bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predefined‐time backstepping control for a nonlinear strict‐feedback system
Authors: Liu Bojun , Hou Mingshan , Wu Cihang , Wang Wencong , Wu Zhonghua , Huang Bing 
Published: February 2021

AbstractTwo novel predefined‐time control algorithms for a nonlinear strict‐feedback system are proposed in this short communication. It is required that the upper bound of system convergence time is exactly a positive constant parameter in each algorithm, and it can be selected arbitrarily by users. Composite state tracking errors are introduced to the backstepping design process by using some novel smooth time‐varying tuning functions. In order to address the problem of explosion of complexity in the first algorithm, the second algorithm extends the predefined‐time control strategy to a dynamic surface control (DSC) case. Furthermore, the proposed predefined‐time DSC algorithm can guarantee global stability rather than semi‐global stability for the closed‐loop system compared with traditional DSC algorithms. Simulation results show the effectiveness of the two control schemes.
Adaptive observer design for a class of Lipschitz nonlinear systems with multirate outputs and uncertainties: Application to attitude estimation with gyro bias
Authors: Bonargent Tristan , Ménard Tomas , Gehan Olivier , Pigeon Eric 
Published: February 2021

AbstractThe design of an adaptive observer for a class of multi‐input multi‐output Lipschitz nonlinear systems with uncertainties and multirated outputs is proposed in this paper. The sampling instants of the different outputs can be asynchronous and irregular. The exponential convergence of the proposed observer is proved with the help of a Lyapunov approach. The stability is ensured, provided that some conditions, including a persistent excitation condition and a maximum value condition on the sample rate of each output, are verified. The performances of the observer are illustrated through simulations of the attitude estimation problem using sensors from an inertial measurement unit and considering gyro bias.
Is Urinary Incontinence Associated with Lichen Sclerosus in Females? A Systematic Review and Meta-Analysis
Authors: Kirby L. , Gran S. , Kreuser-Genis I. , Owen C. , Simpson R. 
Published: February 2021

Abstract

Background
Lichen sclerosus (LS) is a scarring chronic inflammatory disease with a predilection for genital skin in both sexes. The aetiology of LS is controversial, but evidence increasingly suggests that the occluded exposure of susceptible epithelium to urine is involved in the pathogenesis of genital LS in males. This theory has not yet been robustly investigated in females.

Objectives
This review and meta-analysis examined whether there is an association between urinary incontinence (UI) and genital lichen LS in females.

Methods
We performed a comprehensive search of MEDLINE, Embase and CINAHL to identify observational studies assessing the prevalence of UI in females with LS. DerSimonian and Laird random-effects models were used to estimate the overall pooled prevalence and risk ratio compared to controls. Heterogeneity was assessed.

Results
In total, eight studies met the inclusion criteria and five studies were included in a meta-analysis. Three studies were graded as moderate quality and five were poor. The pooled prevalence for UI in LS was 0.35 (95% confidence interval [CI] 0.13–0.58, I2 = 98.4%). The risk ratio of UI in LS was 0.97 (95% CI 0.53–1.75, I2 = 87.5%).

Conclusion
There appears to be no difference between patients with LS and those without LS in terms of UI. Studies are limited by clinical and methodological quality and heterogeneity is high. Well-designed prospective studies are needed.
Synthesis of Hierarchical Porous Silica by Sol‐Gel of Sodium Silicate and Nanoemulsion Templating: Effective Combination Conditions
Authors: Hessien Manal , Prouzet Eric 
Published: February 2021

AbstractHierarchical porous materials have attracted a considerable attention owing to the increased interest in their applications. Hierarchical Porous Silica (HPS) was synthesized by combining the sol‐gel of sodium silicate (SS) and oil in water nanoemulsion (O/W‐NE) templating. The oil droplets of NE acted as pore forming agent and the sol‐gel built the silica framework. The O/W‐NE was prepared by a low energy method, i. e., the phase inversion composition (PIC) method. The influence of pH of SS and NE on HPS was studied. The volume of ammonia, used to induce gelling, was studied as a factor influencing the HPS. The calcined samples were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), FTIR, N2 adsorption and small‐angel X‐ray scattering (SAXS). The results show that the microstructure is highly affected by pH and can be; macropores inserted in a dense matrix; a blend of a dense and a porous structure; or fully hierarchical porous silica. HPS has a specific surface area of 240 m2/g and a large pore volume (1.5 cm3/g) and a surface roughness of 2.95.
Multisite Coordination Ligands on Cyclotriphosphazene Core for the Assembly of Metal Clusters and Porous Coordination Polymers
Authors: Jeevananthan Velusamy , Thangavelu Senthil A. Gurusamy , Loganathan Pushparaj , Shanmugan Swaminathan 
Published: February 2021

AbstractIn this review, we account the recent advancements on cyclotriphosphazene (N3P3Cl6) based multi‐site coordination ligands for the synthesis of multi‐metallic architectures. In case of N3P3Cl6, Phosphorous centres with two chlorides use to be bonded with nitrogen [−P(Cl2)=N−]3 at alternative positions in six membered ring to provide a robust planar structure to anchor the ligand arms with wide flexibility. Cyclic P−N robust motif is renowned as the potential support for the design of multi‐site ligands originating from phosphorus centres by viable substitution of variable number of ligand units (1 to 6) consist of one or more coordination site(s) via geminal and/or non‐geminal modes. Despite these phosphorus centres are promising to support in ligand structure, occasionally involve in coordination with transition metals as well. Three of alternative nitrogen atoms in this heterocyclic core are supposed to function as Lewis base centres while the electron releasing substituents occurred to tether on phosphorus centres, also when the resultant ring size favours adequate interaction towards the transition metal ions with respect to skeletal flexibility. The ligand modes vary with respect to numbers and orientation of coordination sites, which is imperative to enrich the ligation ability. Moreover, several examples of cyclotriphosphazene core ligands consist of the spacer oxygen atom while tethering with exocyclic ligand units to incorporate more flexibility. In accordance with coordination sites on ligand framework and choice of metal, the skeletal ring nitrogen atom(s) of the cyclotriphosphazene can be involved in coordination with metal ions. Indeed, the coordination of ligands is reported to coordinate with main group, transition and lanthanide metal ions to form variety of metal clusters and porous coordination polymers. Subsequently, the geometry of homo or heterometallic complexes with respect to versatile coordination modes of metallic complexes tends to afford inherent chemical properties for specific application. In terms of exocyclic ligands, the heterocyclic units such as pyridyloxy‐, pyrazolyl‐, pyridylalkylamino‐, bipyridyl‐, 1,10‐phenanthroline, porphyrinato, hydrazide, hydrazone, Schiff's base and spirocyclic amine units attached to cyclotriphosphazene were exploited to form series of metal complexes. Similarly, the variety of metal clusters, polymeric network (1D to 3D) and porous coordination polymers have been reported on basis of cyclic core molecule substituted with ligand units, pyridyloxy‐, multi‐carboxylic, aromatic amines substituted pyridyloxy‐ and imidazole moiety involved to form variety of products.
Metal‐, Photocatalyst‐, Light‐ and Electrochemical‐Free C‐3 Trifluoromethylation of Quinoxalin‐2(1H)‐ones, Imidazo[1,2‐a]pyridines and 2H‐Indazoles
Authors: Dutta Nibedita Baruah , Bori Jugal , Gogoi Pinku , Baishya Gakul 
Published: February 2021

AbstractWe report an efficient protocol for the synthesis of 3‐trifluoromethylquinoxalin‐2(1H)‐ones, 3‐trifluoromethylimidazo[1,2‐a]pyridines and 3‐(trifluoromethyl)‐2H‐indazoles under metal‐, photocatalyst‐, light‐ and electrochemical‐free conditions. The combination of Langlois’ reagent (sodium triflinate) with the oxidant (NH4)2S2O8in DMSO: H2O (10 : 1) works as an efficient reagent system to promote this free radical trifluoromethylation reaction. The trifluoromethyl radical generated by the oxidation of sodium triflinate with (NH4)2S2O8attacks on to the C‐3 position of quinoxalin‐2(1H)‐ones, imidazo[1,2‐a]pyridines and 2H‐indazoles; and the excess SO4•−completes the reaction furnishing their respective 3‐trifluoromethyl derivatives in very good to excellent yields. Radical scavenging experiments with (2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl (TEMPO), butylated hydroxy toluene (BHT), and 1,1‐diphenylethylene also prove the participation of radical.
Naked Eye and Colorimetric Detection of Cyanide with a 1,3‐Diethyl‐2‐thiobarbituric Acid Substituted Ferrocene Chemosensor
Authors: Babu Balaji , Mack John , Nyokong Tebello 
Published: February 2021

AbstractA 1,3‐diethyl‐2‐thiobarbituric‐acid‐substituted ferrocene (FET) has been evaluated for its cyanide sensing ability by UV‐visible absorption spectroscopy and other characterization methods. FET provides a ratiometric colorimetric chemosensor for the CN− anion detection in 1 : 1 DMSO/H2O (v/v) solution. The addition of CN− results in an immediate color change from dark blue to pale orange that is visible to the naked eye. Mechanism studies and molecular modelling with TD‐DFT calculations demonstrate that nucleophilic addition of CN− to an electrophilic sp2‐hybridized carbon atom blocks charge transfer from the ferrocene ring complex to the thiobarbituric acid moiety. The FET sensor exhibits excellent selectivity for CN− and a limit of detection of 0.2 μM.
Single Cell Reactomics: Real‐Time Single‐Cell Activation Kinetics of Optically Trapped Macrophages
Authors: Vasse Gwenda F. , Buzón Pedro , Melgert Barbro N. , Roos Wouter H. , van Rijn Patrick 
Published: February 2021

AbstractMacrophages are well known for their role in immune responses and tissue homeostasis. They can polarize towards various phenotypes in response to biophysical and biochemical stimuli. However, little is known about the early kinetics of macrophage polarization in response to single biophysical or biochemical stimuli. Our approach, combining optical tweezers, confocal fluorescence microscopy, and microfluidics, allows us to isolate single macrophages and follow their immediate responses to a biochemical stimulus in real‐time. This strategy enables live‐cell imaging at high spatiotemporal resolution and omits surface adhesion and cell–cell contact as biophysical stimuli. The approach is validated by successfully following the early phase of an oxidative stress response of macrophages upon phorbol 12‐myristate 13‐acetate (PMA) stimulation, allowing detailed analysis of the initial macrophage response upon a single biochemical stimulus within seconds after its application, thereby eliminating delay times introduced by other techniques during the stimulation procedure. Hence, an unprecedented view of the early kinetics of macrophage polarization is provided.
The political economy of theCOVID‐19 pandemic
Authors: Boettke Peter , Powell Benjamin 
Published: February 2021

AbstractWe argue that the policy response to the COVID‐19 pandemic by all levels of government around the world is not consistent with recommendations from standard welfare economics. Thus, it is important to ask why such policies have been adopted. That opens the door to examining the political economy of the COVID‐19 pandemic. This requires examining the incentives and information that confront policymakers and voters and the institutional environments that shape their incentives and information. This lead article frames questions addressed in the remainder of the symposium.
Employing Photocatalysis for the Design and Preparation of DNA‐Encoded Libraries: A Case Study
Authors: Kölmel Dominik K. , Zhu Hongyao , Flanagan Mark E. , Sakata Sylvie K. , Harris Anthony R. , Wan Jinqiao , Morgan Barry A. 
Published: February 2021

AbstractThis Personal Account describes the authors’ foray into DNA‐encoded libraries. The article addresses several key aspects of this hit generation technology, from the development of new synthetic methodology to the subsequent conception, design, and delivery of a DNA‐encoded library. In particular, we have been engaged in adapting photocatalytic reactions to the idiosyncratic requirements of DNA‐encoded chemistry. We have chosen one such methodology, namely a photocatalytic [2+2] cycloaddition reaction, to showcase how we employed property‐based computational analyses to guide the selection and validation of building blocks for the production of a library. Ultimately, these novel bond disconnections and design principles led to the assembly of a DNA‐encoded library that is composed of structurally diverse compounds within largely desirable property space and, therefore, well positioned to deliver novel chemical matter for drug discovery programs.
Supporting Black women's pursuits in STEM
Authors: Nguyen Thai‐Huy , Gasman Marybeth , Washington Lockett Amanda , Peña Vanessa 
Published: February 2021

AbstractResearch related to achievement in Science, Technology, Engineering & Math (STEM) does not provide a clear understanding of the conditions that influence the experiences and performance of Black women. Studies make it difficult to tease out the forces shaping student aspirations and outcomes in STEM, which can lead to flawed explanations that do not take in account the influence of macro forces that can structure students' pathways to degree. This study addresses these concerns by identifying and exploring the opportunities—both past and present—that facilitate the achievement of Black women undergraduate students in STEM at 10 Historically Black Colleges and Universities (HBCUs).
A community cultural wealth analysis of newcomer student writing: Identifying strengths
Authors: Kelly Laura Beth , Duncan Taylor , Herrera Daniela 
Published: February 2021

AbstractIn this study, the researchers analyzed writing produced by newcomer immigrant and refugee students in a literacy workshop facilitated by visiting college tutors. Fourteen adolescent students, primarily from Central America, worked over a semester with a college partner to read mentor texts about youth immigration experiences, write their own stories, and produce digital presentations of their work. Using the community cultural wealth framework, the researchers analyzed these digital presentations and found examples of aspirational, linguistic, familial, social, navigational, and resistant capital. The authors consider how the examples of capital that students revealed could support educators in knowing their students better and thus planning appropriate instruction for them.
DNA damage induced by cylindrospermopsin on different tissues of the biomonitor fish Poecilia reticulata
Authors: Rabelo Jéssica C. S. , Hanusch Alex L. , de Jesus Lázaro Wender O. , Mesquita Lorena A. , Franco Fernanda C. , Silva Raquel A. , Sabóia‐Morais Simone M. T. 
Published: February 2021

AbstractThe cyanotoxin cylindrospermopsin (CYN) is the second biggest cause of poisoning worldwide, both in humans and animals. Although CYN primarily affects the aquatic environments and can be absorbed in fishes by multiple routes, data reporting its toxicity and mechanism of action are still scarce in this group. Using P. reticulata as model species, it was evaluated whether CYN promotes mutagenic and genotoxic effects in different fish target tissues. Adult females were exposed in a static way to 0 (control), 0.5, 1.0, and 1.5 μg L−1 of pure CYN for 24 and 96 hours. For the first time, DNA damage was detected in fish brain after CYN exposition. In brain cells, a concentration‐response DNA damage was observed for both exposure times, suggesting a direct or indirect action of CYN in neurotoxicity. For the liver cells, 96 hours caused an increase in DNA damage, as well the highest percentage of DNA in the tail was reached when used 1.5 μg L−1 of CYN. In peripheral blood cells, an increase in DNA damage was observed for all tested concentrations after 96 hours. In erythrocytes, micronuclei frequency was higher at 1.5 μg L−1 treatment while the erythrocyte nuclear abnormalities (ENA) frequency was significantly higher even at the lowest CYN concentration. Such data demonstrated that acute exposition to CYN promotes genotoxicity in the brain, liver, and blood cells of P. reticulata, as well mutagenicity in erythrocytes. It rises an alert regarding to the toxic effects of CYN for aquatic organisms as well as for human health.
Enhanced expression of cyclooxygenase‐2 related multi‐drug resistance gene in melanoma and osteosarcoma cell lines by TSG‐6 secreted from canine adipose‐derived mesenchymal stem/stromal cells
Authors: Yang Se‐Jin , An Ju‐Hyun , Park Su‐Min , Lee Jeong‐Hwa , Chae Hyung‐Kyu , Lee Kyung‐Mi , Song Woo‐Jin , Youn Hwa‐Young 
Published: February 2021

AbstractBackgroundMultiple drug resistance (MDR) of cancer cells is the main cause of intrinsic or acquired desensitization to chemotherapy in many cancers. A number of studies have found high expression of COX‐2 to be a factor for expression of MDR gene in several cancer. Furthermore, adipose tissue derived mesenchymal stem/stromal cells (ADSC) have been found to increase cyclo‐oxygenase‐2 (COX‐2) expression in some tumour cells. The mechanism for this, however, is not yet clear and needs further study.ObjectiveThe purpose of this study was to determine whether tumour necrosis factor‐alpha stimulated gene/protein 6 (TSG‐6) secreted from ADSCs is associated with an increase in MDR genes by inducing COX‐2 gene expression in melanoma and osteosarcoma cell lines.MethodsADSCs were transfected with TSG‐6 siRNA or Control RNA respected, and cancer cell line were transfected with COX‐2 siRNA or Control RNA respected. Using trans well coculture system, the interactions of ADSCs with tumour cells were investigated.ResultsIncreased COX‐2 expression was observed in cancer cell co‐cultured with ADSCs. Additionally, we identified that COX‐2 expression was related to drug resistance genes (P‐glycoprotein, multidrug resistance‐associated protein). Transfecting canine ADSCs with small interfering RNA, TSG‐6 secreted from ADSCs was found to be a major factor in the regulation of COX‐2 expression and drug resistance genes in osteosarcoma and melanoma cell lines.ConclusionTSG‐6 mediated COX‐2 up‐regulation is a possible mechanism of chemoresistance development induced by ADSCs. These findings provide better understanding about the mechanism associated with ADSC‐induced chemoresistance in cancer.
Cryopreservation of dog semen in a Tris extender with two different 1% soybean preparations compared with a Tris egg yolk extender
Authors: Hermansson Ulrika , Johannisson Anders , Axnér Eva 
Published: February 2021

AbstractEgg yolk is widely used as a cryoprotectant in dog semen extenders, but there is a risk of contamination with animal pathogens. In addition, egg yolk may vary in composition, making it difficult to standardize the extender. Lecithin is an animal protein‐free alternative to egg yolk for semen cryopreservation. Recently, it was shown that 1% of soybean lecithin type II‐S was better than 2% for freezing canine semen. The aim of the study was to compare two different types of soybean lecithin, with egg yolk as a control. Ejaculates from eight dogs were divided into three equal parts and diluted with a Tris‐based extender, containing either 20% egg yolk, 1% soybean lecithin Type II‐S or 1% soybean lecithin Type IV‐S. The samples were then frozen. Sperm motility was evaluated by computer‐assisted sperm analysis (CASA), acrosome integrity (FITC‐PNA/PI) and sperm membrane integrity (SYBR‐14/PI) post‐thaw, as well as after 2 and 4 hr incubation at 37°C. Post‐thaw sperm chromatin structure assay and plasma membrane integrity were evaluated by flow cytometry. Total motility, sperm plasma membrane integrity and acrosome integrity were significantly better in the egg yolk extender than in the two soybean lecithin‐based extenders. Individual motility post‐thaw differed more than in the fresh samples, illustrating individual differences in tolerance to the cryostress. The DNA Fragmentation Index (% DFI) was significantly lower in the Tris egg yolk (TEY) extender compared to any of the soybean‐based extenders. The number of high green stained spermatozoa were significantly higher in Type IV‐S compared to the control TEY extender. In conclusion, egg yolk was superior to the two lecithin‐based extenders to cryopreserve canine semen.
A systematic evaluation of wind's capacity credit in the Western United States
Authors: Jorgenson Jennie , Awara Sarah , Stephen Gord , Mai Trieu 
Published: February 2021

AbstractThe degree to which wind energy can contribute to the capacity needed to meet resource adequacy requirements, also known as capacity credit (CC), can be impacted by many factors. The CC varies regionally with wind resource and correlation to net load and may also vary with wind technology (land‐based versus offshore) and turbine specifications. We use a probabilistic resource adequacy tool to systematically assess the CC of multiple technologies for near‐term wind deployment across the Western US power system to help inform planning decisions. We find that wind CC varies by weather year and location but averages 16% for land‐based turbines and 41% for offshore turbines, with large regional variations. The average wind CC increases to 20% for land‐based and 53% for offshore when considering only the sites in the top 25th percentile of capacity factor. The CC of land‐based wind is generally lower than its capacity factor, which indicates a low correlation of generation to system needs. However, offshore wind shows a substantially higher CC, which is driven by not only a higher capacity factor but also a greater correlation with system needs.
Hazardous wastewater treatment by low‐cost sorbent with in situ regeneration using hybrid solar energy‐electrochemical system
Authors: Khan Muhammad Masood , Asghar Hafiz Muhammad Anwar , Saulat Hammad , Chawla Muhammad , Rafiq Sikander , Khan Muhammad Mahmood , Ya Jie Wang , Aslam Muhammad , Mukhtar Ahmad 
Published: February 2021

AbstractHazardous industrial wastes negatively impact the environment by creating issues for aquatic as well as human's life. This study investigates the treatment of hazardous industrial wastewater using cost‐effective graphite adsorbent along with electrochemical regeneration integrated with renewable solar energy. The synthetic industrial effluent containing crystal violet dye was treated using an adsorbent (Nyex™ 1000) having a surface area of 1.0 m2 g−1. The efficiency of removing solute was found to be more than 90%. The adsorbent regeneration efficiency was achieved at 99.5% by passing a charge of 100 C g−1 at current density of 10 mA cm−2 for 1 h. Solar energy was integrated with electrochemical reactor for the regeneration of adsorbent to make the system cost‐effective and self‐sustainable.Practitioner points

Industrial hazardous wastewater treatment with a cost‐effective graphite integrated adsorbent.
Development of renewable solar energy‐integrated with electrochemical system for regeneration.
Regeneration efficiency of adsorbent Nyex™ 1000 was achieved around 99.5% with integrated system.
Sustainable system was introduced to incorporate with renewable energy for waste water treatment.