bluuebunny/crossref_metadata_2025_split huggingface dataset:
Asymmetric Flow Reactions Catalyzed by Immobilized Diphenylprolinol Alkyl Ether: Michael Reaction and Domino Reactions
Authors: Hayashi Yujiro , Hattori Shusuke , Koshino Seitaro 
Published: May 2022

AbstractFlow reactions using an immobilized diphenylprolinol alkyl ether catalyst 2 were investigated in three reactions of α,β‐unsaturated aldehydes and nitroalkanes such as nitromethane 3, nitroethanol 10, and nitroalkane 11, bearing two carbonyl groups. Whereas reactions using the corresponding monomer catalyst diphenylprolinol silyl ether 1 were slow, fast reactions were found with the immobilized polymer catalyst 2 in a batch system, and the latter was then applied to a flow system. In the Michael reaction of nitromethane 3, the polymer catalyst showed high reactivity in the initial 30 h and then decreased gradually. Good overall yield (72%) and turnover number (TON, 495) were obtained for a 60 h flow reaction, and the enantioselectivity of the product was excellent throughout. The TONs of domino reactions of nitroethanol 10 and nitroalkane 11, with two carbonyl groups, were 48 and 81, respectively.
Glyphosate and aminomethylphosphonic acid in human hair quantified by an LC‐MS/MS method
Authors: Alvarez Jean‐Claude , Etting Isabelle , Larabi Islam Amine 
Published: May 2022

AbstractAn LC‐MS/MS method for hair testing of glyphosate and aminomethylphosphonic acid (AMPA), its main biodegradation product, has been developed. After decontamination, 50 mg of hair was ground and sonicated in water for 2 h. The method was fully validated in the 5–500 pg/mg range for glyphosate and 10–500 pg/mg for AMPA, and the limits of detection were 2 and 5 pg/mg, respectively. Matrix effect for glyphosate and AMPA was compensated by an isotope‐labeled internal standard. Hair samples from four farmers who regularly used glyphosate and one farmer who used glyphosate but not his wife and 14 hair samples from nonoccupationally exposed subjects were tested. Glyphosate was found in head hair of three farmers, with concentration in the range 14–188 pg/mg. The fourth was found negative but with hair colored in red. Glyphosate was detected in 10 of 14 hair samples from nonoccupationally exposed subjects at concentrations of 11.5 pg/mg or lower and only in one segment (0–3 cm) of the farmer's spouse (6 pg/mg). AMPA was detected in five subjects, above the limit of quantification only in two of three occupationally exposed subjects with positive glyphosate.Further studies should be conducted to validate this potential new biomarker that could be useful for assessing long‐term exposure to glyphosate.
Real‐World longitudinal practice patterns in the use of PD‐1 and PD‐L1 inhibitors as First‐Line therapy in patients with Non‐Small cell lung cancer in the United States
Authors: Veluswamy Rajwanth , Hirsch Fred R. , Taioli Emanuela , Wisnivesky Juan , Strauss Ross , Harrough Douglas , Tang Boxiong , Barnes Gisoo 
Published: May 2022

AbstractBackgroundImmune checkpoint inhibitors targeting the programmed cell death protein‐1 (PD‐1) and programmed death ligand‐1 (PD‐L1) axis (collectively referred to as PD[L]1i) have demonstrated clinical benefits in non‐small cell lung cancer (NSCLC) patients. The purpose of this United States‐based real‐world study is to examine changes in the landscape of first‐line therapies for NSCLC since the introduction of PD(L)1i.MethodsPatients with NSCLC initiating first‐line treatment between May 1, 2017, and October 31, 2020, were identified in the IBM MarketScan® database. Patients were assigned groups based on first‐line therapy: PD(L)1i monotherapy, chemotherapy alone, PD(L)1i with chemotherapy, or targeted therapy for patients with actionable driver mutations.ResultsA total of 5431 patients with NSCLC starting first‐line treatment were identified: chemotherapy alone 2568 (47%), PD(L)1i with chemotherapy 1364 (25%), PD(L)1i monotherapy 790 (15%), and targeted therapy 709 (13%). The use of PD(L)1i monotherapy and targeted therapy remained consistent, while the percentage of patients receiving PD(L)1i with chemotherapy more than doubled. Over a third of patients in 2019 and 2020 received chemotherapy alone. Patients aged ≥65 years (odds ratio [OR]: 0.80; 95% confidence interval [CI]: 0.68–0.95), females (OR: 0.86; 95% CI: 0.74–0.98), and those with respiratory (OR: 0.82; 95% CI: 0.71–0.94) or kidney (OR: 0.56; 95% CI: 0.40–0.77) disease were less likely to have received PD(L)1i with chemotherapy than patients that received chemotherapy alone.ConclusionsSince the approval of PD(L)1i for NSCLC, their use has significantly increased for first‐line treatment, especially when used in combination with chemotherapy. A significant proportion of patients received chemotherapy alone.
A Stereocontrolled Total Synthesis of Lipoxin B4 and its Biological Activity as a Pro‐Resolving Lipid Mediator of Neuroinflammation
Authors: Frank Lee C. , Brown Carla E. , Nielsen Alexander J. , Kim Changmo , Livne‐Bar Izhar , Parsons Philip J. , Boldron Christophe , Autelitano François , Weaver Donald F. , Sivak Jeremy M. , Reed Mark A. 
Published: May 2022

AbstractTwo stereocontrolled, efficient, and modular syntheses of eicosanoid lipoxin B4 (LXB4) are reported. One features a stereoselective reduction followed by an asymmetric epoxidation sequence to set the vicinal diol stereocentres. The dienyne was installed via a one‐pot Wittig olefination and base‐mediated epoxide ring opening cascade. The other approach installed the diol through an asymmetric dihydroxylation reaction followed by a Horner‐Wadsworth‐Emmons olefination to afford the common dienyne intermediate. Finally, a Sonogashira coupling and an alkyne hydrosilylation/proto‐desilylation protocol furnished LXB4 in 25 % overall yield in just 10 steps. For the first time, LXB4 has been fully characterized spectroscopically with its structure confirmed as previously reported. We have demonstrated that the synthesized LXB4 showed similar biological activity to commercial sources in a cellular neuroprotection model. This synthetic route can be employed to synthesize large quantities of LXB4, enable synthesis of new analogs, and chemical probes for receptor and pathway characterization.
Kinetics and isotherm studies for the adsorption of boron from water using titanium dioxide
Authors: Haddadi Ejaz , Gujar Jotiram G. , Sonawane Shriram S. 
Published: May 2022

AbstractBoron is a necessary element for plants that are generally found in the ground and seawater, but it can also be poisonous in large doses. Contamination of water with boric acid or borate ions is a global concern. Due to the absence of the chemical charge that boron possesses, its removal is often difficult. To investigate boron's adsorption characteristics, kinetic, isotherm, and isothermal studies were performed. The adsorption of boron was shown to be a pH‐dependent mechanism, with the best results at around pH 9.0. About 47% of the boron from a solution of 50 mg L−1 was removed using 5 g titanium dioxide in 30 min. It was also demonstrated that boron adsorption kinetics increased with temperature, which is best described by the pseudo‐second‐order kinetic model (R2 > 0.98) and also fits well with Elovich and pseudo‐first‐order models (R2 > 0.94) at pH 9.0. Equilibrium was reached in about 40 min for all the samples. The film boundary layer diffusion step limits the rate. Experimental results correspond well to the Freundlich isotherm (R2 = 0.95–0.99). Langmuir and Temkin's isotherms also fitted reasonably well (R2 = 0.94–0.98). The Freundlich and Langmuir constants indicate favourable adsorption. The Gibbs free energy (ΔG) values increased negatively (from −11.47 to −15.63 kJ mol−1) with increasing temperature, signifying a feasible and spontaneous process. The enthalpy change (ΔH) value of about 30.35 kJ mol−1 indicated endothermic physical adsorption. The results indicate that titanium dioxide is an excellent and safe adsorbent for the removal of boron from water.
Oxygen uncoupling behaviour for ilmenite ore oxygen carrier generated from a calcination treatment mixed with natural manganese ore
Authors: Liu Xue , Li Lin , Zhou Zhihao , Sun Zhenkun , Duan Lunbo 
Published: May 2022

AbstractChemical looping with O2 uncoupling aims at using an oxygen carrier (OC) with O2 uncoupling behaviour to promote fuel conversion. Natural ilmenite ores have been considered highly promising OCs for chemical looping technology; however, they do not possess any O2 uncoupling behaviour. Mn‐modified ilmenite ores as OCs are capable of O2 uncoupling, while most of them are synthesized via complicated procedures by using costly chemicals. In this study, a strategy of calcination treatment on ilmenite ores mixed with manganese ores has been established to introduce Mn into the ilmenite OCs, endowing them with O2 uncoupling behaviour in a simple and low‐cost manner. The O2 uncoupling behaviour from Mn‐modified ilmenite ores is mainly due to the newly formed (Fe1−xMnx)2O3/(Fe1−xMnx)3O4 crystal phases generated during the calcination treatment, which also alleviate the thermodynamic limit of the Mn2O3‐Mn3O4 redox pair. As a result, the Mn‐modified ilmenite ore OCs can release O2 at high temperatures when decreasing the oxygen partial pressure. But more importantly, the reduced OCs can be restored in the air isothermally. This established simple calcination treatment method can be used as a low‐cost strategy for producing ilmenite‐based OCs with O2 uncoupling behaviour. The O2 uncoupling behaviour is expected to be beneficial to chemical looping combustion of fuels, promote fuel conversion, minimize OC loading, and reduce energy consumption.
Structural and Biological Insights into the Hot‐Spot Marine Natural Products Reported from 2012 to 2021
Authors: Liu Mingyu , Zhang Xingwang , Li Guoqiang 
Published: May 2022

Comprehensive SummaryThe vast marine ecosystem contains a sea of natural products, which are potential model molecules for new drug development. With more than one thousand new structures been discovered each year, the past decade has become the golden time for marine natural product discovery, leading to a valuable but extra‐large chemical database. Serving as an epitome of the most promising compounds, which take the ultra‐new skeletons and/or excellent bioactivities, this review covers 243 hot‐spot marine natural products reported from 2012 to 2021, to abstract some important chemical and/or biological inspirations for marine natural product study and marine drug development in the future. In addition, some general rules regarding to the source organism, structure‐specialty, organism‐structure specificity, and organism‐bioactivity relationship of these outstanding compounds will also be presented.
Radical‐Mediated Selective Functionalization of Unactivated Primary C—H Bonds
Authors: Wang Zhan‐Lin , Wang Fei 
Published: May 2022

AbstractRadical‐mediated sp3 C—H functionalization has found broad applications in synthesis and late‐stage derivatization of complex molecules. The site‐selectivity of a given reaction is mainly dictated by the bond strength, polarity and steric accessibility of diverse C—H bonds as well as the characters of hydrogen atom acceptors. Unactivated sp3 C—H bonds usually follow the relative reactivity sequence of tertiary > secondary > primary, which is even recognized as the innate preferences of certain substrates. The development of innovative methods capable of overriding the “inherent” site‐selectivity is exceedingly attractive. Although it has been demonstrated that secondary C—H bonds could be selectively converted in the presence of weaker tertiary C—H bonds by tuning the steric and electronic properties of hydrogen atom acceptors, the selective activation of primary C—H bonds remains a daunting challenge. Herein, we highlight the recently emerging attempts towards this goal by interrogating the steric effect of hydrogen atom acceptors.
Spirooxindol‐1,3‐oxazine Alkaloids: Highly Potent and Selective Antitumor Agents Evolved from Iterative Structure Optimization
Authors: Eichhorst Annika , Gallhof Malte , Voss Alice , Sekora Anett , Eggers Leon , Huyen Le Thi , Junghanss Christian , Murua Escobar Hugo , Brasholz Malte 
Published: May 2022

AbstractSpirooxindole‐1,3‐oxazines are a small and structurally unique class of spirooxindole alkaloids. To date, only four of these compounds have been isolated from natural sources, and their biological properties remained unknown thus far. Dioxyreserpine is a synthetic spirooxindole‐1,3‐oxazine, that can readily be prepared from the Rauvolfia alkaloid (–)‐reserpine by catalytic photooxygenation. While dioxyreserpine itself was now identified as a moderately effective antitumoral agent, structurally modified analogs of it emerged as a new class of highly potent and selective growth inhibitors of various human cancers, including pancreatic cancers. Systematic structural optimization ultimately led to an inhibitor displaying low‐micromolar IC50‐values against six cancer cell lines as well as selective apoptosis induction in vitro.
Safety, Tolerability, and Pharmacokinetics of Single and Multiple Ascending Oral Doses of Youkenafil Hydrochloride, a Phosphodiesterase Type 5 Inhibitor, in Healthy Chinese Male Volunteers
Authors: Liang Beibei , Wang Jin , Bai Nan , Chi Yulong , Wang Rui , Cai Yun 
Published: May 2022

AbstractYoukenafil hydrochloride is a novel selective phosphodiesterase type 5 inhibitor for the treatment of erectile dysfunction. Its safety, tolerability, and pharmacokinetics were evaluated in healthy Chinese male volunteers. In addition, this study explored the effect of food on the pharmacokinetic parameters of youkenafil hydrochloride. The study was divided into 3 trials: a single ascending dose (25, 50, 100, 150, or 200 mg youkenafil), multiple dose (50, 100, or 150 mg youkenafil once daily for 7 consecutive days), and food effect (50 mg youkenafil single dose). The overall tolerability of youkenafil was good. Youkenafil was rapidly absorbed after a single oral dose. Food intake impeded absorption efficiency but had no significant effect on area under the plasma concentration–time curve values. The mean accumulation ratio in area under the plasma concentration–time curve and maximum plasma concentration ranged from 1.3 to 1.6 and from 1.2 to 1.4 after once‐daily dosing. There was no apparent accumulation following consecutive administration for 7 days. Less than 1% of the dose was found in urine as the intact drug for all dose groups. Single‐dose youkenafil up to 200 mg and multiple doses up to 150 mg were generally safe and well tolerated.
Sulfonates as Versatile Structural Counterions of Epoxidized Salts
Authors: Kui Tony , Chardin Charline , Rouden Jacques , Livi Sébastien , Baudoux Jérôme 
Published: May 2022

AbstractIonic liquids have recently emerged as monomers to synthesize multifunctional polymeric materials. Among such species, ionic epoxy‐based networks represent promising but underdeveloped materials that are hindered by tricky access to the functionalized ionic liquid monomers. To date, the reported epoxidized imidazolium salts have focused on highly toxic epichlorohydrin. This study concerns flexible and efficient methods to synthesize versatile building blocks with sulfonates as valuable anions. The judicious combination of an aliphatic or aromatic sulfonate with an imidazolium leads to new epoxidized salts with high structural variability and good chemical and thermal stability (>300 °C).
CO2/N2 Separation on Highly Selective Carbon Nanofibers Investigated by Dynamic Gas Adsorption
Authors: Selmert Victor , Kretzschmar Ansgar , Weinrich Henning , Tempel Hermann , Kungl Hans , Eichel Rüdiger‐A. 
Published: May 2022

AbstractThe development of highly selective adsorbents for CO2 is a key part to advance separation by adsorption as a viable technique for CO2 capture. In this work, polyacrylonitrile (PAN) based carbon nanofibers (CNFs) were investigated for their CO2 separation capabilities using dynamic gas adsorption. The CNFs were prepared by electrospinning and subsequent carbonization at various temperatures ranging from 600 to 1000 °C. A thorough investigation of the CO2/N2 selectivity resulted in measured values of 53–106 at 1 bar and 25 °C on CNFs carbonized at 600, 700, or 800 °C. Moreover, the selectivity increased with lower measurement temperatures and lower CO2 partial pressures, reaching values up to 194. Further analysis revealed high long‐term stability with no degradation over 300 cycles and fast adsorption kinetics for CNFs carbonized at 600 or 700 °C. These excellent properties make PAN‐based CNFs carbonized at 600 or 700 °C promising candidates for the capture of CO2.
Autonomic management of group communication for Internet of Things applications
Authors: Riker André , Mota Renato , Rośario Denis , Pereira Vasco , Curado Marilia 
Published: May 2022

SummaryDense Internet of Things (DIoT) is fazed by message loss, congestion, and energy consumption, due to a large number of connected devices. One of the main challenges in DIoT environments is to achieve self‐adaptable communication without human intervention, where the system is able to dynamically manage its own settings to mitigate common problems. Seeking to promote self‐adaptability in DIoT, this paper presents the Autonomic management of GRoup communication for intErnEt of thiNgs applications (AGREEN). It is an autonomous solution for IoT platforms that configures the communication settings to ensure the dynamic control of IoT devices considering a comprehensive set of aspects, such as traffic loss, sensing relevance, amount of energy harvested, and the number of monitoring nodes with renewable and non‐renewable energy. Extensive evaluation results show that AGREEN is able to autonomously change the number of nodes in the monitoring group and to improve system performance in terms of message loss, energy consumption, and communication interval compared to standard protocols designed for IoT.
Hybrid energy storage design and dispatch strategy evaluation with sensitivity analysis:Techno‐economic‐environmentalassessment
Authors: Citalingam Kanagaswarran , Go Yun Ii 
Published: May 2022

AbstractInternational Energy Agency reported the net‐zero carbon target by 2050 in its recent annual report. The global energy landscape is expected to anticipate an energy transition with an increase in renewable energy share from 12% to 35% for electricity sector by 2050. Most of the countries in the world had pledged to be become net‐zero or carbon neutral countries by 2050. Solar photovoltaic (PV) and wind energy will contribute 50% of energy mix in this context. Solar PV and wind energy are intermittent resources that highly depending on the weather and climate conditions. The intermittency issues caused mismatch between electricity generation and demand profiles. This will greatly affect the requirement of meeting the daily load profile, satisfying the peak demand and resulting in generation of surplus, and so on. Energy storages play a vital role in this scenario by allowing this excess energy to be stored and used to meet the demand during low energy production. Previous literature evaluated the feasibility of utilizing battery energy storage in large‐scale solar PV plant in Malaysia using load following dispatch strategy, which can be further enhanced by utilizing a hybrid energy storage system. This study aims to develop an optimized hybrid energy storage system utilizing battery and supercapacitors to complement a large‐scale solar PV system. This study also evaluates two dispatch strategies that are load following and cycle charging for three different power system configurations. Subsequently, a market leading battery is modelled with parameters such as nominal voltage, capacity, round‐trip efficiency, minimum and maximum state of charge, and maximum and minimum charge and discharge current in four different scenarios utilizing two dispatch strategies. These studies are conducted using power system and energy storage modelling tools with localized energy data for the Malaysia context. The proposed hybrid energy storage system demonstrates an improvement of about 30% in annual throughput under the load following dispatch strategy. The hybrid power system also increases the renewable energy fraction by 5% in the system. This study creates an optimized framework in the development of energy storage for grid integration that permits high level of solar PV penetration in the transmission and distribution network.
A systematic review of task scheduling approaches in fog computing
Authors: Bansal Sumit , Aggarwal Himanshu , Aggarwal Mayank 
Published: May 2022

AbstractDue to increased use of IoT devices and data sensors a huge amount of data is being produced for processing in real‐time. Fog computing has evolved as a solution for fast processing of data. To complete the data processing as per requirement of user, it is processed at fog nodes which are near the user. To complete work in a specified time with limited resources, task scheduling is performed. With the increased amount of data to be processed, the completion of task within given time in fog computing is a major challenge. So, scheduling of tasks and resources is a very important issue. A lot of research has been undertaken in recent years. In this survey, authors have reviewed various task scheduling algorithms suggested by researchers to meet the user requirements. The focus of this article is on diverse scheduling techniques being deployed in fog computing. An effort has been made to classify existing approaches, research issues and determine significant issues existing in this field. There are four major scheduling categories that are used by researchers namely, static, dynamic, heuristic, and hybrid. As per this study, 17% researchers deployed static, 23% dynamic, 47% heuristic, and 13% hybrid approaches, respectively. Analysis shows that for QoS (Quality of Service) parameters 19% researchers are focused on response time, 18% on cost and energy consumption, and 16% on makespan. For QoS parameter other factors have much smaller contribution in comparison to the above factors. In the tools used, researchers observed that 40% of the researches have used iFogSim, according to literature. Besides, this research article also discusses open issues and future work in the field of fog computing. This article also underlines various open issues and future directions in the field of fog computing.
An improved genetic algorithm approach to spectrum sensing for long range based cognitive radio networks
Authors: Yalçın Sercan 
Published: May 2022

AbstractBy designing cognitive radio networks (CRNs) for low power wide area networks (LPWANs), adaptive spectrum sensing plays an important role in using frequency bands effectively. With spectrum sensing, existing spectrum holes are filled by enabling secondary users to use the licensed band that primary users do not use. Many researchers have proposed various optimization or artificial intelligence techniques in CRNs for spectrum sensing. However, there is hardly any adaptive spectrum sensing method integrated into the LoRa communication standard, which is a very popular LPWAN technology. For this purpose, an adaptive optimization based spectrum sensing methodology with an improved genetic algorithm is proposed in this study. Depending on this methodology, two fitness functions adapted to the LoRa‐based network are defined. Thanks to these functions, the movement of individuals in the network population is provided. In parallel, received signal strength values of optimum LoRa nodes were determined by genetic coding, and bands to be used by SUs instead of PUs were discovered considering minimum bit errors. To verify the success of the proposed method, various simulation experiments were carried out. The performance results strikingly show that the proposed method is quite successful for LoRa‐CRNs. For example, the proposed method significantly improved the bit error rate performance, and reduced the number of faulty transmissions caused by packet collisions. It also reduced the packet error rate by more than 8% per minute in a 200‐node network.