The increasing use of wood leads to the need for a better understanding of its thermal properties with the aim of quantitatively identifying the exchange of thermal energy between wood and the ...surrounding solar radiation as precisely as possible. Reliable and rapid measurement of thermal conductivity is one of the most important current industrial requirements. The aim of this study is to examine the validity of using the modified transient plane source method (MTPS), which uses the principle of one-sided heating of the sample, and is defined by the ASTM D7984-21 (2021) standard, for determining the thermal conductivity of complex biocomposite composite materials such as wood. The analysis of the available literature shows a lack of data on the thermal conductivity of the type of wood originating in Croatia. In this study, the thermal conductivities of beech and fir wood samples in the longitudinal direction was determined by the MTPS method depending on the temperature and moisture content in the samples. Measurements were made on samples with a moisture content of 0%, 10%, and 20% in the temperature range from 20 to 80 °C.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
•Multi-objective optimization of gear pair parameters was conducted.•Main goal was reducing the transmission volume and power losses.•Five optimization variables were used; z1, b, m, x1, and ...x2.•Solutions have shown that the trade-off between volume and efficiency is obligatory.•Combination of the lower gear module, the lower face width, and the higher profile shift coefficients yield good results.
Besides satisfying the essential strength requirements, gearbox design should ensure additional desirable properties in order to be competitive. For example, a gearbox should be efficient, durable, quiet, compact, and light. Nowadays, as a consequence of rising environmental concerns, high efficiency is a rather desirable feature. In this article, a genetic algorithm was used for conducting a multi-objective optimization of gear pair parameters with a goal of reducing the transmission volume and power losses. Gearing efficiency primarily depends on the normal load, sliding velocities, and the friction coefficient. Gearing efficiency was calculated analytically, using the approximate load distribution formulae and efficiency formulation developed by Schlenk. The resulting formula was included in the genetic algorithm as an objective. To verify it, results were compared to the ones obtained by other authors. Optimization variables consisted of the gear module, the face width, the pinion and wheel profile shift coefficients and the number of teeth of the pinion. Solutions have shown that the trade-off between volume and efficiency is obligatory and a combination of the lower gear module, the lower face width, the higher profile shift coefficients and the higher number of teeth of the pinion yield good results regarding both objectives.
The increasing use of wood leads to the need for a better understanding of its thermal properties with the aim of quantitatively identifying the exchange of thermal energy between wood and the ...surrounding solar radiation as precisely as possible. Reliable and rapid measurement of thermal conductivity is one of the most important current industrial requirements. The aim of this study is to examine the validity of using the modified transient plane source method (MTPS), which uses the principle of one-sided heating of the sample, and is defined by the ASTM D7984-21 (2021) standard, for determining the thermal conductivity of complex biocomposite composite materials such as wood. The analysis of the available literature shows a lack of data on the thermal conductivity of the type of wood originating in Croatia. In this study, the thermal conductivities of beech and fir wood samples in the longitudinal direction was determined by the MTPS method depending on the temperature and moisture content in the samples. Measurements were made on samples with a moisture content of 0%, 10%, and 20% in the temperature range from 20 to 80 °C.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Oral mucositis (OM) occurs in more than 95% of patients irradiated in the head and neck area. This paper aims to determine the occurrence and characteristics of OM in patients with head and neck ...cancer (HNC), as well as the involvement of dentists/oral medicine specialists in treating such patients.
: This study was conducted at the Department of Otorhinolaryngology and Department of Oral Medicine, University Hospital Center Zagreb, from April to August 2022, on patients irradiated in the head and neck area. A unique OM questionnaire was created on the incidence, characteristics, oral care, and involvement of dentists in the overall care.
: Thirty patients filled out the questionnaire. Of the 22 patients who had developed OM, 14 had grade-three OM. Ten patients were treated for OM in line with the instructions of an oral medicine specialist, eight based on the instructions of a specialist responsible for monitoring of the underlying disease, and four were not treated at all. Sixteen patients had not been referred to a dentist before the start of RT.
: These results showed insufficient care and treatment of OM, as well as insufficient involvement of dentists in the oncology team.
This study investigated the impact of educational video content in the final part of the PE lesson on students’ health literacy and their perceptions of the usefulness and satisfaction of PE lessons. ...The study included 160 students in grades 6 to 8 from an elementary school in Croatia, with an average age of 13.75 years, of which 93 (58%) were female. The experimental group (n=111) participated in the PE lessons with educational video content, while the control group (n=49) participated in the standard PE lesson. At the beginning and at the end of the research, both groups completed a theoretical written knowledge test on health literacy and a questionnaire to assess attitudes towards PE lessons. An ANCOVA was used to measure the impact of the experimental programme on post-intervention results while including initial results as a covariate. After the experiment, statistically significant differences were observed between the results of the experimental and control groups of students for Theoretical knowledge (9.90±0.29 vs. 8.33±0.43, F(1,159) = 8.998, p = 0.003) and Perception of the usefulness of PE lessons (2.93±0.06 vs 2.69±0.09, F(1,163) = 4.434, p = 0.037), while no statistically significant differences were observed for Satisfaction with PE lessons (2.95±0, 09 vs. 3.02±0.06, p = 0.553). The intervention positively affected students’ knowledge and perception of PE lessons without impairing their satisfaction, indicating that integrating educational video content into PE lessons connecting physical activity and health literacy is viable.
Svrha ovog prikaza slučaja bila je opisati vrlo rijetku oralnu leziju kao posljedicu primarne plućne tuberkuloze. Prikaz slučaja: Opisan je bolesnik s refraktornom bezbolnom ulceracijom ventralne ...površine jezika. Pacijentu je uzeta detaljna medicinska anamneza te obavljen klinički pregled sluznice usne šupljine i palpacija regionalnih limfnih čvorova. Kliničkim pregledom ustanovljena je ulceracija na ventrolateralnoj površini jezika promjera oko dva centimetra. Palpacijom regionalnih limfnih čvorova nije otkriveno njihovo povećanje. Toluidinski test sumnjive lezije učinjen je tijekom svakoga kontrolnog pregleda. Biopsijski uzorci za histopatološku analizu uzeti su tri puta. Histopatološka analiza prvoga biopsijskog uzorka pokazala je nespecifičnu upalu, druga kazeoznu nekrozu bez pozitivnog bojenja prema Ziehl-Neelsenu, a treća granulomatoznu upalu visoko sumnjivu na sarkoidozu. Pacijent je tijekom hospitalizacije obavio cjelovit fizikalni pregled, te laboratorijsku i radiološku dijagnostiku. Fizikalni pregled prsnog koša pokazao je bilateralno prisutne grube krepitacije, a laboratorijski nalazi krvne slike normocitnu anemiju kronične bolesti. Na rendgenskoj snimci pluća uočeni su mali multipli čvorovi bilateralno, a nalaz direktnog sputuma bio je pozitivan. Zaključak: Iako je oralna tuberkuloza rijetko stanje, mora se uzeti u obzir u diferencijalnoj dijagnozi refraktornih bezbolnih oralnih ulkusa.
The aim of this case report was to discuss an extremely rare oral lesion as a result of primary pulmonary tuberculosis.
In this case report, the patient with refractory painless ulceration at ventral ...surface of the tongue was described. Detailed medical history was taken followed by clinical examination of the oral mucosa and palpation of regional lymph nodes. Clinical examination revealed ulceration on the patient's ventro-lateral surface of the tongue, approximately two centimeters in diameter. Palpation of regional lymph nodes has not revealed enlargement. The toluidine blue test of the suspected lesion was performed at each control examination. Biopsy samples for histopathologic diagnosis were taken three times. The analysis of the first biopsy sample for histopathology revealed a non-specific inflammation, the second biopsy revealed a caseous necrosis without positive Ziehl-Neelsen staining and the third biopsy revealed a granulomatous inflammation which was highly suspicious of sarcoidosis. During hospitalization, the patient underwent a complete physical examination, and laboratory and radiological diagnostics. Physical chest examination revealed bilaterally coarse crepitations and laboratory findings of his complete blood count revealed normocytic anemia of chronic disease. Radiographic examination of lungs showed multiple small nodules bilaterally and positive direct sputum smear.
Although oral tuberculosis is a rare condition, it must be taken into account in differential diagnosis of refractory painless oral ulcers.
Inflammation is an underlying mechanism behind fibrotic processes and differentiation of cells into myofibroblasts. Presented study therefore provides new data on activation of autoimmune and ...inflammatory immune response genes that accompany activation of p38 and cell differentiation in primary cells derived from Dupuytren's disease (DD) patients.
Primary non-Dupuytren's disease cells (ND) were isolated from macroscopically unaffected palmar fascia adjacent to diseased tissue obtained from patients diagnosed with the last stage of DD and cultured in vitro. Gene expression, collagen gel contraction assay and analysis of secreted proteins were performed in ND cells treated with TGF-β1 and/or inhibitor of p38 phosphorylation.
During differentiation of ND fibroblasts, increased expression of immune response genes PAI-1, TIMP-1, CCL11, and IL-6 was found. These changes were accompanied by increased cell contractility and activation of p38 and its target kinase MK2. Inhibition of p38 phosphorylation reversed these processes in vitro.
TGF-β1 induced p38 phosphorylation in ND cells grown from macroscopically unaffected palmar fascia adjacent to diseased tissue from DD patients. This was accompanied by activation of the cytokine genes CCL-11 and IL-6 and secretion of extracellular matrix regulatory proteins PAI-1 and TIMP-1. A combined approach directed toward inflammation and p38 MAPK-mediated processes in DD might be considered for improving management of DD patients and prevention of recurrence.
Tumor supressor gene FHIT was identified at chromosome 3p14.2 spanning the FRA3B fragile site and is very often inactivated in different types of cancer. The aim of this study was to examine the ...frequency of FHIT gene LOH as well as FHIT mRNA and protein expression in sporadic colon adenocarcinoma.
The results of LOH, real-time qRT-PCR and imunohistochemical analyses were correlated with clinico-pathological characteristics of patients and their tumors in order to evaluate the role of FHIT gene/protein in sporadic colon adenocarcinoma tumorigenesis.
One hundred and thirty one (96.3%) samples were informative for both markers and 33/131 (25.2%) demonstrated LOH. Expression of FHIT mRNA was significantly decreased in colon tumors relative to that in corresponding normal tissue (p=7.2×10−6). Most of the samples (54.0%) were negative for FHIT protein, 26.4% adenocarcinomas showed a weak to moderate immunostaining and 19.6% adenocarcinomas showed strong FHIT immunostaining. No correlation was found between FHIT gene LOH status, mRNA expression or FHIT protein immunostaining and clinico-pathological characteristics. Expression of FHIT mRNA was significantly decreased in FHIT LOH positive tumors (p=0.027). Patients with LOH negative tumors or FHIT protein positive tumors had longer survival but this findings were not statistically significant.
Our overall results suggest that reduced expression of FHIT gene may be associated with the progression of these malignant tumors.
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