Mobility Of Probe Research Articles

Coupling of ethanolamine ammonia-lyase protein and solvent dynamics characterized by the temperature-dependence of EPR spin probe mobility and dielectric permittivity.

Electron paramagnetic resonance (EPR) spectroscopy is used to address the remarkable persistence of the native Arrhenius dependence of the 2-aminopropanol substrate radical rearrangement reaction in B12-dependent ethanolamine ammonia-lyase (EAL) from Salmonella typhimurium from physiological to cryogenic (220 K) temperatures. Two-component TEMPOL spin probe mobility in the presence of 10 mM (0.08% v/v) 2-aminopropanol over 200-265 K demonstrates characteristic concentric aqueous-cosolvent mesodomain and protein-associated domain (PAD, hydration layer) solvent phases around EAL in the frozen solution. The mesodomain formed by the relatively small amount of 2-aminopropanol is highly confined, as shown by an elevated temperature for the order-disorder transition (ODT) in the PAD (230-235 K) and large activation energy for TEMPOL rotation. Addition of 2% v/v dimethylsulfoxide expands the mesodomain, partially relieves PAD confinement, and leads to an ODT at 205-210 K. The ODT is also manifested as a deviation of the temperature-dependence of the EPR amplitude of cob(II)alamin and the substrate radical, bound in the enzyme active site, from Curie law behavior. This is attributed to an increase in sample dielectric permittivity above the ODT at the microwave frequency of 9.5 GHz. The relatively high frequency dielectric response indicates an origin in coupled protein surface group-water fluctuations of the Johari-Goldstein β type that span spatial scales of ∼0.1-10 Å on temporal scales of 10-10-10-7 s. The orthogonal EPR spin probe rotational mobility and solvent dielectric measurements characterize features of EAL protein-solvent dynamical coupling and reveal that excess substrate acts as a fluidizing cryosolvent to enable native enzyme reactivity at cryogenic temperatures.

Evaluation of gingival displacement methods in terms of periodontal health at crown restorations produced by digital scan: 1-year clinical follow-up.

The purpose of this clinical study was to compare the effects of the gingival displacement techniques of retraction cord, cordless paste system, and Er,Cr:YSGG laser troughing on the periodontal tissues around the crown restoration produced using a digital scan. This was analyzed by recording the probing depth (PD), plaque index, gingival index (GI), mobility, sensitivity, and bleeding on probing (BOP) index. This study included 60 mandibular 1st molars from 52 participants (20 males and 32 females) requiring crown restoration. The margin lines of the crown preparations were placed 1 mm subgingivally. Based on the gingival displacement technique used, the patients were divided into three groups: retraction cord, cordless paste system, and Er,Cr:YSGG laser troughing. A digital scan of the prepared tooth was performed. Follow-up appointments were scheduled at five different times: 1st day, 1st month, 3rd month, 6th month, and 1st year. Six periodontal indices were used to assess the periodontal health. The chi-square test was used to compare categorical variables depending on the groups. There was a significant difference in the PD, GI, and BOP index scores among the three techniques during the 1-year clinical monitoring (p < 0.001). The PD in the three zones of the buccal surface showed a significant increase with time in the retraction cord and cordless paste system groups (p < 0.001). The highest GI scores were observed in the retraction cord group on the 1st day. The Er,Cr:YSGG laser troughing procedure produced lower PD, GI, and BOP index scores as compared to the retraction cord and cordless paste system procedures in the 1-year period.

Surface acoustic wave nebulization improves compound selectivity of low-temperature plasma ionization for mass spectrometry

Mass spectrometry coupled to low-temperature plasma ionization (LTPI) allows for immediate and easy analysis of compounds from the surface of a sample at ambient conditions. The efficiency of this process, however, strongly depends on the successful desorption of the analyte from the surface to the gas phase. Whilst conventional sample heating can improve analyte desorption, heating is not desirable with respect to the stability of thermally labile analytes. In this study using aromatic amines as model compounds, we demonstrate that (1) surface acoustic wave nebulization (SAWN) can significantly improve compound desorption for LTPI without heating the sample. Furthermore, (2) SAWN-assisted LTPI shows a response enhancement up to a factor of 8 for polar compounds such as aminophenols and phenylenediamines suggesting a paradigm shift in the ionization mechanism. Additional assets of the new technique demonstrated here are (3) a reduced analyte selectivity (the interquartile range of the response decreased by a factor of 7)—a significant benefit in non-targeted analysis of complex samples—and (4) the possibility for automated online monitoring using an autosampler. Finally, (5) the small size of the microfluidic SAWN-chip enables the implementation of the method into miniaturized, mobile LTPI probes.

On the Mutual Relationships between Molecular Probe Mobility and Free Volume and Polymer Dynamics in Organic Glass Formers: cis-1,4-poly(isoprene).

We report on the reorientation dynamics of small spin probe 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO) in cis-1,4-poly(isoprene) (cis-1,4-PIP10k) from electron spin resonance (ESR) and the free volume of cis-1,4-PIP10k from positron annihilation lifetime spectroscopy (PALS) in relation to the high-frequency relaxations of cis-1,4-PIP10k using light scattering (LS) as well as to the slow and fast processes from broadband dielectric spectroscopy (BDS) and neutron scattering (NS). The hyperfine coupling constant, 2Azz′(T), and the correlation times, τc(T), of cis-1,4-PIP10k/TEMPO system as a function of temperature exhibit several regions of the distinct spin probe TEMPO dynamics over a wide temperature range from 100 K up to 350 K. The characteristic ESR temperatures of changes in the spin probe dynamics in cis-1,4-PIP10k/TEMPO system are closely related to the characteristic PALS ones reflecting changes in the free volume expansion from PALS measurement. Finally, the time scales of the slow and fast dynamics of TEMPO in cis-1,4-PIP10k are compared with all of the six known slow and fast relaxation modes from BDS, LS and NS techniques with the aim to discuss the controlling factors of the spin probe reorientation mobility in polymer, oligomer and small molecular organic glass-formers.

Modern means of assessing the impact of emergencies on the environmental condition of the ground layer of atmosphere

The problem of emergencies will not leave humanity as long as it exists, and therefore it is necessary to at least create conditions under which it is possible to reduce the risks of injuries, diseases and deaths of people who are in the emergency zone. This can be achieved by raising awareness of the nature of the emergency, the hazardous substances that are released in connection with it. Theoretical analysis of various remote means of assessing the impact of emergencies of man-made areas on the ecological state of the atmospheric air of the surrounding areas. It has been found that the use of remote sensing equipment greatly simplifies the procedure of operational monitoring of the environment during emergencies, as well as contributes to the health of professionals. A comparison of different remote means of environmental monitoring of air quality was performed: In particular, stationary automatic stations, mobile automatic stations, probes, and unmanned aerial vehicles (UAVs) were compared. It is proposed to use UAVs as remote means of operational monitoring of air quality. The functional scheme of UAV system implementation for the needs of operative ecological monitoring is offered. The legal features of the use of unmanned aerial vehicles as remote means of monitoring air quality during emergencies are analyzed.

Ultra-Wideband MIMO Array for Penetrating Lunar Regolith Structures on the Chang’e-5 Lander

The Chang’e-5 lunar exploration mission of China is equipped with a Lunar Regolith Penetrating Radar (LRPR) for measuring the thickness and structures of the lunar regolith in the landing area. Since the LRPR is stationary, an ultra-wideband multiple-input multiple-output (MIMO) array is designed as a replacement for conventional mobile subsurface probing systems. The MIMO array, with 12 antenna elements and a switch matrix, operates in the frequency band from 1.0 to 4.75 GHz. In this work, the design and layout of the antenna elements were optimized with respect to the lander. To this end, the antenna elements were designed as miniaturized Vivaldi antennas with quarter elliptical slots (i.e., quarter elliptical slotted antenna, or QESA). QESAs are significantly small while being able to mitigate the impact of the lander on antenna electrical performances. QESAs also have a wide operating bandwidth, flat gain, and excellent time domain characteristics. In addition, a high-temperature resistant ultra-light radome with high transmissivity is designed to protect the external antenna array. After calibration, the MIMO array is used to detect targets embedded in volcanic ash. The detection depth reaches 2.5 m, and the detection effect is good.

Biomolecular phase separation through the lens of sodium-23 NMR.

Phase separation is a fundamental physicochemical process underlying the spatial arrangement and coordination of cellular events. Detailed characterization of biomolecular phase separation requires experimental access to the internal environment of dilute and especially condensed phases at high resolution. In this study, we take advantage from the ubiquitous presence of sodium ions in biomolecular samples and present the potentials of 23Na NMR as a proxy to report the internal fluidity of biomolecular condensed phases. After establishing the temperature and viscosity dependence of 23Na NMR relaxation rates and translational diffusion coefficient, we demonstrate that 23Na NMR probes of rotational and translational mobility of sodium ions are capable of capturing the increasing levels of confinement in agarose gels in dependence of agarose concentration. The 23Na NMR approach is then applied to a gel‐forming phenylalanine‐glycine (FG)‐containing peptide, part of the nuclear pore complex involved in controlling the traffic between cytoplasm and cell nucleus. It is shown that the 23Na NMR together with the 17O NMR provide a detailed picture of the sodium ion and water mobility within the interior of the FG peptide hydrogel. As another example, we study phase separation in water‐triethylamine (TEA) mixture and provide evidence for the presence of multiple microscopic environments within the TEA‐rich phase. Our results highlight the potentials of 23Na NMR in combination with 17O NMR in studying biological phase separation, in particular with regards to the molecular properties of biomolecular condensates and their regulation through various physico‐ and biochemical factors.

Photophysics of Fluorescent Contact Sensors Based on the Dicyanodihydrofuran Motif.

Fluorescent molecular rotors have been used for measurements of local mobility on molecular length scales, for example to determine viscosity, and for the visualization of contact between two surfaces. In the present work, we deepen our insight into the excited‐state deactivation kinetics and mechanics of dicyanodihydrofuran‐based molecular rotors. We extend the scope of the use of this class of rotors for contact sensing with a red‐shifted member of the family. This allows for contact detection with a range of excitation wavelengths up to ∼600 nm. Steady‐state fluorescence shows that the fluorescence quantum yield of these rotors depends not only on the rigidity of their environment, but – under certain conditions – also on its polarity. While excited state decay via rotation about the exocyclic double bond is rapid in nonpolar solvents and twisting of a single bond allows for fast decay in polar solvents, the barriers for both processes are significant in solvents of intermediate polarity. This effect may also occur in other molecular rotors, and it should be considered when applying such molecules as local mobility probes.

In vivo investigation of diode laser application on red complex bacteria in non-surgical periodontal therapy: a split-mouth randomised control trial

Assessment of the efficacy of a single 810 nm diode laser application as an adjunctive treatment modality during the first intervention of non-surgical periodontal therapy (NPT). 25 patients diagnosed with chronic periodontitis underwent a split-mouth randomised control trial. The periodontal pockets of the test quadrants were treated with an 810 nm diode laser as an adjunct to NPT (Picasso GaAlAs; AMD Lasers). The laser was set at 1.0 W continuous wave, 400 µm tip, 796 W/cm2 peak power density and a 32 J/cm2 energy density. Therapeutic outcomes were evaluated based on the clinical parameters, which included probing pocket depth, recession, clinical attachment level, full mouth plaque score, full mouth bleeding on probing and tooth mobility. The baseline bacterial collection was completed from the periodontal pockets and then re-evaluated at 6 weeks. Clinical parameters demonstrated no statistical difference, with the exception of a statistically significant (P < 0.05) reduction in bleeding on probing for the test side. The test side resulted in a statistical increase of Capnocytophagaspecies and Treponemadenticola. The single application of the diode laser did not significantly improve the bacterial nor the clinical parameters in patients with chronic periodontitis.Trial registration number: PACTR201909915338276.

Dihydropyracyloporphyrins

A pyrrole ethyl ester with a fused dihydropyracylene unit was prepared by reacting 5-nitro-1,2-dihydropyracylene with ethyl isocyanoacetate in the presence of a phosphazene base. Cleavage of the ester moiety, followed by reaction with an acetoxymethylpyrrole and acetic acid in refluxing ethanol, afforded a tripyrrane, and subsequent ‘3 + 1’ condensation with a pyrrole dialdehyde gave a dihydropyracyloporphyrin. Cyclotetramerization of the dihydropyracylopyrrole with benzaldehyde and BF3·Et2O gave a sterically crowded tetrakis(dihydropyracylo)-porphyrin and the reduced five-membered rings proved to be an excellent NMR probe for conformational mobility. The new porphyrins and their nickel(II) complexes also showed potentially valuable highly red shifted UV–vis spectra.

Intrathoracic use of a small ultrasonic probe for localizing small lung tumors in thoracoscopic surgery: Empirical results and comparison with preoperative CT images.

To evaluate the use of a small mobile ultrasound probe to localize small lung tumors during thoracoscopic surgery under thoracic CO2 insufflation. We prospectively enrolled 20 patients (26 tumors) scheduled to undergo thoracoscopic pulmonary wedge resection between April 2016 and October 2018. Ultrasonographic tumor detection was performed with an ARIETTA 850 and L51K probe (Hitachi, Tokyo, Japan). Ultrasonography was repeated after achieving adequate lung collapse under a positive intrathoracic pressure of 8-15mmHg. The appearance on preoperative CT versus the ultrasonographic localization was compared for each tumor. The receiver operating characteristic curves were compared for the tumor dimension of the lung window, consolidation dimension of the lung window, tumor dimension of the mediastinal window (MD), and tumor depth from the lung surface. The average age was 62years (range 42-79years), average pathological tumor size was 9mm (range 3-22mm), and average tumor depth was 6mm (range 1-25mm). Although no tumors could be visualized before lung collapse, 22 tumors (85%) were detectable with ultrasonography after lung collapse. Of these 22 tumors, 16 were well-depicted, while six were poorly delineated. MD showed the largest area under the receiver operating characteristic curve (0.81), and tumors with a MD of ≤ 6mm had a high risk of difficult localization using ultrasonography. This ultrasonographic method obtained high tumor detection rates, especially for tumors with a MD > 6mm. Tumors with a MD ≤ 6mm may require another localization method. University Hospital Medical Information Network Clinical Trials Registry (UMIN000036921).

Data Fusion for Multi-Source Sensors Using GA-PSO-BP Neural Network

The development of real-time road condition systems will better monitor road network operation status. However, the weak point of all these systems is their need for comprehensive and reliable data. For traffic data acquisition, two sources are currently available: 1) floating vehicles and 2) remote traffic microwave sensors (RTMS). The former consists of the use of mobile probe vehicles as mobile sensors, and the latter consists of a set of fixed point detectors installed in the roads. First, the structure of a three-layer BP neural network is designed to achieve the fusion of the floating car data (FCD) and the fixed detector data (FDD) efficiently. Second, in order to improve the accuracy of traffic speed estimation, a multi-source data fusion model that combines information from floating vehicles and microwave sensors, and that, by using GA-PSO-BP neural network is proposed. The proposed model has combined GA and PSO ingeniously. The hybrid model can not only overcome the difficulties of the traditional fusion model of its estimation inaccuracy, but also compensate the insufficiency of the traditional BP algorithm. Finally, this system has been tested and implemented on actual roads, and the simulation results show the accuracy of data has reached 98%.

Optical Tweezing and Photothermal Properties of Resonant Dielectric and Metallic Nanospheres

Optically trapped nanoparticles can be used as efficient mobile probes of nanoscopic forces and temperatures. However, it is crucial that the trapped particle has minimal influence on the system under study while providing a strong enough optical response to actually allow for optical manipulation. This puts severe constraints on the particle size and thermal properties. In particular, strong optical responses associated with plasmon resonances in noble metal nanoparticles and Mie resonances in high index dielectric particles can significantly affect trap stability through enhanced radiation pressure forces and photoinduced heating. Using Mie theory and hot Brownian motion analysis, we calculate trap stability and photothermal properties for nanospheres composed of the best (Ag) and most widely used (Au) plasmonic materials as well as for crystalline and amorphous Si, the prototypic high-index dielectric, using polystyrene as a low-index reference material. We calculate trap stability properties for optical tweezers based on high numerical aperture optics (NA = 1.2) for three of the most widely used laser wavelengths (532, 785, and 1064 nm) and for the case of trapping in water. The results reveal the specific particle size ranges for which optical tweezing is possible in two and three dimensions and indicate that crystalline Si nanoparticles trapped using near-infrared laser beams are the optimal choice for temperature-sensitive optical manipulation applications with small particles.

EMC 2 : an emergency management system using mobile cloud computing

A natural or unexpected man-made emergency may occur at any time and which affects the economy as well as human life of the country. The most important task in an emergency is to collect the essential information about the emergency places and do a proper analysis to take effective action. In those situations, mobile gadgets are very much helpful to collect the information in a significant way. The mobile devices have certain limitations such as less battery power, lack of Internet connectivity for data transmission or less computational resources. So the energy hungry applications can be offloaded to the cloud to reduce the workload of the mobile devices. To overcome these problems, the authors propose an emergency management system named as EMC 2 , which follows peer-to-peer communication using Bluetooth technology. EMC 2 first detects the available mobile devices present in a network using mobile probing service (MPS) and then it chooses the suitable mobile device among them using mobile ranking service (MRS). EMC 2 also determines the best network resources while roaming in heterogeneous access networks (HANs). The experimental results of authors- proposed EMC 2 approach shows the increased performance and out-performs in terms of receiving time as compared to the baseline algorithm.

Relaxation Constant in the Folding of Thin Viscoelastic Sheets

If one folds a thin viscoelastic sheet under an applied force, a line of plastic deformation is formed which shapes the sheet into an angle. We determine the parameters that define this angle experimentally and show that, no matter how much load one applies, it is impossible to make angles less than a certain minimum angle in a definite time. Moreover, it is shown that regardless of whether the sheet is released freely afterward or kept under the load, a logarithmic relaxation process follows the first deformation. The slope of this logarithm is the same in both conditions and depends neither on the applied force nor on the thickness of the sheet, which indicates it is directly a probe of the molecular mobility of the material. This intrinsic relaxation constant was measured 0.01 and 5.7 for Mylar and paper sheets, respectively. It is also suggested that the observed minimum angle of folding can be defined as a characteristic index for the plasticity of different materials.

Pyrene and nile red fluorescence probes for in‐situ study of polarity and viscosity of soil organic coatings implicated in soil water repellency

AbstractSoil water repellency, that is, the reduced ability of soils to absorb water, is thought to be caused by organic coatings with predominantly non‐polar properties on soil particle surfaces. Given the important role of particle surface polarity in determining soil water repellency, we explored the use of fluorescent probes as a method for the direct in‐situ determination of the distribution and polarity of organics on bulk soil surfaces, and of their molecular mobility. We used nile red and pyrene, which have both been used successfully as environmental probes in previous studies, but have not been applied before to bulk soils. The probes were either (a) co‐deposited with other organics known to induce water‐repellent behaviour with acid‐washed sand to produce ‘model soils’ or (b) adsorbed directly onto sandy soils that were naturally water repellent to different degrees, and studied using fluorescence microscopy and steady‐state and time‐resolved fluorescence. Reliable measurements could be made using pyrene as an in‐situ probe on both model and natural soils, and a viscosity/mobility probe on model soils, whereas nile red was found not to be a useful probe. On model soils, made using hexadecane (HEX), octadecane (OCT) or stearic acid (SA) on acid‐washed sand, pyrene excimer formation kinetics showed a decrease in environment mobility as the organic layer changes from a liquid through to a hard wax. Spectra from pyrene adsorbed to natural soils indicated varying environmental polarity and heterogeneity within the soil samples studied.Highlights Exploration of in‐situ fluorescent probes to study polarity and viscosity of organics on soils. Fluorescent probes have never been used in situ on bulk soils before. Pyrene probe shows variation in mobility, polarity and heterogeneity of organics on soils. Pyrene is a useful in‐situ fluorescent probe of polarity and mobility of organics on soils.

An Empirical Study of Additional Stopover Behaviors of Car Tourists Affecting by Traffic Congestion Information Using Mobile Probe Data

Car tourists may make some additional stopovers for sightseeing, meal, shopping, or leisure activities which is not originally planned, to avoid becoming involved in the traffic congestion occurring on the homeward route. The objective of this paper is to examine whether this induced stopover behavior exists and to empirically analyze the tendency of additional stopovers by departure time periods for homeward trip and level of traffic congestions. An analysis of route search data and GPS travel trajectory data collected by mobile car navigation application is conducted. The study results show car tourists tend to have additional stopovers when the departure time for homeward trip is early, and differences in the tendency of additional stopovers by congestion levels are observed, implying the impact of traffic congestion on additional stopover behaviors to some extent. The study results suggest the possibility of promoting additional stopovers in tourism areas for congestion avoidance by providing predicted near future traffic congestion and surrounding tourism information, which is beneficial to both tourism promotion and traffic congestion mitigation.

Spin probe interaction and mobility in confined cyclohexane: Effects of pore size and pore surface composition of silica gel matrices

The spectral behavior of the spin probe TEMPO in the bulk cyclohexane (CHX) and its confined states in a series of silica gels (SG) using ESR is reported. The spectral parameter Azz’ and the characteristic ESR temperature T50G of slow to fast regime transition of TEMPO change dramatically in the virgin SG-SIL‘s compared to the bulk CHX sligtly depending on the pore size. These observations result from the interrelation between the mutual interaction of the TEMPO with the SG‘s and the altered phase behavior of the CHX from DSC. This is supported by the modified (silanized) SG matrices.

Microbiological evaluation of LOCATOR® Legacy attachments: A cross-sectional clinical study.

ObjectiveThis retrospective cross‐sectional study aimed to evaluate quantitatively the oral microbiome in the tri‐lobe central cavity of Locator Legacy attachment and verify whether it harbors a different, potentially more pathogenic, bacterial spectrum than the adjacent edentulous ridge.Materials and MethodsEdentulous patients rehabilitated with implant overdentures using Locator Legacy attachments were recruited for this study. The clinical examination comprised probing depths, mobility, peri‐implant, and periodontal health along with intraoral swabs for microbiological evaluation, polymerase chain reaction (PCR) testing, and candida culture. The swabs were collected from the trilobed cavity of the attachment and the adjacent edentulous ridge. PCR was performed to detect six specific bacteria, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Treponema denticola, Prevotella intermedia, and Parvimonas micra. Statistical analyses were performed using McNemar's test and Wilcoxon's rank sum test with the significance set to p < .05.ResultsA total of 50 participants with a mean age of 71.5 ± 9.6 years participated in the study. No significant differences in the microbiome were found between samples from the ridge and the attachment. No significantly different numbers in the candida cultures were identified, and the presence of a removable prostheses did not demonstrate a significant association with the prevalence of candida.ConclusionsWithin the limits of this study and the investigated bacterial species, the trilobed cavity of the attachment does not seem to increase the bacterial load.

Recent developments in nuclear heating measurement methods inside the OSIRIS reactor

Nuclear heating inside a Material Testing Reactor (MTR) needs to be known in order to design and to run irradiation experiments that have to fulfill target temperature constraints. To improve the incore nuclear heating knowledge of the French OSIRIS reactor operated by CEA, an innovative calorimetric system CALMOS (French acronym for CALorimètre Mobile OSiris) has been studied, manufactured and tested. This device can be inserted in any in-core experimental location. It is based on a mobile probe moving axially along the core height. First tests of this new probe, offering several ways for the heating evaluation, were performed in the reactor periphery. Then, two complete prototypes dedicated to incore measurements (calorimeter and the associated displacement system) were designed and tested during several reactor cycles. This paper presents a comprehensive analysis of all the results collected during the measurement campaigns carried out between 2013 and 2015 with these new prototypes in various reactor conditions. A comparison is made with previous calorimeters and obtained advantages are emphasized. This new calorimeter has been designed as a real operational measurement system, well suited to characterize the radiation field inside an MTR reactor.