全文获取类型
收费全文 | 500篇 |
免费 | 34篇 |
出版年
2023年 | 1篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 9篇 |
2017年 | 7篇 |
2016年 | 8篇 |
2015年 | 18篇 |
2014年 | 18篇 |
2013年 | 21篇 |
2012年 | 28篇 |
2011年 | 35篇 |
2010年 | 11篇 |
2009年 | 25篇 |
2008年 | 34篇 |
2007年 | 28篇 |
2006年 | 21篇 |
2005年 | 18篇 |
2004年 | 26篇 |
2003年 | 24篇 |
2002年 | 12篇 |
2001年 | 17篇 |
2000年 | 12篇 |
1999年 | 9篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 15篇 |
1991年 | 9篇 |
1990年 | 12篇 |
1989年 | 11篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 8篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1980年 | 2篇 |
1979年 | 13篇 |
1978年 | 7篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1973年 | 3篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1967年 | 3篇 |
1965年 | 3篇 |
排序方式: 共有534条查询结果,搜索用时 391 毫秒
51.
Angelo Campanozzi Sonia Avallone Antonio Barbato Roberto Iacone Ornella Russo Gianpaolo De Filippo Giuseppina D’Angelo Licia Pensabene Basilio Malamisura Gaetano Cecere Maria Micillo Ruggiero Francavilla Anna Tetro Giuliano Lombardi Lisa Tonelli Giuseppe Castellucci Luigi Ferraro Rita Di Biase Antonella Lezo Silvia Salvatore Silvia Paoletti Alfonso Siani Daniela Galeone Pasquale Strazzullo MINISAL-GIRCSI Program Study Group 《PloS one》2015,10(4)
Background
Hypertension is the leading cause of death in developed countries and reduction of salt intake is recommended as a key preventive measure.Objective
To assess the dietary sodium and potassium intakes in a national sample of Italian children and adolescents and to examine their relationships with BMI and blood pressure (BP) in the framework of the MINISAL survey, a program supported by the Italian Ministry of Health.Population and Methods
The study population included 1424 healthy subjects (766 boys, 658 girls) aged 6-18 years (mean age: 10.1±2.9) who were consecutively recruited in participating National Health Service centers in 10 Italian regions. Electrolyte intake was estimated from 24 hour urine collections tested for completeness by the concomitant measurement of creatinine content. Anthropometric indices and BP were measured with standardized procedures.Results
The average estimated sodium intake was 129 mmol (7.4 g of salt) per day among boys and 117 mmol (6.7 g of salt) among girls. Ninety-three percent of the boys and 89% of the girls had a consumption higher than the recommended age-specific standard dietary target. The estimated average daily potassium intakes were 39 mmol (1.53 g) and 36 mmol (1.40 g), respectively, over 96% of the boys and 98% of the girls having a potassium intake lower than the recommended adequate intake. The mean sodium/potassium ratio was similar among boys and girls (3.5 and 3.4, respectively) and over 3-fold greater than the desirable level. Sodium intake was directly related to age, body mass and BP in the whole population.Conclusions
The Italian pediatric population is characterized by excessive sodium and deficient potassium intake. These data suggest that future campaigns should focus on children and adolescents as a major target in the framework of a population strategy of cardiovascular prevention. 相似文献52.
Alessandra V.R. da Silva Bibiana M. De Souza Marcia P. dos Santos Cabrera Nathalia B. Dias Paulo C. Gomes João Ruggiero Neto Rodrigo G. Stabeli Mario S. Palma 《生物化学与生物物理学报:生物膜》2014
Polycationic peptides may present their C-termini in either amidated or acidic form; however, the effects of these conformations on the mechanisms of interaction with the membranes in general were not properly investigated up to now. Protonectarina-MP mastoparan with an either amidated or acidic C-terminus was utilized to study their interactions with anionic and zwitterionic vesicles, using measurements of dye leakage and a combination of H/D exchange and mass spectrometry to monitor peptide–membrane interactions. Mast cell degranulation, hemolysis and antibiosis assays were also performed using these peptides, and the results were correlated with the structural properties of the peptides. The C-terminal amidation promotes the stabilization of the secondary structure of the peptide, with a relatively high content of helical conformations, permitting a deeper interaction with the phospholipid constituents of animal and bacterial cell membranes. The results suggested that at low concentrations Protonectarina-MP interacts with the membranes in a way that both terminal regions remain positioned outside the external surface of the membrane, while the α-carbon backbone becomes partially embedded in the membrane core and changing constantly the conformation, and causing membrane destabilization. The amidation of the C-terminal residue appears to be responsible for the stabilization of the peptide conformation in a secondary structure that is richer in α-helix content than its acidic congener. The helical, amphipathic conformation, in turn, allows a deeper peptide–membrane interaction, favoring both biological activities that depend on peptide structure recognition by the GPCRs (such as exocytosis) and those activities dependent on membrane perturbation (such as hemolysis and antibiosis). 相似文献
53.
54.
Mapping macroecology 总被引:2,自引:1,他引:1
Although macroecology arose from geographical ecology, it has diverted from a geographical perspective. At present, most macroecological studies use a statistical approach that adopts an 'individual species focus' and relies on comparisons between species to test for broad-scale ecological patterns. Sometimes, space is included as part of the analysis, but almost always in a single dimension. In both situations, observed relationships are depicted using bivariate scatter-plots. We argue that current macroecological approaches may interfere with our perception of patterns and have important implications for their biological interpretation. We use the literature concerned with spatial variation in the range sizes of species (Rapoport's rule) to illustrate our point of view. Given the current lack of maps actually showing the patterns we are trying to explain, we contend that macroecology could benefit greatly by returning to its geographical roots, at least when data contain spatial structure. 相似文献
55.
Colafranceschi M Capuani G Miccheli A Campo S Valerio M Tomassini A Giuliani A Arseni B Rossi S De Santis R Carminati P Ruggiero V Conti F 《Journal of biochemical and biophysical methods》2007,70(3):355-361
A combined application of high resolution (1)H NMR spectroscopy and multivariate statistical techniques focused on establishing a consistent statistical approach to metabonomic studies was tested. The data reduction, which is preliminary to the application of multivariate analysis to NMR spectra, was carried out by means of two complementary methods: pure Pattern Recognition (PR) and Assigned Signal Analysis (ASA). The simultaneous use of both approaches allowed us to obtain additional information in the analysis of metabonomic data, compared to the use of PR alone. This additional information consists in the possibility of a biochemical interpretation of the effects induced by treatment with xenobiotics, such as drugs or drug vehicles, on the metabolic networks of the systems under investigation. This approach allowed us to ascertain that a single-dose treatment with ST1959 vehicled by Sesame oil affects the production of hepatic glucose associated to an increment of the amino acid ketogenic process. 相似文献
56.
Iorio R Scrimaglio R Rantucci E Delle Monache S Di Gaetano A Finetti N Francavilla F Santucci R Tettamanti E Colonna R 《Bioelectromagnetics》2007,28(1):72-75
Some effects of extremely low frequency electromagnetic fields (ELF-EMFs) on human spermatozoa are reported. Significant increases in the values of the motility and of the other kinematic parameters have been observed when spermatozoa were exposed to an ELF-EMF with a square waveform of 5 mT amplitude and frequency of 50 Hz. By contrast, a 5 mT sine wave (50 Hz) and a 2.5 mT square wave (50 Hz) exposure did not produce any significant effect on sperm motility. The effects induced by ELF-EMF (50 Hz; 5 mT) during the first 3 h of exposure persisted for 21 h after the end of the treatment. These results indicate that ELF-EMF exposure can improve spermatozoa motility and that this effect depends on the field characteristics. 相似文献
57.
Makoto Ogura Abraham D. Abernethy Ryan D. Blissett Karriann Ruggiero Sovanda Som J. Max Goodson Ralph Kent Apostolos G. Doukas Nikolaos S. Soukos 《World journal of microbiology & biotechnology》2007,23(11):1637-1646
Photomechanical waves (PW), the product of an intense light beam interaction with a target material, enhance molecular delivery
across biological membranes and skin. The ability to deliver methylene blue (MB), a fluorescent probe and photosensitizer,
into bacterial biofilms was demonstrated by applying PW on saliva-derived multi-species biofilms that were developed on agar
surfaces in 24-well plates. PW were generated with a Q-switched Nd:YAG laser and were directed into the biofilms in the presence
of 25 μg/ml MB. The biofilms were then irradiated with red light at 665 nm. After illumination, adherent bacteria were scraped
and spread over the surface of blood agar plates. Survival fractions were calculated by counting bacterial colonies. Microbial
analysis was performed via a colony lift method and a DNA checkerboard assay using whole genomic probes to 40 oral microorganisms.
Visual analysis by confocal scanning laser microscopy demonstrated that the application of PW enhanced the penetration depth
of MB in biofilms. Exposure to MB, PW and light led to a significant reduction of the mean levels of log10 CFU counts compared with the group that received MB and light (P = 0.006). The DNA checkerboard assay showed some benefit from PW-assisted phototargeting in 25 biofilm microorganisms relative
to phototreatment alone. Our data provide a basis for further exploration and optimization of PW parameters for complete eradication
of microorganisms in oral microcosm biofilms. 相似文献
58.
59.
Roberto Angelini Simona Lobasso Ruggiero Gorgoglione Ann Bowron Colin G. Steward Angela Corcelli 《Journal of lipid research》2015,56(9):1787-1794
Barth syndrome (BTHS), an X-linked disease associated with cardioskeletal myopathy, neutropenia, and organic aciduria, is characterized by abnormalities of cardiolipin (CL) species in mitochondria. Diagnosis of the disease is often compromised by lack of rapid and widely available diagnostic laboratory tests. The present study describes a new method for BTHS screening based on MALDI-TOF/MS analysis of leukocyte lipids. This generates a “CL fingerprint” and allows quick and simple assay of the relative levels of CL and monolysocardiolipin species in leukocyte total lipid profiles. To validate the method, we used vector algebra to analyze the difference in lipid composition between controls (24 healthy donors) and patients (8 boys affected by BTHS) in the high-mass phospholipid range. The method of lipid analysis described represents an important additional tool for the diagnosis of BTHS and potentially enables therapeutic monitoring of drug targets, which have been shown to ameliorate abnormal CL profiles in cells. 相似文献
60.
Low E Kim B Francavilla C Shiau TP Turtle ED O'Mahony DJ Alvarez N Houchin A Xu P Zuck M Celeri C Anderson MB Najafi RR Jain RK 《Bioorganic & medicinal chemistry letters》2011,21(12):3682-3685
Structure stability/activity relationships (SXR) of a new class of N,N-dichloroamine compounds were explored to improve antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Candida albicans while maintaining aqueous solution stability. This study identified a new class of solution-stable and topical antimicrobial agents. These agents are sulfone-stabilized and possess either a quaternary ammonium or sulfonate appendages as a water solubilizing group. Several unique challenges were confronted in the synthesis of these novel compounds which are highlighted in the discussion. 相似文献