Fe-Ni-based alloys as highly active and low-cost oxygen evolution reaction catalyst in alkaline media.

NiFe-based oxo-hydroxides are highly active for the oxygen evolution reaction but require complex synthesis and are poorly durable when deposited on foreign supports. Herein we demonstrate that easily processable, Earth-abundant and cheap Fe-Ni alloys spontaneously develop a highly active NiFe oxo-hydroxide surface, exsolved upon electrochemical activation. While the manufacturing process and the initial surface state of the alloys do not impact the oxygen evolution reaction performance, the growth/composition of the NiFe oxo-hydroxide surface layer depends on the alloying elements and initial atomic Fe/Ni ratio, hence driving oxygen evolution reaction activity. Whatever the initial Fe/Ni ratio of the Fe-Ni alloy (varying between 0.004 and 7.4), the best oxygen evolution reaction performance (beyond that of commercial IrO2) and durability was obtained for a surface Fe/Ni ratio between 0.2 and 0.4 and includes numerous active sites (high NiIII/NiII capacitive response) and high efficiency (high Fe/Ni ratio). This knowledge paves the way to active and durable Fe-Ni alloy oxygen-evolving electrodes for alkaline water electrolysers.

Prospective two-arm study of the testicular function in patients with COVID-19.

BACKGROUND: The COVID-19 pandemic has led the international community to conduct extensive research into potential negative effects of the disease on multiple organs and systems in the human body. One of the most discussed areas is potential of the virus to compromise the testicular function. However, the lack of prospective studies on this topic makes it impossible to draw reliable conclusions on whether the disease affects the male reproductive system and, if so, to what extent. OBJECTIVES: The current trial is aimed at investigating the effect of SARS-CoV-2 on the testicular function, hormone levels and determining the extent of impact on spermatogenesis and damage to testicular tissue. MATERIALS AND METHODS: This prospective study included healthy controls and cases of patients suffering from viral pneumonia based on chest computed tomography (CT) and a positive SARS-CoV-2 throat swab exhibited moderate symptoms (World Health Organization (WHO) classification). Epidemiological, clinical, laboratory and ultrasound data were collected. A semen analysis was performed in cases during their hospital stay and 3 months after the discharge home. We also assessed the testicles obtained during autopsies of patients who died of COVID-19 (n = 20). RESULTS: A total of 88 participants were included (44 controls and 44 cases). Blood testosterone levels were significantly decreased in 27.3% of the cases (12/44). The mean level (7.3±2.7 nmol/L) was lower than that in the healthy controls (13.5±5.2 nmol/L, p < 0.001). An increase in luteinizing hormone (LH) and follicle-stimulating hormone (FSH) was also detected compared to the healthy controls (p = 0.04 and p = 0.002). The semen analysis revealed decreased motility in COVID-19 patients (p = 0.001), and a higher number of immobile sperm (during COVID-19: 58.8% and at 3 months 47.4%, p = 0.005). All parameters returned to normal at 3 months after discharge. Direct mixed agglutination reaction (MAR) test at 3 months showed an increase of Ig A (p = 0.03). In the majority of autopsies (18/20), structural disorders of the testicular tissue, with signs of damage to germ cells were observed. DISCUSSION AND CONCLUSION: COVID-19 and its management strategies significantly affect male hormone levels and sperm quality at the onset of the disease. Postmortem examination of testicular tissue confirmed inflammation and viral infiltration of the testicles. However, in patients with moderate to severe disease, the studied parameters of the testicular function returned to normal values within 3 months.

How noninvasive treatment of uterine fibroids affects endometrial receptivity: a prospective cohort study.

OBJECTIVE: To investigate the effect of the ultrasonic energy during MRI-guided high-intensity focused ultrasound ablation (HIFU) of uterine fibroids on molecular and tissue markers of endometrial receptivity in women of reproductive age. MATERIAL AND METHODS: A prospective cohort study of 60 women of reproductive age was conducted. The main group consisted of 32 patients suffering from the symptomatic course of uterine fibroids who received treatment with HIFU ablation of uterine fibroids. The control group consisted of 28 healthy fertile women examined voluntarily. The endometrium obtained with pipelle biopsy on days 20-22 of the cycle was examined by scanning electron microscopy and immunohistochemistry before and three months after the treatment. The results were processed by the method of variation statistics using the SPSS 22.0. RESULTS: The focused ultrasound rays passing through the endometrium did not cause any change in the maturation rate or the state of intercellular contacts. At the same time, a significant increase in the frequency of asynchronous maturation of pinopodia was found to be 14.28% before HIFU versus 50.00% after HIFU; p = .021 and the number of heteromorphic secretory cells 5.88% before HIFU versus 53.33% after HIFU; p = .002 in implantation endometrium. A significant decrease in the stromal expression of CD95+bright in the endometrium to the level comparable with control values was observed after HIFU (from 70.22 ± 9.77 c/s to 48.81 ± 5.47 c/s; p < .001; the control level - 47.80 ± 2.13 c/s). The ratio and expression of steroid receptors, proliferation markers, p53-dependent apoptosis and its blockers, regulators and markers of angiogenesis, LIF and LIF-R signaling molecules in the stroma and endometrial glands did not change significantly after treatment. CONCLUSION: This study did not reveal any significant negative effects of HIFU ablation of uterine fibroids on endometrial receptivity in women of reproductive age.