bluuebunny/crossref_metadata_2025 huggingface dataset:
Spiroborate‐Based Host Materials with High Triplet Energies and Ambipolar Charge‐Transport Properties
Authors: Hayakawa Masahiro , Kameda Mayu , Kawasumi Ryosuke , Nakatsuka Soichiro , Yasuda Nobuhiro , Hatakeyama Takuji
Published: January 2023

Organic light‐emitting diodes (OLEDs) receive considerable attention because of their commercial use in flat panel displays. Herein, highly efficient spiroborate‐based host materials are reported for use in blue OLEDs. Our designed spiroborates (SBOX) were simple to synthesize and exhibited high triplet excitation energies, narrow S‐T gaps, and balanced charge carrier mobilities. A blue OLED containing one of the designed spiroborates, SBON, as a host exhibited a high external quantum efficiency (27.6 %) and low turn‐on voltage (3.7 V) compared to those observed using 3,3′‐di(9H‐carbazol‐9‐yl)‐1,1′‐biphenyl (17.6 % and 4.5 V, respectively), indicating their potential as host materials in OLEDs.
Pore‐Environment‐Dependent Photoresponsive Oxidase‐Like Activity in Hydrogen‐Bonded Organic Frameworks
Authors: Tong Linjing , Lin Yuhong , Kou Xiaoxue , Shen Yujian , Shen Yong , Huang Siming , Zhu Fang , Chen Guosheng , Ouyang Gangfeng
Published: January 2023

Mimicking the bioactivity of native enzymes through synthetic chemistry is an efficient means to advance the biocatalysts in a cell‐free environment, however, remains long‐standing challenges. Herein, we utilize structurally explicit hydrogen‐bonded organic frameworks (HOFs) to mimic photo‐responsive oxidase, and uncover the important role of pore environments on mediating oxidase‐like activity by means of constructing isostructural HOFs. We discover that the HOF pore with suitable geometry can stabilize and spatially organize the catalytic substrate into a favorable catalytic route, as with the function of the native enzyme pocket. Based on the desirable photo‐responsive oxidase‐like activity, a visual and sensitive HOFs biosensor is established for the detection of phosphatase, an important biomarker of skeletal and hepatobiliary diseases. This work demonstrates that the pore environments significantly influence the nanozymes’ activity in addition to the active center.
Functional Roles of Polymers in Room‐Temperature Phosphorescent Materials: Modulation of Intersystem Crossing, Air Sensitivity and Biological Activity
Authors: Su Hao , Hu Kan , Huang Wenhuan , Wang Tao , Zhang Xiaolong , Chen Biao , Miao Hui , Zhang Xuepeng , Zhang Guoqing
Published: January 2023

Organic room‐temperature phosphorescent (RTP) materials routinely incorporate polymeric components, which usually act as non‐functional or “inert” media to protect excited‐state phosphors from thermal and collisional quenching, but are lesser explored for other influences. Here, we report some exemplary “active roles” of polymer matrices played in organic RTP materials, including: 1) color modulation of total delayed emissions via balancing the population ratio between thermally‐activated delayed fluorescence (TADF) and RTP due to dielectric‐dependent intersystem crossing; 2) altered air sensitivity of RTP materials by generating various surface morphologies such as nano‐sized granules; 3) enhanced bacterial elimination for enhanced electrostatic interactions with negatively charged bio‐membranes. These active roles demonstrated that the vast library of polymeric structures and functionalities can be married to organic phosphors to broaden new application horizons for RTP materials.
Iridium‐Catalyzed Chemo‐, Diastereo‐, and Enantioselective Allyl‐Allyl Coupling: Accessing All Four Stereoisomers of (E)‐1‐Boryl‐Substituted 1,5‐Dienes by Chirality Pairing
Authors: Jung Yongsuk , Yoo Seok Yeol , Jin Yonghoon , You Jaehyun , Han Seungcheol , Yu Jeongwoo , Park Yoonsu , Cho Seung Hwan
Published: January 2023

Here, we report a highly chemo‐, diastereo‐, and enantioselective allyl‐allyl coupling between branched allyl alcohols and α‐silyl‐substituted allylboronate esters, catalyzed by a chiral iridium complex. The α‐silyl‐substituted allylboronate esters can be chemoselectively coupled with allyl electrophiles, affording a diverse set of enantioenriched (E)‐1‐boryl‐substituted 1,5‐dienes in good yields, with excellent stereoselectivity. By permuting the chiral iridium catalysts and the substrates, we efficiently and selectively obtained all four stereoisomers bearing two consecutive chiral centers. Mechanistic studies via density functional theory calculations revealed the origins of the diastereo‐ and chemoselectivities, indicating the pivotal roles of the steric interaction, the β‐silicon effect, and a rapid desilylation process. Additional synthetic modifications for preparing a variety of enantioenriched compounds containing contiguous chiral centers are also included.
Peroxodicarbonate as a Green Oxidizer for the Selective Degradation of Kraft Lignin into Vanillin
Authors: Zirbes Michael , Graßl Tobias , Neuber Rieke , Waldvogel Siegfried R.
Published: January 2023

Lignin, the world's largest resource of renewable aromatics, with annually roughly 50 million tons of accruing technical lignin, mainly Kraft lignin, is highly underdeveloped regarding the production of monoaromatics. We demonstrate the oxidative depolymerization of Kraft lignin at 180 °C to produce vanillin 1 in yields up to 6.2 wt % and 92 % referred to the maximum yield gained from the quantification reaction utilizing nitrobenzene. Using peroxodicarbonate (C2O62−) as “green” oxidizer for the degradation, toxic and/or harmful reagents are prevented. Also, the formed waste can serve as makeup chemical in the pulping process. Na2C2O6 is synthesized in an ex‐cell electrolysis of aqueous Na2CO3 at BDD anodes, achieving a yield of Na2C2O6 with 41 %. At least, the oxidation and degradation of Kraft lignin is analysis via UV/Vis and NMR spectroscopy.
Copolymer Mediated Engineering of Halide Perovskites and Associated Devices: Current State and Future
Authors: Mathur Avi , Khamgaonkar Saikiran , Maheshwari Vivek
Published: January 2023

The field of halide perovskites has advanced significantly within a decade, as engineering strategies are addressing many of the challenges and as a result improved environmental stability and electro‐optical properties have been achieved. The use of the copolymer additive strategy has received significant attention in recent years as a variety of polymers with significant differences in properties such as water affinity, polarity, elastic modulus, ion conductivity and basis for interaction with perovskite can be selected and combined with halide perovskite. As a result, there has been a rapid increase in publications reporting the effectiveness of the inexpensive and readily available copolymer additives in altering the physicochemical, mechanical, and electro‐optical properties of the halide perovskites‐based high‐performance devices. This article is an effort to provide insight into the current state of copolymer‐mediated engineering of halide perovskites with a perspective on the reported improvements in the properties and performance of the perovskite‐based devices. Critical analysis is done on the potential of the copolymer–perovskite materials toward realizing commercial applications.
Fractional‐order PID and internal model control‐based dual‐loop load frequency control using teaching–learning optimization
Authors: Veerendar Tejavath , Kumar Deepak , Sreeram Victor
Published: January 2023

A load frequency controller is essential to counter load disturbances and minimize unscheduled power flow between interlinked areas of a power system. Hence, this paper proposes a fractional‐order proportional‐integral derivative (FOPID)‐based dual‐loop control approach for load frequency control of multi‐area nonreheated thermal power systems (NRTPS) using teaching–learning optimization (TLO). A stability equation‐based predictive model is used with internal model control in the internal loop of the proposed approach, whereas the external loop contains TLO‐based FOPID controller. The proposed method is tested on two‐area and three‐area NRTPSs under various operating conditions. It is validated from the simulation results that the proposed approach improves the system response substantially compared to the well‐known existing techniques. The robustness of the proposed method is also demonstrated by performing sensitivity analysis with parametric uncertainties, random load disturbances, generation rate constraints, and governor dead zone.
It is not the time to abandon intraoperative frozen section in endometrioid adenocarcinoma: A large‐scale, multi‐center, and retrospective study
Authors: Yang Xiaohang , Yin Jingjing , Fu Yu , Shen Yuanming , Zhang Chuyao , Yao Shuzhong , Xu Congjian , Xia Min , Lou Ge , Liu Jihong , Lin Bei , Wang Jianliu , Zhao Weidong , Zhang Jieqing , Cheng Wenjun , Guo Hongyan , Guo Ruixia , Xue Fengxia , Wang Xipeng , Han Lili , Li Xiaomao , Zhang Ping , Zhao Jianguo , Li Wenting , Dou Yingyu , Wang Zizhuo , Liu Jingbo , Li Kezhen , Chen Gang , Sun Chaoyang , Wang Beibei , Yang Xingsheng
Published: January 2023

Introduction

Stage IB (deep myometrial invasion) high‐grade endometrioid adenocarcinoma (EA), regardless of LVSI status, is classified into high‐intermediate risk groups, requiring surgical lymph node staging. Intraoperative frozen section (IFS) is commonly used, but its adequacy and reliability vary between reports. Hence, we determined the utility of IFS in identification of high‐risk factors, including deep myometrial invasion and high‐grade.

Method

We retrospectively analyzed 9,985 cases operated with hysterectomy and diagnosed with FIGO stage I/II EA in postoperative paraffin section (PS) results at 30 Chinese hospitals from 2000 to 2019. We determined diagnostic performance of IFS and investigated whether the addition of IFS to preoperative biopsy and imaging could improve identification of high‐risk factors.

Results

IFS and postoperative PS presented the highest concordance in assessing deep myometrial invasion (Kappa: 0.834), followed by intraoperative gross examination (IGE Kappa: 0.643), MRI (Kappa: 0.395), and CT (Kappa: 0.207). IFS and postoperative PS presented the highest concordance for high‐grade EA (Kappa: 0.585) compared to diagnostic curettage (D&C 0.226) and hysteroscope (Hys 0.180). Sensitivity and specificity for detecting deep myometrial invasion were 86.21 and 97.20% for IFS versus 51.72 and 88.81% for MRI, 68.97 and 94.41% for IGE. These figures for detecting high‐grade EA were 58.21 and 96.50% for IFS versus 16.42 and 98.83% for D&C, 13.43 and 98.64% for Hys. Parallel strategies, including MRI‐IFS (Kappa: 0.626), D&C‐IFS (Kappa: 0.595), and Hys‐IFS (Kappa: 0.578) improved the diagnostic efficiencies of individual preoperative examinations. Based on the high sensitivity of IFS, parallel strategies improved the sensitivities of preoperative examinations to 89.66% (MRI), 64.18% (D&C), 62.69% (Hys), respectively, and these differences were statistically significant (p = 0.000).

Conclusion

IFS presented reasonable agreement rates predicting postoperative PS results, including deep myometrial invasion and high‐grade. IFS helps identify high‐intermediate risk patients in preoperative biopsy and MRI and guides intraoperative lymphadenectomy decisions in EA.
Tailored BiVO4/In2O3 nanostructures with boosted charge separation ability toward unassisted water splitting
Authors: Lee Mi Gyoung , Yang Jin Wook , Park Ik Jae , Lee Tae Hyung , Park Hoonkee , Cheon Woo Seok , Lee Sol A. , Lee Hyungsoo , Ji Su Geun , Suh Jun Min , Moon Jooho , Kim Jin Young , Jang Ho Won
Published: January 2023

The development of new heterostructures with high photoactivity is a breakthrough for the limitation of solar‐driven water splitting. Here, we first introduce indium oxide (In2O3) nanorods (NRs) as a novel electron transport layer for bismuth vanadate (BiVO4) with a short charge diffusion length. In2O3 NRs reinforce the electron transport and hole blocking of BiVO4, surpassing the state‐of‐the‐art photoelectrochemical performances of BiVO4‐based photoanodes. Also, a tannin–nickel–iron complex (TANF) is used as an oxygen evolution catalyst to speed up the reaction kinetics. The final TANF/BiVO4/In2O3 NR photoanode generates photocurrent densities of 7.1 mA cm−2 in sulfite oxidation and 4.2 mA cm−2 in water oxidation at 1.23 V versus the reversible hydrogen electrode. Furthermore, the “artificial leaf,” which is a tandem cell with a perovskite/silicon solar cell, shows a solar‐to‐hydrogen conversion efficiency of 6.2% for unbiased solar water splitting. We reveal significant advances in the photoactivity of TANF/BiVO4/In2O3 NRs from the tailored nanostructure and band structure for charge dynamics.
A Simple Four‐Step Synthesis of the Potato Alkaloid Demissidine from the Common Sapogenin Tigogenin
Authors: Baj Aneta , Kaewnok Nirawit , Rivas‐Loaiza Juan A. , Szymańska Magdalena , Witkowski Stanisław , Wojtkielewicz Agnieszka , Morzycki Jacek W.
Published: January 2023

A simple synthesis method of solanidane alkaloids from common steroidal sapogenins was developed. Previously described multi‐step transformations of tigogenin to demissidine (8–12 steps) were shortened to four steps only. The key‐step of the present synthesis was the epimerization at C25 of the lactam intermediate. Different approaches to this reaction, i. e., a classical one via enolate, and a chemoselective umpolung transformation, were thoroughly investigated. The epimerization step is unnecessary if the starting sapogenin has the same configuration at C25 as the target alkaloid because the configuration at C25 (either R or S) remains intact throughout the synthesis. Thus, the related solanidane alkaloids, 12β‐hydroxy‐25‐epi‐demissidine and 5‐epi‐demissidine, were synthesized in the three‐step procedure with retention of configuration at this stereogenic center from rockogenin (25R‐5α‐sapogenin) or sarsasapogenin (25S‐5β‐sapogenin), respectively.
In Situ X‐ray Diffraction Studies on the Reduction of V2O5 and WO3 by Using Hydrogen
Authors: Keilholz Simon , Paul Roman , Dorsch Leonhard Yuuta , Kohlmann Holger
Published: January 2023

The reduction of metal oxides with hydrogen is widely used for the production of fine chemicals and metals both on the laboratory and industry scale. In situ methods can help to elucidate reaction pathways and to gain control over such synthesis reactions. In this study, the reduction of WO3 and V2O5 with hydrogen was investigated by in situ X‐ray powder diffraction with regard to intermediates and the influence of heating rates and hydrogen flow rates. Mixtures of V4O9, V6O13 and VO2 in two modifications were identified as intermediates on the way to phase‐pure V2O3. None of the intermediates occurs in a single phase and therefore cannot be prepared this way. In contrast, the intermediates of the WO3 reduction, H0.23WO3 and W10O29, appear consecutively and can be isolated. For both reactions, the heating and flow rates have little influence on the formation of intermediates.
Belongingness on the go: Examining road warrior consultants’ experiences of belongingness with their firms
Authors: Bhatt Mamta , Vakkayil Jacob
Published: January 2023

We examine how “road warrior consultants,” who spend a majority of workweek at the client location, describe their experiences of belongingness with their companies. Based on observations and semi‐structured interviews with consultants, we identified three facets of consultants' experiences that were significant for organizational belongingness, namely: (1) connection with colleagues which refers to their interactions with others at their firm; (2) differentiation at the client firm which signifies experiences of differences and being an outsider at the client firm; (3) centrality of oneself at the consulting firm or experiences of handling significant roles in their firm. Our findings contribute to the literatures on consulting and belongingness, and also have broader implications for understanding belongingness dynamics in client‐service professions.
Design of recustomize finite impulse response filter using truncation based scalable rounding approximate multiplier and error reduced carry prediction approximate adder for image processing application
Authors: Senthilkumar S. , Samuthira Pandi V. , Sripriya T. , Pragadish N.
Published: January 2023

Recustomize finite impulse response (RFIR) filter is designed to achieve lesser power consume, cost, area, and higher speed of system operation. This is used to remove the noises from the image and signal. Previously, several filters were designed for removing noises, but that filters consume more area, power, cost, and delay and did not provide accurate results and the error rate was increased. To overcome these issues, this work is proposed. In this work, the Recustomize finite impulse response (RFIR) filter is designed using truncation‐based scalable rounding approximate multiplier (TOSAM) and error reduced carry prediction approximate adder (ERCPAA) for image processing application. Here, TOSAM‐ERCPAA is used to speed up the filter design with less area and less power consumption. The proposed ERCPAA adder is divided into three blocks, such as carry prediction logic, approximate full adder cells array, constant truncation along error lessening logic, which can reduce the power and area. The proposed RFIR‐ TOSAM‐ERCPAA filter is designed and executed in Verilog programming language and the simulation is done in Xilinx ISE 14.5 design tools.
Inter‐Alkali‐Metal Dative Bond in the MMN3−(M=Alkali Metal) Cluster
Authors: Kanti Guha Ankur
Published: January 2023

Alkali metals are generally Lewis acids. On the contrary, Lewis basic character of alkali metals forming donor – acceptor complexes is a very rare phenomenon. In this contribution, I have theoretically designed an anionic cluster MMN3−(M=alkali metals) on the basis of experimentally known reagent, alkali salt of azide ion MN3, which shows unprecedented M:−→M donor‐acceptor interaction. To the best of author's knowledge, the characterization of such donor‐acceptor interaction among alkali metals is unprecedented. Formation of the 2c–2e donor‐acceptor bonds have been confirmed by quantum theory of atoms in molecules and electron localization function analyses. The calculated bond dissociation energies are significant suggesting their possible spectroscopic identification.
Discriminative accuracy of the A/T/N scheme to identify cognitive impairment due to Alzheimer's disease
Authors: Pascoal Tharick A. , Leuzy Antoine , Therriault Joseph , Chamoun Mira , Lussier Firoza , Tissot Cecile , Strandberg Olof , Palmqvist Sebastian , Stomrud Erik , Ferreira Pamela C. L. , Ferrari‐Souza João Pedro , Smith Ruben , Benedet Andrea Lessa , Gauthier Serge , Hansson Oskar , Rosa‐Neto Pedro
Published: January 2023

Introduction

The optimal combination of amyloid‐β/tau/neurodegeneration (A/T/N) biomarker profiles for the diagnosis of Alzheimer's disease (AD) dementia is unclear.

Methods

We examined the discriminative accuracy of A/T/N combinations assessed with neuroimaging biomarkers for the differentiation of AD from cognitively unimpaired (CU) elderly and non‐AD neurodegenerative diseases in the TRIAD, BioFINDER‐1 and BioFINDER‐2 cohorts (total n = 832) using area under the receiver operating characteristic curves (AUC).

Results

For the diagnosis of AD dementia (vs. CU elderly), T biomarkers performed as well as the complete A/T/N system (AUC range: 0.90–0.99). A and T biomarkers in isolation performed as well as the complete A/T/N system in differentiating AD dementia from non‐AD neurodegenerative diseases (AUC range; A biomarker: 0.84–1; T biomarker: 0.83–1).

Discussion

In diagnostic settings, the use of A or T neuroimaging biomarkers alone can reduce patient burden and medical costs compared with using their combination, without significantly compromising accuracy.
Differences in red blood cell mass profiles impact intravascular volume and outcome risk in chronic heart failure
Authors: Miller Wayne L. , Grill Diane E. , Mullan Brian P.
Published: January 2023

Aims

To identify different red blood cell mass (RBCM) profiles, separate from haemoglobin concentrations, and their impact on blood volume expansion and clinical outcomes in chronic heart failure.

Methods and results

RBCM was measured at hospital discharge using standardized nuclear medicine indicator‐dilution methodology in patients following diuretic treatment for clinical congestion. Individual RBCM phenotypes were prospectively identified and analysed for heart failure‐related mortality or first rehospitalization over 1 year.

Of 132 patients, 42 (32%) demonstrated normal RBCM, 36 (27%) RBCM deficit (true anaemia), and 54 (41%) RBCM excess (erythrocythemia). Dilutional ‘anaemia’ defined by haemoglobin <12 g/dL with normal or an excess in RBCM with plasma volume expansion was identified in 37 (28%) patients. There were 61 composite outcome events, which included 38 deaths (29% of cohort) occurring over the 1 year follow‐up period [14/36 (39%) in RBCM deficit, 12/42 (29%) in normal RBCM, and 12/54 (22%) in RBCM excess subgroups]. By Kaplan–Meier and multivariate analyses, RBCM excess was independently associated with the best event‐free survival while RBCM deficit (true anaemia) the poorest outcomes; both compared with normal RBCM (P < 0.001). Dilutional ‘anaemia’ demonstrated a lower risk compared with true anaemia (P = 0.03).

Conclusions

Markedly different RBCM profiles are identifiable among comparably compensated heart failure patients, and this variability carries significant implications for post‐hospital outcomes. Novel to this analysis and in contrast to RBCM deficit is the independent association of RBCM excess with better event‐free survival compared with normal RBCM. The distinction of RBCM profiles to guide risk stratification and individualized patient management strategies warrants further study.
Decrease of air pollution during lockdown in Tuscany (Italy): An effect on sperm DNA fragmentation?
Authors: Calamai Costanza , Ammar Oumaima , Marchiani Sara , Degl'Innocenti Selene , Fino Marisa , Righi Lorenzo , Dabizzi Sara , Maggi Mario , Baldi Elisabetta , Vignozzi Linda , Muratori Monica
Published: January 2023

In March 2020, the Italian government imposed a national lockdown which was almost completely removed in June 2020. Due to the abrupt stop of human activities, emissions of air pollutants decreased. Air pollution is an environmental risk factor for noncommunicable disease and mortality. Emerging evidence also suggests a role in male infertility. In this study, we compared sperm DNA fragmentation (sDF) levels and conventional semen parameters between subjects undergoing sDF determination and routine semen analysis in a single Italian centre, during about 6 months before (N = 119) and after lockdown (N = 105). After lockdown, we found an improvement of sperm progressive motility (48.00[38.50–58.00]% vs. 42.00[33.00–53.00]%) and sDF levels (as total: 24.79[18.33–33.97]% vs. 35.02[25.04–45.73]%, p < .001; brighter: 14.02[10.69–17.93]% vs 18.54[13.58–25.82]%, p < .001 and dimmer sDF: 9.24[5.64–15.78]% vs. 12.24[8.08–19.10]%, p < .01), mirrored by a decrease of leukocyte semen concentration (p < .01). The improvement of sperm motility and DNA quality was maintained after adjusting for leukocyte concentration and several conditions known to affect sperm motility and/or sDF levels. With a significant decrease in air pollution observed in Tuscany during and after lockdown, associated improvement in sperm motility and DNA quality in patients referred to the infertility clinic is suggestive of the potential role of air pollution in male infertility.
A high‐order stabilized solver for the volume averaged Navier‐Stokes equations
Authors: Geitani Toni El , Golshan Shahab , Blais Bruno
Published: January 2023

The volume‐averaged Navier‐Stokes equations are used to study fluid flow in the presence of fixed or moving solids such as packed or fluidized beds. We develop a high‐order finite element solver using both forms A and B of these equations. We introduce tailored stabilization techniques to prevent oscillations in regions of sharp gradients, to relax the Ladyzhenskaya–Babuska–Brezzi inf‐sup condition, and to enhance the local mass conservation and the robustness of the formulation. We calculate the void fraction using the particle centroid method. Using different drag models, we calculate the drag force exerted by the solids on the fluid. We implement the method of manufactured solution to verify our solver. We demonstrate that the model preserves the order of convergence of the underlying finite element discretization. Finally, we simulate gas flow through a randomly packed bed and study the pressure drop and mass conservation properties to validate our model.
Stability effect of multidimensional velocity components in numerical flux SLAU
Authors: Furusawa Yoshikatsu , Kitamura Keiichi
Published: January 2023

In computational fluid dynamics of compressible fluid flow, the simple low‐dissipation advection upstream (SLAU) scheme formulated with multidimensional velocity components (normal and parallel to a cell interface) is a widely employed all‐speed scheme. As a variant of SLAU, the mSLAU scheme, which adopts only a velocity component normal to the cell interface instead of multidimensional velocity components, is used for rotorcraft calculations. However, although mSLAU has been claimed to be empirically stable, it has been pointed out that using only the cell‐interface‐normal velocity component instead of the multidimensional velocity components causes numerical instability. Therefore, to clarify the roles of the multidimensional velocity components for computational stability, we solved some benchmark problems associated with using SLAU or mSLAU. We discovered that the multidimensional velocity components contributed to stability against poor‐quality grids by isotropically producing enough amount of numerical dissipation, especially in low‐subsonic and supersonic flows. Although mSLAU could practically treat moderate Mach number flows (approximately 0.1 < M < 1.0) when coupled with the minmod limiter, using only the cell‐interface‐normal velocity component can deteriorate convergence of calculations and lead to susceptibility in the grid geometry.
Jump forecasting in foreign exchange markets: A high‐frequency analysis
Authors: Uzun Sevcan , Sensoy Ahmet , Nguyen Duc Khuong
Published: January 2023

Using tick data for 14 emerging and developed market currencies covering the period from January 2018 until April 2021, we first detect jumps by Lee and Mykland methodology then apply various machine learning algorithms to forecast out of sample jump occurrences and their direction. Our results show that the arrival and the direction of intraday jumps in the foreign exchange market can be predicted with these algorithms combined with liquidity metrics and technical indicators, even for the Covid pandemic period where volatility in the foreign exchange market is very high. Among all the methods considered, multilayer perceptron has the highest average accuracy for jump prediction overall, followed by support vector machine and random forest methodologies with slightly less average accuracy results. Results are robust to alternative sampling schemes. Accordingly, central bankers can adjust liquidity injection timing with these jump prediction models in the foreign exchange markets where they can try to minimize jump strength if not completely eliminate its occurrence. For investors, having information regarding jump occurrence timings gives an opportunity to hedge against foreign exchange risks more efficiently.
Fine characterization of pore evolution of oil shale during thermal simulation
Authors: Liu Gaofei , Liu Rong , Liu Qianghao , Xu Meijing
Published: January 2023

Oil shale is a kind of organic‐rich fine‐grained sedimentary, whose pore evolution is affected not only by the evolution of inorganic minerals, but also by the thermal evolution of organic matter (OM). Meanwhile, the interaction between inorganic minerals and OM makes the pore evolution of oil shale more complex. Therefore, it is more important to fine the evolution characteristic of pores in different maturity stages and explore the pore size range affected by each influencing factor. This study selects immature oil shale (Tmax = 430°C, TOC = 8.2%) of Nenjiang Formation in Songliao Basin as a research object, and samples with different maturity are obtained through a series of thermal simulation experiments. Combined with petromineralogy, organic geochemistry and reservoir physical property analysis, the evolution process of pores is determined. The volume and specific surface area evolution of mesopores is different from that of macropores in the immature to mature stage, the volume and specific surface area evolution of which is same in the mature to over‐mature stage. There is a strong positive correlation between volumes of macropores and porosity (R2 = 0.94), between volumes of mesopores and specific surface area (R2 = 0.96). The influencing factors mainly affect the pore size less than 400 nm. Hydrocarbon generation of OM affects the whole pore sizes. Residual oil is stored in pores with pore size of 5–25 nm. The effect of carbonate dissolution and pyrite pyrolysis on mesopores is stronger than that of macropores. The transformation of illite/smectite to illite mainly affects the pore size greater than 100 nm. In the whole process of thermal simulation, the OM thermal evolution, the inorganic minerals dissolution and pyrolysis and the clay minerals transformation are the main influencing factors of pore evolution.
Preparation of 3‐Bromo‐1,2,4,5‐tetrazine
Authors: Hoff Lukas V. , Schnell Simon D. , Benchimol Elie , Foutinho Fabio Pereira , Tomio Andrea , Rickhaus Michel , Gademann Karl
Published: January 2023

In this synthetic procedure, a seven‐step protocol for the preparation of monosubstituted 3‐bromo‐1,2,4,5‐tetrazine is presented. The procedure features efficient transformations and purification methods starting from commercially readily available starting materials and affords the title compound on a gram scale with 13 % overall yield in reliable purity (>97 %). Detailed experimental procedures, supported by images and additional notes, allow the preparation of a valuable advanced building block, enabling further applications in bioconjugation, protein labelling, bio‐orthogonal chemistry, heterocycle syntheses, high energy materials, and drug release, among others.
What are the predictors of sexting behavior among adolescents? The positive youth development approach
Authors: Pistoni Carlo , Martinez Damia Sara , Alfieri Sara , Marta Elena , Confalonieri Emanuela , Pozzi Maura
Published: January 2023

Introduction

Research supporting adolescent sexual health and empowerment is needed. The study investigates sexting among adolescents using the resources that characterized the Positive Youth Development Approach (PYD) and considering the impact of parental monitoring. The study aims to describe sexting among three different groups of adolescents (i.e., Non Sexters [NS], Passive Sexters [PS], and Active Sexters [AS]) considering age and sex (first aim). It also seeks to identify predictors among the PYD's resources and parental monitoring that explain the probability of falling into the sexter or the non sexter groups (second aim) as well as the probability of falling into the active or the passive sexter groups (third aim).

Method

The national representative sample was composed of 1866 Italian adolescents: 980 girls and 886 boys aged between 13 and 19 years old (M = 16.26; SD = 1.49). Participants completed a questionnaire that measured sexting behavior, PYD resources, and parental monitoring scales. Chi‐squared and multivariate logistic regressions were performed.

Results

Almost half of the participants (46.0%) were NS, 36.2% were PS, and 17.8% were AS. Results show that sex, age, Connection, and Child Disclosure are significant predictors of sexting behavior.

Conclusions

Results highlighted that sexting can be seen as a relational activity that adolescents use to establish connections as part as their sexual exploration. A parenting approach that promotes disclosure may help adolescents explore safely their sexuality and be accountable. Results also indicate that parents need to build educational alliances with schools to promote sexual health and empowerment among teenagers while preventing risk of harm.
Property and biological effects of the cuttlebone derived calcium phosphate particles, a potential bioactive bone substitute material
Authors: Tangsuksant Thanin , Ummartyotin Sarute , Pongprayoon Thirawudh , Arpornmaeklong Premjit , Apinyauppatham Komsan
Published: January 2023

Cuttlebone (CB) is a marine waste‐derived biomaterial and a rich source of calcium carbonate for the biosynthesis of the calcium phosphate (CaP) particles. The current study aimed to synthesize CB derived biphasic calcium phosphate (CB‐BCP) and investigate biological activity of the CB‐CaP: hydroxyapatite (CB‐HA), beta‐tricalcium phosphate (CB‐b‐TCP) and biphasic 60:40 (w/w) HA/b‐TCP (CB‐BCP) with the human dental pulp stem cells (hDPSCs). The particles were synthesized using solid state reactions under mild condition and properties of the particles were compared with a commercial BCP as a reference material. Morphology, particle size, physicochemical properties, mineral contents, and the ion released patterns of the particles were examined. Then the particle/cell interaction, cell cytotoxicity and osteogenic property of the particles were investigated in the direct and indirect cell culture models. It was found that an average particles size of the CB‐HA was 304.73 ± 4.19 nm, CB‐b‐TCP, 503.17 ± 23.06 nm and CB‐BCP, 1394.67 ± 168.19 nm. The physicochemical characteristics of the CB‐CaP were consistent with the HA, b‐TCP and BCP. The highest level of calcium (Ca) was found in the mineral contents and the preincubated medium of the CB‐BCP and traces of fluoride, magnesium, strontium, and zinc were identified in the CB‐CaP. The cell cytotoxicity and osteogenic property of the particles were dose dependent. The particles adhered on cell surface and were internalized into the cell cytoplasm. The CB‐BCP and CB‐HA indirectly and directly promote osteoblastic differentiations of the hDPSCs in stronger levels than other groups. The CB‐BCP and CB‐HA were potential bioactive bone substitute materials.
A generic rotamer model to explain the temperature dependence of BSA protein fluorescence
Authors: Chou Yun‐Chu , Lin Tong‐You , Tsai Min‐Yeh
Published: January 2023

Protein fluorescence signals essential information about the conformational dynamics of proteins. Different types of intrinsic fluorophores reflect different protein local or global structural changes. Bovine Serum Albumin (BSA) is a transport protein that contains two intrinsic fluorophores: Tryptophan134 (Trp134) and Tryptophan213 (Trp213). This protein displays an interesting temperature dependence of the tryptophan fluorescence. However, the molecular mechanism of the temperature dependence is still unclear. In this work, we propose a generic rotamer model to explain this phenomenon. The model assumes the presence of rotamer‐specific fluorescence lifetimes. The fluorescence temperature dependence is caused by the population shifts between different rotamers due to thermal effects. As a proof of concept, we show that the tryptophan's two fluorescence lifetimes (𝜏1 = 0.4–0.5 ns and 𝜏2 = 2‐4 ns) are sufficient to qualitatively explain the fluorescence intensity change at different temperatures, both in buffer solution (water) and in the protein. To computationally verify our rotamer hypothesis, we use an all‐atom molecular dynamics simulation to study the effects of temperature on the two tryptophans' rotamer dynamics. The simulations show that Trp134 is more sensitive to temperature, consistent with experimental observations. Overall, the results support that the temperature dependence of fluorescence in the protein BSA is due to local conformational changes at the residue level. This work sheds light on the relationship between tryptophan's rotamer dynamics and its ability to fluorescence.
The benefits of participating in a culturally translated youth mentoring program and service‐learning experience for Aotearoa New Zealand mentors
Authors: Deane Kelsey L. , Bullen Pat , Williamson‐Dean Rachel , Wilder Kiri
Published: January 2023

The aim of this article is to demonstrate “mentoring through service‐learning” models can be powerful avenues to support the development of emerging adult practitioners, and are scalable to new global contexts when careful attention is paid to the local culture and evidence‐based principles for mentoring and service‐learning. The study presents outcome findings for mentors who participated in Campus Connections Aotearoa, a culturally translated version of a US‐based service‐learning experience and therapeutic youth mentoring program implemented in New Zealand, based on a mixed‐method, pre‐post evaluation survey involving 62 ethnically diverse mentors (81% female). A large, significant increase in mentoring self‐efficacy and small to moderate significant increases for attunement to others, sociability and leadership, and problem‐solving and perspective‐taking were found. Open‐ended survey responses revealed self‐reported changes in both personal and professional growth. The discussion highlights the importance of theory and evidence‐driven design decisions and an intensive evidence‐informed training curriculum for mentoring‐based service‐learning programs.
The mediating role of resilience in the relationship between helicopter parenting and several indicators of mental health among emerging adults
Authors: Seki Tolga , Haktanir Abdulkadir , Şimşir Gökalp Zeynep
Published: January 2023

Helicopter parenting has received much attention in the last decade. The growing literature on this phenomenon illustrates the negative consequences of helicopter parenting. The detrimental effects of helicopter parenting on emerging adults may be especially more present in collectivist cultures. Studies carried out with this population have demonstrated that mental health problems among this group are more prevalent than those of other groups. Hence, an understanding of the factors affecting mental health at this age is critical. The deleterious effects of helicopter parenting on mental health among emerging adults are well‐documented. However, there is a lack of literature investigating the mediating role of resilience between helicopter parenting and mental health issues (i.e., depression, anxiety, and stress). To bridge this gap, we collected data from 402 emerging adults (M = 21.31, SD = 2.01). Our results revealed that although helicopter parenting was a risk factor for several indicators of mental health among emerging adults, resilience mitigates the potential detrimental effect of helicopter parenting.
Confinement effect and efficient adsorption of furfural onto ZIF‐8‐derived microporous carbon
Authors: Yuan Min , Liu Zhiqing , Lv Tiantian , Dong Jinxiang , Shi Qi
Published: January 2023

BACKGROUND

The separation of furfural from a low‐concentration multicomponent and acid‐containing aqueous solution is a highly demanding process; traditional distillation requires an excessive amount of energy. Herein, we demonstrated ZIF‐8‐derived microporous carbon (C) as a promising adsorbent for the separation of furfural using adsorption isotherms, dynamic column adsorption, adsorption kinetics and desorption studies.

RESULTS

In the competitive adsorption kinetics experiments with a furfural/acetic acid concentration of 50/20 g L−1, the acetic acid adsorbed in the micropores of NCZIF‐81000C‐800A gradually was replaced by furfural, whereas the amount of acetic acid in the mesopores of NCZIF‐8800C‐800A slowly increased. In addition, the micropores of NCZIF‐81000C‐800A exhibited highly efficient and fast adsorption characteristics toward furfural over a wide furfural/acetic acid concentration range (0–50/0–20 g L−1) with the furfural adsorption capacity reaching an adsorption equilibrium within 10 min. The results show that the high Brunauer–Emmett–Teller surface area of NCZIF‐81000C‐800A is responsible for the high furfural adsorption capacity (1205.3 mg g−1) and the confined microporous structure can strengthen the π–π interactions between porous C and furfural, thereby enhancing the selectivity of furfural/acetic acid (61.4) in the furfural/acetic acid (50/20 g L−1) dynamic column adsorption system. Meanwhile, the desorption ratio of furfural in the dynamic desorption system reached as high as 98.6%.

CONCLUSION

The unique micropore‐confinement effect and excellent adsorption behavior make NCZIF‐81000C‐800A an efficient adsorbent for furfural in the furfural–acetic acid system. © 2023 Society of Chemical Industry (SCI).
Significance and influence of various promoters on Cu‐based catalyst for synthesizing methanol from syngas: a critical review
Authors: Saw Shiva Kumar , Datta Sudipta , Chavan PD , Gupta Pavan K , Kumari Shweta , Sahu Gajanan , Chauhan Vishal
Published: January 2023

Methanol synthesis from syngas is an effective method for producing fuel additives, oxygenated fuels, and other chemicals. Several promoted catalytic systems have been tested for the synthesis of methanol. Catalysts based on noble metals are extremely active in generating methanol from syngas. However, sintering, poisoning, and related expenses accounted for the switch to Cu‐based catalysts. The promotion of Cu‐based catalysts, even with small doses of an effective promoter, resulted in a considerable change in product selectivity. A suitable promoter is required for Cu‐based catalysts used in the synthesis of methanol because it significantly impacts the electronic, geometric, or acid/base surface properties, which in turn affect the catalyst's activity and selectivity. It also significantly impacts the interactions between the catalyst's active ingredients. However, the interactions between the active component and the promoter can be adjusted or influenced by appropriate support. The present paper primarily focuses on several promoters in the copper‐based catalyst for synthesizing methanol from syngas. We briefly deliberated on the need for copper‐based catalysts for methanol synthesis, their reaction and mechanism, the reasons for promoter addition concerning their role and influence, the importance of CO2 addition in feed synthesis gas and their impact on the catalyst. This paper mainly highlights the selectivity and activity of various promoted Cu‐based catalysts, although different reaction parameters are the cause of promotion and inhibition in the catalyst. The effects of reaction conditions, including pressure, temperature, gas hourly space velocity (GHSV), and syngas composition, are briefly reported. This paper also comprehensively compares the effects of adding various promoters in small amounts to copper‐based catalysts. This review intends to be illustrative rather than exhaustive. © 2023 Society of Chemical Industry (SCI).
Functional equivalence classes in rats: Repeated olfactory discrimination reversals and delayed stimulus probes
Authors: Galizio Mark , Lawson Kyndra , Shaw Johnathan , Bruce Katherine
Published: January 2023

The simultaneous matching‐to‐sample procedures that are widely used to study stimulus equivalence in human participants have generally been unsuccessful in animals. However, functional equivalence classes have been demonstrated in pigeons and sea lions using a concurrent repeated reversal discrimination procedure. In this procedure, responding to one set of stimuli is reinforced but responding to a different set is not and the set associated with reinforcement is changed with multiple reversals during the experiment. The experiments reported here were designed to assess whether functional equivalence classes could be demonstrated in rats using similar techniques. Rats were initially trained with two sets of olfactory stimuli (six odors/set). Following many reversals, probe reversal sessions were conducted in which rats were exposed to a subset of the members of each set and, later in the session, the withheld stimuli were introduced. Responding to these delayed probe trials in accord with the reversed contingencies constituted transfer of function. There was some evidence of transfer in Experiment 1, but the effects were relatively weak and variable. Experiment 2 introduced procedural changes and found strong evidence of transfer of function consistent with the formation of functional equivalence classes. These procedures offer a promising strategy to study symbolic behavior in rodents.
Choice dynamics in concurrent ratio schedules of reinforcement
Authors: Bellow Daniel , Lattal Kennon A.
Published: January 2023

The generalized matching law predicts performance on concurrent schedules when variable‐interval schedules are programmed but is trivially applicable when independent ratio schedules are used. Responding usually is exclusive to the schedule with the lowest response requirement. Determining a method to program concurrent ratio schedules such that matching analyses can be usefully employed would extend the generality of matching research and lead to new avenues of research. In the present experiments, ratio schedules were programmed dependently such that responses to either of the two options progressed the requirement on both schedules. Responding is not exclusive because the probability of reinforcement increases on both schedules as responses are allocated to either schedule. In Experiment 1, performance on concurrent variable‐ratio schedules was assessed, and reinforcer ratios were varied across conditions to investigate changes in sensitivity. Additionally, the length of a changeover delay was manipulated. In Experiment 2, performance was compared under concurrently available, dependently programmed variable‐ratio and fixed‐ratio schedules. Performance was well described by the generalized matching law. Increases in the changeover delay decreased sensitivity, whereas sensitivity was higher when variable‐ratio schedules were employed, compared with fixed‐ratio schedules. Concurrent ratio schedules can be a viable approach to studying functional differences between ratio and interval schedules.
Ocular microvasculature in adult Xenopus laevis: Scanning electron microscopy of vascular casts
Authors: Lametschwandtner Alois , Minnich Bernd
Published: January 2023

The microvascular anatomy of choriocapillaris, iris, ciliary body, and superficial vascular hyaloid system of eyes was studied in the permanent aquatic Xenopus laevis by scanning electron microscopy of vascular casts and was compared with that published in two semiaquatic ranid species (Rana esculenta and Rana temporaria), and the urodelian species Triturus criststus carnifex. Results showed that the choriocapillaris in Xenopus consisted of a dense meshwork of wide capillaries displaying polygonal arrays at the scleral side with venules leaving the centers and arterioles supplied from the periphery. The choriocapillaris lacked the multilayered capillary meshwork described in ranids. Iris and ciliary body were supplied by nasal and temporal branches of the iridial artery, which either originated with a common stem from the hyaloid artery or arose as individual vessels from the proximal portions of the semicircular nasal and temporal branches of the hyaloid artery. These branches ran in the pupillary margin and supplied the two‐dimensional capillary network of the iris, as well as the three‐dimensional network of the ciliary body. Iris and ciliary body drained via parallel running vasa recta into the choriocapillaris. The superficial vascular hyaloid bed (system) was supplied by the hyaloid artery. This artery coursed along the scleral surface of the ventrotemporal choriocapillaris toward the ora serrata, where it bifurcated into a temporal and a nasal semicircular branch. Seven to 10 arterial meridional twigs arose from these branches and supplied the superficial hyaloid capillary bed. Capillaries drained into branches of the hyaloid vein, which ascended toward the ora serrata, where the hyaloid vein joined the temporal branch of the ciliary vein.