Significant Differences In Strength Research Articles

Egg White-Based Gels with Candelilla Wax: A Study of Rheological, Mechanical, Calorimetric and Microstructural Properties

Bigels (BGs) are innovative composite systems that integrate oleogel and hydrogel structures, and are gaining increasing attention for their unique textural and functional properties in food applications. This study evaluated the rheological and mechanical properties of egg white-based bigels incorporating candelilla wax (CW) as an oleogelator. The results indicate that different egg white protein (EWP) (5–10%) concentrations and hydrogel-to-oleogel ratios (20:80 to 80:20) significantly influenced the structural and functional properties of the bigels. Compression testing revealed no significant differences in strength across the tested range; however, higher EWP concentrations enhanced the stability of the BGs. Furthermore, increased candelilla wax oleogel (CWO) content (60%) markedly improved emulsion stability, resulting in superior strength, as confirmed by dynamic light scattering. Rheological studies demonstrated shear-thinning behavior, particularly at higher hydrogel content related to the oleogel (W/O), which exhibited the highest yield stress. Microstructural investigations confirmed the presence of a continuous oleogel phase within the bigels (W/O) and revealed the formation of a complex structure. These findings suggest that a reduced hydrogel-to-oleogel ratio can be utilized across various food systems, opening new possibilities for creating customized food structures with desirable textural and functional attributes.

Assessing Strength Effort in Pre-Adolescent Girls: Insights into Effort Accuracy at Different Strength Thresholds

Objectives. This study aimed to examine the peculiarities of strength effort assessment in girls aged 10, 11, and 12 years. Specifically, it sought to understand how these age groups evaluate effort at different percentages of their maximum strength (1/3, 1/2, and 2/3). Materials and methods. The study involved 75 girls divided into three age groups: 10 years (n = 20), 11 years (n = 25), and 12 years (n = 30). Participants’ maximum hand strength was measured using a dynamometer, and their ability to assess effort at 1/3, 1/2, and 2/3 of this maximum was recorded. Results. The error of effort assessment was calculated and analyzed using paired and independent samples t-tests. Statistical significance was set at α = 0.05. The analysis revealed no significant age-related differences in hand maximum strength or strength effort assessment among the different age groups. The most accurate assessment of effort occurred at 2/3 of maximum strength for all age groups. Significant differences were found in effort assessment between 1/3 and 1/2 of maximum strength, and between 1/3 and 2/3 of maximum strength, with improvements noted as the effort percentage increased. However, no significant differences were observed between effort levels at 1/2 and 2/3 of maximum strength. Conclusions. The study indicates that the ability to assess strength effort remains stable across the age range of 10 to 12 years, with the most precise assessment occurring at 2/3 of maximum strength. The findings suggest that while overall strength assessment abilities are consistent, targeted training may enhance precision at different effort levels. This contributes to the understanding of motor function development and highlights the need for interventions to improve effort assessment skills in young girls.

Effects of primer components of silane and 10-methacryloyloxydecyl dihydrogen phosphate on resin bonding to tribochemical silica-coated highly translucent zirconia.

To assess the influence of different primer compositions-silane (S), 10-methacryloyloxydecyl dihydrogen phosphate (MDP), and the combination of silane and MDP (S + MDP)-on the bonding performance of MDP-free and MDP-containing resin cements to highly translucent zirconia. Tribochemical silica-coated zirconia plates were pretreated with one of three experimental primers, S, MDP, or S + MDP, with untreated specimens serving as controls. Subsequently, these plates were bonded to stainless-steel rods using either two MDP-free or two MDP-containing resin cements. Tensile bond strength was measured after 24h (TC0) and following thermal cycling (4-60°C for 10,000 cycles; TC10,000). Data were analyzed using a three-way analysis of variance (ANOVA), followed by one-way ANOVA and Tukey-Kramer post hoc tests (α = 0.05). X-ray photoelectron spectroscopy (XPS) assessed the elemental mass concentrations on the zirconia surfaces. For MDP-free resin cements, MDP-treated specimens exhibited significantly greater bond strengths than controls, regardless of the aging conditions. However, a significant reduction in bond strength was observed between TC0 and TC10,000 in most of the MDP-free resin cement groups, except for one S + MDP group. Conversely, for MDP-containing resin cements, the S + MDP group exhibited no statistically significant differences between aging conditions. Notably, XPS analysis detected silicon, zirconium, and aluminum on the zirconia surfaces. No significant difference in tensile bond strength was observed between aging conditions for MDP-containing resin cements bonded to tribochemical silica-coated zirconia primed with S + MDP. The combination of MDP-containing primers and resin cements demonstrated superior bonding performance to tribochemical silica-coated zirconia.

Gluing osteochondral fragments: development of a novel strategy for dual adhesive application in a preclinical model

This study proposes a novel dual adhesive approach for fixing osteochondral fractures, aiming to address the limitations of current fixation methods by incorporating both a bone adhesive (phosphoserine modified calcium phosphate cement PM-CPC) and a cartilage adhesive (methacrylated phosphoserine-containing gelatin MePGa hydrogel). The feasibility and efficacy of this approach were investigated using an ex vivo bovine knee model. Results indicate successful gluing of osteochondral cylinders with both adhesives, with no significant difference in adhesion strength between the groups (adhesion strength mean of 1211.6 kPa, SD 602.4 kPa, and mean of 1299.6 kPa, SD 850.9 kPa for groups 1 and 2 respectively). Importantly, the inclusion of the hydrogel component in the dual adhesive system aims to enhance cartilage repair potential, complementing the mechanical support provided by the bone adhesive. Each adhesive offers distinctive benefits: PM-CPC for mechanical support and bone repair, and MePGa hydrogel for cartilage repair. The study demonstrates the potential of the dual adhesive strategy for osteochondral repair, though further refinement and in vivo validation are needed.

Analysis of the relationship between upper body speed capacity and lower body strength of elite handball players specialized in winger position

Background and Study Aim. The physical demands of the winger position in elite handball require a unique combination of upper body speed and lower body strength. Therefore, identifying the optimal relationship between these two physical characteristics could improve performance for players in this role. This study aims to analyze the relationship between upper body speed capacity and lower body strength in elite handball players specializing in the winger position. Material and Methods. The study included 16 elite handball players specializing in the winger position from various teams in the National Handball League (Liga Zimbrilor). Four of these players were members of the Dinamo Bucharest team. Tests for evaluating the explosive strength of the lower limbs included the Squat Jump (SJ), Counter Movement Jump (CMJ), Counter Movement Jump with Free Arms (CMJb), and the maximum strength test (1RM) in squats. Specific technical training tests included triangular movement, a 30-meter sprint, and long-distance handball throws, focusing on speed and execution technique. Data analysis was conducted using KyPlot 6.0 software. Statistical indicators included median, standard deviation, coefficient of variation, and non-parametric Spearman correlation tests. Statistical significance was set at p < 0.05. Results. The results show no statistically significant differences in lower limb strength between high-performance handball players (HPHP) and those specialized in the winger position (PSW) across various jump and squat tests (p > 0.05). The Countermovement Jump (CMJ) test approached statistical significance (p = 0.084), while the CMJ with free arms (CMJb) and squat strength test did not show significant differences (p = 0.231 and p = 0.789, respectively). In the specific fitness tests, no significant differences were observed in the Triangle Movement test (p = 0.826), the 30-meter sprint (p = 0.404), or the handball throw test (p = 0.147). Correlation analysis indicated that squats and CMJb had positive correlations with improved performance in speed and distance tests, while CMJ showed a negative correlation with technical performance in agility tests. Conclusions. The findings suggest that lower limb strength and technical fitness are similar between elite handball players, regardless of specialization. This supports a unified training approach across player roles. However, targeted exercises like squats and CMJb may enhance specific performance aspects. These exercises improve dynamic strength and stability, which can benefit wingers' technical execution and speed.

Predictive Role of Atrial Strain, Aortic Stiffness, and Muscle-Related Factors for Maximal and Submaximal Exercise Capacity in Fontan Patients.

Fontan patients' exercise capacity and associated risks of morbidity and mortality necessitate a comprehensive study. We aim to explore maximal and submaximal exercise capacity, assessing the impact of cardiovascular and peripheral factors, including atrial strain, aortic stiffness, and muscle-related factors. Fontan patients and matched controls were examined. Clinical details were recorded, and atrial strain and aortic stiffness were measured using echocardiography. Hand grip and knee extensor strength were assessed, and muscle oxygenation was recorded. Cardiopulmonary exercise test determined exercise capacity, with peak oxygen uptake/kg (VO2/kg) and oxygen uptake efficiency slope/kg (OUES/kg) as markers for maximal and submaximal capacity, respectively. Thirty-one Fontan patients (median age = 18, range = 7-31years) and 30 controls (median age = 18, range = 7-32years) were studied. No significant differences in body composition and muscle strength were observed between Fontan patients and controls (p > 0.05). Fontan patients exhibited lower peak VO2/kg and OUES/kg (p < 0.001 for both), along with decreased atrial strain and increased aortic stiffness compared to controls (p < 0.001). Aortic pulse wave velocity (PWV), left atrial strain contractile phase (LASct), and knee extensor strength independently predicted peak VO2/kg (R2 = 0.514) and OUES/kg (R2 = 0.486) in Fontan patients; age was a predictor for peak VO2/kg. Atrial contractile strain, aortic stiffness, and knee extensor muscle strength are predictors of submaximal exercise capacity; furthermore, age, along with these variables, serves as predictors of maximal exercise capacity in Fontan patients. Evaluating hemodynamic, vascular, and muscular parameters, in conjunction with assessing both maximal and submaximal exercise capacities, is crucial for optimizing disease management in Fontan patients. Clinicaltrials.gov registration: NCT05011565.

A Study on the Compressive Behavior of Additively Manufactured AlSi10Mg Lattice Structures.

The mechanical behavior of the metallic components fabricated by additive manufacturing (AM) technologies can be influenced by adjustments in their microstructure or by using specially engineered geometries. Manipulating the topological features of the component, such as incorporating unit cells, enables the production of lighter metamaterials, such as lattice structures. This study investigates the mechanical behavior of lattice structures created from AlSi10Mg, which were produced using the laser beam powder bed fusion (LB-PBF) process. Specifically, their behavior under pure compressive loading has been numerically and experimentally investigated using ten different configurations. Experimental methods and finite element analysis (FEA) were used to investigate the behavior of body-centered cubic (BCC) lattice structures, specifically examining the effects of tapering the struts by varying their diameters at the endpoints (dend) and midpoints (dmid), as well as altering the height of the joint nodes (h). The unit cells were designed with varying parameters in such a way that dend is changed at three levels, while dmid and h are changed at two levels. Significant differences in Young's modulus, yield strength, and ultimate compressive strength between the various specimen configurations were observed both experimentally and numerically. The FEA underestimated the Young's modulus corresponding to the configurations with thinner struts in comparison to the higher values found experimentally. Conversely, the FEA overestimated the Young's modulus of those configurations with larger strut diameters with respect to the experimentally determined values. Additionally, the proposed FE method consistently underestimated the yield strength relative to the experimental values, with notable discrepancies in specific configurations.

On the Origin of Enhanced Tempering Resistance of the Laser Additively Manufactured Hot Work Tool Steel in the As-Built Condition

Abstract In laser additive manufacturing (AM) of hot work tool steels, direct tempering (DT) of the tool from as-built (AB) condition without prior conventional austenitization and quenching results in enhanced tempering resistance. To date, intercellular retained austenite (RA) decomposition, leading to a shift in secondary hardening peak temperature, and finer martensite substructure are reported to be responsible for such a behavior. In this work, authors aimed at studying the strengthening contributions by performing isothermal tempering tests for long times (up to 40 hours) at elevated temperatures (up to 650 °C) on DT and quenched and tempered (QT) specimens. The thermal softening kinetics and the microstructural evolution were evaluated with the support of computational thermodynamics. The results suggest that the main contributor to enhanced temper resistance in DT condition is the larger fraction of thermally stable and extremely fine (~ 20 nm) secondary (tempering) V(C,N) compared with QT. This could be explained by the reduction of available V and C in austenitized and quenched martensite for a later secondary V(C,N) precipitation during tempering, because of equilibrium precipitation of relatively large (up to 500 nm) vanadium-rich carbonitrides during the austenitization process. A complementary effect of the substructure refinement (i.e., martensite block width) in rapidly solidified highly supersaturated martensite was also quantified in terms of Hall–Petch strengthening mechanism. The significant effect of secondary V(C,N) was successfully validated by assessing a laser AM processed vanadium-free hot work tool steel in QT and DT condition, where no significant differences in strength and temper resistance between the two conditions were evident. Graphical Abstract

The hidden burden of atopic dermatitis in central and Eastern European countries

ABSTRACT Background Atopic dermatitis (AD) imposes a hidden burden through its negative effects on quality of life and productivity. We aim to estimate this hidden burden in adults and adolescents in Central and Eastern European (CEE) countries. Methods We created a burden of disease model to quantify AD’s hidden burden. Humanistic burden was calculated by estimating the monetary value of quality-adjusted life years (QALYs) lost, using prevalence data from the Global Burden of Disease study and gross domestic product (GDP) per capita for each country. Indirect economic burden was estimated based on productivity loss from absenteeism and presenteeism, adjusted for labor force participation and unemployment rates. Total hidden burden was determined by combining productivity losses and QALYs lost. Results QALY loss due to AD ranged from 1,832 to 58,596 annually in CEE countries, equating to 38 million to approximately 1 billion Euros per country. Productivity losses ranged from 3.6 to 148.9 million Euros annually. The total hidden burden of AD represents 0.11% to 0.43% of the GDP. Conclusions Our estimates reflect significant differences in population size, prevalence, and economic strength among CEE countries. Adjusting findings to country-specific GDP provided insights into AD’s true hidden burden, offering valuable information for decision-making.

A network analysis of voice hearing, emotional distress and subjective recovery before and after cognitive behavioural interventions.

There is a need to identify and to better understand key processes involved in voice hearing, which can inform the targeting and development of psychological interventions for distressing voices. The current study aimed to examine interrelations between the negative impact of voices, voice characteristics, emotional distress and recovery before and after cognitive behavioural interventions for voices (Coping Strategy Enhancement, guided self-help Cognitive Behavioural Therapy, Relating Therapy and Person-Based Cognitive Therapy). The sample consisted of 172 participants from the Sussex Voices Clinic who completed pre- and post-treatment assessments. The negative impact of voices, voice characteristics, emotional distress and recovery were used to estimate two networks, before and after cognitive behavioural interventions, using the graphical lasso method with the extended Bayesian information criterion. Centrality indices were also computed, and the two networks were compared on connectivity, structure and individual edge weights. Depression, anxiety and the negative impact of voices were identified as key central symptoms and acted as bridge symptoms in pre- and post-treatment networks. There were no significant differences in network structure (M = 0.155, p = .57), global strength (S = 0.188, p = .07) and centralities (C = -0.318, p = -.06) between the two networks. Our findings suggest that anxiety and depression are promising treatment targets, that can lead to reductions in voice-related distress, whereas the characteristics of voices and subjective recovery play little role in the network structure. Limitations include the lack of a control group and the lack of diversity within the sample.

Evaluating RhD Assessment By Automated Methodology: A Potential ‘Blind Spot’ For RhD Variant Identification

Abstract Background Automated blood typing platforms are ideal for blood donor centers, given their broad recognition of RhD antigen variants, resulting in products from such donors to be labeled as RhD positive. However, this ‘blind spot’ for variants may be problematic for hospital-based transfusion services, since RhD variants may require provision of RhD- RBC units and Rh immune globulin. The extent to which automated methods accurately characterize variant D antigen expression is not known. As such, the objective of our study was to assess D typing results, as well as RHD genotyping, among two automated testing platforms at our facility. Methods The study site is a single tertiary care center with analysis done from 12/2020-1/2024. At our facility, all females &amp;lt;60 years of age with RhD antigen testing results of ≤2+ agglutination (0-4+ scale) via automated methods [solid phase testing 12/20-4/22 (Neo, Immucor, Norcross, GA) and gel testing 5/22-1/24 (Erytra, Grifols, Emeryville, CA)] are assessed by a tube RhD antigen test (Grifols reagents). If tube testing confirms a ≤2+ result (0-4+ scale), molecular variant D analysis is performed (Versiti, Milwaukee, WI). Patients typed as Rh negative with anti-D antibodies, or those with inconsistent D typing, are also subjected to genetic D testing. The Wilcoxon matched pairs signed rank test was employed for comparative data (P&amp;lt; 0.05 was deemed significant). Results Amongst tested patients, 73 demonstrated ≤2+ agglutination via an automated typing method, leading to variant D genetic analysis. Of these, 71% (n=52) harbored variant D antigens. Within this subgroup, 29 (56%) subjects exhibited variants associated with potential allo-anti-D development (n=5 partial D variants; n=24 weak D variants). Notably, 4 patients with partial D and 1 with weak D demonstrated allo-anti-D antibodies. Of 23 patients with variant D who underwent automated gel testing, 20 concurrent tube testing results were available. Gel testing revealed significantly stronger agglutination compared to tube testing (p &amp;lt; 0.001). In contrast, for paired solid phase and tube testing (n=11), there was no statistically significant difference in agglutination strength (p = 0.28). Conclusion Automated testing, particularly gel-based platforms, exhibits reduced sensitivity to RhD antigen variant identification when compared to tube testing, placing subsets of patients potentially at risk for forming allo-anti-D. Implementing protocols for verification of D status could enhance the sensitivity of variant D detection for facilities that largely rely on automated methods for antigen typing.

Investigation of Fracture Strength and SEM Images of Different CAD-CAM Materials Applied to Two Different Inlay Cavities

Introduction: This study aims to determine and compare the fracture strength and failure modes of zirconia-reinforced lithium silicate glass ceramics (ZLS) and yttria-stabilized zirconia-based ceramic MOD and MO inlay restorations. Materials and Methods: Stumps representing the maxillary second premolar were prepared using HyperDent software and CAD/CAM milling units. Thirty-two epoxy resin die models were obtained, with 16 samples in each group. Subsequently, restorations were fabricated using Vita Suprinity (VITA Zahnfabrik, Bad Sackingen, Germany) and IPS e.max ZirCAD CAD/CAM (Ivoclar et all., Liechtenstein) blocks to restore the inlay cavities. The specimens were subjected to aging and then tested for fracture using a universal testing machine. The resulting fractures were classified. Data normality was assessed using the Shapiro-Wilk test, and homogeneity of variances was evaluated using the Levene test. The interaction between restorative material type and cavity surface was tested using two-way ANOVA. Results: The fracture strength of IPS e.max ZirCAD material (mean value: 723.18±57.51) is higher than that of Vita Suprinity ZLS material (689.86±113.61), but this difference is not statistically significant (F=3.46, p=0.073). The group with 3-surface cavities in the tooth material (768.00±60.60) has significantly different fracture strength compared to the group with 2-surface cavities (645.037±71.20) (F=47.18, p&lt;0.001). Conclusions: Having a 3-surface cavity may further enhance the fracture resistance of inlay restorations, and this difference is statistically significant. There is no significant difference in fracture strength among restorative materials.

Comparison of quadriceps and hamstring muscle strength ratios between dominant and non-dominant legs in Saudi under-17 and under-19 premier league football players: A cross-sectional study

Football’s global popularity is often overshadowed by frequent lower limb injuries, particularly hamstring strains, which are linked to imbalances in the strength ratio of hamstring-to-quadriceps (H/Q). Research on these factors among Saudi Premier League players, specifically in Madinah City, is limited. Our study is a cross-sectional study that assessed 42 male professional football players from Ohoud Football Club, divided into Underage 17 (UD- 17) and Under age 19 (UD-19) of age groups. The Strength of muscle for hamstrings and quadriceps, as well as the H/Q ratio, was measured using handheld dynamometers (HDD), and demographic data were analyzed using SPSSv26. Results showed that UD-19 players had significantly greater quadriceps strength on both dominants (dominant and non-dominant) sides compared to UD-17 players, with no significant differences in strength of hamstring. The ratio of hamstring to quadriceps was significantly higher in UD-17 players on the dominant side compared to UD-19 players, but statistically significant differences were not found on the non-dominant side. These results suggest that quadriceps strength develops with age and training, potentially reducing injury risk, while the strength of hamstring stabilizes earlier. Tailored training programs focusing on quadriceps strength and balanced hamstring development are recommended for improving injury prevention and performance. Future research involving larger and more diverse samples could further validate these findings and provide a deeper understanding of muscle dynamics in young football players.

The effect of specimen size on the unconfined compressive strength of cement-stabilized granular mixtures made of natural and recycled aggregates

The cement-stabilization technique is employed on natural and recycled granular materials to improve their mechanical properties. The strength of these materials is assessed by the unconfined compressive strength on laboratory compacted specimens, typically after 7 days of curing. Standards and technical specifications specify different values of specimen height and diameter and different loading modes of testing. This makes the comparison between different materials and with the acceptance limits of technical specifications difficult. The research investigates the effect of specimen size and loading mode on the unconfined compressive strength of both natural and recycled cement-stabilized granular materials. The results revealed significant differences in strength due to variations in specimen size and loading mode. As expected, an increase in specimen slenderness resulted in a decrease in compressive strength. A linear regression model was developed to quantify the effect of the experimental variables on the compressive strength of the two cement-stabilized materials.

Gender differences in the mental symptom network of high school students in Shanghai, China: a network analysis

BackgroundAdolescence is a critical period for the onset of mental health issues. In China, high school students face significant academic and social pressures, leading to high rates of mental health challenges. Gender differences in the manifestation of these symptoms have been observed, with boys and girls exhibiting distinct psychological profiles.ObjectiveThis study aims to explore the structure of psychological symptoms among Chinese high school students using network analysis, focusing on identifying core symptoms and gender differences in symptom networks. The key objectives are to: 1) identify the central psychological symptoms for boys and girls, and 2) uncover the interactions between symptoms to inform targeted interventions.MethodsA cluster sampling method was used to recruit 3,769 high school students (2,206 males and 1,563 females) in Shanghai. The Middle School Students Mental Health Scale (MSSMHS) was administered, and network analysis was conducted using the R packages bootnet and qgraph to assess symptom network edges, centrality, and network strength. Comparisons between male and female networks were made.ResultsNetwork analysis showed tightly connected symptom networks for both genders, with 43 non-zero edges for boys (sparsity 0.04) and 39 for girls (sparsity 0.13). Depression was the core symptom for boys (centrality 1.20), while anxiety was central for girls (centrality 1.46). Boys showed a stronger link between interpersonal sensitivity and depression (edge value 0.20), while girls exhibited a stronger connection between anxiety and obsessive-compulsive symptoms (edge value 0.16). Network comparison tests revealed no significant differences in overall network strength between boys (4.625) and girls (4.660), with P-values greater than 0.05 across all comparisons.ConclusionThis study highlights significant gender differences in the psychological symptom networks of Chinese high school students. Depression and anxiety emerged as core symptoms for boys and girls, respectively. These findings provide a foundation for developing gender-sensitive mental health interventions, emphasizing the need for tailored approaches based on gender-specific symptom profiles.

Determining the respiratory functions and isometric strength differences among recreational athletes and non-athletes: a cross-sectional analysis

Understanding the differences in respiratory functions and isometric strength between recreational athletes and non-athletes has a significant importance in the fields of Sports science, exercise physiology, and performance enhancement. The purpose of this study was to determine the respiratory functions and isometric strength differences among recreational athletes and non-athletes. A cross-sectional design was selected for this research with 16 recreational athletes and 16 non-athletes. Respiratory functions were assessed using spirometry tests, measuring parameters such as forced vital capacity (FVC), peak expiratory flow rate (PEFR), and forced expiratory volume in one second (FEV1). Isometric strength was measured by a handheld dynamometer for dominant and non-dominant hands. The results of the study showed a significant difference between recreational athletes and non-athletes for respiratory function parameters (FVC = t-3.00, p-.006 &amp; FEV1= t-2.221, p-.011), whereas PEFR is insignificant (t-218, p-.219). The isometric strength is also significant between recreational athletes and non-athletes (Dominant arm = t—3.039, p-.005 &amp; non-dominant arm= t-.255, p-.001). The study findings revealed significant differences in respiratory functions and isometric strength between recreational athletes and non-athletes, and there was a significant relationship between parameters. Athletes typically exhibit remarkable isometric strength due to their consistent engagement in activities designed to enhance muscle function. Future research should give priority to conducting long term studies that directly compare the effects of different sports disciplines on respiratory functions and isometric strength. Keywords: Isometric Strength, Pulmonary Functions, Forced Vital Capacity, Peak Expiratory Flow Rate, FEV1, Recreational Athletes.

Characterisation of Snakehead Fish, Channa striata (Bloch, 1793), Byproduct and Its Gelatin Properties

This study aims to identify the characteristics of skin, bones, and scales as a biomaterial byproduct of snakehead fish, Channa striata (Bloch, 1793) before and after the extraction process into gelatin, based on 36 fresh snakehead fish samples. The biomaterials were identified, including their proximate composition (by weight of protein, fat, moisture, ash) collagen, amino acids. The physicochemical properties of gelatin in terms of yield, gel strength, viscosity pH, and functional groups were determined for scales, skin and bones. Combined, these biomaterials made up about 47.74 % of the total byproduct by weight of snakehead fish that would usually be discarded. Moisture and protein content of the skin was higher than that of scales and bone (P &lt; 0.05), and fat content was higher in bone than in skin and scales (P &lt; 0.05). The lowest ash content was in skin (&lt;1 %), compared to scales and bone (P &lt; 0.05). The collagen content of scales was higher than that of skin and bone (P &lt; 0.05). Glycine and proline in the three biomaterials were nearly equal and highest in skin, scale, and bone, respectively. There were significant differences in viscosity and gel strength of the three types of gelatin (P &lt; 0.05), the highest viscosity was in skin gelatin while the best gel strength was in scale gelatin, while pH was not significantly different (P &gt; 0.05). The application of the same method and solvent can produce different properties and characteristics of gelatin, and the presence of functional groups helps determine the occurrence of changes in the secondary structure of gelatin from the three biomaterials.

Evaluation of Etching Time Effect on Shear Bond Strength of Orthodontic Brackets Bonded with Self-Adhesive Composite: An in-Vitro Study

Introduction: Precise acid etching of the tooth surface is a significant factor in the strength of the bracket bond. The current study aimed to determine the effect of different application times of acid etching on the shear bond strength of metallic orthodontic brackets under controlled laboratory conditions. Methods: Sixty intact premolar teeth were selected for this in-vitro study. The samples were divided into four groups based on the different acid etching times: 20, 25, 30, and 35 seconds. The teeth surfaces were etched with 37% phosphoric acid according to the specified times, and brackets were bonded to the enamel surface using GC Ortho connect composite. Shear bond strength values of the brackets was measured using a Universal Testing Machine. The amount of Adhesive Remnant Index was also observed using a stereomicroscope. Additionally, the surface roughness of the tooth enamel after bracket bonding was examined using SEM. The results related to shear bond strength were analyzed with one-way ANOVA statistical test and using SPSS version 16 software. The non-parametric Kruskal Wallis (Wallis-Kruskal) test was also used to check the frequency of ARI index. Results: The highest shear bond strength was observed at 25 seconds, and the lowest at 30 seconds. However, there was no significant difference in the shear bond strength of brackets was observed among the four groups (p=0.186). The highest ARI score was observed at 35 seconds, and the lowest at 20 seconds. No statistically significant difference was observed in the ARI scores in different groups. SEM images revealed that the enamel surface porosity was highest at 20 seconds. Conclusion: The results indicate that the shear bond strength and ARI at different acid etching times do not significantly differ. Therefore, orthodontic bracket bonding can be performed with less acid etching time.

Comparative strength of ligature points achieved by various surgical knot-tying techniques: an observational study using Maxon™ monofilament sutures.

Surgical knot-tying requires careful selection of the appropriate technique for optimal outcomes; however, evidence is lacking about the common ligation techniques combining square and slip knots (combination knots). This study investigates the strength of a combination knot, compared with other techniques. In this observational cohort study, we assessed the strengths of square, slip-granny, slip-reef, and combination knots using absorbable monofilament sutures, and compared them using ANOVA and a multilevel linear regression analysis. We also assessed the correlation between the number of throws and knot strength using Spearman's correlation analysis. Among 80 ligatures, ANOVA indicated significant differences in knot strength among the techniques (p < 0.01). Multilevel linear regression showed that a combination knot was stronger than a slip knot (p < 0.01) and comparable to a square knot (p = 0.0721). Secondary analysis indicated that for combination knots, five throws could achieve sufficient knot strength. Combination knots are as strong as square knots and stronger than slip knots, and thus present a reasonable option for surgical ligation.

Expected outcome for reconstructive hand surgery after spinal cord injuries related to level of injury and sex.

This retrospective, multicentre study maps grip strength and grasp ability after tendon transfer surgery in patients with tetraplegia. Data were analysed in the whole group and in subgroups stratified into the International Classification for Surgery of the Hand in Tetraplegia (ICSHT) and sex. In total, 200 arms (143 patients) had tendon transfer surgery to restore grip and pinch function, 74% were men, 42% were ICSHT group ≤3 and 58% ICSHT were group ≥4. The one-year outcome across all participants for grip strength was 5.2 kg, pinch strength 2.1 kg and a score of 108 for the Grasp and Release test. Men had significantly higher grip and pinch strength compared to women, while there was no significant difference with respect to grasp ability. ICSHT group ≥4 had significantly higher grip strength and grasp ability compared to ICSHT group ≤3, whereas no significant difference in pinch strength between ICSHT groups was seen.Level of evidence: III.