PCB126 impairs human sperm functions by affecting post-translational modifications and mitochondrial functions.

Over the past few decades, there has been a consistent decline in semen quality across the globe, with environmental pollution being identified as the primary cause. Among the various contaminants present in the environment, persistent organic pollutants (POPs) have garnered significant attention due to their high toxicity, slow degradation, bio-accumulation, and long-range migration. PCBs, which include 210 congeners, are a crucial type of POPs that are known to have harmful effects on the environment and human health. Among the various PCB congeners, 3,3',4,4',5-pentachlorobiphenyl (PCB126) is a typical environmental endocrine-disrupting chemical that is widely distributed and has been associated with several health hazards. However, the impact and mechanism of PCB126 on human sperm function has not been fully elucidated. We aimed to investigate the effects of different concentrations of PCB126 (0.01, 0.1, 1, 10 µg/mL) on sperm motility, viability, hyperactivation, and acrosome reaction after incubation for different periods (1 and 2 h), delving deeper into the molecular mechanism of human sperm dysfunction caused by PCB126. First, we investigated the link between PCB126 treatment and the occurrence of protein modifications that are critical to sperm function regulation, such as tyrosine phosphorylation and lysine glutarylation. Second, we examined the potential impact of PCB126 on different parameters related to mitochondrial function, including reactive oxygen species, malondialdehyde levels, mitochondrial membrane potential, mitochondria respiration and adenosine triphosphate generation. Our findings indicate that exposure to environmental pollutants such as PCB126 in vitro may have a negative impact on human sperm functions by interfering with post-translational modifications and mitochondrial functions.

Hexachlorocyclohexane impairs human sperm motility by affecting lysine glutarylation and mitochondrial functions.

Decreased sperm motility is a leading cause of male infertility and persistent organic pollutants are known to contribute significantly to the development of this disease. The effects of organochlorine pesticides such as hexachlorocyclohexane (HCH) on human sperm function and their mechanisms of action have received much attention, but are still not fully understood. Herein, we discovered that HCH has a concentration- and time-dependent inhibitory effect on human sperm motility in vitro. Moreover, HCH could reduce the levels of lysine glutarylation (Kglu) and glucose-6-phosphate dehydrogenase activity in sperm. Meanwhile, HCH could increase reactive oxygen species and thereby lead to mitochondrial depolarization and the down-regulation of adenosine triphosphate levels. In particular, we observed that sodium glutarate (Na-glu), the precursor of glutaryl-CoA, could alleviate the inhibitory effect of HCH on sperm Kglu levels, whereas the ROS scavenger N-acetyl-L-cysteine (NAC) had no effect. Intriguingly, both Na-glu and NAC were able to partially inhibit the HCH-induced increase in sperm ROS levels and impaired sperm motility. In conclusion, we propose that HCH inhibits sperm Kglu, leading to the disruption of mitochondrial energy metabolism, which in turn adversely affects sperm motility.

Electronic properties and transistors of the NbS2-MoS2-NbS2 NR heterostructure.

Based on density function theory and nonequilibrium Green's functions, we construct a NbS2-MoS2-NbS2 NR inplane heterostructure. The effects of channel length, width, chirality and vacancy of the heterostructure on transport properties are systematically investigated. The electron transport of the armchair-edge heterostructure device shows ballistic transport properties, while the zigzag-edge heterostructure device exhibits resonance tunneling transport properties. Further study indicates NbS2-MoS2-NbS2 field effect transistors (FETs) to be excellent ambipolar transistors. The FETs have high performances with current on/off ratio 4.7 × 105 and subthreshold swing 90 mV/decade with channel length m = 16 and width n = 6.  Increases in the channel length sharply reduce the off-state current and enhance the performance of the devices significantly.

Bandgap opening/closing of graphene antidot lattices with zigzag-edged hexagonal holes.

How to predict the bandgap size of graphene antidot lattices (GALs) is a key problem in the field of graphene-based nanoelectronics. Here, we have obtained the universal rules on bandgap opening/closing of GALs with zigzag-edged hexagonal holes (ZH-GALs), as well as the means to control the bandgap size. In the simple case that the electronic property depends on the choice of the supercell, the quantitative relationship between Eg and the density/diameter of antidots is fitted. Turning to complex structures, we reveal that the bandgap opening in ZH-GALs results mainly from the intervalley scattering. In this interpretation, according to their relative position, the antidots can be divided into three categories. A relatively large bandgap appears in ZH-GALs, only when the numbers of the three categories are unequal. This could be explained based on a mechanism similar to diffraction. A formula according to the explanation is provided to estimate the bandgap, which can be used to predict the electronic properties of GALs and guide the design of semiconductor and photoelectronic devices based on GALs.

[Construction of TDRG1 shRNA expression vector and interfering effect of TDRG1 shRNA expression vector on NTERA-2 cells].

OBJECTIVE: To construct short hairpin RNA interfering expression vector of TDRG1,and detect the specific interfering effect of TDRG1-shRNA expression vector on NTERA-2 cells. METHODS: Oligos for short hairpin RNA targefing for TDRG1 were designed and connected to the expression vector pGPU6/GFP/Neo to construct the TDRG1 shRNA expression vector. The recombinant plasmid TDRG1-shRNA486, TDRG1-shRNA738, TDRG1-shRNA921 and lipofectamine ™2000 were used to generate and transfect shRNA into NTERA-2 cells. Expression of TDRG1 mRNA was assayed by RT-PCR. RESULTS: TDRG1-shRNA expression vector was successfully constructed. TDRG1-shRNA486 was more effective in the suppression of TDRG1 with significant reduction of TDRG1 mRNA. CONCLUSION: TDRG1-shRNA can interfere the expression of TDRG1 in NTERA-2 cells.

[Effects of tadalafil on erectile dysfunction: on-demand versus once-daily dosing].

OBJECTIVE: To evaluate the effects of tadalafil administered on demand or once a day in the treatment of erectile dysfunction (ED). METHODS: We randomly assigned 61 ED patients to three groups to receive tadalafil on demand, at 5 mg once daily, and at 10 mg once daily, respectively. After 42 days of medication, we compared the therapeutic effects among different groups using the patients' sexual encounter profile (SEP) diaries, detected the adverse reactions and assessed the safety of tadalafil. RESULTS: Fifty-three (86.7%) of the patients completed the investigation, and all responded well to tadalafil medication, with a significantly improved success rate of sexual intercourse and a low rate of mild adverse effects. The mean positive rates of SEP were basically similar between the on-demand and once-daily groups. CONCLUSION: There are no significant differences in the improvement of penile erection and sexual satisfaction of ED patients treated by on-demand and once-daily administration of tadalafil.

Bandgap opening in graphene antidot lattices: the missing half.

The electronic structure of graphene antidot lattices (GALs) with zigzag hole edges was studied with first-principles calculations. It was revealed that half of the possible GAL patterns were unintentionally missed in the usual construction models used in earlier studies. With the complete models, the bandgap of the GALs was sensitive to the width W of the wall between the neighboring holes. A nonzero bandgap was opened in hexagonal GALs with even W, while the bandgap remained closed in those with odd W. Similar alternating gap opening/closing with W was also demonstrated in rhombohedral GALs. Moreover, analytical solutions of single-walled GALs were derived based on a tight-binding model to determine the location of the Dirac points and the energy dispersion, which confirmed the unique effect in GALs.