Realizing the Direct Synthesis of High Silica IWS Zeolite with Improved Hydrothermal Stability.

Direct synthesis of germanosilicate zeolites with low Ge content and improved hydrothermal stability is a great challenge. Herein, we successfully achieve the direct synthesis of IWS zeolite with a Si/Ge ratio higher than 4 for the first time. High silica IWS zeolites can be prepared in a wide range of Si/Ge ratios (4-16) by utilizing bulky 1,3-bis(1-adamantyl)-imidazolium (BAdaI+) as an efficient organic structure-directing agent from the concentrated synthesis gel under fluoride conditions. It is proven by a series of characterizations that Ge atoms preferentially occupy the double-four-ring (D4R) units. Theoretical calculations reveal the preferential interactions of guest organic structure-directing agents (OSDAs) and host IWS zeolites with different Si/Ge ratios. The introduction of more Ge atoms cannot improve the host-guest interaction when the BAdaI+ molecule is accommodated within the nanopores of IWS zeolite compared to other OSDAs. The obtained IWS zeolite shows an extremely high specific surface area (905 m2/g) and pore volume (1.31 cm3/g). Due to the low Ge content, IWS zeolite exhibits outstanding hydrothermal stability and experiences high temperature steam heating with no loss of crystallinity and only a slight loss of microporosity.

The influence of high-temperature frequency variation on the life-history traits of pyridaben-sensitive and -resistant strains of Tetranychus truncatus.

With a generally warming global climate, the number of Tetranychus truncatus specimens in the Hexi region in China has been increasing. As ectotherms, the growth and development of T. truncatus are greatly affected by changes in environmental temperature. The effect of heatwaves on organisms depends on a delicate balance between damage and repair periods. Therefore, we simulated nine patterns of periodically recurring changes in the frequency of high-temperature days using an intraday gradual temperature change model to study and compare the effects on the development and reproduction of pyridaben-sensitive and -resistant strains of T. truncatus. The results showed that the influence of the frequency of high-temperature days on developmental stages, longevity and fecundity was different between the two strains. The egg and immature stages of the sensitive strain were all affected by hot days, whereas the adult stage was less affected by the frequency. The egg stage of the resistant strain was less affected; it was mainly affected in the immature and adult stages. Under the moderate condition of increasing the proportion of days at normal temperature, the longevity of the resistant strain gradually increased and reached a maximum at a 1:3 frequency, and then it decreased with the increase in high-temperature days. The longevity of the sensitive strain was less affected by frequency, and there was no significant difference between most treatment and control groups. In addition, both sensitive and resistant strains were able to complete growth and development under all nine frequencies of high-temperature days, but the reproductive rate was lower than it was at normal temperatures, indicating that both strains of T. truncatus adapted to high temperatures at the expense of reduced reproduction rates. This lays a key theoretical foundation for predicting the occurrence of agricultural pest populations under the background of climate warming and developing appropriate control strategies.

Spindle Nanorods of CeO2 and NiS Heterointerface Coated by the NC Layer: A High-Performance Bifunctional Electrocatalyst for Water Splitting.

Currently, nickel sulfides are widely employed in the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), thanks to the narrow electronegativity difference of only 0.67 eV between nickel and sulfur. Among them, NiS stands out in terms of the OER performance; however, its HER performance and stability remain somewhat inadequate. The construction of heterogeneous interfaces can efficiently improve the HER performance and regulate the electronic structure of the NiS catalyst. CeO2 has been discovered to possess exceptional electronic modulation capabilities, which may lead to the effective enhancement of both HER and OER of the NiS catalyst. As a result, a nitrogen-doped carbon-coated CeO2-NiS heterogeneous interface catalyst (NC/NiS-CeO2) is designed as a bifunctional electrocatalyst for HER and OER with high performance. The NC/NiS-CeO2 catalyst demonstrates excellent HER (47 mV at 10 mA cm-2) and OER (92 mV at 10 mA cm-2) performances in a 1 M KOH alkaline solution. Characterization analysis reveals that the coupling of the heterostructure interface, which consists of CeO2 and NiS, significantly enhances electron conduction, the synergistic effect, and the electrocatalytic activity of the electrode. This study demonstrates that the HER and OER activity can be effectively improved by constructing a rational heterogeneous interface.

RuSe2-CoTe Heterogeneous Surfaces Coated with NC Layer for Excellent HER Performance under Alkaline Condition.

Electrocatalytic hydrogen production has been a promising high-purity hydrogen production technology, attracting a large number of researchers' research interest. Ru has a hydrogen binding capacity similar to Pt, but its price is far lower than Pt, making it a promising alternative to Pt. However, a single Se electronic structure modulation is not sufficient to enable RuSe2 to be used for practical applications on a large scale due to the lack of electrons. Therefore, choosing a suitable way to electronically modulate the Ru atoms in RuSe2 can effectively improve the activity of the catalyst. Cobalt telluride (CoTe) can significantly enhance electrocatalytic performance due to tellurium's low electronegativity and excellent metal properties. In this work, the NC layer possesses excellent electrical conductivity and CoTe acts as an electron donor to optimize the electronic structure locally and trigger electron transfer efficiently. The RuSe2-CoTe/NC electrode requires an overpotential of only 25.4 mV (10 mA cm-2), which is superior to that of RuSe2/NF (65 mV) and CoTe/NC (115 mV). Meanwhile, the Tafel slope of RuSe2-CoTe/NC (67.8 mV dec-1) was better than that of RuSe2/NF (113.6 mV dec-1) and CoTe/NC (209.5 mV dec-1), showing that the build-up of the superior heterojunction makes the RuSe2-CoTe/NC with better hydrogen evolution reaction (HER) reaction kinetics. In addition, after 30 h of long-term stability testing, no significant decrease in catalytic activity was observed, proving the good stability of the RuSe2-CoTe/NC catalyst.

Direct synthesis of ultrathin FER zeolite nanosheets via a dual-template approach.

The synthesis of zeolites with nanosheet morphology has been attracting extensive attention. Despite the steady progress, the direct synthesis of ultrathin nanosheets of FER zeolite with thickness of less than 10 nm is still a great challenge. Herein we report a facile synthesis of FER zeolite nanosheets (named SCM-37) by using octyltrimethylammonium chloride (OTMAC) and 4-dimethylaminopyridine (4-DMAP) as dual organic templates. The effects of synthesis parameters, including initial molar ratio of SiO2/Al2O3, crystallization temperature and time were investigated. It turned out that the crystallization field of SCM-37 was narrow. A two-step crystallization method was utilized to obtain pure and completely crystallized SCM-37 zeolite. SCM-37 was characterized by multiple techniques, including X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen physisorption, Fourier transform infrared (FTIR), ammonia-temperature programmed desorption (NH3-TPD) and nuclear magnetic resonance (NMR), and compared with the conventional FER zeolite (C-FER). The two most significant features of SCM-37 are the ultrathin crystal nanosheet and extremely high external surface area. The thickness of SCM-37 along the a-axis is 4∼7 nm, while that of C-FER is over 20 nm. The external surface area reaches 198 m2 g-1, which is over ten times larger than that of C-FER. The catalytic performances of the FER zeolites were evaluated by the cracking of 1,3,5-triisopropylbenzene (TiPB). Although possessing a lower amount of total acid sites, SCM-37 showed higher conversion of TiPB, as well as selectivity to the deep cracking products. The superior performance of SCM-37 was attributed to the higher external surface area arising from the ultrathin nanosheets.

[Molecular design and biological activity analysis of antimicrobial peptide RIKL].

Natural antimicrobial peptides have strong bactericidal activities. An obstacle of the development of antimicrobial peptides resides in the difficulty of developing peptides with high biocompatibility. In this study, molecular dynamics analysis was employed to assess the structural characteristics and biological activities of peptides. A (RXKY)2(YRY)2 structure was used as a template to design an antimicrobial peptide RIKL of high-efficiency and low-toxicity, where X represents Ile and Y represents Leu. The secondary structure of the antimicrobial peptide was detected by circular dichroism (CD), and the structures of RIKL in water and in POPC/POPG membrane environment were measured using molecular dynamics. The biological activity of RIKL was further studied by assessing its antimicrobial activity, hemolytic activity, eukaryotic cytotoxicity, and salt ion stability. CD results showed that RIKL presented an α-helical structure in a simulated bacterial membrane environment. Molecular dynamics simulation predicted that the secondary structure of RIKL could be partly retained in water and POPG environment, while this secondary structure was weakened in the POPC environment. Antimicrobial test suggested that RIKL had high antimicrobial activities, and the geometric mean of the Minimum Inhibitory Concentration (MIC) was 3.1 µmol/L. The hemolysis indicated that RIKL had no hemolytic activity within the detection range, and cytotoxicity test suggested the cytotoxicity of RIKL was low. Stability test showed that RIKL maintained antimicrobial activities under different pH, serum concentrations and salt environments. Based on the above results, RIKL has high cell selectivity and has the potential as a highly effective antibacterial drug.

SCM-25: A Zeolite with Ordered Meso-cavities Interconnected by 12 × 12 × 10-Ring Channels Determined by 3D Electron Diffraction.

Zeolites with large cavities that are accessible via wide pore windows are desirable but very rare. They have been dominantly used as catalysts in industry. Here we report a novel porous germanosilicate SCM-25, the zeolite structure containing ordered meso-cavities (29.9 × 7.6 × 6.0 Å3) interconnected by 10- and 12-ring channels. SCM-25 was synthesized as nanosized crystals by using a simple organic structure-directing agent (OSDA). Three-dimensional (3D) electron diffraction shows that SCM-25 crystallizes in the orthorhombic space group Cmmm with a = 14.62 Å, b = 51.82 Å, c = 13.11 Å, which is one of the zeolites with the largest unit cell dimensions. We demonstrate that 3D electron diffraction is a powerful technique for determining the complex structure of SCM-25, including the disorders and distributions of framework atoms silicon and germanium. SCM-25 has a high surface area (510 m2/g) and high thermal stability (700 °C). Furthermore, we propose a potential postsynthetic strategy for the preparation of zeolites with ordered meso-cavities by applying the ADOR (assembly-disassembly-organization-reassembly) approach.

Syntheses of MTT-Type Zeolites with the Presence of Both Octyltrimethylammonium Chloride and SFE-Type Zeolite Seeds.

Structure-directing agents (SDAs) play important roles in directing the formation of specific zeolite frameworks. Mechanisms and working hypothesis were proposed for understanding how SDAs work during the crystallization of zeolites. The lately reported cooperative structure-directing effect based on the investigation into the synthetic system containing both seed and organic species is one of them and is believed to be effective for synthesizing zeolites which are difficult to access or with novel structures. However, more examples are still needed to support the thesis. Herein, we report for the first time the syntheses of MTT-type zeolites with the simultaneous presences of octyltrimethylammonium chloride (OTMAC) and SFE zeolite seeds in the borosilicate system. SFE borosilicate zeolites serve as exotic seeds for the crystallization of MTT-type zeolites and together with OTMAC play cooperative structure-directing roles. Besides, Al,B-MTT and heteroatom (Zr, V, and Fe)-incorporated MTT-type zeolites were directly synthesized with the introduction of metal sources into the borosilicate system. Physicochemical properties of the obtained MTT zeolites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N2 physisorption, NH3-TPD, 27Al NMR, 13C NMR, 11B NMR, UV-visible spectroscopy, and UV Raman spectroscopy. The herein-reported phenomenon provides an example to better understand the mechanism of zeolite crystallization, and the synthesized zeolites may act as promising catalytic materials in several organic reactions.

The Characteristics of Polycyclic Aromatic Hydrocarbons in Different Emission Source Areas in Shenyang, China.

Particulate matter (PM) was collected in three different areas, SY-1, SY-2, and SY-3, in Shenyang, China, during the warm and cold seasons from 2012 to 2014. SY-1 was located beside a thermal power plant, far from the central area. SY-2 was near a coal heating boiler on the main road, close to the central area. SY-3 was on the main road, without fixed emission sources. Nine PM-bound polycyclic aromatic hydrocarbons (PAHs) were analyzed. The results showed that the mean concentration of total PAHs was higher in the cold season (92.6-316 ng m-3) than in the warm season (18.4-32.2 ng m-3). Five- and six-ring PAHs occupied a large percentage at all sites in the warm season, and four-ring PAHs were the dominant components in the cold season. Several diagnostic PAH ratios indicated that the main sources of PAHs in Shenyang in the warm and cold seasons were not only coal burning but also vehicle emission. In this study, we suggest that a benzo[a]pyrene/benzo[ghi]perylene ratio ([BaP]/[BgPe]) of 0.6 was a useful indicator to speculate the relative significance of coal burning and vehicle exhaust. Although the Shenyang government has undertaken actions to address air pollution, the PM and PAH concentrations did not decrease significantly compared to those in our previous studies. The cancer risk calculated from the BaP equivalent total concentration at all three sites in the warm and cold seasons exceeded the acceptable limit established by the US EPA.

High Number of Circulating Tumor Cells Predicts Poor Survival of Cutaneous Melanoma Patients in China.

BACKGROUND Melanoma is an aggressive cancer with complex etiology and poor prognosis. Surgical resection is still the primary treatment of melanoma, but shows limited efficacy in late-stage patients. Additionally, reliable prognostic markers of skin melanoma patients are still lacking. Circulating tumor cells (CTCs) have shown promise in predicting prognosis of multiple cancers. Evaluating the prognostic value of CTC number in melanoma patients. MATERIAL AND METHODS CTCs were isolated by immunomagnetic capture from 7.5-mL samples of blood from 100 patients with cutaneous melanoma. Baseline CTC number (pre-treatment) and post-treatment CTC number were measured. Baseline CTC number and CTC number alteration were correlated with clinicopathological features and survival. RESULTS Forty-three (43%) patients had more than 6 CTCs, whereas 57 (57%) had 6 cells or less. High baseline CTC count was associated with deep local invasion, lymph node metastasis, and distance metastasis, with P value of 0.003, 0.047, and 0.034, respectively. High baseline CTC count was also correlated with short overall survival time and was considered as an independent prognostic factor (P value=0.012, hazard ratio=2.262). CTC cell alteration was associated with progression-free survival and disease-specific survival (with P values of 0.012 and 0.009, respectively). CONCLUSIONS Baseline CTC count was correlated with adverse pathological features and was predictive of survival in melanoma patients. Alteration of CTC count before and after treatment was an indicator of therapy response and prognosis. Measuring the baseline and post-treatment CTC counts is a powerful tool in monitoring melanoma progression, drug response, and survival.

Survival analysis of patients with advanced non-small cell lung cancer receiving tyrosine kinase inhibitor (TKI) treatment: A multi-center retrospective study.

BACKGROUND: The study was conducted to assess differences in overall survival (OS) in patients with non-small cell lung cancer (NSCLC) receiving different treatment modalities of tyrosine kinase inhibitors (TKIs). METHODS: A total of 463 NSCLC patients receiving TKI treatment were included. OS was compared according to treatment timing in all patients, the elderly, and patients positive for EGFR mutations. RESULTS: One hundred and seventy two patients received TKIs as first-line treatment, 220 as second-line, and 67 as third-line. The results between the three groups were not statistically significant: the one, two, and three-year OS rates were: 55.3%, 22.3%, and 11.3% (first-line); 59.6%, 27.8%, and 14.9% (second-line); and 53.8%, 41.3%, and 29.5% (third-line), respectively (P = 0.095). Results between the three groups of elderly patients were also not statistically significant (P = 0.469). The one and two-year OS rates in EGFR mutation-positive patients receiving first-line treatment were 48% and 17.5%, respectively. The one, two, and three-year OS rates of patients receiving second-line treatment were: 54.2%, 30.3%, and 20.2%, respectively. There were no statistically significant differences between the groups with EGFR mutations receiving first-line or second-line treatment. Thirteen EGFR mutation-positive patients received third-line TKI treatment for a median duration of 7 months. Their one and two-year OS rates were 69.8% and 58.2%, respectively, which were higher than in the other two groups (P = 0.015). CONCLUSION: Three lines of TKI therapy can prolong survival in NSCLC patients. Elderly patients can benefit from TKI therapy. EGFR mutation-positive patients can benefit from second-line or third-line TKI therapy.

High expression of CD47 predicts adverse prognosis in Chinese patients and suppresses immune response in melanoma.

BACKGROUND: Cluster of differentiation 47 (CD47) negatively regulates macrophage phagocytosis and is correlated with adverse survival of multiple cancers. In melanoma patients, especially in Chinese melanoma patients, its prognostic value is unclear. In this study, we aim to study the prognostic value of CD47 in a Chinse melanoma patient cohort and its immunomodulation roles in mouse model. METHOD: 164 melanoma tissue specimens were collected. The expression of CD47 in these clinical samples was examined by immunohistochemistry staining (IHC). The correlation between CD47 expression and clinicopathological parameters was assessed by statistical analysis. Prognostic values CD47 expression were also investigated. In an animal model, effects of CD47 expression on immune infiltration were examined. RESULTS: CD47 expression was positively correlated with TNM stage, distant metastasis, and death of melanoma patients with the P value of 0.008, 0.018, and 0.032 respectively. High expression of CD47 was an independent prognostic marker of overall survival (HR=1.563, 95% CI: 1.069-2.285) and progression free survival (HR=1.542, 95% CI: 1.053-2.258) of Chinese melanoma patients. CONCLUSION: In conclusion, high expression of CD47 predicted poor survival in a Chinese melanoma patient cohort and impaired antitumor immune response in the animal model. Targeting CD47 might be a novel option for melanoma patients.

Trends and Prospects of Stem Cell Research in China.

Great progresses have been made in fundamental and clinical stem cell research in China in recent years. The official policy on stem cells, which was announced in 2015, seems as the spring of stem cell therapy in China. However, the regulation, governance, and management of clinical expectations are still challenging. This review summarized the current stem cell research and development in the field, as well as its rapidly evolving commercial, regulatory and ethical environment in China. As expected, the prospects of stem cells in China look prospective.