27 research outputs found
New potential antitumoral fluorescent tetracyclic thieno[3,2-b]pyridine derivatives: interaction with DNA and nanosized liposomes
Fluorescence properties of two new potential antitumoral tetracyclic thieno[3,2-b]pyridine derivatives were studied in solution and in liposomes of DPPC (dipalmitoyl phosphatidylcholine), egg lecithin (phosphatidylcholine from egg yolk; Egg-PC) and DODAB (dioctadecyldimethylammonium bromide). Compound 1, pyrido[2',3':3,2]thieno[4,5-d]pyrido[1,2-a]pyrimidin-6-one, exhibits reasonably high fluorescence quantum yields in all solvents studied (0.20 ≤ ΦF ≤ 0.30), while for compound 2, 3-[(p-methoxyphenyl)ethynyl]pyrido[2',3':3,2]thieno[4,5-d]pyrido[1,2-a]pyrimidin-6-one, the values are much lower (0.01 ≤ ΦF ≤ 0.05). The interaction of these compounds with salmon sperm DNA was studied using spectroscopic methods, allowing the determination of intrinsic binding constants, Ki = (8.7 ± 0.9) × 103 M-1 for compound 1 and Ki = (5.9 ± 0.6) × 103 M-1 for 2, and binding site sizes of n = 11 ± 3 and n = 7 ± 2 base pairs, respectively. Compound 2 is the most intercalative compound in salmon sperm DNA (35%), while for compound 1 only 11% of the molecules are intercalated. Studies of incorporation of both compounds in liposomes of DPPC, Egg-PC and DODAB revealed that compound 2 is mainly located in the hydrophobic region of the lipid bilayer, while compound 1 prefers a hydrated and fluid environment
Qualidade físico-química e de fritura de tubérculos de cultivares de batata na safra de inverno
Quando e onde se acidentam e morrem os motociclistas em Belo Horizonte, Minas Gerais, Brasil
A comparative study of nutritional composition and potential use of some underutilized tropical fruits of Arecaceae
Dijet Resonance Search with Weak Supervision Using root S=13 TeV pp Collisions in the ATLAS Detector
This Letter describes a search for narrowly resonant new physics using a machine-learning anomaly
detection procedure that does not rely on signal simulations for developing the analysis selection. Weakly
supervised learning is used to train classifiers directly on data to enhance potential signals. The targeted
topology is dijet events and the features used for machine learning are the masses of the two jets. The
resulting analysis is essentially a three-dimensional search A → BC, for mA ∼ OðTeVÞ, mB; mC ∼
Oð100 GeVÞ and B, C are reconstructed as large-radius jets, without paying a penalty associated with
a large trials factor in the scan of the masses of the two jets. The full run 2 ffiffi
s p ¼ 13 TeV pp collision
dataset of 139 fb−1 recorded by the ATLAS detector at the Large Hadron Collider is used for the search.
There is no significant evidence of a localized excess in the dijet invariant mass spectrum between 1.8 and
8.2 TeV. Cross-section limits for narrow-width A, B, and C particles vary with mA, mB, and mC. For
example, when mA ¼ 3 TeV and mB ≳ 200 GeV, a production cross section between 1 and 5 fb is
excluded at 95% confidence level, depending on mC. For certain masses, these limits are up to 10 times
more sensitive than those obtained by the inclusive dijet search. These results are complementary to the
dedicated searches for the case that B and C are standard model boson
Valorisation of Biowastes for the Production of Green Materials Using Chemical Methods
With crude oil reserves dwindling, the hunt for a sustainable alternative feedstock for fuels and materials for our society continues to expand. The biorefinery concept has enjoyed both a surge in popularity and also vocal opposition to the idea of diverting food-grade land and crops for this purpose. The idea of using the inevitable wastes arising from biomass processing, particularly farming and food production, is, therefore, gaining more attention as the feedstock for the biorefinery. For the three main components of biomass—carbohydrates, lipids, and proteins—there are long-established processes for using some of these by-products. However, the recent advances in chemical technologies are expanding both the feedstocks available for processing and the products that be obtained. Herein, this review presents some of the more recent developments in processing these molecules for green materials, as well as case studies that bring these technologies and materials together into final products for applied usage
The influence of preparation conditions on the characteristics of chitosan-alginate dressings for skin lesions
In this work, the preparation and characterization of membranes obtained through chitosan and alginate coacervation and designed for use as wound dressings were evaluated. The influence of different stirring rates and rates of addition of chitosan solution to alginate solution on the final characteristics of the biomaterial was analyzed in detail, aiming at a simple and easily scalable membrane production protocol. The results show that membranes with dry thickness from 66 to 80 pm, wet thickness from 106 to 633 mu m, tensile strength varying from 6.86 to 31.14 MPa, elongation at break from 3.97 to 8.42%, and maximum water uptake up to 19 g of water per gram of membrane and that are able to prevent the permeation of bacteria can be obtained in a fairly reproducible way by the procedure established. The membranes prepared at flow ratio of 40 mL/h and stirring equal to 100 rpm showed a high potential for use on highly exuding wounds. (c) 2008 Wiley Periodicals, Inc.10942703271
The burden of road traffic injuries in Guyana: Time to prioritise road safety investments
Background Guyana, like other low- and middle-income countries (LMICs), is rapidly motorising with limited systemic support for road safety initiatives. Understanding the epidemiology of road traffic injuries (RTIs) is an important first step in prioritising investments.Aims/Objectives/Purpose To quantify the burden of RTIs in Guyana and inform priority action areas for prevention efforts at the national level.Methods A review of PubMed, grey literature, and internet search engines was performed. Ministry of Health (MoH) data for select years were accessed electronically, and police data from 2000–2010 were obtained during a site visit. A stakeholder analysis was conducted following meetings with representatives from key ministries and civil society.Results/Outcomes MoH data indicates RTIs are a leading cause of death among persons aged 5–64 years. According to police data, there were 115 road traffic (RT) deaths, or 14.8 RT deaths per 100 000 population in 2010; this rate has been stable for the past 3 years, but represents a decrease from 22.8 earlier in the decade. For the period 2000–2010 pedestrians accounted for the largest proportion of RT deaths, followed by motorcycle users and bicyclists. While conscientious, the lead agency is understaffed and underfunded.Significance/Contribution to the Field RTIs are a major concern in Guyana. We offer the following priority areas for consideration in Guyana: improving data systems; capacity building for road safety; investing in the Emergency Medical Systems; improving infrastructure; fostering greater inter-sectoral collaboration; and increasing funding for injury prevention programmes. These areas might hold relevance to other LMICs in the region
Morphological and histochemical study of the myotomal muscle in pacu (Piaractus mesopotamicus Holmberg, 1887) during the initial growth phases
Morphological and histochemical methods were used to evaluate the myotomal muscle characteristics of pacu (Piaractus mesopotamicus) from hatching to 40 days old. During the larval period, the musculature consisted predominantly of white muscle. White and red muscle mass increased at 10, 20, 30 and 40 days after hatching. The larvae had round muscle fibers with a moderate degree of maturation and central nuclei. In subsequent phases, small and immature fibers were visible near larger and more differentiated fibers. Undifferentiated cells or presumptive myoblasts located in embryogenic zones were visible in the dorsal and ventral regions, and were more evident at 30 and 40 days. The red muscle fibers located in the subdermal region, had oxidative metabolism and slow contraction, whereas the more predominant white muscle fibers had glycolytic metabolism and fast contraction. Our findings indicate that during the initial phases, myotomal muscle growth in pacu occurs by both, muscle fiber hypertrophy and hyperplasia. The analysis of frequency of red and white muscle fibers shows that hyperplastic growth is intense in this period. As the growth rate in adult fish is related to the number of muscle fibers in young fish, extrinsic factors could change the muscle fiber phenotype and influence their ultimate size