bluuebunny/crossref_metadata_2025 huggingface dataset:
Two novel nomograms for predicting the risk of hospitalization or mortality due to COVID‐19 by the naïve Bayesian classifier method
Authors: Karaismailoglu Eda , Karaismailoglu Serkan
Published: February 2021

Coronavirus disease 2019 (COVID‐19) has become a global pandemic that has affected millions of people worldwide. The presence of multiple risk factors for COVID‐19 makes it difficult to plan treatment and optimize the use of medical resources. The aim of this study is to determine potential risk factors for hospitalization or mortality in patients with COVID‐19 via two novel naive Bayesian nomograms. The publicly available COVID‐19 National data published by the Mexican Ministry of Health through the “Dirección General de Epidemiología” website was analyzed. Univariable logistic regression was utilized to identify potential risk factors that may affect hospitalization or mortality in patients with COVID‐19. The naïve Bayesian classifier method was implemented to predict nomograms. The nomograms were verified by the area under the receiver operating characteristic curve (AUC), classification accuracy (CA), F1 score, precision, recall, and calibration plot. A total of 979,430 patients (45.3 ± 15.9 years old, and 51.1% male) tested positive for COVID‐19 from January 1 to November 22, 2020. Among them, 22.3% of the patients required hospitalization and 99,964 patients (9.8%) died. The most important risk factors to predict the probability of hospitalization and mortality were pneumonia, age, chronic kidney failure, chronic obstructive respiratory disease, and diabetes. The performance measures demonstrated good discrimination and calibration (hospitalization: AUC = 0.896, CA = 0.880; mortality: AUC = 0.903, CA = 0.899). Two novel nomograms to estimate the risk of hospitalization and mortality were proposed, which could be used to facilitate individualized decision‐making for patients newly diagnosed with COVID‐19.
The high tolerance of different pomegranate cultivars to the excess of boron in irrigation water is due to their capacity to limit boron transport from the root to the leaves
Authors: Olmo‐Vega Antonio , Simón‐Grao Silvia , Simón Inmaculada , Alfosea‐Simón Marina , Martínez‐Nicolás Juan José , García‐Sánchez Francisco
Published: February 2021

Background: Presently, irrigation waters often have a high concentration of boron (B), and the fruit trees in the Mediterranean areas, in general, are exposed to a high risk of B toxicity.

Aims: To test the hypothesis that pomegranate trees are very tolerant to the presence of B in the irrigation water, to elucidate the physiological mechanisms behind this tolerance, and to assess differences between different varieties.

Methods: In this study, the physiological and nutritional behavior of three pomegranate cultivars (‘Mollar de Elche', ‘Valenciana', and ‘Wonderful'), treated with five B concentrations (0.25, 1.25, 2.5, 5.0, 10.0 mg L−1), were studied. At day 30 and 60 after the start of the treatments, growth measurements, gas exchange parameters and organic solutes were recorded.

Results: Almost no significant differences were observed between the B treatments for any of the cultivars. Increasing the B concentration in the nutrient solution increased B concentrations in the leaves, but they never exceed 40 mg kg−1 of B. In the roots, however, B concentrations were very high, up to 400 mg kg−1.

Conclusion: Pomegranate trees are very tolerant to B excess due to their ability to accumulate B in great quantities in the root, without causing toxicity to this part of the plant, thus limiting its transport to the shoots.
A proof‐of‐concept of parallel single‐drop microextraction for the rapid and sensitive biomonitoring of pesticides in urine
Authors: Mafra Gabriela , Will Camila , Huelsmann Ricardo , Merib Josias , Carasek Eduardo
Published: February 2021

In this study, a lab‐made parallel single‐drop microextraction methodology using the magnetic ionic liquid trihexyltetradecylphosphonium tetrachloromanganate (II) as extraction solvent was developed to determine the pesticides tebuconazole, pendimethalin, dichlorodiphenyltrichloroethane, and dichlorodiphenyldichloroethylene in human urine samples. The experimental setup consisted of a 96‐well plate system containing a set of magnetic pins that allowed for the manipulation of up to 96 samples simultaneously, providing an enhanced drop stability compared to traditional single‐drop microextraction approaches. The optimal conditions employed 5.38 ± 0.55 mg of extraction solvent, 1.5 mL of diluted urine samples (1:10), extraction time of 130 min, and subsequent dilution in 20 μL of acetonitrile. The method exhibited satisfactory analytical performance, with limits of detection of 7.5 μg/L for all analytes and coefficients of determination higher than 0.9955. Intraday and interday precisions ranged from 3 to 17% (n = 3) and 15 to 18% (n = 9), respectively, with relative recovery of analytes ranging from 70 to 122%. The method proposed was successfully applied in two human urine samples and no sign of the analytes was detected. The results demonstrated that the proposed method allowed for cost‐effective and high‐throughput methodology to be explored as a valuable tool in bioanalytical applications.
Substrate inhibition versus product feedback inhibition: In the perspective of single molecule enzyme kinetics
Authors: Dhatt Sharmistha , Nandi Mintu , Chaudhury Pinaki
Published: February 2021

In this work, we study the origin of dynamic disorder in a simple reaction network of substrate inhibition and product feedback inhibition loop. It is well established that dynamic disorder arises in a biochemical reaction network not only due to enzymatic fluctuations influencing the catalytic rate but also due to the physical presence of inhibitors owing to their transition between active and inhibited states of enzymes. But we show here, for networks, where there is explicitly no physical presence of an inhibitor but either the reactant or the product in time course of the reaction possesses to be the one. There is a strikingly noticeable dependence of the randomness parameter on the substrate concentration that can discriminate between both the phenomena under consideration.
Non‐Motor Fluctuations in Parkinson's Disease: Validation of the Non‐Motor Fluctuation Assessment Questionnaire
Authors: Kleiner Galit , Fernandez Hubert H. , Chou Kelvin L. , Fasano Alfonso , Duque Kevin R. , Hengartner Diana , Law Albie , Margolius Adam , Poon Yu‐Yan , Sáenz Farret Michel , Saleh Philip , Vizcarra Joaquin A. , Stebbins Glenn T. , Espay Alberto J. ,   PSG NoMoFA Study Group
Published: February 2021

Background

In patients with Parkinson's disease (PD), sleep, mood, cognitive, autonomic, and other non‐motor symptoms may fluctuate in a manner similar to motor symptoms.

Objectives

To validate a final version of a patient‐rated questionnaire that captures the presence and severity of non‐motor fluctuations in levodopa‐treated PD patients (NoMoFA).

Methods

We recruited PD subjects from five movement disorders centers across the US and Canada. We assessed the internal consistency, floor and ceiling effects, test–retest reliability, and concurrent validity of NoMoFA. Classical test theory and item response theory methods informed item reduction and Delphi process yielded a final questionnaire.

Results

Two hundred subjects and their care‐partners participated in the study (age: 66.4 ± 9.6 years; disease duration: 9 ± 5.5 years; median Hoehn and Yahr [H&Y] OFF: 3 [range 1−5]; mean Unified Parkinson's Disease Rating Scale (UPDRS) III ON score: 27.4 ± 14.9). Acceptability of the scale was adequate. There were floor effects in 8/28 items. Cronbach's alpha was 0.894. While eight items had “item‐to‐total” correlations below the cutoff of 0.4, removing these items did not improve Cronbach's alpha. Test–retest reliability was acceptable (intraclass correlation coefficient [ICC] 0.73; 95% confidence interval, 0.64−0.80). Concurrent validity was adequate with all Spearman's rho values comparing NoMoFA score to other measures of parkinsonian severity showing significance and in the expected direction. A final Delphi panel eliminated one item to avoid redundancy.

Conclusions

The final 27‐item self‐administered NoMoFA is a valid and reliable questionnaire, capturing both static and fluctuating non‐motor symptoms in PD. © 2021 International Parkinson and Movement Disorder Society
Optimal polynomial decay for a Timoshenko system with a strong damping and a strong delay
Authors: Makheloufi Hocine , Bahlil Mounir , Feng Baowei
Published: February 2021

In this article, we consider a linear Timoshenko system with a strong damping and a strong constant delay acting on the transverse displacement of the beam. Using the semigroup techniques, we first establish the global well‐posedness result under a condition on the weight of the delayed feedback and the weight of the nondelayed feedback. Then, we show that the system is not exponentially stable even in the case of equal‐speed wave propagations. In this regard, we prove that the solution decays polynomially with rate
. And in addition, by recent result due to A. Borichev and Y. Tomilov, we show the optimality of that rate.
Technical Note: Patient‐morphed mesh‐type phantoms to support personalized nuclear medicine dosimetry — a proof of concept study
Authors: Carter Lukas M. , Camilo Ocampo Ramos Juan , Bolch Wesley E. , Lewis Jason S. , Kesner Adam L.
Published: February 2021

Purpose

Current standard practice for clinical radionuclide dosimetry utilizes reference phantoms, where defined organ dimensions represent population averages for a given sex and age. Greater phantom personalization would support more accurate dose estimations and personalized dosimetry. Tailoring phantoms is traditionally accomplished using operator‐intensive organ‐level segmentation of anatomic images. Modern mesh phantoms provide enhanced anatomical realism, which has motivated their integration within Monte Carlo codes. Here, we present an automatable strategy for generating patient‐specific phantoms/dosimetry using intensity‐based deformable image registration between mesh reference phantoms and patient CT images. This work demonstrates a proof‐of‐concept personalized dosimetry workflow, presented in comparison to the manual segmentation approach.

Methods

A linear attenuation coefficient phantom was generated by resampling the PSRK‐Man reference phantom onto a voxel grid and defining organ regions with corresponding Hounsfield unit (HU) reference values. The HU phantom was co‐registered with a patient CT scan using Plastimatch B‐spline deformable registration. In parallel, major organs were manually contoured to generate a “ground truth” patient‐specific phantom for comparisons. Monte Carlo derived S‐values, which support nuclear medicine dosimetry, were calculated using both approaches and compared.

Results

Application of the derived B‐spline transform to the polygon vertices comprising the PSRK‐Man yielded a deformed variant more closely matching the patient’s body contour and most organ volumes as‐evaluated by Hausdorff distance and Dice metrics. S‐values computed for fluorine‐18 for the deformed phantom using the Particle and Heavy Ion Transport code System showed improved agreement with those derived from the patient‐specific analog.

Conclusions

Deformable registration techniques can be used to create a personalized phantom and better support patient‐specific dosimetry. This method is shown to be easier and faster than manual segmentation. Our study is limited to a proof‐of‐concept scope, but demonstrates that integration of personalized phantoms into clinical dosimetry workflows can reasonably be achieved when anatomical images (CT) are available.
Randomized, Double-Blind, Placebo-Controlled Phase II Study of Yeast-Brachyury Vaccine (GI-6301) in Combination with Standard-of-Care Radiotherapy in Locally Advanced, Unresectable Chordoma
Authors: DeMaria Peter Joseph , Bilusic Marijo , Park Deric M. , Heery Christopher R. , Donahue Renee N. , Madan Ravi A. , Bagheri Mohammad Hadi , Strauss Julius , Shen Victoria , Marté Jennifer L. , Steinberg Seth M. , Schlom Jeffrey , Gilbert Mark R. , Gulley James L.
Published: February 2021

Background

Brachyury is a transcription factor overexpressed in chordoma and is associated with chemotherapy resistance and epithelial-to-mesenchymal transition. GI-6301 is a recombinant, heat-killed Saccharomyces cerevisiae yeast-based vaccine targeting brachyury. A previous phase I trial of GI-6301 demonstrated a signal of clinical activity in chordomas. This trial evaluated synergistic effects of GI-6301 vaccine plus radiation.

Materials and Methods

Adults with locally advanced, unresectable chordoma were treated on a randomized, placebo-controlled trial. Patients received three doses of GI-6301 (80 × 107 yeast cells) or placebo followed by radiation, followed by continued vaccine or placebo until progression. Primary endpoint was overall response rate, defined as a complete response (CR) or partial response (PR) in the irradiated tumor site at 24 months. Immune assays were conducted to evaluate immunogenicity.

Results

Between May 2015 and September 2019, 24 patients enrolled on the first randomized phase II study in chordoma. There was one PR in each arm; no CRs were observed. Median progressive-free survival for vaccine and placebo arms was 20.6 months (95% confidence interval [CI], 5.7–37.5 months) and 25.9 months (95% CI, 9.2–30.8 months), respectively. Hazard ratio was 1.02 (95% CI, 0.38–2.71). Vaccine was well tolerated with no vaccine-related serious adverse events. Preexisting brachyury-specific T cells were detected in most patients in both arms. Most patients developed T-cell responses during therapy, with no difference between arms in frequency or magnitude of response.

Conclusion

No difference in overall response rate was observed, leading to early discontinuation of this trial due to low conditional power to detect statistical difference at the planned end of accrual.

Implications for Practice

Chordoma is a rare neoplasm lacking effective systemic therapies for advanced, unresectable disease. Lack of clinically actionable somatic mutations in chordoma makes development of targeted therapy quite challenging. While the combination of yeast-brachyury vaccine (GI-6301) and standard radiation therapy did not demonstrate synergistic antitumor effects, brachyury still remains a good target for developmental therapeutics in chordoma. Patients and their oncologists should consider early referral to centers with expertise in chordoma (or sarcoma) and encourage participation in clinical trials.
Metastatic Myxofibrosarcoma with Durable Response to Temozolomide Followed by Atezolizumab: A Case Report
Authors: Lambden Jason P. , Kelsten Max F. , Schulte Brian C. , Abbinanti Susan , Hayes John P. , Villaflor Victoria , Agulnik Mark
Published: February 2021

Myxofibrosarcoma (MFS) is a well-recognized histotype of soft tissue sarcomas that generally presents with localized disease. Herein, we describe the case of a patient with metastatic MFS who experienced durable response to sixth-line therapy with temozolomide. Upon further progression, his tumor was notable for a high tumor mutational burden, and he was subsequently treated with seventh-line immunotherapy, atezolizumab, achieving a second durable response. This case highlights the role of immunotherapy after administration of alkylating agents. Review of the literature indicates that recurrent tumors treated with alkylating agents often experience hypermutation as a means of developing resistance and that checkpoint inhibitors are subsequently effective in these tumors.

Key Points
Prospects and Applications of Palladium Nanoparticles in the Cross‐coupling of (hetero)aryl Halides and Related Analogues
Authors: Ayogu Jude I. , Onoabedje Efeturi A.
Published: February 2021

Discovering efficient methods for the formation of carbon‐carbon bonds is a central ongoing theme in organic synthesis. Cross‐coupling reactions catalysed by metal nanoparticles are attractive alternatives to the traditional use of metal counterparts due to the catalytic tunability, selectivity, recyclability and reusability of the nanoparticles. The ongoing search for sustainable processes demands that reusable and environmentally benign catalysts are used. While the advantages of nanoparticles catalysts over bulk catalysts cannot be overemphasised, the problem of sintering, agglomeration and leaching are drawbacks to their full industrial applications. Hence, efforts are being made towards advancing the efficiency of the catalytic nanoparticle systems over the years. This review presents the progress, the challenges and the prospects of palladium nanoparticle with focus on Heck, Suzuki, Hiyama and Sonogashira cross‐coupling reactions involving (hetero) aryl halides and the analogues.
Mechanical and thermal study of 3D printing composite filaments from wind turbine waste
Authors: Rahimizadeh Amirmohammad , Kalman Jordan , Fayazbakhsh Kazem , Lessard Larry
Published: February 2021

The subject of composite waste from the wind turbine blades has become more serious and challenging. Inspired by the recent popularity of the 3D printing industry, this work presents a step‐by‐step recycling solution to manufacture fiber reinforced filaments for fused filament fabrication. Polylactic acid filaments reinforced with 3, 5, and 10 wt% recyclate content are manufactured and tested using thermogravimetric analysis (TGA), and micro computed tomography (μCT). TGA results elucidate that an increase in the recyclate content translates into a reduction in the mean fiber length. Visualizing μCT results, it is confirmed that fibers are predominantly aligned along the filament length. Tensile specimens per ASTM D636 standard are manufactured and tested with results showing an improvement of, respectively, 20% and 28% in the specific tensile strength and modulus compared with pure PLA samples. The mechanical performance of the newly introduced recycled parts is also assessed through a coherent set of theoretical models, where an excellent agreement between the experiments and predictions is observed.
Intensity of usual care physical therapy during inpatient rehabilitation for people with neurologic diagnoses
Authors: DiPasquale Jake , Trammell Molly , Clark Kelly , Fowler Hayden , Callender Librada , Bennett Monica , Swank Chad
Published: February 2021

Background

Early, intense rehabilitation is essential to promote recovery after stroke, spinal cord injury (SCI), and traumatic brain injury (TBI). However, intensity of usual care rehabilitation interventions during inpatient rehabilitation are poorly characterized.

Objective

To describe the intensity of usual care rehabilitation interventions completed during the subacute phase of recovery from neurologic injury.

Design

Observational.

Setting

Inpatient rehabilitation facility.

Interventions

Twenty‐two usual care physical therapy interventions were grouped into six categories: gait (four activities), functional (two), strengthening (four), aerobic (six), balance (four), and wheelchair (two).

Patients

Patients admitted to inpatient rehabilitation with a primary diagnosis of stroke, SCI or TBI within 6 months of injury.

Main Outcome Measure(s)

Cardiovascular intensity (physiological and perceived) was recorded during rehabilitation activity sessions. Physiological intensity was assessed by heart rate reserve (HRR) via a Polar A370 Fitness Watch and characterized as very light (<30%), light (30–39%), moderate (40–59%), vigorous (60–89%), and near maximal (≥90%). Perceived intensity was assessed using the Rating of Perceived Exertion scale.

Results

Patients (stroke n = 16 [number of activity sessions = 338/average session duration = 16.4 min]; SCI n = 15 [299/27.4 min]; TBI n = 15 [340/14.2 min]) participated. For patients with stroke, moderate‐to‐vigorous HRR was attained between 42% (aerobic exercise) to 55% (wheelchair propulsion) of activity sessions. For patients with SCI, moderate‐to‐vigorous HRR was attained between 29% (strength training) to 46% (gait training) of activity sessions. For patients with TBI, moderate‐to‐vigorous HRR was attained between 29% (balance activities) to 47% (gait training) of activity sessions. Associations between HRR and rate of perceived exertion were very weak across stroke (r = 0.12), SCI (r = 0.18), and TBI (r = 0.27).

Conclusions

Patients with stroke, SCI, and TBI undergoing inpatient rehabilitation achieve moderate‐to‐vigorous intensity during some usual care activities such as gait training. Patient perception of intensity was dissimilar to physiological response.
Revealing the changes of IgG subclass‐specific N‐glycosylation in colorectal cancer progression by high‐throughput assay
Authors: Liu Si , Yu Yuting , Liu Yuanyuan , Lin Jiajing , Fu Yang , Cheng Liming , Liu Xin
Published: February 2021

Purpose

The changes of glycosylation of different IgG subclass in colorectal cancer (CRC) were rarely investigated. The authors aimed to use a simple and high‐throughput analytical method to explore the changes of subclass‐specific IgG glycosylation in CRC, and to find the specific glyco‐biomarkers for early detection of this disease.

Experimental design

Serum samples from 71 cancer patients and 22 benign patients with 50 age‐ and sex‐matched healthy controls were collected from two independent cohorts. Subclass‐specific IgG glycosylation was profiled by MALDI‐MS followed by the structural identification through MALDI‐MS/MS. The exported MS data was automatically and rapidly processed by the self‐developed MATLAB code.

Results

Statistical analysis suggested the significantly decreased galactosylation and remarkably increased agalactosylation of IgG1 or IgG2 in the malignant transformation of CRC, which enables the differentiation between cancer patients and healthy controls. The changes of glycan features were elucidated by the exploration of individual glycopeptides, showing the biantennary fucosylated glycan without galactose (H3N4F1) or with two galactose (H5N4F1) of IgG1 and IgG2 could distinguish cancer group from both benign and control groups.

Conclusions and clinical relevance

Through the simple and high‐throughput procedures, this study revealed the important role of IgG glycopeptides in the premature pathology of CRC.
2D Transition‐Metal Silicides as Analogs of MXenes: A First‐Principles Exploration
Authors: Lan Xiaoli , Yu Linke , Lv Xiaodong , Li Fengyu
Published: February 2021

The family of 2D transition metal carbides, carbonitrides, and nitrides (MXenes) has aroused scientific research due to their unique electrical, optical, and chemical properties and their versatile applications. Based on first‐principles calculations, ten transition metal silicide (M2Si, M = Sc, Ti, V, Cr, Mn, Co, Zn, Y, Nb, and Mo) monolayers are studied. Three stable 2D M2Si (M = Mn, Co, and Y) crystals are identified through the investigation of thermodynamic, dynamical, and thermal perspectives. Among them, Y2Si monolayer is a nonmagnetic metal, whereas Mn2Si and Co2Si monolayers are antiferromagnetic metals. The three monolayers are chemically inert to H2 and N2, but highly active to O2, and only Y2Si with its surface functionalized by oxygen exhibits good thermal stability, whose magnetic and electronic properties retain its pristine counterpart. In addition, it is found that the Y2Si shows good electrocatalytic performance in hydrogen evolution reaction (HER). These stable 2D M2Si monolayers have potential in the fields of electronics and electrocatalysis.
The fractional energy balance equation
Authors: Lovejoy Shaun , Procyk Roman , Hébert Raphael , Del Rio Amador Lenin
Published: February 2021

Classical Energy Balance Equations (EBEs) are differential equations of integer order (h = 1), here we generalize this to fractional orders: the Fractional EBE (FEBE, 0 < h ≤ 1). In the FEBE, when the Earth is perturbed by a forcing, the temperature relaxes to equilibrium via a slow power‐law process: h = 1 is the exceptional (but standard) exponential case. Our FEBE derivation is phenomenological, it complements derivations based on the classical continuum mechanics heat equation (that imply h = 1/2 for the surface temperature) and of the more general Fractional Heat Equation which allows for 0 < h < 2. Unlike some of the earlier “scale free” models based purely on scaling, the FEBE has an extra blackbody radiation term that allows for energy balance. It therefore has two scaling regimes (not one), it has the advantage of being stable to infinitesimal step‐function perturbations and it has a finite Equilibrium Climate Sensitivity. We solve the FEBE using Green's functions, whose high‐ and low‐frequency limits are power laws with a relaxation scale transition (several years). When stochastically forced, the high‐frequency parts of the internal variability are fractional Gaussian noises that can be used for monthly and seasonal forecasts; when deterministically forced, the low‐frequency response describes the consequences of anthropogenic forcing, it has been used for climate projections. The FEBE introduces complex climate sensitivities that are convenient for handling periodic (especially annual) forcing. The FEBE obeys Newton's law of cooling, but the heat flux crossing a surface nonetheless depends on the fractional time derivative of the temperature. The FEBE's ratio of transient to equilibrium climate sensitivity is compatible with GCM estimates. A simple ramp forcing model of the industrial‐epoch warming combining deterministic (external) with stochastic (internal) forcing is statistically validated against centennial‐scale temperature series.
Molecular trees with extremal values of Sombor indices
Authors: Deng Hanyuan , Tang Zikai , Wu Renfang
Published: February 2021

Based on elementary geometry, a class of novel graph invariants was introduced by Gutman, of which the simplest is the Sombor index SO, defined as , where G = (V, E) is a simple graph and dG(v) denotes the degree of v in G. In this paper, the chemical importance of the Sombor index is investigated and it is shown that the new index is useful in predicting physico‐chemical properties with high accuracy compared to some well‐established and often used indices. We obtain a sharp upper bound for the Sombor index among all molecular trees with fixed numbers of vertices, and characterize those molecular trees achieving the extremal value. Also, we obtain the extremal values of the reduced Sombor index for molecular trees.
Emergent learning during crisis: A case study of the arctic circle border crossing at Storskog in Norway
Authors: Steen Riana , Rønningsbakk Bernt
Published: February 2021

This explorative study addresses emergent learning related to the refugee crisis in Norway in 2015. We define emergent learning as organizational learning that occurs as a benign by‐product of solving immediate problems as they arise. The study is based mainly on secondary data; media coverage, public evaluation report, and other public documentation. The results from empirical research confirm that emergent learning has had a profound influence on how the Storskog crisis in 2015 was managed. Our findings also reveal suboptimal problem solving, insufficient management capacity, and public organizations who were not prepared to respond fast enough.
Adaptive hierarchical sliding mode control for full nonlinear dynamics of uncertain ridable ballbots under input saturation
Authors: Do Van‐Thach , Lee Soon‐Geul , Van Mien
Published: February 2021

This research proposes a nonlinear adaptive controller based on a hierarchical sliding mode control (HSMC) framework to stabilize the operation of a ridable ballbot based on the full nonlinear dynamics (FND). The FND of ballbots is a multiple‐input‐multiple‐output underactuated system with a non‐invertible input matrix. By applying a novel approach to transform the FND into two subsystems, the invertibility of the input matrix of the transformed subsystems can be guaranteed. Thus, an HSMC scheme can be applied to control the ridable ballbot system based on stabilizing the transformed subsystems. In addition, to improve the robustness of HSMC, a new adaptive law is proposed to deal with the effects of exogenous disturbances and parameter variations on the modeled dynamics. Chattering and actuator saturation phenomena are also reduced or avoided with the proposed controller. Comparative simulations are conducted to demonstrate the merit features of the proposed approach and the robustness of the developed control algorithm.
Structural properties and surface oxidation states of sputter‐deposited TiO2−x thin films
Authors: Jana Swapan , Debnath Anil Krishna , Putta Veerender , Bahadur Jitendra , Chauhan Anil Kumar , Bhattacharya Debarati
Published: February 2021

Titanium dioxide (TiO2−x) films were deposited on silicon (100) substrates from pure titanium (Ti) targets using direct current magnetron sputtering technique. TiO2−x thin films were grown in the thickness range of 515–672 Å with varying sputter powers of 75 and 100 W, at both room temperature (RT) and 200°C substrate temperature (Ts). Structural and compositional characterization of the films, which included surface morphology and study of surface chemical states, was performed. The influences of sputter power and substrate temperature on these parameters were specifically analyzed. Grazing incidence X‐ray diffraction showed that the thin films were amorphous at RT and crystallinity could be achieved only at Ts. The latter showed anatase phase at sputter power of 75 W and transformed into anatase–rutile mixed phase at 100 W. The thickness, roughness, and mass density of the thin films were measured using X‐ray reflectivity. It was observed that for Ts films, the roughness and mass density increased with higher sputter power. Field emission scanning electron microscopy and atomic force microscopy also corroborated this surface roughness result. It was observed from X‐ray photoelectron spectroscopy that the core levels of Ti‐2p3/2 and O‐1s and their corresponding binding energies indicated that only one of the Ti oxidation states, i.e., Ti4+, existed in the films. This work provides insight about the growth of TiO2−x thin films influenced by Ts deposition and different sputter power.
Palladium‐ Catalyzed C−P Bond Forming Reactions: An Overview
Authors: Kanchana U. S. , Diana Elizabeth J. , Mathew Thomas V. , Anilkumar Gopinathan
Published: February 2021

Transition metal catalyzed synthesis of organo‐phosphorus compounds show rapid advances. Due to the powerful bond‐forming ability under mild reaction conditions and wide functional group tolerance made palladium‐catalyzed reactions an inevitable tool for the synthesis of various structurally diversed complex molecules. This review is an account of palladium‐catalyzed Carbon‐Phosphorous bond forming reactions. For proving an insight into the synthetic and mechanistic knowledge of its chemistry some of the mechanisms of this type of catalysis are also added. This review focuses on the recent advances in Palladium‐catalyzed C−P bond forming reactions and covers literature from 2001 to 2020.
Review on Hydrogen Storage Performance of MgH2: Development and Trends
Authors: Hou Quanhui , Yang Xinglin , Zhang Jiaqi
Published: February 2021

Hydrogen storage technology is related to the process of hydrogen energy market. Efficient and safe hydrogen storage materials have always been the goal pursued by people. In the past few years, oceans of materials for hydrogen storage have been researched, MgH2 is considered to be one of the most potential hydrogen storage materials due to its high hydrogen storage capacity, good reversibility and price advantage. However, its development has been limited by its good thermodynamic stability and slow dehydrogenation kinetics. In this paper, the improvement of hydrogen storage performance of MgH2 is summarized from catalyst doping, MgH2 nanosizing, alloying and the construction of composite system. In particular, catalyst doping and MgH2 nanosizing will be more effective modification strategies. With the development of nanotechnology, monatomic catalyst will also become a research hotspot. In view of the changes in thermodynamic properties caused by the nanofabrication of MgH2, the loadless freestanding nano MgH2 will undoubtedly receive more attention.
Synthesis and Cytotoxicity of Some Imidazo[4,5‐b]pyridine Derivatives and Their Regioselective N‐Alkylation
Authors: Doganc Fatima , Alp Mehmet , Karabay Arzu , Koç Aslı , Eren Gokcen , Göker Hakan
Published: February 2021

Some imidazopyridine‐carboxamides and carboximidamides were synthesized and their cytotoxic activities were tested against human leukemia cell lines (K562 and HL‐60), human colon cancer cell line (HCT‐116), human multiple myeloma cell lines (U266 and H929) and normal mouse fibroblast cell line (L929) by MTT (Tetrazolium salt colorimetric assay). Among them, imidazopyridine‐2‐phenylcarboxamide analogues 21 a–23, gave the lowest IC50 value with the range of 5.9–9.8 μM. Since the imidazopyridine ring exist in three tautomeric forms, N‐alkylation with benzyl bromide under basic conditions (K2CO3, in DMF) formed the mixture of three regioisomers. Their structural assignments (16 a, 20 a, 16 b, 20 b–22 b and 16 c) were made with the use of two‐dimensional 1H−1H NOE (Nuclear overhauser effect spectroscopy, NOESY) and 1H/13C‐15N HMBC (Heteronuclear Multiple Bond Correlation) experiments. We observed that, N‐benzylation occurs at a higher ratio on the pyridine moiety as N4‐regiosomer. In order to analyze the possible interactions of compounds 21 a–23, which were found to display good cytotoxic effect against the cancer cell lines tested were selected to dock into Aurora A kinase (AURKA) active site. The results reported that the compounds occupied the ATP pocket via forming interactions with Lys141, Lys162, Thr217, and Tyr 219 indicating the binding affinity to the AURKA.
Super‐Small TiO2 Nanoparticles Homogeneously Embedded in Mesoporous Carbon Matrix Based on Dental Methacrylates and KOH Activation
Authors: Ban Jianzhen , Wang Xiaoyan , Yin Shanshan , Cheng Ya‐Jun , Ji Lianmin , Müller‐Buschbaum Peter , Gao Jie , Xia Yonggao
Published: February 2021

Mesoporous TiO2/C nanohybrids with large specific surface area and well‐defined pore size distribution are prepared by KOH activation treatment using dental resin monomers as solvent and carbon source. Super‐small sized TiO2 nanoparticles are uniformly distributed in porous carbon to realize a significant improvement of the electrochemical properties. The morphology, BET specific surface area and pore size distribution are characterized by SEM, TEM and N2 adsorption/desorption isotherm, respectively. The prepared mesoporous TiO2/C delivers a reversible capacity as high as 387 mAh/g after 100 discharge/charge cycles at 0.2 C current density (1 C=335 mA/g) in conjunction with a good rate capability (184, 70, and 92 mAh/g at 1, 2, and 5 C current densities, respectively).
Designing CoFe2O4/Cellulose@L‐aspargine‐Co Nanocomposite: An Ultra‐Efficient Recyclable Catalyst in the Quick Reduction of Nitro Compounds under Eco‐Friendly Conditions
Authors: Sorkhabi Serve , Ghadermazi Mohammad , Mozafari Roya
Published: February 2021

In this work, novel magnetic nanoparticles CoFe2O4/MCC (microcrystalline cellulose) @L‐aspargine‐Co have been synthesized via simple procedure and have been fully characterized using several techniques such as scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM), energy‐dispersive X‐ray spectroscopy (EDX), X‐ray atomic mapping, powder X‐ray diffraction (XRD), Fourier transform spectroscopy infrared (FT‐IR) and coupled plasma optical emission spectrometry (ICP‐OES). The catalytic efficiency of this nanocatalyst has been examined in the eco‐friendly reduction of different substituted nitro compounds to corresponding amines with sodium borohydride (NaBH4). The reactions were conducted in water at room temperature with high turnover numbers (TON) and turnover frequencies (TOF). The nontoxic nature, green reaction conditions, short reaction times, simple work‐up method and elimination of by‐products are some advantages of this approach. This organometallic catalyst was successfully recycled for eight times without losing the catalytic efficiency.
Meso‐macroporous Carbons Decorated with Ample Nitrogen Sites as Bifunctional Catalysts in CO2 Catalytic Conversion and Oxygen Reduction Reaction
Authors: Liu Jing , Shan Xinggang , Wang Gangqiang , Kong Weiping
Published: February 2021

Electrocatalysts are vulnerable for poisoning during the process of oxygen reduction reaction (ORR), even the air containing traces of acidic CO2 gas, leading to low activity and durability in fuel cells. Herein, an anti‐CO2 poisoning metal‐free carbon ORR catalysts were derived from fructose and g‐C3N4, along with NaCl as both pore‐forming template and structure protective agent, conducting to a three‐dimensional meso‐macroporous carbon (3D‐NHPC‐x) architecture with large BET surface areas (479∼753 m2/g), ultrahigh nitrogen doping level (14.7 wt %∼16.5 wt %) and high ratios of pyridinic and pyrrolic characteristics. The samples were designated as 3D‐NHPC‐x, and the absorbed CO2 electrocatalyst shows a half‐wave potential of 0.76 V (vs. RHE) in alkaline electrolyte with robust long‐term stability and methanol tolerance, which may provide a facile route of producing high‐performance and anti‐CO2 poisoning ORR catalyst. The 3D‐NHPC‐x can also be employed as efficient catalysts in CO2 capture and catalytic conversion to cyclic carbonate, superior to various materials used in the field. This work develops green and sustainable route for preparation of efficient and anti‐CO2 poisoning hierarchical porous carbon based ORR catalysts.
Relaxor Ferroelectric Polymers: Insight into High Electrical Energy Storage Properties from a Molecular Perspective
Authors: Liu Yang , Lin Yen-Ting , Haibibu Aziguli , Xu Wenhan , Zhou Yao , Li Li , Kim Seong H. , Wang Qing
Published: February 2021

Relaxor ferroelectric polymers exhibit both high dielectric constants and low remnant polarization and thus deliver much higher energy densities and greater charge–discharge efficiencies than normal ferroelectrics for capacitive energy storage applications. Herein, dielectric energy storage behavior of several newly discovered relaxor ferroelectric polymers is studied from a molecular perspective. It is observed that the homopolymers exhibit very slim polarization–electric field loops and the highest charge–discharge efficiencies among ferroelectric polymers, which are attributed to the highly disordered chain conformation as evidenced from the scanning probe microscopy results. Based on the findings on the relaxor homopolymers, the benchmark relaxor ferroelectric terpolymers is revisited and insights into their outstanding capacitive performance are provided. Moreover, it is found that the disordered chain conformation in relaxor ferroelectric polymers remains as the ground state at varied temperatures and applied electric fields, which is in stark contrast to relaxor perovskites whose ground state is strongly dependent on temperatures and external electric fields. The discovery of the absence of thermal‐ and field‐induced phase transition in relaxor ferroelectric polymers makes this class of ferroelectric materials more attractive for advanced electronic and energy applications.
Immobilization of a copper complex based on the tripodal ligand (2‐aminoethyl)bis(2‐pyridylmethyl)amine (uns‐penp)
Authors: Brückmann Tim , Becker Jonathan , Turke Kevin , Smarsly Bernd , Weiß Morten , Marschall Roland , Schindler Siegfried
Published: February 2021

A new derivative of the ligand (2‐aminoethyl)bis(2‐pyridylmethyl)amine (uns‐penp), capable for covalent immobilization on silica, was synthesized. Silica powder for column chromatography and mesoporous monoliths served as surface material. Functionalized silica was sufficiently characterized with reflectance UV/Vis and FTIR techniques. Copper(I) was successfully complexed with the immobilized ligand and exhibits reversible reactivity towards dioxygen at low temperatures. Suspending the oxygen species with toluene at low temperatures led to selective oxygenation to benzaldehyde, determined by GC‐MS. Copper(I) complexes with the ligands Me‐PTS‐uns‐penp and Me‐Prop‐uns‐penp were prepared and characterized to model the reaction behavior towards dioxygen in solution. Additionally, solid copper peroxido complexes with these ligands were obtained by precipitation with the sterically demanding anion tetraphenylborate. Furthermore, these complexes could be obtained in a reversible reaction by treating corresponding copper(I) complexes with dioxygen. With all oxygenated copper complexes catalytic oxidation of toluene was observed.
Crystal Structure and Hirshfeld Surface Analysis of Trimethoxy(1‐naphthyl)silane – Intermolecular Interactions in a One‐Component Single‐Crystalline Trimethoxysilane
Authors: Bauer Jonathan O.
Published: February 2021

Weak intermolecular interactions play a major role in structure formation of molecular crystals. Trimethoxy(1‐naphthyl)silane (1), the first one‐component single‐crystalline trimethoxysilane, was analyzed by single‐crystal X‐ray diffraction. Weak intermolecular interactions were studied by Hirshfeld surface analysis along with 2D fingerprint plots. Both C(methyl)−H⋅⋅⋅C and C(naphthyl)−H⋅⋅⋅C interactions were found. A C(naphthyl)−H⋅⋅⋅O hydrogen bond between a silicon‐bound methoxy oxygen and an aromatic hydrogen atom was identified to be a crucial structure‐forming interaction within the crystal packing. Therefore, the tendency of molecular aryl‐substituted methoxysilanes to crystallize seems to be mainly dependent on the balance between accessible C−H⋅⋅⋅O hydrogen bonds and C−H⋅⋅⋅π interactions.
Naked Methodology: Baring It All for a Realistic Account of Marine Social Science
Authors: Ounanian Kristen
Published: February 2021

This chapter portrays what is often overlooked in research—that it involves not simply design, data collection, and analysis, but also failure and redesign. To demystify the process, it presents the evolution of a study of six coastal communities from a mixed methods qualitative and quantitative approach to a qualitative macroethnography. Intending to employ an innovative method, the Factorial Survey Approach, the researcher confronted serious challenges in the process, engendering reflections on (a) the limitations of the method, specifically in fishing communities, (b) the pressure to prove methodological bilingualism as an interdisciplinary graduate student, and (c) individual ontological growth. The chapter considers the collective tendency in (social) science to conceal the imperfections of field research, obscuring insights gained from situations when things do not go according to plan.
Radical Interdependence: Buddhist Philosophical Foundations for Social Theory
Authors: Long William J.
Published: February 2021

This Chapter asserts that a Buddhist perspective provides a systematic and genuine alternative to Western models of IR not so much because it arose in Asia, but because it is founded on distinctive first-order philosophical principles or substructures that differ from those that dominate in the West. The chapter explains this fundamentally different worldview through the concept of “radical interdependence”—the basic Buddhist “truth” about the nature of our existence that departs from most Western understandings of reality and interdependence. Buddhism offers a different starting point for thinking about the world we live in, one it characterizes as deeply interdependent. Moreover, Buddhism maintains that the failure to appreciate the full extent of interdependence limits our human potential and is the ultimate source of all conflicts, up to and including interstate war, whereas an understanding the truth of radical interdependence is the key to imagining a different vision for politics and IR.
Basics of Dental Implantology for the Oral Surgeon
Authors: Ebenezer Supriya , Kumar Vinay V. , Thor Andreas
Published: February 2021

Over the past decades, implant dentistry has evolved to be a very predictable treatment modality for the replacement of lost teeth and has now become one of the most common oral surgical procedures carried out worldwide. This chapter introduces the history and evolution of dental implants, discusses the concept of osseointegration, mentions the types of implants and discusses clinical decision making and execution of straight forward implant placement. It must be noted that the field of implantology is rapidly developing with new treatment concepts and increasing use of digital technology. The surgical part of implant treatment although extremely important, is only a part of the overall treatment, the other important factors being the laboratory and prosthodontics. This chapter only provides a basic surgical overview of implantology for the beginner surgeon clinician.
Preoperative Evaluation and Investigations for Maxillofacial Surgery
Authors: Krishnan B. , Parida Satyen
Published: February 2021

Patients undergoing oral and maxillofacial surgeries have unique perioperative considerations as the surgical field is in proximity to the airway and poses a challenge to the anesthesiologist in the matter of airway management. A well-structured preoperative evaluation plays a decisive role for the successful performance of the planned surgical intervention, as well as to overcome any challenges posed due to the pre-existing health condition of the patient. Each physiologic system can be adversely affected by associated comorbidities that may or may not have clinical importance for the surgeons. Thus, the effects of coexisting diseases on the cardiovascular, respiratory, gastrointestinal, renal, and endocrine systems may be significant. Moreover, to mitigate risks related to these associated comorbidities, as well as to the impact of surgery/anesthesia on the patient, specific risk reduction strategies for the entire perioperative period need to be implemented. Risk management and optimization strategies involve the rational use of adjunctive laboratory and imaging studies and professional opinions of consultants of other specialties. A team approach is critical in establishing a working framework of perioperative management that would be able to keep morbidity and mortality related to the maxillofacial surgery, to an absolute minimum.
Fibro-osseous Lesions in the Maxillofacial Region
Authors: Kaur Taranjit
Published: February 2021

Fibro-osseous lesions have posed a diagnostic dilemma since the beginning when the first case was reported in the late nineteenth century. Since then, various lesions are included in this group, yet the understanding of the lesions remains obscure for the clinician/surgeon. The main reason for this is their histological resemblance with one another, where they all show varying degrees of healthy bone replaced by fibrous tissue and some amount of bone/cementum-like tissue intermingled in between. This chapter is written with the aim of simplifying these groups of bony lesions for its readers and highlighting the key idea of interdisciplinary approach in the management of these lesions where the oral pathologist along with radiologist and clinician plays a pivotal role in differentially diagnosing these lesions, for the maxillofacial surgeon to choose and perform her/his duty of managing them, rightfully, for their patients. The spectrum of these lesions has seen several changes during the course of history yet there is still ample scope for ambiguity in identification and classification of the lesions, hence the authors have chosen few most commonly encountered lesions in the Indian subcontinent, for the description and discussion.