Read by QxMD icon Read

RF pattern

Philippa R P Krahn, Sheldon M Singh, Venkat Ramanan, Labonny Biswas, Nicolas Yak, Kevan J T Anderson, Jennifer Barry, Mihaela Pop, Graham A Wright
BACKGROUND: Radiofrequency (RF) ablation has become a mainstay of treatment for ventricular tachycardia, yet adequate lesion formation remains challenging. This study aims to comprehensively describe the composition and evolution of acute left ventricular (LV) lesions using native-contrast cardiovascular magnetic resonance (CMR) during CMR-guided ablation procedures. METHODS: RF ablation was performed using an actively-tracked CMR-enabled catheter guided into the LV of 12 healthy swine to create 14 RF ablation lesions...
March 15, 2018: Journal of Cardiovascular Magnetic Resonance
Young-Duk Kim, Guk-Jin Son, Chan-Ho Song, Hee-Kang Kim
Recently, radar technology has attracted attention for the realization of an intelligent transportation system (ITS) to monitor, track, and manage vehicle traffic on the roads as well as adaptive cruise control (ACC) and automatic emergency braking (AEB) for driving assistance of vehicles. However, when radar is installed on roads or in tunnels, the detection performance is significantly dependent on the deployment conditions and environment around the radar. In particular, in the case of tunnels, the detection accuracy for a moving vehicle drops sharply owing to the diffuse reflection of radio frequency (RF) signals...
March 11, 2018: Sensors
Cristian A Linte, Jon J Camp, Maryam E Rettmann, Dieter Haemmerich, Mehmet K Aktas, David T Huang, Douglas L Packer, David R Holmes
In spite of significant efforts to improve image-guided ablation therapy, a large number of patients undergoing ablation therapy to treat cardiac arrhythmic conditions require repeat procedures. The delivery of insufficient thermal dose is a significant contributor to incomplete tissue ablation, in turn leading to the arrhythmia recurrence. Ongoing research efforts aim to better characterize and visualize RF delivery to monitor the induced tissue damage during therapy. Here, we propose a method that entails modeling and visualization of the lesions in real-time...
April 2018: Journal of Medical Imaging
Wyger M Brink, Zhiyi Wu, Andrew G Webb
PURPOSE: To demonstrate a simple head-sized phantom for realistic static and RF field characterization in high field systems. METHODS: The head-sized phantom was composed of an ellipsoidal compartment and a spherical cavity to mimic the nasal cavity. The phantom was filled with an aqueous solution of polyvinylpyrrolidone (PVP), to mimic the average dielectric properties of brain tissue. The static and RF field distributions were characterized on a 7T MRI system and compared to in vivo measurements and simulations...
March 1, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Intu Sharma, Yogita Batra, V Flauraud, Jürgen Brugger, Bodh Raj Mehta
The growth of MoS2 layers of desired dimensions at predefined locations is essential for fabricating opto-electronic devices based solely on MoS2 or on hetero-structures based on MoS2. Here we present a new route for patterned growth of MoS2 by combining radio frequency (RF) magnetron sputtering, stencil mask lithography and vapour phase sulfurization. The present method does not involve chemical etchants and organic photoresist and hence provides a simplified process of achieving MoS2 patterns. Here, the control over the number of layers (mono, few and bulk) of MoS2 is achieved by varying the thickness of Mo films...
March 1, 2018: Journal of Nanoscience and Nanotechnology
Jun Li, Wen-Qiong Wang, Shuai Tang, Wei-Bin Song, Li-Jiang Xuan
The phytochemical study of Euphorbia helioscopia afforded euphornin (1) in a large amount. Alkaline hydrolysis of 1 using potassium carbonate yielded the main product monodeacetyleuphornin (2), whose structural modification at 14-OH gave rise to 21 acylated derivatives euphornoate A-U (3-23). Thus, a mini compound library of jatrophanes was established to screen for MDR modulators. Biological studies clearly demonstrated the effect of C-14 pattern modification in MDR reversal activity and several compounds with RF values over 300 fold at 20 μM (6, 16, 20, 22, 23) were thought to be promising MDR modulators...
February 12, 2018: Fitoterapia
Viktor Pfaffenrot, Sascha Brunheim, Stefan H G Rietsch, Peter J Koopmans, Thomas M Ernst, Oliver Kraff, Stephan Orzada, Harald H Quick
PURPOSE: To design and evaluate an 8/15-channel transmit/receive (Tx/Rx) head-neck RF coil combination with region-specific B1+ shimming for whole-brain MRI with focus on improved functional MRI of the cerebellum at 7 T. METHODS: An 8-channel transceiver RF head coil was combined with a 7-channel receive-only array. The noise parameters and acceleration capabilities of this 8Tx/15Rx coil setup were compared with a commercially available 1Tx/32Rx RF head coil. Region-specific 8-channel B1+ shimming was applied when using the 8Tx/15Rx RF coil...
February 9, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Xiaoxi Kou, Rui Li, Lixia Hou, Lihui Zhang, Shaojin Wang
Radio frequency (RF) heating has been successfully used for inactivating microorganisms in agricultural and food products. Athermal (non-thermal) effects of RF energy on microorganisms have been frequently proposed in the literature, resulting in difficulties for developing effective thermal treatment protocols. The purpose of this study was to identify if the athermal inactivation of microorganisms existed during RF treatments. Escherichia coli and Staphylococcus aureus in apple juice and mashed potato were exposed to both RF and conventional thermal energies to compare their inactivation populations...
February 1, 2018: International Journal of Food Microbiology
Sareesh Naduvil Narayanan, Nirupam Mohapatra, Pamala John, Nalini K, Raju Suresh Kumar, Satheesha B Nayak, P Gopalakrishna Bhat
The purpose of the study was to evaluate the changes in amygdala morphology and emotional behaviors, upon exposure to chronic RF-EMR in adolescent rats. Four weeks old male albino Wistar rats were exposed to 900 MHz (power density:146.60 μW/cm2) from a mobile phone in silent-mode for 28 days. Amygdala morphology was studied using cresyl violet, TUNEL and Golgi-Cox staining. Place preference behavior was studied using light/dark chamber test and following this brain caspase-3 activity was determined. Number of healthy neurons was decreased in the basolateral amygdala and cortical amygdala but not in the central amygdala after RF-EMR exposure...
January 31, 2018: Environmental Toxicology and Pharmacology
Muthu Subash Kavitha, Takio Kurita, Byeong-Cheol Ahn
The objectives of this study are to assess various automated texture features obtained from the segmented colony regions of induced pluripotent stem cells (iPSCs) and confirm their potential for characterizing the colonies using different machine learning techniques. One hundred and fifty-one features quantified using shape-based, moment-based, statistical and spectral texture feature groups are extracted from phase-contrast microscopic colony images of iPSCs. The forward stepwise regression model is implemented to select the most appropriate features required for categorizing the colonies...
January 25, 2018: Computers in Biology and Medicine
Nayana George, Minjun Chen, Nancy Yuen, Christine M Hunt, Ayako Suzuki
We examined the effect of gender, age, and drug properties on liver events reporting frequency (RF) to assess patient- and drug-related risks for drug-induced liver injury (DILI). We performed a data-mining analysis of the WHO VigiBase™ to 1) identify drugs with gender- and age-biased RF and 2) characterize drug properties using the Liver Toxicity Knowledge Base. Age-, gender-specific Empirical Bayes Geometric Mean of relative reporting ratio of liver events with 90% confidence interval (CI) was calculated for 375 drugs with DILI potential...
January 29, 2018: Regulatory Toxicology and Pharmacology: RTP
James Bishop, Marco Fronzi, Christopher Elbadawi, Vikram Nikam, Joshua Pritchard, Johannes E Fröch, Ngoc My Hanh Duong, Michael J Ford, Igor Aharonovich, Charlene J Lobo, Milos Toth
Diamond is an ideal material for a broad range of cur- rent and emerging applications in tribology, quantum photonics, high power electronics and sensing. However, top-down processing is very challenging due to its extreme chemical and physical proper- ties. Gas-mediated electron beam induced etching (EBIE) has re- cently emerged as a minimally-invasive, facile means to dry etch and pattern diamond at the nano-scale using oxidizing precursor gases such as O2 and H2O. Here we explain the roles of oxygen and hydrogen in the etch process and show that oxygen gives rise to rapid, isotropic etching, whilst the addition of hydrogen gives rise to anisotropic etching and the formation of topographic surface pat- terns...
January 24, 2018: ACS Nano
Hancheng Lin, Yiwen Luo, Qiran Sun, Ji Zhang, Ya Tuo, Zhong Zhang, Lei Wang, Kaifei Deng, Yijiu Chen, Ping Huang, Zhenyuan Wang
Many studies have proven the usefulness of biofluid-based infrared spectroscopy in the clinical domain for diagnosis and monitoring the progression of diseases. Here, we present a state-of-the-art study in the forensic field that employed Fourier transform infrared microspectroscopy for post-mortem diagnosis of sudden cardiac death (SCD) by in situ biochemical investiga-tion of alveolar edema fluid in lung tissue sections. The results of amide-related spectral absorbance analysis demonstrated that the pulmonary edema fluid of the SCD group was richer in protein components than that of the neurologic catastrophe (NC) and lethal multiple injuries (LMI) groups...
January 24, 2018: Analytical Chemistry
Xin Wang, Peijie Lin, Joshua W K Ho
BACKGROUND: It has been observed that many transcription factors (TFs) can bind to different genomic loci depending on the cell type in which a TF is expressed in, even though the individual TF usually binds to the same core motif in different cell types. How a TF can bind to the genome in such a highly cell-type specific manner, is a critical research question. One hypothesis is that a TF requires co-binding of different TFs in different cell types. If this is the case, it may be possible to observe different combinations of TF motifs - a motif grammar - located at the TF binding sites in different cell types...
January 19, 2018: BMC Genomics
Simone Perna, Ilaria Avanzato, Mara Nichetti, Giuseppe D'Antona, Massimo Negro, Mariangela Rondanelli
This systematic review aimed to investigate the association of fish and sea fish dietary patterns (FishDiet) and meat or processed meat dietary patterns (MeatDiet) with bone mineral density (BMD) and/or risk of fractures (RF). This review includes 37 studies with a total of 432,924 subjects. The results suggest that MeatDiet and FishDiet did not affect BMD or RF in 48.2% of the subjects with MeatDiet and in 86.5% of the subjects with FishDiet. Positive effects on bone were found in 3% of subjects with MeatDiet and in 12% with FishDiet...
September 18, 2017: Nutrients
M Y Pustylnik, I L Semenov, E Zähringer, H M Thomas
The effect of micron-sized particles on a low-pressure capacitively coupled rf discharge is studied both experimentally and using numerical simulations. In the laboratory experiments, microparticle clouds occupying a considerable fraction of the discharge volume are supported against gravity with the help of the thermophoretic force. The spatiotemporally resolved optical emission measurements are performed with different arrangements of microparticles. The numerical simulations are carried out on the basis of a one-dimensional hybrid (fluid-kinetic) discharge model describing the interaction between plasma and microparticles in a self-consistent way...
September 2017: Physical Review. E
Valentina Hartwig, Stefania Romeo, Olga Zeni
The purpose of this review is to make a contribution to build a comprehensive knowledge of the main aspects related to the occupational exposure to electromagnetic fields (EMFs) in magnetic resonance imaging (MRI) environments. Information has been obtained from original research papers published in international peer-reviewed journals in the English language and from documents published by governmental bodies and authorities. An overview of the occupational exposure scenarios to static magnetic fields, motion-induced, time-varying magnetic fields, and gradient and radiofrequency fields is provided, together with a summary of the relevant regulation for limiting exposure...
January 18, 2018: Medical & Biological Engineering & Computing
Zengyu Gan, Yi Wang, Ting Wu, Xuefeng Xu, Xinzhong Zhang, Zhenhai Han
Lower promoter activity is closely associated with lower MdPIN1b expression in the M9 interstem, which might contribute to the dwarfing effect in apple trees. Apple trees grafted onto dwarfing rootstock Malling 9 (M9) produce dwarfing tree architecture with high yield and widely applying in production. Previously, we have reported that in Malus 'Red Fuji' (RF) trees growing on M9 interstem and Baleng Crab (BC) rootstock, IAA content was relatively higher in bark tissue of M9 interstem than that in scion or rootstock...
January 17, 2018: Plant Molecular Biology
Viktoriya Sabchyshyn, Irina Konon, Lawrence M Ryan, Ann K Rosenthal
OBJECTIVE: Calcium pyrophosphate deposition disease (CPDD) is arthritis caused by calcium pyrophosphate (CPP) crystal deposition in joints. It is commonly associated with aging as well as a handful of metabolic syndromes. Recent epidemiologic studies suggest a positive association of CPDD and rheumatoid arthritis (RA). Yet how these diseases are related remains unclear. We set out to describe 21 well-characterized patients with both diagnoses. METHODS: Medical records of patients with both RA and CPDD identified at a single academic practice site were reviewed for age, gender, age of CPDD and RA onset, disease duration, joint involvement, and lab values including rheumatoid factor (RF), cyclic citrullinated peptide antibody (CCP), iron studies, and parathyroid hormone and calcium levels...
December 2, 2017: Seminars in Arthritis and Rheumatism
Matteo Ridolfi, Stef Vandermeeren, Jense Defraye, Heidi Steendam, Joeri Gerlo, Dirk De Clercq, Jeroen Hoebeke, Eli De Poorter
Radio frequency (RF)-based indoor positioning systems (IPSs) use wireless technologies (including Wi-Fi, Zigbee, Bluetooth, and ultra-wide band (UWB)) to estimate the location of persons in areas where no Global Positioning System (GPS) reception is available, for example in indoor stadiums or sports halls. Of the above-mentioned forms of radio frequency (RF) technology, UWB is considered one of the most accurate approaches because it can provide positioning estimates with centimeter-level accuracy. However, it is not yet known whether UWB can also offer such accurate position estimates during strenuous dynamic activities in which moves are characterized by fast changes in direction and velocity...
January 9, 2018: Sensors
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"