bluuebunny/crossref_metadata_2025 huggingface dataset:
Phytochemical Contents and Antioxidant Capacities of Two Aloe greatheadii var. davyana Extracts
Authors: Botes Lisa , Van der Westhuizen Francois H. , Loots Du Toit
Published: October 2008

Aloe greatheadii var. davyana (Asphodelaceae) is used among rural South African communities to treat arthritis, skin cancer, burns, eczema, psoriasis, digestive problems, high blood pressure and diabetes, despite very little supporting scientific evidence. Due to increased interest by both the scientific community and industry regarding the medicinal uses of this plant species, we identified, quantified and compared the phytochemical contents and antioxidant capacities of two extracts of A. greatheadii; a leaf gel extract (LGE) and a 95 % aqueous ethanol leaf gel extract (ELGE), using various modified extraction procedures, GC-MS and spectrophotometry. Apart from extensively characterizing this medicinal plant with regards to its organic acid, polyphenols/phenolic acid, alcohol, aldehyde, ketone, alkane, pyrimidine, indole, alkaloid, phytosterol, fatty acid and dicarboxylic acid contents and antioxidant capacities, we describe a modified extraction procedure for the purpose of general phytochemical characterization, and compare this to a 95 % aqueous ethanol extraction technique. From the results it is clear that A. greatheadii contains a variety of compounds with confirmed antioxidant capacity and other putative health benefits (such as blood glucose, cholesterol and cortisol lowering properties) relating to the prevention or treatment of diabetes, cardiovascular disease, cancer and hypertension. The results also indicate that separate ethyl acetate/diethyl ether and hexane extractions of the LGE, better serve for general phytochemical characterization purposes, and 95 % aqueous ethanol extraction for concentrating selective groups of health related compounds, hence justifying its use for biological in vivo efficacy studies.
Phytochemical Analysis of the Essential Oil from Botanically Certified Oleogum Resin of Boswellia sacra (Omani Luban)
Authors: Al-Harrasi Ahmed , Al-Saidi Salim
Published: October 2008

The yield of hydrodistillation of a botanically certified Oleogum Resin of Boswellia sacra essential oil (5.5%); and its chemical constituents were determined. The GC/MS technique was used for the analysis of the oil. Several oil components were identified based upon comparison of their mass spectral data with those of reference compounds published in literature or stored in a computer library. The oil was characterized by the high content of the monoterpenes (34) which constituted 97.3% in which E-β-ocimene and limonene were the major constituents. The remaining 2.7% was accounted for the sesquiterpenes (16) in which the E-caryophyllene was the major constituent. The analysis proved the complete absence of the diterpenes.
An Amperometric Biosensor for Uric Acid Determination Prepared From Uricase Immobilized in Polyaniline-Polypyrrole Film
Authors: Arslan Fatma
Published: October 2008

A new amperometric uric acid biosensor was developed by immobilizing uricase by a glutaraldehyde crosslinking procedure on polyaniline-polypyrrole (pani-ppy) composite film on the surface of a platinum electrode. Determination of uric acid was performed by the oxidation of enzymatically generated H2O2 at 0.4 V vs. Ag/AgCl. The linear working range of the biosensor was 2.5×10-6 – 8.5×10-5 M and the response time was about 70 s. The effects of pH, temperature were investigated and optimum parameters were found to be 9.0, 55 oC, respectively. The stability and reproducibility of the enzyme electrode have been also studied.
Electrochemical Assay of Human Islet Amyloid Polypeptide and Its Aggregation
Authors: Zhou Nandi , Chen Zhenyu , Zhang Dongmei , Li Genxi
Published: October 2008

Square wave voltammetry is used in this work to detect human islet amyloid polypeptide (hIAPP) by using the oxidized signal of the tyrosine residue in hIAPP. A detection limit of 1×10-6 M for hIAPP has been obtained. A kinetic study of the aggregation process has been carried out according to the relationship between the anodic peak current in the square wave voltammograms of hIAPP and the incubation period. The results show that the nucleation starts in the first hour of incubation and then, during the next two hours, aggregation may occur rapidly. hIAPP can therefore be monitored with a label-free electrochemical method with low detection limit and high sensitivity. This electrochemical method can be also utilized to study the kinetics of hIAPP aggregation, and it may be also employed to study the conformational changes of the polypeptide.
Sensors and Biosensors for the Determination of Small Molecule Biological Toxins
Authors: Wang Xiang-Hong , Wang Shuo
Published: October 2008

The following review of sensors and biosensors focuses on the determination of commonly studied small molecule biological toxins, including mycotoxins and small molecule neurotoxins. Because of the high toxicity of small molecule toxins, an effective analysis technique for determining their toxicity is indispensable. Sensors and biosensors have emerged as sensitive and rapid techniques for toxicity analysis in the past decade. Several different sensors for the determination of mycotoxins and other small molecule neurotoxins have been reported in the literature, and many of these sensors such as tissue biosensors, enzyme sensors, optical immunosensors, electrochemical sensors, quartz crystal sensors, and surface plasmon resonance biosensors are reviewed in this paper. Sensors are a practical and convenient monitoring tool in the area of routine analysis, and their specificity, sensitivity, reproducibility and analysis stability should all be improved in future work. In addition, accuracy field portable sensing devices and multiplexing analysis devices will be important requirement for the future.
INVESTIGATION OF 90SR ACUMULATION IN PINEWOOD (PINUS SYLVESTRIS L.)/90SR KAUPIMOSI PAPRASTOSIOS PUŠIES (PINUS SYLVESTRIS L.) MEDIENOJE TYRIMAS/НАКОПЛЕНИЕ 90SR В ДРЕВЕСИНЕ ПРОСТОЙ СОСНЫ (PINUS SYLVESTRIS L.)
Authors: Butkus Donatas , Bataitienė Ingrida Pliopaitė , Bataitis Tautvydas
Published: October 2008

The paper presents changes of 90Sr activity in pinewood (Pinus sylvestris L.), which in studied conditions varies from (0,03±0,01) Bq/kg to (2,32±0,34) Bq/kg. Activity was defined experimentally and by modelling, using the model FORM. The measured results and those established by the model differ averagly by 13%. For definition of the accumulated 90Sr activity in wood of a simple pine, the method of summarization of activity integrals was used after establishment of function of dependence between 90Sr activities and pine biomass augment. By this method it was estimated that in the wood of 50‐year pines in 2006 90Sr activity was 620 Bq. 90Sr transfer coefficient from ground to pinewood was studied in the work. During the pine growth this coefficient varied from (2,0 ± 1,0) · 10−4 m2/kg to (9,7 ± 1,0) · 10−4 m2/kg.

Santrauka

Pateikiami 90Sr medienoje tyrimo rezultatai, pagal kuriuos jis kinta nuo (0,03±0,01) Bq/kg iki (2,32±0,34) Bq/kg. Autoriai siūlo 90Sr sukauptam pušies medienoje kiekiui modeliuoti naudoti FORM modelį. Vidutinis skirtumas tarp tyrimo ir modelio rezultatų yra 13 %. Norint įvertinti visą sukauptą 90Sr medyje kiekį, taikomas savitojo aktyvumo integralų sumavimo metodas, prieš tai nustačius 90Sr savitojo aktyvumo ir medžio biomasės prieaugio ryšio funkciją. Pagal pasiūlytą modelį įvertinta, kad per 1950–2000 m. pušis sukaupė 620 Bq. Darbe yra įvertintas 90Sr pernašos iš dirvožemio į paprastosios pušies medieną koeficientas. 1950–2000 m. laikotarpiu jis kito nuo (2,0±1,0) ⋅ 10-4 m2 /kg iki (9,7±1,0) ⋅ 10–4 m2 /kg.

Резюме

Приводятся данные об изменении концентрации активности 90Sr в древесине простой сосны (Pinus sylvestris L.), в изучаемых условиях меняющейся от (0,03±0,01) Бк/кг до (2,32±0,34) Бк/кг. Концентрация активности определялась как экспериментально, так и с использованием модели FORM. Различия между измеренными результатами и установленными при помощи модели в среднем составляют 13%. Для определения общей активности 90Sr в древесине простой сосны в работе предложен метод суммирования интегралов активности после установления функции зависимости концентрации активности от годового прироста массы древесины. Этим методом установлено, что активность 90Sr в древесине 50-летней сосны в 2006 г. составляла 620 Бк. Изучен коэффициент переноса 90Sr из почвы в древесину простой сосны. Во время роста сосны он менялся от (2,0±1,0) - 10–4 м2 /кг до (9,7±1,0) - 10–4 м2 /кг.
User Information Sharing and Hospital Website Privacy Policies
Authors: McCoy Matthew S. , Wu Angela , Burdyl Sam , Kim Yungjee , Smith Noell Kristen , Gonzales Rachel , Friedman Ari B.
Published: April 2024

Importance

Hospital websites frequently use tracking technologies that transfer user information to third parties. It is not known whether hospital websites include privacy policies that disclose relevant details regarding tracking.

Objective

To determine whether hospital websites have accessible privacy policies and whether those policies contain key information related to third-party tracking.

Design, Setting, and Participants

In this cross-sectional content analysis of website privacy policies of a nationally representative sample of nonfederal acute care hospitals, hospital websites were first measured to determine whether they included tracking technologies that transferred user information to third parties. Hospital website privacy policies were then identified using standardized searches. Policies were assessed for length and readability. Policy content was analyzed using a data abstraction form. Tracking measurement and privacy policy retrieval and analysis took place from November 2023 to January 2024. The prevalence of privacy policy characteristics was analyzed using standard descriptive statistics.

Main Outcomes and Measures

The primary study outcome was the availability of a website privacy policy. Secondary outcomes were the length and readability of privacy policies and the inclusion of privacy policy content addressing user information collected by the website, potential uses of user information, third-party recipients of user information, and user rights regarding tracking and information collection.

Results

Of 100 hospital websites, 96 (96.0%; 95% CI, 90.1%-98.9%) transferred user information to third parties. Privacy policies were found on 71 websites (71.0%; 95% CI, 61.6%-79.4%). Policies were a mean length of 2527 words (95% CI, 2058-2997 words) and were written at a mean grade level of 13.7 (95% CI, 13.4-14.1). Among 71 privacy policies, 69 (97.2%; 95% CI, 91.4%-99.5%) addressed types of user information automatically collected by the website, 70 (98.6%; 95% CI, 93.8%-99.9%) addressed how collected information would be used, 66 (93.0%; 95% CI, 85.3%-97.5%) addressed categories of third-party recipients of user information, and 40 (56.3%; 95% CI, 44.5%-67.7%) named specific third-party companies or services receiving user information.

Conclusions and Relevance

In this cross-sectional study of hospital website privacy policies, a substantial number of hospital websites did not present users with adequate information about the privacy implications of website use, either because they lacked a privacy policy or had a privacy policy that contained limited content about third-party recipients of user information.
Professional Experiences and Career Trajectories of Mid- to Senior-Career Women Clinician-Scientists
Authors: Szczygiel Lauren A. , Greene Amanda K. , Cutter Christina M. , Jones Rochelle D. , Feldman Eva L. , Paradis Kelly C. , Settles Isis H. , Singer Kanakadurga , Spector Nancy D. , Stewart Abigail J. , Ubel Peter A. , Jagsi Reshma
Published: April 2024

Importance

Despite increasing evidence and recognition of persistent gender disparities in academic medicine, qualitative data detailing the association of gender-based experiences with career progression remain sparse, particularly at the mid- to senior-career stage.

Objective

To investigate the role gender has played in everyday professional experiences of mid- to senior-career women clinician-scientists and their perceptions of gender-related barriers experienced across their careers.

Design, Setting, and Participants

In this qualitative study, a total of 60 of 159 invited clinician-scientists who received National Institutes of Health K08 or K23 awards between 2006 and 2009 and responded to a survey in 2021 agreed to participate. Invitees were selected using random, purposive sampling to support sample heterogeneity. Semistructured in-depth interviews were conducted January to May 2022. For this study, interviews from 31 women were analyzed using the framework approach to thematic analysis. Data analyses were performed between August and October 2023.

Main Outcomes and Measures

Descriptive themes of participant experiences of gender and gender-based barriers in academic medicine.

Results

A total of 31 women clinician-scientists (8 identifying as Asian [25.8%], 14 identifying as White [45.2%], and 9 identifying as members of a minority group underrepresented in medicine [29.0%]; 14 aged 40-49 years [45.2%] and 14 aged 50-59 years [45.2%]) were included. Among them, 17 participants (54.8%) had children who required adult supervision or care, 7 participants (22.6%) had children who did not require supervision or care, and 6 participants (19.4%) did not have children. There were 4 dominant themes identified within participant experiences in academic medicine: the mental burden of gendered expectations at work and home, inequitable treatment of women in bureaucratic processes, subtle and less subtle professional exclusion of women, and value of communities built on shared identities, experiences, and solidarity.

Conclusions and Relevance

This study found that women perceived the institution of academic medicine as a male-centric system misaligned with the needs of women, with associated feelings of exclusion, disillusionment, and loss of trust in their institutions. Findings suggest that the confluence of domestic obligations and unaccommodating institutional environments may make it difficult for women clinician-scientists to achieve established timelines of career progression and productivity; these findings may have long-term implications for the well-being and retention of women in academic medicine.
Patient-Reported Outcomes as a Recruitment Strategy for Clinical Trial Enrollment
Authors: Verdini Nicholas P. , Bryl Karolina L. , Baser Raymond E. , Lapen Kaitlyn , Mao Jun J. , Gillespie Erin F.
Published: April 2024

Importance

Clinical trials are critical for progress in oncology; however, only 5% of the adult cancer population participates. Harnessing data that are routinely collected (ie, electronic patient-reported outcomes [ePROs]) may serve as a method to promote trial enrollment.

Objective

To evaluate if an ePRO-prompted recruitment strategy is associated with increased clinical trial enrollment.

Design, Setting, and Participants

A randomized substudy was conducted from September 2022 to March 2023 at a multisite tertiary cancer center as part of an ongoing clinical trial that was testing a symptom-intervention for cancer-related fatigue. Patients with breast cancer who were undergoing radiotherapy who completed at least 1 ePRO questionnaire during the study period were included. Physician-level cluster randomization assigned fatigue-eligible patients to either receive a portal message invitation to a symptom-intervention trial or standard of care (SOC; physician-based referral).

Exposure

ePRO questionnaires distributed in routine practice were queried weekly and screened for moderate or greater fatigue, the principle inclusion criterion for the primary trial. To assess the association of the portal message source with response and enrollment, every other patient received a message from the primary radiation oncology team or the referral service.

Main Outcomes and Measures

Clinical trial response/referral and enrollment.

Results

A total of 1041 patients completed ePRO questionnaires, of whom 394 (38%; 53 Asian [13.6%], 43 Black [11.0%], 29 Hispanic [7.4%], and 262 White individuals [66.5%]; median [IQR] age, 55 [47-65] years) endorsed moderate or greater fatigue while receiving treatment. A total of 210 patients (53.3%) were assigned to receive a portal message and 184 (46.7%) patients, SOC. In the portal message group, 73 patients (35%) responded and 41 (20%) enrolled compared with 1 patient (0.5%) referred and 0 enrolled in the SOC group (P < .001). The response rate to portal messages favored the referral service vs the primary radiation oncology service (44% vs 26%; P = .01), but there was no significant difference in enrollments.

Conclusions and Relevance

The study results suggest that use of routine care ePROs was associated with greater enrollment in a symptom-intervention trial compared with physician-based referral. Messaging directly from the referral service may support enrollment and help reduce oncology physician-level barriers to trial enrollment for studies testing symptom interventions.
Addressing Financial Toxicity in Head and Neck Cancer—A Crucial Imperative
Authors: Mady Leila J. , Goldberg Zachary N. , de Almeida John R.
Published: April 2024

This Viewpoint calls for consideration of the financial costs of head and neck cancer care when choosing treatment strategies for patients who may face severe financial stress or insolvency due to cancer treatment.
From Electrolyte and Electrode Materials to Large‐Area Protonic Ceramic Fuel Cells: A Review
Authors: Guo Shihang , Jiang Lulu , Li Yifeng , Zhong Peng , Ismail Sara Adeeba , Norby Truls , Han Donglin
Published: April 2024

Fuel cells can efficiently convert the chemical energy in fuels like hydrogen and methane into electricity and are an important component for the forthcoming hydrogen society. Compared with conventional solid oxide fuel cells (SOFCs) and proton exchange membrane fuel cells (PEMFCs), protonic ceramic fuel cells (PCFCs) using proton conducting solid oxides as the electrolyte operate at intermediate temperature (400–700 °C), enabling the reduction in cost by using inexpensive catalysts and structural materials. In the last couple of decades, the development of electrolyte and electrode materials for PCFCs has seen significant advances, including fabrication of large‐size cells, promoting PCFCs to step out of the lab toward real applications. This review provides a historic overview of the development of proton conducting oxides, summarizes recent progress on the development of electrolyte and electrode materials and large‐size cells, and discusses present problems and challenges ahead.
Fabrication of Flexible and Conductive Microneedle Array Electrodes from Silk Fibroin by Mesoscopic Engineering
Authors: Wang Xiao , Qiu Wu , Lu Changsheng , Jiang Zerong , Hou Chen , Li Yanru , Wang Yan , Du Haiman , Zhou Jin , Liu Xiang Yang
Published: April 2024

Conventional electrodes are of significant challenges in acquiring bioelectric signals concerning a high signal‐to‐noise ratio (SNR), long‐term and comfortable wear, low motional noise, etc. To resolve these issues, silk fibroin (SF) materials are adopted to create flexible microneedle array electrodes (FMNA‐electrode) based on meso‐engineering. The research approaches involve constructing flexible conductive electrodes from non‐conductive and bristle‐regenerated SF. By controlling the molecular interchain nucleation in the refolding process of unfolded regenerated SF molecules, this goal can be achieved. In this process, silver nanowires (Ag NWs) are adopted as meso‐dopants to reconstruct the meso‐electronic structure of SF films at the surface, while polyurethane (PU) is selected as molecular templates to facilitate the molecular nucleation in the refolding of SF molecules. This leads to the occurrence of SF‐PU meso‐hybridization, giving rise to more flexible meso‐hybridized SF. The SF‐PU FMNA‐electrode demonstrates biocompatibility, comfort wearing, long‐term monitoring capability, low motional noise, and a high SNR in the application of collecting ECG, EMG, and EOG signals. The outperformance of SF‐PU FMNA‐electrode is superior to both conventional wet and commercially available dry electrodes, paving the way for the next generation of flexible, skin‐friendly, durable, and high‐performance health monitoring devices and brain‐machine interfaces.
Catalytic Oxidation of BTX (Benzene, Toluene, and Xylene) Using Metal Oxide Perovskites
Authors: Yuan Jianhua , Li Guixiang , Liu Xiao , Yang Yun , Yu Fei , Cao Jianglin , Fei Zhaofu , Ma Jie , Nazeeruddin Mohammad K. , Dyson Paul J.
Published: April 2024

The high toxicity, volatility, and dispersion of the light aromatics, benzene, toluene, and xylene (BTX) pose a serious threat to the environment and human health. Compared to incineration, catalytic oxidation technologies for BTX removal offer benefits such as low energy consumption, high efficiency, and low pollution. ABO3–type perovskite catalysts (ABO3–PCs) are particularly promising materials for the catalytic oxidation of BTX due to their high activity and thermal stability, as well as their adjustable elemental composition and flexible structure allowing their properties to be improved. Nonetheless, the full potential of ABO3–PCs for the oxidation of BTX has yet to be reached. This review systematically and critically analyses progress in the catalytic oxidation of BTX by ABO3–PCs. Catalytic performance is assessed for each category of perovskite, including non–doped, doped (A–, B–, or A/B–site doped), and loading type (noble metal, metal oxide, and matrix composite), with structure–activity relationships are established. A kinetic model and proposed mechanism for the catalytic oxidation of BTX are also presented. Finally, the challenges and opportunities of ABO3–PCs applied to BTX oxidation and other reactions are highlighted.
Solution Processed Hybrid Lead Perovskite Films for White Light Emission and Lasing Applications
Authors: Chowdhury Subhadip , Mukhopadhyay Mrinmay K , Sanyal Milan K , Bhunia Satyaban , Satpati Biswarup , Giri Rajendra P , Bharatiya B , Shen Chen , Murphy Bridget M
Published: April 2024

2D organic–inorganic hybrid lead halide perovskite films are fascinating optoelectronic materials for white‐light emission and lasing applications. Here, it is demonstrated that nano‐meter‐thick films of perovskites can be formed at room temperature using Langmuir–Schaefer (LS) deposition technique. In situ X‐ray measurements reveal a self‐assembly process of the 2D perovskite formation at the air–water interface. This formation process requires the presence of stearic acid monolayer on the water subphase having a solution of lead‐perovskite in dimethylformamide. Microscopy and X‐ray measurements of these nanofilms transferred onto substrates show crystalline phase formation that deviates from the known orthorhombic structure of the bulk crystals. The nanofilms exhibit novel broad optical emission with sharp band‐edge transition in temperature‐dependent photoluminescence studies. Also, their band‐edge emission is distinctly blue‐shifted compared to that of thicker 2D perovskite flakes prepared by the slow‐cooling chemical synthesis process. 2D flakes exhibit lasing that cannot be obtained in the LS nanofilms as their thicknesses are lower than the lasing wavelength prohibiting wave‐guide formation. The results show that the 2D single‐crystalline nature of the LS films and flakes are suitable materials to develop broad‐band white light emission across the entire visible range and to obtain lasing without external cavities, respectively.
High‐Resolution 3D Printing of Dual‐Curing Thiol‐Ene/Epoxy System for Fabrication of Microfluidic Devices for Bioassays
Authors: Böcherer David , Li Yuanyuan , Rein Christof , Franco Corredor Santiago , Hou Peilong , Helmer Dorothea
Published: April 2024

The customized processing of polymer materials in the microscale by high‐resolution 3D printing provides an easy access to advanced applications in the fields of optics, microfluidics, tissue engineering, and life science. However, the 3D printing of enclosed structures in the scale of tens of microns such as closed microfluidic channels remains a challenge as channel structures often are clogged by residual cured resin. Dual‐curing systems based on off‐stoichiometric thiol‐ene and thiol‐ene/epoxy chemistry are well‐known for adhesive‐free bonding in the fabrication of cast or injection molded microfluidic devices. Herein, the first high‐resolution stereolithography 3D printing of a dual‐curing thiol‐ene/epoxy system in the microscale for the fabrication of customized microfluidic devices is presented. In the first curing step, by high‐resolution 3D printing open microfluidic structures are produced. Consecutively, the microchannels are sealed by adhesive‐free dry bonding upon thermal initiation, producing well‐controlled structures with channel sizes down to 80 µm. Before bonding, the intermediate material allows for tailored surface modification with biotin, which allows for consecutive immobilization of various biomolecules. A DNA‐bioassay with specific patterning is shown in the sealed chip. The presented work paves the way toward the fabrication of customized microfluidic devices for a large range of specific bioassays.
Advancing Monolithic Perovskite/TOPCon Tandem Solar Cells by Customizing Industrial‐Level Micro‐Nano Structures
Authors: Jiang Shengguo , Ding Zetao , Li Xin , Zhang Liping , Ying Zhiqin , Yang Xi , Yang Zhenhai , Yang Weichuang , Zeng Yuheng , Ye Jichun
Published: April 2024

Texturing silicon solar cells with micro/nano‐structures is crucial for achieving outstanding optical performance in perovskite/silicon tandem solar cells (TSCs). However, ensuring excellent electrical properties remains a challenge due to reduced passivation quality of the bottom silicon sub‐cells and difficulties in perovskite formation on textured substrates. Here, an industrial‐level sub‐micron random pyramid (sMRP) structure on the front side of a tunnel oxide passivating contact (TOPCon) solar cell using a simple alkaline texturing process is presented, resulting in excellent optical and electrical properties. Through meticulous fabrication process tuning, uniform sMRP textures with a size of 0.6–0.8 µm are achieved, exhibiting low reflectance comparable to industrial‐level micron random pyramid (MRP) structures. Optimizing annealing temperatures of double‐sided TOPCon structures textured with front‐sided sMRP and rear‐sided MRP, yields high passivation quality, with a remarkable implied open‐circuit voltage (iVOC) of 713 mV. Furthermore, the sMRP‐textured surface facilitates the formation of a high‐quality perovskite film with larger grain sizes and fewer internal pinholes compared to the polished counterpart. Consequently, a proof‐of‐concept p‐i‐n typed perovskite/TOPCon TSC featuring sMRP textures obtains an outstanding efficiency of 28.67%, providing a promising approach for the commercial production of high‐efficiency perovskite/TOPCon TSCs.
Metal–Organic Framework‐Coated Glass Vials: A Step Forward in Analytical Platforms
Authors: Taima‐Mancera Iván , Trujillo‐Rodríguez María J. , Pasán Jorge , Pino Verónica
Published: April 2024

A robust microextraction device in the form of a glass vial internally coated with metal–organic frameworks (MOFs) is designed, fabricated by in situ growth of different Zr‐based MOFs, and fully characterized for its novel use as an analytical platform. This device, uniformly coated by the MOF, ensures high simplicity and short times when used as an analytical microextraction tool, as the device acts as both the sample container and the extraction device, being tested for monitoring the presence of a group of endocrine‐disrupting chemicals in pool waters. The thin film format and MOF nature allow for high extraction efficiency and preconcentration of these target contaminants. Adsorption and desorption of the analytes are studied through kinetic experiments, with uptakes up to 90% for propylparaben in the UiO‐66‐abdc vial, and an extremely fast desorption in just seconds. The UiO‐66‐abdc vial does not require more than 15 min to perform a complete extraction‐desorption cycle, with limits of detection down to 0.10 µg L−1 in pool waters. The MOF‐coated vials are demonstrated to be easily (and highly) reusable by simple washing for a few min followed by drying. The simplicity of the method can be pushed further working in static mode or by a simple manual shaking.
Shaping the Infrared luminescence of Colloidal Nanocrystals Using a Dielectric Microcavity
Authors: Bossavit Erwan , Zhang Huichen , Ledos Nicolas , Cavallo Mariarosa , Mastrippolito Dario , Curti Leonardo , Khalili Adrien , Colle Albin , Lample Pierrick , Weis Mateusz , Margaillan Florent , Lafosse Xavier , Prado Yoann , Péronne Emmanuel , Pierucci Debora , Ithurria Sandrine , Boschetto Davide , Diroll Benjamin T. , Degiron Aloyse , Lhuillier Emmanuel
Published: April 2024

As they have gained maturity, colloidal nanocrystals (NCs) have also expand the spectral range over of which they could be used for photonic and optoelectronic applications. In particular, the infrared use of NCs has become of utmost interest to develop cost‐effective alternatives to current technologies. It is then critical not to let the material dictate the light–matter interaction, which is why the coupling of NCs to photonic cavities has been proposed. For infrared NCs, this approach has first been devoted to the control of absorption with in mind the increase of the signal magnitude for detectors. A Lot of efforts have been focused on the use of metallic metasurfaces. However, these generate significant optical losses and yield low quality factor. Here, this study rather focus on the coupling of infrared NCs to a dielectric mirror cavity. HgTe/CdS core‐shell NCs are used and integrated into a cavity made of aperiodic dielectric mirrors. The effect of the substrate is systematically study on spectral linewidth, carrier dynamic, and emission directivity. The cavity is shown to narrow the PL by a factor 10, while focusing the emission over a 12° angle. Monitoring the power dependence of the emission, this study shows that the cavity leads to 250 K increase in the effective electronic temperature.
Polarizable H‐Bond Concept in Aromatic Poly(thiourea)s: Unprecedented High Refractive Index, Transmittance, and Degradability at Force to Enhance Lighting Efficiency
Authors: Watanabe Seigo , Cavinato Luca M. , Calvi Vladimir , van Rijn Richard , Costa Rubén D. , Oyaizu Kenichi
Published: April 2024

Developing transparent and highly refractive environmentally friendly polymers has not been realized yet toward sustainable optoelectronics. This work describes poly(thiourea)s (PTUs) design following a new “polarizable group synergy” concept, combining highly polarizable hydrogen bonding groups and aromatic‐based spacers to form densely packed and high‐refractive‐index polymer networks. Specifically, PTUs containing m‐ and p‐phenylene spacers exhibit an easy synthesis, high thermostability (Tg = 159 °C), visible transparency (>92%T at 1 µm‐film), ultra‐high refractive index (nD = 1.81) based on the random H‐bonding arrays with a high packing constant (Kp = 0.738), and straightforward preparation of flexible films via solvent‐based techniques. Capitalizing on these assets, PTU‐films are integrated into benchmark graphene‐based lighting device architectures based on the light‐emitting electrochemical cells (LECs) concept. A joint optical modeling and experimental validation confirm the increase in external quantum efficiency expected by the enhanced light out‐coupling of PTU‐films. Finally, PTUs are efficiently depolymerized to low molecular weight compounds by simply adding diamines under heating, following the dynamic covalent bond exchange between thiourea moieties. Overall, this work highlights the PTU family as new promising materials with a unique polarizable H‐bond design to meet efficient and sustainable thin‐film lighting devices.
Wavelength‐Linearly‐Dependent and Polarization‐Sensitive Perfect Absorbers based on Optically Anisotropic Germanium Selenide (GeSe)
Authors: Guo Zhengfeng , Gu Honggang , Yu Yali , Zhang Qihang , Wei Zhongming , Liu Shiyuan
Published: April 2024

Perfect absorbers, widely utilized in solar energy‐harvesting devices, optical communications, sensors, displays, and filters, achieve 100% light absorption. However, perfect absorbers employing micro/nanostructures encounter challenges such as high cost and complexity in simulation and fabrication. Here, novel wavelength‐linearly‐dependent and polarization‐sensitive perfect absorbers utilizing optically anisotropic germanium selenide (GeSe) are proposed. A simple and cost‐effective GeSe‐SiO2‐Si multilayered optical thin film is constructed and optimized to achieve destructive interference, leading to perfect absorption. The operating wavelength can be linearly tuned from 900 nm to 1300 nm by adjusting the GeSe thickness from 125 nm to 200 nm. Leveraging the significant optical anisotropy, the polarization angle is introduced as an additional parameter to dynamically and finely control the operating wavelength, enabling the creation of polarization‐sensitive perfect absorbers. Experimental results validate the feasibility of fabricating and dynamically modulating the proposed wavelength‐linearly‐dependent and polarization‐sensitive perfect absorbers. This study introduces a novel approach for designing and fabricating reconfigurable perfect absorbers utilizing low‐symmetry materials, facilitating mass production and on‐chip integrated systems.
High‐Permittivity Polysiloxanes for Bright, Stretchable Electroluminescent Devices
Authors: von Szczepanski Johannes , Wolf Jana , Hu Wei‐Hsu , Schneider René , Danner Patrick M. , Kupferschmid André , Jenatsch Sandra , Hany Roland , Nüesch Frank A. , Opris Dorina M.
Published: April 2024

Stretchable alternating current electroluminescent (ACEL) devices have a bright future in wearable electronics and soft robotics. Still, their market application is hindered by high operating voltages. The voltage can be reduced by increasing the relative permittivity of the dielectric elastomer in the emissive layer. Here, a fluorine‐free high‐permittivity silicone elastomer functionalized with cyanopropyl side groups, specially designed for application in stretchable ACEL devices, is introduced. The polar silicone elastomer exhibits excellent mechanical properties and a dielectric permittivity four times higher than commercial PDMS. Light‐emitting devices based on the polar elastomer reach 7.5 times higher maximum luminance at the same electric field than PDMS‐based devices and turn on at a 50% lower electric field. Besides, the polar elastomer‐based devices perform better than all materials tested in literature in achieving high luminance at low electric fields. Stretchable ACEL devices are built from the polar elastomer which shows bright and uniform light emission and can be operated up to 50% strain. The high‐permittivity silicones are promising materials for stretchable ACEL devices and can help their breakthrough to market application by overcoming the drawback of high operating voltages.
Bi‐Functional Chelating Ligand Enables Ultra‐Stable Blue Emissive CsPbBr3 Nanoplatelets Film
Authors: Lin Hao , Gao Pei‐Li , Dong Jia‐Yi , Li Jie‐Lei , Lian Zhen‐Dong , Xu Jin‐Cheng , Ng Kar Wei , Chen Shi , Su Shi‐Chen , Liu Hong‐Chao , Wu Zhao‐Xin , Wang Shuang‐Peng
Published: April 2024

Quantum‐confined perovskite CsPbBr3 Nanoplatelets (NPLs) have recently emerged as promising blue‐emitting materials for perovskite light‐emitting diodes (PeLEDs). Yet, their susceptibility to optical instability in solid films under ambient conditions poses a significant hindrance. This study introduces a novel chelating strategy that utilizes metal manganese ions and multidentate ligands, markedly improving the structural stability, and emission efficiency of NPLs. The approach involves adding Diethylenetriaminepentaacetic acid (DTPA) to the perovskite precursor solution, which allows for strong coordination to surface [PbBr6]4− octahedrons via its multiple chelation sites. Ensuing metal manganese ion integration during the purification phase addresses Pb2+ and Br− site vacancies, culminating in near‐perfect octahedral structures with significantly fewer vacancies. These metal manganese ions are then further immobilized on the NPLs surface by the chelating effect of unbound DTPA functional groups. The resultant CsPbBr3 NPLs films demonstrate an impressive PLQY of 66%, showcasing remarkable air stability with consistent blue emission for up to 5 days. The CsPbBr3 NPLs‐based PeLEDs show electroluminescence at 460 nm with a current efficiency of 1.07 cd A−1 and a maximum luminance of 220 cd m−2. The proposed chelating strategy positions perovskite NPLs as an extremely promising prospect in future applications of high‐definition displays and high‐quality lighting.
Formation of Anisotropic Conducting Interlayer for High‐Resolution Epidermal Electromyography Using Mixed‐Conducting Particulate Composite
Authors: Zhao Zifang , Yu Han , Wisniewski Duncan J. , Cea Claudia , Ma Liang , Trautmann Eric M. , Churchland Mark M. , Gelinas Jennifer N. , Khodagholy Dion
Published: April 2024

Epidermal electrophysiology is a non‐invasive method used in research and clinical practices to study the electrical activity of the brain, heart, nerves, and muscles. However, electrode/tissue interlayer materials such as ionically conducting pastes can negatively affect recordings by introducing lateral electrode‐to‐electrode ionic crosstalk and reducing spatial resolution. To overcome this issue, biocompatible, anisotropic‐conducting interlayer composites (ACI) that establish an electrically anisotropic interface with the skin are developed, enabling the application of dense cutaneous sensor arrays. High‐density, conformable electrodes are also microfabricated that adhere to the ACI and follow the curvilinear surface of the skin. The results show that ACI significantly enhances the spatial resolution of epidermal electromyography (EMG) recording compared to conductive paste, permitting the acquisition of single muscle action potentials with distinct spatial profiles. The high‐density EMG in developing mice, non‐human primates, and humans is validated. Overall, high spatial‐resolution epidermal electrophysiology enabled by ACI has the potential to advance clinical diagnostics of motor system disorders and enhance data quality for human‐computer interface applications.
Cation‐Loaded Porous Mg2+‐Zeolite Layer Direct Dendrite‐Free Deposition toward Long‐Life Lithium Metal Anodes
Authors: Su Ben , Wang Xingyu , Chai Lei , Huo Sida , Qiu Jingyi , Huang Qiang , Li Shuang , Wang Yue , Xue Wendong
Published: April 2024

Lithium metal, with ultrahigh theoretical specific capacity, is considered as an ideal anode material for the lithium‐ion batteries. However, its practical application is severely plagued by the uncontrolled formation of dendritic Li. Here, a cation‐loaded porous Mg2+‐Zeolite layer is proposed to enable the dendrite‐free deposition on the surface of Li metal anode. The skeleton channels of zeolite provide the low coordinated Li+‐solvation groups, leading to the faster desolvation process at the interface. Meanwhile, anions‐involved solvation sheath induces a stable, inorganic‐rich SEI, contributing to the uniform Li+ flux through the interface. Furthermore, the co‐deposition of sustained release Mg2+ realizes a new faster migration pathway, which proactively facilitates the uniform diffusion of Li on the lithium substrate. The synergistic modulation of these kinetic processes facilitates the homogeneous Li plating/stripping behavior. Based on this synergistic mechanism, the high‐efficiency deposition with cyclic longevity exceeding 2100 h is observed in the symmetric Li/Li cell with Mg2+‐Zeolite modified anode at 1 mA cm−2. The pouch cell matched with LiFePO4 cathode fulfills a capacity retention of 88.4% after 100 cycles at a severe current density of 1 C charge/discharge. This synergistic protective mechanism can give new guidance for realizing the safe and high‐performance Li metal batteries.
A New‐Generation Base Editor with an Expanded Editing Window for Microbial Cell Evolution In Vivo Based on CRISPR‒Cas12b Engineering
Authors: Hao Wenliang , Cui Wenjing , Liu Zhongmei , Suo Feiya , Wu Yaokang , Han Laichuang , Zhou Zhemin
Published: April 2024

Base editors (BEs) are widely used as revolutionary genome manipulation tools for cell evolution. To screen the targeted individuals, it is often necessary to expand the editing window to ensure highly diverse variant library. However, current BEs suffer from a limited editing window of 5–6 bases, corresponding to only 2–3 amino acids. Here, by engineering the CRISPR‒Cas12b, the study develops dCas12b‐based CRISPRi system, which can efficiently repress gene expression by blocking the initiation and elongation of gene transcription. Further, based on dCas12b, a new‐generation of BEs with an expanded editing window is established, covering the entire protospacer or more. The expanded editing window results from the smaller steric hindrance compared with other Cas proteins. The universality of the new BE is successfully validated in Bacillus subtilis and Escherichia coli. As a proof of concept, a spectinomycin‐resistant E. coli strain (BL21) and a 6.49‐fold increased protein secretion efficiency in E. coli JM109 are successfully obtained by using the new BE. The study, by tremendously expanding the editing window of BEs, increased the capacity of the variant library exponentially, greatly increasing the screening efficiency for microbial cell evolution.
Adoption of nontraditional governance characteristics in US farmer cooperatives
Authors: Grashuis Jasper , Martinez‐Georges Celina
Published: April 2024

Although the governance of farm producer‐owned and ‐controlled organizations is shaped by the complex interaction of mixed member, director, and manager objectives, its conceptualization in the literature is limited to the assignment of control to members, board directors, and managers. Such a categorization is imperfect as there exist other governance characteristics such as member vote distribution, board director identity, manager identity, and CEO identity. Using 371 survey responses from US farmer cooperatives, we inform the adoption of nontraditional governance characteristics in terms of proportional vote distribution, nonmember board directors (i.e., outside directors), and nonmember managers and CEOs. Furthermore, we relate the adoption of nontraditional characteristics to the competitive scope, organizational function, organizational size, and capital structure of the survey respondents by means of various empirical techniques. Generally, nontraditional adaptation of the governance structure, which implies an advanced delegation of control to decision specialists who are non‐members, is positively associated with the competitive scope and organizational size. Also, such nontraditional adaptation is more common to marketing cooperatives as compared to supply cooperatives. Our study motivates a multi‐dimensional conceptualization of governance, which is necessary to better understand the internal coordination of member and manager objectives. [EconLit Citations: Q13].
Halophytes and heavy metals: A multi‐omics approach to understand the role of gene and genome duplication in the abiotic stress tolerance of Cakile maritima
Authors: Thomas Shawn K. , Hoek Kathryn Vanden , Ogoti Tasha , Duong Ha , Angelovici Ruthie , Pires J. Chris , Mendoza‐Cozatl David , Washburn Jacob , Schenck Craig A.
Published: April 2024

Premise

The origin of diversity is a fundamental biological question. Gene duplications are one mechanism that provides raw material for the emergence of novel traits, but evolutionary outcomes depend on which genes are retained and how they become functionalized. Yet, following different duplication types (polyploidy and tandem duplication), the events driving gene retention and functionalization remain poorly understood. Here we used Cakile maritima, a species that is tolerant to salt and heavy metals and shares an ancient whole‐genome triplication with closely related salt‐sensitive mustard crops (Brassica), as a model to explore the evolution of abiotic stress tolerance following polyploidy.

Methods

Using a combination of ionomics, free amino acid profiling, and comparative genomics, we characterize aspects of salt stress response in C. maritima and identify retained duplicate genes that have likely enabled adaptation to salt and mild levels of cadmium.

Results

Cakile maritima is tolerant to both cadmium and salt treatments through uptake of cadmium in the roots. Proline constitutes greater than 30% of the free amino acid pool in C. maritima and likely contributes to abiotic stress tolerance. We find duplicated gene families are enriched in metabolic and transport processes and identify key transport genes that may be involved in C. maritima abiotic stress tolerance.

Conclusions

These findings identify pathways and genes that could be used to enhance plant resilience and provide a putative understanding of the roles of duplication types and retention on the evolution of abiotic stress response.
Age at peak height velocity in Polish adolescents: Effect of socioeconomic factors
Authors: Gomula Aleksandra , Nowak‐Szczepanska Natalia , Králík Miroslav , Malina Robert M. , Zaręba Monika , Koziel Slawomir
Published: April 2024

Age at peak height velocity (APHV) is an indicator of maturity timing which is applicable to both sexes, and which is influenced by environmental factors. The objective of this study was to assess variation in APHV associated with several indicators of socioeconomic status (SES) in a longitudinal sample of Polish adolescents. The sample included 739 boys born in 1983 and followed annually from 12 to 16 years, and 597 girls born in 1985 and followed annually from 9 to 13 years. The height records were fitted with the SITAR model to estimate APHV. SES was estimated using principal component analysis of indicators of familial status based on parental education, family size, living conditions and household possessions. Statistical analyses included analysis of variance (one‐way for general SES and three‐way for parental education and family size) and Tukey post‐hoc tests for unequal samples. General SES (p <.001) and family size (p < .05) significantly influenced APHV among boys, while only maternal education (p < .05) significantly influenced APHV among girls. Among youth from families of higher SES, as defined by the respective indicators, APHV was attained significantly earlier, on average, than in peers from families of lower SES. Overall, the results showed a sex‐dependent effect of SES on APHV, and highlighted the influence of favorable socioeconomic conditions for optimal growth and maturation during adolescence.