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https://read.qxmd.com/read/30776861/-clinical-diagnosis-and-surgical-management-of-110-cases-of-facial-nerve-schwannomas
#1
N Sai, W J Han, M M Wang, X Qin, T Zhang, W D Shen, J Liu, P Dai, S M Yang, D Y Han
Objective: To elucidate the clinical behavior, causes of misdiagnosis, surgical management, and outcomes of facial nerve schwannomas (FNS). Methods: A retrospective review in Chinese People's Liberation Army General Hospital from January 1, 2002 to December 31, 2015 was carried out and evaluated 110 patients with FNS, including 50 males and 60 females, aged 16-67 years old. The appropriate surgical strategy was selected based on each patient's clinical manifestations, facial nerve function, and imaging characteristics...
February 7, 2019: Zhonghua Er Bi Yan Hou Tou Jing Wai Ke za Zhi, Chinese Journal of Otorhinolaryngology Head and Neck Surgery
https://read.qxmd.com/read/30776781/waterborne-copper-is-more-toxic-to-the-killifish-poecilia-vivipara-in-elevated-temperatures-linking-oxidative-stress-in-the-liver-with-reduced-organismal-thermal-performance
#2
Yuri Dornelles Zebral, Mauricio Roza, Juliana da Silva Fonseca, Patrícia Gomes Costa, Caroline Stürmer de Oliveira, Tayndy Gubert Zocke, Juliana Lemos Dal Pizzol, Ricardo Berteaux Robaldo, Adalto Bianchini
In this study, we measured the interactive effect of temperature (22 °C and 28 °C) and waterborne copper (Cu) contamination (9 μg/L and 20 μg/L) on the killifish Poecilia vivipara. Endpoints analyzed included parameters involved in Cu-accumulation, antioxidant capacity (antioxidant capacity against peroxyl radicals [ACAP] and total antioxidant capacity [TAC]), oxidative damage (lipid peroxidation [LPO]) and upper thermal tolerance (critical thermal maximum [CTMax]). Results show that Cu hepatic accumulation was elevated in 28 °C in comparison to 22 °C in both exposure groups...
February 7, 2019: Aquatic Toxicology
https://read.qxmd.com/read/30776639/butterfly-cluster-like-lamellar-biobr-tio-2-nanocomposite-for-enhanced-sunlight-photocatalytic-mineralization-of-aqueous-ciprofloxacin
#3
Jamshaid Rashid, Ammara Abbas, Leng Chee Chang, Aneela Iqbal, Ihsan Ul Haq, Adeela Rehman, Saif Ullah Awan, Muhammad Arshad, Mohsin Rafique, M A Barakat
The present study for the first time reports facile in-situ room temperature synthesis of butterfly cluster like lamellar BiOBr deposited over TiO2 nanoparticles for photocatalytic breakdown of ciprofloxacin (CIP). The butterfly cluster arrangement of BiOBr resulted in an increase in surface area from 124.6 to 160.797 m2 ·g-1 and subsequently increased incident light absorption by the composite photocatalyst. The XRD indicated the existence of TiO2 as spherical ≈10-15 nm diameter particles with [101] preferential growth planes of anatase phase while the lamellar BiOBr showing growth along [110] and [102] preferential planes that were also confirmed by the HR-TEM images...
February 11, 2019: Science of the Total Environment
https://read.qxmd.com/read/30776565/in-situ-overhauser-enhanced-nuclear-magnetic-resonance-at-less-than-1-%C3%AE-t-using-an-atomic-magnetometer
#4
Hyun Joon Lee, Seong-Joo Lee, Jeong Hyun Shim, Han Seb Moon, Kiwoong Kim
The development of atomic magnetometers has led to nuclear magnetic resonance (NMR) in zero and ultralow magnetic fields without using cryogenic sensors. However, in-situ detection, meaning that a sample locates in the detection space beside a vapor cell, has been conducted only with parahydrogen-induced polarization. Other hyperpolarization techniques remain unexplored yet. In this work, we demonstrate that Overhauser dynamic nuclear polarization allows in-situ NMR detection with an atomic magnetometer at less than 1 μT...
February 10, 2019: Journal of Magnetic Resonance
https://read.qxmd.com/read/30776484/biosynthesis-of-silver-nanoparticle-using-extract-of-zea-mays-corn-flour-and-investigation-of-its-cytotoxicity-effect-and-radical-scavenging-potential
#5
T Rajkumar, Andras Sapi, Gitishree Das, Trishna Debnath, AbuZar Ansari, Jayanta Kumar Patra
Silver nanoparticles (AgNPs) possesses a number of exceptional pharmaceutical properties and applications as compared with other types of metallic nanoparticles. Currently, AgNPs was biosynthesized using an aqueous extract of Zea mays L. (corn flour) powder. Further, the effect of concentration of reagents, extract, temperature and time of synthesis was also studied along with the cytotoxicity and radical scavenging potential. UV-vis spectra of AgNPs gave a surface plasmon resonance at ~420 nm. The absorption peak became sharp with the increase in time...
January 17, 2019: Journal of Photochemistry and Photobiology. B, Biology
https://read.qxmd.com/read/30776310/hydrogen-bonded-polyrotaxane-cation-structure-in-nickel-dithiolate-anion-radical-salts-ferromagnetic-and-semiconducting-behavior-associated-with-structural-phase-transition
#6
Yuki Shirakawa, Kiyonori Takahashi, Hiroyasu Sato, Norihisa Hoshino, Hayato Anetai, Shin-Ichiro Noro, Tomoyuki Akutagawa, Takayoshi Nakamura
The pseudo-polyrotaxane structure of [(H-bpy+)(DB[24]crown-8)]∞ (H-bpy+ = monoprotonated 4,4-bipyridinium; DB[24]crown-8 = dibenzo[24]crown-8) was incorporated into anion radical salts, [Ni(dmit)2]- (dmit2- = 1,3-dithio-2-thione-4,5-dithiolate). (H-bpy+)(DB[24]crown-8)[Ni(dmit)2]- crystallized into two polymorphs: crystals 1 and 2. Crystal 1 had a lower density and looser packing structure. In crystal 1, H-bpy+ formed a one-dimensional hydrogen bonding chain, which passed though the crown ether ring of DB[24]crown-8...
February 18, 2019: Chemistry: a European Journal
https://read.qxmd.com/read/30776266/cochlear-implantation-in-patients-with-canal-wall-down-mastoidectomy-cavities
#7
Song Gao, Yi Jiang, Guo-Jian Wang, Bei Cheng Li, Yong-Yi Yuan, Bo Gao, Dejun Zhang, Jianan Li, Qian Yu, Pu Dai
BACKGROUND: Safe cochlear implantation (CI) is challenging in patients with a canal wall down (CWD) mastoidectomy cavity. OBJECTIVES: We reviewed the outcomes of CI and proposed surgical management principles according to the presentation status of CWD mastoidectomy cavity. MATERIAL AND METHODS: The cases of eight patients (nine ears) with CWD mastoidectomy cavity who underwent CI were retrospectively reviewed. The basis of the surgical decision, postoperative complications, and postimplant auditory performance were analysed...
November 2018: Acta Oto-laryngologica
https://read.qxmd.com/read/30776239/exploring-cycloreversion-reaction-of-cyclobutane-pyrimidine-dimers-quantum-mechanically
#8
Donglian Huang, Shanfeng Chen, Jingzhi Pu, Xuecai Tan, Yan Zhou
Cyclobutane pyrimidine dimer (CPD) is a major photoproduct of deoxyribonucleic acid (DNA) that is damaged by ultraviolet light. This DNA lesion can be repaired by DNA photolyase with the aid of UV light and two cofactors. To understand the repair mechanism of CPD and whether protonation of CPD participates in the DNA repair process, the cycloreversion reactions of four CPD models and proton transfers between the adjacent residue Glu283 and CPD models were explored through quantum mechanical method. Two-dimensional maps of potential energy surface in vacuum and in implicit water solution were calculated at the ωB97XD/6-311++G(2df,2pd) level...
February 18, 2019: Journal of Physical Chemistry. A
https://read.qxmd.com/read/30776233/catalytic-mechanism-for-2-3-dihydroxybiphenyl-ring-cleavage-by-non-heme-extradiol-dioxygenases-bphc-insights-from-qm-mm-analysis
#9
Junjie Wang, Jinfeng Chen, Xiaowen Tang, Yanwei Li, Ruiming Zhang, Ledong Zhu, Yanhui Sun, Qingzhu Zhang, Wenxing Wang
An extradiol-cleaving catecholic dioxygenase, BphC, plays important roles in catabolism of biphenyl/polychlorinated biphenyls (PCBs) aromatic contaminants in the environment. To better elucidate the biodegradable pathway, a theoretical investigation of the ring-open degradation for 2,3-dihydroxybiphenyl (DHBP) was performed with the aid of quantum mechanical/molecular mechanical (QM/MM) calculations. A quintet state of the DHBP-iron-dioxygen group adducts was found to be reactive ground state with a substrate radical-FeII-superoxo (DHBP• ↑-FeII-O2• ‾↓) character...
February 18, 2019: Journal of Physical Chemistry. B
https://read.qxmd.com/read/30776185/the-dual-role-of-benzophenone-in-visible-light-nickel-photoredox-catalyzed-c-h-arylations-hydrogen-atom-transfer-and-energy-transfer
#10
Abhishek Dewanji, Patricia E Krach, Magnus Rueping
A dual catalytic protocol for the direct arylation of non-activated C(sp3 )-H bonds has been developed. Upon photochemical excitation, the excited triplet state of a diaryl ketone photosensitizer abstracts a hydrogen atom from an aliphatic C-H bond. This inherent reactivity was exploited for the generation of benzylic radicals which subsequently enter a nickel catalytic cycle, accomplishing the benzylic arylation.
February 18, 2019: Angewandte Chemie
https://read.qxmd.com/read/30775916/metal-free-catalytic-synthesis-of-thiocarbamates-using-sodium-sulfinates-as-the-sulfur-source
#11
Pengli Bao, Leilei Wang, Huilan Yue, Yun Shao, Jiangwei Wen, Daoshan Yang, Xiaohui Zhao, Hua Wang, Wei Wei
A novel molecular iodine-catalyzed protocol for the construction of thiocarbamates from readily available sodium sulfinates, isocyanides, and water has been described. The present methodology offers a facile and practical route to a variety of thiocarbamates in moderate to good yields with favorable functional group tolerance by use odorless sodium sulfinates as the sulfur source. The mechanistic studies suggest the present transformation involves a radical process.
February 18, 2019: Journal of Organic Chemistry
https://read.qxmd.com/read/30775906/nafion-radical-hybrid-films-on-carbon-nanotube-transistors-for-monitoring-antipsychotic-drug-effects-on-stimulated-dopamine-release
#12
Viet Anh Pham Ba, Dong-Guk Cho, Seunghun Hong
We developed floating electrode-based carbon nanotube biosensors for the monitoring of antipsychotic drug effects on the dopamine release from PC12 cells under potassium stimulation. Here, carbon nanotube field-effect transistors with floating electrodes were functionalized with ABTS• radicals by nafion films. This method allows us to build selective biosensors for dopamine detection with a detection limit down to 10 nM even in the presence of other neurotransmitters such as glutamate and acetylcholine, resulting from the selective interaction between ABTS• radicals and dopamine...
February 18, 2019: ACS Applied Materials & Interfaces
https://read.qxmd.com/read/30775845/regioselective-bromination-and-functionalization-of-dibenzo-hi-st-ovalene-as-highly-luminescent-nanographene-with-zigzag-edges
#13
Qiang Chen, Di Wang, Martin Baumgarten, Dieter Schollmeyer, Klaus Müllen, Akimitsu Narita
Dibenzo[hi,st]ovalene (DBOV) is a nanographene with a combination of zigzag and armchair edges, consisting of 38 sp2 carbons. Excellent optical properties with strong red emission have been demonstrated. Here we report the regioselective bromination of DBOV bearing two mesityl groups (DBOV-Mes) by treatment with N-bromosuccinimide (NBS) under a mild condition. The dibrominated DBOV was further subjected to transition-metal-catalyzed cross-coupling reactions, i.e. Suzuki and Sonogashira coupling, demonstrating the edge-decoration of DBOV with different functional groups...
February 18, 2019: Chemistry, An Asian Journal
https://read.qxmd.com/read/30775833/asymmetric-total-syntheses-of-the-akuammiline-alkaloids-strictamine-and-rhazinoline
#14
Yong Qin, Wenfei Li, Zhitao Chen, Di Yu, Xin Peng, Guohua Wen, Siqi Wang, Fei Xue, Xiao-Yu Liu
Strictamine and rhazinoline are representative methanoquinolizidine-containing akuammiline alkaloids that possess different stereochemistry at the C16 position. A unified approach to the enantioselective total syntheses of these two molecules is described. The key steps in this synthesis include a photocatalytic intra/intermolecular type II radical cascade reaction, a Tsuji-Trost allylation, a palladium- or nickel-mediated cyclization, and a late-stage intramolecular N-alkylation reaction.
February 18, 2019: Angewandte Chemie
https://read.qxmd.com/read/30775733/towards-high-level-theoretical-studies-of-large-biodiesel-molecules-an-oniom-rrkm-master-equation-approach-to-the-isomerization-and-dissociation-kinetics-of-methyl-decanoate-radicals
#15
Qinghui Meng, Yicheng Chi, Lidong Zhang, Peng Zhang, Liusi Sheng
The isomerization and dissociation reactions of methyl decanoate (MD) radicals were theoretically investigated by using high-level theoretical calculations based on a two-layer ONIOM method, employing the QCISD(T)/CBS method for the high layer and the M06-2X/6-311++G(d,p) method for the low layer. Temperature- and pressure-dependent rate coefficients for the involved reactions were computed by using the transition state theory and the Rice-Ramsperger-Kassel-Marcus/Master-equation method. The structure-reactivity relationships were explored for the complicated multiple-well interconnected system of ten isomeric MD radicals...
February 18, 2019: Physical Chemistry Chemical Physics: PCCP
https://read.qxmd.com/read/30775233/extended-exposure-to-stiff-microenvironments-leads-to-persistent-chromatin-remodeling-in-human-mesenchymal-stem-cells
#16
Anouk R Killaars, Joseph C Grim, Cierra J Walker, Ella A Hushka, Tobin E Brown, Kristi S Anseth
Bone marrow derived human mesenchymal stem cells (hMSCs) are a promising cell source for regenerative therapies; however, ex vivo expansion is often required to achieve clinically useful cells numbers. Recent results reveal that when MSCs are cultured in stiff microenvironments, their regenerative capacity can be altered in a manner that is dependent on time (e.g., a mechanical dosing analogous to a chemical one). It is hypothesized that epigenomic modifications are involved in storing these mechanical cues, regulating gene expression, and ultimately leading to a mechanical memory...
February 6, 2019: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
https://read.qxmd.com/read/30775056/successful-treatment-of-a-case-of-tentorial-dural-arteriovenous-fistula-causing-subarachnoid-hemorrhage-with-invagination-of-the-brainstem-by-huge-and-multiple-venous-pouches
#17
Natsumi Fujii, Makoto Ideguchi, Takafumi Nishizaki, Norio Ikeda, Taichi Shimabukuro, Tomomi Okamura, Machiko Oono
Background: We present a case of tentorial dural arteriovenous fistula (TDAVF) causing subarachnoid hemorrhage with mass effect of large venous pouches, which was struggling to diagnosis and management due to complex vasculature and severe general condition. Case Description: A 43-year-old man was transferred to our hospital due to sudden consciousness disturbance. A neurological examination revealed tetraparesis and pupil dilatation with no light reflex. Imaging findings showed a large lesion in the brainstem with subarachnoid and intraventricular hemorrhage...
2019: Surgical Neurology International
https://read.qxmd.com/read/30774971/3d-printable-hyaluronic-acid-based-hydrogel-for-its-potential-application-as-a-bioink-in-tissue-engineering
#18
Insup Noh, Nahye Kim, Hao Nguyen Tran, Jaehoo Lee, Chibum Lee
Background: After recognition of 3D printing and injectable hydrogel as a critical issue in tissue/organ engineering and regenerative medicine society, many hydrogels as bioinks have been developed worldwide by using polymeric biomaterials such as gelatin, alginate, hyaluronic acid and others. Even though some gels have shown good performances in 3D bioprinting, still their performances do not meet the requirements enough to be used as a bioink in tissue engineering. Method: In this study, a hydrogel consisting of three biocompatible biomaterials such as hyaluronic acid (HA), hydroxyethyl acrylate (HEA) and gelatin-methacryloyl, i...
2019: Biomaterials Research
https://read.qxmd.com/read/30774933/current-concepts-and-recent-advances-in-understanding-and-managing-lumbar-spine-stenosis
#19
REVIEW
Carlos Bagley, Matthew MacAllister, Luke Dosselman, Jessica Moreno, Salah Aoun, Tarek El Ahmadieh
Lumbar spinal stenosis is a degenerative process that is extremely frequent in today's aging population. It can result in impingement on the nerves of the cauda equina or on the thecal sac itself, and lead to debilitating symptoms such as severe leg pain, or restriction in the perimeter of ambulation, both resulting in dependency in daily activities. The impact of the disease is global and includes financial repercussions because of its involvement in the active work force group. Risk factors for the disease include some comorbidities such as obesity or smoking, daily habits such as an active lifestyle, but also genetic factors that are not completely elucidated yet...
2019: F1000Research
https://read.qxmd.com/read/30774920/%C3%AE-c-h-hetero-arylation-via-cu-catalyzed-radical-relay
#20
Zuxiao Zhang, Leah M Stateman, David A Nagib
A Cu-catalyzed strategy has been developed that harnesses a radical relay mechanism to intercept a distal C-centered radical for C-C bond formation. This approach enables selective δ C-H (hetero)arylation of sulfonamides via intramolecular hydrogen atom transfer (HAT) by an N-centered radical. The radical relay is both initiated and terminated by a Cu catalyst, which enables incorporation of arenes and heteroarenes by cross-coupling with boronic acids. The broad scope and utility of this catalytic method for δ C-H arylation is shown, along with mechanistic probes for selectivity of the HAT mechanism...
January 28, 2019: Chemical Science
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