全文获取类型
收费全文 | 145877篇 |
免费 | 10615篇 |
国内免费 | 641篇 |
专业分类
耳鼻咽喉 | 1824篇 |
儿科学 | 3754篇 |
妇产科学 | 2857篇 |
基础医学 | 18638篇 |
口腔科学 | 3062篇 |
临床医学 | 14386篇 |
内科学 | 29847篇 |
皮肤病学 | 1895篇 |
神经病学 | 13093篇 |
特种医学 | 5672篇 |
外科学 | 22993篇 |
综合类 | 2242篇 |
现状与发展 | 1篇 |
一般理论 | 179篇 |
预防医学 | 13511篇 |
眼科学 | 3048篇 |
药学 | 10480篇 |
2篇 | |
中国医学 | 192篇 |
肿瘤学 | 9457篇 |
出版年
2023年 | 708篇 |
2022年 | 1120篇 |
2021年 | 2721篇 |
2020年 | 1566篇 |
2019年 | 2545篇 |
2018年 | 3085篇 |
2017年 | 2273篇 |
2016年 | 2397篇 |
2015年 | 2888篇 |
2014年 | 4284篇 |
2013年 | 6413篇 |
2012年 | 9364篇 |
2011年 | 9957篇 |
2010年 | 5517篇 |
2009年 | 5015篇 |
2008年 | 8824篇 |
2007年 | 9404篇 |
2006年 | 8961篇 |
2005年 | 9117篇 |
2004年 | 8742篇 |
2003年 | 8250篇 |
2002年 | 8047篇 |
2001年 | 1636篇 |
2000年 | 1434篇 |
1999年 | 1722篇 |
1998年 | 1741篇 |
1997年 | 1419篇 |
1996年 | 1356篇 |
1995年 | 1310篇 |
1994年 | 1119篇 |
1993年 | 1084篇 |
1992年 | 1049篇 |
1991年 | 1090篇 |
1990年 | 1014篇 |
1989年 | 939篇 |
1988年 | 939篇 |
1987年 | 937篇 |
1986年 | 936篇 |
1985年 | 1042篇 |
1984年 | 1061篇 |
1983年 | 972篇 |
1982年 | 1203篇 |
1981年 | 1223篇 |
1980年 | 1030篇 |
1979年 | 742篇 |
1978年 | 767篇 |
1977年 | 664篇 |
1976年 | 588篇 |
1975年 | 541篇 |
1974年 | 572篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
231.
232.
Janice F. Munro Debra Haire-Joshu Edwin B. Fisher H. James Wedner 《The Journal of asthma》1996,33(5):313-325
Low-income minority patients from East St. Louis, Illinois, a depressed midwestern urban city, who had visited acute care settings with asthma symptoms, participated in a focus group. Questions were constructed around the Health Belief Model to characterize participants' experiences in receiving asthma care, their confidence in long-term asthma self-management, barriers they perceived to managing their asthma, and recommendations they would make for improving asthma care in their community. Analysis of comments suggests an appreciable understanding of asthma triggers, limited coping behaviors for asthma symptoms, very limited practice of active asthma management, perception of the health care system as frequently insensitive to their needs or their knowledge of their own care, exchange of well-articulated information regarding how to deal with the system, and an apparent lack of awareness of any potential contribution of patient education or support system. 相似文献
233.
Dr. Caroline S. Zeind Pharm.D. Dr. Kerry O. Cleveland M.D. Dr. Madhavi Menon M.D. Dr. James R. Brown Pharm.D. Dr. David K. Solomon Pharm.D. 《Pharmacotherapy》1996,16(4):547-561
The optimum therapy for cryptococcal meningitis in patients with the acquired immunodeficiency syndrome (AIDS) remains unresolved. Traditional therapy consists of amphotericin B with or without flucytosine. Obstacles exist in administering these agents to patients with AIDS. Mortality rates during initial therapy are relatively high. Given the lack of proved benefit, we do not recommend adding flucytosine to amphotericin B routinely. The search for more efficacious and less toxic agents continues. The oral triazoles, especially fluconazole, have increased the options for treatment of this disease. New strategies and novel approaches in managing cryptococcal meningitis in patients with AIDS continue to be developed. 相似文献
234.
Three saxophone players with upper limb amputations have been successfully rehabilitated to play their musical instruments using skin-conductivity touch control. Each attained a standard of musicianship sufficient to perform the standard repertoire of the instrument in a concert setting. The mechanical and electrical modifications to the saxophone are described, as well as the principles of operation of the skin-conductivity touch control module. The touch control module is commercially available for prosthetists who wish to fit musicians or others with upper extremity amputations who require rapid accurate control of a number of channels of powered prosthetic function. 相似文献
235.
Jan E. Zejda Thomas S. Hurst Ernest M. Barber Charles Rhodes James A. Dosman 《American journal of industrial medicine》1993,23(5):743-750
A cross-sectional survey on respiratory health in swine producers showed that 30% of 301 examined men usually used a dust mask when working inside a barn. They did not differ significantly from dust mask nonusers in respect to respiratory symptoms and lung function. This analysis was undertaken to determine whether the respiratory health of dust mask users was associated with reasons why they had started individual respiratory protection. The subjects were recontacted in order to identify those who started using a mask to deliberately prevent symptoms (42 men) and those who started protection because of pre-existing respiratory symptoms (44 men). Not unexpectedly, betweengroup comparisons of respiratory symptoms and lung function suggest that swine producers who wear dust masks for preventive purposes have better respiratory health than those who wear dust masks because of symptoms or those who do not use individual respiratory protection. The individual reasons for starting dust mask usage should be examined among potential determinants of the outcomes of prospective studies which can then provide more valid assessment of the effect of individual respiratory protection. © 1993 Wiley-Liss, Inc. 相似文献
236.
Human papillomavirus--a study of male sexual partners 总被引:2,自引:0,他引:2
Male sexual partners of a cohort of women with genital-tract abnormalities which were associated with human papillomavirus infection were examined for evidence of infection with human papillomavirus. Of the 214 male partners who were examined, 93.5% had visible genital lesions. Of the 196 lesions that were biopsied, 72.5% showed histological evidence of infection with human papillomavirus, and only 20.4% of subjects with histological evidence of human papillomavirus were aware of a lesion. An unexpectedly high proportion (6.1%) of lesions on which a biopsy was performed, particularly those with flat, red, indurated morphology, also showed histological evidence of penile intraepithelial neoplasia. This was not significantly more common among the partners of the women with cervical intraepithelial neoplasia than it was among the partners of the women with other evidence of genital human papillomavirus infection. Penile intraepithelial neoplasia was significantly (P less than 0.001) more common among subjects with no history of non-genital warts. We conclude that the male partners of women with human papillomavirus-associated lesions are very likely to be infected with human papillomavirus, and thus may act as a significant reservoir for the reinfection of their female partners. As the awareness of human papillomavirus-associated lesions was low among the male partners, colposcopic examination and treatment of their male partners, and/or barrier contraception, may be a necessary part of the management of women who are undergoing treatment for human papillomavirus-associated genital disease. 相似文献
237.
Williams C. A. Jones H. D. Freeman R. W. Wernke M. J. Williams P. L. Roberts S. M. James R. C. 《Regulatory toxicology and pharmacology : RTP》1994,20(3)
Reference doses (RfDs) and reference concentrations (RfCs) developed by the United States Environmental Protection Agency (USEPA) are typically used in the quantitation of risk of potential adverse human health effects from exposure to environmental chemicals. For a large number of chemicals, however, USEPA RfDs and RfCs have not yet been determined. Thus, for risk assessments that involve a large number of chemicals, there is insufficient toxicity information with which to evaluate potential adverse human health effects for all chemicals present at a particular site. Due to this insufficiency, the risk assessor must either (1) ignore potential exposures on the assumption that omitting these exposures does not significantly alter decisions concerning the remediation of the site or (2) undertake a lengthy and costly analysis to generate the necessary RfDs or RfCs. A potential solution to this problem is to develop estimated permissible concentrations (EPCs), values which represent permissible environmental concentrations or related acceptable daily dosages derived from occupational exposure limits. In the present analysis, acceptable daily dosages determined using the EPC method were compared to USEPA RfDs or RfCs which were converted to dosages based on standard exposure assumptions. Based on a comparative analysis of EPCs and USEPA reference values for 103 chemicals, it was found that EPC daily dosages represent a reasonably conservative surrogate value when USEPA or state reference values are unavailable. Given that there are hundreds of chemicals with occupational exposure limits but no state or USEPA reference values, acceptance of the EPC methodology would provide an interim solution for the problem of insufficient toxicity information for a substantial number of environmental chemical contaminants. 相似文献
238.
Dr. Thomas C. Hardin Pharm.D. FCCP Dr. Steven C. Butler M.D. Dr. Sabine Ross M.D. Dr. John H. Wakeford Pharm.D. Dr. James H. Jorgensen Ph.D. 《Pharmacotherapy》1994,14(2):147-152
Study Objectives . To evaluate the pharmacodynamic antibacterial activity of ticarcillin-clavulanic acid (T-C) and ampicillin-sulbactam (A-S) combinations against reference bacterial strains in patients with end-stage renal disease maintained on long-term hemodialysis. Design . Randomized, crossover, controlled study. Setting . National Institutes of Health-funded general clinical research unit in a Veterans Administration Medical Center. Patients . Nine adult men with end-stage renal disease maintained on long-term hemodialysis. Two subjects did not complete the study due to problems of vascular access, and another withdrew for personal reasons. Interventions . On a nondialysis day, each subject was randomly administered either T-C 3.1 g or A-S 3 g as a slow intravenous infusion over 30 minutes. Serial blood samples were collected for measurement of antibiotic serum concentrations and determination of serum bactericidal titers. Following a washout period, the study was repeated with the alternative antibiotic combination. Measurements and Main Results . The mean observed apparent β-half-life of clavulanic acid was substantially shorter than that for the other three drugs. The bactericidal activity of both A-S and T-C against non-β-lactamase-producing (Nβ-LP) strains of S. aureus and E. coli was consistently high, as indicated by geometric mean SBTs of at least 1:5 at 24 hours. Against β-lactamase-producing (β-LP) S. aureus, the geometric mean SBTs for A-S were at least 1:25 throughout the study period, while the geometric mean SBTs for T-C decreased over 24 hours from 1:29 to 1:6. Against β-LP E. coli, the bactericidal activities for both A-S and T-C were poor, with geometric mean peak SBTs of only 1:6 and 1:3, respectively. The geometric mean SBT for T-C against this E. coli strain had declined to 1:1 at 6 hrs. Conclusion . Increasing the dosing interval for T-C in patients with end-stage renal disease may lead to periods of insufficient clavulanic acid to protect ticarcillin from β-lactamase degradation. 相似文献
239.
Dr. James C. Garrelts Pharm.D. W. Dale Horst Ph.D. Beryl Silkey Sc.M. Dr. Suzanne Gagnon M.D. 《Pharmacotherapy》1994,14(4):438-445
Study Objectives . To characterize patient sociodemographics and health, describe vancomycin treatment parameters and clinician-rated outcomes, and determine costs associated with treatment including preparation and administration, adverse events, and toxicity. Design . A prospective study to develop a model for costs associated with antibiotic treatment (vancomycin). Setting . A community hospital. Patients . One hundred adults with active infections. Interventions . Mean duration of therapy was 10 days, and most patients received 2000 mg/day. Serum concentrations were monitored in two of three patients. Detailed cost analyses were completed on a subset of 26 patients selected at random from the overall sample. Measurements and Main Results . Sepsis and skin and skin structure infections were the most common indications for vancomycin therapy. Treatment was effective in 81 patients, failed in 9, and was not evaluable in 10. Thirty-eight percent of patients experienced adverse events attributable to the drug. Phlebitis was common, and red man syndrome, nephrotoxicity, and ototoxicity were infrequent. Conclusions . Total cost of vancomycin treatment for 100 patients was $30,251: $23,855 for preparation and administration, $1710 for monitoring serum concentrations, and $4686 for treating adverse reactions. Drug costs accounted for only 55% of the total cost. Vancomycin is safe and effective, but phlebitis is underreported and significantly affects cost. 相似文献
240.
Dr. James Hui Ph.D. Dr. Yow-Ming C. Wang Ph.D. Dr. Appavu Chandrasekaran Ph.D. Dr. Douglas R. Geraets Pharm.D. Dr. James H. Caldwell M.D. Dr. Larry W. Robertson Ph.D. Dr. Richard H. Reuning Ph.D. 《Pharmacotherapy》1994,14(5):607-612
Study Objective . To compare digoxin tablets and liquid-filled capsules with respect to excretion of the drug and its metabolites in urine and feces at steady state. Design . A randomized, crossover trial, each period lasting 3 weeks, with no washout period. Setting . A university hospital. Patients . Six patients, five of whom were elderly, with histories of gastrointestinal disorders, such as hypochlorhydria, intestinal bacterial overgrowth, and inflammatory bowel disease. Interventions . The patients received digoxin once/day in either tablet or capsule form for 3 weeks, and then were switched to the other formulation. Total urinary and fecal excretion from the last 3 days of each regimen were analyzed for the drug and metabolites. Measurements and Main Results . No statistically significant differences were found between tablets and capsules in recovery of digoxin or its metabolites in urine or feces (p=0.05). One subject had a 4-fold increase in urinary drug excretion and 50% decrease in fecal excretion after taking the capsules compared with tablets. Intersubject variability in extent and type of metabolite excretion was greater than intrasubject variability. Conclusions . Fecal analyses may be an accurate way to classify patients as formers of digoxin reduction products. 相似文献