17 research outputs found
Bush encroachment control and risk management in semi-arid rangelands
We study the role of bush encroachment control for a farmer’s income and income risk in a stochastic ecological-economic model of grazing management in semiarid rangelands. In particular, we study debushing as an instrument of risk management that complements the choice of an adaptive grazing management strategy for that sake. We show that debushing, while being a good practice for increasing the mean pasture productivity and thus expected income, also increases the farmer’s income risk. The optimal extent of debushing for a risk-averse farmer is thus determined from balancing the positive and negative consequences of debushing on intertemporal and stochastic farm income.bush encroachment, expected utility, farm income, intertemporal optimization, risk aversion, risk management, semi-arid rangeland
Residual Adhesive Removal Methods for Rebonding of Debonded Orthodontic Metal Brackets: Systematic Review and Meta-Analysis
Debonding of orthodontic brackets is a common occurrence during orthodontic treatment. Therefore, the best option for treating debonded brackets should be indicated. This study aimed to evaluate the bond strength of rebonded brackets after different residual adhesive removal methods. This systematic review and meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. PubMed, Web of Science, The Cochrane Library, SciELO, Scopus, LILACS, IBECS, and BVS databases were screened up to December 2020. Bond strength comparisons were made considering the method used for removing the residual adhesive on the bracket base. A total of 12 studies were included for the meta-analysis. Four different adhesive removal methods were identified: sandblasting, laser, mechanical grinding, and direct flame. When compared with new orthodontic metallic brackets, bond strength of debonded brackets after air abrasion (p = 0.006), mechanical grinding (p = 0.007), and direct flame (p < 0.001) was
significantly lower. The use of an erbium-doped yttrium aluminum garnet (Er:YAG) laser showed similar shear bond strength (SBS) values when compared with those of new orthodontic brackets (p = 0.71). The Er:YAG laser could be considered an optimal method for promoting the bond of debonded orthodontic brackets. Direct flame, mechanical grinding, or sandblasting are also suitable, obtaining clinically acceptable bond strength values
Effect of Collagen Crosslinkers on Dentin Bond Strength of Adhesive Systems: A Systematic Review and Meta-Analysis
This study aimed to identify the role of crosslinking agents in the resin-dentin bond strength (BS) when used as modifiers in adhesives or pretreatments to the dentin surface through a systematic review and meta-analysis. This paper was conducted according to the directions of the PRISMA 2020 statement. The research question of this review was: "Would the use of crosslinkers agents improve the BS of resin-based materials to dentin?" The literature search was conducted in the following databases: Embase, PubMed, Scielo, Scopus, and Web of Science. Manuscripts that reported the effect on the BS after the use of crosslinking agents were included. The meta-analyses were performed using Review Manager v5.4.1. The comparisons were performed by comparing the standardized mean difference between the BS values obtained using the crosslinker agent or the control group. The subgroup comparisons were performed based on the adhesive strategy used (total-etch or self-etch). The immediate and long-term data were analyzed separately. A total of 50 articles were included in the qualitative analysis, while 45 articles were considered for the quantitative analysis. The meta-analysis suggested that pretreatment with epigallocatechin-3-gallate (EGCG), carbodiimide, ethylenediaminetetraacetic acid (EDTA), glutaraldehyde, and riboflavin crosslinking agents improved the long-term BS of resin composites to dentin (p ≤ 0.02). On the other hand, the use of proanthocyanidins as a pretreatment improved both the immediate and long-term BS values (p ≤ 0.02). When incorporated within the adhesive formulation, only glutaraldehyde, riboflavin, and EGCG improved the long-term BS to dentin. It could be concluded that the application of different crosslinking agents such as carbodiimide, EDTA, glutaraldehyde, riboflavin, and EGCG improved the long-term BS of adhesive systems to dentin. This effect was observed when these crosslinkers were used as a separate step and when incorporated within the formulation of the adhesive system
Genome-wide association study identifies 32 novel breast cancer susceptibility loci from overall and subtype-specific analyses.
Breast cancer susceptibility variants frequently show heterogeneity in associations by tumor subtype1-3. To identify novel loci, we performed a genome-wide association study including 133,384 breast cancer cases and 113,789 controls, plus 18,908 BRCA1 mutation carriers (9,414 with breast cancer) of European ancestry, using both standard and novel methodologies that account for underlying tumor heterogeneity by estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 status and tumor grade. We identified 32 novel susceptibility loci (P < 5.0 × 10-8), 15 of which showed evidence for associations with at least one tumor feature (false discovery rate < 0.05). Five loci showed associations (P < 0.05) in opposite directions between luminal and non-luminal subtypes. In silico analyses showed that these five loci contained cell-specific enhancers that differed between normal luminal and basal mammary cells. The genetic correlations between five intrinsic-like subtypes ranged from 0.35 to 0.80. The proportion of genome-wide chip heritability explained by all known susceptibility loci was 54.2% for luminal A-like disease and 37.6% for triple-negative disease. The odds ratios of polygenic risk scores, which included 330 variants, for the highest 1% of quantiles compared with middle quantiles were 5.63 and 3.02 for luminal A-like and triple-negative disease, respectively. These findings provide an improved understanding of genetic predisposition to breast cancer subtypes and will inform the development of subtype-specific polygenic risk scores
Problematyka modernizacji obiektów służby zdrowia z XX wieku na przykładzie szpitali z województwa lubelskiego
Most hospitals in Poland date back to the 20th century. Due to developments in technology and medicine, these buildings need to be adapted to meet modern needs. Due to these needs and the possibility of EU funding for hospitals, modernisation has become an extremely topical subject. The aim of the research was to identify what types of modernisation work had been carried out after 2004 and to identify the main problems associated with this work. The subjects of the study were 38 hospitals from the Lubelskie Voivodeship in which various types of modernisation work had been carried out. Based on the data collected on these hospitals, interviews with selected managers and the authors' own experience of working on the modernisation of hospitals from the 20th century, seven main problems associated with the ten different modernisation works identified were distinguished. The authors formulated ten questions which can be helpful to hospital managers before embarking on building upgrades and that will help them define the main problems, objectives and a more holistic rather than fragmented approach to adapting hospitals to modern requirements.Większość szpitali w Polsce pochodzi z XX wieku. W związku z rozwojem technologii i medycyny budynki te wymagają przystosowania do współczesnych potrzeb. W związku z tymi potrzebami oraz możliwością dofinansowania szpitali ze środków Unii Europejskiej, modernizacja stała się niezwykle aktualnym tematem. Celem badań było zidentyfikowanie jakie rodzaje prac modernizacyjnych zostały wykonane po 2004 roku oraz określenie głównych problemów związanych z tymi pracami. Przedmiotem badań było 38 szpitali z województwa lubelskiego, w których były wykonywane różnego rodzaju prace modernizacyjne. Na podstawie zebranych danych o tych szpitalach, rozmów z wybranymi zarządcami oraz doświadczeń własnych autorów związanych z pracą przy modernizacji szpitali z XX wieku, wyróżniono siedem głównych problemów związanych ze zidentyfikowanymi dziesięcioma różnymi pracami modernizacyjnymi. Autorzy sformułowali dziesięć pytań, które będą pomocne dla zarządców szpitali przed przystąpieniem do modernizacji budynków oraz które pomogą im zdefiniować główne problemy, cele oraz bardziej holistyczne a nie fragmentaryczne podejście do przystosowania szpitali do współczesnych wymagań
Cytotoxicity and genotoxicity of bioceramic root canal sealers compared to conventional resin-based sealer
Abstract The aim of this study was to evaluate cytotoxicity and genotoxicity of calcium-silicate based sealers and comparing them with a gold standard—an epoxy-based sealant. Two experimental cell lines were used, gingival fibroblasts (hGF) and monocyte/macrophage peripheral blood cell line (SC). The cytotoxicity (XTT assay) and genotoxicity (comet assay) were evaluated both after 24-h and 48-h incubation. Additionally, after 48-h incubation, the cell apoptosis and cell cycle progression was detected. BioRoot Flow induced a significant decrease in hGF cells viability compared to the negative control groups both after 24-h (p 20% DNA damage). BioRoot Flow and BioRoot RCS, may have potential genotoxic effects and induce apoptosis in hGF cells which may irritate periapical tissues, resulting in a delayed healing. The findings of the study would be useful in selection of an appropriate sealant for root canal filling without causing cytotoxicity and genotoxicity
XX/XY Chimerism in Internal Genitalia of a Virilized Heifer
Five DSD heifers underwent genetic analysis in the present study. We cytogenetically analyzed in vitro cultured leukocytes and searched for SRY, AMELX/AMELY and ZFX/ZFY genes in leukocytes and hair follicles, finding that four of the studied heifers were freemartins (XX/XY leukocyte chimerism). The fifth case had an underdeveloped vulva localized ventrally and cranially to the mammary gland, a normal female sex chromosome complement (60,XX) in the leukocytes, and a lack of Y-chromosome-derived genes in the leukocytes and hair follicles. Postmortem anatomical examination of this heifer revealed the presence of normal ovaries with follicles, uterus, and oviducts, but molecular detection of the SRY, ZFX, ZFY,AMELX, and AMELY genes in these organs indicated the presence of a cell line carrying the Y chromosome. Further analysis of twelve microsatellite markers revealed the presence of additional variants at six loci in DNA samples derived from the reproductive organs; XX/XY chimerism was thus suspected in these samples. On the basis of the detection of AMELY (Y-linked) versus AMELX (X-linked) and SOX9 (autosomal) versus AMELY genes by droplet digital PCR (ddPCR), the Y/X and Y/autosome ratios were evaluated; they indicated the presence of XX and XY cell lines in the reproductive tissues. Our study showed that XX/XY chimerism can be present in the internal reproductive organs of the virilized heifers with a normal female set of sex chromosomes (60,XX) and a lack of Y-chromosome-derived genes in the leukocytes. The etiology of this phenomenon remains unknown
Porcelain veneers in vital vs. non-vital teeth : a retrospective clinical evaluation
Nowadays, the ceramic veneer approach can be considered more predictable than direct composite veneer. To date, there is a lack of studies comparing the clinical performance of anterior veneers cemented on vital teeth (VT) and non-vital teeth (NVT). This longitudinal clinical study investigated the performance of ceramic veneers in VT or anterior NVT. A total of 55 patients were evaluated in the study. Two groups were defined based on the vitality status of the teeth (93 teeth—vital and 61 teeth—non-vital). The United States Public Health Service (USPHS) criteria were used to assess the clinical status. The data were evaluated statistically with the Mann–Whitney U test. All restorations were considered acceptable, and only one veneer in VT failed for the criteria of secondary caries. There were no statistically significant differences in any of the criteria evaluated (p ≤ 0.671). The ceramic veneers evaluated showed a satisfactory clinical performance both in VT and NVT
Porcelain Veneers in Vital vs. Non-Vital Teeth: A Retrospective Clinical Evaluation
Nowadays, the ceramic veneer approach can be considered more predictable than direct composite veneer. To date, there is a lack of studies comparing the clinical performance of anterior veneers cemented on vital teeth (VT) and non-vital teeth (NVT). This longitudinal clinical study investigated the performance of ceramic veneers in VT or anterior NVT. A total of 55 patients were evaluated in the study. Two groups were defined based on the vitality status of the teeth (93 teeth—vital and 61 teeth—non-vital). The United States Public Health Service (USPHS) criteria were used to assess the clinical status. The data were evaluated statistically with the Mann–Whitney U test. All restorations were considered acceptable, and only one veneer in VT failed for the criteria of secondary caries. There were no statistically significant differences in any of the criteria evaluated (p ≤ 0.671). The ceramic veneers evaluated showed a satisfactory clinical performance both in VT and NVT