The Berkeley sample of stripped-envelope supernovae Shivvers, Isaac; Filippenko, Alexei V; Silverman, Jeffrey M ...
Monthly Notices of the Royal Astronomical Society,
01/2019, Letnik:
482, Številka:
2
Journal Article
Two dry surfaces can instantly adhere upon contact with each other through intermolecular forces such as hydrogen bonds, electrostatic interactions and van der Waals interactions
. However, such ...instant adhesion is challenging when wet surfaces such as body tissues are involved, because water separates the molecules of the two surfaces, preventing interactions
. Although tissue adhesives have potential advantages over suturing or stapling
, existing liquid or hydrogel tissue adhesives suffer from several limitations: weak bonding, low biological compatibility, poor mechanical match with tissues, and slow adhesion formation
. Here we propose an alternative tissue adhesive in the form of a dry double-sided tape (DST) made from a combination of a biopolymer (gelatin or chitosan) and crosslinked poly(acrylic acid) grafted with N-hydrosuccinimide ester. The adhesion mechanism of this DST relies on the removal of interfacial water from the tissue surface, resulting in fast temporary crosslinking to the surface. Subsequent covalent crosslinking with amine groups on the tissue surface further improves the adhesion stability and strength of the DST. In vitro mouse, in vivo rat and ex vivo porcine models show that the DST can achieve strong adhesion between diverse wet dynamic tissues and engineering solids within five seconds. The DST may be useful as a tissue adhesive and sealant, and in adhering wearable and implantable devices to wet tissues.
Photodynamic inactivation is a phenomenon that has the potential to cause microbial inactivation using visible light. It works on the principle that photosensitizers within the microbial cell can be ...activated using specific wavelengths to trigger a series of cytotoxic reactions. In the last few years, efforts to apply this intervention technology for food safety have been on the rise. This review article offers a detailed commentary on this research. The mechanism of photodynamic inactivation has been discussed as have the factors that influence its efficacy in food. Efforts to inactivate bacteria, fungi, and viruses have been analyzed in dedicated sections and so has the application of this technology to specific product classes such as fresh produce, dry fruits, seafood, and poultry. The challenges and opportunities facing the application of this technology to food systems have been evaluated and future research directions proposed. Thus, this review will provide insights for researchers and industry personnel looking for a novel solution to combat microbial contamination and resistance.
Soft materials capable of transforming between three-dimensional (3D) shapes in response to stimuli such as light, heat, solvent, electric and magnetic fields have applications in diverse areas such ...as flexible electronics
, soft robotics
and biomedicine
. In particular, magnetic fields offer a safe and effective manipulation method for biomedical applications, which typically require remote actuation in enclosed and confined spaces
. With advances in magnetic field control
, magnetically responsive soft materials have also evolved from embedding discrete magnets
or incorporating magnetic particles
into soft compounds to generating nonuniform magnetization profiles in polymeric sheets
. Here we report 3D printing of programmed ferromagnetic domains in soft materials that enable fast transformations between complex 3D shapes via magnetic actuation. Our approach is based on direct ink writing
of an elastomer composite containing ferromagnetic microparticles. By applying a magnetic field to the dispensing nozzle while printing
, we reorient particles along the applied field to impart patterned magnetic polarity to printed filaments. This method allows us to program ferromagnetic domains in complex 3D-printed soft materials, enabling a set of previously inaccessible modes of transformation, such as remotely controlled auxetic behaviours of mechanical metamaterials with negative Poisson's ratios. The actuation speed and power density of our printed soft materials with programmed ferromagnetic domains are orders of magnitude greater than existing 3D-printed active materials. We further demonstrate diverse functions derived from complex shape changes, including reconfigurable soft electronics, a mechanical metamaterial that can jump and a soft robot that crawls, rolls, catches fast-moving objects and transports a pharmaceutical dose.
Background
Patients with chronic granulomatous disease (CGD), whom inherit abnormal function of NADPH oxidase 2 (Nox2), suffer from hyperinflammatory responses in lung as well as bacterial and fungal ...infection. There have been studies to reveal the function of Nox2 in hyperinflammatory diseases, especially in asthma, but the exact role of Nox2 in asthma is still unclear and controversial. Therefore, we attempted to clarify the exact role of Nox2 in asthma, using various experimental asthma models.
Methods
Asthma phenotypes were analyzed in response to various allergen‐induced experimental asthma using Nox2‐deficient mice and recombinase gene‐activating‐1‐deficient mice. To understand the underlying mechanisms of exaggerated Th2 effector functions, we investigated the degree of T‐cell activation, levels of activation‐induced cell death (AICD), and regulatory T (Treg)‐cell differentiation in Nox2‐deficient T cells.
Results
Asthma phenotypes were increased through enhanced Th2 differentiation and function in Nox2‐null mice regardless of dose and route of various allergens. Nox2‐deficient T cells also showed hyperactivation, reduced AICD, and diminished Treg‐cell differentiation through increased AKT phosphorylation (T308/S473) and enhanced mitochondrial ROS production.
Conclusion
Our findings indicate that Nox2 deficiency results in exaggerated experimental asthma, which is caused by enhanced Th2 effector function in a T‐cell‐intrinsic manner.
Background Diabetes mellitus is a risk factor for cardiovascular disease ( CVD ) and has been associated with 2- to 4-fold higher mortality. Diabetes mellitus-related mortality has not been ...reassessed in individuals receiving routine care in the United States in the contemporary era of CVD risk reduction. Methods and Results We retrospectively studied 963 648 adults receiving care in the US Veterans Affairs Healthcare System from 2002 to 2014; mean follow-up was 8 years. We estimated associations of diabetes mellitus status and hemoglobin A1c (HbA1c) with all-cause and CVD mortality using covariate-adjusted incidence rates and multivariable Cox proportional hazards regression. Of participants, 34% had diabetes mellitus. Compared with nondiabetic individuals, patients with diabetes mellitus had 7.0 (95% CI , 6.7-7.4) and 3.5 (95% CI, 3.3-3.7) deaths/1000-person-years higher all-cause and CVD mortality, respectively. The age-, sex-, race-, and ethnicity-adjusted hazard ratio for diabetes mellitus-related mortality was 1.29 (95% CI, 1.28-1.31), and declined with adjustment for CVD risk factors (hazard ratio, 1.18 95% CI, 1.16-1.19) and glycemia (hazard ratio, 1.03 95% CI, 1.02-1.05). Among individuals with diabetes mellitus, CVD mortality increased as HbA1c exceeded 7% (hazard ratios, 1.11 95% CI, 1.08-1.14, 1.25 95% CI, 1.22-1.29, and 1.52 95% CI, 1.48-1.56 for HbA1c 7%-7.9%, 8%-8.9%, and ≥9%, respectively, relative to HbA1c 6%-6.9%). HbA1c 6% to 6.9% was associated with the lowest mortality risk irrespective of CVD history or age. Conclusions Diabetes mellitus remains significantly associated with all-cause and CVD mortality, although diabetes mellitus-related excess mortality is lower in the contemporary era than previously. We observed a gradient of mortality risk with increasing HbA1c >6% to 6.9%, suggesting HbA1c remains an informative predictor of outcomes even if causality cannot be inferred.
We conducted genome-wide association analyses of over 250,000 participants of European (EUR) and African (AFR) ancestry from the Million Veteran Program using electronic health record-validated ...post-traumatic stress disorder (PTSD) diagnosis and quantitative symptom phenotypes. Applying genome-wide multiple testing correction, we identified three significant loci in European case-control analyses and 15 loci in quantitative symptom analyses. Genomic structural equation modeling indicated tight coherence of a PTSD symptom factor that shares genetic variance with a distinct internalizing (mood-anxiety-neuroticism) factor. Partitioned heritability indicated enrichment in several cortical and subcortical regions, and imputed genetically regulated gene expression in these regions was used to identify potential drug repositioning candidates. These results validate the biological coherence of the PTSD syndrome, inform its relationship to comorbid anxiety and depressive disorders and provide new considerations for treatment.
A compact multiple-input-multiple-output (MIMO) antenna with a small size of 26×40 mm 2 is proposed for portable ultrawideband (UWB) applications. The antenna consists of two planar-monopole (PM) ...antenna elements with microstrip-fed printed on one side of the substrate and placed perpendicularly to each other to achieve good isolation. To enhance isolation and increase impedance bandwidth, two long protruding ground stubs are added to the ground plane on the other side and a short ground strip is used to connect the ground planes of the two PMs together to form a common ground. Simulation and measurement are used to study the antenna performance in terms of reflection coefficients at the two input ports, coupling between the two input ports, radiation pattern, realized peak gain, efficiency and envelope correlation coefficient for pattern diversity. Results show that the MIMO antenna has an impedance bandwidth of larger than 3.1-10.6 GHz, low mutual coupling of less than -15 dB, and a low envelope correlation coefficient of less than 0.2 across the frequency band, making it a good candidate for portable UWB applications.
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