全文获取类型
收费全文 | 8781篇 |
免费 | 470篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 111篇 |
儿科学 | 267篇 |
妇产科学 | 180篇 |
基础医学 | 1137篇 |
口腔科学 | 486篇 |
临床医学 | 674篇 |
内科学 | 1700篇 |
皮肤病学 | 227篇 |
神经病学 | 696篇 |
特种医学 | 300篇 |
外科学 | 1069篇 |
综合类 | 29篇 |
预防医学 | 1246篇 |
眼科学 | 191篇 |
药学 | 602篇 |
中国医学 | 65篇 |
肿瘤学 | 299篇 |
出版年
2023年 | 79篇 |
2022年 | 118篇 |
2021年 | 206篇 |
2020年 | 153篇 |
2019年 | 195篇 |
2018年 | 317篇 |
2017年 | 212篇 |
2016年 | 222篇 |
2015年 | 216篇 |
2014年 | 281篇 |
2013年 | 463篇 |
2012年 | 649篇 |
2011年 | 798篇 |
2010年 | 351篇 |
2009年 | 260篇 |
2008年 | 558篇 |
2007年 | 589篇 |
2006年 | 524篇 |
2005年 | 479篇 |
2004年 | 486篇 |
2003年 | 355篇 |
2002年 | 366篇 |
2001年 | 196篇 |
2000年 | 233篇 |
1999年 | 155篇 |
1998年 | 34篇 |
1997年 | 35篇 |
1996年 | 26篇 |
1995年 | 30篇 |
1994年 | 26篇 |
1993年 | 15篇 |
1992年 | 70篇 |
1991年 | 67篇 |
1990年 | 43篇 |
1989年 | 58篇 |
1988年 | 39篇 |
1987年 | 61篇 |
1986年 | 30篇 |
1985年 | 28篇 |
1984年 | 20篇 |
1983年 | 15篇 |
1982年 | 13篇 |
1980年 | 12篇 |
1979年 | 16篇 |
1978年 | 16篇 |
1976年 | 12篇 |
1974年 | 18篇 |
1973年 | 18篇 |
1972年 | 16篇 |
1967年 | 11篇 |
排序方式: 共有9279条查询结果,搜索用时 46 毫秒
1.
2.
3.
4.
5.
6.
Ángela M. Ortega-Galán M. Dolores Ruiz-Fernández Rocío Ortiz-Amo José Cabrera-Troya Inés M. Carmona-Rega Olivia Ibáñez-Masero 《Enfermería clínica》2019,29(1):10-17
Objective
To discover the experiences of end-of-life patients attended by the emergency services, through the discourse of the family caregivers who accompanied the family member in this care transit.Method
A qualitative approach study, based on the paradigm of hermeneutical phenomenology. In total, 81 family caregivers participated. The techniques used were the in-depth interview and the discussion group, with a total of 5 discussion groups and 41 interviews. The period of data collection was carried out between January 2013 and June 2014.Results
In the network of discourses obtained with respect to “Urgent Care”, all the codes were grouped in relation to a single argumentative line: deficiencies in urgent care. Among them, we found different dimensions that are established depending on the different times of care, or the different determinant aspects of these deficiencies: disorganization of the care received, lack of experience of the professionals in emergencies, application of general protocols in the emergency services, inadequate care in the treatment received, delays in emergency care.Conclusions
In general, we highlight the dissatisfaction of the family members with respect to the care received from the emergency services. The needs of these types of situation are not covered from these services and are of low quality. Therefore, it is necessary to reorient the care protocols for these patients. 相似文献7.
The degree of metabolic acidosis at birth has been calculated in cord artery and vein samples from 21 term fetuses with cord artery pH less than 7.20. The aim of the study was to compare base deficit values calculated from either Siggaard-Andersen alignment nomogram (BD blood) or the Acid-Base chart (BD extra cellular fluid, BDecf). BDblood was found to be consistently higher in the cord artery as compared with BDecf, 13.2 +/- 3.5 and 9.9 +/- 2.9 mmol/l (Mean +/- SD), respectively. A significant correlation was found between cord artery PCO2 and BDblood whereas BDecf appeared unaffected by PCO2. In cases with cord entanglement BDecf a-v differences were increased to 3.4 +/- 2.3 mmol/l as compared with the small a-v difference noted in acidotic cases without cord entanglement, 1.1 +/- 1.25 mmol/l. It is speculated that with acutely emerging, intermittent asphyxia due to cord compression, a cord artery and vein difference in metabolic acidosis may exist and where the vein captures the basal level and the artery the acute changes. It is concluded that BDecf in both cord artery and vein add valuable information on the mechanisms behind metabolic acidosis. 相似文献
8.
ngela P. de Mattos Tereza C.M. Ribeiro Patrícia S.A. Mendes Sandra S. Valois Carlos M.C. Mendes Hugo C. Ribeiro Jr 《Nutrition Research》2009,29(7):462-469
Although previous studies have shown successful treatment of persistent diarrhea (PD) with the use of yogurt-based diets, some recent ones speculate the need of special formulas for the nutritional management of PD complicated cases. In the present study, we tested the hypothesis that the consumption of 3 lactose-free diets, with different degrees of complexity, is associated with lower stool output and shorter duration of diarrhea when compared with the use of a yogurt-based one on the nutritional management of PD. A total of 154 male infants, aged between 1 and 30 months, with PD and with or without dehydration, were randomly assigned to 1 of 4 treatment groups. Throughout the study, the patients were placed in a metabolic unit; their body weights and intakes of oral rehydration solution, water, and formula diets, in addition to outputs of stool, urine, and vomit, were measured and recorded at 24-hour intervals. Four different diets were used in this study: diet 1, yogurt-based formula; diet 2, soy-based formula; diet 3, hydrolyzed protein-based formula; and diet 4, amino acid–based formula. Throughout the study, only these formula diets were fed to the children. The data showed that children fed the yogurt-based diet (diet 1) or the amino acid–based diet (diet 4) had a significant reduction in stool output and in the duration of diarrhea. The use of an inexpensive and worldwide-available yogurt-based diet is recommended as the first choice for the nutritional management of mild to moderate PD. For the few complicated PD cases, when available, a more complex amino acid–based diet should be reserved for the nutritional management of these unresponsive and severe presentations. Soy-based or casein-based diets do not offer any specific advantage or benefits and do not seem to have a place in the management of PD. 相似文献
9.
Lucio Lucchin Amleto D’Amicis Maria Gabriella Gentile Nino Carlo Battistini Maria Antonia Fusco Augusta Palmo Maurizio Muscaritoli Franco Contaldo Emanuele Cereda 《Mediterranean journal of nutrition and metabolism》2009,2(3):171-179
Aim and methods Nutrition, unhealthy lifestyles and cancer appear to be strictly related, but few authors have analysed the interest in dietary
information of cancer patients and their families. This survey was conducted in the Veneto area (Italy) to investigate the
concern of cancer patients and their family members about diet as a health tool before and after diagnosis of cancer.
Results Seven hundred and four questionnaires were collected: 380 from cancer patients and 324 from family members of cancer subjects.
Breast cancer (BC) was the most frequent disease for patients (61.8%) as well as families (26.5%). Generally, the importance
of having precise diet information after diagnosis is recognised by 40.3% of patients, with significant differences between
the various types of cancer: gastric and colon/rectum cancer (GCC) patients were more concerned than BC women about precise
information concerning a diet to follow immediately after diagnosis (p = 0.000, ODs = 3.10, CI 1.68–5.71) or during treatments (p = 0.001, ODs = 2.67, CI 1.46–4.89). The nutritional information is supplied to patients in 34% of cases and to relatives
in 30.3%, often from non-medical sources. In total healthcare workers (family doctor, oncologist, surgeon, dietician) represented
the exclusive source of dietary information for 24.9% of patients and 22.9% of family members. Diet after diagnosis changes
in 69.1% of GCC patients and in 39.2% of BC women. Relatives, particularly women, report difficulties preparing patients’
meals in 30.7% of cases, changes in the eating habits of the entire family in 29.9% and discontent connected with patients
diet in 13.9%. The concern about proper nutrition after diagnosis increases more in GCC subjects (p < 0.025) when compared to BC subjects and in patients with more recent diagnosis (p < 0.041) when compared with patients with diagnosis >5 years ago, while in family members the interest in diet after diagnosis
increases more in women than in men (p < 0.030) without other differences regarding the degree of relationship, type of cancer or diagnosis time. Relatives (92.7%)
have more interest in nutritional education than patients (74.9%). Cancer patients <65 years were more interested in educational
initiatives concerning nutrition (p = 0.000, ODs = 4.46, CI 2.6–7.4) than older patients (>65 years) and female subjects were more concerned than male patients
(p = 0.008, ODs = 2.11, CI 1.2–3.6).
Conclusions The interest in the dietary knowledge and in educational initiatives concerning nutrition is high in cancer patients and their
relatives, although it decreases with the age. The poor attention paid to nutrition of cancer patients by various healthcare
workers deserves consideration, since the psychophysical wellbeing and perhaps also survival of cancer patients can be improved
by correct dietary management, as well as, naturally, by the principal treatments themselves. 相似文献
10.
E Cereda A Ezhaya M Gil Quintero E Bellora E Dubini R Micheletti A Schiavone A Brambilla G B Schiavi A Donetti 《Journal of medicinal chemistry》1990,33(8):2108-2113
Amidines (guanidine, formamidine, and acetamidine) were introduced as substitutes for the cationic heads present in atropine, scopolamine, and corresponding quaternary derivatives. Amidine systems are intermediate in structure between tertiary amines and quaternary compounds, at least as regards ionization and electronic properties, but differ from the latter in shape (planar not tetrahedral). They have additional binding opportunities on account of their hydrogen-bond-forming capacity. The effect of the introduction of these cationic heads on the affinity for different muscarinic acetyl choline receptor (m-AcChR) subtypes was investigated in vitro, in binding displacement studies, and in functional tests on isolated organs. All new compounds (3a,b-5a,b) showed high affinity for the m-AcChR considered, comparable or slightly inferior to that of the parent drugs (1a-e). The new amidine derivatives proved effective as spasmolytic agents, with little tendency to cause central effects. However, no separation was achieved of spasmolytic and other untoward effects, like inhibition of salivation. Thus, amidine moieties are effective bioisosteric substitutes for conventional cationic heads present in antimuscarinic agents. Their unusual physical-chemical properties make them useful tools when modulation of pharmacokinetic or pharmacodynamic effects is required. 相似文献