bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uncertainty Quantification of Michaelis–Menten Kinetic Rates and Its Application to the Analysis of CRISPR‐Based Diagnostics
Authors: Avaro Alexandre S. , Santiago Juan G. 
Published: September 2022

AbstractMichaelis–Menten kinetics is an essential model to rationalize enzyme reactions. The quantification of Michaelis–Menten parameters can be very challenging as it is sensitive to even small experimental errors. We here present a quantification of the uncertainty inherent to the experimental determination of kinetic rate parameters for enzymatic reactions. We study the influence of several sources of uncertainty and bias, including the inner filter effect, pipetting errors, number of points in the Michaelis–Menten curve, and flat‐field correction. Using Monte Carlo simulations and analyses of experimental data, we compute typical uncertainties of
,
, and catalytic efficiency
. As a salient example, we analyze the extraction of such parameters for CRISPR‐Cas systems. CRISPR diagnostics have recently attracted much interest and yet reports of these enzymatic kinetic rates have been highly unreliable and inconsistent.
Total Syntheses of (±)‐Dracocephalone A and (±)‐Dracocequinones A and B
Authors: Hwang Taehwan , Tuccinardi Joseph P. , Beard Alexandra A. , Jackson Amy C. , Jung Min J. , Wood John L. 
Published: September 2022

AbstractDescribed herein are the first total syntheses of (±)‐dracocephalone A (1) and (±)‐dracocequinones A (4) and B (5). The synthesis was initially envisioned as proceeding through an intramolecular isobenzofuran Diels–Alder reaction, a strategy that eventually evolved into a Lewis acid‐promoted spirocyclization. This highly diastereoselective transformation set the stage for trans‐decalin formation and a late‐stage Suárez oxidation that produced a [3.2.1] oxabicycle suited for conversion to 1. Brønsted acid‐mediated aromatization, followed by a series of carefully choreographed oxidations, allowed for rearrangement to a [2.2.2] oxabicycle poised for conversion to 4 and 5.
HECTD1‐Mediated Ubiquitination and Degradation of Rubicon Regulates Autophagy and Osteoarthritis Pathogenesis
Authors: Liao Shiyao , Zheng Qiangqiang , Shen Haotian , Yang Guang , Xu Yuzi , Zhang Xiaolei , Ouyang Hongwei , Pan Zongyou 
Published: September 2022

ObjectiveOsteoarthritis (OA) is one of the most common degenerative joint diseases and is associated with autophagy suppression. However, the molecular mechanism of autophagy regulation in the context of OA is not fully understood. In this study, we sought to determine the role that HECTD1 plays in the pathogenesis of OA.MethodsWe used RNA sequencing analysis to explore the differential expression of E3 ubiquitin ligase genes in healthy human cartilage and human cartilage affected by OA. Using surgery‐ and aging‐induced OA mouse models, we comprehensively analyzed the function of the screened gene Hectd1 in the development of OA; furthermore, we dissected the mechanism by which HECTD1 regulates autophagy and OA progression using a combination of molecular biologic, cell biologic, and biochemical approaches.ResultsHECTD1 was significantly down‐regulated in human OA cartilage samples compared to healthy cartilage samples. Overexpression of HECTD1 in mouse joints alleviated OA pathogenesis, whereas conditional depletion of Hectd1 in cartilage samples aggravated surgery‐ and aging‐induced OA pathogenesis. Mechanistically, HECTD1 bound to Rubicon and ubiquitinated Rubicon at lysine residue 534, which targets Rubicon for proteasomal degradation. More importantly, HECTD1‐mediated Rubicon degradation regulated chondrocyte autophagy, leading to mitigation of stress‐induced chondrocyte death and the subsequent progression of OA.ConclusionHECTD1 plays a crucial role in the pathogenesis of OA, in that HECTD1 regulates chondrocyte autophagy by ubiquitinating and targeting Rubicon for proteasomal degradation.
A promising nanostructured bimetallic catalyst for the production of second‐generation biodiesel: reuse and stability study
Authors: Sánchez Faba Edgar M. , Ferrero Gabriel O. , Eimer Griselda A. 
Published: September 2022

AbstractThe stability and reusability of a promising bimetallic mesoporous catalyst (5Na/20Ce/SBA‐15) to produce first‐ and second‐generation biodiesel was studied. Soybean oil, waste frying oil, and Jatropha hieronymi oil were used as lipid raw materials. Under optimized reaction conditions (10 wt % of catalyst, methanol to oil molar ratio of 40 : 1, 60 °C, and vigorous magnetic stirring), the minimum FAME content required by the EN 14214 standard was achieved in 3 h with soybean oil and waste frying oil. Three alternatives were considered concerning the reuse of the catalyst (without and with regeneration), concluding that washing followed by calcination between each run is suitable for the material to recover its activity. FAME contents over 87 wt % were obtained in five cycles when using waste frying oil. Key quality properties of the produced biofuel were evaluated and found to comply with international standards for its commercialization as automotive diesel fuel without further treatment.
Acceptorless Dehydrogenation of Alcohols and Transfer Hydrogenation of Aldehydes in Water Using a Single Bifunctional, Bistate, Water‐soluble Ruthenium Catalyst
Authors: Hazra Susanta , Nair Abhishek , Dolui Pritam , Malik Ekta , Elias Anil J. 
Published: September 2022

AbstractA water‐soluble bifunctional, bistate ruthenium catalyst has been developed using the 8‐aminoquinoline ligand which responds to an acid‐base stimuli and is catalytically active for two complementary reactions. The “Ru‐amino state” is highly active for catalytic transfer hydrogenation of various aldehydes using formic acid as the hydrogen source resulting in a range of primary alcohols. On the other hand, the “Ru‐amido state” is active for the acceptorless dehydrogenation of alcohols to yield carboxylate salts or ketones. The reactions can be carried out in air without an inert atmosphere and the products can be purified by simple extraction without the use of any chromatographic techniques. A range of functional groups which include electron‐rich and deficient (hetero)arenes and alkenes, alkynes, halides, esters, cyano, and nitro groups, are all well tolerated, indicating excellent chemoselectivity for transfer hydrogenation.
Design of discrete PID controllers for maximizing stability margins
Authors: Guo Tong‐Yi , Hwang Chyi , Lu Li‐Shin 
Published: September 2022

AbstractThe objective of this paper is to provide a discrete PID controller design procedure for maximizing stability margins. First, a new and complete characterization of the entire set of stabilizing discrete PID controllers for a given plant is presented. Then, based on this characterization, an efficient algorithm is developed for testing if, for a given plant, there exists a digital PID controller gain parameter space corresponding to closed‐loop poles being inside the circle of radius
centered at the origin. The developed algorithm is finally applied along with a bisection strategy to determine, for a specified small positive number
, a minimum value
and the corresponding
discrete PID controller set for achieving at least
of stability margin. To illustrate the features of our new characterization of stabilizing digital PID controller sets and the effectiveness of the presented algorithms to the maximum stability‐margin discrete PID controller design, two numerical examples are provided.
Synthesis, Antifungal Activity, and Molecular Docking Study of Novel 3‐Carene‐Derived 4‐Substituted Phenyl‐1,2,4‐Triazolinthiones Bearing gem‐Dimethylcyclopropane Moiety
Authors: Li Baoyu , Yu Youpei , Duan Wengui , Lin Guishan , Wen Rongzhu , Zhang Zhaolei 
Published: September 2022

AbstractFor exploring new natural product‐based leading compounds with antifungal activity, 15 novel 3‐carene‐derived 4‐substituted phenyl‐1,2,4‐triazolinthiones 7a∼7o bearing gem‐dimethylcyclopropane moiety were synthesized and structurally characterized by UV/VIS, FT‐IR, 1H‐NMR, 13C‐NMR, ESI‐MS and elemental analysis. The preliminary bioassay at 50 μg/mL showed that all of the target compounds exhibited certain in vitro inhibitory activities against the eight tested fungi, in which compound 7g (R=m, p‐Cl) displayed better inhibition activity (85.0 %) against P. piricola than that of the positive control Chlorothalonil. Furthermore, a reasonable and effective 3D structure of phytofungal CYP51 was constructed by homology modeling. Molecular docking study revealed that the total scores of all the target compounds were higher than that of Prothioconazole. In addition, it was found that compound 7g could readily embed into the binding site, and therein shared similar interactions with the case of Prothioconazole. Thus, compound 7g deserved further study as an antifungal leading compound.
Effect of hypoxia and uremia on oxidative stress on erythrocytes from hemodialysis patients
Authors: Dias Gabriela F. , Tozoni Sara S. , Bohnen Gabriela , van Spitzenbergen Beatriz A. K. , Grobe Nadja , Nakao Lia S. , Pecoits‐Filho Roberto , Kotanko Peter , Moreno‐Amaral Andréa N. 
Published: September 2022

AbstractOxidative stress (OS) is essential in uremia‐associated comorbidities, including renal anemia. Complications experienced by hemodialysis (HD) patients, such as hypoxemia and uremic toxins accumulation, induce OS and premature death of red blood cells (RBC). We aimed to characterize reactive oxygen species (ROS) production and antioxidant pathways in HD‐RBC and RBC from healthy controls (CON‐RBC) and evaluate the role of uremia and hypoxia in these pathways. ROS production, xanthine oxidase (XO) and superoxide dismutase (SOD) activities, glutathione (GSH), and heme oxygenase‐1 (HO‐1) levels were measured using flow cytometry or spectrophotometry in CON‐RBC and HD‐RBC (pre‐ and post‐HD), at baseline and after 24 h incubation with uremic serum (S‐HD) and/or under hypoxic conditions (5% O2). Ketoprofen was used to inhibit RBC uremic toxins uptake. HD‐RBC showed higher ROS levels and lower XO activity than CON‐RBC, particularly post‐HD. GSH levels were lower, while SOD activity and HO‐1 levels of HD‐RBC were higher than control. Hypoxia per se triggered ROS production in CON‐RBC and HD‐RBC. S‐HD, on top of hypoxia, increased ROS levels. Inhibition of uremic toxins uptake attenuated ROS of CON and HD‐RBC under hypoxia and uremia. CON‐RBC in uremia and hypoxia showed lower GSH levels than cells in normoxia and non‐uremic conditions. Redox mechanisms of HD‐RBC are altered and prone to oxidation. Uremic toxins and hypoxia play a role in unbalancing these systems. Hypoxia and uremia participate in the pathogenesis of OS in HD‐RBC and might induce RBC death and thus compound anemia.
New roles of DNA‐binding and forkhead‐associated domains of Fkh1 and Fkh2 in cellular functions
Authors: Zhou Hui , Shi Bu‐Jun 
Published: September 2022

AbstractTwo yeast forkhead transcription factors Fkh1 and Fkh2 regulate the transcription of CLB2 cluster genes important for mitosis. Both proteins contain a DNA‐binding domain (DBD) and a forkhead‐associated domain (FHAD), which are essential for ternary complex formation with transcription factor Mcm1, the transcription of CLB2 cluster genes and the physical interaction with Ndd1 and Clb2. Fkh2 also contains an additional C′ domain that contains six consensus Cdk phosphorylation sites, but the function of this domain is dispensable. Here, we found new roles of the DBD, the FHAD, and the C′ domain of Fkh1 and Fkh2 in cellular functions. The Fkh2 DBD determines the genetic interaction with NDD1, while both the FHAD and DBD of Fkh1 or Fkh2 determine cell morphology and stability of their own transcripts. Both HFADs, but not DBDs, also mediate physical interaction between Fkh1 and Fkh2. DBD and HFAD of Fkh1 and DBD, but not HFAD, of Fkh2 are also fundamental for nuclear localization. However, the Fkh2‐specific C′ domain has no role in these aspects except in the stability of some fkh mutant transcripts, which is either increased or decreased in the presence of this domain. These findings reveal that Fkh1 and Fkh2 have multiple cellular functions and function mainly via their DBD and FHAD through a domain‐controlled feedback regulation mechanism.
Electro‐assisted Molecular Assembly Giving Atomic‐Scale Catalytic Active‐Site Detection
Authors: Fan Qianqian , Liu Zirui , Qiu Feng , Mao Yong , Liu Qingju , Zhang Longzhou 
Published: September 2022

AbstractThe artificially accurate design of nonmetal electrocatalysts’ active site has been a huge challenge because no pure active species with the specific structure could be strictly controlled by traditional synthetic methods. Species with a multiconfiguration in the catalyst hinder identification of the active site and the subsequent comprehension of the reaction mechanism. We have developed a novel electro‐assisted molecular assembly strategy to obtain a pure pentagon ring on perfect graphene avoiding other reconstructed structures. More importantly, the active atom was confirmed by the subtle passivation process as the topmost carbon atom. Recognition of the carbon‐defect electrocatalysis reaction mechanism was first downsized to the single‐atom scale from the experimental perspective. It is expected that this innovative electro‐assisted molecular assembly strategy could be extensively applied in the active structure‐controlled synthesis of nonmetal electrocatalysts and verification of the exact active atom.
cis‐Clerodane Diterpenoids with Structural Diversity and Anti‐inflammatory Activity from Tinospora crispa
Authors: You Jin‐Qiu , Liu Yi‐Nan , Zhou Jun‐Su , Sun Xin‐Yu , Lei Chun , Mu Qing , Li Jing‐Ya , Hou Ai‐Jun 
Published: September 2022

Comprehensive SummaryTwelve new cis‐clerodane diterpenoids, designated as crispinoids A—L (1—12), together with three known analogues (13—15), were isolated from Tinospora crispa. Their structures were fully assigned by comprehensive spectroscopic techniques, single‐crystal X‐ray diffraction experiments, and electronic circular dichroism (ECD) analyses. The isolated clerodanes displayed diverse heterocyclic frameworks including 6/6/6‐, 6/5/6/6‐, 6/6/5‐, 6/6‐, and 6/5/6‐fused ring systems. Some of the isolates showed ATP‐citrate lyase (ACLY) and nuclear factor kappa B (NF‐κB) pathway inhibition. The NF‐κB inhibitors further suppressed the lipopolysaccharide (LPS)‐induced inflammatory responses in RAW 264.7 cells.
Targeted Management of Perovskite Film by Co(II) Sulfophenyl Porphyrin for Efficient and Stable Solar Cells†
Authors: Feng Xiao‐Xia , Lv Xudong , Cao Jing , Tang Yu 
Published: September 2022

Comprehensive SummaryIn the lead halide perovskite solar cells (PSCs), the redox reaction of I– and Pb2+ ions in perovskite materials under the fabrication and operation processes causes the formation of defects to destroy the cell efficiency and long‐term stability. Herein, we have employed a Co(II) sulfophenyl porphyrin (CoTPPS) to modify the perovskite film. The sulfonic group could coordinate with Pb2+ to efficiently passivate the uncoordinated Pb2+. Additionally, Co2+ ions in CoTPPS could react with I2 generated under the thermal and light stress to yield the Co3+ and I–, thus achieving the regeneration of I– in perovskite film. Therefore, the CoTPPS could realize the targeted management of the imperfections in perovskite film. As a result, the modified PSCs reveal the remarkably enhanced cell performance. More importantly, the CoTPPS modified device retains 75% of its initial efficiency value storing at 85°C for 2000 h and about 70% of its efficiency when being continuously illuminated at a simulated sunlight for 1200 h. This strategy tackles the chemical reaction and inhibits the defect generation, thus improving the operational stability and efficiency of PSCs.
Precise and Controllable Assembly of Block Copolymers†
Authors: Jin Bixin , Chen Yiqi , Luo Yunjun , Li Xiaoyu 
Published: September 2022

Comprehensive SummaryWith the development of nanotechnology, the precise synthesis of nanoparticles with nicely‐defined dimensions and structures has been well‐developed, and the functionalization and subsequent applications of the resultant nanostructures are becoming increasingly important. Comparing to inorganic nanoparticles, the nanostructures based on soft matters, especially block copolymer assemblies, are much lower in cost, easier to fabricate and richer in morphology. However, the dimensional control over the block copolymer assemblies is not as easy. Only in recent decade, with the discovery of living Crystallization‐Driven Self‐Assembly (CDSA) by Manners and Winnik, researchers become able to precisely tune the sizes of block copolymer assemblies in a relatively wide range. This discovery has inspired tremendous research effort in the self‐assembly field, and considerable progress has been made recently. This review summarizes the main progress in the precise and controllable self‐assembly field in the past five years, and is mostly focused on four aspects, including in‐depth understanding of the assembly methods, extension of this method to two‐dimensional nanostructures, utilization of this method to fabricate hierarchical structures, and the potential applications of these well‐defined nanostructures. We hope not only to make a periodic systematic summary of previous studies, but also to provide some useful thinking for the future development of this field.
Cardiac metastasis from small cell lung cancer origin: A case report and review of the literature
Authors: Tian Lei , Liu Miaomiao , He Liya , Zhang Qi , Li Qiaofang , Zhang Hongzhen 
Published: September 2022

AbstractBackgroundCardiac metastasis from small cell lung cancer (SCLC) origin is rare, whereas the incidence is anticipated to increase with the extended survival rates. Case: We here describe a case report of a 48‐year‐old male patient diagnosis with SCLC in 2020. In June 2021, he resorted to hospital due to shortness of breath, no obvious changes were found in repeated echocardiography, electrocardiogram and chest computer tomography from June 2021 to September 2021. Due to the persistence of the complaints, cardiac magnetic resonance (CMR) imaging was performed in September 30th, 2021, which showed a mass in the right atrioventricular groove. The patient underwent pericardiocentesis and small cell carcinoma cells were found in the pericardial effusion, confirming the diagnosis of cardiac metastasis.ConclusionPatients with a history of SCLC who develop new cardiac symptoms of unknown etiology should undergo imaging studies such as CMR. The importance of CMR for patients with SCLC is highlighted. The literature regarding metastatic cardiac tumors is reviewed.
An intelligent intrusion detection system for distributed denial of service attacks: A support vector machine with hybrid optimization algorithm based approach
Authors: Sokkalingam Sumathi , Ramakrishnan Rajesh 
Published: September 2022

SummaryCloud computing offers comfortable service to business sectors as they can concentrate on their products. Over the internet, cloud computing is liable to various security threats and attacks which is a primary obstacle to the growth of cloud computing services. Distributed denial of service (DDoS) is one such attack that exploits cloud computing services using compromised machines; hence, its detection is a significant field of research. Several DDoS detection schemes have been proposed in the past, but they fail to detect real‐time active DDoS attacks because of their growth in severity and volume. Machine learning (ML) techniques are efficient in making predictions; hence, in this study, a hybrid ML intrusion detection system (IDS) model is proposed. The performance of the proposed IDS model is improved by employing a 10‐fold cross‐validation technique to perform feature selection, reducing data dimensions on the publicly available benchmark NSL‐KDD dataset. Performance validation of the proposed hybrid IDS model is done using the confusion matrix. Support vector machine (SVM) parameters are fine‐tuned using hybrid Harris Hawks optimization (HHO) and particle swarm optimization (PSO) algorithms. The performance of these hybrid algorithms is compared with other classical algorithms such as C4.5, K‐nearest neighbor, and SVM using performance metrics such as precision, sensitivity, specificity, F1 score, and accuracy. From these comparisons, it can be inferred that the proposed SVM with hybrid optimization HHO‐PSO machine learning IDS model performs better DDoS detection with good performance metric values.
Effect of Halide Anions on the Electroreduction of CO2 to C2H4: A Density Functional Theory Study**
Authors: Ma Xifei , Xing Lu , Yao Xiaoqian , Zhang Xiangping , Liu Lei 
Published: September 2022

AbstractThe halide anions present in the electrolyte improve the Faradaic efficiencies (FEs) of the multi‐hydrocarbon (C2+) products for the electrochemical reduction of CO2 over copper (Cu) catalysts. However, the mechanism behind the increased yield of C2+ products with the addition of halide anions remains indistinct. In this study, we analysed the mechanism by investigating the electronic structures and computing the relative free energies of intermediates formed from CO2 to C2H4 on the Cu (100) facet based on density functional theory (DFT) calculations. The results show that formyl *CHO from the hydrogenation reaction of the adsorbed *CO acts as the key intermediate, and the C−C coupling reaction occurs preferentially between *CHO and *CO with the formation of a *CHO‐CO intermediate. We then propose a free‐energy pathway of C2H4 formation. We find that the presence of halide anions significantly decreases the free energy of the *CHOCH intermediate, and enhances desorption of C2H4 in the order of I−>Cl−>Br−>F−. Lastly, the obtained results are rationalized through Bader charge analysis.
Benzothiadiazole‐Based Green Hybridized Local and Charge‐Transfer (HLCT) Fluorophores as Solution‐Processed Non‐Doped Emitters for Simple Structured Electroluminescent Devices
Authors: Kongsabay Suwapat , Loythaworn Thidarat , Petdee Sujinda , Chasing Pongsakorn , Funchien Patteera , Waengdongbung Wijitra , Wongkaew Praweena , Sudyodsuk Taweesak , Promarak Vinich 
Published: September 2022

AbstractHerein, two new solution‐processable HLCT fluorophores (CBzF and CBzFC) based on benzothiadiazole (Bz) derivatives were designed and synthesized (HLCT=hybridized local and charge transfer). Their optical and photophysical properties were experimentally and theoretically studied and verified by the solvatochromic effect and density functional theory calculations. The two molecules demonstrate high solubility, HLCT features, and an intense green fluorescence with solid‐state photoluminescence quantum yields of 63–72 %. Both fluorophores are effectively applied as non‐doped emitters for solution‐processed double‐layered OLEDs, which produce intense green emission colors with low turn‐on voltages (3.0–3.2 V). Specifically, the CBzFC‐based solution‐processed device achieves a high maximum luminescence (24400 cd m−2), high maximum efficiencies (EQEmax=5.59 %, CEmax=12.24 cd A−1, and PEmax=10.54 lm W−1), and decent efficiency low‐off.