711 research outputs found
The influence of delayed light curing on the degree of conversion and polymerization contraction stress in dual-cured resin luting agents
The aim of the study was to assess the effect of delayed photo-initiation on the polymerization contraction stress (PCS) and degree of conversion (DC) of a dual-cure resin-luting agent. Thirty-five disk (6 mm × 1 mm) samples (n = 10 each group) of dual cure resin luting agent for PCS assessment were fabricated and polymerized using two illuminated quartz rods. Based on the delay in photo-initiation, 30 disks were divided among six groups [group A-0 min (min) delay, group B-2 min, group C-4 min, group D-6 min, group E-8 min and group F-10 min]. A non-photoinitiated group (group G – chemical cure – n = 5) was included as control. The PCS for all specimens was assessed using a Tensometer. For DC evaluation thirty-five specimens were divided into seven groups with delays in photo-initiation (group H-0 min, group I-2 min, group J-4 min, group K-6 min, group L-8 min and group M-10 min, group N-chemical cure). DC was assessed using attenuated total reflectance spectroscopic technique. Statistical comparison among groups was performed using analysis of variance (α = 0.05). The maximum and minimum PCS and DC values with delayed photo-initiation was observed in group-C (3.34 MPa) & group-F (2.44 MPa); and group-M (0.78 MPa) and group-H (0.55 MPa) respectively. Chemically cured samples showed the least PCS (group-G, 1.94) and DC (group-N, 0.53) values in their respective categories. PCS significantly decreased with delayed photo-initiation. A significant increase in DC was noticed when photo-initiation was delayed in the dual cure resin luting agent
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Variable responses of human and non-human primate gut microbiomes to a Western diet
BACKGROUND: The human gut microbiota interacts closely with human diet and physiology. To better understand the mechanisms behind this relationship, gut microbiome research relies on complementing human studies with manipulations of animal models, including non-human primates. However, due to unique aspects of human diet and physiology, it is likely that host-gut microbe interactions operate differently in humans and non-human primates. RESULTS: Here, we show that the human microbiome reacts differently to a high-protein, high-fat Western diet than that of a model primate, the African green monkey, or vervet (Chlorocebus aethiops sabaeus). Specifically, humans exhibit increased relative abundance of Firmicutes and reduced relative abundance of Prevotella on a Western diet while vervets show the opposite pattern. Predictive metagenomics demonstrate an increased relative abundance of genes associated with carbohydrate metabolism in the microbiome of only humans consuming a Western diet. CONCLUSIONS: These results suggest that the human gut microbiota has unique properties that are a result of changes in human diet and physiology across evolution or that may have contributed to the evolution of human physiology. Therefore, the role of animal models for understanding the relationship between the human gut microbiota and host metabolism must be re-focused.P40 OD010965 - NIH HHS; P40 RR019963 - NCRR NIH HHS; P51 OD011132 - NIH HHS; R01 RR016300 - NCRR NIH HHS; 5R01RR016300 - NCRR NIH HH
What, how and who: Cost-effectiveness analyses of COVID-19 vaccination to inform key policies in Nigeria.
While safe and efficacious COVID-19 vaccines have achieved high coverage in high-income settings, roll-out remains slow in sub-Saharan Africa. By April 2022, Nigeria, a country of over 200 million people, had only distributed 34 million doses. To ensure the optimal use of health resources, cost-effectiveness analyses can inform key policy questions in the health technology assessment process. We carried out several cost-effectiveness analyses exploring different COVID-19 vaccination scenarios in Nigeria. In consultation with Nigerian stakeholders, we addressed three key questions: what vaccines to buy, how to deliver them and what age groups to target. We combined an epidemiological model of virus transmission parameterised with Nigeria specific data with a costing model that incorporated local resource use assumptions and prices, both for vaccine delivery as well as costs associated with care and treatment of COVID-19. Scenarios of vaccination were compared with no vaccination. Incremental cost-effectiveness ratios were estimated in terms of costs per disability-adjusted life years averted and compared to commonly used cost-effectiveness ratios. Viral vector vaccines are cost-effective (or cost saving), particularly when targeting older adults. Despite higher efficacy, vaccines employing mRNA technologies are less cost-effective due to high current dose prices. The method of delivery of vaccines makes little difference to the cost-effectiveness of the vaccine. COVID-19 vaccines can be highly effective and cost-effective (as well as cost-saving), although an important determinant of the latter is the price per dose and the age groups prioritised for vaccination. From a health system perspective, viral vector vaccines may represent most cost-effective choices for Nigeria, although this may change with price negotiation
Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.
Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition
A long-period transiting substellar companion in the super-Jupiters to brown dwarfs mass regime and a prototypical warm-Jupiter detected by TESS
We report on the confirmation and follow-up characterization of two
long-period transiting substellar companions on low-eccentricity orbits around
TIC 4672985 and TOI-2529, whose transit events were detected by the TESS space
mission. Ground-based photometric and spectroscopic follow-up from different
facilities, confirmed the substellar nature of TIC 4672985 b, a massive gas
giant, in the transition between the super Jupiters and brown dwarfs mass
regime. From the joint analysis we derived the following orbital parameters: P
= 69.0480 d, Mp = 12.74 Mjup, Rp = 1.026 Rjup and e = 0.018. In addition, the
RV time series revealed a significant trend at the 350 m/s/yr level, which is
indicative of the presence of a massive outer companion in the system. TIC
4672985 b is a unique example of a transiting substellar companion with a mass
above the deuterium-burning limit, located beyond 0.1 AU and in a nearly
circular orbit. These planetary properties are difficult to reproduce from
canonical planet formation and evolution models. For TOI-2529 b, we obtained
the following orbital parameters: P = 64.5949 d, Mp = 2.340 Mjup, Rp = 1.030
Rjup and e = 0.021, making this object a new example of a growing population of
transiting warm giant planets.Comment: Accepted in A&
Loss of Sex and Age Driven Differences in the Gut Microbiome Characterize Arthritis-Susceptible *0401 Mice but Not Arthritis-Resistant *0402 Mice
<div><h3>Background</h3><p>HLA-DRB1*0401 is associated with susceptibility, while HLA-DRB1*0402 is associated with resistance to developing rheumatoid arthritis (RA) and collagen-induced arthritis in humans and transgenic mice respectively. The influence of gut-joint axis has been suggested in RA, though not yet proven.</p> <h3>Methodology/Principal Findings</h3><p>We have used HLA transgenic mice carrying arthritis susceptible and -resistant HLA-DR genes to explore if genetic factors and their interaction with gut flora gut can be used to predict susceptibility to develop arthritis. Pyrosequencing of the 16S rRNA gene from the fecal microbiomes of DRB1*0401 and DRB1*0402 transgenic mice revealed that the guts of *0401 mice is dominated by a Clostridium-like bacterium, whereas the guts of *0402 mice are enriched for members of the <em>Porphyromonadaceae</em> family and <em>Bifidobacteria</em>. DRB1*0402 mice harbor a dynamic sex and age-influenced gut microbiome while DRB1*0401 mice did not show age and sex differences in gut microbiome even though they had altered gut permeability. Cytokine transcripts, measured by rtPCR, in jejuna showed differential TH17 regulatory network gene transcripts in *0401 and *0402 mice.</p> <h3>Conclusions/Significance</h3><p>We have demonstrated for the first time that HLA genes in association with the gut microbiome may determine the immune environment and that the gut microbiome might be a potential biomarker as well as contributor for susceptibility to arthritis. Identification of pathogenic commensal bacteria would provide new understanding of disease pathogenesis, thereby leading to novel approaches for therapy.</p> </div
The sac evolution imaging follow-up after endovascular aortic repair:An international expert opinion-based Delphi consensus study
Objective: Management of follow-up protocols after endovascular aortic repair (EVAR) varies significantly between centers and is not standardized according to sac regression. By designing an international expert-based Delphi consensus, the study aimed to create recommendations on follow-up after EVAR according to sac evolution. Methods: Eight facilitators created appropriate statements regarding the study topic that were voted, using a 4-point Likert scale, by a selected panel of international experts using a three-round modified Delphi consensus process. Based on the experts' responses, only those statements reaching a grade A (full agreement ≥75%) or B (overall agreement ≥80% and full disagreement <5%) were included in the final document. Results: One-hundred and seventy-four participants were included in the final analysis, and each voted the initial 29 statements related to the definition of sac regression (Q1-Q9), EVAR follow-up (Q10-Q14), and the assessment and role of sac regression during follow-up (Q15-Q29). At the end of the process, 2 statements (6.9%) were rejected, 9 statements (31%) received a grade B consensus strength, and 18 (62.1%) reached a grade A consensus strength. Of 27 final statements, 15 (55.6%) were classified as grade I, whereas 12 (44.4%) were classified as grade II. Experts agreed that sac regression should be considered an important indicator of EVAR success and always be assessed during follow-up after EVAR. Conclusions: Based on the elevated strength and high consistency of this international expert-based Delphi consensus, most of the statements might guide the current clinical management of follow-up after EVAR according to the sac regression. Future studies are needed to clarify debated issues.</p
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