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Morphology regulation is an effective strategy for improving the sensor sensitivity of transition metal oxide nanostructures. In this work, SnO2with three different morphologies (nanorods, nanoparticles, and nanopillars) has been synthesized by a simple one-step solvothermal process with the addition of various solute ratios at 180 °C for 6 h for detecting formaldehyde (HCHO) at the optimum working temperature of 320 °C. Compared to nanorods and nanopillars, the created SnO2nanoparticles exhibit a much faster response time and sensitivity than other samples, showing the fastest recovery time (18 s) with the highest sensitivity of 6–100 ppm of the HCHO gas. The sensing mechanism of the sensors is investigated by Brunauer–Emmett–Teller (BET) methods and X-ray photoelectron spectroscopy (XPS) analysis, revealing that the pore size distribution and amount of OVand OCimprove the charge transfer and HCHO adsorption of nanoparticle sensors. Such an effect of morphology control on sensing performance paves an idea for the development of different structure-based HCHO sensors.

The utilization and selectivity of single atoms have garnered significant attention among researchers. However, they are easy to agglomerate because of their high surface energy. To overcome this challenge, it is crucial to seek suitable carriers to anchor single metal atoms to achieve optimal performance. In this work, the structures of transition metal single atoms embedded in hexagonal boron nitride (MB2N2, M = Fe, Co, Ni, Cu, Zn) are constructed and used for the adsorption and sensing of lithium battery thermal runaway gases (H2, CO, CO2, CH4) through the DFT method. The adsorption behavior of MB2N2was evaluated through the adsorption energy, sensitivity, and recovery time. The calculation results indicate that CoB2N2exhibits strong adsorption capacity for both H2and CO. The sensitivity of FeB2N2toward CO is as high as 3.232 × 1016. Subsequently, the adsorption mechanism was studied through TDOS and PDOS, and the results showed that hybridization between orbitals enhanced the gas adsorption performance. This study presents novel approaches for designing single-atom carriers and developing MB2N2sensors for detecting lithium battery thermal runaway gases.

To investigate the application of modified hexagonal boron nitride (h-BN) in the detection and monitoring of harmful gases (NO2, NO, NH3, and CO), first-principles calculations are applied to study the geometric structure and electronic behavior of the adsorption system. In this paper, the four adsorption sites, namely, B, N, bridge, and hollow sites, are considered to explore the stable adsorption structure of metals (M = Rh, Pd, Ag, Ir, Pt, and Au) on the BN surface. The calculation results demonstrate that the geometric structures of metal at the N-site are relatively stable. Subsequently, the different adsorption structures of NO2, NO, NH3, and CO on M-BN are researched. The electron transfer, charge difference density, and work function of the stable adsorption structure are calculated. The results show that NO2, NO, and CO have the strongest adsorption capacity in the Ir-BN system, with adsorption energies of −2.705, −5.064, and −3.757 eV, respectively. The Pt-BN system has an excellent adsorption performance (−2.251 eV) for NH3. Compared with the M-BN system, the work function of the adsorption system increases after adsorbing NO2, while it decreases after adsorbing NH3. This work shows that h-BN with metal modification is a potential material for online monitoring of harmful gases.

Construction of heterojunction has been considered as an efficient strategy to enhance the gas-sensing performances of metal oxide semiconductors. On this basis, hierarchical In2O3/In2S3microsphere heterostructures were synthesized by partial oxidation of In2S3precursors which were obtained viaa facile hydrothermal method. Besides, gas sensors based on the acquired materials were fabricated to investigate their sensing performances toward triethylamine (TEA). The results reveal that the gas sensor based on In2O3/In2S3exhibits a high response of 37 at 300 °C toward 0.45 mg/L TEA, which is 3.7 times higher than that of bare In2O3. Meanwhile, it also possesses fast response/recovery time (19 s/154 s), good repeatability, selectivity and long-term stability. The excellent sensing performances toward TEA are mainly attributed to the massive oxygen vacancy defects and heterojunction formed between In2O3and In2S3. This work provides a facile temperature-dependent route to controllably synthesize hierarchical In2O3/In2S3microsphere heterostructures, and the In2O3/In2S3sensor shows great application prospects in TEA detection.

Two-dimensional (2D) porous bimetallic oxide nanosheets are attractive for high-performance gas sensing because of their porous structures, high surface areas, and cooperative effects. Nevertheless, it is still a huge challenge to synthesize these nanomaterials. Herein, we report a general strategy to fabricate porous cobalt-based bimetallic oxide nanosheets (Co–M–O NSs, M = Cu, Mn, Ni, and Zn) with an adjustable Co/M ratio and the homogeneous composition using metal–organic framework (MOF) nanosheets as precursors. The obtained Co–M–O NS possesses the porous nanosheet structure and ultrahigh specific surface areas (146.4–220.7 m2g–1), which enhance the adsorption of CO molecules, support the transport of electrons, and expose abundant active sites for CO-sensing reaction. As a result, the Co–M–O NS exhibited excellent sensing performances including high response, low working temperature, fast response–recovery, good selectivity and stability, and ppb-level detection limitation toward CO. In particular, the Co–Mn–O NS showed the highest response of 264% to 100 ppm CO at low temperature (175 °C). We propose that the excellent sensing performance is ascribed to the specific porous nanosheet structure, the relatively highly active Co3+ratio resulting from cation substitution, and large amounts of chemisorbed oxygen species on the surface. Such a general strategy can also be introduced to design noble-metal-free bimetallic metal oxide nanosheets for gas sensing, catalysis, and other energy-related fields.

Background: Colorectal cancer (CRC) is the third most prevalent type of cancer in the world. Its prognosis is closely related to the disease stage at the time of diagnosis. Early detection of symptomless CRC or precursor lesions through population screening could reduce CRC mortality. However, screening programs are only effective if enough people are willing to participate. The incidence of CRC has a significantly increasing trend in China. Objective: Evaluation of the necessity of screening colonoscopy for community fecal occult blood-positive patients and exploration of the differences in the epidemiology of colorectal adenomas (CRA) and CRC of community screening patients and patients with different symptoms. Methods: We selected the 40–79 years age group of healthy people in the community of the Fengxian District of Shanghai who had two consecutive fecal occult blood and screening colonoscopies completed in our hospital between June 1, 2014 and October 31, 2014 as the screening group. Patients in the same age group with different symptoms (such as abdominal pain, bloody stool, diarrhea, change in bowel habits, weight loss, anemia, etc.) who had completed colonoscopy in our hospital during the same period comprised up the control group. Differences in the detection rates of colorectal polyps and CRC in the two groups and differences in the detection rates of CRA and early CRC between the two groups were compared. Results: There were 2251 patients in the colonoscopy screening group and 1836 patients in the control group. The colorectal polyps detection rates of the two groups were 19.46% (438/2251) and 21.95% (403/1836), respectively, and the difference was not statistically significant (p= 0.052). The CRC detection rates of the two groups were 0.8% (18/2251) and 2.02% (37/1836), respectively, the difference of which was statistically significant (p= 0.001). The detection rates of CRA were 17.73% (399/2251) and 19.88% (365/1836), respectively, which was not statistically significantly different (p= 0.083). Finally, the detection rates of early CRC were 0.36% (8/2251) and 0.44% (8/1836), respectively, which was not statistically significantly different in the two groups (p= 0.803). Conclusion: The detection rates of CRA among community screening patients and patients with different symptoms were not different. However, the detection rate of CRC in community screening patients was lower than that of the patients with different symptoms. Therefore community colonoscopy screening of fecal occult blood-positive asymptomatic healthy people is necessary, as it can help with the early detection and treatment of CRA.

Compared to current dominated metal complexes, organic photosensitizers used in photocatalytic hydrogen production present the relative superiority due to not including precious and rare metal elements, low in cost and abundant in resources. Recently, Gueret et al. synthesized triazatriangulenium derivative TATA+organic dyes with more outstanding visible-light-driven hydrogen production in the contrast of the popular ruthenium metal complexes under the same experimental conditions. In order to seek more highly efficient dyes than TATA+, we designed a series of organic molecules T+02-T+13with different side chains using density functional theory (DFT) and time-dependent DFT (TDDFT), based on the TATA+derivative parent T+01as prototype. We further comprehensively investigated their properties, such as energy levels, absorption spectra, free energy changes, ΔG01and ΔG02, which are respectively the photoinduced electron transfer from the sacrificial electron donor to the excited photosensitizer (PS*) and the electron transfer from the reduced form of PS (PS–) to the H2-evolving catalyst, the oxidation potential (Eox), and the reduction potential (Ered). The results show that T+12exhibits not only a higher molar extinction coefficient with an increment of 16.1%, a larger absolute value of the free energy of light-induced electron transfer, but also a more negative reduction potential (Ered= −1.51 V vs SCE) compared to T+03(Ered= −1.22 V vs SCE). Therefore, T+12is a very promising photosensitizer (PS) candidate for visible-light-driven hydrogen production.

Herein, 2-vinylpyridines as a new type of electron-poor system for the asymmetric cross Rauhut–Currier reaction are reported. 2-Vinylpyridines are chemo- and enantioselectively activated by a newly designed chiral phosphine catalyst. The new reaction provides a powerful synthetic tool for accessing structurally diverse, highly valued chiral pyridine building blocks in good yields and with high enantioselectivities. Preliminary mechanistic studies reveal that two NH protons in the catalyst are critical for the synergistic activation of the substrates and governing the stereoselectivity of this reaction.

A strategy for the facile construction of the chiral quinolinylmethanolic structure, a core featured in cinchona alkaloids, is reported. A new reactivity is harnessed by TfOH-promoted chemoselective activation of α-C–H over O–H bond in quinolinylmethanols. The new reactivity is successfully engineered with an iminium catalysis in a synergistic manner to create a powerful conjugate addition–cyclization cascade process for synthesis of chiral quinoline derived γ-butyrolactones in good yields and with good to excellent enantioselectivities. The method enables the first total synthesis of natural product broussonetine in three steps.

An efficient, green and atom‐economical iron‐catalyzed hydroamination of vinylpyridines with azoles has been developed. This reaction works smoothly for a diverse range of vinylpyridines and azoles, including diazoles and triazoles. The reaction was catalyzed by 5 mol % FeCl3in toluene at 110 °C for 3 h to afford the anti‐Markovnikov hydroamination products in moderate to excellent yields and excellent selectivities. Oh, the IRONy! An efficient, green and atom‐economical iron‐catalyzed strategy for the hydroamination of vinylpyridines with azoles has been developed. The reaction affords only anti‐Markovnikov hydroamination products in moderate to excellent yields.

The duplex stainless steels (UNS S32304) after solid solution annealing at two different temperature (1323K and 1573K) were subjected to the same cold rolling with ε =3 and subsequent annealing for 230 min at 1323 K . The corresponding interface character distribution (ICD) were determined by electron backscatter diffraction (EBSD). The results show that a larger population of phase boundaries (PB) having K-S orientation relationship (OR) between the neighboring δ and γ grains was introduced and therefore higher intergrannular corrosion resistance (ICR) were resulted in the specimen initially solid-solution annealed at 1573K.

Apply Niche Theory to give a comprehensive analysis of the marine industry niche present status. Explain marine economic development situation and overall features in coastal provinces from three perspectives of niche strength, niche width and niche overlap, specifically using biology quantitative models: Shannon-Wiener index and Pianka formula etc. Ultimately, based on the marine industry niche quantitative analysis and evaluation, the industrial structure and general characteristics of marine economy development in coastal provinces in China can be exactly explained.

By using the entropy method and coordination degree function to measure the comprehensive evaluation indicators of low- carbon port logistics and regional sustainable development of Tianjin.The results show that,Since 2000, the coordination degree between low- carbon port logistics and urban economy subsystem stay a high steady state, the dynamic coordination degree is best; The coordination degree of between subsystem of urban social and subsystem of ecological is slight fluctuation, but is generally stable.

We report on mild and selective filling of multiwalled carbon nanotubes (MWCNTs) with Prussian blue (PB) to explore the filling/electrochemistry/mass-transfer in nanochannels and the biosensing mode of nanochannel interior-exterior cooperation. PB-filled MWCNTs (MWCNTs-PBin) are prepared by filling MWCNTs with the gradually growing PB and then selectively removing the outer-surface PB by careful chemical washing. The prepared MWCNTs-PBincomposites possess high filling yield (mass ratio of PB to MWCNTs, (30 ± 3)%) and electroactivity percentage (mass ratio of electroactive PB to total PB, (45 ± 3)%). The MWCNTs-PBincomposites on Au electrode exhibit strong and stable electrocatalytic activity of filled PB for H2O2reduction and electroanalysis. The filling of the MWCNTs with electroactive PB also provides a new experimental platform to deal with the widely concerned issue of mass transfer inside nanochannels. The normalized cyclic voltammetric responses of filled PB on MWCNTs-PBinelectrode at relatively low scan rates (below 125 and 75 mV s–1for mass transfer of K+and K++ H2O2, respectively) were found to be equivalent to those of conventionally electrodeposited PB on MWCNTs/Au and Au electrodes, demonstrating that the mass transfer of K+and H2O2inside our MWCNTs is comparable to those outside our MWCNTs at the low scan rates. Furthermore, the unoccupied outer surfaces of MWCNTs-PBinare conveniently exploited to bind 4-(1-pyrenyl) butyric acid through π–π stacking interaction and then to anchor glucose oxidase or lactate oxidase through the EDC/NHS chemistry. Thus, we have developed a novel cooperative biosensing mode by combining outer-surface biocatalyzed oxidation of substrate with interior PB-catalyzed reduction of enzymatically generated H2O2, which endows our biosensors with low detection potential (−0.1 V) and satisfactory sensitivity/selectivity.

Three‐dimensional porous platinum (Ptpor) films are prepared based on Pt electrodeposition on polyaniline (PANI) modified electrodes followed by selective dissolution of PANI with HNO3. Electrochemical quartz crystal microbalance data suggest that the PANI‐H2PtCl6interaction involves redox and coordination reactions, depending on the working potential. The Ptporshows better electrocatalytic performance than the Pt/PANI and conventionally electrodeposited Pt. The Ptpormodified glassy carbon electrode (GCE) can electrocatalyze the oxidation of H2O2with a sensitivity of 414 µA cm−2mM−1and a detection limit of 9 nM, and the chitosan‐glucose oxidase/Ptpor/GCE can sense glucose with a sensitivity of 93.4 µA cm−2mM−1.

A wedge-shaped 304 austenitic stainless steel with varied thickness longitudinally was cold rolled into a flat one and then annealed at 1323K for 10 min. The grain boundary character distributions (GBCDs) in the specimen as processed were examined by the means of Electron backscatter diffraction (EBSD). The results showed that, at the regions with low pre-strains ranged from 4% to 6%, quite high fractions of S3n (n=0,1,2,3) grain boundaries and large-sized S3n (n=0,1,2,3) grain clusters are introduced compared with the regions of quite low ( less than 2.5%) or relatively high pre-strain. The surface appearance of after corrosion test reveals that grain dropping due to intergranular corrosion (IGC) is depressed and the penetration of IGC from the surface into the interior in the cross-section is arrested significantly as well in the regions with high fractions of S3n boundaries and large-sized S3n grain clusters.

CO2conversion into valuable chemicals and fuels is a sustainable route to the concurrent mitigation of the energy crisis and the greenhouse effect. Herein, first principles calculations were employed to study the photocatalytic CO2reduction over pristine WS2, S-vacancy WS2, and Pt cluster loaded WS2. Our results indicate that the introducing of S-vacancy and loading of Pt clusters can improve the optical absorption in the visible-light region. Furthermore, S-vacancy can lower the barrier (by about 0.17 eV) for *COOH intermediate formation. For Pt/WS2, the strong metal–support interaction is confirmed by high adsorption energy and charge transfer. Importantly, the electron-rich Pt cluster promotes *CO intermediates to facilitate the formation of *CHO intermediates and to further protonate to CH4. This study provides some useful insights into designing the catalysts for the reduction of CO2and further widens the applications of WS2-based catalytic materials.

Background. This study was to evaluate the prognostic value of the preoperative neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and carcinoembryonic antigen (CEA) in colorectal cancer (CRC) patients and to identify the potential and easily accessible prognostic biomarkers for CRC. Methods. We retrospectively reviewed altogether the records of 330 CRC patients according to inclusion criteria. The clinical characteristics include age at diagnosis, body mass index (BMI), preoperative CEA level, neutrophil , lymphocyte, and platelet count, tumor primary site and size, clinical pathological TNM stage, and survival status were recorded through the review of medical records. The overall survival (OS) was calculated using the Kaplan–Meier method. The Cox proportional hazards model was used for the univariate and multivariate analysis to evaluate the prognostic factors of CRC. Results. A total of 330 patients were finally included in the current study. The mean follow-up duration was 32.8 ± 19.1 months (range, 0.1–67.7). Compared with the median OS, preoperative high NLR, PLR, and CEA, and low BMI had lower median OS. The NLR and PLR value rise indicates lower median OS in stage I-II CRC; however, the NLR value and CEA level rise indicates lower median OS in stage III-IV CRC. Preoperative high NLR, PLR, and CEA level and low BMI have poorer OS by univariate analysis. By multivariate analysis, the age, sex, N, M stage, and BMI demonstrated independently influence the OS of CRC. NLR was an independent predictor of stage I-II CRC, and the CEA level was an independent predictor of stage III-IV CRC. Conclusions. Our results show that preoperative high NLR, PLR, CEA, and low BMI had poorer OS, NLR was an independent predictor of stage I-II CRC, and the CEA level was an independent predictor of stage III-IV CRC.