Facile synthesis of the Z-scheme graphite-like carbon nitride/silver/silver phosphate nanocomposite for photocatalytic oxidative removal of nitric oxides under visible light

In this study, a novel ternary Z-scheme Graphite-like Carbon Nitride (g-C₃N₄)/Silver (Ag)/Silver Phosphate (Ag₃PO₄) photocatalyst was designed and prepared using a two-step method (sodium chloride (NaCl) template-assisted strategy plus selective deposition). Its photocatalysts performance against removing 400 ppm of Nitric Oxides (NOx) was then investigated. We found 50 wt% g-C₃N₄/Ag/Ag₃PO₄(AP-CN 2:1) catalyst removes up to 74% of NO in 90 min under the illumination of visible light (>420 nm), which is respectively 3.5 and 1.8 times higher than using g-C₃N₄ or Ag₃PO₄, alone. This improved performance was attributed to the formation of Z-scheme g-C₃N₄/Ag/Ag₃PO₄ heterojunction, driven by the built-in electric field across the g-C₃N₄/Ag/Ag₃PO₄ interface. These separated the electron-hole but enhanced the original strong oxidation and reduction performance of related components. The superior performance is also attributed to the improved surface area, enhanced hydrophilicity (H₂O₂) and better visible-light-harvesting capability of the composite compound. More importantly, the AP-CN 2:1 sample maintained a NO removal rate of more than 73% even after four rounds of recycling. The photocatalytic oxidation removal mechanism was evaluated using the radical-capture experiments, electron spin resonance (ESR) and ion-exchange high-performance liquid chromatography (HPLC) analysis. The findings of this work offer a simple but effective design of a highly reactive and practical ternary Z-scheme heterojunction photocatalysts for the removal of toxic NO.

[A single-arm prospective study on induction chemotherapy and subsequent comprehensive therapy for advanced hypopharyngeal squamous cell carcinoma: report of 260 cases in a single center]

Objective: To study the significance of induction chemotherapy and subsequent comprehensive therapy for overall survival rate (OS) and larynx dysfunction-free survival rate (LDFS) in patients with advanced hypopharyngeal carcinoma. Methods: Patients who met the inclusion criteria with the diagnoses of advanced hypopharyngeal carcinoma between 2011 and 2017 received 2 or 3 cycles of TPF regimen induction chemotherapy. Patients who attained complete response (CR) received radical chemotherapy. Patients who attained partial response (PR) and the reduction of tumor volume was more than 70% were defined as large PR and received concurrent chemoradiotherapy. When the tumor volume reduction of PR patients was less than 70%, they were defined as small PR. (CR+large PR) group was defined as effective group. Patients who did not reach CR and large PR were defined as uneffective group and underwent radical surgery and received adjuvant radiotherapy as appropriate after the surgery. The end points of the study were OS, progression-free survival (PFS) and LDFS. Chi-square (χ(2)) test was used for correlation analysis. Survival analysis was performed by the Kaplan-Meier method with a Log-rank test. Cox proportional hazards model was used for univariate and multivariate survival analysis. Results: A total of 260 patients were enrolled in the study. The follow-up period ranged from 5 to 83 months, with an average of 24.7 months. The 3-year and 5-year OS rate was 46.0% and 32.6%, respectively. The 3-year and 5-year PFS rate was 41.0% and 26.6%, respectively. The 3-year and 5-year LDFS rate was 37.9% and 24.8%, respectively. Poor outcome of induction chemotherapy, advanced N stage, strong positive Ki-67 immunohistochemistry (all P<0.001) were negative prognostic factors. The advanced clinical stage was positively related to the poor outcome of induction chemotherapy (P=0.015). There was no significant difference in OS and PFS between the large PR group and the small PR group (all P>0.005). Conclusion: TPF regimen induction chemotherapy and subsequent comprehensive therapy for patients with advanced hypopharyngeal carcinoma may improve the quality of life of patients, with high OS rate and LDFS rate.

Role of miR-579-3p in the development of squamous cell lung carcinoma and the regulatory mechanisms

OBJECTIVE

The aim of this study was to explore the role of microRNA-579-3p (miR-579-3p) in the development of squamous cell lung carcinoma (SCLC). Our findings might provide new insights into the treatment of SCLC.

PATIENTS AND METHODS

Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was performed to examine the expression level of miR-579-3p in 30 pairs of CRC tissues and para-cancerous tissues. The relation between miR-579-3p expression and clinical features of SCLC patients was analyzed. MiR-579-3p expression in SCLC cells was further verified by qRT-PCR as well. In addition, the effects of miR-579-3p on the migration and invasion of SK-MES-1 cells were examined through the transwell assay.

RESULTS

QRT-PCR results revealed for the first time that miR-579-3p was significantly down-regulated in SCLC tissues. This indicated that miR-579-3p was possibly involved in the development of SCLC. According to bioinformatics prediction websites and the luciferase activity assay, macrophage scavenger receptor 1 (MSR1) was predicted and verified as the target gene of miR-579-3p. Transfection of miR-579-3p mimics significantly reduced the protein expression level of MSR1 in cells, eventually inhibiting the proliferation, invasion, and migration of SCLC cells.

CONCLUSIONS

The miR-579-3p/MSR1 axis might be a novel regulatory pathway of apoptosis, which could be used as potential therapeutic sites in SCLC.

Mechanism study on TiO2 inducing O2- and OH radicals in O3/H2O2 system for high-efficiency NO oxidation

To achieve high NO oxidation efficiency, excessive O₃ must be used, which would lead to the high cost and escape of ozone. Herein, we adopted low cost and environmental-friendly TiO₂ as the catalyst of low concentration O₃ and H₂O₂ system for high-efficiency NO_x oxidation. The Ti sites on TiO₂ were the deprotonation sites of H₂O₂ and H₂O into Ti-OOH and Ti-OH species, respectively. We found that the surface of rutile phase TiO₂ had a low concentration Ti-OOH component but a large amount of Ti-OH after contacting with H₂O₂ solution, thus lots of ·OH and a few O₂^- radicals formed with introducing O₃ molecules. H₂O₂ solution induced the formation of a large amount of Ti-OOH and Ti-OH species on the anatase phase TiO₂ surface, thus lots of O₂^- generated in the O₃/H₂O₂ system. O₂^- and OH radicals could efficiently oxidize NO, in which O₂^- radicals could oxidize NO to NO₃^- in one step with high selectively. Therefore, anatase TiO₂ had better performance in NO_x oxidation than rutile phase TiO₂. The effect of temperature and SO₂ concentration on NO oxidation was also investigated, the results showed that TiO₂-A/O₃/H₂O₂ system promoted NO oxidation at a low temperature and a low concentration of SO₂.

Hierarchical Construction of Higher-Order Exceptional Points

The realization of higher-order exceptional points (HOEPs) can lead to orders of magnitude enhancement in light-matter interactions beyond the current fundamental limits. Unfortunately, implementing HOEPs in the existing schemes is a rather difficult task, due to the complexity and sensitivity to fabrication imperfections. Here we introduce a hierarchical approach for engineering photonic structures having HOEPs that are easier to build and more resilient to experimental uncertainties. We demonstrate our technique by an example that involves parity-time symmetric optical microring resonators with chiral coupling among the internal optical modes of each resonator. Interestingly, we find that the uniform coupling profile is not required to achieve HOEPs in this system-a feature that implies the emergence of HOEPs from disorder and provides resilience against some fabrication errors. Our results are confirmed by using full-wave simulations based on Maxwell's equation in realistic optical material systems.

Detecting Rare Variants and Heteroplasmy of Mitochondrial DNA from High-Throughput Sequencing in Patients with Coronary Artery Disease

Background

Although mutations and dysfunction of mitochondrial DNA (mtDNA) are related to a variety of diseases, few studies have focused on the relationship between mtDNA and coronary artery disease (CAD), especially the relationship between rare variants and CAD.

Material/Methods

Two-stage high-throughput sequencing was performed to detect mtDNA variants or heteroplasmy and the relationship between them and CAD phenotypes. In the discovery stage, mtDNA was analyzed by high-throughput sequencing of long-range PCR products generated from the peripheral blood of 85 CAD patients and 80 demographically matched controls. In the validation stage, high-throughput sequencing for mtDNA target regions captured by GenCap Kit was performed on 100 CAD samples and 100 controls. Finally, tRNA fine mapping was performed between our study and the reported Chinese CAD study.

Results

Among the tRNA genes, we confirmed a highly conserved rare variant, A5592G, previously reported in the Chinese CAD study, and 2 novel rare mutations that reached Bonferroni’s correction significance in the combined analysis were found (P=7.39×10⁻⁴ for T5628C in tRNA^Ala and P=1.01×10⁻⁵ for T681C in 12S rRNA) in the CAD study. Both of them were predicted to be pathological, with T5628C disrupting an extremely conservative base-pairing at the AC stem of tRNA^Ala. Furthermore, we confirmed the controversial issue that the number of non-synonymous heteroplasmic sites per sample was significantly higher in CAD patients.

Conclusions

In conclusion, our study confirmed the contribution of rare variants in CAD and showed that CAD patients had more non-synonymous heterogeneity mutations, which may be helpful in identifying the genetic and molecular basis of CAD.

[Protection of nerve function during transoral endoscopic thyroidectomy by vestibular approach]

Objective: To explore the method of functional protection in transoral endoscopic thyroidectomy by vestibular approach. Methods: Retrospective analysis was performed on the case data of 66 patients who underwent transoral endoscopic thyroidectomy by vestibular approach in the Department of Otorhinolaryngology Head and Neck Surgery of Beijing Tongren Hospital from February 2018 to February 2020. There were 11 males and 55 females aged 22-64 years, including 19 patients with benign diseases and 47 patients with malignant diseases. Important neurological functions were protected by a combination of anatomical exposure and intraoperative nerve monitoring. The clinical data and the effect of neurofunctional protection were summarized. SPSS 25.0 software was used for statistical analysis. Results: All operations were successfully completed with none transferred to open surgery. Three weeks after surgery, the numbness and tingling symptoms in the lower jaw and lower lip were basically relieved. There was no permanent mental nerve palsy, no permanent recurrent laryngeal nerve palsy but 2 cases with temporary recurrent laryngeal nerve palsy, no external branch injury of superior laryngeal nerve. There were 3 cases of temporary parathyroid gland dysfunction, 1 case of neck infection, 2 cases of subcutaneous effusion, 1 case of neck skin injury, and 2 cases of postoperative eye conjunctivitis. Conclusion: In transoral endoscopic thyroidectomy by vestibular approach, anatomical exposure can decrease mental nerve injury, and anatomical exposure combined with intraoperative nerve monitoring can protect the functions of the external branches of the superior laryngeal nerve and the recurrent laryngeal nerve.

Functional diversification of three delta-class glutathione S-transferases involved in development and detoxification in Tribolium castaneum

Glutathione S-transferases (GSTs) are members of a multifunctional enzyme superfamily. Forty-one GSTs have been identified in Tribolium castaneum; however, none of the 41 GSTs has been functionally characterized. Here, three delta-class GSTs, TcGSTd1, TcGSTd2 and TcGSTd3, of T. castaneum were successfully cloned and expressed in Escherichia coli. All of the studied GSTs catalysed the conjugation of reduced glutathione with 1-chloro-2,4-dinitrobenzene. Insecticide treatment showed that the expression levels of TcGSTd3 and TcGSTd2 were significantly increased after exposure to phoxim and lambda-cyhalothrin, whereas TcGSTd1 was slightly upregulated only in response to phoxim. A disc diffusion assay showed that overexpression of TcGSTD3, but not TcGSTD1 or TcGSTD2, in E. coli increased resistance to paraquat-induced oxidative stress. RNA interference knockdown of TcGSTd1 caused metamorphosis deficiencies and reduced fecundity by regulating insulin/target-of-rapamycin signalling pathway-mediated ecdysteroid biosynthesis, and knockdown of TcGSTd3 led to reduced fertility and a decreased hatch rate of the offspring, probably caused by the reduced antioxidative activity in the reproductive organs. These results indicate that TcGSTd3 and TcGSTd2 may play vital roles in cellular detoxification, whereas TcGSTd1 may play essential roles in normal development of T. castaneum. These delta-class GSTs in T. castaneum have obtained different functions during the evolution.

The effect of CuO loading on different method prepared CeO2 catalyst for toluene oxidation

The support effect on CeO₂ supported CuO catalysts are extensively investigated, but few studies have been reported in volatile organic compounds (VOCs) oxidation. Herein, CuO was impregnated on three conventional method synthesized CeO₂ to study its impact on toluene total oxidation over CeO₂ at low temperature (≤280 °C). Characterization results demonstrated that the shape and specific surface area of CeO₂ affected the degree of CuO dispersion, which determine the interaction between CuO and CeO₂. CuO significantly enhanced the toluene adsorption capacity of CeO₂, but lots of oxygen vacancies were lost during its loading. Although strong CuCe interaction induced new oxygen vacancies, the increase or decrease of final amount was related to the original surface properties of CeO₂. Mechanism analysis suggested that the activation of oxygen on oxygen vacancies controlled the toluene oxidation reaction rate. Therefore, the promotion or inhibition effect of CuO on CeO₂ for toluene oxidation depends on physical and chemical properties. Through this study, we have drawn some valuable information in guiding the synthesis and design of CuO-CeO₂ based catalysts.

[Analysis for potential targeting genes of TPF regimen induction chemotherapy in hypopharyngeal squamous cell carcinoma]

Objective: To analyze the differentially expressed genes related to the chemosensitivity with the TPF regimen for hypopharyngeal squamous cell carcinoma and to measure potential functional targeting genes expressions. Methods: Twenty-nine patients with primary hypopharyngeal cancer who underwent induction chemotherapy with TPF from January 2013 to December 2017 in Beijing Tongren Hospital were enrolled for microarray analysis, including 28 males and 1 female, aged from 43 to 73 years old. Among them, 16 patients were sensitive to chemotherapy while 13 patients were non-sensitive. Illumina Human HT-12 Bead Chip was applied to analyze the gene expressions and online bioinformatics analysis was used to analyze the differentially expressed genes. Reverse transcription and quantitative real-time PCR (RT-qPCR) was used to measure the mRNA expression of potential functional genes of TPF induction chemotherapy in 43 samples, 29 from original patients and 14 from additional patients. Graphpad prism 7.0 software was used for statistical analysis. Results: A total of 1 381 significantly differentially expressed genes were screened out. By GO analysis, up-regulated genes included sequestering in extracellular matrix, chemokine receptor binding and potassium channel regulator activity; down-regulated genes included regulation of angiogenesis, calcium ion binding and natural killer cell activation involved in immune response. With KEGG database analysis, down-regulated pathways included ECM-receptor interaction and peroxisome and up-regulated pathways included Glutathione metabolism and PPAR signaling pathway. The expressions of CD44 and IL-6R were significantly different and appeared biologically significant. CD44 was significantly upregulated in insensitive tissues (0.54±0.06) compared with sensitive tissues (0.33±0.04)(P<0.01). IL-6R was significantly downregulated in insensitive tissues (0.44±0.03) compared with sensitive tissues. (0.68±0.03) (P<0.01). Conclusion: CD44 and IL-6R may be potentially functional genes of TPF induction chemotherapy in hypopharyngeal squamous cell carcinoma.

Novel Fe-doped CePO4 catalyst for selective catalytic reduction of NO with NH3: The role of Fe3+ ions

Novel Fe-doped CePO₄ (Fe_xCe_1-x) catalyst was firstly successfully synthesized via a simple co-precipitation method and demonstrated excellent NH₃-SCR performance in comparison with FePO₄ and CePO₄. In order to study the promoting effects of Fe³⁺ ion on the NH₃-SCR activity of CePO₄ catalyst, various characterizations were conducted. It was found that NH₃ capacity of Fe_xCe_1-x catalyst was controlled by P sites and depended on their specific surface area. Interestingly, Fe species in Fe_xCe_1-x were not a Lewis acid site for NH₃ adsorption, but it could promote the activation of NH₃. More importantly, Fe³⁺ doping could induce the redox equilibrium of Fe³⁺ + Ce³⁺ ⇆ Fe²⁺ + Ce⁴⁺, which significantly improved redox properties of CePO₄ catalyst. Accordingly, improved catalytic activity of Fe_xCe_1-x catalysts could be attributed to the collective effects of the higher surface area, better redox properties and easily activated NH₃. Among them, superior redox property of Fe_xCe_1-x catalysts was the main reason boosting their high catalytic activity. Finally, the reaction process analyzed by in situ DRIFT proposed that the NH₃-SCR reaction over CePO₄ and Fe_xCe_1-x occurred mainly via Eley-Rideal mechanism. We anticipated this work could promote the development of novel NH₃-SCR catalyst.

[Spectrum analysis of pathological classification in 463 cases with nasal and paranasal sinuses malignant tumors]

Objective:The characteristics of pathological histological classification of nasal and paranasal sinuses malignant tumors in the past 10 years were analyzed, so as to provide possible basis, direction and ideas for the development of relevant effective treatment measures for nasal and paranasal sinuses malignant tumors in clinical practice. Method:The clinical data of patients with nasal and paranasal sinuses malignant tumors admitted to PLA general hospital from January 2009 to December 2018 were collected. Pathological types were retrospectively analyzed, and disease spectrum distribution, composition ratio and variation tendency of these patients were calculated. Result:Among the 463 patients, the overall pathological types in the top 5 were as follows: squamous cell carcinoma, adenoid cystadenocarcinoma, olfactory neuroblastoma, melanoma, adenocarcinoma. As for male patients, the pathological types in the top 5 were squamous cell carcinoma, adenoid cystic carcinoma, olfactory neuroblastoma, adenocarcinoma, neuroendocrine carcinoma and rhabdomyosarcoma were tied for fifth; the top 5 most common pathological types in female patients were squamous cell carcinoma, adenoid cystic carcinoma, melanoma, rhabdomyosarcoma, and adenocarcinoma. From 2009 to 2013, there were 183 patients with nasal and paranasal sinuses malignant tumors, the top 5 pathological types were squamous cell carcinoma, adenoid cystadenocarcinoma, olfactory neuroblastoma, melanoma, neuroendocrine carcinoma and rhabdomyosarcoma were tied for fifth; From 2014 to 2018, 280 patients with nasal and paranasal sinuses malignant tumors were diagnosed, the top 5 pathological types were squamous cell carcinoma, adenoid cystadenocarcinoma, melanoma, adenocarcinoma, and rhabdomyosarcoma. The ratio of the number of patients from 2009 to 2013 and 2014 to 2018 was about 0.65∶1. Malignant tumors of the nasal and paranasal sinuses tend to occur between the ages of 41 and 60, and the pathological types in the top 5 were squamous cell carcinoma,adenoid cystic carcinoma, adenocarcinoma, melanoma, neuroendocrine carcinoma. Conclusion:Malignant tumors of nasal cavity and sinus were more common in male, and the pathological types such as squamous cell carcinoma, adenoid cystic carcinoma, olfactory neuroblastoma were more common. All age groups have the disease, but the age group of 41-60 years old is the high-risk group of nasal and nasal sinus malignant tumors. However, the incidence rate of melanoma has gradually increased in the past five years, which needs to be paid more attention to.

Glucose-derived porous carbon as a highly efficient and low-cost counter electrode for quantum dot-sensitized solar cells

The power conversion efficiency of the QDSCs assembled with a CdS/CdSe sensitized TiO₂ photoanode and the C₉₀₀ CE is up to 5.61% under one sun illumination.

Anchoring CuS nanoparticles on accordion-like Ti3C2 as high electrocatalytic activity counter electrodes for QDSSCs

A Ti₃C₂/CuS composite has been fabricated as a counter electrode for quantum dot-sensitized solar cells by anchoring CuS nanoparticles on Ti₃C₂via a facile ion-exchange method at room temperature.

Controllable positions of Cu2+ to enhance low-temperature SCR activity on novel Cu-Ce-La-SSZ-13 by a simple one-pot method

Regulation of Cu²⁺ ions to migrate to more active SCR reaction sites can efficiently improve low-temperature SCR activity.

Dual-template assembled hierarchical Cu-SSZ-13: morphology evolution, crystal growth and stable high-temperature selective catalytic reduction performance

Assembled hierarchical Cu-SSZ-13 zeolites maintained excellent high-temperature activity due to mesoporous inhibition of ammonia oxidation.

CO2 hydrogenation to high-value products via heterogeneous catalysis

Recently, carbon dioxide capture and conversion, along with hydrogen from renewable resources, provide an alternative approach to synthesis of useful fuels and chemicals. People are increasingly interested in developing innovative carbon dioxide hydrogenation catalysts, and the pace of progress in this area is accelerating. Accordingly, this perspective presents current state of the art and outlook in synthesis of light olefins, dimethyl ether, liquid fuels, and alcohols through two leading hydrogenation mechanisms: methanol reaction and Fischer-Tropsch based carbon dioxide hydrogenation. The future research directions for developing new heterogeneous catalysts with transformational technologies, including 3D printing and artificial intelligence, are provided.

Carbon dioxide (CO₂) capture and conversion provide an alternative approach to synthesis of useful fuels and chemicals. Here, Ye et al. give a comprehensive perspective on the current state of the art and outlook of CO₂ catalytic hydrogenation to the synthesis of light olefins, dimethyl ether, liquid fuels, and alcohols.

Experimental Observation of PT Symmetry Breaking near Divergent Exceptional Points

Standard exceptional points (EPs) are non-Hermitian degeneracies that occur in open systems. At an EP, the Taylor series expansion becomes singular and fails to converge-a feature that was exploited for several applications. Here, we theoretically introduce and experimentally demonstrate a new class of parity-time symmetric systems [implemented using radio frequency (rf) circuits] that combine EPs with another type of mathematical singularity associated with the poles of complex functions. These nearly divergent exceptional points can exhibit an unprecedentedly large eigenvalue bifurcation beyond those obtained by standard EPs. Our results pave the way for building a new generation of telemetering and sensing devices with superior performance.

The utilization of dye wastewater in enhancing catalytic activity of CeO2-TiO2 mixed oxide catalyst for NO reduction and dichloromethane oxidation

Waste is a misplaced resource. Herein, anionic (orange II sodium salt and Ponceau 2R) and cationic (Rhodamine B and Methylene blue) dye wastewater assisted photo-treatment (referred as DAPT) method was developed to modify sol-gel synthesized CeO₂-TiO₂ (CeTi) mixed oxide catalyst. Catalytic activity test results showed that both anionic and cationic dye wastewater could be used as "fuel" of photo-treatment to enhance the activity of CeTi catalyst in NO reduction and dichloromethane oxidation. Characterization and DFT calculation results revealed that DAPT process increased the amount of Ce³⁺ ions on CeTi samples, which could induce the formation of Ce-V_O-Ti (oxygen vacancy (V_O) in Ce-O-Ti short range structure). These Ce-V_O-Ti defects not only could be adsorption sites for NH₃, dichloromethane and oxygen, but also promoted the redox shift of Ce³⁺+ Ti⁴⁺ ⇋ Ce⁴⁺+ Ti³⁺ by enhancing the oxidizability of Ce⁴⁺ and Ti⁴⁺ species. Furthermore, defects changed the polarity of Ce-O and Ti-O, which was conducive to the activation of lattice oxygen. All these improvements contributed to the excellent catalytic activity of CeTi catalysts. We expected this work to be instructive on constructing structure-activity over CeO₂-TiO₂ based catalysts and utilizing dye wastewater.

Controlling directional absorption with chiral exceptional surfaces

Significant efforts have been dedicated to engineering optical systems with predefined, excitation-dependent light absorption. An important concept along this line is that of exceptional points which allow for engineering directional light absorbing schemes. Current systems, however, do not lend themselves to easy design criterion or robust experimental realization. Here we demonstrate that an optical microring resonator coupled to a waveguide terminated with a mirror supports a chiral exceptional surface that can be used as a platform for tailoring directional light absorption in a straightforward fashion. We further demonstrate that this configuration can be used to implement a unidirectional coherent perfect absorber with controllable differential loss by tuning only a single parameter.