1,317 research outputs found
Optical Emission Spectroscopy Diagnostics of Cold Plasmas for Food Sterilization
There is a growing need for economical, effective, and safe methods of sterilizing fresh produce. The most common method is a chlorine wash, which is expensive and may introduce carcinogens. High voltage cold atmospheric pressure plasmas are a promising solution that has demonstrated a germicidal effect; however, the responsible chemical mechanisms and reaction pathways are not fully understood. To elucidate this chemistry, we used optical emission spectroscopy to measure the species produced in the plasma generated by a 60 Hz pulsed dielectric barrier discharge in a plastic box containing various fill gases (He, N2, CO2, dry air, or humid air). In addition to estimating chemical species concentrations, we performed preliminary calculations of electronic, vibrational, rotational, and translational temperatures
Differences in pigment circadian rhythmicity in green- and red-leafed tree species in the sun and shade
Light flux and quality are crucial factor for setting endogenous plant circadian rhythms. Evaluating the daily rhythmicity of leaf chlorophyll content is an effective method to monitor the plant physiological endogenous clock in response to environmental signals such as light availability/quality. Here, we used a leaf-clip sensor to monitor diurnal rhythms in the content of chlorophyll and flavonoids such as flavonols and anthocyanins in three green- (Ailanthus altissima, Tilia platyphyllos and Platanus x acerifolia) and two red-leafed (Acer platanoides cv. Crimson King and Prunus cerasifera var. pissardii) tree species, adapted to sun (L) or shade (S). Significant differences in chlorophyll content (Chl) and its variations during the day were observed among treatments in all the analyzed species. S-plants had more Chl than L-plants irrespective of leaf color, and Chl variations were more distinct during the day than in L-plants. In particular, contents were lowest in the morning (9:00) and in the middle of the day (at 12:00 and 15:00), and the highest at dusk (21:00). The less evident trends in Chl variation in L-plants were attributed to a decrease in Chl content in high light, which likely masked any increases in the shaded counterparts during the afternoon. Daily flavonol levels did not vary no notably during the day. In sun-exposed red leaves, anthocyanins partially screened mesophyll cells from incident light, and its levels were similar to the Chl dynamics in the shaded counterparts. This study provides new bases for further work on endogenous rhythms of plant pigments and improves our understanding of plant physiology in the context of day/night rhythmicity
A novel SCN9A splicing mutation in a compound heterozygous girl with congenital insensitivity to pain, hyposmia and hypogeusia
Congenital insensitivity to pain (CIP) is a rare autosomal recessive disorder presenting with a spectrum of clinical features caused by mutations in different genes. A 10\u2010year\u2010old girl with CIP, hyposmia and hypogeusia, and her unaffected twin and parents underwent next generation sequencing of SCN9A exons and flanking splice sites. Transcript analysis from whole blood successfully assayed the effect of the mutation on the mRNA splicing by polymerase chain reaction amplification on cDNA and Sanger sequencing. We identified the novel splicing variant c.1108\u20102A>G compound with the p.Arg896Gln (c.2687G>A) missense mutation previously described in a homozygous patient. The new intronic variant was predicted to induce exon 10 skipping. Conversely, SCN9A mRNA assay demonstrated its partial deletion with a loss of 46 nucleotides causing a premature stop codon in position p.Gln369 (NP_002968). Genetic analysis showed that the two variants were biallelic, being the mother and brother heterozygous carriers of the missense mutation, and the father heterozygous for the splicing mutation. Skin biopsy showed lack of Meissner's corpuscles, loss of epidermal nociceptors and normal autonomic organ innervation. We report a novel splicing mutation and provide clues on its pathogenic effect, broadening the spectrum of genotypes and phenotypes associated to CIP
A Computer Aided Detection system for mammographic images implemented on a GRID infrastructure
The use of an automatic system for the analysis of mammographic images has
proven to be very useful to radiologists in the investigation of breast cancer,
especially in the framework of mammographic-screening programs. A breast
neoplasia is often marked by the presence of microcalcification clusters and
massive lesions in the mammogram: hence the need for tools able to recognize
such lesions at an early stage. In the framework of the GPCALMA (GRID Platform
for Computer Assisted Library for MAmmography) project, the co-working of
italian physicists and radiologists built a large distributed database of
digitized mammographic images (about 5500 images corresponding to 1650
patients) and developed a CAD (Computer Aided Detection) system, able to make
an automatic search of massive lesions and microcalcification clusters. The CAD
is implemented in the GPCALMA integrated station, which can be used also for
digitization, as archive and to perform statistical analyses. Some GPCALMA
integrated stations have already been implemented and are currently on clinical
trial in some italian hospitals. The emerging GRID technology can been used to
connect the GPCALMA integrated stations operating in different medical centers.
The GRID approach will support an effective tele- and co-working between
radiologists, cancer specialists and epidemiology experts by allowing remote
image analysis and interactive online diagnosis.Comment: 5 pages, 5 figures, to appear in the Proceedings of the 13th
IEEE-NPSS Real Time Conference 2003, Montreal, Canada, May 18-23 200
IN THE SEARCH OF LEPTIN AGONISTS AS ANTI-OBESITY DRUGS: PROTEIN/PROTEIN DOCKING, MOLECULAR DYNAMICS, AND VIRTUAL SCREENING
The body weight control is a mechanism thinly regulated by several hormonal, metabolic, and nervous pathways (1). Recessive homozygous mutations in the ob/ob and db/db mouse strain cause extreme obesity. The products of the ob and db genes are leptin and its receptor, respectively. The leptin receptor is crucial for energy homeostasis and regulation of food uptake. Leptin is a 16 kDa hormone that is mainly secreted by fat cells into the bloodstream. Under normal circumstances, circulating leptin levels are proportionate to the fat body mass. Sensing of elevated leptin levels by the hypothalamic neurocircutry activates a negative feedback loop resulting in reduced food intake and increased energy expenditure. Decreased leptin concentrations lead to opposite effectsTherefore rational design of leptin agonists could be an appealing challenge in the battle against obesity. Unfortunately only the crystal structure of leptin is available, but not that of the leptin receptor. In this work, first, we built, by homology modelling, the leptin receptor starting from FASTA sequence and the similarity search of templates. The obtained model was used to perform a protein-protein docking with the crystal structure of leptine by means Gramm-X server, with the aim to define the complementary surfaces of the two proteins. The complex of leptin/leptin receptor was then used as starting point to carry out molecular dynamics simulations in water solvent to characterize the key residues involved into the protein-protein interaction. Snapshots of leptin were used as template to build a pharmacophore hypothesis to carry out virtual screening on a large database of compounds.
(1) Friedman, J. M., Halaas, J. L. Nature 1998, 395, 763-770
IN THE SEARCH OF LEPTIN AGONISTS AS ANTI-OBESITY DRUGS: PROTEIN/PROTEIN DOCKING, MOLECULAR DYNAMICS, AND VIRTUAL SCREENIN
High quality factor single-crystal diamond mechanical resonators
Single-crystal diamond is a promising material for MEMs devices because of
its low mechanical loss, compatibility with extreme environments, and built-in
interface to high-quality spin centers. But its use has largely been limited by
challenges in processing and growth. We demonstrate a wafer bonding-based
technique to form diamond on insulator, from which we make single-crystal
diamond micromechanical resonators with mechanical quality factors as high as
338,000 at room temperature. Variable temperature measurements down to 10 K
reveal a nonmonotonic dependence of quality factor on temperature. These
resonators enable integration of single-crystal diamond into MEMs technology
for classical and quantum applications.Comment: 15 pages total, 4 figures, 1 tabl
Relationship between perception of emotional home atmosphere and fruit and vegetable consumption in European adolescents: Results from the I.Family survey
Objective: Consumption of fruits and vegetables (F&V) among adolescents falls below recommendations in many Western countries. The impact of social and emotional aspects of family life on adolescent dietary behaviour may contribute to this, yet remains under-investigated. The present study examines the association between adolescents'' perceptions of emotional home atmosphere (EHA) and their F&V consumption frequency.
Design: An FFQ was used to assess F&V consumption frequency. EHA was assessed by an eight-item measure with three subscales: Perceived home warmth, strictness and relational tension. EHA subscales were used as binary variables: A score equal to or above the median value was considered as a higher perception, while a score below the median was considered as a lower perception of the EHA in question. Country differences in meeting the European 5-a-day recommendations were described. Further, the association between EHA and F&V consumption frequency was investigated using multiple linear regression.
Setting: Regional examination centres in eight European countries.
Participants: Adolescents (n 3196) aged 12-18 years.
Results: The mean F&V consumption frequency was 3·27 (sd 2·84) times/d. Only 16·1 % of boys and 18 % of girls in our study sample met the recommendation of five F&V daily. After controlling for age, sex, education level of the parents and country of origin, perceived home warmth was associated with a 16 (95 % CI 9, 22) % higher F&V consumption frequency (P < 0·001).
Conclusions: F&V consumption frequency was suboptimal in the survey areas. Interventions targeting perceived warmth as a component of EHA could potentially have a positive effect on adolescents'' dietary behaviour
High-intensity activity is more strongly associated with metabolic health in children compared to sedentary time: a cross-sectional study of the I.Family cohort
Background: Physical activity (PA) during childhood is important for preventing future metabolic syndrome (MetS). To examine the relationship between PA and MetS in more detail, accurate measures of PA are needed. Previous studies have only utilized a small part of the information available from accelerometer measured PA. This study investigated the association between measured PA and MetS in children with a new method for data processing and analyses that enable more detailed interpretation of PA intensity level. Methods: The association between PA pattern and risk factors related to MetS was investigated in a cross- sectional sample of children (n = 2592, mean age 10.9 years, 49.4% male) participating in the European multicenter I. Family study. The risk factors examined include body mass index, blood pressure, high-density lipoprotein cholesterol, insulin resistance and a combined risk factor score (MetS score). PA was measured by triaxial accelerometers and raw data was processed using the 10 Hz frequency extended method (FEM). The PA output was divided into an intensity spectrum and the association with MetS risk factors was analyzed by partial least squares regression. Results: PA patterns differed between the European countries investigated, with Swedish children being most active and Italian children least active. Moderate intensity physical activity was associated with lower insulin resistance (R2 = 2.8%), while vigorous intensity physical activity was associated with lower body mass index (R2 = 3.6%), MetS score (R2 = 3.1%) and higher high-density lipoprotein cholesterol (R2 = 2.3%). PA of all intensities was associated with lower systolic- and diastolic blood pressure, although the associations were weaker than for the other risk factors (R2 = 1.5% and R2 = 1.4%). However, the multivariate analysis implies that the entire PA pattern must be considered. The main difference in PA was observed between normal weight and overweight children. Conclusions: The present study suggests a greater importance of more PA corresponding to an intensity of at least brisk walking with inclusion of high-intense exercise, rather than a limited time spent sedentary, in the association to metabolic health in children. The methods of data processing and statistical analysis enabled accurate analysis and interpretation of the health benefits of high intensity PA that have not been shown previously. © 2021, The Author(s)
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