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https://www.readbyqxmd.com/read/29458161/multiple-mycotoxin-analysis-in-nut-products-occurrence-and-risk-characterization
#1
Sara C Cunha, S Sá, José O Fernandes
Nuts consumption plays an important role in Mediterranean diet, being a good source of proteins, vitamins, minerals and unsaturated fatty acids. However, nuts can be also a source of harmful mycotoxins with negative impact on human health. In this work, the occurrence of 16 mycotoxins belonging to different chemical classes, was assessed in several nut products. The analytical method used was based on modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) procedure followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis...
February 16, 2018: Food and Chemical Toxicology
https://www.readbyqxmd.com/read/29458102/%C3%AE-irradiated-chitosan-based-injectable-hydrogels-for-controlled-release-of-drug-montelukast-sodium
#2
Sadaf Hafeez, Atif Islam, Nafisa Gull, Abbas Ali, Shahzad Maqsood Khan, Saba Zia, Kalsoom Anwar, Saba Urooge Khan, Tahir Jamil
Novel pH-sensitive γ-irradiated low molecular weight chitosan (CS) (pre-irradiated) and poly (vinyl alcohol) (PVA) blended injectable hydrogels, crosslinked with varying concentrations of glycerol, were fabricated for drug delivery application. The effect of low molecular weight irradiated CS on controlled drug release was evaluated to address the problem of higher viscosity and lower solubility of high molecular weight CS. The FTIR spectra of hydrogels depicted the presence of all the incorporated functional groups and the developed interactions (physical and chemical)...
February 16, 2018: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/29457972/a-stable-metal-organic-framework-featuring-local-buffer-environment-for-carbon-dioxide-fixation
#3
Hongming He, Qi Sun, Wenyang Gao, Jason A Perman, Fuxing Sun, Guangshan Zhu, Briana Aguila, Katherine Forrest, Brian Space, Shengqian Ma
A majority of metal-organic frameworks (MOFs) fail to preserve their physical and chemical properties after exposure to acidic, neutral, or alkaline aqueous solutions, therefore limiting their practical applications in many areas. The strategy demonstrated herein is the design and synthesis of an organic ligand that behaves as a buffer to drastically boost the aqueous stability of a porous MOF (JUC-1000), which maintains its structural integrity at low and high pH values. The local buffer environment resulting from the weak acid-base pairs of the custom-designed organic ligand also greatly facilitates the performance of JUC-1000 in the chemical fixation of carbon dioxide under ambient conditions, outperforming a series of benchmark catalysts...
February 19, 2018: Angewandte Chemie
https://www.readbyqxmd.com/read/29457892/boronic-acid-catalyzed-regio-and-1-2-cis-stereoselective-glycosylation-of-unprotected-sugar-acceptors-via-s-n-i-type-mechanism
#4
Masamichi Tanaka, Akira Nakagawa, Nobuya Nishi, Kiyoko Iijima, Ryuichi Sawa, Daisuke Takahashi, Kazunobu Toshima
Regio- and 1,2-cis-stereoselective chemical glycosylation of unprotected glycosyl acceptors has been in great demand for the efficient synthesis of natural glycosides. However, simultaneously regulating these selectivities has been a long-standing problem in synthetic organic chemistry. In nature, glycosyl transferases catalyze regioselective 1,2-cis-glycosylations via the SN i mechanism, yet no useful chemical glycosylations based on this mechanism have been developed. In this paper, we report a highly regio- and 1,2-cis-stereoselective SN i-type glycosylation of 1,2-anhydro donors and unprotected sugar acceptors using p-nitrophenylboronic acid (10e) as a catalyst in the presence of water under mild conditions...
February 19, 2018: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/29457824/understanding-the-conformational-analysis-of-gababutin-based-hybrid-peptides
#5
Maruthi Konda, Rohit G Jadhav, Sayan Maiti, Shaikh M Mobin, Brice Kauffmann, Apurba K Das
Constrained γ-amino acid gababutin (Gbn) based peptides that form different conformations have been synthesized. Striving to rationalize the impact of side chain orientations framing tetrapeptide-based supramolecular organic frameworks and morphological entities, Gbn incorporated hybrid peptides Boc-Gbn-Aib-Aaa-Aib-OMe (where Aaa = Phe(F) for peptide 1, Leu(L) for peptide 2 and Tyr(Y) for peptide 3) were synthesized by changing the amino acid at the third position. The solution state dual folded conformation (C12 /C10 H-bonded) is probed by 2D NMR spectroscopy in support of a DMSO-d6 titration and VT NMR experiments...
February 19, 2018: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/29457808/cds-nanosphere-decorated-hollow-polyhedral-zco-derived-from-a-metal-organic-framework-mof-for-effective-photocatalytic-water-evolution
#6
Wenxia Chen, Jiasheng Fang, Yiwei Zhang, Guangliang Chen, Shuo Zhao, Chao Zhang, Ran Xu, Jiehua Bao, Yuming Zhou, Xin Xiang
Semiconductor nanostructures have received considerable attention in the field of photocatalytic hydrogen evolution. However, eco-friendly, high efficiency, and low-cost semiconductor materials are still desired. In consideration of this, herein, we design a new and economic noble-metal-free CdS/Znx Co3-x O4 (CdS/ZCO) nanohybrid photocatalyst using a metal-organic framework (MOF) template, which is a framework structure composed of organic ligands and metal ion nodes with different numbers of connections. The as-prepared CdS/ZCO composites with a large specific surface area and porous hollow structure exhibit remarkable catalytic activity and high stability for hydrogen generation...
February 19, 2018: Nanoscale
https://www.readbyqxmd.com/read/29457805/urinary-metabolomic-study-of-the-antagonistic-effect-of-p-ginseng-in-rats-with-estrogen-decline-using-ultra-performance-liquid-chromatography-coupled-with-quadrupole-time-of-flight-mass-spectrometry
#7
He Lin, Zhongying Liu, Zifeng Pi, Lihui Men, Weijia Chen, Zhiqiang Liu
Estrogens are biologically active steroid hormones mainly released from the ovary by ovarian secretion of estrogen into the circulating blood to regulate or function at the distal target. Estrogens play an important role in the central nervous system, cardiovascular system and immune system, especially for post-menopausal women. Panax ginseng Mayer has been reported to relieve women's menopausal symptoms and affect estrogen activities. However, the mechanism of its estrogen regulation has not yet been clearly investigated...
February 19, 2018: Food & Function
https://www.readbyqxmd.com/read/29457715/embedding-a-diketopyrrolopyrrole-based-crosslinking-interfacial-layer-enhances-the-performance-of-organic-photovoltaics
#8
Hsiang-Lin Hsu, Ying-Chieh Chao, Yu-Hua Liao, Chung-Lin Chung, Ya-Juan Peng, ChihPing Chen, Ru-Jong Jeng
In this study, we prepared DPPBTDA, a diketopyrrolopyrrole (DPP)-based small molecule presenting a terminal crosslinkable azido group, as a cathode modified layer for organic photovoltaics (OPVs) having the inverted device structure glass/indium tin oxide (ITO)/zinc oxide (ZnO) with or without interfacial layer (IFL)/active layer/MoO3/Ag. The active layer comprised a blend of poly[4,8-bis(5-(2-ethylhexyl)thien-2-yl)benzo[1,2-b;4,5-b´]dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene)-2-carboxylate-2,6-diyl] (PTB7-Th) as the electron donating moiety and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as the electron acceptor...
February 19, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29457712/strong-electrochemiluminescence-from-mofs-accelerator-enriched-quantum-dots-for-enhancing-sensing-of-trace-ctni
#9
Xia Yang, Yan-Qing Yu, Ling-Zhi Peng, Yan-Mei Lei, Ya-Qin Chai, Ruo Yuan, Ying Zhuo
Sensitive and feasible electrochemiluminescence (ECL) bioassay relies on the achievement of the ECL signal tags with high and stable signal intensity. In this work, strong electrochemiluminescence (ECL) emission was achieved from metal organic framework (MOFs) accelerator enriched Quantum Dots (CdTe), which was applied as an efficient ECL signal tag for trace biomarker detection. It is particularly worth noting that a novel mechanism to drastically enhance the ECL intensity of CdTe is established because the isoreticular metal organic framework-3 (IRMOF-3) with 2-amino terephthalic acid (2-NH2-BDC) as organic ligand is not only devoted for loading large amount of CdTe via encapsulating effect and internal/external decoration, but also as a novel co-reactant accelerator for promoting the conversion of co-reactant S2O82- into the sulfate radical anion (SO4•-), further boosting the electrochemiluminescence (ECL) emission of CdTe...
February 19, 2018: Analytical Chemistry
https://www.readbyqxmd.com/read/29457679/features-of-protonation-of-the-simplest-weakly-basic-molecules-so2-co-n2o-co2-and-others-by-solid-carborane-superacids
#10
Evgenii Stoyanov, Irina S Stoyanova
Experimental study on protonation of simple weakly basic molecules (L) by the strongest solid superacid, H(CHB11F11), showed that basicity of SO2 is high enough (during attachment to the acidic H atoms at partial pressure of 1 atm) to break the bridged H-bonds of the polymeric acid and to form a mixture of solid mono- and disolvates, LH+‧‧‧An- and L-H+-L. With a decrease in the basicity of L = CO (via C), N2O, and CO (via O), only proton monosolvates are formed, which approach L-H+-An species with convergence of the strengths of bridged H-bonds...
February 19, 2018: Angewandte Chemie
https://www.readbyqxmd.com/read/29457524/safety-and-effect-on-ablation-size-of-hydrochloric-acid-perfused-radiofrequency-ablation-in-animal-livers
#11
Tian-Qi Zhang, Sen-Miao Huang, Yang-Kui Gu, Fei Gao, Zhi-Mei Huang, Xiong-Ying Jiang, Ding-Xin Liu, Jin-Hua Huang
PURPOSE: Our objective was to determine the safety and ablation size of hydrochloric acid-perfused radiofrequency ablation (HCl-RFA) in liver tissue, prospectively using in vivo rabbit and ex vivo porcine liver models. MATERIALS AND METHODS: The livers in 30 rabbits were treated in vivo with perfusions of normal saline (controls) and HCl concentrations of 5%, 10%, 15%, and 20%, during RFA at 103°C and 30 W for 3 minutes. For each experimental setting, 6 ablations were created...
February 18, 2018: International Journal of Hyperthermia
https://www.readbyqxmd.com/read/29457518/surface-modification-of-doxorubicin-loaded-nanoparticles-based-on-polydopamine-with-ph-sensitive-property-for-tumor-targeting-therapy
#12
Dongdong Bi, Lei Zhao, Runqi Yu, Haowen Li, Yifei Guo, Xiangtao Wang, Meihua Han
One major challenge of current surface modification of nanoparticles is the demand for chemical reactive polymeric layers, such modification is always complicated, inefficient, and may lead the polymer lose the ability to encapsulate drug. To overcome this limitation, we adopted a pH-sensitive platform using polydopamine (PDA) as a way of functionalizing nanoparticles (NPs) surfaces. All this method needed to be just a brief incubation in weak alkaline solution of dopamine, which was simple and applicable to a variety of polymer carriers regardless of their chemical reactivity...
November 2018: Drug Delivery
https://www.readbyqxmd.com/read/29457453/exquisite-enzyme-fenton-biomimetic-catalysts-for-hydroxyl-radical-production-by-mimicking-an-enzyme-cascade
#13
Qi Zhang, Shuo Chen, Hua Wang, Hongtao Yu
Hydrogen peroxide (H2O2) is a key reactant in Fenton process. As a byproduct of enzymatic reaction, H2O2 can be obtained via the catalytical oxidation of glucose using glucose oxidase in the presence of O2. Another oxidation product (gluconic acid) can suitably adjust the microenvironmental pH contributing to the Fe3+/Fe2+ cycle in the Fenton reaction. Enzymes are extremely efficient at catalyzing a variety of reactions with high catalytic activity, substrate specificity and yields in living organisms. Inspired by the multiple functions of natural multienzyme systems, an exquisite nanozyme-modified α-FeOOH/porous carbon (PC) biomimetic catalyst constructed by in situ growth of glucose oxidase-mimicking Au nanoparticles and crystallization of adsorbed ferric ions within carboxyl into hierarchically PC is developed as an efficient enzyme-Fenton catalyst...
February 19, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29457452/a-multiple-stimuli-responsive-fluorescent-sensor-from-citric-acid-and-1-2-aminoethyl-piperazine
#14
Wen Yang, Fangbing Liu, Ran Li, Xiaoji Wang, Wentao Hao
Multi-responsive fluorescent supramolecular materials are quite interesting for that they combine the multi-responsiveness of supramolecules and the high-sensitivity of fluorescent materials. Different from the multi-responsive supramolecular materials based on host-guest interaction, in this report a supramolecular ionic network was fabricated by 1-(2-aminoethyl) piperazine (AEPZ) and citric acids via ionic interactions. Despite that there is none conventional chromophores, the obtained supramolecular ionic material can emit strong fluorescence...
February 19, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29457447/effects-of-chain-orientation-in-self-organized-buffer-layers-based-on-poly-3-alkylthiophene-s-for-organic-photovoltaics
#15
Fanji Wang, Kazuhito Hashimoto, Hiroshi Segawa, Keisuke Tajima
Surface-segregated monolayers (SSMs) based on two poly(3-alkylthiophene)s with semifluoroalkyl groups at either the side chains (P3DDFT) or one end of the main chain (P3BT-F17) were used as self-organized buffer layers at the electrode interfaces in bulk heterojunction (BHJ) organic photovoltaic devices (OPVs). Both of the SSMs greatly shifted the vacuum levels of the BHJ films at the surface due to the aligned permanent dipole moments of the semifluoroalkyl chains. Hole extraction in the BHJ of poly(3-hexylthiophene) (P3HT):[6,6]-phenyl C61-butyric acid methyl ester (PCBM) became more efficient in the presence of the P3DDFT buffer layer, resulting in an improved power conversion efficiency...
February 19, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29457368/emergence-of-two-novel-sublineages-ind2001bd1-and-ind2001bd2-of-foot-and-mouth-disease-virus-serotype-o-in-bangladesh
#16
M A Siddique, M R Ali, A S M R U Alam, H Ullah, A Rahman, R P Chakrabarty, M A Amin, S A Hoque, S P Nandi, M Sultana, M A Hossain
Foot-and-mouth disease (FMD) is endemic in Bangladesh, and the implementation of a control programme for this disease is at an early stage, according to the FAO- and OIE-proposed Progressive Control Pathway for FMD (PCP-FMD) Roadmap. To develop an effective control programme, understanding of foot-and-mouth disease virus (FMDV) serotypes, even subtypes within the serotypes is essential. The present investigation aims at viral VP1 coding region sequence-based analysis of FMD samples collected from 34 FMD outbreaks during 2012-2016 in Bangladesh...
February 18, 2018: Transboundary and Emerging Diseases
https://www.readbyqxmd.com/read/29457170/sensitive-detection-of-alkaline-phosphatase-by-dephosphorylation-initiated-transcription-reaction-mediated-dual-signal-amplification
#17
Fei Ma, Wen-Jing Liu, Li Liang, Bo Tang, Chun-Yang Zhang
We develop a new fluorescence method for the sensitive detection of alkaline phosphatase (ALP) based on dephosphorylation-initiated transcription reaction-mediated dual signal amplification. This research demonstrates for the first time a significant improvement in ALP assay performance by using a nucleic acid amplification strategy, which enables sensitive detection of ALP activity in vitro and in cell extracts. Importantly, this method can be further applied for kinetic analysis and ALP inhibition assay.
February 19, 2018: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/29456966/metabolic-profile-of-oral-squamous-carcinoma-cell-lines-relies-on-a-higher-demand-of-lipid-metabolism-in-metastatic-cells
#18
Ana Carolina B Sant'Anna-Silva, Gilson C Santos, Samir P Costa Campos, André Marco Oliveira Gomes, Juan Alberto Pérez-Valencia, Franklin David Rumjanek
Tumor cells are subjected to a broad range of selective pressures. As a result of the imposed stress, subpopulations of surviving cells exhibit individual biochemical phenotypes that reflect metabolic reprograming. The present work aimed at investigating metabolic parameters of cells displaying increasing degrees of metastatic potential. The metabolites present in cell extracts fraction of tongue fibroblasts and of cell lines derived from human tongue squamous cell carcinoma lineages displaying increasing metastatic potential (SCC9 ZsG, LN1 and LN2) were analyzed by1 H NMR (nuclear magnetic resonance) spectroscopy...
2018: Frontiers in Oncology
https://www.readbyqxmd.com/read/29456882/effects-of-osmolytes-and-macromolecular-crowders-on-stable-gaaa-tetraloops-and-their-preference-for-a-cg-closing-base-pair
#19
Kaethe N Leonard, Joshua M Blose
Osmolytes and macromolecular crowders have the potential to influence the stability of secondary structure motifs and alter preferences for conserved nucleic acid sequences in vivo . To further understand the cellular function of RNA we observed the effects of a model osmolyte, polyethylene glycol (PEG) 200, and a model macromolecular crowding agent, PEG 8000, on the GAAA tetraloop motif. GAAA tetraloops are conserved, stable tetraloops, and are critical participants in RNA tertiary structure. They also have a thermodynamic preference for a CG closing base pair...
2018: PeerJ
https://www.readbyqxmd.com/read/29456867/heterologous-and-endogenous-u6-snrna-promoters-enable-crispr-cas9-mediated-genome-editing-in-aspergillus-niger
#20
Xiaomei Zheng, Ping Zheng, Jibin Sun, Zhang Kun, Yanhe Ma
Background: U6 promoters have been used for single guide RNA (sgRNA) transcription in the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein (CRISPR/Cas9) genome editing system. However, no available U6 promoters have been identified in Aspergillus niger, which is an important industrial platform for organic acid and protein production. Two CRISPR/Cas9 systems established in A. niger have recourse to the RNA polymerase II promoter or in vitro transcription for sgRNA synthesis, but these approaches generally increase cloning efforts and genetic manipulation...
2018: Fungal Biology and Biotechnology
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