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81.
A Del Corso D Barsacchi M Giannessi M G Tozzi M Camici J L Houben M Zandomeneghi U Mura 《Archives of biochemistry and biophysics》1990,283(2):512-518
Analysis by HPLC of the protein-free supernatant obtained after denaturation of aldose reductase shows that the native form of the enzyme (ARb) contains a tightly bound NADP+, which is absent in the oxidatively modified form (ARa). The absorption, fluorescence, and circular dichroism spectra of ARb and ARa are consistent with the presence of the cofactor only in the native form of aldose reductase. On the other hand, the modified enzyme, in appropriate thiol reducing conditions, can tightly bind NADP+. This indicates a potential reversibility of the modification of aldose reductase, at least in terms of retention of the cofactor. 相似文献
82.
83.
Alexander Kurz Kay L. Double Isabel Lastres-Becker Alessandro Tozzi Michela Tantucci Vanessa Bockhart Michael Bonin Moisés García-Arencibia Silke Nuber Falk Schlaudraff Birgit Liss Javier Fernández-Ruiz Manfred Gerlach Ullrich Wüllner Hartmut Lüddens Paolo Calabresi Georg Auburger Suzana Gispert 《PloS one》2010,5(7)
84.
Enrico Domenici David R. Willé Federica Tozzi Inga Prokopenko Sam Miller Astrid McKeown Claire Brittain Dan Rujescu Ina Giegling Christoph W. Turck Florian Holsboer Edward T. Bullmore Lefkos Middleton Emilio Merlo-Pich Robert C. Alexander Pierandrea Muglia 《PloS one》2010,5(2)
Despite significant research efforts aimed at understanding the neurobiological underpinnings of psychiatric disorders, the diagnosis and the evaluation of treatment of these disorders are still based solely on relatively subjective assessment of symptoms. Therefore, biological markers which could improve the current classification of psychiatry disorders, and in perspective stratify patients on a biological basis into more homogeneous clinically distinct subgroups, are highly needed. In order to identify novel candidate biological markers for major depression and schizophrenia, we have applied a focused proteomic approach using plasma samples from a large case-control collection. Patients were diagnosed according to DSM criteria using structured interviews and a number of additional clinical variables and demographic information were assessed. Plasma samples from 245 depressed patients, 229 schizophrenic patients and 254 controls were submitted to multi analyte profiling allowing the evaluation of up to 79 proteins, including a series of cytokines, chemokines and neurotrophins previously suggested to be involved in the pathophysiology of depression and schizophrenia. Univariate data analysis showed more significant p-values than would be expected by chance and highlighted several proteins belonging to pathways or mechanisms previously suspected to be involved in the pathophysiology of major depression or schizophrenia, such as insulin and MMP-9 for depression, and BDNF, EGF and a number of chemokines for schizophrenia. Multivariate analysis was carried out to improve the differentiation of cases from controls and identify the most informative panel of markers. The results illustrate the potential of plasma biomarker profiling for psychiatric disorders, when conducted in large collections. The study highlighted a set of analytes as candidate biomarker signatures for depression and schizophrenia, warranting further investigation in independent collections. 相似文献
85.
86.
M Camici M G Tozzi S Allegrini A Del Corso O Sanfilippo M G Daidone C De Marco P L Ipata 《Cancer biochemistry biophysics》1990,11(3):201-209
The enzymatic pattern of five enzymes involved in the purine salvage pathway, namely purine nucleoside phosphorylase (EC 2.4.2.1), adenosine deaminase (EC 3.5.4.4), 5'-nucleotidase (EC 3.1.3.5), alkaline phosphatase (EC 3.1.3.1), and hypoxanthine-guanine phosphoribosyltransferase (EC 2.4.2.8) has been evaluated both in human intestinal and breast carcinomas and compared to that of normal tissues. A higher level of hypoxanthine-guanine phosphoribosyltransferase was associated with tumor tissues. This metabolic alteration should lead to an elevated synthesis of nucleotides in cancer cells, might confer selective growth advantages to neoplastic tissues, and account, at least in part, for the difficulties encountered in the chemotherapy of human tumors, by using compounds affecting only the purine de novo biosynthesis. 相似文献
87.
Francesco Gesualdo Giovanni Stilo Eleonora Agricola Michaela V. Gonfiantini Elisabetta Pandolfi Paola Velardi Alberto E. Tozzi 《PloS one》2013,8(12)
Twitter has the potential to be a timely and cost-effective source of data for syndromic surveillance. When speaking of an illness, Twitter users often report a combination of symptoms, rather than a suspected or final diagnosis, using naïve, everyday language. We developed a minimally trained algorithm that exploits the abundance of health-related web pages to identify all jargon expressions related to a specific technical term. We then translated an influenza case definition into a Boolean query, each symptom being described by a technical term and all related jargon expressions, as identified by the algorithm. Subsequently, we monitored all tweets that reported a combination of symptoms satisfying the case definition query. In order to geolocalize messages, we defined 3 localization strategies based on codes associated with each tweet. We found a high correlation coefficient between the trend of our influenza-positive tweets and ILI trends identified by US traditional surveillance systems. 相似文献
88.
Cytosolic 5'-nucleotidase (cN-II), which acts preferentially on 6-hydroxypurine nucleotides, is essential for the survival of several cell types. cN-II catalyses both the hydrolysis of nucleotides and transfer of their phosphate moiety to a nucleoside acceptor through formation of a covalent phospho-intermediate. Both activities are regulated by a number of phosphorylated compounds, such as diadenosine tetraphosphate (Ap?A), ADP, ATP, 2,3-bisphosphoglycerate (BPG) and phosphate. On the basis of a partial crystal structure of cN-II, we mutated two residues located in the active site, Y55 and T56. We ascertained that the ability to catalyse the transfer of phosphate depends on the presence of a bulky residue in the active site very close to the aspartate residue that forms the covalent phospho-intermediate. The molecular model indicates two possible sites at which adenylic compounds may interact. We mutated three residues that mediate interaction in the first activation site (R144, N154, I152) and three in the second (F127, M436 and H428), and found that Ap?A and ADP interact with the same site, but the sites for ATP and BPG remain uncertain. The structural model indicates that cN-II is a homotetrameric protein that results from interaction through a specific interface B of two identical dimers that have arisen from interaction of two identical subunits through interface A. Point mutations in the two interfaces and gel-filtration experiments indicated that the dimer is the smallest active oligomerization state. Finally, gel-filtration and light-scattering experiments demonstrated that the native enzyme exists as a tetramer, and no further oligomerization is required for enzyme activation. 相似文献
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90.
Grazia TM 《Nucleosides, nucleotides & nucleic acids》2011,30(12):1276-1283
A number of scientists have been involved for decades in the study of nucleotide metabolism in different species of living beings. We are, therefore, aware of the relevant roles of purine compounds and of the many different ways in which these compounds influence cell life, acting both inside and outside the cells. Nevertheless, the consequences of an alteration (lack of expression, or hypo- or hyperexpression) in the activity of enzymes involved in the metabolism of these compounds are sometimes surprising, and far from being mechanistically explained. Alterations in enzyme activities involved in nucleotide metabolism are frequently associated with syndromes characterized by two different types of problems--one, metabolic, which is expected and can be easily explained, and the second, neurological and behavioral. Neurological and behavioral impairments are more difficult to explain and show a very high degree of individual variability. The molecular bases of the neurological impairment linked to purine metabolism disorders have been extensively studied. These studies have generated a lot of hypotheses but very few certainties. In this short review, neurological and behavioral symptoms linked to the dysfunction of some enzymes involved in purine synthesis, catabolism, and salvage will be briefly described, with particular attention to their metabolic and regulatory consequences. Finally, attention will be focused on the 5'-nucleotidase family members and on their involvement in the regulation of purine and pyrimidine metabolism. 相似文献