bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analytika učení: nový přístup ke zkoumání učení (nejen) ve virtuálním prostředí
Authors: Juhaňák Libor , Zounek Jiří 
Published: November 2016

Cílem studie je představit a popsat nově se formující výzkumnou oblast označovanou jako analytika učení (learning analytics), která se zaměřuje na využití kvantitativních metod v rámci výzkumu učení (převážně) ve virtuálním prostředí. V první části příspěvku se věnujeme historickým kořenům analytiky ve vzdělávání a mapujeme různé inspirační zdroje, ze kterých analytika učení jakožto svébytná oblast výzkumů vychází a čerpá. Dáváme analytiku učení do souvislosti s příbuznými výzkumnými oblastmi v kontextu výzkumů technologiemi podporovaného učení (technology enhanced learning). Druhá část studie se zaměřuje na samotné vymezení analytiky učení a zpřesnění pojmů. Zároveň přibližuje a srovnává některé z užívaných konceptů (úrovně analytiky ve vzdělávání, proces analytiky učení). Třetí část prezentuje hlavní výzkumné směry analytiky učení, které lze identifikovat v doposud publikovaných odborných zdrojích.
Direct plasma irradiation affects expression of RNAs in cultured mammalian cells
Authors: Kobayashi Mime , Tokaji Hideto , Kumagai Shinya 
Published: November 2016

Abstract
The expression of RNAs in mouse NIH3T3 cells was altered by low-temperature atmospheric-pressure plasma irradiation. Cell culture liquid media were removed before plasma irradiation so that direct plasma effects can be assessed. After 5 s irradiation, the cells were cultured in media for 1 or 3 h and RNA expression was analyzed using a microarray. When analyzed 1 and 3 h after plasma irradiation, the upregulation of hypothetical transmembrane proteins and U3 small nucleolar RNAs was detected at both time points. Our results provide a basic principle for understanding the molecular mechanisms of plasma effects on mammalian cells.
NiO gate GaN-based enhancement-mode hetrojunction field-effect transistor with extremely low on-resistance using metal organic chemical vapor deposition regrown Ge-doped layer
Authors: Suzuki Asamira , Choe Songbeak , Yamada Yasuhiro , Otsuka Nobuyuki , Ueda Daisuke 
Published: November 2016

Abstract
In this paper, we present a normally-off GaN-based transistor with an extremely low on-resistance (R
on) fabricated by using a Ge-doped n++-GaN layer for ohmic contacts. We developed a novel GaN regrowth technique using Ge as a dopant, which achieved an extremely high doping concentration of 1 × 1020 cm−3, and thereby the lowest specific contact resistance of 1.5 × 10−6 Ω·cm2. The NiO gate fabricated using an atomic layer deposition technique reduced the spacing between the source and drain electrodes. The fabricated device showed the record-breaking R
on of 0.95 Ω·mm with the maximum drain current and transconductance of 1.1 A/mm and 490 mS/mm, respectively. Note that the obtained threshold voltage was 0.55 V. This extremely low R
on characteristic indicates the great potential of NiO-gate GaN-based heterojunction field-effect transistors.
Barrier inhomogeneities and interface states of metal/4H-SiC Schottky contacts
Authors: Huang Lingqin , Geiod Rechard , Wang Dejun 
Published: November 2016

Abstract
The barrier and interface states of Ti, Mo, Ni, and Pt contacts to 4H-SiC were investigated. It is found that the barrier heights for all the contacts are Gaussianly distributed and the barrier inhomogeneity varies with the contact metal type. However, the energy-averaged interface states density in the band gap is metal-insensitive. When considering Gaussian distribution, the interface states density extracted from the electrical properties is consistent with the average density of Gaussianly distributed 4H-SiC surface states, indicating that the barrier inhomogeneities at metal/SiC contacts mainly originate from the spatial variation of surface states on SiC surface. The barrier height and barrier inhomogeneity could be modulated by the contact metal, obeying the barrier height theory of Cowley and Sze.
Effects of CO2laser irradiation on matrix-rich biofilm development formation–an in vitro study
Authors: Zancopé Bruna Raquel , Dainezi Vanessa B. , Nobre-dos-Santos Marinês , Duarte Sillas , Pardi Vanessa , Murata Ramiro M. 
Published: November 2016

BackgroundA carbon dioxide (CO2) laser has been used to morphologically and chemically modify the dental enamel surface as well as to make it more resistant to demineralization. Despite a variety of experiments demonstrating the inhibitory effect of a CO2laser in reduce enamel demineralization, little is known about the effect of surface irradiated on bacterial growth. Thus, this in vitro study was preformed to evaluate the biofilm formation on enamel previously irradiated with a CO2laser (λ = 10.6 µM).MethodsFor this in vitro study, 96 specimens of bovine enamel were employed, which were divided into two groups (n = 48): 1) Control-non-irradiated surface and 2) Irradiated enamel surface. Biofilms were grown on the enamel specimens by one, three and five days under intermittent cariogenic condition in the irradiated and non-irradiated surface. In each assessment time, the biofilm were evaluated by dry weigh, counting the number of viable colonies and, in fifth day, were evaluated by polysaccharides analysis, quantitative real time Polymerase Chain Reaction (PCR) as well as by contact angle. In addition, the morphology of biofilms was characterized by fluorescence microscopy and field emission scanning electron microscopy (FESEM). Initially, the assumptions of equal variances and normal distribution of errors were conferred and the results are analyzed statistically by t-test and Mann Whitney test.ResultsThe mean of log CFU/mL obtained for the one-day biofilm evaluation showed that there is statistical difference between the experimental groups. When biofilms were exposed to the CO2laser, CFU/mL and CFU/dry weight in three day was reduced significantly compared with control group. The difference in the genes expression (Glucosyltransferases (gtfB) and Glucan-binding protein (gbpB)) and polysaccharides was not statically significant. Contact angle was increased relative to control when the surface was irradiated with the CO2laser. Similar morphology was also visible with both treatments; however, the irradiated group revealed evidence of melting and fusion in the specimens.ConclusionIn conclusion, CO2laser irradiation modifies the energy surface and disrupts the initial biofilm formation.
Drug Use Patterns in Wastewater and Socioeconomic and Demographic Indicators
Authors: Zhuang Xiaowei , Moshi Michael A. , Quinones Oscar , Trenholm Rebecca A. , Chang Ching-Lan , Cordes Dietmar , Vanderford Brett J. , Vo Van , Gerrity Daniel , Oh Edwin C. 
Published: September 2024

ImportanceMeasuring drug use behaviors in individuals and across large communities presents substantial challenges, often complicated by socioeconomic and demographic variables.ObjectivesTo detect spatial and temporal changes in community drug use by analyzing concentrations of analytes in influent wastewater and exploring their associations with area-based socioeconomic and sociodemographic metrics like the area deprivation index (ADI) and rural-urban commuting area (RUCA) codes.Design, Setting, and ParticipantsThis longitudinal, cross-sectional wastewater study was performed from May 2022 to April 2023 and included biweekly influent wastewater samples of 39 analytes from 8 sampling locations across 6 wastewater treatment plants in southern Nevada. Statistical analyses were conducted in December 2023.Main Outcomes and MeasuresIt was hypothesized that wastewater monitoring of pharmaceuticals and personal care products (PPCPs) and high-risk substances (HRSs) could reveal true spatial and temporal drug use patterns in near–real time. Data collection of samples for PPCPs and HRSs was performed using mass spectrometry. Both ADI and RUCA scores were utilized to characterize neighborhood contexts in the analysis. The false discovery rate (FDR) method was utilized to correct for multiple comparisons (PFDR).ResultsOver the 12-month wastewater monitoring period, 208 samples for PPCPs and HRSs were collected, and analysis revealed an increase in the consumption of HRSs and the seasonal variation in PPCP use in southern Nevada. There was a significant increase in levels of stimulant-associated analytes, such as cocaine (β = 9.17 × 10−4; SE = 1.29 × 10−4; PFDR = 1.40 × 10−10), and opioids or their metabolites, notably norfentanyl (β = 1.48 × 10−4; SE = 1.88 × 10−4; PFDR = 1.66 × 10−12). In contrast, DEET, an active ingredient in mosquito and tick repellents, demonstrated a seasonal use pattern (β = −4.85 × 10−4; SE = 2.09 × 10−4; PFDR = 4.87 × 10−2). Wastewater from more disadvantaged or rural neighborhoods, as assessed through ADI and RUCA scores, was more likely to show a significant positive correlation with HRSs, such as cocaine (β = 0.075; SE = 0.038; P = .05) and norfentanyl (β = 0.004; SE = 0.001; P = 1.64 × 10−5).Conclusions and RelevanceThese findings suggest that wastewater monitoring of PPCPs and HRSs offers a complementary method to existing public health tools, providing timely data for tracking substance use behaviors and use of PPCPs at a population level.
Comparing Confirmed Sodium Nitrite Suicide Deaths With Poison Center Surveillance Estimates
Authors: Bloom Joshua , Sharpe Alexis , Nulman Seth , Monday Katrina , Marraffa Jeanna M. , Stayton Catherine , Clark Carla , Slone Michele , Cooper Gail , Su Mark K. 
Published: September 2024

ImportanceSodium nitrite is a curing agent increasingly used for self-harm and suicide, and multiple locales have reported increasing cases. However, approaches to forensic investigation of these cases are not standardized, and current modes of surveillance in the United States may be inadequate.ObjectiveTo define a potential standard approach for identifying sodium nitrite deaths based on forensic confirmation, and compare findings based on this standard to poison center surveillance.Design, Setting, and ParticipantsThis retrospective case series of sodium nitrite exposures and deaths was conducted in 2 urban medical examiner jurisdictions in New York State from 2000 to 2022. The population-based sample included individuals from (1) medical examiner reports of decedents where the cause of death was sodium nitrite and (2) poison center reports of intentional exposures to sodium nitrite.ExposureSodium nitrite as either cause of death (medical examiner reports) or intentional exposure (poison center reports).Main Outcomes and MeasuresMedical examiner determination of sodium nitrite deaths was considered the criterion standard and relied largely on confirmatory blood nitrite testing. Poison center records were assessed for intentional exposures to sodium nitrite.ResultsIn this case series of 36 decendents, median (range) age was 28 (20-57) years; 23 (63.8%) were male; 6 (16.7%) were African-American, 5 (13.9%) were Chinese, 13 (36.1%) were White, and 4 (11.1%) had unknown race; and 6 (16.7%) were Hispanic. No deaths were found from 2000 to 2018, and yearly increases in deaths from 2019 to 2022; these deaths were largely missed by local poison center surveillance. Most cases (83.3% [n = 30]) had postmortem blood nitrite concentrations available, and multiple decedents had evidence of suicide kit recommendations from internet sources.Conclusions and RelevanceIn this case series of decedents in 2 New York medical examiner jurisdictions, sodium nitrite deaths increased yearly, and the medical examiners were able to obtain confirmatory nitrite concentrations in most cases. These findings suggest that poison center surveillance underestimates confirmed deaths from sodium nitrite; public health authorities should rely on multiple data sources when analyzing this problem, and forensic analyses should be standardized.
A Review on Direct‐Write Nanoprinting of Functional 3D Structures with Focused Electron Beams
Authors: Reisecker V. , Winkler R. , Plank H. 
Published: September 2024

AbstractFollowing Moore`s law, the performance of devices should double within a two‐year span, which can either be done by reducing the size of the individual components or adapting the working mechanism. In most cases the same mantra applies – pushing the size while keeping the quality. As manufacturing techniques are approaching the atomic scale, however, miniaturization reaches its intrinsic limit, shifting focus toward higher‐dimensional architectures realized by stacking planar layers or fabricating true, free‐standing nanostructures. A mask‐less, additive manufacturing technique with the capability to produce such 3D structures at the nanoscale is called Focused Electron Beam Induced Deposition (FEBID). Applying a focused electron beam in a conventional scanning electron microscope together with a gaseous metal‐precursor gives access to a vast library of complex, 3D nanostructures, which exhibit feature sizes down to the 10 nm‐range and can be printed in a single step on most substrates. This review aims at introducing the technique to a broader scientific community, breaking down the most important processing routes and highlighting disciplines explored so far ranging from nanooptics and nanomagnetism, over scanning probes and field emitters to sensing and particle trapping. Finally, a future roadmap of the technique is discussed, and prospective research focus identified.
Enhanced Hydrogen Bonding Through Strong Water‐Locking Additives for Long‐Term Cycling of Zinc Ion Batteries
Authors: Jiang Ruheng , Naren Tuoya , Chen Yuejiao , Chen Zhao , Zhang Chunxiao , Xie Yiman , Chen Libao , Qi Yuyang , Meng Qingfei , Wei Weifeng , Zhou Liangjun 
Published: September 2024

AbstractThe promising energy storage devices, zinc ion batteries (ZIBs), face challenges such as dendritic growth and side reactions, which hinder their application and development. As a polar group, hydroxyl groups can utilize hydrogen bonding to stably anchor water molecules, preventing contact between water and the anode. Moreover, they can attract and guide Zn2+ to rapidly and uniformly deposit on the anode. Here, the introduction of multi‐hydroxyl water‐locking additive Lactobionic acid (LA) molecules is proposed into conventional electrolytes. Through an in situ reaction between the highly reactive carboxyl groups on LA molecules and the zinc anode, a stable multi‐hydroxyl protective layer is formed on the anode surface, effectively preventing interface corrosion and dendritic growth. As a result, the Zn||Zn symmetric cell with LA exhibits remarkable performance, cycling for 2300 h under 1 mA cm−2 and 1 mAh cm−2. Even under more rigorous conditions of 10 mA cm−2 and 10 mAh cm−2, it maintains over 800 h of cycling durability. Moreover, in the Zn||NH4V4O10 full cell configuration, an impressive capacity retention rate of 80.35% after 2000 cycles at a current density of 5 A g−1. This innovative method can open a new avenue for designing high‐performance ZIBs.
Solvent‐ and Temperature‐Switched Chemoselectivity: Controlled Synthesis of Diverse Pyrazolo[5,1‐a]isoquinolines
Authors: Li Chunmei , Xu Meng , Wang Chen , Zhang Furen , Shen Zhenlu 
Published: September 2024

AbstractDivergent synthesis of two types of functionalized pyrazolo[5,1‐a]isoquinolines was established via a one‐pot two‐step protocol involving a tunable dehydrogenation process and deacylative oxidation accompanied by elimination of the HNO2 pathway. Key attributes of the procedure included the initial formation of C,N‐cyclic‐N’‐acyl azomethine imines and subsequent switchable chemoseletivity that either led to aroyl‐ and nitro‐substituted pyrazolo[5,1‐a]isoquinolines or proceeded via deacylative oxidation and elimination of HNO2 pathway to afford the aromatized pyrazolo[5,1‐a]isoquinolines. The present approach features the use of readily available amines and aldehydes as raw materials, switchable chemoselectivity, wide functional group tolerance such as nitro, halide, aryl, aroyl and sulfonyl group, and easy separation and purification. A combination of control experiments and density functional theory (DFT) calculations provided important insights into the possible mechanism.
High Output, Biocompatible, Fully Flexible Fiber‐Based Magneto‐Mechano‐Electric Generator for Standalone‐Powered Electronics
Authors: Ram Nayak , Pabba Durga Prasad , Kaarthik J. , Hwang Geon‐Tae , Vaduganathan Karthik , Venkateswarlu Annapureddy 
Published: September 2024

AbstractHarvesting magnetic noise fields around power cables emerges as an attractive approach due to its potential as a renewable and ubiquitous energy source for powering wireless sensor networks (WSNs) in IoT applications, miniature electronics, and implantable medical devices. Flexible polymer‐based magneto‐mechano‐electric (MME) generators gain attention for their effectiveness in magnetic energy harvesting owing to their durability and flexibility. In this study, a lead‐free, flexible MME generator is developed by using Polyvinylidene fluoride (PVDF)‐Aluminium nitride (AlN)‐nanofiber composites fabricated via electrospinning with different AlN compositions and integrated with a magnetostrictive Metglas layer that offers self‐bias characteristics. The MME generator is modeled using COMSOL Multiphysics to analyze the magnetic flux density distribution over the Metglas surface and the piezoelectric effect of the nanofiber composites, with the simulation results aligning well with the experimental data. The optimized, flexible MME generator, incorporating 15 wt.% of AlN in the PVDF/Metglas composite, achieves an open‐circuit voltage of 18.5 V and a power density of 0.93 mW‐cm−3 when exposed to an Alternating Current (AC) magnetic noise field of 6 Oe at a resonance frequency of 50 Hz. The generated power is sufficient to operate LEDs and sensor. This newly developed lead‐free, flexible MME generator shows significant promise for advanced applications in self‐powered WSNs.
Recent Progress of Transition Metal‐Based Oxide Composite Electrode Materials in Supercapacitor
Authors: Xiong Chuanyin , Su Yadong 
Published: September 2024

AbstractAs an electrochemical energy storage device with high power density, supercapacitors are favored by researchers. Transition metal‐based oxide materials have attracted extensive attention from researchers due to their high theoretical pseudocapacitance characteristics and are used to design and construct high‐performance composite electrode materials for supercapacitors. In this miniature review, the application and existing problems of several typical transition metal‐based oxide composites in the field of supercapacitors in recent years are summarized. Finally, the development trend of transition metal‐based oxide composites in the field of supercapacitors is prospected. The aim is to provide some timely and effective new ideas for the research work of researchers in related fields.
Regulating Cold Energy from the Universe by Bifunctional Phase Change Materials for Sustainable Cooling
Authors: Wang Siqi , Wu Minqiang , Han Han , Du Ruxue , Zhao Zhengchuang , Liu Wenjia , Wu Si , Wang Ruzhu , Li Tingxian 
Published: September 2024

AbstractHarvesting cold energy from the universe by radiative cooling (RC) is a promising zero‐carbon route for green cooling. However, low power density and spatiotemporal energy mismatch of RC are great challenges for realizing efficient space cooling. Herein, a facile strategy for regulating cold energy from the universe by bifunctional phase change materials (PCM) for sustainable cooling is proposed. A bifunctional phase‐change composite film (PCCF) by integrating RC coating with PCM for 24‐h cold energy harvesting, storage, and utilization is demonstrated. The bifunctional PCCF can harvest cold energy from the universe and regulate the redundant cold energy generated by nighttime RC to compensate for the cold shortage of daytime RC, realizing flexible regulation of all‐day RC and setting new records of cooling power up to 180 W m−2 with sub‐ambient temperature drop of 11.95 °C. The work offers a promising strategy for zero‐carbon sustainable cooling by maximizing RC with cold energy storage.
High rate capability and ultra‐long cycling life: Electrochemical synthesis of PEDOT based electrode material doped with AMPS and its supercapacitor application
Authors: Yazar Sibel , Yilmaz Sıla Melahat , Atun Gülten 
Published: September 2024

AbstractPoly(3,4‐ethylene dioxythiophene) (PEDOT) is a conducting polymer that can be used in flexible bioelectronic devices. The electrode/electrolyte interface interaction is one of the most important factors in improving the electrochemical performance of energy storage materials, and these polymers are often combined with a negatively charged poly(styrene sulfonate) (PSS) chain to improve their interaction with alkali metal cations such as sodium and potassium. In this work, we performed a one‐step electrochemical synthesis of PEDOT on carbon fabric using the molecule 2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid (AMPS) to create highly effective materials for supercapacitor electrodes. The electrode had a significant increase in capacitance value, measured 16.4 times higher than that of the PEDOT electrode. The 2‐electrode system exhibited a specific capacitance value of 495.2 F g−1 at a scan rate of 5 mV s−1. It exhibited a high operating voltage of 2.3 V in aqueous electrolyte system. It showed a significant energy density of 109.0 Wh kg−1 when operating at 6.1 kW kg−1 power density and 85.2 Wh kg−1 when operating at 30.6 kW kg−1 power density. Recent findings reveal that the capacitance retention performance value of the device increased significantly to 113.9% after 25,000 cycles in 3.0 M NaCl aqueous electrolyte, demonstrating its outstanding long‐term durability. Thus, the creation of the synthesized supercapacitor electrode is a significant advance in the study of conducting polymers, which often have a limited lifetime in real‐world electronic applications.