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To repair the damage to the epoxy/carbon fiber laminate, a single-lap test was performed between sulfuric acid anodized aluminum plate and carbon fiber laminate to study the effect of the anodized layer on the interlaminar shear strength. Then, carbon fiber laminates were prepared by wet-laying method to simulate the damage caused by penetrating cracks, and double-sided adhesive sheets were made from 0.5mm thick 2024-T3 aluminum alloy and carbon fiber laminates to match the thickness and material of the simulated damage plate. The adhesive matrix used was E51 bisphenol-A epoxy resin with 1.5wt.% nanorubber added for modification and toughening. After double-sided patching, tensile tests were performed to investigate the effect of different materials on the tensile strength of double-sided adhesive patches. We observed SEM images of the fracture surface of the patch after tensile failure and analyzed the strengthening mechanisms of different material patches. The results show that the shear strength between the single-layer sulfuric acid anodized aluminum plate and the carbon fiber laminate is 9.792 MPa, which is 61.5% higher than the shear strength of the nonanodized aluminum plate. The tensile strength of the 2024-T3 aluminum patch specimen is 271.83 MPa, which is 48.43% and 23.97% higher than the perforated specimen without patch and the specimen with carbon fiber laminate patch, respectively, and reaches 72.56% of the undamaged carbon fiber laminate. The specimens with aluminum plate patches showed a maximum bending strength of 616.47 MPa, which increased by 70.83% compared to the 360.875 MPa of the perforated specimens. The maximum bending strength of the aluminum plate patch specimen reached 74.76% of that of the undamaged specimen. However, the maximum bending strength of the composite patch specimen is as high as 1101.9 MPa, far exceeding that of other samples. Due to the poor toughness of the sample, it cannot withstand large strains. The addition of 1.5wt.% nanorubber results in shear yield bands and induces silver grains to absorb a large amount of energy during stress deformation.

Background: An elevated DNA Fragmentation Index (DFI) has been associated with male infertility; therefore measuring the sperm nuclear DNA integrity appears to be useful in predicting the ability of spermatozoa to fertilize oocytes.

Aim: To evaluate the effect of micronutrient supplementation over DFI values in subfertile men.

Methods: This was a retrospective/comparative study that included a total of 306 subfertile males consulting the clinic from March 2011 to November 2017, who had performed the Sperm Chromatin Dispersion test (SCD) — a method used to detect DNA fragmentation — along with the initial semen analysis. Of the included population, $n=$ 146 had received two daily oral capsules of a standardized combined micronutrient compound (${\text{Profertil}}^{\text{®}}$, Lenus Pharma, Vienna, Austria) for three months plus lifestyle change (study group). Each capsule contains L-carnitine, L-arginine, coenzyme Q10, zinc, vitamin E, folic acid, glutathione and selenium. Those who did not receive the active treatment ($n=$ 160) but only engaged with lifestyle changes were considered controls. The SCD test was performed in both groups at baseline and after 3 months.

Results: For the first statistical analysis, patients with an initial mean DFI of >15% were considered ($n=$ 66 [37 were study and 29 were controls]). After 3 months, both groups displayed a significant decrease of mean DFI values. However, this decrease was more evident in the study group as compared to controls (10.54% vs. 14.48%, $\alpha =$ 0.05; $p=$ 0.013). For the second statistical approach the entire population was considered ($n=$ 306). After 3 months, only the study group displayed a significant decrease of the mean initial DFI value (10.16% to 6.49%, $p$ < 0.0001); decrease that was more evident as compared to controls (6.49% vs. 8.82%, $\alpha =$ 0.05; $p=$ 0.000020).

Conclusions: Among subfertile men with a DFI >15%, both regimes significantly decreased sperm DNA fragmentation; however, when any baseline DFI value was considered, only treatment with the active standardized micronutrient compound achieved a significant better result.