bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrating real‐world data and modeling to project changes in femoral neck bone mineral density and fracture risk in premenopausal women
Authors: Beck Denise , Winzenborg Insa , Gao Wei , Mostafa Nael M. , Noertersheuser Peter , Chiuve Stephanie E. , Owens Charlotte , Shebley Mohamad
Published: March 2021

Decline of bone mineral density (BMD) during menopause is related to increased risk of fractures in postmenopausal women, however, this relationship in premenopausal women has not been established. To quantify this relationship, real‐world data (RWD) from the National Health and Nutrition Examination Survey (NHANES), and longitudinal data from the elagolix phase III clinical trials were modeled across a wide age range, and covariates were evaluated. The natural changes in femoral neck BMD (FN‐BMD) were well‐described by a bi‐exponential relationship with first‐order BMD formation (k1) and resorption (k2) rate constants. Body mass index (BMI) and race (i.e., Black) were significant predictors indicating that patients with high BMI or Black race experience a relatively lower BMD loss. Simulations suggest that untreated premenopausal women with uterine fibroids (UFs) from elagolix phase III clinical trials (median age 43 years [minimum 25–maximum 53]) lose 0.6% FN‐BMD each year up to menopausal age. For clinical relevance, the epidemiological FRAX model was informed by the simulation results to predict the 10‐year risk of major osteoporotic fracture (MOF). Premenopausal women with UFs, who received placebo only in the elagolix phase III trials, have a projected FN‐BMD of 0.975 g/cm2 at menopause, associated with a 10‐year risk of MOF of 2.3%. Integration of modeling, RWD, and clinical trials data provides a quantitative framework for projecting long‐term postmenopausal risk of fractures, based on natural history of BMD changes in premenopausal women. This framework enables quantitative evaluation of the future risk of MOF for women receiving medical therapies (i.e., GnRH modulators) that adversely affect BMD.
Multifractal and joint multifractal analysis of soil micronutrients extracted by two methods along a transect in a coarse textured soil
Authors: Farias de França e Silva Ênio , García‐Tomillo Aitor , Silva de Souza Diego Henrique , Vidal‐Vázquez Eva , Machado Siqueira Glécio , da Costa Dantas Daniel , Paz‐González Antonio
Published: March 2021

Understanding the spatial behaviour of soil nutrients is essential for fertilizer management. Traditionally, comparison of soil testing methods has been performed using simple correlation analysis. The aims of this work were: (a) to characterize patterns of spatial variability of micronutrient concentrations obtained by two different soil testing methods, using single multifractal spectra, and (b) to compare the scale‐dependent relationship between the two datasets by joint multifractal analysis. The soil study site was located in Pernambuco state, Brazil. A 384‐m transect was marked every 3 m on an Orthic Podzol, cropped to sugar cane, in Pernambuco state, Brazil. Both, Mehlich‐3 and DTPA‐extracted micronutrients were measured in each of the 132 collected soil samples. The spatial distributions of available Fe, Mn, Cu and Zn could be fitted with multifractal models, regardless of the soil testing method. The generalized dimension, Dq versus q, and singularity spectra, f(α) versus α, showed a multifractal nature. Except for Fe, the scaling heterogeneity of the spatial distributions was higher for the Mehlich‐3 than for the DTPA datasets. Moreover, Zn exhibited the highest multifractality in both cases. Joint multifractal analysis demonstrated strong positive correlations between the scaling indices of the studied micronutrients extracted by the two methods. There were, however, different degrees of association between the scaling indices of these micronutrients, which ranked as: Zn > Cu > Fe > Mn. Except for Mn, Pearson product moment correlations between concentrations of available micronutrients extracted by the two solutions at the single or point measurement scale were weaker than those of the respective scaling indices at multiple scales. Therefore, single multifractal analysis captured a great complexity in the spatial distribution of available Fe, Mn, Cu and Zn. Knowledge of the scaling behaviour of these available nutrients could be useful for transferring information about variability from one scale to another for soil fertility management. This study suggests that correlation analysis at the single or point measurement scale may not be sufficient to fully characterize the concentrations of microelements extracted by two different methods, whereas joint multifractal analysis showed potential to improve calibration of soil micronutrient testing.

Highlights

Mehlich‐3 and DTPA‐extracted micronutrients showed high statistical variability across a transect.

All the spatial distributions of Fe, Mn, Cu and Zn displayed a well‐defined multifractal structure.

Joint correlations of extracted micronutrients were stronger than single statistical correlations.

Our approach fully characterized complex spatial distributions arising from nonlinear processes.
Impact of natural and synthetic growth enhancers on the productivity and yield of quinoa (chenopodium quinoa willd.) cultivated under normal and late sown circumstances
Authors: Rashid Nabila , Khan Shahbaz , Wahid Abdul , Basra Shahzad Maqsood Ahmed , Alwahibi Mona S. , Jacobsen Sven‐Erik
Published: March 2021

Quinoa (Chenopodium quinoa Willd.) has attracted attention in agricultural community as alternative crop in harsh climatic regions due to its high tolerance level under biotic and abiotic conditions. Natural and synthetic growth enhancers are supposed to boost up the growth, development and economical yield of field crops under normal and unfavourable growing conditions. Two successive field experiments were conducted to explore the impact of moringa leaf extract (MLE), sorghum water extract (sorgaab), hydrogen peroxide and ascorbic acid on growth and grain quality of quinoa cultivated under normal and late sown conditions. MLE at 3%, sorgaab at 3%, hydrogen peroxide at 100 µM and ascorbic acid at 500 µM were applied at anthesis stage of crop cultivated during growing seasons of 2016–2017 and 2017–2018. Seeds of quinoa genotype UAF‐Q7 were sown at Research Area of Directorate of Farms, University of Agriculture, Faisalabad‐Pakistan. All the foliar treatments significantly improved the physiological and growth attributes. Maximum improvement in synthesis of chlorophyll (29% and 12%) and carotenoids contents (42% and 28%) and net rate of photosynthesis (58% and 70%) and respiration (26% and 14%) was recorded by MLE application over control (no spray) under normal and late sowing. Mineral elements, antioxidants activities and seed protein contents were also improved by all foliar treatments but mainly by MLE application. MLE application produced highest grain (47%) and straw (52%) yields under normal and late sown environments. Application of MLE is considered good biostimulant to improve the productivity and yield of quinoa crop cultivated under normal and even in late sown circumstances.
Ab initio molecular dynamics simulation of the structural and electronic properties of aluminoborosilicate glass
Authors: Gong Haiming , Song Bin , Yang Yuting , Wang Peixian , Cao Zhiqiang , Chen Xiaojie , Zhao Gaoling , Peng Shou , Liu Yong , Han Gaorong
Published: March 2021

In this study, the structural and electronic properties of aluminoborosilicate glass, which has a wide range of applications in fields such as microelectronics and displays, were examined using ab initio molecular dynamic simulations. Computing models containing 220 atoms correctly described the local structure of the glass. The reliability of the computing models was verified by the consistency between the experimental results, obtained using high‐energy X‐ray diffraction and solid‐state nuclear magnetic resonance, and the simulation results pertaining to structural factors, pair distribution functions, Qn distribution, and elastic properties. The presence of B and Al increased the flexibility and asymmetry of the system, as shown by the bond angle and ring size distributions. Based on the electronic properties, we observed that the introduction of Al and B atoms into the network could also cause covalent interactions with the O atoms, similar to that with Si atoms. However, the Na and Mg atoms still interacted with all kinds of atoms in the network via charge transfer and exhibited highly non‐localized effects on the charge of the network formers. These results extend our understanding of the structure of aluminoborosilicate glass and have guiding significance for improving and designing new types of this glass.
Challenges and opportunities of multimodal data in human learning: The computer science students' perspective
Authors: Mangaroska Katerina , Martinez‐Maldonado Roberto , Vesin Boban , Gašević Dragan
Published: March 2021

Multimodal data have the potential to explore emerging learning practices that extend human cognitive capacities. A critical issue stretching in many multimodal learning analytics (MLA) systems and studies is the current focus aimed at supporting researchers to model learner behaviours, rather than directly supporting learners. Moreover, many MLA systems are designed and deployed without learners' involvement. We argue that in order to create MLA interfaces that directly support learning, we need to gain an expanded understanding of how multimodal data can support learners' authentic needs. We present a qualitative study in which 40 computer science students were tracked in an authentic learning activity using wearable and static sensors. Our findings outline learners' curated representations about multimodal data and the non‐technical challenges in using these data in their learning practice. The paper discusses 10 dimensions that can serve as guidelines for researchers and designers to create effective and ethically aware student‐facing MLA innovations.
Correlation between wing bone microstructure and different flight styles: The case of the griffon vulture (gyps fulvus) and greater flamingo (phoenicopterus roseus)
Authors: Frongia Gian N. , Naitana Salvatore , Farina Vittorio , Gadau Sergio D. , Stefano Marco D. , Muzzeddu Marco , Leoni Giovanni , Zedda Marco
Published: March 2021

Flying is the main means of locomotion for most avian species, and it requires a series of adaptations of the skeleton and of feather distribution on the wing. Flight type is directly associated with the mechanical constraints during flight, which condition both the morphology and microscopic structure of the bones. Three primary flight styles are adopted by avian species: flapping, gliding, and soaring, with different loads among the main wing bones. The purpose of this study was to evaluate the cross‐sectional microstructure of the most important skeletal wing bones, humerus, radius, ulna, and carpometacarpus, in griffon vultures (Gyps fulvus) and greater flamingos (Phoenicopterus roseus). These two species show a flapping and soaring flight style, respectively. Densitometry, morphology, and laminarity index were assessed from the main bones of the wing of 10 griffon vultures and 10 flamingos. Regarding bone mineral content, griffon vultures generally displayed a higher mineral density than flamingos. Regarding the morphology of the crucial wing bones involved in flight, while a very slightly longer humerus was observed in the radius and ulna of flamingos, the ulna in griffons was clearly longer than other bones. The laminarity index was significantly higher in griffons. The results of the present study highlight how the mechanics of different types of flight may affect the biomechanical properties of the wing bones most engaged during flight.
Lymphoepithelioma‐like carcinoma of the vagina: A rare case report and review of the literature
Authors: Kim Youngsun , Kim So‐Woon
Published: March 2021

A 78‐year‐old woman with the chief complaint of vaginal bleeding was referred to our institution. Pelvic magnetic resonance imaging showed a 2.1 cm × 2.0 cm soft tissue mass in the left vaginal area with left inguinal lymph node enlargement. A positron emission tomography/computer tomography scan showed a focal hypermetabolic lesion in the left vaginal area with involvement of vulvar area. Pelvic examination showed a vaginal wall mass and the patient underwent surgical excision of the mass. The results of pathology indicated lymphoepithelioma‐like carcinoma (LELC) in the vagina. The patient was admitted subsequently in the oncological department for additional chemoradiation treatment. LELC is extremely rare in the vagina, and only three cases have been reported in the literature. Here we report an extremely rare case of this tumor and review of the previous literature.
Materials matter: Understanding the importance of sociomaterial assemblages for OSCE candidate performance
Authors: Rees Charlotte E. , Ottrey Ella , Barton Peter , Dix Samantha , Griffiths Debra , Sarkar Mahbub , Brooks Ingrid
Published: March 2021

Introduction

The OSCE is a sociomaterial assemblage—a meshing together of human and material components producing multiple effects. Materials matter because they shape candidate performance, with potentially calamitous career consequences if materials influence performance unjustly. Although the OSCE literature refers to materials, few papers study the sociomateriality of OSCEs. Therefore, we explored OSCE stakeholders’ talk about sociomaterial assemblages to better understand their importance for candidate performance.

Methods

We conducted 15 focus groups with OSCE candidates (n = 42), examiners (n = 20) and simulated patients (n = 17) after an Australian postgraduate nursing OSCE. Sociomateriality informed our team‐based framework analysis of data.

Results

Participants identified a multiplicity of OSCE materials (objects, technologies and spaces) thought to matter for candidate performance. Candidates’ unfamiliarity with materials and missing or malfunctioning materials were reported to yield numerous negative impacts (eg cognitive overload, negative affect, time‐wasting), thereby adversely affecting candidate performance. Both examiners and candidates made micro‐adjustments to sociomaterial assemblages during the OSCE in order to make it work (eg candidates saying what they would do rather than doing it). Sometimes, such tinkering extended so far that sociomaterial assemblages were ruptured (eg examiners ignoring rubrics to help pass candidates), potentially influencing OSCE standardisation.

Discussion

Our novel empirical study extends previous conceptual work by illustrating wide‐ranging sociomaterial assemblages influencing OSCE candidate performance. Further research is now needed employing sociomaterial approaches to further elucidate sociomaterial entanglements in diverse OSCEs. We encourage OSCE stakeholders to become more attuned to the productive nature of materials within all stages of OSCE design and implementation.
Item banks for measurement of refractive error‐specific quality of life
Authors: Kandel Himal , Khadka Jyoti , Watson Stephanie L , Fenwick Eva K , Pesudovs Konrad
Published: March 2021

Purpose

To evaluate the psychometric properties of refractive error‐specific quality of life (QoL) item banks and assess their performance using computerised adaptive testing (CAT) simulations.

Methods

In this cross‐sectional study a 392‐item questionnaire, grouped under 11 QoL domains, was interviewer‐administered to 305 people with refractive error [mean age ± S.D., 30.5 ± 14.1 (range (18 to 83) years; male, 50.5%; mean ± S.D. spherical equivalent refractive error −2.4 ± 2.9 (range: −15.0 to +11.0) Dioptres; spectacles (n = 257), contact lens (n = 37), refractive surgery (n = 25), uncorrected refractive error (n = 57)]. Rasch analysis was conducted on each QoL domain using the Andrich rating scale model to investigate parameters including response category functioning, person‐ and item‐reliability, infit and outfit statistics, unidimensionality, targeting, differential item functioning and local item dependency. The resulting item banks underwent CAT simulations in 1,000 cases with 'high' and 'moderate' precision stopping rules.

Results

Rasch analysis iterations resulted in 13 refractive error‐specific item banks (Convenience, Health concerns, Economic, Activity limitation, Mobility, Emotional, Social, Visual symptoms frequency, Visual symptoms severity, Visual symptoms bothersome, Comfort symptoms frequency, Comfort symptoms severity and Comfort symptoms bothersome), containing a total of 366 items. The item banks had good psychometric properties including satisfactory measurement precision, infit and outfit statistics and unidimensionality. In CAT simulations, the mean number of items required to achieve high and moderate measurement precision was 9.4 and 4.7, respectively.

Conclusion

Overall, refractive error‐specific QoL item banks show promise in their ability to comprehensively and precisely evaluate a range of quality of life parameters. These items banks when administered using a CAT system offer unique outcome tools for implementation in clinical trials, healthcare and research.
Republicanism and Structural Domination
Authors: Hasan Rafeeq
Published: March 2021

What is domination? According to a leading strand of republican political philosophy, a person is dominated when under the unconstrained power of another. Call this the dyadic conception of domination, because it involves a two‐person relation. I argue that domination is better understood structurally. Structural domination is domination by institutions. Rather than a master dominating a slave and a boss dominating a worker (as in dyadic domination), structural domination holds that the institution of slavery dominates the slave and labor law dominates the worker. Without the structural conception, I contend, one misdescribes the power dynamics of paradigm cases of domination.
Clinical performance of a novel hyperspectral imaging device for cutaneous melanoma and pigmented skin lesions in Caucasian skin
Authors: Christensen Gustav Boelsgaard , Nagaoka Takashi , Kiyohara Yoshio , Johansson Iva , Ingvar Christian , Nakamura Atsushi , Sota Takayuki , Nielsen Kari
Published: March 2021

Background

The quest for diagnostic tools for the detection of cutaneous malignant melanoma (cMM) is ongoing. A challenge in cMM care is not overlooking cMM at an early stage, while simultaneously avoiding unnecessary biopsies or excisions of benign pigmented skin lesions (PSLs). A novel hyperspectral imaging (HSI) device is shown to have potential for differentiating equivocal PSLs in Asian skin types. Our objective was to assess the accuracy of the HSI device in distinguishing between cMM and benign PSLs in patients with Caucasian skin types.

Methods

Patients with Caucasian skin types (Fitzpatrick I‐II), enrolled for excisional biopsies of PSLs were included and examined using the HSI device. The discrimination index (DI) was used to demonstrate the sensitivity (SE) and specificity (SP) in comparison with the re‐evaluated histopathology diagnoses.

Results

In 186 patients, 202 pigmented skin lesions were included. The sensitivity to detect cMM was 96.7% (87/90), and the specificity for benign lesions was 42.1% (45/107). The AUC was 0.800 (95% confidence interval (CI): 0.740‐0.861).

Conclusions

Our novel HSI device showed a high sensitivity in detecting malignant lesions in patients with Caucasian skin types. Compared with analogous technologies, as multispectral imaging or electrical impedance spectroscopy, our device showed similar or better accuracy in differentiating cMM from benign PSLs. Therefore, it might be a useful clinical tool in skin types I‐IV and where further triage of pigmented skin lesions is important.
Two novel HLA alleles identified in Russian bone marrow donors: HLA‐A*02:957 and ‐C*12:03:67
Authors: Khamaganova Ekaterina , Leonov Evgeny , Abdrakhimova Alena , Khizhinskiy Stanislav , Savchenko Valeriy
Published: March 2021

Characterization of two novel HLA class I alleles, A*02:957 and C*12:03:67.
Methods of Rotor-Unbalance Determination
Authors: Baker J. G.
Published: March 2021

Rotor-unbalance determinations both in balancing machines and from vibration readings taken on the rotor during normal operation have in some cases been rather complicated and often subject to considerable error. This paper suggests methods intended to improve balancing methods in these cases.

In part I a more or less conventional method of calculating unbalance corrections from vibration readings is reviewed and the limitations and errors pointed out. Next, an extension of the method is developed which is in some cases simpler and inherently more accurate.

In part II a mathematical method is developed for determining unbalance corrections in cases where the locations of the corrections are completely prescribed in contradistinction to the ordinary case in which the axial position of the correction is prescribed but the angular position is to be determined. Also, a balancing machine is described which reads directly the unbalance corrections required at four preselected locations in a rigid rotor. This balancing machine is especially suited for the quick determination of unbalance corrections required in an internal-combustion-engine crankshaft.

In part III center-of-percussion balancing is described which is a method of taking vibration readings which can be interpreted directly in terms of unbalance. This method is applicable only under certain conditions which are noted.
Vibration of Locomotive Driving Wheels Caused by Unbalance
Authors: Horger O. J. , Nelson C. W.
Published: March 2021

Results of road service tests on steam locomotives are presented to show the influence of unbalance in driving wheels in causing vibrations of the wheel on the rail. These results are accompanied by a correlated theoretical study of conditions under which these vibrations occur. A method is given for eliminating such vibrations based on test results. The effect of unbalance and weight of reciprocating parts is also discussed relative to the track and locomotive.
Torsional Vibration in Geared-Turbine Propulsion Equipment
Authors: Poritsky H. , Robinson C. S. L.
Published: March 2021

Two alternative methods are presented by the authors for the determination of torques in the propelling machinery of ships when friction is taken into account. One is called the “direct method,” while the other is called the “method of normal coordinates.” The latter is described at length, showing the great saving of numerical work possible by its use when compared to the direct method.

The paper points out that at critical propeller speeds oscillatory torques are limited only by damping. Two types of damping are taken into account: One is damping of the propeller in water; the other is friction in the driving mechanism, introduced as solid friction in the shafts similar to damping in the metal.
The Orthogonally Stiffened Plate Under Uniform Lateral Load
Authors: Schade Henry A.
Published: March 2021

The problem of designing structures with orthogonally stiffened plates under lateral loading has been solved approximately by the infinite-strip method and has been applied, for example, to the double-bottom structure of a ship. Under certain conditions where the side ratio, that is, the ratio of the longitudinal dimension to the transverse dimension, is small, the approximate solution is inadequate. The author gives herein an exact solution applicable to all side ratios.
Fragmentation Characteristics of Rocks Under Indentation by a Single Polycrystalline Diamond Compact Cutter
Authors: Ji Zhaosheng , Shi Huaizhong , Dai Xianwei , Song Hengyu , Li Gensheng , Shen Zhonghou
Published: March 2021

Polycrystalline diamond compact (PDC) bit accounts for the most drilling footage in the development of deep and geothermal resources. The goal of this paper is to investigate the PDC cutter-rock interaction and reveal the rock fragmentation mechanism. A series of loading and unloading tests are conducted to obtain the curves of contact force versus penetration displacement. A single practical PDC cutter is fixed on the designed clamping devices that are mounted on the servo experiment system TAW-1000 in the tests. The craters morphology and quantified data were obtained by scanning the fragmented rock specimen using a three-dimensional morphology scanner. Finally, a numerical model is established to get the stress and deformation fields of the rock under a single PDC cutter. The results show that there are two kinds of failure modes, i.e., brittle failure and plastic failure, in the loading process. Marble is more prone to brittle fracture and has the lowest specific energy, followed by shale and granite. The brittle failure in marble mainly occurs behind the cutter while that happens ahead of the cutter for shale. Curves of contact force versus penetration displacement illustrate that a cutter with a back rake angle of 40 deg has a better penetration result than that with a back rake angle of 30 deg. Enhancing loading speed has a positive effect on brittle fragmentation. The distribution of von Mises stress indicates the initiation point and direction, which has a good agreement with the experiment. The research is of great significance for optimizing the PDC bit design and increasing the rate of penetration.
Corrosion-Fatigue Crack Growth Performance of Titanium Grade 29 Welds in Tapered Stress Joints
Authors: Rombado Gabriel , Baker David A. , Haldorsen Lars M. , da Silva Craidy Pedro , Feiger Jim H. , Hudak Stephen J.
Published: March 2021

Design of a steel catenary riser requires the use of connection hardware to decouple the large bending moments induced by the host floater at the hang-off location. Reliability of this connection hardware is essential, particularly in applications involving high pressure and high temperature fluids. One option for this connection hardware is the metallic tapered stress joint. Titanium (Ti) Grade 29 has been identified as an attractive material candidate for demanding stress joint applications due to its “high strength, low weight, superior fatigue performance and innate corrosion resistance”.2 Titanium stress joints for deepwater applications are typically not fabricated as a single piece due to titanium ingot volume limitations, thus making an intermediate girth weld necessary to satisfy length requirements. As with steel, the potential effect of hydrogen embrittlement induced by cathodic and galvanic potentials must be assessed to ensure long-term weld integrity. This paper describes testing from a joint industry project (JIP) conducted to qualify titanium stress joint (TSJ) welds for ultra-deepwater applications under harsh service and environmental conditions. Corrosion-fatigue crack growth rate (CFCGR) results for Ti Grade 29 flat welding-groove weld (1G/PA) gas tungsten arc welding (GTAW) specimens in seawater under cathodic potential and sour brine under galvanic potential are presented and compared to vendor recommended design curves.
Control of Vibratory MEMS Gyroscope With the Drive Mode Excited Through Parametric Resonance
Authors: Perl T. , Maimon R. , Krylov S. , Shimkin N.
Published: March 2021

In this paper, we present a control strategy for a micro-electro-mechanical gyroscope with a drive mode excited through parametric resonance. The reduced order two degrees-of-freedom model of the device is built, and the drive mode control is implemented using phase-locked loop (PLL) and automatic gain control (AGC) loop. A sense mode vibration control algorithm is developed as well for enhanced sensor performance. The analysis of the drive mode control loops is conducted using the multiple scales method. The robustness of the suggested control loops to parameters perturbation is demonstrated using the model. A simplified linear model of the control loops is shown to predict the device behavior with good accuracy.
Effect of Gradient Porosity and Catalyst Loading on the Performance of Direct Methanol Fuel Cell With Ordered Electrode
Authors: Jiang Jinghui , Sun Xianda
Published: March 2021

Constructing the ordered catalyst layer is one of the most effective strategies to maximize the catalyst utilization in direct methanol fuel cells (DMFCs). To gain insight into the mass and charge transports in ordered catalyst layer, herein, a two-dimensional two-phase mass-transport model involving Knudsen diffusion was proposed. It is found that the simulation results of the model with Knudsen diffusion are more consistent with the experimental results than that of the model without Knudsen diffusion. It has been demonstrated that higher porosity near the oxygen diffusion layer facilitates the oxygen transport, and the optimal porosity is obtained by balancing mass and charge transport resistances in the ordered catalyst layer. In contrast, higher catalyst loading near membrane improves the cell performance significantly. The highest peak power density of 56.5 mW/cm2 is achieved, when the catalyst loading of the outer and inner layer is 0.15 mg/cm2 and 0.85 mg/cm2, respectively.
Effects of Cooling Configurations on the Aerothermal Performance of a Turbine Endwall With Jet Impingement and Film Cooling
Authors: Bu Hongyan , Guo Zhendong , Song Liming , Li Jun
Published: March 2021

With the increase of turbine inlet temperature and the application of premixed combustion, turbine components, particularly the turbine endwall, work in a harsh environment and must be effectively cooled to ensure the component durability. Recently, new cooling schemes that employ both external film cooling and internal jet impingement cooling have drawn much attention due to their extraordinary performance. In this study, a numerical model of turbine endwall with jet impingement and film cooling was established and validated against the experiment. To investigate the effects of geometric parameters related to this cooling scheme, four parameters including impingement hole-to-hole pitch Pi, impingement hole diameter Di, impingement channel height H, and film hole diameter Df were selected to adjust within a reasonable range. The uniform design method was used to collect a database that represented the design space formed by the four parameters. Performance criteria including area-averaged overall cooling effectiveness, standard deviation of overall cooling effectiveness, and total pressure drop coefficient of the cooling system were evaluated through computational fluid dynamics (CFD) calculations. To explore and exploit the design space, a Kriging model was built from the database. Analysis of variance (ANOVA) was conducted afterward to investigate the main effect of each parameter and the correlation between parameters. Finally, based upon the knowledge obtained from ANOVA, typical designs were selected which yielded either best or poorest performances. Through detailed analysis of flow and heat transfer mechanisms of these designs, the influence of each parameter was illustrated clearly and suggestions for the design of similar cooling schemes were drawn.
Professional Team Sports Organizations’ Corporate Social Responsibility Activities: Corporate Image and Chosen Communication Outlets’ Influence on Consumers’ Reactions
Authors: Lee Cindy , Bang Hyejin , Shonk David J.
Published: March 2021

As professional sport teams’ involvement with corporate social responsibility (CSR) activities are prevalent and expected by the public, there has been more attention on the factors that can influence consumers’ reactions to CSR activities. This study investigated the influence of two factors—corporate image and organization choice of communication vehicle—on individuals’ responses, perceived motive, and change of attitude to a professional team sports organization’s CSR activities. A total of 225 usable surveys were collected from a university located in the southern region of the United States for data analyses. The study showed that corporate image had a main effect on perceived motives, Munfavorable = 5.07, Mfavorable = 5.60, F(1, 216) = 6.38, p < .05, , and attitudes, Munfavorable = 4.64, Mfavorable = 5.49; F(1, 216) = 18.34, p < .05, , toward the team due to CSR activities, while there was no main effect for the professional team sports organization’s chosen communication vehicle, F(2, 217) = 1.09, p > .05, for their CSR activities. The importance of building good corporate image and communicating CSR activities to the fan base are also discussed.
Cra and cAMP Receptor Protein Have Opposing Roles in the Regulation of
fruB
in Vibrio cholerae
Authors: Beck Christina , Perry Sayde , Stoebel Daniel M. , Liu Jane M.
Published: March 2021

Vibrio cholerae
is the causative agent of cholera disease. While current treatments of care are accessible, we still lack an understanding of the molecular mechanisms that allow
V. cholerae
to survive in both aquatic reservoirs and the human small intestine, where pathogenesis occurs.
Supplemental Material: New zircon radiometric U-Pb ages and Lu-Hf isotopic data from the ultramafic-mafic sequences of Ranau and Telupid (Sabah, eastern Malaysia): Time to reconsider the geological evolution of Southeast Asia?
Authors: Tsikouras Basilios , al. et
Published: March 2021

Petrographic, geochemical, and dating results.
Effects of manual acupuncture combined with donepezil in a mouse model of Alzheimer’s disease
Authors: Jiang Jing , Liu Gang , Shi Suhua , Li Yujie , Li Zhigang
Published: March 2021

Objectives:

To explore whether combined therapy with donepezil and acupuncture is better than treatment with donepezil or acupuncture individually in a rat model of Alzheimer’s disease.

Methods:

In this study, we randomly divided 40 7.5-month-old senescence-accelerated mouse prone 8 (SAMP8) male mice into four groups: SAMP8, SAMP8+D, SAMP8+MA and SAMP8+D+MA. An additional 10 7.5-month-old SAMR1 male mice were included as a healthy control group (SAMR1). Mice in the SAMP8+D group were given donepezil at a dose of 0.65 µg/g/day; mice in the SAMP8+MA group underwent manual acupuncture at GV20, GV26 and Yintang for 20 min per day; mice in the SAMP8+D+MA received both donepezil and manual acupuncture; and mice in the SAMR1 and SAMP8 groups underwent restraint only to control for the effects of handling. After the 15-day treatment, the Morris water maze test, micro-PET(positron-emission tomography), H&E (haematoxylin and eosin) staining, and immunohistochemistry were used to study the differences between donepezil (SAMP8+D), acupuncture (SAMP8+MA), and donepezil combined with acupuncture (SAMP8+D+MA) therapy for the treatment of Alzheimer’s disease.

Results:

We found that, compared with the untreated SAMP8 group, donepezil, manual acupuncture, and combined therapy with donepezil and manual acupuncture all improved spatial learning and memory ability, the level of glucose metabolism in the brain, and the content of Aβ amyloid in the cortex. Moreover, combined therapy outperformed treatment with donepezil or acupuncture individually in the SAMP8 mice.

Conclusion:

This study shows that the combination of manual acupuncture and donepezil in an Alzheimer’s disease animal model is superior to acupuncture and donezepil alone. However, randomised controlled trials should be undertaken to clarify the clinical efficacy of combination therapy.
Electroacupuncture exerts an anti-migraine effect via modulation of the 5-HT7 receptor in the conscious rat
Authors: Pei Pei , Liu Lu , Zhao Luo-Peng , Qu Zheng-Yang , Tang Chu-Ying , Wang Lin-Peng , Yang Wenming
Published: March 2021

Background:

Acupuncture has been recommended as an alternative therapy for migraine. Emerging evidence suggests that the 5-HT7 receptor (5-HT7R) plays a significant facilitatory role in descending modulation in migraine pathophysiology, and that activation of 5-HT7R in the descending pathway is involved in migraine central sensitisation.

Objective:

To investigate the ability of electroacupuncture (EA) to ameliorate central sensitisation via modulation of 5-HT7R in the descending pain pathways using a rat model of migraine induced by repetitive dural electrical stimulation (DES).

Design:

64 male Sprague-Dawley rats were randomly divided into four groups: Normal group; DES group (receiving dural electrical stimulation only); DES+GB20 group (DES model group treated with EA at GB20); and DES+Sham group (DES model group treated with EA at a non-traditional (sham) acupuncture point). The presence of cutaneous allodynia was determined by measuring facial and hind-paw withdrawal latencies to electronic von-Frey. The expression of 5-HT7R in the descending pathways (periaqueductal grey, raphe magnus nucleus, and trigeminal nucleus caudalis) was assessed using immunofluorescence and Western blotting.

Results:

Facial and hind-paw withdrawal thresholds were significantly increased in the DES+GB20 group compared with the untreated DES group. The expression of 5-HT7R was significantly decreased in the DES+GB20 group compared with the DES group (one-way analysis of variance (ANOVA), P<0.05). No significant differences in behaviour or expression were found between the rats in the DES+Sham group and the untreated DES group (one-way ANOVA, P>0.05).

Conclusion:

EA at GB20 may ameliorate central sensitisation in migraine by inhibiting the activation of 5-HT7 receptors in the descending pain pathway in a rat model of migraine.
Acupuncture at PC6 prevents cardiac hypertrophy in isoproterenol-treated mice
Authors: Zhang Miao , Du Qigen , Yang Fubiao , Guo Ying , Hou Yunlong , Zhu Pengyu
Published: March 2021

Objectives:

To investigate the effect of acupuncture at PC6 on cardiac hypertrophy in isoproterenol (ISO)-treated mice.

Methods:

48 male C57BL/6 mice underwent subcutaneous injection of ISO for 14 days and were randomly divided into four groups (n=12 each) that remained untreated (ISO group), received verum manual acupuncture (MA) treatment at PC6 (ISO+MA(PC6) group), sham MA at location on the tail not corresponding to any traditional acupuncture point (ISO+MA(tail) group), or propranolol (ISO+PR group). An additional 12 mice were given an injection of phosphate-buffered saline (PBS) and formed a healthy control (Normal) group. After performing echocardiography and measuring the ratio of heart weight (HW)/tibia length (TL) at 14 days, all mice were euthanased. Morphological examination was performed following haematoxylin and eosin and Masson’s staining of heart tissues. Ultrastructural changes were observed by electron microscopy. Cardiac protein expression of atrial natriuretic peptide (ANP) and tumour necrosis factor α (TNFα) were measured by immunohistochemical (IHC) staining and Western blotting.

Results:

Compared with the untreated model group, acupuncture at PC6 lowered the heart rate, reduced the ratio of HW/TL, improved the left ventricular (LV) anterior wall thickness (LVAWd), LV end-diastolic anterior wall thickness (LVAWs), LV end-systolic posterior wall thickness (LVPWd), LV end-diastolic posterior wall thickness (LVPWs), and fractional shortening (FS) as observed by echocardiography (ISO+MA(PC6) vs. ISO groups: P<0.05). Moreover, evidence from morphological studies demonstrated that acupuncture at PC6 inhibited myocardial hypertrophy and collagen deposition, and normalised the ultrastructural changes. In addition, ANP and TNFα expression were attenuated in the verum acupuncture group compared with the untreated model group (ISO+MA(PC6) vs. ISO groups: P<0.05).

Conclusions:

The results demonstrated that acupuncture at PC6 attenuates sympathetic overactivity. Additionally, it may improve cardiac performance by reversing adverse cardiac remodelling. Acupuncture has potential as a treatment for sympathetic hypertension.
Electroacupuncture inhibits mast cell degranulation via cannabinoid CB2 receptors in a rat model of allergic contact dermatitis
Authors: Wang Zhigang , Lu Min , Ren Jie , Wu Xiaoxue , Long Man , Chen Longyun , Chen Zebin
Published: March 2021

Objective:

Cannabinoid CB2 receptors (CB2Rs) are mainly present on immune cells including mast cells, which participate in 2,4-dinitrofluorobenzene (DNFB)-induced allergic contact dermatitis (ACD). In this study, we aimed to investigate whether inhibition of mast cell degranulation was involved in the anti-ACD effect of electroacupuncture (EA) at ST36 via CB2R.

Methods:

Sprague-Dawley rats were sensitised and challenged with DNFB following EA stimulation for 1 week. Ear swelling, serum IgE levels, local cytokine production and mast cell infiltration were evaluated. Additionally, rat peritoneal mast cells (RPMCs) were isolated and cultured for detection of CB2R expression, mitogen-activated protein kinase (MAPK) signalling activation and mast cell degranulation (including β-hexosaminidase and histamine release) in the presence or absence of CB2R antagonists.

Results:

EA treatment inhibited ear swelling, suppressed IgE and cytokine production, decreased the number of mast cells and curbed mast cell degranulation, which was associated with the inhibition of p38 phosphorylation in DNFB-induced ACD. Importantly, EA enhanced the expression of CB2R mRNA and protein in the RPMCs. CB2R antagonist AM630 but not CB1R antagonist AM251 effectively reversed the suppressive effect of EA on p38 activation, mast cell infiltration and degranulation.

Conclusion:

These findings provide more evidence to support the hypothesis that EA promotes CB2R expression in mast cells, which is followed by inhibition of the p38 MAPK pathway, potentially resulting in the anti-ACD effect of EA. This suggests that EA at ST36 may be an effective candidate therapy for treating inflammatory skin diseases such as ACD.
Effects of electroacupuncture on anxiety and depression in unmarried patients with polycystic ovarian syndrome: secondary analysis of a pilot randomised controlled trial
Authors: Wang Zhi , Dong Haoxu , Wang Qing , Zhang Lina , Wu Xiaoke , Zhou Zhongming , Yang Li , Huang Dongmei
Published: March 2021

Objective:

To evaluate the efficacy of electroacupuncture (EA) for the treatment of anxiety and depression in unmarried patients with polycystic ovarian syndrome (PCOS) by secondary analysis of a randomised controlled trial.

Methods:

A prospective pilot randomised controlled trial of unmarried women with PCOS was conducted from November 2012 to March 2016. Participants were assigned to the acupuncture group (receiving EA for 16 weeks) or the control group (receiving sham acupuncture for 16 weeks), with 27 patients in each group. The pre-specified primary outcomes and all secondary outcomes, with the exception of serum levels of neurotransmitters including norepinephrine (NE), epinephrine (AD), serotonin (5-HT) and γ-aminobutyric acid (GABA), will be reported separately. Additional outcome measures selected for this secondary analysis included anxiety and depression scale scores (Zung-SAS and Zung-SDS), 36-Item Short Form (SF-36) scale scores, PCOS Quality of Life (PCOSQOL) scale scores and Chinese Quality of Life (CHQOL) scale scores.

Results:

After the16-week intervention, an increase in serum NE and reduction in 5-HT were observed in the acupuncture group (P=0.028 and P=0.023, respectively). The serum level of GABA decreased in both groups after the interventions (both P<0.001). However, there were no significant differences between the two groups in the levels of any neurotransmitters (p>0.05). After EA treatment, SAS and SDS scores were decreased in the acupuncture group (P=0.007 and P=0.027, respectively) and were lower than those of the control group (P=0.003 and P=0.004, respectively). The SF-36 domain scores for mental health, vitality, social functioning, general health and health transition, the total CHQOL scores, and the infertility problems and body hair domains of the PCOSQOL improved significantly after EA (P<0.05).

Conclusion:

EA appears to improve symptoms of anxiety/depression and quality of life in PCOS patients and may influence serum levels of NE and 5-HT. These findings should be interpreted with caution, given the secondary nature of the outcome measures reported herein.

Trial registration number:

NCT01812161; ChiCTR-TRC-12002529
Relationship between muscle spindles and myofascial trigger spots according to Hoffmann reflex pathway and tissue morphology characteristics in a rat model
Authors: Liu Lin , Huang Qiang-Min , Liu Qing-Guang , Nguyen Thi-Tham , Yan Jian-Qin , Bo Cheng-Zhi
Published: March 2021

Objectives:

To determine how muscle spindles are involved in the pathophysiology of chronic myofascial trigger spots (MTrSs, similar to myofascial trigger points) in a rat injury model according to the characteristics of the Hoffmann reflex (H-reflex) and the anatomical relationship between muscle spindles and MTrSs.

Methods:

16 male Sprague-Dawley rats (7 weeks old) were randomly divided into experimental and control groups. A blunt strike injury and eccentric exercise were applied to the gastrocnemius muscle of rats in the experimental group once a week for 8 weeks as a MTrS modelling intervention. Subsequently, the rats were reared normally and rested for 4 weeks. At the end of the 12th week, the rats were examined for the presence of MTrSs defined by the detection of a palpable taut band exhibiting both a local twitch response and spontaneous electrical activity. After modelling, evocation of the H-reflex and morphological examination of muscle spindles and MTrSs were conducted.

Results:

The threshold (0.35±0.04 mA) of the H-reflex and latency (1.24±0.18 ms) of the M wave recorded at MTrSs were not significantly different to those at non-MTrSs (P>0.05). Compared with non-MTrSs, a lower Mmax (4.28±1.27 mV), higher Hmax (median (IQR) 0.95 (0.80–1.08) mV) and Hmax/Mmax (median (IQR) 0.21 (0.16–0.40)), and shorter H wave latency (4.60±0.89 ms) were recorded at MTrSs (P<0.05). Morphologically, there was a close anatomical relationship between the MTrS cells and the muscle spindles.

Discussion:

Compared with normal muscles, the H-reflex myoelectrical activity was enhanced and some muscle spindles might have been influenced by active MTrSs. Thus, muscle spindles may play an important role in the pathological mechanism underlying myofascial trigger points.
Attenuation imaging as a new ultrasonographic application for identifying placental haematoma
Authors: Yamaguchi Masahiro , Umazume Takeshi , Noshiro Kiwamu , Watari Hidemichi
Published: March 2021

We present a case in which attenuation imaging (ATI), a recently developed ultrasonographic application, facilitated the diagnosis of preplacental and postplacental haematoma. Placental abruption is a serious condition that affects the prognosis of infants and is difficult to diagnose. Ultrasonography is the primary imaging modality that complements the clinical findings in the diagnosis; however, its sensitivity is low, and improved diagnostic accuracy is desired. Here, we found that placental haematomas on the placental fetal surface observed at 19 weeks of gestation were indistinct from placental parenchyma in B-mode ultrasonographic imaging. In ATI, the placental parenchyma was colour-mapped, but the haematoma portion was not, which helped identify the haematoma. ATI, which also colour-maps uniform tissues, did not colour-map vessels within the placenta. ATI has a breakthrough potential for improving the diagnosis of placental abruption.