1,388 research outputs found
Effect of maturity and harvest season on antioxidant activity, phenolic compounds and ascorbic acid of Morinda citrifolia L. (noni) grown in Mexico (with track change)
Antioxidant activity diphenylpicrylhydrazyl (DPPH), the ferric-reducing antioxidant power assay (FRAP), nitric oxide (NO)], total polyphenols, phenolic compounds and ascorbic acid of Morinda citrifolia L. fruits were investigated as a function of maturity and three seasons patterns in Mexico. Maturity was evaluated in early, middle, sub-mature and mature stages (1 to 4) according to color and firmness. Significant differences were observed in the antioxidant activities and chemical composition of the fruits at different maturity and seasons. During February-March and May- June, fruits from middle and mature stages exhibited the highest antioxidant activities and total polyphenol content compared to other stages, while in November, ripe fruits reached the greatest antioxidant efficacy, total phenolic and ascorbic acid contents. Total polyphenols and ascorbic acid reached the highest amounts during May-June, although antioxidant activities were moderate compared to greater values in February-March or November depending upon maturity. The ability of M. citrifolia fruits to inhibit NO production by LPSactivated RAW 264.7 cells was quite comparable to or higher than N-nitro-L-arginine methyl ester (LNAME). This work shows that season and maturity stages have a profound effect on the antioxidant capacity, phenols and ascorbic acid of M. Citrifolia fruits.Keywords: Morinda citrifolia, diphenylpicrylhydrazyl (DPPH) radical scavenging, maturity, seasons, total polyphenol and phenolics compounds, reducing power, ascorbic acid, scavenging nitric oxide.African Journal of Biotechnology Vol. 12(29), pp. 4630-463
Echinococcus granulosus infection in foxes in Coquimbo region, Chile
Echinococcus granulosus is a cestode of zoonotic importance that infects a wide range of animals. The main definitive host of this parasite is the domestic dog, which most commonly becomes infected by ingestion of infected tissues from ruminant livestock. In some areas, however, wild carnivores have been reported to be infected with E. granulosus and to potentially have a role in the maintenance of infection. This study explores E. granulosus infection in free-ranging foxes in rural areas of the Coquimbo region. Fecal samples of live-trapped culpeo (Lycalopex culpaeus) and chilla (L. griseus) foxes were obtained in six of previously designed rural sites of the Coquimbo region in Chile between 2005 and 2006. Overall, Echinococcus granulosus coproantigen prevalence in wild foxes by a coproELISA test was 6% (2/33) and ranged from 0% to 20% in the different study sites. The presence of E. granulosus in wild carnivores for the maintenance of this parasite in this region is discussed
Can luteal regression be reversed?
The corpus luteum is an endocrine gland whose limited lifespan is hormonally programmed. This debate article summarizes findings of our research group that challenge the principle that the end of function of the corpus luteum or luteal regression, once triggered, cannot be reversed. Overturning luteal regression by pharmacological manipulations may be of critical significance in designing strategies to improve fertility efficacy
Interleaved Parton Showers and Tuning Prospects
General-purpose Monte Carlo event generators have become important tools in
particle physics, allowing the simulation of exclusive hadronic final states.
In this article we examine the Pythia 8 generator, in particular focusing on
its parton-shower algorithms. Some relevant new additions to the code are
introduced, that should allow for a better description of data. We also
implement and compare with 2 to 3 real-emission QCD matrix elements, to check
how well the shower algorithm fills the phase space away from the soft and
collinear regions. A tuning of the generator to Tevatron data is performed for
two PDF sets and the impact of first new LHC data is examined
Essential and checkpoint functions of budding yeast ATM and ATR during meiotic prophase are facilitated by differential phosphorylation of a meiotic adaptor protein, Hop1
A hallmark of the conserved ATM/ATR signalling is its ability to mediate a wide range of functions utilizing only a limited number of adaptors and effector kinases. During meiosis, Tel1 and Mec1, the budding yeast ATM and ATR, respectively, rely on a meiotic adaptor protein Hop1, a 53BP1/Rad9 functional analog, and its associated kinase Mek1, a CHK2/Rad53-paralog, to mediate multiple functions: control of the formation and repair of programmed meiotic DNA double strand breaks, enforcement of inter-homolog bias, regulation of meiotic progression, and implementation of checkpoint responses. Here, we present evidence that the multi-functionality of the Tel1/Mec1-to-Hop1/Mek1 signalling depends on stepwise activation of Mek1 that is mediated by Tel1/Mec1 phosphorylation of two specific residues within Hop1: phosphorylation at the threonine 318 (T318) ensures the transient basal level Mek1 activation required for viable spore formation during unperturbed meiosis. Phosphorylation at the serine 298 (S298) promotes stable Hop1-Mek1 interaction on chromosomes following the initial phospho-T318 mediated Mek1 recruitment. In the absence of Dmc1, the phospho-S298 also promotes Mek1 hyper-activation necessary for implementing meiotic checkpoint arrest. Taking these observations together, we propose that the Hop1 phospho-T318 and phospho-S298 constitute key components of the Tel1/Mec1- based meiotic recombination surveillance (MRS) network and facilitate effective coupling of meiotic recombination and progression during both unperturbed and challenged meiosis
Bow shocks, nova shells, disc winds and tilted discs: the nova-like V341 Ara has it all
V341 Ara was recently recognized as one of the closest (d ≃ 150 pc) and brightest (V ≃ 10) nova-like cataclysmic variables. This unique system is surrounded by a bright emission nebula, likely to be the remnant of a recent nova eruption. Embedded within this nebula is a prominent bow shock, where the system’s accretion disc wind runs into its own nova shell. In order to establish its fundamental properties, we present the first comprehensive multiwavelength study of the system. Long-term photometry reveals quasi-periodic, super-orbital variations with a characteristic time-scale of 10–16 d and typical amplitude of ≃1 mag. High-cadence photometry from theTransiting Exoplanet Survey Satellite (TESS) reveals for the first time both the orbital period and a ‘negative superhump’ period. The latter is usually interpreted as the signature of a tilted accretion disc. We propose a recently developed disc instability model as a plausible explanation for the photometric behaviour. In our spectroscopic data, we clearly detect antiphased absorption and emission-line components. Their radial velocities suggest a high mass ratio, which in turn implies an unusually low white-dwarf mass. We also constrain the wind mass-loss rate of the system from the spatially resolved [O III] emission produced in the bow shock; this can be used to test and calibrate accretion disc wind models. We suggest a possible association between V341 Ara and a ‘guest star’ mentioned in Chinese historical records in AD 1240. If this marks the date of the system’s nova eruption, V341 Ara would be the oldest recovered nova of its class and an excellent laboratory for testing nova theory
The distribution of tuberculosis in Porto Alegre: analysis of the magnitude and tuberculosis-HIV coinfection
Objective Analyzing the geographical distribution of the tuberculosis (TB), its incidence and prevalence and TB-HIV coinfection in the districts of Porto Alegre from 2007 to 2011. Method An ecological, descriptive study of time series that used descriptive and geoprocessing techniques. Results In total, were recorded 3,369 incident cases and 3,998 prevalent cases of pulmonary TB. In both contexts, there was predominance of cases in males and in Caucasians. Seventeen districts showed prevalence rates above 79.2 cases/100,000 inhabitants, considering that 15 of them had incidence rates above 73.7 cases/100,000 inhabitants. The TB-HIV coinfection rates reached 67% in some districts, which is above the city average value (30%). Conclusion The distribution analysis showed that the reformulation and restructuring of policies and health services in Porto Alegre are essential
Angular and Current-Target Correlations in Deep Inelastic Scattering at HERA
Correlations between charged particles in deep inelastic ep scattering have
been studied in the Breit frame with the ZEUS detector at HERA using an
integrated luminosity of 6.4 pb-1. Short-range correlations are analysed in
terms of the angular separation between current-region particles within a cone
centred around the virtual photon axis. Long-range correlations between the
current and target regions have also been measured. The data support
predictions for the scaling behaviour of the angular correlations at high Q2
and for anti-correlations between the current and target regions over a large
range in Q2 and in the Bjorken scaling variable x. Analytic QCD calculations
and Monte Carlo models correctly describe the trends of the data at high Q2,
but show quantitative discrepancies. The data show differences between the
correlations in deep inelastic scattering and e+e- annihilation.Comment: 26 pages including 10 figures (submitted to Eur. J. Phys. C
Plastisol Foaming Process. Decomposition of the Foaming Agent, Polymer Behavior in the Corresponding Temperature Range and Resulting Foam Properties
The decomposition of azodicarbonamide, used as foaming agent in PVC - plasticizer (1/1) plastisols was studied by DSC. Nineteen different plasticizers, all belonging to the ester family, two being polymeric (polyadipates), were compared. The temperature of maximum decomposition rate (in anisothermal regime at 5 K min-1 scanning rate), ranges between 434 and 452 K. The heat of decomposition ranges between 8.7 and 12.5 J g -1. Some trends of variation of these parameters appear significant and are discussed in terms of solvent (matrix) and viscosity effects on the decomposition reactions. The shear modulus at 1 Hz frequency was determined at the temperature of maximum rate of foaming agent decomposition, and differs significantly from a sample to another. The foam density was determined at ambient temperature and the volume fraction of bubbles was used as criterion to judge the efficiency of the foaming process. The results reveal the existence of an optimal shear modulus of the order of 2 kPa that corresponds roughly to plasticizer molar masses of the order of 450 ± 50 g mol-1. Heavier plasticizers, especially polymeric ones are too difficult to deform. Lighter plasticizers such as diethyl phthalate (DEP) deform too easily and presumably facilitate bubble collapse
Prospective Study Examining Clinical Outcomes Associated with a Negative Pressure Wound Therapy System and Barker’s Vacuum Packing Technique
Background
The open abdomen has become a common procedure in the management of complex abdominal problems and has improved patient survival. The method of temporary abdominal closure (TAC) may play a role in patient outcome.
Methods
A prospective, observational, open-label study was performed to evaluate two TAC techniques in surgical and trauma patients requiring open abdomen management: Barker’s vacuum-packing technique (BVPT) and the ABTheraTM open abdomen negative pressure therapy system (NPWT). Study endpoints were days to and rate of 30-day primary fascial closure (PFC) and 30-day all-cause mortality.
Results
Altogether, 280 patients were enrolled from 20 study sites. Among them, 168 patients underwent at least 48 hours of consistent TAC therapy (111 NPWT, 57 BVPT). The two study groups were well matched demographically. Median days to PFC were 9 days for NPWT versus 12 days for BVPT (p = 0.12). The 30-day PFC rate was 69 % for NPWT and 51 % for BVPT (p = 0.03). The 30-day all-cause mortality was 14 % for NPWT and 30 % for BVPT (p = 0.01). Multivariate logistic regression analysis identified that patients treated with NPWT were significantly more likely to survive than the BVPT patients [odds ratio 3.17 (95 % confidence interval 1.22–8.26); p = 0.02] after controlling for age, severity of illness, and cumulative fluid administration.
Conclusions
Active NPWT is associated with significantly higher 30-day PFC rates and lower 30-day all-cause mortality among patients who require an open abdomen for at least 48 h during treatment for critical illness
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