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Chemical fixation of carbon dioxide (CO2) may be a pathway to retard the current trend of rapid global warming. However, the current economic cost of chemical fixation remains high because the chemical fixation of CO2 usually requires high temperature or high pressure. The rational design of an efficient catalyst that works at ambient conditions might substantially reduce the economic cost of fixation. Here, we report the rational design of covalent organic frameworks (COFs) as efficient CO2 fixation catalysts under ambient conditions based on the finding of “pore enrichment”, which is concluded by a detailed investigation of the 10994 COFs. The best predicted COF, Zn-Salen-COF-SDU113, is synthesized, and its efficient catalytic performance for CO2 cycloaddition to terminal epoxide is confirmed with a yield of 98.2% and turnover number (TON) of 3068.9 under ambient conditions, which is comparable to the reported leading catalysts. Moreover, this COF achieves the cycloaddition of CO2 to 2,3-epoxybutane under ambient conditions among all porous materials. This work provides a strategy for designing porous catalysts in the economic fixation of carbon dioxide., Currently the cost of CO2 chemical fixation remains high because of harsh reaction conditions. Here, the authors report a covalent organic framework screened from 10994 candidates as the efficient CO2 fixation catalyst under ambient conditions based on the finding of a “pore enrichment effect”.

Single-atom catalysts (SACs) have attracted extensive attention in the field of heterogeneous catalysis. However, the fabrication of SACs with high loading and high-temperature stability remains a grand challenge, especially on oxide supports. In this work, we have demonstrated that through strong covalent metal-support interaction, high-loading and thermally stable single-atom Pt catalysts can be readily prepared by using Fe modified spinel as support. Better catalytic performance in N2O decomposition reaction is obtained on such SACs than their nanocatalyst counterpart and low-surface-area Fe2O3 supported Pt SACs. This work provides a strategy for the fabrication of high-loading and thermally stable SACs for applications at high temperatures.

Single-atom catalysts (SACs) have demonstrated superior catalytic performance in numerous heterogeneous reactions. However, producing thermally stable SACs, especially in a simple and scalable way, remains a formidable challenge. Here, we report the synthesis of Ru SACs from commercial RuO2 powders by physical mixing of sub-micron RuO2 aggregates with a MgAl1.2Fe0.8O4 spinel. Atomically dispersed Ru is confirmed by aberration-corrected scanning transmission electron microscopy and X-ray absorption spectroscopy. Detailed studies reveal that the dispersion process does not arise from a gas atom trapping mechanism, but rather from anti-Ostwald ripening promoted by a strong covalent metal-support interaction. This synthetic strategy is simple and amenable to the large-scale manufacture of thermally stable SACs for industrial applications., Large scale production of thermally stable single-atom catalysts (SACs) remains challenging. Here, the authors report scalable synthesis of Ru SACs by heating physical mixture of commercial RuO2 and Fe-containing support, which is significantly promoted by strong metal-support interaction.

Heterogeneous gold nanocatalysts have both inspired researchers with their unique catalytic performance and frustrated them due to the contradictions observed in their activities and stabilities. A recent breakthrough has shown that gold nanoparticles (NPs) can retain their catalytically active size over a MgGa2O4 spinel support upon sintering at high temperatures. Herein, we report the catalytic activity of anti-sintering Au MgGa2O4 for use in water gas shift reaction (WGSR) and catalytic combustion reactions, and the promoting effect of ceria. Upon adding ceria to 800°C-aged Au MgGa2O4, the CO conversion in the WGSR was increased from ∼1.5% to ∼34.0% at 450°C, and the “light-off” temperatures (T50) for methane combustion and CO oxidation were decreased by ∼80 and ∼100°C, respectively. Characterizations using XRD, HAADF-STEM, EDS mapping, H2-TPR, XPS, and DRIFTs confirmed the proximate contact of Au with ceria and their significant synergistic effect, which thereby combined the benefits of ceria toward the dissociation of H2O or O2 and the Au NPs toward activating CO or CH4. These results show that this stepwise stabilization-activation strategy is efficient for rationally constructing stable and active gold nanocatalysts, which may open up possibilities for the wide application of gold nanocatalysts at elevated temperatures.

Ambient conversion of carbon dioxide into various liquid fuels or chemicals is a potential economical solution for reducing CO2 emissions, which may be responsible for recent climate change. Here, we report a highly active dual single-Pd-atom catalyst for ambient conversion of CO2 to formic acid using a step-by-step catalyst design strategy by the density functional theory (DFT) method. The theoretically predicted catalyst is synthesized experimentally and verified to capture a significant amount of CO2 (5.05 mmol/g, 273 K), and it can efficiently convert CO2 to formic acid under ambient conditions (30 °C, 1 bar) with a turnover frequency (TOF) as high as 13.46 h-1, which is the first such report in the field of heterogeneous catalysts. Two major factors contributing to this extraordinary catalytic activity include a pore enrichment effect of the microporous structures of the covalent triazine framework and a ternary synergetic effect among two neighbouring Pd atoms and rich nitrogen environment. Our work may aid the development of heterogeneous catalysts to produce other commonly used fuels from CO2 under ambient conditions.

To explore the effects of the Chinese herbal compound Tongjingling (TJL) on the ROS level, mitochondrial membrane potential (MMP) and mitochondrial ultrastructure in spermatogenic cells in varicocele (VC) rats with liver-qi stagnation (LQS).Totally, 72 male SPF Wistar rats were randomly divided into six groups of equal number, sham operation, VC+LQS model, low-, medium- and high-dose TJL, and L-carnitine (LC) control. The VC+LQS model was established by the Saypol method combined with tail-clamping. At 4 weeks after modeling, the rats in the low-, medium- and high-dose TJL groups were treated intragastrically with TJL at 0.6, 1.2 and 2.4 g/ml respectively, those in the sham operation and VC+LQS model groups with 0.9% saline, and those in the LC control group with LC oral liquid at 2.1 ml/kg, qd, for 8 weeks. Then the ROS level and MMP in the spermatogenic cells were measured by flow cytometry and the mitochondrial ultrastructure observed under the transmission electron microscope.The ROS level in the spermatogenic cells was significantly higher in the VC+LQS model and low-dose TJL groups than in the sham operation group (［62.72 ± 9.90］% and ［52.25 ± 8.15］% vs ［36.53 ± 5.25］%, P0.01), but remarkably lower in the medium-dose TJL (［41.65 ± 4.89］%), high-dose TJL (［39.60 ± 5.19］%) and LC control (［38.33 ± 7.46］%) than in the VC+LQS model group (P0.01). MMP in the spermatogenic cells was significantly lower in the VC+LQS model and low-dose TJL than in the sham operation group (［34.80 ± 20.18］% and ［44.39 ± 19.60］% vs ［60.24 ± 22.25］%, P0.01 and P0.05), but markedly higher in the medium-dose TJL (［50.62 ± 14.83］%), high-dose TJL (［52.42 ± 7.55］%) and LC control (［50.75 ± 15.65］%) than in the VC+LQS model group (P0.05). The mitochondria in the spermatogenic cells of the VC+LQS model rats exhibited swelling, vacuolization, rupture or disappearance of the mitochondrial cristae, and breakdown of the internal structure. The pathological injury of the mitochondrial structure was improved in different degrees in the TJL and LC groups.TJL can reduce the ROS level, increase MMP and improve pathological injury of the mitochondrial ultrastructure in the spermatogenic cells of VC rats with LQS, which may be the underlying molecular mechanism of TJL improving fertility in infertile VC patients.

Anti-sintering platinum-based catalyst for propane dehydrogenation (PDH) is promising to avoid corrosive oxychlorination re-dispersion of sintered Pt during coke combustion. Herein, we report an anti-sintering Pt/MgAl2O4 catalyst and optimizations on its activity for PDH with group IB metals (Cu, Ag and Au). Using a suite of characterizations including BET, H2 chemisorption, XRD, STEM, CO-DRIFTs, XANES, XPS, TG/DTA, TPO, C3H6-TPD and TPSR of C3H6 with H2, we reveal that Cu and Ag dilute the surface Pt atoms and donate electron to Pt while the case for Pt-Au is inverse. As a result, significant enhancements in propane conversion and propylene selectivity were obtained on the Pt-Cu/MgAl2O4 and Pt-Ag/MgAl2O4 catalysts. The Pt-Cu/MgAl2O4 exhibited excellent C3H6 yield and regeneration stability, presumably due to the formation of intermetallic compounds and little phase segregation during cyclic dehydrogenation-regeneration runs.

High performance liquid chromatography (HPLC) analysis showed that the content of chlorogenic acid in burdock standard water extract (BSWE) was about 1.22and#177;0.07 mg/g and no araciin and arctigenin was detected. The inulin was determined to be 174.33and#177;3.68 mg/g in BSWE by colorimetry method. The amino acids were analyzed by the amino acid analyzer and showed that asparagine and arginine are higher and determined to be 3021.00and#177;13.53mg/100g, 2042.33and#177;8.62mg/100g in BSWE, respectively. The results of aphrodisiac pharmacological experiments showed that the number of riding, insertions and the latency of rats in BSWE groups showed significant differences as compared with control, at the 7th day and 15th day after drug administration. Further study indicated that the aphrodisiac effect of BSWE is mostly associated with its regulation on NO, sialic acid and antioxidative ways and arginine should be one of the active components in BSWE.

Hydrogen storage and CO2 capture are of great importance for efficient fuel usage and environmentally clean methods. Here, we report a series of 7,7,8,8-tetracyanoquinodimethane-derived covalent triazine frameworks (TCNQ-CTFs) with different specific surface areas for hydrogen and CO2 storage. Such TCNQ-CTFs exhibit maximum H2 and CO2 adsorption capacities up to 2.79 wt% (77 K, 1 bar) and 5.99 mmol/g (273 K, 1 bar), respectively, which are the highest values among reported covalent triazine frameworks.Theory simulation by using the Grand Canonical Monte Carlo (GCMC) method revealed that abundant nitrogen and defects induced by annealing treatment are the reasons for the high adsorption capacity of the material. This work not only contributes a superior material for both hydrogen and CO2 storage under ambient conditions but also deepens the knowledge on its adsorption mechanism, thus guiding people to engineer more efficient storage materials.

Background: Previous findings indicate that testosterone level is negatively correlated with the incidence and mortality of cardiovascular diseases in men. Endothelial progenitor cells (EPCs) play a critical role in endothelial healing and vascular integrity. This study aimed to examine the effects of dihydrotestosterone (DHT), an active metabolite of testosterone, on human EPC function and investigate the underlying mechanism. Methods: EPCs were isolated from peripheral blood of healthy adult males and incubated with a series of concentrations (1, 10, and 100 nmol/L in dimethyl sulfoxide) of DHT for 24 h or with 10 nmol/L DHT for different periods (6, 12, 24, 36, and 48 h). EPC proliferation, migration, and adhesion were determined by MTT assay, modified Boyden chamber assay, and cell counting, respectively. Furthermore, vascular endothelial growth factor (VEGF) production was examined by ELISA, RhoA activity was determined through pull-down assay. The protein level of RhoA was quantified by Western blot analysis. Results: DHT significantly increased the proliferative, migratory, and adhesive abilities of EPCs in a dose- and time-dependent manner and upregulated the levels of VEGF and activated RhoA. However, RhoA inhibitor C3 exoenzyme or ROCK inhibitor Y-27632 significantly inhibited DHT-induced proliferation, migration, and adhesion, as well as VEGF production. Moreover, C3 exoenzyme inhibited the activation of RhoA stimulated by DHT. Conclusions: DHT promotes EPC proliferation, migration, and adhesion activities via RhoA/ROCK pathway.

The efficacy and safety of physiotherapeutic prophylaxis for venous thromboembolism in critically ill patients with heparin contraindication remains unclear. In the present study it was hypothesized that physiotherapy prophylaxis with intermittent pneumatic compression (IPC) would be safe and effective for patients unable to receive low-molecular-weight heparin (LMWH). In addition, this study investigated whether a combined therapy of IPC with LMWH would be more effective for the prophylaxis of deep vein thrombosis (DVT) in critical patients. A total of 500 patients were divided into four groups according to the prophylaxis of DVT. The IPC group consisted of 95 patients with heparin contraindication that received IPC treatment; the LMWH group consisted of 185 patients that received an LMWH injection; the LMWH + IPC group consisted of 75 patients that received IPC treatment and LMWH injection; and the control group consisted of 145 patients that received no IPC treatment or injection of LMWH. Each patient was evaluated clinically for development of DVT and the diagnosis was confirmed by Doppler study. Venous thromboembolism was a common complication among the trauma patients with severe injuries. Patients responded positively to the treatment used in the intervention groups. Patients exhibited an improved response to LMWH + ICP compared with IPC or LMWH alone, while no significant difference was detected between the IPC and LMWH groups. These results were applicable to patients that had a Wells score of ≥3; however, no significant differences in DVT incidence were observed among the patients who had a Wells score of

Our objective was to observe the effectiveness of the calcium ionophore A23187 or strontium chloride on the activation and subsequent embryonic development of 3-day-old human unfertilized oocytes after in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). A total of 279 3-day-old unfertilized oocytes after IVF or ICSI were randomized to be activated by the calcium ionophore A23187 (n=138) or strontium chloride (n=141). The activated oocytes were cultured in vitro for 3-5 days. Activation rate, pronucleus formation, cleavage rate, and developmental potential of parthenotes during culture were evaluated. A total of 170 unfertilized oocytes were activated; 65 developed to cleavage stage, 19 developed to greater than the eight-cell stage, and five blastocysts were obtained. The activation rate of the calcium ionophore A23187 group was higher than that of the strontium chloride group (75.4% and 46.8%, respectively; p

To supply reliable materials for the assessment of recurrence risk,prenatal diagnosis and the supervision of high risk persons,we analyzed 10811 patients with the methods of cytogenetics,fluorescent in situ hybridization and molecular genetic PCR methods. The result of cytogenetics:there were 555 abnormal karyotypes of peripheral blood on 5390 cases (10.30%);In 2171 patients who asked for prenatal diagnosis,145 abnormal karyotypes were found (6.68%);We also karyotyped chorionic villous cells of 62 patients with spontaneous abortion and found 28 abnormal karyotypes (45.16%). The PCR results of 23 patients with Down's syndrome were all positive while the results of 155 normal persons were all negative. The method of cytogenetics is very important for diagnosis of abnormal karyotypes;Molecular genetic methods by PCR and FISH are quick,convenient and applicable way.