Increase In Relative Intensity Research Articles

Dual Emission Bands of a 2D Perovskite Single Crystal with Charge Transfer State Characteristics.

Several hybrid halide 2D-perovskite species emit light with an emergent and controversial broadband emission Stokes-shifted down from the narrow band emission. This paper uncovers the sub- and above-bandgap emission and absorption characteristics of PEA2PbI4 prepared with gap states introduced during single crystal growth. Here, gap states led to coexistent intrinsic and heterostructured electronic frameworks that are selectively accessible with ultraviolet (UV) and infrared (IR) light, respectively, resulting in the phenomenon of photoluminescence (PL) switching from narrowband green to broadband red. Electron-energy dependent cathodoluminescence shows a relative increase in the broadband red PL intensity as the electron penetration depth increases from 30 nm to 2 μm, confirming the heterostructured framework is formed in the bulk of the crystal. Excitation-emission power slope of 2.5 and up-conversion pump transient absorption (TA) spectra suggest that the IR up-conversion excitation with red photoluminescence, peaked at 655 nm, is a multiphoton process occurring in the heterostructured framework through a nonlinear optical response. The energetic pathways toward the dual emission bands are revealed by pump-probe transient absorption spectroscopy, showing energetically broad gap states with high sensitivity to an IR pump are upconverted and subsequently quickly relax from high to low energy levels within 4 ps. Furthermore, the up-conversion red PL demonstrates a linear polarization with magnetic field effects, thus affirming that the band-like heterostructured framework is crystallographically aligned with characteristics of spatially extended charge-transfer states.

P-423 Effect of pergafast 201 on in vitro meiotic maturation of pig oocytes

Abstract Study question Does pergafast 201 (PF201) have harmful effects on selected markers of in vitro maturation of pig oocytes? Summary answer PF201 affects the course of in vitro oocyte maturation, reaching the metaphase II stage, formation of the meiotic spindle and methylation of selected epigenetic markers. What is known already PF201 is a chemical used as a color developer and currently serves as a replacement for bisphenol A and S in related paper and other products. Bisphenol A and S are already proven endocrine disruptors that can released into the environment and from there enter the human body, where they disrupt physiological hormonal functions. In the case of PF201, toxicity to aquatic organisms, persistence in the environment and affinity to some proteins associated with non-infectious diseases have already been confirmed. Therefore, further testing of the biological effect of PF201 is necessary to assess the risks to human health and reproduction. Study design, size, duration Cumulus-oocytes complexes (COCs) from the ovaries of slaughtered prepubertal sows were used. In vitro maturation dynamics of PF201-treated COCs were compared with control COCs (n ≥ 30). The meiotic spindle was assessed under a confocal microscope after fluorescence labeling of meiotic chromosomes and spindle microtubules. Dimethylation of histone H3 at lysine K4 (H3K4me2) and trimethylation at lysine K9 (H3K4me3) were imaged under a fluorescence microscope after fluorescent labeling, the intensity was subsequently evaluated in the ImageJ software. Participants/materials, setting, methods COCs were treated with PF201 in at least five independent experiments using the following concentrations: 300 pM, 30 nM and 3 µM, dissolved in DMSO to a final concentration of 0.05%. A vehicle control was used when COCs were cultured in medium with the same concentration of DMSO. COCs were cultured for 48 hours to metaphase II in 5.0% CO2 at 39 °C. Main results and the role of chance PF201 exposure in vitro affected meiotic maturation of pig oocytes, their ability to reach metaphase II, meiotic spindle formation, and epigenetic histone modifications. Treatment with 30 nM concentration of PF201 in vitro caused a significant accumulation of oocytes in metaphase I stage (35% vs. 7% in controls, p < 0.05), consistent with a non-linear effect. Moreover, according to our results, PF201 also disrupts the formation of the meiotic spindle in pig oocytes and probably affects the organization of the meiotic spindle at multiple levels. After 300 pM (30%) and 30 nM (25% vs. 10% in controls, p < 0.05) in vitro treatment of PF201, a significant increase in abnormalities of the meiotic spindle, most often irregular arrangement of the spindle, reduction of the meiotic figure, faulty attachment of chromosomes to tubulin and elongated poles of the meiotic spindle located far apart. A significant increase in the relative fluorescence intensity of epigenetic markers was also observed after treatment of oocytes with PF201. For histone H3K4me2, a significant increase in relative fluorescence intensity was observed after treatment with 300 pM and 3 µM concentrations, while for histone H3K9me3, a significant increase in relative intensity was observed after treatment with 30 nM and 3 µM concentrations. Limitations, reasons for caution As work with human oocytes encounters a number of ethical and legal regulations, a porcine model was chosen, which is physiologically close to the human oocyte. However, it would be great benefit if the effects of PF201 were evaluated in human discarded oocytes that can be obtained from IVF laboratories. Wider implications of the findings It is increasingly difficult for the human population to avoid exposure to environmentally toxic substances, and this fact could explain the decline in human fertility in recent decades. The finding that PF201 negatively affects meiotic maturation suggests, that it may reduce fertilization rates, thus requiring a re-evaluation of its use. Trial registration number MZE-RO0718

Improved reactivity and energy release performance of core-shell structured fuel-rich Si/PTFE energetic composites

Si is an attractive fuel in pyrotechnic applications due to its high gravimetric and volumetric energy density. In this article, core-shell structured fuel-rich Si/PTFE (CS-PSi) energetic composites were prepared through high-power ultrasonic mixing. The energy release performance of the CS-PSi composites with different equivalence ratios (ϕ=1.5, 2.5, and 3.5) is characterized, and the magnetic stirring mixed Si/PTFE (MS-PSi, ϕ=3.5) composite is also studied for comparison. For the CS-PSi composites, with the increase in equivalence ratio, the relative intensity and burning rate both increase. Evaluated in a closed vessel, the CS-PSi (ϕ=2.5) exhibits the optimum pressure performance in terms of peak pressure and pressurization rate. By modifying the equivalence ratio, the reactivity, as indicated by the pressurization rate, of the CS-PSi energetic composites can be tuned accordingly. Having the same equivalence ratio (ϕ=3.5), the relative intensity, burning rate, peak pressure, and pressurization rate of the CS-PSi composite are 6.1, 4.3, 1.3, and 4.1 times larger than those of MS-PSi counterpart, respectively, while the apparent activation energy of the CS-PSi composites is reduced by 23.6%. The improved reactivity and superior energy release performance of the CS-PSi composites can be attributed to the higher degree of intimacy between the reactants as a result of core-shell configuration. Our approach provides a facile and efficient way to elevate the performance of the Si/PTFE energetic composites.

FRET Imaging of Nonuniformly Distributed DNA SAMs on Gold Reveals the Role Played by the Donor/Acceptor Ratio and the Local Environment in Measuring the Rate of Hybridization.

Mixed DNA SAMs labeled with a fluorophore (either AlexaFluor488 or AlexaFluor647) were prepared on a single crystal gold bead electrode using potential-assisted thiol exchange and studied using Förster resonance energy transfer (FRET). A measure of the local environment of the DNA SAM (e.g., crowding) was possible using FRET imaging on these surfaces since electrodes prepared this way have a range of surface densities (ΓDNA). The FRET signal was strongly dependent on ΓDNA and on the ratio of AlexaFluor488 to AlexaFluor647 used to make the DNA SAM, which were consistent with a model of FRET in 2D systems. FRET was shown to provide a direct measure of the local DNA SAM arrangement on each crystallographic region of interest providing a direct assessment of the probe environment and its influence on the rate of hybridization. The kinetics of duplex formation for these DNA SAMs was also studied using FRET imaging over a range of coverages and DNA SAM compositions. Hybridization of the surface-bound DNA increased the average distance between the fluorophore label and the gold electrode surface and decreased the distance between the donor (D) and acceptor (A), both of which result in an increase in FRET intensity. This increase in FRET was modeled using a second order Langmuir adsorption rate equation, reflecting the fact that both D and A labeled DNA are required to become hybridized to observe a FRET signal. The self-consistent analysis of the hybridization rates on low and high coverage regions on the same electrode showed that the low coverage regions achieved full hybridization 5× faster than the higher coverage regions, approaching rates typically found in solution. The relative increase in FRET intensity from each region of interest was controlled by manipulating the donor to acceptor composition of the DNA SAM without changing the rate of hybridization. The FRET response can be optimized by controlling the coverage and the composition of the DNA SAM sensor surface and could be further improved with the use of a FRET pair with a larger (e.g., > 5 nm) Förster radius.

Estimation of future extreme rainfall in Barcelona (Spain) under monofractal hypothesis

AbstractClimate change effects on subdaily rainfall (from 5 min to a few hours) can hardly be measured in mid‐latitude climates due to the high natural variability of the precipitation patterns and their effects on local topography. The goal of this study was to obtain change projections of intensity–duration–frequency (IDF) curves, for up to 2‐h precipitation events, comparing two approaches that use the daily outputs of the downscaled Coupled Model Intercomparison Project Phase 5 (CMIP5) multi‐model projections: (a) direct scaling of the expected probable precipitation, from 2‐year to 500‐year return periods of daily rainfall and (b) a new semi‐stochastic approach, built by combining the physically forced outputs of climate models (on a daily scale) and stochastic simulation given by the probability distribution of a concentration index (n‐index) for individual rainfall events (on a subdaily scale). The approaches were applied to a set of 27 stations located around Barcelona, Spain, including a long reference series (with 5‐min rainfall records since 1927), representing the highly variable Mediterranean climate. The validation process showed a systematic error (bias) generally smaller than 10%, especially for rainfall extreme events with durations of less than 2 h. The concentration n‐index and IDF curves were projected by 10 downscaled CMIP5 climate models under 2 emission scenarios (RCP4.5 and RCP8.5), obtaining a consensual increase in both relative concentration and absolute intensities in Barcelona. Ensemble projection of rainfall concentration (n‐index) showed an increase up to 10% by 2071–2100 and about 20% (15%–30% range) for maximum intensities of 2‐year to 500‐year return periods. Results provide robustness in decision‐making regarding the design of stormwater management infrastructure at a local scale.

The fabrication and characterisation of surimi gel modified by konjac glucomannan with the different hydrolysis degree

SummaryThe gel performance of surimi‐based products is indispensable technological attribute responsible for their high popularity. Here, surimi gels with tunable gel properties were successfully fabricated based on the double network theory. Konjac glucomannan (KGM) hydrolysed for various periods (0, 5, 15, 30, 60 and 90 min) was introduced into surimi systems. Corresponding structural characterisations including FTIR, XRD, SDS‐PAGE and grafting degree assessment, were conducted to confirm the presence of double crosslinking reactions. Furthermore, the gel strength, dynamic rheology, thermal stability and in vitro digestibility of the surimi gels were investigated. Red shifts in the amide A band and an increase in relative intensity indicated that hydrogen bonding existed in the complex systems, according to the FTIR spectra. The XRD patterns suggested that the crystalline structures were weakened by interfering with the protein chain arrangement due to the Maillard reaction. In addition, SDS‐PAGE and o‐phthalaldehyde (OPA) assays also confirmed that myofibrillar protein and hydrolysed KGM were partially linked by covalent bonding. The SK‐2 group showed the greatest mechanical strength and lowest digestibility amongst all groups due to its dense hierarchical structure. This work may provide inspiration for the design and development of surimi gels with improved gel properties via microarchitectural modulation.

Resistance Training-Induced Acute Hypoalgesia in Women With Persistent Pain After Breast Cancer Treatment.

Fogh Rasmussen, GH, Madeleine, P, Arroyo-Morales, M, Voigt, M, and Kristiansen, M. Resistance training-induced acute hypoalgesia in women with persistent pain after breast cancer treatment. J Strength Cond Res 37(3): e16-e24, 2023-The aim of this study was to determine whether a single bout of resistance training (RT) produces acute exercise-induced hypoalgesia (EIH) in breast cancer survivors (BCS) suffering from persistent pain ≥1.5 years after treatment. Twenty individuals with self-reported pain ≥3 on a 0-10 Numerical Rating Scale after treatment for breast cancer completed 3 experimental sessions, (a) familiarization; (b) 1 repetition maximum (1RM) normalization, and (c) training, consisting of 3 sets of 10 repetitions at 60% of 1 repetition maximum. Pressure pain thresholds (PPTs) were measured before and after training for the dorsal and ventral shoulder regions of the affected side. Movement-evoked pain (MEP) and rating of perceived exertion (RPE) were collected immediately after each set. A p -value less than 0.05 was considered statistically significant. The results demonstrated a significant increase in PPTs of the ventral shoulder region after a single bout of RT ( p ≤ 0.05), indicating a localized analgesic response for this area. By contrast, no change was detected in PPTs on the dorsal shoulder region. No significant differences were found in MEP between sessions despite a significant increase in load and RPE during 1RM assessment ( p ≤ 0.05), indicating that MEP was not affected by increase in absolute and relative intensity. In conclusion, a single bout of submaximal RT reduced PPTs for the ventral shoulder region of BCS with persistent pain after treatment and was well tolerated. Hence, RT may be a useful therapeutic tool for managing persistent pain after breast cancer treatment in clinical practice.

Physical properties and luminescence of highly stable erbium-doped antimony glasses for NIR broadband amplification

Glasses with compositions (0.8-x)Sb2O3−0.2Na2O-(x)WO3-(0.0025) Er2O3, (0 ≤ x ≤ 0.4 mol) has been synthesized by the melt-quenching technique. Physical, optical characteristics and spectroscopy have been identified and investigated. As the glass composition changes, definite variations in physio-optical properties can be observed as well as the temperature of the glass transition (Tg), the density (ρ), molar volume (Vm), bandgap energy (Eg), and the refractive index (n). The Judd-Ofelt theory has been performed using a UV–VIS-NIR absorption spectrum to examine the compositional effect on Er3+ spectroscopic properties. Some basic spectroscopic parameters including electric dipole line strengths, Judd-Ofelt parameters, the rate of radiative probability, and the lifetime of radiative levels, are determined. A high NIR emission at 1.53 μm was observed when exciting glasses at 980 nm. The FWHM, the effective line-width (Δλeff), the emission cross-section (σem), and the gain bandwidth values were calculated using the theory of Füchtbauer–Ladenburg, and the findings were critically analyzed. the decay of fluorescence spectra for the 4I13/2 level was registered, and the lifetime for the studied glasses was calculated. Upconversion luminescence was observed in the green and red regions under 980 nm excitation, with a relative increase in emission intensity due to the added tungsten content. Based on the results obtained, the studied glasses are favorable materials for broadband amplifiers in WDM systems and optical devices.

A fluorescence turn-down-up detection of Cu2+ and pesticide quinalphos using carbon quantum dot integrated UiO-66-NH2

Synthesis of a fluorescent probe consisting of carbon quantum dot integrated metal–organic framework (OPCD@UiO-66-NH 2 ) via a facile one-pot route has been reported. Carbon dot derived from orthophenylenediamine (OPCD) with a PLQY (26%) has been deposited on UiO-type metal organic framework by introducing OPCD during the synthesis of MOF. The resulting fluorescent OPCD@UiO-66-NH 2 composite shows better fluorescence properties as well as photostability than pristine OPCD. The molecular interaction between UiO-66-NH 2 and Cu 2+ can be sensed by encapsulated OPCD. As a result the OPCD@UiO-66-NH 2 shows remarkable fluorescence quenching on addition of Cu 2+ . However, in presence of organophosphorus pesticide quinalphos, the fluorescence intensity (at λ 425 ) of CD@UIO-66-NH 2 is regained because of competitive binding of Cu 2+ with quinalphos and releasing OPCD@UIO-66-NH 2 to the medium. Thus a dual sensor for Cu 2+ and quinalphos can be established by measuring fluorescence intensity at λ 425 . The relative increase in fluorescence intensity for quinalphos (F/F 0 ) works linearly in the concentration range 0–16 μM and the limit of detection is found to be 0.3 nM. The specific and selective recognition of our probe towards organophosphorus pesticide quinalphos makes it suitable for real field applications. • A carbon dot integrated UiO fluorescence sensor has been designed for detection of quinalphos in aqueous medium. • The sensing mechanism is based on disruption of non-radiative CD@UiO-Cu 2+ complex in presence of quinalphos. • The limit of detection is 0.3 nM which is lowest among the published papers. • The sensors can be successfully used to detect quinalphos in real samples.

Luminescent Analysis of Blood Serum for Diagnostics of Pathological and Pre-Pathological States of Cancer Patients.

This study is devoted to the development of a methodological approach to mathematical analysis and data interpretation of blood serum phosphorescence intensity in cancer patients for determining the pathological states and differential diagnostics of oncological process stages. The purpose of the study is blood serum phosphorescence research in patients with colorectal cancer (CRC) and stomach adenocarcinoma (SAC) and determination of the ultraweak luminescence role for diagnostics of the disease, determining its stages, control of pathogenetic therapy efficiency and forecast of recovery. The values of phosphorescence intensity of blood serum films in patients with CRC and SAC are significantly higher than the corresponding values for the control group. Contrary to the absolute intensity, the relative intensity increase compared to the control group is much more informative for oncoprocess diagnostics, since it exhibits three times increase even at the first stage of tumoral process. Serum phosphorescence intensity continues to increase with progressing of the disease. As the result of our study, the relative intensity increase compared to the first stage can be recommended as an informative indicator for differential diagnostics of oncological process stages. As a conclusion, determination of blood serum phosphorescence intensity can be considered as a sensitive and specific diagnostic method in oncology. With a correct methodological approach to data processing and interpretation, this method can be used in clinical practice for determining the oncopathological states, differential diagnostics of oncoprocess stages and diagnostics of precancer changes, which precede tumoral process development.

Forecasting the labor intensity and labor income share for G7 countries in the digital age

The development of digital technology has raised concerns about a decline in labor activity. In this paper, we offer predictions of the possible dynamics of the share of labor income for G7 countries, based on an assessment of the parameters of the factor-augmenting CES function. Particular attention is paid not only to the parameter of elasticity of substitution, but also to the measurement of relative labor intensity, which is ignored in most similar works. We show that a decrease in the share of labor income under a substitution elasticity of less than one occurs due to a trend towards an increase in relative labor intensity while reducing the ratio of investment to output. This pattern is a theoretical anomaly and can be reasonably explained by the growth of monopoly power under the development of the digital economy. Continuation of this trend in the next 30 years may lead to a decrease in the share of labor income in the G7 countries by an average of 5–16%.

Characteristics of discharge and beyond extreme ultraviolet spectra of laser induced discharge gadolinium plasma

The gadolinium (Gd) plasma is a potential beyond-EUV (BEUV) source for the extension of extreme ultraviolet lithography at 13.5 nm. A laser induced discharge plasma (LDP) is an effective way to excite the target material into high temperature plasma. A pulsed CO2 laser ablates a Gd plate cathode and produces an initial plasma, triggers a discharge between a Gd plate cathode and a stainless-steel cone anode, the current produces high temperature discharge plasma and creates an environment for BEUV radiation. A RLC model is used to estimate the equivalent circuit resistance and inductance, the resistance is about 0.70–0.75 Ω and the inductance is about 2.3–2.4 μH. A grazing incident ultraviolet spectrometer is established to study the Gd plasma’s BEUV radiation. With the laser energy above 120 mJ and voltage above 6.7 kV, Gd plasma spectra near the 6.7 nm is obtained. It is found that the relative spectral intensity increases and the peak of emission moves to a shorter wavelength corresponding to a higher voltage and laser energy. An atomic code combined with a simplified collisional-radiative model is used to calculate the theoretical spectra and estimate the electron temperature and density range of the LDP plasma.

Electromyographic traces of motor unit synchronization of fatigued lower limb muscles during gait.

The study of the signal in the frequency domain has shown to be a good tool to identify muscular fatigue. Previous research has shown that the low frequency band and 40Hz frequency band increase their relative intensity with the onset of fatigue. These findings were obtained in rectus femoris, but the behaviours of other muscles of the lower limb are unknown. In this article we explored the changes in the low frequency and 40Hz frequency band of lower limb muscles with respect to fatigue. Thirty healthy subjects were recruited to analyse the electromyography (EMG) of biceps femoris, tibialis anterior and gastrocnemius medialis and lateralis of both legs during gait. Four two-minutes walks at a self-selected speed were recorded, the first two walks with a normal muscular function and the last two walks after a fatigue protocol. All the signals were decomposed using wavelet transformations. The signals were normalized in time and spectral intensities normalized to the sum of intensities in the frequency domain. Two frequency bands were studied in each walk: the 40-Hz (34-53Hz) and the low frequency (< 25Hz) bands. A ratio of the spectral intensities of those frequency bands at each walk was obtained by dividing the 40-Hz frequency band spectral intensity by the low frequency band spectral intensity. Statistical parametric mapping techniques were used to compare the ratios of the prefatigue walks against the postfatigue walks. The results of the Statistical Non-Parametric Mapping (SnPM) analysis of all muscles depict a higher relative spectral intensity in the low frequency band in the comparison of fatigue versus prefatigue recordings except for the right gastrocnemius lateralis. The critical thresholds F* were exceeded by multiple suprathreshold clusters with p values <0.05, showing that the low frequency band increased its relative spectral intensity in the case of fatigue. The obtained results suggest that the low frequency band increases its relative spectral intensity in all the studied muscles when fatigue onsets. This increase in relative spectral intensity may be linked to an increase in motor unit synchronization promoted by the central nervous system to ensure good motor control.

The dependence of recombination in GaAs solar cells on the number of included GaInAs quantum objects

The experimental characteristics of GaAs p-i-n structures with InGaAs quantum objects (QOs) have been investigated. The study of electroluminescence spectra has shown that an increase of the number of QOs layers leads to relative increase in electroluminescence intensity from QOs and decrease it from the GaAs matrix. The observed increase in QOs recombination has resulted in a drop of open circuit voltage. It has been shown that recombination through deep levels in the QOs begins to dominate over recombination in the matrix at lower number of QOs layers than that through band-to-band recombination.

Antimicrobial and Antivirulence Impacts of Phenolics on Salmonella Enterica Serovar Typhimurium.

Salmonella enterica serovar Typhimurium (ST) remains a major infectious agent in the USA, with an increasing antibiotic resistance pattern, which requires the development of novel antimicrobials capable of controlling ST. Polyphenolic compounds found in plant extracts are strong candidates as alternative antimicrobials, particularly phenolic acids such as gallic acid (GA), protocatechuic acid (PA) and vanillic acid (VA). This study evaluates the effectiveness of these compounds in inhibiting ST growth while determining changes to the outer membrane through fluorescent dye uptake and scanning electron microscopy (SEM), in addition to measuring alterations to virulence genes with qRT-PCR. Results showed antimicrobial potential for all compounds, significantly inhibiting the detectable growth of ST. Fluorescent spectrophotometry and microscopy detected an increase in relative fluorescent intensity (RFI) and red-colored bacteria over time, suggesting membrane permeabilization. SEM revealed severe morphological defects at the polar ends of bacteria treated with GA and PA, while VA-treated bacteria were found to be mid-division. Relative gene expression showed significant downregulation in master regulator hilA and invH after GA and PA treatments, while fliC was upregulated in VA. Results suggest that GA, PA and VA have antimicrobial potential that warrants further research into their mechanism of action and the interactions that lead to ST death.

Interface-by-design in zirconia-polyurea matrix hybrid composites

This study investigates the incorporation of zirconia particles in polyurea matrix to form hybrid composites. Pristine zirconia particles in the monoclinic phase are first premixed with an oligomeric diamine−a reactant for polyurea−as an alternative method of surface functionalization that does not require the use of organosilanes. Interfacial interactions between the zirconia particles and polyurea are revealed via attenuated total reflectance-Fourier transform infrared spectroscopy, where a shift and broadening of the urea-carbonyl stretching and an increase in relative intensity of the corresponding disordered vs. ordered N–H stretching are shown in hybrid composites vs. bulk polyurea. The composition dependence of the viscoelastic relaxation characteristics and dynamic storage modulus in hybrid composites as determined by dynamic mechanical analysis are also elaborated upon. Additionally, we evaluate the potential of exploiting zirconia-polyurea hybrids to enabling dynamic impedance optimization at the interface of a select bi-layer construct, particularly when considering the material response under dynamic loading environments.

Far-Off Resonance: Multiwavelength Raman Spectroscopy Probing Amide Bands of Amyloid-β-(37-42) Peptide.

Several neurodegenerative diseases, like Alzheimer’s and Parkinson’s are linked with protein aggregation into amyloid fibrils. Conformational changes of native protein into the β-sheet structure are associated with a significant change in the vibrational spectrum. This is especially true for amide bands which are inherently sensitive to the secondary structure of a protein. Raman amide bands are greatly intensified under resonance conditions, in the UV spectral range, allowing for the selective probing of the peptide backbone. In this work, we examine parallel β-sheet forming GGVVIA, the C-terminus segment of amyloid-β peptide, using UV–Vis, FTIR, and multiwavelength Raman spectroscopy. We find that amide bands are enhanced far from the expected UV range, i.e., at 442 nm. A reasonable two-fold relative intensity increase is observed for amide II mode (normalized according to the δCH2/δCH3 vibration) while comparing 442 and 633 nm excitations; an increase in relative intensity of other amide bands was also visible. The observed relative intensification of amide II, amide S, and amide III modes in the Raman spectrum recorded at 442 nm comparing with longer wavelength (633/785/830 nm) excited spectra allows unambiguous identification of amide bands in the complex Raman spectra of peptides and proteins containing the β-sheet structure.

Characterisation of the dynamic nature of lipids throughout the lifespan of genetically identical female and male Daphnia magna

Lipids play a significant role in regulation of health and disease. To enhance our understanding of the role of lipids in regulation of lifespan and healthspan additional studies are required. Here, UHPLC-MS/MS lipidomics was used to measure dynamic changes in lipid composition as a function of age and gender in genetically identical male and female Daphnia magna with different average lifespans. We demonstrate statistically significant age-related changes in triglycerides (TG), diglycerides (DG), phosphatidylcholine, phosphatidylethanolamine, ceramide and sphingomyelin lipid groups, for example, in males, 17.04% of TG lipid species decline with age whilst 37.86% increase in relative intensity with age. In females, 23.16% decrease and 25.31% increase in relative intensity with age. Most interestingly, the rate and direction of change can differ between genetically identical female and male Daphnia magna, which could be the cause and/or the consequence of the different average lifespans between the two genetically identical genders. This study provides a benchmark dataset to understand how lipids alter as a function of age in genetically identical female and male species with different average lifespan and ageing rate.

OX2 receptors mediate the inhibitory effects of orexin-A on potassium chloride-induced increases in intracellular calcium ion levels in neurons derived from rat dorsal root ganglion in a chronic pain model.

AimsOrexin‐A is known to induce anti‐nociceptive effects in animal models of chronic pain. We have found that orexin‐A inhibits KCl loading‐induced increases in the intracellular calcium ion levels ([Ca2+]i) in C‐fiber‐like neurons of rats showing inflammatory nociceptive behavior. Here, we examined the effects of orexin‐A on the depolarization of C‐fiber‐like neurons derived from a rat model for another type of chronic pain, namely neuropathic pain. Thus, we analyzed the effects of orexin‐A on KCl‐induced increases in [Ca2+]i in C‐fiber‐like neurons of rats with sciatic nerve ligation.MethodsPaw withdrawal and threshold force in response to tactile stimuli were evaluated using von Frey filaments. Sham‐operated rats served as controls. [Ca2+]i in neurons were visualized by calcium fluorescent probe. Changes in [Ca2+]i were assessed using relative fluorescence intensity.ResultsSeven days after sciatic nerve ligation, paw withdrawal and threshold force for tactile stimuli were increased and reduced, respectively. KCl loading to neurons from either sciatic nerve‐ligated or control rats increased relative fluorescence intensity. The KCl‐induced increase in relative fluorescence intensity in sciatic nerve‐ligated, but not that of control, rats was inhibited by orexin‐A. The OX1 and OX2 receptor antagonist MK‐4305 and OX2 receptor antagonist EMPA, but not the OX1 receptor antagonist SB 334867, each counteracted orexin‐A‐induced inhibition of KCl‐provoked increases in relative fluorescence intensity.ConclusionThe present findings constitute neuropharmacological evidence that OX2 but not OX1 receptors mediate the inhibitory effects of orexin‐A on KCl‐induced increases in [Ca2+]i in C‐fiber‐like neurons of rats showing hyperalgesia provoked by sciatic nerve ligation.

Assessment of the antidiabetic potentiality of glyburide loaded glyceryl monostearate solid lipid nanoparticles

The high rate homogenisation techniques was used for preparing glyburide loaded glyceryl monostearate solid lipid nanoparticles (Glb-SLNs) to improve the drug's solubility and oral bioavailability. It was mediated through pseudo-ternary phase diagrams to optimize the surfactant/co-surfactant ratio. The optimized Glb-SLNs were characterized by FT-IR spectroscopy, DSC, powder X-ray diffraction study and SEM analysis. In rat skeletal muscle cells (L6 myocytes) and in streptozotocin and high-fat diet-induced diabetic rats, anti-diabetic activity was evaluated. Flow cytometry analysis has accessed the effects of glucose uptake performed by the 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl) amino)-2- deoxyglucose (2-NBDG) in L6 myotubes. In normal rats and diabetic rats, parameters such as the blood glucose level, serum insulin, serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), lipid peroxidase, catalase, glutathione, and HbA1c levels were assessed. Glb-SLNs at a dose of 50 μM showed a relative increase in relative fluorescence intensity of 92.5% to represent the glucose uptake potentiality. In vivo results revealed that the treatment with SLNs of glyburide (Glb-SLNs) normalized blood-glucose levels and serum biochemical parameters as compared with those of STZ controls. The protective effect was further confirmed by histopathological examination of the liver. These animals showed a comparable histopathological regeneration on Glb-SLNs treatment. These positive results demonstrated the success of the proposed SLNs approach in enhancing glyburide oral bioavailability and confirmed its potential as an effective system for diabetes treatment.