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https://www.readbyqxmd.com/read/28821991/transcranial-doppler-in-autonomic-testing-standards-and-clinical-applications
#1
REVIEW
Lucy Norcliffe-Kaufmann, Brahyan Galindo-Mendez, Ana-Lucia Garcia-Guarniz, Estibaliz Villarreal-Vitorica, Vera Novak
When cerebral blood flow falls below a critical limit, syncope occurs and, if prolonged, ischemia leads to neuronal death. The cerebral circulation has its own complex finely tuned autoregulatory mechanisms to ensure blood supply to the brain can meet the high metabolic demands of the underlying neuronal tissue. This involves the interplay between myogenic and metabolic mechanisms, input from noradrenergic and cholinergic neurons, and the release of vasoactive substrates, including adenosine from astrocytes and nitric oxide from the endothelium...
August 18, 2017: Clinical Autonomic Research: Official Journal of the Clinical Autonomic Research Society
https://www.readbyqxmd.com/read/28821661/attenuated-activity-across-multiple-cell-types-and-reduced-monosynaptic-connectivity-in-the-aged-perirhinal-cortex
#2
A P Maurer, S N Burke, K Diba, C A Barnes
The perirhinal cortex (PER), which is critical for associative memory and stimulus discrimination, has been described as a wall of inhibition between the neocortex and hippocampus. With advanced age, rats show deficits on PER-dependent behavioral tasks and fewer PER principal neurons are activated by stimuli, but the role of PER interneurons in these altered circuit properties in old age has not been characterized. In the present study, PER neurons were recorded while rats traversed a circular track bi-directionally in which the track was either empty or contained 8 novel objects evenly spaced around the track...
August 11, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28821242/methodological-factors-affecting-joint-moments-estimation-in-clinical-gait-analysis-a-systematic-review
#3
REVIEW
Valentina Camomilla, Andrea Cereatti, Andrea Giovanni Cutti, Silvia Fantozzi, Rita Stagni, Giuseppe Vannozzi
Quantitative gait analysis can provide a description of joint kinematics and dynamics, and it is recognized as a clinically useful tool for functional assessment, diagnosis and intervention planning. Clinically interpretable parameters are estimated from quantitative measures (i.e. ground reaction forces, skin marker trajectories, etc.) through biomechanical modelling. In particular, the estimation of joint moments during motion is grounded on several modelling assumptions: (1) body segmental and joint kinematics is derived from the trajectories of markers and by modelling the human body as a kinematic chain; (2) joint resultant (net) loads are, usually, derived from force plate measurements through a model of segmental dynamics...
August 18, 2017: Biomedical Engineering Online
https://www.readbyqxmd.com/read/28816504/validity-and-reliability-of-the-3-min-all-out-running-test-to-measure-critical-velocity-in-hot-environments
#4
Yu-Hsuan Kuo, Ching-Feng Cheng, Wei-Chieh Hsu, Del P Wong
This study's aim was to investigate the test-retest reliability of the 3-min all-out running test (3MRT) in hot environments. Twelve male sprinters (age 21.2 ± 1.8 years; height 1.78 ± 0.01 m; weight 71.0 ± 1.6 kg; [Formula: see text] 55.0 ± 1.0 mL kg(-1) min(-1)) performed an incremental exercise test in a laboratory, during which the first and second ventilatory thresholds (VT1 and VT2) and [Formula: see text] were determined. In addition, they performed two 3MRTs on an outdoor track in a hot environment, during which the critical velocity (CV) and anaerobic capacity (D') were estimated...
August 17, 2017: Research in Sports Medicine
https://www.readbyqxmd.com/read/28813869/effects-of-assistance-timing-on-metabolic-cost-assistance-power-and-gait-parameters-for-a-hip-type-exoskeleton
#5
Jusuk Lee, Keehong Seo, Bokman Lim, Junwon Jang, Kyungrock Kim, Hyundo Choi
There are many important factors in developing an exoskeleton for assisting human locomotion. For example, the weight should be sufficiently light, the assist torque should be high enough to assist joint motion, and the assistance timing should be just right. Understanding how these design parameters affect overall performance of a complex human-machine system is critical for the development of these types of systems. The present study introduces an assistance timing controller that regulates assistance timing such that peak joint velocity and peak assistance power are offset by a reference value for our hip-type exoskeleton...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28811568/dynamic-x-ray-radiography-reveals-particle-size-and-shape-orientation-fields-during-granular-flow
#6
François Guillard, Benjy Marks, Itai Einav
When granular materials flow, the constituent particles segregate by size and align by shape. The impacts of these changes in fabric on the flow itself are not well understood, and thus novel non-invasive means are needed to observe the interior of the material. Here, we propose a new experimental technique using dynamic X-ray radiography to make such measurements possible. The technique is based on Fourier transformation to extract spatiotemporal fields of internal particle size and shape orientation distributions during flow, in addition to complementary measurements of velocity fields through image correlation...
August 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28808087/the-drosophila-lc8-homologue-cut-up-specifies-the-axonal-transport-of-proteasomes
#7
Tabita Kreko-Pierce, Benjamin A Eaton
Because of their functional polarity and elongated morphologies, microtubule-based transport of proteins and organelles is critical for normal neuronal function. The proteasome is required throughout the neuron for the highly regulated degradation of a broad set of protein targets whose functions underlie key physiological responses including synaptic plasticity and axonal degeneration. Molecularly, the relationship between proteasome transport and the transport of the targets of proteasomes is unclear. The dynein motor complex is required for the microtubule-based motility of numerous proteins and organelles in neurons...
August 14, 2017: Journal of Cell Science
https://www.readbyqxmd.com/read/28806783/the-utilization-of-critical-care-ultrasound-to-assess-hemodynamics-and-lung-pathology-on-icu-admission-and-the-potential-for-predicting-outcome
#8
Wanhong Yin, Yi Li, Xueying Zeng, Yao Qin, Dong Wang, Tongjuan Zou, Ling Su, Yan Kang
AIM: Critical care ultrasound (CCUS) has been used by many Intensive Care Units(ICUs) worldwide, so as to guiding the diagnosis and the treatment. However, none of the publications currently systematically describe the utilization of CCUS to analyze the characteristics of hemodynamics and lung pathology upon the new admission to ICU and its potential role in patients' prognosis prediction. In this retrospective clinical study, we have demonstrated and analyzed the characteristics of hemodynamics and lung pathology assessed by CCUS and investigated its potential to predict patient outcome...
2017: PloS One
https://www.readbyqxmd.com/read/28806080/dissociative-photoionization-of-the-elusive-vinoxy-radical
#9
Jonathan D Adams, Preston G Scrape, Shih-Huang Lee, Laurie J Butler
These experiments report the dissociative photoionization of vinoxy radicals to m/z = 15 and 29. In a crossed laser-molecular beam scattering apparatus, we induce C-Cl bond fission in 2-chloroacetaldehyde by photoexcitation at 157 nm. Our velocity measurements, combined with conservation of angular momentum, show that 21% of the C-Cl photofission events form vinoxy radicals that are stable to subsequent dissociation to CH3 + CO or H + ketene. Photoionization of these stable vinoxy radicals, identified by their velocities, which are momentum-matched with the higher-kinetic-energy Cl atom photofragments, shows that the vinoxy radicals dissociatively photoionize to give signal at m/z = 15 and 29...
August 14, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28801308/egfr-mutations-compromise-hypoxia-associated-radiation-resistance-through-impaired-replication-fork-associated-dna-damage-repair
#10
Mohammad Saki, Haruhiko Makino, Prashanthi Javvadi, Nozomi Tomimatsu, Lianghao Ding, Jennifer E Clark, Elaine Gavin, Kenichi Takeda, Joel Andrews, Debabrata Saha, Michael D Story, Sandeep Burma, Chaitanya Nirodi
Epidermal growth factor receptor (EGFR) signaling has been implicated in hypoxia-associated resistance to radiation or chemotherapy. Non-small cell lung carcinomas (NSCLC) with activating L858R or ΔE746-E750 EGFR mutations exhibit elevated EGFR activity and downstream signaling. Here, relative to wild type (WT) EGFR, mutant (MT) EGFR expression significantly increases radiosensitivity in hypoxic cells. Gene expression profiling in human bronchial epithelial cells (HBEC) revealed that MT-EGFR expression elevated transcripts related to cell cycle and replication in aerobic and hypoxic conditions and down-regulated RAD50, a critical component of non-homologous end-joining (NHEJ) and homologous recombination (HR) DNA repair pathways...
August 11, 2017: Molecular Cancer Research: MCR
https://www.readbyqxmd.com/read/28799370/nucleation-in-food-colloids
#11
Malcolm J W Povey
Nucleation in food colloids has been studied in detail using ultrasound spectroscopy. Our data show that classical nucleation theory (CNT) remains a sound basis from which to understand nucleation in food colloids and analogous model systems using n-alkanes. Various interpretations and modifications of CNT are discussed with regard to their relevance to food colloids. Much of the evidence presented is based on the ultrasound velocity spectrometry measurements which has many advantages for the study of nucleating systems compared to light scattering and NMR due to its sensitivity at low solid contents and its ability to measure true solid contents in the nucleation and early crystal growth stages...
December 7, 2016: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28793270/pancreatic-islet-blood-flow-dynamics-in-primates
#12
Juan A Diez, Rafael Arrojo E Drigo, Xiaofeng Zheng, Olga V Stelmashenko, Minni Chua, Rayner Rodriguez-Diaz, Masahiro Fukuda, Martin Köhler, Ingo Leibiger, Sai Bo Bo Tun, Yusuf Ali, George J Augustine, Veluchamy A Barathi, Per-Olof Berggren
Blood flow regulation in pancreatic islets is critical for function but poorly understood. Here, we establish an in vivo imaging platform in a non-human primate where islets transplanted autologously into the anterior chamber of the eye are monitored non-invasively and longitudinally at single-cell resolution. Engrafted islets were vascularized and innervated and maintained the cytoarchitecture of in situ islets in the pancreas. Blood flow velocity in the engrafted islets was not affected by increasing blood glucose levels and/or the GLP-1R agonist liraglutide...
August 8, 2017: Cell Reports
https://www.readbyqxmd.com/read/28780359/change-regularity-of-water-quality-parameters-in-leakage-flow-conditions-and-their-relationship-with-iron-release
#13
Jingqing Liu, Huabin Shentu, Huanyu Chen, Ping Ye, Bing Xu, Yifu Zhang, Hamid Bastani, Hongxi Peng, Lei Chen, Tuqiao Zhang
The long-term stagnation in metal water supply pipes, usually caused by intermittent consumption patterns, will cause significant iron release and water quality deterioration, especially at the terminus of pipelines. Another common phenomenon at the terminus of pipelines is leakage, which is considered helpful by allowing seepage of low-quality drinking water resulting from long-term stagnation. In this study, the effect of laminar flow on alleviating water quality deterioration under different leakage conditions was investigated, and the potential thresholds of the flow rate, which can affect the iron release process, were discussed...
July 16, 2017: Water Research
https://www.readbyqxmd.com/read/28779955/fluid-resuscitation-in-septic-patients-improves-systolic-but-not-diastolic-middle-cerebral-artery-flow-velocity
#14
Annika A de Goede, Bert G Loef, Auke C Reidinga, Arjen Schaafsma
To investigate the effects of fluid resuscitation on cerebral hemodynamics in sepsis, the following set of transcranial Doppler (TCD) parameters was used: maximal change in flow velocity (FV) during stroke onset (acc), maximal FV during first (sys1) or second (sys2) phase of systole and mean diastolic FV (dias@560). We aim to evaluate changes in cerebral hemodynamics that result from (i) sepsis and (ii) adequate fluid resuscitation in critically ill septic patients. In the majority of 16 septic patients sys2 was initially absent but reappeared during the period of fluid resuscitation; whereas sys2 absence was never seen in healthy controls...
August 2, 2017: Ultrasound in Medicine & Biology
https://www.readbyqxmd.com/read/28776234/combination-of-antibody-coated-physical-based-microfluidic-chip-with-wave-shaped-arrays-for-isolating-circulating-tumor-cells
#15
Hongmei Chen, Baoshan Cao, Hongda Chen, Yu-Sheng Lin, Jingjing Zhang
Circulating tumor cells (CTCs) are found in the peripheral blood of patients with metastatic cancers, which have critical significance in cancer prognosis and diagnostics. Enumeration is significantly valuable since number of CTCs is strongly correlated to severity of disease. This article is proposed and demonstrated an antibody-coated, size-based microfluidic chip with wave-shaped arrays could efficiently capture CTCs combining two separation methods of both size- and deformability-based and affinity-based segregation...
September 2017: Biomedical Microdevices
https://www.readbyqxmd.com/read/28772551/polyvinylpyrrolidone-based-bio-ink-improves-cell-viability-and-homogeneity-during-drop-on-demand-printing
#16
Wei Long Ng, Wai Yee Yeong, May Win Naing
Drop-on-demand (DOD) bioprinting has attracted huge attention for numerous biological applications due to its precise control over material volume and deposition pattern in a contactless printing approach. 3D bioprinting is still an emerging field and more work is required to improve the viability and homogeneity of printed cells during the printing process. Here, a general purpose bio-ink was developed using polyvinylpyrrolidone (PVP) macromolecules. Different PVP-based bio-inks (0%-3% w/v) were prepared and evaluated for their printability; the short-term and long-term viability of the printed cells were first investigated...
February 16, 2017: Materials
https://www.readbyqxmd.com/read/28765846/enhanced-enzymatic-activity-from-phosphotriesterase-trimer-gold-nanoparticle-bioconjugates-for-pesticide-detection
#17
John A Hondred, Joyce C Breger, Nate T Garland, Eunkeu Oh, Kimihiro Susumu, Scott A Walper, Igor L Medintz, Jonathan C Claussen
The rapid detection of organophosphates (OPs), a class of strong neurotoxins, is critically important for monitoring acute insecticide exposure and potential chemical warfare agent use. Herein, we improve the enzymatic activity of a phosphotriesterase trimer (PTE3), an enzyme that selectively recognizes OPs directly, by conjugation with distinctly sized (i.e., 5, 10, and 20 nm diameter) gold nanoparticles (AuNPs). The number of enzymes immobilized on the AuNP was controlled by conjugating increasing molar ratios of PTE3 onto the AuNP surface via metal affinity coordination...
August 2, 2017: Analyst
https://www.readbyqxmd.com/read/28763450/a-mathematical-model-describes-the-malignant-transformation-of-low-grade-gliomas-prognostic-implications
#18
Magdalena U Bogdańska, Marek Bodnar, Monika J Piotrowska, Michael Murek, Philippe Schucht, Jürgen Beck, Alicia Martínez-González, Víctor M Pérez-García
Gliomas are the most frequent type of primary brain tumours. Low grade gliomas (LGGs, WHO grade II gliomas) may grow very slowly for the long periods of time, however they inevitably cause death due to the phenomenon known as the malignant transformation. This refers to the transition of LGGs to more aggressive forms of high grade gliomas (HGGs, WHO grade III and IV gliomas). In this paper we propose a mathematical model describing the spatio-temporal transition of LGGs into HGGs. Our modelling approach is based on two cellular populations with transitions between them being driven by the tumour microenvironment transformation occurring when the tumour cell density grows beyond a critical level...
2017: PloS One
https://www.readbyqxmd.com/read/28754986/direct-estimation-of-the-global-distribution-of-vertical-velocity-within-cirrus-clouds
#19
Donifan Barahona, Andrea Molod, Heike Kalesse
Cirrus clouds determine the radiative balance of the upper troposphere and the transport of water vapor across the tropopause. The representation of vertical wind velocity, W, in atmospheric models constitutes the largest source of uncertainty in the calculation of the cirrus formation rate. Using global atmospheric simulations with a spatial resolution of 7 km we obtain for the first time a direct estimate of the distribution of W at the scale relevant for cirrus formation, validated against long-term observations at two different ground sites...
July 28, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28750164/fast-transport-of-water-droplets-over-a-thermo-switchable-surface-using-rewritable-wettability-gradient
#20
Theneyur Narayanaswamy Banuprasad, Thamarasseril Vijayan Vinay, Subash Cherumannil Karumuthil, Soney Varghese, Sajan D George, Subramanyan Namboodiri Varanakkottu
In spite of the reported temperature dependent tunability in wettability of Poly(N-isopropyl acrylamide) (PNIPAAm) surfaces for below and above lower critical solution temperature (32 °C), the transport of water droplets are inhibited by the large contact angle hysteresis. Herein, for the first time, we report on-demand, fast and reconfigurable droplet manipulation over a PNIPAAm grafted structured polymer surface using temperature-induced wettability gradient. Our study reveals that the PNIPAAm grafted on intrinsically superhydrophobic surfaces exhibit hydrophilic nature with high contact angle hysteresis below 30 °C, and superhydrophobic nature with ultra-low contact angle hysteresis above 36 °C...
July 27, 2017: ACS Applied Materials & Interfaces
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