22 research outputs found

    The Bletia catenulata ornamental orchid is self-compatible but pollinator-dependent for reproduction

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    Bletia catenulata is a native Brazilian orchid whose populations have suffered from predatory collection. Aiming at elucidating aspects of its reproductive biology and the relation with seed germination, pollination tests were carried out in flowers of plants cultivated in a greenhouse. Manual cross and self-pollination resulted in high percentage of fructification (76.7-86.7 %), being only 26.7 % for natural pollination, in which the absence of pollinators, due to flower isolation, resulted in absence of fruits. In vitro seed germination for all fruits from the different pollination processes was low, being 8.6 % the highest percentage for protocorms. Thus, B. catenulata is selfcompatible, resulting in viable seeds, but pollinator-dependent for sexual reproduction

    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

    Mechanical characterization of Ti-12Mo-13Nb alloy for biomedical application hot swaged and aged

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    Beta titanium alloys were developed for biomedical applications due to the combination of its mechanical properties including low elasticity modulus, high strength, fatigue resistance, good ductility and with excellent corrosion resistance. With this perspective a metastable beta titanium alloy Ti-12Mo-13Nb was developed with the replacement of both vanadium and aluminum from the traditional alloy Ti-6Al-4V. This paper presents the microstructure, mechanical properties of the Ti-12Mo-13Nb hot swaged and aged at 500 °C for 24 h under high vacuum and then water quenched. The alloy structure was characterized by X-ray diffraction and transmission electron microscopy. Tensile tests were carried out at room temperature. The results show a microstructure consisting of a fine dispersed α phase in a β matrix and good mechanical properties including low elastic modulus. The results indicate that Ti-12Mo-13Nb alloy can be a promising alternative for biomedical application.SCOPUS: cp.jinfo:eu-repo/semantics/publishe

    Effect of hot swaging on microstructure and properties of aged Ti-10Mo-20Nb alloy

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    Mechanical properties of metastable β-Ti alloys are highly dependent on the final microstructure, which is controlled by the thermomechanical processing. These alloys are used for biomedical applications and require a high mechanical strength as well as a low Young’s modulus to avoid stress shielding. Previous work on the development of cold swaged Ti-10Mo-20Nb alloy showed that the best compromise strength and Young’s modulus was obtained when the forming is followed by an aging heat treatment at 500 °C. In this work, Ti-10Mo-20Nb alloy was hot swaged and aged at 500 °C for 10 min, 4h and 24h. The microstructure was analyzed by X-ray diffraction, optical microscopy and transmission electron microscopy. Mechanical characterization was based on Vickers microhardness tests and Young’s modulus measurements. Aging at 500°C for 10 min after hot swaging resulted in a nearly 100% β phase microstructure while aging at 500°C for 4h or 24h led to a bimodal microstructure consisting on α precipitates dispersed in the β matrix. The higher hardness to Young’s modulus ratio was obtained for the sample aged at 500 °C for 4h. This value was higher than those obtained for the Ti-6Al-4V alloy and commercially pure Ti.SCOPUS: cp.kinfo:eu-repo/semantics/publishe

    Self-pollination of the orchid Cycnoches haagii from Brazilian Cerrado results in albino phenotype seedlings

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    Cycnoches haagii Barb. Rodr. is an epiphytic orchid very targeted by collectors, but no reference was found in the literature about its reproductive biology. Thus, the purpose of this study was to obtain initial information regarding pollination types and its influence on seed viability of this native orchid of the Brazilian Cerrado, in order to enable future propagation and preservation programs. Pollination among flowers of the same plant (geitonogamy) or different plants (xenogamy) were carried out. Seeds extracted from the capsules were sown in B&G medium, with full and half strength. Seeds from geitonogamic resulted in 25% of albino protocorms and consequently in albino seedlings. This phenomenon did not occur in seedlings derived from xenogamic pollination. Pigment analysis showed that even the albino seedlings presented chlorophylls and carotenoids, however, in significantly minor concentrations, 16% and 37% respectively, in relation to green seedlings. Geitonogamic and xenogamic pollinations resulted in C. haagii viable seeds with high germination percentage (90%) under in vitro conditions. The germination of seeds from xenogamic pollination resulted in chlorophyll or normal seedlings only, and can be recommended at conservation programs. On the other hand, although geitonogamic pollination should be avoided at conservation programs of this orchid species as it leads to albino seedlings, it showed a very interesting system to obtain seedlings with this phenotype, an interesting plant material to future investigation

    Paradoxical Role of Matrix Metalloproteinases in Liver Injury and Regeneration after Sterile Acute Hepatic Failure

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    Acetaminophen (APAP) poisoning is one of the leading causes of acute hepatic failure and liver transplantation is often the only lifesaving alternative. During the course of hepatocyte necrosis, an intense accumulation of neutrophils is often observed within the liver microenvironment. Despite the classic idea that neutrophil accumulation in tissues causes collateral tissue damage, there is a growing body of evidence showing that neutrophils can also orchestrate the resolution of inflammation. In this work, drug-induced liver injury was induced by oral administration of APAP and pharmacological intervention was made 12 h after this challenge. Liver injury and repair kinetics were evaluated by a novel combination of enzyme quantifications, ELISA, specific antagonists of neutrophil enzymes and confocal intravital microscopy. We have demonstrated that neutrophil infiltration is not only involved in injury amplification, but also in liver tissue repair after APAP-induced liver injury. In fact, while neutrophil depletion led to reduced hepatic necrosis during APAP poisoning, injury recovery was also delayed in neutropenic mice. The mechanisms underlying the neutrophil reparative role involved rapid degranulation and matrix metalloproteinases (MMPs) activity. Our data highlights the crucial role of neutrophils, in particular for MMPs, in the resolution phase of APAP-induced inflammatory response.status: publishe
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