390 research outputs found
Basic Research of Material Properties of Mycelium-Based Composites
The subject of this research is growing mycelium-based composites and exploring their basic material properties. Since the building industry is responsible for a large amount of annual CO(2) emissions, rethinking building materials is an important task for future practices. Using such composites is a carbon-neutral strategy that offers alternatives to conventional building materials. Yet, in order to become competitive, their basic research is still needed. In order to create mycelium-based composites, it was necessary to establish a sterile work environment and develop shaping procedures for objects on a scale of architectural building elements. The composite material exhibited qualities that make it suitable for compression-only structures, temporary assemblies, and acoustic and thermal insulation. The methodology includes evaluating several substrates, focused on beech sawdust, with two mycelium strains (Pleurotus ostreatus and Ganoderma lucidum), density calculations, compression tests, three-point flexural tests and capillary water absorption. The results of this study are presented through graphical and numerical values comparing material and mechanical properties. This study established a database for succeeding investigations and for defining the potentials and limitations of this material. Furthermore, future applications and relevant examinations have been addressed
Muscle power after stroke
Stroke is the leading cause of disability worldwide. It often leads to mobility limitations resulting from deficits in muscle performance. While reduced muscle strength and rate of force production have been reported, little is known about the power generating capability of people after stroke and its relationship to mobility. Research in other populations has found that measures of muscle power may have a greater association with activity performance than do measures of muscle force alone. Consequently, in an attempt to optimise power, investigators have focused on identifying ideal parameters within which to train for power. One such parameter is the identification of the loading level at which maximal power is generated. Literature reporting optimal loads from both young athletic and healthy older populations has yielded mixed results, making the applicability to a hemiparetic population difficult. The purpose of this study was to investigate muscle power performance at differing loads and to determine at what load muscle power is best elicited in hemiparetic and age and gender matched control groups. A secondary aim was to ascertain whether there is a relationship between the muscle power values obtained and activities such as gait, stair climbing and standing from a chair. Twenty nine hemiparetic volunteers and twenty nine age and gender matched controls were evaluated. Involved and uninvolved legs of the stroke group and a comparison leg of the control group underwent testing. Leg press muscle power was measured using a modified supine leg press machine at 30%, 50% and 70% of a one-repetition maximum (1-RM) load. Participants were positioned on the leg press machine and asked to push, with a single leg, as hard and as fast as they could. Data was collected via a mounted force platform and a linear transducer connected to a platform on which the participants lay. From these, power was able to be calculated. The activities were timed while being performed as fast as possible. The results showed that peak muscle power values differed significantly between the involved, uninvolved and control legs. Peak leg power in all three leg groups was greatest when pushing against a load of 30% of 1-RM. Involved leg peak power tested at 30% of 1-RM (Mean:240; SD:145 W) was significantly lower (p<0.05) than the uninvolved leg (Mean:506; SD:243 W). Both the involved and uninvolved legs generated significantly lower peak power (p<0.05) than the control leg (Mean:757; SD:292 W). Correlations were found between the involved leg peak power and gait speed and involved leg peak power and stair climbing (r=0.6-0.7, p<0.05). No correlation was found between paretic leg peak power and chair stands. The control group leg peak power demonstrated significant associations with the performance of all three activities.In summary, there were significant differences between the involved and the uninvolved leg in power production after stroke. As well, there are significant differences between the uninvolved leg and the leg of those not affected by stroke. Power was related to a number of activities
Factors Associated with Successful Mobilization and Collection of Peripheral Blood Hematopoietic Stem Cells in Autologous and Allogeneic Donors
BACKGROUND: Peripheral blood hematopoietic stem cells (PBSC) have largely replaced bone marrow derived stem cells in autologous transplantations, and have become the preferred source of stem cells in the majority of allogeneic transplantations. Sufficient number of mobilized and collected hematopoietic stem cells (HSC) is needed for successful hematopoietic stem cell transplantation.MATERIAL AND METHOD: This study was performed in the Institute for Transfusion Medicine of RM and the University Clinic of Hematology from 2008 till 2016. There were 30 allogeneic and 90 autologous donors that underwent mobilization and collection of PBSC. The association between possible predictive factors such as demographic characteristics, laboratory parameters and collection parameters in both groups, and mobilization strategy and clinical characteristics in autologous donors and number of collected PBSC was analyzed.RESULTS: There were 226 apheresis, 182 in autologous donors (mean 2, range 1-3) and 44 apheresis in 30 allogeneic donors (mean 1.5, range 1-2). The mean number of collected MNC in autologous donors was 3.09 x 108/kg and 2.85 x 106/kg CD34+ cells, and 3.23 x 108/kg MNC and 3.20 x 106/kg CD34+ cells in allogeneic donors. Significantly larger number of MNC and CD34+ cells was collected with the WBC set. There was a statistically significant correlation between the total number of collected MNC in autologous donors and platelet count before mobilization, the number of cycles in one apheresis procedure, quantity of collected graft and the number of collected MNC and CD34+ cells on the first day of harvestration. There was a statistically significant correlation between the total number of collected MNC in allogeneic donors and platelet count before mobilization, the number of cycles in one apheresis procedure, quantity of collected graft and number of MNC on first day of harvestration. There was a strong correlation between the number of collected MNC and CD34+ cells on the first harvest and the total number of collected MNC and CD34+ cells in poor mobilizers, and inverse correlation with the number of apheresis procedures. Donors who donated MNC Γ’β°Β€ 0.7 x 108/kg and/or Γ’β°Β€ 0.7 x 106/kg CD34+ cells on the first harvest (84.6%) were strong predictors of poor mobilizers.CONCLUSION: Determining the proper level of baseline and preaheresis laboratory parameters for initiating mobilization and apheresis procedure which is safe for donors and greatly efficient in collection of PBSC is needed for optimization of these procedures, as well as for early intervention in poor mobilizers
Adverse Reactions to Intravenous Immunoglobulins - Our Experience
BACKGROUND: Adverse reactions to intravenous immunoglobulins (IVIG) are divided by organ system involved, or by timing of onsetΓ’β¬βimmediate which occur during infusion usually rate-related, true IgE-mediated anaphylaxis and delayed reaction which occur hours to days after the infusion.
AIM: To describe the adverse events of patients given IVIG infusions.
METHODS: Total number of patients receiving IVIG was 41 with 25 males (60.97%) and 16 females (39.02%), age 2 months-35 years. A total number of infusions was 1350.
RESULTS: Total number of adverse reactions 15, 14 patients with immediate-type and 1 with delayed type. Total percentage of adverse reactions in a given sample was 1.1% of all IVIG infusions. Fever was the most common immediate type of reaction occurring in 11 patients (78.57%) followed by acrocyanosis 10 patients (71.42%), skin rash 9 patients (64.28%) and headache 8 patients (57.14). Delayed-type of reactions (like fever, headache and vomiting) was present in one patient. Majority of the adverse effects occurred at the infusion rate higher than 1, 5 ml/kg/hour, which is still within recommended speed.
CONCLUSION: About 1.1% of IVG infusions where with adverse events. Most common manifestations where: fever, acrocyanosis, skin rash and headache, which occurred 1-6 hours from the beginning of the infusion. The occurrence of adverse reactions to IVIG was related to the infusion rates in a fashion that faster infusion rate gives more reactions. Adverse reactions were managed by reduction of the infusion rate and administration of medications such as paracetamol, antihistamines and steroids
Analysis of Factors that Influence Hematopoietic Recovery in Autologous Transplanted Patients with Hematopoietic Stem Cells from Peripheral Blood
BACKGROUND: Successful hematopoietic stem cell transplantation (HSCT) requires a rapid and durable
hematopoietic recovery.
AIM: The aim of our study was to analyse factors that influence hematopoietic recovery after autologous HSCT.
MATERIALS AND METHODS: Multiple regression analysis was used to analyse factors affecting neutrophil and
platelet engraftment in 90 autologous transplanted patients β 30 with acute myeloid leukaemia (AML), 30 with
lymphoma and 30 with multiple myeloma (MM) from 2008 till 2016.
RESULTS: The neutrophil recovery in AML patients was significantly influenced by transfusion support with
random-donor platelets, sex and number of transplanted mononuclear cells (MNC) and CD34+ cells; and in
lymphoma patients, it was influenced by sex, age, mobilisation strategy and some transplanted MNC. The
influence of investigated factors on neutrophil engraftment in MM patients was not statistically significant. The
platelet recovery in AML patients was influenced by transfusion support with random-donor platelets; in lymphoma
patients, it was influenced by sex, age, time from diagnosis to harvesting and time from diagnosis to HSCT; and in
MM patients it was influenced by transfusion support with random-donor platelets.
CONCLUSION: Additional studies are necessary to better understanding of engraftment kinetic to improve the
safety of HSCT and to minimise potential complications and expenses related to HSCT
Is received dose from ingested soil independent of soil PAH concentrations?-Animal model results
Polycyclic aromatic hydrocarbon (PAH) bioavailability from ingested soils will vary between soils; however, the nature of this variation is not well characterized. A juvenile swine model was used to link external exposure to internal benzo[a]pyrene (BaP) and anthracene exposure following oral PAH ingestion of 27 different impacted site soils, soots, or spiked artificial soils. Internal exposure of BaP and anthracene, represented by area under the plasma-time curve, did not relate to soil concentration in impacted site soils, but did relate in spiked artificial soil. Point of departure modeling identified soil PAH concentrations greater than 1900βmgβkgβ1 as the point where area under the curve becomes proportional to external dose. A BaP internal exposure below 1900βmgβkgβ1 had an upper 95% confidence interval estimate of 33% of external exposure. Weak relationships between soil:simulated gastrointestinal fluid PAH partitioning and area under the curve values suggest that differences in internal PAH exposure between soils may not be dominated by differences in PAH partitioning. The data seem to best support exposure assessment assuming constant internal PAH exposure below soil concentrations of 1900βmgβkgβ1. However, because constant internal exposure would challenge several existing paradigms, a bioavailability estimate of 33% of the external exposure is suggested as a likely workable solution. Environ Toxicol Chem 2016;35:2261β226
Allopurinol Reduces the Lethality Associated with Acute Renal Failure Induced by Crotalus durissus terrificus Snake Venom: Comparison with Probenecid
In Brazil, among registered snake bites, those by the genus Crotalus originate the highest mortality rate. The rattlesnake Crotalus durissus terrificus is the most frequently implicated in these accidents. The kidney is a particularly vulnerable organ to the venom of this rattlesnake. In fact, the most serious complication of Crotalus snake bite is the renal dysfunction, and among the fatal cases of Crotalus bites in Brazil 5% are patients treated with antivenom. The hyperuricemia has been observed in human accidents with snake venoms, but this parameter has not received any special attention as a relevant factor in the etiology of renal dysfunction caused by these venoms. This study examined the effects of treatments with low-cost and low-risk uricostatic (allopurinol) and uricosuric (probenecid) drugs on the envenomation by C. d. terrificus, showing that allopurinol and probenecid mitigated certain nephrotoxic effects, as well as the survival of envenomed mice was improved through the effects of allopurinol on reduction of oxidative stress and intracellular formation of uric acid. This new knowledge provides consistent evidences linking uric acid with the renal dysfunction induced by rattlesnake bites and that the allopurinol deserves to be clinically evaluated as an approach complementary to anti-snake venom serotherapy
Evaluation of the Reproductive and Developmental Risks of Caffeine
A risk analysis of in utero caffeine exposure is presented utilizing epidemiological studies and animal studies dealing with congenital malformation, pregnancy loss, and weight reduction. These effects are of interest to teratologists, because animal studies are useful in their evaluation. Many of the epidemiology studies did not evaluate the impact of the βpregnancy signal,β which identifies healthy pregnancies and permits investigators to identify subjects with low pregnancy risks. The spontaneous abortion epidemiology studies were inconsistent and the majority did not consider the confounding introduced by not considering the pregnancy signal. The animal studies do not support the concept that caffeine is an abortafacient for the wide range of human caffeine exposures. Almost all the congenital malformation epidemiology studies were negative. Animal pharmacokinetic studies indicate that the teratogenic plasma level of caffeine has to reach or exceed 60 Β΅g/ml, which is not attainable from ingesting large amounts of caffeine in foods and beverages. No epidemiological study described the βcaffeine teratogenic syndrome.β Six of the 17 recent epidemiology studies dealing with the risk of caffeine and fetal weight reduction were negative. Seven of the positive studies had growth reductions that were clinically insignificant and none of the studies cited the animal literature. Analysis of caffeine's reproductive toxicity considers reproducibility and plausibility of clinical, epidemiological, and animal data. Moderate or even high amounts of beverages and foods containing caffeine do not increase the risks of congenital malformations, miscarriage or growth retardation. Pharmacokinetic studies markedly improve the ability to perform the risk analyses. Birth Defects Res (Part B) 92:152β187, 2011. Β© 2011 Wiley-Liss, Inc
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