全文获取类型
收费全文 | 1790篇 |
免费 | 114篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 81篇 |
妇产科学 | 15篇 |
基础医学 | 179篇 |
口腔科学 | 35篇 |
临床医学 | 300篇 |
内科学 | 381篇 |
皮肤病学 | 34篇 |
神经病学 | 72篇 |
特种医学 | 373篇 |
外科学 | 82篇 |
综合类 | 49篇 |
预防医学 | 187篇 |
眼科学 | 11篇 |
药学 | 117篇 |
肿瘤学 | 66篇 |
出版年
2021年 | 13篇 |
2019年 | 15篇 |
2018年 | 12篇 |
2017年 | 11篇 |
2016年 | 12篇 |
2015年 | 20篇 |
2014年 | 21篇 |
2013年 | 40篇 |
2012年 | 38篇 |
2011年 | 33篇 |
2010年 | 54篇 |
2009年 | 49篇 |
2008年 | 39篇 |
2007年 | 80篇 |
2006年 | 36篇 |
2005年 | 36篇 |
2004年 | 31篇 |
2003年 | 24篇 |
2002年 | 26篇 |
2001年 | 28篇 |
2000年 | 32篇 |
1999年 | 39篇 |
1998年 | 100篇 |
1997年 | 89篇 |
1996年 | 112篇 |
1995年 | 84篇 |
1994年 | 91篇 |
1993年 | 79篇 |
1992年 | 38篇 |
1991年 | 49篇 |
1990年 | 48篇 |
1989年 | 65篇 |
1988年 | 68篇 |
1987年 | 48篇 |
1986年 | 64篇 |
1985年 | 59篇 |
1984年 | 27篇 |
1983年 | 31篇 |
1982年 | 34篇 |
1981年 | 29篇 |
1980年 | 23篇 |
1979年 | 18篇 |
1978年 | 23篇 |
1977年 | 18篇 |
1976年 | 17篇 |
1975年 | 15篇 |
1974年 | 9篇 |
1972年 | 6篇 |
1969年 | 6篇 |
1966年 | 7篇 |
排序方式: 共有1985条查询结果,搜索用时 0 毫秒
11.
Shared care: a review of the literature 总被引:7,自引:1,他引:6
This review examines broad issues of concern regarding the primary/secondarycare interface. The main purpose was to identify areas of goodpractice which could be adapted for more general use. One ofthe most fundamental aspects identified was communication, whichis discussed in some detail. Also covered are shared prescribingand disease management. The data suggest that the most effectivesystem(s) of shared care has yet to be established. Furtherqualitative and economic evaluations are required, taking intoaccount patient preferences. Although the literature does describecertain practice exemplars, it is clear that inter- and intra-professionalcommunication continues to be a problem. Whilst informationtechnology may provide some of the solutions, it is concludedthat a culture change, which compels health professionals tomake sharing of patient information a much higher priority,is reauired. Keywords. Shared care, seamless care, hospital, general practice, family practice. 相似文献
12.
JJ Favre Ph Chaffanjon JG Passagia JP Chirossel 《Surgical and radiologic anatomy : SRA》1995,17(2):133-138
Summary The authors report the results of a series of dissections and anatomic sections of the fronto-basal region of the brain and of the anterior cranial fossa in human cadavers. The constant presence of an arachnoidal cistern above the olfactory nerve was verified. The arachnoid separates from the pial membrane and forms a bridge with the ventral part of the olfactory bulb and tract, from the lateral edge of the olfactory sulcus to the medial edge of the gyrus rectus. The cistern is wide in its anterior portion, between the gyrus rectus and the olfactory bulb, and is reduced to a virtual slit in its posterior portion where the tract is lodged in the olfactory sulcus. The olfactory nerve can be separated without damaging fronto-basal arachnoidial adhesions over several centimeters. Dissection of this region after intravascular injection of colored media shows the constant presence of an artery destined to the olfactory bulb and tract. It originates either from the lateral surface of the anterior cerebral a. (segment A2), or from the medial fronto-basal a., and consistently provides terminal branches in front of the olfactory trigone in the medial olfactory sulcus. At their ventral extremity, the olfactory structures are therefore vascularised independently for several centimeters, from the lower face of the frontal lobe. The independent vascularisation of the olfactory nerve, the tenuous and easily detachable adhesions, and the actual presence of a true arachnoidal cistern all contribute to enabling surgical techniques which conserve olfactory function during anterior approaches.
Vascularisation du nerf olfactif. Rapports méningés et applications chirurgicales
Résumé Les auteurs rapportent les résultats d'une série de dissections et de coupes de la région fronto-basale de l'encéphale et de la fosse crânienne antérieure sur sujets cadavériques. La présence constante d'une citerne arachnoïdienne au dessus du n. olfactif a été vérifiée. L'arachnoïde se sépare du feuillet pial et passe en pont à la partie ventrale du bulbe et du tractus olfactifs, du bord latéral du sillon olfactif au bord médial du gyrus rectus. La citerne est large dans sa portion antérieure, entre le gyrus rectus et le bulbe olfactif, se réduit à une fente virtuelle postérieure lorsque le tractus se loge dans le sillon olfactif. Le n. olfactif peut être séparé sans dommage des adhérences arachnoïdiennes fronto-basales sur quelques centimètres. La dissection de cette région, après injection intravasculaire de masses colorées montre, de façon originale, la présence constante d'une artère destinée au tractus et au bulbe olfactifs. Elle naît soit de la face latérale de l'a. cérébrale antérieure (segment A2), soit de l'a. fronto-basale médiale, pour donner ses branches terminales toujours en avant du trigone olfactif dans le sillon orbitaire médial. Sur quelques centimètres à leur extrémité ventrale, les structures olfactives ont donc une vascularisation indépendante de la face inférieure du lobe frontal. L'indépendance vasculaire du n. olfactif, des adhérences ténues, facilement détachables, et la réalité vérifiée d'une véritable citerne arachnoïdienne permettent d'imaginer des techniques conservatrices de la fonction olfactive utilisées dans plusieurs indications de la chirurgie de la fosse crânienne antérieure.相似文献
13.
Mercan R; Mayer JF; Walker D; Jones S; Oehninger S; Toner JP; Muasher SJ 《Human reproduction (Oxford, England)》1997,12(9):1886-1889
The aim of this study was to compare the efficacy of pure follicle
stimulating hormone (FSH) with that of FSH/human menopausal gonadotrophin
(HMG) combination in downregulated cycles. A total of 357 patients was
evaluated retrospectively. Sixty percent of patients in the FSH group and
55% in the FSH/HMG group were new; the others were repeat patients.
Ovulation was suppressed with leuprolide acetate in all patients, followed
by either FSH (n = 218) or FSH/HMG (n = 119). There was no difference in
patients' age, infertility factors, number of ampoules used, length of
stimulation, oestradiol levels on day of human chorionic gonadotrophin
(HCG) administration, number of oocytes recovered or the number of embryos
transferred. Also, nuclear maturity at aspiration and fertilization rates
were not different between the two groups. FSH stimulation resulted in a
significantly higher percentage of mature oocytes that showed the typical
'mature' morphological characteristics (P < 0.0001). The clinical
pregnancy rates per transfer were 40 and 28% in patients stimulated with
pure FSH and FSH/HMG respectively (P < 0.05). The significantly higher
number of immature oocytes matured in vitro in the FSH/HMG group (P =
0.001) suggests a possible effect on in-vitro maturation, due to
luteinizing hormone present in HMG. The difference in mature oocyte quality
may be an important determinant in the higher pregnancy rates for the FSH-
stimulated patients.
相似文献
14.
Are active and passive smoking harmful? Determining causation 总被引:4,自引:0,他引:4
Assessing the evidence regarding any causal question involves examining the strength of the studies conducted and applying a series of "diagnostic tests" for causation. We have reviewed the strength of the evidence incriminating smoking as a cause of lung cancer, and passive smoking as a cause of respiratory illness and decreased pulmonary function in children. There are eight prospective studies of smoking and lung cancer which have consistently shown a strong relationship. These studies have confirmed the temporality of the association and demonstrated a dose-response gradient. The studies addressing the effects of passive smoking in children are considerably weaker. Although they are consistent in suggesting increased infections for children less than one year of age, neither increased risk nor a dose-response gradient is consistently found in older children and the effect size, when present, is small. The rules for assessing causation applied here can be used to integrate new information concerning the health hazards of smoking. 相似文献
15.
Acute effects of the selective cholinergic channel activator (nicotinic agonist) ABT-418 in Alzheimer’s disease 总被引:4,自引:4,他引:0
To explore further the potential for cognitive enhancement utilizing nicotinic stimulation in Alzheimer’s disease (AD), six
otherwise healthy subjects with moderate AD received placebo and three doses (6, 12, and 23 mg) of the novel selective cholinergic
channel activator (ChCA) (nicotinic agonist) ABT-418 over 6 h in a double-blind, within-subjects, repeated-measures design.
Subjects showed significant improvements in total recall and a decline in recall failure on a verbal learning task. Qualitatively
similar improvements were seen in non-verbal learning tasks such as spatial learning and memory, and repeated acquisition.
No significant behavioral, vital sign, or physical side effects were seen. These results confirm that stimulating central
nicotinic receptors has acute cognitive benefit in AD patients. These findings suggest that selective ChCAs have a potential
therapeutic role in dementing disorders, and that further studies with this or similar agents in AD and/or Parkinson’s disease
are warranted.
Received: 27 February 1998/Final version: 9 September 1998 相似文献
16.
17.
Harley B Messinger Egilius LH Spierings Arnaud JP Vincent John Lebbink 《Cephalalgia : an international journal of headache》1991,11(1):13-18
In two headache questionnaire surveys we inquired about the occurrence of headache in the mothers, fathers, siblings and children of the respondents. In total, 633 people completed valid questionnaires, 260 in the first survey and 373 in the second. The hypothesis was that familial headache occurrence would be positively associated with headache frequency. In each survey, the regression of headache frequency on the number of parents having headache was highly significant. Neither sex nor the sibling and children variables were significant predictors. In the cross-tabulations of the parental occurrence of headache with headache frequency we saw a clear "break-point" between the "no headache" and the headache frequency categories studied. For the final analyses the dichotomy "headache/no headache" was related in fourfold tables to headache occurrence in the father and the mother separately, and to the number of headache parents. The positive associations were not simply due to the large number of migraine cases since they remained after removing the migraineurs. 相似文献
18.
Rogers WH O'Rourke TW Ware JE Brook RH Newhouse JP 《Health policy (Amsterdam, Netherlands)》1991,18(2):131-139
We assess how cost sharing for medical services affects restricted activity days (RADs) and work loss disability days (WLDs), using data from a controlled experiment. We grouped the experimental insurance plans into four categories, one providing free care and the other three requiring varying amounts of cost sharing. RADs per person per year decreased by one to two days with greater cost sharing, with the strongest effects among those of average or poor health status, especially the non-poor. Unlike RADs, WLDs showed no systematic differences by plan. 相似文献
19.
JP Bound PW Harvey BJ Francis F Awwad AC Gatrell 《Archives of disease in childhood》1997,76(2):107-112
OBJECTIVE: To analyse the prevalence of neural tube defects in small geographical areas and seek to explain any spatial variations with reference to environmental lead and deprivation. SETTING: The Fylde of Lancashire in the north west of England. DESIGN: Cases were ascertained as part of a prospective survey of major congenital malformations in babies born in the Fylde to residents there between 1957 and 1981. A matched case-control analysis used infants with cardiovascular system, alimentary tract, and urinary system malformations as controls. Conditional logistic regression was used to assess the effects of more than 10 micrograms/l lead in drinking water and the Townsend deprivation score. RESULTS: The prevalence of neural tube defects in 1957-73 was higher in Blackpool, Fleetwood, and North Fylde, whereas the three control groups showed no significant spatial variation. In 1957-81 mothers living in electoral wards with either a higher proportion of houses with more than 10 micrograms/l lead in the water or a higher deprivation score had a greater risk of having a baby with a neural tube defect. For spina bifida and cranium bifidum alone, this was also true. For anencephaly, deprivation was less important although the effect of lead was still seen. In some neural tube defects, lead may act independently of other possible factors associated with deprivation. It seemed unlikely that lead levels changed significantly during the survey. The percentage of houses with 10 micrograms/l or more of lead in the water in 1984-5 was similar to that found in Great Britain 10 years previously. CONCLUSION: There is evidence to suggest that lead is one cause of neural tube defects, especially anencephaly. This could link the known preventive actions of hard water and folic acid. Calcium is a toxicological antagonist of lead. One cause of a deficiency of folic acid is impaired absorption secondary to zinc deficiency, which may be produced or exacerbated by lead. 相似文献
20.
FJ Cowan JT Warner LM Lowes JP Riberio JW Gregory 《Archives of disease in childhood》1997,77(2):109-114
AIMS: To define outcome measures for auditing the clinical care of children and adolescents with insulin dependent diabetes mellitus (IDDM) and to assess the benefit of appointing a dedicated paediatric trained diabetes specialist nurse (PDSN). METHODS: Retrospective analysis of medical notes and hospital records. Glycaemic control, growth, weight gain, microvascular complications, school absence, and the proportion of children undergoing an annual clinical review and diabetes education session were assessed. The effect of the appointment of a PDSN on the frequency of hospital admission, length of inpatient stay, and outpatient attendance was evaluated. RESULTS: Children with IDDM were of normal height and grew well for three years after diagnosis, but grew suboptimally thereafter. Weight gain was above average every year after diagnosis. Glycaemic control was poor at all ages with only 16% of children having an acceptable glycated haemoglobin. Eighty five per cent of patients underwent a formal annual clinical review, of whom 16% had background retinopathy and 20% microalbuminuria in one or more samples. After appointing the PDSN the median length of hospital stay for newly diagnosed patients decreased from five days to one day, with 10 of 24 children not admitted. None of the latter was admitted during the next year. There was no evidence of the PDSN affecting the frequency of readmission or length of stay of children with established IDDM. Non-attendance at the outpatient clinic was reduced from a median of 19 to 10%. CONCLUSIONS: Outcome measures for evaluating the care of children with IDDM can be defined and evaluated. Specialist nursing support markedly reduces the length of hospital stay of newly diagnosed patients without sacrificing the quality of care. 相似文献