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Abstract Since its identification in the vitreous humour of the eye and laboratory biosynthesis, hyaluronic acid (HA) has been a vital component in several pharmaceutical, nutritional, medicinal, and cosmetic uses. However, little is known about its potential toxicological impacts on aquatic inhabitants. Herein, we investigated the hematological response of Clarias gariepinus to nominal doses of HA. To achieve this objective, 72 adult fish were randomly and evenly distributed into four groups: control, low-dose (0.5 mg/l HA), medium-dose (10 mg/l HA), and high-dose (100 mg/l HA) groups for two weeks each during both the exposure and recovery periods. The findings confirmed presence of anemia, neutrophilia, leucopoenia, lymphopenia, and eosinophilia at the end of exposure to HA. In addition, poikilocytosis and a variety of cytomorphological disturbances were observed. Dose-dependent histological alterations in spleen morphology were observed in the exposed groups. After HA removal from the aquarium for 2 weeks, the groups exposed to the two highest doses still exhibited a notable decline in red blood cell count, hemoglobin concentration, mean corpuscular hemoglobin concentration, and an increase in mean corpuscular volume. Additionally, there was a significant rise in neutrophils, eosinophils, cell alterations, and nuclear abnormalities percentages, along with a decrease in monocytes, coupled with a dose-dependent decrease in lymphocytes. Furthermore, only the highest dose of HA in the recovered groups continued to cause a significant increase in white blood cells. White blood cells remained lower, and the proportion of apoptotic RBCs remained higher in the high-dose group. The persistence of most of the haematological and histological disorders even after recovery period indicates a failure of physiological compensatory mechanisms to overcome the HA-associated problems or insufficient duration of recovery. Thus, these findings encourage the inclusion of this new hazardous agent in the biomonitoring program and provide a specific pattern of hematological profile in HA-challenged fish. Further experiments are highly warranted to explore other toxicological hazards of HA using dose/time window protocols.

Steel plates play a pivotal role in the construction of different types of structures used in civil engineering. According to Eurocode 3, plated structures may be designed using three different approaches: the effective width method, the reduced stress method, and the finite element analysis. For the particular case of elements under stress gradients, the effective width method utilises the local buckling coefficient of a plate to calculate the effective cross-sectional area for structural elements. Since the effective width method was developed for uniform web and flange panels, Eurocode 3 and most design codes have no specific provisions for the particular case of non-rectangular panels, stating that they may conservatively be treated as rectangular panels with larger width. With the final objective of improving design rules for tapered members, this paper presented an extensive numerical analysis to evaluate the elastic local buckling behaviour of trapezoidal plates with simply supported end conditions under stress gradients. The study identifies the relative importance of several parameters that influence the local buckling coefficient, such as the tapering ratio of the panel, normalized plate length, and stress ratio. Numerical results are used to propose approximate closed-form expressions that can be used to compute the local buckling coefficient for trapezoidal plates in a direct way. The results show that the proposed formula offers a significant improvement over current Eurocode 3 and most design codes.

Abstract Background Recently, there is increased demand for periodontal plastic surgery and development of new surgical approaches for aesthetic purposes. Gingival recession (GR) is the exposure of the root surfaces leading to esthetic problems, hypersensitivity, caries of the roots and teeth loss. Coronally advanced flap is considered a predictable treatment of GR but it needs a filler like subperiosteal connective tissue graft (CTG) which is considered as the gold standard treatment approach. The aim of the present study is to compare the clinical benefits and effectiveness of a xenogenic collagen matrix (mucoderm, botiss, dental, Berlin, Germany) to CTG for treatment of GR. Results Regarding clinical parameters, mean preoperative values for attached gingiva, probing depth, clinical attachment loss and gingival recession for group I were (1.8 ± 0.7 mm, 1.2 ± 0.3 mm, 6.6 ± 0.4 mm and 5.4 ± 0.2 mm) respectively. While mean postoperative values were (2.3 ± 0.9 mm, 1.1 ± 0.4 mm, 3.4 ± 0.5 mm and 2.7 ± 0.7 mm For group two preoperative mean values were (1.9 ± 0.3 mm, 1.1 ± 0.5 mm, 6.8 ± 0.5 mm and 5.4 ± 0.2 mm) respectively. While mean for postoperative values of attached gingiva, probing depth, clinical attachment loss and gingival recession for group tow were (2.5 ± 0.6 mm, 0.8 ± 0.3 mm, 3.7 ± 0.2 mm and 3.1 ± 0.3 mm) respectively All of the clinical parameters measured showed a significant difference between pre ad postoperative measurements while there was no significant differences between the two groups (test and control group). Regarding the patients satisfaction the percentage was greater in test group but the difference was not statistically significant. Conclusions In general, all of the parameters measured showed a significant difference between pre and postoperative measurements for each group but there is no significant difference between the two groups using (two treatment approaches. Both treatment procedures are considered efficient in increasing zone of attached gingiva and decreasing its clinical attachment loss. Mucoderm is considered as an efficient alternative to CTG for treatment of gingival recession.

This paper presents a computational model for determining the axial responses of short circular steel–reinforced concrete-filled steel tubular (SRCFST) columns. A novel confinement model is formulated for the concrete core, which is effectively confined by the external circular steel tube and the embedded steel section. The modelling scheme of the confinement is programmed using a mathematical model that utilises fibre-element discretisation of column cross-sections. The numerical predictions are verified by experimental measurements and results obtained from finite-element analysis, demonstrating the accuracy of the modelling technology. In addition, existing concrete confinement models for concrete in circular concrete-filled steel tubular columns are assessed. The new confinement model is shown to be superior in replicating the responses of SRCFST columns. The influences of the design parameters on the column's performance are numerically investigated and ranked in order of importance through a sensitivity analysis. In this study, not only is the validity of current design standards in determining the axial load capacity of SRCFST columns examined but a new design formula is also proposed. The proposed confinement model can be employed in numerical procedures for the inelastic simulation of SRCFST columns; the design formula is suitable for use in practical design. [ABSTRACT FROM AUTHOR]

This paper presents a fiber element analysis model that simulates the structural responses of square steel‐reinforced concrete‐filled steel tubular (SRCFST) short columns under concentric compression including local buckling effects. The method of effective widths is utilized to model the gradual postlocal buckling of the steel tube walls of a SRCFST column loaded axially to failure. A new confinement model is developed for the concrete based on test results, considering the confinement induced by the embedded steel section. This confinement model is incorporated into the fiber model, and its accuracy is verified by experimental results. The accuracy of various confinement models proposed for concrete‐filled steel tubular (CFST) square columns in predicting the performance of SRCFST columns is evaluated. A parametric study is performed to investigate the performance of SRCFST columns with various parameters. The applicability of the design formulas specified in current standards for CFST columns to the design of SRCFST columns is examined. A formula is proposed to predict the strength of SRCFST short columns. The developed inelastic simulation model, confinement model, and design formula are found to yield performance predictions of SRCFST columns with good accuracy. [ABSTRACT FROM AUTHOR]