keyword
MENU ▼
Read by QxMD icon Read
search

C-H activation

keyword
https://www.readbyqxmd.com/read/29141141/electronic-and-torsional-effects-on-hydrogen-atom-transfer-from-aliphatic-c-h-bonds-a-kinetic-evaluation-via-reaction-with-the-cumyloxyl-radical
#1
Michela Salamone, Teo Martin, Michela Milan, Miquel Costas, Massimo Bietti
A kinetic study on the HAT reactions from the aliphatic C-H bonds of a series of 1-Z-pentyl, 1-Z-propyl and Z-cyclohexyl derivatives, and of a series of N-alkylamides and N-alkylphthalimides to the electrophilic cumyloxyl radical (CumO•) has been carried out. With 1-pentyl and 1-propyl derivatives, α-CH2 activation towards CumO• is observed for Z = Ph, OH, NH2, NHAc, evidenced by an increase in kH as compared to the unsubstituted alkane substrate. A decrease in kH has been instead measured for Z = OAc, NPhth, CO2Me, Cl, Br, CN, indicative of α-CH2 deactivation with HAT that predominantly occurs from the most remote methylenic site...
November 15, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/29141119/distal-weak-coordination-of-acetamides-in-ruthenium-ii-catalyzed-c-h-activation-processes
#2
Qingqing Bu, Torben Rogge, Vladislav Kotek, Lutz Ackermann
C-H activations with challenging arylacetamides were accomplished by versatile ruthenium(II) biscarboxylate catalysis. The distal C-H functionalization was characterized by ample scope, including twofold oxidative C-H functionalizations and alkyne hydroarylations, through facile base-assisted internal electrophilic-type substitution (BIES) C-H ruthenation by weak O coordination.
November 15, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/29140285/chitosan-cyclodextrin-tpp-nanoparticles-loaded-with-quercetin-as-novel-bacterial-quorum-sensing-inhibitors
#3
Hao Thanh Nguyen, Francisco M Goycoolea
The widespread emergence of antibiotic-resistant bacteria has highlighted the urgent need of alternative therapeutic approaches for human and animal health. Targeting virulence factors that are controlled by bacterial quorum sensing (QS), seems a promising approach. The aims of this study were to generate novel nanoparticles (NPs) composed of chitosan (CS), sulfo-butyl-ether-β-cyclodextrin (Captisol(®)) and/or pentasodium tripolyphosphate using ionotropic gelation technique, and to evaluate their potential capacity to arrest QS in bacteria...
November 15, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29140118/-11-c-choline-pet-ct-for-detection-and-localization-of-parathyroid-adenomas
#4
Ahmad Parvinian, Erica L Martin-Macintosh, Ajit H Goenka, Jolanta M Durski, Brian P Mullan, Brad J Kemp, Geoffrey B Johnson
OBJECTIVE: The purpose of this study is to determine the efficacy of (11)C-choline PET/CT for the detection of parathyroid adenomas by retrospectively reviewing a large patient population. MATERIALS AND METHODS: In this single-institution retrospective study, 7088 (11)C-choline PET/CT scans performed of 2933 men with prostate cancer from January 2005 through February 2016 were evaluated. Patients with suspected parathyroid adenomas were identified through a review of the electronic medical record and relevant imaging...
November 15, 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/29139566/patient-reported-rates-of-chronic-pain-and-recurrence-after-groin-hernia-repair
#5
K-J Lundström, H Holmberg, A Montgomery, P Nordin
BACKGROUND: The effectiveness of different procedures in routine surgical practice for hernia repair with respect to chronic postoperative pain and reoperation rates is not clear. METHODS: This was prospective cohort study based on a unique combination of patient-reported outcomes and national registry data. Virtually all patients with a groin hernia repair in Sweden between September 2012 and April 2015 were sent a questionnaire 1 year after surgery. Persistent pain, defined as at least 'pain present, cannot be ignored, and interferes with concentration on everyday activities' in the past week was the primary outcome...
November 15, 2017: British Journal of Surgery
https://www.readbyqxmd.com/read/29139272/-comparative-study-on-specific-chromatograms-and-main-active-components-of-wild-and-cultivated-rhizomes-of-paris-polyphylla-var-yunnanensis
#6
Ke Zan, Yu-Ming Gao, Gan Cui, Jie Liu, Li-Nong Guo, Jian Zheng, Shuang-Cheng Ma
The present study is to compare specific chromatograms and main acitive components between wild and cultivated rhizomes of Paris polyphylla var. yunnanensis by HPLC. HPLC analysis was performed on a Waters XSelect HSS T3 C₁₈ clumn (4.6 mm×250 mm, 5 μm), with a mobile phase consisting of acetonitrile (A)-water (B) at a flow rate of 1 mL•min⁻¹ (0-50 min,30%-50%A;50-80 min,50% A,80-85 min,50%-30%A;85-100 min,30% A). The detection wavelength was 203 nm and the column temperature was controlled at 30 ℃, and the injection volume was 10 μL...
August 2017: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/29139184/achieving-strong-positive-cooperativity-through-activating-weak-non-covalent-interactions
#7
Yan-Long Ma, Hua Ke, Arto Valkonen, Kari Rissanen, Wei Jiang
Positive cooperativity achieved through activating weak non-covalent interactions is common in biological assemblies but is rarely observed in synthetic complexes. Two new naphthotubes have been synthesized and the syn isomer binds DABCO-based organic cations with high orientational selectivity. Surprisingly, the ternary complex with two hosts and one guest shows a high cooperativity factor (α=580), which is the highest reported for synthetic systems without involving ion-pairing interactions. The X-ray single-crystal structure revealed that the strong positive cooperativity likely originates from eight C-H⋅⋅⋅O hydrogen bonds between the two head-to-head-arranged syn tube molecules...
November 14, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/29139129/reproductive-biology-of-female-striped-marlin-kajikia-audax-in-the-western-pacific-ocean
#8
H-Y Chang, C-L Sun, S-Z Yeh, Y-J Chang, N-J Su, G DiNardo
Length and mass data for 1260 (536 females, 683 males, 41 sex unknown) striped marlin Kajikia audax were collected at the fish markets of Tungkang, Singkang and Nanfangao from July 2004 to September 2010. Of these samples, 534 gonads (236 females and 298 males) ranging from 95 to 206 cm in eye-to-fork length (LEF ) and 8 to 88 kg in round mass (MR ), were collected. Chi-square tests indicated sex ratios were homogeneous among months in 2004 and 2006-2008, but not in 2005, 2009 and 2010; and there were significant differences in sex ratio by size...
November 15, 2017: Journal of Fish Biology
https://www.readbyqxmd.com/read/29139124/histochemical-distribution-of-four-types-of-enzymes-and-mucous-cells-in-the-gastrointestinal-tract-of-reared-half-smooth-tongue-sole-cynoglossus-semilaevis
#9
Y Z Wang, J F Sun, A J Lv, S L Zhang, Y Y Sung, H Y Shi, X C Hu, S J Chen, K Z Xing
The histochemical distribution of acid phosphatase (ACP), alkaline phosphatase (ALP), non-specific esterase (NSE), peroxidase (POD) and mucous-cell types was evaluated in the gastrointestinal tract of the half-smooth tongue sole Cynoglossus semilaevis. The enzymes were detected in the entire stretch of the gastrointestinal tract. ACP activity was found in the supranuclear region of enterocytes and the lamina propria of the intestine, as well as the cytoplasm of epithelial cells of the stomach. The staining intensity of ACP in the anterior and posterior intestines was stronger than in the stomach...
November 15, 2017: Journal of Fish Biology
https://www.readbyqxmd.com/read/29139009/lfm-a13-a-potent-inhibitor-of-polo-like-kinase-inhibits-breast-carcinogenesis-by-suppressing-proliferation-activity-and-inducing-apoptosis-in-breast-tumors-of-mice
#10
Kazim Sahin, Mehmet Tuzcu, Mehmet Yabas, Cemal Orhan, Nurhan Sahin, Ibrahim H Ozercan
The goals of the present study were to define the anticancer activity of LFM-A13 (α-cyano-β-hydroxy-β-methyl-N-(2,5-dibromophenyl)-propenamide), a potent inhibitor of Polo-like kinase (PLK), in a mouse mammary cancer model induced by 7,12-dimethylbenz(a)anthracene (DMBA) in vivo and explore its anticancer mechanism(s). We also examined whether the inhibition of PLK by LFM-A13 would improve the efficiency of paclitaxel in breast cancer growth in vivo. To do this, female BALB/c mice received 1 mg of DMBA once a week for 6 weeks with oral gavage...
November 15, 2017: Investigational New Drugs
https://www.readbyqxmd.com/read/29138954/identification-of-compounds-from-palicourea-rigida-leaves-with-topical-anti-inflammatory-potential-using-experimental-models
#11
Rafael P Pinheiro, Muiara A Moraes, Bruna C S Santos, Rodrigo L Fabri, Glauciemar Del-Vechio-Vieira, Célia H Yamamoto, Ana Lúcia S M Araújo, Aílson L A Araújo, Orlando V Sousa
Palicourea rigida Kunth is traditionally used for the treatment of skin diseases, kidney pains and ovarian inflammation. Based on these traditional uses, this study evaluated the topical anti-inflammatory activity of the ethanol extract from P. rigida leaves (EEPR) and identified bioactive compounds. Ear edema was induced in Swiss mice by the topical application of Croton oil, arachidonic acid, phenol and capsaicin. Histopathological analysis and myeloperoxidase and N-acetyl-β-D-glucosaminidase activities were determined...
November 14, 2017: Inflammopharmacology
https://www.readbyqxmd.com/read/29138768/the-role-of-trinuclear-species-in-a-palladium-acetate-trifluoroacetic-acid-catalytic-system
#12
Jiří Váňa, Jan Lang, Mária Šoltésová, Jiří Hanusek, Aleš Růžička, Miloš Sedlák, Jana Roithová
Reactions catalyzed by palladium(ii) acetate and trifluoroacetic acid (TFA) have a clear preactivation phase. However, the structure of real catalytic species remains unclear. We show that the key species are cyclic trinuclear complexes of composition [Pd3(OAc)6-x(OTFA)x] (x = 1-6) formed by a sequential ligand exchange from [Pd3(OAc)6]. Furthermore, we prove that the trinuclear palladium backbone of the precatalyst remains preserved during the first phase of the C-H activation reaction of acetanilides. In other words, the reaction pathway including the trinuclear species should be taken into account in discussion about mechanisms of the reactions catalyzed by palladium acetates...
November 15, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29138638/tissue-source-and-cell-expansion-condition-influence-phenotypic-changes-of-adipose-derived-stem-cells
#13
Lauren H Mangum, Shanmugasundaram Natesan, Randolph Stone, Nicole L Wrice, David A Larson, Kyle F Florell, Barbara A Christy, Maryanne C Herzig, Andrew P Cap, Robert J Christy
Stem cells derived from the subcutaneous adipose tissue of debrided burned skin represent an appealing source of adipose-derived stem cells (ASCs) for regenerative medicine. Traditional tissue culture uses fetal bovine serum (FBS), which complicates utilization of ASCs in human medicine. Human platelet lysate (hPL) is one potential xeno-free, alternative supplement for use in ASC culture. In this study, adipogenic and osteogenic differentiation in media supplemented with 10% FBS or 10% hPL was compared in human ASCs derived from abdominoplasty (HAP) or from adipose associated with debrided burned skin (BH)...
2017: Stem Cells International
https://www.readbyqxmd.com/read/29138421/mperiod2-brdm1-and-other-single-period-mutant-mice-have-normal-food-anticipatory-activity
#14
Julie S Pendergast, Robert H Wendroth, Rio C Stenner, Charles D Keil, Shin Yamazaki
Animals anticipate the timing of food availability via the food-entrainable oscillator (FEO). The anatomical location and timekeeping mechanism of the FEO are unknown. Several studies showed the circadian gene, Period 2, is critical for FEO timekeeping. However, other studies concluded that canonical circadian genes are not essential for FEO timekeeping. In this study, we re-examined the effects of the Per2 (Brdm1) mutation on food entrainment using methods that have revealed robust food anticipatory activity in other mutant lines...
November 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29138389/phage-display-and-selection-of-lanthipeptides-on-the-carboxy-terminus-of-the-gene-3-minor-coat-protein
#15
Johannes H Urban, Markus A Moosmeier, Tobias Aumüller, Marcus Thein, Tjibbe Bosma, Rick Rink, Katharina Groth, Moritz Zulley, Katja Siegers, Kathrin Tissot, Gert N Moll, Josef Prassler
Ribosomally synthesized and post-translationally modified peptides (RiPPs) are an emerging class of natural products with drug-like properties. To fully exploit the potential of RiPPs as peptide drug candidates, tools for their systematic engineering are required. Here we report the engineering of lanthipeptides, a subclass of RiPPs characterized by multiple thioether cycles that are enzymatically introduced in a regio- and stereospecific manner, by phage display. This was achieved by heterologous co-expression of linear lanthipeptide precursors fused to the widely neglected C-terminus of the bacteriophage M13 minor coat protein pIII, rather than the conventionally used N-terminus, along with the modifying enzymes from distantly related bacteria...
November 15, 2017: Nature Communications
https://www.readbyqxmd.com/read/29138257/clinical-juvenile-arthritis-disease-activity-score-proves-to-be-a-useful-tool-in-treat-to-target-therapy-in-juvenile-idiopathic-arthritis
#16
Joost F Swart, E H Pieter van Dijkhuizen, Nico M Wulffraat, Sytze de Roock
OBJECTIVES: To assess if the Juvenile Arthritis Disease Activity Score (JADAS71) could be used to correctly identify patients with juvenile idiopathic arthritis (JIA) in need of antitumour necrosis factor therapy (anti-TNF) therapy 3 and 6 months after start of methotrexate (MTX). METHODS: Monocentric retrospective cohort study from 2011 to 2015 analysing all patients with oligoarticular JIA (OJIA) (n=39) and polyarticular course JIA (PJIA) (n=74) first starting MTX...
November 14, 2017: Annals of the Rheumatic Diseases
https://www.readbyqxmd.com/read/29137993/characterization-of-cold-adapted-and-ethanol-tolerant-%C3%AE-glucosidase-from-bacillus-cellulosilyticus-and-its-application-for-directed-hydrolysis-of-cellobiose-to-ethanol
#17
Jian Wu, Alei Geng, Rongrong Xie, Hongcheng Wang, Jianzhong Sun
A β-glucosidase gene from Bacillus cellulosilyticus was expressed in Escherichia coli BL21 and characterized. The recombinant enzyme (BcBgl1A) showed the optimal activity at 40°C, and the half-life of BcBgl1A activity at 40 °C was 24 h. BcBgl1A was sensitive to heat and exhibited obvious cold-adapted activity, retained 27.2% and 46.5% of the optimal activity at 4 and 20°C, respectively. The best activity was observed at pH 7.0 and stable over the range of pH 6.0-8.0. The activity was significantly enhanced by Fe(2+), Fe(3+) and Mn(2+), also showed a high level of NaCl tolerance...
November 11, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/29137992/ir-spectroscopy-analysis-of-pancreatic-lipase-related-protein-2-interaction-with-phospholipids-3-monitoring-dppc-lipolysis-in-mixed-micelles
#18
Eduardo Mateos-Diaz, Priscila Sutto-Ortiz, Moulay Sahaka, Jorge A Rodriguez, Frédéric Carrière
Usual methods for the continuous assay of lipolytic enzyme activities are mainly based on the titration of free fatty acids, surface pressure monitoring or spectrophotometry using substrates labeled with specific probes. These approaches only give a partial information on the chemistry of the lipolysis reaction and additional end-point analyses are often required to quantify both residual substrate and lipolysis products. We used transmission infrared (IR) spectroscopy to monitor simultaneously the hydrolysis of phospholipids by guinea pig pancreatic lipase-related protein 2 (GPLRP2) and the release of lipolysis products...
November 11, 2017: Chemistry and Physics of Lipids
https://www.readbyqxmd.com/read/29137937/design-synthesis-and-evaluation-of-3-arylidene-azetidin-2-ones-as-potential-antifungal-agents-against-alternaria-solani-sorauer
#19
Wang Delong, Wu Yongling, Wang Lanying, Feng Juntao, Zhang Xing
A new concise and facile method was explored to synthesize a collection of new 3-arylidene azetidin-2-ones, which could be regarded as the derivatives of the hybrid scaffold of bioactive natural cinnamamide and heterocycle azetidi-2-one. The structures of the synthesized compounds were characterized by (1)H, (13)C NMR, and MS; and their antifungal activity were evaluated against Alternaria solani Sorauer. These antifungal data were subjected to a quantitative structure-activity relationship (QSAR) analysis using Codessa software on the basis of the results from B3LYP/6-31G(d,p) quantum calculations...
November 4, 2017: Bioorganic & Medicinal Chemistry
https://www.readbyqxmd.com/read/29137723/the-promise-and-problems-of-non-physician-practitioners-in-general-surgery-education-results-of-a-multi-center-mixed-methods-study-of-faculty
#20
James E Coverdill, Jeff Scott Shelton, Adnan Alseidi, David C Borgstrom, Daniel L Dent, Russell Dumire, Jonathan Fryer, Thomas H Hartranft, Steven B Holsten, M Timothy Nelson, Mohsen M Shabahang, Stanley R Sherman, Paula M Termuhlen, Randy J Woods, John D Mellinger
BACKGROUND: Nurse Practitioners and Physician Assistants - called non-physician practitioners or NPPs - are common, but little is known about their educational promise and problems. METHODS: General surgery faculty in 13 residency programs were surveyed (N = 279 with a 71% response rate) and interviewed (N = 43) about experiences with NPPs. The survey documents overall patterns and differences by program type and primary service; interviews point to deeper rationales and concerns...
November 5, 2017: American Journal of Surgery
keyword
keyword
105563
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"