Initial Time Research Articles

Near-infrared imaging of in vivo performance of orally administered solid forms to rats: Feasibility study with indocyanine green

This study demonstrates the applicability of near-infrared (NIR) imaging to evaluating in vivo oral formulation performance. As a NIR probe and model drug, indocyanine green (ICG) and acetaminophen (ACE) were selected, respectively. The fluorescence intensity of ICG greatly increased upon dissolution, with the dissolved ICG passing through the gastrointestinal tract over time. Both compounds (0.05 mg of ICG and 0.5 mg of ACE) were encapsulated in gelatin and hydroxypropyl methylcellulose (HPMC) capsules in the solid form. In vitro, the HPMC capsules showed a disintegration lag time, a feature that was not observed for the gelatin capsules. After oral administration of each capsule to rats, blood samples were collected, followed by fluorescent imaging of the abdominal region. At 0.25 h after HPMC capsule administration, the fluorescence area and intensity were significantly small and relatively weak compared to that of the gelatin capsule. These tendencies resulted from the difference in capsule disintegration times, leading to a change in gastric emptying, which corresponded well with the initial time profile of the plasma concentration of ACE. These results indicate that possibility of NIR imaging with ICG to evaluate in vivo performance of orally administered formulations.

Horizontal bearing characteristic and seismic fragility analysis of CFRP composite pipe piles subject to chloride corrosion

This paper studies the time-dependent horizontal bearing characteristic and seismic fragility analysis of carbon fiber reinforced polymers (CFRP) composite pipe piles under chloride corrosion. A diffusion model of chloride ions in CFRP composite pipe piles is established based on Fick's second law, allowing for the prediction of corrosion initiation time of CFRP composite pipe piles. The flexural stiffness of composite pipe piles for different CFRP replacement ratios is calculated, and the time-dependent horizontal bearing capacity of CFRP composite pipe pile is calculated using the finite difference method. Considering the uncertainties of structural modeling and earthquake waves, an analysis is conducted to study the effect of earthquakes on piles with different CFRP replacement ratios at various service times. The seismic fragility curves are then derived. The research results show that with the increase of service time, the flexural stiffness of CFRP composite pipe piles decreases. Moreover, higher CFRP replacement ratios result in reduced loss of pile bending stiffness and greater stability of the flexural bearing capacity. As the service time increases, the failure probability of composite pipe piles under seismic action exhibits a smaller increase, particularly for higher CFRP replacement ratios, thereby resulting in a lower loss of seismic performance.

One-Pot template free synthesis of bimetallic alloy Pt-M/C (M = Fe, Co & Cu) with improved activity for electrocatalytic oxidation of methanol

We prepared a simple, one-step synthesis of Pt-M (M = Co, Cu & Fe)/C supported on Vulcan-XC-72 carbon using the polyol reduction method. The morphology, structure and elemental composition of the prepared catalysts were confirmed by transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). Electrochemical characterization including electrochemical impedance, cyclic voltammetry and chronoamperometry were studied to compare the electrochemical activity of the as-prepared catalyst with standard 20 wt % Pt/C. From transmission electron microscopy studies, the estimated average particle size for PtFe/C, PtCo/C and PtCu/C were 16, 12 and 10 nm respectively. In cyclic voltammetry studies, the PtFe/C catalyst exhibited the maximum current density for electrooxidation of methanol (14.88 mA cm−2), compared to PtCu/C (9.96 mA cm−2), PtCo/C (4.66 mA cm−2) and Pt/C (2.34 mA cm−2). Also, the negative sweep onset potential and greater If/Ib ratio verified the enhanced activity of the PtFe/C catalyst. The stability of the catalyst was studied using chronoamperometric methods, which reveals the slow decay of the prepared catalyst and higher current density for initial and final time intervals. Impedance studies confirm that the PtFe/C catalyst exhibits the smallest semicircle, suggesting a significantly higher electrooxidation rate in comparison to the other catalysts. The electrocatalytic activity of the prepared catalyst follows the order: PtFe/C > PtCu/C > PtCo/C > Pt/C.

Numerical simulation of transient boiling and void cross flow in non-uniformly heated 5 × 5 rod bundle

A multi-dimensional numerical simulation has been conducted for a transient boiling experiment by applying rapid and non-uniform power to fluid in a 5×5 bundle channel simulated a BWR fuel assembly in atmospheric pressure. The experiment is to investigate thermal hydraulic behavior in applying transient power to subcooled reactor coolant in a stand-by mode of a nuclear power plant such as reactivity initiated accident (RIA). The numerical simulation has been conducted by TRACE (version 5.0 / patch 5) which is a nuclear system analysis code to solve thermal hydraulics of boiling two phase flow by a two fluid model. The bundle channel in the upward vertical direction has been simulated by a three dimensional component with the Cartesian coordinate system attaching heat structures to simulate heating rods for thermal conduction and heat transfer calculation. It has been revealed that the numerical result is possible to simulate the void cross flow through the sub-channel in the bundle channel qualitatively as observed in the experiment. However, there was room for improvement for a wall heat transfer model in TRACE because the numerical result is larger than the experimental result in terms of the rising rate of the rod temperature during the rapid initial increasing of applied power, and it has been inferred that the evaluation model for an onset of nucleate boiling in TRACE also has to be improved because the void initiation time in the numerical result was earlier than the experimental result. Therefore, TRACE has been optimized by modifying the two physical models described above. The numerical results with the modified TRACE have been in better agreement with the experimental results than those with the original TRACE. Using the modified TRACE, a numerical experiment has been conducted putting an inlet velocity and subcooling of fluid and applied power as parameters in addition to the experimental conditions. The results have shown that there is a square law correlation between a void cross flow and applied power to the fluid. The experiments and analyses in this study have elucidated the behavior of transient boiling two phase flow in a fuel assembly of a nuclear power plant at the transient event such as RIA.

CORRELATION BETWEEN 1,5-ANHYDROGLUCITOL LEVELS AND GLYCEMIC VARIABILITY IN TYPE 2 DIABETIC PATIENTS USING CONTINUOUS GLUCOSE MONITORING

CORRELATION BETWEEN 1,5-ANHYDROGLUCITOL LEVELS AND GLYCEMIC VARIABILITY IN TYPE 2 DIABETIC PATIENTS USING CONTINUOUS GLUCOSE MONITORING

Effects of micrometer-scale cavities on the shock-to-detonation transition in a heterogeneous LX-17 energetic material

Cavities and other fracture structures within energetic materials may have significant impact on their performance. The mechanism on how hot spots induced by cavity collapse affect the detonation initiation process is still not fully understood. In this work, two-dimensional simulations are conducted for heterogeneous LX-17 energetic material containing array-distributed cavities to investigate the detonation initiation process induced by the impaction of the incident shock wave (ISW), and the impacts of cavity size and volume fraction on the shock-to-detonation transition (SDT) are also evaluated. First, we fix the cavity radius to be 40 μm and the cavity volume fraction to be 12.57%, and compare the detonation initiation processes for neat and heterogeneous LX-17 energetic materials. The results indicate that cavities within LX-17 can accelerate the detonation initiation, i.e., shortening the initiation distance and time. Then, the flow characteristics and incident shock wave evolutions during the cavity collapse process are analyzed. The results show that the interaction between the cavity and the incident shock wave results in the local hot spots and causes LX-17 reactant to auto-ignite, so as to accelerate the shock-to-detonation transition. Finally, the influence of the cavity size and volume fraction on the detonation initiation process is assessed. It is found that as the cavity volume fraction increases, the detonation initiation distance and time increase and even become larger than the results predicted of the neat case, i.e., the acceleration effect of cavities on the detonation initiation weakens and the cavities even inhibits the shock-to-detonation transition. When the cavity volume fraction is fixed, it is found cases of small-size cavity predict longer initiation distance and time than cases of large-size cavity. The analysis indicates that increasing cavity volume fraction corresponds to smaller density of LX-17 reactant, and the hot spot duration time is shorter for cases of small-size cavity than cases of large-size cavity. Therefore, the detonation initiation distance and time increase as the cavity volume fraction increases and the cavity size decreases.

Manual Motor Function as a Classifier for Alzheimer’s Disease

AbstractBackgroundIn contrast to numerous reports of gross motor problems in Mild Cognitive Impairment (MCI) and Alzheimer’s disease (AD), fine motor function has been relatively understudied. We examined if performance on manual motor tasks can distinguish between cognitively normal (CN) subjects, and individuals with MCI or AD, and which fine motor features are most informative.Method47 CN, 25 MCI, and 16 AD participants completed computerized tests of unimanual (dominant and non‐dominant hand) tapping, synchronous bimanual tapping, and alternate bimanual tapping. Outcome measures included initial reaction time, tapping speed, and variance. We used imbalanced random forest learning for classification modeling. The model was trained on 70% of the data and tested on the remaining 30% using 5‐fold cross‐validation. To investigate the contribution of individual variables to the classification model, we conducted permutation feature importance analysis.ResultThe overall classification accuracy of the training data was 56%, while the overall classification accuracy of the test data was 70%. The group‐specific accuracy, defined as the proportion of subjects predicted to belong to a certain group who are truly a member of that group, was 76% for CN, 33% of amnestic MCI, and 86% for AD. In 50% of the cases amnestic MCI subjects were classified as control subjects, and in 17% of the cases as AD subjects. The group‐specific precision, defined as the proportion of subjects who received a certain group label who truly belonged to that group (i.e., ‘true positives’) was 76% for controls, 100% for amnestic MCI, and 45% for AD. The three most important features that were used for classification of the test hold‐out data were 1) variance in tapping speed during dominant hand finger tapping; 2) the number of dual tapping trials without gaps or onset delays; and 3) initial reaction time for non‐dominant hand finger tapping.ConclusionSupervised machine learning can discriminate CN and AD subjects based on finger tapping performance features, but is less effective for distinguishing MCI subjects from CN and AD subjects. Finger tapping performance could be a cost‐effective tool for augmenting existing AD biomarkers.

Flexible Robust Control Strategy for Synchronization of Uncertain Non-Linear Systems with Control Input Non-Linearity

A robust global fuzzy sliding mode controller is designed in this paper for the synchronization of non-linear systems with control input non-linearities (CIN) and uncertainties. A consistent global fuzzy sliding mode control (GFSMC) law is developed, which guarantees the suppression of the reaching phase and the presence of the sliding phase from the initial time. Chattering phenomenon, which is characteristic of customary sliding mode control (SMC), avoided by the on-line fuzzy regulation of the sliding surface in the controller, when the system is subject to disturbances and CIN. Finite-time boundedness (FTB) properties are designed with adequate conditions, which are entrenched in terms of linear matrix inequalities (LMIs) with the help of cost and Lyapunov functions. Numerical simulations for the synchronization problem of the chaotic modified Colpitt’s system and Duffing system clearly show the good performance of the proposed control scheme. The present work provides a regular procedure to design GFSMC for a class of non-linear systems with CIN.

Clinical and Genomic Characterization of Long-Term Responders Receiving Immune Checkpoint Blockade for Metastatic Non–Small-Cell Lung Cancer

ObjectivesUnderstand from a real-world cohort the unique clinical and genomic determinants of a durable response to immune checkpoint inhibitors (ICIs). Materials and MethodsThis is a retrospective study of patients with NSCLC who received any ICI-based regimen as first or second line therapy. Long-term responders (LTR) achieved an overall survival (OS) ≥ 3 years from time of treatment start, while nonresponders (NR) were patients who had an OS of 6 to 12 months from time of treatment start. Clinical and demographic covariables were collected from electronic medical records. Fisher's exact test and Mann-Whitney test were used to analyze the association of a long-term response to ICI in relation to clinical and genomic variables. All P-values were considered significant at P-value < .05. ResultsA total of 72 patients were included in this study (LTR n = 37, NR n = 35). There were no significant differences in age, sex, race, and BMI between groups. The presence of liver metastases at the time of ICI initiation and PD-L1 status were not associated with LTR to ICIs. Patients in the LTR were more likely to experience irAEs at 3-,6- and 12-months. KRAS mutant tumors were numerically more common in the LTR group (n = 13 vs. 8). ConclusionWe observe no strong clinical and biomarkers of a prolonged response to ICIs. Additional large prospective cohort studies are needed to investigate the genomic footprint of long-term responders.

Backpack satellite transmitters reduce survival but not nesting propensity or success of greater sage-grouse.

Telemetry technology is ubiquitous for studying the behavior and demography of wildlife, including the use of traditional very high frequency (VHF) radio telemetry and more recent methods that record animal locations using global positioning systems (GPS). Satellite-based GPS telemetry allows researchers to collect high spatial-temporal resolution data remotely but may also come with additional costs. For example, recent studies from the southern Great Basin suggested GPS transmitters attached via backpacks may reduce the survival of greater sage-grouse (Centrocercus urophasianus) relative to VHF transmitters attached via collars that have been in use for decades. While some evidence suggests GPS backpacks reduce survival, no studies have examined the effects of GPS backpacks on breeding behavior and success. Therefore, we compared survival, breeding behavior, and nest success of sage-grouse hens marked with both VHF collars and GPS backpack transmitter over a 7-year period in central Idaho, USA. GPS backpacks reduced spring-summer survival of sage-grouse hens relative to hens with VHF collars, where daily mortality probability was 68%-82% higher from March 1 to August 1. Yet satellite GPS backpacks did not consistently affect nest success or the likelihood or timing of nest initiation relative to VHF collars. Daily nest survival varied annually and with timing of nest initiation and nest age, but marginal effects of transmitter type were statistically insignificant and interactions between transmitter type and study year produced no meaningful patterns. Our results corroborate recent studies for the effect of satellite GPS backpacks on sage-grouse survival, but also suggest that these transmitters do not appear to affect components of fecundity. Our results therefore add important context to recent debate surrounding the effects of GPS backpacks on sage-grouse, and the relative strengths and weaknesses of different transmitter types for understanding behavior and population dynamics.

Childhood and adolescent factors shaping vulnerability to underage entry into sex work: a quantitative hierarchical analysis of female sex workers in Nairobi, Kenya

ObjectiveTo explore factors associated with early age at entry into sex work, among a cohort of female sex workers (FSWs) in Nairobi, Kenya.BackgroundYounger age at sex work initiation increases the...

Resource recovery from palm kernel shell and its application for wastewater treatment: a circular economy approach

In this study, cationic Methylene Blue (MB) dye removal was investigated through a batch adsorption process using a ternary adsorbent developed from palm oil biomass, graphene oxide, and iron oxide (M-PKSGO). Box-Behnken Design (BBD) was applied for modelling and analyzing the effects of independent operational parameters including pH of initial MB dye solution, M-PKSGO dosage and adsorption time on dye removal and adsorption capacity. The experimental results show an adsorption capacity of 82.7 mg/g was achieved using 1 g/L of M-PKSGO with 135 min at pH 11. Hence, the M-PKSGO composite is proven as an effective adsorbent for cationic dye removal from wastewater. The utilization of biomass from the palm oil industries promotes a circular economy via resource recovery activities. Overall, this work brings to light the opportunities created by green adsorbents in promoting a circular economy and stimulates further research and development in this highly pertinent field.

Experimental Investigation on Thermal Insulation of Sustainable 3D Printable Concrete by Using Corncob Powder

The construction industry is witnessing the latest technology advancement in the form of 3D printing, which promises to revolutionize the sector by reducing costs, material wastage, and environmental impact. One significant approach to achieving these goals is through the incorporation of various supplementary cementitious materials. This research work aims to study the utilization of corn cob powder (organic waste from agricultural industries) as a thermal insulation material in conjunction with other cement supplementary materials (fly ash, and silica fume). The study focuses on evaluating the material’s rheological properties, such as slump, initial and final setting times, and flowability. Furthermore, the investigation extends to analyzing the hardened properties of the concrete, including compressive strength, split tensile strength, and flexural strength under varying temperature conditions. Results shown that the compressive, split tensile and flexural strength was increased up 5 % to 7% with the inclusion of corn cob powder at 5% and it exhibits good resistance to high temperatures.

Pre-course instructional videos and home-based laparoscopic suturing simulation enhances the educational impact of a laparoscopic training course

IntroductionWe developed a home-based laparoscopic suturing simulation (HBLSS) technique, which is intended to improve the impact of a structured laparoscopic training course. MethodA group of sixteen students were provided with the educational video, and after two weeks, all students were observed and timed performing a laparoscopic reef knot. The students were then randomized into two cohorts. The exclusive video group continued using the video for a further two weeks. The second group were shown the HBLSS technique and told to use this in conjunction with the video for a further two weeks. ResultsThe entire cohort had an initial median time to form an intracorporeal reef knot of 190 s (range 459, IQR 128). After two additional weeks of using the educational video exclusively, the median time was reduced to 85 s (range 282, IQR 125), whereas the HBLSS and educational video group had a median post-training time of 28.5 s (range 36, IQR 18.5). There was a clear statistical difference between the exclusive video group and the HBLSS and video group (P = 0.008). There was also an improvement from the movement of both instruments to one instrument, reduced crossing of instruments and reduced transverse movement in the HBLSS and video group. ConclusionA combination of video-based teaching and HBLSS was associated with improved laparoscopic intra-corporeal knot-tying skills in comparison to the exclusive video-based teaching. This reflects the importance of imparting both cognitive and psychomotor skills to students practising laparoscopic surgery.

Supplemental parenteral nutrition initiation timing and clinical outcomes in critically ill patients: An exploratory data analysis

Supplemental parenteral nutrition initiation timing and clinical outcomes in critically ill patients: An exploratory data analysis

Numerical and experimental investigation of the electrical and thermal behaviors of the Li-ion batteries under normal and abuse operating conditions

This paper presents the results of a comprehensive investigation of the electrical and thermal behaviors of the Lithium (Li)-ion batteries under normal and abuse conditions. In the first part of the study, an electrochemical-thermal coupled model is developed to predict the thermal and electrical characteristics of a Li-ion battery at 20 and 50 °C temperatures for varying discharge rates based on a detailed sensitivity analysis of the electrochemical and thermal model parameters. The experimental and model data are consistent, considering the discharging processes at 0.5, 1, and 1.5C rates under 20 and 50 °C operating temperatures. In the second part of the study, thermal abuse experiments are conducted by heating the Li-ion cell using the film heater at various charge states of battery. Simulations are carried out for the heating tests by enhancing the electrochemical-thermal model using the temperature-dependent Arrhenius equations. The results show that the thermal abuse model can predict the thermal runaway initiation time within the approximate 10 % margin of error, and the maximum surface temperature with 10.5 % of error compared to the experimental results of the completely charged Li-ion cell.

Characterization of a radiofrequency linear plasma device in uniform and convergent magnetic fields

A linear radiofrequency plasma device is constructed, where a source operating at a frequency of 13.56 MHz and a maximum power of several kW is attached to a cylindrical vacuum chamber about 1 m in length. Seven solenoids are located around the source and the chamber, providing various magnetic field configurations by changing the solenoid currents. The plasma density of the radiofrequency linear plasma device is initially characterized in uniform and convergent magnetic field configurations. A blue mode argon plasma, being inherent to the helicon or high-density discharge, is observed in the chamber downstream of the source for both configurations, while the density near the antenna is lower than that in the chamber. Furthermore, the density for the convergent magnetic field configuration is found to be larger than that for the uniform case, providing a maximum density of about . Spatiotemporal measurements of the ion saturation current reveal that the density peak is formed near the rf antenna at the initial time of the discharge and the peripheral high-density region subsequently appears downstream of the antenna, implying that the rf power is efficiently coupled with the electrons downstream of the antenna once the initial plasma is created. A few ms after turning on the rf power, the density over the whole region reduces, which seems to be due to a neutral depletion.

Artificial neural network surrogate modeling for uncertainty quantification and structural optimization of reinforced concrete structures

AbstractOptimization approaches are important to design sustainable structures. In structural mechanics, different design objectives can be defined, for example, to minimize the required construction material or to maximize the structural durability. In this paper, the durability of a reinforced concrete (RC) structure is assessed by advanced finite element (FE) models to simulate the cracking behavior and the chloride transport process. The corrosion initiation time is used as durability measure to be maximized within an optimization approach, where the concrete cover is defined as design variable. The variability of structural loads and material parameters and unavoidable construction imprecision leads to a probabilistic reliability and durability assessment, where aleatory as well as epistemic uncertainties are quantified by random variables, intervals and probability‐boxes. The FE simulation models cannot directly be applied to structural analyses and optimizations with polymorphic uncertain parameters and design variables because of the high computational demand of the multi‐loop algorithm (Monte Carlo simulation, interval analysis, global optimization). In this paper, a new surrogate modeling strategy is presented, where artificial neural networks are trained sequentially to speed‐up the coupled mechanical and transport simulation FE models. The new approach is applied to the uncertainty quantification and the structural durability optimization of a RC structure.

Effect of delayed cell infusion in patients with large B-cell lymphoma treated with chimeric antigen receptor T-cell therapy.

Complications occurring after lymphodepleting chemotherapy (LDC) may delay chimeric antigen receptor (CAR) T-cell infusion. The effect of these delays on clinical outcomes is unclear. We performed a retrospective analysis of 240 patients with relapsed/refractory large B-cell lymphoma treated with standard-of-care axicabtagene ciloleucel (axi-cel) and identified 40 patients (16.7%) who had delay in axi-cel infusion. Of these, 85% had delay due to infection. At time of LDC initiation, patients with delayed infusion had lower absolute neutrophil count (P=0.006), lower platelets (P=0.004), lower hemoglobin (P<0.001) and higher C-reactive protein (P=0.001) than those with on-time infusion. Patients with delayed infusion had lower day 30 overall response rates (59.0% vs. 79.4%; P=0.008) and shorter median progression-free survival (PFS) (3.5 vs. 8.2 months; P=0.002) and overall survival (7.8 vs. 26.4 months; P=0.046) than those with on-time infusion. The association with PFS was maintained on multivariate analysis. There was also an association between extent of delay and survival, with shorter median PFS in patients who had delays of 2-5 days (1.8 vs. 8.2 months; P=0.001) and >5 days (4.6 vs. 8.2 months; P=0.036), but not 1 day (5.7 vs. 8.2 months; P=0.238). Following propensity score matching, patients with delayed infusion continued to have shorter median PFS (3.5 vs. 6.0 months; P=0.015). Levels of pro-inflammatory cytokines on day of infusion were significantly higher in patients with delayed infusion. Together, these findings suggest that delays in CAR T-cell administration after initiation of LDC are associated with inferior outcomes. Further studies are needed to guide strategies to improve efficacy in such patients.

Adsorption of Nickel Ions on the γ-Alumina Surface: Competitive Effect of Protons and Its Impact on Concentration Profiles.

Mesoporous γ-alumina is used as an adsorbent in the decontamination of water from heavy metals (e.g., nickel and cobalt) and as a support for heterogeneous catalysts prepared by impregnation. In these cases, alumina extrudates are in contact with aqueous solutions containing precursors of the active metal phase to be deposited. The proton concentration (or pH) in the metal solution in contact with alumina can impact the adsorption efficiency of decontamination processes and the activities of catalysts. Yet, it is difficult to quantify the effect of the pH inside the pores since protons are not detected by classical imaging techniques. In this article, the effect of protons on nickel adsorption on alumina is evaluated using a novel technique coupling liquid analysis (pH, conductivity, and UV/vis) and laser-induced breakdown spectroscopy (or LIBS) analysis of concentration gradients inside the solid. Both methods are in excellent agreement. The results show a slow diffusion of protons inside alumina pores (diffusion continues even after 940 min), yielding high proton concentration gradients. On the other hand, the nickel species penetrate the extrudates faster but are slowly displaced by protons under certain operating conditions. As a result, different metal concentration profiles are obtained, depending on the initial pH and contact time. These findings are interesting in catalysis since they prove the possibility of controlling the deposition of the active metal on catalysts by regulating the operating conditions of impregnation. For typical industrial impregnation times (a few minutes to 1 to 2 h), protons do not have enough time to deeply penetrate inside extrudates, so the initial pH of the metal solution will have nearly no effect on the metal distribution. Conversely, decontamination processes have much longer contact times; therefore, lower initial pH values should have negative impacts on the adsorption efficiency due to the protons displacing the adsorbed nickel.