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https://www.readbyqxmd.com/read/28822891/comparative-toxicity-of-the-plasticizer-dibutyl-phthalate-to-two-freshwater-algae
#1
Shurui Gu, Hao Zheng, Qingqing Xu, Cuizhu Sun, Mei Shi, Zhenyu Wang, Fengmin Li
Phthalate esters (PAEs), a family of emerging environmental contaminants, have been frequently detected in soils and water. However, intensive studies on the toxicity of PAEs have focused on growth response of terrestrial and aquatic animals, while only limited attention has been paid to aquatic plants, especially phytoplankton, the primary producer in aquatic ecosystems. Therefore, the acute toxic effects and underlying mechanisms of dibutyl phthalate (DBP) at different concentrations (0-20mgL(-1)) on two typical freshwater algae (Scenedesmus obliquus and Chlorella pyrenoidosa) were investigated...
August 12, 2017: Aquatic Toxicology
https://www.readbyqxmd.com/read/28822304/a-flow-through-elevated-temperature-and-pressure-nmr-apparatus-for-in-situ-co2-sequestration-studies
#2
Erika L Sesti, Jinlei Cui, Sophia E Hayes, Mark S Conradi
We report an apparatus for in-situ nuclear magnetic resonance (NMR) studies of chemical reactions of dissolved (13)CO2 with minerals (rock or powder) under continuous flow. The operating range of the apparatus is 18-150°C and 1-140bar. A flow pump is used to circulate a CO2-water solution, with a heated mixing vessel where CO2 gas equilibrates with a water solution. The NMR probe is built around a strong zirconia ceramic vessel, with o-ring sealed connections; the mineral is contained inside. The horizontal orientation of the zirconia vessels allows use of a radio frequency (rf) solenoid for improved spin sensitivity...
August 12, 2017: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/28822236/synthesis-structural-studies-and-biological-activity-of-novel-cu-ii-complexes-with-thiourea-derivatives-of-4-azatricyclo-5-2-1-0-2-6-dec-8-ene-3-5-dione
#3
Aleksandra Drzewiecka-Antonik, Paweł Rejmak, Marcin T Klepka, Anna Wolska, Piotr Pietrzyk, Karolina Stępień, Giuseppina Sanna, Marta Struga
The new Cu(II) complexes of 1/2/3-(bromophenyl)-3-(1,7,8,9-tetramethyl-3,5-dioxo-4-azatricyclo[5.2.1.0(2,6)]dec-8-en-4-yl)thiourea derivatives have been synthesized. The spectroscopic studies together with density functional theory calculations of Cu(II) complexes revealed that two parent ligands coordinate to the copper cation in bidentate fashion via thiocarbonyl S and deprotonated N atoms forming rarely observed four-membered chelate ring, with nearly planar [CuN2S2] moiety. In solid state, the mononuclear complex is formed for thiourea derivative with 3-bromophenyl, whereas for Cu(II) connection with 2- and 4-bromophenyl-thioureas the formation of dinuclear complexes is observed, the latter formed by the stacking of mononuclear complexes...
August 9, 2017: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/28822035/identification-and-functional-characterization-of-a-p-coumaroyl-coa-2-hydroxylase-involved-in-the-biosynthesis-of-coumarin-skeleton-from-peucedanum-praeruptorum-dunn
#4
Ruolan Yao, Yucheng Zhao, Tingting Liu, Chuanlong Huang, Sheng Xu, Ziwei Sui, Jun Luo, Lingyi Kong
A p-coumaroyl CoA 2'-hydroxylase responsible for the formation of coumarin lactone ring was identified from Peucedanum praeruptorum Dunn and functionally characterized in vitro. Coumarins are important plant secondary metabolites with a variety of biological activities. Ortho-hydroxylation of cinnamates leads to the formation of coumarin lactone ring and is generally thought to be a key step in coumarin biosynthesis. However, ortho-hydroxylases, especially p-coumaroyl CoA 2'-hydroxylase (C2'H) responsible for the biosynthesis of the most common coumarin skeleton, have received insufficient attention...
August 18, 2017: Plant Molecular Biology
https://www.readbyqxmd.com/read/28822032/synthesis-of-rigid-polyurethane-foams-from-phosphorylated-biopolyols
#5
Juan Carlos de Haro, Daniel López-Pedrajas, Ángel Pérez, Juan Francisco Rodríguez, Manuel Carmona
Renewable resources are playing a key role on the synthesis of biodegradable polyols. Moreover, the incorporation of covalently linked additives is increasing in importance in the polyurethane (PU) market. In this work, previously epoxidized grape seed oil and methyl oleate were transformed into phosphorylated biopolyols through an acid-catalyzed ring-opening hydrolysis in the presence of H3PO4. The formation of phosphate polyesters was confirmed by FT-IR and (31)P-NMR. However, the synthesis of a high-quality PU rigid foam was not possible using exclusively these polyols attending to their low hydroxyl value...
August 18, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28821932/cometabolic-degradation-of-dibenzofuran-and-dibenzothiophene-by-a-naphthalene-degrading-comamonas-sp-jb
#6
Xiangyu Ji, Jing Xu, Shuxiang Ning, Nan Li, Liang Tan, Shengnan Shi
Comamonas sp. JB was used to investigate the cometabolic degradation of dibenzofuran (DBF) and dibenzothiophene (DBT) with naphthalene as the primary substrate. Dehydrogenase and ATPase activity of the growing system with the presence of DBF and DBT were decreased when compared to only naphthalene in the growing system, indicating that the presence of DBF and DBT inhibited the metabolic activity of strain JB. The pathways and enzymes involved in the cometabolic degradation were tested. Examination of metabolites elucidated that strain JB cometabolically degraded DBF to 1,2-dihydroxydibenzofuran, subsequently to 2-hydroxy-4-(3'-oxo-3'H-benzofuran-2'-yliden)but-2-enoic acid, and finally to catechol...
August 18, 2017: Current Microbiology
https://www.readbyqxmd.com/read/28821710/green-br%C3%A3-nsted-acid-ionic-liquids-as-novel-corrosion-inhibitors-for-carbon-steel-in-acidic-medium
#7
Shuyun Cao, Dan Liu, Peng Zhang, Lixia Yang, Peng Yang, Hui Lu, Jianzhou Gui
New ionic liquids with multiple Brönsted acid sites were synthesized in ≥98% yield, and their inhibiting properties for the corrosion of carbon steel in 0.5 M HCl solution had been evaluated using electrochemical impedance spectroscopy, potentiodynamic polarization and weight loss method, finally the possible inhibiting mechanism was proposed according to UV-visible spectroscopic measurements and surface analysis including SEM and XPS techniques. The designed cation structure of Brönsted acid ionic liquids (BAILs), with one phenyl and two imidazolium rings, makes them good mixed-type inhibitors via the adsorption of BAILs on the steel surface to suppress both anodic and cathodic processes, obeying Langmuir adsorption isotherm...
August 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28821449/daphnauranins-a-and-b-two-new-antifeedants-isolated-from-daphne-aurantiaca-roots
#8
Sheng-Zhuo Huang, Qing-Yun Ma, Fan-Dong Kong, Zhi-Kai Guo, Qi Wang, Hao-Fu Dai, Yu-Qing Liu, Jun Zhou, You-Xing Zhao
Daphnauranins A (1) and B (2), two sesquiterpenoids were isolated from the roots of Daphne aurantiaca Diels. One is an unprecedented 5/7 oxacycloheptane ring system, the other is a sesquiterpene-lignan complex. Their structures were elucidated by comprehensive spectroscopic methods including MS and NMR. Their absolute configurations were further confirmed by the quantum ECD calculations. Daphnauranins A and B showed anti-insect activities against male fruit fly with anti-feeding rate up to 46.2±7.1 and 44...
August 15, 2017: Fitoterapia
https://www.readbyqxmd.com/read/28821380/unique-transcriptional-profile-of-native-persisters-in-escherichia-coli
#9
Shinya Matsumoto, Yuto Kawai, Satoshi Miyagawa, Yuka Iwamoto, Shujiro Okuda, Alicia Sánchez-Gorostiaga, Miguel Vicente, Satoshi Tsuneda
Non-dividing persisters, bacteria that can survive in the presence of antibiotics by pausing their metabolic activity, are among the many causes of the refractory nature of bacterial infections. Here we constructed a recombinant Escherichia coli strain that enables to distinguish non-dividing from dividing cell based on Z-ring during cell division. Then, non-dividing cells and dividing cells were successfully separated using a fluorescence activated cell sorter. The sorted non-dividing cells showed significantly higher tolerance toward ofloxacin than dividing cells, which indicates that persisters were concentrated with the methodology...
August 15, 2017: Journal of Bioscience and Bioengineering
https://www.readbyqxmd.com/read/28821194/primary-benign-and-malignant-thyroid-neoplasms-with-signet-ring-cells-cytologic-histologic-and-molecular-features
#10
Nada A Farhat, Ayse M Onenerk, Jeffrey F Krane, Dora Dias-Santagata, Peter M Sadow, William C Faquin
Objectives: Signet ring cells (SRCs) can be seen in a variety of thyroid tumors and can pose a diagnostic pitfall on cytology. This study describes the cytologic, histomorphologic, and molecular aspects of a cohort of primary thyroid tumors with SRCs. Methods: A search was performed of the Massachusetts General Hospital and Brigham and Women's Hospital (Boston, MA) pathology archives for the keywords thyroid, signet, and signet ring features between 2000 and 2014...
September 1, 2017: American Journal of Clinical Pathology
https://www.readbyqxmd.com/read/28821153/combination-of-microsized-mineral-particles-and-rosin-as-a-basis-for-converting-cellulosic-fibers-into-sticky-superhydrophobic-paper
#11
Xiaoyan Yu, Peiwen Bian, Yang Xue, Xueren Qian, Haipeng Yu, Wenshuai Chen, Xiaohai Hu, Peng Wang, Dong Wu, Qinghui Duan, Limei Li, Jing Shen, Yonghao Ni
The unique features of cellulosic paper including flexibility, biodegradability, and low cost enables it as a versatile, sustainable biomaterial for promising applications. In the paper industry, microsized mineral particles are widely used in the production of printing/writing paper grades, while rosin derived from trees is the earliest internal sizing agent for paper hydrophobication. On the basis of existing commercial practices associated with the use of mineral particles and rosin in paper production, we present a process concept of converting cellulosic fibers (paper-grade pulp) into "sticky" superhydrophobic paper involving the use of microsized mineral particles and rosin (a tree-derived natural product, mainly a mixture of resin acids, especially abietic acid with chemical formula of C19H29COOH)...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28820941/a-photoactivatable-probe-for-super-resolution-imaging-of-enzymatic-activity-in-live-cells
#12
Elias A Halabi, Zacharias Thiel, Nils Trapp, Dorothea Pinotsi, Pablo Rivera-Fuentes
A dual-activatable, fluorogenic probe was developed to sense esterase activity with single-molecule resolution. Without enzymatic pre-activation, the diazoindanone-based probe has an electron poor core and, upon irradiation, undergoes Wolff rearrangement to give a ring-expanded xanthene core that is non-emissive. If the probe is pre-activated by carboxylesterases, the tricyclic core becomes electron-rich and the photoinduced Wolff rearrangement produces a highly emissive rhodol dye. Live-cell and solution studies confirmed the selectivity of the probe and revealed that the photoactivated dye does not diffuse away from the original location of activation because the intermediate ketene forms a covalent bond with surrounding macromolecules...
August 18, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28820934/supramolecular-sensors-for-opiates-and-their-metabolites
#13
Elena G Shcherbakova, Ben Zhang, Samer Gozem, Tsuyoshi Minami, Peter Y Zavalij, Mariia Pushina, Lyle Isaacs, Pavel Anzenbacher
The present work develops a sensing approach for opiates using acyclic cucurbituril (aCBs) sensors comprising four glycouril units terminated on both ends with naphthalene fluorophore walls. The connectivity between the glycourils and the naphthalene rings largely defines the opening size of the cucurbituril cavity and its diameter. The large hydrophobic binding cavity is flexible and is able to adapt to guests of various size and topology. The recognition event between the aCBs and guests results in modification of the fluorescence of the terminal walls, a fluorescence response that can be used to sense the drugs of abuse morphine, heroin and oxycodone as well as their metabolites...
August 18, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28820835/simultaneous-stiles-bunnell-tendon-transfer-enhances-intrinsic-function-of-the-second-toe-transplantations
#14
Yu-Te Lin, Charles Yuen Yung Loh, Shwu-Huei Lien, Chih-Hung Lin, Fu-Chan Wei
Claw finger is sequelae of fingers without intrinsic function. Claw toe deformity is common after toe transfers as simultaneous intrinsic reconstruction has yet to be reported in the literature. We present our experience of simultaneous tendon transfers during the second toe transplantation. Seven 2nd toe transfers were performed in 5 metacarpal-like and metacarpal hands. The Stiles-Bunnell tendon transfer was incorporated into toe transfers. Toe lumbrical tendons were repaired to the Flexor Digitorum Sublimis of the same recipient digit...
August 8, 2017: Plastic and Reconstructive Surgery
https://www.readbyqxmd.com/read/28820653/fibrous-skeleton-of-the-heart-anatomic-overview-and-evaluation-of-pathologic-conditions-with-ct-and-mr-imaging
#15
Farhood Saremi, Damián Sánchez-Quintana, Shumpei Mori, Horia Muresian, Diane E Spicer, Cameron Hassani, Robert H Anderson
The fibrous skeleton is concentrated at the base of the ventricular mass. It provides electrical insulation at the atrioventricular level and fibrous continuity for the leaflets of the mitral, aortic, and tricuspid valves. Its components include the fibrous trigones, the fibrous area of aortic-mitral continuity, the subvalvar collar of the mitral valve, the membranous septum, the interleaflet triangles, the tendon of Todaro, and likely the conus ligament. The majority of the mitral annulus is fibrous, but the only true fibrous part of the tricuspid annulus is where the valvar leaflets are attached to the central fibrous body...
August 18, 2017: Radiographics: a Review Publication of the Radiological Society of North America, Inc
https://www.readbyqxmd.com/read/28820625/multimodal-image-analysis-of-the-retina-in-hunter-syndrome-mucopolysaccharidosis-type-ii-case-report
#16
Isadora Darriba Macedo Salvucci, Simone Finzi, Maria Kiyoko Oyamada, Chong Ae Kim, Sérgio Luis Gianotti Pimentel
INTRODUCTION: We report a case of retinal and posterior ocular findings in a 33-year-old man diagnosed with Hunter syndrome (Mucopolysaccharidosis type II) in a multimodal imaging way. CASE PRESENTATION: Our patient was complaining of blurred night vision for the past 3 years. He had not received any systemic treatment for Hunter syndrome. Vision acuity was 20/20 in both eyes and corneas were clear. Fundus examination revealed bilateral crowded and hyperemic optic nerve heads (elevated in the ocular ultrasound) and areas of subretinal hypopigmentation...
August 18, 2017: Ophthalmic Genetics
https://www.readbyqxmd.com/read/28820603/walrobsins-a-and-b-two-anti-inflammatory-limonoids-from-root-barks-of-walsura-robusta
#17
Fa-Liang An, Dong-Mei Sun, Rui-Jun Li, Miao-Miao Zhou, Ming-Hua Yang, Yong Yin, Ling-Yi Kong, Jun Luo
Walrobsins A (1) and B (2), two limonoids featuring an unprecedented 5-oxatricyclo[5.4.1(1,4)]hendecane ring system, were isolated from the root barks of Walsura robusta. Their structures, including their absolute configurations, were determined by analyses of HR-ESIMS, 1D/2D NMR, and X-ray crystallography. Compounds 1 and 2 possessed a stable hemiketal structure formed between the OH-11 and 3-carbonyl group in the hexatomic oxoheterocyclic ring. Compound 1 showed significant anti-inflammatory activity with an IC50 value of 7...
August 18, 2017: Organic Letters
https://www.readbyqxmd.com/read/28820600/magnesiate-addition-ring-expansion-strategy-to-access-the-6-7-6-tricyclic-core-of-hetisine-type-c20-diterpenoid-alkaloids
#18
Jason J Pflueger, Louis C Morrill, Justine N deGruyter, Melecio A Perea, Richmond Sarpong
A synthetic strategy to access the fused 6-7-6 tricyclic core of hetisine-type C20-diterpenoid alkaloids is reported. This strategy employs a Diels-Alder cycloaddition to assemble a fused bicyclic anhydride intermediate, which is elaborated to a vinyl lactone-acetal bearing an aromatic ring in five steps. Aromatic iodination is followed by magnesium-halogen exchange with a trialkyl magnesiate species, which undergoes intramolecular cyclization. Subsequent oxidation provides the desired 6-7-6 tricyclic diketoaldehyde, with carbonyl groups at all three positions for eventual C-N bond formation and subsequent elaboration...
August 18, 2017: Organic Letters
https://www.readbyqxmd.com/read/28820586/dissociation-chemistry-of-3-oxetanone-in-the-gas-phase
#19
Sumitra Godara, Pooja Verma, Manikandan Paranjothy
3-Oxetanone is a strained cyclic molecule which plays an important role in synthetic chemistry. A few studies exist in the literature about the equilibrium properties of this molecule and the dissociation patterns of substituted 3-oxetanones. For the unsubstituted 3-oxetanone, formation of ketene (CH2CO) and formaldehyde (HCHO) was considered to be the major dissociation pathway. In a recent work, pyrolysis products of 3-oxetanone molecule in the gas phase were investigated by Fourier transform infrared spectroscopy and photoionization mass spectrometry...
August 18, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28820583/processing-2-methyl-l-tryptophan-through-tandem-transamination-and-selective-oxygenation-initiates-indole-ring-expansion-in-the-biosynthesis-of-thiostrepton
#20
Zhi Lin, Jia Ji, Shuaixiang Zhou, Fang Zhang, Jiequn Wu, Yinlong Guo, Wen Liu
Thiostrepton (TSR), an archetypal member of the family of ribosomally synthesized and post-translationally modified thiopeptide antibiotics, possesses a biologically important quinaldic acid (QA) moiety within the side-ring system of its characteristic thiopeptide framework. QA is derived from an independent L-Trp residue; however, its associated transformation process remains poorly understood. We here report that during the formation of QA, the key expansion of an indole to a quinoline relies on the activities of the pyridoxal-5'-phosphate-dependent protein TsrA and the flavoprotein TsrE...
August 18, 2017: Journal of the American Chemical Society
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