11,183 research outputs found

    Studies on the rejection of the transplanted homologous dog liver.

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    Dogs in which livers have been replaced with hepatic homografts usually die in 5 to 10 days. Liver metabolism is not detectably abnormal at first, but gradual deterioration of function commences on the fourth or fifth day. There was histologic evidence of rejection in all dogs dying after 4 days. This ranged from minimal mononuclear infiltration to almost complete destruction of parenchyma. In the longest survivor, 20 1/2 days, histologic changes were less profound than in many animals dying earlier. Widespread histologic changes were found in host reticuloendothelial system, involving the bone marrow, kidneys, lungs, lymph nodes, and other tissues. These consisted of fixed tissue proliferation and infiltration of mononuclear cells, principally plasma cells. These changes were thought to be due to a general host reticuloendothelial response to the antigenic stimulus of the homograft

    Printing three-dimensional tissue analogues with decellularized extracellular matrix bioink

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    The ability to print and pattern all the components that make up a tissue (cells and matrix materials) in three dimensions to generate structures similar to tissues is an exciting prospect of bioprinting. However, the majority of the matrix materials used so far for bioprinting cannot represent the complexity of natural extracellular matrix (ECM) and thus are unable to reconstitute the intrinsic cellular morphologies and functions. Here, we develop a method for the bioprinting of cell-laden constructs with novel decellularized extracellular matrix (dECM) bioink capable of providing an optimized microenvironment conducive to the growth of three-dimensional structured tissue. We show the versatility and flexibility of the developed bioprinting process using tissue-specific dECM bioinks, including adipose, cartilage and heart tissues, capable of providing crucial cues for cells engraftment, survival and long-term function. We achieve high cell viability and functionality of the printed dECM structures using our bioprinting method.open11349353sciescopu

    Neutron Stars in Teleparallel Gravity

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    In this paper we deal with neutron stars, which are described by a perfect fluid model, in the context of the teleparallel equivalent of general relativity. We use numerical simulations to find the relationship between the angular momentum of the field and the angular momentum of the source. Such a relation was established for each stable star reached by the numerical simulation once the code is fed with an equation of state, the central energy density and the ratio between polar and equatorial radii. We also find a regime where linear relation between gravitational angular momentum and moment of inertia (as well as angular velocity of the fluid) is valid. We give the spatial distribution of the gravitational energy and show that it has a linear dependence with the squared angular velocity of the source.Comment: 19 pages, 14 figures. arXiv admin note: text overlap with arXiv:1206.331

    P17ā€…Dietary nitrate supplementation increases fractional exhaled nitric oxide : implications for the assessment of airway health in athletes

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    Background: Fractional exhaled nitric oxide (FeNO) is a simple tool that has an established role in the assessment of airway inflammation in athletes. Specifically, FeNO provides information concerning asthma phenotypes, aetiology of respiratory symptoms, response to anti-inflammatory agents, course of disease and adherence to medication. It is recognised that FeNO can be influenced by a variety of external factors (e.g. atopic status, exercise, respiratory tract infection), however, there remains limited research concerning the impact of dietary nitrate ingestion. The primary aim of this study was therefore to evaluate the effect of acute dietary nitrate supplementation on FeNO and resting pulmonary function parameters. Method: The study was conducted as a randomised double-blind placebo-controlled trial. Thirty male endurance trained athletes (age: 28 Ā± 6 yrs; BMI: 23 Ā± 2 kg.m-2) free from cardio-respiratory and metabolic disease, and stable at time of study entry (i.e. entirely asymptomatic without recent respiratory tract infection) attended the laboratory on two separate occasions. On arrival to the laboratory, athletes consumed either 140ml nitrate-rich beetroot juice (15.2 mmol nitrate) (NIT) or nitrate-depleted beetroot juice (0 mmol nitrate) (PLA). In accordance with international guidelines all athletes performed resting FeNO and forced spirometry (2.5hrs post ingestion). Airway inflammation was evaluated using established FeNO thresholds: (intermediate [ā‰„25ppb] and high [>50ppb]). Results: All athletes demonstrated normal baseline lung function (FEV1 % predicted >80%). A three-fold rise in resting FeNO was observed following NIT (median [IQR]): 32ppb [37] in comparison to PLA: 10ppb [12] (P0.05). Conclusion: Dietary nitrate ingestion should be considered when employing FeNO for the assessment of airway health in athletes. Our findings have implications concerning the decision to initiate or modify inhaler therapy. Further research is therefore required to determine the impact of chronic dietary nitrate ingestion on pulmonary function and bronchoprovocation testing in athletes with pre-existing asthma and/or exercise-induced bronchoconstriction

    Linear Superiorization for Infeasible Linear Programming

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    Linear superiorization (abbreviated: LinSup) considers linear programming (LP) problems wherein the constraints as well as the objective function are linear. It allows to steer the iterates of a feasibility-seeking iterative process toward feasible points that have lower (not necessarily minimal) values of the objective function than points that would have been reached by the same feasiblity-seeking iterative process without superiorization. Using a feasibility-seeking iterative process that converges even if the linear feasible set is empty, LinSup generates an iterative sequence that converges to a point that minimizes a proximity function which measures the linear constraints violation. In addition, due to LinSup's repeated objective function reduction steps such a point will most probably have a reduced objective function value. We present an exploratory experimental result that illustrates the behavior of LinSup on an infeasible LP problem.Comment: arXiv admin note: substantial text overlap with arXiv:1612.0653

    Mental health care for parents of babies with congenital heart disease during intensive care unit admission: Systematic review and statement of best practice

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    INTRODUCTION: Congenital heart disease (CHD) is one of the most common causes of infant admission to pediatric intensive care and is associated with profound psychological stress for mothers, fathers and their infants. Intensive care unit admission represents an opportunity to offer evidence-based strategies to prevent or minimize severe psychological distress and promote secure bonding and attachment, alongside high-quality infant medical care. OBJECTIVES: We aimed to identify, synthesize and critically appraise published evidence on the efficacy and cost-effectiveness of mental health interventions delivered in neonatal, pediatric or cardiac intensive care units for parents of infants with CHD. A secondary goal was to develop recommendations for advancing health policy, practice and research in the field. METHODS: In accordance with a prospectively registered protocol (CRD42019114507), six electronic databases were systematically searched for studies reporting results of a controlled trial of a mental health intervention for parents of infants aged 0-12ā€Æmonths with a congenital anomaly requiring intensive care unit admission. To maximize generalizability of results, trials involving infants with any type of structural congenital anomaly requiring surgery were included. Outcomes included intervention type, process, efficacy, and cost-effectiveness. RESULTS: Across all forms of congenital anomaly, only five trials met inclusion criteria (four in CHD, one in gastrointestinal malformation). All interventions engaged parents face-to-face, but each had a distinct therapeutic approach (parent-infant interaction and bonding, early pediatric palliative care, psycho-education, parenting skills training, and family-centered nursing). Four of the five trials demonstrated efficacy in reducing maternal anxiety, although the quality of evidence was low. Positive results were also found for maternal coping, mother-infant attachment, parenting confidence and satisfaction with clinical care, as well as infant mental (but not psychomotor) development at 6ā€Æmonths. Mixed results were found for maternal depression and infant feeding. No evidence of efficacy was found for improving parent, infant or family quality of life, physical health or length of infant hospital stay, and there were no data on cost-effectiveness. CONCLUSIONS: Stronger evidence for the efficacy of mental health interventions to buffer the effects of intensive care unit admission for parents of infants with CHD is urgently needed. Robust, high-quality trials are lacking, despite the established need and demand, and health policies prioritizing parent mental health care in the context of early childhood adversity are needed

    Migration patterns and winter population dynamics of rice planthoppers in Indochina: New perspectives from field surveys and atmospheric trajectories

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    This is the author accepted manuscript. The final version is available from Elsevier Masson via the DOI in this record.Rice planthoppers (RPH) are the most serious insect pests of rice production in East Asia, frequently out-breaking in China, Korea and Japan each summer. They are unable to overwinter in temperate East Asia, and summer populations arise anew each year via northward spring migration from south-east Asia. The annual migration cycle is generally believed to be a closed loop with mass returns to south-east Asia in the autumn, but this leg of the journey and the overwintering dynamics are much less studied than the spring immigrations. Previous studies have indicated that the north-central Vietnam (NCV) region is a key location for both the spring colonisation of China and for receiving return migrants from southern China each autumn. However, NCV experiences a three-month rice-free fallow period during mid-winter, and so it cannot be the principal over-wintering region for RPH populations. In this study, the continental-scale migration patterns of RPH in East Asia were explored using data from light trap catches, field surveys and atmospheric trajectory simulations. Our results confirmed that large numbers of return migrants arrive in NCV from southern China each autumn, but that they are unable to survive there over winter. The NCV region is recolonised in the early-spring (mid-February to mid-March) of each year by migrants from winter rice-growing regions in north-east Thailand, southern Laos and south-central coastal Vietnam, which are transported on favourable high-altitude synoptic winds. The following generation initiates the colonisation of East Asia from a large source population in NCV. Our results provide a new perspective on RPH migration patterns and over-wintering dynamics in East Asia, which is governed by crop production, environmental conditions and synoptic wind patterns at a continental scale.National Natural Science Foundation of China (NSFC)Natural Science Foundation of Jiangsu ProvinceBiotechnology and Biological Sciences Research Council (BBSRC)Science and Technology Facilities Council (STFC

    The Antimalarial and Antimicrobial Activity and Brine Shrimp Toxicity of Clematis Brachiata Extracts

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    The in vitro antimalarial activity of the root extract in partly supports the ethnobotanical use of the plant to manage malaria. Clematis brachiata Thunberg (Ranunculaceae) is used in Kenya for the management of headaches, malaria and other febrile illnesses, abdominal disorders, yaws and for skin disorders. Old stems and leaves are chewed for the management of toothaches and sore throats. Extracts of the plant were subjected to tests for antimalarial, antibacterial and antifungal activity. The toxicity of the extracts was assessed using the brine shrimp lethality bioassay. The root extract gave the highest in vitro antimalarial activity against the mulitidrug resistant strain, Plasmodium falciparum VI/S (IC50=39.24 mg/ml). The stem and leaf extracts had insignificant antiplasmodial activity. The leaf, stem and root extracts had no bacterial or fungal inhibitory effects even at very high concentrations of 10 mg/ml. The LD50 values of the stem and leaf methanol extracts against the brine shrimp larvae was 365.60 and 66.5 mg/ml, respectively. (E & C Afr Jnl Pharm Sci: 2002 5(1): 15-18

    Use of clinical guidelines in cardiology practice in Sudan

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    Rationale, aims, and objective: The aim of this study was to explore the views of prescribers in cardiology in Sudan about the use of guidelines in clinical practice and the extent to which guidelines whether national or international can be adopted in clinical practice in Sudan. Methods: Interviews were conducted with the consultants in 2 of the main cardiac hospitals in Sudan. This was followed by a survey amongst the doctors in the hospitals to examine the views of a larger population of prescribers about the matter investigated. Results: Twelve consultants were interviewed, and 47 prescribers (60%) replied to the questionnaire that followed. Most doctors relied on foreign guidelines to prescribe for their patients. The doctors acknowledged the limitation of using foreign guidelines in Sudan. A number of doctors were not in favour of following any guidelines, as they perceived that the practice in Sudan does not allow implementation of guidelines. Conclusion: The prescribers in Sudan had to rely on guidelines made in foreign countries if they want to get the benefit of evidenceā€based medicine to their patients, but they had to find a way to adapt these guidelines to their patients and to the health care system they are working within. However, it is not known if this adaptation of foreign guidelines is providing the benefits intended or is risking evidenceā€based medicine
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