1,095 research outputs found
Flapless Cone Beam Computed Tomography-Guided Implant Surgery with Contextual Transcrestal Sinus Lift Augmentation Using New Bone Compactor Tools
In the present paper, the authors present a case report of premolar edentulism in the upper jaw treated through a guided flapless oral implant surgery with contextual crestal sinus lift, performed with a system of manual screw-tapered bone expanders (B&B Dental, San Benedetto, BO, Italy). The surgery was planned by means of dedicated software, through which the data obtained from the CBCT and from intraoral scanner impression were matched, with consequent production of a surgical template. The proposed surgical procedure is minimally invasive, very simple, and fast and ensures good comfort for the patient by avoiding the elevation of mucoperiosteal flaps and uncomfortable malleting maneuvers. In addition, the presented method shows a good degree of correspondence between the ideal position of the implant in the planning phase and the actual one detectable after the surgery
Quantum phase slips in superconducting Nb nanowire networks deposited on self-assembled Si templates
Robust porous silicon substrates were employed for generating interconnected
networks of superconducting ultrathin Nb nanowires. Scanning electron
microscopy analysis was performed to investigate the morphology of the samples,
which constitute of polycrystalline single wires with grain size of about 10
nm. The samples exhibit nonzero resistance over a broad temperature range below
the critical temperature, fingerprint of phase slippage processes. The
transport data are satisfactory reproduced by models describing both thermal
and quantum fluctuations of the superconducting order parameter in thin
homogeneous superconducting wires.Comment: accepted for publication on Applied Physics Letter
Sustainable solutions for the construction sector: integration of secondary raw materials in the production cycle of concrete
The construction industry is one of the largest consumers of raw materials and energy and one of the highest contributor to green-houses gases emissions. In order to become more sustainable it needs to reduce the use of both raw materials and energy, thus lim-iting its environmental impact. Developing novel technologies to integrate secondary raw materials (i.e. lightweight recycled aggre-gates and alkali activated âcementlessâ binders - geopolymers) in the production cycle of concrete is an all-inclusive solution to im-prove both sustainability and cost-efficiency of construction industry. SUS-CON âSUStainable, Innovative and Energy-Efficiency CONcrete, based on the integration of all-waste materialsâ is an European project (duration 2012-2015), which aim was the inte-gration of secondary raw materials in the production cycle of concrete, thus resulting in innovative, sustainable and cost-effective building solutions. This paper presents the main outcomes related to the successful scaling-up of SUS-CON concrete solutions in traditional production plants. Two European industrial concrete producers have been involved, to design and produce both pre-cast components (blocks and panels) and ready-mixed concrete. Recycled polyurethane foams and mixed plastics were used as aggre-gates, PFA (Pulverized Fuel Ash, a by-product of coal fuelled power plants) and GGBS (Ground Granulated Blast furnace Slag, a by-product of iron and steel industries) as binders. Eventually, the installation of SUS-CON concrete solutions on real buildings has been demonstrated, with the construction of three mock-ups located in Europe (Spain, Turkey and Romania
Retreatment with pegylated interferon plus ribavirin of chronic hepatitis C non-responders to interferon plus ribavirin: A meta-analysis.
BACKGROUND/AIMS: Efficacy of retreatment with pegylated interferon (PEG-IFN) plus ribavirin of non-responders to standard or pegylated IFN plus ribavirin has been assessed in various studies, but sustained virologic response (SVR) rates are variable and factors influencing efficacy and tolerability still remain incompletely defined. We aimed to focus on SVR rates and to identify factors influencing them in this meta-analysis. METHODS: MEDLINE as well as a manual search were used. Studies were included if they were controlled or uncontrolled trials, if they had been published as full-length papers and if they included non-responders to standard or pegylated IFN and ribavirin therapy. Fourteen trials were included in the meta-analysis. Data on study populations, interventions, and outcomes were extracted from trials using a random-effects model. Primary outcome was the SVR rate. RESULTS: The pooled estimate of SVR rate was 16.3% (95% Confidence Interval - 95% CI, 8.3-29.6%). There was a significant heterogeneity among studies (p<0.0001). Heterogeneity was less apparent in studies that included fewer patients with cirrhosis or overweight. By meta-regression, higher SVR rate was observed in trials with a lower prevalence of subjects with genotype 1 infection and with fewer overweight patients. The use of a 24-week retreatment stopping rule did not affect SVR rate. CONCLUSIONS: The overall modest efficacy argues against an indiscriminate retreatment with PEG-IFN and ribavirin of all non-responders. Restricting retreatment to non-overweight patients or to those with genotype 2 or 3 infection, using a 24-week retreatment stopping rule, would optimize the potential benefit with a scarce likelihood of missing a curative response
Can bone compaction improve primary implant stability? An in vitro comparative study with osseodensification technique
Background: This study aims to analyze bone compaction and osseodensification techniques and to investigate how cancellous bone compaction could influence primary implant stability (PS). Methods: Two different surgical protocols (bone compactorsâBC; osseodensification drillsâOD) were compared by placing 20 implants into 20 fresh pig ribs for each procedure. Peak insertion torque (PIT) and peak removal torque (PRT) were investigated using an MGT-12 digital torque gauge, and implant stability quotient (ISQ) was analyzed using an OsstellÂŽ Beacon device. Results: Analysis of our data (T-test p < 0.05) evidenced no statistically significant difference between BC and OD in terms of PIT (p = 0.33) or ISQ (p = 0.97). The comparison of PRT values showed a statistically significant difference between BC and OD protocols (p = 0.009). Conclusions: Cancellous bone compaction seems to improve PS, preserving a significant amount of bone and evenly spreading trabeculae on the entire implant site. Although the PIT and ISQ values obtained are similar, the PRT values suggest a better biological response from the surrounding bone tissue. Nevertheless, a larger sample and further in vivo studies are necessary to validate the usefulness of this protocol in several clinical settings
Study of void closure in hot rolling of stainless steel slabs
Continuous casting products contain void defects due to the shrinkage occurring during solidification. These defects, having different and irregular shapes and sizes, are located and distributed within the material depending on casting conditions. In order to deliver safe and sound products, these voids must be reduced during the subsequent hot forming processes, but it becomes very difficult when slabs are directly hot rolled without any previous forming processes (i.e., cogging), so obtaining a cheaper and more sustainable process chain. Many studies on voids closure present in literature are based on the evaluation of a process parameter called "stress triaxiality ratio". Aim of this research is to optimize the hot rolling process performed to reduce shrinkage voids of the billet due to casting. In particular, the results of a study on voids closure during hot rolling of stainless steel slabs (AISI 316L) coming from continuous casting process are reported. A FE analysis of the effects of the main process parameters of hot rolling on the "voids closure index" were investigated. Afterwards, experimental tests were performed to validate the research from an industrial point of view. A correlation between the void closure index and the final residual void percentage along the rolled slabs was found
Nonsense-mediated decay mechanism is a possible modifying factor of clinical outcome in nonsense cd39 beta thalassemia genotype
Nonsense-mediated mRNA decay (NMD) is a surveillance system to prevent the synthesis of non-functional proteins. In β-thalassemia, NMD may have a role in clinical outcome. An example of premature translation stop codons appearing for the first time is the β-globin cd39 mutation; when homozygous, this results in a severe phenotype. The aim of this study was to determine whether the homozygous nonsense cd39 may have a milder phenotype in comparison with IVS1,nt110/cd39 genotype. Genotypes have been identified from a cohort of 568 patients affected by β-thalassemia. These genotypes were compared with those found in 577 affected fetuses detected among 2292 prenatal diagnoses. The nine most common genotypes, each with an incidence rate of 1.5% or over, and together accounting for 80% of genotype frequencies, underwent statistical analysis. Genotype prevalence was calculated within the overall group. Results are expressed as proportions with 95% confidence intervals; Pâ¤0.05 was considered statistically significant. A binomial distribution was assumed for each group; z-tests were used to compare genotype frequencies observed in the patient group with frequencies in the affected fetus group. In the absence of selecting factors, prevalence of these two genotypes was compared between a cohort of 568 β-thalassemia patients (PTS) and 577 affected fetuses (FOET) detected during the same period. IVS1,nt110/cd39 was significantly more prevalent in FOET than PTS (P<0.0001), while there was no significant difference in prevalence of cd39/cd39 in FOET compared with PTS (P=0.524). These results suggest a cd39 genotype NMD mechanism may be associated with improved clinical outcomes in thalassemia major
Characterization of quasiparticle relaxation times in microstrips of NbReN for perspective applications for superconducting single-photon detectors
The study of the flux-flow instability in superconducting materials has recently gained renewed attention due to
its potential implications for the use of the analyzed materials as micrometer-sized superconducting detectors
for single photons. The values of the quasiparticle relaxation time (ĎE) measured for these detectors are affected
by pinning properties. Here, we report electric transport properties of NbReN microstrips of different quality.
For the strip characterized by high resistivity, and large critical currents and pinning, we estimate a value of
ĎE that is almost two orders of magnitude larger compared to that of another strip with a smaller value for
the critical current, for which we measure ĎE âź 12 ps. This low value is comparable to those reported in the
literature for microstrips made of other highly-disordered superconductors. Our results suggest that NbReN
microstrips have great potential for the realization of superconducting single-photon detectors, depending on
further optimization of their fabrication process and the superconducting properties affected by it
Effects of a scalable home-visiting intervention on child development in slums of urban India: evidence from a randomised controlled trial
Background:
An estimated 63.4 million Indian children under 5 years are at risk of poor development. Home visits that use a structured curriculum to help caregivers enhance the quality of the home stimulation environment improve developmental outcomes. However, achieving effectiveness in poor urban contexts through scalable models remains challenging.
Methods:
Using a cluster randomised controlled trial, we evaluated a psychosocial stimulation intervention, comprising weekly home visits for 18 months, in urban slums of Cuttack, Odisha, India. The intervention is complementary to existing early childhood services in India and was run and managed through a local branch of a national NGO. The study ran from August 2013 to July 2015. We enrolled 421 children aged 10â20 months from 54 slums. Slums were randomised to intervention or control. Primary outcomes were children's cognitive, receptive language, expressive language and fine motor development assessed using the BayleyâIII. Prespecified intentâtoâtreat analysis investigated impacts and heterogeneity by gender. Trial registrations: ISRCTN89476603, AEARCTRâ0000169.
Results:
Endline data for 378 (89.8%) children were analysed. Attrition was balanced between groups. We found improvements of 0.349 of a standard deviation (SD; p = .005, stepdown p = .017) to cognition while impacts on receptive language, expressive language and fine motor development were, respectively, 0.224 SD (p = .099, stepdown p = .184), 0.192 SD (p = .085, stepdown p = .184) and 0.111 (p = .385, stepdown p = .385). A child development factor improved by 0.301 SD (p = .032). Benefits were larger for boys. The quality of the home stimulation environment also improved.
Conclusions:
This study shows that a potentially scalable homeâvisiting intervention is effective in poor urban areas
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