全文获取类型
收费全文 | 274393篇 |
免费 | 15829篇 |
国内免费 | 1075篇 |
专业分类
耳鼻咽喉 | 3132篇 |
儿科学 | 8922篇 |
妇产科学 | 6034篇 |
基础医学 | 38206篇 |
口腔科学 | 10425篇 |
临床医学 | 21975篇 |
内科学 | 62031篇 |
皮肤病学 | 6963篇 |
神经病学 | 24699篇 |
特种医学 | 7873篇 |
外国民族医学 | 27篇 |
外科学 | 30753篇 |
综合类 | 1840篇 |
现状与发展 | 1篇 |
一般理论 | 112篇 |
预防医学 | 27345篇 |
眼科学 | 4967篇 |
药学 | 17588篇 |
中国医学 | 999篇 |
肿瘤学 | 17405篇 |
出版年
2023年 | 1843篇 |
2022年 | 4007篇 |
2021年 | 7054篇 |
2020年 | 4571篇 |
2019年 | 6343篇 |
2018年 | 8165篇 |
2017年 | 6212篇 |
2016年 | 6360篇 |
2015年 | 7165篇 |
2014年 | 9546篇 |
2013年 | 12358篇 |
2012年 | 19017篇 |
2011年 | 19654篇 |
2010年 | 10351篇 |
2009年 | 9203篇 |
2008年 | 15522篇 |
2007年 | 16203篇 |
2006年 | 15007篇 |
2005年 | 14992篇 |
2004年 | 13777篇 |
2003年 | 12585篇 |
2002年 | 10124篇 |
2001年 | 5666篇 |
2000年 | 5485篇 |
1999年 | 5118篇 |
1998年 | 2357篇 |
1997年 | 1962篇 |
1996年 | 1851篇 |
1995年 | 1556篇 |
1994年 | 1526篇 |
1993年 | 1334篇 |
1992年 | 3067篇 |
1991年 | 2891篇 |
1990年 | 2652篇 |
1989年 | 2616篇 |
1988年 | 2383篇 |
1987年 | 2179篇 |
1986年 | 2063篇 |
1985年 | 1929篇 |
1984年 | 1443篇 |
1983年 | 1192篇 |
1982年 | 754篇 |
1981年 | 636篇 |
1980年 | 623篇 |
1979年 | 1037篇 |
1978年 | 715篇 |
1977年 | 572篇 |
1975年 | 619篇 |
1974年 | 642篇 |
1973年 | 623篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
Aneurisma de aorta abdominal infrarrenal en asociación con riñón en herradura: aportación de un caso
Nerea Senarriaga Ruiz de la Illa Reyes Vega Manrique Isabel Lacasa Viscasillas Iñaki Iriarte Soldevilla Miguel Unda Urzaiz 《Actas urologicas espa?olas》2009,33(10):1141-1144
We review the association between surgically resolvable aortic disease and horseshoe kidney with a discussion of diagnostic problems and therapeutic options.Male patient 81 years of age with horseshoe kidney and an abdominal aortic aneurysm that was discovered by chance in an abdominal ultrasound during a check-up for his prostate condition.A retroperitoneal approach was used in order to resect the aneurysm and perform an aorto-aortic bypass with no complications occurring. Two years after the diagnosis, the patient is still asymptomatic from a vascular point of view.The co-presence of horseshoe kidney and aortic disease needing surgical correction is infrequent, but it significantly increases the technical complexity of aortic reconstruction. A literature review is included. 相似文献
64.
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
65.
Human immunodeficiency virus infection in urban Rwanda. Demographic and behavioral correlates in a representative sample of childbearing women 总被引:9,自引:0,他引:9
S Allen C Lindan A Serufilira P Van de Perre A C Rundle F Nsengumuremyi M Carael J Schwalbe S Hulley 《JAMA》1991,266(12):1657-1663
OBJECTIVE.--To determine behavioral and demographic risk factors for human immunodeficiency virus (HIV) infection in central Africa. DESIGN.--Cross-sectional survey. SETTING.--Kigali, Rwanda. PARTICIPANTS.--A representative sample of 1458 childbearing women aged 19 to 37 years who were recruited from outpatient prenatal and pediatric clinics at the only community hospital in the city. MAIN OUTCOME MEASURE.--Antibodies to HIV assessed by enzyme immunoassay and confirmed by Western blot or indirect immunofluorescence. RESULTS.--The HIV seroprevalence was 32% overall. Infection rates were higher in women who were single, in those in steady relationships that began after 1981, and in the 33% of women reporting more than one lifetime sexual partner. Women in legal marriages or monogamous partnerships had lower rates of infection, but even low-risk women had prevalences on the order of 20%. History of venereal disease in the past 5 years, although the strongest risk factor in a multiple logistic analysis (odds ratio, 2.7; 95% confidence interval, 2.0 to 3.7), was reported by only 30% of those infected. Having a male sexual partner who drank alcohol or who had higher income were significant risk factors for HIV infection in the multivariate analysis, but use of oral contraceptives and having an uncircumcised partner were not. CONCLUSIONS.--The epidemic of the acquired immunodeficiency syndrome in Rwanda has spread beyond high-risk groups to the general population of women without known risk factors. For most of these women, a steady male partner is the source of their HIV risk and therefore a vital target for intervention efforts. 相似文献
66.
67.
Henyse G V Silva Rosangela P Tórtora Maria Lucia F Farias 《Gynecological endocrinology》2005,21(3):174-179
To evaluate the impact of pregnancy on bone, we studied bone turnover at the first (T1) and third (T3) trimester of gestation in 58 adolescents and 28 healthy adolescents who had never been pregnant. Total body (TB) and lumbar spine (LS) bone mineral density (BMD) and body composition were evaluated by dual-energy X-ray absorptiometry in all control patients (C) and after parturition in 28 pregnant patients (G). Paired and unpaired t tests, Mann-Whitney and Pearson correlation tests were used. Bone turnover markers were above the reference range for adult women in more than 80% of the adolescents, with no difference between C and G patients at T1. Increase in urinary N-telopeptide crosslinks of type I collagen and serum bone-specific alkaline phosphatase, markers of bone turnover, was seen during pregnancy ( p < 0.0001). Body composition did not differ between groups, but LS BMD, percentage of expected LS BMD, LS Z-score, percentage of expected TB BMD and TB Z-score were lower in G than C patients ( p < 0.05). TB BMD was positively correlated with LS BMD (r2 = 0.52). The inverse correlations between bone markers and LS BMD suggest that the increased bone turnover during pregnancy probably explains the low bone density after parturition. The impact on future peak bone mass must be studied. 相似文献
68.
Esparza-Gordillo Jorge; Goicoechea de Jorge Elena; Buil Alfonso; Berges Luis Carreras; Lopez-Trascasa Margarita; Sanchez-Corral Pilar; Rodriguez de Cordoba Santiago 《Human molecular genetics》2005,14(8):1107
Some MCP SNP and aHUS-associated MCP mutation 相似文献
69.
B Sarmento D C Ferreira L Jorgensen M van de Weert 《European journal of pharmaceutics and biopharmaceutics》2007,65(1):10-17
The aim of the present study was to probe the structural integrity of insulin after being entrapped into chitosan/alginate nanoparticles produced by ionotropic polyelectrolyte pre-gelation. By manipulating the alginate:chitosan mass ratio and the pH during nanoparticle production, desired nanoparticles with a mean size of 850 (+/-88)nm and insulin association efficiency of 81 (+/-2)% were obtained. Insulin secondary structure was assessed by Fourier transform infrared (FTIR) and circular dichroism (CD) after entrapment into nanoparticles and after release from the particles under gastrointestinal simulated conditions. FTIR second-derivative spectra and area-overlap compared to an insulin standard confirmed that no significant conformational changes of insulin occurred in terms of alpha-helix and beta-sheet content. Far-UV-CD spectra corroborated the preservation of insulin structure during the nanoparticle production procedure. The presented nanoparticulate system is a promising carrier for insulin oral delivery since it preserves insulin structure and therefore also, potentially, its bioactivity. 相似文献
70.
L. van den Bemt M. P. de Vries L. van Knapen M. Jansen M. Goossens J. W. M. Muris C. P. van Schayck 《Clinical and experimental allergy》2006,36(2):233-237
BACKGROUND: Exposure to a high level of house dust mite allergens (HDMAs) is considered as a risk factor for HDM sensitization and development of asthma in genetically disposed people. Mattresses are one of the most important sources of HDMA in people's living environment. OBJECTIVE: The aim of this study was to evaluate the association between mattress characteristics and HDMA concentrations on mattresses. METHODS: Dust samples of mattress surfaces were taken to evaluate the level of Der p 1 allergen. All participants filled in a questionnaire about the type of mattress, the type of covering (upper layer) of the mattress, dwelling characteristics and cleaning habits. Humidity and temperature of the bedroom were measured at the time of dust sampling. RESULTS: One hundred and sixty-eight questionnaires were filled in. Synthetic upper layer of the mattress was associated with a higher level of Der p 1 compared with cotton upper layer (2.6 vs. 0.8 microg/g Der p 1). Moreover, higher relative humidity (RH) was associated with significant higher concentrations and density of Der p 1. CONCLUSIONS: Two factors were associated with lower levels of Der p 1 found on mattresses, namely: a cotton upper layer of the mattress compared with a layer of synthetic material and lower RH at the time of sampling. As far as we know, the association between type of upper layer and concentration of Der p 1 has not been described before and could lead to the formulation of practical advices in order to reduce HDMA concentrations on mattresses. 相似文献