Similar Cross-sectional Area Research Articles

Assessing the Effectiveness of Dowel Bars in Jointed Plain Concrete Pavements Using Finite Element Modelling

Aggregate interlocking and dowel bar systems are the two primary mechanisms in a jointed plain concrete pavement for transferring the wheel loads from the loaded slab to the adjacent unloaded slab, avoiding critical stresses and excessive deformations across the joint. Aggregate interlocking is suitable for small joint openings, while the dowel bar provides effective load transmission for both smaller and wider joint openings. In this study, a three-dimensional finite element model was developed to investigate the structural performance of dowelled jointed plain concrete pavements. The developed model was compared with an analytical solution, i.e., Westergaard’s method. The current study investigated the effectiveness of the dowel bars in jointed plain concrete pavements considering the modulus of elasticity and the thickness of the base layer, as well as dowel bar diameter and length. Furthermore, the load transfer efficiency (LTE) of a rounded dowel bar was compared with that of plate dowel bars (i.e., rectangular and diamond-shaped dowel bars) of a similar cross-sectional area and length. This study showed that the LTE was enhanced by 4% when the base layer’s modulus of elasticity increased from 450 MPa to 6000 MPa, while the increase in stress was 23%. A 1.2% improvement in the LTE and a 2.1% reduction in flexural stress were observed as the base layer’s thickness increased from 100 to 250 mm. Moreover, increasing the dowel bar’s diameter from 20 mm to 38 mm enhanced the LTE by 4.3% and 3.8% for base layer moduli of 450 MPa and 4000 MPa, respectively. The corresponding rise in stresses was 10% and 5%. The diamond-shaped dowel bar of a 50 × 32 mm size showed a 0.48% increase in the LTE, while sizes of 100 × 16 mm and 200 × 8 mm reduced the stress 6.7% and 23.1%, respectively, compared to that in the rounded dowel bar. With rectangular dowel bars, a 4% rise in the stress was noted compared to that with the rounded dowel bar. Increasing the length of the diamond-shaped dowel bar slightly improved the LTE but had no impact on the stress in the concrete slab. The findings from this study can help highway engineers improve pavements’ durability, make cost-effective decisions, contribute to resource savings in large-scale concrete pavement projects, and enhance the overall quality of infrastructure.

Roadmap for Power Generation of Industrial Hot Extruded Bi2Te3-Based Thermoelectric Device in Real-World Heat Sources.

Recovering waste heat through thermoelectric (TE) technology is critical for enhancing energy efficiency. However, commercial devices often require n- and p-type thermoelectric units to have similar cross-sectional areas and conductivities, complicating optimization of their figure of merit (ZT). Moreover, real-world heat sources are not constant temperature sources, and only heat flux can be measured. Given these constraints, selecting appropriate parameters for TE devices to maximize their output power for specific heat sources is of significant scientific and practical importance. In this work, we studied a series of n- and p-type Bi2Te3-based TE materials, prepared using commercial hot extrusion techniques, with average conductivities of approximately 650 S cm-1, 820 S cm-1, 1050 S cm-1, and 1300 S cm-1 over the temperature range of 50-250 °C. These materials were assembled into four different thermoelectric devices (HE1, HE2, HE3, and HE4). Finite element simulations for devices HE1, HE2, HE3, and HE4 (TE leg: 1.4 mm × 1.4 mm × 1.6 mm, device area: 40 mm × 40 mm) showed maximum power densities of 3953.5 W m-2 and 1300.8 W m-2 at 67,000 W m-2 and 33,500 W m-2 heat fluxes, respectively. The fabricated devices achieved maximum power densities of 2907.1, 3014.0, 2910.9, and 2525.4 W m-2 at 67,000 W m-2 heat flux, with discrepancies attributed to interface thermal resistance. Based on these findings, we have plotted output performance roadmaps for TE devices with different average electrical conductivities under various heat flux densities (67,000 W m-2 and 33,500 W m-2) as functions of external load and TE leg height. These roadmaps enable rapid design of TE devices tailored to specific external heat source conditions and cost requirements, thereby maximizing waste heat recovery. This study's use of electrical conductivity as a performance indicator for final device output power density offers direct guidance for practical waste heat recovery applications.

CHCHD10P80L knock-in zebrafish display a mild ALS-like phenotype

Mutations in the nuclear-encoded mitochondrial gene CHCHD10 have been observed in patients with a spectrum of diseases that include amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). To investigate the pathogenic nature of disease-associated variants of CHCHD10 we generated a zebrafish knock-in (KI) model expressing the orthologous ALS-associated CHCHD10P80L variant (zebrafish: Chchd10P83L). Larval chchd10P83L/P83L fish displayed reduced Chchd10 protein expression levels, motor impairment, reduced survival and abnormal neuromuscular junctions (NMJ). These deficits were not accompanied by changes in transcripts involved in the integrated stress response (ISR), phenocopying previous findings in our knockout (chchd10−/−). Adult, 11-month old chchd10P83L/P83L zebrafish, displayed smaller slow- and fast-twitch muscle cell cross-sectional areas compared to wild type zebrafish muscle cells. Motoneurons in the spinal cord of chchd10P83L/P83L zebrafish displayed similar cross-sectional areas to that of wild type motor neurons and significantly fewer motor neurons were observed when compared to chchd2−/− adult spinal cords. Bulk RNA sequencing using whole spinal cords of 7-month old fish revealed transcriptional changes associated with neuroinflammation, apoptosis, amino acid metabolism and mt-DNA inflammatory response in our chchd10P83L/P83L model. The findings presented here, suggest that the CHCHD10P80L variant confers an ALS-like phenotype when expressed in zebrafish.

The Effect of Preoperative Carbohydrate-containing Fluid Consumption on Maternal Oxidative Stress Markers During Elective Cesarean Delivery

PurposeThe purpose of this study was to evaluate the effect of carbohydrate loading prior to the cesarean surgery under spinal anesthesia on thiols and ischemia-modified albumin (IMA) levels. DesignProspective, randomized placebo-controlled study. MethodsSeventy-nine pregnant women planned for cesarean sections under spinal anesthesia at Karaman Training and Research Hospital were randomized into a control group (group C) (n = 42), and an oral carbohydrate preloading group (group OCH) (n = 37). OCH loading requires consuming 400 mL the night before surgery and 200 mL up to 2 hours before anesthesia. Group OCH consumed an oral carbohydrate-rich beverage (Nutricia-Fantomalt), and group C consumed an equal volume of water. This study investigated thiol-disulfide homeostasis after preoperative carbohydrate consumption. Preoperative gastric fluid, volume, antral cross-sectional area, hypotension following the birth, and fetal blood gas parameters were compared across groups. FindingsThiols and IMA levels did not differ across groups before and after surgery (P > .05). Gastric ultrasonography showed similar antral cross-sectional area and stomach volume between groups (P = .172, P = .128, respectively). When surgery caused hypotension, group OCH received more ephedrine for surgery-induced hypotension, although this difference is not statistically significant (P = .704). A clustered error bar (95% confidence interval) plot with an interpolation line was used for a time-based comparison of mean differences in heart rate and mean arterial pressure between the groups. ConclusionsThis study supports that mothers' thiols and IMA levels were unaffected by preoperative OCH loading before cesarean surgery. We did not examine thiol and its derivatives in umbilical cord blood; hence, we can not comment on thiol/disulfide homeostasis levels in neonates.

Attrition and morphological analysis of CaCO3 corresponding to oxy-fuel circulating fluidized bed conditions

The specific surface area of CaCO3 has always been an essential parameter for various oxy-fuel combustion processes and chemical looping processes. However, the circulating of bed material through the furnace, cyclone and loop-seal in an oxy-fuel circulating fluidized bed (CFB) reactor may trigger the particle size changes as a result of rapid collisions among particles and friction with the inner refractory wall. Rather than considering only the effect of initial particle size, it is significantly important to emphasize on the change in limestone particle size due to in-reactor attrition. In addition, the changes are further enhanced with calcination reaction that occurred under high-temperature conditions. Herein an investigative account of limestone in a lab-scale CFB process was presented by using two types of fluidizing media (Air, CO2) to determine its attrition and morphological changes under simulated operating conditions for riser and loop-seal. A significant difference in attrition index was observed as calcination of limestone occurred at high temperature under air atmosphere which was not observed under CO2 condition. With similar cross-sectional area observed for both the tested (CO2 condition) and re-carbonated limestone, it was concluded that re-carbonation of calcined lime at high CO2 concentration in the loop-seal resulted in a comparable abrasion resistance that further improved desulfurization performance by reducing the amount of ultra-fine particles generated from limestone.

Wave blocking performance of the symmetrical double-wing floating breakwater

In this paper, a double-wing floating breakwater (DWFB) is proposed, that is, the wing with a curved upper surface and flat lower surface is installed on both sides of the box-type floating breakwater (FB). The analytical model of the DWFB under wave action is established to solve the wave diffraction problem. The modified mild slope equation (MMSE) is used to deal with the unsteady water depth problem above the wing, and the reflection coefficient, transmission coefficient, and the wave excitation force in the surge, heave, and pitch are obtained. After the analytical model is verified, the effect of the wing shape and wing size (height and length) on the wave blocking performance of the DWFB is analyzed, and then the single-wing FB and DWFB are compared. The results show that the increase in wing length is obvious to reduce the transmission coefficient. The single-wing floating breakwater (SWFB) with a longer wing length but similar cross-sectional area to the DWFB has a smaller transmission coefficient when the wave number is between 0.45 and 0.85. However, as the wave number continues to increase, the wave blocking performance of the DWFB is relatively better.

PIEZO1 gain-of-function gene variant is associated with elevated tendon stiffness in humans.

Prolonged periods of increased physical demands can elicit anabolic tendon adaptations that increase stiffness and mechanical resilience or conversely can lead to pathological processes that deteriorate tendon structural quality with ensuing pain and potential rupture. Although the mechanisms by which tendon mechanical loads regulate tissue adaptation are largely unknown, the ion channel PIEZO1 has been implicated in tendon mechanotransduction, with human carriers of the PIEZO1 gain-of-function variant E756del displaying improved dynamic vertical jump performance compared to noncarriers. Here, we sought to examine whether increased tendon stiffness in humans could explain this increased performance. We assessed tendon morphological and mechanical properties with ultrasound-based techniques in 77 participants of Middle- and West-African descent, and we measured their vertical jumping performance to assess potential functional consequences in the context of high tendon strain-rate loading. Carrying the E756del gene variant (n = 30) was associated with 46.3 ± 68.3% (p = 0.002) and 45.6 ± 69.2% (p < 0.001) higher patellar tendon stiffness and Young's modulus compared to non-carrying controls, respectively. While these tissue level measures strongly corroborate the initial postulate that PIEZO1 plays an integral part in regulating tendon material properties and stiffness in humans, we found no detectable correlation between tendon stiffness and jumping performance in the tested population that comprised individuals of highly diverse physical fitness level, dexterity, and jumping ability.

Bed inventory balance and stability of dual circulating fluidized bed systems

Experiments and modelling are conducted for general understanding on the imbalance phenomenon and for discussion on the strategies to improve the bed inventory balance and stability of a dual circulating fluidized bed (DCFB) system. The experiments are carried out in a 15.5 m high pilot-scale DCFB cold test system. A fluid-dynamic DCFB model is developed based on a 1.5-dimensional semi-empirical model of an industrial CFB boiler, validated by experimental data. The effects of control methods and operation conditions on the bed inventory balance and on the stability of the pilot- and large-scale DCFB systems are discussed. A “stable-unbalanced” state, where the system reaches a steady state, consisting of unbalanced bed inventories, is observed in both experiments and model simulation. To maintain a balanced state and similar bed inventory in the DCFB systems with similar cross-sectional areas, it is recommended to keep similar total pressure drops or gas velocities in both reactors.

A biomechanical comparison of a novel two-loop suture technique and two sutures for laryngoplasty in the horse.

Evaluation of the strength of the novel suture technique by comparison with a 2-interrupted suture technique. 40 equine larynges. 40 larynges were used; 16 laryngoplasties were performed using the currently accepted 2-suture technique and 16 using the novel suture technique. These specimens were subjected to a single cycle to failure. Eight specimens were used to compare the rima glottidis area achieved with 2 different techniques. The mean force to failure, as well as the rima glottidis area of both constructs, were not significantly different. The cricoid width did not have a significant effect on the force to failure. Our results suggest that both constructs are equally strong and can achieve a similar cross-sectional area of the rima glottidis. Laryngoplasty ("tie-back") is currently the treatment of choice for horses with exercise intolerance due to recurrent laryngeal neuropathy. Failure to maintain the expected degree of arytenoid abduction post-surgery occurs in some horses. We believe this novel 2-loop pulley load-sharing suture technique can help achieve and, more importantly, maintain the desired degree of abduction during surgery.

Molecular and Morphological Characteristics of the De-Obstructed Rat Urinary Bladder-An Update.

Many patients with outlet obstruction secondary to prostatic enlargement have lower urinary tract symptoms (LUTSs) and an increased frequency of micturition. The standard treatment is transurethral resection of the prostate (TURP), which alleviates obstruction and symptoms. However, after TURP, 20–40 percent of patients continue to experience LUTSs. The aim of the present study in rats was to identify the mechanisms that do not normalize after the removal of the obstruction and that could explain the persisting symptoms. We had microarray data from control, obstructed, and de-obstructed female rat bladders, which made it possible to study 14,553 mRNA expressions. We also had a bank of electron micrographs from similar detrusors. Microarrays: There were significant differences between the control and obstructed bladders for 1111 mRNAs. The obstructed and de-obstructed bladders differed significantly for 1059 mRNAs. The controls and the de-obstructed bladders differed significantly for 798 mRNAs. We observed many mRNAs that were increased in the obstructed bladder and then decreased to control levels after de-obstruction, and many mRNAs that were decreased in the obstructed bladder and then increased following de-obstruction. mRNAs that were significantly higher or lower in the de-obstructed bladder than in the control bladder were also found. Ultrastructure: The detrusor cells in the obstructed bladders had cross-sectional areas that were much larger than those in the controls. The control cells had smooth outlines and similar cross-sectional areas. The de-obstructed detrusor cells had larger cross-sectional areas than the controls, as well as corrugated surfaces. The cell areas varied, suggesting that the shrinkage of the de-obstructed cells was not even. We did not find any points of contact of the gap junction plaque type between the detrusor cells. There were abundant finger-like processes between the detrusor cells in the obstructed and in de-obstructed bladders, which were only occasionally found in the control detrusors. They are the only possible localization for gap junction channels. The de-obstructed rat bladder is not an organ with properties intermediate between those of the control and obstructed bladders. Instead, de-obstructed bladders have gene expressions, morphologies, and functional properties of the individual cells and their organization, which make them distinctly different from both control and obstructed bladders.

Chronic Excessive Fructose Intake Maximizes Brown Adipocyte Whitening but Causes Similar White Adipocyte Hypertrophy Than a High-Fat Diet in C57BL/6 Mice

Objective: This study aimed to evaluate the differential role of a high-fat diet (HF) or high-fructose diet (HFRU) on white adipose tissue and brown adipose tissue remodeling in C57BL/6 mice.Methods: The animals were randomly assigned to receive HF (50% of energy as lipids), HFRU (50% of energy as fructose), or a control diet (C, 10% of energy as lipids) for 12 weeks. Results: The HF group became overweight from the 7th week onwards, but both HF and HFRU groups showed hyperinsulinemia, oral glucose intolerance, and adverse adipose tissue remodeling. HF and HFRU groups showed interscapular brown adipose tissue whitening, tough the reduced QA [nuclei] suggested maximized brown adipocyte dysfunction due to the HFRU diet. In contrast, HF and HFRU diets exerted similar effects upon subcutaneous white adipocytes, with a similar average cross-sectional area. Immunohistochemistry confirmed the whitening enhancement with reduced UCP1 immunodensity in the HFRU group. Conclusion: In conclusion, HF and HFRU diets had indistinguishable effects upon white adipocyte morphology, but the HFRU diet provoked a more pronounced whitening than the HF diet after a 12-week protocol. These results point to the silent and harmful impact that excessive fructose has upon the metabolism of lean mice.

Measurement and Analysis of Power Losses in Sintered Cores for Power Electronic Devices in Renewable Energy Systems

Abstract Measurement of power losses in inductive devices in highly efficient power electronic systems is crucial for choosing appropriate components. A calorimetric method for measuring power losses below 10 W is presented in the following paper to decompose the inductive devices’ power losses. A fully enclosed double-jacked calorimetric chamber is constructed to measure the temperature with digital temperature sensors TMP275, providing a resolution of 0.1 W/K. The finite element method is used with analytical calculation to estimate core and conduction losses to decompose power losses. Power losses are measured for an inductor with a 3C95 ferrite core and four types of windings, where three were made of wire with a different number of strands, whereas the fourth has been made using copper foil. All windings have similar cross-sectional areas for comparison.

ANALYTICAL STUDY OF FLEXURAL BEHAVIOR OF COLD FORMED STEEL SECTIONS WITH AND WITHOUT PERFORATION

This work is about the investigation of flexural behavior cold formed steel member of different cross sections with and without perforation under similar cross sectional area. This work gives idea about the performance of different sections under same loading condition among selected sections and highlights the increasing the flexural strength of member by using stiffener arrangement. In this work three different cross sectional shapes are selected which are C – section, Z – section and Hat shaped section of same cross sectional area analyzed with and without lip under same loading and end condition as well as with perforation. The selected specimens were analyzed analytically using ANSYS Workbench software which shown better comparison among analyzed different geometries of members. Effectiveness of providing edge stiffener to different perforated sections also determined in this work.

Strength Training Reduces Fat Accumulation and Improves Blood Lipid Profile Even in the Absence of Skeletal Muscle Hypertrophy in High-Fat Diet-Induced Obese Condition

The aim was to investigate the effect of strength training on skeletal muscle morphology and metabolic adaptations in obese rats fed with unsaturated high-fat diet (HFD). The hypothesis was that strength training induces positive metabolic adaptations in obese rats despite impaired muscle hypertrophy. Male Wistar rats (n = 58) were randomized into two groups and fed a standard diet or a high-fat diet (HFD) containing 49.2% of fat. After induction and maintenance to obesity, the rats were divided into four groups: animals distributed in sedentary control (CS), control submitted to strength training protocol (CT), obese sedentary (ObS), and obese submitted to strength training protocol (ObT). The exercise protocol consisted of 10 weeks of training on a vertical ladder (three times a week) with a load attached to the animal’s tail. At the end of 10 weeks, strength training promoted positive changes in the body composition and metabolic parameters in obese animals. Specifically, ObT animals presented a reduction of 22.6% and 14.3% in body fat and adiposity index when compared to ObS, respectively. Furthermore, these rats had lower levels of triglycerides (ObT = 23.1 ± 9.5 vs. ObS = 30.4 ± 6.9 mg/dL) and leptin (ObT = 13.2 ± 7.2 vs. ObS = 20.5 ± 4.3 ng/mL). Training (ObT and CT) induced a greater strength gain when compared with the respective control groups. In addition, the weight of the flexor hallucis longus (FHL) muscle was higher in the ObT group than in the CT group, representing an increase of 26.1%. However, training did not promote hypertrophy as observed by a similar cross-sectional area of the FHL and plantar muscles. Based on these results, high-intensity strength training promoted an improvement of body composition and metabolic profile in obese rats that were fed a high-fat diet without skeletal muscle adaptations, becoming a relevant complementary strategy for the treatment of obesity.

Broadband infrared and THz transmitting silicon core optical fiber

Silicon waveguide structures are a viable alternative for the transmission of signals over a wide range of frequencies, and new fabrication methods are key to increased applications. In this work, THz transparency of silicon-core, silica clad fibers, refined using a traveling solvent method, is demonstrated. The ≈ 200 µm core of these fibers is shown to have good transmission from 4.8–9 µm and 1–7 THz. Fibers were drawn on a conventional optical fiber tower using the scalable molten core technique and CO2 laser annealed, resulting in large-grain crystalline cores with broadband transmission. The spectral properties are comparable to those of rectangular guides of similar cross-sectional area cut from high resistivity float zone silicon wafers.

A/J pelių linijoje esanti 10 chromosoma neveikia C57BL/J pelių raumenų savybių. Pelių modelis žmonių metabolizmo ir senėjimo tyrimuose

Tyrimo pagrindimas. Raumenų masė yra vienas iš esminių rodiklių, kurie paveikia atsigavimą po sunkios ligos ar traumos. Maža raumenų masė susijusi su didesne ligonių, sergančių vainikinių arterijų ligomis, mirštamumo rizika (Nichols et al., 2019. Sarkopenijos paplitimas tarp senyvo amžiaus žmonių apima nuo 7 iki 50% populiacijos (Bijlsma et al., 2013). Dėl savo filogenetinio panašumo pelės ilgą laiką tarnavo kaip žmogaus biologijos modeliai, įskaitant genetinių raumenų masę lemiančius veiksnius (Morse, 2007). Mūsų tikslas buvo ištirti, ar A/J pelių linijos 10 chromosomoje esantys genų variantai veikia C57BL/6J pelių linijos raumenų Metodai. Ištyrėme C57BL / 6J (B6, n = 11) ir C57BL/6J-Chr10A/J/NaJ (B6.A10, n = 10) pelių linijas. B6.A10 linija turi B6 linijos genetinį foną, tačiau skiriasi 10 chromosoma, kuri yra iš A/J linijos, vietoj 10 chromosomos – iš B6 linijos. Buvo įvertinta kūno masė, plekšninio raumens masė ir morfometrinės savybės, blauzdikaulio Rezultatai. Plekšninio raumens masė nesiskyrė tarp B6 ir B6.A10 linijų (9.3 ± 0.7 mg ir 9.8 ± 0.4 mg atitinkamai, p &gt; 0.05). Taip pat nenustatėme skirtumo tarp raumeninių skaidulų kiekio (860 ± 148 ir 913 ± 136, atitinkamai B6 ir B6.A10 linijų, p &gt; 0.05). B6 ir B6.A10 pelės turėjo vienodą raumeninių skaidulų skerspjūvio plotą: I tipo skaidulų (1616 µm² ± 303 ir 1752µm² ± 136, B6 ir B6.A10 linijos atitinkamai, p &gt; 0.05) ir II tipo skaidulų (1689 µm² ± 291 ir 1734µm² ± 179, B6 ir B6.A10 linijos atitinkamai, p &gt; Išvada. 10 chromosoma, esanti B6.A10 pelių linijoje neturi jokių genų, kurie gali paveikti B6 linijos pelių raumenų savybes.Raktažodžiai: raumenų masė, skerspjūvio plotas, raumeninės skaidulos.

Gas sensing properties of silicon nanowires with different cross-sectional shapes toward ammonia: a first-principles study

Nanostructure-based sensors working based on the adsorption-desorption mechanism received much attention in a wide variety of applications as a way to achieve both ultrasensitive sensing and small dimensions. In this paper, the adsorption of ammonia molecule on silicon nanowire surface with square, circular, and triangular cross-sectional shapes, which has almost similar cross-sectional area (1.2 nm2), is studied. The effects of various adsorption configurations are considered on the sensing properties, utilizing first-principles ab initio density functional theory calculations. Structural properties such as bond lengths and bond angles are obtained along with electronic properties such as band structure, charge transfer, and projected density of states for several adsorption configurations. The most stable and most sensitive structure is calculated to be the triangular nanowire considering formation enthalpy as a stability factor. For this nanowire, adsorption energy, covalent bond length, and charge transfer between ammonia and nanowire are calculated to be 1.296 eV, 3.124 A, and 0.227 |e|, respectively. We also consider nanowires with fully hydrogen-passivated surface and nanowires with a dangling bond. It has been shown that nanowires with a dangling bond are more sensitive toward ammonia than fully passivated nanowires.

Abnormal Cortical and Trabecular Bone in Youth With Type 1 Diabetes and Celiac Disease

This study compared bone health in youth with type 1 diabetes and celiac disease (CD) versus type 1 diabetes alone. This was a case-control study of 42 youth with coexisting type 1 diabetes and CD and 40 with type 1 diabetes matched for age, sex, diabetes duration, and HbA1c. Bone mineral density (BMD), bone mineral content (BMC), and BMC-to-lean tissue mass (LTM) ratio were measured using DXA and reported as z-scores for height. Total, trabecular, and cortical bone and muscle parameters were measured using peripheral quantitative computed tomography (pQCT) and reported as z-scores for age. Mean age at assessment was 14.3 ± 3.1 years; diabetes duration, 8.0 ± 3.5 years; HbA1c, 8.2 ± 1.5% (66 ± 5 mmol/mol); and 25-hydroxy vitamin D, 71 ± 21 nmol/L. Comparing youth with coexisting CD versus type 1 diabetes alone, DXA showed lower BMC-to-LTM ratio (0.37 ± 1.12 vs. 0.73 ± 2.23, P = 0.007) but no difference in total BMD. Youth with coexisting CD also had lower BMC-to-LTM ratio versus the general population (P = 0.04). Radial pQCT showed lower total BMC (-0.92 ± 1.40 vs. -0.26 ± 1.23, P = 0.03) despite similar bone and muscle cross-sectional area. In multivariable linear regression, lower BMC was associated with higher insulin dose (P = 0.03) but not HbA1c. Youth with both type 1 diabetes and CD have lower BMC relative to LTM and lower BMC, indicating abnormal trabecular and cortical bone development despite similar bone and muscle size. These findings suggest that the two conditions confer a lower bone turnover state. We recommend further examination of bone health in this population; future research should examine early interventions to improve bone health.

Method of determining the relaxation force of fish

There have been repeated cases of fish sales during the spawning period in the Ukrainian market, which consumer value is much lower, and fish re-freezing products. The aforementioned methods of abuse can be identified by commodity experts, while ordinary consumers, unfortunately, often cannot independently determine the quality of the fish. The basis of the vast majority of sensory checks of the elastic properties of fish is the process of compressing the product. The advantage of determining the surface relaxation rate is that it is non-destructive testing and the product appearance of the product after the examination does not change. However, this method requires some practical experience and depends essentially on the qualifications of an expert. The method and equipment for instrumental assessment of relaxation compression deformation force to define structural and mechanical properties of fish is given; it makes possible to minimize the experimenter influence on the results and obtain a quantitative value of relaxation speed at anytime in the experiment. The method of investigation of relaxation force and the rate of fish carcasses relaxation was theoretically grounded. A 3D-diagram of force that act on the indenter while pressing the surface of white cupid carcass is given. The type of dynamometer and measuring device for fixation of relaxation force dynamics is grounded. There was developed the sensor for determining the dynamics of the relaxation force with a constant depth of lowering of the indenter; scheme and photo of it is given. The mathematical models of relaxation velocity at axial deformation of compression and tension were constructed. The proposed method for quantifying the relaxation rate involves the construction of a compression deformation curve in the second of pressing a fish carcass and determining their angle of inclination. Based on the mathematical analysis of the deformation curves, it was found that for chilled meat of white cupid for 8 hours of storage, the relaxation rate at strain by 33% is greater than for the compression deformation; the primary force upon pressing on the product is 23% greater than when the specimen is subjected to a similar cross-sectional area. The developed methodology and system allows to determine the relaxation force when squeezing a fish sample just like a commodity science expert does and make quantitative assessment of its structural and mechanical properties.

Biomechanics of the jaw of the durophagous bonnethead shark

Durophagy in chondrichthyan fishes is thought to entail a set of morphological characteristics, such as hypertrophied adductor muscles, molariform teeth, and high bite forces. However, these characteristics are not common to all durophagous chondrichthyans. In some durophagous chondrichthyans, the jaws are better suited biomechanically to resist bending in the area where prey is processed. Resistance to bending is in part, quantified by second moment of area (I), which uses the neutral axis of an object to analyze the arrangement of material. This study investigated whether the lower jaw of the bonnethead shark, Sphyrna tiburo, is more resistant to bending under the crushing/molariform teeth compared to the grasping teeth. Using computerized tomography (CT) scanning, the jaws of ten bonnethead sharks were visualized, then digitally resliced at identical positions along the jaw for all specimens. I increased along the lower jaw from anterior to posterior as the teeth transform from grasping to crushing, with the largest absolute increase occurring about the transition from grasping to crushing teeth. When the lower jaw is compared to that of a rod of similar cross-sectional area, the shape exceeds that of a rod by 1.6 to 5.7 times, meaning the shape of the jaw is better suited to resist bending than if the same size jaw was shaped as a solid rod. These results suggest the lower jaw of S. tiburo is adapted to resist bending more under the molariform teeth where crushing occurs than at the anterior grasping teeth.