keyword
MENU ▼
Read by QxMD icon Read
search

PPM

keyword
https://www.readbyqxmd.com/read/28636451/assessing-hydrogen-peroxide-vapor-exposure-from-hospital-sterilizers
#1
Robert Cornelia, P Richard Warburton
This study examined the hydrogen peroxide concentrations measured near four models of hydrogen peroxide sterilizers, from two manufacturers, monitored in seven hospitals across the US and Canada over several years. The results showed that the majority of sterilizers do not emit hazardous levels of hydrogen peroxide and none of them exceeded the OSHA PEL of 1 ppm (8 hour time weighted average (TWA)), however several of the sterilizers exceeded 3 ppm, the short term exposure limit in a couple of states, Washington and Hawaii...
June 21, 2017: Journal of Occupational and Environmental Hygiene
https://www.readbyqxmd.com/read/28636267/strontium-releasing-fluorapatite-glass-ceramics-crystallization-behavior-microstructure-and-solubility
#2
Isabelle Denry, Ourania-Menti Goudouri, Jeffrey D Harless, E M Hubbard, Julie A Holloway
The purpose of this work was to investigate the effect of strontium partial replacement for calcium on the crystallization behavior, microstructure and solubility of fluorapatite glass-ceramics. Four glass compositions were prepared with increasing amounts of strontium partially replacing calcium. The crystallization behavior was analyzed by differential scanning calorimetry and X-ray diffraction (XRD). The microstructure was investigated by scanning electron microscopy. The chemical solubility was quantified according to ISO standard 10993-14...
June 21, 2017: Journal of Biomedical Materials Research. Part B, Applied Biomaterials
https://www.readbyqxmd.com/read/28634492/effectiveness-of-different-preventive-programs-in-cariogram-parameters-of-young-adults-at-high-caries-risk
#3
Said Karabekiroğlu, Nimet Ünlü
OBJECTIVE: To evaluate the effectiveness of different preventive programs in young adults at high caries risk using Cariogram software. METHODS: Sixty-six young adults with high caries risk were evaluated. Dental caries risk for all subjects was determined according to WHO criteria. Subjects were divided into three different preventive groups (control: OH, fluoride varnish: FV, and chlorhexidine varnish: CV). They were followed for 12 weeks (baseline: T0, 1 week: T1, 4 weeks: T2, and 12 weeks: T3)...
2017: International Journal of Dentistry
https://www.readbyqxmd.com/read/28633598/metabolism-of-inhaled-methylethylketone-in-rats
#4
Frédéric Cosnier, Stéphane Grossmann, Hervé Nunge, Céline Brochard, Samuel Muller, Anne-Marie Lambert-Xolin, Sylvie Sebillaud, Benoît Rieger, Aurélie Thomas, Marie-Josèphe Décret, Manuella Burgart, Laurent Gaté, Benoît Cossec, Pierre Campo
Methylethylketone (MEK) is widely used in industry, often in combination with other compounds. Although nontoxic, it can make other chemicals harmful. This study investigates the fate of MEK in rat blood, brain and urine as well as its hepatic metabolism following inhalation over 1 month (at 20, 200 or 1400 ppm). MEK did not significantly accumulate in the organism: blood concentrations were similar after six-hour or 1-month inhalation periods, and brain concentrations only increased slightly after 1 month's exposure...
February 28, 2017: Drug and Chemical Toxicology
https://www.readbyqxmd.com/read/28632272/interfacial-synthesis-of-a-three-dimensional-hierarchical-mos2-ns-ag-np-nanocomposite-as-a-sers-nanosensor-for-ultrasensitive-thiram-detection
#5
Xiu Liang, Yi-Shuo Wang, Ting-Ting You, Xiao-Juan Zhang, Nan Yang, Guang-Sheng Wang, Peng-Gang Yin
Interfacial self-assembly of ordered nanostructures at oil-water interfaces towards the fabrication of nanofilms has attracted the interest of plenty of scientists, since its discovery in 2004. Herein, further developments have been achieved, and we report a new strategy for the synthesis of a three-dimensional (3D) hierarchical nanostructure, through an interfacial synthesis driven microemulsion process. Thus, the synthesis route has been simplified, with the rigorous experimental conditions of traditional compositing technology...
June 20, 2017: Nanoscale
https://www.readbyqxmd.com/read/28631452/the-impact-of-the-anaesthetic-conserving-device-on-occupational-exposure-to-isoflurane-among-intensive-care-healthcare-professionals
#6
Jennifer Herzog-Niescery, Heike Vogelsang, Philipp Gude, Hans-Martin Seipp, Horst Bartz, Waldemar Uhl, Thomas P Weber, Martin Bellgardt
BACKGROUND: Use of Anesthetic Conserving Devices (ACD) for inhalational isoflurane sedation in intensive care units (ICU) has grown in recent years, and healthcare professionals are concerned about isoflurane pollution and exposure-related health risks. Real-time measurements to determine isoflurane exposure in ICU personnel during short-term patient care procedures and ACD handling have not yet been performed. METHODS: Isoflurane concentrations in the breathing zones of ICU staff (25 cm around the nose and mouth) were measured, by photoacoustic gas monitoring, during daily practice including tracheal suctioning, oral hygiene, body care, and patient positioning...
June 14, 2017: Minerva Anestesiologica
https://www.readbyqxmd.com/read/28629996/production-of-medically-useful-nitric-monoxide-using-ac-arc-discharge
#7
S R Li, Y F Huang, Z Liu, M H Sui, J M Liu, K P Yan
Inhaled nitric monoxide (iNO) is increasingly used as a medical treatment for acute respiratory distress syndrome. A course of the existing nitric monoxide (NO) therapy with gas cylinders could cost up to approximately $15,000 for an average of 30.2 h. Moreover, a gas cylinder containing a mixture of N2 and NO may potentially leak NO. The objective of this study is to develop an efficient and cost-effective on-site iNO generation system. In the present setup, NO was generated by using dry air or mixed oxygen/nitrogen (O2/N2) and an AC power source with an output power level of 5-30 W at atmospheric pressure...
June 16, 2017: Nitric Oxide: Biology and Chemistry
https://www.readbyqxmd.com/read/28629233/a-new-antibiotic-produced-by-the-cyanobacterium-symbiotic-fungus-simplicillium-lanosoniveum
#8
Qinglin Dong, Rongzhen Dong, Xiangying Xing, Yukuan Li
The culture broth of the cyanobacterium-symbiotic fungus Simplicillium lanosoniveum var. Tianjinienss Q. L. Dong exhibited unanticipated antibacterial activities against the Gram-positive bacteria, particularly the pathogenic bacterium Staphylococcus aureus, indicating the secretion of antibiotic-like metabolite, for which the modified Sabouraud medium was the suitable medium. The antibiotic-like metabolite was separated with macroporous resins CT-12 (absorption) and 95% ethanol (desorption), purified by ion-exchange resins D301T and displayed a characteristic absorption peak at 228 nm, suggesting the presence of nitrogen...
June 19, 2017: Natural Product Research
https://www.readbyqxmd.com/read/28628907/whispering-gallery-mode-esr-spectroscopy-and-parameters-measurement-in-single-crystal-srlaalo4-at-millikelvin-temperature
#9
M A Hosain, J-M Le Floch, J Krupka, M E Tobar
A cylindrical single crystal SrLaAlO4 Whispering Gallery mode dielectric resonator was cooled to millikelvin temperature using a dilution refrigerator. By controlling a DC-magnetic field, impurity ions' spins were coupled to a variety of modes allowing the measurement of hybrid spin-photon systems. This Electron Spin Resonance mapping technique allowed us to detect Cu(2+),Fe(3+) and Mn(4+) impurity ions (at the level of parts per million (ppm) to parts per billion (ppb)), verified by the measurement of the spin parameters along with their site symmetry...
June 11, 2017: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/28627877/detection-and-quantification-of-hydrogen-peroxide-in-aqueous-solutions-using-chemical-exchange-saturation-transfer-cest
#10
David Ryoo, Xiang Xu, Yuguo Li, Joel Tang, Jia Zhang, Peter C M van Zijl, Guanshu Liu
The development of new analytical methods to accurately quantify hydrogen peroxide is of great interest. In the current study, we developed a new magnetic resonance (MR) method for noninvasively quantifying hydrogen peroxide (H2O2) in aqueous solutions based on chemical exchange saturation transfer (CEST), an emerging MRI contrast mechanism. Our method can detect H2O2 by its specific CEST signal at ~6.2 ppm downfield from water resonance, with more than 1000 times signal amplification compared to the direct NMR detection...
June 19, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28627816/spectrophotometric-determination-of-selenium-through-triiodide-anion
#11
Otilia Bizerea-Spiridon, Radu Nartita, Alexandru F Rogobete, Adina Negrea, Ramona Stroescu, Teofana O Bizerea, Constantin Ilie, Otilia Marginean
BACKGROUND: Selenium is a chemical element found in the human body that plays a crucial role in its regulation. Depending on the concentration, it may have beneficial or have toxic effects. Selenium is incorporated as selenocysteine amino acid residue in selenoproteins which play an important role in many biological functions: anti-oxidant defense, regulation of the immune function and of the inflammatory response, metabolism of thyroid hormones, functioning of the central nervous system, biosynthesis of DNA and RNA, fertility, and reproduction...
May 1, 2017: Clinical Laboratory
https://www.readbyqxmd.com/read/28624471/vitamin-e-antagonizes-ozone-induced-asthma-exacerbation-in-balb-c-mice-through-the-nrf2-pathway
#12
Liju Duan, Jinquan Li, Ping Ma, Xu Yang, Shunqing Xu
Millions of people are regularly exposed to ozone, a gas known to contribute significantly to worsening the symptoms of patients with asthma. However, the mechanisms underlying these ozone exacerbation effects are not fully understood. In this study, we examined the exacerbation effect of ozone in OVA-induced asthma mice and tried to demonstrate the protective mechanism of vitamin E (VE). An asthma mouse model was established, and used to identify the exacerbating effects of ozone by assessing cytokine and serum immunoglobulin concentrations, airway leukocyte infiltration, histopathological changes in lung tissues, and airway hyper-responsiveness...
June 14, 2017: Food and Chemical Toxicology
https://www.readbyqxmd.com/read/28624184/-31-p-mas-nmr-spectroscopy-with-93-nb-decoupling-and-dft-calculations-a%C3%A2-structural-characterization-of-defects-in-a-niobium-phosphate-phase
#13
Guillaume Girard, Filipe Vasconcelos, Lionel Montagne, Laurent Delevoye
The present study has investigated the structure of four niobium phosphates compounds using (31)P MAS NMR spectroscopy. Niobium (93)Nb decoupling, applied during (31)P NMR acquisition led to a resolution enhancement by a factor of 2-3, which allowed distinguish phosphorous sites separated by 1 ppm or less. The assignment of (31)P spectra has been completed by use of first-principles calculations derived from the original XRD structures. One of the compounds, Na3.04Nb7P4O29, contains a sodium vacancy, clearly revealed in the (31)P MAS spectrum obtained with (93)Nb decoupling...
June 2, 2017: Solid State Nuclear Magnetic Resonance
https://www.readbyqxmd.com/read/28624117/a-case-of-pacemaker-malfunction-should-i-intervene
#14
Colin Yeo, David H Birnie, Girish M Nair
A 53year old lady was noted to have persistent bradycardia in the recovery unit shortly after a dual chamber permanent pacemaker (PPM) was implanted. The patient was asymptomatic. The pacemaker was implanted for symptomatic intermittent complete heart block. She had surgical closure of an atrial septal defect three decades earlier and a previous tricuspid valve replacement with concomitant biatrial cryomaze procedure for paroxysmal atrial fibrillation.
June 8, 2017: Journal of Electrocardiology
https://www.readbyqxmd.com/read/28623572/nutritional-fe-mn-ni-and-cr-and-growth-responses-of-rice-plant-affected-by-perennial-application-of-two-bio-solids
#15
Seyed Majid Mousavi, Mohammad Ali Bahmanyar, Hemmatollah Pirdashti, Salahedin Moradi
Trace toxic elements often restrict the land application of different bio-solids in agriculture. In order to evaluate the separate influence of the municipal solid waste compost (MSW), sewage sludge (SS) and combined application with inorganic fertilizers (chemical fertilizer (CF)) on nutritional (Fe, Mn, Ni, and Cr) and growth responses of rice plant, a research was conducted on paddy soil from 2013 to 2015. Obtained results showed that SS levels were superior to MSW in most studied traits. The maximum chlorophyll content (46...
July 2017: Environmental Monitoring and Assessment
https://www.readbyqxmd.com/read/28622602/assessment-of-the-phenolic-profile-antimicrobial-activity-and-oxidative-stability-of-transgenic-perilla-frutescens-l-overexpressing-tocopherol-methyltransferase-%C3%AE-tmt-gene
#16
Bimal Kumar Ghimire, Chang Yeon Yu, Ill-Min Chung
This study evaluated the effects of enhanced concentrations of α-tocopherol and phenolic compounds on the resistance and stability of Perilla oil in transgenic Perilla frutescens plants against various tested pathogenic bacteria by over-expressing the γ-tmt gene. The concentration of phenolic compounds in the non-transgenic samples was 9313.198 ± 18.887 μg g(-1) dry weight (DW), whereas the total concentration of the transgenic samples ranged from 9118.015 ± 18.822 to 10527.612 ± 20.411 μg g(-1) DW...
June 7, 2017: Plant Physiology and Biochemistry: PPB
https://www.readbyqxmd.com/read/28621738/integration-of-p-cuo-thin-sputtered-layers-onto-microsensor-platforms-for-gas-sensing
#17
Lionel Presmanes, Yohann Thimont, Imane El Younsi, Audrey Chapelle, Frédéric Blanc, Chabane Talhi, Corine Bonningue, Antoine Barnabé, Philippe Menini, Philippe Tailhades
P-type semiconducting copper oxide (CuO) thin films deposited by radio-frequency (RF) sputtering were integrated onto microsensors using classical photolithography technologies. The integration of the 50-nm-thick layer could be successfully carried out using the lift-off process. The microsensors were tested with variable thermal sequences under carbon monoxide (CO), ammonia (NH₃), acetaldehyde (C₂H₄O), and nitrogen dioxide (NO₂) which are among the main pollutant gases measured by metal-oxide (MOS) gas sensors for air quality control systems in automotive cabins...
June 16, 2017: Sensors
https://www.readbyqxmd.com/read/28621456/absorption-distribution-and-excretion-of-four-forms-of-titanium-dioxide-pigment-in-the-rat
#18
Thomas P Farrell, Berna Magnuson
Titanium dioxide (TiO2 ) is a white color additive that has a long history of global approval and use in food. There is, however, considerable confusion regarding the applicability of the biological effects of novel, engineered, nano-sized forms of TiO2 developed for nonpigmentary applications to the safety of oral exposure to food grade TiO2 pigment. The objective of this study was to assess the absorption, distribution, and routes of excretion in rats after oral exposure to food grade TiO2 . Four different grades of TiO2 (200 ppm) or control (0 ppm) diets were fed to rats for 7 consecutive days, followed by control diet only for 1, 24, or 72 h...
June 16, 2017: Journal of Food Science
https://www.readbyqxmd.com/read/28621272/radiopacity-of-mineral-trioxide-aggregate-with-and-without-inclusion-of-silver-nanoparticles
#19
Mariana Ss Mendes, Leonardo D Resende, Cláudia A Pinto, Denise P Raldi, Flavia Gr Cardoso, Sandra M Habitante
AIM: The aim of this study was to investigate the inclusion of silver nanoparticles (Ag NPs) in the mineral trioxide aggregate (MTA) composition to know which changes will result in the radiopacity of the material. MATERIALS AND METHODS: The experiment was performed according to the American National Standard Institute/American Dental Association specification no. 57/2000 and ISO 6876/2001. Five plates with five holes measuring 1 mm in depth and 5 mm in internal diameter were filled according to the different experimental groups as follows: white mineral trioxide aggregate (WMTA) + NP50 - W MTA with liquid Ag NP 50 ppm, WMTA + NP30 - W MTA with liquid Ag NP 30 ppm, WMTA + NP22 - W MTA with liquid Ag NP 22 ppm, WMTA + NPP - white MTA with liquid Ag NP and powder 1%, WMTA (control)...
June 1, 2017: Journal of Contemporary Dental Practice
https://www.readbyqxmd.com/read/28620861/testing-a-ratio-of-photosynthesis-to-o3-uptake-as-an-index-for-assessing-o3-induced-foliar-visible-injury-in-poplar-trees
#20
Yasutomo Hoshika, Elisa Carrari, Lu Zhang, Giulia Carriero, Sara Pignatelli, Gianni Fasano, Alessandro Materassi, Elena Paoletti
Visible foliar injury by ozone (ozone visible injury) is known as a biomarker to assess potential phytotoxicity of ozone. We investigated ozone visible injury in an ozone-sensitive poplar (Oxford clone) under a 2-year free-air controlled exposure (FACE) experiment and calculated three ozone indices (i.e., accumulative ozone exposure over 40 ppb during daylight hours (AOT40), phytotoxic ozone dose above a flux threshold of 0 nmol m(-2) s(-1) (POD0), and the cumulative value of the ratio of hourly ozone uptake to net photosynthesis (ΣU/P n ) to assess the critical level (CL) at the time of the first symptom onset of ozone visible injury...
June 16, 2017: Environmental Science and Pollution Research International
keyword
keyword
37259
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"