Precise detection of trace level protein using MIP-MoS2 nanocomposite functionalized PCF based interferometer.

Fiber optic interferometry combined with recognizing elements has attracted intensive attention for the development of different biosensors due to its superior characteristic features. However, the immobilization of sensing elements alone is not capable of low-concentration detection due to weak interaction with the evanescent field of the sensing transducer. The utilization of different 2D materials with high absorption potential and specific surface area can enhance the intensity of the evanescent field and hence the sensitivity of the sensor. Here, a biosensor has been fabricated using an inline hetero fiber structure of photonic crystal fiber (PCF) and single-mode fiber (SMF) functionalized with a nanocomposite of molybodenum di-sulfide (MoS2) and molecular imprinting polymer (MIP) to detect trace levels of bovine serum albumin (BSA). The sensor showed a wide dynamic detection range with a high sensitivity of 2.34 × 107 pm/µg L-1. It shows working potential over a wide pH range with a subfemtomolar detection limit. The compact size, easy fabrication, stable structure, long detection range, and high sensitivity of this sensor would open a new path for the development of different biosensors for online and remote sensing applications.

A chitosan-camouflaged nanomedicine triggered by hierarchically stimuli to release drug for multimodal imaging-guided chemotherapy of breast cancer.

Breast cancer remains one of the most intractable diseases, especially the malignant form of metastasis, with which the cancer cells are hard to track and eliminate. Herein, the common known carbohydrate polymer chitosan (CS) was innovatively used as a shelter for the potent tumor-killing agent. The designed nanoparticles (NPs) not only enhance the solubility of hydrophobic paclitaxel (PTX), but also provide a "hide" effect for cytotoxic PTX in physiological condition. Moreover, coupled with the photothermal (PTT) properties of MoS2, results in a potent chemo/PTT platform. The MoS2@PTX-CS-K237 NPs have a uniform size (135 ± 17 nm), potent photothermal properties (η = 31.5 %), and environment-responsive (low pH, hypoxia) and near infrared (NIR) laser irradiation-triggered PTX release. Through a series of in vitro and in vivo experiments, the MoS2@PTX-CS-K237 showed high affinity and specificity for breast cancer cells, impressive tumor killing capacity, as well as the effective inhibitory effect of metastasis. Benefit from the unique optical properties of MoS2, this multifunctional nanomedicine also exhibited favorable thermal/PA/CT multimodality imaging effect on tumor-bearing mice. The system developed in this work represents the advanced design concept of hierarchical stimulus responsive drug release, and merits further investigation as a potential nanotheranostic platform for clinical translation.

Mo than meets the eye: genomic insights into molybdoenzyme diversity of Seleniivibrio woodruffii strain S4T.

Seleniivibrio woodruffii strain S4T is an obligate anaerobe belonging to the phylum Deferribacterota. It was isolated for its ability to respire selenate and was also found to respire arsenate. The high-quality draft genome of this bacterium is 2.9 Mbp, has a G+C content of 48%, 2762 predicted genes of which 2709 are protein-coding, and 53 RNA genes. An analysis of the genome focusing on the genes encoding for molybdenum-containing enzymes (molybdoenzymes) uncovered a remarkable number of genes encoding for members of the dimethylsulfoxide reductase family of proteins (DMSOR), including putative reductases for selenate and arsenate respiration, as well as genes for nitrogen fixation. Respiratory molybdoenzymes catalyze redox reactions that transfer electrons to a variety of substrates that can act as terminal electron acceptors for energy generation. Seleniivibrio woodruffii strain S4T also has essential genes for molybdate transporters and the biosynthesis of the molybdopterin guanine dinucleotide cofactors characteristic of the active centers of DMSORs. Phylogenetic analysis revealed candidate respiratory DMSORs spanning nine subfamilies encoded within the genome. Our analysis revealed the untapped potential of this interesting microorganism and expanded our knowledge of molybdoenzyme co-occurrence.

[Determination of 24 elements migration in Yixing clay pottery by inductively coupled plasma mass spectrometry].

OBJECTIVE: To establish an analytical method for determining the migration of 24 elements in Yixing clay pottery in 4% acetic acid simulated solution by inductively coupled plasma mass spectrometry. METHODS: Four types of Yixing clay pottery, including Yixing clay teapot, Yixing clay kettle, Yixing clay pot, and Yixing clay electric stew pot, were immersed in 4% acetic acid as a food simulant for testing. The migration amount of 24 elements in the migration solution was determined using inductively coupled plasma mass spectrometry. RESULTS: Lithium, magnesium, aluminum, iron, and barium elements with a mass concentration of 1000 µg/L; Lead, cadmium, total arsenic, chromium, nickel, copper, vanadium, manganese, antimony, tin, zinc, cobalt, molybdenum, silver, beryllium, thallium, titanium, and strontium elements within 100 µg/L there was a linear relationship within, the r value was between 0.998 739 and 0.999 989. Total mercury at 5.0 µg/L, there was a linear relationship within, the r value of 0.995 056. The detection limit of the elements measured by this method was between 0.5 and 45.0 µg/L, the recovery rate was 80.6%-108.9%, and the relative standard deviation was 1.0%-4.8%(n=6). A total of 32 samples of four types of Yixing clay pottery sold on the market, including teapots, boiling kettles, casseroles, and electric stewing pots, were tested. It was found that the migration of 16 elements, including beryllium, titanium, chromium, nickel, cobalt, zinc, silver, cadmium, antimony, total mercury, thallium, tin, copper, total arsenic, molybdenum, and lead, were lower than the quantitative limit. The element with the highest migration volume teapot was aluminum, magnesium, and barium; The kettle was aluminum and magnesium; Casserole was aluminum, magnesium, and lithium; The electric stew pot was aluminum. CONCLUSION: This method is easy to operate and has high accuracy, providing an effective and feasible detection method for the determination and evaluation of element migration in Yixing clay pottery.

Hydrangea-like TiO2/Bi2MoO6 porous nanoflowers triggering highly sensitive electrochemical immunosensing to tumor marker.

Rapid and sensitive detection of carcinoembryonic antigen (CEA) is of great significance for cancer patients. Here, molybdenum (Mo) was doped into bismuth oxide (Bi2O3) by one-pot hydrothermal method forming porous tremella Bi2MoO6 nanocomposites with a larger specific surface area than the spherical structure. Then, a new kind of hydrangea-like TiO2/Bi2MoO6 porous nanoflowers (NFs) was prepared by doping titanium into Bi2MoO6, where titanium dioxide (TiO2) grew in situ on the surface of Bi2MoO6 nanoparticles (NPs). The hydrangea-like structure provides larger specific surface area, higher electron transfer ability and biocompatibility as well as more active sites conducive to the attachment of anti-carcinoembryonic antigen (anti-CEA) to TiO2/Bi2MoO6 NFs. A novel label-free electrochemical immunosensor was then constructed for the quantitative detection of CEA using TiO2/Bi2MoO6 NFs as sensing platform, showing a good linear relationship with CEA in the concentration range 1.0 pg/mL ~ 1.0 mg/mL and a detection limit of 0.125 pg/mL (S/N = 3). The results achieved with the designed immunosensor are comparable with many existing immunosensors used for the detection of CEA in real samples.

Magnetic MoS2/Fe3O4 composite as an effective activator of persulfate for the degradation of tetracycline: performance, activation mechanisms and degradation pathways.

The activated persulfate (PS) process could produce sulfate radical (SO4·-) and rapidly degrade organic pollutants. The application of Fe3O4 as a promising PS activator was limited due to the rapid conversion of Fe2+ to Fe3+ on its surface. Mo4+ on MoS2 surface could be used as a reducing site to convert Fe3+ to Fe2+, but the separation and recovery of MoS2 was complex. In this study, MoS2/Fe3O4 was prepared to accelerate the Fe3+/Fe2+ cycle on Fe3O4 surface and achieved efficient separation of MoS2. The results showed that MoS2/Fe3O4 was more effective for PS activation compared to Fe3O4 or MoS2, with a removal efficiency of 91.8% for 20 mg·L-1 tetracycline (TC) solution under the optimal conditions. Fe2+ and Mo4+ on MoS2/Fe3O4 surface acted as active sites for PS activation with the generation of SO4•-, •OH, •O2-, and 1O2. Mo4+ acted as an electron donor to promote the Fe3+/Fe2+ cycling and thus improved the PS activation capability of MoS2/Fe3O4. The degradation pathways of TC were inferred as hydroxylation, ketylation of dimethylamino group and C-N bond breaking. This study provided a promising activated persulfate-based advanced oxidation process for the efficient degradation of TC by employing MoS2/Fe3O4 as an effective activator.

Investigation of multidirectional toxicity induced by high-dose molybdenum exposure with Allium test.

In this study, the multifaceted toxicity induced by high doses of the essential trace element molybdenum in Allium cepa L. was investigated. Germination, root elongation, weight gain, mitotic index (MI), micronucleus (MN), chromosomal abnormalities (CAs), Comet assay, malondialdehyde (MDA), proline, superoxide dismutase (SOD), catalase (CAT) and anatomical parameters were used as biomarkers of toxicity. In addition, detailed correlation and PCA analyzes were performed for all parameters discussed. On the other hand, this study focused on the development of a two hidden layer deep neural network (DNN) using Matlab. Four experimental groups were designed: control group bulbs were germinated in tap water and application group bulbs were germinated with 1000, 2000 and 4000 mg/L doses of molybdenum for 72 h. After germination, root tips were collected and prepared for analysis. As a result, molybdenum exposure caused a dose-dependent decrease (p < 0.05) in the investigated physiological parameter values, and an increase (p < 0.05) in the cytogenetic (except MI) and biochemical parameter values. Molybdenum exposure induced different types of CAs and various anatomical damages in root meristem cells. Comet assay results showed that the severity of DNA damage increased depending on the increasing molybdenum dose. Detailed correlation and PCA analysis results determined significant positive and negative interactions between the investigated parameters and confirmed the relationships of these parameters with molybdenum doses. It has been found that the DNN model is in close agreement with the actual data showing the accuracy of the predictions. MAE, MAPE, RMSE and R2 were used to evaluate the effectiveness of the DNN model. Collective analysis of these metrics showed that the DNN model performed well. As a result, it has been determined once again that high doses of molybdenum cause multiple toxicity in A. cepa and the Allium test is a reliable universal test for determining this toxicity. Therefore, periodic measurement of molybdenum levels in agricultural soils should be the first priority in preventing molybdenum toxicity.

Valleytronics in bulk MoS2 with a topologic optical field.

The valley degree of freedom1-4 of electrons in materials promises routes towards energy-efficient information storage with enticing prospects for quantum information processing5-7. Current challenges in utilizing valley polarization are symmetry conditions that require monolayer structures8,9 or specific material engineering10-13, non-resonant optical control to avoid energy dissipation and the ability to switch valley polarization at optical speed. We demonstrate all-optical and non-resonant control over valley polarization using bulk MoS2, a centrosymmetric material without Berry curvature at the valleys. Our universal method utilizes spin angular momentum-shaped trefoil optical control pulses14,15 to switch the material's electronic topology and induce valley polarization by transiently breaking time and space inversion symmetry16 through a simple phase rotation. We confirm valley polarization through the transient generation of the second harmonic of a non-collinear optical probe pulse, depending on the trefoil phase rotation. The investigation shows that direct optical control over the valley degree of freedom is not limited to monolayer structures. Indeed, such control is possible for systems with an arbitrary number of layers and for bulk materials. Non-resonant valley control is universal and, at optical speeds, unlocks the possibility of engineering efficient multimaterial valleytronic devices operating on quantum coherent timescales.

[Elesclomol-Cu Induces Cuproptosis in Human Acute Myeloid Leukemia Cells].

OBJECTIVE: To investigate the effects of elesclomol-Cu (ES-Cu) on the proliferation and cuproptosis of human acute myeloid leukemia (AML) cells. METHODS: The effects of ES-Cu on the proliferation of AML cells and the AML cells pre-treated with ammonium tetrathiomolybdate (TTM) were examined by CCK-8 assay. The Calcein/PI kit was used to detected the changes in activity and cytotoxicity of AML cells induced by ES-Cu. Flow cytometry and Cytation3 fully automated cell imaging multifunctional detection system were used to analyze DCFH-DA fluorescence intensity, so as to determine the level of reactive oxygen species (ROS). The GSH and GSSG detection kits were used to measure the intracellular GSH content. Western blot was used to detected the expression of cuproptosis-related proteins ATP7B, FDX1, DLAT and DPYD. RESULTS: ES-Cu inhibited the proliferation of Kasumi-1 and HL-60 cells in a concentration-dependent manner (r Kasumi-1=-0.99， r HL-60=-0.98). As the concentration of ES-Cu increased, the level of intracellular ROS also increased (P <0.01-0.001). TTM could significantly reverse the inhibitory effect of ES-Cu on cell proliferation and its promoting effect on ROS. With the increase of ES-Cu concentration, the content of GSH was decreased (r =-0.98), and Western blot showed that the protein expressions of ATP7B, FDX1, DLAT and DPYD were significantly reduced (P <0.05). CONCLUSION: ES-Cu can induce cuproptosis in AML cells, which provides a new idea for the treatment of AML.

A novel photoelectrochemical self-screening aptamer biosensor based on CAU-17-derived Bi2WO6/Bi2S3 for rapid detection of quorum sensing signal molecules.

Quorum sensing signal molecule is an important biomarker released by some microorganisms, which can regulate the adhesion and aggregation of marine microorganisms on the surface of engineering facilities. Thus, it is significant to exploit a convenient method that can effectively monitor the formation and development of marine biofouling. In this work, an advanced photoelectrochemical (PEC) aptamer biosensing platform was established and firstly applied for the rapid and ultrasensitive determination of N-(3-Oxodecanoyl)-l-homoserine lactone (3-O-C10-HL) released from marine fouling microorganism Ponticoccus sp. PD-2. The visible-light-driven Bi2WO6/Bi2S3 heterojunction derived from metal-organic frameworks (MOFs) CAU-17 and self-screened aptamer were employed as the photoactive materials and bioidentification elements, respectively. Appropriate amount of MoS2 quantum dots (QDs) conjugated with single-stranded DNA were introduced by hybridization to enhance the photocurrent response of the PEC biosensor. The self-screening aptamer can specifically recognize 3-O-C10-HL, accompanied by increasing the steric hindrance and forcing MoS2 QDs to leave the electrode surface, resulting in an obvious reduction of photocurrent and achieving a dual-inhibition signal amplification effect. Under the optimized conditions, the photocurrent response of PEC aptasensor was linear with 3-O-C10-HL concentration from 1 nM to 10 µM, and the detection limit was as low as 0.26 nM. The detection strategy also showed a high reproducibility, superior specificity and good stability. This work not only provides a simple, rapid and ultrasensitive PEC aptamer biosensing strategy for monitoring quorum sensing signal molecules in marine biofouling, but also broadens the application of MOFs-based heterojunctions in PEC sensors.

Engineering surface state density of monolayer CVD grown 2D MoS2 for enhanced photodetector performance.

This study demonstrates the effect of nitrogen doping on the surface state densities (Nss) of monolayer MoS2 and its effect on the responsivity and the response time of the photodetector. Our experimental results shows that by doping monolayer MoS2 by nitrogen, the surface state (Nss) increases thereby increasing responsivity. The mathematical model included in the paper supports the relation of photocurrent gain and its dependency on trap level which states that the increasing the trap density increases the photocurrent gain and the same is observed experimentally. The experimental results at room temperature revealed that nitrogen doped MoS2 have a high NSS of 1.63 X 1013 states/m2/eV compared to undoped MoS2 of 4.2 x 1012 states/m2/eV. The increase in Nss in turn is the cause for rise in trap states which eventually increases the value of photo responsivity from 65.12 A/W (undoped MoS2) to 606.3 A/W (nitrogen doped MoS2). The response time calculated for undoped MoS2 was 0.85 sec and for doped MoS2 was 0.35 sec. Finally, to verify the dependence of surface states on the responsivity, the surface states were varied by varying temperature and it was observed that upon increment in temperature, the surface states decreases which causes the responsivity values also to decrease.

Investigating the impact of elevated urinary trace elements on non-alcoholic fatty liver disease using vibration-controlled transient elastography.

Introduction: Non-alcoholic fatty liver disease (NAFLD) is a global public health concern. However, limited data are available on urinary trace elements and NAFLD caused by various exposure factors. This study aimed to investigate the relationship between the presence of 16 trace elements in urine and NAFLD using data from the National Health and Nutrition Examination Survey (NHANES). Methods: By utilizing the NHANES data from 2017 to 2018, 1613 participants who fulfilled the research criteria were identified from the initial pool of 2979 participants with available urine trace element detection data. Among them, 706 individuals had been diagnosed with NAFLD based on a coefficient of attenuation parameter (CAP) value of at least 274 db/m, determined using vibration-controlled transient elastography (VCTE); whereas the remaining 907 participants were classified as non-NAFLD. The data obtained were used to construct univariate and multivariate logistic regression models and restricted cubic spline models (RCS) analyses. Results: The presence of arsenic, iodine, barium, cesium, molybdenum, lead, tin, and tungsten in the urine of individuals with NAFLD showed a positive correlation with the likelihood of developing NAFLD. The risk of NAFLD had a non-linear dose-dependent relationship with urinary iodine, molybdenum, barium, and cesium. NAFLD was also associated with elevated levels of barium and cesium in urine, which were identified as significant risk factors. Conclusion: These findings suggest a positive association between exposure to trace elements in the urine and the risk of NAFLD. Specifically, urinary barium and cesium appeared to have the greatest impact on the risk of NAFLD. These results provide novel insights into the diagnosis and treatment of NAFLD.

Ultrasensitive detection of zearalenone based on electrochemiluminescent immunoassay with Zr-MOF nanoplates and Au@MoS2 nanoflowers.

In this work, an effective competitive-type electrochemiluminescence (ECL) immunosensor was constructed for zearalenone determination by using Zr-MOF nanoplates as the ECL luminophore and Au@MoS2 nanoflowers as the substrate material. Zr-MOF have an ultra-thin sheet-like structure that accelerates the transfer of electrons, ions and co-reactant intermediates, which exhibited strong and stable anodic luminescence. The three-dimensional Au@MoS2 nanoflowers would form a thin film modification layer on the glassy carbon electrode (GCE). And its good electrical conductivity and higher specific surface area utilization further improving the sensitivity of the ECL immunosensor. Under the optimized conditions, the proposed immunosensor exhibited satisfactory stability, sensitivity and accuracy, and its ECL signal was proportional to the logarithm of ZEN concentration (0.0001-100 ng/mL) and the limit of detection (LOD) was 0.034 pg/mL. In addition, the results of recovery experiment acquired for wheat flour and pig urine samples further proved the feasibility of the immunosensor for the detection of real samples, indicating its potential for ultrasensitive detection of ZEN.

Molybdenum and cadmium co-induce necroptosis through Th1/Th2 imbalance-mediated endoplasmic reticulum stress in duck ovaries.

Cadmium (Cd) and excess molybdenum (Mo) pose serious threats to animal health. Our previous study has determined that Cd and/or Mo exposure can cause ovarian damage of ducks, while the specific mechanism is still obscure. To further investigate the toxic mechanism of Cd and Mo co-exposure in the ovary, forty 8-day-old female ducks were randomly allocated into four groups for 16 weeks, and the doses of Cd and Mo in basic diet per kg were as follows: control group, Mo group (100 mg Mo), Cd group (4 mg Cd), and Mo + Cd group (100 mg Mo + 4 mg Cd). Cadmium sulfate 8/3-hydrate (CdSO4·8/3H2O) and hexaammonium molybdate ((NH4)6Mo7O24·4H2O) were the origins of Cd and Mo, respectively. At the 16th week of the experiment, all ovary tissues were collected for the detection of related indexes. The data indicated that Mo and/or Cd induced trace element disorders and Th1/Th2 balance to divert toward Th1 in the ovary, which activated endoplasmic reticulum (ER) stress and then provoked necroptosis through triggering RIPK1/RIPK3/MLKL signaling pathway, and eventually caused ovarian pathological injuries and necroptosis characteristics. The alterations of above indicators were most apparent in the joint group. Above all, this research illustrates that Mo and/or Cd exposure can initiate necroptosis through Th1/Th2 imbalance-modulated ER stress in duck ovaries, and Mo and Cd combined exposure aggravates ovarian injuries. This research explores the molecular mechanism of necroptosis caused by Mo and/or Cd, which reveals that ER stress attenuation may be a therapeutic target to alleviate necroptosis.

Desirable Strong and Tough Adhesive Inspired by Dragonfly Wings and Plant Cell Walls.

The production of wood-based panels has a significant demand for mechanically strong and flexible biomass adhesives, serving as alternatives to nonrenewable and toxic formaldehyde-based adhesives. Nonetheless, plywood usually exhibits brittle fracture due to the inherent trade-off between rigidity and toughness, and it is susceptible to damage and deformation defects in production applications. Herein, inspired by the microstructure of dragonfly wings and the cross-linking structure of plant cell walls, a soybean meal (SM) adhesive with great strength and toughness was developed. The strategy was combined with a multiple assembly system based on the tannic acid (TA) stripping/modification of molybdenum disulfide (MoS2@TA) hybrids, phenylboronic acid/quaternary ammonium doubly functionalized chitosan (QCP), and SM. Motivated by the microstructure of dragonfly wings, MoS2@TA was tightly bonded with the SM framework through Schiff base and strong hydrogen bonding to dissipate stress energy through crack deflection, bridging, and immobilization. QCP imitated borate chemistry in plant cell walls to optimize interfacial interactions within the adhesive by borate ester bonds, boron-nitrogen coordination bonds, and electrostatic interactions and dissipate energy through sacrificial bonding. The shear strength and fracture toughness of the SM/QCP/MoS2@TA adhesive were 1.58 MPa and 0.87 J, respectively, which were 409.7% and 866.7% higher than those of the pure SM adhesive. In addition, MoS2@TA and QCP gave the adhesive good mildew resistance, durability, weatherability, and fire resistance. This bioinspired design strategy offers a viable and sustainable approach for creating multifunctional strong and tough biobased materials.

Characteristics, source analysis, and health risk assessment of potentially toxic elements pollution in soil of dense molybdenum tailing ponds area in central China.

The issue of potentially toxic elements (PTEs) contamination of regional soil caused by mining activities and tailings accumulation has attracted wide attention all over the world. The East Qinling is one of the three main molybdenum mines in the world, and the concentration of PTEs such as Hg, Pb and Cu in the slag is high. Quantifying the amount of PTEs contamination in soil and identifying potential sources of contamination is vital for soil environmental management. In the present investigation, the pollution levels of 8 PTEs in the Qinling molybdenum tailings intensive area were quantitatively identified. Additionally, an integrated source-risk method was adopted for resource allocation and risk assessment based on the PMF model, the ecological risk, and the health risk assessment model. The mean concentrations of Cu, Ni, Pb, Cd, Cr, Zn, As, and Hg in the 80 topsoil samples ranged from 0.80 to 13.38 times the corresponding background values; notably high levels were observed for Pb and Hg. The source partitioning results showed that PTEs were mainly affected by four pollution sources: natural and agricultural sources, coal-burning sources, combined transport and mining industry sources, and mining and smelting sources. The health risk assessment results revealed that the risks of soil PTEs for adults are acceptable, while the risks for children exceeded the limit values. The obtained results will help policymakers to obtain the sources of PTEs of tailing ponds intensive area. Moreover, it provides priorities for the governance of subsequent pollution sources and ecological restoration.

Assessing petrochemical effluent effect on heavy metal pollution in Musa Estuary: A numerical modeling approach.

The objective of this study is to assess the effect of petrochemical effluent on heavy metal pollutant in the Musa Estuary ecosystem in the North-western region of the Persian Gulf, through numerical modeling. The outfall of 30 petrochemical plants poses a potential threat to the estuary's seawater and sediment quality, environment, and public health. A combined hydrodynamic and ecologic modeling framework is applied to predict the spatial distribution of BOD and hazardous heavy metals in this estuary. MIKE 21 Flow Model (FM) CFD software is applied to simulate the tidal waves hydrodynamics, next to applying the MIKE ECO Lab models to predict the distribution of BOD and heavy metals in ambient water. The accuracy of the modeling framework is validated against measured water level, current speed, and water quality data. The results reveal that the level of lead concentration corresponds with the national standard, while the BOD, arsenic, molybdenum and vanadium exceed the limit in some areas, particularly in the tidal zone. The optimal outlet locations that effectively meet the standard concentrations of the heavy metals in the ambient water of the estuary are determined. The results confirm that the new outlet configuration corresponds with the standards: 0.198 µg/L for arsenic concentrations, 0.182 µg/L for molybdenum, 1.530 µg/L for vanadium, and 1.132 mg/L for BOD, at maximum. This study contributes to the perception of estuarine dynamics and provides practical implications for estuarine sustainable management and pollution control.

Interactions of monolayer molybdenum disulfide sheets with metalloid antimony in aquatic environment: Adsorption, transformation, and joint toxicity.

The tremendous application potentiality of transitional metal dichalcogenides (TMDs), such as molybdenum disulfide (MoS2) nanosheets, will unavoidably lead to increasing release into the environment, which could influence the fate and toxicity of co-existed contaminants. The present study discovered that 59.8 % of trivalent antimony [Sb(III)] was transformed by MoS2 to pentavalent Sb [Sb(V)] in aqueous solutions under light illumination, which was due to hole oxidation on the nanosheet surfaces. A synergistic toxicity between MoS2 and Sb(III, V) to algae (Chlorella vulgaris) was observed, as demonstrated by the lower median-effect concentrations of MoS2 + Sb(III)/Sb(V) (13.1 and 20.9 mg/L, respectively) than Sb(III)/Sb(V) (38.8 and 92.5 mg/L, respectively) alone. Particularly, MoS2 at noncytotoxic doses notably increased the bioaccumulation of Sb(III, V) in algae, causing aggravated oxidative damage, photosynthetic inhibition, and structural alterations. Metabolomics indicated that oxidative stress and membrane permeabilization were primarily associated with down-regulated amino acids involved in glutathione biosynthesis and unsaturated fatty acids. MoS2 co-exposure remarkably decreased the levels of thiol antidotes (glutathione and phytochelatins) and aggravated the inhibition on energy metabolism and ATP synthesis, compromising the Sb(III, V) detoxification and efflux. Additionally, extracellular P was captured by the nanosheets, also contributing to the uptake of Sb(V). Our findings emphasized the nonignorability of TMDs even at environmental levels in affecting the ecological hazard of metalloids, providing insight into comprehensive safety assessment of TMDs.

MoS2-based nanocomposites and aerogels for antibiotic pollutants removal from wastewater by photocatalytic degradation process: A review.

Photocatalytic technologies based on molybdenum disulfide (MoS2) catalysts are effective, eco-friendly, and promising for antibiotic pollutants treatment. The technologies used by MoS2-based nanocomposites and aerogels for efficient degradation of antibiotics are reviewed in detail for the first time in this paper. The fundamental aspects of MoS2 were comprehensively scrutinized, encompassing crystal structure, optical properties, and photocatalytic principle. Then, the main synthesized methods and advantages/disadvantages for the preparation of MoS2-based nanocomposites and aerogels were systematically presented. Besides, a comprehensive overview of diverse MoS2-based nanocomposites and aerogels photo-degradation systems that enhanced the degradation of antibiotic pollutants were revealed. Meanwhile, the photo-degradation mechanism concentrated on the photoelectron transfer pathways and reactive oxygen species (ROS) were systematically evaluated. Finally, the challenges and perspectives for deeply development of MoS2-based nanocomposites and aerogels were discussed. This review may help researchers to deeply understand the research status of MoS2-based nanocomposites and aerogels for antibiotics removal, and makes clear the photo-degradation mechanism from photoelectron transfer pathways and ROS aspects of MoS2-based nanocomposites and aerogels.

Bioresorbable molybdenum temporary epicardial pacing wires.

Cardiac pacing with temporary epicardial pacing wires (TEPW) is used to treat rhythm disturbances after cardiac surgery. Occasionally, TEPW cannot be mechanically extracted and remain in the thorax, where they may rarely cause serious complications like migration and infection. We aim to develop bioresorbable TEPW that will dissolve over time even if postoperative removal is unsuccessful. In the present study, we demonstrate a completely bioresorbable design using molybdenum (Mo) as electric conductor and the resorbable polymers poly(D, L-lactic-co-glycolic acid) (PLGA) and polycaprolactone (PCL) for electrically insulating double-coating. We compared the pacing properties of these Mo TEPW demonstrators to conventional steel TEPW in Langendorff-perfused rat hearts and observed similar functionality. In vitro, static immersion tests in simulated body fluid for up to 28 days elucidated the degradation behaviour of uncoated Mo strands and the influence of polymer coating thereon. Degradation was considerably reduced in double-coated Mo TEPW compared to the uncoated and the PLGA-coated condition. Furthermore, we confirmed good biocompatibility of Mo degradation products in the form of low cytotoxicity in cell cultures of human cardiomyocytes and cardiac fibroblasts. STATEMENT OF SIGNIFICANCE: Temporary pacing wires are routinely implanted on the heart surface to treat rhythm disturbances in the days following cardiac surgery. Subsequently, these wires are to be removed. When removal attempts are unsuccessful, wires are cut at skin level and the remainders are left inside the chest. Retained fragments may migrate within the body or become a centre of infection. These complications may be prevented using resorbable pacing wires. We manufactured completely resorbable temporary pacing wires using molybdenum as electrical conductor and assessed their function, degradation and biological compatibility. Our study represents an important step in the development of a safer approach to the treatment of rhythm disturbances after cardiac surgery.