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Harry B Gray, Jay R Winkler
Prior to 1950, the consensus was that biological transformations occurred in two-electron steps, thereby avoiding the generation of free radicals. Dramatic advances in spectroscopy, biochemistry, and molecular biology have led to the realization that protein-based radicals participate in a vast array of vital biological mechanisms. Redox processes involving high-potential intermediates formed in reactions with O2 are particularly susceptible to radical formation. Clusters of tyrosine (Tyr) and tryptophan (Trp) residues have been found in many O2-reactive enzymes, raising the possibility that they play an antioxidant protective role...
October 2016: Israel Journal of Chemistry
Siyuan Zhai, Yinxin Zhao, Min Ji, Wenfang Qi
A spiral fiber based biofilm reactor was developed to remove nitrate and chromate simultaneously. The denitrification and Cr(VI) removal efficiency was evaluated with synthetic groundwater (NO3(-)-N=50mg/L) under different Cr(VI) concentrations (0-1.0mg/L), carbon nitrogen ratios (C/N) (0.8-1.2), hydraulic retention times (HRT) (2-16h) and initial pHs (4-10). Nitrate and Cr(VI) were completely removed without nitrite accumulation when the Cr(VI) concentration was lower than 0.4mg/L. As Cr(VI) up to 1.0mg/L, the system was obviously inhibited, but it recovered rapidly within 6days due to the strong adaption and domestication of microorganisms in the biofilm reactor...
February 11, 2017: Bioresource Technology
Jaideep Honavar, Stephen Doran, Karina Ricart, Sadis Matalon, Rakesh P Patel
Chlorine (Cl2) gas exposure and toxicity remains a concern in military and industrial sectors. While post-Cl2 exposure damage to the lungs and other tissues has been documented and major underlying mechanisms elucidated, no targeted therapeutics that are effective when administered post-exposure, and which are amenable to mass-casualty scenarios have been developed. Our recent studies show nitrite administered by intramuscular (IM) injection post-Cl2 exposure is effective in preventing acute lung injury and improving survival in rodent models...
February 22, 2017: Toxicology Letters
Xianliang Luo, Qi Wang, Baodong Zheng, Liangmei Lin, Bingyan Chen, Yafeng Zheng, Jianbo Xiao
In the bamboo shoot processing industries, bamboo shoot shells are discarded without any utilization. As a cheap potential dietary fibers resource, bamboo shoot (Leleba oldhami Nakal) shell was decomposed to dietary fibers by multiple enzymes. The extraction yields of insoluble dietary fiber and soluble dietary fiber were 56.21% and 8.67%, respectively. The resulting fibers showed significant swelling capacity, water holding capacity and exhibit in vitro binding capacities to fat, cholesterol, bile acids and nitrites...
February 22, 2017: Food and Chemical Toxicology
Qianyu Hang, Haiyan Wang, Zhaosheng Chu, Zeying Hou, Yuexi Zhou, Chunmei Li
Vallisneria-sulfur based mixotrophic denitrification (VSMD) process was put forward for the treatment of nitrate-rich agricultural runoff with low COD/TN (C/N) ratio in free water surface constructed wetland mesocosms, whose feasibility and mechanism were thoroughly studied through 273-day operation. The results showed that the average NO3(-)-N removal efficiency and denitrification rate of VSMD mesocosms were 97.7% and 1.5gNO3(-)-Nm(-3)d(-1) under 5.0 or higher C/N ratio conditions in phase II (7-117d), which were similar with those of Vallisneria packed heterotrophic denitrification (VHD) mesocosms...
February 23, 2017: Science of the Total Environment
Chongjun Chen, Weijing Zhu, Xiaoxiao Huang, Tian C Zhang, Weixiang Wu, Faqian Sun
  Effects of hydraulic retention time (HRT) and nitrogen loading rate (NLR) on performance of anammox UASBs amended with spherical plastic and bamboo charcoal carriers were investigated. During the experimental period, the performance of reactors was continuously evaluated by monitoring ammonium-N, nitrite-N, and nitrate-N at HRT of 48, 36, 24, and 12 hours. With HRTs between 24 and 48 hours, the ammonium-N and nitrite-N removal efficiency was higher than 99%, while the total nitrogen (TN) removal efficiency was almost higher than 90%...
January 1, 2017: Water Environment Research: a Research Publication of the Water Environment Federation
Bo Liu, Rui-Ming Han, Wen-Lin Wang, Hong Yao, Feng Zhou
To reveal the detailed vertical oxygen distribution at the sediment-water interface (SWI) and its relation with the oxygen consumption processes during and after aeration of polluted urban rivers, experimental systems constructed with collected sediment and in situ overlying water from a polluted urban river were aerated above or beneath the sediment-water interface 12 h a day for 15 days and left nonaerated for the following 10 days. The results showed that aeration of water or sediment both increased dissolved oxygen (DO) concentrations in the SWI, characterized by shifts in a "decrease-increase-decrease" manner during around 3 h for the aeration of water treatment (AW) and 6 h for the aeration of sediment treatment (AS)...
February 24, 2017: Environmental Science and Pollution Research International
Yasmin Chebaro, Michael Lorenz, Alice Fa, Rui Zheng, Michael Gustin
Candida albicans is an opportunistic fungal pathogen that is highly resistant to different oxidative stresses. How reactive sulfur species (RSS) such as sulfite regulate gene expression and the role of the transcription factor Zcf2 and the sulfite exporter Ssu1 in such responses is not known. Here, we show that C. albicans specifically adapts to sulfite stress and that Zcf2 is required for that response as well as induction of genes predicted to remove sulfite from cells and to increase the intracellular amount of a subset of nitrogen metabolites...
February 24, 2017: Genetics
Tipparat Parakaw, Kran Suknuntha, Pornpun Vivithanaporn, Axel Schlagenhauf, Supachai Topanurak, Suthat Fucharoen, Kovit Pattanapanyasat, Alan Schechter, Nathawut Sibmooh, Sirada Srihirun
In the presence of red blood cells (RBCs), nitrite inhibits platelets through its conversion to nitric oxide (NO) by the reductase activity of partially deoxygenated hemoglobin. Inhaled sodium nitrite is being investigated as a therapy for pulmonary hypertension. Here, we measured platelet aggregation, P-selectin expression, platelet-leukocyte aggregates and phosphorylated vasodilator-stimulated phosphoprotein (P-VASP(Ser239)) following sodium nitrite inhalation in healthy subjects. In vitro incubation of nitrite with deoxygenated whole blood showed an increase in P-VASP(Ser239), which was inhibited by ODQ, a soluble guanylyl cyclase (sGC) inhibitor...
February 21, 2017: Nitric Oxide: Biology and Chemistry
Alexandre Lamas, José Manuel Miranda, Beatriz Vázquez, Alberto Cepeda, Carlos Manuel Franco
In recent years, the use of nitrites and sulfites as food preservatives has been a cause for concern due to the health problems that these additives can cause in humans. Natural products have been studied as an alternative, but most of them have hardly been applied in the food industry for technological and economic reasons. In this sense, organic salts such as sodium acetate are a good alternative due to their affordability. Thus, this study evaluated the capacity of sodium nitrite, sodium sulfite, a sodium acetate product (TQI C-6000), and chitosan to inhibit two important foodborne pathogens, Salmonella enterica and Listeria monocytogenes...
October 31, 2016: Foods (Basel, Switzerland)
Giovanni Parolari, Agnese Aguzzoni, Tania Toscani
Dry cured hams were investigated for their ability to develop red color even at low temperature (3-4 °C) and in the absence of added nitrites; results were compared with those obtained from nitrite-free hams made at conventional warm maturing temperatures. Colorimetric parameters (L*, a*, b*, and hue) and concentration of the main pigments Zn protoporphyrin IX (ZnPP) and heme were measured at three stages of preparation (six, nine, and 12 months), showing that red color was successfully formed at low temperatures, though at a slower rate and less intensively than under warm conditions...
April 29, 2016: Foods (Basel, Switzerland)
Nouf M Al-Rasheed, Laila Fadda, Hala A Attia, Iman A Sharaf, Azza M Mohamed, Nawal M Al-Rasheed
The study aims to compare, through histological and biochemical studies, the effects of quercetin, melatonin and their combination in regulation of immuno-inflammatory mediators and heat shock protein expressions in sodium nitrite induced hypoxia in rat lungs. The results revealed that NaNO2 injection caused a significant decrease in Hb in rats, while serum levels of TNF-α, IL-6 and CRP, VEGF and HSP70 were elevated compared to the control group. Administration of melatonin, quercetin or their combination before NaNO2 injection markedly reduced these parameters...
March 1, 2017: Acta Pharmaceutica
M Stojanovic, V Zivkovic, I Srejovic, V Jakovljevic, N Jeremic, D Djuric
This study aimed to assess the role of H2S in homocysteine-induced cardiodynamic effects in the isolated rat heart. The hearts were retrogradely perfused according to the Langendorff technique. The maximum and minimum rates of pressure in the left ventricle (dp/dt max, dp/dt min), systolic and diastolic left ventricular pressures (SLVP, DLVP), heart rate (HR), and coronary flow (CF) were measured. A spectrophotometrical method was used to measure the following oxidative stress markers: index of lipid peroxidation (thiobarbituric acid reactive substances, TBARS), nitrite level (NO2(-)), superoxide anion radicals (O2(•-)), and hydrogen peroxide (H2O2) concentrations...
December 2016: Physiol Int
Junhong Fan, Shawpong Wan, Luhao Liu, Zhijian Zhao, Zanlin Mai, Dong Chen, Wei Zhu, Zhou Yang, Lili Ou, Wenqi Wu
To identify risk factors that can predict which patient is likely to progress from systemic inflammatory response syndrome (SIRS) to uroseptic shock after minimally invasive percutaneous nephrolithotomy (MPCNL) for the upper urinary tract stones. We retrospectively reviewed 156 patients who suffered infectious complications after MPCNL from March 2014 to February 2016. Perioperative risk factors that could potentially contribute to uroseptic shock were compared to those of patients with only SIRS. 135 of the 156 patients developed to SIRS only, the remaining 21 patients progressed to uroseptic shock...
February 22, 2017: Urolithiasis
Meryem Temiz-Resitoglu, Sefika Pinar Kucukkavruk, Demet Sinem Guden, Pelin Cecen, Ayse Nihal Sari, Bahar Tunctan, Aysegul Gorur, Lulufer Tamer-Gumus, Cuneyt Kemal Buharalioglu, Kafait U Malik, Seyhan Sahan-Firat
Mammalian target of rapamycin (mTOR), a serine/threonine kinase plays an important role in various pathophysiological processes including cancer, metabolic diseases, and inflammation. Although mTOR participates in Toll-like receptor 4 signalling in different cell types, the role of this enzyme in sepsis pathogenesis and its effects on hypotension and inflammation in endotoxemic rats remains unclear. In this study we investigated the effects of mTOR inhibition on lipopolysaccharide (LPS)-induced changes on expressions and/or activities of ribosomal protein S6 (rpS6), an mTOR substrate, nuclear factor-κB (NF-κB) p65, inhibitor κB (IκB)-α, inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 with production of nitric oxide, peroxynitrite, prostacyclin, and tumor necrosis factor (TNF)-α and activity of myeloperoxidase (MPO), which results in hypotension and inflammation...
February 20, 2017: European Journal of Pharmacology
Camila Michels, Simone Perazzoli, Hugo M Soares
Metal and metal oxide nanoparticles are getting attention over the past years. They can be used to several purposes, especially in commercial and medical applications. Undoubtedly, this lead to higher production and, consequently, increasing the risks of exposition, once they can be released into environment without a proper control. However, their impact over the bacteria present in wastewater treatment plants (WWTP), manly over nitrifying bacteria, which are the most susceptible to toxic compounds, are still not very well established...
February 19, 2017: Science of the Total Environment
W Yu, W Seo, T Tan, B Jung, B Ziaie, W Yu, W Seo, T Tan, B Jung, B Ziaie, B Ziaie, W Seo, W Yu, T Tan, B Jung
This paper reports a low-cost solution to the early detection of urinary nitrite, a common surrogate for urinary tract infection (UTI). We present a facile method to fabricate a disposable and flexible colorimetric [1] nitrite sensor and its urine-activated power source [2] on a hydrophobic (wax) paper through laser-assisted patterning and lamination. Such device, integrated with interface circuitry and a Bluetooth low energy (BLE) module can be embedded onto a diaper, and transmit semi-quantitative UTI monitoring information in a point-of-care and autonomous fashion...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Sylvia C Schaefer, James T Hollibaugh
Nitrification is a two-step process linking the reduced and oxidized sides of the nitrogen cycle. These steps are typically tightly coupled with the primary intermediate, nitrite, rarely accumulating in coastal environments. Nitrite concentrations can exceed 10 µM during summer in estuarine waters adjacent to Sapelo Island, Georgia, USA. Similar peaks at other locations have been attributed to decoupling of the two steps of nitrification by hypoxia; however, the waters around Sapelo Island are aerobic and well-mixed...
February 22, 2017: Environmental Science & Technology
Esraa M Zakaria, Nabila N El-Maraghy, Ahmed F Ahmed, Abdelmonim A Ali, Hany M El-Bassossy
Poly(ADP-ribose) polymerase (PARP) enzyme contributes to nephropathy, a serious diabetic complication which may lead to end-stage renal disease. The study aims to investigate the effect of PARP over-activation on kidney functions in a type 2 diabetic rat model. The study also tests the therapeutic use of PARP inhibitors in diabetic nephropathy. Type 2 diabetes was induced in adult male rats by high-fructose/high-fat diet and low streptozotocin dose. Then, the PARP inhibitor 4-aminobenzamide (4-AB) was administered daily for 10 weeks...
February 21, 2017: Naunyn-Schmiedeberg's Archives of Pharmacology
Song Yao, Liping Chen, Detian Guan, Zhongguo Zhang, Xiujun Tian, Aimin Wang, Guotian Wang, Qian Yao, Dangcong Peng, Jiuyi Li
Source separation and treatment of human urine have been recognized as a resource-efficient alternative to conventional urban drainage, not only reducing nutrient loads on municipal wastewater treatment plants, but recovering valuable resources from waste streams. In this work, on-site phosphorus (P) recovery from real urine was carried out by using the brine from a reverse osmosis process as the flush water for urine-diverting toilets and a P precipitant, while nitrogen (N) was removed via short-cut nitrification-denitrification (SCND) in a membrane bioreactor (MBR)...
February 16, 2017: Chemosphere
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