全文获取类型
收费全文 | 62582篇 |
免费 | 4059篇 |
国内免费 | 668篇 |
专业分类
耳鼻咽喉 | 678篇 |
儿科学 | 1364篇 |
妇产科学 | 823篇 |
基础医学 | 7993篇 |
口腔科学 | 1365篇 |
临床医学 | 6502篇 |
内科学 | 13740篇 |
皮肤病学 | 1259篇 |
神经病学 | 6525篇 |
特种医学 | 2948篇 |
外国民族医学 | 2篇 |
外科学 | 9627篇 |
综合类 | 1390篇 |
一般理论 | 15篇 |
预防医学 | 3315篇 |
眼科学 | 1125篇 |
药学 | 3994篇 |
6篇 | |
中国医学 | 422篇 |
肿瘤学 | 4216篇 |
出版年
2024年 | 60篇 |
2023年 | 556篇 |
2022年 | 939篇 |
2021年 | 1865篇 |
2020年 | 1143篇 |
2019年 | 1631篇 |
2018年 | 1963篇 |
2017年 | 1500篇 |
2016年 | 1712篇 |
2015年 | 2041篇 |
2014年 | 2536篇 |
2013年 | 3096篇 |
2012年 | 4879篇 |
2011年 | 4981篇 |
2010年 | 2959篇 |
2009年 | 2534篇 |
2008年 | 4071篇 |
2007年 | 4187篇 |
2006年 | 3812篇 |
2005年 | 3807篇 |
2004年 | 3368篇 |
2003年 | 3229篇 |
2002年 | 2937篇 |
2001年 | 894篇 |
2000年 | 824篇 |
1999年 | 783篇 |
1998年 | 592篇 |
1997年 | 459篇 |
1996年 | 387篇 |
1995年 | 310篇 |
1994年 | 271篇 |
1993年 | 214篇 |
1992年 | 283篇 |
1991年 | 248篇 |
1990年 | 199篇 |
1989年 | 196篇 |
1988年 | 181篇 |
1987年 | 135篇 |
1986年 | 138篇 |
1985年 | 119篇 |
1984年 | 140篇 |
1983年 | 103篇 |
1982年 | 88篇 |
1981年 | 66篇 |
1980年 | 66篇 |
1979年 | 62篇 |
1978年 | 55篇 |
1977年 | 62篇 |
1975年 | 54篇 |
1974年 | 55篇 |
排序方式: 共有10000条查询结果,搜索用时 20 毫秒
41.
Rodolphe Korichi Sophie Mac-Mary Ahmed Elkhyat Jean-Marie Sainthillier Pascal Ränsch Philippe Humbert Eric Viviant Germaine Gazano Christian Mahé 《Skin research and technology》2006,12(3):206-210
BACKGROUND/AIMS: The purpose of this work was to develop a new sensor for objective in vivo measurement of the cutaneous temperature based on micro-electro-mechanical systems (MEMS), and to compare these performances with those of a classical thermocouple. Research on this new sensor was carried out to allow the quantification of the thermal properties of the made-up skin. METHODS: Sixteen female subjects divided into two different age groups (18-35 and >50 years old) were recruited for this study. Several zones of the face and forearms were made up at random with foundations containing or not a thermoregulator raw material. The quantity of foundation applied on the skin was standardized and measurements were carried out first before make-up, and then 10 s and 5 min after make-up. The new sensor and the thermocouple were used successively on each zone. The cutaneous temperature was expressed in degrees celsius. RESULTS/CONCLUSION: The two systems are similar in terms of repeatability and reproducibility, with some differences in sensibility. The data measured by the MEMS sensor appear lower than those measured by the thermocouple. After make-up, the MEMS sensor detects a progressive increase of the temperature in time whereas the thermocouple detects a decrease. We found the same evolution on the face but in a more attenuated way. These results tend to show that the devices do not measure the same phenomenon. The thermocouple appears more sensitive to the thermal response of the made-up surface whereas the MEMS sensor appears more sensitive to the heat transfers in the interface between the skin and make-up. 相似文献
42.
Baher Husain Christian Kuehne Christian Waydhas Ulrike Lewan Claudia Ose Dieter Nast-Kolb Steffen Ruchholtz 《European Journal of Trauma》2006,32(6):548-554
Abstract
Background: Does there exist a difference in the outcome of severely injured children and severely injured healthy adults?
Methods: The data of 1,566 severely injured patients, treated between May 1998 and December 2002 in our emergency department of the
University Essen/Germany, were analyzed. Patients with an injury severity score (ISS) > 24 were included in the present study.
Patients younger as 18 (17) years were located to the children group c. Patients aged 18 and up to the age of 54 were included
in the adult group a.
Results: Fifty-four children and 252 adults met the selection criteria. ISS and the Glasgow coma scale (GCS) before intubation were
not statistically different in both groups. Seriously injured children stayed significantly shorter on the intensive care
unit, required significantly less ventilator days. Furthermore, the incidence of single organ failure (SOF) and multiple organ
failure (MOF) was significantly lower in the children group. Mortality in the children group (29.6%) was lower than that in
the adult group (33.7%). There was no death due to MOF in the children group as compared to 2.4% (n = 6) in the adults.
Conclusion: The incidence of SOF and MOF was significantly lower in the children group although there was no difference in ISS, GCS and
injury patterns. The prognosis of severely injured children was found to be better than those of adults. Moreover, there was
no death due to MOF in the children group. 相似文献
43.
Body weight and comorbidity predict mortality in COPD patients treated with oxygen therapy. 总被引:1,自引:0,他引:1
The aim of this study was to investigate the association between clinical variables and all-cause and respiratory mortality in patients with chronic obstructive pulmonary disease (COPD) undergoing long-term oxygen therapy (LTOT). The authors retrospectively studied a historic cohort of 128 patients with COPD (126 males, mean age+/-SD 68.9+/-9.7 yrs, body mass index (BMI) 25.1+/-4.5 kg.m-2, and forced expiratory volume in one second 25.4+/-8.8% predicted), who were being treated with long-term oxygen therapy in a tertiary teaching hospital between 1992 and 1999. Comorbidity, assessed with the Charlson Index, was present in 38% of the patients. Vital status and cause of death were assessed through the population death registry. A total of 78 patients (61%) had died by the end of follow-up. Three-year survival was 55%. Death was due to respiratory causes in 77% of cases. On Cox analysis, BMI<25 kg.m-2, comorbid conditions, age>or=70 yrs and cor pulmonale were associated with all-cause mortality. The BMI and comorbidity were the only significant predictive factors when the analysis was restricted to respiratory mortality. In conclusion, body mass index<25 kg.m-2 and comorbidity were predictors of all-cause and respiratory mortality in a cohort of chronic obstructive pulmonary disease patients treated with long-term oxygen therapy. These factors should be taken into account when considering the management and prognosis of these patients. 相似文献
44.
45.
Anton H. Schwabegger Barbara DelFrari Christian Apprich 《European journal of plastic surgery》2006,28(8):534-536
Whereas decubitus ulcer in the back or hip region is a common entity in plegic or elderly patients, the occurrence in the lateral shoulder region is seldom seen. However, resulting from continuous lateral decubitus positioning or limited compliance by the patient, pressure sores may occur in almost any region of the body, but predominately, they arise in acral zones with underlying bone prominences. The deltoid area is such an anatomically critical region, especially if the underlying deltoid muscle is paralyzed. The transposition of a pedicled deltoid flap, slightly modified as a hatchet flap, is described for cover of a decubitus ulcer in the deltoid region in a paraplegic male. Although utilization of the deltoid flap as a free flap is an established procedure for selected indications [Russell et al. (1985) Extremity reconstruction using the free deltoid flap. Plast Reconstr Surg 76:586–595, Serafin D (1996) The deltoid flap. In: Serafin D (ed) Atlas of microsurgical composite tissue transplantation, chapter 19. Saunders, Philadelphia, PA, pp 153–159, Wang et al. (2003) The free deltoid flap: microscopic anatomy studies and clinical application to oral cavity reconstruction. Plast Reconstr Surg 112:404–411], transposition as a pedicled flap, to the best of our knowledge, has not been previously described in the available literature. 相似文献
46.
Nestin expression persists in astrocytes of organotypic slice cultures from rat cortex 总被引:11,自引:0,他引:11
Rainald Schmidt-Kastner Christian Humpel 《International journal of developmental neuroscience》2002,20(1):29-38
Nestin is an intermediate filament protein typical for neural precursor cells that is down-regulated in the post-natal rodent brain. Re-expression of nestin has been observed in reactive astrocytes after injury. In this study, organotypic slice cultures from rat cortex were examined for expression of nestin and glial fibrillary acidic protein between 2 and 8 weeks in culture. Immunoreactivity for nestin and glial fibrillary acidic protein was seen in astrocytes which persisted throughout the observation period. Immunofluorescence double labeling showed widespread co-localization of nestin and glial fibrillary acidic protein. Image analysis revealed that levels of nestin-immunoreactivity plateaued after 5 weeks in culture. By comparison nestin immunoreactivity was absent from glial cells of the cortex in mature rats. These immunohistochemical findings of a persistent expression of nestin in glial cells of organotypic slice culture of the rat cortex indicate a different time course of glial maturation in vitro. This difference could be related to the altered trophic stimulation in vitro; differences in neuronal maturation, activity or survival; slow degeneration of the vasculature; or intrinsic properties of astrocytes. 相似文献
47.
48.
49.
50.
Christian Miel 《L'évolution Psychiatrique》2002,67(2):326
In this article we shall see how using drugs disturbs the activity of projective identification and symbolical processes. The addict clinic makes known the early difficulties of expression of projective identification in correction with mother object apprehended like persecuting or idealizing. Because of real trauma or difficulties to realize the process of separation-individuation, the repression has not succeeded to put up or has become insufficient. In the same way, the psychic work of projection and introjection has been put in parentheses by the drug. This one, by activating a narcissistic libido to hold the representations of destructive instincts, substitutes an incorporation act to introjection, signs the breaking off the object relation and compromises the process of symbolization. The incorporation act expresses a traumatic experience, which has not been symbolized in an incorporation fantasy. It’s going on by a process of demetaphorisation. Contrary to psychotic personality, the stop of the projective identification avoids the loss of the identity feeling. The percept system is distorted to accuse the destabilising effects of an external and internal reality. 相似文献