43 research outputs found

    Characterization of Sequential Collagen-Poly(Ethylene Glycol) Diacrylate Interpenetrating Networks and Initial Assessment of Their Potential for Vascular Tissue Engineering

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    Collagen hydrogels have been widely investigated as scaffolds for vascular tissue engineering due in part to the capacity of collagen to promote robust cell adhesion and elongation. However, collagen hydrogels display relatively low stiffness and strength, are thrombogenic, and are highly susceptible to cell-mediated contraction. In the current work, we develop and characterize a sequentially-formed interpenetrating network (IPN) that retains the benefits of collagen, but which displays enhanced mechanical stiffness and strength, improved thromboresistance, high physical stability and resistance to contraction. In this strategy, we first form a collagen hydrogel, infuse this hydrogel with poly(ethylene glycol) diacrylate (PEGDA), and subsequently crosslink the PEGDA by exposure to longwave UV light. These collagen-PEGDA IPNs allow for cell encapsulation during the fabrication process with greater than 90% cell viability via inclusion of cells within the collagen hydrogel precursor solution. Furthermore, the degree of cell spreading within the IPNs can be tuned from rounded to fully elongated by varying the time delay between the formation of the cell-laden collagen hydrogel and the formation of the PEGDA network. We also demonstrate that these collagen-PEGDA IPNs are able to support the initial stages of smooth muscle cell lineage progression by elongated human mesenchymal stems cells

    TIRSPEC : TIFR Near Infrared Spectrometer and Imager

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    We describe the TIFR Near Infrared Spectrometer and Imager (TIRSPEC) designed and built in collaboration with M/s. Mauna Kea Infrared LLC, Hawaii, USA, now in operation on the side port of the 2-m Himalayan Chandra Telescope (HCT), Hanle (Ladakh), India at an altitude of 4500 meters above mean sea level. The TIRSPEC provides for various modes of operation which include photometry with broad and narrow band filters, spectrometry in single order mode with long slits of 300" length and different widths, with order sorter filters in the Y, J, H and K bands and a grism as the dispersing element as well as a cross dispersed mode to give a coverage of 1.0 to 2.5 microns at a resolving power R of ~1200. The TIRSPEC uses a Teledyne 1024 x 1024 pixel Hawaii-1 PACE array detector with a cutoff wavelength of 2.5 microns and on HCT, provides a field of view of 307" x 307" with a plate scale of 0.3"/pixel. The TIRSPEC was successfully commissioned in June 2013 and the subsequent characterization and astronomical observations are presented here. The TIRSPEC has been made available to the worldwide astronomical community for science observations from May 2014.Comment: 20 pages, 21 figures, 2 tables. Accepted for publication in Journal of Astronomical Instrumentatio

    In-vitro evaluation of antibacterial potential of cyanoacrylate tissue adhesives for intraoral wound closure

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    Background: Cyanoacrylate tissue adhesives have been used as a substitute to silk for intraoral wound closure. Placement of sutures provides a corridor for accumulation of microorganisms into tissue which leads to infection. Cyanoacrylate-based adhesives exhibit many properties of an ideal wound closure agent, minimizing the problems generated by suturing thread. The antimicrobial properties of cyanoacrylates have been extensively assessed in other fields of medicine. However, there is a dearth in the literature on the antibacterial effect of cyanoacrylates in oral environment against oral microflora. Aim: To assess the antibacterial properties of two commonly used formulations of cyanoacrylate tissue adhesives against oral pathogens. Materials and Methods: Iso-amyl cyanoacrylate and a blend of n-butyl and 2-Octyl cyanoacrylates were applied on sterile filter paper discs and placed on culture plates. Plates for aerobic & anaerobic bacterial cultures were incubated in blood agar & Brain-Heart infusion agar respectively.Following incubation period, the bacterial inhibitory halos were measured in millimeters. In order to evaluate the bactericidal efficacy, samples were collected from the inhibitory halos and re-cultured on new bacterial culture plates. Antibacterial activity was assessed against five bacteria: A.actinomycetemcomitans, P.gingivalis, T.forsythia, L.amylovorus and S.aureus. Statistical analysis used:  The data collected was analysed using Mann Whitney u test. Results: Cyanoacrylates demonstrated potent inhibitory effects against all test organisms. The zones of inhibition against gram positive bacteria were found to be larger than gram negative bacteria. The bactericidal activity of Iso amyl cyanoacrylate was found to be more potent than n-butyl + 2 octyl cyanoacrylate. Conclusions: Due to its potent antibacterial properties, cyanoacrylate tissue adhesives can be considered as appealing alternatives to silk sutures for intraoral wound closure and help prevent postoperative

    VaTEST III : validation of 8 potential super-earths from TESS data

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    Funding: The ULiege’s contribution to SPECULOOS has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) (grant Agreement n◦ 336480/SPECULOOS). This research is in part funded by the European Union’s Horizon 2020 research and innovation programme (grants agreements n◦ 803193/BEBOP), and from the Science and Technology Facilities Council (STFC; grant n◦ ST/S00193X/1, and ST/W000385/1).NASA’s all-sky survey mission, the Transiting Exoplanet Survey Satellite (TESS), is specifically engineered to detect exoplanets that transit bright stars. Thus far, TESS has successfully identified approximately 400 transiting exoplanets, in addition to roughly 6 000 candidate exoplanets pending confirmation. In this study, we present the results of our ongoing project, the Validation of Transiting Exoplanets using Statistical Tools (VaTEST). Our dedicated effort is focused on the confirmation and characterisation of new exoplanets through the application of statistical validation tools. Through a combination of ground-based telescope data, high-resolution imaging, and the utilisation of the statistical validation tool known as TRICERATOPS, we have successfully discovered eight potential super-Earths. These planets bear the designations: TOI-238b (1.61 +0.09−0.10 R ⊕ ), TOI-771b (1.42 +0.11−0.09 R ⊕ ), TOI-871b (1.66 +0.11−0.11 R ⊕ ), TOI-1467b (1.83 +0.16−0.15 R ⊕ ), TOI-1739b (1.69 +0.10−0.08 R ⊕ ), TOI-2068b (1.82 +0.16−0.15 R ⊕ ), TOI-4559b (1.42 +0.13−0.11 R ⊕ ), and TOI-5799b (1.62 +0.19−0.13 R ⊕ ). Among all these planets, six of them fall within the region known as ‘keystone planets’, which makes them particularly interesting for study. Based on the location of TOI-771b and TOI-4559b below the radius valley we characterised them as likely super-Earths, though radial velocity mass measurements for these planets will provide more details about their characterisation. It is noteworthy that planets within the size range investigated herein are absent from our own solar system, making their study crucial for gaining insights into the evolutionary stages between Earth and Neptune.Peer reviewe

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
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