全文获取类型
收费全文 | 9767篇 |
免费 | 545篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 40篇 |
儿科学 | 178篇 |
妇产科学 | 182篇 |
基础医学 | 1306篇 |
口腔科学 | 445篇 |
临床医学 | 813篇 |
内科学 | 2652篇 |
皮肤病学 | 255篇 |
神经病学 | 994篇 |
特种医学 | 297篇 |
外科学 | 1168篇 |
综合类 | 26篇 |
一般理论 | 2篇 |
预防医学 | 457篇 |
眼科学 | 131篇 |
药学 | 559篇 |
中国医学 | 27篇 |
肿瘤学 | 820篇 |
出版年
2024年 | 8篇 |
2023年 | 72篇 |
2022年 | 153篇 |
2021年 | 290篇 |
2020年 | 158篇 |
2019年 | 230篇 |
2018年 | 272篇 |
2017年 | 217篇 |
2016年 | 223篇 |
2015年 | 276篇 |
2014年 | 384篇 |
2013年 | 475篇 |
2012年 | 767篇 |
2011年 | 788篇 |
2010年 | 409篇 |
2009年 | 372篇 |
2008年 | 654篇 |
2007年 | 671篇 |
2006年 | 592篇 |
2005年 | 641篇 |
2004年 | 553篇 |
2003年 | 496篇 |
2002年 | 477篇 |
2001年 | 100篇 |
2000年 | 87篇 |
1999年 | 90篇 |
1998年 | 107篇 |
1997年 | 74篇 |
1996年 | 73篇 |
1995年 | 68篇 |
1994年 | 57篇 |
1993年 | 40篇 |
1992年 | 48篇 |
1991年 | 46篇 |
1990年 | 47篇 |
1989年 | 44篇 |
1988年 | 30篇 |
1987年 | 35篇 |
1986年 | 34篇 |
1985年 | 23篇 |
1984年 | 23篇 |
1983年 | 24篇 |
1982年 | 18篇 |
1981年 | 8篇 |
1980年 | 18篇 |
1979年 | 9篇 |
1976年 | 9篇 |
1974年 | 8篇 |
1970年 | 6篇 |
1968年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Roberta Cassano Teresa Ferrarelli Maria Vittoria Mauro Paolina Cavalcanti Nevio Picci 《Drug delivery》2016,23(3):1037-1046
The present article reports the preparation, characterization and performance evaluation of solid lipid nanoparticles (SLNs) based on polyoxyethylene-40 stearate (PEG-40 stearate) for the administration of antifungal agents such as ketoconazole and clotrimazole. These nanoparticles could be useful in the treatment of vaginal infections sustained by Candida albicans. In particular, PEG-40 stearate was made to react with acryloyl chloride in order to introduce an easily polymerizable moiety for the creation of a second shell and to ensure a slow drug release. In addition, the differences on the release profiles between PEG-40 stearate-based nanoparticles, PEG-40 stearate acrylate based and polymerized ones, were analyzed under conditions, simulating the typical environment of Candida albicans infection. Then, the antifungal activity of nanoparticles was also evaluated in terms of minimal inhibitory concentration. Moreover, the nanoparticles were submitted to in vitro studies for evaluating the drug permeability at the site of action. Results indicated that the obtained particles are potentially useful for the treatment of vaginal infections sustained by Candida albicans. 相似文献
82.
This paper reviews the state-of-the-art technologies, characterizations, materials (precursors and encapsulants), and challenges concerning multicolor and white light-emitting diodes (LEDs) based on carbon dots (CDs) as color converters. Herein, CDs are exploited to achieve emission in LEDs at wavelengths longer than the pump wavelength. White LEDs are typically obtained by pumping broad band visible-emitting CDs by an UV LED, or yellow–green-emitting CDs by a blue LED. The most important methods used to produce CDs, top-down and bottom-up, are described in detail, together with the process that allows one to embed the synthetized CDs on the surface of the pumping LEDs. Experimental results show that CDs are very promising ecofriendly candidates with the potential to replace phosphors in traditional color conversion LEDs. The future for these devices is bright, but several goals must still be achieved to reach full maturity. 相似文献
83.
84.
Francesco Cogliati Dezza Alessandra Oliva Vera Mauro Francesco Eugenio Romani Raissa Aronica Giulia Savelloni Elena Casali Serena Valeri Francesca Cancelli Claudio Maria Mastroianni 《Le infezioni in medicina : rivista periodica di eziologia, epidemiologia, diagnostica, clinica e terapia delle patologie infettive》2022,30(2):211
85.
86.
Mauro S. B. Silva Laurine Decoster Sara Trova Nour E.H. Mimouni Virginia Delli Konstantina Chachlaki Qiang Yu Ulrich Boehm Vincent Prevot Paolo Giacobini 《Proceedings of the National Academy of Sciences of the United States of America》2022,119(30)
Women with polycystic ovary syndrome (PCOS) frequently experience decreased sexual arousal, desire, and sexual satisfaction. While the hypothalamus is known to regulate sexual behavior, the specific neuronal pathways affected in patients with PCOS are not known. To dissect the underlying neural circuitry, we capitalized on a robust preclinical animal model that reliably recapitulates all cardinal PCOS features. We discovered that female mice prenatally treated with anti-Müllerian hormone (PAMH) display impaired sexual behavior and sexual partner preference over the reproductive age. Blunted female sexual behavior was associated with increased sexual rejection and independent of sex steroid hormone status. Structurally, sexual dysfunction was associated with a substantial loss of neuronal nitric oxide synthase (nNOS)-expressing neurons in the ventromedial nucleus of the hypothalamus (VMH) and other areas of hypothalamic nuclei involved in social behaviors. Using in vivo chemogenetic manipulation, we show that nNOSVMH neurons are required for the display of normal sexual behavior in female mice and that pharmacological replenishment of nitric oxide restores normal sexual performance in PAMH mice. Our data provide a framework to investigate facets of hypothalamic nNOS neuron biology with implications for sexual disturbances in PCOS.Polycystic ovary syndrome (PCOS) is a highly prevalent disease affecting 5 to 18% of women of reproductive age worldwide (1, 2). PCOS is diagnosed upon the presence of at least two out of three prime features: high circulating levels of androgens (hyperandrogenism), menstrual irregularities (oligo-anovulation), and polycystic-like ovarian morphology (2, 3). Beyond its implications leading to female infertility, the disease is associated with several metabolic disruptions, cardiovascular diseases, and psychosocial disorders (4). Among these neurological implications, it has become clear that approximately 30% or more of patients with PCOS experience sexual dysfunctions, with clinical studies reporting a high risk of low sexual arousal, desire, and satisfaction and impaired lubrication and orgasm (5–9). These symptoms allude to disturbances in brain circuits controlling sexual function in the context of PCOS.Neural circuits driving female sexual behaviors are conserved among vertebrate species operating under the influence of sex steroid hormone modulation, which is paramount for partner interaction, receptivity, and sexual performance (10, 11). Indeed, gonadal sex hormones are implicated in shaping circuit architecture in the hypothalamus during development and activating these neonatally programmed circuits over reproductive adult life in many species (12–16). The hypothalamus integrates sensorial stimuli and autonomic arousal from endogenous sex drive cues (e.g., estrous phase, energy status, hormone milieu, genital stimulation) to convey this information to other brain areas and peripheral nerves (10, 17). The ventromedial nucleus of the hypothalamus (VMH) is considered the hub of specialized neurons, with intrinsic properties driving different components of sexual behavior (18–21). The VMH harbors neurons expressing neuronal nitric oxide synthase (nNOS), the enzyme responsible for the production of nitric oxide (NO), a key gaseous neurotransmitter that stimulates female sexual behavior (22, 23) and communicates with other circuits within the social brain (24, 25). Despite current advances unraveling novel pathways in the female sexual brain with specific behavioral responses, there is a clear lack of knowledge on how disturbances in these circuits may participate in sexual dysfunctions affecting one-third of women with PCOS.Growing evidence indicates that androgen excess in utero induces a developmental reprogramming of the female fetal brain toward the manifestation of PCOS traits later in life (26–29). Some studies have suggested that the clinical signs of hyperandrogenism have detrimental sexual effects (5), indicating a negative correlation between androgen levels and sexual function in PCOS. In recent years, it has been proposed that prenatal anti-Müllerian hormone excess may trigger gestational hyperandrogenism via the inhibition of placental aromatase (29, 30) and that women with PCOS display higher circulating levels of androgens and AMH during pregnancy as compared to healthy women (29, 31). Prenatal AMH-treated mice (PAMH) reliably recapitulate all the mouse equivalents of the PCOS Rotterdam criteria (29, 32) and are thus a preclinical model to mimic the human PCOS condition. PAMH female mice also display pronounced neuroendocrine dysfunction leading to exacerbated luteinizing hormone (LH) secretion (29), as in women with PCOS (33), denoting the presence of prenatally reprogrammed defects within the gonadotropin-releasing hormone (GnRH) neuronal network. Thus, prenatal AMH excess–mediated disruptions in the female brain may be key to understanding the pathophysiology of PCOS.Here, we investigated whether prenatal AMH excess could underpin defects in sex circuits promoting sexual dysfunction in PCOS-like female mice. We uncovered a profound decrease of nNOS and progesterone receptor (PR) expression in the VMH. These anatomical changes were also associated with significant impairment of sexual receptivity in PCOS-like female mice. Nevertheless, normal sexual function in PAMH female mice was restored to control levels upon peripheral injection of NO donor. Performing a series of acute functional manipulations in freely moving female mice, we showed that chemogenetic silencing of nNOSVMH neurons in control female mice recapitulates PCOS-like sexual dysfunctions. Taken together, we unveiled a brain pathway potentially underpinning the etiology of low sexual drive in PCOS while pointing to prospective therapeutic approaches to rescue normal sexual function in these women. 相似文献
87.
Michela Ricca Maria Francesca Alberghina Negin Derakhshan Houreh Aybuke Sultan Koca Salvatore Schiavone Mauro Francesco La Russa Luciana Randazzo Silvestro Antonio Ruffolo 《Materials》2022,15(9)
A multi-analytical approach was employed to study wall paintings located in the Sotterra church at Paola, in the province of Cosenza, Italy. The site is an underground church (hence the name of Sotterra, which means “under the earth”) rediscovered in the second half of the 19th century, during the building works of the Madonna del Carmine church on the same area. This underground church preserves valuable mural paintings having different styles. The construction’s dating and overlapped modifications made until the site was abandoned is also debated. A wall painting, depicting “The Virgin” as part of the “Annunciation and the Archangel Gabriel” present on the opposite side of the apse, was selected and investigated using both in situ and laboratory-based analysis. Preliminarily, the non-destructive investigations involved several analytical techniques (IR imaging, UV-Induced Visible Fluorescence, and X-ray Fluorescence analyses) that provided mapping and characterization of pictorial layers and first data about deterioration phenomena. On the basis of this information, a more in-depth study was conducted on micro-fragments aimed at characterizing the stratigraphy and to identify the artist’s technique. Cross-sections were analysed using polarized optical microscopy and electron scanning microscopy coupled with energy-dispersive X-ray spectroscopy to obtain morphological and chemical information on the selected pictorial micro-fragments of the wall painting. The results allowed to characterize the pigments and provide better readability of the whole figure, revealing details that are not visible to the naked eye, important for future historical-artistic and conservative studies. The results represent the first step of a systematic archaeometric research aimed at supporting the ongoing historical-stylistic studies to distinguish the different building phases hypothesized for this religious site which remained buried for three centuries. 相似文献
88.
Elena Cichero Anna Basile Maria Caterina Turco Mauro Mazzei Paola Fossa 《Medicinal chemistry research》2012,21(12):4430-4436
HSC70 has been identified as an important molecular target involved in the ΔF508-CFTR cystic fibrosis. HSC70 associates ΔF508-CFTR to a much greater extent than WT-CFTR and after this step, it recruits other co-chaperones (BAG1, CHIP) and performs the ubiquitination and proteosomal degradation of the protein. Up to now, several X-ray data concerning the HSC70:BAG1 complexes are available. Thus, we performed an “in silico” investigation focused to explore which different amino acid residues are involved in the binding of ATP, the natural substrate, and the co-crystallized ligands at the HSC70/BAG-1 interface. The study allowed us to evaluate sildenafil and KM11060, which proved to be also CFTR correctors, as potential HSC70:BAG1 inhibitors, and also let us derive interesting perspectives for the development of new CFTR correctors. 相似文献
89.
90.
Patrizio Tatti Leonardo Masselli Patrizia Di Mauro Giuseppe Pipicelli Annalisa Pipicelli Annabel Barber 《Mediterranean journal of nutrition and metabolism》2012,5(1):67-69
We evaluated if a nutritional supplement containing arginine, glutamine, β-hydroxy-β-methyl butyrate commonly used to improve the healing of diabetic foot ulcers had any effect on the kidney function in the diabetic patients. We hypothesized that the action on the skin may be nonspecific and that the supplement might also act on other structural elements of the kidney. We compared the evolution of the blood creatinine and of the overnight albumin excretion in 16 diabetic subjects with mild to moderate nephropathy 6 months prior to and during the 6 months of treatment. The creatinine level remained stable during the treatment, while microalbuminuria decreased to nearly 50% of the initial value (p < 0.000). 相似文献