Differences In Peak Amplitude Research Articles

Sensorimotor Processing in Elite and Sub-Elite Adolescent Sprinters during Sprint Starts: An Electrophysiological Study.

Most studies on sprint performance have focused on kinematics and kinetics of the musculoskeletal system for adults, with little research on the central sensorimotor transmission and processes, especially for adolescent sprinters. This study aimed to determine whether differences in the integrity of the central auditory system and audiomotor transmissions between the elite and sub-elite adolescent sprinters may affect their performance in the 100 m time. Twenty-nine adolescent junior high school students, including elite national-class and sub-elite regional-class athletes, were assessed. Visual and auditory evoked potentials (VEP and AEP) as well as electroencephalography (EEG) and electromyography (EMG) were recorded and analyzed during a sprint start. The electrophysiological results clearly reveal differences in central auditory transmission between elite and sub-elite groups, and between sexes. There were significant differences between elite and sub-elite groups, and during a sprint start, the EEG activities for elite female and male athletes showed significant time-dependent differences in peak amplitudes following the three auditory cues (ready, set, and gunshot). These findings can provide coaches with a more comprehensive consideration for sports-specific selection based on the athletes' individual conditions, e.g., sensorimotor neuroplastic training for providing precise and efficient training methods to improve young sprinters' performance.

The influence of cerebellum on visual selective attention in patients with multiple lacunar cerebral infarction and its neuromodulatory mechanisms.

This study aims to investigate the influence of the cerebellum on visual selective attention function and its neuromodulatory mechanism in patients with multiple lacunar cerebral infarction (MLCI). A retrospective analysis was conducted on 210 patients admitted with MLCI from January 2016 to May 2022. Analyzed the electrophysiological characteristics of the P3a and P3b components of vision in both groups, as well as source reconstruction simulations of dipole activation in the brains of the two groups, and analyzed the brain regions with differences in activation strength between the two groups. This study found that there was no significant difference in peak amplitude between the two groups, but compared with the control group, the peak latency of the case group was significantly prolonged. Specifically, the P3a peak latency induced by the novel stimulus was longer than that induced by the target stimulus P3b peak latency. Source reconstruction results showed decreased and increased activation in several brain regions in the case group compared to the control group. The study suggests that the impairment of distracted attention capture is more pronounced in patients with MLCI. The cerebellum indirectly influences the ventral and dorsal frontoparietal attention networks by modulating the levels of excitation and inhibition within the cerebral cortex of the attention network. This may represent a potential mechanism through which the cerebellum regulates visual selective attention information in MLCI patients.

Study on Pyrolysis and Oxidation Characteristics of Coal Gangue Based on TGA-DSC.

Coal gangue spontaneous combustion has caused serious environmental and ecological problems. To investigate the reaction kinetic parameters of the gangue and the exothermic characteristics of the spontaneous combustion of the influence of the law, this study employs the thermogravimetric method to explore the characteristic parameters of the pyrolysis and oxidative combustion process of the gangue from the perspective of thermodynamics, and, at the same time, using the differential scanning calorimetry (DSC) on the exothermic effect of the gangue to explore the gangue to obtain the gangue and the original coal TG/DTG/DSC curves to be compared and from the perspective of thermodynamics. The change rule and potential parameters in the pyrolysis and oxidative combustion process of coal gangue (CG) were analyzed, the oxidation kinetic properties of CG were studied, and the reaction mechanism of oxidative spontaneous combustion of CG was further explained. The results show that the TG/DTG/DSC curves of CG in different gas atmospheres will have significant differences in all stages, and in the process of pyrolysis and oxidative combustion, the thermogravimetric curves of CG and those of the original coal show a consistent trend, except for the large difference in peak amplitude in different stages; in different gas atmospheres, as the rate of warming increases, the TG/DTG/DSC curves of the gangue are tilted toward the high-temperature region, they are inclined to the high-temperature region with the increase of the heating rate, and the phenomenon of "hysteresis" of characteristic temperature occurs. The research results provide a theoretical basis for the construction of a spontaneous combustion early warning system based on the fine division of gangue pyrolysis and oxidation combustion stages.

Peak amplitude difference sensitivity (PADS): An interrogation technique for PCF-SPR sensors using symmetrical arrays of plasmonic layers

In this research paper, plasmonic materials are used in somearrays consisting of goldand aluminum-doped zinc oxide (AZO) to make a unique photonic crystal fiber sensor with multipleloss peaks. Using plasmonic layer arrays, a unique dispersion relation with severalpeaks has been introduced. Compared to a sensor with a single peak, the proposed sensor has multiple peaks that can be applicable for different wavelength range to detect the refractive index efficiently. A new interrogation technique named Peak Amplitude Difference Sensitivity (PADS) is proposed in this manuscript while in this sensor, the maximum PADS of 396.175 RIU−1 and maximum wavelength sensitivity (WS) of 85,300 nm/RIU is achieved. Furthermore, thesensor has a high wavelengthresolution of 1.17×10-6 RIU. With an ultra-high linearity of R2=0.99978, this sensor obtained a high figure of merit (FOM) of 370.8 RIU−1, indicating precise detection accuracy. The proposed design canlead to major improvements in the ultra-high precision in detecting the biological organic molecules and can be used in extensive applications.

CHARACTERIZATION OF THE AVERAGE POWER, FREQUENCY AND AMPLITUDE OF ACOUSTIC SIGNAL PEAKS OVER THE LUNGS IN CHILDREN WITH COMMUNITY-ACQUIRED PNEUMONIA USING THE NEW DEVICE "TREMBITA-CORONA"

Background. Community-acquired pneumonia (CАР) is an urgent problem today and a significant cause of morbidity and mortality in children. Diagnosis of pneumonia is complex and requires a comprehensive study. At present, respiratory acoustics is a promising method of diagnosis.
 Aim: to investigate the features of average power values, frequencies and amplitudes of acoustic signal peaks over the lungs in children with community-acquired pneumonia using a new acoustic diagnostic device "Trembita-Corona".
 Materials and methods. 120 children aged from 1 month to 18 years who were treated in pediatric departments were studied. The children were divided into two groups: Group I - 60 patients with CAP, Group II - 60 healthy children. The children from the 1st group underwent complex examinations, which required CAP. All children were also examined using the "Trembita-Corona" acoustic monitoring device for the diagnosis of breathing sounds and localization of lung damage zones.
 The study was conducted in accordance with the international principles of conducting clinical studies GCP, GLP, the protocol was approved at the meeting of the Commission on Bioethical Expertise at the National Medical University named after O.O. Bogomolets (protocol No. 138 of November 10, 2020). Informed consent of parents/guardians was obtained for conducting the study, which was approved at the same meeting of the Commission on Bioethical Expertise at Bogomolets National Medical University (protocol № 138 of November 10, 2020).
 Mathematical processing was carried out on specialized software developed in the Python language in the Google Codelabs environment. Further statistical processing of the obtained results was carried out in specialized programs Medstart, EZR (R-Statistics) and "Matlab".
 Results. In children, the clinical picture of CAP consisted of pulmonary (respiratory) complaints, symptoms of intoxication, RF, and local physical changes. All patients were examined for respiratory lung sounds in the frequency range from 0.1 Hz to 30 kHz using the "Trembita-Corona" device and the corresponding original software. The most promising are the studies of breathing noises in the ranges of 0, 1, 2, 3, 4, 5, 6 octaves. Also, significant differences in average signal power between children with CAP and healthy children in 0,1,2,3,4,5,6 octaves were found. Using the "Trembita-Corona" acoustic monitoring device, reliable differences in peak frequency between children with CAP and healthy children in 0 and 5 octaves and reliable differences in peak amplitude between children with CAP and healthy children in 0, 1, 2, 3 were found. ,4,5,6 octaves. Therefore, the use of the "Trembita-Corona" acoustic monitoring device and the use of the developed specialized software in the Python language in the Google Codelabs environment together make it possible to hear specific acoustic signals over the entire surface of the lungs in children with CAP.
 Conclusion. The "Trembita-Corona" acoustic monitoring device is a new and promising acoustic method for determining the location of the pathological process in the lungs. Significant differences were found: in the average signal strength between children with CAP and healthy children in 0,1,2,3,4,5,6 octaves; on the frequency of peaks between children with CAP and healthy children in 0 and 5 octaves; by the amplitude of peaks between children with CAP and healthy children in 0,1,2,3,4,5,6 octaves.

Simultaneous Determination for Lansoprazole and Simvastatin drugs via Ultraviolet Spectrophotometry

A semi-novel, accurate, sensitive, simple, requiring no prior separation and economical procedures have been developed for the simultaneous analysis of binary mixture of Lansoprazole (Lanso) and Simvastatin (Semva). The first method is the Derivative of ratio spectra, in which the absorption spectrum of one drug as interfering drug were subtracted from the absorption spectrum of the mixture and then the net spectrum derivative, the first derivative (for Lanso) and second derivative (for Semva). Beer’s law was obeyed in the concentration ranges of (1-90) and (4-70) μg.ml-1 and the results showed that the method was precise and accurate with RSD% of (0.0161-0.0235), (0.0360-0.0525) and R.E% (0.3125-0.4545), (-0.0909-0.0312) for Lanso and Semva respectively. The second method based on ratio difference, where the absorption spectrum of mixtures the drugs was divided by the on the absorption spectrum of a suitable the interfering drug. The difference in peak amplitudes between the two selected wavelengths in the ratio spectra were recorded for each drug. Beer’s law was obeyed in the concentration ranges of (0.1-30) and (1-40) μg.ml-1 and the results of the method were precise and accurate with RSD% of (0.2880-0.4580), (0.1294-0.9880) and R.E% of (-0.0090-0.0909), (-0.0651-0.0710) for Lanso and Semva respectively of this method.
 The proposed methods were successfully applied for the determination of the two compounds.

КОГНІТИВНІ ПОТЕНЦІАЛИ ГОЛОВНОГО МОЗКУ ЧОЛОВІКІВ, ВИКЛИКАНІ СПРИЙНЯТТЯМ ОБЛИЧ ОСІБ РІЗНОЇ СТАТІ З РІЗНОЮ ЕМОЦІЙНОЮ МОДАЛЬНІСТЮ

The calculation of the difference in peaks of the event-related potential in men during exposure to different-sex faces with differential emotional modality using the MATLAB and EEGLAB software packages. The electrical activity of the brain of 20 male students of Taras Shevchenko Kyiv National University was recorded to identify the difference in the activation of brain structures during the demonstration of portraits of different sexes with positive and negative emotional modalities. Statistically significant differences in peak amplitude were recorded for components N250, N400, and P300 when subjects were presented with male and female portraits with a positive emotional modality, while when exposed to a series of images with a negative emotional modality, no statistical differences were registered in any of the componenStatistically significant differences in the peak amplitude were recorded for the N250, N400, and P300 components when subjects were presented with male and female portraits with a positive emotional modality, while when exposed to a series of images with a negative emotional modality, no statistical differences were registered in any of the components.

Identification of fracturing behavior in thermally cracked granite using the frequency spectral characteristics of acoustic emission

The frequency characteristics of acoustic emission (AE) during triaxial compression of thermally cracked and unheated (“fresh”) granite samples were investigated with the aim of understanding the influence of pre-existing cracks on precursor information regarding macroscopic failure. The peak frequency during the damage process was the same for thermally cracked and fresh granites. Analysis of AE signals showed that signals with low peak frequency appeared before failure of the sample, implying the initiation of macrocracks with progressive growth of cracks. The peak amplitude of the frequency spectrum recorded in the thermally cracked samples was much lower than that in the fresh samples. This result suggests two reasons for the difference in peak amplitude: reduction in shear modulus and the attenuation filtering phenomenon caused by thermal cracks (i.e., the differences in overall bulk properties). In particular, the maximum value of peak amplitude in the low-frequency band for the thermally cracked samples was smaller than that for fresh samples. This characteristic can be related to the properties of source of AE signals, such as the stress drop and crack size. Assuming that pre-existing thermal cracks grow during the pre-failure stage, the events with low peak frequency and low peak amplitude in the heat-treated samples are interpreted as exhibiting a low stress drop for individual events. Therefore, although AE signals with low frequency can be considered as precursors to rock failure, cracking behavior suggested by events with low frequency depends on the initial damage condition of the rock sample.

Deep carbonate reservoir and gas prediction based on multicomponent seismic amplitude attributes — A case study

Multicomponent seismic exploration provides more valuable information for the prediction of underground structures, lithology, fluids, and fractures. Most studies on lithology estimation and fluid description using PP- and PS-wave seismic data mainly focus on relatively shallow targets with high porosity. Focusing on deep carbonate (dolomite) reservoirs with low porosity (generally less than 5%), we first analyze the characteristics of the seismic response difference between PP and PS waves, and then we combine logging data and seismic forward modeling to implement the identification of fluids using the amplitude difference between PP and PS waves. Data sets are acquired over grain beach dolomite reservoirs in the Cambrian Longwangmiao Formation, the central Sichuan Basin, Western China. The reservoirs are filled with different types of fluids (e.g., gas, water, bitumen, etc.). Based on comparisons between seismic responses of PP and PS waves, we observe that, at the location of the gas-bearing layer, PP-wave amplitude exhibits strong peaks and PS-wave amplitude finds relatively weak peaks, which is different from that obtained for the water-saturated layer. However, at the location of bitumen-filled reservoirs, PP- and PS-wave amplitudes exhibit strong peaks, and the reflection amplitude of PP waves is stronger than that of PS waves. Therefore, the amplitude difference of PP and PS waves provides valuable information and feasibility for fluid identification. We verify that the maximum peak amplitude attribute of PS waves may better characterize the distribution of porous dolomite reservoirs than that of PP waves, and using the attribute of maximum peak amplitude difference between PP and PS waves, we may distinguish gas-bearing and water-saturated layers. Comparing with actual drilling results, we conclude that our PP/PS interpretation technique is feasible for fluid identification in deep carbonate reservoirs.

Mathematically Processed UV Spectroscopic Method for Quantification of Chlorthalidone and Azelnidipine in Bulk and Formulation: Evaluation of Greenness and Whiteness

A simple, eco-friendly four analytical methods were established by improving the selectivity through the application of mathematical processing of UV absorption spectra for concurrent quantification of chlorthalidone (CTL) and azelnidipine (AZE). The UV absorption spectra were recorded using environment-friendly ethanol (10% v/v) and were mathematically processed using simple software provided with a UV spectrophotometer. The analytes’ peak amplitude was determined using zero-crossing point first derivative spectra and ratio first derivative spectra of CTL and AZE, which were measured at 238.5 nm and 239.5 nm for CTL and 272.1 nm and 342.1 nm for AZE, respectively. The peak amplitude difference was determined from the ratio spectra of CTL and AZE by measuring the peak amplitudes at 211.8 and 267.2 nm for CTL and 328.4 and 286.1 nm for AZE. Further, ratio spectra of CTL and AZE were converted into zero-order spectra by subtracting the constant followed by multiplication with divisor spectra, and the peak amplitudes were measured at 226.9 nm and 257.3 nm for CTL and AZE zero-order spectra, respectively. Further, validation results of all the four methods confirmed the accuracy and precision of the methods by displaying good recovery (98.37–100.34%) and percentage relative standard deviation (0.397–1.758%), respectively. Good linearity was observed in the range of 1–15 μg/mL for both analytes with less than a 1 μg/mL limit of quantification. Further, the greenness and whiteness of the methods were evaluated by recently proposed AGREEness, complexGAPI, and white analytical chemistry techniques. The proposed UV spectroscopic methods were environmentally friendly, safe, economic, and effective, hence, could be used for regular quality control study of a formulation containing CTL and AZE.

Heat transfer characteristics of a periodically transient flow for turbulent wall-bounded dual jet

The thermal characteristics and aerodynamic behaviours of an unsteady flow for a turbulent wall-bounded dual jet are computationally studied in the present paper. It is quite important to analyse thermal characteristics of such flows, as a function of independent parameters like Reynolds number. These jets are used in different industrial applications, such as, cooling of electronic devices and heat exchange systems. The capabilities of different Reynolds-Averaged Navier-Stokes (RANS) turbulence modeling approaches, such as, renormalization groupk-ɛ(RNG), realizablek-ɛ, standardk-ω,and shear-stress transportk-ω(SST) models in predicting thermal performance of a turbulent dual jet are investigated. The comparison shows that among four turbulence models, the SSTk-ωmodel provides a good agreement with the reported experimental results. The transient RANS equations have been used to simulate the complex behaviour of a turbulent dual jet. The Reynolds number (Re) is varied from 10,000 to 40,000 for a fixed offset ratio of 2 under isothermal boundary wall conditions. The results reveal that the axial position of the merge point is independent of Re and remains almost constant as Re is further increased. It is also noticed that the velocity becomes self-similar and independent of Re after a streamwise position of X = 30. The time series of U and V velocity signals unveil sinusoidal oscillations and display peak to peak amplitude difference at the far axial location. The FFT assessment of the U velocity signal displays a solo peak dominant frequency which is the same as shown by V velocity in the FFT plot corresponding to the Strouhal number of the vortex shedding phenomenon. The average Nusselt number and the average heat flux increase with Re. A correlation has been developed for the average Nusselt number and the average heat flux. These outcomes will improve the current knowledge of various engineering and industrial applications to enhance the heat transfer in different heat exchange systems, such as, electronics cooling systems.

A comprehensive investigation of vortex-induced vibrations and flow-induced rotation of an elliptic cylinder

This work finds its motivation in heat exchanger design and flow control. Flow-induced vibration is studied numerically for combined vortex-induced vibrations and vortex-induced rotations of a horizontally positioned elliptic cylinder. The aspect ratio is taken as 2, and the value of reduced velocities (Ured) considered for the present simulation is between 2 and 12. The body can have to and fro motions in a transverse (y) direction, in-line (x) direction as well as in azimuthal (θ) direction, which provides three degrees of freedom (DOF) to the body. It is found that for one-DOF (y-direction only) and two-DOF (y and x directions) cases, lock-in regions are the same while it is wider for the case of the three-DOF system. With the rotational DOF, y-directional motion is amplified and when it is compared with the one-DOF and two-DOF cases, difference in peak amplitude is about 30%. The rotational response reaches a maximum value within the synchronization regime, and the frequency behavior of rotational and transverse oscillations is showing the same characteristics. The phase difference is plotted to check their synchronization with respective forces and moments. For all DOFs and Ured, synchronized or desynchronized regions, 2S mode of vortex shedding was observed. For one-DOF and two-DOF cases, the transverse vibrational frequency ratio (fy/fn) becomes equal to unity for the range 3.75≤Ured≤5. For three-DOF, fy/fn and rotational frequency ratio (fR/fn) become close to the unity for 3.75≤Ured≤6. The three-DOF system shows smaller wake width and vortex formation length whereas the vortex strength is maximum.

Cortical Sources of Respiratory Mechanosensation, Laterality, and Emotion: An MEG Study.

Airway obstruction activates mechanoreceptors that project to the cerebral cortices in humans, as evidenced by scalp encephalography recordings of cortical neuronal activation, i.e., respiratory-related evoked potential (RREP). However, neural evidence of both high spatial and temporal resolution of occlusion-elicited cortical activation in healthy individuals is lacking. In the present study, we tested our hypothesis that inspiratory mechanical stimuli elicit neural activation in cortical structures that can be recorded using magnetoencephalography (MEG). We further examined the relationship between depression and respiratory symptoms and hemispheric dominance in terms of emotional states. A total of 14 healthy nonsmoking participants completed a respiratory symptom questionnaire and a depression symptom questionnaire, followed by MEG and RREP recordings of inspiratory occlusion. Transient inspiratory occlusion of 300 ms was provided randomly every 2 to 4 breaths, and approximately 80 occlusions were collected in every study participant. Participants were required to press a button for detection when they sensed occlusion. Respiratory-related evoked fields (RREFs) and RREP peaks were identified in terms of latencies and amplitudes in the right and left hemispheres. The Wilcoxon signed-rank test was further used to examine differences in peak amplitudes between the right and left hemispheres. Our results showed that inspiratory occlusion elicited RREF M1 peaks between 80 and 100 ms after triggering. Corresponding neuromagnetic responses peaked in the sensorimotor cortex, insular cortex, lateral frontal cortex, and middle frontal cortex. Overall, the RREF M1 peak amplitude in the right insula was significantly higher than that in the left insula (p = 0.038). The RREP data also showed a trend of higher N1 peak amplitudes in the right hemisphere compared to the left (p = 0.064, one-tailed). Subgroup analysis revealed that the laterality index of sensorimotor cortex activation was significantly different between higher- and lower-depressed individuals (−0.33 vs. −0.02, respectively; p = 0.028). For subjective ratings, a significant relationship was found between an individual’s depression level and their respiratory symptoms (Spearman’s rho = 0.54, p = 0.028, one-tailed). In summary, our results demonstrated that the inspiratory occlusion paradigm is feasible to elicit an RREF M1 peak with MEG. Our imaging results showed that cortical neurons were activated in the sensorimotor, frontal, middle temporal, and insular cortices for the M1 peak. Respiratory occlusion elicited higher cortical neuronal activation in the right insula compared to the left, with a higher tendency for right laterality in the sensorimotor cortex for higher-depressed rather than lower-depressed individuals. Higher levels of depression were associated with higher levels of respiratory symptoms. Future research with a larger sample size is recommended to investigate the role of emotion and laterality in cerebral neural processing of respiratory sensation.

Development of Ecofriendly Derivative Spectrophotometric Methods for the Simultaneous Quantitative Analysis of Remogliflozin and Vildagliptin from Formulation.

Three rapid, accurate, and ecofriendly processed spectrophotometric methods were validated for the concurrent quantification of remogliflozin (RGE) and vildagliptin (VGN) from formulations using water as dilution solvent. The three methods developed were based on the calculation of the peak height of the first derivative absorption spectra at zero-crossing points, the peak amplitude difference at selected wavelengths of the peak and valley of the ratio spectra, and the peak height of the ratio first derivative spectra. All three methods were validated adapting the ICH regulations. Both the analytes showed a worthy linearity in the concentration of 1 to 60 µg/mL and 2 to 90 µg/mL for VGN and RGE, respectively, with an exceptional regression coefficient (r2 ≥ 0.999). The developed methods demonstrated an excellent recovery (98.00% to 102%), a lower percent relative standard deviation, and a relative error (less than ±2%), confirming the specificity, precision, and accuracy of the proposed methods. In addition, validated spectrophotometric methods were commendably employed for the simultaneous determination of VGN and RGE from solutions prepared in the laboratory and the formulation. Hence, these methods can be utilized for the routine quality control study of the pharmaceutical preparations of VGN and RGE in pharmaceutical industries and laboratories. The ecofriendly nature of the anticipated spectrophotometric procedures was confirmed by the evaluation of the greenness profile by a semi-quantitative method and the quantitative and qualitative green analytical procedure index (GAPI) method.

Simultaneous determination of Xipamide and Triamterene by zero order, first derivative, derivative ratio and ratio difference spectrophotometric methods.

Validated, rapid and sensitive spectrophotometric techniques were established for simultaneous determination of Xipamide and Triamterene. The first technique based on determination of Triamterene with zero-crossing of Xipamide using zero order method at 367.0 nm. The second technique based on determination of both Xipamide and Triamterene by first derivative method with zero-crossing of Triamterene and Xipamide respectively, at 265.6 and 388.6 nm. Third technique is ratio difference spectrophotometric method depending on obtaining peak amplitude difference at 256.0 and 273.0 nm for Xipamide and 288.0, 302.0 nm for Triamterene. Fourth method is derivative ratio spectrophotometric method depending on obtaining the first derivative of the ratio spectrum with zero-crossing of Xipamide and Triamterene at 365.2 and 308.6 nm; respectively. Linear relationship was obtained upon using concentration range (1.0-10.0 µg/mL) for Xipamide and (1.0-16.0 µg/mL) for Triamterene with LOD less than 0.3 µg/mL for both drugs. The suggested spectrophotometric techniques showed Lower LOD and more sensitivity other than any reported spectrophotometric methods and were applied in pure and dosage form (Epitens®).

Spectrophotometric Determination of Polyvinyl Pyrrolidone in Pure and Pharmaceutical Dosage Form.

Recently, functional polymers have attracted significant attention in the areas of pharmaceuticals and biomedical applications, so it is important to develop simple techniques to analyze functional polymers in their pharmaceutical dosage forms. Three simple, accurate, and sensitive UV spectrophotometric methods have been developed and validated for determination of polyvinyl pyrrolidone (PVP) in the presence of benzalkonium chloride (BZ) and sodium lactate in ternary mixtures. Method A is a derivative ratio spectra zero-crossing (DRSZ) method which measures PVP peak amplitude at 303.1 nm. Method B is a double divisor ratio derivative (DDRD), used for determination of both PVP and BZ in the presence of sodium lactate at 272.6 and 271.5 nm, respectively. Method C is a double divisor ratio derivative-ratio difference spectrophotometric method (DDRD-RDSM), a new and hybrid method of double divisor and ratio difference that hasn't been applied before. It measures peak amplitude difference of the ratio spectra at ΔP278 - 252.4 and ΔP260.9 - 213 for PVP and BZ, respectively. Linear ranges for PVP (5.00-35.00, 10.00-40.00, and 10.00-40.00 µg/mL) was obtained by using DRSZ, DDRD, and DDRD-RDSM, respectively. While the linear range for BZ (5.00-60 µg/mL) was obtained by using both DDRD and DDRD-RDSM. All results were statistically compared with reported methods. No significant differences were observed. The developed methods were applied to the analysis of the investigated drugs in pure and pharmaceutical dosage forms. The proposed methods are of great value, improving the efficiency of routine analysis of PVP and BZ in their pharmaceutical dosage forms.

Development and Validation of Green UV Derivative Spectrophotometric Methods for Simultaneous Determination Metformin and Remogliflozin from Formulation: Evaluation of Greenness.

The recent trend in green analytical chemistry is the development of green analytical methods using environmentally friendly solvents. Therefore, three ecofriendly manipulated UV spectroscopic techniques have been validated for the concurrent quantification of newly approved remogliflozin etabonate (REM) and metformin HCl (MET) tablets using water as a solvent. The first method was established using first derivative absorption spectroscopic method by determining the peak amplitude at 233.0 nm for REM and 252.2 nm for MET, a zero crossing of one the component. The second and third methods were based on the peak amplitude difference and first-order derivative absorption of the ratio spectra developed by the manipulation of scanned UV spectra. REM and MET showed good linearity in the series of 1–20 µg ml−1 and 2.5–35 µg ml−1, respectively, by all three methods with an excellent correlation coefficient (r2 ≥ 0.998). Further, the proposed UV spectroscopic techniques were validated as per International Council for Harmonization guidelines. The methods showed good sensitivity, accuracy, and precision. Anticipated procedures were effectively utilized for the concurrent quantification of REM and MET in laboratory prepared mixtures and tablets. The high percent recovery with low standard deviation found for both analytes by all three methods confirms the accuracy and precision of the procedures. Finally, the greenness of the proposed spectroscopic methods, evaluated by semi-quantitative and quantitative methods, showed the eco-friendly nature of the methods. Furthermore, the proposed approaches were simple, accurate, sensitive, economic, and environmentally friendly and hence can be utilized for regular quality control of REM and MET formulation.

The Influence of Surface Electromyography Visual and Clinician Verbal Feedback on Swallow Effort Ratio at Different Bolus Volumes in a Healthy Population

Background/Aims: The effortful swallow is a common treatment intervention requiring increased intensity to facilitate adaptations and modify swallow kinematics. The type of feedback and bolus volume provided may influence the intensity of the effortful swallow. To determine the increased effortful swallow intensity, a clinician can collect the peak amplitude of an effortful swallow and a typical swallow and compute a “swallow effort ratio” (SER). Dividing the effortful swallow surface electromyography (sEMG) peak amplitude by the typical swallow sEMG peak amplitude derives the SER. A higher SER suggests increased intensity. An increase in the SER may have clinical relevance in swallowing therapy as a threshold of intensity is required to elicit neuroplastic change. The purpose of this investigation was to determine whether sEMG visual and clinician verbal feedback increases the SER. Additionally, the investigation examined whether the SER is influenced by different liquid bolus volumes. Methods: Eighty-two nondysphagic, healthy adults were assigned at random to 2 groups. One group received no feedback, and the other received verbal and visual feedback while performing typical and effortful swallows at 3 liquid volumes. Results: An analysis of covariance compared the typical and effortful peak swallow amplitudes among 3 volumes in the 2 feedback groups. There was a significant effect on the peak amplitude values by feedback group F(2, 79) = 22.82, p < 0.001. There were no differences in peak amplitude by volume regardless of feedback F(2, 78) = 0.413, p = 0.663. Conclusion: It appears that sEMG visual and clinician verbal feedback increases the SER, which may be a surrogate for intensity. An increased SER may have a positive effect on swallow intervention as intensity is known to influence outcomes of exercise and elicit neuroplastic change.

Three Simple and Economic Spectrophotometric Methods for Simultaneous Determination of Chitosan and Ascorbic Acid

Three simple, precise, and sensitive UV spectrophotometric methodshave been developed and validated for the determination of Chitosan (CH) in the presence of Ascorbic acid (AA) in a binary mixture. Method A is a derivative ratio method (1DD) that measures the peak amplitude of the first derivative for CH and AA at 207.2 and 282 nm; respectively. Method B is a ratio difference method (RDSM) that measures the peak amplitude difference of the ratio spectra (DP204.6- 202.9) and (DP268-230) for CH and AA; respectively. Method C is a mean centering of ratio spectra method (MCR) that measures CH and AA at 204.6 and 269.1 nm; respectively. Method A, B, and C were able to successfully determine the studied drugs in a concentration range of 0.5-9 mg/mL for CH and 2-20 mg/mL for AA. All results were statistically compared with the reported methods, where no significant difference was observed. The proposed methods were applied to the analysis of the studied drugs in pure and pharmaceutical formulations.

Spectrophotometry analysis for simultaneous determination of the new antiviral drug combination: Daclatasvir/sofosbuvir in their pure form and pharmaceutical preparation

Daclatasvir and Sofosbuvir are recently co-formulated as antiviral combination for treatment of hepatitis C virus (HCV). Several spectrophotometry methods were developed and validated for determination of the partially overlapped spectra of Daclatasvir and Sofosbuvir with simple data manipulation. Daclatasvir can be directly determined at 316.0 nm with in a linear range of 2.5–25.0 μg/mL. Three approaches were applied for determination of Sofosbuvir; the first is using dual wavelength method at which the absorbance difference between 350.0nm and 270.0nm was recorded and absorption subtraction method where the two drugs have an isosbestic point at 272.0nm. The second approach is derivative spectroscopy using first derivative method, Sofosbuvir can be determined at 253.0nm at which Daclatasvir showed a zero crossing point. The third approach is manipulation of ratio spectra using ratio difference method at which the overlapping spectra of Sofosbuvir divided by a divisor from Daclatasvir where the difference in peak amplitude measured at 257.0nm and 228.0 nm. Ratio derivative method was also applied at which the first derivative corresponding to each ratio spectrum was recorded then the amplitude values were measured at 270.0nm. In these methods Sofosbuvir showed linearity in the range of 10.0–80.0 μg/mL. These methods were validated according to ICH guidelines and was successfully applied to pharmaceutical formulation and showed nonsignificant difference when compared to a well established published method.