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The production plan of an open-pit mine depends on the block model, so it's crucial to determine the appropriate method and size for partitioning it. This study proposes a new method based on a closed shell three-dimensional geological model for determining block model size in open-pit mines. Instead of using regular block models, the shell model is directly cut, and the discrete geological body is referred to as the "mining model." Mining parameters and the shovel-truck's performance are integrated into the method. Bench height determines the Z-axis size, bench slope angle determines the inclination angle, and shovel width determines the X-axis size of the block model. The operation efficiency of the shovel-truck considers the probability distribution of simultaneous operations, allowing the determination of the Y-axis size of block models for different types of shovels. The developed "Mining Model" module in the software "Life Cycle Mining System" is used for practical implementation. By comparing the results with traditional block models, the superiority of the proposed method is demonstrated. This study provides a more accurate model for optimizing the production plan of open-pit mines throughout their life cycle. [ABSTRACT FROM AUTHOR]

Inspired by a critical organelle called rough endoplasmic reticulum (RER), a wave‐energy attenuation nano‐carbon foam (WANF) with a unique hierarchical composite structure consisting of 3D‐lamelle, 2D‐perforations and 1D‐microspheres is constructed by incorporating graphene oxide (GO) and polydimethylsiloxane (PDMS) into a carbon nanotubes (CNTs)‐based aerogel. Benefiting by unusual mechanisms like vortex shedding, secondary reflection and resonance, WANF displays excellent acoustic wave absorption, achieving a sound absorption coefficient of over 0.9 with a bandwidth of 4.75 kHz at a thickness of 20 mm. Significantly, it features obvious acoustic absorption intensity in medium‐low frequency range. Moreover, the nano‐carbon aerogel skeleton (NCAS) of WANF endows it with good electromagnetic wave absorption through dielectric loss, exhibiting a minimum reflection loss of −48.61 dB and an efficient electromagnetic absorption with a bandwidth of 5.35 GHz. The excellent wave‐energy attenuation performance of WANF indicates an attracting double‐stealth effect in sonic and electromagnetic area, which shows great potential in integrate protection of advanced military equipment and sensitive electronic infrastructures. [ABSTRACT FROM AUTHOR]

Reasonable production capacity is related to the economic benefits of an open-pit coal mine. This study analyzes the relationship between the working face length, the annual advancing speed and the production capacity. It constructs a production capacity function relationship model. Take the Baorixile open-pit coal mine as an example. The remaining unmined parts are divided into four regions, and the range of production capacity in each region is analyzed by the established model and the determined respectively. On this basis, three mining district division plans are proposed. By analyzing and comparing the stripping ratio, mining life of the district, fault influence, difficulty of transition connection in the mining districts, the convenience of transportation system layout and other indexes of each plan, Plan 3 is determined to be the optimal plan. The production capacity planning results of each mining district in this plan are as follows: the production capacity of the 3rd mining district is 30–35 Mt/a; the production capacity of the 4th mining district in Region 1 is 20–31 Mt/a, and the production capacity in Region 2 is 24–33 Mt/a; the production capacity of the 5th mining district is 20–27 Mt/a. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Research on the method of determining the block size for an open-pit mine integrating mining parameters and shovel-truck's operation efficiency." The original article contained an error in the Acknowledgements section, specifically the grant number for the National Natural Science Foundation of China. The corrected version of the article acknowledges the correct grant number. The authors of the article are Weiqiang Guo, Guangwei Liu, Jiaming Li, Senlin Chai, and Shupeng Guo. [Extracted from the article]

This study presents an experimental method for investigating the compressive creep behavior of C-S-H micropillars at micro-scale. The micropillars with two different diameters (5 μm and 0.5 μm) in hardened cement paste (HCP) are fabricated using focused ion beam (FIB) milling and subjected to compression using an indenter with flat-end tip. Multi-stage loading protocols are used to sequentially obtain the elastic modulus, creep behavior, and compressive strength of the individual C-S-H micropillar sample. The sinking effect of C-S-H micropillars during the compression introduces a part of irrelevant deformation to the displacement measured by the indenter. To address this, a numerical procedure is used to quantify the sinking deformation and to determine the true stress-strain relationship of the C-S-H micropillar from the measured indentation force-displacement relationship. The results show that the measured specific creep compliance of all C-S-H micropillars can be well described by power-law functions with an average R2 > 0.99. In contrast, if the specific creep curves are fitted by logarithmic functions, the average R2 is only 0.59. It is indicated that the micropillar creep tests capture the short-term creep of C-S-H. Moreover, micropillar creep tests measure the creep compliance of C-S-H that is one order of magnitude faster than the most macroscopic creep tests. This experimental study emphasizes the impact of imposed stress status on the creep behavior of C-S-H at microscale. [ABSTRACT FROM AUTHOR]

• Exceptional properties of developed Ultra-High Performance Concrete (UHPC). • Structural design considerations for UHPC overlay on concrete bridge. • Construction techniques for successful UHPC overlay implementation. As ultra-high performance concrete (UHPC) has superior mechanical and durability properties, it is a promising solution to apply a thin layer of UHPC on top of normal concrete bridge decks to extend the service life and enhance the structure integrity. However, the large autogenous shrinkage characteristics of UHPC is still an issue, and there is a lack of research focus on the structural design and stress analysis of the concrete bridge deck and UHPC overlay system. Thus, this study first designs and evaluates a new low-shrinkage UHPC mixture internally cured with a high-strength, high-abrasion resistant, and porous aggregate (calcined bauxite, CB), and the optical mixture design is validated by testing the fresh, mechanical, autogenous shrinkage, abrasion, and impact properties of the UHPCs. Second, the outdoor UHPC overlay-NC composite slab experiments and the numerical modeling are carried out to analyze the shrinkage performance of the UHPC, debonding potential of the overlay layer, stress and strains development in the system. Then, the significant influencing factors and the key measures to assure the UHPC-NC interface bonding properties are obtained, including proposing a grouped L-shape steel rebar arrangement for strengthening the interface. Finally, the applicability of the new low-shrinkage UHPC mixture as overlay materials on a real concrete bridge deck is demonstrated. Based on these, the engineering design scheme and the construction recommendations of an environmentally-cured low-shrinkage UHPC overlay on concrete bridge deck is given. The utilization of UHPC overlay on concrete bridge decks offers a novel paving system that substantially enhances strength, abrasion resistance, and durability. [ABSTRACT FROM AUTHOR]

Fresh concrete exposed to hot, dry, or windy conditions is very sensitive to plastic shrinkage cracking. However, there are some challenges in assessing and controlling plastic shrinkage cracking since a number of factors should be considered, of which the evaporation of bleeding water from the surface of concrete is an important one. In this article, the characteristics of evaporation from the surface of fresh concrete were experimentally studied, and the variables include the w/c ratio and the wind velocity. Based on a conventional method for the calculation of evaporation from bulk water surface, a modified model was proposed to predict the rate of evaporation from fresh concrete surface. The initial rate of evaporation was calculated by assuming that the surface of fresh concrete is always covered by bleeding water and that the evaporation rate of the bleeding water is equal to that of the bulk water. The modified model was then verified by experimental data, and applied to analyze the effect of wind velocity and temperature on the surface drying of fresh concretes. This method is capable of predicting the time-dependent variation of evaporation rate of the fresh concrete under different environment conditions. The findings are of significance for assessing the cracking risk of structural concrete during the plastic stage and for consequently taking measures to prevent it from plastic cracking. [ABSTRACT FROM AUTHOR]

• Grouped L-shape rebar connectors can alleviate UHPC delamination from NSC substrate. • Grouped connectors can increase the degree of restraint to UHPC overlay by 13%∼38%. • The bond-slip behavior of these L-shape rebar connectors is evaluated by simulation. Ultra-high performance concrete (UHPC) overlay deployed in concrete bridge deck pavement exhibits a high amount of shrinkage that can lead to warping and debonding from the substrate of normal-strength concrete (NSC). This paper is to use grouped L-shape rebar connectors as a solution to alleviate the warping and debonding of the UHPC overlay which is cast on the NSC substrate. The rebar connectors are designed to be post-installed vertically in the hardened NSC substrate, and the rest part of the connectors are anchored in the UHPC overlay after the UHPC casting. In this study, an outdoor UHPC-NSC composite slab test was carried out, and two types of UHPC materials with distinct autogenous shrinkage were produced to cast the overlay. Different schemes of the rebar connector layout with various installing rates were performed. The restrained shrinkage of the UHPC overlay was monitored by the embedded strain sensors, and the UHPC overlay's long-term warping behavior was evaluated. In addition, a numerical model was established considering the shrinkage and creep of UHPC, the contact between the UHPC and the NSC substrate, and the concrete-to-rebar interaction. The results show that the grouped L-shape steel rebar connectors significantly affect the restrained shrinkage of the UHPC overlay by increasing the degree of restraint to the UHPC overlay by 13%-38%. The grouped L-shape steel rebar connectors are proven effective in alleviating warping and delamination in the UHPC-NSC composite slabs. Therefore, the use of grouped rebar connections is feasible in bridge deck pavement engineering. [ABSTRACT FROM AUTHOR]

Rutting is one of the most prevalent road distresses in asphalt pavement (AP), it is therefore critical to accurately predict the development of rutting to guide pavement design and maintenance. Based on the measured rutting data obtained from the RIOHTrack in China, the the most widely used MEPDG rutting model is evaluated for its applicability. Due to the original MEPDG rutting model being highly sensitive to a rapid increase of the number of load repetitions (NLR), a modified MEPDG rutting model is proposed by introducing a growth coefficient ($\alpha$ α) for the NLR to reduce the effect of the rapid increase of NLR on the rutting prediction. The applicability of the modified rutting model is then verified by various pavement structures tested in the RIOHTrack, and the value of coefficient ($\alpha$ α) based on the different annual average growth rates of traffic volume is provided for facilitating application. Moreover, the growth rate of the flow ruts is indicated as the critical parameter to describe the rutting development and used for rutting prediction, and the correlations between the pavement structures and the parameter are analyzed. The findings can guide for predicting the rut depth of the asphalt pavement within the whole service life. [ABSTRACT FROM AUTHOR]

Rutting is one of the most prevalent road distresses in asphalt pavement (AP), it is therefore critical to accurately predict the development of rutting to guide pavement design and maintenance. Based on the measured rutting data obtained from the RIOHTrack in China, the the most widely used MEPDG rutting model is evaluated for its applicability. Due to the original MEPDG rutting model being highly sensitive to a rapid increase of the number of load repetitions (NLR), a modified MEPDG rutting model is proposed by introducing a growth coefficient ($\alpha$ α) for the NLR to reduce the effect of the rapid increase of NLR on the rutting prediction. The applicability of the modified rutting model is then verified by various pavement structures tested in the RIOHTrack, and the value of coefficient ($\alpha$ α) based on the different annual average growth rates of traffic volume is provided for facilitating application. Moreover, the growth rate of the flow ruts is indicated as the critical parameter to describe the rutting development and used for rutting prediction, and the correlations between the pavement structures and the parameter are analyzed. The findings can guide for predicting the rut depth of the asphalt pavement within the whole service life. [ABSTRACT FROM AUTHOR]

Concrete creep is strongly affected by its internal relative humidity and temperature evolutions. Microprestress-solidification (MPS) theory, as one of the most advanced creep theories, is capable of simulating long-term compressive creep of concrete under changing environment (temperature and relative humidity) conditions. However, for tensile creep which is an indispensable part of concrete material and structure analysis, the experimental evidences of thermal and relative humidity effects are lacking. Moreover, the applicability of MPS theory-based model originally developed for compressive creep of hardened concrete to tensile creep modeling of early-age concrete is unknown. This study measures the tensile creep of early-age concrete under different temperature histories (constant normal and high temperature; temperature increase upon and during loading) at loading ages of 1, 7, and 28 days. The applicability of MPS theory-based model to tensile creep is verified. The original MPS model capable of modeling long-term compressive creep has been extended to model early age tensile creep under different temperature histories, which will allow more accurate stress calculation and cracking potential assessment for concrete at early ages. However, the limitation of MPS model when considering relative humidity effect should be noticed and possibly improved in the future. [ABSTRACT FROM AUTHOR]

Ultra-high performance concrete (UHPC) shows very different properties such as high level of autogenous shrinkage and low creep coefficient compared to conventional concrete. One of the problems posed by this is that when UHPC is used as a thin, bonded overlay for concrete bridge decks or pavements, there is limited information regarding the shrinkage-induced warping of the overlay and optimization designs to minimize it. This study conducted a hygro-mechanical finite element analysis to investigate the warping behavior of UHPC overlay cast on mature substrate of normal strength concrete (NSC). The simulation results were validated with the observations from outdoor overlay tests. It is shown that incorporating the shrinkage and creep of UHPC and the bonding behavior of the overlay-to-substrate interface can predict the UHPC overlay's warping deformation in an accurate way. Based on the model, a parametric study was carried out to investigate the influences of sealed curing period, the roughness degree (the bond strength) of overlay/substrate interface, the overlay thickness, the rebar reinforcement inside the overlay, and the amount of total (free) shrinkage of UHPC on the magnitude of the overlay's warping. The findings obtained in this study include the following: (1) The UHPC's shrinkage and the bond strength between UHPC overlay and substrate are two essential factors affecting the overlay's warping behavior, (2) With an increase in UHPC overlay thickness, the calculated overlay's warping deformation is slightly increased, and (3) Internal rebar reinforcement has a limited contribution to reduce the overlay's warping. [ABSTRACT FROM AUTHOR]

Internal curing (IC) technology using prewetted lightweight fine aggregates (LWFAs) as additives has been proved an effective means for mitigating both autogenous shrinkage and early-age cracking under sealed curing conditions. However, for practical structures in the field, concrete experiences more complex environmental conditions compared to under sealed curing. To better utilize internal curing technology for durable concretes, this study conducts comprehensive investigations on both control and internally cured concretes at water/cement (w/c) ratio of 0.3 and 0.4 in terms of the influence of age when concrete is exposed to drying and the drying duration on the developments of integrated shrinkage, internal relative humidity, compressive and flexural strengths, mass loss, and cracking potential. The results are beneficial for producing internally cured concrete with increased resistance to early-age cracking and enhanced durability for infrastructure applications. [ABSTRACT FROM AUTHOR]

A stable microbial consortium, separated from a refinery wastewater sample, was able to utilize carbazole as the sole source of carbon, nitrogen, and energy, and liberated ammonia from excess nitrogen. Two bacterial strains (NCY and NCW) were isolated from the microbial consortium using a nutrient agar plate. Based on the 16S rDNA sequence analysis, the two bacteria were identified as Chryseobacterium sp. NCY and Achromobacter sp. NCW, respectively. No intermediates of carbazole degradation were detected by high-performance liquid chromatography. The substrate specificity assay showed that the consortium could utilize compounds similar to carbazole, such as phenanthrene, naphthalene, and imidazole. Neither the pure strain NCY nor NCW could degrade carbazole after domestication for several times. It was suggested that the two bacteria formed a microbial consortium capable of metabolizing carbazole. [ABSTRACT FROM AUTHOR]

A reliable method of separating and identifying glucosinolates in rapeseed has been developed by using reversed-phase high-performance liquid chromatography (HPLC) with confirmation by electrospray mass spectrometry and ultraviolet spectroscopy. Volatile ion-pairing regent and acetic acid was added to modify the mobile phase. After extraction, deproteinization, and centrifugation, glucosinolates were first purified by a column packed with Diethylaminoethyl-(DEAE)-sephadex A-25 and then were injected into the chromatographic system. Confirmation of identity was accomplished using both negative-ion electrospray mass spectrometry and ultraviolet spectroscopy. Seven species of glucosinolates were determined by using this method. [ABSTRACT FROM AUTHOR]

• The pore parameters are measured from MIP, BSE, and X-ray CT scanning techniques. • The pore characteristics of cement pastes subject to freeze-thaw cycles are assessed. • The intrinsic permeability of cement paste is obtained by three different methods. • The GEM method is a more suitable tool for cementitious materials with low porosity. Assessing the permeability of concrete subject to unexpected freeze-thaw cycles at early age is critical to ensure the durability and service life of concrete structures. However, measuring permeability of concrete and cement paste has been a challenge. In this study, the intrinsic permeability of cement paste is calculated by using Katz-Thompson equation, general effective media (GEM) method, and Navier-Stokes method based on the pore parameters measured from the mercury intrusion porosimetry (MIP), the backscattered electron (BSE) imaging, and the X-ray computed tomography (CT) techniques. The pastes are subject to freeze-thaw cycles at the age of 1 and 7 days followed by sealed curing until the age of 40 days. The water-to-cement (w/c) ratios of paste are 0.3 and 0.5, representing the high- and low-strength concrete, respectively. The measured pore characteristics and the calculated intrinsic permeability are then compared to that of the control samples. The measurable pore size range of each technique is quantified, and the applicability of each computing method for permeability is discussed. The results of this study provide the insight into the feasibility of different measuring techniques for pore parameters and the predicting methods for permeability, particularly for cementitious materials subject to freeze-thaw cycles. [ABSTRACT FROM AUTHOR]

Fillers have been commonly used to replace a portion of cement in ultra-high-performance concrete (UHPC) for economic and eco-friendly purposes. However, mostly only the type and amount of filler are addressed, and limited efforts have been made on the size and shape effects of filler. This study used inert mineral fillers with different morphologies (approximately spherelike versus needlelike) to study the effect of the shape and different particle sizes (fineness) within the same filler type to study the effect of the size. A systematic study was carried out to investigate these effects on the workability, strength, hydration, modification of the particle-size distribution (PSD), and microstructure of the designed nonfibrous UHPC matrixes. The mixture proportion design is based on a modified Andreasen and Andersen model, and three mixtures devoid of fillers were prepared firstly to study the effect of superplasticizer dosage on the UHPC matrix to determine the saturation dosage. Results reveal that larger-sized approximately spherelike filler (limestone or quartz) results in a slightly negative effect on the strength, whereas larger-sized needlelike wollastonite enhances the strength of the mixture. The mixtures with 20% substitution of cement by the seven different fillers obtained increased workability, decreased cost, and higher strength or no more than 4% strength reduction compared with the control mixture devoid of filler. This quantification of size and shape effects of fillers will provide an effective theoretical basis, and particular fillers could be intelligently chosen in the engineering practice for the production of UHPC. [ABSTRACT FROM AUTHOR]

Highlights • RF exposure reduced testosterone levels and its synthesis genes in mice testis. • RF exposure reduced levels in CamkI/Rorα mRNA/protein expression. • KN-93 blocked the inhibitory effect of RF exposure on testosterone synthesis and regulatory factors of CamkI and Rorα in primary Leydig cells. • Ionomycin reversed the down-regulation effect of RF exposure on intracellular [Ca2+]i and CamkI/Rorα mRNA/protein expression in vitro. Abstract Exposure to radiofrequency fields (RF) has been reported to induce adverse effects on testosterone production and its daily rhythm. However, the mechanisms underneath this effect remain unknown. In this study, male mice were exposed to 1800 MHz radiofrequency fields (RF, 40 μW/cm2 power intensity and 0.0553 W/Kg SAR) 2 h per day for 32 days. The data suggested that RF exposure: (i) significantly reduced testosterone levels, (ii) altered the expression of genes involved in its synthesis (Star, P450scc, P450c17 and 3β-Hsd) in testicular tissue, (iii) significantly reduced regulatory protein CaMKI/ROR α. Similar observations were also made in cultured primary Leydig cells exposed in vitro to RF. However, all of these observations were blocked by CaMK inhibitor, KN-93, and ionomycin reversed the down-regulation effects on intracellular [Ca2+]i and CaMKI/ROR α expression induced by RF exposure. Thus, the data provided the evidence that RF-induced inhibition of testosterone synthesis might be mediated through CaMKI/ROR α signaling pathway. Capsule: CaMKI/RORα signaling pathway was involved in the inhibition of testosterone synthesis induced by RF exposure. [ABSTRACT FROM AUTHOR]

Assessing the stress development in concrete requires an appropriate tensile creep model which is capable of incorporating the effect of the field environment conditions. This study quantifies the effect of temperature variation on the very early-age stress developments in restrained concrete by adopting a modified microprestress-solidification (MPS) theory-based creep model. The MPS creep model is first calibrated and verified based on the measured direct tensile creep data under normal and high temperature histories, it is then used to predict the very early-age stress development of the fully restrained concrete specimens under variable temperature history since casting. The predicted results are in good agreement with the experimental results. The tensile stress in restrained specimens can be relaxed by 80 %–87% within the first three days since casting. The predicted stress exhibits an obvious deviation from the measured one if temperature effect is not considered. Therefore, it is of importance to consider the temperature effect on concrete creep when the temperature variation in concrete is significant, and MPS creep model is valid for tensile stress prediction in concrete at very early ages. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new method of Direct Friction Stir Processing is proposed to fabricate Mg/SiCp surface composite like a planter. [•] The tool was designed as a hollow and pinless tool, and the reinforcement were preplaced. [•] The reinforcement particles were homogeneous and dispersed in the stir zone. [•] The micro-hardness and wear property were promoted by refinement crystallization and reinforcement particles. [ABSTRACT FROM AUTHOR]

According to the 'novel weapons hypothesis', invasive success depends on harmful plant biochemicals, including allelopathic antimicrobial roots exudate that directly inhibit plant growth and soil microbial activity. However, the combination of direct and soil-mediated impacts of invasive plants via allelopathy remains poorly understood. Here, we addressed the allelopathic effects of an invasive plant species (Rhus typhina) on a cultivated plant (Tagetes erecta), soil properties and microbial communities. We grew T. erecta on soil samples at increasing concentrations of R. typhina root extracts and measured both plant growth and soil physiological profile with community-level physiological profiles (CLPP) using Biolog Eco-plates incubation. We found that R. typhina root extracts inhibit both plant growth and soil microbial activity. Plant height, Root length, soil organic carbon (SOC), total nitrogen (TN) and AWCD were significantly decreased with increasing root extract concentration, and plant above-ground biomass (AGB), below-ground biomass (BGB) and total biomass (TB) were significantly decreased at 10 mg·mL-1 of root extracts. In particular, root extracts significantly reduced the carbon source utilization of carbohydrates, carboxylic acids and polymers, but enhanced phenolic acid. Redundancy analysis shows that soil pH, TN, SOC and EC were the major driving factors of soil microbial activity. Our results indicate that strong allelopathic impact of root extracts on plant growth and soil microbial activity by mimicking roots exudate, providing novel insights into the role of plant–soil microbe interactions in mediating invasion success. [ABSTRACT FROM AUTHOR]

Hyporheic zone is an important region of nitrogen removal in river systems. Hyporheic exchange generally leads to heterogeneous redox environments, which are conducive to nitrogen transformation. This study seeks to determine the influence of hyporheic upwelling fluxes on inorganic nitrogen (NH 4 + , NO 3 − , and NO 2 − ) concentrations in the sediment pore water of the Weihe River, China. The patterns and magnitudes of hyporheic water exchange on 12 August 2016 were derived by a one-dimensional heat transport model, and inorganic nitrogen concentrations in the pore water, surface water, and groundwater were obtained. The results indicated that hyporheic water exchange was characterized by upwelling at each point during the test period. Moreover, NH 4 + dominated the hyporheic zone from 0 to 45 cm, likely due to organic nitrogen mineralization. Additionally, a non-linear relationship was observed between NH 4 + concentrations and upwelling fluxes. This relationship was derived by analyzing the effect of upwelling on biogeochemical activity and nitrogen transformation. Notably, increasing upwelling fluxes less than 400 mm/d resulted in high NH 4 + concentrations, whereas fluxes exceeding 400 mm/d led to low NH 4 + concentrations. Overall, the variations in inorganic nitrogen associated with hyporheic water exchange are of great importance for controlling nitrogen pollution and maintaining sustainable health in river systems. [ABSTRACT FROM AUTHOR]

Seven luminescent iridium(III) complexes were prepared to investigate the relationships between chemical structures and properties of protein staining. For the first time, the effect of the main ligand, the π conjugation effect of the ancillary ligand, and the charge effect of organometallic complexes on protein staining has been revealed. Most importantly, this study gives the first experimental evidence of the potential applications of charge-neutral organometallic complexes in protein staining, which could open an avenue of exploiting novel protein staining agents in the future. [ABSTRACT FROM AUTHOR]

The aim of the present study was to elucidate whether the GATA-4/SF-1 signalling pathway is involved in the inhibitory effects of melatonin on testosterone production in both the TM3 Leydig cell line and in C57BL/6J mice. In-vitro experiments demonstrated that melatonin treatment significantly reduced testosterone levels in cell culture medium ( P < 0.05 or P < 0.01); and decreased intracellular cyclic adenosine monophospha accumulation ( P < 0.05 or P < 0.01) and mRNA/protein expression of GATA-4 , SF-1 (NR5A1) , StAR , P450SCC (CYP11A1) and 3β-HSD ( P < 0.05 or P < 0.01). These effects were blocked by N-acetyl-2-benzyltryptamin, a melatonin receptor antagonist. Similar effects of melatonin on testosterone production ( P < 0.05 or P < 0.01) and down-regulation of transcription factors GATA-4 and SF-1 ( P < 0.01) were also observed in mice treated with intratesticular injections of melatonin. Overall, the data suggest that the inhibitory effects of melatonin on testosterone production are mediated via down-regulation of GATA-4 and SF-1 expression. [ABSTRACT FROM AUTHOR]

In this study, we explored the circadian effects of daily radiofrequency field (RF) exposure on reproductive functional markers in adult male Sprague-Dawley rats. Animals in circadian rhythm (as indicated by melatonin measurements), were divided into several groups and exposed to 1800 MHz RF at 205 μw/cm2 power density (specific absorption rate 0.0405 W/kg) for 2 h/day for 32 days at different zeitgeber time (ZT) points, namely, ZT0, ZT4, ZT8, ZT12, ZT16 and ZT20. Sham-exposed animals were used as controls in the study. From each rat, testicular and epididymis tissues were collected and assessed for testosterone levels, daily sperm production and sperm motility, testis marker enzymes γ-GT and ACP, cytochrome P450 side-chain cleavage (p450cc) mRNA expression, and steroidogenic acute regulatory protein (StAR) mRNA expression. Via these measurements, we confirmed the existence of circadian rhythms in sham-exposed animals. However, rats exposed to RF exhibited a disruption of circadian rhythms, decreased testosterone levels, lower daily sperm production and sperm motility, down-regulated activity of γ-GT and ACP, as well as altered mRNA expression of cytochrome P450 and StAR. All of these observations were more pronounced when rats were exposed to RF at ZT0. Thus, our findings indicate potential adverse effects of RF exposure on male reproductive functional markers, in terms of both the daily overall levels as well as the circadian rhythmicity. [ABSTRACT FROM AUTHOR]

Abstract: An approach for fabrication of core–shell composite beads was described, with polystyrene–divinylbenzene (PS–DVB) as the core and multi-walled carbon nanotubes (MWCNTs) as the shell through electrostatic attraction-induced self-assembly. MWCNTs were easily quaternized with a defined number of bonded layers and desirable positive charge by a multi-step synthesis, using methylamine and 1,4-butanediol diglycidyl ether as monomers to build a branching polymer that has quaternary ammonium groups. PS–DVB beads were sulfonated by sulfuric acid to provide opposite charge, which had electrostatic interaction with quaternized MWCNTs. Functionalization of MWCNTs was characterized by techniques that include Fourier transform infrared spectroscopy, thermogravimetry and scanning electron microscopy. The dispersion of MWCNTs in deionized water was enhanced after the grafting of cationic polyelectrolytes on them, which was in agreement with the positive charge at any pH value. With the PS–DVB/MWCNT composite beads as anion exchange phase and potassium hydroxide solutions as eluent, the common inorganic anions were well separated with high stability. [Copyright &y& Elsevier]

Abstract: A single pump cycling-column-switching technique has been developed for the iodate analysis in edible salt. Homemade high exchange capacity columns were adopted for the separation of iodate and chloride. Iodate could be retained and concentrated in a homemade concentrator column after eluents passing through the suppressor. With UV detection, iodate exhibited satisfactory linearity in the range of 0.1–10.0mg/L with a correlation coefficient of 0.9996. The detection limit (LOD) was 45.53μg/L, based on the signal-to-noise ratio of 3 (S/N =3) and a 100μL injection volume. Relative standard deviations (RSDs) for retention time, peak area and peak height were all less than 2.1%. Recoveries of added iodate were in the range of 98.4–101.6% for the spiked samples. The quantitative determination of iodate in edible salt was accomplished by this column-switching technique, without any pretreatment and interference. The results on six samples were statistically compared with results determined by conventional titrimetric method. [Copyright &y& Elsevier]

Highlights: [•] Cationic polyelectrolytes were introduced onto multi-walled carbon nanotubes surface. [•] Agglomeration between quaternized multi-walled carbon nanotubes and PS-DVB beads. [•] The application of multi-walled carbon nanotubes in ion chromatography. [Copyright &y& Elsevier]

Abstract: A simple ion chromatographic method for simultaneous detection of iodide and iodate in a single running was proposed, with columns packed with homemade functionalized polystyrene-divinylbenzene (PS-DVB) resins and column-switching technique. Homemade resins were functionalized with controllable amounts of quaternary ammonium groups. The low-capacity anion-exchange column and high-capacity anion-exchange column were prepared, due to the resins having different exchange capacities. With this method, iodide and iodate in povidone iodine solution were detected simultaneously in a short time with iodide being eluted off first. A series of standard solutions consisting of target anions of various concentrations from 0.01mg/L to 100mg/L were analyzed. Each anion exhibited satisfactory linearity, with correlation coefficient r ≥0.9990. The detection limits (LODs) for iodide and iodate obtained by injecting 100μL of sample were 5.66 and 14.83μg/L (S/N=3), respectively. A spiking study was performed with satisfactory recoveries between 101.2% and 100.6% for iodide and iodate. [Copyright &y& Elsevier]

The indoor total volatile organic compound (TVOC) concentrations and their relationship to potential influencing factors were evaluated. Samples ( n = 2302) were collected from 2007 to 2009 both in old structures and new construction in the city of Hangzhou from bedrooms, sitting rooms and studies that had been decorated within the previous year. The average TVOC concentration in all the newly decorated rooms was 0.65±0.69 mg/m. 35.8% of samples exceeded the China standard. Over the past 3 years, the TVOC concentration decreased and then increased ( P < 0.05). The percentage of samples exceeding the China standard in the three rooms decreased in the following order: sitting room>study>bedroom. The characteristics of the TVOC source were a key factor influencing the TVOC concentration. In addition, the TVOC concentration was also ( P < 0.05) related to the temperature, humidity, time from the end of decoration to sampling (DR), and the amount of time windows and doors were closed before sampling (DC). The temperature and humidity were less important than the DR and DC. A model to relate the TVOC concentration to the five factors (temperature, humidity, source, DR, and DC) was established based on 288 samples ( R = 0.83). The model illustrated that the time for the TVOC concentration to meet the China standard was different for the various rooms, and when the other factors were fixed, the impact of DC ( t) on the TVOC concentration could be quantified as ((( t+1)/2)−1)×100%. [ABSTRACT FROM AUTHOR]

Ex situ nitrification and sequential in situ denitrification represents a novel approach to nitrogen management at landfills. Simultaneous ammonia and organics removal was achieved in a continuous stirred tank reactor (CSTR). The results showed that the maximum nitrogen loading rate (NLR) and the maximum organic loading rate (OLR) was 0.65gNl−1 d−1 and 3.84gCODl−1 d−1, respectively. The ammonia and chemical oxygen demand (COD) removal was over 99% and 57%, respectively. In the run of the CSTR, free ammonia (FA) inhibition and low dissolved oxygen (DO) were found to be key factors affecting nitrite accumulation. In situ denitrification was studied in a municipal solid waste (MSW) column by recalculating nitrified leachate from CSTR. The decomposition of MSW was accelerated by the recirculation of nitrified leachate. Complete reduction of total oxidized nitrogen (TON) was obtained with maximum TON loading of 28.6gNt−1 TSd−1 and denitrification was the main reaction responsible. Additionally, methanogenesis inhibition was observed while TON loading was over 11.4gNt−1 TSd−1 and the inhibition was enhanced with the increase of TON loading. [Copyright &y& Elsevier]