全文获取类型
收费全文 | 10434篇 |
免费 | 949篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 125篇 |
儿科学 | 464篇 |
妇产科学 | 239篇 |
基础医学 | 1067篇 |
口腔科学 | 178篇 |
临床医学 | 1665篇 |
内科学 | 1396篇 |
皮肤病学 | 95篇 |
神经病学 | 746篇 |
特种医学 | 367篇 |
外科学 | 665篇 |
综合类 | 121篇 |
一般理论 | 16篇 |
预防医学 | 2916篇 |
眼科学 | 114篇 |
药学 | 644篇 |
1篇 | |
中国医学 | 10篇 |
肿瘤学 | 566篇 |
出版年
2023年 | 66篇 |
2022年 | 70篇 |
2021年 | 103篇 |
2020年 | 145篇 |
2019年 | 169篇 |
2018年 | 247篇 |
2017年 | 213篇 |
2016年 | 218篇 |
2015年 | 227篇 |
2014年 | 258篇 |
2013年 | 517篇 |
2012年 | 538篇 |
2011年 | 567篇 |
2010年 | 409篇 |
2009年 | 335篇 |
2008年 | 553篇 |
2007年 | 598篇 |
2006年 | 576篇 |
2005年 | 590篇 |
2004年 | 536篇 |
2003年 | 476篇 |
2002年 | 560篇 |
2001年 | 196篇 |
2000年 | 147篇 |
1999年 | 217篇 |
1998年 | 264篇 |
1997年 | 293篇 |
1996年 | 288篇 |
1995年 | 218篇 |
1994年 | 135篇 |
1993年 | 185篇 |
1992年 | 82篇 |
1991年 | 80篇 |
1990年 | 91篇 |
1989年 | 82篇 |
1988年 | 80篇 |
1987年 | 69篇 |
1986年 | 84篇 |
1985年 | 87篇 |
1984年 | 85篇 |
1983年 | 64篇 |
1982年 | 105篇 |
1981年 | 64篇 |
1980年 | 54篇 |
1979年 | 59篇 |
1978年 | 54篇 |
1977年 | 43篇 |
1976年 | 52篇 |
1974年 | 30篇 |
1972年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Ellen A. Eisen Paige E. Tolbert Marilyn F. Hallock Richard R. Monson Thomas J. Smith Susan R. Woskie 《American journal of industrial medicine》1994,26(2):185-202
A case-control study of larynx cancer was conducted within a cohort of automobile workers exposed to metal working fluids, commonly referred to as machining fluids (MF). Results are based on 108 cases of larynx cancer and 5:1 matched controls. Risks associated with specific types of MF, as well as specific components of the fluids were evaluated. Based on a retrospective exposure assessment, lifetime exposures to straight and soluble fluids, grinding particulate, biocides, selected metals, sulfur, and chlorine were examined. Exposure to asbestos and acid mists at two of the three study sites was also characterized. Results suggest that straight mineral oils are associated with almost a two-fold excess in larynx cancer risk. There was also evidence of an association with elemental sulfur, commonly added to straight MF to improve the integrity of the materials under extreme pressure and heat. It is not clear whether sulfur is causally related to an excess relative risk of larynx cancer or whether the observed association is the result of unmeasured confounding by another contaminant or process feature. For example, the high stress operations that require MF enriched with sulfur are also more likely to produce polycyclic aromatic hydrocarbons (PAHs) during the process. Thus, the observed association with sulfur may be due to an association with PAH. The finding of excess risk of laryngeal cancer associated with MF is consistent with several previous reports in the literature. This is the first study, however, to distinguish straight mineral oils from other types of MF. Based on these findings, a general reduction in concentrations of straight mineral oil particulate in occupational environments would be prudent. 相似文献
83.
Egidio L. Romano res Soyano Ramón F. Montaño Murray Ratcliffe Marilyn Olson Guillermo Suarez Nelly Martínez and Geoffrey Worstey 《Vox sanguinis》1994,66(3):194-199
Thirteen infants, 10 with A-O and 3 with B-O hemolytic disease of the newborn (ABO-HDN), were treated with synthetic A or B blood group trisaccharides (ATS, BTS) which cause dissociation of maternal antibody bound to infant red cells. The clinical outcome was compared with that of a control group of 21 infants treated with phototherapy during the preceding year. Exchange transfusion was required in 2 out of 13 infants in the experimental group and in 7 in the control group. A randomized prospective controlled study is necessary to confirm these results. 相似文献
84.
Epiderrnolysis bullosa (EB), a heterogeneous group of rare, inherited disorders, is manifested by recurrent blistering of the skin induced by the slightest trauma. Little information exists regarding the nutrition management of patients with EB. This study presents information on growth, identifies potential nutrition problems, and provides guidelines for nutrition management of persons with EB. Eighty patients attending a dermatology clinic for EB patients are described. Severity of disease ranged from mild blistering of the knees, elbows, and feet to extensive blistering and scarring of the skin and entire gastrointestinal tract. Of the 18 children with EB simplex, which is a mild form of the disease, 4 (22%) were at nutritional risk. None of the 13 adults with EB simplex were underweight and 8 (62%) were overweight. Of the patients with the more severe forms of EB, 27 of the 35 (77%) children with dystrophic EB and 4 of the 7 (57%) children with junctional EB were at risk for malnutrition. Of the 7 adults with dystrophic EB, 6 (86%) were underweight. Common nutrition problems included protein-energy malnutrition, chewing and swallowing problems, constipation, anemia, and vitamin/mineral deficiencies. When nutrition care protocols address these problems, growth, development, and nutritional status can improve. For those with severe nutrition problems, gastrostomy feeding or similar nutrition therapies should be considered. J Am Diet Assoc. 1995; 95:575-579. 相似文献
85.
BACKGROUND: A simple, rapid, inexpensive method for measuring the flow in a
patient's vascular access would permit routine monitoring during
haemodialysis, and hence provide information of access graft deterioration
sufficiently early to increase the success of minimally invasive remedial
procedures. This paper reports the validation of such a method in animals.
METHODS: A PTFE graft was implanted in sheep between the carotid artery and
the jugular vein. While the sheep was under general anaesthesia and on an
haemodialysis circuit, ultrasound velocity in its blood was perturbed by
the injection of a 5-10 ml bolus of isotonic NaCl. The pump tubing flow was
measured by a transit-time blood flow meter. This flow was combined with
the areas of perturbation generated by the injection before and after
mixing in the access flow to estimate graft flow. The calculated graft flow
was compared to flow measured directly by a transit-time probe on the same
carotid artery. RESULTS: Over a 10-fold range, 120-1260 ml/min, graft flow
measured by ultrasound velocity dilution agreed well with graft flow
measured directly with a scatter of 76 ml/min about the regression line.
CONCLUSION: Ultrasound velocity dilution provides a method for measuring
flow in the graft accurate enough for clinical evaluation of patients on
dialysis.
相似文献
86.
87.
Clinical trial of a prevention and treatment protocol for skin breakdown in two nursing homes. 总被引:1,自引:0,他引:1
Susan Hunter Julie Anderson Darlene Hanson Patricia Thompson Diane Langemo Marilyn G Klug 《Journal of wound, ostomy, and continence nursing》2003,30(5):250-258
OBJECTIVE: Our objective was to assess the effectiveness of skin care protocols, including a body wash and skin protectant, on skin breakdown in 2 nursing homes. DESIGN: This was a quasi-experimental pretest/posttest design study.Setting and subjects Adult residents (n = 136) of 2 skilled nursing homes consented to participate in this study. Seventy percent were women; the sample average age of 82 years. INSTRUMENTS: A researcher-designed data recording form documented resident demographics, incidence and type of skin breakdown or pressure ulcer, presence of urinary or fecal incontinence, and assessment of the effectiveness of body wash and skin protectant. METHODS: Baseline data on prevalence of pressure ulcers and skin protocol were collected weekly for a 3-month period followed by a week-long educational program by the researchers about skin care and the body wash and skin protectant. During the 3-month trial with the body wash and skin protectant incorporated into routine care, research assistants recorded resident data weekly and researchers again assessed prevalence and incidence of pressure ulcers and skin breakdown weekly. RESULTS: Incorporation of a body wash and skin protectant into a skin care prevention and early intervention protocol in 2 nursing homes documented a decrease in skin breakdowns from 68 pre-intervention to 40 postintervention; the decrease in agency B was statistically significant. There was a statistically significant decrease in stage I and II pressure ulcer incidence overall (pre-intervention = 19.9%, postintervention = 8.1%). Nurses evaluated the body wash and skin protectant as effective for 98% of the time used. CONCLUSION: Implementation of a protocol for skin care along with staff education, including the prophylactic use of a body wash and skin protectant, reduced the incidence of skin breakdown, including pressure ulcers and perineal dermatitis, in 2 long-term care facilities. 相似文献
88.
Andrew M Speer Mark W Willis Peter Herscovitch Margaret Daube-Witherspoon Jennifer Repella Shelton Brenda E Benson Robert M Post Eric M Wassermann 《Neuropsychopharmacology》2003,54(8):818-825
BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) affects the excitability of the motor cortex and is thought to influence activity in other brain areas as well. We combined the administration of varying intensities of 1-Hz rTMS of the motor cortex with simultaneous positron emission tomography (PET) to delineate local and distant effects on brain activity. METHODS: Ten healthy subjects received 1-Hz rTMS to the optimal position over motor cortex (M1) for producing a twitch in the right hand at 80, 90, 100, 110, and 120% of the twitch threshold, while regional cerebral blood flow (rCBF) was measured using H(2)(15)O and PET. Repetitive transcranial magnetic stimulation (rTMS) was delivered in 75-pulse trains at each intensity every 10 min through a figure-eight coil. The regional relationship of stimulation intensity to normalized rCBF was assessed statistically. RESULTS: Intensity-dependent rCBF increases were produced under the M1 stimulation site in ipsilateral primary auditory cortex, contralateral cerebellum, and bilateral putamen, insula, and red nucleus. Intensity-dependent reductions in rCBF occurred in contralateral frontal and parietal cortices and bilateral anterior cingulate gyrus and occipital cortex. CONCLUSIONS: This study demonstrates that 1-Hz rTMS delivered to the primary motor cortex (M1) produces intensity-dependent increases in brain activity locally and has associated effects in distant sites with known connections to M1. 相似文献
89.
Ronald R. Watson PhD Mary E. Mohs MS RD Cteamond Eskelson PhD Richard E. Samptiner MD Barbara Hartmann PhD 《Alcoholism, clinical and experimental research》1986,10(4):364-385
The prevalence and incidence of heavy alcohol consumption are major problems which have been increasing in many countries in recent years. It is crucial for physicians to consistently identify early drinking problems as well as the various end disease states in order to minimize suffering and maximize recovery. This paper reviews the evolutionary development of clinical tools for detection of alcohol abuse. The focus is primarily on clinical/biochemical indicators of alcohol abuse, emphasizing but not limited to changes in hematological characteristics, liver enzyme activity, lipids, immune function factors, hormones, neurological factors, and some physically based tests. Use of test combinations and sophisticated statistical analysis of pattern changes in test batteries evidence increased diagnostic efficiency. 相似文献
90.