Collective effects of rising average temperatures and heat events on oviparous embryos.

Survival of the immobile embryo in response to rising temperature is important to determine a species' vulnerability to climate change. However, the collective effects of 2 key thermal characteristics associated with climate change (i.e., rising average temperature and acute heat events) on embryonic survival remain largely unexplored. We used empirical measurements and niche modeling to investigate how chronic and acute heat stress independently and collectively influence the embryonic survival of lizards across latitudes. We collected and bred lizards from 5 latitudes and incubated their eggs across a range of temperatures to quantify population-specific responses to chronic and acute heat stress. Using an embryonic development model parameterized with measured embryonic heat tolerances, we further identified a collective impact of embryonic chronic and acute heat tolerances on embryonic survival. We also incorporated embryonic chronic and acute heat tolerance in hybrid species distribution models to determine species' range shifts under climate change. Embryos' tolerance of chronic heat (T-chronic) remained consistent across latitudes, whereas their tolerance of acute heat (T-acute) was higher at high latitudes than at low latitudes. Tolerance of acute heat exerted a more pronounced influence than tolerance of chronic heat. In species distribution models, climate change led to the most significant habitat loss for each population and species in its low-latitude distribution. Consequently, habitat for populations across all latitudes will shift toward high latitudes. Our study also highlights the importance of considering embryonic survival under chronic and acute heat stresses to predict species' vulnerability to climate change.

Efectos colectivos del aumento de las temperaturas promedio y los eventos de calor en embriones ovíparos Resumen La supervivencia de los embriones inmóviles en respuesta al incremento de temperatura es importante para determinar la vulnerabilidad de las especies al cambio climático. Sin embargo, los efectos colectivos de dos características térmicas claves asociadas con el cambio climático (i. e., aumento de temperatura promedio y eventos de calor agudo) sobre la supervivencia embrionaria permanecen en gran parte inexplorados. Utilizamos mediciones empíricas y modelos de nicho para investigar cómo el estrés térmico crónico y agudo influye de forma independiente y colectiva en la supervivencia embrionaria de los lagartos en todas las latitudes. Recolectamos y criamos lagartos de cinco latitudes e incubamos sus huevos en un rango de temperaturas para cuantificar las respuestas específicas de la población al estrés por calor crónico y agudo. Posteriormente, mediante un modelo de desarrollo embrionario parametrizado con mediciones de tolerancia embrionaria al calor, identificamos un impacto colectivo de las tolerancias embrionarias al calor agudo y crónico en la supervivencia embrionaria. También incorporamos la tolerancia embrionaria crónica y aguda al calor en modelos de distribución de especies híbridas para determinar los cambios de distribución de las especies bajo el cambio climático. La tolerancia embrionaria al calor crónico (T­crónico) permaneció constante, mientras que la tolerancia al calor agudo (T­agudo) fue mayor en latitudes altas que en latitudes bajas. La tolerancia al calor agudo ejerció una influencia más pronunciada que la tolerancia al calor crónico. En los modelos de distribución de especies, el cambio climático provocó la pérdida de hábitat más significativa para cada población y especie en su distribución de latitudes bajas. En consecuencia, el hábitat para poblaciones en todas las latitudes se desplazará a latitudes altas. Nuestro estudio también resalta la importancia de considerar la supervivencia embrionaria bajo estrés térmico crónico y agudo para predecir la vulnerabilidad de las especies al cambio climático.

Highly Sensitive and Selective Toluene Gas Sensors Based on ZnO Nanoflowers Decorated with Bimetallic AuPt.

Efficient sensors for toluene detecting are urgently needed to meet people's growing demands for both environment and personal health. Metal oxide semiconductor (MOS)-based sensors have become brilliant candidates for the detection of toluene because of their superior performance over gas sensing. However, gas sensors based on pure MOS have certain limitations in selectivity, operating temperature, and long-term stability, which hinders their further practical applications. Noble metals (including Ag, Au, Pt, Pd, etc.) have the ability to enhance the performance of MOS-based sensors via surface functionalization. Herein, ZnO nanoflowers (ZNFs) modified with bimetallic AuPt are prepared for toluene detection through hydrothermal method. The response of a AuPt@ZNF-based gas sensor can reach 69.7 at 175 °C, which is 30 times, 9 times, and 10 times higher than that of the original ZNFs, Au@ZNFs, and Pt@ZNFs, respectively. Furthermore, the sensor also has a lower optimal operating temperature (175 °C), good stability (94% of previous response after one month), and high selectivity towards toluene, which is the result of the combined influence of the electronic and chemical sensitization of noble metals, as well as the unique synergistic effect of the AuPt alloy. In summary, AuPt@ZNF-based sensors can be further applied in toluene detection in practical applications.

High-performance MoS2phototransistors with Hf1-xAlxO back-gate dielectric layer grown by plasma enhanced atomic layer deposition.

Molybdenum sulfide (MoS2) as an emerging optoelectronic material, shows great potential for phototransistors owing to its atomic thickness, adjustable band gap, and low cost. However, the phototransistors based on MoS2have been shown to have some issues such as large gate leakage current, and interfacial scattering, resulting in suboptimal optoelectronic performance. Thus, Al-doped hafnium oxide (Hf1-xAlx) is proposed to be a dielectric layer of the MoS2-based phototransistor to solve this problem because of the relatively higher crystallization temperature and dielectric constant. Here, a high-performance MoS2phototransistor with Hf1-xAlxO gate dielectric layer grown by plasma-enhanced atomic layer deposition has been fabricated and studied. The results show that the phototransistor exhibits a high responsivity of 2.2 × 104A W-1, a large detectivity of 1.7 × 1017Jones, a great photo-to-dark current ratio of 2.2 × 106%, and a high external quantum efficiency of 4.4 × 106%. The energy band alignment and operating mechanism were further used to clarify the reason for the enhanced MoS2phototransistor. The suggested MoS2phototransistors could provide promising strategies in further optoelectronic applications.

Two-dimensional molybdenum ditelluride waveguide-integrated near-infrared photodetector.

Low-cost, small-sized, and easy integrated high-performance photodetectors for photonics are still the bottleneck of photonic integrated circuits applications and have attracted increasing attention. The tunable narrow bandgap of two-dimensional (2D) layered molybdenum ditelluride (MoTe2) from ∼0.83 to ∼1.1 eV makes it one of the ideal candidates for near-infrared (NIR) photodetectors. Herein, we demonstrate an excellent waveguide-integrated NIR photodetector by transferring mechanically exfoliated 2D MoTe2onto a silicon nitride (Si3N4) waveguide. The photoconductive photodetector exhibits excellent responsivity (R), detectivity (D*), and external quantum efficiency at 1550 nm and 50 mV, which are 41.9 A W-1, 16.2 × 1010Jones, and 3360%, respectively. These optoelectronic performances are 10.2 times higher than those of the free-space device, revealing that the photoresponse of photodetectors can be enhanced due to the presence of waveguide. Moreover, the photodetector also exhibits competitive performances over a broad wavelength range from 800 to 1000 nm with a highRof 15.4 A W-1and a largeD* of 59.6 × 109Jones. Overall, these results provide an alternative and prospective strategy for high-performance on-chip broadband NIR photodetectors.

Photodetectors integrating waveguides and semiconductor materials.

Photodetectors integrating substrates and semiconductor materials are increasingly attractive for applications in optical communication, optical sensing, optical computing, and military owing to the unique optoelectronic properties of semiconductor materials. However, it is still a challenge to realize high-performance photodetectors by only integrating substrates and semiconductor materials because of the limitation of incident light in contact with sensitive materials. In recent years, waveguides such as silicon (Si) and silicon nitride (Si3N4) have attracted extensive attention owing to their unique optical properties. Waveguides can be easily hetero-integrated with semiconductor materials, thus providing a promising approach for realizing high-performance photodetectors. Herein, we review recent advances in photodetectors integrating waveguides in two parts. The first involves the waveguide types and semiconductor materials commonly used to fabricate photodetectors, including Si, Si3N4, gallium nitride, organic waveguides, graphene, and MoTe2. The second involves the photodetectors of different wavelengths that integrate waveguides, ranging from ultraviolet to infrared. These hybrid photodetectors integrating waveguides and semiconductor materials provide an alternative way to realize multifunctional and high-performance photonic integrated chips and circuits.

Characteristics of tunable aluminum-doped Ga2O3thin films and photodetectors.

Aluminum-doped Ga2O3(AGO) thin films were prepared by plasma-enhanced atomic layer deposition (PE-ALD). The growth mechanism, surface morphology, chemical composition, and optical properties of AGO films were systematically investigated. The bandgap of AGO films can be theoretically set between 4.65 and 6.8 eV. Based on typical AGO films, metal-semiconductor-metal photodetectors (PDs) were created, and their photoelectric response was examined. The preliminary results show that PE-ALD grown AGO films have high quality and tunable bandgap, and AGO PDs possess superior characterizations to undoped films. The AGO realized using PE-ALD is expected to be an important route for the development of a new generation of gallium oxide-based photodetectors into the deep-ultraviolet.

Exposure to low levels of antidiabetic glibenclamide had no evident adverse effects on intestinal microbial composition and metabolic profiles in amphibian larvae.

Unmetabolized human pharmaceuticals may enter aquatic environments, and potentially exert adverse effects on the survival of non-target organisms. Here, Pelophylax nigromaculatus tadpoles were exposed to different concentrations of antidiabetic glibenclamide (GLB) for 30 days to evaluate its potential ecotoxicological effect in amphibians using intestinal microbiomic and metabolomic profiles. The mortality rate of GLB-exposed groups appeared to be lower than that of the control group. Despite not being statistically significant, there was a tendency for a decrease in intestinal microbial diversity after exposure. The relative abundance of bacteria phylum Firmicutes was shown to decrease, but those of other phyla did not in GLB-exposed tadpoles. Some potentially pathogenic bacteria (e.g., Clostridium, Bilophila, Hafnia) decrease unexpectedly, while some beneficial bacteria (e.g., Akkermansia, Faecalibacterium) increased in GLB-exposed tadpoles. Accordingly, GLB-induced changes in intestinal microbial compositions did not seem harmful to animal health. Moreover, minor changes in a few intestinal metabolites were observed after GLB exposure. Overall, our results suggested that exposure to low levels of GLB did not necessarily exert an adverse impact on amphibian larvae.

Metformin exposure altered intestinal microbiota composition and metabolites in amphibian larvae.

The antidiabetic pharmaceutical metformin (MET) is largely unmetabolized by the human body. Its residues are readily detectable in various aquatic environments and may have adverse impacts on the growth and survival of aquatic species. To date, its toxicological effects have scarcely been explored in non-fish species. Here, we exposed the tadpoles of black-spotted pond frog (Pelophylax nigromaculatus) to different concentrations (0, 1, 10 and 100 µg/L) of MET for 30 days and measured the body size, intestinal microbiota and metabolites to evaluate potential effects of MET exposure in amphibian larvae. MET exposure did not affect the growth and intestinal microbial diversity of tadpoles. However, intestinal microbial composition changed significantly, with some pathogenic bacteria (e.g., bacterial genera Salmonella, Comamonas, Stenotrophomonas, Trichococcus) increasing and some beneficial bacteria (e.g., Blautia, Prevotella) decreasing in MET-exposed tadpoles. The levels of some intestinal metabolites associated with growth and immune performance also changed significantly following MET exposure. Overall, our results indicated that exposure to MET, even at environmentally relevant concentrations, would cause intestinal microbiota dysbiosis and metabolite alteration, thereby influencing the health status of non-target aquatic organisms, such as amphibians.

Embryonic development, hatchling performance and metabolic profile after egg exposure to environmentally relevant levels of chlorpyrifos in an aquatic turtle.

The extensive use of organophosphorus insecticides poses a threat to the survival of non-target organisms. Ecotoxicological outcomes of embryonic exposure to insecticides are rarely evaluated in various oviparous species. In this study, soft-shelled turtle (Pelodiscus sinensis) eggs were incubated in moist substrate containing different levels (0, 2, 20 and 200 µg/kg) of chlorpyrifos to investigate its toxic effects on embryonic development and survival, and hatchling physiological performance. Chlorpyrifos exposure had no significant impacts on embryonic development rate and egg survival in P. sinensis. Similarly, embryonic chlorpyrifos exposure neither obviously affected the size and locomotor performance of hatchlings, nor changed the activities of superoxide dismutase and catalase, and content of malondialdehyde in their erythrocytes. Based on liquid chromatography-mass spectrometry analysis, minor metabolic perturbations related to amino acid, lipid and energy metabolism in hatchlings after embryonic chlorpyrifos exposure were revealed by hepatic metabolite profiling. Overall, our results suggested that embryonic exposure to environmentally relevant levels of chlorpyrifos had only a limited impact on physiological performances of hatchlings, although it would result in a potential risk of hepatotoxicity in P. sinensis.

Study of an Ultrasensitive Label-Free Electrochemiluminescent Immunosensor Fabricated with a Composite Electrode for Detecting the Glutamate Decarboxylase Antibody.

Antibody testing for the glutamic acid decarboxylase 65 antibody (GADA) is widely used as a golden standard for autoimmune diabetes diagnosis, while current methods for antibody testing are not sensitive enough for clinical usage. Here, a label-free electrochemiluminescent (ECL) immunosensor for detecting GADA in autoimmune diabetes is fabricated and investigated. In the designed immunosensor, a composite film including the multiwalled carbon nanotubes (MWCNTs), zinc oxide (ZnO), and Au nanoparticles (AuNPs) was prepared through nanofabrication processes to improve the performance of sensor. The MWCNTs, which can provide a larger specific surface area, ZnO as a good photocatalytic material, and AuNPs that can enhance the ECL signal of luminol and immobilize the GAD65 antigen were applied to prefunctionalize indium tin oxide (ITO) glass based on a nanofabrication process. The GADA concentration was detected using the ECL immunosensor after incubating with GAD65 antigen-coated prefunctionalized ITO glass. After a direct immunoreaction, it is found that the degree of decreased ECL intensity has a good linear regression toward the logarithm of the GADA concentration in the range of 0.01 to 50 ng mL-1 with a detection limit down to 10 pg mL-1. Human serum samples positive or negative for GADA all nicely fell in the expected area. The fabricated immunosensor with excellent sensitivity, specificity, and stability has potential capability for clinical usage in GADA detection.

Sexual size monomorphism may evolve in lizards with a body size maximizing reproductive performance for both sexes.

We used Takydromus septentrionalis, a sexually size-monomorphic lacertid lizard, as a model system to test the hypothesis that sexual size monomorphism may evolve in lizards where reproductive performance is maximized at a similar body size for both sexes. We allowed lizards housed in laboratory enclosures to lay as many clutches (for females) as they could or to mate as many times (for males) as they could in a breeding season. Size-assortative mating was weak but evident in T. septentrionalis, as revealed by the fact that male and female snout-vent lengths (SVLs) in mating pairs were significantly and positively correlated. Mating frequency (indicative of male reproductive performance) varied from 1 to 8 per breeding season, generally increasing as SVL increased in adult males smaller than 67.4 mm SVL. Clutch frequency varied from 1 to 7 per breeding season, with female reproductive performance (determined by clutch frequency, annual fecundity, and annual reproductive output) maximized in females with a SVL of 68.0 mm. Accordingly to our hypothesis, the reproductive performance was maximized in the intermediate sized rather than the largest individuals in both sexes, and the body size maximizing reproductive performance was similar for both sexes. Future work could usefully investigate other lineages of lizards with sexually monomorphic species in a phylogenetic context to corroborate the hypothesis of this study.

Integration Technology of Micro-LED for Next-Generation Display.

Inorganic micro light-emitting diodes (micro-LEDs) based on III-V compound semiconductors have been widely studied for self-emissive displays. From chips to applications, integration technology plays an indispensable role in micro-LED displays. For example, large-scale display relies on the integration of discrete device dies to achieve extended micro-LED array, and full color display requires integration of red, green, and blue micro-LED units on the same substrate. Moreover, the integration with transistors or complementary metal-oxide-semiconductor circuits are necessary to control and drive the micro-LED display system. In this review article, we summarized the 3 main integration technologies for micro-LED displays, which are called transfer integration, bonding integration, and growth integration. An overview of the characteristics of these 3 integration technologies is presented, while various strategies and challenges of integrated micro-LED display system are discussed.

Advances in Noble Metal-Decorated Metal Oxide Nanomaterials for Chemiresistive Gas Sensors: Overview.

Highly sensitive gas sensors with remarkably low detection limits are attractive for diverse practical application fields including real-time environmental monitoring, exhaled breath diagnosis, and food freshness analysis. Among various chemiresistive sensing materials, noble metal-decorated semiconducting metal oxides (SMOs) have currently aroused extensive attention by virtue of the unique electronic and catalytic properties of noble metals. This review highlights the research progress on the designs and applications of different noble metal-decorated SMOs with diverse nanostructures (e.g., nanoparticles, nanowires, nanorods, nanosheets, nanoflowers, and microspheres) for high-performance gas sensors with higher response, faster response/recovery speed, lower operating temperature, and ultra-low detection limits. The key topics include Pt, Pd, Au, other noble metals (e.g., Ag, Ru, and Rh.), and bimetals-decorated SMOs containing ZnO, SnO2, WO3, other SMOs (e.g., In2O3, Fe2O3, and CuO), and heterostructured SMOs. In addition to conventional devices, the innovative applications like photo-assisted room temperature gas sensors and mechanically flexible smart wearable devices are also discussed. Moreover, the relevant mechanisms for the sensing performance improvement caused by noble metal decoration, including the electronic sensitization effect and the chemical sensitization effect, have also been summarized in detail. Finally, major challenges and future perspectives towards noble metal-decorated SMOs-based chemiresistive gas sensors are proposed.

Understanding the Effect of Top Electrode on Ferroelectricity in Atomic Layer Deposited Hf0.5Zr0.5O2 Thin Films.

It is commonly believed that the impact of the top electrodes on the ferroelectricity of hafnium-based thin films is due to strain engineering. However, several anomalies have occurred that put existing theories in doubt. This work carries out a detailed study of this issue using both theoretical and experimental approaches. The 10 nm Hf0.5Zr0.5O2 (HZO) films are prepared by atomic layer deposition, and three different top capping electrodes (W/MO/ITO) are deposited by physical vapor deposition. The electrical testing finds that the strain does not completely control the ferroelectricity of the devices. The results of further piezoelectric force microscopy characterization exclude the potential interference of the top capping electrodes and interface for electrical testing. In addition, through atomic force microscopy characterization and statistical analysis, a strong correlation between the grain size of the top electrode and the grain size of the HZO film has been found, suggesting that the grain size of the top electrode can induce the formation of the grain size in HZO thin films. Finally, the first-principles calculation is carried out to understand the impact of the strain and grain size on the ferroelectric properties of HZO films. The results show that the strain is the dominant factor for ferroelectricity when the grain size is large (>10 nm). However, when the grain size becomes thinner (<10 nm), the regulation effect of grain sizes increases significantly, which could bring a series of benefits for device scaling, such as device-to-device variations, film uniformity, and domain switch consistency. This work not only completes the understanding of ferroelectricity through top electrode modulation but also provides strong support for the precise regulation of ferroelectricity of nanoscale devices and ultrathin HZO ferroelectric films.

Minor metabolomic disturbances induced by glyphosate-isopropylammonium exposure at environmentally relevant concentrations in an aquatic turtle, Pelodiscus sinensis.

The ecotoxicological and environmental impacts of glyphosate-based herbicides have received considerable attention due to their extensive use globally. However, the potential for adverse effects in cultured non-fish vertebrate species are commonly ignored. In this study, effects on growth, indicators of functional performance, gut microbial diversity, liver antioxidant responses and metabolite profiles were evaluated in soft-shelled turtle hatchlings (Pelodiscus sinensis) exposed to different concentrations of glyphosate-isopropylammonium (0, 0.02, 0.2, 2 and 20 mg/L). No significant changes in growth or functional performance (food intake, swimming speed), gut microbiota, and liver antioxidant responses (SOD and CAT activities, MDA content) were observed in exposed turtles. However, hepatic metabolite profiles revealed distinct perturbations that primarily involved amino acid metabolism in turtles exposed to environmentally relevant concentrations. Overall, our results suggested that metabolite profiles may be more sensitive than phenotypic or general physiological endpoints and gut microbiota profiling, and indicate a potential mechanism of hepatotoxicity caused by glyphosate-isopropylammonium based on untargeted metabolomics analysis. Furthermore, the toxicity of glyphosate at environmentally relevant concentrations might be relatively minor in aquatic turtle species.

Divergent responses in the gut microbiome and liver metabolome to ammonia stress in three freshwater turtles.

Ammonia is a common pollutant in aquaculture system, and toxic to all aquatic animals. However, different aquatic animals exhibit diverse physiological responses to high-level ammonia exposure, potentially indicating their divergent resistance to ammonia stress. In this study, juveniles of three freshwater turtles (Mauremys reevesii, Pseudemys nelsoni and Trachemys scripta elegans) were exposed to different concentrations of ammonia (0, 0.3 and 3.0 mg/L) for 30 days, and their swimming, growth performance, gut microbiota, and hepatic metabolites were measured to evaluate the interspecific difference in physiological responses to ammonia stress. Despite no differences in swimming ability, growth rate, and gut microbial diversity, observable changes in microbial community composition and hepatic metabolite profiles were shown in ammonia-exposed turtles. A relatively higher abundance of potentially pathogenic bacteria was found in M. reevesii than in the other two species. Moreover, microbial compositions and metabolic responses differed significantly among the three species. M. reevesii was, out of the three tested species, the one in which exposure to ammonia had the greatest effect on changes in bacterial genera and hepatic metabolites. Conversely, only a few metabolites were significantly changed in T. scripta elegans. Integrating these findings, we speculated that native M. reevesii should be more vulnerable to ammonia stress compared to the invasive turtle species. Our results plausibly reflected divergent potential resistance to ammonia among these turtles, in view of differential physiological responses to ammonia exposure at environmentally relevant concentrations.

Heterostructured α-Fe2 O3 @ZnO@ZIF-8 Core-Shell Nanowires for a Highly Selective MEMS-Based ppb-Level H2 S Gas Sensor System.

Highly selective and sensitive H2 S sensors are in high demand in various fields closely related to human life. However, metal oxide semiconductors (MOSs) suffer from poor selectivity and single MOS@metal organic framework (MOF) core-shell nanocomposites are greatly limited due to the intrinsic low sensitivity of MOF shells. To simultaneously improve both selectivity and sensitivity, heterostructured α-Fe2 O3 @ZnO@ZIF-8 core-shell nanowires (NWs) are meticulously synthesized with the assistance of atomic layer deposition. The ZIF-8 shell with regular pores and special surface functional groups is attractive for excellent selectivity and the heterostructured α-Fe2 O3 @ZnO core with an additional electron depletion layer is promising with enhanced sensitivity compared to a single MOS core. As a result, the heterostructured α-Fe2 O3 @ZnO@ZIF-8 core-shell NWs achieve remarkable H2 S sensing performance with a high response (Rair /Rgas  = 32.2 to 10 ppm H2 S), superior selectivity, fast response/recovery speed (18.0/31.8 s), excellent long-term stability (at least over 3 months), and relatively low limit of detection (down to 200 ppb) at low operating temperature of 200 °C, far beyond α-Fe2 O3 @ZIF-8 or α-Fe2 O3 @ZnO core-shell NWs. Furthermore, a micro-electromechanical system-based H2 S gas sensor system with low power consumption is developed, holding great application potential in smart cities.

Recent Progress on Flexible Room-Temperature Gas Sensors Based on Metal Oxide Semiconductor.

With the rapid development of the Internet of Things, there is a great demand for portable gas sensors. Metal oxide semiconductors (MOS) are one of the most traditional and well-studied gas sensing materials and have been widely used to prepare various commercial gas sensors. However, it is limited by high operating temperature. The current research works are directed towards fabricating high-performance flexible room-temperature (FRT) gas sensors, which are effective in simplifying the structure of MOS-based sensors, reducing power consumption, and expanding the application of portable devices. This article presents the recent research progress of MOS-based FRT gas sensors in terms of sensing mechanism, performance, flexibility characteristics, and applications. This review comprehensively summarizes and discusses five types of MOS-based FRT gas sensors, including pristine MOS, noble metal nanoparticles modified MOS, organic polymers modified MOS, carbon-based materials (carbon nanotubes and graphene derivatives) modified MOS, and two-dimensional transition metal dichalcogenides materials modified MOS. The effect of light-illuminated to improve gas sensing performance is further discussed. Furthermore, the applications and future perspectives of FRT gas sensors are also discussed.

Highly sensitive and stable MEMS acetone sensors based on well-designed α-Fe2O3/C mesoporous nanorods.

Highly sensitive and stable acetone gas sensors based on MEMS substrate supported carbon nanoparticles decorated mesoporous α-Fe2O3 (C-d-mFe2O3) nanorods (NRs) derived from Fe-MIL-88B-NH2 NRs were first synthesized via a sequential process including a facile hydrothermal reaction and one-step pyrolysis at a moderate temperature in air. The MEMS architecture ensures low power consumption, small size, and high integration of the sensor. The obtained C-d-mFe2O3 NRs exhibit good thermal stability and superior acetone sensing performance with excellent response (Ra/Rg = 5.2 to 2.5 ppm) and selectivity, fast response/recovery speed (10/27 s), and low detection limit of 500 ppb at 225 °C. Furthermore, the acetone sensor exhibits remarkable long-term stability and repeatability even after being stored in air for over 10 months. The enhanced acetone sensing performance could be attributed to the large specific surface area of mesoporous α-Fe2O3 NRs, highly conductive carbon nanoparticles on the surface, and the formation of α-Fe2O3/C heterojunction. Density functional theory (DFT) calculations help to further confirm the superior acetone sensing performance. The competitive performance makes C-d-mFe2O3 NRs gas sensor a great potential for practical application in environmental harmful acetone gas monitoring.

Effects of chronic exposure to the fungicide vinclozolin on gut microbiota community in an aquatic turtle.

Environmental issues associated with the widespread use of agricultural chemicals are being seriously concerned. Of them, toxicological impacts of fungicides in aquatic organisms are often overlooked. Here, soft-shelled turtle (Pelodiscus sinensis) hatchlings were exposed to different concentrations of vinclozolin (0, 5, 50, 500 and 5000 µg/L) for 60 days to investigate the impact of fungicide exposure on their gut microbial composition and diversity. Vinclozolin exposure significantly affected the composition of the gut microbiota in hatchling turtles. Unexpectedly, gut bacterial diversity and richness of vinclozolin-exposed turtles (but not for the 5000 µg/L-exposed group) were relatively higher than control ones. At the phylum level, the abundance of Firmicutes was decreased, while that of Proteobacteria was increased in high-concentration groups. At the genus level, some bacterial genera including Cellulosilyticum, Romboutsia and Clostridium_sensu_stricto, were significantly changed after vinclozolin exposure; and some uniquely observed in high-concentration groups. Gene function predictions showed that genes related to amino acid metabolism were less abundant, while those related to energy metabolism more abundant in high-concentration groups. The prevalence of some pathogens inevitably affected gut health status of vinclozolin-exposed turtles. Such gut microbiota dysbiosis might be potentially linked with hepatic metabolite changes induced by vinclozolin exposure.