Prediction of mechanical properties - Modulus of rupture and modulus of elasticity - of five tropical species by nondestructive methods

This paper analyzes the usability of different dynamic moduli of elasticity and wood density for the prediction of mechanical properties – static modulus of elasticity and modulus of rupture – in samples with grain deflection from the longitudinal direction. Five tropical hardwoods (Afzelia bipindensis, Intsia bijuga, Millettia laurentii, Astronium graveolens and Microberlinia brazzavillensis) with different grain characteristics were used for this purpose.  The fiber deflection was caused by the presence of interlocked grain or the working process. The three nondestructive techniques used in this study –  longitudinal and flexural resonance method and ultrasound method –  provided higher values of modulus of elasticity than the static bending test, but close correlation was observed between these variables. The weakest correlation was found for the ultrasound method which is probably caused by its measuring mechanism. The prediction of the modulus of rupture is less accurate when the dynamic modulus of elasticity is compared with the static modulus of elasticity; on the other hand, it was still good in comparison with the density model, which is inapplicable when grain deflection occurs in wood. In the wood of Zebrano where the interlocked grain was strongly developed, almost all of the correlation coefficients showed the lowest values and the prediction of modulus of rupture by nondestructive techniques was unsatisfactory

Promjena sadržaja vode u drvu tijekom izlaganja umjetnoj svjetlosti i njezin utjecaj na mjerenje boje

This paper discusses the differences between colour parameters of dried and conditioned wood surfaces irradiated by light. Samples of two wood species – Hevea (Hevea brasiliensis Müll. Arg.) and Jatoba (Hymenaea courbaril L.) – were exposed to artificial sunlight. During this process, sample moisture content decreased by 6 %. The colour parameters were measured immediately after irradiation and after conditioning on former moisture content level. Statistically significant differences were found between colour parameter values. Nevertheless these differences were too low for practical importance.U radu se analiziraju razlike parametara boje površine suhoga i kondicioniranog drva nakon izlaganja umjetnoj svjetlosti. Uzorci dviju vrsta drva – Hevea brasiliensis Mull Arg. i Hymenaea courbaril L. – bili su izloženi umjetnoj Sunčevoj svjetlosti. Tijekom tog procesa sadržaj vode u uzorcima smanjen je za 6 %. Parametri boje izmjereni su odmah nakon izlaganja svjetlosti i nakon kondicioniranja uzoraka na početni sadržaj vode. Utvrđene su statistički značajne razlike između vrijednosti parametara boja. Ipak te su razlike premalene da bi imale praktičnu važnost

Influence of obesity on the development of osteoarthritis of the hip: a systematic review

OBJECTIVE: To evaluate the evidence for the influence of obesity as a risk factor for the occurrence of osteoarthritis (OA) of the hip. METHODS: A bibliographical search of Medline, EMBASE and the Cochrane library until April 2000 was carried out. Articles describing studies of the relationship between obesity and the occurrence of hip OA were selected. The quality of the studies was assessed with a standardized set of criteria. The outcome of the studies was compared with respect to study characteristics and the quality score for the study. A best-evidence synthesis was used to summarize the results of the individual studies. RESULTS: Five longitudinal and seven cross-sectional studies were included in this review. There was no association between outcome and study design or methodological quality. The associations between obesity and hip OA were, however, stronger in studies in which the diagnosis of hip OA was based not only on radiological criteria but also on clinical symptoms. Overall, moderate evidence was found for a positive association between obesity and the occurrence of hip OA, with an odds ratio of approximately 2. CONCLUSION: The evidence for a positive influence of obesity on the development of hip OA is moderate

Prevalence and Risk Factors for Delirium in Elderly Patients With Severe Burns: A Retrospective Cohort Study

Little is known about delirium in elderly burn center patients. The aim of this study is to provide information on the prevalence of delirium and risk factors contributing to the onset of delirium. All patients aged 70 years or older admitted with burn injuries to the Burn Center, Maasstad Hospital, in 2011 to 2017 were eligible for inclusion. We retrospectively collected data regarding the presence of delirium, potential risk factors contributing to the onset of delirium and outcome after delirium. We included elderly 90 patients in this study. The prevalence of delirium in our population was 13% (N = 12). Risk factors for delirium were advanced age, increased American Society for Anesthesiologists score, physical impairment and the use of anticholinergic drugs during admission. Patients with delirium had a poorer outcome, with prolonged hospital stay and increased mortality 6 and 12 months after discharge. Delirium is diagnosed in 13% of the elderly patients admitted to our burn center. Risk factors for delirium found in this study are advanced age, poor physical health status, physical impairment, and the use of anticholinergic drugs. Delirium is related to poor outcomes, including prolonged hospital stay and mortality after discharge

Burns in the elderly: a nationwide study on management and clinical outcomes

Background: In modern-day burn care, advanced age remains an important predictor for mortality among burn victims. In this study, we compared the complete treatment trajectory (including prehospital and surgical treatment) and the outcomes between an elderly burn population and a younger adult burn population. Methods: In this nationwide study, data from the Dutch Burn Repository were used. This is a uniform national registration for Dutch specialized burn care. All adult patients that were admitted to one of the three Dutch burn centres from the period 2009 to 2015 were included in the analysis. Burn patients were considered as elderly when ≥65 years of age, and were then further subdivided into three age categories: 65–74, 75–85 and 85+ years. Younger adults in the age category 18–64 years were used as the reference group. Surgical management was studie

Strength Training for Arthritis Trial (START): design and rationale

Background Muscle loss and fat gain contribute to the disability, pain, and morbidity associated with knee osteoarthritis (OA), and thigh muscle weakness is an independent and modifiable risk factor for it. However, while all published treatment guidelines recommend muscle strengthening exercise to combat loss of muscle mass and strength in knee OA patients, previous strength training studies either used intensities or loads below recommended levels for healthy adults or were generally short, lasting only 6 to 24 weeks. The efficacy of high-intensity strength training in improving OA symptoms, slowing progression, and affecting the underlying mechanisms has not been examined due to the unsubstantiated belief that it might exacerbate symptoms. We hypothesize that in addition to short-term clinical benefits, combining greater duration with high-intensity strength training will alter thigh composition sufficiently to attain long-term reductions in knee-joint forces, lower pain levels, decrease inflammatory cytokines, and slow OA progression. Methods/Design This is an assessor-blind, randomized controlled trial. The study population consists of 372 older (age ≥ 55 yrs) ambulatory, community-dwelling persons with: (1) mild-to-moderate medial tibiofemoral OA (Kellgren-Lawrence (KL) = 2 or 3); (2) knee neutral or varus aligned knee ( -2° valgus ≤ angle ≤ 10° varus); (3) 20 kg.m-2 ≥ BMI ≤ 45 kg.m-2; and (3) no participation in a formal strength-training program for more than 30 minutes per week within the past 6 months. Participants are randomized to one of 3 groups: high-intensity strength training (75-90% 1Repetition Maximum (1RM)); low-intensity strength training (30-40%1RM); or healthy living education. The primary clinical aim is to compare the interventions’ effects on knee pain, and the primary mechanistic aim is to compare their effects on knee-joint compressive forces during walking, a mechanism that affects the OA disease pathway. Secondary aims will compare the interventions’ effects on additional clinical measures of disease severity (e.g., function, mobility); disease progression measured by x-ray; thigh muscle and fat volume, measured by computed tomography (CT); components of thigh muscle function, including hip abductor strength and quadriceps strength, and power; additional measures of knee-joint loading; inflammatory and OA biomarkers; and health-related quality of life. Discussion Test-retest reliability for the thigh CT scan was: total thigh volume, intra-class correlation coefficients (ICC) = 0.99; total fat volume, ICC = 0.99, and total muscle volume, ICC = 0.99. ICC for both isokinetic concentric knee flexion and extension strength was 0.93, and for hip-abductor concentric strength was 0.99. The reliability of our 1RM testing was: leg press, ICC = 0.95; leg curl, ICC = 0.99; and leg extension, ICC = 0.98. Results of this trial will provide critically needed guidance for clinicians in a variety of health professions who prescribe and oversee treatment and prevention of OA-related complications. Given the prevalence and impact of OA and the widespread availability of this intervention, assessing the efficacy of optimal strength training has the potential for immediate and vital clinical impact

Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field