全文获取类型
收费全文 | 1496篇 |
免费 | 125篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 31篇 |
妇产科学 | 34篇 |
基础医学 | 131篇 |
口腔科学 | 68篇 |
临床医学 | 106篇 |
内科学 | 459篇 |
皮肤病学 | 37篇 |
神经病学 | 155篇 |
特种医学 | 53篇 |
外科学 | 155篇 |
综合类 | 20篇 |
一般理论 | 1篇 |
预防医学 | 129篇 |
眼科学 | 18篇 |
药学 | 182篇 |
中国医学 | 8篇 |
肿瘤学 | 35篇 |
出版年
2022年 | 12篇 |
2021年 | 30篇 |
2020年 | 18篇 |
2019年 | 19篇 |
2018年 | 21篇 |
2017年 | 24篇 |
2016年 | 24篇 |
2015年 | 33篇 |
2014年 | 48篇 |
2013年 | 48篇 |
2012年 | 78篇 |
2011年 | 74篇 |
2010年 | 52篇 |
2009年 | 43篇 |
2008年 | 41篇 |
2007年 | 59篇 |
2006年 | 51篇 |
2005年 | 62篇 |
2004年 | 57篇 |
2003年 | 56篇 |
2002年 | 43篇 |
2001年 | 36篇 |
2000年 | 50篇 |
1999年 | 37篇 |
1998年 | 22篇 |
1997年 | 20篇 |
1996年 | 25篇 |
1995年 | 11篇 |
1994年 | 11篇 |
1993年 | 16篇 |
1992年 | 38篇 |
1991年 | 28篇 |
1990年 | 24篇 |
1989年 | 44篇 |
1988年 | 27篇 |
1987年 | 29篇 |
1986年 | 43篇 |
1985年 | 36篇 |
1984年 | 32篇 |
1983年 | 39篇 |
1982年 | 23篇 |
1981年 | 13篇 |
1980年 | 11篇 |
1979年 | 14篇 |
1978年 | 10篇 |
1977年 | 20篇 |
1974年 | 11篇 |
1973年 | 12篇 |
1972年 | 7篇 |
1970年 | 7篇 |
排序方式: 共有1629条查询结果,搜索用时 15 毫秒
11.
A. G. Rockall A. P. Newman-Sanders M. A. al-Kutoubi J. A. Vale 《Postgraduate medical journal》1997,73(857):129-136
Many serious and potentially treatable diseases of the urinary tract may have haematuria as their only manifestation. However, asymptomatic microscopic haematuria detected by dipstick testing may be seen in up to 16% of screening populations. The great majority of such cases will have no sinister underlying cause, particularly in those under 40 years of age, and so the schedule of further investigations, some of which may be invasive, time-consuming and expensive, needs to be rationalised. In addition, the increasing popularity of ''fast track'' clinics for the investigation of haematuria enhances the need for a clear strategy of investigation. Analysis of the epidemiology of asymptomatic haematuria and its causes combined with a consideration of the risk-benefit profile of the available investigations, makes it possible to set out an algorithm for the initial management of this common finding. Careful clinical assessment and basic laboratory tests for renal function, analysis of the urinary sediment and cytological examination of the urine are followed by ultrasound and plain radiography of the urinary tract. Flexible cystoscopy under local anaesthetic is central to the algorithm in patients of all ages. The importance of a nephrological opinion and consideration of renal biopsy, especially in younger patients with other evidence of glomerular disease, is stressed. The role of intravenous urography in excluding pathology of the upper urinary tract, especially in patients over the age of 40, is also considered. 相似文献
12.
A rapid microagglutination test for the diagnosis of Legionella pneumophila (serogroup 1) infection 总被引:4,自引:3,他引:4 下载免费PDF全文
A rapid microagglutination test has been developed which can be performed in 30 minutes. Ninety-seven percent of 96 patients diagnosed as having Legionella pneumophila (serogroup 1) infection by indirect immunofluorescence were also detected by the rapid microagglutination test. 相似文献
13.
14.
Martin Martins J Do Vale S Trinca A Saldanha C Martins E Silva J 《Physiology & behavior》2004,82(4):741-749
Behavioral and neuroendocrine differences may be postulated in hirsute subjects since central effects of gonadal steroids are well established. We conducted a controlled clinical study with 25 consecutive young hirsute participants compared with 20 consecutive controls. Neuropsychological evaluation included the Minnesota Multiphasic Personality Inventory (MMPI) and the Edinburgh Inventory of Manual Preference (EIMP). Neuroendocrine reactivity was assessed by the adrenocorticotropic hormone (ACTH) and cortisol responses to corticotropin releasing hormone (CRH). Hirsute participants presented a flattened personality profile with lower neurotic triad scores--146 +/- 20 versus 166 +/- 28. Left-hand preference was more common in hirsute participants--4/21 versus 0/20. Decreased ACTH [area under the curve (AUC)--36 +/-2 8 vs. 72 +/- 63 pg/ml h] and cortisol (AUC--18 +/- 4 vs. 25 +/- 10 microg/dl h) responses to CRH were found in the hirsute group. In the hirsute group, higher manual preference scores were associated with lower ACTH responses to CRH, while the opposite association was found in the control group. In the hirsute group, the hyporeactive hypothalamic-pituitary-adrenal (HPA) axis was associated with lower behavior-deviant scores, while in the control group, the hyporeactive HPA axis was associated with more psychopathology. We conclude that personality and HPA axis reactivity are different in hirsute female participants when compared with controls, with a trend for differences regarding handedness. Personality and handedness are differently associated with HPA reactivity. Distinctive features in hirsute participants are probably established very early during ontogenic development. 相似文献
15.
Studies on the origin of redox enzymes in seminal plasma and their relationship with results of in-vitro fertilization 总被引:3,自引:0,他引:3
Yeung CH; Cooper TG; De Geyter M; De Geyter C; Rolf C; Kamischke A; Nieschlag E 《Molecular human reproduction》1998,4(9):835-839
Glutathione (GSH), GSH peroxidase (GPX), GSH reductase (GRD), superoxide
dismutase (SOD) and catalase-like enzyme activity were quantified in
seminal plasma from normozoospermic patients, men with known distal ductal
occlusion, proven fathers and male partners of couples receiving in-vitro
fertilization (IVF) treatment for both male and female causes. Glutathione
was non-detectable (< 2.5 microM) in seminal plasma. None of the enzyme
activities per unit volume were lower in semen from vasectomized men,
suggesting that they did not originate substantially from the testis or
epididymis. The strongest relationships between enzyme activities and
accessory gland markers were between zinc and GRD (r = 0.678), SOD (r =
0.602) and GPX (r = 0.548), suggesting a largely prostatic origin of these
enzymes. Only weak relationships between accessory gland markers and
catalase-like activity suggested a multi-glandular source of this enzyme.
There was no relationship between the activity of any of the enzymes in the
IVF patients with their fertilization rates in vitro or the establishment
of pregnancy after IVF. Nor was there any correlation of enzyme activity
with the morphology and percentage of motile spermatozoa in semen or with
the percentage motility of spermatozoa immediately after swim-up or after
overnight incubation. These findings suggest that the protective enzymes in
the seminal plasma are contributed largely by the prostate and little by
the epididymis, and that in most cases of IVF, they have no major influence
on the outcome.
相似文献
16.
17.
18.
Castro-Costa CM Oriá RB Vale OC Arruda JA Horta WG D'Almeida JA Santos TJ Ramos RS Gifoni MA 《Arquivos de neuro-psiquiatria》2000,58(4):986-989
In this retrospective (1980-1998) study, we have analyzed clinico-demographically, from the records of the University Hospital of Fortaleza (Brazil), a group of 87 patients showing signs and symptoms of motor neuron diseases (MNDs). Their diagnosis was determined clinically and laboratorially. The WFN criteria were used for amyotrophic lateral sclerosis (ALS) diagnosis. The clinico-demographic analysis of the 87 cases of MNDs showed that 4 were diagnosed as spinal muscular atrophy (SMA), 5 cases as ALS subsets: 2 as progressive bulbar paralysis (PBP), 2 as progressive muscular atrophy (PMA) and 1 as monomelic amyotrophy (MA), and 78 cases of ALS. The latter comprised 51 males and 27 females, with a mean age of 42.02 years. They were sub-divided into 4 groups according to age: from 15 to 29 years (n= 17), 30 to 39 years (n= 18), 40 to 69 years (n= 39) and 70 to 78 years (n= 4). From the 78 ALS patients, 76 were of the classic sporadic form whilst only 2 were of the familial form. The analysis of the 87 patients with MNDs from the University Hospital of Fortaleza showed a predominance of ALS patients, with a high number of cases of juvenile and early onset adult sporadic ALS. 相似文献
19.
Seasonality of diarrhetic shellfish poisoning at a coastal lagoon in Portugal: rainfall patterns and folk wisdom. 总被引:3,自引:0,他引:3
Of the three types of toxicity known so far in Portuguese shellfish, only diarrhetic shellfish poisoning (DSP) and amnesic shellfish poisoning (ASP) are produced by microalgae that seem to have been present in the last decades or centuries. The most important paralytic shellfish poisoning (PSP) producer, Gymnodinium catenatum, is hypothesised to have been introduced quite recently as only in 1976 PSP toxicity was detected for the first time in shellfish from Galicia, NW Iberian Peninsula. While ASP presents very short episodes of contamination, the concentration of DSP toxins in some years surpasses human safety values for much longer periods. It is traditionally stated that shellfish should be consumed in 'months with R' (September-April). A retrospective study of the maximum monthly DSP levels attained in mussels from a coastal lagoon-Ria de Aveiro-between 1994 and 2001, showed that the highest frequency of months with concentrations surpassing the safety level of 2 microg/g digestive glands were found in June-September, followed by May and October. These months correspond with the months of lowest historical average rainfall in the period 1941-1998.Oscillations in the rainfall pattern coincided with earliest (or latest) detection by HPLC of DSP toxins in mussel in the years studied. In a semi-closed lagunar environment prone to in situ growth of DSP-producer microalgae, like Dinophysis acuminata, rainfall affects river output, lowering salinity and disrupting water column stability that favours Dinophysis growth. The seasonality of DSP recurrence may be connected to the folk adage on safety of shellfish consumption, after many years of empirical observations by coastal populations of diarrhoea episodes in summertime. 相似文献
20.
Kirsten J. Dickers Sally M. Bradberry Paul Rice Gareth D. Griffiths J. Allister Vale 《Adverse drug reactions and toxicological reviews》2003,22(3):137-142
Abrin is a toxic protein obtained from the seeds of Abrus precatorius (jequirity bean), which is similar in structure and properties to ricin. Abrin is highly toxic, with an estimated human fatal dose of 0.1–1 µg/kg, and has caused death after accidental and intentional poisoning. Abrin can be extracted from jequirity beans using a relatively simple and cheap procedure. This satisfies one criterion of a potential chemical warfare agent, although the lack of large scale production of jequirity seeds means that quantity is unavailable for ready mass production of abrin for weapons. This contrasts with the huge cultivation of Ricinus seeds for castor oil production. At the cellular level, abrin inhibits protein synthesis, thereby causing cell death. Many of the features observed in abrin poisoning can be explained by abrin-induced endothelial cell damage, which causes an increase in capillary permeability with consequent fluid and protein leakage and tissue oedema (the so-called vascular leak syndrome). Most reported cases of human poisoning involve the ingestion of jequirity beans, which predominantly cause gastrointestinal toxicity. Management is symptomatic and supportive. Experimental studies have shown that vaccination with abrin toxoid may offer some protection against a subsequent abrin challenge, although such an approach is unlikely to be of benefit in a civilian population that in all probability would be unprotected. 相似文献