keyword
MENU ▼
Read by QxMD icon Read
search

Free radical

keyword
https://www.readbyqxmd.com/read/28806069/oxidation-kinetics-of-bromophenols-by-nonradical-activation-of-peroxydisulfate-in-the-presence-of-carbon-nanotube-and-formation-of-brominated-polymeric-products
#1
Chao-Ting Guan, Jin Jiang, Cong-Wei Luo, Jun Ma, Su-Yan Pang, Yang Zhou, Yi Yang
This work demonstrated that bromophenols (BrPs) could be readily oxidized by peroxydisulfate (PDS) activated by a commercial carbon nanotube (CNT), while furfuryl alcohol (a chemical probe for singlet oxygen (1O2)) was quite refractory. Results obtained by radical quenching experiments, electron paramagnetic resonance spectroscopy, and Fourier transform infrared spectroscopy further confirmed the involvement of nonradical PDS-CNT complexes rather than 1O2. Bicarbonate and chloride ion exhibited negligible impacts on BrPs degradation by the PDS/CNT system, while a significant inhibitory effect was observed for natural organic matter...
August 14, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28806066/thiol-mediated-synthesis-of-hyaluronic-acid-epigallocatechin-3-o-gallate-conjugates-for-the-formation-of-injectable-hydrogels-with-free-radical-scavenging-property-and-degradation-resistance
#2
Chixuan Liu, Ki Hyun Bae, Atsushi Yamashita, Joo Eun Chung, Motoichi Kurisawa
Hyaluronic acid (HA)-based biomaterials have demonstrated only limited in vivo stability as a result of rapid degradation by hyaluronidase and reactive oxidative species. The green tea catechin, (-)-epigallocatechin-3-O-gallate (EGCG), has received considerable attention because of its powerful antioxidant and enzyme-inhibitory activities. We describe here the synthesis of HA-EGCG conjugate using a thiol-mediated reaction and its use for the preparation of a long-lasting injectable hydrogel. HA-EGCG conjugates with tunable degrees of substitution were synthesized by the nucleophilic addition reaction between EGCG quinone and thiolated HA under mild conditions...
August 14, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28805673/alk-status-assessment-with-liquid-biopsies-of-lung-cancer-patients
#3
REVIEW
Paul Hofman
Patients with advanced stage non-small cell lung carcinoma (NSCLC) harboring an anaplastic lymphoma kinase ALK gene rearrangement, detected from a tissue sample, can benefit from targeted ALK inhibitor treatment. However, while treatment is initially effective in most cases, relapse or progression occurs due to different resistance mechanisms including mutations in the tyrosine kinase domain of echinoderm microtubule-associated protein-like 4 (EML44)-ALK. The liquid biopsy concept has recently radically changed the clinical care of NSCLC patients, in particular for those harboring an epidermal growth factor receptor (EGFR) gene mutation...
August 12, 2017: Cancers
https://www.readbyqxmd.com/read/28805669/effect-of-mediterranean-diet-and-antioxidant-formulation-in-non-alcoholic-fatty-liver-disease-a-randomized-study
#4
Ludovico Abenavoli, Marta Greco, Natasa Milic, Francesca Accattato, Daniela Foti, Elio Gulletta, Francesco Luzza
Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, characterized by liver fatty acid accumulation and fibrosis, not due to excessive alcohol consumption. Notably, nutritional habits have been reported to be implicated in the onset and severity of the hepatic damage, while the Mediterranean diet has shown beneficial effects on NAFLD. Free radicals and oxidative stress were suggested to be involved in the pathogenesis and progression of NAFLD, and several data highlighted the efficacy of antioxidant supplementation in its treatment...
August 12, 2017: Nutrients
https://www.readbyqxmd.com/read/28805383/cu-ii-catalyzed-ortho-selective-aminomethylation-of-phenols
#5
Jin-Ling Dai, Nan-Qi Shao, Jin Zhang, Run-Ping Jia, Dong-Hui Wang
A Cu(II)-catalyzed ortho-selective functionalization of free phenols with trifluoroborates to afford Csp2-Csp3 coupling products under mild conditions has been developed. A variety of functional groups on the phenol and the potassium ami-nomethyltrifluoroborate substrates were found compatible, fur-nishing the corresponding products in moderate to excellent yields. A single-electron transfer radical coupling mechanism involving a six-membered transition state is proposed to rationalize the high levels of ortho-selectivity in the reaction...
August 14, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28805054/a-scalable-field-study-protocol-and-rationale-for-passive-ambient-air-sampling-a-spatial-phytosampling-for-leaf-data-collection
#6
Tonny J Oyana, Slawomir M Lomnicki, Chuqi Guo, Stephania A Cormier
Stable, bioreactive, radicals known as environmentally persistent free radicals (EPFRs) have been found to exist on the surface of airborne PM2.5. These EPFRs have been found to form during many combustion processes, are present in vehicular exhaust, and persist in the environment for weeks and biological systems for up to 12 hours. To measure EPFRs in PM samples, high volume samplers are required and measurements are less representative of community exposure; therefore, we developed a novel spatial phytosampling methodology to study the spatial patterns of EPFR concentrations using plants...
August 14, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28805047/outcomes-of-post-prostatectomy-radiotherapy-at-a-regional-cancer-centre
#7
Luke Nicholls, Amber Winter, Ashley Harwood, Ashley Plank, Preeti Bagga, Winnie Wong, Eric Khoo
INTRODUCTION: To investigate the efficacy and toxicity of radiation therapy (RT) after radical prostatectomy (RP) for prostate cancer at Radiation Oncology Centres, Toowoomba. METHODS: The electronic medical records of 130 consecutive patients with histologically proven prostate adenocarcinoma who underwent post-prostatectomy RT between January 2008 and December 2014 were analysed. Primary endpoint was Biochemical Recurrence (BCR) after RT. BCR was defined by PSA > 0...
August 14, 2017: Journal of Medical Radiation Sciences
https://www.readbyqxmd.com/read/28804604/why-whey-camel-whey-protein-as-a-new-dietary-approach-to-the-management-of-free-radicals-and-for-the-treatment-of-different-health-disorders
#8
REVIEW
Gamal Badr, Nancy K Ramadan, Leila H Sayed, Badr M Badr, Hossam M Omar, Zeliha Selamoglu
The balance between free radicals and antioxidants is an important factor for maintaining health and slowing disease progression. The use of antioxidants, particularly natural antioxidants, has become an important strategy for dealing with this cause of widespread diseases. Natural antioxidants have been used as therapeutic tools against many diseases because they are safe, effective, and inexpensive and are among the most commonly used adjuvants in the treatment of several diseases. Camel whey protein (CWP) is considered a strong natural antioxidant because it decreases oxidative stress, enhances immune system function, and increases glutathione levels...
April 2017: Iranian Journal of Basic Medical Sciences
https://www.readbyqxmd.com/read/28803791/squamous-differentiation-predicts-poor-response-to-cisplatin-based-chemotherapy-and-unfavorable-prognosis-in-urothelial-carcinoma-of-the-urinary-bladder
#9
Akinori Minato, Naohiro Fujimoto, Tatsuhiko Kubo
OBJECTIVE: The efficacy of chemotherapy on UCSD is not known. This study was conducted to investigate the efficacy of cisplatin-based chemotherapy and prognosis of patients with UC with or without SD of the bladder. METHODS: Patients with invasive bladder cancer (clinical T3-4aN0M0) who were treated between March 2003 and March 2015 with 2 or 3 cycles of neoadjuvant chemotherapy followed by radical cystectomy were retrospectively evaluated. Treatment outcomes were compared for each pathologic type in UCSD and pure UC...
July 22, 2017: Clinical Genitourinary Cancer
https://www.readbyqxmd.com/read/28803516/well-defined-protein-immobilization-on-photo-responsive-phosphorylcholine-polymer-surfaces
#10
Masako Tanaka, Shugo Kawai, Yasuhiko Iwasaki
In this study, we propose a new polymer substrate that is able to covalently couple intended proteins and reduce nonspecific protein fouling. Poly[2-methacryloyloxyethyl phosphorylcholine (MPC)-ran-N-methacryloyl-(L)-tyrosinemethylester (MAT)] [P(MPC/MAT)] was synthesized by free-radical polymerization. The photooxidation of the MAT unit in the copolymer was observed under ultraviolet (UV) light at 254 nm. P(MPC/MAT) was spin-coated on silicon (Si) and gold substrates. Without UV irradiation of the polymer-coated surface, P(MPC/MAT) physisorbed on the substrates, and the thickness of the polymer layer was less than 10 nm, regardless of the polymer concentration in the coating solution...
August 14, 2017: Journal of Biomaterials Science. Polymer Edition
https://www.readbyqxmd.com/read/28803365/energy-drinks-and-their-component-modulate-attention-memory-and-antioxidant-defences-in-rats
#11
M T Costa Valle, N S Couto-Pereira, C Lampert, D M Arcego, A P Toniazzo, R P Limberger, E Dallegrave, C Dalmaz, M D Arbo, M B Leal
PURPOSE: This study aimed to evaluate the effects of the subchronic consumption of energy drinks and their constituents (caffeine and taurine) in male Wistar rats using behavioural and oxidative measures. METHODS: Energy drinks (ED 5, 7.5, and 10 mL/kg) or their constituents, caffeine (3.2 mg/kg) and taurine (40 mg/kg), either separately or in combination, were administered orally to animals for 28 days. Attention was measured though the ox-maze apparatus and the object recognition memory test...
August 12, 2017: European Journal of Nutrition
https://www.readbyqxmd.com/read/28803127/direct-antioxidant-properties-of-methotrexate-inhibition-of-malondialdehyde-acetaldehyde-protein-adduct-formation-and-superoxide-scavenging
#12
Matthew C Zimmerman, Dahn L Clemens, Michael J Duryee, Cleofes Sarmiento, Andrew Chiou, Carlos D Hunter, Jun Tian, Lynell W Klassen, James R O'Dell, Geoffrey M Thiele, Ted R Mikuls, Daniel R Anderson
Methotrexate (MTX) is an immunosuppressant commonly used for the treatment of autoimmune diseases. Recent observations have shown that patients treated with MTX also exhibit a reduced risk for the development of cardiovascular disease (CVD). Although MTX reduces systemic inflammation and tissue damage, the mechanisms by which MTX exerts these beneficial effects are not entirely known. We have previously demonstrated that protein adducts formed by the interaction of malondialdehyde (MDA) and acetaldehyde (AA), known as MAA-protein adducts, are present in diseased tissues of individuals with rheumatoid arthritis (RA) or CVD...
August 2, 2017: Redox Biology
https://www.readbyqxmd.com/read/28802888/predictors-for-intravesical-recurrence-following-radical-nephroureterectomy-for-upper-tract-urothelial-carcinoma-a-national-multicenter-analysis
#13
Chan Ho Lee, Ja Yoon Ku, Chang Wook Jeong, Ja Hyeon Ku, Cheol Kwak, Hyeon Hoe Kim, Bum Sik Tae, Seock Hwan Choi, Hyun Tae Kim, Tae-Hwan Kim, Tae Gyun Kwon, Eu Chang Hwang, Seung Il Jung, Taek Won Kang, Dong Deuk Kwon, Hong Koo Ha
INTRODUCTION: The purpose of this study was to identify the prognostic impact of intravesical recurrence (IVR) on oncologic outcomes and the clinicopathologic factors that predict IVR in patients who undergo radical nephroureterectomy (RNU) for upper tract urothelial carcinoma. PATIENTS AND METHODS: Between January 2000 and December 2015, 760 patients with upper tract urothelial carcinoma underwent RNU at 5 institutions in Korea, and patient data were retrospectively collected...
July 22, 2017: Clinical Genitourinary Cancer
https://www.readbyqxmd.com/read/28802887/clinical-outcomes-of-patients-with-t1-nested-variant-of-urothelial-carcinoma-compared-to-pure-urothelial-carcinoma-of-the-bladder
#14
Abhijith D Mally, Amy L Tin, Justin K Lee, Prassannah Satasivam, Eugene K Cha, S Michele Donat, Harry W Herr, Bernard H Bochner, Daniel D Sjoberg, Guido Dalbagni
PURPOSE: Evaluate oncologic outcomes of patients with cT1 nested variant (NV) of urothelial carcinoma (UC) and compare with cases of pure UC of the bladder. MATERIALS AND METHODS: We retrospectively identified 30 patients with NV who, between 1997 and 2012, underwent transurethral resection with T1 tumor stage, followed by restaging transurethral resection within 3 months confirming non-muscle-invasive disease. Radical cystectomy within 3 months of restaging transurethral resection was considered "early" treatment...
July 14, 2017: Clinical Genitourinary Cancer
https://www.readbyqxmd.com/read/28802408/down-regulation-of-malate-synthase-in-mycobacterium-tuberculosis-h37ra-leads-to-reduced-stress-tolerance-persistence-and-survival-in-macrophages
#15
Kumar Sachin Singh, Rishabh Sharma, Deepa Keshari, Nirbhay Singh, Sudheer Kumar Singh
Malate synthase is a condensing enzyme responsible for conversion of glyoxylate to malate in the presence of acetyl-CoA. This reaction helps in bypassing the TCA cycle reactions involving carbon loss and leads to diverting some of the carbon skeletons to gluconeogenic events while rest can continue to provide TCA cycle intermediates. Malate synthase (GlcB) is encoded by MRA_1848 of Mycobacterium tuberculosis H37Ra (Mtb-Ra). We developed a knockdown (KD) Mtb-Ra strain by down-regulating GlcB. The survival studies suggested increased susceptibility to oxidative and nitrosative stress as well as to rifampicin...
September 2017: Tuberculosis
https://www.readbyqxmd.com/read/28802232/the-activity-of-hou-po-da-huang-tang-is-improved-through-intestinal-bacterial-metabolism-and-hou-po-da-huang-tang-selectively-stimulate-the-growth-of-intestinal-bacteria-associated-with-health
#16
Xing-Yan Liu, Huai-You Wang, Xue-Qing Li, Juan-Juan Wu, Bo-Yang Yu, Ji-Hua Liu
Hou-Po-Da-Huang Tang (HPDHT) was used for the treatment of intestinal tract diseases in China. However, the underlying mechanisms via the intestinal bacteria remain largely unclear. Therefore, the aim of this study was to evaluate the metabolism of HPDHT by the human intestinal bacteria and its modulating effect on the intestinal bacteria. As a result, a total of 34 compounds were identified in HPDHT and transformed HPDHT (T-HPDHT). Among them, 12 metabolites were proved to be transformed by human intestinal bacteria...
August 9, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
https://www.readbyqxmd.com/read/28802019/effects-of-ultrasound-treatment-on-physicochemical-functional-properties-and-antioxidant-activity-of-whey-protein-isolate-in-the-presence-of-calcium-lactate
#17
Zhanmei Jiang, Kun Yao, Xiangying Yuan, Zhishen Mu, Zengli Gao, Juncai Hou, Lianzhou Jiang
BACKGROUND: The aim of this study was to investigate the effects of ultrasound applied at various powers (0, 200, 400, 600 or 800 W) and for different times (20 or 40 min) on the physicochemical, functional properties and antioxidant activities of whey protein isolate (WPI) dispersions in the presence of 1.20 mmol L(-1) calcium lactate. RESULTS: Surface hydrophobicity and free sulfhydryl group of the WPI dispersions containing 1.2 mmol L(-1) calcium lactate were significantly enhanced after sonication...
August 12, 2017: Journal of the Science of Food and Agriculture
https://www.readbyqxmd.com/read/28800540/rapid-extraction-of-amomum-tsao-ko-essential-oil-and-determination-of-its-chemical-composition-antioxidant-and-antimicrobial-activities
#18
Qi Cui, Li-Tao Wang, Ju-Zhao Liu, Hui-Mei Wang, Na Guo, Cheng-Bo Gu, Yu-Jie Fu
A simple, green and efficient extraction method named modified-solvent free microwave extraction (M-SFME) was employed for the extraction of essential oils (EOs) from Amomun tsao-ko. The process of M-SFME was optimized with the prominent preponderance of such higher extraction yield (1.13%) than those of solvent free microwave extraction (SFME, 0.91%) and hydrodistillation (HD, 0.84%) under the optimal parameters. Thirty-four volatile substances representing 95.4% were identified. The IC50 values of EOs determined by DPPH radical scavenging activity and β-carotene/linoleic acid bleaching assay were 5...
August 3, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28800457/fucosylated-chondroitin-sulfate-oligosaccharides-exert-anticoagulant-activity-by-targeting-at-intrinsic-tenase-complex-with-low-fxii-activation-importance-of-sulfation-pattern-and-molecular-size
#19
Junhui Li, Shan Li, Lufeng Yan, Tian Ding, Robert J Linhardt, Yanlei Yu, Xinyue Liu, Donghong Liu, Xingqian Ye, Shiguo Chen
Fucosylated chondroitin sulfates (fCSs) are structurally unusual glycosaminoglycans isolated from sea cucumbers that exhibit potent anticoagulant activity. These fCSs were isolated from sea cucumber, Isostichopus badionotus and Pearsonothuria graeffei. Fenton reaction followed by gel filtration chromatography afforded fCS oligosaccharides, with different sulfation patterns identified by mass and NMR spectroscopy, and these were used to clarify the relationship between the structures and the anticoagulant activities of fCSs...
July 28, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28800072/phosphate-linked-silibinin-dimers-plsd-new-promising-modified-metabolites
#20
Valeria Romanucci, Raffaele Gravante, Martina Cimafonte, Cinzia Di Marino, Gilles Mailhot, Marcello Brigante, Armando Zarrelli, Giovanni Di Fabio
By exploiting the regioselective protection of the hydroxyl groups of silibinin along with the well-known phosphoramidite chemistry, we have developed an efficient strategy for the synthesis of new silibinin-modified species, which we have named Phosphate-Linked Silibinin Dimers (PLSd), in which the monomer units are linked by phosphodiester bonds. The antioxidant abilities of the new PLSd were estimated on HepG2 cells using DPPH free radical scavenging and xanthine/xanthine oxidase assays. The new phosphate-metabolites showed a higher anti-oxidant activity than the silibinin, as well as very low toxicity...
August 11, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
keyword
keyword
6574
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"