Bactericidal effect of nanostructures via lytic transglycosylases of Escherichia coli

The time profiles of active cell ratios depended on the growth phase and the absence of some lytic transglycosylases of E. coli. Significant cell damage was not found on the autolysis inhibition condition.

Effects of Drugs Reabsorption Time Delays for a Pharmacokinetics Model in Humans

A three-compartmental delay model is formulated to describe the pharmacokinetics of drugs subjected to both intravenous and oral doses with reabsorptions by the central compartment. Model dynamics are analyzed rigorously, and two equilibrium points are obtained to be locally asymptotically stable under certain conditions. Time delays used as lags in reabsorption of drugs by central compartment from other two compartments caused rebounds or peaks and fluctuations in the time profiles for amounts of drug in all the compartments. Sensitivity analysis revealed that elimination rates decrease the amounts in all compartments. Furthermore, reabsorption rates cause superimposition at the initial phases of the drug amount profiles; subsequently, the quantities decrease in compartment one and increase in compartments two and three, respectively.

Evaporating primordial black holes in gamma ray and neutrino telescopes

A primordial black hole in the last stages of evaporation and located in the local neighborhood can produce a detectable signal in gamma ray and neutrino telescopes. We re-evaluate the expected gamma ray and neutrino fluxes from these transient point events and discuss the consequences for existing constraints. For gamma rays we improve the current bounds by a factor of few, while for neutrinos we obtain significantly different results than the existing literature. The capability and advantages of neutrino telescopes in the search for primordial black holes is discussed thoroughly. The correlations of gamma ray and neutrino energy and time profiles will be promoted as a powerful tool in identifying the primordial black holes, in case of detection.

Simultaneous ALMA–Hinode–IRIS Observations on Footpoint Signatures of a Soft X-Ray Loop-like Microflare

Microflares have been considered to be among the major energy input sources to form active solar corona. To investigate the response of the low atmosphere to events, we conducted an Atacama Large Millimeter/submillimeter Array (ALMA) observation at 3 mm, coordinated with Interface Region Imaging Spectrograph (IRIS) and Hinode observations, on 2017 March 19. During the observations, a soft X-ray loop-type microflare (active region transient brightening) was captured using the Hinode X-ray telescope in high temporal cadence. A brightening loop footpoint is located within narrow fields of view of ALMA, IRIS slit-jaw imager, and Hinode spectropolarimeter. Counterparts of the microflare at the footpoint were detected in Si iv and ALMA images, while the counterparts were less apparent in C ii and Mg ii k images. Their impulsive time profiles exhibit the Neupert effect pertaining to soft X-ray intensity evolution. The magnitude of thermal energy measured using ALMA was approximately 100 times smaller than that measured in the corona. These results suggest that impulsive counterparts can be detected in the transition region and upper chromosphere, where the plasma is thermally heated via impinging nonthermal particles. Our energy evaluation indicates a deficit of accelerated particles that impinge the footpoints for a small class of soft X-ray microflares. The footpoint counterparts consist of several brightening kernels, all of which are located in weak (void) magnetic areas formed in patchy distribution of strong magnetic flux at the photospheric level. The kernels provide a conceptual image in which the transient energy release occurs at multiple locations on the sheaths of magnetic flux bundles in the corona.

Numerical methodology for evaluation the combustion and emissions characteristics on WLTP in the light duty dual-fuel diesel vehicle

The worldwide aim of reducing environmental impact from internal combustion engines bring more and more stringent emission regulations. In 2017 by EU has been adopted new harmonized test procedure called WLTP. In general terms this test was designed for determining the levels of harmful emissions and fuel consumption of traditional and hybrid cars. This procedure contains specific driving scenarios which representing real-life driving patterns. Test cycles contain vehicle velocity versus time profiles and directly in powertrain analysis on the test benches cannot be used. In order to back calculate drive cycles to engine rpm versus torque profiles a simple longitudinal vehicle dynamics method was used in this paper. Moreover, in order to determine most representative engine operation points duing WLTP a density based grid clustering method was implemented. The experimental part of the study focuses on the comparative evaluation of the effect of various diesel to LPG substitution ratios (0% LPG, 10% LPG, 20% LPG and 30% LPG) on combustion and emission characteristics of dual-fuel diesel engine.

Analysis of Dynamic Efficacy Profile of Corneal Cross-Linking: Role of Oxygen and Rate Constants

Purpose:To explore (theoretically) the key parameters and their influence on the time profiles of photosensitizer (riboflavin), free radicals, singlet oxygen, oxygen and the efficacy of corneal collagen crosslinking (CXL)in both type-I and oxygen-mediated type-II mechanisms, specially the role of oxygen and the initiator regeneration. Methodology:Coupled kinetic equations are derived and numerically solved under the quasi-steady state condition for the 2-pathway mechanisms of CXL. The key parameters explored include (bI, V, Q', K, K',Q,P) and their influence on the time profiles of photosensitizer (riboflavin, C), radicals (R), singlet oxygen(S), oxygen (X) and efficacy (E), parameters of (K,K',Q) define the relative strength of type-I and type-II process. The oxygen depletion profile, X(t), and the associated singlet oxygen, S(t), depend on the parameters of V, Q' and the initial value of oxygen. The coupling strength given by (bI) governs almost all profiles, where b is an effective absorption parameter and I is the UV light intensity.Results:Our numerical method for CXL dynamic profiles demonstrated the following important features: (i) Type-I and type-II coexit in CXL, in the presence of oxygen. However, there is no type-II when oxygen is depleted or in a condition without oxygen. (ii) Type-I with bimolecular termination, the radical R(t) is a function of [K'(bIgC)]0.5, leading to the steady-state efficacy given by a scaling law of 1/(bI)0.5, in contract to that of type-II which is almost independent to the light intensity. (iii) The depletion rate (2 to 5 minutes) of X(t) is much faster than that of C(t) (10 to 20 minutes), (iv) Thepure type-II profile, has a transition point from straight line to saturating curve and matches the depletion point of singlet oxygen S(t). (v) Improved CXL efficacy of type-I and type-II may be achieved by external supply of photoinitiator (riboflavin) and oxygen, respectively.

Tritium labeling of antisense oligonucleotides via different conjugation agents

A novel approach to tritium-labeled antisense oligonucleotides (ASO) was established by conjugating N-succinimidyl propionate, as well as maleimide-derivatives, to the 3′-end of ASOs targeting metastasis-associated lung adenocarcinoma transcript 1 (Malat1) containing amino- or sulfhydryl-linkers. In vitro stability and Malat1 RNA reduction studies demonstrated that N-ethylmaleimide (NEM) could be used as a stable tag while maintaining the desired target interaction. The corresponding radioactive label conjugation using [3H]-NEM resulted in tritium-labeled ASOs with a high molar specific activity of up to 17 Ci/mmol. Single-dose in vivo studies in mice were carried out to compare [3H]-ASOs with their unlabeled counterpart ASOs, with and without conjugation to N-acetylgalactosamine (GalNAc), for tissue and plasma concentrations time profiles. Despite the structural modification of the labeled ASOs, in vitro target interaction and in vivo pharmacokinetic behaviors were similar to that of the unlabeled ASOs. In conclusion, this new method provides a powerful technique for fast and safe access to tritium-labeled oligonucleotides, e.g., for pharmacokinetic, mass balance, or autoradiography studies. Graphical abstract

Influencing Geometrical Parameters of Tools in Friction Stirring Technology: A Short Review

Friction stirring based “Green” processes are ruled by geometrical and process aspects of the tools used for generating desired properties in the processed materials. Considering only geometrical aspects, the developments in tool geometry, its modifications with the time, profiles and their corresponding impacts on the property generation are addressed in the present work. It is a censorious and judicious review which consolidates the relevant information apropos of all geometrical aspects of tools and their roles in property generation.

In silico evaluation of limited sampling strategies for individualized dosing of extended half-life factor IX concentrates in hemophilia B patients

Purpose Hemophilia B is a bleeding disorder, caused by a factor IX (FIX) deficiency. Recently, FIX concentrates with extended half-life (EHL) have become available. Prophylactic dosing of EHL-FIX concentrates can be optimized by assessment of individual pharmacokinetic (PK) parameters. To determine these parameters, limited sampling strategies (LSSs) may be applied. The study aims to establish adequate LSSs for estimating individual PK parameters of EHL-FIX concentrates using in silico evaluation. Methods Monte Carlo simulations were performed to obtain FIX activity versus time profiles using published population PK models for N9-GP (Refixia), rFIXFc (Alprolix), and rIX-FP (Idelvion). Fourteen LSSs, containing three or four samples taken within 8 days after administration, were formulated. Bayesian analysis was applied to obtain estimates for clearance (CL), half-life (t1/2), time to 1% (Time1%), and calculated weekly dose (Dose1%). Bias and precision of these estimates were assessed to determine which LSS was adequate. Results For all PK parameters of N9-GP, rFIXFc and rIX-FP bias was generally acceptable (range: −5% to 5%). For N9-GP, precision of all parameters for all LSSs was acceptable (< 25%). For rFIXFc, precision was acceptable for CL and Time1%, except for t1/2 (range: 27.1% to 44.7%) and Dose1% (range: 12% to 29.4%). For rIX-FP, all LSSs showed acceptable bias and precision, except for Dose1% using LSS with the last sample taken on day 3 (LSS 6 and 10). Conclusion Best performing LSSs were LSS with samples taken at days 1, 5, 7, and 8 (N9-GP and rFIXFc) and at days 1, 4, 6, and 8 (rIX-FP), respectively.

pH-Induced Modulation of Vibrio fischeri Population Life Cycle

Commonly used as biological chemosensors in toxicity assays, Vibrio fischeri bacteria were systematically characterized using complementary physicochemical and biological techniques to elucidate the evolution of their properties under varying environmental conditions. Changing the pH above or below the optimal pH 7 was used to model the long-term stress that would be experienced by V. fischeri in environmental toxicology assays. The spectral shape of bioluminescence and cell-surface charge during the exponential growth phase were largely unaffected by pH changes. The pH-induced modulation of V. fischeri growth, monitored via the optical density (OD), was moderate. In contrast, the concomitant changes in the time-profiles of their bioluminescence, which is used as the readout in assays, were more significant. Imaging at discrete timepoints by scanning electron microscopy (SEM) and helium-ion microscopy (HIM) revealed that mature V. fischeri cells maintained a rod-shaped morphology with the average length of 2.2 ± 1 µm and diameter of 0.6 ± 0.1 µm. Detailed morphological analysis revealed subpopulations of rods having aspect ratios significantly larger than those of average individuals, suggesting the use of such elongated rods as an indicator of the multigenerational environmental stress. The observed modulation of bioluminescence and morphology supports the suitability of V. fischeri as biological chemosensors for both rapid and long-term assays, including under environmental conditions that can modify the physicochemical properties of novel anthropogenic pollutants, such as nanomaterials and especially stimulus-responsive nanomaterials.