125 research outputs found
Normalized Gaussian Path Integrals
Path integrals play a crucial role in describing the dynamics of physical
systems subject to classical or quantum noise. In fact, when correctly
normalized, they express the probability of transition between two states of
the system. In this work, we show a consistent approach to solve conditional
and unconditional Euclidean (Wiener) Gaussian path integrals that allow us to
compute transition probabilities in the semi-classical approximation from the
solutions of a system of linear differential equations. Our method is
particularly useful for investigating Fokker-Planck dynamics, and the physics
of string-like objects such as polymers. To give some examples, we derive the
time evolution of the d-dimensional Ornstein-Uhlenbeck process, and of the Van
der Pol oscillator driven by white noise. Moreover, we compute the end-to-end
transition probability for a charged string at thermal equilibrium, when an
external field is applied.Comment: 15 pages (7 of appendices), one figur
New drugs on the Internet : the case of Camfetamine
Copyright © 2014 Eduardo Cinosi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedThe number of new psychoactive substances (NPS) advertised for sale online is constantly increasing and it has become a phenomenon of global concern. Among NPS, Camfetamine has been rediscovered as recreational drug in 2011. Very little information is still available in the scientific literature on its nature and potential health risks. Methods. Data in scientific literature were integrated with a multilingual qualitative assessment of a range of online resources over the period of 32 months (May 2011âJanuary 2014). Results. N-Methyl-3-phenyl-norbornan-2-amine (Camfetamine) may act as an indirect dopaminergic agonist in the central nervous system and may have mild-moderate opioid activity too. There are no current epidemiological data about recreational use of Camfetamine; our research shows that it is indeed used especially by individuals with a history of recreational polydrug misuse. It facilitates mental alertness, induces relaxation, and, unlike many other stimulants, seems not to be associated with severe physical effects. Valid causes for concern issued in our research may be Camfetamine intravenous or intramuscular administration as well as its use in conjunction with other psychoactive substances. Conclusions. It is here highlighted that more large-scale studies need to be carried out to confirm and better describe both the extent of Camfetamine misuse and possible psychotropic/adverse effectsPeer reviewedFinal Published versio
Chemical Features and Biological Effects of Astaxanthin Extracted from Haematococcus pluvialis Flotow: Focus on Gastrointestinal System
The main purpose of this review is to analyze published data concerning the antioxidant
properties of astaxanthin, a xanthophyll, produced by the microalga Haematococcus pluvialis in response to specific conditions of âenvironmental stressâ and characterized by its typical deep red color. Natural astaxanthin establishes effective protections against oxidative stress, neutralizing free radicals in both the inner and outer layer of cell membranes, especially in mitochondria. The most recent preclinical and clinical studies that have investigated the beneficial properties of this molecule toward the gastrointestinal tract were included
Substance use in the club scene of Rome : a pilot study
Date of Acceptance: 28/08/2014 Copyright © 2014 Alessandro Emiliano Vento et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedOver the last few years, a wide number of unregulated substances have been marketed on the Web and in smart and head shops; they are usually advertised as legal alternatives to commonly known drugs and are defined as âsmart drugs,â âlegal highs,â and ânovel psychoactive substancesâ (NPS). Aim of our work is to describe use habits and distribution of NPS in a population of young adults in Rome club scene. Methods. A self-administered questionnaire was proposed to subjects over 18 years of age at the entrance of 5 nightclubs in Rome. Socioeconomic characteristics and substance use were investigated. Results. Preliminary results give evidence that 78% of respondents have a lifetime history of NPS use. In addition, 56% of the sample has consumed illicit drugs in the past and 39% has used psychoactive substances in the 12 hours preceding the questionnaire administration. Conclusions. A significant proportion of subjects report use of novel psychoactive substances; traditional illicit drugs consumption, particularly cocaine, appears to be very high as well in the club scene. These data highlight a serious public health challenge, since pharmacological, toxicological, and psychopathological effects linked to interactions among all these substances may be unpredictable and sometimes fatal in vulnerable individualsPeer reviewedFinal Published versio
Conversion of the Native N-Terminal Domain of TDP-43 into a Monomeric Alternative Fold with Lower Aggregation Propensity.
TAR DNA-binding protein 43 (TDP-43) forms intraneuronal cytoplasmic inclusions associated with amyotrophic lateral sclerosis and ubiquitin-positive frontotemporal lobar degeneration. Its N-terminal domain (NTD) can dimerise/oligomerise with the head-to-tail arrangement, which is essential for function but also favours liquid-liquid phase separation and inclusion formation of full-length TDP-43. Using various biophysical approaches, we identified an alternative conformational state of NTD in the presence of Sulfobetaine 3-10 (SB3-10), with higher content of α-helical structure and tryptophan solvent exposure. NMR shows a highly mobile structure, with partially folded regions and ÎČ-sheet content decrease, with a concomitant increase of α-helical structure. It is monomeric and reverts to native oligomeric NTD upon SB3-10 dilution. The equilibrium GdnHCl-induced denaturation shows a cooperative folding and a somewhat lower conformational stability. When the aggregation processes were compared with and without pre-incubation with SB3-10, but at the identical final SB3-10 concentration, a slower aggregation was found in the former case, despite the reversible attainment of the native conformation in both cases. This was attributed to protein monomerization and oligomeric seeds disruption by the conditions promoting the alternative conformation. Overall, the results show a high plasticity of TDP-43 NTD and identify strategies to monomerise TDP-43 NTD for methodological and biomedical applications
Effects of turmeric powder on intestinal and biliary functions: The influence of curcuminoids concentration on spontaneous contractility
Two turmeric food powders (C1 and C2) were studied for curcuminoid content and their effects on the guinea pig intestinal tract in vitro. C1 contained a higher curcuminoid content than C2 (5.22% vs 2.31%). C1 and C2 increased gallbladder (similar to 10%) and biliary smooth muscle tone (similar to 15%), without affecting the sphincter of Oddi smooth muscle contractility. C2 was more effective than C1 in lowering ileum tone (-22% vs -37%), whereas the reverse occurred in the colon (-50% vs 20%). Standard Fast Fourier transforms and absolute powers analysis of the frequency bands highlighted that, in the bile duct, C2 induced contractions of higher variability and ampler oscillations of low-frequency waves. At the Oddi sphincter, C1 had a biphasic effect, increasing and then drastically decreasing the oscillations. The same occurred with C2 in the ileum, while both samples reduced the fluctuations in the colon
Validation of the Italian translation of the perceived stigma scale and resilience assessment in inflammatory bowel disease patients
BACKGROUND Stigmatization is the separation of an individual from a group due to aspects that make them different. Resilience may in turn influence the perception of stigma. Patients with inflammatory bowel disease (IBD) are susceptible to stigma, although data are very limited. AIM To validate an Italian translation of the IBD perceived stigma scale (PSS) in relation to patientsâ resilience. METHODS Consecutive IBD outpatients were prospectively enrolled (December 2018-September 2019) in an Italian, tertiary referral, IBD center. Clinical and demographic data were collected. Stigma and resilience were evaluated through the IBD-PSS and the 25-item Connor-Davidson Resilience Scale, respectively. The International Quality of Life Assessment Project approach was followed to translate the IBD-PSS into Italian and to establish data quality. Higher scores represent greater perceived stigma and resilience. Multivariable analysis for factors associated with greater stigma was computed. RESULTS Overall, 126 IBD patients (mean age 46.1 ± 16.9) were enrolled. The International Quality of Life Assessment criteria for acceptable psychometric properties of the scale were satisfied, with optimal data completeness. There was no ceiling effect, whilst floor effect was present (7.1%). The discriminant validity and the internal consistency reliability were good (Cronbach alpha = 0.87). The overall internal consistency was 95%, and the test-retest reliability was excellent 0.996. The median PSS score was 0.45 (0.20-0.85). Resilience negatively correlated with perceived stigma (Spearmanâs correlation = -0.18, 95% confidence intervals: -0.42-0.08, P = 0.03). CONCLUSION We herein validated the Italian translation of the PSS scale, also demonstrating that resilience negatively impacts perceived stigma
Magnolia officinalis L. bark extract and respiratory diseases: From traditional Chinese medicine to western medicine via network target
The understanding of the use of Magnolia officinalis L. (Magnoliaceae) as a possible dietary supplement for supporting the treatment of airway pathologies might be of clinical interest. Two commercially available bark extracts (M. officinalis extract [MOE]) were characterized by quantitation in honokiol and magnolol content by means of high-performance liquid chromatography with UV detection. MOE effects, as well as those of the reference compounds per se, on some targets connected to airway pathologies (antibacterial- and lung and trachea relaxing- activities) were investigated. Results showed that MOE possessed interesting antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Streptococcus pneumoniae. This was accompanied by a spasmolytic and antispasmodic activity, possibly owing to its ability to concurrently modulate different targets such as H-1-, beta(2)- and muscarinic receptors and l-type calcium channels involved in bronchodilation. All these effects were directly related to the MOE content in honokiol and magnolol. In conclusion, the properties of MOE highlighted here strongly encourage its application as dietary supplement in the treatment of airway diseases
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