全文获取类型
收费全文 | 4708篇 |
免费 | 248篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 78篇 |
儿科学 | 102篇 |
妇产科学 | 101篇 |
基础医学 | 623篇 |
口腔科学 | 217篇 |
临床医学 | 355篇 |
内科学 | 866篇 |
皮肤病学 | 136篇 |
神经病学 | 313篇 |
特种医学 | 110篇 |
外科学 | 677篇 |
综合类 | 18篇 |
预防医学 | 735篇 |
眼科学 | 110篇 |
药学 | 369篇 |
中国医学 | 49篇 |
肿瘤学 | 104篇 |
出版年
2023年 | 45篇 |
2022年 | 29篇 |
2021年 | 87篇 |
2020年 | 74篇 |
2019年 | 100篇 |
2018年 | 199篇 |
2017年 | 104篇 |
2016年 | 136篇 |
2015年 | 118篇 |
2014年 | 122篇 |
2013年 | 222篇 |
2012年 | 388篇 |
2011年 | 527篇 |
2010年 | 218篇 |
2009年 | 102篇 |
2008年 | 318篇 |
2007年 | 366篇 |
2006年 | 308篇 |
2005年 | 283篇 |
2004年 | 279篇 |
2003年 | 227篇 |
2002年 | 195篇 |
2001年 | 79篇 |
2000年 | 135篇 |
1999年 | 69篇 |
1998年 | 15篇 |
1997年 | 12篇 |
1996年 | 14篇 |
1995年 | 7篇 |
1994年 | 11篇 |
1993年 | 11篇 |
1992年 | 13篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1985年 | 7篇 |
1983年 | 5篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 7篇 |
1977年 | 6篇 |
1976年 | 16篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1967年 | 7篇 |
1934年 | 4篇 |
排序方式: 共有4963条查询结果,搜索用时 31 毫秒
1.
2.
Neuroimaging in Pineal Tumors 总被引:4,自引:0,他引:4
F Reis MD AV Faria MD PhD VA Zanardi MD PhD JR Menezes MD F Cendes MD PhD LS Queiroz MD PhD 《Journal of neuroimaging》2006,16(1):52-58
BACKGROUND AND PURPOSE: The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. METHODS: Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. RESULTS: CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2-weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. CONCLUSIONS: Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread. 相似文献
3.
R. Alcázar-Olán D. Reyes-Chiquete R. Plancarte-Sánchez 《Clinical & translational oncology》2003,5(2):65-69
Resumen El equipo médico debe estar preparado para evaluar a los pacientes que solicitan muerte asistida.
En esta revisión hemos recopilado de la literatura internacional los criterios médicos y psicológicos para evaluar a los pacientes
que solicitan muerte asistida con la finalidad de aliviar las necesidades fisicas, psicológicas y sociales de los pacientes
y sus familias.
Se realizó un estudio de tipo exploratorio seleccionando los artículos que propusieran protocolos de valoración psicológica
y médica de los pacientes que solicitan muerte asistida. Se analizó qué aspectos son los que se evalúan con mayor frecuencia
en la literatura internacional.
Se identificaron dos posturas generales para la valoración del paciente: por un lado la valoración de su competencia para
la toma de decisiones y por otro la valoración del sufrimiento físico, seguido por el sufrimiento psicológico, social, existencial/espiritual,
la relación médico-paciente y la relación médico-familiares. Finalmente se enumeran una serie de principios que pueden guiar
al clínico ante la petición de muerte asistida.
相似文献
4.
5.
Bâ A 《Developmental psychobiology》2005,47(4):408-414
Thiamine deficiency (B1 vitamin) was induced during three periods of rat central nervous system (CNS) ontogenesis. Females were fed a thiamine deficient diet such that developing offspring were exposed either to pre-, peri-, or postnatal thiamine deficiency. To control the effects of undernourishment generated by different thiamine deficiencies, every treatment group had its own pair-fed control pup from a non drug-treated but undernourished dam. Seven different developmental abilities (exploratory activity, emotional reaction, hind paws lifting reflex, wire grasping times, crawling and leap execution latencies, and nociception) were recorded in the offspring from the 10th to the 45th postnatal day. The vulnerability of developing brain to the specific lack of B1 vitamin increases from prenatal (28%) to perinatal (43%) and postnatal periods (57%). 相似文献
6.
Involvement of CD14 and beta2-integrins in activating cells with soluble and particulate lipopolysaccharides and mannuronic acid polymers 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Flo TH Ryan L Kilaas L Skjâk-Braek G Ingalls RR Sundan A Golenbock DT Espevik T 《Infection and immunity》2000,68(12):6770-6776
Lipopolysaccharide (LPS) and related bacterial products can be recognized by host inflammatory cells in a particulate, bacterium-bound form, as well as in various soluble, released forms. In the present study we have compared the mechanisms used by LPS, detoxified LPS (DLPS), and mannuronic acid polymers (M-polymers), in solution or covalently linked to particles, in stimulating monocytes to tumor necrosis factor (TNF) production. The addition of recombinant LPS binding protein (LBP) and/or soluble CD14 (sCD14) enhanced the production of TNF from monocytes stimulated with soluble LPS, DLPS, or M-polymer, but did not affect the response to M-polymer or DLPS attached to particles. Treatment of monocytes with antibody to CD14, CD18, or CD11b showed that CD14, but not CR3 (CD11b/CD18), mediated monocyte TNF production in response to the soluble antigens. In contrast, anti-CD14, anti-CD11b and anti-CD18 monoclonal antibodies all inhibited the response to the particulate stimuli. On the other hand, B975, a synthetic analog of Rhodobacter capsulatus lipid A, completely abrogated the monocyte TNF response induced by LPS but did not affect the TNF induction by DLPS or M-polymer, either in soluble or particulate forms. These data demonstrate that the engagement of immune receptors by bacterial products such as LPS, DLPS, and M-polymer is dependent upon the presentation form of their constituent carbohydrates, and that factors such as aggregation state, acylation, carbohydrate chain length, and solid versus liquid phase of bacterial ligands influence the mechanisms used by cells in mediating proinflammatory responses. 相似文献
7.
Tadokoro CE Vallochi AL Rios LS Martins GA Schlesinger D Mosca T Kuchroo VK Rizzo LV Abrahamsohn IA 《Journal of autoimmunity》2004,23(2):103-115
Trypanosoma cruzi is an intracellular parasite that induces a strong Th1-type response and immunosuppression during the acute phase of infection. To study how the infection with T. cruzi would modulate the development of an autoimmune disease, we immunized C57BL/6 mice and IL-10 or iNOS knock-out mice of the same background with the encephalitogenic MOG 35-55 peptide and infected them with T. cruzi. Our results demonstrate that infection with T. cruzi completely prevents EAE development and furthermore induces complete and lasting remission in mice that were infected with this parasite after they had developed clinical EAE. Nitric oxide and IL-10 participate in triggering the mechanisms associated with EAE suppression by the infection. Decreased lymphoproliferation and increased frequencies of Annexin-positive cells and of T cells bearing CD95, CD95L or CTLA-4 were observed in the spleen from immunized/infected mice, as well as lower IL-2 and increased TGF-beta production in comparison with only immunized mice. Our results indicate that several effector and regulatory mechanisms of the immune response that arise during the acute phase of T. cruzi infection lastingly affect the expansion and/or effector functions of encephalitogenic cells, preventing the onset or inducing complete remission of EAE. 相似文献
8.
García-Sellés FJ Díaz-Perales A Sánchez-Monge R Alcántara M Lombardero M Barber D Salcedo G Fernández-Rivas M 《International archives of allergy and immunology》2002,128(2):115-122
BACKGROUND: Lipid transfer proteins (LTPs) are major allergens of Rosaceae fruits in the Mediterranean area. IgE-cross-reactivity has been demonstrated in vitro among LTPs from peach, apple, chestnut and Artemisia pollen. The aim of this study was to evaluate the reactivity to LTPs from peach, apple, chestnut and Artemisia pollen by means of skin prick tests (SPTs). METHODS: Forty-seven patients allergic to peach (peach group), 20 patients sensitized to Artemisia pollen with no food allergies (Artemisia group), and 12 control subjects were skin tested with fresh peach, as well as with whole extracts and purified LTPs of peach, apple, chestnut and Artemisia pollen. RESULTS: The rates of positive SPTs for peach, apple, chestnut and Artemisia LTPs were, respectively, 91, 77, 23, and 36% in the peach group, and 30, 5, 15 and 40% in the Artemisia group. No response was observed in the control subjects. SPTs with peach LTP strongly correlated with SPTs conducted with fresh peach. In the peach group, the most frequent pattern of reactivity to LTPs was the combination peach-apple (45%), followed by peach-apple-Artemisia-chestnut (21%). Significant correlations were found between peach and apple LTPs, and between Artemisia and chestnut LTPs. Positive SPTs to chestnut LTP were only observed in patients with positive SPTs to Artemisia LTP. All the patients with positive case histories to chestnut reacted to chestnut LTP. CONCLUSIONS: LTPs are plant panallergens with different patterns of cross-reactivity. They are major allergens of Rosaceae fruits and seem to be involved in allergic reactions to unrelated foodstuffs such as chestnut, probably through sensitization to the cross-reactive Artemisia LTP. Rosaceae LTPs could be useful tools for in vivo diagnosis of Rosaceae fruit allergy. 相似文献
9.
Adrià Rofes Emmanuel Mandonnet Vânia de Aguiar Brenda Rapp Kyrana Tsapkini Gabriele Miceli 《Cognitive neuropsychology》2019,36(3-4):117-139
ABSTRACTElectrical Stimulation (ES) is a neurostimulation technique that is used to localize language functions in the brain of people with intractable epilepsy and/or brain tumors. We reviewed 25 ES articles published between 1984 and 2018 and interpreted them from a cognitive neuropsychological perspective. Our aim was to highlight ES as a tool to further our understanding of cognitive models of language. We focused on associations and dissociations between cognitive functions within the framework of two non-neuroanatomically specified models of language. Also, we discussed parallels between the ES and the stroke literatures and showed how ES data can help us to generate hypotheses regarding how language is processed. A good understanding of cognitive models of language is essential to motivate task selection and to tailor surgical procedures, for example, by avoiding testing the same cognitive functions and understanding which functions may be more or less relevant to be tested during surgery. 相似文献
10.
Myo-inositol transport in the central nervous system 总被引:18,自引:0,他引:18