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Environmental Monitoring and Assessment – Normal Response Models
Published in Song S. Qian, Mark R. DuFour, Ibrahim Alameddine, Bayesian Applications in Environmental and Ecological Studies with R and Stan, 2023
Song S. Qian, Mark R. DuFour, Ibrahim Alameddine
The study was designed to understand the effects of hypoxia on the benthic infauna community. Data were derived from sediment core samples taken in 15 locations over an approximately 5,000 km2 area off the central coast of Louisiana near Terrebonne Bay from August 2–12, 2003. Five of these sampling sites were located within the hypoxic zone about 10 km from the nearest coast, four were located immediately to the north of the hypoxic zone (toward the Louisiana coastline, inshore sites), and six were located to the south of the hypoxic zone (away from the Louisiana coastline, offshore sites). Each sediment core sample was divided into three parts for analysis of benthic macroinvertebrate species composition, which was then used to derive species abundance (total number of individuals per square meter) and species richness (total number of species), the two response variables of interest. The average dissolved oxygen concentration in the hypoxic zone was mg/L, substantially lower than the dissolved oxygen concentration outside the zone (3–5 mg/L) [Baustian et al., 2009].
What Do the Heart Arteries Do When They Are Damaged? The Infinite Insults and Finite Responses in CHD
Published in Mark C Houston, The Truth About Heart Disease, 2023
In conclusion, oxidative stress is an imbalance of radical oxygen species (ROS) and radical nitrogen species (RNS) (the bad guys) with a decrease in antioxidant defenses (the good guys) that contributes to CHD and MI in humans based on genetics and environment. Oxidative stress is like having too much fire in the arteries but no fire extinguishers to put out the fire, i.e., not having enough antioxidants. The oxidative stress will damage cells to the point that they do not function or they die. If this happens in the coronary arteries, the result is CHD or MI. It is important to balance the oxidative stress and the oxidative defense. The predominant ROS produced by cells is called superoxide anion and is part of our normal metabolism with oxygen and the breakdown of our food to make energy or ATP. In addition, the superoxide anion reduces nitric oxide and produces other downstream ROS and RNS, which leads to endothelial and glycocalyx dysfunction and CHD. Our antioxidant defense is supplied by various compounds (enzymes) that will break down the ROS and also by the intake of vitamins, minerals, and antioxidants in our diet or in supplements.
Approaches for Identification and Validation of Antimicrobial Compounds of Plant Origin: A Long Way from the Field to the Market
Published in Mahendra Rai, Chistiane M. Feitosa, Eco-Friendly Biobased Products Used in Microbial Diseases, 2022
Lívia Maria Batista Vilela, Carlos André dos Santos-Silva, Ricardo Salas Roldan-Filho, Pollyanna Michelle da Silva, Marx de Oliveira Lima, José Rafael da Silva Araújo, Wilson Dias de Oliveira, Suyane de Deus e Melo, Madson Allan de Luna Aragão, Thiago Henrique Napoleão, Patrícia Maria Guedes Paiva, Ana Christina Brasileiro-Vidal, Ana Maria Benko-Iseppon
The microdilution test is performed on flat-bottomed 96-well microtiter plates and each row of a microplate corresponds to a line. Successive dilutions (1:1) of the antimicrobial agent are performed in the culture medium. Then the same volume of inoculum is added. A well corresponding to 100% growth is prepared without the presence of the antimicrobial agent and a sterility control that has the culture medium and the antimicrobial agent. Then the plates should be incubated in the same conditions as described for the macrodilution test. Dissolved Oxygen (DO) should be measured at the beginning (zero time) and the end of the test using a microplate reader. The IMC will be determined as the lowest concentration of the sample capable of promoting a certain minimum value of OD reduction compared to the growth control. This value can be 50 or 90%, for example.
SARS-CoV-2 RT-qPCR Ct values in saliva and nasopharyngeal swab samples for disease severity prediction
Published in Journal of Oral Microbiology, 2023
Kristina Snipaitiene, Birute Zablockiene, Rasa Sabaliauskaite, Kristina Zukauskaite, Elzbieta Matulyte, Tautvile Smalinskaite, Mindaugas Paulauskas, Rolandas Zablockis, Mantvydas Lopeta, Julius Gagilas, Alina Puriene, Ligita Jancoriene, Sonata Jarmalaite
The bioethics approval was obtained by the Regional Bioethics Committee (No. 2020/7-N4˗1245˗725), and the study was conducted following the Declaration of Helsinki. The informed consent forms were gained from all the participants before the beginning of the study. The SARS-CoV-2 infection was confirmed by RT-qPCR from NPS before the hospitalization at VUHSK. According to the disease severity, patients were dichotomized into two cohorts: mild and moderate disease cases (N = 47, Cohort I) and severe disease cases (N = 53, Cohort II). The patients were divided into groups dependent on the disease severity according to the National Institutes of Health guidelines [16], which briefly define the severe cases as individuals having an oxygen saturation measured by pulse oximetry on room air at sea level (SpO2) <94%, a ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (PaO2/FiO2) <300 mm Hg, and a respiratory rate >30 breaths/min, or lung infiltrates >50%; moderate – SpO2≥94% and evidence of lower respiratory disease during clinical assessment or imaging; mild – any of the various signs and symptoms of COVID-19 (e.g. fever, cough, sore throat, malaise, headache, muscle pain, nausea, vomiting, diarrhoea, loss of taste and smell) but do not have shortness of breath, dyspnoea, or abnormal chest imaging.
Dexmedetomidine enables copper homeostasis in cerebral ischemia/reperfusion via ferredoxin 1
Published in Annals of Medicine, 2023
Qingduo Guo, Meina Ma, Hong Yu, Yuepeng Han, Dong Zhang
Isolation of mitochondria was performed using a tissue mitochondrial isolation kit (Beyotime, Shanghai, China). Fresh brain tissue was homogenized in mitochondrial isolation reagent and centrifuged at 600 × g, 4 °C for 5 min. The obtained supernatant was centrifuged at 11,000 × g, 4° C for 10 min, and the precipitate was the mitochondria, which was then resuspended in storage buffer. Clark electrode instrument was applied to measure dissolved oxygen solubility in a 25 °C water bath. Fresh mitochondria were placed in the chamber until the rate of oxygen consumption stabilized. Supplementation with succinate to test low oxygen consumption rate (R IV) followed by ADP to stimulate high oxygen consumption rate (R III). RCR (R III/R IV) may indicate the mitochondrial capacity for oxidative phosphorylation.
In vitro model to compare the oxygen offloading behaviour of dodecafluoropentane emulsion (DDFPe)
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Meghna S. Jayaraman, Kaitlin Graham, Evan C. Unger
Sodium chloride and sodium sulphite were purchased from Sigma Aldrich (St. Louis, MO) while water (18MΩ·cm) from an in-house purification system was used as the diluent. Dissolved oxygen measurements were obtained using an Oakton DO110 meter. Silastic tubing (1.47 mm I.D. × 1.96 mm O.D.) was purchased from VWR. DDFPe with 2% w/v PFC (active) and without PFC (PTB + sucrose blank) was prepared similar to the method previously described by Lundgren et al. [18]. Specifically, sucrose solution was homogenized along with PEG-Telomer B (PTB) and DDFP (except for the blank). Each emulsion was processed using a semi-sealed, stainless steel containment system attached to an Avestin Emulsiflex-C50 homogenizer. The homogenates were then subject to terminal sterile filtration immediately prior to filling into 10 ml vials.