bluuebunny/crossref_metadata_2025 huggingface dataset:
Das Ladungsübergangsspektrum von Thiocyanat‐ und Selenocyanatkomplexen der Übergangsmetalle
Authors: Schmidtke Hans‐Herbert
Published: August 2023

Das Spektrum einer Reihe N‐ und S‐(Se‐)gebundener Thiocyanat‐ und Selenocyanatkomplexe von Metallionen der drei Übergangsperioden wurde im sichtbaren und nahen UV‐Bereich aufgenommen. Insgesamt 47 intensive Banden von 38 verschiedenen tetra‐ und hexakoordinierten Metallkomplexen wurden als Ladungsübergangsbanden identifiziert. Die optischen Elektronegativitäten der Liganden ergeben sich zu x(‐NCS) = 2,6; x(‐SCN) = 2,9; x(‐SeCN) = 2,8. Daneben wurden weitere Elektronegativitätswerte für einige Metalle bestimmt. Das Auftreten unterschiedlicher Werte je nach Bindungsverhalten wird theoretisch erklärt. Außerdem wird die Frage diskutiert, ob bei quadratischer Symmetrie der Ligandenfeldparameter mit wachsender Zentralionenladung kleiner wird.
Application de la diffusion à l'ètude des interactions entre la Sérum Albumine Humaine et les cations métalliques
Authors: Salvinien De J. , Brun B. , Kamenka N.
Published: August 2023

On a essayé de mettre en évidence les interactions entre la Sérum Albumine Humaine et les ions zinc et calcium par mesure des coefficients de self‐diffusion des espèces en présence dans le milieu réactionnel.

On a employé la méthode du tube capillaire. Les mesures sont faites à 25°C et 37°C en milieux tampons de différents pH. On a pu relier la mesure des coefficients de self‐diffusion an calcul de v, le nombre moyen de cations métalliques liés par molécule de protéine.
Self‐Diffusion of Spherical Ions and of Water in Aqueous solutions
Authors: Weiss Alarich , Nothnagel K. H.
Published: August 2023

By NMR‐Spin‐echo technique the self‐diffusion coefficients in aqueous solutions of a number of ions and of water have been measured. Measurements have been performed as a function of the concentration of the dissolved salt and of the temperature. Water (H2O) and heavy water (D2O) have been used as solvents. Only in the case of H2O, however, the self‐diffusion of the solvent has been measured. The following liquid systems have been studied in detail: LiClH2O (D,DH2O); Li2SiF6H2O (D,D,DH2O; [(CH3)4X]2YF6D2O with X  N, P, As, Sb, and Y  Si, Ge (D(CH3)4X+,DYF6−). At various concentrations the self‐diffusion coefficients of the ions and of the water as a function of the temperature may be described by an Arrhenius law. At constant concentration in some cases two different activation energies (frequency factors resp.) occur, one for an upper, the other for a lower temperature range. The result of the measurements are discussed and partially compared with theoretical calculations.
Nuclear Relaxation and Diffusion in Nematic Liquid solutions
Authors: Krüger G. J. , Spiesecke H.
Published: August 2023

The self diffusion coefficients and proton magnetic relaxation times were measured in some pure liquid crystals of the nematic type and in solutions of small molecules therein.
Dielectric Behaviour of solutions of Alkali Chlorides and Nitrates in the Microwave Region
Authors: Barthel J. , Behret H. , Schmithals F.
Published: August 2023

At 25°C the complex dielectric constants (DC) of solutions of alkali chlorides and nitrates in polar solvents are measured in the microwave region (1 GHz to 33 GHz). The interpretation of frequency dependence of the DC by relaxation processes shows increasing as well as decreasing relaxation times with increasing concentration of salt–according to the solvent.
Molecular Motion and Light Scattering in Liquids
Authors: Volterra V. , Bucaro J. A. , Litovitz T. A.
Published: August 2023

The use of light scattering techniques for the investigation of molecular motions in liquids is considered. In addition to orientational motion information about certain aspects of translational motion can be obtained. This information includes the details of isolated binary collisions, the correlation of successive collisions and structural relaxation time of the liquid lattice.
Fluctuation Theoretical and Turbidimetric Studies of Fast Mixing Processes in Liquids by Dynamic Volume Pulse Techniques. Part 1. Fluctuation Theory
Authors: Craubner H.
Published: August 2023

Fast optimum mixing processes in open, binary ideal liquid mixtures are theoretically treated as a superposition of a temporal set of noninterfering concentration fluctuations. For periodically generated volume pulses the relations of the quasi‐stationary mixing equilibrium as well as the temporal course of the corresponding concentration fluctuations are deduced. It is shown that the ”optimum differential mixing time ϑ” is a characteristic elementary time quantum. It also corresponds to the “waiting time θ*” which elapses during the equilibration of a sudden compression of the local mixture concentration: ϑ = ϑ*.

The investigation of the time course of concentration fluctuations (ε = γ‐&γmacr; ; γ = volume fraction of constituent 1) results in an estimation of ϑ. A statistical‐thermodynamic fluctuation theory is used for the calculation of ϑ by means of a liquid model. The mean differential mixing time 〈ϑ〉 corresponds to the quotient of the “average course time (Verlaufszeit)” (〈ϑϵ〉 = 1.5 · 10−5sec) and the “fluctuation probabilityP(ε)”: 〈ϑ〉 = 〈ϑϵ/P(ϵ) · 10−2sec. The mean square relative deviation is given by 〈ε2/(&γmacr;)2= 〈(γ ‐ &γmacr;)2〉/(&γmacr;)2= 1/n̄1≈︁ 10−22(n̄1≈︁ 1022= average number of molecules of constituent 1 per cm3).

It is shown that the elementary time quantum ϑ may also be interpreted as a relaxation time. Such an approach permits some understanding of the molecular events which proceed during fast mixing processes e.g. dependence on temperature and viscosity. Optical observation i.e. turbidity measurement is discussed on the basis of coupling fast mixing processes to polymer precipitation as an indicator reaction.
Kinetic Analysis of Ultrasonic Relaxation Spectra Caused by H‐Bond Polymerization The Two State Model and the Multistep Model
Authors: Rassing Jørgen
Published: August 2023

A kinetic analysis based on two different types of kinetic models has been applied to the previously published ultrasonic relaxation spectra of N‐methyl acetamide dissolved in carbon tetrachloride. The first model used is a two state model which describes the kinetics of the hydrogen bond association in terms of two states, a bonded state and a non bonded state. The other model used consists of an infinite number of elementary reaction steps in which hydrogen bonds are formed. Both models are treated in such a way that they agree with the fact that the equilibrium condition of the system is described by an infinite number of equilibria between monomers and polymers. The accuracy with which the two different models describe the measured relaxation is judged by comparing the concentration dependence of the relaxation parameters predicted from the two models with the actually measured concentration dependence of the relaxation parameters. The concentration dependence of the relaxation time predicted from both models corresponds to the one measured. The concentration dependence observed for the relaxation strength, however, can be explained only in terms of the multistep model. Finally the possibility of fitting the experimental data to the theoretical expression of the relaxation of the multistep model is discussed.
Motions of Protons in CH‐, CH2‐, CH3‐ and C2H5‐Halides by Cold Neutron Transmission Experiments
Authors: Fischer C. O.
Published: August 2023

Total cross sections of CH3I, CH2DI, CH3CH2I, CD3CH2I, CH3CD2I, CH2I2, CH2Br2and CHBr3have been measured with cold neutrons between 4 Å and 17 Å. The slopesSof the scattering cross section per proton vs. the neutron wavelength indicate the different types of protonic motions in the investigated liquids.

The high slopeS= 12.6 ± 0.4 barn/Å for protons in CH3I is explained by relative free internal rotation of the methyl group. This rotation is not influenced by the substitution of a proton by a deuteron as in CH2DI (S= 12.6 ± 0.4 barn/Å). But the motion of the protons becomes strongly hindered by increasing the rotational mass when substituting a proton by a halide nucleus as in CH2I2(S= 5.6 ± 0.5 barn/Å) and in CH2Br2(S= 6.2 ± 0.5 barn/Å). In CHBr3no internal molecular motion of the proton is possible and the low cross section slopeS= 2.0 ± 0.8 barn/Å shows, that the rotations of the CHBr3molecules are much more hindered than rotations of CH2Br2.

In CH3CH2I the neutron‐proton scattering is weaker than in CH3I. Comparison of the CD3CH2I and CH3CD2I cross sections with the CH3CH2I result indicates within the experimental errors no difference between the scattering power of methyl and methylene protons in ethyl iodide. This leads to the conclusion that all protons in ethyl iodide participate at the same microdynamic process which exchanges momentum and energy with the cold neutron. Therefore an internal rotation of the ethyl group around the C–I bond is assumed.
Time‐dependent Correlations in Simple Liquids
Authors: Verlet L.
Published: August 2023

The time‐dependent correlations in simple liquids can be investigated through computer simulation. It is shown how the results concerning the self motion can be interpreted in the framework of the generalized hydrodynamics.
Basic Concepts and Problems in the Theory of Critical Phenomena
Authors: Münster A.
Published: August 2023

The basic concepts in the theory of critical phenomena are developed for fluid one‐component systems. Only in the last section other critical phenomena are discussed. In the first part thermodynamic theory is reviewed. In the second part, by inserting the thermodynamic result into the compressibility integral, it is demonstrated that from the molecular point of view the nature of the critical point is to be explained by an anomalous behaviour of density fluctuations. The Ornstein‐Zernike theory is sketched and the problem of the Fisher exponent n is briefly discussed. In the third part the concept of critical exponents is introduced and definitions for the most important special cases are presented. Thermodynamic inequalities and scaling laws are briefly discussed. In the concluding part the general character of critical phenomena is emphasized and the scheme of corresponding critical quantities is indicated for some special cases. Theoretical and experimental values of critical exponents are presented and briefly discussed.
Critical Neutron Scattering from the Heisenberg Ferromagnets EuO and EuS
Authors: Als‐Nielsen J. , Dietrich O. W. , Passell L.
Published: August 2023

The magnetic neutron scattering from isotopically enriched powders of EuO and EuS near their Curie temperatures has been studied. Results of the critical exponents for the static properties in standard notation were

magnified image

Spin wave scattering at T<<Tc confirmed that EuO has predominantly nearest neighbor interaction only with J1 = 0.602 ± 0.008 K, J2 = 0.155 ± 0.014 K whereas in EuS J1 = 0.234 ± 0.016 K, J2 = 0.098 ± 0.014 K.

The renormalization of spin wave energies were determined. The characteristic frequency at T=Tc, ωc (q,k = 0), obeyed the 5/2 law predicted by scaling and with amplitudes for both EuO and EuS which are in remarkable agreement with the mode‐mode coupling calculation of Riedel and Wegner. Above Tc the ratio ωc(q,k)/ωc(q,k= 0) versus k/q displayed a pronounced minimum at k/q ≈︁ 1.5 as predicted by Resibois and Piette.
Light Scattering and Absolute Determination of the Compressibility of CCIF3 near the Critical Point
Authors: Schoenes Franz‐Jörg
Published: August 2023

The isothermal compressibility of CCIF3 has been determined by a combination of turbidity and light scattering intensity measurements in the vicinity of the critical point and along the critical isochore to be

magnified image

for the temperature range 3 · 10−4 ≤ (Tc · Tc)/Tc ≤ 5.5 · 10−2. The critical exponent of the compressibility agrees within the error limits with the results obtained on other one‐component systems, binary fluid mixtures and the three‐dimensional Ising model.
The Determination of the Critical Exponents v, y and η of the Binary Systems Decane‐Chlorex and Dodecane‐Chlorex by Light Scattering
Authors: Jaeckel K. , Majer U.
Published: August 2023

From our measurements we have obtained a mean value of η = 0.05. The reciprocal scattered intensity at the critical concentration extrapolated to zero angle follows the power‐law Ic,o−1 ∝[(T ‐ Tc)/Tcy]. We have found deviations from this power‐law in the temperature range [(T ‐ Tc)/Tc]≤ 3 ·10−5. These deviations may be explained by taking into account the uncertainty in the critical concentration with the help of the “pseudospinodal curve” concept, as proposed by Chu, Schoenes, and Fisher.
Character of the Rotational Movements in some Polar Liquids up to the Critical Region
Authors: Gerschel A.
Published: August 2023

The orientational properties and rotational dynamics of some molecules have been studied over the whole liquid range through dielectric measurements. The gradual decrease of angular correlations between next neighbours is followed through the evolution of the static dielectric constant, meanwhile the increasing amplitude of the small angular oscillations (librations) appears in the far infra‐red spectra, and the decrease with increasing temperature of the dielectric relaxation time is measured in microwave. The outcome of these investigations is that isotropic gas‐like rotational motions appear from below the critical temperature. Therefore no kind of anomaly could be detected in the critical region.
Der Einfluß der Schwerkraft auf die Messung der inneren Energie und der isochoren Wärmekapazität in der Nähe des kritischen Zustands
Authors: Baehr H. D.
Published: August 2023

Meßwerte der inneren Energie u und der isochoren Wärmekapazitat cv werden in der Nähe des kritischen Zustands durch die Schwerkraft erheblich beeinflußt. Aus diesem Grunde ist es bisher nicht möglich gewesen, den Charakter der Singularität von cv am kritischen Punkt eindeutig zu bestimmen. Über experimentelle und theoretische Arbeiten, die den Einfluß der Schwerkraft auf die Messung von u und cv zum Gegenstand haben, wird zusammenfassend berichtet.
Calculations of Phase Equilibria at High Pressure in the Critical Region
Authors: Peter S. , Wenzel H.
Published: August 2023

The Redlich‐Kwong equation of state was used to calculate vapour liquid equilibria of binary systems in which both components are in the vicinity of their critical points. The systems CO2‐H2S, n‐heptane‐C2H4, and benzene‐C2H6 were selected. Furthermore, an attempt was made to compute gas‐gas‐equilibria. Calculations on the systems NH3 ‐ N2, NH3 ‐Ar, and NH3 ‐ CH4 which exhibit gas‐gas‐equilibria of the second type provided a qualitative agreement with experiment. In the systems He ‐ CO2, He ‐ C2H4, and He ‐ Xe which form gas‐gas‐equilibria of the first type the calculations agree fairly well with experiment.
Selected Properties of Polar, Ionic and Metallic Fluids in the Supercritical Region
Authors: Franck E. U.
Published: August 2023

A survey is given of selected properties of polar, ionic and metallic fluids in critical and supercritical regions. New experimental data of the following properties and phenomena in this range are presented and discussed: The static dielectric constant of water, the infrared and Raman spectra of water, ion dissociation of water and ammonia, electrolytic conductance of supercritical bismuth trichloride, electronic conductance and metal‐nonmetal transition in dense gaseous metals.
Bladder malignancy as a cause of spontaneous bladder rupture: A systematic review
Authors: Da Huang Johnson , Shao Emily Ximin , Tham Chui Ming , Chung Eric , Rhee Handoo
Published: August 2023

Objectives

To characterise cases of spontaneous rupture of the urinary bladder in the context of bladder cancer.

Methods

A systematic review was performed to characterise cases of spontaneous bladder rupture in patients with bladder cancer. The Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) system was utilised, with databases being searched for relevant cases. Patient characteristics were extracted, including age, sex, presenting signs and symptoms, management modalities, tumour histology and mortality.

Results

Thirty cases were included. Seventeen (57%) were male, and the median age of presentation was 59. Abdominal pain and peritonism were the most common presenting symptoms, in 80% and 60% of patients, respectively. Most patients (n = 16, 53%) had urothelial cell carcinoma. Nine patients (30%) died during their initial hospitalisation.

Conclusion

Spontaneous bladder perforation in the context of bladder cancer is a rare cause of acute abdomen. The diagnosis is associated with high mortality, highlighting the aggressive nature of the malignancies that cause spontaneous bladder rupture. This raises important questions about the role of emergency cystectomy, the timing of systemic therapy and the appropriate involvement of palliative care.
Re‐examining the functioning of educational markets: Does the private‐subsidised sector contribute to school diversification?
Authors: Carrasco Alejandro , Gutiérrez Gabriel
Published: August 2023

This article offers new empirical evidence regarding the limits of the premises of educational privatisation policies. Educational markets rely on the assumption that private participation has the potential to boost school diversification and open new educational opportunities for students from disadvantaged backgrounds. Using a fresh empirical approach, we draw on the Chilean case to investigate this rationale, which remains a controversial issue in the global educational discussion regarding privatisation. We examine the assumption of diversification by analysing three aspects: the attributes used by private subsidised schools to position themselves in the educational market (‘Value Proposition’), the extent to which they embody these stated attributes and the alignment between them and parental preferences. Based on surveys and administrative records, our findings suggest that although schools display clear identities to position themselves in the educational market, there is also a mismatch between what some types of schools offer and what families receive. Our data also reveal a high level of social stratification between school types which cannot only be explained based on parental preferences or school admissions. We interpret the unfulfilled promise of diversification as a failure in the privatisation process. Based on these findings, we discuss the policy‐related factors of incoherent and unequal diversification in the Chilean educational system.
Downregulation of microRNA‐326 enhances ZNF322A expression, transcriptional activity and tumorigenic effects in lung cancer
Authors: Huang Shih‐Hsuan , Hsieh Hung‐Chia , Shieh Jiunn‐Min , Su Wou‐Chou , Wang Yi‐Ching
Published: August 2023

Zinc finger protein ZNF322A is an oncogenic transcription factor. Overexpression of ZNF322A activates pro‐metastasis, cancer stemness, and neo‐angiogenesis‐related genes to enhance lung cancer progression. However, the upstream regulator of ZNF322A is not well defined. Dysregulation of microRNAs (miRNAs) can mediate cancer cell growth, migration, and invasion to promote tumorigenesis. Here, we uncover the mechanism of miRNA‐mediated transcriptional regulation in ZNF322A‐driven oncogenic events. ZNF322A harbors several putative miRNA‐binding sites in the 3′‐untranslated region (UTR). We validated that miR‐326 downregulated ZNF322A‐3′‐UTR luciferase activity and mRNA expression. Furthermore, miR‐326 suppressed the expression of ZNF322A‐driven cancer‐associated genes such as cyclin D1 and alpha‐adducin. Reconstitution experiments by ectopic overexpression of ZNF322A abolished miR‐326‐suppressed cancer cell proliferation and cell migration capacity. Moreover, miR‐326 attenuated ZNF322A‐induced tumor growth and lung tumor metastasis in vivo. Clinically, the expression of miR‐326 negatively correlated with ZNF322A mRNA expression in surgically resected tissues from 120 non‐small cell lung cancer (NSCLC) patients. Multivariate Cox regression analysis demonstrated that NSCLC patients with low miR‐326/high ZNF322A profile showed poor overall survival. Our results reveal that the deregulated expression of miR‐326 leads to hyperactivation of ZNF322A‐driven oncogenic signaling. Targeting the miR‐326/ZNF322A axis would provide new therapeutic strategies for lung cancer patients.
Enthalpie et Entropie de Fusion du Polystyrolène Isotactique
Authors: Dedeurwaerder R. , Oth J. F. M.
Published: August 2023

L'enthalpie ΔHu et l'entropie ΔSu de fusion du polystyrolène isotactique ont été déterminées à partir de mesures d'abaissements de la température de fusion que présente un échantillon donné quand on lui additionne des quantités variables d'un diluant. Les mesures faites avec la benzophénone et le phénanthréne conduisent aux résultats suivants: magnified image Les mesures montrent également que les deux diluants choisis sont de très bons solvants pour le polystyrolène.

Le degré de cristallinité de l'échantillon de polystyrolène isotactique utilisé pour ces mesures est de l'ordre de 22,5%.
La Tension Superficielle A la Surface de Séparation de Deux Solutions non Miscibles
Authors: Bellemans A.
Published: August 2023

La tension superficielle à l'interface de deux solutions non miscibles est discutée sur la base du modèle des solutions strictement régulières, dans l'approximation du random mixing. La variation de la tension superficielle σ en fonction de la température T est approximativement linéaire dans le domaine 0.4 <T/Tc < 0.9:.

où Tc est la température critique de démixtion du système. Au voisinage immédiat de celle‐ci, on a.

cette modification de la forme analytique de σ est due à l'épaississement rapide de la couche interfaciale lorsque T tend vers Tc.
Action Comparée des Organomagnésiens et des Organocadmiques sur des Chlorures D'acides Aromatiques Substitués en Ortho II. Chlorures des Acides O. Formyl‐, O. Acétyl‐ et O. Benzoylbenzoiques
Authors: Renson M.
Published: August 2023

Nous avons déterminé par spectrographie infra‐rouge la structure des acides o.formyl‐, o.acétyl‐ et o.benzoyl‐benzoïques, ainsi que celle de leurs chlorures.

Par action de ces derniers avec les dérivés organocadmiques, on obtient des phtalides mono‐ ou di‐substituées. L'action des organomagnésiens est plus complexe et donne avec les chlorures des deux premiers acides des dérivés des phtalides correspondantes. Par contre le chlorure de l'acide o.benzoyl‐benzoïque donne au moins dans un cas une dicétone dérivant de sa forme normale. Ces réactions sont discutées en relation avec les propriétés antérieurement connues du chlorure d'acide de l'aspirine.
Ingredient branding for medicinal and aromatic plants: An alternative branding strategy to ensure differentiation and suppliers empowerment
Authors: Chandra Pramod
Published: August 2023

Indian medicinal and aromatic plants (MAPs) are globally known for their unique medicinal properties. However, due to limited strategic marketing and branding interventions in the sector, the MAPs are sold as commodities across markets, and intermediaries typically control the market mechanism of these resources. Consequently, the baseline suppliers of the sector remain relegated in the whole MAP business value chain. To address the inequalities of the existing Indian MAP business and enable suppliers to play an inclusive role in the country's MAP business value chain, this article attempts to conceptualize an ingredient branding strategy for the MAP resources and offers two strategic options. With a constructivist philosophical approach, conceptual methodology synthesizes related concepts and theories and offers the ingredient branding strategy for Indian MAP resources. The critical contribution of the article lies in its ability to reflect on a brand ecosystem framework and two strategic options for MAP ingredient branding.
The purpose of the company beyond its position in the market: The new agent of social development
Authors: Rodrich‐Portugal Rolando , Marino‐Jiménez Mauro , Mayurí‐Aguilar Guillermo , Abad‐Neyra Sue Anna
Published: August 2023

The purpose of companies as profit generators has been questioned because of the relationship between strategy and results in the recent systemic crises. Therefore, it is necessary to implement strategies that allow economic sustainability, based on a better relationship with society and the environment. This means turning companies into agents for the development and protection of the community, as well as building trust for their own stakeholders. This article analyzes the bases for the consolidation of a purpose related to these principles, using system thinking for the integrated participation of Corporate Social Responsibility (CSR) and the Sustainable Development Goals (SDGs). This strategy allows replicability based on archetypes that explain dynamic relationships in organizations, with the flexibility and openness required to adapt to different contexts.
Disparities in the use of colorectal cancer screening in a universally insured population during the COVID‐19 pandemic
Authors: Munigala Satish , Schoenfeld Andrew J. , Mani Vivitha , Banaag Amanda , Umoh Ada , Coles Christian L. , Koehlmoos Tracey Perez
Published: August 2023

Background

Despite the known efficacy of colorectal cancer (CRC) screening, the rates of individuals undergoing such testing have remained lower than target thresholds, even prior to the healthcare disruptions associated with the COVID‐19 pandemic. We evaluated the impact of the COVID‐19 pandemic on CRC screening within a nationally representative US population and assessed disparities in screening across racial/ethnic groups and socioeconomic (SES) strata.

Methods

We performed a retrospective cross‐sectional study using all eligible TRICARE beneficiaries aged 45–64 years between FY 2018 and 2021. High‐risk individuals, those with a previous or current CRC diagnosis, and/or a personal/family history of colonic polyps, were excluded. The pre‐COVID‐19 period (September 1, 2018–March 31, 2020) was compared to the COVID‐19 period (April 1, 2020–September 30, 2021). Secondary analyses were performed, evaluating the interaction between the COVID‐19 time period, race, and our proxy for socioeconomic status.

Results

During the study period, we identified 1,749,688 eligible individuals. Following the onset of the COVID‐19 pandemic, CRC screening overall decreased from 34% in the pre‐pandemic period to 30% following the onset of the pandemic (p < 0.001). This finding persisted even after adjusting for confounders in multivariable analysis (odds ratio [OR] for the pandemic timeframe: 0.79; 95% CI: 0.27, 0.31; p < 0.001). In the setting of SES, in the pandemic period, the odds of individuals from both Senior Enlisted (OR: 0.55; 95% CI: 0.54, 0.56) and Junior Enlisted sponsor ranks (OR: 0.27; 95% CI: 0.25, 0.30) were diminished as compared to Senior Officers.

Conclusions and Relevance

We found a 21% reduction in the odds of CRC screening in the context of the COVID‐19 pandemic. Reductions in colonoscopies and other types of screening tests were not offset by changes in the use of at‐home tests such as Cologuard.
Chemical Profiles and Cytotoxic Activities of Essential Oils from Six Species ofBaccharisSubgenusCoridifoliae(Asteraceae)
Authors: Paes de Almeida Valter , Tolouei Sara Emília Lima , Minteguiaga Manuel , Chaves Douglas Siqueira de Almeida , Heiden Gustavo , Khan Shabana Iqrar , Trott John , Wang Mei , Dellacassa Eduardo , Raman Vijayasankar , Farago Paulo Vitor , Khan Ikhlas Ahmed , Gasparotto Junior Arquimedes , Manfron Jane
Published: August 2023

SeveralBaccharisspecies are popularly known in traditional medicine as“carquejas”,“vassouras”, “ervas‐santas” and “mio‐mios”, and are used as anti‐inflammatories, digestives, and diuretics. This study aimed to investigate the chemical compositions and cytotoxic activities of essential oils (EOs) of sixBaccharisspecies belonging to subgenusCoridifoliae, namelyB. albilanosa,B. coridifolia,B. erigeroides,B. napaea,B. ochracea, andB. pluricapitulata. GC/MS analyses of the EOs showed that the oxygenated sesquiterpenes spathulenol (7.32–38.22 %) and caryophyllene oxide (10.83–16.75 %) were the major components for all the species. The EOs of almost all species were cytotoxic against cancer (BT‐549, KB, SK‐MEL and SK‐OV‐3) and normal kidney (VERO and LLC‐PK1) cell lines, whereasB. erigeroidesEO showed cytotoxicity only against LLC‐PK1. This article augments the current knowledge about the chemical‐biological properties ofBaccharissubgenusCoridifoliaeand discusses the therapeutic potentials of these economically unexploited plants.
Exploring the Therapeutic Properties of Alga‐Based Silver Nanoparticles: Anticancer, Antibacterial, and Free Radical Scavenging Capabilities
Authors: Khan Amir Hamza , Hassan Said , Aamir Muhammad , Khan Muhammad Waseem , Haq Fazal , Hayat Junaid , Rizwan Muhammad , Ullah Amin , Ullah Izzat , Zengin Gokhan , Farid Arshad
Published: August 2023

The current study was designed to evaluate the antioxidant, anticancer and antimicrobial activities of silver nanoparticles (AgNPs) biosynthesized by Spirulina platensis extract. The biosynthesized silver nanoparticles were characterized using Fourier transform infrared (FT‐IR) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X‐ray diffraction (XRD) analysis. The antioxidant activity of the biosynthesized AgNPs were determined via DPPH radical scavenging assay while its anticancer activity was determined using the MTT assay. The antimicrobial activity of the biosynthesized AgNPs were analyzed by disc diffusion method. Spirulina platensis acts as a reducing and capping agent. The efficacy of silver nanoparticles (AgNPs) in inhibiting the growth of Gram‐negative bacteria, specifically Acetobacter, Klebsiella, Proteus vulgaris, and Pseudomonas aeruginosa, was assessed by the utilisation of the diffusion method. The study aimed to evaluate the efficacy of biosynthesized silver nanoparticles (AgNPs) against many strains of Pseudomonas aeruginosa bacteria. The findings of the study revealed that when administered in doses of 50 μl, 75 μl, and 100 μl, the largest observed zone of inhibition corresponded to measurements of 10.5 mm, 14 mm, and 16 mm, respectively. A zone of inhibition with dimensions of 8 mm, 10.5 mm, and 12 mm was detected during testing against Acetobacter at concentrations of 50 μl, 75 μl, and 100 μl, respectively. The findings also indicate that there is a positive correlation between the concentration of AgNP and the DPPH scavenging ability of silver nanoparticles. The percentage of inhibition observed at concentrations of 500 μg/ml, 400 μg/ml, 300 μg/ml, 200 μg/ml, and 100 μg/ml were recorded as 80±1.98, 61±1.98, 52±1.5, 42±1.99, and 36±1.97, respectively. In addition, it was observed that the silver nanoparticles exhibited the greatest antioxidant activity at a concentration of 500 g/ml, with a measured value of 80.89±1.99. The IC‐50 values, representing the inhibitory concentration required to achieve 50 % inhibition, were found to be 8.16, 19.15, 30.14, 41.13, and 63.11 at inhibition levels of 36±1.97, 42±1.99, 52±1.5, 61±1.98, and 80±1.98, respectively.
Difficulty in diagnosing peritonitis caused by multidrug‐resistant tuberculosis
Authors: Aoyama Sayaka , Yamashita Shun , Ishizuka Kosuke , Katsukura Shinichi , Matsuura Hiroki , Kato Mikiro
Published: August 2023

Key Clinical Message

The low sensitivity of ascites culture for acid‐fast bacilli necessitates a peritoneal biopsy when tuberculous peritonitis is suspected. Findings in the peritoneum on computed tomography may prompt suspicion of tuberculous peritonitis.

A 47‐year‐old Nigerian man presented with fever, abdominal distention, and weight loss. Abdominal computed tomography revealed massive ascites and peritoneal thickening. Despite failing to culture acid‐fast bacilli from ascites, histological examination and culture of peritoneum revealed multidrug‐resistant tuberculosis peritonitis. Peritoneal biopsy is mandatory when tuberculosis peritonitis is suspected.
Design and study of a novel ammonia‐based CO2 capture process with bipolar membrane electrodialysis
Authors: Song Zhengyuan , Sun Guogang , Wang Zetao , Yuan Shiwei , Xi Chenhao
Published: August 2023

Aqueous ammonia is a promising absorbent in the field of post combustion CO2 capture. However, the high volatilization of NH3 results in a high energy requirement, as well as solid precipitation during the CO2 regeneration process. A novel process was designed to reduce energy consumption and solve the problem. The bipolar membrane electrodialysis (EDBM) unit and CO2 regeneration reactor were taken as the regeneration part. In the novel process, the bubble in the EDBM unit would be eliminated, and the regeneration of CO2 and aqueous ammonia would be operated separately, which significantly reduced energy consumption and avoided the risk of precipitation during regeneration. According to the simulation and calculation results, the CO2 regeneration energy consumption of the novel process using H2SO4 for CO2 regeneration is 39.0% lower than that of the conventional ammonia‐based process, which shows good energy saving potential. Moreover, the novel process will be more competitive as membrane technology develops.
A deep graph convolutional network model of NOx emission prediction for coal‐fired boiler
Authors: Wang Yingnan , Zhao Chunhui
Published: August 2023

To deal with environmental problems caused by NOx production in thermal plants, it is imperative to establish a reliable model to predict NOx concentration in the combustion process. NOx formation in a coal‐fired boiler is complex, and many variables affect NOx emissions. The effective information fusion of these variables can improve the accuracy of NOx concentration prediction. However, the existing NOx prediction algorithms based on thermal parameters rarely consider the mechanical knowledge of the boiler operation, and it is not easy to incorporate the topological information of production into modelling. Therefore, a graph convolutional network is proposed for NOx emission prediction. First, the key variables affecting NOx generation are selected according to the knowledge and the random forest‐based variable importance. Then, the model structure is designed by exploring the topological information among thermal variables to capture the complex spatial dependence. The model inputs are constructed by coding different operation variables, and the adjacency matrix is generated according to the correlation information between variables, which can fuse data information and reduce redundancy. On this basis, the prediction model of NOx concentration is established. Historical data from a 660 MW coal‐fired boiler are used in the experiment. The prediction results show that the proposed model can effectively fuse the information of characteristic variables and fully exploit the non‐linear mapping relationship between process variables and NOx emission. When compared with three typical models in NOx modelling, the proposed model has better performance with a determination coefficient of 0.906.
Entropy and improved k‐nearest neighbor search based under‐sampling (ENU) method to handle class overlap in imbalanced datasets
Authors: Kumar Anil , Singh Dinesh , Yadav Rama Shankar
Published: August 2023

Many real‐world application datasets such as medical diagnostics, fraud detection, biological classification, risk analysis and so forth are facing class imbalance and overlapping problems. It seriously affects the learning of the classification model on these datasets because minority instances are not visible to the learner in the overlapped region and the performance of learners is biased towards the majority. Undersampling‐based methods are the most commonly used techniques to handle the above‐mentioned problems. The major problem with these methods is excessive elimination and information loss, that is, unable to retain potential informative majority instances. We propose a novel entropy and neighborhood‐based undersampling (ENU) that removed only those majority instances from the overlapped region which are having less informativeness (entropy) score than the threshold entropy. Most of such existing methods improved sensitivity scores significantly but not in many other performance contexts. ENU first computes entropy and threshold score for majority instances and, a local density‐based improved KNN search is used to identify overlapped majority instances. To tackle the problem effectively ENU defined four improved KNN‐based procedures (ENUB, ENUT, ENUC, and ENUR) for effective undersampling. ENU outperformed in sensitivity, G‐mean, and F1‐score average ranking with reduced information loss as compared to the existing state‐of‐the‐art methods.
High Entropy Pr‐Doped Hollow NiFeP Nanoflowers Inlaid on N‐rGO for Efficient and Durable Electrodes for Lithium‐Ion Batteries and Direct Borohydride Fuel Cells
Authors: Basumatary Padmini , Hyeok Choi Ji , Emin Kilic Mehmet , Konwar Dimpul , Soo Yoon Young
Published: August 2023

The selection and design of new electrode materials for energy conversion and storage are critical for improved performance, cost reduction, and mass manufacturing. A bifunctional anode with high catalytic activity and extended cycle stability is crucial for rechargeable lithium‐ion batteries and direct borohydride fuel cells. Herein, a high entropy novel three‐dimensional structured electrode with Pr‐doped hollow NiFeP nanoflowers inlaid on N‐rGO was prepared via a simple hydrothermal and self‐assembly process. For optimization of Pr content, three (0.1, 0.5, and 0.8) different doping ratios were investigated. A lithium‐ion battery assembled with NiPr0.5FeP/N‐rGO electrode achieved an outstanding specific capacity of 1.61 Ah g−1 at 0.2 A g−1 after 100 cycles with 99.3 % Coulombic efficiencies. A prolonged cycling stability of 1.02 Ah g−1 was maintained even after 1000 cycles at 0.5 A g−1. In addition, a full cell battery with NiPr0.5FeP/N‐rGO∥LCO (Lithium cobalt oxide) delivered a promising cycling performance of 0.52 Ah g−1 after 200 cycles at 0.15 A g−1. Subsequently, the NiPr0.5FeP/N‐rGO electrode in a direct borohydride fuel cell showed the highest peak power density of 93.70 mW cm−2 at 60 °C. Therefore, this work can be extended to develop advanced electrode for next‐generation energy storage and conversion systems.
Palladium‐Catalyzed [4+2] Cycloaddition of Vinyl Benzoxazinanones with 1,3‐Indanedione: Approach to Spiro‐Tetrahydroquinoline Scaffolds
Authors: Wei Qinglang , Tu Liang , Li Sen , Zheng Yongsheng , Liu Jikai
Published: August 2023

A palladium catalyzed decarboxylative [4+2] cycloaddition of vinyl benzoxazinanones with 2‐arylidene indan‐1,3‐dione has been established, which afford a series of bioactive spiro‐tetrahydroquinolines (27 examples) in moderate to good yield (up to 87 %) with high diastereoselectivities. The synthetic utility of this reaction was demonstrated by gram‐scale synthesis. Compounds synthesized by this method potently inhibited proliferation in a panel of cancer cell lines. Particularly, the most potent compounds 3 ae, 3 ah, 3 aj and 3 fa displayed selective inhibition of MDA‐MB‐231 breast carcinoma cells with IC50 values of 1.292, 0.6118, 0.6558, 1.656 and 2.215 μM, respectively.
Base Promoted Synthesis of 4‐Quinolones Fused with Medium‐Sized Rings
Authors: Wang Mengdan , Ma Junying , Wang Junling , Lu Weiwei , Pan Bingli
Published: August 2023

In the presence of cesium carbonate, ynones bearing an ortho‐amino group reacted with cyclic β‐ketoesters through conjugated addition/carbon‐carbon σ‐bond cleavage/nucleophilic aromatic substitution tandem reaction to obtain 4‐quinolones fused with medium‐sized rings in good yields. This is the first example of synthesis of 4‐quinolones through base‐promoted insertion reactions of carbon‐carbon triple bonds into carbon‐carbon σ‐bonds. Notable features of this program are mild and transition‐metal‐free reaction conditions.
Analysis and design of a vertical sectored tank
Authors: Ferrer Gisbert Pablo Sebastián , Ferrer Gisbert Carlos Manuel , Ferrán Gozálvez José Javier , Redón Santafé Miguel , Torregrosa Soler Juan Bautista , Sánchez Romero Francisco Javier
Published: August 2023

This article describes the conceptual design and the structural analysis of a vertical cylindrical partitioned tank for an international chemical company. Vertical cylindrical tanks are commonly used in the chemical industry worldwide as vessels to contain liquids. Most of these plants have reduced area for the installation of the container tanks. Many of them need to renew their manufacturing process according to the new technologies and requirements. In addition, in some cases, the preparation of mixtures is carried out on small surfaces. All this factors led to the idea of designing a vertical sectorised tank, considering that alternative hydrostatic pressure cases can lead to eccentric loads on the upper surfaces. Therefore, bending stresses and compression and tension stresses will occur. A Finite Element Method calculation was performed to determine the wall thickness fulfilling the structural requirements for two distinguishing design alternatives. This article describes the particular models designed and the detailed FEM simulation and mechanical calculation carried out to determine the optimized solution of partitioned tanks with a diamond‐shaped inner bracing system that manages to meet all the structural, manufacturing, constructive and environmental needs with a target thickness of 12 mm.
Dynamic testing of a new integrated collector storage solar water heater (ICSSWH) according to standard ISO 9459‐5: Use of a numerical approach for long‐term prediction in different climatic conditions
Authors: Messaouda Anis , Hamdi Mohamed , Hazami Majdi , Guizani Amen Allah
Published: August 2023

This work analyzes the performance of a new Integrated Collector Storage Solar Water Heater (ICSSWH) by using Dynamic System Testing (DST) method according to Standard ISO 9459‐5. The long‐term performance study of the system in different climatic conditions has been achieved by a coupling model between DST results and a numerical approach based on the system transient behavior. Results of the experimental dynamic system evaluation showed that the total store heat capacity Cs, the useful collector surface Ac* and the storage tank heat losses coefficient Us are, respectively, 0.87 MJ/K, 1.21 m2 and 10 W/K. In Tunisian climatic conditions, the ICSSWH system allows covering until 79.3% from a typical family need for a daily consumption of 170 L. The results found allow optimizing the energy gain of the ICSSWH as well as selecting a specific load volume according to the location. Especially, investigations showed that in Stockholm and Riadh climatic conditions, the ICSSWH's solar fraction reached 27% and 83%, respectively, for a daily load volume of 250 L. More importantly, the experimental effort of DST identification can be minimized by coupling DST data with a robust numerical approach.
Investigation of the synergistic effect of red phosphorus and magnesium hydroxide on the thermal degradation behavior and flame resistance of the intumescent fire‐retardant polypropylene system
Authors: Thi Nhung Hac , Doanh Truong Cong , Dat Doan Tien , Oanh Ho Thi , Nguyen Ha Tran , Van Nguyen Tuyen , Tran Quang Vinh , Hoang Mai Ha
Published: August 2023

High fire‐resistance polypropylene (PP) composites were prepared by using environment‐friendly flame retardants including expandable graphite (EG), red phosphorus (RP), and magnesium hydroxide (MH). Synergism between EG, RP, and MH on the thermo‐oxidation behavior and flame resistance of PP was found. The incorporation of MH and RP formed highly thermally stable mixtures of magnesium phosphates consisting of Mg3(PO4)2, Mg(PO3)2, and α‐Mg2P2O7 at both amorphous and crystalline phases in the burning process. The mixture not only covered the surface of burning materials but also could reinforce the char structure of the PP/EG composites, thereby significantly enhancing the condensed phase flame retardant mechanism of the composites. Mass ratios of the flame retardants were also optimized to obtain the composite with the highest flame retardant efficiency. The result revealed that the combination of EG, RP, and MH in PP at MH/RP mass ratio of 3/2 with only a total additive content of 18 wt.% could make its limiting oxygen index (LOI) increase from 16.8% to 27.2% and the UL‐94 rating was improved from none to V‐0. In addition, the mechanical properties of the composites were improved via the surface treatment of MH and RP with calcium stearate and silicone oil, respectively.
Promoting engagement in online learning beyond COVID‐19: Possible strategies and directions for future research
Authors: Hew Khe Foon , Huang Weijiao
Published: August 2023

In the aftermath of the global pandemic, online learning is now ubiquitous around the world. Yet, although online learning has become a common learning approach across the globe, it is still viewed as a weaker option than on‐campus face‐to‐face learning. Specifically, the lack of student engagement in online learning poses a persistent problem to many educators. In this article, we describe three key challenges of fully online learning: students being more easily distracted, students lacking self‐regulation skills and students feeling isolated. Next, we present three possible strategies to address these challenges: promoting active learning through the online flipped classroom model, promoting self‐regulation skills and reducing the sense of isolation through the use of chatbots. For each of the three strategies, we provide a description with relevant empirical studies based on our own work as well as previous work in the literature and discuss possible directions for further research.
Multishell diffusion MRI reveals whole‐brain white matter changes in HIV
Authors: Minosse Silvia , Picchi Eliseo , Conti Allegra , di Giuliano Francesca , di Ciò Francesco , Sarmati Loredana , Teti Elisabetta , de Santis Silvia , Andreoni Massimo , Floris Roberto , Guerrisi Maria , Garaci Francesco , Toschi Nicola
Published: August 2023

Diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) have been previously used to explore white matter related to human immunodeficiency virus (HIV) infection. While DTI and DKI suffer from low specificity, the Combined Hindered and Restricted Model of Diffusion (CHARMED) provides additional microstructural specificity. We used these three models to evaluate microstructural differences between 35 HIV‐positive patients without neurological impairment and 20 healthy controls who underwent diffusion‐weighted imaging using three b‐values. While significant group effects were found in all diffusion metrics, CHARMED and DKI analyses uncovered wider involvement (80% vs. 20%) of all white matter tracts in HIV infection compared with DTI. In restricted fraction (FR) analysis, we found significant differences in the left corticospinal tract, middle cerebellar peduncle, right inferior cerebellar peduncle, right corticospinal tract, splenium of the corpus callosum, left superior cerebellar peduncle, left superior cerebellar peduncle, pontine crossing tract, left posterior limb of the internal capsule, and left/right medial lemniscus. These are involved in language, motor, equilibrium, behavior, and proprioception, supporting the functional integration that is frequently impaired in HIV‐positivity. Additionally, we employed a machine learning algorithm (XGBoost) to discriminate HIV‐positive patients from healthy controls using DTI and CHARMED metrics on an ROIwise basis, and unique contributions to this discrimination were examined using Shapley Explanation values. The CHARMED and DKI estimates produced the best performance. Our results suggest that biophysical multishell imaging, combining additional sensitivity and built‐in specificity, provides further information about the brain microstructural changes in multimodal areas involved in attentive, emotional and memory networks often impaired in HIV patients.