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https://www.readbyqxmd.com/read/28719742/integrated-smartphone-app-chip-system-for-on-site-ppb-level-colorimetric-quantitation-of-aflatoxins
#1
Xiaochun Li, Fan Yang, Jessica X H Wong, Hua-Zhong Yu
We demonstrate herein an integrated, smartphone-app-chip (SPAC) system for on-site quantitation of food toxins, as demonstrated with aflatoxin B1 (AFB1), at parts-per-billion (ppb) level in food products. The detection is based on an indirect competitive immunoassay fabricated on a transparent plastic chip with the assistance of a microfluidic channel plate. A 3D-printed optical accessory attached to a smartphone is adapted to align the assay chip and to provide uniform illumination for imaging, with which high-quality images of the assay chip are captured by the smartphone camera and directly processed using a custom-developed Android app...
July 18, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28719659/dengue-prediction-by-the-web-tweets-are-a-useful-tool-for-estimating-and-forecasting-dengue-at-country-and-city-level
#2
Cecilia de Almeida Marques-Toledo, Carolin Marlen Degener, Livia Vinhal, Giovanini Coelho, Wagner Meira, Claudia Torres Codeço, Mauro Martins Teixeira
BACKGROUND: Infectious diseases are a leading threat to public health. Accurate and timely monitoring of disease risk and progress can reduce their impact. Mentioning a disease in social networks is correlated with physician visits by patients, and can be used to estimate disease activity. Dengue is the fastest growing mosquito-borne viral disease, with an estimated annual incidence of 390 million infections, of which 96 million manifest clinically. Dengue burden is likely to increase in the future owing to trends toward increased urbanization, scarce water supplies and, possibly, environmental change...
July 18, 2017: PLoS Neglected Tropical Diseases
https://www.readbyqxmd.com/read/28719614/beat-id-towards-a-computationally-low-cost-single-heartbeat-biometric-identity-check-system-based-on-electrocardiogram-wave-morphology
#3
Joana S Paiva, Duarte Dias, João P S Cunha
In recent years, safer and more reliable biometric methods have been developed. Apart from the need for enhanced security, the media and entertainment sectors have also been applying biometrics in the emerging market of user-adaptable objects/systems to make these systems more user-friendly. However, the complexity of some state-of-the-art biometric systems (e.g., iris recognition) or their high false rejection rate (e.g., fingerprint recognition) is neither compatible with the simple hardware architecture required by reduced-size devices nor the new trend of implementing smart objects within the dynamic market of the Internet of Things (IoT)...
2017: PloS One
https://www.readbyqxmd.com/read/28719406/toward-a-biopsychosocial-ecology-of-the-human-microbiome-brain-gut-axis-and-health
#4
Karl J Maier, Mustafa al'Absi
OBJECTIVE: Rapidly expanding insights to the human microbiome and health suggest that Western medicine is poised for significant evolution, or perhaps revolution - this while the field continues on a trajectory from reductionism to a biopsychosocial (BPS) paradigm recognizing biological, psychological, and social influences on health. The apparent sensitivity of the microbiota to perturbations across BPS domains suggests that a broad and inclusive framework is needed to develop applicable knowledge in this area...
July 18, 2017: Psychosomatic Medicine
https://www.readbyqxmd.com/read/28719217/single-molecule-study-on-polymer-nanoparticle-interactions-the-particle-shape-matters
#5
Zhandong Li, Bin Zhang, Yu Song, Yurui Xue, Lixin Wu, Wenke Zhang
The study on the nanoparticle-polymer interactions is very important for the design/preparation of high performance polymer nanocomposite. Here we present a method to quantify the polymer-particle interaction at single molecule level by using AFM-based single molecule force spectroscopy (SMFS). As a proof-of-concept study, we choose Poly-L-Lysine (PLL) as the polymer and several different types of polyoxometalates (POM) as the model particles to construct several different polymer nanocomposites and to reveal the binding mode and quantify the binding strength in these systems...
July 18, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28719213/full-dimensional-excited-state-intramolecular-proton-transfer-dynamics-of-salicylic-acid
#6
Tim Raeker, Bernd Hartke
Not all photodynamical processes are ultrafast processes in the range of 100 fs. Thus, using high-level ab initio methods for systems evolving along deactivation pathways in the excited state for picoseconds is not feasible. We will present full-dimensional photodynamics using the floating-occupation configuration-interaction (FOCI) treatment with single and paired double excitations based on the semiempirical RM1 Hamiltonian. Salicylic acid (SAc) served as our sample system which is a well-studied system both experimentally and theoretically by static calculations...
July 18, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28719206/direct-quantum-dynamics-using-grid-based-wavefunction-propagation-and-machine-learned-potential-energy-surfaces
#7
Gareth W Richings, Scott Habershon
We describe a method for performing nuclear quantum dynamics calculations using standard, grid-based algorithms, including the multi configurational time-dependent Hartree (MCTDH) method, where the potential energy surface (PES) is calculated ``on-the-fly''. The method of Gaussian process regression (GPR) is used to construct a global representation of the PES using values of the energy at points distributed in molecular configuration space during the course of the wavepacket propagation. We demonstrate this direct dynamics approach for both an analytical PES function describing 3-dimensional proton transfer dynamics in malonaldehyde, and for 2- and 6-dimensional quantum dynamics simulations of proton transfer in salicylaldimine...
July 18, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28719202/quadrupolar-nmr-relaxation-from-ab-initio-molecular-dynamics-improved-sampling-and-cluster-models-vs-periodic-calculations
#8
Adam Philips, Alex Marchenko, Lionel Alexandre Truflandier, Jochen Autschbach
Quadrupolar NMR relaxation rates are computed for (17)O, (2)H nuclei of liquid water, and of (23)Na(+) , and (35)Cl(-) in aqueous solution, via Kohn-Sham (KS) density functional theory ab-initio molecular dynamics (aiMD) and subsequent KS electric field gradient (EFG) calculations along the trajectories. The calculated relaxation rates are within about a factor of two of experimental results, and improved over previous aiMD simulations. The relaxation rates are assessed with regard to the lengths of the simulations as well as configurational sampling...
July 18, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28719100/deuteration-of-hyperpolarized-%C3%A2-%C3%A2-c-labelled-zymonic-acid-enables-sensitivity-enhanced-dynamic-mri-of-ph
#9
Christian Hundshammer, Stephan Düwel, Simone Köcher, Malte Gersch, Benedikt Feuerecker, Christoph Scheurer, Axel Haase, Steffen J Glaser, Markus Schwaiger, Franz Schilling
Aberrant pH is characteristic of many pathologies such as ischemia, inflammation or cancer. Therefore, a non-invasive and spatially resolved pH determination is valuable for disease diagnosis, characterization of response to treatment and the design of pH-sensitive drug delivery systems. We recently introduced hyperpolarized zymonic acid (ZA) as a novel MRI probe of extracellular pH utilizing dissolution dynamic polarization (DNP) for a more than 10,000-fold NMR signal enhancement. Here we present a strategy to enhance the sensitivity of this approach by deuteration of ZA (ZAd)...
July 18, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/28718930/genesis-1-1-a-hybrid-parallel-molecular-dynamics-simulator-with-enhanced-sampling-algorithms-on-multiple-computational-platforms
#10
Chigusa Kobayashi, Jaewoon Jung, Yasuhiro Matsunaga, Takaharu Mori, Tadashi Ando, Koichi Tamura, Motoshi Kamiya, Yuji Sugita
GENeralized-Ensemble SImulation System (GENESIS) is a software package for molecular dynamics (MD) simulation of biological systems. It is designed to extend limitations in system size and accessible time scale by adopting highly parallelized schemes and enhanced conformational sampling algorithms. In this new version, GENESIS 1.1, new functions and advanced algorithms have been added. The all-atom and coarse-grained potential energy functions used in AMBER and GROMACS packages now become available in addition to CHARMM energy functions...
July 18, 2017: Journal of Computational Chemistry
https://www.readbyqxmd.com/read/28718884/dispersal-host-genotype-and-environment-shape-the-spatial-dynamics-of-a-parasite-in-the-wild
#11
Adam Ekholm, Tomas Roslin, Pertti Pulkkinen, Ayco Jm Tack
Dispersal, environment and genetic variation may all play a role in shaping host-parasite dynamics. Yet, in natural systems, their relative importance remains unresolved. Here, we do so for the epidemiology of a specialist parasite (Erysiphe alphitoides) on the pedunculate oak (Quercus robur). For this purpose, we combine evidence from a multi-year field survey and two dispersal experiments, all conducted at the landscape scale. Patterns detected in the field survey suggest that the parasite is structured as a metapopulation, with trees in denser oak stands characterized by higher parasite occupancy, higher colonization rates and lower extinction rates...
July 18, 2017: Ecology
https://www.readbyqxmd.com/read/28718650/self-regulated-nanoparticle-assembly-at-liquid-liquid-interfaces-a-route-to-adaptive-structuring-of-liquids
#12
Caili Huang, Mengmeng Cui, Zhiwei Sun, Feng Liu, Brett A Helms, Thomas P Russell
The controlled structuring of liquids into arbitrary shapes can be achieved in biphasic liquid media using the interfacial assemblies of nanoparticle surfactants (NP-surfactants), that consist of a polar nanoparticle "head group" bound to one or more hydrophobic polymer "tails". The non-equilibrium shapes of the suspended liquid phase can be rendered permanent by the jamming of the NP-surfactants formed and assembled at the interface between the liquids as the system attempts to minimize the interfacial area between the liquids...
July 18, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28718641/in-silico-skin-model-a-multiscale-simulation-study-of-drug-transport
#13
Kishore Gajula, Rakesh Gupta, D B Sridhar, Beena Rai
Accurate in-silico models are required to predict the release of drug molecules through skin in order to supplement the in-vivo experiments for faster development/testing of drugs. The upper most layer of the skin, stratum corneum (SC), offers main resistance for permeation of actives. Most of the SC's molecular level models comprise of cholesterol, and phospholipids only, which is far from the reality. In this study we have implemented a multiscale modelling framework to obtain the release profile of three drugs namely Caffeine, Fentanyl and Naphthol through skin SC...
July 18, 2017: Journal of Chemical Information and Modeling
https://www.readbyqxmd.com/read/28718616/photo-thermally-driven-refreshable-microactuators-based-on-graphene-oxide-doped-paraffin
#14
Sichao Hou, Miao Wang, Shouwu Guo, Ming Su
Actuators based on phase change materials (paraffin) can simultaneously produce large stroke length and large force due to thermal expansion, but the low thermal conductivity of paraffin requires high power input and long actuation time. The graphene oxide (GO) doped paraffin dynamic actuator addresses the key challenges in the design of thermal phase change actuators: Thermal conductivity and light absorbing is increased and the response time is reduced compared to the standard phase change actuator designed with metal heating resistors...
July 18, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28718450/dynamics-and-energetics-of-the-mammalian-phosphatidylinositol-transfer-protein-phospholipid-exchange-cycle
#15
Aby Grabon, Adam Orlowski, Ashutosh Tripathi, Joni Vuorio, Matti Javanainen, Tomasz Róg, Max Lönnfors, Mark I McDermott, Garland Siebert, Pentti Somerharju, Ilpo Vattulainen, Vytas A Bankaitis
Phosphatidylinositol-transfer proteins (PITPs) regulate phosphoinositide signaling in eukaryotic cells. The defining feature of PITPs is their ability to exchange phosphatidylinositol (PtdIns) molecules between membranes, and this property is central to PITP-mediated regulation of lipid signaling. Yet, the details of the PITP-mediated lipid exchange cycle remain entirely obscure. Here, all-atom molecular dynamics (MD) simulations of the mammalian StART-like PtdIns/ phosphatidylcholine (PtdCho) transfer protein PITPα, both on membrane bilayers and in solvated systems, informed downstream biochemical analyses that tested key aspects of the hypotheses generated by the MD simulations...
July 17, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28718281/long-distance-modulation-of-disorder-to-order-in-protein-allostery
#16
Jingheng Wang, Gregory S Custer, Dorothy Beckett, Silvina Matysiak
Elucidation of the molecular details of allosteric communication between distant sites in a protein is key to understanding and manipulating many biological regulatory processes. Although protein disorder is acknowledged to play an important thermodynamic role in allostery, the molecular mechanisms by which this disorder is harnessed for long distance communication are known for a limited number of systems. Transcription repression by the E. coli biotin repressor, BirA, is allosterically activated by binding of the small molecule effector biotinoyl-5'-AMP...
July 18, 2017: Biochemistry
https://www.readbyqxmd.com/read/28718175/deployment-of-spatial-attention-to-a-structural-framework-exogenous-alerting-and-endogenous-goal-directed-factors
#17
Lisa N Jefferies, Vincent Di Lollo
The main question examined in the present work was whether spatial attention can be deployed to an appropriate structural framework not only endogenously when the framework is displayed continuously, as in previous work, but also exogenously, when it is displayed transiently 100 ms before the target. The results of five experiments answered that question in the negative. We found that the onset transient triggered by a brief presentation of the structural framework did enhance the response to the upcoming target...
July 17, 2017: Attention, Perception & Psychophysics
https://www.readbyqxmd.com/read/28717902/fusion-of-heart-rate-variability-and-pulse-rate-variability-for-emotion-recognition-using-lagged-poincare-plots
#18
Atefeh Goshvarpour, Ataollah Abbasi, Ateke Goshvarpour
Designing an efficient automatic emotion recognition system based on physiological signals has attracted great interests within the research of human-machine interactions. This study was aimed to classify emotional responses by means of a simple dynamic signal processing technique and fusion frameworks. The electrocardiogram and finger pulse activity of 35 participants were recorded during rest condition and when subjects were listening to music intended to stimulate certain emotions. Four emotion categories, including happiness, sadness, peacefulness, and fear were chosen...
July 17, 2017: Australasian Physical & Engineering Sciences in Medicine
https://www.readbyqxmd.com/read/28717901/performance-assessment-of-a-programmable-five-degrees-of-freedom-motion-platform-for-quality-assurance-of-motion-management-techniques-in-radiotherapy
#19
Chen-Yu Huang, Paul Keall, Adam Rice, Emma Colvill, Jin Aun Ng, Jeremy T Booth
Inter-fraction and intra-fraction motion management methods are increasingly applied clinically and require the development of advanced motion platforms to facilitate testing and quality assurance program development. The aim of this study was to assess the performance of a 5 degrees-of-freedom (DoF) programmable motion platform HexaMotion (ScandiDos, Uppsala, Sweden) towards clinically observed tumor motion range, velocity, acceleration and the accuracy requirements of SABR prescribed in AAPM Task Group 142...
July 17, 2017: Australasian Physical & Engineering Sciences in Medicine
https://www.readbyqxmd.com/read/28717531/the-role-of-vitamin-d-supplementation-on-erectile-function
#20
REVIEW
Raidh A Talib, Kareim Khalafalla, Önder Cangüven
In the last few years growing evidence highlighted vitamin D (VD) deficiency is one of the several dynamics that associates with increased atherosclerotic cardiovascular (ASCV) diseases. ASCV diseases and erectile dysfunction (ED) share common risk factors such as diabetes mellitus, hypertension, smoking, hyperlipidemia, and a sedentary lifestyle. The aim of this review was to summarize current progress in VD research by focusing effect of low VD level on different body systems and erectile function. Here we examine research linking VD deficiency and ED and discuss how VD influences ED and its classic risk factors that also associate to increased ED risk...
June 2017: Turkish Journal of Urology
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