Journal of Cleaner Production
·
2021
·
IF 9.297
Fengjiao Lai,Feng Yan,Pengju Wang,Chunyan Li,Xuehua Shen,Zuotai Zhang
The development of heterogeneously functional catalysts is of great significance in selective catalysis for biomass valorization. Herein, we report for the first time the applicability of chitin/Ag co-modified H 3 PW 12 O 40 composites (Chx-AgPW) as catalysts for producing valuable furans from carbohydrates and biomass. The as-prepared Ch15-AgPW catalyst exhibited the best catalytic performance, due to the dual Brǿnsted-Lewis acidity and appropriate chitin content. When the amount of Ch15-AgPW catalyst was 0.25 mmol, an excellent 5-hydroxymethylfurfural (HMF) yield of 78.3% could be achieved at 150 °C for 3 h with nearly 100% glucose conversion in the H 2 O/MIBK (V H2O:MIBK = 4:6) solvent system. Furthermore, high-yield HMF could also be obtained from other carbohydrates such as fructose (85.3%), sucrose (72.3%), cellobiose (65.6%), starch (52.7%) and inulin (43.5%). Additionally, corn stover , rice straw and sugarcane bagasse under typical reaction conditions simultaneously produced furfural and HMF in yields of 64.6%–72.2% and 18.5%–25.6%, respectively. Combined with the characterization, mechanism study demonstrated that the surface functional groups in chitin were conductive to rapid absorption of the substrates; the Brǿnsted acid sites from heteropoly anion (H 2 [PW 12 O 40 ] - ) promoted the initial depolymerization of biomass and the final dehydration to furans; the introduction of Ag + favored the isomerization of intermediates. After reaction finished, the Ch15-AgPW catalyst could be easily recovered by filtration and effectively reused at least eight cycles without substantial loss in catalytic activity . This work provides a novel strategy to synthesize stable heterogeneous catalysts with tunable acidity for producing bio-based fuels and chemicals from renewable resources .
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Chihe Sun,Qiang Liao,Ao Xia,Cheng Chen,Qian Fu,Yun Huang,Xun Zhu,Fubao Sun
A multifunctional carbon solid acid with binding and catalytic domains was prepared by co-carbonisation of β-cyclodextrin and polyvinyl chloride followed by sulfonation. The abundant –OH group on the surface of β-cyclodextrin cavity increased the hydrophilicity and dispersibility of catalyst, and the grafting of –Cl group collectively promoted its adsorption performance (45.8% within 6 h). Additionally, the oxidation and substitution of alkyl chains and aliphatic bridges in carbon precursors were responsible to introduce catalytic functional –SO 3 H group. The catalyst directionally facilitated disaccharide hydrolysis with strong bond-breaking effects on α–1, 4 and β–1, 4–glycosidic bonds; the hydrolysis rates ranged 72.7%–84.3%, and the monosaccharide yields ranged 68.7%–78.2%. However, the destruction of α–1, 1–glycosidic bond was weak, and the fracture of α, β–1, 2–glycosidic bond was likely to cause fructose decomposition. The reaction rate constants of glucose production and decomposition increased with the increase of temperature. The apparent activation energy of glucose production was 98.6 kJ/mol, decreased by 25.9% and 10.4% compared with homogeneous dilute acids and conventional carbon solid acids. The binding domains of catalyst not only played important role in enhancing the surface hydrolysis reaction of saccharides, but also decreased the activation energies.
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Zhuoli Xu,Fuping Li,Yue Wang,Kang Zhao,Yufei Tang
In this work, ZrB 2 –ZrC–SiC composite nanofibers were prepared by electrospinning combined with the carbothermal reduction method. The morphology, phase composition, and oxidation resistance of the composite nanofibers were investigated. The results showed that ZrB 2 –ZrC–SiC composite nanofibers with good crystallinity were obtained after calcination at 1550 °C. The obtained fibers distributed uniformly, and the average diameter was about 375 nm. ZrB 2 –ZrC–SiC nanofibers were oxidized at 587 °C, which was higher than that of the ZrB 2 –ZrC nanofibers. It revealed that the addition of SiC could improve the oxidation resistance of ZrB 2 –ZrC composite nanofibers.
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2021
·
IF 6.953
Teng Wang,Chen Shen,Feng Guo,Yuqin Zhao,Jie Wang,Kunlai Sun,Bin Wang,Yan Chen,Yin Chen
A polysaccharide, CSL-0.1, was isolated from the medicinal lichen, Usnea longissima . CSL-0.1 was a neutral rhamnose-containing glucogalactomannan with a molecular weight of 7.86 × 10 4 Da. The polysaccharide had a core mannan structure with (1 → 6)-α- d -Man p units as the main chain and was substituted at the O -2 positions with side chains containing (1 → 2)-α- d -Man p residue, [3)-α-Glc p (1 → 4)-α-Glc p (1→] and 6- O -substituted β- d -Gal f units. 2- O - and 2,3-di- O -substituted Rha p units. The effects of CSL-0.1 on intestinal immunity and antioxidant activity were evaluated. CSL-0.1 increased the spleen and thymus indices in a dose-dependent manner and conferred immunomodulation on reversing the Th1/Th2-related cytokine imbalance in cyclophosphamide (CP)-induced immunosuppressed mice. CSL-0.1 could also enhance the levels of secretory immunoglobulin A in CP-injected mice. Additionally, the antioxidant levels in the liver and intestine of the mice were increased 20%–50% after intragastric injection by CSL-0.1.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Nano
·
2021
·
IF 15.881
Ze-Lin Qiu,Li-Feng Fang,Yu-Jie Shen,Wen-Han Yu,Bao-Ku Zhu,Claus Hélix-Nielsen,Wenjing Zhang
Separating low/high-valent ions with sub-nanometer sizes is a crucial yet challenging task in various areas (e.g., within environmental, healthcare, chemical, and energy engineering). Satisfying high separation precision requires membranes with exceptionally high selectivity. One way to realize this is constructing well-designed ion-selective nanochannels in pressure-driven membranes where the separation mechanism relies on combined steric, dielectric exclusion, and Donnan effects. To this aim, charged nanochannels in polyamide (PA) membranes are created by incorporating ionic polyamidoamine (PAMAM) dendrimers via interfacial polymerization. Both sub-10 nm sizes of the ionic PAMAM dendrimer molecules and their gradient distributions in the PA nanofilms contribute to the successful formation of defect-free PA nanofilms, containing both internal (intramolecular voids) and external (interfacial voids between the ionic PAMAM dendrimers and the PA matrix) nanochannels for fast transport of water molecules. The external nanochannels with tunable ionizable groups endow the PA membranes with both high low/high-valent co-ion selectivity and chemical cleaning tolerance, while the ion sieving/transport mechanism was analyzed by employing the Donnan steric pore model with dielectric exclusion.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2021
·
IF 7.514
Hao Huang,Di Wang,Tarun Belwal,Li Dong,Ling Lu,Ying Zou,Li Li,Yanqun Xu,Zisheng Luo
The postharvest senescence accompanied by yellowing limited the shelf-life of broccoli. In this study, we developed a novel W/O/W double emulsion co-delivering brassinolide and cinnamon essential oil and applied it to broccoli for preservation. Results showed that double emulsion prepared by whey protein concentrate-high methoxyl pectin (1:3) exhibited best storage stability with largest particle size (581.30 nm), lowest PDI (0.23) and zeta potential (−40.31 mV). This double emulsion also exhibited highest encapsulation efficiency of brassinolide (92%) and cinnamon essential oil (88%). The broccoli coated with double emulsion maintained higher chlorophyll contents and activities of chlorophyllase and magnesium-dechelatase were reduced by 9% and 24%, respectively. The energy metabolic enzymes (SDH, CCO, H + -ATPase, Ca 2+ -ATPase) were also activated, inducing higher level of ATP and energy charge. These results demonstrated W/O/W double emulsion co-delivering brassinolide and cinnamon essential delayed the senescence of broccoli via regulating chlorophyll degradation and energy metabolism.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RAPID COMMUNICATIONS IN MASS SPECTROMETRY
·
2021
·Vol. 35
·期 16
·e9129
·
IF 2.419
Pengxuan Xi,Wanxue Cao,Li Li,Weimin Shi,Fuxin Li,Haitao Xu,Xiaojie Xu,Yu Ke,Jianye Zhang
Rationale Tebipenem pivoxil (TBPM-PI) has been developed as the first oral carbapenem drug in the world to treat otolaryngological and respiratory infections in pediatric patients. Due to its structural properties and external factors, some related impurities, which may cause side effects in patients, might be formed during the synthesis and storage of TBPM-PI. It was vital to rapidly separate and identify the related impurities to guarantee the safe use of TBPM-PI. Methods A method using ultra-high-performance liquid chromatography (UHPLC) coupled with quadrupole time-of-flight tandem mass spectrometry (QTOF-MS/MS) was developed to separate and detect TBPM-PI and related impurities in an oral pharmaceutical formulation. LC/MS and MS/MS spectra of these compounds in the formulation were acquired to confirm their elemental compositions and propose their structures based on LC/MS data and fragmentation pathways of available reference substances. Results LC/MS parameters and MS/MS fragmentation pathways of reference substances of TBPM-PI and related impurities were summarized in detail. Based on this, a total of 23 related impurities were found and characterized in the oral pharmaceutical formulation. Eight of these were verified by comparison with reference substances and the structures of the other 15 were proposed for the first time. In addition, four of these compounds were produced by the reaction of excipients and pre-existing related impurities. Conclusions A UHPLC/QTOF-MS method was established and used for the separation and identification of 23 related impurities in a TBPM-PI oral pharmaceutical formulation. Moreover, it was proved that new related impurities could be produced by the reaction of excipients in the pharmaceutical formulation and related impurities in the corresponding active pharmaceutical ingredient (API).
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2021
·
IF 4.821
Chunhe Yu,Dongmiao Qin,Xiaohua Jiang,Xiangfei Zheng,Biyang Deng
In this work, bright yellow fluorescent nitrogen-doped carbon quantum dots (YN-CQDs) are produced by a facile, inexpensive and eco-friendly hydrothermal technique using extract of chlorophyll from lettuce leaf as precursor. The quantum yield (QY) of as-synthesized YN-CQDs was up to 38%, which was higher than the previously reported quantum yield of most CQDs prepared using other biomass. Silver ion (Ag + ) can covalently bond with carboxyl, hydroxyl and amino groups on the surface of YN-CQDs and quench the fluorescence of YN-CQDs through static quenching. Upon addition of methimazole (MZ) to the YN-CQDs/Ag + dispersion system, Ag + releases from the YN-CQDs/Ag + complex due to the high affinity of MZ for Ag + and the quenched fluorescence of the YN-CQDs was recovered. Hence, we developed an off–on sensing method for the detection of MZ using YN-CQDs/Ag + as a fluorescent probe. Under optimal conditions, with addition of MZ, the fluorescence recovery of YN-CQDs/Ag + system happens with a good linearity in the range of 0.003 ~ 60 μmol/L and a detection limit of 0.8 nmol/L. The YN-CQDs/Ag + system exhibited good MZ determination performance. The established off–on fluorescence sensing platform was successfully employed for detecting MZ in mouse plasma.
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Nanomedicine
·
2021
·
IF 6.4
Jian Yu,Luyao Yi,Rui Guo,Jingmei Guo,Hongye Yang,Cui Huang
Background The dentin exposure always leads to dentin hypersensitivity and/or caries. Given the dentin’s tubular structure and low mineralization degree, reestablishing an effective biobarrier to stably protect dentin remains significantly challenging. This study reports a versatile dentin surface biobarrier consisting of a mesoporous silica-based epigallocatechin-3-gallate (EGCG)/nanohydroxyapatite delivery system and evaluates its stability on the dentinal tubule occlusion and the Streptococcus mutans (S. mutans) biofilm inhibition.Materials and Methods The mesoporous delivery system was fabricated and characterized. Sensitive dentin discs were prepared and randomly allocated to three groups: 1, control group; 2, casein phosphopeptide–amorphous calcium phosphate (CPP–ACP) group; and 3, the mesoporous delivery system group. The dentin permeability, dentinal tubule occlusion, acid and abrasion resistance, and S. mutans biofilm inhibition were determined for 1 week and 1 month. The in vitro release profiles of EGCG, Ca, and P were also monitored.Results The mesoporous delivery system held the ability to sustainably release EGCG, Ca, and P and could persistently occlude dentinal tubules with acid and abrasion resistance, reduce the dentin permeability, and inhibit the S. mutans biofilm formation for up to 1 month compared with the two other groups. The system provided prolonged stability to combat oral adverse challenges and served as an effective surface biobarrier to protect the exposed dentin.Conclusion The establishment of the dentin surface biobarrier consisting of a mesoporous delivery system indicates a promising strategy for the prevention and the management of dentin hypersensitivity and caries after enamel loss.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemistryOpen
·
2021
·Vol. 10
·期 5
·560-566
·
IF 2.911
Yingshuang Hui,Yulu Zhan,Wenrong Hou,Lou Gao,Yahong Zhang,Yi Tang
Graphical The product control of C6 aldose toward C6, C4 and C2 alditols have been achieved, which have depended on the well-matched between retro-aldol condensation and hydrogenation process driving by temperature, H 2 pressure and injection modes. Alcohols have a wide range of applicability, and their functions vary with the carbon numbers. C6 and C4 alditols are alternative of sweetener, as well as significant pharmaceutical and chemical intermediates, which are mainly obtained through the fermentation of microorganism currently. Similarly, as a bulk chemical, C2 alditol plays a decisive role in chemical synthesis. However, among them, few works have been focused on the chemical production of C4 alditol yet due to its difficult accumulation. In this paper, under a static and semi-flowing procedure, we have achieved the product control during the conversion of C6 aldose toward C6 alditol, C4 alditol and C2 alditol, respectively. About C4 alditol yield of 20 % and C4 plus C6 alditols yield of 60 % are acquired in the one-pot conversion via a cascade retro-aldol condensation and hydrogenation process. Furthermore, in the semi-flowing condition, the yield of ethylene glycol is up to 73 % thanks to its low instantaneous concentration.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2021
·
IF 6.057
Yulu Liu,Lei Cao,Minghui Zan,Jiahui Peng,Panyong Wang,Xinpei Pang,Yan Zhang,Li Li,Wen-Fei Dong,Qian Mei
As an important bioactive component in plants, chlorogenic acid (CGA) has been widely studied for its potential role in human health. In this work, cyan fluorescent silicon quantum dots were successfully synthesized via a simple one-pot method for the rapid detection of CGA. The optimal excitation and emission wavelength of the obtained SiQDs was 350 nm and 470 nm, respectively. When the CGA was added, the maximum emission intensity of the SiQDs can be effectively quenched due to dynamic and static mixed quenching mechanisms. More significantly, there was a remarkable linear correlation between fluorescence quenching efficiency and a broad concentration of CGA solution range from 10 to 150 μmol/L with a limit of detection (LOD) of 0.43 μmol/L. Furthermore, the proposed SiQDs were successfully applied to analyze CGA in coffee beans and instant coffee after simple pretreatment with satisfactory results. Based on these, a high sensitivity and excellent selectivity fluorescent probe detection system was constructed, and it provides a valuable platform for the detection of CGA and has broad application prospects in the biological and pharmaceutical analysis field.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2021
·
IF 5.279
Danqiu Luo,Xiaohuan Huang,Bangyan Liu,Wenying Zou,Yuangen Wu
The rapid and onsite detection of glyphosate herbicides in agricultural products is still a challenge. Herein, a novel colorimetric nanozyme sheet for the rapid detection of glyphosate has been successfully prepared through the physical adsorption of porous Co3O4 nanoplates on a polyester fiber membrane. Glyphosate can specifically inhibit the peroxidase-mimicking catalytic activity of porous Co3O4 nanoplates, thereby the visual detection of glyphosate can be realized by distinguishing the change in the color intensity of the established nanozyme sheet. The prepared nanozyme sheet has good sensitivity and selectivity, with a detection limit of 0.175 mg·kg–1 for glyphosate detection just by the naked eyes. It can effectively detect glyphosate within 10 min, and the color spots can maintain more than 20 min. The nanozyme sheet is not easily affected by the external environment in detection and storage. The merits of the nanozyme sheet facilitate its practical application in the large-scale preliminary screening of glyphosate residues in agricultural products.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）