29 research outputs found
Influential Article Review- Employing the Quality Startup Management System Structure in Hong Kong Businesses
This paper examines business models. We present insights from a highly influential paper. Here are the highlights from this paper: The innovation and technology industries have become key areas to which the HKSAR Government is committed for advanced technology development and new economic driven. In order to nurture and support local technology startups grow and flourish successfully, HKSTP had signed a memorandum of understanding (MOU) with Hong Kong Quality Assurance Agency (HKQAA) to support incubation programmes through business matching and quality assurance mechanisms for startup companies. Hong Kong Society for Quality (HKSQ) was invited by HKQAA to be one of members in the advisory committee for this recognition scheme. Then, focus group was formed from different parties, including but not limited to incubatees, incubators, investors, HKSTP, HKQAA, HKSQ and other concerned stakeholders. This paper aims to introduce a systematic approach model named “Quality Startup Management System (QStarMS) Model” through literature review and analysis, focus group and case study. QStarMS integrated Business Side of startup using Business Model Generation/Canvas (BMG/C) and Management Side under ISO 9001:2015 Quality Management System, as well as, to simplify the model to fit startups requirements and overcome their limitations. Finally, we will report the recently progress of the QStarMS implementation through HKQAA Registration – Startups scheme. For our overseas readers, we then present the insights from this paper in Spanish, French, Portuguese, and German
Development of thermally sprayed environmental barrier coatings
Ceramic matrix composites (CMCs) are candidate materials for high-temperature applications such as gas turbines. As corrosion by water vapor and deposits is a limiting issue, the application of suitable environmental barrier coatings (EBCs) is inevitable. Gas tightness, chemical stability and a good adhesion of the EBC are crucial aspects for providing an effective barrier against the combustion atmosphere. Thermal spray technologies offer a variety of promising process routes to the manufacturing of ceramic coating systems complying with these demands. This contribution covers coatings for both silicon and oxide based CMCs. Different EBC materials (e.g. silicates, aluminates, rare-earth oxides) were examined and optimized for use as EBC by air plasma spraying (APS). Different thermal spray techniques including high-velocity oxygen-fuel spraying (HVOF), suspension plasma spraying (SPS) and plasma-spray physical vapor deposition (PS-PVD) techniques were assessed for the manufacture of coatings with low amorphous phase content. The application of bond coat as well as alternative surface modification technologies was tested to increase the adhesion of the EBCs. Microstructures and chemical stability of the coatings were analyzed and the performance was tested in terms of adhesion strength or degradation under high-temperature exposure including cyclic oxidation
Development of environmental barrier coatings for Al2O3/Al2O3 CMCs with improved Adhesion by texturing with laser ablation
Al2O3 /Al2O3 ceramic matrix composites (CMC) are candidate materials for high-temperature applications such as gas turbines. As water vapor corrosion of oxide/oxide CMC is a major issue, the application of suitable environmental barrier coatings (EBC) is inevitable. Besides the gas tightness a good adhesion of the EBC is a crucial aspect for providing an effective barrier against the combustion atmosphere. Due to the brittleness of the ceramic matrix conventional surface treatments like grinding and sandblasting fail to increase roughness without causing damage to the substrate. Therefore there is a need for new methods of surface preparation of CMCs.
This work examines the suitability of surface preparation with laser ablation for use prior to air plasma spraying (APS) on an oxide/oxide-CMC. Laser ablation allows controlling of the surface’s structure and roughness. The effects of different laser parameters on the alumina surface were examined and a variety of different structures, for example a honeycomb or a cauliflower like structure, were prepared.
The laser treated surfaces were coated with potential EBC-candidates, such as Y2O3 and Gd2Zr2O7 and the impact of laser textures on the coating adhesion was examined. Evaluation of the coated samples was done by pull-off adhesion testing and thermal cycling. Results indicate that laser pretreatment helps to increase the adhesion strength of the EBC-system
Donor-But Not Recipient-Derived Cells Produce Collagen-1 in Chronically Rejected Cardiac Allografts
Fibrosis is a prominent feature of chronic allograft rejection, caused by an excessive production of matrix proteins, including collagen-1. Several cell types produce collagen-1, including mesenchymal fibroblasts and cells of hematopoietic origin. Here, we sought to determine whether tissue-resident donor-derived cells or allograft-infiltrating recipient-derived cells are responsible for allograft fibrosis, and whether hematopoietic cells contribute to collagen production. A fully MHC-mismatched mouse heterotopic heart transplantation model was used, with transient depletion of CD4+ T cells to prevent acute rejection. Collagen-1 was selectively knocked out in recipients or donors. In addition, collagen-1 was specifically deleted in hematopoietic cells. Tissue-resident macrophages were depleted using anti-CSF1R antibody. Allograft fibrosis and inflammation were quantified 20 days post-transplantation. Selective collagen-1 knock-out in recipients or donors showed that tissue-resident cells from donor hearts, but not infiltrating recipient-derived cells, are responsible for production of collagen-1 in allografts. Cell-type-specific knock-out experiments showed that hematopoietic tissue-resident cells in donor hearts substantially contributed to graft fibrosis. Tissue resident macrophages, however, were not responsible for collagen-production, as their deletion worsened allograft fibrosis. Donor-derived cells including those of hematopoietic origin determine allograft fibrosis, making them attractive targets for organ preconditioning to improve long-term transplantation outcomes
Severe T cell hyporeactivity in ventilated COVID-19 patients correlates with prolonged virus persistence and poor outcomes
Coronavirus disease 2019 (COVID-19) can lead to pneumonia and hyperinflammation. Here we show a sensitive method to measure polyclonal T cell activation by downstream effects on responder cells like basophils, plasmacytoid dendritic cells, monocytes and neutrophils in whole blood. We report a clear T cell hyporeactivity in hospitalized COVID-19 patients that is pronounced in ventilated patients, associated with prolonged virus persistence and reversible with clinical recovery. COVID-19-induced T cell hyporeactivity is T cell extrinsic and caused by plasma components, independent of occasional immunosuppressive medication of the patients. Monocytes respond stronger in males than females and IL-2 partially restores T cell activation. Downstream markers of T cell hyporeactivity are also visible in fresh blood samples of ventilated patients. Based on our data we developed a score to predict fatal outcomes and identify patients that may benefit from strategies to overcome T cell hyporeactivity.Coronavirus disease 2019 (COVID-19) can lead to pneumonia and hyperinflammation. Here we show a sensitive method to measure polyclonal T cell activation by downstream effects on responder cells like basophils, plasmacytoid dendritic cells, monocytes and neutrophils in whole blood. We report a clear T cell hyporeactivity in hospitalized COVID-19 patients that is pronounced in ventilated patients, associated with prolonged virus persistence and reversible with clinical recovery. COVID-19-induced T cell hyporeactivity is T cell extrinsic and caused by plasma components, independent of occasional immunosuppressive medication of the patients. Monocytes respond stronger in males than females and IL-2 partially restores T cell activation. Downstream markers of T cell hyporeactivity are also visible in fresh blood samples of ventilated patients. Based on our data we developed a score to predict fatal outcomes and identify patients that may benefit from strategies to overcome T cell hyporeactivity
Genetic overlap between autoimmune diseases and non-Hodgkin lymphoma subtypes
Epidemiologic studies show an increased risk of non-Hodgkin lymphoma (NHL) in patients with autoimmune disease (AD), due to a combination of shared environmental factors and/or genetic factors, or a causative cascade: chronic inflammation/antigen-stimulation in one disease leads to another. Here we assess shared genetic risk in genome-wide-association-studies (GWAS). Secondary analysis of GWAS of NHL subtypes (chronic lymphocytic leukemia, diffuse large B-cell lymphoma, follicular lymphoma, and marginal zone lymphoma) and ADs (rheumatoid arthritis, systemic lupus erythematosus, and multiple sclerosis). Shared genetic risk was assessed by (a) description of regional genetic of overlap, (b) polygenic risk score (PRS), (c)"diseasome", (d)meta-analysis. Descriptive analysis revealed few shared genetic factors between each AD and each NHL subtype. The PRS of ADs were not increased in NHL patients (nor vice versa). In the diseasome, NHLs shared more genetic etiology with ADs than solid cancers (p = .0041). A meta-analysis (combing AD with NHL) implicated genes of apoptosis and telomere length. This GWAS-based analysis four NHL subtypes and three ADs revealed few weakly-associated shared loci, explaining little total risk. This suggests common genetic variation, as assessed by GWAS in these sample sizes, may not be the primary explanation for the link between these ADs and NHLs
Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility
Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes
Investigation of hospital discharge cases and SARS-CoV-2 introduction into Lothian care homes
Background
The first epidemic wave of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in Scotland resulted in high case numbers and mortality in care homes. In Lothian, over one-third of care homes reported an outbreak, while there was limited testing of hospital patients discharged to care homes.
Aim
To investigate patients discharged from hospitals as a source of SARS-CoV-2 introduction into care homes during the first epidemic wave.
Methods
A clinical review was performed for all patients discharges from hospitals to care homes from 1st March 2020 to 31st May 2020. Episodes were ruled out based on coronavirus disease 2019 (COVID-19) test history, clinical assessment at discharge, whole-genome sequencing (WGS) data and an infectious period of 14 days. Clinical samples were processed for WGS, and consensus genomes generated were used for analysis using Cluster Investigation and Virus Epidemiological Tool software. Patient timelines were obtained using electronic hospital records.
Findings
In total, 787 patients discharged from hospitals to care homes were identified. Of these, 776 (99%) were ruled out for subsequent introduction of SARS-CoV-2 into care homes. However, for 10 episodes, the results were inconclusive as there was low genomic diversity in consensus genomes or no sequencing data were available. Only one discharge episode had a genomic, time and location link to positive cases during hospital admission, leading to 10 positive cases in their care home.
Conclusion
The majority of patients discharged from hospitals were ruled out for introduction of SARS-CoV-2 into care homes, highlighting the importance of screening all new admissions when faced with a novel emerging virus and no available vaccine
SARS-CoV-2 Omicron is an immune escape variant with an altered cell entry pathway
Vaccines based on the spike protein of SARS-CoV-2 are a cornerstone of the public health response to COVID-19. The emergence of hypermutated, increasingly transmissible variants of concern (VOCs) threaten this strategy. Omicron (B.1.1.529), the fifth VOC to be described, harbours multiple amino acid mutations in spike, half of which lie within the receptor-binding domain. Here we demonstrate substantial evasion of neutralization by Omicron BA.1 and BA.2 variants in vitro using sera from individuals vaccinated with ChAdOx1, BNT162b2 and mRNA-1273. These data were mirrored by a substantial reduction in real-world vaccine effectiveness that was partially restored by booster vaccination. The Omicron variants BA.1 and BA.2 did not induce cell syncytia in vitro and favoured a TMPRSS2-independent endosomal entry pathway, these phenotypes mapping to distinct regions of the spike protein. Impaired cell fusion was determined by the receptor-binding domain, while endosomal entry mapped to the S2 domain. Such marked changes in antigenicity and replicative biology may underlie the rapid global spread and altered pathogenicity of the Omicron variant