Read by QxMD icon Read

Diurnal variation

Seung Hoon Kim, Eun Jung Lee, Jong Chul Han, Sae Woon Sohn, Taekkwan Rhee, Changwon Kee
PURPOSE: To investigate whether diurnal fluctuation in intraocular pressure (IOP) can influence the result of the correlations between IOP-related factors and progression of normal tension glaucoma (NTG). METHODS: Glaucoma progression was defined as visual field (VF) progression and changes in the optic disc and/or retinal nerve fiber layer (RNFL). Two different methods were used to evaluate the impact of the diurnal fluctuation in IOP. 'Conventional method' used in previous studies included all IOP measurements during the follow up time...
2016: PloS One
Abdulkadir Tunç, Belma Doğan Güngen, Ferhat Evliyaoğlu, Yeşim Güzey Aras, Aysel Kaya Tekeşin
The aim of this study was to investigate retinal nerve fiber layer (RNFL), ganglion cell layer (GCL) thickness, macular changes (central subfield thickness (CST), cube average thickness (CAT), cube volume (CV) in patients with migraine using spectral-domain optical coherence tomography (OCT) and to assess if there was any correlation with white matter lesions (WML). In this prospective case-control study, RNFL, GCL thickness and macular changes of 19 migraine patients with aura (MA), 41 migraine without aura (MO) and 60 age- and gender-matched healthy subjects were measured using OCT device...
October 21, 2016: Acta Neurologica Belgica
Laszlo Kunos, Zsofia Lazar, Fruzsina Martinovszky, Adam D Tarnoki, David L Tarnoki, Daniel Kovacs, Bianka Forgo, Peter Horvath, Gyorgy Losonczy, Andras Bikov
PURPOSE: Obstructive sleep apnoea (OSA) is a prevalent disorder, characterised by collapse of the upper airways during sleep. The impact of sleep-disordered breathing on pulmonary function indices is however currently not well described. The aim of the study was to evaluate diurnal change in lung function indices in a cohort of patients with OSA and relate pulmonary function changes to disease severity. METHODS: 42 patients with OSA and 73 healthy control subjects participated in the study...
October 21, 2016: Lung
Stephanie H Cook, Robert-Paul Juster, Benjamin J Calebs, Justin Heinze, Alison L Miller
Much of the extant scientific research examining hypothalamic-pituitary-adrenal (HPA)-axis functioning is conducted among White heterosexuals. Very little research examines HPA-axis functioning between different minority groups. Individuals who identify as both sexual and racial minorities may experience increased stigma and discrimination that can affect HPA-axis functioning. In the current study, we examined diurnal cortisol rhythm in young White gay men (WGM) compared to young Black gay men (BGM). The sample consisted of 70 healthy gay men (mean [SD] age=22...
October 13, 2016: Psychoneuroendocrinology
Tong Zhao, Lingxiao Yang, Weida Yan, Junmei Zhang, Wei Lu, Yumeng Yang, Jianmin Chen, Wenxing Wang
Daytime and night-time PM1 and PM2.5 samples were simultaneously collected at the summit of Mount Tai during summer and autumn 2014. The mass concentrations and chemical compositions were analysed to determine the temporal variations of PM1 and PM2.5 and their contributions to visibility impairment. In summer, the average mass concentrations of PM1 and PM2.5 were 38.16μg/m(3) and 53.33μg/m(3), respectively. In autumn, the values were 42.75μg/m(3) and 59.16μg/m(3). Water-soluble inorganic ions were the most abundant species in both PM1 and PM2...
October 18, 2016: Science of the Total Environment
Víctor Resco de Dios, Arthur Gessler, Juan Pedro Ferrio, Josu G Alday, Michael Bahn, Jorge Del Castillo, Sébastien Devidal, Sonia García-Muñoz, Zachary Kayler, Damien Landais, Paula Martín-Gómez, Alexandru Milcu, Clément Piel, Karin Pirhofer-Walzl, Olivier Ravel, Serajis Salekin, David T Tissue, Mark G Tjoelker, Jordi Voltas, Jacques Roy
BACKGROUND: Molecular clocks drive oscillations in leaf photosynthesis, stomatal conductance, and other cell and leaf-level processes over ~24 h under controlled laboratory conditions. The influence of such circadian regulation over whole-canopy fluxes remains uncertain; diurnal CO2 and H2O vapor flux dynamics in the field are currently interpreted as resulting almost exclusively from direct physiological responses to variations in light, temperature and other environmental factors. We tested whether circadian regulation would affect plant and canopy gas exchange at the Montpellier European Ecotron...
October 20, 2016: GigaScience
Xiang Li, Timothy R Dallmann, Andrew A May, Daniel S Tkacik, Andrew T Lambe, John T Jayne, Philip L Croteau, Albert A Presto
We measured the gas-particle partitioning of vehicle emitted primary organic aerosol (POA) in a traffic tunnel with three independent methods: artifact corrected bare-quartz filters, thermodenuder (TD) measurements, and thermal-desorption gas-chromatography mass-spectrometry (TD-GC-MS). Results from all methods consistently show that vehicle emitted POA measured in the traffic tunnel is semivolatile under a wide range of fleet compositions and ambient conditions. We compared the gas-particle partitioning of POA measured in both tunnel and dynamometer studies and found that volatility distributions measured in the traffic tunnel are similar to volatility distributions measured in the dynamometer studies, and predict similar gas-particle partitioning in the TD...
October 20, 2016: Environmental Science & Technology
Lionel Sebbag, Shin Ae Park, Philip H Kass, David J Maggs, Mayssa Attar, Christopher J Murphy
OBJECTIVE: To evaluate repeatability and reproducibility of tear osmolarity measured using the TearLab(™) osmometer in normal dogs and to assess its diagnostic potential in dogs with keratoconjunctivitis sicca (KCS). ANIMALS STUDIED: Beagle dogs; six normal and five with KCS. PROCEDURES: Tear osmolarity and Schirmer tear test-1 (STT-1) values were obtained at various times. Normal dogs were assessed for diurnal variation and repeatability and reproducibility of measurements...
October 20, 2016: Veterinary Ophthalmology
Nuria Galindo, Eduardo Yubero
The present work reports diurnal and nocturnal concentrations of water-soluble ions associated to PM10 samples collected during the warm and cold seasons in the urban center of Elche (Southeastern Spain). Statistical differences between daytime and nighttime levels of PM10 were only observed during winter. The lower concentrations during the night were most likely the result of a reduction in traffic-induced road dust resuspension, since nocturnal concentrations of calcium also exhibited a significant decrease compared to daytime levels...
October 18, 2016: Environmental Science and Pollution Research International
Chang-Sheng Sheng, Yi-Bang Cheng, Fang-Fei Wei, Wen-Yi Yang, Qian-Hui Guo, Fei-Ka Li, Qi-Fang Huang, Lutgarde Thijs, Yan Li, Jan A Staessen, Ji-Guang Wang
OBJECTIVE: No previous study addressed the relative contributions of environmental and genetic cues to the diurnal blood pressure rhythmicity. We firstly investigated the explained variance of environmental and clock genes in relation to the night-to-day ratio (NDR) and morning surge (MS), respectively. DESIGN AND METHOD: From 24-h ambulatory recordings of systolic blood pressure (SBP) obtained in untreated Chinese patients (51% women; mean age, 51 years), we computed NDR in 897 and MS in 637...
September 2016: Journal of Hypertension
Zhenyi Chen, Cheng Liu, Wenqing Liu, Tianshu Zhang, Jin Xu
Despite extensive efforts into the characterization of air pollution during the past decade, concurrent real-time characterization of aerosol and NO2 as well as satellite observation above the urban canopy in the megacity of Beijing has sparsely been performed to date. We conducted a simultaneous real-time measurement of aerosol and NO2 in urban Beijing in a pollution episode from November 25, 2015 to December 2, 2015. The aerosol extinction coefficient was measured by a 532 Mie lidar and the NO2 concentration by a Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS)...
October 14, 2016: Science of the Total Environment
Xiaoru Zhang, Yan Yin, Zhenyi Lin, Yongxiang Han, Jian Hao, Liang Yuan, Kui Chen, Jinghua Chen, Shaofei Kong, Yunpeng Shan, Hui Xiao, Wen Tan
To quantify the physical/chemical properties, and the formation and growth processes of aerosol particles on mountainous regions in Southeast China, an intensive field campaign was conducted from April to July 2008 on the top of Mt. Huang (1840m above mean sea level). The average particle number concentration was 2.35×10(3)cm(-3), and the ultrafine particles (<0.1μm) represented 70.5% of the total particle number concentration. Excluding the accumulation mode particles, the average daytime particle number concentrations were prominently higher than those measured at nighttime, suggesting there was a diurnal pattern of changes between planetary boundary layer and free troposphere air...
October 12, 2016: Science of the Total Environment
Christine DeLorenzo, Jean-Dominique Gallezot, John Gardus, Jie Yang, Beata Planeta, Nabeel Nabulsi, R Todd Ogden, David C Labaree, Yiyun H Huang, J John Mann, Fabrizio Gasparini, Xin Lin, Jonathan A Javitch, Ramin V Parsey, Richard E Carson, Irina Esterlis
Positron emission tomography tracers [(11)C]ABP688 and [(18)F]FPEB target the metabotropic glutamate receptor subtype 5 providing quantification of the brain glutamatergic system in vivo. Previous [(11)C]ABP688 positron emission tomography human test-retest studies indicate that, when performed on the same day, significant binding increases are observed; however, little deviation is reported when scans are >7 days apart. Due to the small cohorts examined previously (eight and five males, respectively), we aimed to replicate the same-day test-retest studies in a larger cohort including both males and females...
October 14, 2016: Journal of Cerebral Blood Flow and Metabolism
Satoru Koyanagi, Naoki Kusunose, Marie Taniguchi, Takahiro Akamine, Yuki Kanado, Yui Ozono, Takahiro Masuda, Yuta Kohro, Naoya Matsunaga, Makoto Tsuda, Michael W Salter, Kazuhide Inoue, Shigehiro Ohdo
Diurnal variations in pain hypersensitivity are common in chronic pain disorders, but the underlying mechanisms are enigmatic. Here, we report that mechanical pain hypersensitivity in sciatic nerve-injured mice shows pronounced diurnal alterations, which critically depend on diurnal variations in glucocorticoids from the adrenal glands. Diurnal enhancement of pain hypersensitivity is mediated by glucocorticoid-induced enhancement of the extracellular release of ATP in the spinal cord, which stimulates purinergic receptors on microglia in the dorsal horn...
October 14, 2016: Nature Communications
Antonia E Dalziel, Steven Delean, Sarah Heinrich, Phillip Cassey
Avian influenza viruses are able to persist in the environment, in-between the transmission of the virus among its natural hosts. Quantifying the environmental factors that affect the persistence of avian influenza virus is important for influencing our ability to predict future outbreaks and target surveillance and control methods. We conducted a systematic review and quantitative meta-analysis of the environmental factors that affect the decay of low pathogenic avian influenza virus (LPAIV) in water. Abiotic factors affecting the persistence of LPAIV have been investigated for nearly 40 years, yet published data was produced by only 26 quantitative studies...
2016: PloS One
Y Chen, Kevin K Lehmann, Y Peng, L M Pratt, J R White, S B Cadieux, B Sherwood Lollar, G Lacrampe-Couloume, T C Onstott
In this study, near-infrared continuous wave cavity ring-down spectroscopy was applied to the measurement of the δ(2)H of methane (CH4). The cavity ring-down spectrometer (CRDS) system consisted of multiple DFB laser diodes to optimize selection of spectral line pairs. By rapidly switching measurements between spectral line peaks and the baseline regions, the long-term instrumental drift was minimized, substantially increasing measurement precision. The CRDS system coupled with a cryogenic pre-concentrator measured the δ(2)H of terrestrial atmospheric CH4 from 3 standard liters of air with a precision of ±1...
October 2016: Astrobiology
L F Weissert, J A Salmond, G Miskell, M Alavi-Shoshtari, S K Grange, G S Henshaw, D E Williams
Ozone (O3) concentrations in urban areas are spatially and temporally variable, influenced by chemical production, depletion through deposition and chemical titration processes and dispersion. To date, analysis of intra-urban variability of O3 concentrations, and the influence of local controls on production and depletion rates, has been limited due to the low spatial and/or temporal resolution of measurements. We demonstrate that measurements made using a carefully managed multi-sensor network of low-cost gas-sensitive semiconductor instruments are sufficiently precise to resolve subtle but significant variations in ozone concentration across a region...
October 8, 2016: Science of the Total Environment
Andrzej Bienczak, Adrian Cook, Lubbe Wiesner, Veronica Mulenga, Cissy Kityo, Addy Kekitiinwa, A Sarah Walker, Andrew Owen, Diana M Gibb, David Burger, Helen McIlleron, Paolo Denti
OBJECTIVES: To characterize the effects of CYP2B6 polymorphisms, diurnal variation and demographic factors on nevirapine pharmacokinetics in African children. METHODS: Non-linear mixed-effects modelling conducted in NONMEM 7.3 described nevirapine plasma concentration-time data from 414 children aged 0.3-15 years. RESULTS: Nevirapine pharmacokinetics was best described using a one-compartment disposition model with elimination through a well-stirred liver model accounting for a first-pass effect and transit-compartment absorption...
October 5, 2016: Journal of Antimicrobial Chemotherapy
Lieke J J Klinkenberg, Karin Wildi, Noreen van der Linden, Imre W K Kouw, Marijke Niens, Raphael Twerenbold, Maria Rubini Gimenez, Christian Puelacher, Jean Daniel Neuhaus, Petra Hillinger, Thomas Nestelberger, Jasper Boeddinghaus, Karin Grimm, Zaid Sabti, Judith A P Bons, Jeroen D E van Suijlen, Frans E S Tan, Joop Ten Kate, Otto Bekers, Luc J C van Loon, Marja P van Dieijen-Visser, Christian Mueller, Steven J R Meex
BACKGROUND: Interpretation of serial high-sensitivity cardiac troponin (hs-cTn) measurements for the diagnosis of acute myocardial infarction (AMI) assumes random fluctuation of hs-cTn around an individual's homeostatic set point. The aim of this study was to challenge this diagnostic concept. METHODS: Study 1 examined the presence of a diurnal hs-cTn rhythm by hourly blood sampling, day and night, in 24 individuals without a recent history of AMI. Study 2 assessed morning vs evening diagnostic accuracy of hs-cTnT and hs-cTnI in a prospective multicenter diagnostic study of 2782 unselected patients, presenting to the emergency department with acute chest pain...
October 5, 2016: Clinical Chemistry
Mariusz Sikora, Piotr Konopelski, Kinga Pham, Aleksandra Wyczalkowska-Tomasik, Marcin Ufnal
Non-invasive hemodynamic measurements in rats require placing animals in restrainers. To minimize restraint stress-induced artifacts several habituation protocols have been proposed, however, the results are inconclusive. Here, we evaluated if a 4-week habituation is superior to a shorter habituation, or no habituation. This is the first study comparing different habituation protocols with the use of 4-week continuous telemetry measurements. We did the experiments on male, 16-week old, Sprague Dawley rats. Continuous recordings of mean arterial blood pressure (MABP) and heart rate (HR) were made before and during habituation protocols...
October 4, 2016: Stress: the International Journal on the Biology of Stress
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"