Fitting Analysis Research Articles

Nondestructive evaluation of mechanical heart valve disc thickness degradation due to accelerated durability test using THz-TDS measurements

ABSTRACT Quality assurance and control during the mechanical heart valve components’ production process is paramount to mitigate most of the valve-related complications arising from valve replacement. Nondestructive evaluation of heart valve implants with complex profiles during production is challenging due to the biocompatibility requirements and clean room assembly conditions. This study first tested the UHMWPE disc of TTK Chitra mechanical heart valve models TC1 and TC2 using Terahertz imaging in reflection mode. The UHMWPE discs were raster scanned in X-Y directions to obtain a Terahertz-C scan to locate the macro defects due to wear out, and to distinguish between the true positive and true negative samples. The results were verified with digital microscope studies. Second, this study investigates a unique relationship between Terahertz imaging in reflection mode and heart valve disc degradation due to accelerated durability study. Third, the variation of disc surface roughness due to accelerated durability test was studied by Gaussian curve fitting analysis of fast Fourier transform of the Terahertz reflections. Finally, a comparison between the TC1 and TC2 heart valve model’s wear-out foot print was carried out using Terahertz C-scan. Our results imply that Terahertz time-domain spectroscopy has promising applications in NDE measurements of biocompatible implants.

Pool bio-oxidation and fitting analysis of low-grade arsenic-containing refractory gold ore

To overcome the limitations of geography, climate, and ore characteristics on the ore beneficiation process, bio-oxidation studies on low-grade arsenic-bearing refractory gold ore by pool leaching were carried out, as well as process fitting analysis. The gold particles are encapsulated by pyrite and arsenopyrite. After 60 days of bio-oxidation, the oxidation rates of arsenic, sulfur, and gold were 39%∼69%, 24%∼41%, and 49%∼83%, respectively. The inoculated Acidithiobacillus ferrooxidans, Ferroplasma acidiphilum, and Leptospirillum ferrodiazotrophum could all mediate the initial pyrite/arsenopyrite oxidation and the Fe2+ oxidation reaction, but only the former could mediate the subsequent sulfur compound oxidation. When compared to daily bacterial circulation and bacterial replacement every ten days, aeration improved the gold leaching rate by 14%∼22%. The Boltzmann model could fit both the arsenic and sulfur bio-oxidation, with model fit variances greater than 0.98. Based on the experimental and fitting results, the bio-oxidation cycle was determined to be 60 days, and the bio-oxidation mechanisms are summarized. This study has significant practical implications for the rational utilization of gold resources and provides theoretical and practical guidance for similar gold ores.

Local structure of concentrated NaFSA solutions in propylene carbonate studied by X-ray and neutron diffraction methods

Abstract The microscopic structure of 10 mol% NaFSA [FSA: bis(fluorosulfonyl)amide]-propylene carbonate (PC) solution has been investigated by means of X-ray and neutron diffraction techniques. The solvation structure of Na+ has been determined from least-squares fitting analysis of X-ray intermolecular difference interference terms observed for 10 mol% NaFSA-PC solution and pure liquid PC. In the present solution, onaverage, 6(1) PC molecules are involved in the first solvation shell of Na+ with intermolecular distance rNaO = 2.26(7) Å, and bond angle ∠Na+…O = C = 169(9)°. Intermolecular correlation between neighboring PC molecules in the solution has been derived from simultaneous least-squares fitting analysis of observed H–H, H–X, and X–X (X: atoms except for H) intermolecular partial structure factors determined from neutron diffraction data for H/D isotopically-substituted sample solutions. An indication of anti-parallel configuration of the nearest neighbor PC molecules has been suggested.

Do housing-induced changes in brain activity cause stereotypic behaviours in laboratory mice?

Abnormal repetitive stereotypic behaviours (SBs) (e.g. pacing, body-rocking) are common in animals with poor welfare (e.g. socially isolated/in barren housing). But how (or even whether) poor housing alters animals’ brains to induce SBs remains uncertain. To date, there is little evidence for environmental effects on the brain that also correlate with individual SB performance. Using female mice from two strains (SB-prone DBA/2s; SB-resistant C57/BL/6s), displaying two forms of SB (route-tracing; bar-mouthing), we investigated how housing (conventional laboratory conditions vs. well-resourced ‘enriched’ cages) affects long-term neuronal activity as assessed via cytochrome oxidase histochemistry in 13 regions of interest (across cortex, striatum, basal ganglia and thalamus). Conventional housing reduced activity in the cortex and striatum. However, DBA mice had no cortical or striatal differences from C57 mice (just greater basal ganglia output activity, independent of housing). Neural correlates for individual levels of bar-mouthing (positive correlations in the substantia nigra and thalamus) were also independent of housing; while route-tracing levels had no clear neural correlates at all. Thus conventional laboratory housing can suppress cortico-striatal activity, but such changes are unrelated to SB (since not mirrored by congruent individual and strain differences). Furthermore, the neural correlates of SB at individual and strain levels seem to reflect underlying predispositions, not housing-mediated changes. To aid further work, hypothesis-generating model fit analyses highlighted this unexplained housing effect, and also suggested several regions of interest across cortex, striatum, thalamus and substantia nigra for future investigation (ideally with improved power to reduce risks of Type II error).

Estimated Pulse Wave Velocity is Associated with Intracranial Arterial Stenosis: A Secondary Analysis Based on A Korean Population

The estimated pulse wave velocity (ePWV) was recently proposed to indicate artery stiffness. Although arterial stiffness contributes to intracranial arterial stenosis (ICAS), the correlation between ePWV and ICAS remains unclear. This secondary analysis included 1,011 neurologically healthy Korean participants from a cross-sectional database to explore the association between ePWV and prevalent ICAS. Brain magnetic resonance angiography (MRA) was performed for all patients at their presentation to access the ICAS. The ePWV was derived as: ePWV = 9.587 − 0.402 × age + 4.560 × 10 −3 × age2 − 2.621 × 10-5 × age2 × mean blood pressure (MBP) + 3.176 × 10-3 × age × MBP – 1.832 ×10-2 × MBP. The prevalence of ICAS was 9.99% (n=101). In multivariable logistic regression analyses, per 1m/s increment of ePWV causes 1.36 times the risk of ICAS prevalence after fully adjusting potential confounders. When dividing ePWV into tertiles, the ICAS risk increased by 1.98 times when ePWV increased from the first tertile to the third tertile. Moreover, the relationship between ePWV and ICAS was linear and robust, as suggested by smooth curve fitting and stratification analysis. In conclusion, the ePWV was positively and independently associated with prevalent ICAS in the Korean population.

Association between dietary inflammatory index and anemia in US adults.

Anemia is a widespread global health concern, and recent research has unveiled a link between anemia and inflammation. The Dietary Inflammation Index (DII) is a novel tool used to assess the overall inflammatory potential of an individual's diet. However, until now, there have been no studies demonstrating a connection between DII and anemia. This study aimed to explore the relationship between DII and the risk of anemia among Americans, as well as to examine the influence of other risk factors on this association. Data from 32,244 patients were collected from the National Health and Nutrition Examination Survey (NHANES) database spanning from 1999 to 2018. Using multivariable logistic regression, we examined the correlation between DII and anemia. Subgroup analyses and smoothed curve analyses were conducted to further investigate the association between DII and anemia. The analysis revealed a significant positive association between higher DII scores and increased anemia risk in the American population (Odds Ratio [OR] = 1.06, 95% Confidence Interval [CI] = 1.03 to 1.09, p < 0.0001). This association remained consistent in subgroup analyses, encompassing various age groups, distinct Body Mass Index (BMI) categories, varying diabetes mellitus statuses, histories of hypertension, females, individuals with a RIP <3.5, and Non-Hispanic Black individuals. Notably, the association was particularly significant among non-smokers. Smoothed curve fitting analysis demonstrated a linear relationship between DII and the prevalence of anemia. Our findings underscore a positive correlation between the inflammatory potential of one's diet and the risk of anemia, especially when coupled with other risk factors. Consequently, reducing the consumption of pro-inflammatory foods may serve as one of the effective measures against the development of anemia. Given the variations in gender, age, BMI, and chronic diseases observed in our study, tailored policies could better cater to the specific needs of diverse populations.

Confirmatory factor analysis of the positive factors influencing the performance of Ghanaian construction projects

Purpose This paper aims to identify the unidimensionality and reliability of 84 factors that influence the performance of construction projects and develop a confirmatory factor analysis (CFA) model. Design/methodology/approach The study adopted a deductive research approach and started by identifying the positive factors that influence construction project performance. This was followed by the modification of the identified factors. After that, a questionnaire was developed out of the factors for data collection. Exploratory factor analysis was used to establish the factor structure of the positive factors, and this was verified using CFA afterwards. A model fit analysis was performed to determine the goodness of fit of the hypothesised model, followed by the development of the confirmatory model. Findings The study demonstrated substantial correlation in the data, sufficient unidimensionality and internal reliability. In addition, the estimated fit indices suggested that the postulated model adequately described the sample data. Practical implications The paper revealed that performance can be enhanced if stakeholders identify and leverage the positive factors influencing performance. The paper suggests that project stakeholders, particularly government, project owners, consultants and construction firms, can improve project performance by critically examining economic and financial systems (EFS), regulation and policy-making systems (RPS), effective management practices (EMP) and project implementation strategies (PIS). Originality/value The contribution of this paper to the present literature is identifying the positive factors and developing the confirmatory factor model. The model comprised 42 positive variables under four indicators: EMP, RPS, PIS and EFS.

Evaluation of in vitro dissolution profiles of modified-release metoprolol succinate tablets crushed using mortar and pestle technique

PurposeClinical practice guidelines advise against crushing modified-release dosage forms. Metoprolol succinate modified-release (MS-MR) tablets are commonly crushed in clinical practice to facilitate administration to patients with swallowing difficulties or using feeding tubes. To date, the effect of this practice remains unexplored. The in vitro effects of crushing commercially available MS-MR tablets were explored using a holistic approach. MethodsDissolution profiles of crushed versus whole MS-MR tablets were compared. Tablets were crushed to powder state using pragmatic method mimicking hospital practices. For standardization purposes, the same operator, duration (60 seconds), hand, and mortar-pestle apparatus were used. Dissolution studies were conducted per U.S. Pharmacopeia at pH 1.2, pH 4.5, and pH 6.8 with USP apparatus 2 (paddle) at rotation speed of 50 rpm at 37±0.5 °C in 500 mL dissolution media. Samples were withdrawn at predetermined time points. Percent drug dissolved was measured by validated UV–vis Spectrophotometry. Comprehensive analysis of the dissolution data was conducted using model-independent, model-dependent, and ANOVA-based approaches (SPSS v.23 at α=0.05). Similarity (f2) and difference (f1) factors were calculated to compare the dissolution profiles between crushed (CT) and whole tablets (WT). Goodness of fit (GOF) analysis examined the compliance between in vitro dissolution behaviors and several drug release models. Model selection was based on GOF plots, Akaike criteria and adjusted coefficient of determination (R2adj). Imaging and particle size distribution analysis were conducted to examine associated surface and morphologic changes. ResultsThe dissolution profiles were not similar at pH 4.5 (f2=45.43, f1=18.97) and pH 6.8 (f2=31.47, f1=32.94). CT best fitted with Higuchi (pH 1.2: R2adj=0.9990), Weibull (pH 4.5: R2adj=0.9884), and Korsmeyer-Peppas (pH 6.8: R2adj=0.9719). Contrastingly, WT best fitted with Hopfenberg (pH 1.2: R2adj=0.9986), logistic (pH 4.5: R2adj=0.9839) and first-order (pH 6.8: R2adj=0.9979) models. A significant difference in the dissolution profiles was found between CT and WT using multivariate analysis of variance per time points and between the tablet forms (p=0.004). This was confirmed by unparalleled dissolution profiles. Crushing resulted in variations in particle size and surface morphological changes to the micropellets. ConclusionCrushing practices change the dissolution profile of MS-MR tablets by deforming the surface morphology of embedded micropellets. Amounts of drug dissolved between CT and WT were not the same at the compared time points across gastrointestinal pH ranges. This suggests potential clinical impact on plasma-concentration profiles of critically ill patients using feeding tube.

The saturation effect of body mass index on total lumbar bone mineral density for adults: The NHANES 2011-2020.

To explore the association between body mass index (BMI) and total lumbar bone mineral density (BMD) in adults. This study included 9927 participants from 2011 to 2020 National Health and Nutrition Examination Survey (NHANES). The date on BMI, total lumbar BMD and other covariates were collected. Multivariate linear regression analyses were performed to evaluate the association between BMI and total lumbar BMD. Smoothing curve fitting and saturation effects analysis models were used to analyze the nonlinear relationships and saturation values. Multivariate linear regression analyses revealed that BMI was positively linked to total lumbar BMD in non-adjusted models (β = 0.003, 95% CI: 0.003-0.003, P < .00001). After adjusting for gender and race (β = 0.003, 95% CI: 0.003-0.004, P < .00001) and all covariates (β = 0.004, 95% CI: 0.003-0.004, P < .00001), the association still existed. Smoothing curve fitting showed that there was nonlinear correlation between BMI and total lumbar BMD with saturation effect. The BMI saturation value was 21.2 kg/m2 in the total lumbar BMD based on saturation effects analysis models. There was nonlinear positive correlation between BMI and total lumbar BMD with saturation effect. For adults, keeping the BMI at a reasonable value (21.2 kg/m2) would obtain an optimal balance between BMI and total lumbar BMD.

Species-Abundance Models for the Early Postfire Succession of Subalpine Shrub Grassland

Fire is one of the principal factors influencing subalpine ecosystem succession. Species numbers and plant compositions are used to determine postfire disturbance, vegetation, structural change, and succession. Ecologists also integrate species diversity and mathematical models to enable researchers to obtain increasingly detailed insights into habitats during post-disturbance restoration processes. This study employed five species-abundance models, namely the niche preemption model, the broken-stick model, the log-normal model, the Zipf model, and the Zipf–Mandelbrot model, to perform fitting analysis on the abundance data of postfire species coverage in shrub grasslands near 369 Hut at Xue Mountain in Shei-Pa National Park, Taiwan. We performed the logarithmic transformation on plant-coverage areas for each period of postfire shrub-grassland succession, and then, based on histograms drawn for species–coverage distribution modes, the test results consistently showed normal distributions (p &lt; 0.05). Species-coverage histograms measuring various periods showed that there were comparatively higher numbers of common species during postfire succession and that the numbers of rare species progressively increased. The fitting results of the five species-abundance models showed that although the most suitable abundance models for each period of postfire succession varied, the majority of these periods demonstrated decent fitting with respect to the Zipf–Mandelbrot model. These findings showed that fuel consumption provided nutrients in a manner that facilitated postfire regeneration. Moreover, dominant species, such as Yushania niitakayamensis, and Miscanthus transmorrisonensis, did not fully occupy growing spaces and resource availabilities; consequently, seeded species were able to grow.

Determining optimal ALT cut-off values for predicting significant hepatic histological changes in patients with normal ALT in the grey zone of chronic hepatitis B virus infection.

We aimed to define gender-specific, optimal alanine aminotransferase (ALT) cut-off values for the prediction of significant liver histological changes (SLHC) in Chinese patients with grey zone (GZ) chronic hepatitis B (CHB) and normal ALT. In a retrospective study, we included 1101 consecutive patients with GZ CHB and normal ALT assigned to training or internal validation cohorts. We included an independent cohort of 842 patients for external validation. We performed receiver operating characteristic (ROC) curve, smoothed curve fitting, and threshold effect analyses to determine optimal ALT cut-off values. Area under the curve (AUC) values were calculated to assess their predictive performance. A proportion of 79.3% of patients with GZ CHB and normal ALT (≤40 U/L) had SLHC. ROC curve analysis initially identified optimal ALT cut-off values of 29 U/L (male) and 22 U/L (female). After smoothed curve fitting and threshold effect analyses, new optimal cut-off values were 27 U/L for males and 24 U/L for females. AUCs for these values were 0.836 (male) and 0.833 (female) in the internal validation cohort, and 0.849 (male) and 0.844 (female) in the external validation cohort. The accuracy and discriminative ability of the newly defined ALT cut-off values were greater than those of the current recommendations. This study established novel optimal ALT cut-off values for more precise prediction of SLHC among Chinese patients with GZ CHB and normal ALT levels. This may help identify individuals who will benefit from timely antiviral therapy.

The Impact of NaOH on the Micro-Mechanical Properties of the Interface Transition Zone in Low-Carbon Concrete.

To tackle carbon emissions from cement production and address the decline in concrete's mechanical properties due to the substitution of cement with solid waste (glass powder) and natural mineral admixture (zeolite powder) materials, we employed glass powder and zeolite powder to create composite cementitious materials. These materials underwent alkali activation treatment with a 4% NaOH dosage, replacing 50% of cement to produce low-carbon concrete. Nanoindentation tests and mercury intrusion porosimetry (MIP) were employed to uncover the micro-mechanical properties and influencing mechanisms of alkali-activated low-carbon concrete. The results indicate a notable enhancement in the indentation modulus (19.9%) and hardness (25.9%) of alkali-activated low-carbon concrete compared to non-activated concrete. Simultaneously, the interfacial transition zone thickness decreased by 10 µm. The addition of NaOH led to a reduced volume fraction of pores (diameter >100 nm) and an increased fraction of pores (diameter < 100 nm), thereby reducing porosity by 2.6%, optimizing the pore structure of low-carbon concrete. The indentation modulus, hardness and volume fraction of the hydrated phase derived from Gaussian fitting analysis of the nanoindentation statistics showed that NaOH significantly improved the modulus and hardness of the hydration products of low-carbon concrete. This activation resulted in decreased LDC-S-H gel (low-density hydrated calcium silicate Ca5Si6O16(OH)·4H2O) and pore content, while the HD C-S-H gel (high-density hydrated calcium silicate Ca5Si6O16(OH)·4H2O) and CH (calcium hydroxide crystals Ca(OH)2) content increased by 13.91% and 23.46%, respectively. Consequently, NaOH influenced the micro-mechanical properties of low-carbon concrete by generating more high-density hydration products, reducing pore content, enhancing the pore indentation modulus and hardness, and shortening the interfacial transition zone. This study offers novel insights into reducing carbon emissions and promoting the use of solid waste (glass powder) and natural mineral admixture (zeolite powder) materials in concrete, contributing to the advancement of sustainable construction practices.

Reform of the Evaluation Index System of Civics Teaching in Higher Vocational Colleges and Universities Curriculum Oriented to the Demands of Vocational Positions in the Context of Deep Learning

Abstract Vocational and technical education professional courses have significant occupational relevance, and the teaching and evaluation design ideas of its course Civics should be drawn by the job tenure demand. In this paper, through the matching comparison between the characteristics of graduates of higher vocational colleges and the vector space of job demand characteristics, the residual optimal algorithm is used to construct the matching model of college students’ supply and demand so as to achieve the maximization of the total matching value between supply and demand. On the basis of the CIPP evaluation model and the teaching characteristics of courses in higher vocational colleges and universities, a fit analysis is carried out to construct the evaluation index system for the teaching of Civics and Politics in courses in higher vocational colleges and universities. The study shows that the weights of the four first-level indicators, namely, teaching background, teaching input, teaching process, and teaching effect, are 0.2042, 0.2592, 0.3754, and 0.1612, respectively, of which the teaching process has the most significant proportion of weight. Practical value can be gained from the teaching evaluation system.

Acid Fracturing Technology and Effect Evaluation of Carbonate Horizontal Well in Fuman Oilfield

Since the deep and ultra-deep carbonate rocks in the Fuman oilfield have made continuous breakthroughs, the acidification and fracturing of the reservoir on the south bank of Tarim River have been faced with problems such as faster acidification and shorter effective acidification fracture length with the increased burial depth and formation temperature, which seriously restrict the effect of acidification and fracturing. At present, the Fuman oilfield has achieved remarkable results after acid fracturing construction. In this paper, the acid fracturing construction effects of multiple reservoir reconstruction Wells in Tahe Yueman, Fuyuan, Guole, and Manshen blocks are evaluated and classified by analyzing acid fracturing construction curves, using fracture static pressure fitting and fracture conductivity curve analysis. The characteristics and distribution law of carbonate reservoirs corresponding to different construction curves are studied, and various situations of artificial fractures communicating with natural fracture-cavity systems are analyzed. The research results can accurately guide the design optimization and development of acid pressure.

Association between the systemic immune-inflammation index and obesity among adults: Insights from the NHANES 2017-2018.

Inflammation is an important causative factor of obesity. This study aimed to explore the possible association between the systemic immune-inflammatory index, a novel indicator of inflammation, and obesity. Data were collected from 4395 participants of the National Health and Nutrition Examination Survey 2017-2018 aged ≥ 20 years. The systemic immune-inflammatory index was calculated by multiplying the platelet count by the neutrophil-to-lymphocyte ratio. Obesity was defined as a body mass index ≥ 30 kg/m2. A significant positive correlation was observed between the systemic immune-inflammatory index and body mass index following multivariate linear regression analysis (β = 1.75; 95% confidence interval = 1.16-2.33), which was greatest in adults aged < 60 years without hypertension and diabetes. Smoothed curve fitting and threshold effect analysis were used to characterize the nonlinear association between the systemic immune-inflammatory index and body mass index, and the inflection point was found to be 729.3. The systemic immune-inflammatory index is positively associated with body mass index among adults in the United States and has the potential to enhance efforts to prevent adult obesity.

Deep Learning-based Computational Electromagnetics for Deep Exploration of Oil and Gas Reservoirs

Abstract The exploration potential of oil and gas is substantial, with considerable untapped resources available for future exploration and development. This paper investigates the application of time-frequency electromagnetic (EM) methods within the domain of computational electromagnetics, enhanced by deep learning techniques, for the profound exploration of oil and gas reservoirs. To identify zones favorable for hydrocarbon presence, it captures electric and magnetic field responses across time and frequency domains. From these responses, it extracts crucial parameters such as resistivity and excitation polarizability. The methodology initiates with a forward simulation to establish the most productive construction parameters for the time-frequency EM approach. Subsequently, data collected are processed and analyzed to qualitatively evaluate each physical parameter. This is followed by quantitative constraints on resistivity and polarizability, employing the adaptive differential evolution algorithm to execute a comprehensive parameter inversion using the horizontal E-field (Ex) data derived from the time-frequency EM method. This inversion facilitates the determination of resistivity and polarizability distributions at various depths, culminating in the generation of corresponding depth cross-sections. The inversion fitting and example analyses yielded that the apparent resistivity profiles of low-resistance backslope formations and backslope formations with high and low resistance interlayers form relative anomaly magnitudes of about 13% and 7.8%, respectively. In the real measurement from the depression to the uplift zone, the thickness of the giant inclined low-resistance conductive layer gradually decreases. The points of the extreme values and minima gradually move from the low-frequency band to the high-frequency band, which is identical to the simulation law. The anomaly amplitude is between [-0.4 Ω·m, 0.6 Ω·m], which can be accurately imaged. This study innovatively combines deep learning technology and electromagnetism, which provides a basis for the next decision on oil and gas exploration and target evaluation preference.

Association between advanced lung cancer inflammation index and chronic kidney disease: a cross-sectional study.

Chronic kidney disease (CKD) is one of the common chronic diseases, and malnutrition and inflammation play a key role in the development of CKD. The advanced lung cancer inflammation index (ALI) is a novel index of nutrition and inflammation, and its association with CKD has not yet been clarified. The aim of this study was to explore the potential association between ALI and CKD. We conducted a cross-sectional survey using data extracted from the National Health and Nutrition Examination Survey (NHANES, 2003-2018). Weighted multivariate logistic regression was used to assess the association between ALI and CKD, and smoothed curve fitting and threshold effect analyses were used to describe the nonlinear association between ALI and CKD. Subgroup analyses were performed to further assess the influence of other covariates on the relationship between ALI and CKD. A total of 39,469 adult participants were included in the study, of whom 7,204 (18.25%) were diagnosed with CKD. After adjusting for multiple confounders, we found a significant negative correlation between ALI and CKD (OR = 0.93; 95%CI, 0.91-0.95; p < 0.0001). The risk of CKD tended to decrease with increasing quartiles of ALI. Smoothed curve fitting showed an L-shaped negative correlation between ALI and CKD. Threshold analysis showed a saturation effect of ALI at the inflection point of 55.09. Subgroup analyses and interaction tests showed that this negative association was maintained across age, sex, race, BMI, diabetes, hypertension, cardiovascular disease, and cancer subgroups (P for interaction >0.05). Our findings suggest a significant correlation between ALI and CKD in the US adult population. However, more large-scale prospective studies are still needed to further confirm our findings.

Crystallization of amorphous anodized TiO2 nanotube arrays.

Anodized TiO2 nanotube arrays (TNTAs) prepared by anodization have garnered widespread attention due to their unique structure and properties. In this study, we prepared TNTAs of varying lengths by controlling the anodization time. Among them, the nanotubes anodized for 2 h have an inner diameter of approximately 92 nm and a wall thickness of approximately 12 nm. Then we subjected amorphous TNTAs prepared by the anodization method to annealing treatments, systematically analyzing the evolution of morphology and structure with varying annealing temperatures. As the annealing temperature increases, the amorphous successively undergoes transitions to the anatase phase and then to the rutile phase. During the transition to the anatase phase, the structure of the nanotube array remains intact, with the complete preservation of the tubular array structure. However, during the transition to the rutile phase, the tubular array structure is destroyed. To address why the tubular array remains undamaged during the amorphous-to-anatase transition, we subjected amorphous TNTAs to annealing at 300 °C for different durations. Raman spectroscopy was employed for fit analysis, providing insights into the evolution of the molecular structure during the anatase phase transition. Finally, TNTAs annealed at different temperatures were incorporated into lithium-ion batteries. By combining XRD for semi-quantitative phase content and anatase particle size calculations, we established a correlation between structure and electrochemical performance. The results indicate a significant improvement in electrochemical performance for an amorphous-anatase structure obtained through annealing at 300 °C, providing insights for the design of high-performance energy storage materials.

Exploring the impact of trifluoromethyl (-CF3) functional group on the anti-cancer activity of isoxazole-based molecules: design, synthesis, biological evaluation and molecular docking analysis.

Herein we report the design and synthesis of a series of fully-substituted 4-(trifluoromethyl)isoxazoles and evaluation of their anti-cancer activities against MCF-7, 4T1 and PC-3 cell lines as a proof of concept study. 4-(Trifluoromethyl)isoxazole is a synthetically challenging class of molecules and very few synthetic methods have been developed so far and all of them suffered from several serious limitations. Recently we developed a novel, metal-free, and general synthetic strategy to access synthetically challenging 4-(trifluoromethyl)isoxazoles starting from readily available chalcones using cheap CF3SO2Na as the source of the -CF3 group and multitasking t BuONO as an oxidant as well as the source of N and O and thus we have overcome the limitations of the previous methods. Based on the structure of an isoxazole-based anti-cancer agent, 3-(3,4-dimethoxyphenyl)-5-(thiophen-2-yl)isoxazole 14, we designed a set of 4-(trifluoromethyl)isoxazoles for synthesis and further anti-cancer evaluation. Among various molecules, 3-(3,4-dimethoxyphenyl)-5-(thiophen-2-yl)-4-(trifluoromethyl)isoxazole 2g (IC50 = 2.63 μM) and 3-(thiophen-2-yl)-5-(4-(thiophen-2-yl)-1H-pyrrol-3-yl)-4-(trifluoromethyl)isoxazole 5 (IC50 = 3.09 μM) exhibited the best anti-cancer activity against the human breast cancer cell-lines (MCF-7), 2g being the lead molecule among all. Interestingly, 2g is found to be almost 8 times more active compared to its non-trifluoromethylated analogue, i.e., 3-(3,4-dimethoxyphenyl)-5-(thiophen-2-yl)isoxazole 14 (IC50 = 19.72 μM) which revealed the importance of a 'CF3' moiety in enhancing the anti-cancer activity of 14. Further studies such as apoptosis induction, cell cycle analysis, and nuclear staining revealed an apoptotic cell death mechanism. The in silico molecular docking, induced fit analysis, and ADME studies further supported the effect of a -CF3 moiety on the enhancement of anti-cancer activity of isoxazole-based anti-cancer molecules. Further exploration of the biodistribution and therapeutic efficacy of lead 2gin vivo holds significant promise, positioning it as a potential candidate for anticancer therapy.

Exploring the interstellar medium of NGC 891 at millimeter wavelengths using the NIKA2 camera

In the framework of the IMEGIN Large Program, we used the NIKA2 camera on the IRAM 30-m telescope to observe the edge-on galaxy NGC 891 at 1.15 mm and 2 mm and at a FWHM of 11.1” and 17.6”, respectively. Multiwavelength data enriched with the new NIKA2 observations fitted by the HerBIE SED code (coupled with the THEMIS dust model) were used to constrain the physical properties of the ISM. Emission originating from the diffuse dust disk is detected at all wavelengths from mid-IR to mm. while mid-lR observations reveal warm dust emission from compact H II regions. Indications of mm excess emission have also been found in the outer parts of the galactic disk. Furthermore, our SED fitting analysis constrained the mass fraction of the small (&lt; 15 Å) dust grains. We found that small grains constitute 9.5% of the total dust mass in the galactic plane, but this fraction increases up to ~ 20% at large distances (|z| &gt; 3 kpc) from the galactic plane.