Search

As a persistent pollutant, microplastics (MPs) have been reported to induce sperm quantity decrease in mice. However, the related mechanism remains obscure. Therefore, this study is intended to explore the effects of polystyrene microplastics (PS-MPs) on male reproduction and its related mechanism of blood-testis barrier (BTB) impairment. Thirty-two adult male Wistar rats were divided randomly into four groups fed with PS-MPs for 90 days at doses of 0 mg/day (control group), 0.015 mg/day, 0.15 mg/day, and 1.5 mg/day, respectively. The present results have shown that PS-MP exposure led to the damage of seminiferous tubule, resulted in apoptosis of spermatogenic cells, and decreased the motility and concentration of sperm, while the abnormality of sperm was elevated. Meanwhile, PS-MPs could induce oxidative stress and activate the p38 MAPK pathway and thus deplete the nuclear factor erythroid-2 related factor 2 (Nrf2). Noteworthily, PS-MPs led to the BTB-related protein expression decrease. All these results demonstrated that PS-MP exposure may lead to the destruction of BTB integrity and the apoptosis of spermatogenic cells through the activation of the MAPK-Nrf2 pathway. The current study provided novelty evidence for elucidating the effects of PS-MPs on male reproductive toxicity and its potential mechanism.

Graphene oxide (GO) or reduced-GO offer excellent mechanical, electrical and chemical properties. Their nanocomposites have been increasingly explored for attractive applications in diverse fields. However, due to the flexible feature and weak interlayer interactions of GO sheets, flexural mechanical properties of GO-based composites especially for the bulk materials are largely restrained, which would hinder their use in real situations. Here inspired by amorphous/crystalline heterophase features within nacreous platelets, we construct a centimetre-sized GO-based bulk, the building blocks of which consist of crystalline GO and amorphous/crystalline MnO2 phases adhered by polymer-based crosslinkers. The GO/MnO2 heterophase layers are stacked and hot-pressed with further crosslinking between the layers to form bulk artificial nacre. The resultant GO/MnO2-based layered (GML) bulk exhibits the highest flexural strength (up to 203.4 MPa) among all of GO-based bulk materials. Moreover, an excellent fracture toughness, a strong impact resistance and light weight are also achieved. Mechanical and simulation analyses corroborate that the highly ordered heterophase structure together with complex crosslinking interactions across multiscale interfaces, lead to superior mechanical properties. We expect that these results provide interesting insights into the design of structural materials and allow the use of high-performance GO-based bulks in engineering and military applications.

Graphene oxide (GO) and reduced GO possess robust mechanical, electrical and chemical properties. Their nanocomposites have been extensively explored for applications in diverse fields. However, due to the high flexibility and weak interlayer interactions of GO nanosheets, the flexural mechanical properties of GO-based composites, especially in bulk materials, are largely constrained, which hinders their performance in practical applications. Here, inspired by the amorphous/crystalline feature of the heterophase within nacreous platelets, we present a centimetre-sized, GO-based bulk material consisting of building blocks of GO and amorphous/crystalline leaf-like MnO

Progress toward developing metal implants as permanent hard-tissue substitutes requires both osteointegration to achieve load-bearing support, and energy-dissipation to prevent overload-induced bone resorption. However, in existing implants these two properties can only be achieved separately. Optimized by natural evolution, tooth-periodontal-ligaments with fiber-bundle structures can efficiently orchestrate load-bearing and energy dissipation, which make tooth-bone complexes survive extremely high occlusion loads (>300 N) for prolonged lifetimes. Here, a bioinspired peri-implant ligament with simultaneously enhanced osteointegration and energy-dissipation is presented, which is based on the periodontium-mimetic architecture of a polymer-infiltrated, amorphous, titania nanotube array. The artificial ligament not only provides exceptional osteoinductivity owing to its nanotopography and beneficial ingredients, but also produces periodontium-similar energy dissipation due to the complexity of the force transmission modes and interface sliding. The ligament increases bone-implant contact by more than 18% and simultaneously reduces the effective stress transfer from implant to peri-implant bone by ≈30% as compared to titanium implants, which as far as is known has not previously been achieved. It is anticipated that the concept of an artificial ligament will open new possibilities for developing high-performance implanted materials with increased lifespans.

Microplastics (MPs) considered as a new persistent environmental pollutant could enter into the circulatory system and result in decrease of sperm quantity and quality in mice. However, the effects of Polystyrene MPs (PS MPs) on the ovary and its mechanism in rats remained unclear. In this present study, thirty-two healthy female Wistar rats were exposed to different concentrations of 0.5 µm PS MPs dispersed in deionized water for 90 days. Using hematoxylin-eosin (HE) staining, the number of growing follicles was decreased compared to the control group. In addition, the activity of glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD) were decreased while the expression level of malondialdehyde (MDA) was increased in ovary tissue. Confirmed by immunohistochemistry, the integrated optical density of NLRP3 and Cleaved-Caspase-1 had been elevated by 13.9 and 14 in granulosa cells in the 1.5 mg/kg/d group. Furthermore, compared to the control group, the level of AMH had been decreased by 23.3 pg/ml while IL-1β and IL-18 had been increased by 32 and 18.5 pg/ml in the 1.5 mg/kg/d group using the enzyme-linked immune sorbent assay (ELISA). Besides, the apoptosis of granulosa cells was elevated measured by terminal deoxyribonucleotide transferase-mediated nick end labeling (TUNEL) staining and flow cytometry. Moreover, western blot assays showed that the expressions of NLRP3/Caspase-1 signaling pathway related factors and Cleaved-Caspase-3 were increased. These results demonstrated that PS MPs could induce pyroptosis and apoptosis of ovarian granulosa cells via the NLRP3/Caspase-1 signaling pathway maybe triggered by oxidative stress. The present study suggested that exposure to microplastics had adverse effects on ovary and could be a potential risk factor for female infertility, which provided new insights into the toxicity of MPs on female reproduction.

As a persistent organic pollutant, microplastics (MPs) have been reported to induce sperm quantity decrease in male rats. However, the related mechanism remains obscure. Therefore, this study is intended to explore the effects of polystyrene microplastics (PS-MPs) on male reproduction and its related mechanism of blood-testis barrier (BTB) impairment. Thirty-two adult male Wistar rats were divided randomly into four groups fed with PS-MPs for 90 days at the dose of 0 mg/d (control group), 0.015 mg/d, 0.15 mg/d and 1.5 mg/d respectively. The present results have showed that PS-MPs exposure led to the damage of seminiferous tubule, resulted in apoptosis of spermatogenic cell and decreased the motility and concentration of sperm, while the abnormality of sperm was elevated. Meanwhile, PS-MPs could induce oxidative stress and activate p38 MAPK pathway and thus deplete the nuclear factor erythroid-2 related factor 2 (Nrf2). Noteworthily, the adverse effect of PS-MPs on BTB is only significant in 0.15 mg/d and 1.5 mg/d groups ,which demonstrated that high-dose PS-MPs exposure may lead to the destruction of BTB integrity and the apoptosis of spermatogenic cells through the activation of MAPK-Nrf2 pathway. The current study provided novelty evidence for elucidating the effects of PS-MPs on male reproductive toxicity and its potential mechanism.

The photocatalytic reduction of CO2 is a reaction that involves multi-electron and multi-conversion processes, and its efficiency is strongly affected by the electron transport pathways on the surface of the catalytic material. Here, Pt single-atom-anchored amorphous ZrO2 nanowires (Pt SA/ZrO2) are fabricated as an efficient photocatalyst for CO2 reduction. The co-catalyst exhibited a superior CO yielding rate (16.61 μmol g-1 h-1) and selectivity (97.6 %) outperforming counterparts and most of previously reported ZrO2-based photocatalysts. The amorphous nature endows the material with inherent abundant defects (e.g., oxygen vacancies) and Zr-O-Pt charge bridges allow rapid photoelectron transfer, jointly contributing to the enhanced CO2 reduction performance. We anticipate that design strategies based on anchoring single atoms on amorphous nano-substrates will inspire further development of advanced photocatalysts.

With the wide application of radiation in the fields of space orbit, medical treatment, food, etc., the online monitoring of the total radiation dose becomes particularly important. A method for designing a total radiation dose sensor in a high-dose environment using ordinary quartz fiber has been proposed. The energy deposition attenuation model of the cylindrical probe was established, and the energy deposition results after penetration of the copper attenuation layer with a thickness of 0.1mm-1mm were simulated using geant4, which showed a high consistency with the attenuation model. Experiments have verified that the attenuation curve caused by the induced loss of the fiber exhibits a saturation phenomenon when the attenuation thickness is 0.5mm and works in the linear section at 1mm and 1.5mm. It also shows that the model can be used to make a high-dose radiation sensing system with ordinary quartz fiber and the design provides a theoretical basis.

Increasing interest has recently been devoted to developing small, rapid, and portable electronic devices; thus, it is becoming critically important to provide matching light and flexible energy-storage systems to power them. To this end, compared with the inevitable drawbacks of being bulky, heavy, and rigid for traditional planar sandwiched structures, linear fiber-shaped lithium-ion batteries (LIB) have become increasingly important owing to their combined superiorities of miniaturization, adaptability, and weavability, the progress of which being heavily dependent on the development of new fiber-shaped electrodes. Here, we report a novel fiber battery electrode based on the most widely used LIB material, titanium oxide, which is processed into two-dimensional nanosheets and assembled into a macroscopic fiber by a scalable wet-spinning process. The titania sheets are regularly stacked and conformally hybridized in situ with reduced graphene oxide (rGO), thereby serving as efficient current collectors, which endows the novel fiber electrode with excellent integrated mechanical properties combined with superior battery performances in terms of linear densities, rate capabilities, and cyclic behaviors. The present study clearly demonstrates a new material-design paradigm toward novel fiber electrodes by assembling metal oxide nanosheets into an ordered macroscopic structure, which would represent the most-promising solution to advanced flexible energy-storage systems.

A simple, general and fast method called "electrochemical shock" is developed to prepare monolayered transition-metal dichalcogenide (TMD) QDs with an average size of 2-4 nm and an average thickness of 0.85 ± 0.5 nm with only about 10 min of ultrasonication. Just like nails hammered into a plate, the electrochemical shock with Al3+ ions and the following extraction with the help of oleic acid can disintegrate bulk TMD crystals into ultrafine TMD QDs. The fast-prepared QDs are then applied to detect highly explosive molecules such as 2,4,6-trinitrophenol (TNP) with a low detection limit of 10-6 M. Our versatile method could be broadly applicable for the fast production of ultrathin QDs of other materials with great promise for various applications.

Li–S batteries are regarded as one of the most promising energy-storage devices due to their high theoretical energy density, five times higher than that of lithium-ion batteries (2600 vs. ∼500 W h kg−1). However, the polysulfide shuttle effect is the primary challenge for future applications of Li–S batteries. Herein, a novel barrier layer material, nonstoichiometric W18O49 nanowires, is reported to alleviate the undesirable shuttle effect, thereby largely boosting the specific capacity and cyclability of Li–S batteries. Without particular cathode design, the introduction of W18O49 nanowires enables the commercially available micro-sized sulfur cathode with 70% sulfur loading to deliver a respectable initial discharge capacity of 1142 mA h g−1 and retain a specific capacity of about 809 mA h g−1 after 50 cycles, even at a current density of 0.5 A g−1. To the best of our knowledge, such a capacity fading for Li–S batteries based on high loading of commercial micro-sized sulfur has been rarely reported.

The strong interest in macroscopic graphene and/or carbon nanotube (CNT) fiber has highlighted that anisotropic nanostructured materials are ideal components for fabricating fiber assemblies. Prospectively, employing two-dimensional (2D) crystals or nanosheets of functionality-rich transition metal oxides would notably enrich the general knowledge for desirable fiber constructions and more importantly would greatly broaden the scope of functionalities. However, the fibers obtained up to now have been limited to carbon-related materials, while those made of 2D crystals of metal oxides have not been achieved, probably due to the intrinsically low mechanical stiffness of a molecular sheet of metal oxides, which is only few hundredths of that for graphene. Here, using 2D titania sheets as an illustrating example, we present the first successful fabrication of macroscopic fiber of metal oxides composed of highly aligned stacking sheets with enhanced sheet-to-sheet binding interactions. Regardless of the intrinsically weak Ti-O bond in molecular titania sheets, the optimal fiber manifested mechanical performance comparable to that documented for graphene or CNTs. This work provided important hints for devising optimized architecture in macroscopic assemblies, and the rich functionalities of titania promises fibers with limitless promise for a wealth of innovative applications.

Surface-enhanced Raman spectroscopy (SERS) represents a very powerful tool for the identification of molecular species, but unfortunately it has been essentially restricted to noble metal supports (Au, Ag and Cu). While the application of semiconductor materials as SERS substrate would enormously widen the range of uses for this technique, the detection sensitivity has been much inferior and the achievable SERS enhancement was rather limited, thereby greatly limiting the practical applications. Here we report the employment of non-stoichiometric tungsten oxide nanostructure, sea urchin-like W18O49 nanowire, as the substrate material, to magnify the substrate–analyte molecule interaction, leading to significant magnifications in Raman spectroscopic signature. The enrichment of surface oxygen vacancy could bring additional enhancements. The detection limit concentration was as low as 10−7 M and the maximum enhancement factor was 3.4 × 105, in the rank of the highest sensitivity, to our best knowledge, among semiconducting materials, even comparable to noble metals without ‘hot spots'., Surface-enhanced Raman spectroscopy is widely used for rapid and sensitive molecular detection in chemistry and biology, but typically relies on noble metals. Here the authors report a non-stoichiometric semiconducting material with defect-rich surface that displays excellent detection limits and enhancement factors.