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https://www.readbyqxmd.com/read/28102957/rf-safety-assessment-of-a-bilateral-four-channel-transmit-receive-7-tesla-breast-coil-sar-versus-tissue-temperature-limits
#1
Thomas M Fiedler, Mark E Ladd, Andreas K Bitz
PURPOSE: The purpose of this work was to perform an RF safety evaluation for a bilateral four-channel transmit/receive breast coil and to determine the maximum permissible input power for which RF exposure of the subject stays within recommended limits. The safety evaluation was done based on SAR as well as on temperature simulations. In comparison to SAR, temperature is more directly correlated with tissue damage, which allows a more precise safety assessment. The temperature simulations were performed by applying three different blood perfusion models as well as two different ambient temperatures...
January 2017: Medical Physics
https://www.readbyqxmd.com/read/28102869/design-considerations-to-minimize-the-impact-of-drug-absorption-in-polymer-based-organ-on-a-chip-platforms
#2
V S Shirure, S C George
Biocompatible polymers, such as polydimethylsiloxane (PDMS), are the materials of choice for creating organ-on-a-chip microfluidic platforms. Desirable qualities include ease of fabrication, optical clarity, and hydrophobicity, the latter of which facilitates oxygen transport to encased cells. An emerging and important application of organ-on-a-chip technology is drug discovery; however, a potential issue for polymer-based microfluidic devices has been highlighted by recent studies with PDMS, which have demonstrated absorption (and thus loss) of hydrophobic drugs into PDMS under certain experimental conditions...
January 19, 2017: Lab on a Chip
https://www.readbyqxmd.com/read/28102715/capsaicin-pretreatment-enhanced-the-bioavailability-of-fexofenadine-in-rats-by-p-glycoprotein-modulation-in-vitro-in-situ-and-in-vivo-evaluation
#3
Satish Kumar Bedada, Ramgopal Appani, Praveen Kumar Boga
BACKGROUND AND OBJECTIVE: Capsaicin is the main pungent principle present in chilli peppers has been found to possess P-glycoprotein (P-gp) inhibition activity in vitro, which may have the potential to modulate bioavailability of P-gp substrates. Therefore, purpose of the present study was to evaluate the effect of capsaicin on intestinal absorption and bioavailability of fexofenadine, a P-gp substrate in rats. METHODS: The mechanistic evaluation was determined by non-everted sac and intestinal perfusion studies to explore the intestinal absorption of fexofenadine...
January 19, 2017: Drug Development and Industrial Pharmacy
https://www.readbyqxmd.com/read/28102694/evaluation-of-sample-extraction-methods-for-minimizing-hematocrit-effect-on-whole-blood-analysis-with-volumetric-absorptive-microsampling
#4
Zhengqi Ye, Hong Gao
AIM: Volumetric absorptive microsampler (VAMS) was designed to sample a fixed volume of blood regardless of the hematocrit (HCT) levels. Model compounds with a wide range of hydrophobicity were evaluated for their extraction recoveries from VAMS dried blood samples. RESULTS: For the highly hydrophobic compounds, recoveries with methanol or methanol/acetonitrile extraction were higher compared with using the aqueous mixture of methanol or acetonitrile. Extraction with methanol/acetonitrile (1:1) yielded more consistent recovery across the HCT range of 20-70% than using methanol alone, with good linearity, accuracy and precision achieved from 1 to 2000 ng/ml...
January 19, 2017: Bioanalysis
https://www.readbyqxmd.com/read/28102680/ionicity-of-protic-ionic-liquid-quantitative-measurement-by-spectroscopic-methods
#5
Minming Shen, Yuyang Zhang, Kaizhou Chen, Siying Che, Jia Yao, Haoran Li
The ionicity value, which is a key property of protic ionic liquids, was obtained by the attenuated total reflection Fourier transform infrared spectroscopy and nuclear magnetic resonance respectively for a protic ionic liquid: n-propylammonium acetate. The method of potentiometric titration is found not suitable for such kind of ionic liquid as the ∆pKa of the compositing acid and base is relatively small. In the IR spectrum, molecular species can be directly observed in the range 1200-1800 cm-1, and the ratio of ionic and molecular species can be quantitatively calculated by the area of characteristic absorption peaks calibrated by standard curve from NaAc/HAc solutions...
January 19, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28102508/simvastatin-promotes-hematoma-absorption-and-reduces-hydrocephalus-following-intraventricular-hemorrhage-in-part-by-upregulating-cd36
#6
Qianwei Chen, Xia Shi, Qiang Tan, Zhou Feng, Yuelong Wang, Qiaoying Yuan, Yihao Tao, Jianbo Zhang, Liang Tan, Gang Zhu, Hua Feng, Zhi Chen
We previously found that hematoma worsens hydrocephalus after intraventricular hemorrhage (IVH) via increasing iron deposition and aggravating ependymal cilia injury; therefore, promoting hematoma absorption may be a promising strategy for IVH. Recently, some investigations imply that simvastatin has the ability of accelerating hematoma absorption. Thus, this study was designed to examine the efficacy of simvastatin for IVH in rats. Intracerebral hemorrhage with ventricular extension was induced in adult male Sprague-Dawley rats after autologous blood injection...
January 19, 2017: Translational Stroke Research
https://www.readbyqxmd.com/read/28102421/the-nature-of-the-light-absorption-and-emission-transitions-of-4-hydroxybenzophenone-in-different-solvents-a-combined-computational-and-experimental-study
#7
Francesco Barsotti, Giovanni Ghigo, Silvia Berto, Davide Vione
The photophysics and photochemistry of 4-hydroxybenzophenone (4HOBP) are interesting because they can give some insight into the behavior of humic material. Here we show that 4HOBP has a number of fluorescence peaks: (i) an intense one at excitation/emission wavelengths Ex/Em ∼ 200-230/280-370 nm, likely due to an excitation transition from S0 to S5 or S6, followed by S2 → S0 in emission (Sn denotes the singlet states of 4HOBP); (ii) a minor peak at Ex/Em ∼ 270-300/320-360 nm (S0 → S2 in absorption and S2 → S0 in emission), and (iii) very interesting signals in the typical emission region of humic substances, most notably at Ex/Em ∼ 200-220/400-500 nm and Ex/Em ∼ 260-280/400-470 nm (in both cases the emission corresponded to an S1 → S0 transition)...
January 19, 2017: Photochemical & Photobiological Sciences
https://www.readbyqxmd.com/read/28102314/improved-solar-driven-photocatalytic-performance-of-highly-crystalline-hydrogenated-tio2-nanofibers-with-core-shell-structure
#8
Ming-Chung Wu, Ching-Hsiang Chen, Wei-Kang Huang, Kai-Chi Hsiao, Ting-Han Lin, Shun-Hsiang Chan, Po-Yeh Wu, Chun-Fu Lu, Yin-Hsuan Chang, Tz-Feng Lin, Kai-Hsiang Hsu, Jen-Fu Hsu, Kun-Mu Lee, Jing-Jong Shyue, Krisztián Kordás, Wei-Fang Su
Hydrogenated titanium dioxide has attracted intensive research interests in pollutant removal applications due to its high photocatalytic activity. Herein, we demonstrate hydrogenated TiO2 nanofibers (H:TiO2 NFs) with a core-shell structure prepared by the hydrothermal synthesis and subsequent heat treatment in hydrogen flow. H:TiO2 NFs has excellent solar light absorption and photogenerated charge formation behavior as confirmed by optical absorbance, photo-Kelvin force probe microscopy and photoinduced charge carrier dynamics analyses...
January 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28102312/correlations-of-charge-neutrality-level-with-electronic-structure-and-p-d-hybridization
#9
Arkaprava Das, Subodh K Gautam, D K Shukla, Fouran Singh
The formation of charge neutrality level (CNL) in highly conducting Cadmium oxide (CdO) thin films is demonstarted by the observed variation in the band gap upon annealing and doping. It may be explained by the observation that Tin (Sn) doping breaks the perfect periodicity of CdO cubic crystal structure and creates virtual gap states (ViGS). The level of local CNL resides at the branch point of ViGS, making the energy at which native defect's character changes from predominantly donor-like below CNL to predominantly acceptor-like above the CNL and a schematic band diagram is developed to substantiate the same...
January 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28102286/chelerythrine-down-regulates-expression-of-vegfa-bcl2-and-kras-by-arresting-g-quadruplex-structures-at-their-promoter-regions
#10
Jagannath Jana, Soma Mondal, Payel Bhattacharjee, Pallabi Sengupta, Tanaya Roychowdhury, Pranay Saha, Pallob Kundu, Subhrangsu Chatterjee
A putative anticancer plant alkaloid, Chelerythrine binds to G-quadruplexes at promoters of VEGFA, BCL2 and KRAS genes and down regulates their expression. The association of Chelerythrine to G-quadruplex at the promoters of these oncogenes were monitored using UV absorption spectroscopy, fluorescence anisotropy, circular dichroism spectroscopy, CD melting, isothermal titration calorimetry, molecular dynamics simulation and quantitative RT-PCR technique. The pronounced hypochromism accompanied by red shifts in UV absorption spectroscopy in conjunction with ethidium bromide displacement assay indicates end stacking mode of interaction of Chelerythrine with the corresponding G-quadruplex structures...
January 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28102285/non-destructive-study-of-bulk-crystallinity-and-elemental-composition-of-natural-gold-single-crystal-samples-by-energy-resolved-neutron-imaging
#11
Anton S Tremsin, John Rakovan, Takenao Shinohara, Winfried Kockelmann, Adrian S Losko, Sven C Vogel
Energy-resolved neutron imaging enables non-destructive analyses of bulk structure and elemental composition, which can be resolved with high spatial resolution at bright pulsed spallation neutron sources due to recent developments and improvements of neutron counting detectors. This technique, suitable for many applications, is demonstrated here with a specific study of ~5-10 mm thick natural gold samples. Through the analysis of neutron absorption resonances the spatial distribution of palladium (with average elemental concentration of ~0...
January 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28102239/subcycle-quantum-electrodynamics
#12
C Riek, P Sulzer, M Seeger, A S Moskalenko, G Burkard, D V Seletskiy, A Leitenstorfer
Squeezed states of electromagnetic radiation have quantum fluctuations below those of the vacuum field. They offer a unique resource for quantum information systems and precision metrology, including gravitational wave detectors, which require unprecedented sensitivity. Since the first experiments on this non-classical form of light, quantum analysis has been based on homodyning techniques and photon correlation measurements. These methods currently function in the visible to near-infrared and microwave spectral ranges...
January 18, 2017: Nature
https://www.readbyqxmd.com/read/28102115/can-probiotics-modulate-human-disease-by-impacting-intestinal-barrier-function
#13
Peter A Bron, Michiel Kleerebezem, Robert-Jan Brummer, Patrice D Cani, Annick Mercenier, Thomas T MacDonald, Clara L Garcia-Ródenas, Jerry M Wells
Intestinal barrier integrity is a prerequisite for homeostasis of mucosal function, which is balanced to maximise absorptive capacity, while maintaining efficient defensive reactions against chemical and microbial challenges. Evidence is mounting that disruption of epithelial barrier integrity is one of the major aetiological factors associated with several gastrointestinal diseases, including infection by pathogens, obesity and diabetes, necrotising enterocolitis, irritable bowel syndrome and inflammatory bowel disease...
January 19, 2017: British Journal of Nutrition
https://www.readbyqxmd.com/read/28101932/amino-acid-profiling-of-zinc-resistant-prostate-cancer-cell-lines-associations-with-cancer-progression
#14
Monika Kratochvilova, Martina Raudenska, Zbynek Heger, Lukas Richtera, Natalia Cernei, Vojtech Adam, Petr Babula, Marie Novakova, Michal Masarik, Jaromir Gumulec
BACKGROUND: Failure in intracellular zinc accumulation is a key process in prostate carcinogenesis. Nevertheless, epidemiological studies of zinc administration have provided contradicting results. In order to examine the impact of the artificial intracellular increase of zinc(II) ions on prostate cancer metabolism, PNT1A, 22Rv1, and PC-3 prostatic cell lines-depicting different stages of cancer progression-and their zinc-resistant counterparts were used. To determine "benign" and "malignant" metabolic profiles, amino acid patterns, gene expression, and antioxidant capacity of these cell lines were assessed...
January 19, 2017: Prostate
https://www.readbyqxmd.com/read/28101853/investigation-on-the-effects-of-the-formation-of-a-silver-flower-like-structure-on-graphene
#15
Rozalina Zakaria, Siti Fatimah Az Zahra Yusoff, Kok Chung Law, Chin Seong Lim, Harith Ahmad
In this report, we experimentally investigate the formation of "flower-like silver structures" on graphene. Using an electrochemical deposition technique with deposition times of 2.5 and 5 min, agglomerations of silver nanoparticles (AgNPs) were deposited on the graphene surfaces, causing the formation of "flower-like structures" on the graphene substrate. Localized surface plasmon resonance (LSPR) was observed in the interaction between the structures and the graphene substrate. The morphology of the samples was observed using a field-emission scanning electron microscope (FESEM) and Raman spectroscopy...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28101764/diazepam-in-the-treatment-of-moderate-to-severe-alcohol-withdrawal
#16
Steven J Weintraub
Benzodiazepines ameliorate or prevent the symptoms and complications of moderate to severe alcohol withdrawal, which can include autonomic hyperactivity, agitation, combativeness, hallucinations, seizures, delirium, and death. The benzodiazepines most commonly used for this purpose are lorazepam, chlordiazepoxide, oxazepam, and diazepam. It is widely asserted that no member of this group is superior to the others for treatment of alcohol withdrawal. However, of these, diazepam has the shortest time to peak effect, which facilitates both rapid control of symptoms and accurate titration to avoid over-sedation...
January 18, 2017: CNS Drugs
https://www.readbyqxmd.com/read/28101544/tetrathienyl-functionalized-red-and-nir-absorbing-bodipy-dyes-appending-various-peripheral-substituents
#17
Ping Liu, Feng Gao, Lina Zhou, Yu Chen, Zhijian Chen
A series of boron-dipyrromethene dyes (BODIPYs) 4a-g with different thienyl moieties at 2,3,5,6-positions of the BODIPY core were synthesized by the Stille cross-coupling reaction. The new compounds were characterized by (1)H NMR, (13)C NMR, HRMS, and IR spectroscopy. The single crystal structure of compound 4e was obtained by X-ray crystallography. The optical and electrochemical properties of these dyes were studied by UV/Vis spectroscopy, fluorescence spectroscopy, and cyclic voltammetry. The DFT calculation of the frontier molecular orbitals of these dyes corroborates the observed effects of peripheral substituents on the optical and redox properties...
January 19, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28101541/inner-salt-shaped-small-molecular-photosensitizer-with-extremely-enhanced-two-photon-absorption-for-mitochondrial-targeted-photodynamic-therapy
#18
Wenbo Hu, Tingchao He, Rongcui Jiang, Jun Yin, Lin Li, Xiaomei Lu, Hui Zhao, Lei Zhang, Ling Huang, Handong Sun, Wei Huang, Quli Fan
Herein, we experimentally and theoretically demonstrate an unprecedentedly enhanced two-photon absorption in a small organic molecule by a simple introduction of an inner salt-shaped structure. Moreover, such an inner salt-shaped small molecule also exhibits superior singlet oxygen quantum yield and fascinating structure-inherent mitochondrial-targeting ability for highly efficient two-photon photodynamic therapy via a mitochondrial apoptosis pathway.
January 19, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28101414/anti-confocal-assessment-of-middle-ear-inflammation
#19
David S Jung, John A Crowe, John P Birchall, Michael G Somekh, Chung W See
To improve the diagnostic prediction of recurrence of otitis media with effusion after surgery, an anti-confocal system combined with spectroscopic measurements is proposed to reject unwanted signals from the eardrum and assess the blood content. The anti-confocal system was experimentally evaluated on both optical middle ear phantom and human skin. Results showed effective rejection of signals from the eardrum using a central stop replacing the confocal pinhole, while still detecting signals from the middle ear mucosa...
January 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28101404/model-for-indirect-laser-surgery
#20
Natalia Sapogova, Vladimir Bredikhin, Nikita Bityurin, Vladislav Kamensky, Vjacheslav Zhigarcov, Vladimir Yusupov
We present a theoretical model for laser cutting of biological tissue by a strongly heated fiber tip with a highly absorbing coating. A significant dependence of the cutting speed and cutting depth on the inclination angle of the scalpel to the surface when scattering exceeds absorption in the biological tissue is shown. Experimental evidences of this effect are presented. In the experiment, we used silica fiber with coating made of carbon and silicon organic varnish, the 0.97-µm wavelength laser and porcine skin...
January 1, 2017: Biomedical Optics Express
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