Search

• HDO of m-cresol was studied at 250 °C and 1 atm on Pt/Beta with varying BAS/Pt. • Increasing BAS density increases diffusion constraints of m-cresol and products. • Increasing BAS/Pt ratio reduces both the reaction rate and TOF of HDO. • Products distribution varies due to the combined effects of BAS/Pt and diffusion. • A low BAS/Pt is beneficial for improving stability by reducing coke deposition. Metal/zeolite bifunctional catalysts have been widely explored for hydrodeoxygenation (HDO) of phenolics. However, the effect of acid-metal balance is not clearly understood because it is difficult to decouple this from other effects. In this work, a series of 1 wt.% Pt/Beta catalysts with different Brønsted acid site (BAS) to surface Pt ratios (BAS/Pt) were prepared by varying only the density of BAS, and tested in HDO of m-cresol at 250 °C and atmospheric pressure. Increasing BAS density increases intra-crystallite diffusion constraints of m-cresol/products due to strong chemisorption on BAS, and therefore slows their transportation through BASs toward the Pt sites inside the micropores of zeolite. As a result, both the reaction rate and turnover frequency of HDO are reduced with increasing BAS/Pt ratio. Increasing BAS/Pt ratio increases the yield of ring contraction products but reduces the yields of methylcyclohexane and methylcyclohexanone, because of the increased acid functionality and diffusion constraints of intermediates. A low BAS/Pt ratio is beneficial for improving catalytic stability by reducing coke deposition. [ABSTRACT FROM AUTHOR]

• The kapok fiber VIP was green, degradable and nonpetroleum-based. • Hollow structure and porosity of fibres retained in wet forming process. • The thermal conductivity of kapok fiber VIP was as lower as 6.12 mW/(m·K). • Thermal conductivity of VIPs insensitive to temperature change. Vacuum insulation panel (VIP) is a new type of thermal insulation material with ultra-low thermal conductivity. Most of the VIP core materials are petroleum based, which helps achieve good thermal insulation performance and long service life. However, high cost and poor sustainability are not conducive to the long-term development of this industry. In this study, a new strategy is developed to prepare VIP core materials by using light, eco-friendly, and renewable kapok fibres. The results show that the wet forming process of the kapok fibre core material can maintain their hollow structure of the fibre and the porosity of VIP core could reach above 94%. The prepared kapok fibre VIPs have excellent thermal insulation performance and the thermal conductivity was as lower as 6.12 mW/(m·K) at an internal pressure of 0.05 Pa. Furthermore, these VIPs have outstanding stable thermal performance, and thermal conductivity increased only by 9–13% when the ambient temperature increased from 15 to 55 °C. The VIP density is lower than 105 kg/m3 due to the special thin-walled and large cavity structure of kapok fibres. It was confirmed that kapok fibres are a potential alternative to fume silica for super novel VIPs that are green, renewable, and eco-friendly with sustainable performance. [ABSTRACT FROM AUTHOR]

Tebuconazole is a widely used fungicide that has been detected in water ecosystems, of which the concentrations may affect the endocrine function of aquatic organisms. At present study, tissue-specific bioaccumulation of tebuconazole was found in ovary of adult zebrafish, indicating a potential risk of endocrine disruption. In order to evaluate the potential endocrine disrupting effects, three life stages (2 hpf (hours post-fertilization) −60 dpf (days post-fertilization), Stage I; 60–120 dpf, Stage II; 180–208 dpf, Stage III) of zebrafish (Danio rerio) were chronically exposed to tebuconazole at the concentrations ranging from 0.05 mg/L to 1.84 mg/L. Result showed that exposed to tebuconazole could lead to a male-biased sex differentiation in juvenile zebrafish and significant decrease of the percentage of germ cells in sexually-mature zebrafish. Egg production was significantly inhibited by 57.8% and 19.2% after Stage II- and Stage III-exposures, respectively. The contents of 17β-estradiol in gonad decreased by 63.5% when exposed to 0.20 mg/L tebuconazole at Stage II and by 49.5% after exposed to 0.18 mg/L tebuconazole at Stage III, respectively. For all stages exposure, reductions in 17β-estradiol/testosterone ratio were observed, indicating an imbalance in steroids synthesis. Additionally, tebuconazole reduced the expression of cy p19a, which was consistent with the decrease of E2 level. In overall, the present findings indicated that, playing as an anti-estrogen-like chemical, tebuconazole inhibited the expression of Cyp19, thereby impairing steroid hormones biosynthesis, leading to a diminished fecundity of zebrafish. Image 1 • Tebuconazole plays as an anti-estrogen endocrine disrupting effects on zebrafish. • Tebuconazole induces a male-biased gonadal differentiation in juvenile zebrafish. • Tebuconazole delays development of germ cells in puberty and adult zebrafish. • Block of E 2 pathway may be the disrupting mechanism caused by tebuconazole. Tebuconazole blocks E2 pathway, thereby leading to a male-biased differentiation in juvenile zebrafish and delaying germ cells development in puberty and adult zebrafish, playing an antiestrogen-like role. [ABSTRACT FROM AUTHOR]

[Display omitted] • It was first time to attempt to cross link polydopamine and epigallocatechin-3-gallate together to enhance osteointegration for polyetheretherketone. • It showed that the cross-linked coatings provided phenolic hydroxyl and amino groups and enhanced hydrophilicity of the polyetheretherketone. • It may lay the foundation for the further deployment of the cross-linked polydopamine and epigallocatechin-3-gallate coating in clinical practice. The increasing demand for enhanced osteointegration calls for next-generation polyetheretherketone (PEEK) that can offer fast bone integration. Whether polydopamine (PDA) and epigallocatechin-3-gallate (EGCG) cross-linked coatings could improve osteointegration of PEEK remains unclear. Here, we fabricated a series of PDA and EGCG cross-linked coatings (PE coatings: P2E0.1, P2E0.5, P2E1, and P2E2 coatings) to enhance osteointegration of PEEK. The material characteristics of coatings were studied using scanning electron microscopy, X-ray photoelectron spectroscopy, micro-BCA tests, and static water contact angle tests. We evaluated the cytotoxicity, cell adhesion, and osteogenic effects of the coatings in vitro. Furthermore, the P2E0.5 coating was selected to coat porous PEEK scaffold to observe osteointegration using micro-computed tomography and histology in a rabbit. The results show that the PE coatings provide phenolic hydroxyl and amino groups and enhanced hydrophilicity of PEEK, especially in the P2E0.5 coating. Several lines of cellular evidence suggest that P2E0.5 coatings exhibit a noncytotoxic and excellent osteogenic effect. Compared with PEEK, the P2E0.5-coated PEEK shows higher values of bone volume, trabecular number, and trabecular thickness. This study suggests that the PE coating is a promising candidate for surface modification of PEEK and may lay the foundation for further application of PE coatings in clinical practice. [ABSTRACT FROM AUTHOR]

In order to provide the scientific basis for the environmental risk assessment of cycloxaprid and 6-Cl-PMNI (intermediate of cycloxaprid), the degradation properties of 6-Cl-PMNI in aerobic, anaerobic and/or sterile soil, as well as in water with different pH values at different temperature were explored under laboratory conditions using HPLC for its kinetics study and UPLC-MS/MS for the identification of its metabolites/degradation products. Fortification study showed that the recoveries of 71.4–100.5% with the maximum coefficient variation (CV) of 7.47% were obtained. The linear range was 0.1–10 mg/L with the good linearity of R 2 = 0.9990. For standard, the method LOD (limit of detection) and LOQ (limit of quantification) was 0.03 mg/L and 0.1 mg/L, respectively. Results demonstrated the good performance of the developed method. Kinetics study indicated that the degradation half-lives (t 0.5 ) in pH 3-pH 10 buffers varied from 111.8 d to 288.8 d at 25 °C but rapidly shortened to 1.6–25.7 d at 70 °C. Good negative linear ships (R 2 ≥ 0.8423) between half life and temperature were found. 6-Cl-PMNI could be readily degraded in non-sterile soil (t 0.5 0.8–7.5 d) while slowly degraded in sterile soil (t 0.5 64.8–91.2 d). Three hydrolytic products and one metabolite of 6-Cl-PMNI in aerobic soil were identified. The C C olefinic bond reacted with H 2 O by Markovnikov Additive Reaction and the split of C–Cl were mainly proposed as the possible reaction pathway for 6-Cl-PMNI degradation in water and in soil, respectively. [ABSTRACT FROM AUTHOR]

Plant fibers are a class of biomass resources one of most abundant materials on earth. The bast fiber, as one of the plant fibers with superior specific stiffness and strength, has received constant attention in the field of biocomposites for various industrial sectors. This study is to provide a comprehensive overview of bast fiber composites. The characteristic, chemical composition and performance of five types of most commonly available bast fibers (ramie, jute, kenaf, flax and hemp fibers), and their functionalization in biocomposites are analyzed. The engineering technologies and performance in uses, e.g. flame retardancy, adsorption, reinforcement, biodegradability green sustainability and recyclability of the bast fiber composites are assessed and compiled. The challenges and future development of bast fiber composites are also discussed. The review is expected to provide a platform database but insightful understanding for effective engineering design and broadened applications of bast fiber composites, and for further innovations of functionalized bast fiber composites. [ABSTRACT FROM AUTHOR]

• SREBP-1c is oncogenic via fatty acid and lipid synthesis alters lipogenesis. • Fatty acid related metabolic synthetase is required for tumorigenesis. • Specific fatty acid of palmitic acid is a tumor suppressor gene in fatty acid metabolism. • Inhibition of SREBP-1c is a potential strategy in the treatment of Gastric cancer. Aggressively growing tumors are characterized by significant variations in metabolites, including lipids, and can involve the elevated synthesis of de novo fatty acids. Ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS)-based metabolomics and lipidomics were performed to compare human gastric cancer tissues and adjacent normal tissues from clinical patients. A series of cellular and molecular biological methods were applied to validate the lipidomics results. Palmitic acid (PA) was found to be significantly downregulated in gastric cancer tissues, and it was found that a high concentration of PA specifically inhibited cell proliferation and impaired cell invasiveness and migration in vitro in AGS, SGC-7901, and MGC-803 gastric cancer cell lines. Moreover, sterol regulatory element-binding protein 1 (SREBP-1c) was activated in human gastric cancer tissues, and it promoted the expression of a series of genes associated with the synthesis of fatty acids, such as SCD1 and FASN. SREBP-1c knockdown rescued the migration and invasion defects in AGS and SGC-7901 gastric cancer cells. Taken together, our findings confirmed the variation in fatty acid synthesis in gastric cancer and identified SREBP-1c as a promising target for gastric cancer treatment. [ABSTRACT FROM AUTHOR]

Drug delivery systems (DDSs) have emerged to help delivering the required cargo into the region of the tumor, achieving the objectives of extenuating the potential damage to the body and improving the therapeutic effectiveness. Here, we developed a one-pot process for encapsulating the unstable and hydrophobic d -α-Tocopherol succinate (α-TOS) in zeolitic imidazolate framework-8 (ZIF-8) compounds (defined as α-TOS@ZIF-8) and subsequently coated with a hyaluronic acid (HA) shell to form the HA/α-TOS@ZIF-8 nanoplatform. Of particular note was when the concentration of α-TOS is l mg/mL, the loading rate was high up to 43.03 wt%. The study verified that HA shell, which could act as a smart "switch" and tumor-targeted "guider", had the capacity for extending blood circulation, enhancing the tumor-specific accumulation of DDS via CD44-mediated pathway. HA shell could be disintegrated by hyaluronidase (HAase) in the tumor microenvironment (TME) and the wrapped α-TOS@ZIF-8 exposed, thus leading to the decomposition of ZIF-8 in tumor acidic microenvironment to release the loaded α-TOS. Therefore, the HA/α-TOS@ZIF-8 nanoplatform has been achieved as a tumor-specific and on-demand drug delivery system, which improved the treatment efficiency. Image 1 [ABSTRACT FROM AUTHOR]

• Parental exposure to tebuconazole induced thyroid endocrine disruption in F0 and F1. • Diminished T 4 levels were found in F1 eggs/larvae. • Increased mRNA expression of ugt1ab was observed in F0 and F1 zebrafish. • Developmental toxicity was observed in F1 larvae after parental exposure. Azole fungicides are one class of the most extensively applied current-use pesticides. Tebuconazole is a common azole fungicide that has been frequently detected in aquatic ecosystems, thus raising concerns about its ecological safety. However, adverse effects of tebuconazole remain largely unknown, especially with regard to endocrine function in aquatic organisms. In the present study, sexually immature zebrafish were exposed to different concentrations of tebuconazole (0.05, 0.20 and 0.50 mg/L) for 60 days in order to test for transgenerational toxicity on the thyroid endocrine system. Thyroid hormone homeostasis, neuronal, and cardiovascular development were investigated in the F1 generation, which were reared in tebuconazole-free water. In the F0 generation, exposure to 0.20 and 0.50 mg/L tebuconazole reduced both thyroxine (T 4) and 3,5,3'-triiodothyronine (T 3) levels in females, while the T 3 levels were unchanged in males. Decreased heart rate was found in F1 larvae, as well as diminished T 4 levels in F1 eggs/larvae. We also observed significantly increased expression of ugt1ab mRNA in two generations of zebrafish. Moreover, expression of mRNA associated with neuronal development (e.g. α1-tubulin , mbp , ga p43) and cardiovascular development (e.g. cacna1ab , tnncal) were significantly downregulated in F1 larvae at 5 and 10 dpf. In addition, tebuconazole was detected in F1 eggs following parental exposure, indicating maternal transfer. This study demonstrated that tebuconazole can be transferred to offspring from exposed parents, causing thyroid endocrine disruption and developmental toxicity. [ABSTRACT FROM AUTHOR]

Abstract Developing effective and "green" approaches to handle aquatic pollution problems is currently one of the most important research subjects of environmental remediation. In this paper, an environmentally friendly, low cost, self-cleaning, highly stable and multifunctional TiO 2 enhanced Sodium alginate composite (SAT) aerogel for oil-water separation is developed via a simple combined ionic cross-linking and freeze drying method. The morphological, structural and surface chemical properties of the as-prepared SAT aerogels is characterized by scanning electric microscopy (SEM), X-ray diffraction (XRD), Flourier transformation infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The characterizations demonstrate that the SAT aerogel is of three-dimensional porous microstructure with uniformly dispersed TiO 2 nanoparticles (NPs) on alginate matrix. The hydrophilic alginate matrix combined with this unique morphostructure will ensure the SAT aerogels with underwater oleophobicity and subsequent excellent oil/water separation efficiency (up to 99.7%). Moreover, the firmly attached TiO 2 NPs can also endow the aerogel with better UV-aging resistance, photoinduced self-cleaning and environmental remediation performance. The SAT aerogel exhibits better oil/water separation reusability (at least 60 cycles) compared to SA aerogel and excellent photocatalytic performance for methyl orange (MO) degradation (>85% after 6 times repeated use). The "green" facile fabrication process, excellent oil/water separation, photoinduced self-cleaning and reusable performances make the SAT aerogel promising for practical application in aquatic environments. This work may open up new avenues for designing versatile aerogel for wastewater remediation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Morphology evolution of ZrAlSi phase in Al–18Si–xZr alloys was detected. [•] The morphology transforms from flake-like to block-like with Zr content. [•] Effect of different morphological ZrAlSi on the properties of an A–Si piston alloy was studied. [•] Blocky ZrAlSi phase is good for the elevated-temperature tensile strength. [Copyright &y& Elsevier]

Tebuconazole is widely used as fungicide and has frequently been detected at elevated concentrations in environmental media. To characterize the potential toxicity of tebuconazole on vertebrate and humans. Using zebrafish as a vertebrate model, the toxic effects in liver that produced by low-toxic concentrations of tebuconazole were assessed in adult zebrafish. We further focused on tebuconazole-induced toxicity and its possible mechanism in larval zebrafish using a hepatotoxicity assay. The induction of oxidative stress in adult fish was evaluated by superoxide dismutase (T-SOD), catalase (CAT), peroxidase (POD), glutathione S-transferase (GST) activity, and the increased aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio. Significantly increased enzyme activity was observed in the liver of male and female fish at both exposure and depuration stage. Exposure to maximum non-lethal (MNLC) concentration of tebuconazole from 72 to 120 h post-fertilization (hpf) affected the liver size and yolk retention in larval zebrafish. Decreased fluorescence intensity was observed in larval Tg(Apo14:GFP) zebrafish, indicating liver degeneration after tebuconazole treated. Histopathological examination confirmed the alterations in liver histoarchitecture in exposed zebrafish. Significant 1.28-fold and 1.65-fold increases in reactive oxygen species levels were observed in juveniles exposed to MNLC and lethal concentration 10 (LC 10) group, respectively. The acridine orange staining assay showed that apoptotic cells occurred in the liver regions. These results indicated that tebuconazole exposure resulted in impacts on the ecological risk in fish and vertebrate. Overall, the present study suggested further research in needed to better understand the tebuconazole-induced toxicity mechanism that associated with oxidative stress. Image 1 • Tebuconazole induced hepatotoxicity in both adult and larval zebrafish. • Tg(Apo14: GFP) zebrafish was used for hepatotoxicity assay. • Histopathological results showed alterations in liver histoarchitecture after exposure. • ROS-mediated pathway might induce apoptosis in zebrafish after tebuconazole exposure. [ABSTRACT FROM AUTHOR]

The current conventional photo-therapeutic agents often show low therapy efficacy because of their single treatment model, the limited penetration depth of excitation light and hypoxia in the tumor microenvironment (TME). Herein, a new type of phthalocyanine manganese (MnPcE 4) photosensitizer with strong NIR absorption was designed and fabricated for the first time, and was used to modify pure Bi nanomaterials to obtain an intelligent multifunctional Bi/MnPcE 4 nanocomposites. The Mn2+ in the Bi/MnPcE 4 nanocomposite could catalyze H 2 O 2 to generate O 2 , thus helping to overcome TME hypoxia and enhancing the photodynamic therapy (PDT) efficacy. Further, the nanocomposites showed excellent T 1 -weighted MRI performance. Our novel use of a pure metal Bi core, offers lower toxicity, higher CT imaging performance, and a photothermal therapy (PTT) effect triggered by 808 nm near infrared (NIR) laser. Moreover, in vivo fluorescence imaging (in vivo FL) vividly showed that the nanocomposite rapidly accumulates in tumor sites due to the enhanced permeability and retention (EPR) effect and metabolized in the organs. The presence of Bi enables the use of these nanocomposites as a CT contrast agent, and the Mn content enables them to be used in MRI. This triple imaging ability implies that our nanocomposites have a high potential for use in imaging directed tumor therapy. Image 1 [ABSTRACT FROM AUTHOR]

Abstract It is necessary to develop biodegradable composite films for reducing environmental pollution. Black and biodegradable biochar/gutta percha composite films were developed by adding different contents of biochar (0, 2, 4, 6 and 8%, w/w) into the gutta percha matrix. The results showed that the biochar effectively improved the hydrophobicity and mechanical properties compared with the control film. Moreover, the biochar/gutta percha composite films showed high stretchability and barrier properties. In particular, the 2% BC film had the highest tensile strength (18.3 MPa) and elongation at break (280.4%) and the lowest water vapor permeability value (0.09 × 10−9 g/m/h/Pa) at 34% relative humidity. However, the melting enthalpy (ΔH m) and crystallinity decreased. In addition, these composite films exhibited little electromagnetic interference shielding with a reflection loss up to −1.79 dB at 8.2 GHz. Finally, the composite films were more biodegradable than PE film after 60 days in soil. [ABSTRACT FROM AUTHOR]

Al–Ti–C master alloy has been known as an efficient grain refiner for a series of Al alloys since 1950s. However, the grain refinement mechanism is still not fully elucidated up to now. Herein, we systematically investigate this mechanism by combining Cs-corrected transmission electron microscopy and theoretical calculations. First, the Al/TiC x nucleation interface is determined to be a "Al ∼ Interfacial transition layer ∼ TiC x " sandwich-like structure, with the orientation relationship of [011]Al//[011]TiC x and (1 1 ¯ 1)[011]Al plane inclined 21° to (1 1 ¯ 1)[011]TiC x plane that is beneficial to eliminate the lattice constant misfit between Al and TiC x. The interfacial transition layer, consisting of Al and Ti atoms, play a crucial role in reducing atomic arrangement mismatch between (1 3 ¯ 3)[011]Al and (1 1 ¯ 1)[011]TiC x , thus promoting Al nucleation. Second, rather than directly reacting with Al melt as conventionally reckoned, TiC x with x < 0.92 actually releases Ti atoms to Al melt first after inoculation (720 °C), contributing to the formation of the Ti-containing interfacial transition layer. On the other hand, after Ti releasing, C/Ti ratio in TiC x is increased, which inversely decreases the Ti-releasing capability and leads to grain refinement fading gradually. This study sheds new light on the grain refinement mechanism in Al–Ti–C-refined Al and should build up the foundation for developing high-efficiency TiC x -containing grain refiners. [Display omitted]. [ABSTRACT FROM AUTHOR]

Thiol capped gold nanoparticles with small size, high dispersity, and broad light absorption covering ultraviolet (UV) to near infrared (NIR) region have been developed for catalysis, fluorescence imaging and photodynamic therapy (PDT). The constitution of the metal core in such nanoparticles can strongly influence the luminescence, catalysis, and stability properties. However, to date, a corresponding investigation of the influence of the metallic core on the generation of reaction oxygen species (ROS) and its therapeutic efficiency towards tumor cells remains to be lacking. Herein, we fabricated bimetallic nanoparticles by introducing bismuth into captopril capped gold nanoparticles. Surprisingly, the introduction of the Bi was found enhance the photothermal effect of the nanoparticles to a great extent, and the variation trends for the thermal effect, ROS generation rate, and tumor cell inhibition effect were found to disparate with the changes in the Au and Bi composition. The origin of the photothermal effect was deduced through density functional theory calculations based on microscopic construction. Combined with the intrinsic photodynamic effect, the bimetallic nanoparticles showed an outstanding tumor cell inhibition effect. Furthermore, due to the excellent CT imaging property, our designed nanoparticles provide the exciting possibility to realize CT imaging guided and light-mediated tumor therapy. Image 1 [ABSTRACT FROM AUTHOR]