Next-generation sequencing-guided molecular-targeted therapy and immunotherapy for biliary tract cancers.

BACKGROUND: Chemotherapy is a standard regimen for advanced or relapsed biliary tract cancer (BTC) with a 5-year overall survival (OS) rate of approximately 5% and a median OS of less than a year. Targeted therapies and immunotherapy aimed at providing more personalized treatments for BTCs have been tested. The objective of this study was to evaluate the effects of targeted therapy and immunotherapy on advanced BTC patients. METHODS: Twenty-four advanced/relapsed BTC patients were enrolled and examined with next-generation sequencing (NGS). Eight of them received NGS-guided targeted or immunotherapy, and the other 16 patients underwent routine chemotherapy. Comparison analysis of OS and objective response rate (ORR) was performed. RESULTS: IDH1, BRCA2, MAP2K1, and BRAF (V600E) were the major actionable genes mutated in this cohort. Patients who received NGS-guided therapy exhibited higher OS (not achieved vs. 6.5 months, p < 0.001) and ORR (87.5% vs. 25%, p < 0.001) than those without targetable mutations and who received first-line chemotherapy. BTCs harboring mutations in IDH1, ATM/BRCA2, or MAP2K1/BRAF (V600E) received treatment with dasatinib, olaparib, or trametinib, respectively. Three of the patients had high tumor mutation burden (TMB-H) and were treated with immune-checkpoint inhibitors and chemotherapy. All these patients achieved complete response or partial response. CONCLUSIONS: NGS-guided targeted therapy and immunotherapy are promising personalized therapies for advanced or relapsed BTCs. TMB is a useful biomarker for predicting immunotherapy efficacy.

Immunogenicity and Safety of an Inactivated Enterovirus 71 Vaccine Administered Simultaneously With Hepatitis B Vaccine and Group A Meningococcal Polysaccharide Vaccine: A Phase 4, Open-Label, Single-Center, Randomized, Noninferiority Trial.

BACKGROUND: This study tested the hypothesis that the immunogenicity and safety of the simultaneous administration of enterovirus 71 (EV71) vaccine (dose 1) with recombinant hepatitis B vaccine (HepB) on day 1 and EV71 vaccine (dose 2) with group A meningococcal polysaccharide vaccine (MenA) on day 30 is not inferior to separate administration of each vaccine. METHODS: The study was designed as a randomized, open-label, noninferiority trial. A total of 775 healthy infants aged 6 months were randomly assigned in a ratio of 1:1:1 to receive simultaneous administration of EV71 vaccine (dose 1) and HepB on day 1 and EV71 vaccine (dose 2) and MenA on day 30 (the SI group); administration of doses 1 and 2 of EV71 vaccine on days 1 and 30, respectively (the SE1 group); or administration of HepB and MenA on days 1 and 30, respectively (the SE2 group). RESULTS: According to the per protocol set, antibody responses against EV71, hepatitis B virus (HBV), and group A meningococcal polysaccharide were similar regardless of administration schedule. With the non-inferiority margin setting at 10%, the seroconversion rates of the three pathogens in the SI group (100% [98.25, 100], 44.84% [38.20, 51.63] and 27.83% [21.91, 34.38]) were not inferior to those in SE1 or SE2 group (100% [98.31, 100], 44.35% [37.82, 51.02] and 29.17% [23.20, 35.72], respectively). Frequencies of adverse reactions to each vaccination regimen were comparable (60.62% in the SI group vs 52.33% in the SE1 group and 56.98% in the SE2 group; P = .16). CONCLUSIONS: Simultaneous administration of combined EV71 vaccine with HepB and MenA has noninferior immunogenicity and safety, compared with separate administration of these vaccines. CLINICAL TRIALS REGISTRATION: NCT03274102.

Avian Influenza A Viruses among Occupationally Exposed Populations, China, 2014-2016.

To determine the seroprevalence and seroconversion of avian influenza virus (AIV) antibodies in poultry workers, we conducted a seroepidemiologic study in 7 areas of China during December 2014-April 2016. We used viral isolation and reverse transcription PCR to detect AIVs in specimens from live poultry markets. We analyzed 2,124 serum samples obtained from 1,407 poultry workers by using hemagglutination inhibition and microneutralization assays. We noted seroprevalence of AIV antibodies for subtypes H9N2, H7N9, H6N1, H5N1-SC29, H5N6, H5N1-SH199, and H6N6. In serum from participants with longitudinal samples, we noted seroconversion, with >4-fold rise in titers, for H9N2, H7N9, H6N1, H5N1-SC29, H6N6, H5N6, and H5N1-SH199 subtypes. We found no evidence of H10N8 subtype. The distribution of AIV antibodies provided evidence of asymptomatic infection. We found that AIV antibody prevalence in live poultry markets correlated with increased risk for H7N9 and H9N2 infection among poultry workers.

New Threats from H7N9 Influenza Virus: Spread and Evolution of High- and Low-Pathogenicity Variants with High Genomic Diversity in Wave Five.

H7N9 virus has caused five infection waves since it emerged in 2013. The highest number of human cases was seen in wave 5; however, the underlying reasons have not been thoroughly elucidated. In this study, the geographical distribution, phylogeny, and genetic evolution of 240 H7N9 viruses in wave 5, including 35 new isolates from patients and poultry in nine provinces, were comprehensively analyzed together with strains from first four waves. Geographical distribution analysis indicated that the newly emerging highly pathogenic (HP) and low-pathogenicity (LP) H7N9 viruses were cocirculating, causing human and poultry infections across China. Genetic analysis indicated that dynamic reassortment of the internal genes among LP-H7N9/H9N2/H6Ny and HP-H7N9, as well as of the surface genes, between the Yangtze and Pearl River Delta lineages resulted in at least 36 genotypes, with three major genotypes (G1 [A/chicken/Jiangsu/SC537/2013-like], G3 [A/Chicken/Zhongshan/ZS/2017-like], and G11 [A/Anhui/40094/2015-like]). The HP-H7N9 genotype likely evolved from G1 LP-H7N9 by the insertion of a KRTA motif at the cleavage site (CS) and then evolved into 15 genotypes with four different CS motifs, including PKGKRTAR/G, PKGKRIAR/G, PKRKRAAR/G, and PKRKRTAR/G. Approximately 46% (28/61) of HP strains belonged to G3. Importantly, neuraminidase (NA) inhibitor (NAI) resistance (R292K in NA) and mammalian adaptation (e.g., E627K and A588V in PB2) mutations were found in a few non-human-derived HP-H7N9 strains. In summary, the enhanced prevalence and diverse genetic characteristics that occurred with mammalian-adapted and NAI-resistant mutations may have contributed to increased numbers of human infections in wave 5.IMPORTANCE The highest numbers of human H7N9 infections were observed during wave 5 from October 2016 to September 2017. Our results showed that HP-H7N9 and LP-H7N9 had spread virtually throughout China and underwent dynamic reassortment with different subtypes (H7N9/H9N2 and H6Ny) and lineages (Yangtze and Pearl River Delta lineages), resulting in totals of 36 and 3 major genotypes, respectively. Notably, the NAI drug-resistant (R292K in NA) and mammalian-adapted (e.g., E627K in PB2) mutations were found in HP-H7N9 not only from human isolates but also from poultry and environmental isolates, indicating increased risks for human infections. The broad dissemination of LP- and HP-H7N9 with high levels of genetic diversity and host adaptation and drug-resistant mutations likely accounted for the sharp increases in the number of human infections during wave 5. Therefore, more strategies are needed against the further spread and damage of H7N9 in the world.

Controllable preparation of 2D carbon paper modified with flower-like WS2 for efficient microwave absorption.

In the practical application of microwave absorbing materials, traditional powder materials need to be mixed with the matrix to fabricate composite coatings. However, the complex preparation process of composite coatings and the uneven dispersion of powders in the matrix limit their application. To solve these problems, two-dimensional (2D) F-WS2/CP composite films were prepared by using carbon paper (CP) as a dispersion matrix and loading flower-like WS2 on its surface through a simple hydrothermal method. The morphology and microwave absorption (MA) performance of the composite films are easily regulated by adjusting the amount of reaction precursors. The combination of WS2 and CP facilitates impedance matching and improves the electromagnetic wave attenuation performance based on the synergistic effect of different loss mechanisms including multiple reflections and scattering, interfacial polarization, dipolar polarization, and conduction loss. At a low filler content (5 wt%), the maximum reflection loss (RL) of the composite film is up to -50 dB (99.999% energy absorption) at 12.5 GHz with 2.8 mm thickness. Moreover, at a relatively thin 1.8 mm thickness, its maximum RL remains -35 dB (>99.9% energy absorption). The as-prepared composite film shows excellent MA properties at a thinner thickness and lower filling content, providing inspiration for the preparation of light weight and efficient 2D thin-film microwave absorbers in the future.

Triple therapy in biliary tract cancers: GemOX plus immune checkpoint inhibitor in combination with lenvatinib or NGS-guided targeted therapy.

PURPOSE: The combination of gemcitabine-based chemotherapy and immune checkpoint inhibitors has a good efficacy in advanced biliary tract cancer (BTC). The multi-target TKI lenvatinib and NGS-guided targeted therapy are also promising in BTC treatment. This study aimed to explore the performance of GemOX plus sintilimab and TKI (either lenvatinib or by NGS-guided targeted therapy) for local advanced or metastatic BTCs. METHODS: This prospective single-arm study included patients with local advanced or metastatic BTCs and applied intravenous infusion of standard GemOX plus sintilimab and lenvatinib (no targetable gene alterations) or targeted therapy based on NGS (olaparib for BRCA1/2 mutation, dasatinib for IDH1/2 mutation, afatinib for EGFR amplification, lenvatinib for PDGFR and KIT mutation, and lenvatinib for FGFR/KIT mutation). RESULTS: From November 2020 to December 2021, 22 patients BTCs (6 GBC, 14 iCCA, 1 pCCA and 1 dCCA cases) were enrolled, with an average age of 58.4 years. Partial response (PR) was achieved in 10 cases, stable disease (SD) in 9 cases and progression disease (PD) in 3 cases (13.6%). The objective response rate (ORR) was 45.5%, and the disease control rate (DCR) was 86.4%. During the treatment, the incidence of adverse reactions was 81.8%, and the incidence of grade 3/4 adverse events was 9.09%. For 14 patients with NGS, 5 patients were treated by targeted therapy and there were 1 SD and 4 PR cases. For four patients with positive PD-L1 expression, the ORR was 100%. While among the three patients with super-progression markers such as RET, MDM2 and FGF14/STK24, there were two SD and one PD cases. CONCLUSION: In patients with advanced BTCs, the combination of GemOX plus sintilimab and lenvatinib or NGS-guided targeted therapy showed promising ORR and DCR, especially for the patients with positive PD-L1 expression and targetable gene alterations.

A MXene-based multiple catalyst for highly efficient photocatalytic removal of nitrate.

Photocatalytic removal of nitrate in wastewater has attracted wide attention because of its simple operation and environmental protection. However, the preparation of photocatalysts with high efficiency and high nitrogen selectivity is still a challenge. In this paper, TiO2 is grown in situ on Ti3C2 MXene by a simple calcination method and modified with silver particles. The presence of Ti3C2 reduces the recombination rate of photogenerated electrons and generates more photogenerated electrons. At the same time, the silver particles also increase the photoelectron density and further improve the carrier separation of the catalyst. Due to its unique structure and optical properties, the prepared photocatalyst shows an excellent nitrate removal rate under a high-pressure mercury lamp. At 500 mgN/L, the nitrate removal rate reaches 96.1%, and the nitrogen selectivity reaches 92.6%. Even after 5 cycles, the prepared photocatalyst still maintains a high nitrate photocatalytic removal efficiency (89%). The electron transfer path is verified by density functional theory calculations.

Elevated serum CA19-9 indicates severe liver inflammation and worse survival after curative resection in hepatitis B-related hepatocellular carcinoma.

We explored the prognostic value of preoperative CA19-9 in α-fetoprotein (AFP)-positive and -negative HCC with hepatitis B virus (HBV) background (HBV-HCC), and explored the underlying mechanism. Recurrence-free survival (RFS) and overall survival (OS) were assessed in HBV-HCC patients who underwent curative resection (Cohort 1). Immunohistochemical staining of CA19-9 in HCC and liver parenchyma were quantified in another cohort of 216 patients with resected HCC (Cohort 2). Immunohistochemical staining of CA19-9 and serum CA19-9 level was also compared between patients with HCC and intrahepatic cholangiocarcinoma (ICC) (Cohort 3). In Cohort 1, CA19-9 ≥ 39 U/mL was an independent risk factor for RFS (HR = 1.507, 95% CI = 1.087-2.091, p = 0.014) and OS (HR = 1.646, 95% CI = 1.146-2.366, p = 0.007). CA19-9 ≥ 39 U/mL was also associated with significantly higher incidence of macrovascular invasion (MaVI) compared with CA19-9 < 39 U/mL (23.0% vs. 7.2%, p = 0.002), and elevated aminotransferase and aspartate aminotransferase to platelet ratio index (APRI), and lower albumin. Immunohistochemical staining of CA19-9 revealed that CA19-9 expression was found exclusively in the background liver but not in HCC tumor cells. In contrast, tumor tissue was the main source of CA19-9 in ICC patients. CA19-9 ≥ 39 U/mL was associated with worse OS and RFS in both AFP-positive and negative HCC patients. CA19-9 indicated more severe inflammation and cirrhosis in the liver of HCC patients.

More diversified antibiotic resistance genes in chickens and workers of the live poultry markets.

BACKGROUND: Poultry farms and LPMs are a reservoir of antimicrobial resistant bacteria and resistance genes from feces. The LPM is an important interface between humans, farm animals, and environments in a typical urban environment, and it is considered a reservoir for ARGs and viruses. However, the antibiotic resistomes shared between chicken farms and LPMs, and that of LPM workers and people who have no contact with the LPMs remains unknown. METHODS: We characterized the resistome and bacterial microbiome of farm chickens and LPMs and LPM workers and control subjects. The mobile ARGs identified in chickens and the distribution of the mcr-family genes in publicly bacterial genomes and chicken gut metagenomes was analyzed, respectively. In addition, the prevalence of mcr-1 in LPMs following the ban on colistin-positive additives in China was explored. RESULTS: By profiling the microbiomes and resistomes in chicken farms, LPMs, LPM workers, and LPM environments, we found that the bacterial community composition and resistomes were significantly different between the farms and the LPMs, and the LPM samples possessed more diversified ARGs (59 types) than the farms. Some mobile ARGs, such as mcr-1 and tet(X3), identified in chicken farms, LPMs, LPM workers, and LPM environments were also harbored by human clinical pathogens. Moreover, we found that the resistomes were significantly different between the LPM workers and those who have no contact with the LPMs, and more diversified ARGs (188 types) were observed in the LPM workers. It is also worth noting that mcr-10 was identified in both human (5.2%, 96/1,859) and chicken (1.5%, 14/910) gut microbiomes. Although mcr-1 prevalence decreased significantly in the LPMs across the eight provinces in China, from 190/333 (57.1%) samples in September 2016-March 2017 to 208/544 (38.2%) samples in August 2018-May 2019, it is widespread and continuous in the LPMs. CONCLUSION: Live poultry trade has a significant effect on the diversity of ARGs in LPM workers, chickens, and environments in China, driven by human selection with the live poultry trade. Our findings highlight the live poultry trade as ARG disseminators into LPMs, which serve as an interface of LPM environments even LPM workers, and that could urge Government to have better control of LPMs in China. Further studies on the factors that promote antibiotic resistance exchange between LPM environments, human commensals, and pathogens, are warranted.

Effects of boron doping on structural, electronic, elastic, and optical properties of energetic crystal 2,6-diamino-3,5-dinitropyrazine-1-oxide: a theoretical study using the first principles calculation and Hirshfeld surface analysis.

Boron-contained compounds are one kind of new energetic materials, and have been synthesized successfully lately. However, the effects of introduced boron atoms into the energetic system are unclear. In this work, using the known insensitive energy crystal 2,6-diamino-3,5-dinitropyrazine-l-oxide (LLM-105) as the model compound, boron doping effects on its crystal structure, band gap and structure, intermolecular contacts, sensitivity, elastic property, optical absorption behavior, and dielectric function were studied by the first principles calculations and Hirshfeld surface analysis. One B atom was doped at four different doping sites in the ring (two kinds of nitrogen N1/N2 and carbon atoms C3/C4), respectively, and formed four new crystals LLM-105-B1/B2/B3/B4. The results showed that the B atom and its doping site both make great influence on the structure and properties. The B doping obviously decreased the band gap and weakened the strength of intermolecular contacts, giving rise to higher sensitivity and worse safety. Especially for LLM-105-B4 which has a 0 eV value of band gap, the doped B atom made great contributions to the density of states around the Fermi level, leading to the suddenly move down of lowest unoccupied molecular orbital and directly link of total density of states at the Fermi level. Doping the B atom at the site C3 improved the ductility and plasticity of LLM-105, while LLM-105-B2 was found to be the most brittle and anisotropic crystal. Doping B atoms at sites N2 and C4 increased the absorption to green, orange, and red lights, while the absorption strength to the infrared light was enhanced in most cases. The dielectric constant and polarity were significantly increased by doping boron atoms at sites C3 and C4.

Highly Active Hierarchical Au Nanoparticles/Cellulose@TiO2 Prepared by Surface Charge Assisted Self-Assembly.

The catalyst Au/cellulose@TiO2 with a hierarchical structure was one-pot synthesized by conventional deposition-precipitation urea method. Nanosized TiO2 particles, instead of self-agglomeration, homogeneously dispersed on the microsized microcrystalline cellulose. Simultaneously, gold particles with particle size of about 3.4 nm were mainly well-deposited on TiO2 particles. It was found that the surface charges of TiO2, cellulose and gold species played a key role in assisting in selfassembling them into the hierarchical structure. p-nitrophenol hydrogenation results displayed that the catalytic activity of Au/cellulose@TiO2 was 1.8 times and 10.9 times higher than that of Au/TiO2 and Au/cellulose, respectively. The improvement in catalytic performance of Au/cellulose@TiO2 was closely related to its hierarchical structure that influenced mass transfer of reactants and recycle of catalysts.

Systemic treatment of advanced or recurrent biliary tract cancer.

Biliary tract cancer (BTC) is a disease entity comprising diverse epithelial tumors with features of cholangiocyte differentiation, and it includes cholangiocarcinoma (CCA) and gallbladder cancer (GBC). Depending on its anatomical location, cholangiocarcinoma is categorized as intrahepatic (iCCA), perihilar (pCCA), or distal (dCCA). Nearly two-thirds of patients with biliary tract cancer present with advanced disease at diagnosis and in 68-86% of resections the cancer eventually recurs either locoregionally or at a distance. Chemotherapy is the first-line therapy for advanced or recurrent BTC. With the development of next-generation sequencing (NGS)-guided molecular targeted therapy, more options are available for treatment of advanced BTC. Chemotherapy, and especially a triplet regimen based on gemcitabine/cisplatin/nab-paclitaxel, has had the most significant effect, and fluorouracil, leucovorin, irinotecan plus oxaliplatin (FOLFIRINOX) combined with bevacizumab is promising. Molecular targeted therapy should be based on genome sequencing and appears essential to precision medicine. Fibroblast growth factor receptor (FGFR) inhibitors and isocitrate dehydrogenase (IDH) inhibitors are promising emerging targeted therapies mainly for iCCA. Other targeted therapies such as anti-human epidermal growth factor receptor-2 (HER2) therapies, MEK inhibitors, BRAF inhibitors, and poly ADP ribose polymerase (PARP) inhibitors had tentatively displayed efficacy. Further evaluations of combination strategies in particular are needed. An immune checkpoint inhibitor (ICI) alone is less efficacious, but an ICI in addition to chemotherapy or radiotherapy has resulted in a response according to many case series. However, ICIs are still being evaluated in several ongoing studies. Combination therapies have garnered attention because of interactions between signaling pathways of carcinogenesis in BTC.

Theoretical design of novel high energy metal complexes based on two complementary oxygen-rich mixed ligands of 4-amino-4H-1,2,4-triazole-3,5-diol and 1,1'-dinitramino-5,5'-bistetrazole.

In this study, 16 new energetic metal complexes [M(DNABT)(ATDO), M=Cu, Ni] were designed using the mixed complex construct strategy, which was based on two complementary oxygen-rich high-energy ligands of 1,1'-dinitramino-5,5'-bistetrazole (DNABT) and 4-amino-4H-1,2,4-triazole-3,5-diol (ATDO), then combined with metals Cu and Ni, and further adjusted by the introduction of NO2 and NH2. The molecular and electronic structures, heat of formation (HOF), density, detonation velocity, detonation pressure, and sensitivity were investigated by the density functional theory method. The results showed that in metals, the position and amount of NO2/NH2 have great effects on the structure and property of metal complexes, and these effects coupled with each other. N-NO2 bond is the relatively weak bond, and its max length is related with the sensitivity closely. The designed metal complexes all have high HOF (673~868 kJ mol-1), high density (2.06~2.14 g cm-3), and ideal oxygen balance (- 19.2~- 6.7%), which further make them have higher detonation velocity (8.76~9.84 km s-1) and detonation pressure (37.4~46.6 GPa) than three famous high-energy compounds 1,3,5-trinitro-1,3,5-triazine (RDX); 1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX); or even 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20). At the same time, they are less sensitive than RDX, HMX, and CL-20, making them potential candidates for high-energy density compounds.

A DFT study of the structure-property relationships of bistetrazole-based high-nitrogen energetic metal complexes.

In this work, six series of new energetic metal complexes were designed. Each complex contained a large, high-energy, high-nitrogen, anionic chelating ligand (either the 5,5'-bistetrazolate anion, the 5,5'-azobistetrazolate anion, or the 5,5'-(hydrazine-1,2-diyl)bis-[1H-tetrazol-1-ide] anion-each of which has a different bridging group), Cu or Ni as the metal atom, and two small complexing agent ligands (NH3 and/or NH2NO2). The molecular and electronic structures, heats of formation, densities, detonation properties, and impact sensitivities of the novel complexes were studied using density functional theory. Furthermore, the effects of varying the large chelating ligand (and thus the bridging group), the small complexing agents, and the metal atom on the structure and properties of the complex were investigated and analyzed in depth. The results show that the particular metal, bridging group, and complexing agents included in the energetic complex influence its structure and properties, but the effects of varying the constituents of the complex are complicated or unclear, and these effects are sometimes intertwined. In addition, the detonation pressures, detonation velocities, and impact sensitivities of the novel complexes ranged from 25.9 to 38.6 GPa, from 7.21 to 8.80 km s-1, and from 17 to 48 cm, respectively. Five of the complexes (B3, C3, D3, E3, and F3) appear to possess comparable performance to the famous and widely used high explosive 1,3,5-trinitro-1,3,5-triazinane, making these new complexes attractive to energetic materials experimentalists.

Development of a Novel Terpolymer as a Green and Efficient Decalcifying Agent for Crude Petroleum.

A novel environmental decalcifying agent was prepared with allylpolyethoxy amino carboxylate (APEAA), hydroxyethyl acrylate (HEA), and maleic anhydride (MA) by means of free-radical polymerization in an aqueous solution. The morphology and structure of the samples were characterized through scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrometry, and 1H nuclear magnetic resonance (1H NMR) spectra. The molecular-weight distribution of APEAA-HEA-MA was determined by the gel permeation chromatography method. APEAA-HEA-MA was used as a green decalcifying agent to remove calcium from crude petroleum, and the impact of factors such as monomer ratio, copolymerization time, dosages, and desalination temperature was analyzed. It is found that the decalcification rate of APEAA-HEA-MA could reach to its maximum, and the calcium removal efficiency was approximately 97.88% when the monomer molar ratio of APEAA-HEA-MA was 1:2:5, the reaction time of copolymerization was 2 h, the dosage was 100 ppm, and the desalination temperature was 100 °C. This research work can promote the exploration on facile synthesis of a novel terpolymer and its potential application in refinery desalting processes.

Facile one-step synthesis of TiO2/Ag/SnO2 ternary heterostructures with enhanced visible light photocatalytic activity.

Novel TiO2/Ag/SnO2 composites were successfully prepared by a facile one-step reduction approach using stannous chloride as both SnO2 precursor and reducing agent. The Ag nanoparticles with sizes of 2.04-3.94 nm were located on TiO2 matrix and immobilized by the surrounded SnO2. The resulted TiO2/Ag/SnO2 nanocomposites were used as photocatalyst for photodegradation of methylene blue under visible light. The experimental results demonstrated that the visible light photocatalytic activity of the TiO2/Ag/SnO2 was significantly enhanced in comparison with the individual TiO2 or the binary composite (TiO2/Ag or TiO2/SnO2) and the degradation rate was up to about 9.5 times that of commercial TiO2. The photocatalytic activity of the TiO2/Ag/SnO2 composites could be well controlled by simply tuning the dosages of Ag precursor and the optimized activity of the composites was obtained when the dosage of Ag precursor was 2%. Moreover, the TiO2/Ag/SnO2 photocatalyst exhibited high stability for degradation of methylene blue even after four successive cycles.

The search for new powerful energetic transition metal complexes based on 3,3'-dinitro-5,5'-bis-1,2,4-triazole-1,1'-diolate anion: a DFT study.

In this study, employing a new high oxygen balance energetic 3,3'-dinitro-5,5'-bis-1,2,4-triazole-1,1'-diolate anion (DNBTDO) as the bidentate ligand, NH3 and NH2NO2 as short energetic ligands, and Cu/Ni as the metal atoms, two series of novel energetic metal complexes were computationally designed. Their structures and properties were studied by density functional theory, electrostatic potential data, and molecular mechanics methods. The results showed that the designed metal complexes have high detonation performance and acceptable sensitivity: Cu/Ni(DNBTDO)(NH2NO2)2 (A3/B3) have better detonation properties and lower sensitivity than the most powerful CHNO explosive hexanitrohexaazaisowurtzitane, Cu/Ni(DNBTDO)(NH3)(NH2NO2) (A2/B2) have comparable energetic performance and sensitivity with 1,3,5,7-tetranitro-1,3,5,7-tetrazocane, Ni(DNBTDO)(NH3)2 (B1) has comparative energy level and sensitivity with 1,3,5-trinitro-1,3,5-triazinane. These five energetic metal complexes may be attractive to energetic materials researchers. Besides, both the energetic ligands and metal atoms could have a great influence on the structures, heats of formation, detonation properties, and stability of energetic metal complexes, and the effects are coupled with each other. This study may be helpful in the search for and development of new improved energetic materials.

Facile Photochemical Synthesis of Au/Pt/g-C3N4 with Plasmon-Enhanced Photocatalytic Activity for Antibiotic Degradation.

A novel plasmonic photocatalyst, Au/Pt/g-C3N4, was prepared by a facile calcination-photodeposition technique. The samples were characterized by X-ray diffraction, energy-dispersive spectroscopy, transmission electron microscopy, and UV-vis diffuse reflectance spectroscopy, and the results demonstrated that the Au and Pt nanoparticles (7-15 nm) were well-dispersed on the surfaces of g-C3N4. The Au/Pt codecorated g-C3N4 heterostructure displayed enhanced photocatalytic activity for antibiotic tetracycline hydrochloride (TC-HCl) degradation, and the degradation rate was 3.4 times higher than that of pure g-C3N4 under visible light irradiation. The enhancement of photocatalytic activity could be attributed to the surface plasmon resonance effect of Au and electron-sink function of Pt nanoparticles, which improve the optical absorption property and photogenerated charge carriers separation of g-C3N4, synergistically facilitating the photocatalysis process. Finally, a possible photocatalytic mechanism for degrading TC-HCl by Au/Pt/g-C3N4 heterostructure was tentatively proposed.

A highly reactive and enhanced thermal stability nanocomposite catalyst based on Au nanoparticles assembled in the inner surface of SiO2 hollow nanotubes.

A novel hollow tubular SiO2-Au catalyst with a mesoporous structure (HTMS) was successfully fabricated by a combination of the sol-gel and calcination processes. This method involves the preparation of modified MWCNTs, the sequential deposition of Au and then silica layers through the sol-gel processes, and finally the calcination at the desired temperature to remove the MWCNTs. The obtained samples were characterized by several techniques, such as N2 adsorption-desorption isotherms, transmission electron microscopy, energy-dispersive X-ray spectroscopy analysis, UV-Vis spectra, X-ray diffraction and Thermogravimetric Analysis (TGA). The results established that a different calcination temperature has an obvious influence on the morphology and structure of the final hollow tubular. When the temperature is 550 °C, the obtained materials exhibit the distinctly tubular structure because of the decomposition of MWCNTs and the preservation of hollow tubes. Furthermore, in the catalyst system, the mesoporous silica layer can act as the physical barrier to resist the agglomeration and sintering of Au nanoparticles even after being subjected to harsh treatments up to 650 °C. In our experiments, the catalytic activities of HTMS SiO2-Au were investigated by photometrically monitoring the reduction of p-nitrophenol (p-NPh) by an excess of NaBH4. It was found that the prepared HTMS SiO2-Au catalysts exhibited a high catalytic activity and this sample could be easily recycled without a decrease of the catalytic activities in the reaction.

Synthesis and characterization of a novel Au nanocatalyst with increased thermal stability.

We report the synthesis of a new Au nanocatalyst with increased thermal stability. This catalyst system consisted of gold nanoparticles attached to functionalized TiO2/SiO2 core-shell nanocomposites, together with the encapsulation of mesoporous silica. The synthesis process mainly involved four steps, which included the synthesis of the TiO2/SiO2 core-shell composites, synthesis of the Au/TiO2/SiO2 particles, coating of Au/TiO2/SiO2 with silica, and etching the outer silica layer. TEM images were used to confirm the success of each of the synthesis steps, and both UV-vis adsorption spectra and the catalytic activity evaluation were employed to investigate the degree of re-exposure of Au nanoparticles after the etching treatment. In our experiments, the obtained mesoSiO2/Au/TiO2/SiO2 catalyst showed a superior thermal stability and higher activity for CO conversion compared to the mesoSiO2/Au/SiO2 one. It resisted sintering during the calcination at 500 °C, whereas the unprotected one was found to sinter. Moreover, it was found that on the mesoSiO2/Au/TiO2/SiO2 sample, the outside silica material could hinder the phase transformation of titania to some extent. Thus, small crystalline particles of TiO2 anchored on the silica beads of the core-shell composites, leading to a better dispersion of small Au nanoparticles and improved catalytic capacity to resist sintering.