bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the tree component and its contribution to ecosystem services in the city of Turrialba, Costa Rica
Authors: Benegas Negri Laura Andrea , Rojas Adolfo , Iraheta Alberto , Cardenas Jeanette
Published: August 2021

El análisis y gestión de ecosistemas urbanos es crucial para construir resiliencia en ciudades y avanzar hacia su sostenibilidad. Uno de los componentes fundamentales de estos ecosistemas son los bosques urbanos. Para determinar los aportes y efectos de los árboles en ciudades se analizó una muestra del casco urbano de la ciudad de Turrialba en la zona central de Costa Rica, a través del modelo iTree Eco, que permite valorar los principales servicios ecosistémicos que proveen los árboles en las ciudades. Aunque en este estudio no fue posible cuantificar todos los servicios ecosistémicos que incluye el modelo, se logró analizar los elementos y contexto estructural de la zona de estudio, y el valor de los servicios ecosistémicos de secuestro y almacenamiento de carbono, así como el valor estructural de los árboles. Anualmente, en la zona estudiada, con 18 especies de árboles identificadas, se generan más de 60 000 USD solamente derivados de estos tres servicios ecosistémicos. De las especies identificadas la Zygia longifolia, se destacó por mayor abundancia y área foliar, Erythrina poeppigiana en altura y mayor almacenamiento de carbono, Mangifera indica en mayor secuestro de carbono y producción de oxígeno y Veitchia sp con el mayor valor estructural. Asimismo, se evidenció que, mantener las franjas ribereñas del río Turrialba y sus tributarios, en su paso por el casco urbano de esta ciudad, aporta la mayor cantidad de servicios ecosistémicos derivados de los árboles que todavía alberga y donde existe aún un importante potencial de incluir nuevas plantaciones.
Characterization of vegetation structural changes using multi-temporal LiDAR and its relationship with severity in Calcena wildfire
Authors: Domingo Dario , Lamelas Maria Teresa , García Maria Begoña
Published: August 2021

La caracterización de los cambios estructurales y presencia de huecos tras el fuego puede proporcionar información muy relevante para comprender los efectos ecológicos de los incendios en ecosistemas mediterráneos. En el presente estudio se caracterizan estas variables tras el incendio de Calcena en masas forestales de pinar y encinar, y su relación con la severidad del mismo. Dicho incendio calcinó 4.573 hectáreas en 2012 afectando de forma parcial al Parque Natural de la Dehesa del Moncayo localizado en Aragón (España). Para ello se hace uso de información multi-temporal Light Detection and Ranging (LiDAR) de las coberturas de 2011 y 2016 del Plan Nacional de Ortofotografía Aérea (PNOA), así como imágenes Landsat 7 para estimar la severidad del incendio mediante el índice differenced Normalized Burn Ratio (dNBR). Se evalúan los cambios estructurales producidos utilizando métricas LiDAR pre y post-incendio, así como la distribución de los huecos en el dosel forestal, su tamaño, número y frecuencia, y se analizan sus correlaciones con la severidad del incendio. La severidad fue predominantemente baja (42.32 %) o mediabaja (30.38 %), y produjo una disminución de la altura, de la densidad del dosel forestal y de la diversidad estructural. El tamaño de los huecos se incrementó tras el incendio, reduciéndose el número de huecos pequeños e incrementándose aquellos de tamaño intermedio en torno a 0.2 ha. Los cambios en las métricas LiDAR relacionadas con la altura, variabilidad de la altura en el perfil vertical, y densidad del dosel forestal presentaron las mayores correlaciones, indicando que son las que sufren mayores modificaciones. Los resultados muestran el interés de utilizar los datos LiDAR para caracterizar cambios estructurales y apoyar decisiones en la gestión silvícola.
Productivity of natural grasslands in different geomorphological units of the Sierras Pampeanas of Argentina
Authors: Scaglia Juan Antonio , Flores Daniel German , Martinelli Mariana
Published: August 2021

En las zonas semiáridas de Argentina existe una variación de los pastizales naturales asociados a diferentes unidades de paisaje. Los modelos digitales de terreno son herramientas que han permitido el estudio entre las variables físicas del ambiente y la dinámica y patrones de los ecosistemas semiáridos. Por tal motivo el objetivo de nuestro trabajo fue determinar si existen diferencias en la productividad y composición botánica del pastizal natural en las diferentes unidades geomorfológicas identificadas. La cuantificación de la cantidad de biomasa se realizó por el método del doble muestreo y composición botánica mediante el método de asignación de rangos. Para la determinación de las propiedades geomorfológicas se utilizó un modelo digital del terreno en donde se consideró: pendiente, orientación de laderas, altitud, índice de rugosidad del terreno e índice de humedad topográfica. Se encontraron diferencias en cuanto a la productividad y composición botánica del pastizal natural, influenciado de forma directa e indirecta por las características geomorfológicas como la altura, pendiente y rugosidad. La historia de sobrepastoreo a lo largo de décadas en el piedemonte del área de estudio ha contribuido a la degradación del pastizal mediante la pérdida de especies perennes palatables y la instalación de especies anuales y de baja calidad. Es necesario agregar estaciones de muestreo con escalas temporales más amplias teniendo en cuenta la presión de pastoreo
Dynamics of forest loss in the southeast of the Peruvian Amazon: a case study in Madre de Dios
Authors: Alarcon Aguirre Gabriel , Canahuire Robles Rembrandt R. , Guevara Duarez Felipe M. , Rodríguez Achata Liset , Gallegos Chacón Luis E. , Garate-Quispe Jorge
Published: August 2021

: La Amazonia occidental, puntualmente la región de Madre de Dios, es conocida como la capital de la biodiversidad del Perú y es reconocida mundialmente como uno de los lugares con mayor biodiversidad de la Tierra. Sin embargo, se ha visto amenazada por un grave problema de pérdida de bosques. Las principales amenazas ambientales se deben a una mala gestión del territorio que ocasionan la concentración de tierras, expansión agrícola, ganadería, minería de oro y la explotación económica descontrolada. El presente estudio analiza la dinámica de pérdida de bosques y los cambios de uso de suelo entre 1999-2018. Para la cuantificación de la pérdida de bosque se utilizaron técnicas de sensoramiento remoto, imágenes Landsat 5 Thematic Mapper (TM) y 8 Operational Land Imagery (OLI). Las imágenes fueron procesadas utilizando una clasificación supervisada denominada Neural Net. La metodología incluye procedimientos de validación utilizando puntos de verificación de campo e imágenes de teledetección de media y alta resolución de diferentes sensores (SPOT-5, PlanetScope, WorldView y Drone). Los resultados mostraron una pérdida de bosque durante 1999-2018 de 1698.63 km2 , con una tasa anual de -0.21% y una pérdida promedio de 59.28 km2 /año. Para los cambios de bosques a otros usos de la tierra, encontramos la conversión 841.41 km2 durante 2014-2018. Nuestros resultados indican que la agricultura es la mayor responsable del avance de la deforestación (72.90%), mientras que la minería de oro tiene una mayor incidencia en los sectores focalizados.
Occurrence of microplastics in the digestive tract of fishes from Reserva Natural de Usos Múltiples Monterrico, Guatemala
Authors: Mazariegos Ortíz Carlos Humberto , Xajil-Sabán Marvin , Blanda Elisa , Delvalle-Borrero Denise
Published: August 2021

El objetivo de esta investigación fue evaluar la ingesta de microplásticos (MPS) en peces de la Reserva Natural de Usos Múltiples Monterrico (RNUMM), y su relación con el hábito alimenticio y hábitat. Aunque los MPS son contaminantes emergentes reportados en varias especies acuáticas, a la fecha este es el primer registro que aborda la presencia de MPS en peces de áreas protegidas de Guatemala. El tracto digestivo de 624 individuos de 16 especies de peces se analizaron usando digestión con hidróxido de potasio al 20% e identificación visual de los MPS en el estereomicroscopio. Se encontraron 644 MPS en el 47% de los individuos de 15 especies, con un rango de ingestión promedio entre 1 y 4 MPS. Las formas dominantes fueron las fibras (82%) seguidas por fragmentos (12%) y láminas (6%). Las mayores cantidades de MPS se registraron en las especies omnívoras y de hábitat bentopelágico. Se encontraron diferencias significativas en el número de MPS respecto al hábito alimenticio y al hábitat de las especies, y una correlación negativa entre el factor de condición y la cantidad de MPS para Gobionellus microdon. Nuestros resultados proveen la primera evidencia d ingesta de MPS en peces de la RNUMM. Es necesario generar información adicional para conocer la distribución espacio temporal de los MPS en distintos hábitats dentro del áre protegida y los riesgos para las especies de importancia pesquera.
Potential application of lactic acid bacteria in water treatment systems
Authors: Balboa Luna Cristian , Vergara Gonzalez Luis
Published: August 2021

Actualmente la potencial aplicación de bacterias acido lácticas (BAL) en los sistemas de tratamiento de agua se visualiza como una solución a la producción de agua potable y al tratamiento de aguas residuales, debido a la alta demanda por fuentes de abastecimiento y al aumento del vertimiento de aguas tratadas, debido al incremento de las actividades industriales y el crecimiento poblacional. Bajo este contexto y como respuesta a esta demanda se está recurriendo al tratamiento de fuentes naturales contaminadas, aumentando significativamente su costo. Por ello, el uso de este tipo de bacterias en el agua se muestra como una alternativa, al ser tecnologías de bajo costo que se incorporan al reciclaje de agua, biodegradables y que no generan derivados peligrosos producto del tratamiento. En las fuentes de captación naturales, existen comunidades bacterianas dentro de las cuales es posible encontrar poblaciones de BAL de vida libre, las cuales poseen un rol de protección del ambiente dulceacuícola, dada su versatilidad y propiedades probióticas. Se ha visto que poseen efectos en la remoción de metales pesados del agua, por mecanismos biológicos tales como biosorción y bioacumulación, disminuyendo su presencia en el medio circundante. En este artículo se presenta una revisión respecto al uso de BAL en la biorremediación de sistemas acuícolas, especialmente respecto de su contaminación por metales pesados, con el fin de ser utilizadas en los sistemas de tratamiento de agua del sur de Chile central, entregando a profesionales del ámbito sanitario, una alternativa para la producción de agua de buena calidad.
PREPARATION AND EVALUATION OF MEFENAMIC ACID AND DICYCLOMINE HYDROCHLORIDE AS ORAL DISINTEGRATING TABLET BY DIRECT COMPRESSION METHOD
Authors: M T Ranjitha , Somashekhar C N
Published: August 2021

A new dosage form, Oral disintegrating tablets (ODT’s) as a replacement to conventional oral dosage forms. ODT’s are dosage forms they disintegrate in mouth offering various advantages such as better mouth feel, dose accuracy, improved stability and convenient dosing as compared to oral liquids. So, there is need to designed oral disintegrating tablet to release the medicaments with an enhanced rate. Mefenamic acid is an anti- inflammatory drug while Dicyclomine HCl is anti-cholinergic drug. The combination of Mefenamic acid & Dicyclomine HCl controls pain very effectively, also relaxes bodily spasm which commonly arises during menstruation or intestinal colic spasm. This combination gives the quick onset of action and fast relief than conventional dosage form. For preparation of oral disintegrating tablet nine formulations were designed using Croscarmellose sodium and Crospovidone as superdisintegrants in varying concentration. All the formulations were prepared by direct compression method. Thus, all the formulations of Mefenamic acid and Dicyclomine HCl oral disintegrating tablets were investigated, in which F9 formulation was optimized. The % drug release of, Oral disintegrating tablet batch F9 has shown 96.98% of Mefenamic acid and 94.02 % of Dicyclomine HCl in 18 min, disintegration time in 40 sec and wetting time in 25sec.
EFFECT OF KSHEERBALA TAILA NASYA IN MIGRAINE WITH SPECIAL REFERENCE ARDHAVABHEDAK: A LITERARY REVIEW
Authors: Bachate Vitthal B. , Belge Raman S.
Published: August 2021

Migraine is a neurological disorder that is frequently characterized by intense and debilitating headaches. According to the records, Migraine tends to affect people aged 15 to 55 years and the extreme pain or headache can last for hours or even days. Migraine is the third most prevalant and 7thleading cause of disability worldwide. There is no direct reference of Migraine in Ayurveda, but signs and symptoms of migraine can be co-related with Shiroroga, one of which is Ardhavabhedak. In Ayurveda, Nasyakarma plays a very important role in the management of Urdhvajatrugat Vikara. Thus an attempt has been made to evaluate the probable efficacy of polyherbal formulation Ksheerbala Taila in Ardhavabhedak.
PHARMACEUTICO-ANALYTICAL PROFILE OF ARKA KSHARA THE FORMULATION OF UPAVISHA ARKA (CALOTROPIS PROCERA AIT. R. BR)
Authors: Boudhadas Chandekar Deepali , Venkatrao Pawade Uday , Vithalrao Nikam Ashwin , Pramodrao Anjankar Meghsham
Published: August 2021

Analytical study of Ayurvedic formulation is the need of present scientific era. Though the Ayurvedic drugs are time tested and have been used successfully in the management of various ailments, it is now necessary to prove their quality, efficacy and safety to the scientific world through various parameters. Agadtantra is a branch of Ayurveda dealing with classification, mode of action, clinical manifestations and treatment of various poisons. Arka (Calotropis procera) is included in Upavisha by Rasatarangini. Arka Kshara is an alkaline preparation of Upavisha Arka (Calotropis procera) described in treating many disorders. Till date no data is available regarding analytical profile of Arka Kshara. So, the present study is planned to prepare Arka Kshara and develop its analytical profile. These findings will be useful in establishing quality control standards and standardization of Arka Kshara in future.
ARKA LAVANA THE FORMULATION OF UPAVISHA ARKA (CALOTROPIS PROCERA AIT. R. BR.): AN ANALYTICAL PROFILE
Authors: Vasudeorao Chandankhede Aditi , Pramodrao Anjankar Meghsham , Vithalrao Nikam Ashwin , Venkatrao Pawade Uday
Published: August 2021

Lavana kalpana is one of the most commonly used dosage forms because of its easy administration and dosing. Arka lavana is a herbo mineral preparation containing Upavisha Arka (Calotropis procera) and Saindhava lavana. It is used in the management of Yakrit pleeha, Udara and Gulma roga. As it contains Upavisha, standardization becomes necessary to keep up its therapeutic efficacy. In this study an attempt has been made to find out the authenticity of the raw drugs, to prepare and analyse Arka lavana to set the preliminary standards for the same. Arka lavana was prepared as per the reference of Bhaishajya ratnavali. The analytical study was carried out in terms of organoleptic, physicochemical and TLC evaluation and results were noted. The pharmaceutical and analytical results can be used as reference standard for quality assurance and standardization of Arka lavana for further study.
Music streaming characteristics and emotional consumption as determinants of consumer satisfactions and intention to purchase
Authors: Hsu Chiehwen Ed , Raj Yeshwant S. , Sandy Bob
Published: August 2021

The present study analyzes consumers perceptions of music streaming and how such perceptions might influence customers brand loyalty and purchase intent. The competitive advantages of music streaming, widely known for its cost-saving measures, ease of use, and worldwide accessibility, are carefully reviewed herein. The S-O-R Theory commonly employed in psychology studies is applied in this study to explain the relationship between the product characteristics of streaming music (e.g., price, content quality, functionality, convenience, and design) and consumer behavior as seen by consumption emotions.  This relationship is viewed as either positive or negative in consumer satisfaction and purchase intention. The data were collected through an online web-based survey questionnaire.  One thousand seven (1007) subjects from Indonesia completed the survey. The Structured Equation Modeling (SEM) was used to examine the relationship among product attributes, consumer satisfaction, and purchase intention. Our study findings revealed a strong association between emotion and particular product characteristics, whereby a positive emotion exists across all product characteristics in music streaming services. The design variable is the most popular function of all music streaming services product attributes. Our findings suggest that either positive or negative emotions may predict the functionality constructions in comparison with previous research results. On the other hand, the findings of the present study suggest that only positive emotions can influence the satisfaction level of consumers and, in turn, affect the consumers purchasing intent
From a Literature Review to a Conceptual Framework for Customer-To-Customer Value Co-Creation
Authors: Pandey Sneha , Kumar Divesh
Published: August 2021

Albeit customer-to-customer interaction (CCI) is something inevitable in a socially dense interaction-rich service setup, there has not been any review in this area of literature. However, a considerable amount of extant research has highlighted the importance of inter-customer encounters during a service encounter. Customer-to-customer value co-creation during collective consumption is gaining relevance in the field of contemporary services marketing research. This review deals with searching articles through the Scopus database and systematically reviewing 115 articles related to customer-to-customer value co-creation and CCI. While highlighting their contribution to the services marketing literature and various theories, methodologies followed by the authors, it paves the way for developing the proposed conceptual framework for the process of customer-to-customer value co-creation. This way, the article adds up to the extant multi-approach research area revolving around customer-to-customer interactions/relationships, customer engagement, and value co-creation among the customers during a service encounter. The study recommends practitioners analyze and monitor the aspects proposed through a practical implication.
Emotional Intelligence and Academic Adjustment of Second-Year University Students in Akwa Ibom State, Nigeria
Authors: Uwem Ikpe, Idongesit , Ugochukwu Ezeonwumelu, Victor , Christopher Okoro, Cornelius , Nsikak-Abasi Udofia, , David Akpan, Imaobong.
Published: August 2021

The importance of emotional intelligence on academic outcomes cannot be overstated. Several studies have been conducted in the past to shed light on the associations that exist between EI and these outcomes. Making use of Goleman’s Emotional Intelligence model, the researchers investigated the relationship between the personal skills of EI and academic adjustment of second-year University students in Akwa Ibom State. The correlational design was adopted for the study. The population of the study consisted of all the second year university students from two universities in Akwa Ibom state. A sample of 500 students was selected for the study using the Taro Yamane Sampling formula. The subjects were drawn using simple random sampling technique. The instruments for data collection were adopted standardized “National Health Service Emotional Intelligence Questionnaire” (NHSEIQ) and “Academic Adjustment Scale” (AAS). The instruments were used to obtain information with regards to both the dependent and independent variables. Three research questions and hypotheses were formulated and tested at .05 significance level using the Pearson Product Moment Correlation analysis. The results indicated that there is a positive and significant relationship between emotional intelligence and academic adjustment. Based on the results of the data analysis, a conclusion was drawn that emotional intelligence is a prerequisite for academic adjustment of second-year university students.
Virtual Screening, Molecular Docking and Pharmacophore Modeling of Phytoconstituents of Flavones as Aldose Reductase Inhibitors
Authors: James Jainey P. , Fabin Asmath Maziyuna , Sasidharan Pradija , Kumar Pankaj
Published: August 2021

Flavones are an important class of naturally occurring heterocycles possessing various pharmacological activities. An in silico approach was carried out where 506 compounds containing flavone ring were utilised as ligand against the target aldose reductase enzyme. Aldose reductase is the rate-limiting enzyme in the polyol pathway, which indirectly causes diabetic complications like diabetic nephropathy and diabetic retinopathy. The flavone containing compounds retrieved from the PubChem were investigated by HTVS (high throughput virtual screening) followed by molecular docking using glide SP and XP docking module in Maestro of Schrodinger software. Among them, the best fifteen compounds were selected for further studies. The binding energy calculation was done using the Prime MM-GBSA module. PASS online prediction tools were used for predicting the antidiabetic activity of the compounds. Also, a pharmacophore model was generated for best interacted fifteen compounds by Phase, which can be used for evaluation of the characteristic features essential for this specific biological activity. The ADMET properties of the compounds were determined using the Qikprop module in the Schrodinger software.
Novel Antitubercular Derivatives of Mannich and Schiff Bases of p-Aminosalicylic Acid – Rational Design
Authors: Mennuru Nagendra Babu , Dugasani Swarnalatha , Suggala V. Satyanarayana
Published: August 2021

Aims: The aim of the current study is to utilize computational drug design resources to develop and identify promising structural analogs of p-aminosalicylic acid (PAS), to improvise antitubercular activity followed by their synthesis, characterization, and in-vitro biological activity determination.

Study Design: Design of the structural analogs of PAS by functional group modification at -COOH and -NH2 groups followed by in-silico prediction of biological activity, toxicity, drug-likeness filters, and molecular docking study to select promising analogs. Synthesis of selected analogs, structural characterization, and screening of biological activity of the same.

Methodology: Using the Prediction of Activity Spectrum of Substances (PASS Online) database, prediction of biological activity was performed for PAS and 22 designed structural analogs of PAS. All these analogs were screened for their drug-likeness properties using Lipinski’s rule of five. Later all these 22 analogs were predicted for their toxicities using OSIRIS Property Explorer. At this stage, out of 22 analogs, only 6 analogs were selected to go for molecular docking using AutoDock Tools and AutoDock Vina for the determination of their binding energies by comparing with PAS. The selected 6 analogs were synthesized using three-step syntheses. The synthesized analogs were screened for their antitubercular activity using the Microplate Alamar Blue Assay (MABA) method.

Results: Overall 22 structural analogs were designed and screened for their estimated activity (all analogs showed antitubercular activity as primary activity), drug-likeness (all analogs passed), and toxicities (only 10 analogs passed) using computational tools. Out of 22 analogs, 6 analogs were selected and performed molecular docking using AutoDock Vina. All 6 analogs showed better binding affinity than PAS. These 6 analogs (7a-f) were synthesized, characterized, and screened for their in-vitro antitubercular activity. Results showed that 5 analogs, 7b-7f, showed excellent antitubercular potency greater than PAS and equipotent activity to that of standard drugs. Analog 7a was found to be less potent than PAS.

Conclusion: Hence, the structural analogs of PAS, 7b-7f, were found to have better antitubercular activity than the lead compound, PAS, and equipotent to that of the standards, streptomycin, ciprofloxacin, and pyrazinamide.
Azurocidin is loaded into small extracellular vesicles via its N‐linked glycosylation and promotes intravasation of renal cell carcinoma cells
Authors: Naito Takuya , Jingushi Kentaro , Ueda Koji , Tsujikawa Kazutake
Published: August 2021

Azurocidin (AZU1) is an antimicrobial protein secreted by neutrophils that acts as a chemoattractant for monocytes and macrophages and a permeabilizer of vascular endothelial cells. We previously identified AZU1 to be specifically present in extracellular vesicles (EVs) obtained from renal cell carcinoma (RCC) tissues. Here, we examined the relationship between N‐linked glycosylation and AZU1 loading into small EVs (SEVs). Inhibition of N‐linked glycosylation by introducing mutations in three glycosylation sites inhibited AZU1 loading into SEVs. Furthermore, SEVs released from AZU1‐wild‐type cells increased the Ca2+ concentration in endothelial cells and the endothelial permeability, whereas SEVs released from AZU1‐mutant cells had no significant effect. Anti‐AZU1 antibodies diminished the effect of SEVs on endothelial cell sheets. Collectively, we found that N‐linked glycosylation of AZU1 directs its loading into SEVs, thereby enabling AZU1‐positive SEVs to function as potent permeabilizers of endothelial cells and leading to enhanced transendothelial migration of RCC cells.
Tartrate‐resistant acid phosphatase type 5/ACP5 promotes cell cycle entry of 3T3‐L1 preadipocytes by increasing IGF‐1/Akt signaling
Authors: Lång Pernilla , Patlaka Christina , Andersson Göran
Published: August 2021

Tartrate‐resistant acid phosphatase (TRAP, encoded by ACP5)‐overexpressing mice exhibit hyperplastic obesity. As the molecular mechanism remains elusive, the aims were to characterize the effect of TRAP on preadipocyte proliferation. We investigated cell cycle entry and signal transduction, that is, insulin‐like growth factor 1 (IGF‐1)/ insulin receptor substrate 1 (IRS‐1) and the Akt signaling pathways, in 3T3‐L1 preadipocytes treated with the TRAP 5a isoform. Results show that TRAP 5a increases S‐phase entry. TRAP 5a stimulation increases IGF‐1 mRNA and IRS‐1 activation, indicative of insulin‐like growth factor 1 receptor (IGF1R) activation. Furthermore, TRAP 5a stimulation resulted in Akt signaling pathway activation and subsequent increased nuclear translocation of β‐catenin. In conclusion, TRAP 5a increases proliferation of preadipocytes in a dose‐dependent fashion by promoting entry into S‐phase. Part of this effect is likely due to increased IGF‐1 signaling through the Akt signaling pathway.
Adaptive sliding mode observers for sector‐bounded nonlinear systems
Authors: Mehta Sagar , Vijayaraghavan Krishna
Published: August 2021

This article introduces a novel sliding mode observer design for sector bounded nonlinear systems. The proposed observer can simultaneously estimate both states and unknown parameters in the presence of disturbances and measurement noise. The observer is developed by using a time‐averaged Lyapunov (TAL) functional to analyze the effect of noise (Gaussian) and to adequately reduce its effect on the system. The TAL averages the Lyapunov analysis over a small finite time interval, allowing for intuitive analysis of noises and disturbances acting on the system. The TAL is shown to satisfy all the requirements of a Lyapunov candidate function. The article focuses on the observer design for sector bounded nonlinear systems since several nonlinearities can be modeled using a sector bound. An optimization approach is also developed to provide a tight bound on the effect of the uncertainty on the estimated parameters. The conditions for the existence of the observer are presented in the form of linear matrix inequality (LMI), which can be explicitly solved offline using commercial LMI solvers. Furthermore, the LMI design is also extended to a specific case of a dissipative nonlinear system. The observer design has also been extended to the case where the input disturbance is correlated with the sensor noise.
Self‐Healing Cs3Bi2Br3I6 Perovskite Wafers for X‐Ray Detection
Authors: Daum Manuel , Deumel Sarah , Sytnyk Mykhailo , Afify Hany A. , Hock Rainer , Eigen Andreas , Zhao Baolin , Halik Marus , These Albert , Matt Gebhard J. , Brabec Christoph J. , Tedde Sandro F. , Heiss Wolfgang
Published: August 2021

Self‐healing of defects imposed by external stimuli such as high energy radiation is a possibility to sustain the operational lifetime of electronic devices such as radiation detectors. Cs3Bi2Br3I6 polycrystalline wafers are introduced here as novel X‐ray detector material, which not only guarantees a high X‐ray stopping power due to its composition with elements with high atomic numbers, but also outperforms other Bi‐based semiconductors in respect to detector parameters such as detection limit, transient behavior, or dark current. The polycrystalline wafers represent a size scalable technology suitable for future integration in imager devices for medical applications. Most astonishingly, aging of these wafer‐based devices results in an overall improvement of the detector performance—dark currents are reduced, photocurrents are increased, and one of the most problematic properties of X‐ray detectors, the base line drift is reduced by orders of magnitude. These aging induced improvements indicate self‐healing effects which are shown to result from recrystallization. Optimized synthetic conditions also improve the as prepared X‐ray detectors; however, the aged device outperforms all others. Thus, self‐healing acts in Cs3Bi2Br3I6 as an optimization tool, which is certainly not restricted to this single compound, it is expected to be beneficial also for many further polycrystalline ionic semiconductors.
2D Metallic Transition‐Metal Dichalcogenides: Structures, Synthesis, Properties, and Applications
Authors: Zhao Bei , Shen Dingyi , Zhang Zucheng , Lu Ping , Hossain Mongur , Li Jia , Li Bo , Duan Xidong
Published: August 2021

2D materials and the associated heterostructures define an ideal material platform for investigating physical and chemical properties, and exhibiting new functional applications in (opto)electronic devices, electrocatalysis, and energy storage. 2D transition metal dichalcogenides (2D TMDs), as a member of the 2D materials family including 2D semiconducting TMDs (s‐TMDs) and 2D metallic/semimetallic TMDs (m‐TMDs) have attracted considerable attention in the scientific community. Over the past decade, the 2D s‐TMDs have been extensively researched and reviewed elsewhere. Because of their distinctive physical properties including intrinsic magnetism, charge‐density‐wave order and superconductivity, and potential applications, such as high‐performance electronic devices, catalysis, and as metal electrode contacts, 2D m‐TMDs have grabbed widespread attention in recent years. However, reviews demonstrating the m‐TMDs systematically and comprehensively have been rarely reported. Here, the recent advances in 2D m‐TMDs in the aspects of their unique structures, synthetic approaches, distinctive physical properties, and functional applications are highlighted. Finally, the current challenges and perspectives are discussed.
Hybrid Chalcogenide‐Germanosilicate Waveguides for High Performance Stimulated Brillouin Scattering Applications
Authors: Lai Choon Kong , Choi Duk‐Yong , Athanasios Nicholas J. , Yan Kunlun , Chong Wu Yi , Debbarma Sukanta , Ahmad Harith , Eggleton Benjamin J. , Merklein Moritz , Madden Stephen J.
Published: August 2021

On‐chip stimulated Brillouin scattering (SBS) in arsenic trisulfide (As2S3) planar waveguides lead to a range of outstanding demonstrations in microwave photonics signal generation and processing. However, the lack of other integrated functionalities, high back reflections, and large in‐ and out‐fiber coupling losses in high index contrast waveguides cause a number of serious impairments and lessen the applicability of microwave photonic devices. In this report, a hybrid integration scheme is demonstrated where As2S3 waveguides optimized for SBS gain are coupled with very low losses via a vertical taper to a high index contrast and versatile germanosilicate (Ge:SiO2) platform. The Ge:SiO2 waveguide is optimally mode‐matched to commercially available high numerical aperture optical fiber to achieve very low coupling losses. The structure has very low back reflection due to the adiabatic nature of the taper and negligible refractive index difference across the fiber‐chip interface. The hybrid architecture exhibits a similar Brillouin gain coefficient to its monolithic counterpart but with an improvement of >3 dB/facet fiber‐to‐chip loss and >20 dB reduction in facet reflectivity. The hybrid structures demonstrated will bring chalcogenide‐based chip scale SBS devices closer to practical application.
Universal Patterning for 2D Van der Waals Materials via Direct Optical Lithography
Authors: Cho Seong Rae , Ahn Seonghun , Lee Seung Hyung , Ha Heonhak , Kim Tae Soo , Jo Min‐kyung , Song Chanwoo , Im Tae Hong , Rani Pragya , Gyeon Minseung , Cho Kiwon , Song Seungwoo , Jang Min Seok , Cho Yong‐Hoon , Lee Keon Jae , Kang Kibum
Published: August 2021

Advanced patterning techniques are essential to pursue applications of 2D van der Waals (vdW) materials in electrical and optical devices. Here, the direct optical lithography (DOL) of vdW materials by single‐pulse irradiation of high‐power light through a photomask is reported. The DOL exhibits large‐scale patterning with a sub‐micrometer resolution and clean surface, which can be applied to various combinations of vdW materials and substrates. In addition, the thermal profile during DOL is investigated using the finite element method, and the ideal conditions of DOL according to the materials and substrates are determined.
Holographic Sensors in Biotechnology
Authors: Davies Sam , Hu Yubing , Jiang Nan , Blyth Jeff , Kaminska Monika , Liu Yunzheng , Yetisen Ali K.
Published: August 2021

As populations expand worldwide, medical care will need to diversify its data collection techniques to be able to provide adequate healthcare to global populations, this can be achieved through point‐of‐care analysis by wearable analytical devices. Holographic sensors are reusable optical biosensors with the capability to continuously monitor variations, generating the prospect of in vivo monitoring of patient homeostasis. Holographic optical sensors have emerged as an opportunity for low cost and real‐time point‐of‐care analysis of biomarkers to be realized. This review aims to summarize the fundamentals and fabrications of holographic sensors; a key focus will be directed to examining the biotechnology applications in a variety of analytical settings. Techniques covered include surface relief gratings, inverse opals, metal nanoparticle and nanoparticle free holographic sensors. This article provides an overview of holographic biosensing in applications such as pH, alcohol, ion, glucose, and drug detection, alongside antibiotic monitoring. Details of developments in fabrication and sensitizing techniques will be examined and how they have improved the applicability of holographic sensors to point‐of‐care analytics. Although holographic sensors have made significant progress in recent years, the current challenges, and requirements for advanced holographic technology to fulfil their future potential applications in biomedical devices will be discussed.
Targeted Delivery of Anesthetic Agents to Bone Tissues using Conductive Microneedles Enhanced Iontophoresis for Painless Dental Anesthesia
Authors: Seeni Razina Z. , Zheng Mengjia , Lio Daniel Chin Shiuan , Wiraja Christian , Mohd Yusoff Mohammad Firdaus Bin , Koh William Teck Yeow , Liu Yuchun , Goh Bee Tin , Xu Chenjie
Published: August 2021

Pain management during dental procedures is a cornerstone for successful daily practice. In current practice, the traditional needle and syringe injection is used to administer local anesthesia. However, the appearance of long needles and the pain associated with it often leads to dental anxiety deterring timely interventions. Microneedles (MNs) have emerged as a minimally invasive alternative to hypodermic needles and shown to be effective in transdermal drug delivery applications. In this article, the potential use of MNs for local anesthesia delivery in dentistry is explored. The development of a novel conductive MN array that can be used in combination with iontophoresis technique to achieve drug penetration through the oral mucosa and the underlying bone tissue is presented. The conductive MN array plays a dual‐role, creating micro‐conduits and lowering the resistance of the oral mucosa. The reduced tissue resistance further enhances the application of a low‐voltage current that is able to direct and accelerate the drug molecules to target the sensory nerves supplying teeth. The successful delivery of lidocaine using this new strategy in a clinically relevant rabbit incisor model is shown to be as effective as the current gold standard.
Ultrasensitive Freestanding and Mechanically Durable Artificial Synapse with Attojoule Power Based on Na‐Salt Doped Polymer for Biocompatible Neuromorphic Interface
Authors: Hu Luodan , Li Lei , Chang Kuan‐Chang , Lin Xinnan , Huang Pei , Zhang Shendong
Published: August 2021

The human brain, with high energy‐efficient and parallel processing ability, inspires to mitigate power issues perplexing von Neumann architecture. As one of the essential components constructing the human brain, the emulation of biological synapses exploiting electronic devices consuming power at a biological level lays the foundation for the implementation of energy‐efficient neuromorphic computing. Besides, signal matching between biologically‐related stimuli and the driving voltage of artificial synapses helps to realize intelligent neuromorphic interfaces and sustainable energy. Here, ultra‐sensitive artificial synapse stimulated at 1 mV with energy consumption of 132 attojoule/synaptic event is demonstrated. Biological signal matching and low power application are realized simultaneously based on sodium acetate (NaAc) doped polyvinyl alcohol (PVA) electrolyte. The biphasic current, which comprises the electrical‐ and ion‐mediation current component, contributes to enrich synaptic functions compared to monophasic synaptic behavior. Moreover, freestanding NaAc‐doped PVA membrane functions as both dielectric layer and mechanical support and facilitates to achieve flexible, transferable artificial synapse, which maintains functional stability at an ultralow voltage and power even after bending tests. Thus, encompassing superior sensitivity, low energy, and multiple functionalities with flexible, self‐supported, biocompatible property, takes a step to construct energetically‐efficient, complex neuromorphic systems for wearable, implantable medicines as well as smart bio‐electronic interfaces.
Efficient Visible‐to‐UV Photon Upconversion Systems Based on CdS Nanocrystals Modified with Triplet Energy Mediators
Authors: Hou Lili , Olesund Axel , Thurakkal Shameel , Zhang Xiaoyan , Albinsson Bo
Published: August 2021

Developing high‐performance visible‐to‐UV photon upconversion systems based on triplet–triplet annihilation photon upconversion (TTA‐UC) is highly desired, as it provides a potential approach for UV light‐induced photosynthesis and photocatalysis. However, the quantum yield and spectral range of visible‐to‐UV TTA‐UC based on nanocrystals (NCs) are still far from satisfactory. Here, three different sized CdS NCs are systematically investigated with triplet energy transfer to four mediators and four annihilators, thus substantially expanding the available materials for visible‐to‐UV TTA‐UC. By improving the quality of CdS NCs, introducing the mediator via a direct mixing fashion, and matching the energy levels, a high TTA‐UC quantum yield of 10.4% (out of a 50% maximum) is achieved in one case, which represents a record performance in TTA‐UC based on NCs without doping. In another case, TTA‐UC photons approaching 4 eV are observed, which is on par with the highest energies observed in optimized organic systems. Importantly, the in‐depth investigation reveals that the direct mixing approach to introduce the mediator is a key factor that leads to close to unity efficiencies of triplet energy transfer, which ultimately governs the performance of NC‐based TTA‐UC systems. These findings provide guidelines for the design of high‐performance TTA‐UC systems toward solar energy harvesting.
Trigger‐Detachable Hydrogel Adhesives for Bioelectronic Interfaces
Authors: Xue Yu , Zhang Jun , Chen Xingmei , Zhang Jiajun , Chen Guangda , Zhang Kuan , Lin Jingsen , Guo Chuanfei , Liu Ji
Published: August 2021

Recent electronics technology development has provided unprecedented opportunities for enabling implantable bioelectronics for long‐term disease monitoring and treatment. Current electronics‐tissue interfaces are characterized by weak physical interactions, suffering from potential interfacial failure or dislocation during long‐term application. On the other hand, some new technologies can be used to achieve robust electronics‐tissue interfaces; however, such technologies are limited by potential risks and the discomfort associated with postdetachment of the bioelectronics. Here, a hydrogel‐based electronics‐tissue interface based on the exploitation of dynamic interactions (such as boronate‐diol complexation) that features an interfacial toughness over 400 J m−2 is presented. Moreover, these hydrogel adhesion layers are also trigger‐detachable by dissociating the dynamic complexes (i.e., addition of glucose). These hydrogel‐based bioelectronic interfaces enable the in vivo recording of physiological signals (i.e., electromyograph, blood pressure, or pulse rates). Upon mild triggering, these bioelectronics can be easily detached without causing any damage, trauma, or discomfort to the skin, tissues, and organs. This kind of trigger‐detachable hydrogel adhesives offer general applicability in bioelectronic interfaces, exhibiting promising utility in monitoring, modulating, and treating diseases where temporary monitoring of physiologic signals, interfacial robustness, and postremoval of bioelectronics are required.
Liquid Metal Welding to Suppress Li Dendrite by Equalized Heat Distribution
Authors: Wang Dong , Liu Yumin , Li Guanwu , Qin Chichu , Huang Lu , Wu Yingpeng
Published: August 2021

It is important to understand the growth mechanism of Li dendrites for the protection of Li metal anodes. Herein, joule heat as another inducing mechanism for Li dendrites is proposed and demonstrated by experiments and theoretical simulations. A nonuniform interface structure can lead to disordered surface thermal distribution based on joule heat theory, which may induce chaotic nucleation and growth of dendrites. Based on this concept, a new strategy of liquid metal welding is explored to overcome such joule heat distribution issue. This strategy is universally compatible with other traditional protection routes such as solid electrode interphase films, charging protocols, and electrolytes. Multistrategy synergetic protection strategies result in remarkable performance.
Practicable Applications of Aggregation‐Induced Emission with Biomedical Perspective
Authors: Wang Yuqing , Xia Bozhang , Huang Qianqian , Luo Ting , Zhang Yuanyuan , Timashev Peter , Guo Weisheng , Li Fangzhou , Liang Xing‐Jie
Published: August 2021

Considerable efforts have been made into developing aggregation‐induced emission fluorogens (AIEgens)‐containing nano‐therapeutic systems due to the excellent properties of AIEgens. Compared to other fluorescent molecules, AIEgens have advantages including low background, high signal‐to‐noise ratio, good sensitivity, and resistance to photobleaching, in addition to being exempt from concentration quenching or aggregation‐caused quenching effects. The present review outlines the major developments in the biomedical applications of AIEgens‐containing systems. From a literature survey, the recent AIE works are reviewed and the reasons why AIEgens are chosen in various biomedical applications are highlighted. The research activities on AIEgens‐containing systems are increasing rapidly, therefore, the present review is timely.
Reproducible X‐ray Imaging with a Perovskite Nanocrystal Scintillator Embedded in a Transparent Amorphous Network Structure
Authors: Zhang Hao , Yang Ze , Zhou Min , Zhao Lei , Jiang Tingming , Yang Huiying , Yu Xue , Qiu Jianbei , Yang Yang (Michael) , Xu Xuhui
Published: August 2021

Metal halide perovskites are emerging scintillator materials in X‐ray detection and imaging. However, the vulnerable structure of perovskites triggers unreliable performance when they are utilized in X‐ray detectors under cumulative dose irradiation. Herein, a self‐limited growth strategy is proposed to construct CsPbBr3 nanocrystals that are embedded in a transparent amorphous network structure, featuring X‐imaging with excellent resolution (≈16.8 lp mm−1), and fast decay time (τ = 27 ns). Interestingly, it is found that the performance degradation of the scintillator, caused by the damage from high‐dose X‐ray irradiation, can be fully recovered after a facile thermal treatment process. This indicates a superior recycling behavior of the explored perovskites scintillator for practical applications. The recoverability of the as‐explored scintillator is attributed to the low atom‐migration rate in the amorphous network with high‐viscosity (1 × 1014 cP). This result highlights the practical settlement of the promising perovskites for long‐term, cost‐effective scintillator devices.
High‐Efficiency Ion‐Exchange Doping of Conducting Polymers
Authors: Jacobs Ian E. , Lin Yue , Huang Yuxuan , Ren Xinglong , Simatos Dimitrios , Chen Chen , Tjhe Dion , Statz Martin , Lai Lianglun , Finn Peter A. , Neal William G. , D'Avino Gabriele , Lemaur Vincent , Fratini Simone , Beljonne David , Strzalka Joseph , Nielsen Christian B. , Barlow Stephen , Marder Seth R. , McCulloch Iain , Sirringhaus Henning
Published: August 2021

Molecular doping—the use of redox‐active small molecules as dopants for organic semiconductors—has seen a surge in research interest driven by emerging applications in sensing, bioelectronics, and thermoelectrics. However, molecular doping carries with it several intrinsic problems stemming directly from the redox‐active character of these materials. A recent breakthrough was a doping technique based on ion‐exchange, which separates the redox and charge compensation steps of the doping process. Here, the equilibrium and kinetics of ion exchange doping in a model system, poly(2,5‐bis(3‐alkylthiophen‐2‐yl)thieno(3,2‐b)thiophene) (PBTTT) doped with FeCl3 and an ionic liquid, is studied, reaching conductivities in excess of 1000 S cm−1 and ion exchange efficiencies above 99%. Several factors that enable such high performance, including the choice of acetonitrile as the doping solvent, which largely eliminates electrolyte association effects and dramatically increases the doping strength of FeCl3, are demonstrated. In this high ion exchange efficiency regime, a simple connection between electrochemical doping and ion exchange is illustrated, and it is shown that the performance and stability of highly doped PBTTT is ultimately limited by intrinsically poor stability at high redox potential.