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Currently, organic dyes and other environmental contaminants are focal areas of research, with considerable interest in the production of stable, high-efficiency, and eco-friendly photocatalysts to eliminate these contaminants. In the present work, bismuth-doped zinc ferrite (Bi-ZnFe2O4) nanoparticles (NPs) and bismuth-doped zinc ferrites supported on sulfur-doped graphitic carbon nitride (Bi-ZnFe2O4/S-g-C3N4) (BZFG) photocatalysts were synthesized via a hydrothermal process. SEM, XRD, and FTIR techniques were used to examine the morphological, structural, and bonding characteristics of the synthesized photocatalysts. The photocatalytic competence of the functional BZFG nanocomposites (NCs) was studied against MB under sunlight. The influence of Bi (0.5, 1, 3, 5, 7, 9, and 11 wt.%) doping on the photocatalytic performance of ZnFe2O4 was verified, and the 9%Bi-ZnFe2O4 nanoparticles exhibited the maximum MB degradation. Then, 9%Bi-ZnFe2O4 NPs were homogenized with varying amounts of S-g-C3N4 (10, 30, 50, 60, and 70 wt.%) to further enhance the photocatalytic performance of BZFG NCs. The fabricated Bi-ZnFe2O4/30%S-g-C3N4 (BZFG-30) composite outperformed ZnFe2O4, S-g-C3N4 and other BZFG NCs in terms of photocatalytic performance. The enriched photocatalytic performance of the BZFG NCs might be ascribed to a more efficient transfer and separation of photo-induced charges due to synergic effects at the Bi-ZnFe2O4/S-g-C3N4 interconnection. The proposed modification of ZnFe2O4 using Bi and S-g-C3N4 is effective, inexpensive, and environmentally safe.

Manganese oxides have been widely studied as anode materials for lithium-ion batteries because they have many advantages such as high theoretical capacity, abundant resources, low price and low environmental tox-icity. In this paper, various manganese oxide materials, i.e., MnO2, Mn3O4, MnO, (FeO)0.331(MnO)0.669 were prepared by facile methods. The above compounds were then characterized through X-ray diffraction spec-troscopy (XRD). The oxidation states of Mn in these compounds were found to be: +4, +3/+2, +2 and +2 each of them corresponding to a different crystal system, respectively: hexagonal, tetragonal cubic, cubic. The electrochemical properties of these four different manganese oxides, used as anode materials, were investigated to find the possible relationship between their valence states, crystal systems and their electrochemical properties. The results show that their electrochemical properties are influenced by their crystal system and cell parameters, while incorporating FeO into MnO has an activation effect on the reversible lithium ion in the batteries.

The n-octadecyltrichlorosilane (OTS) had been coated onto the layered double hydroxides (LDH), and the resultant composite of OTS-LDH was further loaded on the surface of melamine sponge by a soaking method to obtain the OTS-LDH/melamine sponge for efficient oil adsorption in this work. The surface chemical compositions of the OTS-LDH/sponge and its precursors were characterized by EDS, XPS, and FTIR. The results from EDS, XPS, and FTIR showed that the OTS had been successfully coated on LDH. The surface morphologies from SEM for the melamine sponge before and after modification illuminated that the surface skeleton of the OTS-LDH/sponge took a rough micro-nanostructure, and the surface had been loaded with the low surface energy material of OTS, which made the OTS-LDH/sponge display the superhydrophobic properties. The experiments of oil–water separation proved that the OTS-LDH/sponge took an excellent oil–water efficiency, and the modified sponge still took the better oil–water separation performance with an oil adsorption capacity of 13.7–21.1 times of the mass of the pristine sponge even after undergoing repeated extrusion for 60 times during the repeated cycle test.

Transition metal mixed oxides have drawn extensive interest as oxygen evolution electrocatalyst alternatives to noble metal-based materials but generally involve prolonged synthesis routes and limited electrocatalytic activity and stability. Herein we report surface sulfurized CoMn2O4 microspikes (S–CoMn2O4-MSs) grown directly at low temperature and ambient atmosphere using a two-step facile synthesis protocol, requiring only 310 s. S–CoMn2O4-MSs showed excellent OER activity with an overpotential of 300 mV at 10 mA cm−2 while pristine Mn3O4 and Co3O4 required 580 and 410 mV to deliver the same current density value. Moreover, we rationally designed the study to gradually decrease the Tafel slope value from 307.5 to 26.2 mV dec−1 for the best electrocatalyst, with excellent stability at 20 mA cm−2 for 24 h without any binder. This overall performance compares well with very recently reported oxides and CoMn2O4 based systems and the as-synthesized material showed highly competitive overall performance. During this work, the stability of the S2− layer remained the main concern and was confirmed by several characterization techniques. We investigated the surface blockage role of the surface S2− layer and, therefore, optimized the degree of sulfurization for best performance. In the end, we attributed and supported the exciting performance of S–CoMn2O4 MSs to the synergistic effect of Co and Mn, their unique morphology, the easily oxidizable lower oxidation states of cobalt (due to surface sulfurization treatment), and the large interior structure for increased contact with the electrolyte.

Acrylic acid-modified starch has been achieved by grafting the starch with an acrylic acid homopolymer by using the biodegradable nonionic surfactant Lutensol-XL-100 (decaoxyethyele n-decyl ether) and ammonium persulfate as a free radical originator. After obtaining the optimized starch-based plastic thin film, a nanocomposite (NC) was created by incorporating nickel-doped zinc oxide nanoparticles (ZnO@Ni NPs), which served as the control for the degradation rate of the composite plastic. The NC was characterized using FTIR, TGA, DSC, and SEM. The ZnO@Ni NPs induced an antibacterial property in the composite film with improved thermal stability and effective to control bacterial growth. The starch-grafted polyacrylic acid exhibited 23.21% biodegradability in 60 days while its NC showed 16.19% at the same time by a soil burial test. It was observed that the composite film exhibited a significant efficacy against the bacteria.

Background SARS-CoV-2 has been identified in the fecal matter of COVID-19 patients. However, sewage transmission has never been shown. In April 2020, a COVID-19 outbreak occurred in a densely populated community in Guangzhou, China. We investigated this outbreak to identify the mode of transmission. Method A home quarantined order was issued in the community. We collected throat swab samples from the residents and environmental samples from the surfaces inside and around the houses, and conducted RT-PCR testing and genome sequencing. We defined a case as a resident in this community with a positive RT-PCR test, with or without symptoms. We conducted a retrospective cohort study of all residents living in the same buildings as the cases to identify exposure risk factors. Result We found eight cases (four couples) in this community of 2888 residents (attack rate=2.8/1000), with onset during April 5–21, 2020. During their incubation periods, Cases 1-2 frequented market T with an ongoing outbreak. Cases 3-8 never visited market T during incubation period, lived in separate buildings from, and never interacted with, Cases 1-2. Retrospective cohort study showed that working as cleaners or waste picker (RR=13, 95% CIexact: 2.3-180), not changing to clean shoes after returning home (RR=7.4, 95% CIexact: 1.8-34), collating and cleaning dirty shoes after returning home (RR=6.3, 95% CIexact: 1.4-30) were significant exposure risk factors. Of 63 samples collected from street-sewage puddles and sewage-pipe surfaces, 19% tested positive for SARS-CoV-2. Of 50 environmental samples taken from cases’ apartments, 24% tested positive. Viral genome sequencing showed that the viruses identified from the squat toilet and shoe-bottom dirt inside the apartment of Cases 1-2 were homologous with those from Cases 3-8 and those identified from sewage samples. The sewage pipe leading from the apartment of Cases 1-2 to the drainage had a large hole above ground. Rainfalls after the onset of Cases 1-2 flooded the streets. Conclusion Our investigation has for the first time pointed to the possibility that SARS-CoV-2 might spread by sewage. This finding highlighted the importance of sewage management, especially in densely-populated places with poor hygiene and sanitation measures, such as urban slums and other low-income communities in developing countries.

A superoleophilic polyurethane sponge had been constructed by means of an immersion method in an ethanol solution of n-octadecyltrichlorosilane. SEM, FTIR, TGA, and XPS unanimously confirmed that PODS had been successfully coated onto the skeleton of polyurethane sponge. The PODS-modified sponge displayed both excellent hydrophobicity with high water contact angle of 152° and good oil affinity. The PODS-modified sponge took the high adsorptive capabilities for the silicone oil, toluene, and peanut oil with 62.1, 73.7, and 98.2 g · g–1 after 50 cycles of extrusion-release, respectively. The superoleophilic sponge in this work exhibited promising opportunities on the oil/water separation and the oil spill remediation.

Transdermal drug delivery is a new means of delivering drugs through the skin to achieve therapeutic effects. Microneedles have several advantages, including low cost, easy self-administration, and high delivery efficiency. Different polymers affect the morphology, mechanical properties, and drug delivery efficiency of microneedles. To study the performance and limitations of microneedles (MNs), we prepared different ratios of polymers. MNs were fabricated from polyvinylpyrrolidone (PVP) and sodium carboxymethyl cellulose (CMC-Na) using the centrifugal molding method. Needle morphology, formability, and other properties of the polymers were evaluated to compare the performances of MNs with different ratios. PVP and CMC-Na were intermixed at different ratios with water as the solvent. The soluble MNs were prepared by mold casting. The morphology, thermodynamic properties, and crystallinity were studied using scanning electron microscopy (SEM), thermogravimetric analysis (TG), differential scanning calorimetric analysis (DSC), and X-ray diffraction (XRD). The results showed that composite microneedles have good thermal stability. Among the different compositions tested, the 10% PVP/2% CMC-Na composite microneedle demonstrated the best performance with a regular surface morphology and relatively high thermal decomposition and melting temperatures. These results indicate that microneedles with appropriate ratios of two different materials possess good formability and other properties.

Pure self-assembled L-cysteine stabilized covellite nanoplates (CuS@L-Cys NPs) with the best control over size, phase purity structure, morphology, and electrochemical properties were synthesized using a facile, template-free hydrothermal route. The effects of temperature (100–180 °C), reaction time (8–24 h), pH of reaction medium (7–14), concentration of base (0.1–2.4 mL NH3) and concentration of thiourea (1–4 mmol) on the morphologies of CuS@L-Cys nanoplates were studied. The photocatalytic performance of CuS@L-Cys NPs under visible light was studied using methyl orange (MO) as a model dye. CuS@L-Cys NPs were reused successfully for the photodegradation of dye due to the recycling ability of CuS@L-Cys NPs. The hydroxyl radicals (˙OH) generated by CuS@L-Cys NPs were detected using terephthalic acid (TA) as a probe molecule through the photoluminescence (PL) technique. The successful capping of L-Cys on the surface of CuS NPs was confirmed by FTIR spectroscopy. The BET surface areas of the hexagonal CuS@L-Cys NPs and oblong CuS@L-Cys NPs were measured to be 11.87 and 5.66 m2 g−1, respectively. The optical band gaps of the hexagonal CuS@L-Cys NPs (2.0 eV) and oblong CuS@L-Cys NPs (2.04 eV) were determined according to direct bandgap calculations. These results support the presence of hexagonal CuS@L-Cys NP catalysts as efficient accelerators of the photodegradation of MO. Furthermore, the L-cysteine (L-Cys) protective layer could efficiently alleviate the photocorrosion of CuS, giving rise to excellent stability. The high photocatalytic activity of the hexagonal CuS@L-Cys NPs can be ascribed to the reduction of photoinduced electron–hole pair recombination and high specific surface area, as confirmed by BET for other representative samples.

In this present investigation, thiazolylcoumarin derivatives (5a-5k) were synthesized from thiosemicarbazide, ethyl acetoacetate, and naphthaldehyde through a multistep route. The formation of thiazolylcoumarin derivatives with bioactive scaffolds was confirmed through nuclear magnetic resonance spectroscopy. A solvatochromic study of synthesized thiazolylcoumarin derivatives was carried out using ultraviolet-visible methods for dimethylformamide (DMF), ethyl acetate, and ethanol solvents. The redox behaviour of as-synthesized thiazolylcoumarin derivatives (5a-5k) was examined in dimethyl sulphoxide by conducting an electrochemical study. Fluorescence properties of thiazolylcoumarin derivatives were studied in DMF, ethanol, and ethyl acetate to visualize the solvent effect on the emitting ability of thiazolylcoumarin derivatives.

Surface modification of carbon fibres (CFs) is an important part of the interfacial study of CF composites. Traditional modification methods feature complicated production processes and a variety of influential factors. The modification technology utilized may cause fibre damage. To solve this problem, a simple and efficient CF surface modification method involving the in-situ carbonisation of micron-sized sucrose particles, is proposed in this paper. Sucrose crystals were introduced on the surface of the CFs by an ethyl acetate suspension coating and carbonised in atmosphere at moderate temperatures. Carbonisation of sucrose at 290 °C in air resulted in not only the formation of a large amount of C O content, but also in micron-sized particles. The attachment of these uniform and reactive particles to the CF surfaces resulted in a markedly improved impact resistance level of the carbon fibre reinforced polymer (CFRP) composite. Meanwhile, the interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) of the carbonised sucrose-deposited fibre/epoxy composites increased by 20.8% and 13.8%, respectively. This method provides a novel, convenient, and effective approach to enhance the mechanical properties of high-performance CFRPs.

Developing a simple and reliable method for the detection of the highly concerning antibiotic, Chloramphenicol (CAP), is of great importance to food safety monitoring. In this study, the authors take the advantages of polyethyleneimine-functionalized reduced graphene oxide and gold nanocubs (PEI-rGO/AuNCs) composite as electrode modification material to develop an electrochemical aptasensor for the detection of CAP using single-stranded DNA-binding protein. PEI-rGO/AuNCs warrants good electrical conductivity and a high surface-to-volume ratio to achieve the purpose of signal amplification. The CAP-binding aptamers were immobilized on the PEI-rGO/AuNCs modified gold electrode via Au-S affinity. Based on the property that single-stranded DNA-binding protein (SSB) can bind to free single-stranded oligonucleotides without binding to folded oligonucleotides, in the presence of CAP, only a small number of SSB will be immobilized on the aptasensor surface results in a larger peak current, which is typically measured at 0.176 V (vs. Ag/AgCl). The assay has a linear response in the 5 pmol·L−1 to 1 μmol·L−1 concentration range, with a 2.08 pmol·L−1 detection limit. Moreover, the proposed method has been applied to detect CAP in spiked chicken samples with satisfactory results.

The constricted visible light harvesting and undesirable rapid recombination of photogenerated e- and h+ set enormously hinder the activity of the photocatalysts. In this work, we design and develop two-dimensional/one-dimensional (2D/1D) S-g-C3N4/Co-NiS heterojunction with intimate heterointerface contact by self-assembly technique. The fast electron transportation of 2D S-g-C3N4 nanosheets (NSs) and the well-matched energy levels of bare S-g-C3N4 and 5% Co-NiS nanorods (NRs) cooperative support the transportation and separation of photo-carriers at the heterointerface of S-g-C3N4/Co-NiS. The as-fabricated samples were evaluated EDX, SEM, UV–vis, XRD, TEM, FTIR, XPS, BET, PL and transient photocurrent. Moreover, this well-defined construction boosts sunlight harvesting and exhibits a large surface area. Benefiting from the intimate coupling and structural features, the 20% S-g-C3N4/Co-NiS heterojunction attains a noteworthy photocatalytic methylene blue (MB) degradation rate of 100%, considerably improved than that of bare NiS (34%), 5% Co-NiS (57%) and pristine S-g-C3N4 (31%). Concurrently, the photocorrosion of bare S-g-C3N4 was suppressed by simultaneous integrating with NiS and engineering with cobalt, which was demonstrated through a chemical stability test with 6 consecutive experimental tests. Such outstanding enrichment in photocatalytic activity and chemical stability was primarily attributed to boosting spatial charge separation and synergistic effects of the 20% 2D/1D S-g-C3N4/Co-NiS nanocomposites (NCs). Antibacterial performance of 20% 2D/1D S-g-C3N4/Co-NiSNCs against 4 infectious species was evaluated in visible light radiance. Our results emphasize the great importance of the efficacious heterointerface blend of 2D/1D S-g-C3N4/Co-NiS NCs as a promising photocatalyst scheme for enhanced photocatalytic degradation of dye and disinfection of pathogens.

A series of sulfonamide derivatives bearing 2,5-disubstituted-1,3,4-thiadiazole (5a–j) have been synthesized. Thiosemicarbazide was reacted with CS2 to get 2-amino-5-mercapto-1,3,4-thiadiazole 1. The intermediate thiadiazole (1) was alkylated by reacting with different halides (2a–c) to afford the alkylated thiadiazoles (3a–c). The title sulfonamide bearing derivatives (5a–j) have been prepared by condensation of sulfonyl chlorides (4a–d) with thiadiazole derivatives (3a–c). The molecular docking studies of target molecules showed strong binding of compounds (5a–j) with target enzyme (PDBID 1V9E) particularly for compound 5f containing fluoro and methoxy groups. The carbonic anhydrase (CA) inhibitory activity showed derivative 5h to be the most potent (IC50 0.60 ± 0.02 µM) as compared to acetazolamide (IC50 0.984 ± 0.12 µM) used as standard. Free radical scavenging activity was measured using ascorbic acid as a reference. It was observed that just like CA inhibition the compound 5h showed greater free radical scavenging activity than all other target molecules. Enzyme inhibition kinetics (Lineweaver-Burk plots) showed a compound (5h) to inhibit the enzyme by mixed type of inhibition (Ki and Kiʹ values 2.91 µM and 3.88 µM, respectively). Compound 5h was further investigated that a smaller value of Ki than Ki′ showed preferred competitive binding over non-competitive manners. The anticancer activity performed against the MCF-7 cell line showed that the compound 5h inhibits 40% cell growth at 125 µM concentration. The mechanism of anticancer potential was further investigated by DNA binding studies through electrochemical methods. The UV-Vis spectroscopy and Cyclic voltammetry results suggested that 5h was weakly bound to DNA (binding constant 30–32 M−1). It is thus proposed that anticancer activity of 5h may be through carbonic anhydrase inhibition rather than by DNA binding. Our investigations suggested the derivative 5h to serve as a lead structure in designing potentially more active carbonic anhydrase inhibitors.

Highly efficient Ag-doped ZnO (Ag-ZnO)/sulfurized graphitic C3N4 heterostructure photocatalyst was synthesized in a two-step hydrothermal route. Initially, Ag (1–9%) was doped into ZnO nanostructure and checked photocatalytic properties. 7% Ag-doped ZnO (7Ag-ZnO) NPs shown best photocatalytic methylene blue (MB) dye degradation under visible radiation, so, it was selected for forming composite with S-g-C3N4. In 1st step, S-g-C3N4 was synthesized by calcinating. In the 2nd step, 7Ag-ZnO/S-g-C3N4 heterostructure photocatalyst was formed by in situ formation of 7Ag-ZnO NPs in the presence of different contents of S-g-C3N4 (3.5–75 wt%) through hydrothermal route. As a result of 7Ag-ZnO/S-g-C3N4 heterostructure, a large number of catalytic active sites were generated for photocatalytic degradation. Interestingly, the 7% Ag-ZnO nanoparticles (NPs) with 25% S-g-C3N4 exhibited 97% MB degraded within 40 min, which was degraded up to 57% by 7Ag-ZnO alone. Moreover, the photo corrosion of ZnO NPs was inhibited by doping with Ag and coupling with S-g-C3N4.

It is still a challenge to explore self-healable and reprocessable polysiloxane elastomer with improved mechanical strength and superior transparency. In this work, a self-healable and reprocessable polysiloxane elastomer with fine mechanical strength and optical transparency is facilely constructed by thiol-ene photopolymerization between thiol-functionalized silicone resin (MDT-SH) and vinyl-terminated polysiloxane and diboronic ester. The UV radiation intensity, molecular structure of MDT-SH and thiol/ene molar ratio play an important role in the thiol-ene photopolymerization and mechanical properties of polysiloxane elastomer. The damaged elastomer is completely repaired at 80 °C after 3 h, and the waste elastomer can be reprocessed into new items with 90% recovery of mechanical property. More importantly, its transmittance at 400–800 nm is higher than 95%, and it is almost unaffected by the healing process. This self-healable, transparent and tough polysiloxane elastomer has the potential to develop flexible electronics and wearable devices.

Organophosphate, carbamate and pyrethroid pesticides are the most common insecticides used worldwide. They may cause chronic poisoning in farmers and acute poisoning in homicidal or suicidal cases. The determination of trace levels of these pesticides in human blood and urine is very challenging. This study focuses on a simultaneous quantitation method that was developed and validated for multi-class nine pesticides belonging to organophosphate, carbamate and pyrethroid classes in human blood and urine. Target pesticides were extracted from blood and urine using a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction method. Capillary column DB-35 ms (15 m × 0.25 mm, 0.25 µm) was used for chromatography with a 0.079 ml/min flow rate of carrier gas at constant pressure mode. Quantitation of sulfotep, phorate, carbofuran, chlorpyriphos, profenophos, triazophos, pyriproxyfen, lambda-cyhalothrin and permethrin was performed by mass spectrometer equipped with electron impact ionization source using selected ion monitoring (SIM) mode. The lower and upper limits of quantitation for all nine pesticides were 0.01 mg/L and 2.0 mg/dL respectively. The proposed method was proved to be simple, fast, sensitive, and robust. It has been applied to the analysis of 9 pesticides samples.

Background: SARS-CoV-2 has been identified in the feces of COVID-19 patients. However, fecal transmission has never been shown epidemiologically. In April 2020, a COVID-19 outbreak occurred in a low-income community in Guangzhou, China. We investigated this outbreak to identify the mode of transmission. Methods: A home quarantined order was issued in the community. We collected throat swab samples from the residents and environmental samples from the surfaces inside and around the houses, and conducted RT-PCR testing and genome sequencing. We defined a case as a resident in this community with a positive RT-PCR test. We conducted a retrospective cohort study among the residents living in the same building as the cases to identify transmission risk factors. Findings: We found eight cases (four couples) in this community of 2888 residents (attack rate=2.8/1000), with onset from April 5 to 21, 2020. During their incubation periods, Cases 1 and 2 frequented a Market T, where an outbreak was ongoing. Cases 3-8 never visited Market T during incubation periods, lived in separate buildings from, and never interacted with, Cases 1 and 2. Retrospective cohort study showed that working as cleaners or street scavengers (RR=13, 95% CI: 1.8-99), not changing to clean shoes after returning home (RR=7.4, 95% CI: 1.7-33), collating and cleaning dirty shoes after returning home (RR=6.3, 95% CI: 1.4-28) were significant exposure risk factors. Of 63 samples collected from street sewage puddles and sewage pipes, 19% tested positive for SARS-CoV-2. Of 50 samples taken from the cases’ apartments, 24% tested positive. RNA sequencing showed that the viruses identified from the squat toilet and the shoe-bottom dirt from the apartments of Cases 1 and 2 are homologous with those from Cases 3-8 and those identified from the sewage samples. The sewage pipe leading from the apartment of Cases 1 and 2 down to the drainage had a large crack above the ground. Rainfalls after the onset of Cases 1 and 2 flooded the streets. Interpretation: Our investigation has for the first time provided epidemiologic evidence that SARS-CoV-2 can be spread by sewage. This finding highlighted the importance of sewage management, especially in densely-populated places with poor hygiene and sanitation measures, such as urban slums and other low-income communities in developing countries. Funding: No. Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: This study was approved by the ethics committees of GZCDC (approval number GZCDC-ECHR-2020A0004).

In recent years, researches in the field of salient object detection have been widely made in many industrial visual inspection tasks. Automated surface inspection (ASI) can be regarded as one of the most challenging tasks in computer vision because of its high cost of data acquisition, serious imbalance of test samples, and high real-time requirement. Inspired by the requirements of industrial ASI and the methods of salient object detection (SOD), a task mode of defect type classification plus defect area segmentation and a novel deeper and mixed supervision network (DMS) architecture is proposed. The backbone network ResNeXt-101 was pretrained on ImageNet. Firstly, we extract five multiscale feature maps from backbone and concatenate them layer by layer. In addition, to obtain the classification prediction and saliency maps in one stage, the image-level and pixel-level ground truth is trained in a same side output network. Supervision signal is imposed on each side layer to realize deeper and mixed training for the network. Furthermore, the DMS network is equipped with residual refinement mechanism to refine the saliency maps of input images. We evaluate the DMS network on 4 open access ASI datasets and compare it with other 20 methods, which indicates that mixed supervision can significantly improve the accuracy of saliency segmentation. Experiment results show that the proposed method can achieve the state-of-the-art performance.

In this study, Benzocoumarin-Thiazoles-Azomethine derivatives with bioactive scaffolds were synthesized and characterized. The present investigation is concerned with the multistep synthesis of thiazole coumarinyl derivatives (5a-k), which were accomplished from naphthaldehyde, ethyl acetoacetate, and thiosemicarbazide. The formation of newly synthesized derivatives was confirmed by 1H NMR and 13C NMR spectroscopic studies. Thiazole coumarinyl derivatives were subjected to UV-Visible studies in different solvents such as ethanol, ethyl acetate, and DMF for solvatochromic studies. The synthesized coumarinyl thiazole compounds showed absorption in the range of 332-390 nm. Electrochemical studies were performed in DMSO and redox behavior was offered by thiazoles. Fluorescence of coumarinyl thiazole compounds were examined in ethanol, ethyl acetate, and DMF to visualize the solvent effect on the emitting ability of compounds. Fluorescence spectra of coumarinyl thiazoles expressed a sharp emission in the range 436-550 nm.

The heterojunctions formed at the interfaces between the metal oxide and graphitic carbon nitride (g-C3N4) play a critical role in photocatalytic reactions. Herein, we synthesized a series of heterostructures by the integration of 7% Ag-decorated ZnO nanocomposite (NC) with different contents (3.5–75 wt%) of sulphur-doped graphitic carbon nitride (S-g-C3N4). A unique heterostructure formed between Ag/ZnO and S-g-C3N4 generates a vast number of heterojunctions and abundant catalytic active sites for photocatalytic degradation. The material characterization was performed by XRD, SEM, TEM, XPS, FTIR, UV-Vis spectroscopy, BET surface area, and transient photocurrent response. The as-synthesized 7% Ag/ZnO NC showed maximum methylene blue (MB) degradation among the series (0–9%) under visible irradiation. Interestingly, the 25% Ag/ZnO/S-g-C3N4 heterostructure exhibited a significant increase in photodegradation of MB and 98% dye degraded in only 60 min, which was degraded up to 59% by 7% Ag/ZnO NC. Moreover, the photo-corrosion of ZnO NPs was inhibited by simultaneous doping with Ag and coupling with S-g-C3N4, which was verified through cyclic photo-degradation with six consecutive dye degradation tests. The synergistic effects of the Ag/ZnO/S-g-C3N4 heterojunction, enhanced photocatalytic activity, and photo-corrosion resistance were demonstrated successfully.

A novel graphene oxide (GO)-based composite, which was covalently functionalized by 1,3-bis(tris(hydroxymethyl)methylamino)propane (BTP), was first fabricated. The adsorption properties of GO-BTP composite toward some inorganic ions including rare earth elements and heavy metal ions, as well as some organic substances such as phenols and dyes were investigated. It can be found that the adsorption capacities of GO-BTP composite for La3+, Er3+, Cu2+, Pb2+, tert-butyl hydroquinone (TBHQ), m-nitrophenol (MNP), p-nitrophenol (PNP), alizarin red S (ARS) and neutral red (NR) were 0, 0.6, 6.32, 16.25, 27.28, 80.88, 101.69, 54.4 and 101.32 mg g−1, respectively. The morphologies and the compositions of GO-BTP composite, as well as the adsorption mechanism, were investigated by scanning electron microscopy, specific surface area analysis by Brunauer–Emmett–Teller method, Fourier transform-infrared spectroscopy, thermal gravimetric analysis, zeta potential measurements and X-ray photoelectron spectroscopy, respectively. The results indicated that the removal rates of GO-BTP composite were around 90% for PNP and 98% for NR even after 10 cycles of sequential adsorption-desorption tests. The GO-BTP composite can be considered as a promising adsorbent in the efficient adsorption of organic substances and the effective separation of mixtures of inorganic and organic pollutants in aqueous solutions.

A series of ternary-composite were synthesized by the integration of 7% silver-mixed ZnO NPs with different contents (3.5–75 wt%) of sulfur-doped graphitic carbon nitride (S-g-C3N4). A unique ternary-composite formed between Ag/ZnO and S-g-C3N4 generates a vast number of catalytic active sites for photocatalytic degradation. The as-synthesized 7% Ag/ZnO nanocomposite showed maximum methylene blue (MB) degradation rate among the series (0–9%) under visible light. The synergistic effects of the Ag/ZnO/S-g-C3N4 ternary-composite enhanced photocatalytic activity, and photo-corrosion resistance was demonstrated successfully. The photo-corrosion of ZnO NPs was inhibited by simultaneous mixing Ag and coupling with S-g-C3N4, which was verified through cyclic photo-degradation with six consecutive dye degradation tests. Interestingly, the 25% Ag/ZnO/S-g-C3N4 ternary-composite exhibited a significant increase in photodegradation of MB.

In this paper, a rider-bicycle system model was developed and optimized which describes rider-bicycle dynamics and rider balancing control strategies in one cycle from unstable to balanced conditions. A dynamic model of rider-bicycle system was presented with the rider's upper-body movement integrated using the Lagrange method. Human balance control strategies were discussed including steering and upper-body movement control based on balancing principles of bicycle. A proportional-derivative-like structure with time delays was developed to describe steering and upper-body movement control models. Riding experiments were performed to validate and optimize the proposed riding balance control models. Finally, the system stability was analyzed and two rider control strategies were discussed separately.

Objectives Although previous studies have suggested an association between second-hand smoke (SHS) exposure and respiratory symptoms, current evidence is inconsistent. Additionally, it remains unclear whether there are frequency–risk relationships between SHS exposure and respiratory symptoms among adolescents. Methods A cross-sectional survey was conducted using a stratified cluster sampling method to obtain a representative sample of high school students in Guangzhou, China. The respiratory symptoms were defined as persistent cough or sputum for three consecutive months during the past 12 months. Self-reported SHS exposure was defined as non-smokers9 inhalation of the smoke exhaled from smokers on ≥1 day a week in the past 7 days. The univariable and multivariable logistic regression models were fitted to explore the potential frequency–risk relationships between SHS exposure and respiratory symptoms. Results Among 3575 students, the overall prevalence of SHS exposure was 69.2%, including 49.5% for SHS in public places, 34.5% in homes, 22.7% in indoor campuses and 29.2% in outdoor campuses. There were significantly increased risks of having respiratory symptoms corresponding to SHS exposure in public places (OR=1.60, 95% CI 1.30 to 1.95), in homes (OR=1.53, 95% CI 1.25 to 1.87), in indoor campuses (OR=1.43, 95% CI 1.14 to 1.79) and in outdoor campuses (OR=1.37, 95% CI 1.10 to 1.69) using no exposure as reference. Notably, we observed monotonic frequency–risk relationships between setting-specific(eg, homes, public places and campuses) SHS exposure and respiratory symptoms. Conclusion Our findings suggest that setting-specific SHS exposure is associated with a significant, dose-dependent increase in risk of respiratory symptoms.

There has been little focus on the possible association between second-hand smoke (SHS) exposure and depressive symptoms among adolescents. Thus, this study aimed to explore the dose–response relationships between SHS exposure and depressive symptoms among adolescents and differentiate these associations in setting-specific exposure and severity-specific outcomes. A cross-sectional study was conducted using a stratified cluster sampling method to obtain a representative sample of high school students in Guangzhou, China. Depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale. Univariable and multivariable logistic regression models were used to explore the potential associations between SHS exposure and depressive symptoms. Among 3575 nonsmoking students, 29.6% were classified as having probable depressive symptoms and 9.6% had severe depressive symptoms. There were monotonically increasing dose–response relationships between setting-specific (public places, homes, or indoor/outdoor campuses) SHS exposure and severity-specific (probable or severe) depressive symptoms. When examining these relations by source of exposure, we also observed similar dose–response relationships for SHS exposure in campuses from smoking teachers and from smoking classmates. Our findings suggest that regular SHS exposure is associated with a significant, dose-dependent increase in risk of depressive symptoms among adolescents, and highlight the need for smoke-free environments to protect the health of adolescents.

The chemical composition of shaddock ( Citrus paradisi ) mainly consisted of polyphenols, proteins and polysaccharides. However, polysaccharides from shaddock materials have received much less consideration than polyphenols. Herein, a water-soluble neutral polysaccharide from the endodermis of shaddock was isolated and showed good bioactivities. Crude polysaccharides from the endodermis of shaddock (EPS) was extracted with hot water and separated on a DEAE Sepharose FF gel filtration column to obtain NEPS. The IR and UV spectra of NEPS showed that NEPS was mainly composed of polysaccharide and there are no proteins existing in NEPS. The DPPH radical scavenging and reducing power of NEPS are much lower than those of crude EPS; however, Citrus flavonoids significantly improved the DPPH radical scavenging potential and reducing power of NEPS. The crude EPS (5 mg/mL) showed a similar inhibitory effect (77.92 ± 5.03%) with NEPS (5 mg/mL) (74.63 ± 4.71%) on α-amylase.

The precipitates and precipitation behavior in Al–0.16wt.%Zr–0.30 wt.%Yb–0.18 wt.%Cr alloy at 500 °C is studied. By adding Zr, Yb and Cr in combination, a relatively high density of coherent and well-dispersed L1 2 -structured (Al, Cr) 3 (Zr, Yb) dispersoids are uniformly precipitated during homogenization at 500 °C. These dispersoids are coherent with the sizes remaining essentially 15–25 nm even after being exposed for 400 h. The (Al, Cr) 3 (Zr, Yb) dispersoid is finer and more coarsening-resistant than L1 2 -structured Al 3 Zr and Al 3 (Zr, Yb) dispersoids around 500 °C. The uniform and high density precipitation leads to an improvement of precipitation-hardening effect by adding Zr, Yb and Cr in combination.

The chemical composition of shaddock mainly includes polyphenols, proteins and polysaccharides. However, polysaccharides from shaddock materials have received much less consideration than polyphenols (Fellers et al., 1990). Herein the chemical compositions, ?-glucosidase and ?-amylase inhibitory activities of crude polysaccharides from the endodermis of shaddock were investigated. The exopolysaccharides (EPS) exhibited a broad and intense peak at 3300-3400 cm-1 that characterized the absorption of the hydroxyl group, and one weak C-H band at around 2941.3 cm-1 in the IR spectrum. The content of neutral sugars in EPS was determined as 37.16%. The content of acidic sugar in EPS was determined as 33.71%. EPS exhibited the highest content of neutral sugar. The content of proteins in EPS was 5.75%. The content of polyphenols was 6.52%. The EPS mainly consisted of four types of polysaccharides with molecular weights of 110 kD, 68 kD, 31 kD and 12 kD. The crude EPS showed significantly higher inhibitory effects on ?-glucosidase and ?-amylase (inhibition to 74.12% and 86.59%, respectively).

Monoclinic BiVO 4 nanorods and nanoplates were synthesized via the CTAB/water/n-butanol/n-octane microemulsion-mediated hydrothermal process. The physical and photophysical properties of the as-prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, and UV–vis diffuse reflectance spectroscopy (UV–vis). It was found that the ratio of H 2 O to CTAB in microemulsion played a key role in the morphology evolution of the products. The possible formation mechanism of BiVO 4 nanostructure with various morphologies was briefly discussed. The Raman results indicated that the symmetry distortions in the local structure of the synthesized BiVO 4 were affected by the morphology of the products. The bandgaps ( E g ) of BiVO 4 nanorods and nanoplates are 2.45 and 2.38 eV, respectively. The synthesized BiVO 4 nanoplates showed superior photocatalytic activity compared with BiVO 4 nanorods due to their higher degree of structural distortion, larger surface area, and thinness.

Highly dispersed ZnO/TiO2 nanotube composites (NTCs) were successfully synthesized by a facile ethylenediamine-assisted deposition-precipitation route. The characterizations from x-ray diffraction, x-ray photoelectron spectroscopy, transmission electron microscopy, Brunauer–Emmett–Teller, Fourier transform infrared, and ultraviolet-visible spectra revealed that hexagonal wurtzite phase ZnO NPs with an average size of about 2 nm were homogeneously dispersed and anchored on the surface of TiO2 nanotubes (NTs) to form ZnO/TiO2 NTCs. The as-prepared ZnO/TiO2 NTCs with the atom ratio Zn/Ti of 1:4 exhibited excellent photocatalytic activity for photodegradation of methyl orange compared with P25 and pure TiO2 NTs, which were mainly caused by an increase of interfacial charge transfer reactions and a decrease of electron-hole pair recombination on ZnO-TNTs heterojunction. Furthermore, ZnO/TiO2 NTCs possessed favorable recycle efficiency due to their relatively high sedimentation rate and only a slight decrease of photocatalytic activity after a six time recycle.

Novel Fe doped mesoporous TiO 2 microspheres were fabricated by an ultrasonic–hydrothermal method when tetrabutyl titanate was used as a precursor and octadecylamine was used as a structure-directing agent. The mesoporous materials were characterized by XRD, SEM, TEM, N 2 adsorption–desorption measurements, XPS, FL, and UV–vis. The results suggest that both ultrasonic treatment and hydrothermal procedure are critical for the fabrication of Fe doped mesoporous TiO 2 microspheres with a combination of regular morphology, large specific surface area, high crystallinity, and high thermal stability. Low-angle XRD and TEM images indicate that the disordered wormhole-like mesostructure of Fe doped TiO 2 microspheres with diameters of about 300−400 nm is actually formed by the agglomerization of nanoparticles with an average size of about 10 nm. The photocatalytic activity of Fe doped mesoporous TiO 2 microspheres was evaluated by the photodegradation of methyl orange. A small amount of Fe 3+ can obviously enhance their photocatalytic activity. The optimal atomic ratio of Fe to Ti for photocatalytic activity is about 0.5 at%.