bluuebunny/crossref_metadata_2025 huggingface dataset:
Keeping Our Nation's Mathematics Teachers
Authors: Curtis Carol
Published: December 2012

Teacher retention has been an issue that has influenced education for many years. The purpose of this research was to uncover the factors that influence a mathematics teacher’s decision to leave the teaching profession. This study compared teachers’ responses by regions of the country, as well as responses between middle school and high school mathematics teachers. Findings from the study indicate an alarmingly high rate of teachers who will be leaving the teaching field for reasons other than retirement. The role of administrators in teacher retention is significant, and implications from the research suggest that an increase in administrator training could play a major role in keeping our nation’s mathematics teachers in the classroom.
Structural and Electronic Properties of Pure Ta, TaNO, and TaZrNO with Ab Initio Calculations
Authors: Chihi T. , Fatmi M. , Guemmaz M. , Parlebas J. C.
Published: December 2012

This paper presents the results of self-consistent first-principle calculations for the crystal structure and electronic structure of pure tantalum, TaNO, and TaZrNO within density functional theory (DFT) for the sake of comparison and shows the influence of allowing elements on the interatomic distance and the Fermi level. The large total densities of states (TDOS) value for TaZrNO implies the highest electronic conductivity. The difference in values is due to the Zr metallic atoms presence in TaZrNO compound. There is a strong interaction between Ta and (N, O) (Ta−N=0.39, Ta−O=0.21) in TaON compound, and Zr presence increases this interaction (Ta−N=1.74, Ta−O=0.30) in TaZrON compound.
Studies on the Cytotoxic Activities of Punica granatum L. var. spinosa (Apple Punice) Extract on Prostate Cell Line by Induction of Apoptosis
Authors: Sineh Sepehr Koushan , Baradaran Behzad , Mazandarani Masoumeh , Khori Vahid , Shahneh Fatemeh Zare
Published: December 2012

The Punica granatum L. var. granatum (pomegranate) has been demonstrated to exert antitumor effects on various types of cancer cells. The present study aimed to evaluate the medicinal herbs Punica granatum L. var. spinosa (apple punice) that are native to Iran. This study was determined to test the possible cytotoxic activity and induction of apoptosis on human prostate cell lines. The effect of ethanol extracts of the herbs on the inhibition of cell proliferation was assessed by MTT colorimetric assay. PC3 cell lines treated with the extracts were analyzed for the induction of apoptosis by cell death detection (ELISA) and TUNEL assay. Dye exclusion analysis was performed for viability rate. Our results demonstrated that the Punica granatum L. var. spinosa extract dose dependently suppressed the proliferation of PC3 cells (IC50= 250.21 μg/mL) when compared with a chemotherapeutic anticancer drug (Toxol) (Vesper Pharmaceuticals) with increased nucleosome production from apoptotic cells. The Punica granatum L. var. spinosa extract attenuated the human prostate cell proliferation in vitro possibly by inducing apoptosis. The Punica granatum L. var. spinosa is likely to be valuable for the treatment of some forms of human prostate cell line.
Molecular Biomarkers of Response to Antiangiogenic Therapy for Cancer
Authors: Duda Dan G.
Published: December 2012

Antiangiogenic therapy for cancer has gone from an intriguing hypothesis in the 1970s to an accepted treatment approach for many cancer types. It has also become a standard of care for certain eye diseases. Yet, despite the use of molecularly targeted drugs with well defined targets, to date there are no biomarkers to guide the use of antiangiogenic therapy in patients. The mechanisms of action of these drugs are also being debated. This paper discusses some of the emerging biomarker candidates for this type of cancer therapy, which have provided mechanistic insight and might be useful in the future for optimizing cancer treatment.
An Isocratic Method for Quantification of Valproic Acid and Its Related Impurities Using Ion Pair Reagent by Ultraperformance Liquid Chromatography
Authors: Thakkar Rakshit , Saravaia Hitesh , Ambasana Mrunal , Patel Madhavi , Shah Anamik
Published: December 2012

A selective ultraperformance liquid chromatographic (UPLC) method for the quantification of valproic acid and its known related impurities using ion pair reagent has been developed. The method includes reversed-phase Acquity HSS T3 column with 100 mm × 2.1 mm i.d. and 1.7 μparticle size. The mobile phase consists of acetonitrile, 5 mM 1-hexanesulphonic acid sodium salt, flow rate is 0.6 mL/min, and UV detection is performed at 215 nm. A system suitability test (SST) was developed to govern the quality of the separation. The developed method has been validated further with respect to linearity, accuracy, precision, selectivity, LOD, LOQ, and Robustness.
Mitochondrial Regulation by PINK1-Parkin Signaling
Authors: Imai Yuzuru
Published: December 2012

Two genes responsible for the juvenile Parkinson’s disease (PD), PINK1 and Parkin, have been implicated in mitochondrial quality control. The inactivation of PINK1, which encodes a mitochondrial kinase, leads to age-dependent mitochondrial degeneration in Drosophila. The phenotype is closely associated with the impairment of mitochondrial respiratory chain activity and defects in mitochondrial dynamics. Drosophila genetic studies have further revealed that PINK1 is an upstream regulator of Parkin and is involved in the mitochondrial dynamics and motility. A series of cell biological studies have given rise to a model in which the activation of PINK1 in damaged mitochondria induces the selective elimination of mitochondria in cooperation with Parkin through the ubiquitin-proteasome and autophagy machineries. Although the relevance of this pathway to PD etiology is still unclear, approaches using stem cells from patients and animal models will help to understand the significance of mitochondrial quality control by the PINK1-Parkin pathway in PD and in healthy individuals. Here I will review recent advances in our understanding of the PINK1-Parkin signaling and will discuss the roles of PINK1-Parkin signaling for mitochondrial maintenance and how the failure of this signaling leads to neurodegeneration.
Membrane Bioincompatibility and Ultrafiltration Effects on Pulse Wave Analysis during Haemodialysis
Authors: Valenzuela Maria-Pau , Almirall Jaume , Amengual María-José
Published: December 2012

Membrane bioincompatibility was demonstrated by successive white blood cell counts and C3a generation. Pulse wave analysis was obtained by applanation tonometry (SphygmoCor) in a sequential way: basal, after 30 minutes with nul ultrafiltration, and after a complete dialysis with ultrafiltration. At 15 minutes of haemodialysis, significant decrease in leukocyte count occurred: versus (), while C3a levels sharply increased from to  ng/mL (). No changes were observed in augmentation index without ultrafiltration: versus . Only aortic systolic blood pressure was lower at 15 minutes: versus  mmHg (), in agreement with a reduction in brachial systolic blood pressure: versus  mmHg (), without changes in aortic or brachial diastolic blood pressure. Important changes in pulse wave analysis were observed after a complete haemodialysis session: augmentation index versus , aortic systolic blood pressure versus mmHg (), without changes in aortic diastolic blood pressure. In summary, haemodialysis with cellulose diacetate acutely induced a transient state of immunoactivation due to bioincompatibility, this phenomenon was nondetectable by pulse wave analysis. Complete haemodialysis session led to important changes in pulse wave analysis.
Study of Position, Shape, and Size of Mental Foramen Utilizing Various Parameters in Dry Adult Human Mandibles from North India
Authors: Budhiraja Virendra , Rastogi Rakhi , Lalwani Rekha , Goel Prabhat , Bose Subhash Chandra
Published: December 2012

Background. As the mental foramen (MF) is an important landmark to facilitate surgical, local anesthetic, and other invasive procedures, the present study was aimed to elucidate its morphological features and morphometric parameters with reference to surrounding landmarks.
Material and Method. 105 dry adult human mandibles of unknown sex were observed for position, shape, and number of mental foramina. Their size was measured using a digital vernier caliper and statistically analyzed by mean and standard deviations (SD).
Results. In most cases (74.3%), the MF was oval in shape and situated on the longitudinal axis of the 2nd premolar tooth (61% on right side and 59.1% on left side). The mean distance for the right and left sides was measured from various landmarks.
Conclusion. Prior knowledge of mental foramen variations helps surgeons in planning surgery in that region to avoid nerve damage and also enable effective mental nerve block anesthesia.
Livros didáticos de história: entrecruzando leituras de imagens e orientações editoriais nas décadas de 1970 e 1980
Authors: Pinto Junior Arnaldo , Bueno João Batista Gonçalves , Guimarães Maria de Fátima
Published: December 2012

Neste artigo estudamos as mudanças e permanências nas formas de editoração de textos escritos e imagens visuais impressas nos livros didáticos de História. Analisamos obras produzidas por diferentes autores nas décadas de 1970 e 1980: Sérgio Buarque de Holanda, Antonio José Borges Hermida, Gilberto Cotrim e Álvaro Duarte Alencar. Reconhecemos que a partir da década de 1970 foram estabelecidos novos padrões editoriais para os livros didáticos de História, os quais alteraram as formas de apresentação dos textos escritos na relação com as imagens visuais. Os diferentes procedimentos de leituras das imagens visuais estabelecidos desde então, constituíram saberes editoriais e escolares que serviram de base teórica e procedimental para desenvolvimento de propostas que emergiram nas obras didáticas produzidas nas décadas posteriores. Esperamos com este estudo contribuir para a construção de práticas de leitura de imagens visuais que possibilitem a fruição, o entendimento e a contextualização das informações que se relacionam ao uso de documentos visuais no ensino de História. Buscamos a valorização de procedimentos didáticos de leitura que permitam a construção, pelos professores e alunos, de interpretações pluridimensionais sobre as imagens visuais como documentos históricos.
Se a estratégia é prática, quem são seus praticantes?
Authors: Coraiola Diego Maganhotto , De Oliveira Samir Adamoglu , Gonçalves Sandro Aparecido
Published: December 2012

Discordando do individualismo metodológico que permeia a maioria das pesquisas sobre o papel e a atuação dos estrategistas na 'Estratégia como Prática', o presente artigo analisa quem são os estrategistas organizacionais, empreendendo discussão e crítica pautadas em pesquisas publicadas seguindo tal vertente. Esse argumento é desenvolvido principalmente oferecendo evidências empíricas para o que se defende, mediante estudo de caso qualitativo sobre o processo de mudança do projeto gráfico de um periódico paranaense. Utilizando conceitos do institucionalismo organizacional para a análise do caso, defende-se ser equivocada a excessiva ênfase no nível microssocial de análise para entender-se quem são os estrategistas, por esta desconsiderar a importância da di­mensão institucional, sua relevância na constituição identitária desse sujeito nas organizações, e a problemática que decorre em se estudar a prática e a práxis estratégica independentemente da influência de estruturas sociais mais amplas.
A estratégia como prática na educação à distância
Authors: Ferreira Jane Mendes , Baratter Marystela Assis , De Matos Débora Pinto Pinheiro , Filho Edson Ronaldo Guarido
Published: December 2012

A estratégia como prática vem despertando a atenção dos pesquisadores da área de estudos organizacionais. A estratégia, neste caso, passa a ser considerada uma prática social e, portanto, além dos elementos internos da organização, ela também é compartilhada pelos membros de um campo organizacional. Não obstante o interesse pelo tema, poucos estudos empíricos têm sido feitos para mostrar a relação entre as práticas organizacionais e o ambiente externo sob esta perspectiva de análise. Um locus privilegiado para mostrar tal relação é o da educação à distância, no Brasil, em função de ser campo relativamente recente e ter apresentado crescimento antes e depois da sua regulamentação por meio de instrumentos legais. Dessa forma, o objetivo deste artigo é verificar como as regras advindas do Ministério da Educação são traduzidas em práticas de estruturação e qualificação dos polos de apoio presencial em uma instituição de ensino à distância. Para alcançar tal objetivo foi realizado um estudo de campo exploratório, de corte transversal, cuja estratégia selecionada foi o estudo de caso qualitativo, utilizando entrevista, consulta a documentos e observação como técnicas de coleta de dados. As análises mostram que a or­ganização, por falta de repertórios de ações disponíveis no campo, busca a conformação às regras. Conclui-se que, em campos maduros, a prática social chamada estratégia pode fornecer uma configuração de ações possíveis para as organizações. No entanto, em campos ainda em estruturação, a conformação às normas torna-se a estratégia.
Inserindo a estratégia como prática no campo dos estudos organizacionais: uma proposta de método de aplicação a partir de um caso prático
Authors: Da Silva Fabiano Oliveira , Hansen Peter Bent
Published: December 2012

O atual cenário acadêmico no campo dos estudos em estratégia organizacional é povoado por diversas abordagens e correntes teóricas. Dentre estas, tem-se observado a emergência das abordagens que con­sideram aspectos sociológicos e subjetivos do “fazer estratégia”, nos quais há destaque para a estratégia como prática. O presente artigo faz uma breve varredura nos postulados teóricos dessa abordagem e ilustra uma proposta de método de aplicação empírica deste corpo teórico, a partir de um estudo de caso realizado no ano de 2011 em uma empresa brasileira de grande porte. Como resultado, além da análise da estratégia em si da organização estudada, há a proposição de um método de aplicação da teoria no campo dos estudos organizacionais, adaptado da sistemática inicialmente formulada por Jarzabkowski
Extended Traffic Crash Modelling through Precision and Response Time Using Fuzzy Clustering Algorithms Compared with Multi-layer Perceptron
Authors: Aghayan Iman , Noii Nima , Kunt Mehmet Metin
Published: December 2012

This paper compares two fuzzy clustering algorithms – fuzzy subtractive clustering and fuzzy C-means clustering – to a multi-layer perceptron neural network for their ability to predict the severity of crash injuries and to estimate the response time on the traffic crash data. Four clustering algorithms – hierarchical, K-means, subtractive clustering, and fuzzy C-means clustering – were used to obtain the optimum number of clusters based on the mean silhouette coefficient and R-value before applying the fuzzy clustering algorithms. The best-fit algorithms were selected according to two criteria: precision (root mean square, R-value, mean absolute errors, and sum of square error) and response time (t). The highest R-value was obtained for the multi-layer perceptron (0.89), demonstrating that the multi-layer perceptron had a high precision in traffic crash prediction among the prediction models, and that it was stable even in the presence of outliers and overlapping data. Meanwhile, in comparison with other prediction models, fuzzy subtractive clustering provided the lowest value for response time (0.284 second), 9.28 times faster than the time of multi-layer perceptron, meaning that it could lead to developing an on-line system for processing data from detectors and/or a real-time traffic database. The model can be extended through improvements based on additional data through induction procedure.
Paradoxes and Opportunities in Logistic Outsourcing Research
Authors: Stojanović Đurđica
Published: December 2012

Historically, very few logistic trends have caught the attention of academics and practitioners to the same extent as outsourcing. A comprehensive literature review reveals two reasons for this continual topicality. The problem complexity and the business environment dynamics – including an interaction with other main trends in logistics and modern supply chains – both led to a permanent literature gap, indicating the need to explore some new aspects of logistics outsourcing (LO). In this paper, a new LO research perspective has been explored by identifying some weaknesses in the main LO research streams and related common viewpoints which led to six ‘logistics outsourcing research paradoxes’. Each of these paradoxes is briefly described and their links with research streams and common views on LO discussed. Finally, the nature of some known opportunities for further research is better explained and some overlooked research opportunities are highlighted.
The Human Cost of Politicizing Immigration: Migration Stigma, US Politics, and Health
Authors: Yang Lawrence H. , Eger Maureen A. , Link Bruce G.
Published: July 2024

This Viewpoint discusses stigma and health consequences associated with migration in the context of the US election and identifies ways to develop structural competencies for physicians and future research.
The Crucial Role of Patient Advocates in Pediatric Oncology Research—Insights From ACCELERATE
Authors: Scobie Nicole , de Rojas Teresa , Buenger Vickie
Published: July 2024

This Viewpoint explores the important role that patient advocates play in pediatric oncology as exemplified by ACCELERATE, a multiparty collaboration that centers advocate involvement in pediatric oncology research.
Being on top versus not dangling at the bottom: Popularity motivation and aggression in youth
Authors: Lansu Tessa A. M. , van den Berg Yvonne H. M.
Published: July 2024

Whereas research on aggression and status motivation in youth has predominantly looked at a promotion focus (striving for popularity), a prevention focus (wanting to avoid low popularity) could also be an important determinant of aggression, as youth who fear low popularity may use strategic aggression to secure their position. The aim of the current study was to develop reliable measures for both popularity motivations, and examine how both motivations are uniquely and jointly related to aggression. Participants were 1123 Dutch secondary school students (M age = 14.4 years, 48% girls), who completed a 3‐item measure of striving for high popularity based on existing questionnaires (Li & Wright, 2014; Ojanen et al., 2005), and a 3‐item measure of avoiding low popularity consisting of an adapted version of the high popularity items. Aggressive behavior was measured through peer nominations. Motivations were moderately correlated (r = .51), but did not always co‐occur within the same person, as 17% of the sample belonged to a cluster that scored low on striving for popularity, but moderately high on avoiding low popularity. When considered simultaneously, striving for high popularity was not related to any type of aggression, whereas avoiding affiliation with unpopular peers was related to strategic aggression. For physical and verbal aggression, gossiping, excluding and bullying, the association of avoiding low popularity with aggression was strongest when youth also strived for high popularity. Future work should take both popularity motivations into account to better understand, predict and intervene on youth's aggression toward peers.
Syncopated Chronologies: Architectural Conservation and Spectral Documentation
Authors: Stebbing Cameron
Published: July 2024

From its very inception, architectural preservation, and the specialist conservation practices that have evolved to support it, have occupied a shifting territory of constant quantification and continually evolving legislation. Architectural designer Cameron Stebbing evokes a menagerie of philosophical ideas used to illustrate and explore the notion that traditional recording techniques ignore hidden and veiled presences within our built environment.
Hard Spirits: Architectural Apparitions in Hayao Miyazaki's Spirited Away
Authors: Chapman Michael
Published: July 2024

Film has a long history of spectral association, from the possibilities of projection, the dancing image that hangs in the air, to the translucence of the media itself. Taking inspiration from a Japanese animation, Michael Chapman, Professor and Chair of Architecture and Industrial Design at Western Sydney University, has created a series of works that seek to fill in the haunted blanks and uncanny parallaxes that exist between the space we view and perceive in the filmic sequence and an ‘objective’ reality of that architecture. He uses some of the compositional protocols of the traditional scroll and machinery to produce his proposal – a parallel world that haunts the absences and holes within the original.
Ensemble Feature Selection for Clustering Damage Modes in Carbon Fiber‐Reinforced Polymer Sandwich Composites Using Acoustic Emission
Authors: Gulsen Abdulkadir , Kolukisa Burak , Caliskan Umut , Bakir‐Gungor Burcu , Gungor Vehbi Cagri
Published: July 2024

Acoustic emission (AE) serves as a noninvasive technique for real‐time structural health monitoring, capturing the stress waves produced by the formation and growth of cracks within a material. This study presents a novel ensemble feature selection methodology to rank features highly relevant with damage modes in AE signals gathered from edgewise compression tests on honeycomb‐core carbon fiber‐reinforced polymer. Two distinct features, amplitude and peak frequency, are selected for labeling the AE signals. An ensemble‐supervised feature selection method ranks feature importance according to these labels. Using the ranking list, unsupervised clustering models are then applied to identify damage modes. The comparative results reveal a robust correlation between the damage modes and the features of counts and energy when amplitude is selected. Similarly, when peak frequency is chosen, a significant association is observed between the damage modes and the features of partial powers 1 and 2. These findings demonstrate that, in addition to the commonly used features, other features, such as partial powers, exhibit a correlation with damage modes.
Influence of Additional Intermediate Thick Al Layers on the Reaction Propagation and Heat Flow of Al/Ni Reactive Multilayers
Authors: Jaekel Konrad , Jiménez Juan Jesús , Riegler Sascha Sebastian , Matthes Sebastian , Glaser Marcus , Bergmann Jean Pierre , Schaaf Peter , Gallino Isabella , Morales Francisco Miguel , Müller Jens , Bartsch Heike
Published: July 2024

This study investigates the effects of sputtering and electron beam evaporation (e‐beam) on the microstructure and reactive properties of Al/Ni reactive multilayers (RMLs). The intermixing zone, a critical factor influencing reaction kinetics, is characterized using high‐resolution transmission electron microscopy and found to be consistently 3 nm for both fabrication methods. Differential scanning calorimetry reveals that e‐beam samples, with thicker Al layers, exhibit slightly higher total molar enthalpy and maintain high reaction temperatures despite reduced reaction velocities in comparison to sputtered samples. X‐ray diffraction confirms the formation of both Al3Ni2 and AlNi phases in the e‐beam samples. These findings indicate that while thicker bilayer structures reduce reaction velocity, they keep thermal output and mitigate the impact of intermixing zones, leading to similar total molar enthalpy. This analysis underscores the significance of deposition technique and bilayer thickness in optimizing the performance of Al/Ni RML, offering the possibility to establish different phase formations in thicker RML. It advances the control over the reactive properties of RMLs in their applications, for example, reactive bonding.
Integration of Heterogeneous Interfaces and Multi‐Dimensional Encapsulation Structure in Fe2N@CNTs Enabling Highly Efficient Thermal Management and Microwave Absorption
Authors: Wang Jian , Miao Zeqing , Gao Kesheng , Li Zhiqiang , Zhang Xiaoning , Yang Chao , Iqbal Safdar , Xiang Gaoming , Cui Anguo , Liu Linhua , Sun Changlong , Wu Hongjing , Yang Jia‐Yue
Published: July 2024

The opposing effects of interface effect on phonon heat conduction and microwave absorption hinder the integration of thermal conduction with microwave absorption. Reconciling this contradiction by rationally optimizing the material structure remains a challenge. Herein, Fe2N@CNTs with heterogeneous interfaces and multi‐dimensional encapsulated structures are fabricated through in situ chemical vapor deposition (CVD) to realize excellent thermal conductivity and microwave absorption. When the mass fraction of active material is 40 wt.%, the thermal conductivity (λ//) of Fe2N@CNTs composite films is 6.69 W m−1 K−1. The minimum reflection loss (RLmin) is up to −54.55 dB at a thickness of 3.43 mm, and the effective absorption bandwidth (EAB) is 5.52 GHz at 1.82 mm. The well‐designed Fe2N@CNTs is an ideal model for gaining insight into electron transportation and phonon multi‐dimensional heat transport. Heterogeneous interface improves the dielectric loss and facilitates microwave and phonon absorption and conversion. The multi‐dimensional encapsulation structure increases the electron transport path and phonon heat transport paths making axial and radial co‐transfer possible. The multi‐dimensional encapsulation structure demonstrates extremely high microwave absorption and thermal management capabilities, which open up new possibilities for multifunctional applications in host materials with internal hollows.
Toward Full‐Color Vision Restoration: Conjugated Polymers as Key Functional Materials in Artificial Retinal Prosthetics
Authors: Askew Leslie , Sweeney Aimee , Cox David , Shkunov Maxim
Published: July 2024

For the prosthetic retina, a device replacing dysfunctional cones and rods, with the ability to mimic the spectral response properties of these photoreceptors and provide electrical stimulation signals to activate residual visual pathways, can relay sufficient data to the brain for interpretation as color vision. Organic semiconductors including conjugated polymers with four different bandgaps providing wavelength‐specific electrical responses are ideal candidates for potential full‐color vision restoration. Here, conjugated polymer photocapacitor devices immersed in electrolyte are demonstrated to elicit a photovoltage measured by a Ag/AgCl electrode 100 microns from the device of ≈−40 mV for 15–39 µW mm−2of incident light power density at three wavelengths: 405 nm for blue photoreceptor candidate material, 534 nm for green, 634 nm for red. Photoresponse is substantially improved by introducing polymer donor/acceptor molecules bulk heterojunctions. Devices with bulk heterojunction configurations achieved at least −70 mV for green candidates with the highest at −200 mV for red cone candidates. These findings highlight the potential for organic materials to bridge the gap toward natural vision restoration for retinal dystrophic conditions such as age‐related macular degeneration, Stargardt disease, or retinitis pigmentosa and contribute to the ongoing advancements in visual prosthetic devices.
Copper‐Cysteine Nanostructures for Synergetic Photothermal Therapy and Chemodynamic Therapy of Bacterial Skin Abscesses
Authors: Bagheri Hadi , Bochani Shayesteh , Seyedhamzeh Mohammad , Shokri Zahra , Kalantari‐Hesari Ali , Turner Raymond J. , Kharaziha Mahshid , Esmaeilzadeh Kimia , Golami Mehdi , Zeighami Habib , Maleki Aziz
Published: July 2024

Skin lesions, including skin bacterial abscesses, have become one of the most important health challenges and usually need systemic high‐dose antibiotics. Therefore, it is of particular importance to develop novel approaches for treating this ever‐growing challenge to human health. To address this challenge, herein a copper nanostructure is developed giving combined photothermal and chemodynamic therapies for focal infection treatment. The Cu‐based nanostructures with intrinsic catalytic properties are prepared by D‐L or L cysteine (Cys) as ligand and copper ions. It is shown that the multifunctional copper‐Cys (Cu‐Cys) nanostructures can produce reactive oxygen species (ROS) and they exhibit near infrared (NIR)‐enhanced catalytic activities to improve ROS production for highly efficient eradication of bacteria. Moreover, the results proved O2 evolution property of the Cu‐Cys nanoparticles (NPs). The nanostructures show shape‐dependent antibacterial activity where DL‐Cu‐Cys NPs show higher bactericidal performance than L‐Cu‐Cys NPs. In vitro results demonstrate that 2.5 and 1.25 µg mL−1 of DL‐Cu‐Cys NPs is enough to achieve rapid killing of Escherichia coli (E. coli) or Staphylococcus aureus (S. aureus) respectively under 808 nm light irradiation in 10 min. This work introduces a unique photoactive nanoagent to efficiently treat subcutaneous abscess by combining NIR light‐triggered photothermal effect and catalytic generation of ROS without using any antibiotic.
All‐in‐One, Wireless, Multi‐Sensor Integrated Athlete Health Monitor for Real‐Time Continuous Detection of Dehydration and Physiological Stress
Authors: Kim Ka Ram , Kang Tae Woog , Kim Hodam , Lee Yoon Jae , Lee Sung Hoon , Yi Hoon , Kim Hyeon Seok , Kim Hojoong , Min Jihee , Ready Jud , Millard‐Stafford Melinda , Yeo Woon‐Hong
Published: July 2024

Athletes are at high risk of dehydration, fatigue, and cardiac disorders due to extreme performance in often harsh environments. Despite advancements in sports training protocols, there is an urgent need for a non‐invasive system capable of comprehensive health monitoring. Although a few existing wearables measure athlete's performance, they are limited by a single function, rigidity, bulkiness, and required straps and adhesives. Here, an all‐in‐one, multi‐sensor integrated wearable system utilizing a set of nanomembrane soft sensors and electronics, enabling wireless, real‐time, continuous monitoring of saliva osmolality, skin temperature, and heart functions is introduced. This system, using a soft patch and a sensor‐integrated mouthguard, provides comprehensive monitoring of an athlete's hydration and physiological stress levels. A validation study in detecting real‐time physiological levels shows the device's performance in capturing moments (400–500 s) of synchronized acute elevation in dehydration (350%) and physiological strain (175%) during field training sessions. Demonstration with a few human subjects highlights the system's capability to detect early signs of health abnormality, thus improving the healthcare of sports athletes.
Granulosa Cell‐Layer Stiffening Prevents Escape of Mural Granulosa Cells from the Post‐Ovulatory Follicle
Authors: Wang Xiaodong , Liao Jianning , Shi Hongru , Zhao Yongheng , Ke Wenkai , Wu Hao , Liu Guoshi , Li Xiang , He Changjiu
Published: July 2024

Ovulation is vital for successful reproduction. Following ovulation, cumulus cells and oocyte are released, while mural granulosa cells (mGCs) remain sequestered within the post‐ovulatory follicle to form the corpus luteum. However, the mechanism underlying the confinement of mGCs has been a longstanding mystery. Here, in vitro and in vivo evidence is provided demonstrating that the stiffening of mGC‐layer serves as an evolutionarily conserved mechanism that prevents mGCs from escaping the post‐ovulatory follicles. The results from spatial transcriptome analysis and experiments reveal that focal adhesion assembly, triggered by the LH (hCG)‐cAMP‐PKA‐CREB signaling cascade, is necessary for mGC‐layer stiffening. Disrupting focal adhesion assembly through RNA interference results in stiffening failure, mGC escape, and the subsequent development of an abnormal corpus luteum characterized by decreased cell density or cavities. These findings introduce a novel concept of “mGC‐layer stiffening”, shedding light on the mechanism that prevents mGC escape from the post‐ovulatory follicle.
pH Sensitive Dual Cross‐Linked Anionic and Amphoteric Interpenetrating Network Hydrogels for Adsorptive Removal of Anionic and Cationic Dyes
Authors: Ahmed Md. Sabbir , Maniruzzaman Md. , Al‐Mamun Md. Rubel , Kanok Kibreya Kabir , Rahman Badal Md. Mizanur , Aziz Md. Abdul , Mazumder Mohammad A. Jafar , Ahamed Parbhej
Published: July 2024

The contamination of water by organic dye compounds are worldwide environmental problem due to their highly toxic nature. To address this environmental issue, a simple technique with highly efficient dye removal was developed to prepare pH‐ sensitive dual‐crosslinked anionic and amphoteric interpenetrating network (IPN) hydrogels based on Na‐carboxymethyl cellulose (Na‐CMC) using jute stick‐based cellulose. Crosslinked Na‐CMC and crosslinked κ‐carrageenan (KC) were interlaced by H‐bonding in anionic IPN hydrogel (An‐gel), but crosslinked Na‐CMC and crosslinked Chitosan (CS) were interlaced by electrostatic interaction in amphoteric IPN hydrogel (Am‐gel). In various operating conditions (pH, temperature, etc.) An‐gel displayed a higher number of swelling ratios of about 2560% at pH 7.2 and Am‐gel of about 1874% at pH 5.5. Based on the point of zero charge, An‐gel achieved the maximum removal efficiency of 81.62 % for methylene blue (MB) at pH 7.2, whereas Am‐gel achieved 85.38% removal efficiency for eosin yellow (EY) at pH 5.5. The adsorption kinetics of IPN hydrogels followed a pseudo‐second order model and best fitted by Langmuir isotherm model. The removal efficiency of MB and EY decreased slightly with increasing temperature. The values of ΔH°, ΔG°, and ΔS° indicated an exothermic, spontaneous, and disordered adsorption process.
Ethics and applications of isotope analysis in archaeology
Authors: Stantis Chris , Schaefer Benjamin J. , Correia Maria Ana , Alaica Aleksa K. , Huffer Damien , Plomp Esther , Di Giusto Marina , Chidimuro Blessing , Rose Alice K. , Nayak Ayushi , Kendall Ellen J.
Published: July 2024

This synthesis explores specific ethical questions that commonly arise in isotopic analysis. For more than four decades, isotope analysis has been employed in archeological studies to explore past human and animal dietary habits, mobility patterns, and the environment in which a human or animal inhabited during life. These analyses require consideration of ethical issues. While theoretical concepts are discussed, we focus on practical aspects: working with descendant communities and other rights holders, choosing methods, creating and sharing data, and working mindfully within academia. These layers of respect and care should surround our science. This paper is relevant for specialists in isotope analysis as well as those incorporating these methods into larger projects. By covering the whole of the research process, from design to output management, we appeal broadly to archaeology and provide actionable solutions that build on the discussions in the general field.
Plasma and CSF biomarkers of aging and cognitive decline in Caribbean vervets
Authors: Varma Curran , Luo Eva , Bostrom Gustaf , Bathini Praveen , Berdnik Daniela , Wyss‐Coray Tony , Zhao Tingting , Dong Xianjun , Ervin Frank R. , Beierschmitt Amy , Palmour Roberta M. , Lemere Cynthia A.
Published: July 2024

INTRODUCTION

Vervets are non‐human primates that share high genetic homology with humans and develop amyloid beta (Aβ) pathology with aging. We expand current knowledge by examining Aβ pathology, aging, cognition, and biomarker proteomics.

METHODS

Amyloid immunoreactivity in the frontal cortex and temporal cortex/hippocampal regions from archived vervet brain samples ranging from young adulthood to old age was quantified. We also obtained cognitive scores, plasma samples, and cerebrospinal fluid (CSF) samples in additional animals. Plasma and CSF proteins were quantified with platforms utilizing human antibodies.

RESULTS

We found age‐related increases in Aβ deposition in both brain regions. Bioinformatic analyses assessed associations between biomarkers and age, sex, cognition, and CSF Aβ levels, revealing changes in proteins related to immune‐related inflammation, metabolism, and cellular processes.

DISCUSSION

Vervets are an effective model of aging and early‐stage Alzheimer's disease, and we provide translational biomarker data that both align with previous results in humans and provide a basis for future investigations.

Highlights

We found changes in immune and metabolic plasma biomarkers associated with age and cognition.

Cerebrospinal fluid (CSF) biomarkers revealed changes in cell signaling indicative of adaptative processes.

TNFRSF19 (TROY) and Artemin co‐localize with Alzheimer's disease pathology.

Vervets are a relevant model for translational studies of early‐stage Alzheimer's disease.
Effect of early menopause on cognition and brain morphology in an Urban Indian Cohort
Authors: Mensegere Abhishek , Singh Sadhana , Stezin Albert , Sundarakumar Jonas S. , Issac Thomas Gregor
Published: July 2024

BACKGROUND

Evidence for the effect of early menopause on cognition among older women is not consistent and is scant among the Indian population.

METHODS

We aimed to examine the effect of early menopause (≤45 years) on cognitive performance and brain morphology among older dementia‐free females of the TLSA cohort using a multiple linear regression analysis.

RESULTS

In a sample of 528 women, 144 (27%) had early menopause. The linear regression analysis showed that women with early menopause performed poorly in cognition and had lesser total gray matter volume [β = −11973.94, p = 0.033], left middle frontal [β = −353.14, p = 0.033], and left superior frontal [β = −460.97, p < 0.026] volume.

CONCLUSION

Dementia‐free women with early menopause had poorer cognition, lower total gray matter, and frontal lobe. More research is needed to explore the link between earlier menopause and cognitive decline and develop ways to address it.

Highlights

Evidence on the effect of early menopause on brain morphology is inconsistent and scant in low and middle‐income countries, such as India.

In a cohort of dementia‐free individuals in urban Bangalore, we observed that participants with early menopause had significantly lower cognitive performance and lower total gray matter and frontal lobe volume.

We recommend increasing awareness of this fact among the medical community and the general public. There is an urgent need to explore the underlying biological mechanism and to discover effective interventions to mitigate the effect.
Synthesis of a Metalla[2]catenane, Metallarectangles and Polynuclear Assemblies from Di(N‐Heterocyclic Carbene) Ligands
Authors: Chang Jin‐Ping , Zhang Ya‐Wen , Sun Li‐Ying , Zhang Le , Hahn F. Ekkehardt , Han Ying‐Feng
Published: July 2024

The 2,7‐fluorenone‐linked bis(6‐imidazo[1,5‐a]pyridinium) salt H2‐1(PF6)2 reacts with Ag2O in CH3CN to yield the [2]catenane [Ag4(1)4](PF6)4. The [2]catenane rearranges in DMF to yield two metallamacrocycles [Ag2(1)2](PF6)2. 2,7‐Fluorenone‐bridged bis‐(imidazolium) salts H2‐L(PF6)2 (L=2 a, 2 b) react with Ag2O in CH3CN to yield metallamacrocycles [Ag2(L)2](PF6)2 with interplanar distances between the fluorenone rings too small for [2]catenane formation. Intra‐ and intermolecular π⋅⋅⋅π interactions between the fluorenone groups were observed by X‐ray crystallography. The strongly kinked 2,7‐fluorenone bridged bis(5‐imidazo[1,5‐a]pyridinium) salt H2‐4(PF6)2 reacts with Ag2O to yield [Ag2(4)(CN)](PF6), while the tetranuclear assembly [Ag4(4)2(CO3)](PF6)2 was obtained in the presence of K2CO3.
Experimental and Theoretical Elucidation of the Luminescence Quenching Mechanism in Highly Efficient Hg2+ and Sulfadiazine Sensing by Ln‐MOF
Authors: Yu Xiaolin , Pavlov Dmitry I. , Ryadun Alexey A. , Kovalenko Konstantin A. , Guselnikova Tatiana Y. , Benassi Enrico , Potapov Andrei S. , Fedin Vladimir P.
Published: July 2024

Heavy metal ions and antibiotic contamination have become a major environmental concern worldwide. The development of efficient recognition strategies of these pollutants at ultra‐low concentrations in aqueous solutions as well as the elucidation of the intrinsic sensing mechanism are challenging tasks. In this work, unique luminescent Ln‐MOF materials (NIIC‐3‐Ln) were assembled by rational ligand design. Among them, NIIC‐3‐Tb demonstrated highly selective luminescence quenching response toward Hg2+ and sulfadiazine (SDI) at subnanomolar concentrations in less than 7 s. In addition, a Hg2+ sensing mechanism through chelation was proposed on the basis of single‐crystal X‐ray diffraction analysis and Hg2+ adsorption study. The interaction mechanism of NIIC‐3‐Tb with SDI was revealed using a newly developed approach involving a (TD‐)DFT based quantification of the charge transfer of a MOF‐analyte supramolecular complex model in the ground and excited states. Effect of ultrasonic treatment on the surface morphology important for MOF sensing performance was revealed by gas adsorption experiments. The presented results indicate that NIIC‐3‐Ln is not only an advanced sensing material for the efficient detection of Hg2+ and SDI at ultra‐low concentrations, but also opens up a new approach to study the sensing mechanism at the molecular level at ultra‐low concentrations.
Large‐Area Layered Membranes with Precisely Controlled Nano‐Confined Channels
Authors: Zhou Can , Zhao Chuangqi , Nie Zhidong , Zhou Tianxu , Kong Shengwen , Sun Yingzhi , Qian Cheng , Zhao Tianyi , Liu Mingjie
Published: July 2024

Two‐dimensional (2D) nanosheets‐based membranes, which have controlled 2D nano‐confined channels, are highly desirable for molecular/ionic sieving and confined reactions. However, it is still difficult to develop an efficient method to prepare large‐area membranes with high stability, high orientation, and accurately adjustable interlayer spacing. Here, we present a strategy to produce metal ion cross‐linked membranes with precisely controlled 2D nano‐confined channels and high stability in different solutions using superspreading shear‐flow‐induced assembly strategy. For example, membranes based on graphene oxide (GO) exhibit interlayer spacing ranging from 8.0±0.1 Å to 10.3±0.2 Å, with a precision of down to 1 Å. At the same time, the value of the orientation order parameter (f) of GO membranes is up to 0.95 and GO membranes exhibit superb stability in different solutions. The strategy we present, which can be generalized to the preparation of 2D nano‐confined channels based on a variety of 2D materials, will expand the application scope and provide better performances of membranes.
Mechanically Interlocked Polyrotaxane Networks with Collective Motions of Multiple Main‐Chain Mechanical Bonds
Authors: Yang Li , Wang Yuanhao , Liu Guoquan , Zhao Jun , Cheng Lin , Zhang Zhaoming , Bai Ruixue , Liu Yuhang , Yang Mengling , Yu Wei , Yan Xuzhou
Published: July 2024

Type I main‐chain polyrotaxanes (PRs) with multiple wheels threaded onto the axle are widely employed to design slide‐ring materials. However, Type II main‐chain PRs with axles threading into the macrocycles on the polymer backbones have rarely been studied, although they feature special topological structures and dynamic characteristics. Herein, we report the design and preparation of Type II main‐chain PR‐based mechanically interlocked networks (PRMINs), based on which the relationship between microscopic motion of mechanical bonds on the PRs and macroscopic mechanical performance of materials has been revealed. The representative PRMIN‐2 exhibits a robust feature in tensile tests with high stretchability (1680 %) and toughness (47.5 MJ/m3). Moreover, it also has good puncture performance with puncture energy of 22.0 mJ. Detailed rheological measurements and coarse‐grained molecular dynamics (CGMD) simulation reveal that the embedded multiple [2]rotaxane mechanical bonds on the PR backbones of PRMINs could undergo a synergistic long‐range sliding motion under external force, with the introduction of collective dangling chains into the network. As a result, the synchronized motions of coherent PR chains can be readily activated to accommodate network deformation and efficiently dissipate energy, thereby leading to enhanced mechanical performances of PRMINs.
Design and development of a novel Co‐MOF catalyst for sustainable pyrimidine synthesis via the Biginelli reaction
Authors: Aziz Dara Muhammed
Published: July 2024

In this study, we introduce a novel porous metal–organic framework named Co2(bbda)2(DMF)2·5H2O, or MOF‐UoR‐1, synthesized via hydrothermal techniques employing a unique Schiff base ligand. The framework underwent comprehensive characterization, confirming its microporous nature through gas‐sorption measurements. MOF‐UoR‐1 demonstrated remarkable efficacy as a catalyst for the one‐step synthesis of pyrimidine analogs. Structural validation of the synthesized pyrimidines was accomplished via 1H‐nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) analyses. Through systematic experimentation, the optimal catalyst dosage (40 mg) was determined, showcasing its effectiveness across various aldehydes, 1,3‐carbonyl compounds, and urea substrates. Noteworthy is the broad applicability of this environmentally friendly protocol, which offers advantages such as high yields (96%), rapid reaction times (90 min), straightforward product isolation, and product purity without necessitating column chromatography. Furthermore, the catalytic integrity of the framework remained intact, enabling its reuse without compromising performance. This research presents a promising approach for the synthesis of pyrimidine derivatives, with significant implications for sustainable and efficient chemical synthesis methodologies.
Facile preparation of hydrophobic PPy@Si/PU foam for efficient oil adsorption by photothermal effects
Authors: Yang Heng , Zang Xiaoling , Zong Jiale , Li Shuhong , Wang Xiangdong
Published: July 2024

Exploring new oil absorbing materials with high adsorption rate remains a global challenge. Hydrophobic porous materials with photothermal conversion property are an attractive option to address oil spills. Herein, the organosilicon (hydroxyl‐terminal polydimethylsiloxane) was used to modify polyurethane (PU) foam to endow it good hydrophobic and compressible properties. Meanwhile, polypyrrole (PPy) with photothermal effect was introduced to endow PU foam with excellent photothermal properties. The PPy@Si/PU composite foams can reach 77.1 and 49.6°C under the laser and simulated sunlight (with the intensity of 1 kW/m2), respectively. The raised temperature of PPy@Si/PU foam makes it adaptable to reduce the crude oil's viscosity and improve its oil adsorption rate. The maximum oil adsorption rate of PPy@Si/PU foam can obtain 175% and 145% under the laser and simulated sunlight, respectively. Therefore, the PPy@Si/PU foam possesses effective photic‐driving oil adsorption capacity, which has a good prospect to be an efficient oil spills treatment material.
Effect of dialdehyde starch on cassava starch/poly(vinyl alcohol) blends fabricated by melt mixing method with glycerol plasticized
Authors: Wang Yuhan , Ma Huihuang , Ying Shuni , Gao Jianfei , Zhou Xiaodong
Published: July 2024

Starch is considered an ideal alternative to petroleum‐based plastics. However, the application of thermoplastic starch (TPS), which produced from cassava starch plasticized with glycerol, is limited by its hydrophilic, poor mechanical properties, and inadequate processability. In this study, dialdehyde starch (DAS) is used as crosslinker to modify TPS/poly(vinyl alcohol) (PVA), and DAS crosslinked cassava starch/PVA blends are fabricated by melt mixing method. Studies on the molecular structure of DAS crosslinked cassava starch/PVA blend indicate that the addition of DAS enhances the intermolecular interactions between cassava starch and PVA, resulting in the formation of a dense internal structure. The plasticizing torque and equilibrium torque of crosslinked cassava starch/PVA blends are increased and the tensile strength reaches 3.60 MPa, an improvement of 186% compared with TPS. Additionally, the water contact angle increases from 87.8° to 119.6° after modification. Compared with other crosslinkers, DAS has obvious advantages, making the DAS crosslinked cassava starch/PVA blend a biodegradable material with excellent properties and promising application prospects.