3-Acetopropanol (3-AP) is an important chemical used as a spice ingredient and pharmaceutical intermediate. Herein, the synthesis of 3-AP is reported via the oxidation of biomass-derived 2-methyltetrahydrofuran (2-MTHF) using molecular oxygen as the oxidant and VOx/NaY as the catalyst. The catalyst was prepared by a wetimpregnation method and characterized by XRD, UV-vis spectroscopy, XPS, and pyridine adsorption FT-IR. VOx-1/NaY, with V(IV) as the dominant valence state, exhibited superior catalytic activity. A 26.9% yield of 3-AP was achieved in acetonitrile over VOx-1/NaY at 110 degrees C for 3 h. The catalyst could be recycled five times with no obvious loss of activity. It was confirmed that the reaction proceeds via a free radical mechanism. V(IV) reacts with molecular oxygen to generate V(V)-O2 center dot-, which initiates the oxidation of 2-MTHF. A plausible reaction mechanism is proposed.

3-Acetyl-1-propanol (3-AP) is an important organic intermediate for spice ingredient and medical intermediate. Hydrogenation-hydrolysis of 2-methylfuran using a Pd/C catalyst in aqueous solution of hydrochloric acid is one of the current industrial synthesis routes for 3-AP. Here, a new route without noble metal catalyst is reported for solvent-free synthesis of 3-AP by the catalytic oxidation of 2-methyl-tetrahydrofuran (2-MTHF), a biomass-derived compound, with molecular oxygen over V2O5 nanosheet. V2O5 nanosheet was synthesized by thermal decomposition of oxalic acid-vanadium salt in air atmosphere, which was characterized by XRD, SEM, N2 physical adsorption, XPS and H2-TPR. 28.8% yield of 3-AP was given with 2-MTHF conversion of 64.8% at 60 degrees C for 5 h using V2O5 nanosheet as the catalyst. The characterization results indicated that more electrons of V2O5-300 sample were transferred from the V(IV) sites to adsorbed oxygen molecules and formed active oxygen species such as O2 & sdot;- as compared with V2O5-600, which brought easier reduction and high activity of V2O5-300. The catalytic activity of V2O5 catalyst does not decrease in six reaction runs. It is revealed that the reaction proceeded via a free radical mechanism.

The crystallization temperature was investigated for the hydrothermal synthesis of Sn-Beta. The crystallization curves of Sn-Beta at different temperature were performed and the crystal growth activation energy was obtained. The synthesized samples, especially the fully crystallized Sn-Beta, were characterized by XRD, SEM, ICP, UV-vis DRS, XPS, FT-IR spectroscopy of framework vibration and pyridine adsorption. The results indicate that the crystallization time shortened from 7 days to 1 day for Sn-Beta with nSi/nSn of 100 when the crystallization temperature was increased from 140 degrees C to 180 degrees C. But no crystal was obtained as the crystallization temperature was higher than 180 degrees C. The catalytic performance of the fully crystallized Sn-Beta obtained at different crystallization temperature was slightly different in the conversion of ethyl levulinate (EL) to gamma-valerolactone (GVL) and the conversion of glucose to methyl lactate due to the slight difference in silanol defects. Sn-Beta with nSi/nSn of 80 can also be successfully synthesized after crystallization at 160 degrees C for 3 d, which shows much higher activity and selectivity than Sn-Beta with nSi/nSn of 100 for the conversion of EL in high concentration (1.6 mol L- 1) to GVL.

Sn-Beta is a good Lewis acid catalyst. Typically, the organic template in as-made Sn-Beta was removed by calcination in air atmosphere at high temperature (>= 500 degrees C). The fast combustion of organic template in air would lead that the actual temperature of sample is out of control, which will result in the partial disintegration of framework Sn species that are the active centers for catalytic reactions. In this work, ozonization at mild conditions (<= 200 degrees C) was used to remove the organic template. It was found that the ozonization temperature greatly affected the template removal. The template removal efficiency reached 89 % at 120 degrees C for 3 h. The ozonized Sn-Beta has more framework Sn sites than Sn-Beta-C, for which the template was removed by traditional calcination route. However, the ozonized Sn-Beta showed slightly poor performance for conversion of glucose to methyl lactate (MLA) than Sn-Beta-C due to the presence of a few organic template. After the template residues were further removed by calcination of the ozonized Sn-Beta in air at 200-250 degrees C for 1 h, the catalytic performance of the ozonized Sn-Beta was significantly improved. Glucose conversion of 98.9 % with 48.7 % yield to MLA at 140 degrees C for 5 h was obtained over the ozonized Sn-Beta re-calcinated at 200 degrees C for 1 h.

Crystal size is one of the most important parameters of zeolite, which greatly affects its properties and performance. Here, the crystal size of Sn-Beta synthesized by hydrothermal route was tailored by adjusting the amount of crystal nuclei in the gel. Si-Beta that was treated with tetraethylammonium hydroxide (TEAOH) was used as the seed for synthesizing Sn-Beta. The seeds were studied by FT-IR, SEM, XRD and laser particle size analysis. It was found that the crystal size of the synthesized Sn-Beta depended on the concentration of TEAOH. Sn-Beta with minimum crystal size (about 500 nm) can be obtained using 0.5 mol L- 1 TEAOH. Additionally, the crystal size distribution of Sn-Beta synthesized by the supernatant as seed was narrower than that synthesized by the solid residue as seed. The catalytic performance of Sn-Beta was tested in the conversion of ethyl levulinate to gamma-valerolactone by Meerwein-Ponndorf-Verley reduction. Sn-Beta with small crystal size showed higher catalytic activity.

Glycerol, as the main byproduct in biodiesel production, is attractive for the synthesis of value-added chemicals with the rapid increase of the biodiesel market in recent years. In this study, we developed a bifunctional Au/Sn-Beta catalyst via a molecule linkage strategy for the one-pot catalytic conversion of glycerol to methyl lactate (MLA) with molecular oxygen as the oxidant. Bifunctional Au/Sn-Beta was constructed using beta-mercaptoethylamine as a linkage molecule to anchor negative Au species on the negative surface of Sn-Beta zeolites. beta-Mercaptoethylamine with a well-defined structure of head and tail functional groups was anchored on Sn-Beta zeolite through the interaction of amine groups with the framework Sn sites and weakly acidic silanols. Gold species with negative charge were captured by thiol groups of beta-mercaptoethylamine anchored on Sn-Beta. Upon calcination, highly dispersed Au nanoparticles (similar to 2 nm) were confined in the crystal of Sn-Beta zeolite, which was proved by Tomogram-section TEM images. Linkage molecules with different structures were employed. The role of the linkage molecule was revealed by XPS, FTIR, and Raman spectroscopy. It was observed that electrons were transferred from Au sites to Sn sites, which facilitated the dispersion and stabilization of Au sites. A yield of 79.3% to MLA with 100% of glycerol conversion was achieved over the prepared Au/Sn-Beta at 160 degrees C for 1.5 h, which was much higher than that over Au/Sn-Beta prepared by the wet impregnation method. The positive charge on Au sites decreased the catalytic oxidation ability of the catalyst. The catalyst showed good catalytic activity and stability in ten batch reaction runs.

Efficient conversion of ethyl levulinate (EL) in high concentration to gamma-valerolactone (GVL) at moderate temperature via catalytic transfer hydrogenation strategy is highly desirable. In this work, hydrothermally synthesized Sn-beta zeolite with high Sn content was employed as a catalyst to realize this aim. Fully crystallized Sn-beta zeolite with high Sn content (nSi/nSn= 60) was successfully synthesized within 12 days using MgCl2 as a promoter. The synthesized zeolites were characterized by XRD, SEM, UV-vis spectroscopy, FT-IR spectroscopy and XPS. The L acid density of Mg-Sn-beta-60-12d increased to 90 mu mol g-1 compared to Mg-Sn-beta-100-7d (56 mu mol g-1). 92 % yield of GVL was achieved on Mg-Sn-beta-60-12d using high concentration of EL (1.2 mol L-1) as reactant at 130 degrees C for 8 h. The performance of Mg-Sn-beta is better than that of Sn-beta with same nSi/nSn. The reaction mechanism over Mg-Sn-beta was discussed. In addition, Mg-Sn-beta-60-12d showed excellent stability and reusability during five runs.

Au/Sn-zeolite catalysts showed high activity for selective conversion of glycerol to methyl lactate, but suffered from poor stability under the reaction conditions in our previous report (ACS Catal. 2017, 7, 7274). Encapsulation of Au nanoparticles within zeolite is a promising strategy to enhance their stability in catalytic reaction. Herein, one-pot synthesis of Au@Sn beta was achieved by a mercaptosilane-assisted hydrothermal synthesis method. The protocol involves crystallization of Sn beta synthesis gels around coordinated Au precursors, resulting in Sn beta framework constraining Au coordination complexes. The confinement of small (similar to 2.89 nm) and uniform Au particles within Sn beta was achieved. The bifunctional catalyst composed of oxidative sites (Au) and Lewis acid sites (Sn) gave 77.3 % methyl lactate (MLA) yield from the base-free selective conversion of glycerol (GLY). The TOF value of Au@Sn beta was higher than that of Au/Sn-zeolite in our previous report. Moreover, the special structure protects Au nanoparticles from sintering or agglomeration and improves the stability and recyclability in selective oxidation of GLY to MLA.

Zr-Beta zeolites with different acid/basic properties were prepared by hydrothermal and post-synthesis methods and subsequent alkaline treatment. The acid/basic properties of Zr-Beta zeolites were characterized by FT-IR spectra of hydroxyl region and probe molecule adsorption (CD3CN, pyridine and CHCl3). The effects of the acid/basic properties of Zr-Beta zeolites on the conversion of furfural (FUR) to furfuryl alcohol (FAL) via Meerwein-Ponndorf-Verley reduction were investigated and discussed. The results indicate that both Brønsted acid sites, including strong and weak Brønsted acid sites, and Lewis acid sites are effective for conversion of FUR, but high yield of FAL can only be obtained over Zr-Beta with sole Lewis acid sites of framework Zr due to the further conversion of FAL to furfuryl ether, angelica lactone and levulinate ester over Brønsted acid sites. Therefore, Al-free Zr-Beta(h) synthesized in fluoride media is more active and selective than the post-synthesized counterpart. Alkali (earth) metal cations modified Zr-Beta(h) can further eliminate weak Brønsted acid sites of silanols and at the same time generate basic sites. Thus, the activity and selectivity of Zr-Beta(h) are further enhanced. 99.5 % of FAL yield was obtained over Na-Zr-Beta(h) with 99.8 % of FUR conversion at 120 °C for 4 h.

Depolymerization of the cellulose part in lignocellulose to glucose is a significant step for lignocellulose valorization. As one of the main by-products of agricultural biomass in crop-producing filed, valorization of corn straw has attracted considerable attention. In this study, a two-step depolymerizing strategy of high-pressure CO2-H2O pretreatment and oxidation-hydrolysis was applied for selective depolymerization of the cellulose component of corn straw to glucose production. Most part of the hemicellulose component could be removed through high-pressure CO2-H2O pretreatment in the presence of low concentration of acetic acid, and then as high as 32.2 % yield of glucose was achieved in water at 170 °C for 6 h without additional catalyst. The active acid sites generated during the partial oxidation of hydroxymethyl groups to carboxyl groups on glucose units of cellulose was shown to be crucial for the efficient valorization of corn straw for glucose production.

Synthesis of chemicals from abundant cellulose is an environmental-friendly route for the biomass conversion. Herein, lactic acid was synthesized from cellulose firstly with an oxidation pretreatment and then through a catalytic process with MoO3/Sn-Beta as the catalyst. During the first step, partial hydroxymethyl groups on cellulose were oxidized by molecular oxygen to the carboxyl acid groups, which acted as the active sites for the following catalytic depolymerization of cellulose. During the second step, conversion of the oxidized cellulose was performed in water with MoO3/Sn-Beta as a catalyst. The hydrolysis of cellulose to glucose was catalyzed by the formed carboxyl acid groups; then, glucose was converted to lactic acid over the Lewis acid sites of MoO3/Sn-Beta. Yield of 21.4

Tin-containing β zeolite exhibits excellent catalytic performance in various biomass conversions to high-value chemicals due to its strong Lewis (L) acidity produced by framework Sn4+ sites. However, it is difficult to incorporate Sn species into the framework of β zeolite due to that the ionic radius of Sn (0.69 Å) is larger than that of Si (0.40 Å). Herein, organic additives with carbonyl, hydroxyl, aldehyde or amine groups were used to stabilize Sn species in the gel and framework Sn4+ in the zeolite. Among all additives, acetone (AC) has the best stabilizing effect on Sn species. The stabilization effect between AC and Sn4+ sites was observed by FT-IR. The characterization results indicate that more tin species were incorporated into β framework and the L acid density increased due to the complexation between carbonyl group and Sn species. Compared to Sn-β-3d synthesized without additive, the L acid density of Sn-β-AC-3d increased by ∼50% (from 21 μmol g‒1 to 34 μmol g‒1). For the conversion of ethyl levulinate to γ-valerolactone, the reaction reached equilibrium faster over Sn-β-AC-3d than over Sn-β-3d at the investigated reaction temperatures. A yield of 98% was obtained over Sn-β-AC-3d at 110 oC. Besides, Sn-β-AC-3d exhibited good stability and reusability.

Sn-Al-Beta zeolites with less silanol defects were synthesized in fluoride media. The effects of the amount of organic template (tetraethylammonium hydroxide, TEAOH), mineralizer (NH4F), Al and Sn on the synthesis, acidity and catalytic performance were systematically studied. The synthesized Sn-Al-Beta zeolites were characterized by XRD, SEM, 27Al MAS NMR, UV-vis DRS and FT-IR spectroscopy of hydroxy region and pyridine adsorption. The optimum values of nTEAOH/nSi and nF-/nSi were same (0.3) for synthesizing Sn-Al-Beta with high crystallinity at 140 oC for 7 d. Moreover, decreasing nF-/nSi facilitated the incorporation of Al into the framework. The crystallization rate of Sn-Al-Beta is similar with that of Sn-Beta. Sn was promoted to enter the framework with the increase of Al content, while elevating Sn content has no effect on the incorporation of Al into the framework. The catalytic performance of Sn-Al-Beta was investigated for conversion of glucose to 5-hydroxymethylfurfural in water-containing solvent. Sn-Al-Beta synthesized in fluoride media is more stable than the post-synthesized sample.

BACKGROUND Tobacco stalk, the main waste from tobacco planting, was used as raw material to produce levulinic acid, one of the most important platform chemicals. It was reported that steam explosion was an efficient method to treat lignocellulose to hydrolyze the hemicellulose component. Oxidation treatment combined with catalysis of Al-2(SO4)(3) proved to be efficient for the conversion of cellulose to levulinic acid in our recent report. Here, tobacco stalk was first treated by steam explosion, and then the solid residue was oxidized and converted to levulinic acid in the presence of Al-2(SO4)(3). RESULTS A xylo-oligosaccharide yield of 6.6 g 100 g(-1) was obtained from tobacco stalk via steam explosion. 15.4 g 100 g(-1) (39.6 mol%) yield of levulinic acid was obtained from oxidized tobacco stalk in water at 180 degrees C in 5 h using Al-2(SO4)(3) as a catalyst. As high as 20.8 g 100 g(-1) (53.5 mol%) yield of levulinic acid can be obtained using NaCl as a co-catalyst. CONCLUSION Steam explosion was efficient for the depolymerization of the hemicellulose component of tobacco stalk to xylo-oligosaccharide. A simple salt of Al-2(SO4)(3) showed good catalytic activity for conversion of oxidized tobacco stalk to levulinic acid. Nicotine in tobacco stalk promoted the formation of lactic acid. Thus, the yield of levulinic acid decreased in the presence of nicotine. NaCl enhanced the catalytic performance of Al-2(SO4)(3). (c) 2024 Society of Chemical Industry (SCI).

The isomerization of glucose to fructose is an important process in the conversion of biomass into valuable fuels and chemicals. Development of efficient catalyst for this reaction has attracted much attention. In this study, Sn‐Beta zeolites with rich silanols were synthesized for glucose isomerization by solid‐state ion‐exchange method, where Si‐Beta zeolites with different amounts of silanols were applied as the precursors. It is confirmed that open Sn sites show much higher catalytic performance than closed Sn sites for glucose isomerization (about 2.1 times). The silanol amount in Si‐Beta not only affects the formation of framework Sn sites in Sn‐Beta but also influences the isomerization reaction. More silanols in the catalyst can promote the 1,2‐H shift in isomerization and reduce the side reactions of formation of mannose and C3 products. Over 3Sn‐Beta‐3h with rich silanols, 64% of fructose yield was obtained. Furthermore, the prepared Sn‐Beta catalyst is stable and recyclable. High fructose yield and facile synthesis method of Sn‐Beta reported in this work will contribute to the development of biomass and sugar industry.

Correction for ‘ Moringa oleifera leaf polysaccharides exert anti-lung cancer effects upon targeting TLR4 to reverse the tumor-associated macrophage phenotype and promote T-cell infiltration’ by Shukai Wang et al. , Food Funct. , 2023, 14 , 4607–4620, https://doi.org/10.1039/D2FO03685A.

目的 评价短视频在介入放射学教学中的效果.方法 研究对象为来自郑州大学医学院影像系 2019 级本科生 82 人,实验组 41 人,对照组 41 人.实验组在常规PPT基础上联合短视频完成授课,对照组采用传统PPT授课.用随堂测验和学生满意度调查评估教学效果.结果 实验组随堂测试分数高于对照组,为(84.9±6.3)分比(78.5±5.8)分(P＜0.01),问卷显示在授课方法、学习兴趣、知识接受度、图像生动性等方面,实验组学生与对照组比较,差异均有统计学意义(均P＜0.05).结论 以短视频教学能够丰富教学手段,配合传统教学方法,可获得良好教学效果.

AIM:To unravel whether ferroptosis involves with the actions by circPDE3B-mediated facilitation of esophageal squamous cell carcinoma (ESCC) progression. METHODS:Human ESCC tissues and cell lines were prepared for the evaluation of ferroptosis. Cellular iron, ROS, GSH, and MDA levels were measured to assess ferroptosis. Flow cytometry was employed to analyze apoptosis and cell cycle. Subcellular fractionation and fluorescence in situ hybridization (FISH) were conducted to validate the localization of circPDE3B. RNA pull-down, RNA immunoprecipitation (RIP), and luciferase assay were subjected to identify the molecular mechanisms. Nude mouse xenograft model was carried out to evaluate the function of circPDE3B/SLC7A11/CBS in vivo. RESULTS:Increased circPDE3B in human ESCC specimens was positively correlated with ferroptosis-related molecules, SLC7A11 and CBS. Functionally, circPDE3B knockdown triggered ferroptosis, apoptosis, and cell cycle arrest in ESCC cells. Whereas, these effects were obviously blocked by miR-516b-5p inhibitor. Mechanistically, not only circPDE3B sponged miR-516b-5p to upregulate CBS, but also directly bound with HNRNPK to stabilize SLC7A11. In mice, depletion of circPDE3B restrained ESCC growth, while this was abolished by overexpression of CBS or SLC7A11. CONCLUSION:In summary, circPDE3B promotes ESCC progression by suppressing ferroptosis through recruiting HNRNPK/SLC7A11 and miR-516b-5p/CBS axes.

目的 评价新型部分覆膜式分支一体化T/Y型支架治疗肝门部胆管恶性梗阻的可行性和安全性.方法 纳入2018年10月至2019年10月接受新型部分覆膜式母子分支一体化T/Y型支架植入术治疗肝门部胆管恶性梗阻患者16例.记录技术成功率、临床成功率、并发症、6个月和12个月支架通畅率和总生存率,比较术前、术后1个月患者的血常规、肝功能、肾功能和CA199水平.结果 16例患者均获得技术成功和临床成功.早期并发症和晚期并发症分别为3例和2例,无大出血、重度感染、胆瘘、穿孔等严重并发症.平均随访时间358.9 d,6个月和12个月支架通畅率分别为66.7％和16.7％,总生存率分别为93.3％、75.0％.术后1个月ALT、AST、TBil、CA199水平较术前明显下降(P<0.01),而WBC、Hb、PLT、Cr、BUN较术前无明显变化(P>0.05).结论 新型部分覆膜式分支一体化T/Y型支架治疗肝门部胆管恶性梗阻安全可行,有待进一步研究其远期疗效.