全文获取类型
收费全文 | 116118篇 |
免费 | 10786篇 |
国内免费 | 4705篇 |
专业分类
耳鼻咽喉 | 885篇 |
儿科学 | 4250篇 |
妇产科学 | 3300篇 |
基础医学 | 11058篇 |
口腔科学 | 3219篇 |
临床医学 | 10747篇 |
内科学 | 17316篇 |
皮肤病学 | 1575篇 |
神经病学 | 7397篇 |
特种医学 | 2127篇 |
外国民族医学 | 37篇 |
外科学 | 11117篇 |
综合类 | 18787篇 |
现状与发展 | 21篇 |
一般理论 | 1篇 |
预防医学 | 13775篇 |
眼科学 | 3311篇 |
药学 | 8880篇 |
65篇 | |
中国医学 | 3401篇 |
肿瘤学 | 10340篇 |
出版年
2024年 | 373篇 |
2023年 | 1768篇 |
2022年 | 3738篇 |
2021年 | 4943篇 |
2020年 | 4553篇 |
2019年 | 3702篇 |
2018年 | 3709篇 |
2017年 | 4046篇 |
2016年 | 4422篇 |
2015年 | 4304篇 |
2014年 | 7794篇 |
2013年 | 8955篇 |
2012年 | 7477篇 |
2011年 | 8106篇 |
2010年 | 6569篇 |
2009年 | 6128篇 |
2008年 | 6132篇 |
2007年 | 6182篇 |
2006年 | 5477篇 |
2005年 | 4898篇 |
2004年 | 4057篇 |
2003年 | 3437篇 |
2002年 | 2862篇 |
2001年 | 2486篇 |
2000年 | 2090篇 |
1999年 | 1684篇 |
1998年 | 1480篇 |
1997年 | 1308篇 |
1996年 | 1119篇 |
1995年 | 969篇 |
1994年 | 889篇 |
1993年 | 736篇 |
1992年 | 676篇 |
1991年 | 603篇 |
1990年 | 519篇 |
1989年 | 442篇 |
1988年 | 339篇 |
1987年 | 289篇 |
1986年 | 282篇 |
1985年 | 376篇 |
1984年 | 309篇 |
1983年 | 212篇 |
1982年 | 259篇 |
1981年 | 191篇 |
1980年 | 150篇 |
1979年 | 115篇 |
1978年 | 95篇 |
1977年 | 80篇 |
1976年 | 87篇 |
1975年 | 53篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.
At our center, since 1982, a body mass index (BMI) of less than 30 has been a prerequisite for placing a patient on the waiting
list for renal transplantation. This decision was made because obese transplant recipients seemed to have a less than favorable
post-transplant outcome. The aim of this study was to evaluate whether this requirement is still justified. Forty-six patients
with a BMI above 30 underwent primary cadaveric renal transplantation between 1972 and 1993. For each of these obese patients,
five consecutive non-obese (BMI 20–25) control patients were selected. Patient and graft survival, causes of graft loss, and
acute rejection rate were evaluated for the two patient groups before and after the year 1982. Within the first 30 post-transplant
days, one patient (2 %) and 11 grafts (24 %) were lost in the group of obese patients whereas seven patients (3 %) and 36
grafts (16 %) were lost in the control group. Among the obese patients, renal circulatory complications were a major cause
of graft loss. In the period 1973–1981, the 1-year patient survival rate was 65 % among obese patients versus 75 % among controls
from 1982 to 1993, this was 90 % versus 93 %. From 1973 to 1981, the 1-year graft survival rate was 25 % among obese patients
versus 53 % among controls (P < 0.05); from 1982 to 1993, it was 68 % versus 84 % (P = NS). Multivariate analysis showed that the immunosuppressive regimen,
age of the patient, BMI, and cold ischemia time of the graft had a significant influence on graft survival. The acute rejection
rate within the first 30 days was 28 % among obese patients and 35 % among controls (P = NS). We conclude that a BMI below
or equal to 30 is still justified as a prerequisite for placement on the waiting list for renal transplantation, for despite
an overall improvement, the outcome of renal transplantation in obese patients remains worse than that in non-obese patients.
Received: 3 February 1997 Received after revision: 4 April 1997 Accepted: 8 April 1997 相似文献
25.
A comparison of 121 mature-age and 270 normal-age entrants who graduated from the University of Queensland Medical School between 1972 and 1987 shows that mature-age entrants are some 7 years older, are more likely to come from public (state) schools and less likely to have parents in professional/technical occupations. Otherwise, the two groups were similar in terms of gender, marital status, number of children, ethnic background and current practice location. The educational background of mature-age entrants prior to admission includes 44.6% with degrees in health-science areas and 31.4% with degrees in non-health areas. Reasons for delayed entry of mature-age entrants include late consideration of medicine as a career (34.7%), financial problems (31.4%), dissatisfaction with previous career (30.6%), poor academic results (19.8%), or a combination of the above factors. Motivations to study medicine include family influences (more so in normal-age entrants), altruistic reasons (more so in mature-age entrants) and a variety of personal/social factors such as intellectual satisfaction, prestige and financial security (similar for both groups) and parental expectations (more so in normal-age entrants). Mature-age entrants experienced greater stress throughout the medical course, especially with regard to financial difficulties, loneliness/isolation from the students and family problems (a greater proportion were married with children). While whole-course grades were similar in both groups, normal-age entrants tended to win more undergraduate honours/prizes and postgraduate diplomas/degrees, including specialist qualifications. Practice settings were similar in terms of group private practice, hospital/clinic practice or medical administration, but there was a greater proportion of mature-age entrants in solo private practice, and a smaller proportion in teaching/research. If given the time over, some two-thirds of both groups would choose medicine as a career. Reasons for job satisfaction include helping patients, intellectual stimulation and financial rewards. Reasons for dissatisfaction include pressure of work, red-tape/paperwork, 'doctor-bashing', long working hours, emotional strain, financial pressure, unfulfilled career expectations and irritation with trivial medical complaints. 相似文献
26.
Benign intracranial hypertension and recombinant growth hormone therapy in Australia and New Zealand
PA Crock JD McKenzie AM Nicoll NJ Howard W Cutfield LK Shield G Byrne 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(4):381-386
Benign intracranial hypertension (BIH) is reported in three children from Australia and one from New Zealand, who were being treated with recombinant human growth hormone (rhGH). Three males and one female, aged between 10.5 and 14.2 y, developed intracranial hypertension within 2 weeks to 3 months of starting treatment. A national database, OZGROW, has been prospectively collecting data on all 3332 children treated with rhGH in Australia and New Zealand from January 1986 to 1996. The incidence of BIH in children treated with growth hormone (GH) is small, 1.2 per 1000 cases overall, but appears to be greater with biochemical GHD (<10IUml -1 ), i.e. 6.5/1000 (3 in 465 cases), relative risk 18.4, 95% confidence interval 1.9-176.1, than in all other children on the database. The incidence in patients with Turner's syndrome was 2.3/1000 (1 in 428 cases). No cases in patients with partial GHD (10–20 IUml -1 ) or chronic renal failure were identified. Possible causative mechanisms are discussed. The authors'practice is now to start GH replacement at less than the usual recommended dose of 14IUm-2 week-1 in those children considered to be at high risk of developing BIH. Ophthalmological evaluation is recommended for children before and during the first few months following commencement of rhGH therapy and is mandatory in the event of peripheral or facial oedema, persistent headaches, vomiting or visual symptoms. The absence of papilledema does not exclude the diagnosis. 相似文献
27.
S. L. Grant P. A. Phillips C. B. Gow 《Clinical and experimental pharmacology & physiology》1994,21(3):243-247
1. Epidermal growth factor is a potent mitogen that causes natriuresis, diuresis and inhibition of arginine vasopressin-induced water reabsorption. 2. The aim of this study was to determine any interaction between epidermal growth factor and the V1 (vascular) and/or V2 (antidiuretic) arginine vasopressin receptor subtypes. 3. Radioligand binding displacement assays demonstrated that although arginine vasopressin related peptides displaced both radioligands from renal medullary membranes at low concentrations epidermal growth factor displaced neither. 4. Arginine vasopressin V2 receptor second messenger cyclic adenosine monophosphate (CAMP) production was inhibited by epidermal growth factor (IC50 2 ± 10?7 mol/L) as was sodium fluoride cAMP production but only at much higher concentrations. 5. Therefore the diuretic effect of epidermal growth factor is not via direct antagonism of arginine vasopressin receptors but seems mediated via inhibition of the V2 second messenger system. 相似文献
28.
Erika G. Gisel 《Occupational therapy international》1994,1(4):209-232
This review addresses the current state of knowledge in oral sensorimotor therapy for children with neurological impairments and ingestive problems. Comprehensive assessment of the child with dysphagia looks at the interaction of oral performance and growth. These domains include eating efficiency, oral-motor skills, oral sensory evaluation, classification of the severity of an eating problem, interaction of respiration and ingestion, aspiration, positioning for feeding, social skills assessment, careload and assessment technologies. Oral sensorimotor therapy improves eating but not drinking skills in children 3–12 years of age. Weight gain is sufficient so that children maintain their growth channel but they do not show catchup growth. Many factors thought to contribute to better ingestive performance need further study, such as jaw and lip control in association with drinking. The earliest possible identification of infants at risk for eating impairments needs to be rigorously pursued. Such an approach offers hope that the later growth deterioration now seen in children with eating impairments may be prevented. Finally, the effect of positioning and the use of eating equipment to promote self-feeding need further study. 相似文献
29.
The treatment of neoplasia with interleukin-2 (IL-2) can be complicated by neurological deficits resembling transient Ischemic attack and stroke. We investigated whether interleukin-2 contributes to the natural course of cerebrovascular ischemia and particularly to the pathogenesis of infection-associated stroke. Plasma levels of interleukin-2 were below the level of detectability in almost all measurements. Patients with and without previous infection (n = 11, 805 ±445 U/ml vs n = 19, 824 ± 501 U/ml) did not have significantly higher levels of soluble interleukin-2 receptors than control subjects with (n = 14, 667 ± 229 U/ml) or without vascular risk factors (n = 17, 567 ± 176 U/ml). Receptor levels increased in patients during the first week after stroke (n = 15, 1157 ± 1013, p < 0.02). Levels of soluble T8 antigen (sT8) were higher in patients (n – 26, 320 ± 112 U/ml) than in healthy control subjects (n = 15, 246 ± 92 U/ml; p < 0.05) and sT8 levels increased during the first week after stroke (p < 0.05). These results reflect an immunological response to the cerebral infarct; they do not indicate a general role of the IL-2 system in the pathogenesis of ischemic stroke with or without previous infection. 相似文献
30.
A. Veggetti F. Mascarello P. A. Scapolo A. Rowlerson M. D. Candia Carnevali 《Anatomy and embryology》1993,187(4):353-361
The myosin composition of lateral muscle in Poecilia reticulata from birth to adult was studied by ATPase histochemistry and immunostaining with myosin isoform-specific antibodies. At birth the muscle consists of two layers containing developmental isoforms of myosin. In deep layer fibres the developmental myosin is replaced by the adult fast-white isoform soon after birth. In the epaxial and hypaxial monolayer fibres the myosin composition present at birth (J1) is replaced within 3 days by another (J2). In some fibres, this J2 composition is retained in the adult, but in others it is slowly replaced by the adult slow-red muscle isoform. Close to the lateral line, all monolayer fibres are already in transition between the J2 myosin and the adult slow-red form at birth, and rapidly complete the transition to slow-red form. These fibres, together with others generated de novo in an underlying hyperplastic zone, form the red muscle layer of the adult. The pink muscle develops during the first month after birth, and by 31 days it consists of an outer, middle and inner layer. A few middle layer fibres are already present at birth, while the outer layer fibres first appear 3 days after birth. The thin inner layer is probably a transitional form between the middle pink and adult white types, and appears at about 31 days. A morphometric analysis showed that growth of the white muscle occurs principally by hypertrophy. Even at the magnification level of the electron microscope, no satellite cells or myoblasts which could give rise to new fibres were found in the white muscle, except in the far epaxial and hypaxial regions and only in the first 10 days. A zone of hyperplastic growth was also found lying just under the superficial monolayer close to the lateral line, and this presumably contributes fibres to the red and pink muscle layers. 相似文献