2,239 research outputs found
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Integration of Direct-Write (DW) and Ultrasonic Consolidation (UC) Technologies to Create Advanced Structures with Embedded Electrical Circuitry
In many instances conductive traces are needed in small, compact and enclosed areas.
However, with traditional manufacturing techniques, embedded electrical traces or antenna
arrays have not been a possibility. By integrating Direct Write and Ultrasonic Consolidation
technologies, electronic circuitry, antennas and other devices can be manufactured directly into a
solid metal structure and subsequently completely enclosed. This can achieve a significant
reduction in mass and volume of a complex electronic system without compromising
performance.Mechanical Engineerin
Pulsed laser ignition of reactive multilayer films
Nanostructured Al/PtAl∕Pt multilayer films were ignited by single pulse irradiation from a Ti:sapphire femtosecond laser system. Critical ignition fluences (0.9–22 J/cm2)(0.9–22J∕cm2) required to initiate a self-propagating reaction were quantified for different multilayer designs. Multilayers with smaller bilayer thickness required relatively lower fluence for ignition. Ignition threshold fluence was also found to be 1.4–3.6 times higher for Al-capped multilayers than for Pt-capped multilayers. Ablation threshold fluences were measured for Al (860±70 mJ/cm2)(860±70mJ∕cm2) and Pt (540±50 mJ/cm2)(540±50mJ∕cm2) and related to the observed difference in ignition fluences for Al- and Pt-capped multilayers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87770/2/144102_1.pd
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Human 3D cellular model of hypoxic brain injury of prematurity.
Owing to recent medical and technological advances in neonatal care, infants born extremely premature have increased survival rates1,2. After birth, these infants are at high risk of hypoxic episodes because of lung immaturity, hypotension and lack of cerebral-flow regulation, and can develop a severe condition called encephalopathy of prematurity3. Over 80% of infants born before post-conception week 25 have moderate-to-severe long-term neurodevelopmental impairments4. The susceptible cell types in the cerebral cortex and the molecular mechanisms underlying associated gray-matter defects in premature infants remain unknown. Here we used human three-dimensional brain-region-specific organoids to study the effect of oxygen deprivation on corticogenesis. We identified specific defects in intermediate progenitors, a cortical cell type associated with the expansion of the human cerebral cortex, and showed that these are related to the unfolded protein response and changes. Moreover, we verified these findings in human primary cortical tissue and demonstrated that a small-molecule modulator of the unfolded protein response pathway can prevent the reduction in intermediate progenitors following hypoxia. We anticipate that this human cellular platform will be valuable for studying the environmental and genetic factors underlying injury in the developing human brain
Physiotherapy for adults with joint hypermobility syndrome: A pilot randomised controlled trial
Background: Joint Hypermobility Syndrome (JHS) is a heritable disorder associated with laxity and pain in multiple joints. Physiotherapy is the mainstay of treatment but there is little research investigating its effectiveness. The aim of this study was therefore to conduct a pilot randomised controlled trial (RCT) to determine the feasibility of conducting a future definitive RCT. Methods: A comprehensive physiotherapy intervention was developed in conjunction with patients and healthcare professionals. It was then piloted and refined on the basis of patient and physiotherapist feedback. A parallel two-arm pilot RCT in two UK secondary care NHS Trusts compared 'Advice' against 'Advice & Physiotherapy'. Inclusion criteria were: >16 years, a diagnosis of JHS, and no other musculoskeletal conditions causing pain. The Advice intervention was a one-off session, supplemented by advice booklets from the Hypermobility Syndromes Association and Arthritis Research UK. All patients could ask questions specific to their circumstances and received tailored advice. Participants were then randomly allocated to 'Advice' (no further advice or physiotherapy) or 'Advice & Physiotherapy' (an additional six 30 minute sessions over 4 months). The Physiotherapy intervention was supported by a patient handbook and delivered on a one-to-one patient-therapist basis. It aimed to increase patients’ physical activity through developing knowledge, understanding and skills to better manage their condition. The primary outcome related to the feasibility of conducting a future definitive RCT. Qualitative interviews with patients and physiotherapists therefore formed a major component of data collection. Secondary outcomes included clinical measures (physical function, pain, global status, self-reported joint count, quality of life, exercise self-efficacy and adverse events); resource use (to estimate cost-effectiveness); and an estimate of the value of information from a future RCT. Outcomes were recorded at baseline, 4 months (at the end of physiotherapy) and 7 months (3 months following physiotherapy). Results: A total of n=29 participants were recruited to the pilot RCT. Recruitment was challenging, primarily due to a perceived lack of equipoise between Advice and Physiotherapy. The qualitative evaluation provided very clear guidance to inform a future RCT, including enhancement of the Advice intervention. Some patients reported that the Advice intervention was useful and the Physiotherapy intervention was evaluated very positively. The rate of return of questionnaires was low within the Advice group but reasonable in the Physiotherapy group. The Physiotherapy intervention showed evidence of promise in terms of primary and secondary clinical outcomes. The Advice arm experienced more adverse events. The value of information estimate indicated the potential for high value from a future RCT. Conclusion: A future definitive RCT of physiotherapy for JHS seems feasible, although the Advice intervention should be made more robust to address perceived equipoise and subsequent attrition
Aggregatibacter actinomycetemcomitans-induced hypercitrullination links periodontal infection to autoimmunity in rheumatoid arthritis
A bacterial etiology of rheumatoid arthritis (RA) has been suspected since the beginnings of modern germ theory. Recent studies implicate mucosal surfaces as sites of disease initiation. The common occurrence of periodontal dysbiosis in RA suggests that oral pathogens may trigger the production of disease-specific autoantibodies and arthritis in susceptible individuals. We used mass spectrometry to define the microbial composition and antigenic repertoire of gingival crevicular fluid in patients with periodontal disease and healthy controls. Periodontitis was characterized by the presence of citrullinated autoantigens that are primary immune targets in RA. The citrullinome in periodontitis mirrored patterns of hypercitrullination observed in the rheumatoid joint, implicating this mucosal site in RA pathogenesis. Proteomic signatures of several microbial species were detected in hypercitrullinated periodontitis samples. Among these, Aggregatibacter actinomycetemcomitans (Aa), but not other candidate pathogens, induced hypercitrullination in host neutrophils. We identified the pore-forming toxin leukotoxin-A (LtxA) as the molecular mechanism by which Aa triggers dysregulated activation of citrullinating enzymes in neutrophils, mimicking membranolytic pathways that sustain autoantigen citrullination in the RA joint. Moreover, LtxA induced changes in neutrophil morphology mimicking extracellular trap formation, thereby releasing the hypercitrullinated cargo. Exposure to leukotoxic Aa strains was confirmed in patients with RA and was associated with both anti-citrullinated protein antibodies (ACPAs) and rheumatoid factor (RF). The effect of HLA-DRB1 shared epitope alleles on autoantibody positivity was limited to RA patients that were exposed to Aa. These studies identify the periodontal pathogen Aa as a candidate bacterial trigger of autoimmunity in RA
Cosmetic outcomes and quality of life in children with cardiac implantable electronic devices
BackgroundAxillary implant location is an alternative implant location in patients for cardiac implantable electronic devices (CIEDs) for the purposes of improved cosmetic outcome. The impact from the patient’s perspective is unknown. The purpose of this study was to compare scar perception scores and quality of life (QOL) in pediatric patients with axillary CIED implant location versus the standard infraclavicular approach.MethodsThis is a multicenter prospective study conducted at eight pediatric centers and it includes patients aged from 8 to 18 years with a CIED. Patients with prior sternotomy were excluded. Scar perception and QOL outcomes were compared between the infraclavicular and axillary implant locations.ResultsA total of 141 patients (83 implantable cardioverter defibrillator [ICD]/58 pacemakers) were included, 55 with an axillary device and 86 with an infraclavicular device. Patients with an ICD in the axillary position had better perception of scar appearance and consciousness. Patients in the axillary group reported, on average, a total Pediatric QOL Inventory score that was 6 (1, 11) units higher than the infraclavicular group, after adjusting for sex and race (P = 0.02).ConclusionsQOL is significantly improved in axillary in comparison to the infraclavicular CIED position, regardless of device type. Scar perception is improved in patients with ICD in the axillary position.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147032/1/pace13522.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147032/2/pace13522_am.pd
Impaired hepatic lipid synthesis from polyunsaturated fatty acids in TM6SF2 E167K variant carriers with NAFLD
Background: Carriers of the transmembrane 6 superfamily member 2 E167K gene variant (TM6SF2(EK/KK)) have decreased expression of the TM6SF2 gene and increased risk of NAFLD and NASH. Unlike common 'obese/metabolic' NAFLD, these subjects lack hypertriglyceridemia and have lower risk of cardiovascular disease. In animals, phosphatidylcholine (PC) deficiency results in a similar phenotype. PCs surround the core of VLDL consisting of triglycerides (TGs) and cholesteryl-esters (CEs). We determined the effect of the TM6SF2 E167K on these lipids in the human liver and serum and on hepatic gene expression and studied the effect of TM6SF2 knockdown on hepatocyte handling of these lipids. Methods: Liver biopsies were taken from subjects characterized with respect to the TM6SF2 genotype, serum and liver lipidome, gene expression and histology. In vitro, after TM6SF2 knockdown in HuH-7 cells, we compared incorporation of different fatty acids into TGs, CEs, and PCs. Results: The TM6SF2(EK/KK) and TM6SF2EE groups had similar age, gender, BMI and HOMA-IR. Liver TGs and CEs were higher and liver PCs lower in the TM6SF2(EK/KK) than the TM6SF2EE group (p Conclusions: Hepatic lipid synthesis from PUFAs is impaired and could contribute to deficiency in PCs and increased intrahepatic TG in TM6SF2 E167K variant carriers. (C) 2017 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.Peer reviewe
A peroxiredoxin-P38 MAPK scaffold increases MAPK activity by MAP3K-independent mechanisms
Peroxiredoxins (Prdxs) utilize reversibly oxidized cysteine residues to reduce peroxides and promote H2O2 signal transduction, including H2O2-induced activation of P38 MAPK. Prdxs form H2O2-induced disulfide complexes with many proteins, including multiple kinases involved in P38 MAPK signaling. Here, we show that a genetically encoded fusion between a Prdx and P38 MAPK is sufficient to hyperactivate the kinase in yeast and human cells by a mechanism that does not require the H2O2-sensing cysteine of the Prdx. We demonstrate that a P38-Prdx fusion protein compensates for loss of the yeast scaffold protein Mcs4 and MAP3K activity, driving yeast into mitosis. Based on our findings, we propose that the H2O2-induced formation of Prdx-MAPK disulfide complexes provides an alternative scaffold and signaling platform for MAPKK-MAPK signaling. The demonstration that formation of a complex with a Prdx is sufficient to modify the activity of a kinase has broad implications for peroxide-based signal transduction in eukaryotes
Charge-transfer Interactions between Sulfur Dioxide and Group 8 Half-sandwich Complexes
M ulliken-type charge-transfer complexes have been formed between basic half-sandwich compounds
and SO, when [M(q5-C,R,)(CO),] (M = Rh or Ir; R, = Me,, H, or H,CF,), [Ir(q5-C,H,)(CO)(C,H,)].
and [M(q5-C,H,)(C,H,),] (M = Co, Rh or Ir) are isolated in SO,-doped argon matrices at 20 K; the
v(C0) bands of the complexes are shifted to high frequency of those of the precursor molecules and
prominent charge-transfer bands are observed; the same species have been detected when the
compounds [M(q5-C,Me,)(CO),] (M = Rh or Ir) are embedded in polyethylene discs and treated
with SO, at 213-298 K; the enthalpy of complexation of [Ir(q5-C,Me,)(CO),] with SO, is -13 f 3
kJ mo1V
- …