全文获取类型
收费全文 | 352篇 |
免费 | 23篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 6篇 |
妇产科学 | 6篇 |
基础医学 | 15篇 |
口腔科学 | 1篇 |
临床医学 | 26篇 |
内科学 | 25篇 |
皮肤病学 | 7篇 |
神经病学 | 5篇 |
特种医学 | 22篇 |
外科学 | 83篇 |
综合类 | 7篇 |
预防医学 | 12篇 |
药学 | 26篇 |
肿瘤学 | 139篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 5篇 |
2019年 | 10篇 |
2018年 | 2篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 4篇 |
2013年 | 6篇 |
2012年 | 11篇 |
2011年 | 21篇 |
2010年 | 6篇 |
2009年 | 6篇 |
2008年 | 11篇 |
2007年 | 32篇 |
2006年 | 12篇 |
2005年 | 11篇 |
2004年 | 12篇 |
2003年 | 17篇 |
2002年 | 9篇 |
2001年 | 9篇 |
2000年 | 12篇 |
1999年 | 11篇 |
1998年 | 13篇 |
1997年 | 10篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 12篇 |
1989年 | 9篇 |
1988年 | 14篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 7篇 |
1984年 | 3篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 3篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1969年 | 3篇 |
排序方式: 共有388条查询结果,搜索用时 31 毫秒
1.
Respiratory tract infections due to Branhamella catarrhalis: epidemiological data from Western Australia 总被引:3,自引:0,他引:3
During a 3-year period Branhamella catarrhalis was isolated in significant numbers from 239 (1.3%) of 19,488 specimens of sputum sent for routine microbiological examination at a 700-bed general hospital. The majority of patients (83%) were over 60 years of age and 65% were male. There was a distinct seasonal variation in isolations with a peak incidence during the winter and early spring, a pattern not found with other pathogens. Susceptibility to amoxycillin decreased by approximately 50% over the 3 years, corresponding to an increased incidence of beta-lactamase-producing strains. There were minimal changes in susceptibility to other antimicrobial agents. Underlying pulmonary disease was the major factor predisposing to B. catarrhalis infection, and 71% of patients were smokers or ex-smokers. 相似文献
2.
Structure-activity relationships for epidermal ornithine decarboxylase induction and skin tumor promotion by anthrones 总被引:2,自引:0,他引:2
DiGiovanni John; Kruszewski Francis H.; Coombs Maurice M.; Bhatt Tarlochan S.; Pezeshk Abbas 《Carcinogenesis》1988,9(8):1437-1443
The present study was designed to compare the skin tumor promotingand epidermal ornithine decarboxylase (ODC) inducing activitiesof various structural analogs of anthralin (1, 8-dihydroxy-9-anthrone)and chrysarobin (1, 8-dihydroxy-3- methyl-9-anthrone). Groupsof 30 SENCAR mice each were initiated with 7, 12-dimethylbenz[a]anthraceneand 2 weeks later promoted with once- or twice-weekly applicationsof various doses of these anthrone derivatives. Carbon-10 (C10)-acylderivatives of anthralin were active skin tumor promoters inthe range of 25440 nmol per mouse. 10-Acetylanthralinwas significantly more active than 10-myristoyl-anthralin atlow doses (e.g. 25 and 50 nmol per mouse) and nearly as potentas the unsubstituted compound. Higher doses ( 100 nmol per mouse)of this derivative were toxic, hence, reducing the final papillomaresponse. On a relative activity scale where anthralin is 1.0,these derivatives had activities that were 0.7 and 0.2, respectively.10, 10-Dipropylanthralin was totally inactive at the doses tested.C6-Substituted derivatives of chrysarobin demonstrated diversetumor promoting activities when tested in the range of 25440nmol per mouse. On a relative activity scale where chrysarobinis 1.0, 6-methoxychrysarobin (physcion anthrone) was 0.9, whereas6-hydroxychrysarobin (emodin anthrone) had no activity. Chrysophanicacid (1, 8-dihydroxy-3-methyl-9, 10-anthraquinone) was alsoinactive as a tumor promoter at the doses tested. In general,the tumor promoting activities of these anthrone derivativescorrelated very well with their ability to induce epidermalODC after a single topical application indicating an importantrole for this enzyme in skin tumor promotion by anthones. Theability of C10-substituted derivatives of anthralin to undergobase catalyzed oxidation in vitro correlated with both ODC inducingand tumor promoting activities. In addition, copper(II) bis(diisopropylsalicylate)was found to inhibit both ODC induction and skin tumor promotionby chrysarobin. These latter data, when taken together, suggesta role for oxidation at C10 in skin tumor promotion by anthronederivatives. 相似文献
3.
DiGiovanni CW Garvin KL Pellicci PM 《The Journal of the American Academy of Orthopaedic Surgeons》1999,7(6):349-357
Surgical techniques continue to be refined to improve the results of primary cemented total hip arthroplasty. Although there has been much research in the areas of cementation and implant design, little work has specifically addressed how bone preparation can be optimized on the femoral side. On the basis of available scientific data, it appears that the broach-only system has several potential advantages over the traditional ream-and-broach technique. Broaching is usually faster, leaves behind more bone stock, and may improve both microinterlock and macrointerlock. Additionally, the excess bone resulting from broaching without reaming does not seem to compromise fixation at the bone-cement interface. Such differences may become even more important as the indications for cemented hip arthroplasty broaden to include increasingly younger and more active patients, because revision in these individuals is likely. In most cases, reaming is probably counterproductive, although it may be advantageous when used to open the femoral canal, to prevent varus stem orientation, and to manage sclerosis or deformity of bone due to a preexisting hip disorder or the presence of internal fixation devices. Regardless of which method is chosen, good bone surface cleansing and cement penetration remain paramount. More studies comparing reamed and nonreamed preparation are necessary to resolve this controversial issue definitively. 相似文献
4.
The formation of cell- and medium-associated metabolites of7,12-dimethylbenz[a]anthracene (DMBA) by primary mouse epidermalcells was examined using high-pressure liquid chromatography.Cells were cultured in the presence of 14C DMBA for varioustime periods prior to harvesting. Ethyl acetate/acetone (2:1)extractable metabolites found associated with cells cochromatographedwith 7-hydroxymethyl-12-methylbenz[a]anthracene (7-OHM-12-MBA),12-hydroxymethyl-7-methylbenz[a]anthracene (12-OHM-7-MBA), (±)-trans-3,4-dihydro-3,4-dihydroxy-7,12-dimethylbenz[a]anthracene ((±)-trans-DMBA-3, 4-diol)and phenols. The major metabolite(s) found within cells cochromatographedwith DMBA-phenol(s). Ethyl acetate/acetone extractable metabolitesfound in the medium cochromatographed with 7-OHM-12-MBA, 12-OHM-7-MBA,(±)-trans-DMBA-3,4-diol, (±)-trans-8,9-dihydro-8,9-dihydroxy-7,12-dimethylbenz[a]anthracene ((± -trans-DMBA-8,9-diol)and phenols. The major ethyl acetate/acetone soluble metabolitefound in the medium cochromatographed with (±)-trans-DMBA-8,9-diol. This metabolite is rapidly excreted unchanged fromthe cells into the medium. In addition, primary epidermal cells rapidly converted 14C DMBAto water soluble metabolites that could not be extracted fromthe medium with ethyl acetate/acetone. Approximately 50% ofthese water soluble metabolites were extractable with organicsolvent upon treatment of the medium with ß-glucuronidase.Phenolic metabolite(s) represented 7585% of the totalß-glucuronidase releasable material. The results indicatedthat primary mouse epidermal cells in culture rapdly convertedDMBA to a variety of hydroxylated products some of which wereconjugated with glucuronic acid. In addition, the formationof (±)-trans-DMBA-3,4-diol and its retention within thecells provides additional support for an important role forthis metabolite in carcinogenesis by DMBA. 相似文献
5.
Anticarcinogenic and cocarcinogenic effects of benzo[e]pyrene and dibenz[a,c]anthracene on skin tumor initiation by polycyclic hydrocarbons 总被引:1,自引:0,他引:1
In the present study, we have examined the effects of benzo[e]pyrene(B[e]P) and dibenz[a,c]anthracene (DB[a,c]A) on the skin tumor-initiatingactivities of methylated and nonmethylated polycyclic aromatichydrocarbons (PAH). B[e]P, when applied 5 min prior to initiationwith seven different PAH skin carcinogens, effectively inhibitedthe tumorinitiating activities of 7,12-dimethylbenz[a]anthracene(DMBA) and dibenz[a,h]anthracene (DB[a,h]A) but had little orno effect on the tumor-initiating activities of 3-methylcholanthrene(MCA), 7-methylbenz[a]anthracene (7-MBA), 12-methylbenz[a]anthracene(12-MBA), and 5-methylchrysene (5-MeC). B[e]P potentiated thetumor-initiating activity of benzo[a]pyrene (B[a]P) by 30%.DB[a,c]A, when applied 5 min prior to initiation, inhibitedthe tumor-initiating activities of DMBA, MCA, and DB[a,h]A buthad little or no effect on the tumor-initiating activities ofB[a]P, 7-MBA, 12-MBA, and 5-MeC. DB[a,c]A, when applied 12,24, or 36 h prior to initiation with B[a]P, which allowed timefor induction of epidermal monooxygenase enzymes, inhibitedtumor initiation. The covalent binding of DMBA and B[a]P toepidermal DNA was examined under the influence of B[e]P. Dosesof 20 and 200 nmol B[e]P given 5 min prior to 10 nmol [3H]DMBAreduced binding to 47 and 22%, respectively, of the controlvalue. In contrast, doses of 200 or 2000 nmol B[e]P given 5min prior to 200 nmol [3H]B[a]P had little or no effect on totalbinding. The data indicate that one cannot predict anti andcocarcinogenic effects of B[e]P and DB[a,c]A on the basis ofa presence or absence of a methyl substituent. In addition,fundamental differences exist in the processing and metabolismof DMBA and B[a]P by mouse epidermal cells. 相似文献
6.
Mark C. Drakos Russell Fiore Conor Murphy Christopher W. DiGiovanni 《Journal of Athletic Training》2015,50(5):553-560
Objective:
To present 3 cases of plantar-plate rupture and turf-toe injury in contact athletes at 1 university and to discuss appropriate diagnosis and treatment algorithms for each case.Background:
Turf toe is a common injury in athletes participating in outdoor cutting sports. However, it has been used as an umbrella term to describe many different injuries of the great toe. In some cases, the injury can be so severe that the plantar plate and sesamoid apparatus may be ruptured. These patients may be better managed with surgery than with traditional nonoperative interventions.Differential Diagnosis:
Turf toe, plantar-plate disruption, sesamoid fracture.Treatment:
For stable injuries in which the plantar plate is not completely disrupted, nonoperative treatment with casting or a stiff-soled shoe, gradual weight bearing, and rehabilitation is the best practice. Unstable injuries require surgical intervention and plantar-plate repair.Uniqueness:
Turf toe and injury to the first metatarsophalangeal joint are relatively common injuries in athletes, but few researchers have detailed the operative and nonoperative treatments of plantar-plate disruption in these patients. We examine 3 cases that occurred over 4 seasons on a collegiate football team.Conclusions:
Turf toe represents a wide array of pathologic conditions involving the first metatarsophalangeal joint. Stress and instability testing are key components to assess in determining whether surgical intervention is warranted to restore optimal function. Stiffer-soled shoes or shoes with steel-plate insertions may help to prevent these injuries and are useful tools for protection during the rehabilitation period.Key Words: metatarsophalangeal joint, great toe, football playersTurf toe is a common injury in athletes participating in outdoor cutting sports. Clanton and Ford1 reported that injury to the foot was the third leading cause of missed athletic participation. Damage to the metatarsophalangeal joint (MTPJ) represents a large percentage of those injuries. However, since Bowers and Martin2 coined the term turf toe, it has been a poorly studied topic of substantial controversy. They originally described turf toe as a sprain to the first MTPJ, but in many instances, the injury has been attributed incorrectly to various pathologic conditions involving the first ray.2 Turf toe historically has been managed nonoperatively with a stiff-soled shoe or short walking boot. Yet in severe cases, the plantar plate may be ruptured and disrupted. These injuries are easy to overlook on physical examination. Therefore, the purpose of our study was to review 3 cases of injury to the plantar plate of the first MTPJ in contact athletes and to focus on diagnosis and treatment of the more severe toe injuries. 相似文献7.
8.
Justin R. Kingery Paul BF Martin Ben R. Baer Laura C. Pinheiro Mangala Rajan Adrienne Clermont Sabrina Pan Khoi Nguyen Khalid Fahoum Graham T. Wehmeyer Mark N. Alshak Han A. Li Justin J. Choi Martin F. Shapiro Margaret L. McNairy Monika M. Safford Parag Goyal 《Journal of general internal medicine》2021,36(8):2378
BackgroundThe clinical course of COVID-19 includes multiple disease phases. Data describing post-hospital discharge outcomes may provide insight into disease course. Studies describing post-hospitalization outcomes of adults following COVID-19 infection are limited to electronic medical record review, which may underestimate the incidence of outcomes.ObjectiveTo determine 30-day post-hospitalization outcomes following COVID-19 infection.DesignRetrospective cohort studySettingQuaternary referral hospital and community hospital in New York City.ParticipantsCOVID-19 infected patients discharged alive from the emergency department (ED) or hospital between March 3 and May 15, 2020.MeasurementOutcomes included return to an ED, re-hospitalization, and mortality within 30 days of hospital discharge.ResultsThirty-day follow-up data were successfully collected on 94.6% of eligible patients. Among 1344 patients, 16.5% returned to an ED, 9.8% were re-hospitalized, and 2.4% died. Among patients who returned to the ED, 50.0% (108/216) went to a different hospital from the hospital of the index presentation, and 61.1% (132/216) of those who returned were re-hospitalized. In Cox models adjusted for variables selected using the lasso method, age (HR 1.01 per year [95% CI 1.00–1.02]), diabetes (1.54 [1.06–2.23]), and the need for inpatient dialysis (3.78 [2.23–6.43]) during the index presentation were independently associated with a higher re-hospitalization rate. Older age (HR 1.08 [1.05–1.11]) and Asian race (2.89 [1.27–6.61]) were significantly associated with mortality.ConclusionsAmong patients discharged alive following their index presentation for COVID-19, risk for returning to a hospital within 30 days of discharge was substantial. These patients merit close post-discharge follow-up to optimize outcomes.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11606-021-06924-0.KEY WORDS: COVID-19, mortality, re-admission, discharge 相似文献
9.
10.