bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of temperature and photoperiod on the seasonal timing of Western honey bee colonies and an early spring flowering plant
Authors: Villagomez Gemma N. , Nürnberger Fabian , Requier Fabrice , Schiele Susanne , Steffan‐Dewenter Ingolf 
Published: May 2021

AbstractTemperature and photoperiod are important Zeitgebers for plants and pollinators to synchronize growth and reproduction with suitable environmental conditions and their mutualistic interaction partners. Global warming can disturb this temporal synchronization since interacting species may respond differently to new combinations of photoperiod and temperature under future climates, but experimental studies on the potential phenological responses of plants and pollinators are lacking. We simulated current and future combinations of temperature and photoperiod to assess effects on the overwintering and spring phenology of an early flowering plant species (Crocus sieberi) and the Western honey bee (Apis mellifera). We could show that increased mean temperatures in winter and early spring advanced the flowering phenology of C. sieberi and intensified brood rearing activity of A. mellifera but did not advance their brood rearing activity. Flowering phenology of C. sieberi also relied on photoperiod, while brood rearing activity of A. mellifera did not. The results confirm that increases in temperature can induce changes in phenological responses and suggest that photoperiod can also play a critical role in these responses, with currently unknown consequences for real‐world ecosystems in a warming climate.
Effect of hypoglycaemia on measures of myocardial blood flow and myocardial injury in adults with and without type 1 diabetes: A prospective, randomised, open‐label, blinded endpoint, cross‐over study
Authors: Noh Radzi M. , Graveling Alex J. , Lang Ninian N. , White Audrey C. , Lee Kuan Ken , Mills Nicholas L. , Newby David E. , Lang Chim C. , Frier Brian M. 
Published: May 2021

AbstractAimsThis study examined the effect of experimentally‐induced hypoglycaemia on measures of myocardial blood flow and myocardial injury in adults with, and without, type 1 diabetes.MethodsIn a prospective, randomised, open‐label, blinded, endpoint cross‐over study, 17 young adults with type 1 diabetes with no cardiovascular risk factors, and 10 healthy non‐diabetic volunteers, underwent hyperinsulinaemic‐euglycaemic (blood glucose 4.5–5.5 mmol/L) and hypoglycaemic (2.2–2.5 mmol/L) clamps. Myocardial blood flow was assessed using transthoracic echocardiography Doppler coronary flow reserve (CFR) and myocardial injury using plasma high‐sensitivity cardiac troponin I (hs‐cTnI) concentration.ResultsDuring hypoglycaemia, coronary flow reserve trended non‐significantly lower in those with type 1 diabetes than in the non‐diabetic participants (3.54 ± 0.47 vs. 3.89 ± 0.89). A generalised linear mixed‐model analysis examined diabetes status and euglycaemia or hypoglycaemia as factors affecting CFR. No statistically significant difference in CFR was observed for diabetes status (p = .23) or between euglycaemia and hypoglycaemia (p = .31). No changes in hs‐cTnI occurred during hypoglycaemia or in the recovery period (p = .86).ConclusionsA small change in CFR was not statistically significant in this study, implying hypoglycaemia may require more than coronary vasomotor dysfunction to cause harm. Further larger studies are required to investigate this putative problem.
Heart failure and atrial fibrillation: tachycardia‐mediated acute decompensation
Authors: Park Jin Joo , Lee Hae‐Young , Kim Kye Hun , Yoo Byung‐Su , Kang Seok‐Min , Baek Sang Hong , Jeon Eun‐Seok , Kim Jae‐Joong , Cho Myeong‐Chan , Chae Shung Chull , Oh Byung‐Hee , Choi Dong‐Ju 
Published: May 2021

AbstractAimsTachycardia is a reversible event that may cause hemodynamic decompensation but may not necessarily cause direct damages to the myocardium. To evaluate the clinical outcomes of patients with heart failure (HF) and atrial fibrillation (AF), whose acute decompensation was tachycardia mediated.Methods and resultsThe Korean Acute Heart Failure registry was a prospective registry that consecutively enrolled 5625 patients with acute HF. Patients were classified into three groups according to the rhythm and aggravating factor: (i) 3664 (65.1%) patients with sinus rhythm (SR), (ii) 1033 (18.4%) patients with AF whose decompensation was tachycardia‐mediated, AF‐TM (+), and (iii) N = 928 (16.5%) patients with AF whose decompensation was not tachycardia‐mediated, AF‐TM (−). The primary outcomes were in‐hospital and post‐discharge 1 year all‐cause mortality. At admission, the mean heart rate was 90.8 ± 23.4, 86.8 ± 26.8, and 106.3 ± 29.7 beats per minute for the SR, AF‐TM (−), and AF‐TM (+) groups, respectively. The AF‐TM (+) group had more favourable characteristics such as de novo onset HF, less diabetes, ischaemic heart disease, and higher blood pressure than the AF‐TM (−) group. In‐hospital mortality rates were 5.1%, 6.5%, and 1.7% for SR, AF‐TM (−), and AF‐TM (+) groups, respectively. In logistic regression analysis, the AF‐TM (+) group had lower in‐hospital mortality after adjusting the significant covariates (odds ratio, 0.49; 95% confidence interval, 0.26–0.93). The mortality rate did not differ between SR and AF‐TM (−) groups. During 1 year follow‐up, 990 (18.5%) patients died. In univariate and multivariate Cox proportional regression analyses, there was no difference in 1‐year all‐cause mortality between the three groups.ConclusionsIn patients with HF and AF, patients whose acute decompensation is tachycardia‐mediated have better in‐hospital, but similar post‐discharge outcomes compared with those with SR or those with AF whose decompensation is not tachycardia‐mediated.Clinical Trial Registration: ClinicalTrial.gov NCT01389843.
Aggregation‐Induced Emission‐Active Carbazolyl‐Modified Benzo[4,5]thiazolo[3,2‐c]oxadiazaborinines as Mechanochromic Fluorescent Materials
Authors: Potopnyk Mykhaylo A. , Volyniuk Dmytro , Luboradzki Roman , Lazauskas Algirdas , Grazulevicius Juozas Vidas 
Published: May 2021

AbstractTwo highly emissive donor‐acceptor type organoboron dyes, based on carbazole donor and benzothiazole‐fused oxadiazaborinine acceptor, were designed and synthesized. The compounds demonstrated high positive solvatofluorochromism in solutions, caused by intramolecular charge transfer. Such carbazolyl‐containing N,O‐chelated organoboron dyes exhibited aggregation‐induced emission properties: in tetrahydrofuran/water mixture with a high water amount, they formed highly emissive nanoaggregates. Both materials demonstrated efficient solid‐state emission in the crystalline and thin film state (PLQY of up to 48 %), as well as significant mechanofluorochromic properties (Δλem=30–38 nm). Moreover, a compound with unsubstituted carbazole unit was isolated as two distinct crystalline polymorphs with different photophysical properties.
Kinetic and Structure‐Activity Studies of the Triazolium Ion‐ Catalyzed Intramolecular Stetter Reaction
Authors: Collett Christopher J. , Young Claire M. , Massey Richard S. , O'Donoghue AnnMarie C. , Smith Andrew D. 
Published: May 2021

AbstractMechanistic studies of the triazolium ion‐catalyzed intramolecular Stetter reaction using initial rates analysis in NEt3/NEt3 ⋅ HCl buffered methanol showed the reaction to be first‐order in catalyst and zero‐order in aldehyde over a broad range of aldehyde concentrations. The observed reaction rate is higher for catalysts bearing N‐aryl substituents with electron‐withdrawing groups. A concurrent, NHC‐independent substrate isomerization was also observed and found to demonstrate a first‐order dependence on aldehyde concentration. The reported data are consistent with deprotonation to form the Breslow intermediate being turnover‐limiting in this process.
Mining web content usage patterns of electronic commerce transactions for enhanced customer services
Authors: Ehikioya Sylvanus A. , Zeng Jinbo 
Published: May 2021

AbstractA successful business intelligence solution can help organizations improve the quality and speed of their decision‐making processes by analyzing the consolidated information collected from their websites. Using the current Web server log standard, which indicates only the locations of served Web pages, may lead to inaccurate business analysis for data driven and frequently updated static content Web pages. A properly defined Web content usage data warehouse that captures both dynamic and static contents of web pages provides rich data source for discovering interesting business rules among users' activities. This paper demonstrates the simplicity of data extract, transform and load procedures to import raw Web content usage log to various data models for data analysis, reporting and data mining tools. In this paper, we use two data mining techniques (expected maximization and the prefixspan algorithms) for visitor grouping and path analysis to find interesting patterns in Web content usage log data, an important component of e‐commerce Web sites traffic analysis. Visitor grouping uses data clustering to group visitors/sessions with similar selected attributes' value. Path analysis mines common visiting path sequence. The ultimate goal is to enable the online merchant provide enhanced and differentiated marketing services generally to its existing and potential customers and tell what items customers are interested in instead of ambiguous URLs.
Direct simplicial dynamics: Simulations in biomechanics
Authors: Raghavan Raghu , Brady Martin L. 
Published: May 2021

AbstractWe develop a method for calculating mechanics of surfaces, of bodies, and of bodies with surfaces, directly with the geometric discretization of such bodies into simplices, rather than discretizing the partial differential equations of continuum mechanics in either finite element or finite difference approximations. We have applied this approach to selected simulations in biomechanics. Simplices have exactly the degrees of freedom to describe symmetric tensors, and our approach constructs the mechanics of media without having to apply a Galerkin basis of piecewise affine maps to differential equations. We also formulate a discrete shape operator as a symmetric affine matrix which may be used to describe bending energies, including anisotropy, for surfaces in a systematic way, analogous to the use of the metric tensor for strain elasticity. Given the uncertainties and complexities of biological tissue mechanics that would make formulating differential equations, constitutive properties, and boundary conditions difficult, we offer direct simplicial mechanics as an alternative for selected applications worthy of consideration. The present version is focused on statics, but we indicate an approach to dynamical phenomena. The methods detailed in this paper have been incorporated into software intended for commercial applications of simulations in biomechanics of tissue and full details on the mathematical method and the formulas needed for implementation are provided here. Several illustrative examples of simulations are given.
Concept of a new overrunning clutch with the characteristic of reverse force transfer at high speed
Authors: Zhao Huiyong , Wang Baohua , Zhang Guangde , Li Jiao 
Published: May 2021

AbstractTo extend the functionality of the overrunning clutch. A new overrunning clutch with the characteristic of reverse torque transfer direction at high speed is proposed in this paper. This clutch consists of a traditional one‐way overrunning clutch and a reverse torque transfer direction subsystem. It has three work scenarios according to the angular velocity relationship between the master shaft and the slave part, which are positive torque transfer direction, overrunning, and reverse torque transfer direction. The principle and schematic structure of this clutch are detailed, relationships among the rollers, springs, and hammers are discussed, and threshold angular velocity of reverse torque transfer direction is achieved. The dynamic model of the reverse torque transfer direction part of this concept is established with Simulink software. A series of simulation scenarios that the slave shaft's rotational speed changed at different spring stiffness is conducted. The results show that the threshold value of the reverse torque transfer direction is increasing with the decrease of the spring stiffness. At last, a prototype system is made to roughly validate the feasibility of this concept.
Combining experimental and logging data for calculation of the true skin factor of a horizontal well
Authors: Ma Yongxin , Li Mingjun , Li Yao , Liu Peng , Yang Binghua , Gao Hongyi 
Published: May 2021

AbstractHorizontal wells are an effective way to develop oil and gas fields with large drain areas, leading to high production rates and recoveries. They have been widely used in low permeability oil‐gas reservoirs, shale gas reservoirs, coalbed methane reservoirs, and so on. To achieve the best production rate of horizontal wells, it is essential to further reduce drilling completion fluid damage to protect the reservoir. The skin factor is the main indicator for evaluating the degree of damage of the drilling completion fluid on the reservoir. However, the skin factor obtained by field tests is the sum of the pseudo‐skin factor and the true skin factor, which cannot precisely evaluate the degree of damage. Therefore, it is important to calculate the true skin factor to correctly evaluate the degree of damage of the drilling completion fluid on a reservoir during the drilling completion process of horizontal wells. In this work, a combined method based on experimental data and logging data is proposed to calculate the true skin factor. First, based on a drilling completion fluid dynamic damage experiment, a relational expression between the initial permeability and the damaged permeability is equated, and then, a relational expression between the permeability of rock samples and the filtration velocity of the drilling completion fluid is formulated. Second, after combining experimental results with logging data, the horizontal reservoir intervals are subdivided and both the damaged permeability of the partial reservoir intervals and the major semiaxis of the damaged ellipse are calculated. Finally, the true skin factor of the horizontal well is computed. This metric provides a more precise evaluation of the effect of drilling completion fluid on a reservoir.
Future direction of agrochemical development for plant disease in China
Authors: Guo Shengxin , He Feng , Song Baoan , Wu Jian 
Published: May 2021

AbstractThe growth of the global population poses a huge challenge to food security. The continuous application of crop protection products has many negative effects including increased pesticide resistance, accumulation of residues, and ecological damage. The challenge for the future is to develop agrochemicals with that are effective, with a high degree of selectivity, environmental friendliness, a low use rate, and cost‐effectiveness. Cutting‐edge developments in natural product chemistry, asymmetric synthesis, and rational drug design, as well as an increasing knowledge of the mechanisms that induce plant immunity, have provided potential solutions. In this review, we discuss the comprehensive use of emerging technologies that will help to tackle these current challenges and issues, highlighting the discovery of novel crop production products and their beneficial properties.
In vitro antioxidant and antitumor study of zein/SHA nanoparticles loaded with resveratrol
Authors: Shi Qiankun , Wang Xinya , Tang Xudong , Zhen Nuo , Wang Yupeng , Luo Zhijian , Zhang Hao , Liu Jingsheng , Zhou Dongfang , Huang Keke 
Published: May 2021

AbstractResveratrol (RES) loaded Zein‐SHA (low‐molecular‐weight sodium hyaluronate) nanoparticles with average diameter of about 152.13 nm and polydispersity index (PDI) of 0.122, which can be used to encapsulate, protect and deliver resveratrol. By measuring ABTS free radical scavenging ability and iron (III) reducing power, it was determined that encapsulated resveratrol has higher in vitro antioxidant activity than free resveratrol. When tested with murine breast cancer cells 4T1, the encapsulated resveratrol also showed higher antiproliferative activity than free resveratrol, with IC50 values of 14.73 and 17.84 μg/ml, respectively. The colloidal form of resveratrol developed in this research may be particularly suitable for functional foods and beverages, as well as dietary supplements and pharmaceutical products.
VIX term structure: The role of jump propagation risks
Authors: Yang Xinglin , Chen Ji 
Published: May 2021

AbstractThe importance of jump clustering is widely recognized in the financial market. We use the Hawkes process to capture jump propagation risks and study their role in modeling the Volatility Index (VIX) term structure. Applying the joint estimation approach to the S&P 500 index and the VIX term structure, we find that incorporating jump propagation risks is important to reconcile the dynamics of joint data and to model the VIX term structure, especially when the market is highly volatile. The long‐term variance factor further improves the description of the VIX term structure for low and medium market volatility levels.
Droplet Microfluidics for Tumor Drug‐Related Studies and Programmable Artificial Cells
Authors: Dimitriou Pantelitsa , Li Jin , Tornillo Giusy , McCloy Thomas , Barrow David 
Published: May 2021

AbstractAnticancer drug development is a crucial step toward cancer treatment, that requires realistic predictions of malignant tissue development and sophisticated drug delivery. Tumors often acquire drug resistance and drug efficacy, hence cannot be accurately predicted in 2D tumor cell cultures. On the other hand, 3D cultures, including multicellular tumor spheroids (MCTSs), mimic the in vivo cellular arrangement and provide robust platforms for drug testing when grown in hydrogels with characteristics similar to the living body. Microparticles and liposomes are considered smart drug delivery vehicles, are able to target cancerous tissue, and can release entrapped drugs on demand. Microfluidics serve as a high‐throughput tool for reproducible, flexible, and automated production of droplet‐based microscale constructs, tailored to the desired final application. In this review, it is described how natural hydrogels in combination with droplet microfluidics can generate MCTSs, and the use of microfluidics to produce tumor targeting microparticles and liposomes. One of the highlights of the review documents the use of the bottom‐up construction methodologies of synthetic biology for the formation of artificial cellular assemblies, which may additionally incorporate both target cancer cells and prospective drug candidates, as an integrated “droplet incubator” drug assay platform.
Porous Fluorocarbon from Rice Husk for the Efficient Separation of Gases
Authors: Bakdash Rashed S. , Aljundi Isam H. , Basheer Chanbasha , Abdulazeez Ismail , Al‐Saadi Abdulaziz A. 
Published: May 2021

AbstractA porous fluorocarbon sorbent is synthesized from rice husk (RH) in a microwave reactor and then evaluated for the adsorption of different gases (CH4, CO2, and N2). The fluorocarbon is characterized by Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Raman spectroscopy, Thermal gravimetric analysis (TGA), and X‐ray photoelectron spectroscopy (XPS). Significant enhancement in the surface area of activated carbon material is obtained from 29 to 531 m2 g−1 after removing naturally present silica in RH. Results reveal that rice husk fluorocarbon (RHF) has a higher adsorption affinity for CO2 (1.8 mmol g−1) than that of the sulfonated rice husk (RHS) (1.4 mmol g−1) at 298 K while the corresponding separation factor of CO2/CH4 is 4 and 3; respectively. Higher separation factors of 12 and 10 are observed for the binary system of CO2/N2, respectively. Quantum chemical density functional theory (DFT) calculations agree with the experimental observations. They reveal that RHF exhibits strong columbic interactions with considerable interaction energies of −87.85, −76.75, and −55.65 kcal mol−1 with CO2, CH4, and N2 gases; respectively. Finally, the adsorption process results are highly reproducible, with a small decrease in the adsorption capacity of less than 5% after repeated trials.
Ritual stone‐built architecture and shell midden foundation: A semisubterranean structure in hyperarid Atacama Desert coast, Northern Chile
Authors: Power Ximena , Sitzia Luca , Yrarrázaval Sebastián , Salazar Diego , Andrade Pedro , Hernández Valentina , Aliste Catalina , Muth Xavier 
Published: May 2021

AbstractHunter‐gatherer architectural practices are one of the main sources of data to understand the complex land use of these societies. In the hyperarid Atacama Desert coast (Northern Chile), hunter‐gatherers‐fishers developed standardized stone‐built architecture during the Late Archaic period (∼5,700–4,000 cal years BP), interpreted so far as sedentary villages or long‐term campsites. Nevertheless, the lack of site formation process studies and systematic chronostratigraphies defy such functional interpretations. To address these issues, we reconstruct the lifecycle of a recently discovered semisubterranean structure at the Zapatero site (~25°S, Taltal). Combining stratigraphy, micromorphology, faunal and lithic analysis, as well as radiocarbon dating, we evidence a broad sequence involving different processes: shell midden formation; a stone‐structure; a prepared burial pit; a burning event; a short‐term occupational episode; and the entombment of the structure. We interpret this sequence as ritualized actions related to commemorative and place‐making activities. Our work stresses the need for new research programs at the Atacama Desert coast, based on geoarchaeological approaches, to understand hunter‐gatherer‐fisher middening and architectural practices from the very materiality involved in stratigraphy‐making processes.