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In brief The current declining trend in male fertility parallels the increasing prevalence of obesity worldwide. This paper revealed that the poor in vitro fertilization rates and decreased sperm motility in obese mice due to excessive oxidative stress enhanced apoptosis and impaired glucose metabolism in the testes. Abstract Obesity is an urgent public health problem in recent decades, linked to reduced reproductive potential, and negatively affects the success of assisted reproduction technology. The aim of this study is to investigate the mechanisms underlying impaired male fertility caused by obesity. Male C57BL/6 mice fed a high-fat diet for 20 weeks served as mouse models with moderate (20% < body fat rate (BFR) < 30%) and severe obesity (BFR > 30%). Our results showed poor in vitro fertilization rates and decreased sperm motility in obese mice. Abnormal testicular structures were identified in male mice with moderate and severe obesity. The expression level of malondialdehyde increased with obesity severity. This finding indicates that oxidative stress plays a role in male infertility caused by obesity, which was further confirmed by the decreased expression of nuclear factor erythroid 2-related factor 2, superoxide dismutase, and glutathione peroxidases. Our study also found that the expression of cleaved caspase-3 and B-cell lymphoma-2 showed an obesity severity-dependent manner indicating that apoptosis is highly correlated with male infertility caused by obesity. Moreover, the expression of glycolysis-related proteins, including glucose transporter 8, lactate dehydrogenase A, monocarboxylate transporter 2 (MCT2), and MCT4, decreased significantly in the testes of obese male mice, suggesting energy supply for spermatogenesis is impaired by obesity. Taken together, our findings provide evidence that obesity impairs male fertility through oxidative stress, apoptosis, and blockage of energy supply in the testes and suggest that male obesity influences fertility through complex and multiple mechanisms.

Al2O3 coatings were prepared by atmospheric plasma spraying (APS) and suspension plasma spraying (SPS). The microstructure, phase composition and nano-hardness of the two coatings were tested. Meanwhile, the friction and wear performance of SPS and APS in different environments were systematically studied. The results showed that both coatings exhibited a stable friction state and low wear rate under different environments. The special fine structure and high hardness value of SPS coating made its wear resistance much higher than that of APS coating. Additionally, the wear mechanisms of the two coatings in dry sliding friction were mainly abrasive wear, fatigue wear and adhesive wear. The APS coating had slight abrasion, while the SPS coating exhibited a negative abrasion state, in the seawater environment.

Manganese dioxide nanosheets combined with cysteine-assisted emitting manganese dioxide nanospheres (Cys-MnO2 nanospheres) is fabricated for the first time as an "off-on" fluorescence detection platform for glutathione (GSH). In this sensing system, Cys-MnO2 nanospheres served as energy donors, while MnO2 nanosheets were used as both energy acceptors and recognition units. MnO2 nanosheets can effectively quench the fluorescence of Cys-MnO2 nanospheres through the fluorescence resonance energy transfer (FRET). The addition of GSH could reduce MnO2 nanosheets into Mn2+, disrupting the FRET process and restoring the fluorescence of Cys-MnO2 nanospheres. Under the optimum conditions, the "switch-on" platform we established has a wide response to GSH with a range of 5-50 μM and 150-800 μM, as well as a superior specificity. Importantly, all components of the sensor are nontoxic, biocompatible, easily prepared, and have a high utilization of raw materials. Moreover, the sensing system achieved satisfactory results in human serum, showing a tremendous potential in the field of biomedicine.

The micro-arc oxidation (MAO) coatings were prepared in four different electrolyte systems, including mixed acid, phosphate, phosphate-aluminate and phosphate-silicate electrolytes. The friction and wear properties of MAO coatings in ambient air, seawater and four groups of saline solutions related to seawater were investigated. The results showed that the addition of silicate to phosphate could increase the density of the coating. The phosphate-aluminate ceramic layer exhibited the lowest wear rate in various environments. Additionally, the friction coefficient and wear rate of MAO coating in seawater were lower than those in ambient air, which was due to the boundary lubrication effect of seawater. Meanwhile, the presence of divalent metal salts in seawater made its lubricity better than other salt solutions.

Manganese dioxide nanosheets combined with cysteine-assisted emitting manganese dioxide nanospheres (Cys-MnO

Micro-molecular drugs have special advantages to cope with challenging diseases, however their structure, physical and chemical properties, stability, and pharmacodynamics have more requirements for the way they are delivered into the body. Carrier-based drug delivery systems can circumvent many limited factors of drug delivery and increase their bioavailability. In this context, stable drug nanocarriers of alkaline amino acids (arginine, Arg) modified conjugated linoleic acid-carboxymethyl chitosan (CLA-CMCS) conjugate were developed, which could generate supramolecular micelles to effectively encapsulate the tyrosinase inhibitor phenylethyl resorcinol (PR). The resulting CCA-NPs were spherical nanoparticles with a mean size around 175 nm. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and cellular uptake investigation demonstrated that the CCA-NPs were non-cytotoxic and had excellent cell transport ability. In addition, these CCA-NPs were able to effectively deliver PR and inhibited melanin formation to reduce pigmentation by enhancing cellular uptake. In conclusion, our research indicated that nanocarriers based on self-assembly amphiphilic polymers constituted a promising and effective drug delivery system in hyperpigmentation targeting.

In this work, Co3O4 nanoparticles (NPs) with an average diameter of about 30 nm were synthesized using MOFs as a template. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) investigation showed that Co3O4 nanocrystals embedded in mesoporous graphitic carbon layer/multiwalled carbon nanotubes (MWCNTs) uniformly. The structure of the final nanocomposite (denoted as Co3O4@C-MWCNTs) was further confirmed by X-ray diffraction (XRD), Raman spectra and Brunauer-Emmett-Teller (BET) techniques. As a result, electrochemical study demonstrated that the Co3O4@C-MWCNTs modified glassy carbon electrode exhibited excellent electrochemical activity toward the reduction of O2 − with a super wide linear range from 5.00 × 10−12 to 1.00 × 10−4 M and very low detection limit (LOD) of 1.67 × 10−12 M (S/N = 3). Importantly, three kinds of stimulants were selected to monitor the flux of O2 − released from living cells. By using phorbol 12-myristate-13-acetate as optimal stimulus, the novel non-enzymatic O2 − sensor can detect O2 − release from cancer cells, which has the great potential application in clinical diagnostics to assess oxidative stress of living cells.

Aiming at of the problem of common conduction state in push-pull DC-DC converter’s power transistor, an optimization solution by improving pulse width modulation(PWM) mode and reasonable setting parameters of the transformer and the inductance was proposed. The solution was analyzed in detail and test of the optimized circuit are carried out. The results show that the optimized circuit can effectively eliminate common conduction state, make the converter have a suitable dead-time and greatly improve the reliability of the converter.

Enzyme-simulating nanomaterials, with obvious advantages of high activity, stability and cost-effectiveness, can surrogate the complex natural enzymes and catalyze enzyme-like reactions in various harsh applications. Herein, a novel fluorescent and colorimetric dual-readout sensing platform toward dopamine detection based on pyrazolate-based porphyrinic metal-organic frameworks (MOFs) by coordination regulation strategy to improve the performance of catechol oxidase mimic enzyme activity was constructed. Specifically, BA (benzoic acid) or PA (4-Formyl-1(H)-pyrazole) was introduced as auxiliary ligands to regulate the growth mode of pyrazolate-based porphyrinic MOF materials. H4TPP (5,10,15,20-Tetra(1H-pyrazol-4-yl) porphyrin) and auxiliary ligands coordinated with Cu(II), exposing Cu sites with insufficient coordination and enhancing the interaction with oxygen-active species. Benefiting from the binuclear copper center structure and the preferential adsorption of reactants in the self-reinforced interface, a highly sensitive and selective detection method for dopamine based on Cu-TPP(PA) MOF material was proposed under the intervention of H2O2. The feasibility of Cu-TPP(PA) MOF in detecting dopamine in human serum samples and as a paper-based analytical device was investigated. This achievement will expand the applications of MOFs in analytical chemistry and open up a new avenue for the design of highly active and stable nano-enzymes.

Considering the crucial roles of superoxide anion (O 2 − ) in pathological conditions, it is of great urgency to establish a reliable approach for real-time determination of O 2 − . Herein, a sensitive non-enzymatic sensor was constructed based on silver nanoparticles (AgNPs) and sodium dodecyl sulfate functionalized carbon nanotubes (SDS-MWCNTs) composites to measure the release of O 2 − from living cells. As an analytical and sensing platform, the AgNPs/SDS-MWCNTs modified glassy carbon electrode exhibited excellent electrochemical performance toward O 2 − with a determination limit as low as 0.0897 nM and wide linear range of 6 orders of magnitude, which was superior to other O 2 − electrochemical sensors. The excellent performance was attributed to the SDS-MWCNTs composites being used as effective load matrix for the deposition of AgNPs. Importantly, this novel non-enzymatic sensor could be applied to determination of O 2 − released from living cells, and the amount of flux of O 2 − increased accordingly with the improving of the concentration of AA, which has the possibility of application in clinical diagnostics to assess oxidative stress of living cells.

Using new photocathodic protection technology to protect 304 stainless steel has attracted extensive attention of corrosion researchers due to the severe resource consumption and economic loss caused by metal corrosion. However, the photocatalytic materials used for photocathodic protection still exist some defects such as high recombination rate and poor transfer efficiency of photoinduced electrons. Herein, PbS quantum dots modified TiO2 nanotubes photoelectrodes were successfully synthesized via electrochemical anodization combined with successive ion layer adsorption and reaction method. PbS(x)/TiO2 nanotubes (x = 2,4,6,8) samples were prepared by changing the deposition amounts of PbS. The results indicated that the PbS(6)/TiO2 nanotubes displayed a stronger photocurrent density of 3.2 mA cm−2 and the optical absorption red-shifted to the visible light region compared with pure TiO2. Moreover, a more negative open circuit potential was obtained when the PbS(6)/TiO2 nanotubes photoanode coupled with 304 stainless steel under visible light irradiation. The prepared composite films as a stable photoanode displayed highly effective photocathodic protection performance for 304 stainless steel.

Ionic liquid-reduced graphene oxide modified electrode (IL-rGO/GCE) was fabricated using a simple and green method, and it exhibited good electrochemical response on Sudan I. The electrochemical behavior of Sudan I was studied sufficiently, and two electrons and two protons are involved in the electrochemical process of Sudan I at IL-rGO/GCE. Some dynamic parameters such as the diffusion coefficient (D) and adsorption capacity (Г⁎) were calculated as D = 1.43 × 10− 6 cm2/s, Г⁎ = 1.97 × 10− 10 mol/cm2 by chronocoulometries. Meanwhile, supported by cyclic voltammetry experiments, the possible electrochemical reaction mechanism of Sudan I was proposed, which is E1CE2 process. Finally, the effect of initial potential and the scanning direction on the electrochemical reaction of Sudan I confirmed further the proposed electrochemical reaction mechanism. This study probably offers the possibility for preparation an excellent Sudan I sensor.

TiO2/PbS heterojunction with Au doped photoelectrode was fabricated by simple hydrothermal, Chemical bath deposition (CBD) and successive ionic layer adsorption and reaction (SILAR) methods. The photoelectrochemical (PEC) characterizations showed the TiO2/PbS heterojunction with Au doped photoanodes had better PEC performance than TiO2 and certain photoelectrocatalytic degradation ability of RhB. The photocurrent density achieved 4.753 mA/cm2 and the degradation efficiency of RhB could be degraded to 47.4%. The improvement of properties was due to the formation of heterojunction and doped element facilitated the separation and mobility of the photoinduced electrons and holes in photoanode. The photoelectrode may be a good candidate for photoelectrocatalytic degradation.

In the present study, vertically aligned single-crystalline TiO2 nanowire arrays with various lengths grown on transparent substrate have been successfully prepared using a facile hydrothermal method. They were then sensitized with a photoactive compound, 5,10,15,20-tetrakis(4-carboxylphenyl)porphyrin. The material was fully characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and ultraviolet-visible absorption spectroscopy (UV-vis). A UV-vis/scanning electrochemical microscope (SECM) platform was developed by utilizing TiO2 nanowire arrays, and the influence of wire length as well as wavelength and intensity of light on the electron transfer rate was discussed in detail through the generated probe approach curves. The results showed that the electron transfer rate at the surface of the TiO2/porphyrin composite was accelerated by increasing the length of the nanowire, probably due to more porphyrin loading and the match of the conduction band edge of TiO2 with the LUMO energy level of the porphyrin molecules, as evidenced by the DFT theoretical calculations. The maximum rate of electron transfer was reached at a wavelength of 546 nm and an illumination intensity of 90%. The efficient PET system constructed in this study will, we believe, provide useful information to help people investigate the mechanism of the charge transfer process of artificial photosynthesis.

An electrochemical sensor for simultaneous determination of 5-hydroxytryptamine (5-HT) and dopamine (DA) was developed in this paper based on an ionic liquid functionalized-graphene (IL-graphene) modified glassy carbon electrode. Transmission electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis were used to characterize the formation of the IL-graphene composites. Due to functionalization of the ionic liquid, IL-graphene can not only be dispersed well in aqueous solutions, but also exhibit a strong positive charge. Cyclic voltammetry and differential pulse voltammetry results demonstrated that 5-HT and DA can be detected selectively and sensitively at the constructed electrode with peak-to-peak separation about 164 mV. Under the optimized condition, the linear responses were obtained in the range of 2.0 × 10−7 to 1.0 × 10−5 M with a detection limit of 6.7 × 10−8 M for 5-HT, and in the range of 1.0 × 10−6 to 1.0 × 10−4 M with a detection limit of 3.3 × 10−7 M for DA (S/N = 3), respectively. Moreover, the designed sensor was further applied to the simultaneous determination 5-HT and DA levels in human serum samples with reliable recovery. The excellent performance of this sensor was ascribed to the network-like structure of IL-graphene which provided large surface area to contact 5-HT or DA.

A valid quantitative structure–activity relationship (QSAR) model was applied to predict IC50 value of pyridazinone derivatives as HCV NS5B protease inhibitors. Various chemical descriptors were calculated by E-Dragon. Six character variables were selected though stepwise multiple linear regression (stepwise-MLR), which included MATS6m, RDF055e, Mor31u, G3m, R1m and R4v +. In addition, twenty-three molecular descriptors were obtained via uninformative variable elimination by partial least squares (UVE-PLS). The selected descriptors using two approaches were basically the same type of molecular descriptors. Subsequently, partial least squares (PLS) and particle swarm optimization support vector machine (PSO-SVM) were utilized to establish the linear and nonlinear models by two set of descriptors and their activity data, respectively. The predictive performance of the proposed models was evaluated by the strict criteria. The results showed that the predictive power of the PSO-SVM models was better than the corresponding PLS models. Thus, it can be inferred that the PSO-SVM models were robust and satisfactory, and could provide some feasible and effective information to design and synthesis of highly potent HCV NS5B polymerase inhibitors.

Photoelectrochemical (PEC) water splitting, as a promising route of STH(solar to hydrogen) conversion, has attracted a lot attention recently. However, the rather high recombination and the low transfer rate of photoinduced electron-hole pairs restrict the applications. In this work, n-ZnO/p-CuS photoanodes were fabricated using hydrothermal method and successive ionic layer adsorption and reaction (SILAR) method. The PEC performance of the ZnO photoanode is significantly improved after depositing CuS. The applied bias photon-to-current efficiency (ABPE) of ZnO/CuS 10 (the cycles of SILAR) photoanode attained 0.368% at a bias of 0.984 V vs SCE which is 45 times than ZnO. The relatively high value of photocurrent density and ABPE are due to the advantages of the ordered structure of ZnO nanorods arrays and the common effect comes from the formation of heterojunction and faster transfer rate of photogenerated electrons which further facilitate charge carrier separation and the light absorption. This work represents a facile strategy using low cost CuS for PEC water splitting that can be applied in photocatalysis.

Derived from diarylamine sensitizer diphenyl-(7-pyridin-4-yl-9H-carbazol-2-yl)-amine (N13), a series of novel D[Formula: see text]A carbazole-based organic dye sensitizers with different [Formula: see text]-linkers were designed for searching more effective sensitizers in dye-sensitized solar cells (DSSCs) design. Optimized geometries, electronic structure, and other parameters, which can evaluate the performance of DSSCs effectively and intuitively, were theoretically calculated by density functional theory (DFT) and time-dependent DFT methods at the M06/6-31G(d,p) level. The results indicated that the maximum absorption wavelength of designed dye was red-shifted and the molar absorption coefficient ([Formula: see text]) became higher. This phenomenon can be explained by the modification of the [Formula: see text]-bridge. The simulated Ultraviolet–visible spectroscopy (UV-Vis) absorption spectrum showed that the designed N,N-diphenyl-7-(5-(7-(5-(pyridin-4-yl)thiophen-2-yl)benzo[c][1,2,5]thiadiazol-4-yl)thiophen-2-yl)-9H-carbazol-2-amine (N22) dye presents the largest red-shifted absorption band and the designed (E)-N,N-diphenyl-7-(2-(5[Formula: see text]-(pyridin-4-yl)-[2,2[Formula: see text]-bithiophene]-5-yl)vinyl)-9H-carbazol-2-amine (N21) dye showed the largest [Formula: see text], both of them depicted a high short-circuit photocurrent density ([Formula: see text]. Meanwhile, the charge separation hampered by long [Formula: see text]-linkers was also observed. These results are helpful for designing new sensitizers and providing effective guiding to experimental synthesis.

Electrochemiluminescence (ECL) of Ru(bpy)(3)(2+) using metabolites of catecholamines: homovanillic acid (HVA) and vanillylmandelic acid (VMA) as co-reactants were investigated in aqueous solution for the first time. When HVA and VMA were co-existent in the buffer solution containing Ru(bpy)(3)(2+), ECL peaks were observed at a potential corresponding to the oxidation of Ru(bpy)(3)(2+), and the ECL intensity was increased noticeably when the concentrations of HVA and VMA were at lower levels. The linear calibration range was from 8.0 × 10(-5) to 1.0 × 10(-9) M for HVA and VMA. The detection limit (S/N = 3) of HVA and VMA was 4.0 × 10(-10) M. The formation of the excited state Ru(bpy)(3)(2+*) was confirmed to result from the reaction between Ru(bpy)(3)(3+) and the intermediates of HVA or VMA radicals. Moreover, it was found that the ECL intensity was quenched significantly when the concentrations of HVA and VMA were relatively higher. The mechanism of self-quenching processes involved in the Ru(bpy)(3)(2+)-HVA and -VMA ECL systems are proposed in this study.

A novel electrocatalytic platform based on 5,15-bis (p-amino)-tetraphenylporphyrin (BATPP)/α-Al2O3 composites (sensitive materials) coated on glassy carbon electrodes, which was constructed by a simple electrochemical method, is reported. The directly simultaneous electrocatalytic oxidation and selective voltammetric peak separation of a mixture including ascorbic acid (AA), dopamine (DA) and uric acid (UA) in a phosphate buffer solution was investigated. The results showed that the platform resolved the overlapping voltammetric responses of AA, DA and UA with potential differences of 136 mV (AA to DA), 143 mV (DA to UA) and 279 mV (AA and UA) for cyclic voltammetry (CV). These results will open new opportunities for the development of an electrochemical sensor for the simultaneous determination of DA, UA and AA in real sample analyses in future.