C1rC1s-C1-inhibitor complex, and terminal C complex (C5b-9). We present two cases of documented CNS vasculitis in which serial measurements of these C-activation products correlate with disease activity. Our results indicate that a temporal association exists between C activation and the clinical presentation of CNS vasculitis. We conclude that physicians should monitor C-activation by-products in plasma when they attempt to follow the clinical course of CNS vasculitis. 相似文献
87.
Yongyot Monsereenusorn Sharon S. Cassidy J. Richard Coast 《Naunyn-Schmiedeberg's archives of pharmacology》1985,331(2-3):166-174
Summary To study reflex responses caused by stimulation of pulmonary C-fibers and lung inflation, we used a preparation in which the left pulmonary artery and veins were ligated and cannulated and the right and left bronchi were cannulated separately in open-chest dogs. These experiments were performed to establish whether the reflex responses to injections of 150 g of capsaicin through the left pulmonary circulation and inflations of this left lung to 30 cm H2O would be diminished if repeated frequently. Furthermore, the sensitivities of the reflex responses evoked by these capsaicin injections and by left lung inflations (LLI) to blockade with lidocaine or with morphine were studied. Both repeated injections of capsaicin into the left pulmonary circulation and repeated inflations of the left lung for up to 100 min produced a persistent triad of reflex responses: bradycardia, hypotension, and cessation of diaphragmatic contractions. Lidocaine injections (50 mg) into the pulmonary artery of the vascularly isolated lung abolished all reflex responses to subsequent injections of capsaicin, but only attenuated the triad of responses to subsequent left lung inflations by half. Morphine sulfate (60 mg) administered to the pulmonary vascular bed of the isolated lung reduced, but did not eliminate, the triad of reflex responses to subsequent capsaicin injections and lung inflations. The influences of morphine upon capsaicin and lung inflation responses were not abolished by naloxone. These results indicate: (a) the sensory fibers which initiate the triad of pulmonary depressor reflex responses are not desensitized by repeated exposure to capsaicin or by repeated lung inflations; (b) sensory fibers other than pulmonary C-fiber receptors contribute to the lung inflation reflex; and (c) morphine and lidocaine interfere with the excitation of pulmonary C-fibers. 相似文献
88.
Ken Wei Tan Sharon Esi Duoduwa Quaye Joel Ruihan Koo Jue Tao Lim Alex R. Cook Borame L. Dickens 《Nutrients》2021,13(4)
Globally, many countries are facing an increasing burden of chronic disease due to ageing populations, of which cardiovascular disease forms a large proportion. Excess dietary sodium contributes to cardiovascular disease risk and requires intervention at a population level. This study aimed to quantify the impact of several salt reduction initiatives on population health over a 30-year horizon using GeoDEMOS, a population model from Singapore. Four interventions were modelled in four demographic groups in 2020 for a total of 16 intervention scenarios. The effect of 0.5, 2.0, and 4.0 g/day reductions in daily salt consumption, along with adherence to the World Health Organization guidelines of a maximum of 5.0 g of salt each day, was modelled in the entire population, including the overweight and obese, the elderly, and diabetics. In each scenario, the number of averted incident cases of acute myocardial infarction and stroke, along with the disability-adjusted life years up to 2050, was monitored. We found 4.0 g/day reductions in salt consumption were the most effective when implemented across the entire population, resulting in 24,000 averted incident cases of cardiovascular disease and 215,000 disability-adjusted life years over 30 years. This is a large figure when compared with the 29,200 projected annual incident cases of cardiovascular disease in 2050. When targeted at specific high-risk demographic groups, the largest effects were observed in the overweight and obese, with the same intervention yielding 10,500 averted incident cases of cardiovascular disease and 91,500 disability-adjusted life years. Quantifying the benefits of salt reduction initiatives revealed a significant impact when administered across the entire population or the overweight and obese. Health promotion efforts directed toward sustainably reducing salt consumption will help to lower the chronic disease burden on the healthcare system in years to come. 相似文献
89.
Vanessa S. Sakalidis Alethea Rea Sharon L. Perrella Jacki McEachran Grace Collis Jennifer Miraudo Stuart A. Prosser Lisa Y. Gibson Desiree Silva Donna T. Geddes 《Nutrients》2021,13(6)
During the COVID-19 pandemic, breastfeeding women have experienced restricted access to support, placing them at increased risk of mental health concerns and limited breastfeeding assistance. This study investigated the effect of the pandemic on feeding choices and maternal wellbeing amongst breastfeeding mothers living in Australian and New Zealand. We conducted a cross-sectional online survey that examined feeding methods, maternal mental wellbeing, worries, challenges, and positive experiences during the pandemic. Most women were exclusively breastfeeding (82%). Partial breastfeeding was associated with perceived low milk supply and longer pregnancy duration during the pandemic. Reduced mental health and wellbeing was associated with lower levels of family functioning, increased perceived stress, and perinatal anxiety. Longer pregnancy duration during the pandemic was associated with lower mental health wellbeing scores, while higher perceived stress scores were reported for regions with higher COVID-19 infection rates and women with perceived low milk supply. Women reported that the pandemic resulted in less pressure and more time for family bonding, while worries about the pandemic, family health, and parenting challenges were also cited. Mental health concerns of breastfeeding women appear to be exacerbated by COVID-19, highlighting a critical need for access to mental health and broader family support during the pandemic. 相似文献
90.
Anderson Madison D. Merkin Sharon Stein Everson-Rose Susan A. Widome Rachel Seeman Teresa Magnani Jared W. Rodriguez Carlos J. Lutsey Pamela L. 《Journal of immigrant and minority health / Center for Minority Public Health》2021,23(4):668-668
Journal of Immigrant and Minority Health - The original version of this article unfortunately contained a typo in co-author name. 相似文献