In recent years, there have been significant advances on materials development for additive manufacturing (AM) applications. However, the use of composites or nanocomposite materials for improved ...performance and multifunctionality are still limited. This review paper attempts to provide a comprehensive review of both commercially available materials as well as research activities related to recent progress on high-performance polymer nanocomposites that are being used in various AM techniques. Four AM techniques including Fused Filament Fabrication (FFF), Selective Laser Sintering (SLS), Multi Jet Fusion (MJF), and Stereolithography (SLA) are discussed. The development of printable polymer composites especially polymer nanocomposites is rapidly expanding the AM materials portfolio, which makes the production of multifunctional parts with complex structures possible.
The ability to replace organs and tissues on demand could save or improve millions of lives each year globally and create public health benefits on par with curing cancer. Unmet needs for organ and ...tissue preservation place enormous logistical limitations on transplantation, regenerative medicine, drug discovery, and a variety of rapidly advancing areas spanning biomedicine. A growing coalition of researchers, clinicians, advocacy organizations, academic institutions, and other stakeholders has assembled to address the unmet need for preservation advances, outlining remaining challenges and identifying areas of underinvestment and untapped opportunities. Meanwhile, recent discoveries provide proofs of principle for breakthroughs in a family of research areas surrounding biopreservation. These developments indicate that a new paradigm, integrating multiple existing preservation approaches and new technologies that have flourished in the past 10 years, could transform preservation research. Capitalizing on these opportunities will require engagement across many research areas and stakeholder groups. A coordinated effort is needed to expedite preservation advances that can transform several areas of medicine and medical science.
The SYMPLICITY HTN-3 randomized, blinded, sham-controlled trial confirmed the safety of renal denervation (RDN), but did not meet its primary efficacy endpoint. Prior RDN studies have demonstrated ...significant and durable reductions in blood pressure. This analysis investigated factors that may help explain these disparate results.
Patients with resistant hypertension were randomized 2 : 1 to RDN (n = 364) or sham (n = 171). The primary endpoint was the difference in office systolic blood pressure (SBP) change at 6 months. A multivariable analysis identified predictors of SBP change. Additional analyses examined the influence of medication changes, results in selected subgroups and procedural factors. Between randomization and the 6-month endpoint, 39% of patients underwent medication changes. Predictors of office SBP reduction at 6 months were baseline office SBP ≥ 180 mmHg, aldosterone antagonist use, and non-use of vasodilators; number of ablations was a predictor in the RDN group. Non-African-American patients receiving RDN had a significantly greater change in office SBP than those receiving sham; -15.2 ± 23.5 vs. -8.6 ± 24.8 mmHg, respectively (P = 0.012). Greater reductions in office and ambulatory SBP, and heart rate were observed with a higher number of ablations and energy delivery in a four-quadrant pattern.
Post hoc analyses, although derived from limited patient cohorts, reveal several potential confounding factors that may partially explain the unexpected blood pressure responses in both the sham control and RDN groups. These hypothesis-generating data further inform the design of subsequent research to evaluate the potential role of RDN in the treatment of resistant hypertension. CLINICALTRIALS.GOV IDENTIFIER: NCT01418261.
Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial pneumonia marked by progressive lung fibrosis and a poor prognosis. Recent studies have highlighted the potential role of infection in ...the pathogenesis of IPF, and a prior association of the
gene with idiopathic fibrotic interstitial pneumonia (including IPF) has been reported. Owing to the important role that the human leukocyte antigen (HLA) region plays in the immune response, here we evaluated if HLA genetic variation was associated specifically with IPF risk.
We performed a meta-analysis of associations of the HLA region with IPF risk in individuals of European ancestry from seven independent case-control studies of IPF (comprising 5159 cases and 27 459 controls, including a prior study of fibrotic interstitial pneumonia). Single nucleotide polymorphisms, classical HLA alleles and amino acids were analysed and signals meeting a region-wide association threshold of p<4.5×10
and a posterior probability of replication >90% were considered significant. We sought to replicate the previously reported
association in the subset of studies independent of the original report.
The meta-analysis of all seven studies identified four significant independent single nucleotide polymorphisms associated with IPF risk. However, none met the posterior probability for replication criterion. The
association was not replicated in the independent IPF studies.
Variation in the HLA region was not consistently associated with risk in studies of IPF. However, this does not preclude the possibility that other genomic regions linked to the immune response may be involved in the aetiology of IPF.
•Ohmic losses dominated overpotentials of a PEM electrolyzer with bilayer mesh PTLs.•Reducing mesh opening size improved PTL/CL contact, reducing ohmic losses.•Delamination at the PTL/CL interface ...was caused by misaligned mesh layers.•Mass transport losses in mesh PTLs due to gas coverage at the PTL/CL interface.
Tailoring the catalyst layer interface is paramount for high performance electrochemical energy conversion, from fuel cells to carbon dioxide electrolyzers. Here, we tailored the catalyst layer (CL) interfacial contact in a polymer electrolyte membrane (PEM) water electrolyzer with bilayer titanium mesh porous transport layers (PTLs). In contrast to typical commercial PTL materials, ohmic losses dominated the overpotentials of a PEM electrolyzer with bilayer mesh PTLs, contributing up to 73% of the overall overpotential (at a current density of 1 A/cm2). Tailoring the mesh opening size (from 1.16 mm to 0.20 mm) led to a 56% reduction in ohmic losses due to the enhanced contact between the mesh PTL and the CL. Non-negligible mass transport losses were attributed to gas pooling at the PTL/CL interface when the pore width exceeded the pore height. However, when the pore height exceeded the pore width, significantly higher mass transport losses were observed, which we attributed to complete gas filling of the pores. Additionally, we found that bilayer mesh PTLs with pore size gradients are susceptible to delamination at the CL/PTL interface due to the misalignment of mesh layers.
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We sought to examine the short- and long-term outcomes of patients who developed contrast-induced acute kidney injury (CI-AKI; defined as an increase in serum creatinine of ≥0.5 mg/dL or a 25% ...relative rise within 48 h after contrast exposure) from the large-scale HORIZONS-AMI trial.
Multivariable analyses were used to identify predictors of CI-AKI, as well predictors of the primary and secondary endpoints. The incidence of CI-AKI in this cohort of ST-segment elevation myocardial infarction (STEMI) patients was 16.1% (479/2968). Predictors of CI-AKI were contrast volume, white blood cell count, left anterior descending infarct-related artery, age, anaemia, creatinine clearance <60 mL/min, and history of congestive heart failure. Patients with CI-AKI had higher rates of net adverse clinical events NACE; a combination of major bleeding or composite major adverse cardiac events (MACE; consisting of death, reinfarction, target vessel revascularization for ischaemia, or stroke) at 30 days (22.0 vs. 9.3%; P < 0.0001) and 3 years (40.3 vs. 24.6%; P < 0.0001). They also had higher rates of mortality at 30 days (8.0 vs. 0.9%; P < 0.0001) and 3 years (16.2 vs. 4.5%; P < 0.0001). Multivariable analysis confirmed CI-AKI as an independent predictor of NACE hazard ratio (HR), 1.53; 95% confidence interval (CI), 1.23-1.90; P = 0.0001, MACE (HR, 1.56; 95% CI, 1.23-1.98; P = 0.0002), non-coronary artery bypass grafting major bleeding (HR, 2.07; 95% CI, 1.57-2.73; P < 0.0001), and mortality (HR, 1.80; 95% CI, 1.19-2.73; P = 0.005) at 3-year follow-up.
Contrast-induced acute kidney injury is associated with poor short- and long-term outcomes after primary percutaneous coronary intervention in STEMI.
Background In 2009, we reported a novel form of delayed anaphylaxis to red meat that is related to serum IgE antibodies to the oligosaccharide galactose-α-1,3-galactose (alpha-gal). Most of these ...patients had tolerated meat for many years previously. The implication is that some exposure in adult life had stimulated the production of these IgE antibodies. Objectives We sought to investigate possible causes of this IgE antibody response, focusing on evidence related to tick bites, which are common in the region where these reactions occur. Methods Serum assays were carried out with biotinylated proteins and extracts bound to a streptavidin ImmunoCAP. Results Prospective studies on IgE antibodies in 3 subjects after tick bites showed an increase in levels of IgE to alpha-gal of 20-fold or greater. Other evidence included (1) a strong correlation between histories of tick bites and levels of IgE to alpha-gal (χ2 = 26.8, P < .001), (2) evidence that these IgE antibodies are common in areas where the tick Amblyomma americanum is common, and (3) a significant correlation between IgE antibodies to alpha-gal and IgE antibodies to proteins derived from A americanum ( rs = 0.75, P < .001). Conclusion The results presented here provide evidence that tick bites are a cause, possibly the only cause, of IgE specific for alpha-gal in this area of the United States. Both the number of subjects becoming sensitized and the titer of IgE antibodies to alpha-gal are striking. Here we report the first example of a response to an ectoparasite giving rise to an important form of food allergy.
Despite advances in asthma care, disparities persist. Black patients are disproportionally affected by asthma and also have poorer outcomes compared with white patients.
We sought to determine ...associations between black and white patients and asthma-related health care use, accounting for complex relationships.
This study was completed as part of the National Heart, Lung, and Blood Institute's Severe Asthma Research Program, a prospective observational cohort. Between November 2012 and February 2015, it enrolled 579 participants 6 years and older with 1 year of observation time and complete data. Inverse probability of treatment weighting was used to balance racial groups with respect to community and family socioeconomic variables and environmental exposure variables. The primary outcome was emergency department (ED) use for asthma. Secondary outcomes included inhaled corticosteroid use, outpatient physician's office visits for asthma, and asthma–related hospitalization.
Black patients had greater odds of ED use over 1 year (odds ratio, 2.19; 95% CI, 1.43-3.35) but also differed in the majority (>50%) of baseline variables measured. After statistical balancing of the racial groups, the difference between black and white patients with respect to ED use no longer reached the level of significance. Instead, in secondary analyses black patients were less likely to see an outpatient physician for asthma management (adjusted odds ratio, 0.57; 95% CI, 0.38-0.85).
The disparity in ED use was eliminated after consideration of multiple variables. Social and environmental policies and interventions tailored to black populations with a high burden of asthma are critical to reduction (or elimination) of these disparities.
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