177,280 research outputs found
Il territorio in età preistorica
No full textViene presentata una rassegna critica dei dati fino ad allora conosciuti relativi alle diverse epoche della preistoria (paleolitico, neolitico, età del rame, età del bronzo) in provincia di Macerata, che comprende i bacini dei fiumi Chienti e Potenza ma anche parte delle alte valli del Musone e dell'Esino. Pur in mancanza di studi sistematici editi del territorio, una notevole quantità di dati conosciuti, a diversi livelli di edizione, permette di tracciare un quadro dell'evoluzione del popolamento nei diversi periodi
Classificazione della 2,3,7,8-tetraclorodibenzo-para-diossina come cancerogena: un percorso accidentato
No full text
Riflessioni sulla psicologia del misticismo
No full textNella prima parte del saggio si individuano tre principali aspetti entro cui è possibile circoscrivere il fenomeno del misticismo: 1) le pratiche meditative; 2) le esperienze contemplative, visionarie ed estatiche; 3) lo stato di coscienza unitivo, non dualista o illuminativo.
Nella seconda parte si investigano le problematiche epistemologiche scaturite dal vivace dibattito scientifico sul controverso rapporto fra ‘esperienza’ e ‘interpretazione’, ripercorrendo alcuni snodi fondamentali della storia degli studi sul misticismo (da W. James al perennialismo, dal costruttivismo al de-costruttivismo), con specifici approfondimenti su possibili contributi del pensiero indiano alla psicologia del misticismo.
Nella terza parte si propone una coerente interpretazione generale della psicologia del misticismo fondata sulle convergenze fra la cartografia degli stati di coscienza di R. Fisher, la teoria della de-automazione di A. Deikman e il forgetting model di R.K.C. Forman, da cui si profila una ‘dialettica del misticismo’ che conferisce un andamento bipolare al percorso contemplativo attraverso una progressiva integrazione di aspetti apparentemente contrastanti (attività/passività, estasi/enstasi, via graduale/via diretta, razionalità/mistero, fase propositiva/fase critica, purificazione/trascendimento della mente).
Vengono infine brevemente investigate le problematiche metodologiche ed epistemologiche sollevate dall’acceso dibattito circa le vere o presunte convergenze fra il misticismo e il nuovo paradigma ‘olistico’che emerge da alcuni settori della odierna ricerca scientifica nel campo della psicologia, delle neuroscienze e della fisica subatomica
Sleep and sleep deprivation as EEG activating methods
No full textObjectives: We examined retrospectively 19 patients with a history of clinical seizures, but normal activity or unclear epileptiform abnormalities in wake EEG recordings and obtained preliminary data for a controlled cohort study to evaluate the effects of sleep deprivation (SD) on interictal epileptic activity. Methods: Nineteen patients referred to our EEG department for diagnostic or follow-up purposes were divided in two groups on the basis of the different EEG protocols applied. The first group (n = 5) underwent two laboratory polysomnographies during afternoon naps, after SD, but the patients failed to fall asleep in one of the two occasions. The second group (n = 14) was submitted to two polysomnographies, the first without SD and the second after SD. Results: The first group of patients demonstrated focal epileptic discharges in 4 patients in which wake after SD appeared to be less activated that sleep after SD. In the second group the results obtained from the waking part of the recordings suggest a lack of activating effect due to SD. Conclusions: SD does not seem to offer greater activation than sleep alone. However, a mild SD may be a convenient activating method for inducing sleep and drowsiness without using any drug
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Effects of Salvia miltiorrhiza on CNS Neuronal Injury and Degeneration: A Plausible Complementary Role of Tanshinones and Depsides
No full textSalvia miltiorrhiza is a very important herbal drug of traditional Chinese medicine. Bioactive constituents are represented by two main groups of secondary metabolites, the lipophilic diterpenic quinones known as tanshinones and the hydrophilic depsides known as salvianolic acids. S. miltiorrhiza extracts and single constituents have been shown to have positive effects in central nervous system neuronal injury and degeneration in several animal models by various biological mechanisms. Both tanshinones and depsides protect against β-amyloid-induced toxicity, but their mechanisms are complementary due to their different structure, the lipophilic tanshinones and the hydrophilic depsides. A number of anti-inflammatory mechanisms is also reported for both tanshinones and depsides. Common mechanisms are the effects on cytokines, inducible nitric oxide synthase, and glial fibrillary acidic protein. In addition, depsides are inhibitors of nitric oxide and cyclooxygenase-2, while tanshinones inhibit hypoxia-inducible factor-1α and nuclear factor kappa β. Both constituents can also modulate the protection of the central nervous system from oxidative stress with different but complementary mechanisms: tanshinones can enhance the activities of superoxide dismutase and glutathione peroxidase, while depsides can decrease reactive oxygen species. Furthermore, neuronal death underlies the symptoms of many human neurological disorders, including Alzheimer's, Parkinson's, and Huntington's diseases, stroke, and amyotrophic lateral sclerosis. Both classes of constituents can enhance the antiapoptotic B-cell leukemia protein-2 family members and decrease the translocation of cytochrome c, and, in addition, depsides decrease caspase-3 and intracellular Ca2+. Again, both classes of constituents have an activity on vascular endothelial growth factor but it is opposite, whereas tanshinones are inhibitors of acetylcholinesterase. Besides the extensive studies reporting on the biological mechanisms of depsides and tanshinones, pharmacokinetics studies are still very limited and not conclusive, especially for brain distribution. Further research is warranted to address the mechanisms of the multitarget actions of S. miltiorrhiza constituents and to translate this knowledge into clinical practice
Controlled local drug delivery strategies from chitosan hydrogels for wound healing
No full textIntroduction: The main target of tissue engineering is the preparation and application of adequate materials for the design and production of scaffolds, that possess properties promoting cell adhesion, proliferation and differentiation. The use of natural polysaccharides, such as chitosan, to prepare hydrogels for wound healing and controlled drug delivery is a research topic of wide and increasing interest.
Areas covered: This review presents the latest results and challenges in the preparation of chitosan and chitosan-based scaffold/hydrogel for wound healing applications. A detailed overview of their behavior in terms of controlled drug delivery, divided by drug categories, and efficacy was provided and critically discussed.
Expert opinion: The need to establish and exploit the advantages of natural biomaterials in combina- tion with active compounds is playing a pivotal role in the regenerative medicine fields. The challenges posed by the many variables affecting tissue repair and regeneration need to be standardized and adhere to recognized guidelines to improve the quality of evidence in the wound healing process. Currently, different methodologies are followed to prepare innovative scaffold formulations and struc- tures. Innovative technologies such as 3D printing or bio-electrospray are promising to create chitosan- based scaffolds with finely controlled structures with customizable shape porosity and thickness. Chitosan scaffolds could be designed in combination with a variety of polysaccharides or active compounds with selected and reproducible spacial distribution, providing active wound dressing with highly tunable controlled drug delivery
Polychlorinated biphenyls in serum, liver and adipose tissue of subjects with hepatocellular carcinoma living in a high polluted area.
No full textBrescia (North Italy) is located in a highly industrialized area with diffuse environmental pollution by
polychlorinated biphenyls (PCBs) and with a high incidence of hepatocellular carcinoma (HCC). We aimed
to investigate the concentration of PCBs congeners in serum, liver and adipose tissue of patients with HCC
living in this area.
We enrolled prospectively 101 HCC incident cases. Lipid-adjusted PCBs concentration of single congeners and total PCBs concentration, computed as the sum of 24 PCBs congeners, were measured in the
serum of all subjects and in the liver and abdominal fat of 59 HCC cases undergoing surgery.
A high correlation was found between PCBs serum and liver (Spearman r = 0.79), serum and fat
(r = 0.91), and liver and fat (r = 0.75) concentrations. Serum PCBs concentration in HCC patients did not
vary according to demographical, clinical or epidemiological variables, apart from age, as PCBs concentration increased linearly with the subject’s age. This study confirms that serum lipid-adjusted PCBs concentration is a valid measure of PCBs body storage and is highly correlated with PCBs concentration detected
in other biological samples
A Validated Method for the Quality Control of Andrographis paniculata Preparations
No full textAndrographis paniculata is a herbal drug of Asian traditional medicine largely employed for the treatment of several diseases. Recently, it has been introduced in Europe for the prophylactic and symptomatic treatment of common cold and as an ingredient of dietary supplements. The active principles are diterpenes with andrographolide as the main representative. In the present study, an analytical protocol was developed for the determination of the main constituents in the herb and preparations of A. paniculata. Three different extraction protocols (methanol extraction using a modified Soxhlet procedure, maceration under ultrasonication, and decoction) were tested. Ultrasonication achieved the highest content of analytes. HPLC conditions were optimized in terms of solvent mixtures, time course, and temperature. A reversed phase C18 column eluted with a gradient system consisting of acetonitrile and acidified water and including an isocratic step at 30°C was used. The HPLC method was validated for linearity, limits of quantitation and detection, repeatability, precision, and accuracy. The overall method was validated for precision and accuracy over at least three different concentration levels. Relative standard deviation was less than 1.13%, whereas recovery was between 95.50% and 97.19%. The method also proved to be suitable for the determination of a large number of commercial samples and was proposed to the European Pharmacopoeia for the quality control of Andrographidis herba
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