bluuebunny/crossref_metadata_2025_split huggingface dataset:
Associations between high‐intensity zones, endplate, and Modic changes and their effect on T2‐mapping with and without spinal load
Authors: Lagerstrand Kerstin , Brisby Helena , Hebelka Hanna 
Published: March 2021

AbstractThe purpose was to investigate if high intensity zones (HIZ), Modic (MC), and endplate changes (EPC) display different behaviors measured with quantitative magnetic resonance imaging (MRI) with and without loading of the spine and if there is a simultaneous presence of these features in the same motion segment. 130 motion segments in patients with chronic low back pain (n = 26, 25–69 year, mean 38 year, 11 males) were examined. HIZs, MCs, and EPCs (i.e., structural findings, reflecting calcifications, erosions, and fissures) were determined with standardized MRI. Different T2‐values with and without loading for these features were then determined with the quantitative MRI method T2‐mapping. Significantly different behaviors were found in the spinal tissues with associated HIZs, MC, and EPC (p < 0.004). HIZ (62% of patients, 1–2/patient) was associated with EPC (100% of patients, 1–7/patient) (p = 0.0003 and 0.0004 for upper and lower EPs), with an occurrence of 91% for upper and 71% for lower endplates adjacent to discs with HIZ. MC (81% of patients, 1–3/patient) were associated with EPC (p < 0.0001) with an occurrence of 87% for endplates adjacent to vertebrae with MC. The occurrence of both HIZ and MC was 43% (p = 0.0001) for upper and 29% (p = 0.003) for lower vertebrae. HIZ was associated with simultaneous presence of both MC and EPC in the same motion segment. T2‐mapping was found to objectively reflect changes in the spinal tissues associated with HIZs, MC, and EPC.
Periodontitis and its higher levels of severity are associated with the triglyceride/high density lipoprotein cholesterol ratio
Authors: Gomes‐Filho Isaac S. , Santos Pedro N. P. , Cruz Simone S. , Figueiredo Ana C. M. G. , Trindade Soraya C. , Ladeia Ana M. , Cerqueira Eneida M. M. , Passos‐Soares Johelle S. , Coelho Julita M. F. , Hintz Alexandre M. , Barreto Maurício L. , Fischer Ricardo G. , Loomer Peter M. , Scannapieco Frank A. 
Published: March 2021

AbstractBackgroundPeriodontitis and the Triglyceride/High Density Lipoprotein Cholesterol (TG/HDL‐C) ratio have both been associated with cardiovascular disease, metabolic syndrome, and obesity. Additionally, the ratio is a possible substitute for predicting insulin resistance. This study investigated the association between periodontitis, its severity levels (exposures), and the TG/HDL‐C ratio (outcome).MethodsA cross‐sectional study of public health service users in Brazil considered socioeconomic‐demographic characteristics, lifestyle behavior, and general and oral health conditions. Anthropometric measurements and blood pressure were also measured. Systemic biomarker data were obtained, as well as assessment of periodontal diagnosis and its severity. The TG/HDL‐C ratio was calculated using the serum triglyceride level over HDL cholesterol and the cut‐off point, TG/HDL‐C ≥2.3 serving as the cutoff indicting dyslipidemia. Logistic and linear regressions were used to statistically analyze the data.ResultsA total of 1011 participants were included, with 84.17% having periodontitis and 49.85% having a TG/HDL‐C ratio ≥2.3. For individuals with periodontitis, the odds of TG/HDL‐C ratio ≥2.3 were 1.47 times greater than in those without periodontitis (ORAdjusted = 1.47, 95% CI: 1.02–2.14). Similar results were found for those with moderate and severe periodontitis, with a slight increase in the measurement magnitude with disease severity.ConclusionA positive relationship between periodontitis and the TG/HDL‐C ratio ≥2.3 was found, suggesting a possible association with periodontal disease severity.
The case of sales in the automotive industry during the COVID‐19 pandemic
Authors: Hoeft Fabian 
Published: March 2021

AbstractAgile methods can be used as a strategy tool by incumbents to explore and exploit market opportunities through times of unprecedented industry transformation. Drawing on 18 interviews with managers at a premium manufacturer based in Asia, the case of sales in the automotive industry during the COVID‐19 crisis provides in‐depth insights into the crisis management, focusing on but looking beyond sales. Six fundamental principles are identified as strategic tools to leverage resources and improve business outcomes while using agile‐work methods.
Healthcare enterprises and public policies on COVID‐19: Insights from the Greek rural areas
Authors: Apostolopoulos Nikolaos , Liargovas Panagiotis , Sklias Pantelis , Apostolopoulos Sotiris 
Published: March 2021

AbstractDespite the difficulties, entrepreneurship met the socioeconomic challenges by providing solutions to rural areas during the COVID‐19 crisis, while healthcare entrepreneurial activity has been adapted to the changing conditions. The Greek rural areas' healthcare enterprises suffer the consequences of the public policies on COVID‐19 as their activities have been affected, their turnover has decreased, and liquidity problems have arisen. Entrepreneurs believe that the announced state and European support will help them overcome the implications. However, some of the support measures that have a loan rational will bring enterprises with bank loans to a halt. Indeed, entrepreneurship in rural areas faces multiple problems that they are trying to overcome during the COVID‐19 crisis. Uncertainty, insecurity and health scare prevailed. Despite the problems, the enterprises showed resilience and did not cease their operations.
Western Yellow‐Billed Cuckoo Nest‐Site Selection and Success in Restored and Natural Riparian Forests
Authors: Stanek Jenna E. , Mcneil Shannon E. , Tracy Diane , Stanek John R. , Manning Jeffrey A. , Halterman Murrelet D. 
Published: March 2021

ABSTRACTThe western distinct population segment of yellow‐billed cuckoo (Coccyzus americanus; western cuckoo) has been extirpated from most of its former breeding range in the United States because of widespread loss and degradation of riparian cottonwood (Populus spp.)‐willow (Salix spp.) forests. Restoration and management of breeding habitat is important to the recovery of this federally threatened species, and identification of high‐quality breeding habitat can help improve the success of recovery. In 2005, the Lower Colorado River Multi‐Species Conservation Program, a long‐term, multi‐agency effort, was initiated to maintain and create wildlife habitat within the historical floodplain of the lower Colorado River (LCR) for federally endangered and threatened species, including western cuckoos. We conducted an empirical, multi‐scale field investigation from 2008–2012 to identify habitat characteristics selected by nesting western cuckoos along the LCR. Multiple logistic regression models revealed that western cuckoos selected nest sites characterized by increased densities of small, native, early successional trees measuring 8–23 cm diameter at breast height, and lower diurnal temperature compared to available habitat in restoration and natural forests. Nesting cuckoos selected sites with increased percent canopy closure, which was also important for nest success in restoration sites along the LCR. Our results show habitat components selected by nesting western cuckoos in restoration and natural riparian forests and can help guide the creation, enhancement, and management of riparian forests with habitat conditions necessary to promote nesting of western cuckoos. © 2021 The Wildlife Society.
Synthesis of Copolymers Polyethyleneimine‐co‐Polyphenylalanine as Gene and Drug Codelivery Carrier
Authors: Liu Chong , Guo Zhaopei , Feng Huimin , Lin Lin , Cui Yuan , Li Yanhui , Tian Huayu 
Published: March 2021

AbstractIn this study, a series of hyperbranched copolymers polyethyleneimine‐co‐polyphenylalanine (PEI‐co‐PPhe) are synthesized by ring‐opening polymerization with phenylalanine‐N‐carboxyanhydride as monomer and PEI‐25k as initiator, using as a gene and drug codelivery carrier. Among them, PEI‐co‐PPhe (1:170) is selected out from transfection efficiency and cytotoxicity tests. Then, doxorubicin‐cis‐aconitic anhydride (CAD) and BCl2‐shRNA (as a therapeutic gene) are coloaded into the PEI‐co‐PPhe carrier to form PEI‐co‐PPhe/Bcl2‐shRNA/CAD complexes as a codeliver system. When the mass ratio of PEI‐co‐PPhe:Bcl2‐shRNA:CAD is 5:1:1, the codeliver system has the most obvious synergistic therapeutic effect against B16F10 cells. Confirmed by confocal laser scanning microscope and flow cytometry, compared with drug and gene alone, the codeliver complexes can be endocytosed into B16F10 cells efficiently. As a result, the appropriate length of PPhe grafted on PEI will improve the gene transfer efficiency and decrease cytotoxicity, as well as effective codelivery of gene and drug into cancer cells to be a promising codelivery carrier for cancer therapy.
Evaluation and Control of the Molar Mass Bimodality and Properties of Polyethylene from Novel Chromocene‐Based Dual Sites Catalysts
Authors: Yao Jiabin , Wang Kai , He Xuelian , Liu Boping 
Published: March 2021

AbstractPolyethylene (PE) with bimodal molecular weight distribution (MWD) has drawn attention from researchers because of its great processability and outstanding mechanical properties. Bimodal PE is successfully prepared by novel SiO2‐supported chromocene (S‐9)/chromium (CrOX) and chromocene (S‐9)/vanadium (V) dual sites catalysts in a single reactor. The molar mass bimodality, crystalline properties, and mechanical properties of the bimodal PE prepared by S‐9/CrOX catalysts are controllable through adjusting the loading of active centers. Those are also adjustable by using S‐9/V catalysts under the condition of adding 0.1 MPa hydrogen. Compared with CrOX/SiO2, 4CrOX4S9 shows an increase in tensile strength and Young's modulus by 38% and 17%, respectively. With the increase in high MW fraction, tensile strength, and Young's modulus both increase. S‐9/CrOX catalysts combining the advantages of two active centers show better tensile properties. S‐9/V catalysts have a similar trend in tensile properties. The complex viscosity, elastic modulus, and loss modulus increase with the growth in MW and the thickness of lamellae. Furthermore, the high and low MW fraction has good compatibility for both dual sites catalysts, and their resistance to slow crack growth is most likely to reach the standards for PE100 and PE100RC and even exceed.
Rapid Self‐Expansion Behavior of the PMMA‐Based Bone Cement with P(MMA‐AA)‐GO Nano‐Units
Authors: Chen Lei , Tang Yufei , Zhao Kang , Liu Jiaxin , Jiang Xiashu , Sun Yani , Wu Zixiang 
Published: March 2021

AbstractThe volume shrinkage of polymethylmethacrylate (PMMA) bone cement is typically addressed by incorporating additives into the matrix. However, the maximum water absorption and swelling capacity of the composite bone cement are not sufficiently improved due to its rapid solidification. In this work, poly(methyl methacrylate‐acrylic acid)‐grafted graphene oxide [P(MMA‐AA)‐GO] nano‐units with the microsphere‐lamellar structure are synthesized, and then P(MMA‐AA)‐GO bone cement (PGBC) is fabricated. The rate of absorption and swelling of PGBC are significantly promoted by the microsphere–lamellar structure of P(MMA‐AA)‐GO nano‐units, achieving maximum absorption and swelling capacity of PGBC before its solidification. PGBC 4 exhibits the maximum equilibrium simulate body fluid (SBF) absorption ratio and equilibrium swelling ratio of 90.2% ± 1.7% and 92.5% ± 4.5%, respectively. Interestingly, the maximum compression strength of the composite before immersion is also observed in PGBC 4 with a value of 77.2 ± 1.1 MPa. The enhanced compression strength of PGBC overcomes the bottleneck of the decreased compression strength resulting from the enhanced absorption behavior. Therefore, PGBC with rapid self‐expansion behavior and improved mechanical properties can not only reduce the injection volume to avoid leakage in the clinic but also provide sufficient mechanical support, which has promising application potential in the clinical setting.
Developing and validating the Caesarean risk assessment nomogram and comparing the effect of cervical ripening balloon, evening primrose oil and misoprostol on childbirth outcomes in term pregnancies: A study protocol
Authors: Hemmatzadeh Shahla , Abbasalizadeh Fatemeh , Mohammad‐Alizadeh‐Charandabi Sakineh , Asghari Jafarabady Mohammad , Mirghafourvand Mojgan 
Published: March 2021

AbstractAimTo develop and validate the nomogram for risk estimation of Caesarean delivery and to compare the effect of cervical ripening balloon, evening primrose oil (EPO) and misoprostol on Bishop Score and duration of the first stage of labour.DesignThe first phase is a prospective study, and the second phase is a randomized controlled trial.MethodsIn the first phase, the nomogram will be developed and validated over 300 participants, and in the second phase, the 90 participants will be allocated to three groups: vaginal 25mcg misoprostol, vaginal 4000mg EPO and double‐balloon catheter, through block randomization method. The Bishop score will be evaluated every 4 hr, and if required the same dose will be repeated. Maximum waiting time for balloon is 12 hr if not effective, the catheter will be removed, and other interventions will be done according to guidelines.DiscussionThe nomogram will help informed decision‐making for women undergoing an induction with an unfavourable cervix and introducing effective low‐complication methods of labour induction can improve the pregnancy outcomes.
Exploring individual predictors of variation in public awareness of expressive and instrumental nonprofit brands
Authors: Hamidullah Madinah F. , Yun Jung Ah (Claire) , McDougle Lindsey M. , Shon Jongmin , Yang Hyuk , Davis Ashley 
Published: March 2021

AbstractExpressive and instrumental functions provide a way to classify activities that take place in the nonprofit sector. These functions also provide a way to better understand individual's philanthropic involvement with certain types of nonprofit organizations. Despite the usefulness of these classifications, only a few studies have explored demographic, social, and ideological differences in individuals' philanthropic involvement along expressive and instrumental dimensions; and, no studies have explored differences in public awareness of nonprofits along these dimensions. Such awareness, though, could likely be an important precursor to an individual's philanthropic involvement. Thus, the purpose of this study is to explore whether variables known to be associated with variation in philanthropic involvement are also associated with variation in awareness of, what we categorize as, expressive and instrumental nonprofit brands. Using data from a survey of public awareness of, and attitudes toward, nonprofit organizations in San Diego County (n = 1002), our findings show that individuals are more aware of instrumental nonprofit brands than they are of expressive nonprofit brands. However, there are important individual differences to consider. We discuss the theoretical relevance of our findings and offer several practical recommendations for nonprofit administrators.
Guaranteed cost control of fractional‐order linear uncertain systems with time‐varying delay
Authors: Chen Liping , Wu Ranchao , Yuan Liguo , Yin Lisheng , Chen YangQuan , Xu Shuiqing 
Published: March 2021

AbstractThis article is concerned with the guaranteed cost control problem for a class of fractional‐order (FO) uncertain delayed linear systems with norm‐bounded time‐varying parametric uncertainty. Based on whether the states are available or not, guaranteed‐cost state‐based feedback stabilization and guaranteed‐cost observer‐based feedback stabilization for such system are addressed, respectively. By employing the linear matrix inequality (LMI) approach and FO Razumikhin theorem, two delay‐independent guaranteed cost controller design methods and their guaranteed costs are first formulated, respectively, in which sufficient conditions of the state feedback and observer gains are presented in form of LMI. Two numerical examples are presented to demonstrate the effectiveness of the theoretical formulation.
Data‐driven (Bilinear) identification and reduction
Authors: Karachalios Dimitrios S. , Gosea Ion Victor , Antoulas Athanasios C. 
Published: March 2021

AbstractIdentifying dynamical systems from measured data is an important step towards accurate modeling and control. Model order reduction (MOR) constitutes a class of methods that can be used to replace large, complex models of dynamical processes with simpler, smaller models. The reduced‐order models (ROMs) can be then used for further tasks such as control, design, and simulation. One typical approach for projection‐based model reduction for both linear and nonlinear dynamical systems is by employing interpolation. Projection‐based methods require access to the internal dynamics of the system which is not always available. The aim here is to compute ROMs without having access to the internal dynamics, by means of a realization independent method. The proposed methodology will fall into the broad category of data‐driven approaches. The method under consideration, which will be referred to as the Loewner framework (LF), was originally introduced by the third author. Based on data, LF identifies state‐space models in a direct way. In the original setup, the framework relies on compressing the full data set to extract dominant features and, at the same time, to eliminate the inherent redundancies. In the broader class of nonlinear control systems, the LF has been already extended to certain classes with a special structure such as quadratic or bilinear systems. The LF in combination with Volterra series‐(VS) offers a non‐intrusive approximation method that is capable of identifying bilinear models from input‐output time‐domain measurements. This method uses harmonic inputs which establish a natural way for data acquisition. The Fourier transform associates these measurements with the derived generalized frequency response functions GFRFs and the LF makes the connection with system theory. In the linear case, the LF associates the so‐called S‐parameters with the linear transfer function by interpolating in the frequency domain. The goal of the proposed method is to extend identification to the case of bilinear systems from time‐domain measurements and to approximate other general nonlinear systems by means of the Carleman bilinearizarion scheme. By identifying the linear contribution with the LF, a considerable reduction is achieved by means of the SVD. The fitted linear system has the same McMillan degree as the original linear system. Then, the performance of the linear model is improved by augmenting a special nonlinear structure. In a nutshell, we learn reduced‐dimension bilinear models directly from a potentially large‐scale system that is simulated/sampled in the time domain. This is done by fitting first a linear model, and afterwards, by fitting the corresponding bilinear operator which will improve the fitting performance.
Predicting near optimal interpolation points for parametric model order reduction using regression models
Authors: Aumann Quirin , Müller Gerhard 
Published: March 2021

AbstractThe design of vibro‐acoustic systems, such as vehicle interiors, regarding optimal vibrational or sound radiation properties requires the solution of many numerical models under varying parameters, as often material or geometric uncertainties have to be considered. Vibro‐acoustic systems are typically large and numerically expensive to solve, so it is desirable to use an efficient parametrized surrogate model for optimization tasks. High quality reduced models of non‐parametric systems can be computed by projection, given a set of optimal expansion points. However, finding a set of optimal expansion points can be computationally expensive and each set is valid for a specific parameter realization only. The method presented in this contribution learns the map between a model's parameter realizations and the corresponding sets of expansion points using data‐driven methods. Queried with an unknown set of parameters, the learned model returns a set of expansion points which are used to compute the corresponding reduced model efficiently. Numerical experiments on two vibro‐acoustic models of different complexity are performed and three data driven regression methods are evaluated: multivariate polynomial regression, k‐nearest neighbors, and support vector regression. Especially k‐nearest neighbors regression yields accurate results for different types of physical models while being computationally inexpensive to fit.
Data‐driven modeling from noisy measurements
Authors: Gosea Ion Victor , Zhang Qiang , Antoulas Athanasios C. 
Published: March 2021

AbstractThe scope of this contribution is to present some recent results on how interpolation‐based data‐driven methods such as

The Loewner framework [1]
The AAA algorithm [2]

can handle noisy data sets. More precisely, it will be assumed that the input‐output measurements used in these methods, i.e., transfer function evaluations, are corrupted by additive Gaussian noise.The notion of “sensitivity to noise” is introduced and it is used to understand how the location of measurement points affects the “quality” of reduced order models. For example, models that have poles with high sensitivity are hence deemed prohibited since even small perturbations could cause an unwanted behavior (such as instability). Moreover, we show how different data splitting techniques can influence the sensitivity values. This is a crucial step in the Loewner framework; we present some illustrative examples that include the effects of splitting the data in the “wrong” or in the “right” way.Finally, some perspectives for the future: we would like to employ statistics and machine learning techniques in order to avoid “overfitting”. More precisely, it is said that a model that has learned the noise instead of the true signal is considered an “overfit” because it fits the given noisy dataset but has a poor fit with other new datasets. We present some possible ways to avoid “overfitting” for the methods under consideration.
Comparative evaluation study of polycomplex carriers based on Eudragit® EPO/S100 copolymers prepared in different media
Authors: Bukhovets Aleksandra V. , Sitenkov Alexander Y. , Moustafine Rouslan I. 
Published: March 2021

AbstractInterpolymer complexes (IPC) Eudragit® EPO/S100 were prepared in different media (water pH of 7.0 and ethanol). According to the elemental analysis, FTIR spectroscopy, and thermal analysis data, IPC prepared in aqueous media (denoted as interpolyelectrolyte complexes—IPECs) is stabilized predominantly by ionic intermacromolecular bonds and has a composition close to equimolar. However, polycomplexes formed in nonaqueous (ethanol) media (denoted as IPC) are stabilized by both hydrogen and ionic bonds and characterized by an almost twofold excess of Eudragit® S100. All samples do not include free copolymer domains. IPECs and IPCs have different behavior in the buffer media mimicking the gastrointestinal tract. Matrices of IPECs are characterized by the surface erosion and pH‐independent swelling profiles with low values of a swelling degree. Matrices of the IPCs swell significantly in the buffer media with pH 1.2, 5.8, and 6.8 with subsequent decrease in the swelling degree due to the surface erosion. According to the assessment of release of the model active pharmaceutical ingredient (API), IPECs are prospective carriers for sustained delivery of II class Biopharmaceutical Classification System (BCS) drug (diclofenac sodium). At the same time, IPCs provide sustained release of the II class BCS and prolonged release of the I class BCS drug (theophylline).