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https://www.readbyqxmd.com/read/29350408/calibration-and-non-orthogonality-correction-of-three-axis-hall-sensors-for-the-monitoring-of-mri-workers-exposure-to-static-magnetic-fields
#1
Antoine Delmas, Lamia Belguerras, Nicolas Weber, Freddy Odille, Cédric Pasquier, Jacques Felblinger, Pierre-André Vuissoz
A Magnetic Resonance Imaging (MRI) scanner uses three different electromagnetic fields (EMF) to produce body images: a static permanent magnetic field (MF), several pulsed magnetic gradients, and a radiofrequency pulse. As a result, any occupation that includes an MRI exposes workers to a strong MF. The World Health Organization has now given the monitoring of occupational EMF exposure a high priority. One design for a low-cost, compact MF exposure monitor (« MR exposimeter ») uses a set of three orthogonally assembled Hall sensors...
January 19, 2018: Bioelectromagnetics
https://www.readbyqxmd.com/read/29350024/rapid-sample-pretreatment-and-accurate-quantification-of-radiosulfur-in-chemically-complex-atmospheric-samples
#2
Mang Lin, Mark H Thiemens
An ultra-low-level liquid scintillation counting (LSC) technique has been used in measuring radiosulfur (cosmogenic 35S) in natural samples. The ideal half-life of 35S (~87 d) renders it a new way to examine various biogeochemical problems. A major limit of the technique is that complex chemical compositions in atmospheric samples may lead to color quenching of LSC cocktails, a serious problem prolonging the pretreatment time (>1 week) and hampering the accurate determination of 35S. For application of the technique where many of the most important atmospheric chemical processes are examined, significant interferences arise and accurate analysis in small samples is not possible...
January 19, 2018: Analytical Chemistry
https://www.readbyqxmd.com/read/29349756/breast-cancer-screening-the-debate-that-never-ends
#3
Sarah M Friedewald
Screening mammography has been shown to decrease breast cancer deaths through randomized controlled trials. However, there remains significant debate surrounding the most appropriate time to commence screening and the optimal screening interval. Several national organizations have recently updated their guidelines by reanalyzing the published data. Interestingly, each organization has come to different conclusions regarding their recommendation for breast cancer screening in the average risk woman. Three of the main organizations that issue guidelines for breast cancer screening in the United States are reviewd in this chapter...
2018: Cancer Treatment and Research
https://www.readbyqxmd.com/read/29349498/plasma-metabolites-associated-with-type-2-diabetes-in-a-swedish-population-a-case-control-study-nested-in-a-prospective-cohort
#4
Lin Shi, Carl Brunius, Marko Lehtonen, Seppo Auriola, Ingvar A Bergdahl, Olov Rolandsson, Kati Hanhineva, Rikard Landberg
AIMS/HYPOTHESIS: The aims of the present work were to identify plasma metabolites that predict future type 2 diabetes, to investigate the changes in identified metabolites among individuals who later did or did not develop type 2 diabetes over time, and to assess the extent to which inclusion of predictive metabolites could improve risk prediction. METHODS: We established a nested case-control study within the Swedish prospective population-based Västerbotten Intervention Programme cohort...
January 18, 2018: Diabetologia
https://www.readbyqxmd.com/read/29348871/radiation-therapy-for-stage-iva-uterine-cervical-cancer-treatment-outcomes-including-prognostic-factors-and-risk-of-vesicovaginal-and-rectovaginal-fistulas
#5
Masaharu Hata, Izumi Koike, Etsuko Miyagi, Reiko Numazaki, Mikiko Asai-Sato, Hisashi Kaizu, Yuki Mukai, Shoko Takano, Eiko Ito, Madoka Sugiura, Tomio Inoue
Purpose: To evaluate the safety and efficacy of radiation therapy for stage IVA uterine cervical cancer and to identify an optimal radiation regimen. Results: Seventeen of the 28 patients developed recurrence after radiation therapy (local recurrence in 10 and distant metastasis in 12). The local control and distant metastasis-free rates at 3 years in all patients were 61% and 49%, respectively. Fourteen patients died after radiation therapy, and all but 2 died of tumor progression...
December 22, 2017: Oncotarget
https://www.readbyqxmd.com/read/29347534/exponential-bound-in-the-quest-for-absolute-zero
#6
Dionisis Stefanatos
In most studies for the quantification of the third law of thermodynamics, the minimum temperature which can be achieved with a long but finite-time process scales as a negative power of the process duration. In this article, we use our recent complete solution for the optimal control problem of the quantum parametric oscillator to show that the minimum temperature which can be obtained in this system scales exponentially with the available time. The present work is expected to motivate further research in the active quest for absolute zero...
October 2017: Physical Review. E
https://www.readbyqxmd.com/read/29347079/optimal-information-transfer-in-enzymatic-networks-a-field-theoretic-formulation
#7
Himadri S Samanta, Michael Hinczewski, D Thirumalai
Signaling in enzymatic networks is typically triggered by environmental fluctuations, resulting in a series of stochastic chemical reactions, leading to corruption of the signal by noise. For example, information flow is initiated by binding of extracellular ligands to receptors, which is transmitted through a cascade involving kinase-phosphatase stochastic chemical reactions. For a class of such networks, we develop a general field-theoretic approach to calculate the error in signal transmission as a function of an appropriate control variable...
July 2017: Physical Review. E
https://www.readbyqxmd.com/read/29346884/nonstationary-dynamics-of-encounters-mean-valuable-territory-covered-by-a-random-searcher
#8
Daniel Campos, Frederic Bartumeus, Vicenç Méndez
Inspired by recent experiments on the organism Caenorhabditis elegans we present a stochastic problem to capture the adaptive dynamics of search in living beings, which involves the exploration-exploitation dilemma between remaining in a previously preferred area and relocating to new places. We assess the question of search efficiency by introducing a new magnitude, the mean valuable territory covered by a Browinan searcher, for the case where each site in the domain becomes valuable only after a random time controlled by a nonhomogeneous rate which expands from the origin outwards...
September 2017: Physical Review. E
https://www.readbyqxmd.com/read/29346713/spark-generated-microbubble-cell-sorter-for-microfluidic-flow-cytometry
#9
Jingjing Zhao, Zheng You
High-speed and accurate cell sorting is of great significance for cell analysis regarding both bioresearch and clinical application. Different from the jet-in-air sorting of commercial flow cytometers, sorting in fully enclosed and disposal microfluidic chips can avoid aerosols and crosscontamination, thus contributing to the improvement of biosafety and test accuracy. However, current microfluidic sorters usually require complicated structures, or otherwise cannot attain high throughput. In this article, a sorting mechanism for microfluidics is proposed for the first time based on the jet flow induced by the spark-generated cavitation microbubble that can be easily realized by a pair of electrodes...
January 18, 2018: Cytometry. Part A: the Journal of the International Society for Analytical Cytology
https://www.readbyqxmd.com/read/29346412/a-comparative-analysis-of-preservation-techniques-for-the-optimal-molecular-detection-of-hookworm-dna-in-a-human-fecal-specimen
#10
Marina Papaiakovou, Nils Pilotte, Ben Baumer, Jessica Grant, Kristjana Asbjornsdottir, Fabian Schaer, Yan Hu, Raffi Aroian, Judd Walson, Steven A Williams
BACKGROUND: Proper collection and storage of fecal samples is necessary to guarantee the subsequent reliability of DNA-based soil-transmitted helminth diagnostic procedures. Previous research has examined various methods to preserve fecal samples for subsequent microscopic analysis or for subsequent determination of overall DNA yields obtained following DNA extraction. However, only limited research has focused on the preservation of soil-transmitted helminth DNA in stool samples stored at ambient temperature or maintained in a cold chain for extended periods of time...
January 2018: PLoS Neglected Tropical Diseases
https://www.readbyqxmd.com/read/29346367/assessment-of-serum-pharmacokinetics-and-urinary-excretion-of-albendazole-and-its-metabolites-in-human-volunteers
#11
Laura Ceballos, Alejandro Krolewiecki, Marisa Juárez, Laura Moreno, Fabian Schaer, Luis I Alvarez, Rubén Cimino, Judd Walson, Carlos E Lanusse
BACKGROUND: Soil Transmitted Helminth (STH) infections negatively impact physical and mental development in human populations. Current WHO guidelines recommend morbidity control of these infections through mass drug administration (MDA) using albendazole (ABZ) or mebendazole. Despite major reductions in STH associated morbidity globally, not all programs have demonstrated the expected impact on prevalence of parasite infections. These therapeutic failures may be related to poor programmatic coverage, suboptimal adherence or the exposure of parasites to sub-therapeutic drug concentrations...
January 2018: PLoS Neglected Tropical Diseases
https://www.readbyqxmd.com/read/29345604/a-new-approach-of-three-dimensional-guidance-in-paediatric-cath-lab-segmented-and-tessellated-heart-models-for-cardiovascular-interventions-in-chd
#12
Nicole Ehret, Muhannad Alkassar, Sven Dittrich, Robert Cesnjevar, André Rüffer, Michael Uder, Oliver Rompel, Matthias Hammon, Martin Glöckler
BACKGROUND: Optimal imaging is essential for catheter-based interventions in CHD. The three-dimensional models in volume-rendering technique currently in use are not standardised. This paper investigates the feasibility and impact of novel three-dimensional guidance with segmented and tessellated three-dimensional heart models in catheterisation of CHD. In addition, a nearly radiation-free two- to three-dimensional registration and a biplane overlay were used. Methods and results We analysed 60 consecutive cases in which segmented tessellated three-dimensional heart models were merged with live fluoroscopy images and aligned using the tracheal bifurcation as a fiducial mark...
January 18, 2018: Cardiology in the Young
https://www.readbyqxmd.com/read/29345392/who-may-benefit-from-on-demand-control-of-deep-brain-stimulation-noninvasive-evaluation-of-parkinson-patients
#13
Daniel Graupe, Nivedita Khobragade, Daniela Tuninetti, Ishita Basu, Konstantin V Slavin, Leo Verhagen Metman
BACKGROUND: In closed-loop on-demand control (ODC) of deep brain stimulation (DBS), stimulation is applied only when symptoms appear. Following stimulation of a fixed duration, DBS is switched off until the symptoms reappear. By repeating these demand-driven cycles, the amount of stimulation delivered can be decreased, thereby reducing DBS side-effects and improving battery-life of the pulse-generator. This article introduces Ro metric for quantification of degree of benefit of ODC and explores candidate selection in tremor-dominant Parkinson's disease (PD)...
January 18, 2018: Neuromodulation: Journal of the International Neuromodulation Society
https://www.readbyqxmd.com/read/29345271/flocculation-on-a-chip-a-novel-screening-approach-to-determine-floc-growth-rates-and-select-flocculating-agents
#14
Anand N P Radhakrishnan, Marco P C Marques, Matthew J Davies, Brian O'Sullivan, Daniel G Bracewell, Nicolas Szita
Flocculation is a key purification step in cell-based processes for the food and pharmaceutical industry where the removal of cells and cellular debris is aided by adding flocculating agents. However, finding the best suited flocculating agent and optimal conditions to achieve rapid and effective flocculation is a non-trivial task. In conventional analytical systems, turbulent mixing creates a dynamic equilibrium between floc growth and breakage, constraining the determination of floc formation rates. Furthermore, these systems typically rely on end-point measurements only...
January 18, 2018: Lab on a Chip
https://www.readbyqxmd.com/read/29345252/optimization-of-lentiviral-vector-production-for-scale-up-in-fixed-bed-bioreactor
#15
A J Valkama, H M Leinonen, E M Lipponen, V Turkki, J Malinen, T Heikura, S Ylä-Herttuala, H P Lesch
Lentiviral vectors (LVs) are promising tools for gene therapy. However, scaling up the production methods of LVs in order to produce high-quality vectors for clinical purposes has proven to be difficult. In this article, we present a scalable and efficient method to produce LVs with transient transfection of adherent 293T cells in a fixed-bed bioreactor. The disposable iCELLis bioreactors are scalable with a large three-dimensional (3D) growth area range between 0.53 and 500 m2, an integrated perfusion system, and a controllable environment for production...
October 5, 2017: Gene Therapy
https://www.readbyqxmd.com/read/29345085/effects-of-ultrasonication-variables-on-the-activity-and-properties-of-alpha-amylase-preparation
#16
Thi Thu Tra Tran, Khanh Tien Nguyen, Van Viet Man Le
Recently, ultrasound was demonstrated to increase enzyme activity in food industry. In most studies, an enzyme-substrate mixture was ultrasonicated. Very little is reported on the ultrasonication of enzyme preparation; the effects of ultrasonication variables on the enzyme activity and properties remained unclear. In this study, an α-amylase preparation was ultrasonicated under different conditions. At the ultrasonic frequency, power, temperature and time of 20 kHz, 25 W/mL, 30°C and 75 sec, respectively the secondary structure of the α-amylase was changed and that improved the catalytic activity by 47% over the control...
January 18, 2018: Biotechnology Progress
https://www.readbyqxmd.com/read/29342498/patient-reminder-and-recall-interventions-to-improve-immunization-rates
#17
REVIEW
Julie C Jacobson Vann, Robert M Jacobson, Tamera Coyne-Beasley, Josephine K Asafu-Adjei, Peter G Szilagyi
BACKGROUND: Immunization rates for children and adults are rising, but coverage levels have not reached optimal goals. As a result, vaccine-preventable diseases still occur. In an era of increasing complexity of immunization schedules, rising expectations about the performance of primary care, and large demands on primary care providers, it is important to understand and promote interventions that work in primary care settings to increase immunization coverage. One common theme across immunization programs in many nations involves the challenge of implementing a population-based approach and identifying all eligible recipients, for example the children who should receive the measles vaccine...
January 18, 2018: Cochrane Database of Systematic Reviews
https://www.readbyqxmd.com/read/29342181/optimization-of-mneongreen-for-homo-sapiens-increases-its-fluorescent-intensity-in-mammalian-cells
#18
Emiko Tanida-Miyake, Masato Koike, Yasuo Uchiyama, Isei Tanida
Green fluorescent protein (GFP) is tremendously useful for investigating many cellular and intracellular events. The monomeric GFP mNeonGreen is about 3- to 5-times brighter than GFP and monomeric enhanced GFP and shows high photostability. The maturation half-time of mNeonGreen is about 3-fold faster than that of monomeric enhanced GFP. However, the cDNA sequence encoding mNeonGreen contains some codons that are rarely used in Homo sapiens. For better expression of mNeonGreen in human cells, we synthesized a human-optimized cDNA encoding mNeonGreen and generated an expression plasmid for humanized mNeonGreen under the control of the cytomegalovirus promoter...
2018: PloS One
https://www.readbyqxmd.com/read/29341922/sustained-release-timolol-maleate-loaded-ocusert-based-on-biopolymer-composite
#19
Revathy V Nair, Shefrin S, Akhil Suresh, Anoop K R, Sreeja C Nair
In the present investigation, the effect of timolol maleate loaded ocuserts was studied as an alternative for conventional anti-glaucoma formulation. Ocuserts were prepared using natural polymer sodium alginate and ethyl cellulose. Physico-chemical properties along with drug entrapment efficiency (94-98%), content uniformity (93.1% ± 0.264-98.00% ± 0.321), in vitro drug release (83.42% ± 0.35 at end of 12 hours), ex vivo permeation all showed satisfactory results, which was found to follow zero order kinetics...
January 13, 2018: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/29341723/improving-a-solid-state-qubit-through-an-engineered-mesoscopic-environment
#20
G Éthier-Majcher, D Gangloff, R Stockill, E Clarke, M Hugues, C Le Gall, M Atatüre
A controlled quantum system can alter its environment by feedback, leading to reduced-entropy states of the environment and to improved system coherence. Here, using a quantum-dot electron spin as a control and probe, we prepare the quantum-dot nuclei under the feedback of coherent population trapping and observe their evolution from a thermal to a reduced-entropy state, with the immediate consequence of extended qubit coherence. Via Ramsey interferometry on the electron spin, we directly access the nuclear distribution following its preparation and measure the emergence and decay of correlations within the nuclear ensemble...
September 29, 2017: Physical Review Letters
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