bluuebunny/crossref_metadata_2025 huggingface dataset:
Guidance on Review Type Selection for Health Technology Assessments: Key Factors and Considerations for Deciding When to Conduct a De Novo Systematic Review, an Update of a Systematic Review, or an Overview of Systematic Reviews
Authors: Kim Joanne Soo Min , Pollock Michelle , Kaunelis David , Weeks Laura
Published: July 2021

BackgroundA systematic review (SR) helps us make sense of a body of research while minimizing bias and is routinely conducted to evaluate intervention effects in a health technology assessment (HTA). In addition to the traditional de novo SR, which combines the results of multiple primary studies, there are alternative review types that use systematic methods and leverage existing SRs, namely updates of SRs and overviews of SRs. This paper shares guidance that can be used to select the most appropriate review type to conduct when evaluating intervention effects in an HTA, with a goal to leverage existing SRs and reduce research waste where possible. MethodsWe identified key factors and considerations that can inform the process of deciding to conduct one review type over the others to answer a research question and organized them into guidance comprising a summary and a corresponding flowchart. This work consisted of three steps. First, a guidance document was drafted by methodologists from two Canadian HTA agencies based on their experience. Next, the draft guidance was supplemented with a literature review. Lastly, broader feedback from HTA researchers across Canada was sought and incorporated into the final guidance. ResultsNine key factors and six considerations were identified to help reviewers select the most appropriate review type to conduct. These fell into one of two categories: the evidentiary needs of the planned review (i.e., to understand the scope, objective, and analytic approach required for the review) and the state of the existing literature (i.e., to know the available literature in terms of its relevance, quality, comprehensiveness, currency, and findings). The accompanying flowchart, which can be used as a decision tool, demonstrates the interdependency between many of the key factors and considerations and aims to balance the potential benefits and challenges of leveraging existing SRs instead of primary study reports. ConclusionsSelecting the most appropriate review type to conduct when evaluating intervention effects in an HTA requires a myriad of factors to be considered. We hope this guidance adds clarity to the many competing considerations when deciding which review type to conduct and facilitates that decision-making process.
Prediction and Detection of COVID-19 from Chest X-Rays using Transfer Learning based Deep Convolutional Neural Networks
Authors: Misra Priyavrat , Panigrahi Niranjan
Published: July 2021

With the ongoing outbreak of the COVID-19 global pandemic, the research community still struggles to develop early and reliable prediction and detection mechanisms for this infectious disease. The commonly used RT-PCR test is not readily available in areas with limited testing facilities, and it lags in performance and timeliness. This paper proposes a deep transfer learning-based approach to predict and detect COVID-19 from digital chest radiographs. In this study, three pre-trained convolutional neural network-based models (VGG16, ResNet18, and DenseNet121) have been fine tuned to detect COVID-19 infected patients from chest X-rays (CXRs). The most efficient model is further used to identify the affected regions using an unsupervised gradient-based localization technique. The proposed system uses a classification approach (normal vs. COVID-19 vs. pneumonia vs. lung opacity) using three supervised classification algorithms followed by gradient-based localization. The training, validation and testing of the system are performed using 21165 CXR images (10192 normal, 1345 pneumonia, 3616 COVID-19, and 6012 lung opacity). Simulation and evaluation results are presented using standard performance metrics, viz, accuracy, sensitivity, and specificity.
Simple Linear Ionic Polysiloxane Showing Unexpected Nanostructure and Mechanical Properties
Authors: Hara Mitsuo , Iijima Yuta , Nagano Shusaku , Seki Takahiro
Published: July 2021

Polysiloxanes are ubiquitous materials in industry and daily life derived from silicates, an abundant resource. They exhibit various properties, which depend on the main-chain network structure. Linear (1D backbone) polysiloxanes provide amorphous materials. They are recognized as fluid materials in the form of grease or oil with a low glass transition temperature. Herein we report that a simple linear polysiloxane, poly(3-aminopropylmethylsiloxane) hydrochloride, shows an elastic modulus comparable to that of stiff resins such as poly(tetrafluoroethylene). By introducing an ammonium salt at all the units of this polysiloxane, inter- and intramolecular ionic aggregates form, immensely enhancing the elastic modulus. This polysiloxane is highly hygroscopic, and its modulus can be altered reversibly 100 million times between moist and dry atmospheres. In addition, it works as a good adhesive for glass substrates with a shear strength of more than 1 MPa in the dry state. Despite its simple structure with a flexible backbone, this polymer unexpectedly self-assembles to form an ordered lamellar nanostructure in dry conditions. Consequently, this work reveals new functions and possibilities for polysiloxanes materials by densely introducing ionic groups.
Using Machine Learning to Predict the Requirement for Revascularization in Patients with Chest Pain in the Emergency Department
Authors: Zheng Zhichang , Wang Nian , Jiang Bo , Ma Chunpeng , Ai Hui , Wang Xiao , Nie Shaoping
Published: July 2021

Background: The study aimed to use machine learning algorithms to predict the need for revascularization in patients presenting with chest pain to the emergency department.Methods: We obtained data from 581 patients with chest pain, 264 who underwent revascularization, and the other 317 were treated with medication alone at 3 months. Using standard algorithms, linear discriminant analysis, and standard algorithms, we analyzed 41 features relevant to coronary artery disease (CAD). Results: We identified seven robust predictive features. The combination of these predictors gave an area under the curve (AUC) of 0.830 to predict the need for revascularization. By contrast, the GRACE score gave an AUC of 0.68.Conclusions: This machine learning-based approach predicts the need for revascularization in patients with CAD.
Objective Understanding of Front of Pack Warning Labels Among Mexican Children of Public Elementary Schools. A Randomized Experiment
Authors: Contreras-Manzano Alejandra , Jauregui Alejandra , Vargas Jorge , Nieto Claudia , Granich Adriana , Escobar María de Lourdes Alemán , Olvera Armando , Cruz-Casarrubias Carlos , Munguía-Serrano Ana , Simón Barquera
Published: July 2021

Background. Warning Labels (WL) are a new approach which highlight excessive amounts of critical nutrients in processed foods or beverages in order to discourage consumption of unhealthful products. This study aimed to evaluate among Mexican school children, the objective understanding of traditional and numeric WL considered by the Mexican regulation. To identify the impact of cartoon characters in the objective understanding of the WL and, to test some communication strategies to facilitate the correct use of the WL.Methods. We carried out a randomized experiment in July of 2019 in public elementary schools Morelos, Mexico. Participants were randomly assigned to one of four groups: 1) Nutrient Facts Panel (NF), 2) Nutrient Facts Panel with cartoon characters (NF+C), 3) Warning Labels (WL), and 4) Warning Labels with cartoon characters (WL+C). After allocation, children assigned to both WL groups (WL or WL+C), were randomly required to watch simultaneously two posters or a video explaining how to correctly interpret WLs. Logistic regression models adjusted by sex, age and cluster (school) were fitted.Results. The proportion of children correctly choosing the healthiest or the least healthy option was higher for WL groups (56.8%, 95%CI; 40.8-72.8) compared to all NF groups (24.3%, 95%CI; 20.4-28.3, p<0.05). The objective understanding of traditional WL was higher (28.7%, 95%CI: 22.8-35.4) than the numeric WL (19%, 95%CI: 14.2-25.0, p<0.05). For choosing the unhealthiest products, WL group responded correctly in a higher proportion when using traditional WL (58.7%, 95%CI: 36.4-81.1) in comparison to WL+C group (48.8%, 95%CI: 25.4-64.2, p<0.05). By tool of communication, the video was 2.23 times more helpful than the posters to the correct interpretation of the WL (p<0.05), being 2.41 times more helpful for choosing the healthiest item (p<0.05) and 1.57 for choosing the unhealthiest choice (p<0.05).Conclusions. In scholar Mexican children, WL were useful to identify easily and quickly healthier and unhealthier packaged products in comparison to NF. Importantly, numeric WL seemed to be as effective as WL to help children identify healthy and unhealthy products. Cartoons displayed on the packages reduced the objective understanding of the WL, especially for breakfast cereals and milks for which cartoons where perceived as the unhealthiest ones.
Prehabilitation Programs for Cancer Patients: a Systematic Review of Randomized-controlled Trials
Authors: Meneses-Echavez Jose F , Loaiza-Betancur Andrés F. , Díaz-López Víctor , Echavarría-Rodríguez Andrés M. , Triana-R Hector R
Published: July 2021

Background: Prehabilitation programs focusing on exercise training as the main component are known as a promising alternative for improving patients’ outcomes before surgical treatment of different cancers. This systematic review aimed to determine the effects of prehabilitation programs compared with usual care for cancer patients.Methods/design: We searched CENTRAL, MEDLINE, and EMBASE from inception to 2020, and hand-searched clinical trial registries. We included randomized controlled trials (RCTs) in adults, survivors of any type of cancer, that compared prehabilitation programs focusing on exercise training as the major component with usual care or other active interventions. Outcome measures were health-related quality of life (HRQL), muscular strength, postoperative complications, average length of stay (ALOS), handgrip strength, and physical activity levels. Two reviewers independently selected the studies, extracted data, assessed the risk of bias and the quality of evidence using the GRADE approach.Results: 14 RCTs published between 2010-2020 met our inclusion criteria (n=1044 participants). Colorectal and lung cancers were the most common diagnoses with 5 studies (36%) each. The studies showed concerns regarding outcome measurement, selective reporting, and attrition. Four comparisons were identified: combined training vs rehabilitation/usual care; high-intensity interval training vs usual care; respiratory muscle training plus aerobic training vs usual care, and pelvic floor training vs usual care. The studies provided no clear evidence of an effect between groups. We assessed the certainty of the body of evidence as very low, downgraded due to serious study limitations and imprecision.Conclusion: It is uncertain whether prehabilitation programs compared with usual care have an effect in cancer patients. We have very little confidence in the results and the true effect is likely to be substantially different from these. Further research is needed before we could draw a more certain conclusion.Systematic review registration: CRD42019125658
Diagnostic performance of [18F]FDG PET in staging grade 1-2, estrogen receptor positive breast cancer
Authors: Iqbal Ramsha , Mammatas Lemonitsa H , Aras Tuba , Vogel Wouter V , de Brug Tim van , Oprea-Lager Daniela E , Verheul Henk M.W. , Hoekstra Otto S , Boellaard Ronald , Oordt Catharina W Menke-van der Houven van
Published: July 2021

BackgroundAccurate staging of early breast cancer (BC) patients is essential for tailored treatment. Currently, the preferred imaging modality for staging is positron emission tomography with [18F]Fluorodeoxyglucose (FDG PET) combined with a diagnostic computed tomography (CT) scan of the thorax/abdomen. However, FDG PET might be insufficient for detection of malignant lesions in grade 1–2, estrogen receptor positive (ER+) BC, due to its low metabolic activity. The main aim of this study was to retrospectively investigate the diagnostic accuracy of FDG PET in this patient population.Methods74 patients diagnosed with grade 1–2, ER + clinical stage IIB/III or locoregional recurrent BC were included. Suspect tumor lesions detected on conventional imaging (mammography, ultrasound, magnetic resonance imaging, diagnostic CT, bone scintigraphy) and FDG PET were confirmed with pathology or follow-up. FDG PET-positive lesions were (semi)quantified with standardized uptake values (SUV) and total lesion glycolysis (TLG), and these FDG PET parameters were correlated with pathological features such as histological subtype, grade, ER, PR and HER2 expression and mitotic activity index.ResultsPre-operative imaging identified 155 lesions that were pathologically verified. Based on pathology, 115/155 (74.2%) lesions identified on FDG PET were classified as true positive, i.e. malignant (in 67 patients) and 17/155 (10.8%) lesions as false positive, i.e. benign (in 9 patients); 7/155 (4.5%) as false negative (in 7 patients) and 16/155 (10.3%) as true negative (in 14 patients). FDG PET incorrectly staged 16/70 (22.9%) patients: 3/70 (4.3%) were downstaged whereas 13/70 (18.6%) were upstaged. SUV did not help to discriminate between true- and false positive lesions (median SUVmax 4.23, IQR: 2.54–6.37 vs. 3.07, IQR: 2.14–5.58, P = 0.44 respectively). For true positive lesions, FDG uptake correlated with histological subtype, showing higher uptake in ductal carcinoma compared to lobular carcinoma (P < 0.05).ConclusionWithin this study FDG PET inadequately staged 22.9% of grade 1–2, ER + BC cases. Incorrect staging can lead to inappropriate treatment choices, potentially affecting survival and quality of life. Prospective studies investigating novel radiotracers are urgently needed.Trial registrationretrospectively registered.
Polystyrene Sulfonate with Well-Defined Structure as Lignosulfonate Analogue for Promoting Lignocellulose Enzymatic Saccharification
Authors: liu tian , Wang Peipei , Tian Jing , Guo Jiaqi , Zhu Wenyuan , Jin Yongcan , Xiao Huining , song junlong
Published: July 2021

Background: Water-soluble lignin (particularly lignosulfonate, LS) has been well documented for its positive impact on enzymatic saccharification for lignocellulose. Even though, the promotion mechanism of LS hasn’t been fully understood. All researches paid all attentions on the natural lignin or its derivatives. Whereas the structure of natural lignin is too complex and not easily to be tailored functional groups. To further our understanding on the promotion mechanism of water-soluble lignin to enzymatic saccharification for lignocellulose and also to pursue better alternatives with different skeleton structure other than natural lignin or its derivatives, therein we reported a synthetic soluble linear aromatic polymer- sodium polystyrene sulfonate (PSS) with well-defined structure to mimic LS for enhancing the enzymatic saccharification efficiency. Results: At the cellulase loading of 10 FPU/g-glucan, the glucose yield of green liquor pretreated poplar increased from 39.8% for the control to 60.3% with PSS addition of 0.1 g/g-substrate. It outperformed LS with addition of 0.2 g/g-substrate by 4.6%. The underlying mechanism was unveiled using Quartz Crystal Microbalance and the results confirmed that the as-formed complexes of cellulase-PSS, which effectively reduced non-productive binding and eventually improving the saccharification efficiency, were only half thickness and with much lower shear moduli than those of LS. Conclusions: The synthetic lignin mimics with controllable structures offer us more opportunities to understand the promotion mechanism of soluble lignins on lignocellulose enzymatic saccharification.
Key Drivers of Consumption-Based Carbon Emissions: Empirical Evidence from SAARC countries
Authors: Shekhawat Komal Kanwar , Yadav Arvind Kumar , Sanu Md Sahnewaz , Kumar Pushp
Published: July 2021

To devise an appropriate climate policy dealing with environmental degradation, reliable measurement of CO2 emissions is essential. In the recent past, most researchers have utilized production-based emissions in their studies, ignoring the important role of consumption-based emissions in environmental degradation. Therefore, the present research examines the drivers of consumption-based CO2 emissions in SAARC nations over the period 1990 to 2018. By employing traditional and second-generation panel cointegration methodologies, the study, more specifically, explores the link between consumption-based CO2 emissions and its four macroeconomic determinates, namely, GDP growth, energy consumption, FDI, and trade openness (measured by Composite Trade Share Index). The study also applies the FMLOS and DOLS techniques for calculating the long-run elasticities of regressors with respect to the explained variable. The results establish a cointegration relationship between the variables and validate the “EKC hypothesis” for the SAARC region. It is also found that in the long run, as expected, energy consumption enhances the consumption-based CO2 emissions while FDI and trade openness improve the environmental quality by plummeting emissions. Most importantly, the study rejects the “pollution-haven hypothesis” for the SAARC region based on the negative and statistically significant coefficient of FDI. Lastly, based on the results, some policies are recommended for the abatement of environmental degradation in SAARC countries. As the SAARC nations rely heavily on fossil-based energy, it is suggestive for these economies to enhance the level of energy efficiency and augment the share of renewable energy sources in the energy-mix. Furthermore, the policy-designers in this region should encourage trade openness and liberalize inward FDI for containing consumption-based emissions.
Priority micronutrient density in foods
Authors: Beal Ty , Ortenzi Flaminia
Published: July 2021

Despite concerted efforts to improve diet quality and reduce malnutrition, micronutrient deficiencies remain widespread globally, especially in low- and middle-income countries and among population groups with increased needs, where diets are often inadequate in iron, zinc, folate, vitamin A, calcium, and vitamin B12. There is a need to understand the top food sources of these commonly lacking micronutrients, which are essential for optimal health. To fill this critical knowledge gap, we built an aggregated global food composition database and developed an approach to rate foods according to their density in priority micronutrients. We show that the top sources of multiple priority micronutrients are organs, small fish, dark green leafy vegetables, shellfish, beef, goat, eggs, milk, cheese, and canned fish with bones. Lamb, mutton, goat milk, and pork are also good sources, followed by yogurt, fresh fish, pulses, and teff.
THE FIRST EXPERIENCE OF LYMPHOTROPIC ANTIBACTERIAL THERAPY FOR ACUTE PANCREATITIS
Authors: Duzhiy Ihor D. , Shimko Volodymyr V. , Pyatikop Hennadiy I. , Al Yamani Navras D.
Published: July 2021

Acute pancreatitis remains one of the most common surgical diseases of the abdominal cavity. Its incidence has been constantly increasing in recent years. Mortality remains high with pancreatitis: 15–45%.
To study capacity for increasing the effectiveness of treatment of acute pancreatitis by lymphotropic administration of antibacterial and anti-inflammatory drugs.
We observed 17 patients with acute pancreatitis, with the average age of 47.7 years; all patients were hospitalized within the first two days of the disease. The treatment was performed in addition to the infusion therapy in accordance with the order of the Ministry of Health of Ukraine No. 297 dated April 2, 2010, using lymphotropic administration of antibacterial therapy, which was tested at the Department of Surgery of SSU and differed in that antibacterial and anti-inflammatory drugs were injected regionally into the pancreas.
In the first 4 days, according to the ultrasound findings, the size of the inflamed pancreas decreased from 31.25, 18.5, and 27.25 cm to 25.25, 15.75, and 18 cm, and the size of the spleen decreased from 262.64 cm3 to 160.99 cm3, which is the evidence of drug targeted effect on the pancreas and spleen.
Lymphotropic antibacterial and anti-inflammatory therapy used for 4 days reduced the size of the head, body and tail of the gland by 6.4, 3.9, and 7.0 cm. The reduction in the size of the gland contributed to the elimination of clinical signs of inflammation, especially pain, and leukocytes number decrease, which indicates the "targeted" effect of the drugs. The reduction in the size of the spleen from 308.9 cm3 to 227.1 cm3 proves the effect produced by lymphotropic use of drugs on the immune system. This is also supported by corrected immunoglobulin levels.
Research on Mobile Point Exchange System Based on Collaborative Filtering Recommendation Algorithm
Authors: Feng Leijie , Mu Zehui
Published: July 2021

This paper describes the development process of the mobile point exchange system from demand analysis, outline design, detailed design and implementation. The system combines current business needs and uses collaborative filtering recommendation algorithms to solve the problem of how to calculate data similarity. The system is written in JAVA language, and uses a layered architecture model to separate business modules and functional modules. The front-end uses HTML, FreeMarker and Vue technologies to achieve page display and data rendering, and the persistence layer framework uses Mybatis to implement customized SQL, Stored procedures and advanced mapping, through the Spring framework to realize the management of JAVABean, dependency injection and transaction management, and finally realize the point redemption function.
Investigating Invariant Item Ordering in Intelligence Tests: Mokken Scale Analysis of KBIT-2
Authors: ÖZBERK Eren Halil , ÜNSAL ÖZBERK Elif Bengi , ULUÇ Sait , ÖKTEM Ferhunde
Published: July 2021

The Kaufman Brief Intelligence Test – Second Edition (KBIT-2) is designed to measure verbal and nonverbal abilities in a wide range of individuals from 4 years 0 months to 90 years 11 months of age. This study examines both the advantages of using Mokken Scale Analysis (MSA) in intelligence tests and the hierarchical order of the items in the KBIT-2: Turkish form by estimating the parameters of each of the three subtests by testing the dimensionality of the KBIT-2 subtests by using the Invariant Item Ordering (IIO) assumptions. 2850 people participated in the study, including children, adolescents, and adults. Participants' ages varied from 48 months (4 years 0 months) to 539 months (44 years 11 months). Automated Item Selection Procedure (AISP) was applied for the assessment of unidimensionality under three different lower bounds as 0.30, 0.40, and 0.55. The items of all three subtests formed a unidimensional scale. Backward Item Selection (BIS) procedure detected seven items in the Matrices and 17 items in the Verbal Knowledge, while six items in the Riddles subtest violated the IIO criteria. KBIT-2: Reliability values obtained using MSA analysis show that all three subtests have a high degree of internal consistency. However, care should be taken when IIO assumptions do not fit the intelligence scales in the original form.
La economía social solidaria y el desarrollo incluyente en América Latina
Authors: Moncayo Muñoz Jesús Enrique , Ordóñez Castaño Iván Andrés , Rivera Pedroza Beatriz Eugenia , Martínez Mora Brehinert Alfredo , Torres Delgado Mauricio Alberto , Rodríguez Martínez Jhoanna , Giraldo G Diana Patricia , Barragán Fernández Omar , Véliz Lázaro Héctor Eduardo , Pastore Rodolfo , Urresta Yépez Ramiro Fernando , Carvajal Pérez Luis Alfredo , Meñaca Villani María Fernanda , Rubio Rodríguez Gustavo Adolfo , Rivera González Miguel Ángel , Rodríguez Barrero Mario Samuel , Fernando Villalobos Diego , de los Ríos Giraldo Aura Liliana , Jara Vargas María del Pilar , Romero Palacios Wilson Eduardo , Berruecos Patiño José Vicente
Published: July 2021

Con base en las posturas de los autores de los diferentes capítulos, este libro pretende incorporar a la economía social y solidaria el concepto de desarrollo incluyente, para de esta manera y en este sentido, lograr entender a lo largo del escrito de qué forma estas dos variables se manifiestan en las prácticas y modelos de gestión en las organizaciones que han optado diferentes organizaciones y proyectos en países como Argentina, Colombia, Ecuador, México y Perú. El acercamiento de la economía social solidaria y el desarrollo incluyente en América Latina se hace bajo la mirada en cuatro momentos: conceptualización, la asociación a través de la economía solidaria, las características de las empresas solidarias y otras tendencias de la economía que pueden conciliarse con la economía social y solidaria. Este libro es una contribución al análisis de la administración y la economía social, que permite presentar la vigencia de las propuestas alternativas de desarrollo económico y social que afloran en el continente. Las ideas expuestas por los investigadores serán un valioso motivo para invitar a la reflexión y al diálogo entre académicos que se preocupen por entender los alcances y la importancia de la economía social.
Taller de proyectos en diseño de vestuario
Authors: Polo Flórez Dolly Viviana
Published: July 2021

Para poder brindar un significado para el conocimiento, se debe poner en tensión y consonancia a los agentes y comunidades que generan, administran y gestionan el propósito del conocer. Esto posibilita la referenciación de propósitos y de relaciones de sentido que permiten preparar las bases comprensivas del mundo como puntos de partida y llegada para el desarrollo. Los actos educativos, tanto los institucionales como los cotidianos, desde aspectos cualitativos y cuantitativos como aportes que se complementan permiten nutrir las nuevas miradas para gestionar el conocimiento. El estudio proyectual esencia del modus–operandi del diseño es conformado por usos y aproximaciones indagadoras que resultan en miradas investigativas. De este modo el sujeto que conoce es un sujeto que construye y cimienta las bases de un desarrollo común.
Determinants of drinking water quality and sanitary risk levels of water storage in food establishments of Addis Ababa, Ethiopia
Authors: Girmay Aderajew Mekonnen , Gari Sirak Robele , Gessew Gebreab Teklebirhan , Reta Mulumebet Tadesse
Published: July 2021

The study aimed to assess the determinants of drinking water quality and sanitary risk levels of water storage. An institution-based cross-sectional study was conducted. One hundred and twenty-five drinking water samples were collected directly from food outlets' drinking water storages. An observational checklist was used to assess the sanitary risk levels of the storages. Data analysis was conducted using multivariable logistic regression. Type of primary source of drinking water, having continuous piped water, type of drinking water storage equipment, drinking water storage having a lid/cover, method of drinking water drawn from the water storages, presence of any method of drinking water treatment, and having functional a hand-washing facility with soap near the toilet were identified as major determinant factors. This study revealed that nearly 30% of the food outlets' drinking water was not microbiologically safe. As a result, these establishments could be a source of different health problems for their customers. In the study, many determinant factors that affect the drinking water quality of the food outlets were identified. In addition, 16.3% and 18.7% of the food outlet drinking water storages were grouped into high and very high contamination risk levels, respectively. Therefore, the existing regulatory body should force the food outlets to have effective hand-washing practices, clean, suitable drinking water storage, and to avoid dipping practice.
Vibration characteristics of pressure pipelines at pumping stations and optimized design for vibration attenuation
Authors: Xu Yude , Liu Zijin , Zhou Dongmeng , Tian Junjiao , Zhu Xinglin
Published: July 2021

To explore the effects of different pressure pipeline layouts on pumping station pipeline vibration, this study establishes an ALGOR numerical model for pipeline flow considering fluid–structure interactions. A data acquisition and signal processing vibration test system is used to obtain vibration signals and verify simulation results including pipeline fluid velocity, fluid pressure, and transient stress. Based on the flow's vibration excitation characteristics, we consider structural vibration reduction technology and propose an optimized design scheme. As an example, we apply this approach to a pressure pipeline at the Ningxia Yanhuanding Pumping Station Project. Results show strong vibrations at the water inlet, the junction between the branch and main pipes, and the water outlet, with even stronger vibration at the inlet than at the outlet. In the optimized design scheme, adjusting the distance between the branch pipes only weakly reduces flow-generated pipeline vibration; increasing the pipe diameter and changing the main pipe's relative orientation show stronger effects. Vibration reduction is optimized for a main pipe dip angle of 2–5° relative to the branch pipes, simultaneously decreasing pumping station energy loss. These results provide a theoretical and practical basis for optimal design of pressure pipelines at high-lift pumping stations.
Influence of aqueous foam syneresis on the shock wave propagation velocity
Authors: Gainullina E.F.
Published: July 2021

Numerical simulation of the spherical shock pulse propagation in aqueous foam with volumetric liquid fraction of 0.0083 has been carried out in accordance with the published experimental data on the explosion of HE in aqueous foam. The assumption is used that the foam structure is destroyed by the shock wave, which leads to the transformation of the foam into a monodisperse gas-droplet mixture. The system of equations for the two-phase gas-droplet model of aqueous foam includes the laws of conservation of mass, momentum, energy for each phase and the equation for the dynamics of the volumetric liquid fraction in a single-pressure, two-velocity, two-temperature approximations in a three-dimensional formulation and takes into account the forces of the Schiller-Naumann interfacial drag, the Ranz-Marshall interphase contact heat exchange and the effect of foam syneresis on the initial distribution of its volumetric liquid fraction. Realistic equations of state in the form of Peng-Robinson and Mie-Gruneisen are used to describe the thermodynamic properties of air and water that make up a gas-droplet mixture. Numerical modeling of the processes under consideration was carried out in the open software of computational fluid dynamics OpenFOAM using the finite volume method based on the iterative two-step PIMPLE algorithm. The analysis of the effect of foam syneresis on the dynamics of shock pulse in aqueous foam is given. It was found that the uneven distribution of the liquid fraction in the foam, caused by its sedimentation under the gravity, leads to the increase in the shock pulse velocity in upper layers of the foam. In comparative analysis of numerical solutions and experimental data at sensor locations, the importance of taking into account syneresis phenomena in modeling the dynamics of shock wave in aqueous foam is shown. The reliability of calculations obtained by the proposed model is confirmed by their agreement with experimental data.
Dynamics of dislocations in the domain structure of the nematic liquid crystal
Authors: Delev V.A.
Published: July 2021

Dynamics and interaction of classical dislocations in the domain structure of π/2 nematic liquid crystal is studied. A feature of twisted nematics is that hydrodynamic flows in Williams domains, together with the tangential component of velocity, also have an axial component, the direction of which is opposite in neighboring domains. Dislocations can move both perpendicular (glide) to Williams domains, and along (climb) them. It was found that when dislocations collide with opposite topological charges S = ±1 at given voltage, their speed increases. It has been shown that dynamics and interaction of dislocations with topological charges S = ±1 are qualitatively well described by the perturbed sine-Gordon equation.
La pandemia de la COVID-19 y su impacto económico, social y salud
Authors: Seminario Randall
Published: July 2021

Es un enfoque sobre la crisis actual que ha ocacionado el coronavirus (COVID-19) y su impacto que h tenido lo económico, social y salud, en la cual asumimos una neva forma de vivir usando gel antibacterial y cubrebocas, lo que nos está direccionando a un cambio de hábitos, exagerando una preocupación constante y obsesiva por la salud.
Ansiedad por coronavirus en personas adultas que acuden a un Centro de Salud en Los Olivos
Authors: Munguia Ramirez Paola Adriana , Estrada Villafuerte Anthuaneth Danielle , León Centeno Karla Mayiela
Published: July 2021

Objetivo: Fue determinar la ansiedad por coronavirus en personas adultas que acuden a un Centro de Salud en Los Olivos. Materiales y métodos: El enfoque metodológico de este estudio fue cuantitativo y su diseño descriptivo-transversal. La población estuvo conformada por 150 personas adultas. La técnica utilizada fue la encuesta y el instrumento de medición fue la Coronavirus Anxiety Scale (CAS), la cual presenta 5 enunciados o ítems, que evalúan la ansiedad por coronavirus a través de síntomas. Resultados: En cuanto a la edad del participante, la mínima fue 30 y la máxima 59 años, siendo la edad media 38,63 años. En relación a la ansiedad, predomino el valor final sin ansiedad disfuncional con 94% (N=141), seguido de la ansiedad disfuncional en un 6% (N=9). En cuanto a la sintomatología, en mareo predominio sin ansiedad disfuncional con 89,3% (N=134), en trastorno del sueño sin ansiedad disfuncional con un 81,3% (N=122), en inmovilidad tónica sin ansiedad disfuncional con un 90,7% (N=136), en pérdida de apetito sin ansiedad disfuncional con un 92,7% (N=139) y en malestar abdominal sin ansiedad disfuncional con un 90% (N=135). Conclusiones: En cuanto a la ansiedad por coronavirus, predomino sin ansiedad disfuncional seguido de ansiedad disfuncional. De acuerdo a la sintomatología, en todas predomino el valor final sin ansiedad disfuncional.
Ansiedad durante la pandemia en ancianos de una población desfavorecida de San Juan de Lurigancho
Authors: Cosio Tapia Agustina
Published: July 2021

Objetivos: Determinar la ansiedad durante la pandemia en ancianos de una población desfavorecida de San Juan de Lurigancho. Materiales y métodos: Este estudio es de enfoque cuantitativo, de diseño descriptivo y corte transversal. La población estuvo conformada por 84 ancianos que fueron atendidas de una población desfavorecida. La técnica utilizada fue la encuesta y el instrumento de medición fue la Escala de Trastorno de Ansiedad Generalizada (TAG-7), que es conformada por 7 ítems y dos dimensiones, las cuales son: cognitivo-emocional y tensión-somática. Resultados: De acuerdo a la edad, la mínima fue 55 y máxima 96, siendo la edad media 72,65. En cuanto a la ansiedad, predomino la ansiedad moderada con 39,3% (n=33), seguido de ansiedad leve en un 32,1% (n=27), sin ansiedad con 17,9% (n=15) y ansiedad severa en un 10,7% (n=9). En relación a la dimensión cognitivo-emocional tuvo mayor predominio la ansiedad leve y moderada con 36,9% (n=31), seguido de sin ansiedad en un 16,7% (n=14) y ansiedad severa con 9,5% (n=8).  En cuanto a la dimensión tensión-somática predomino ansiedad leve en un 35,7% (n=30), seguido de ansiedad moderada con 33,3% (n=28), sin ansiedad en un 22,6% (n=19) y ansiedad severa con 8,3% (n=7). Conclusiones: En relación a la ansiedad, predomino la ansiedad moderada, seguido de ansiedad leve, sin ansiedad y ansiedad severa. En cuanto a las dimensiones, predomino la ansiedad leve, seguido de moderada, sin ansiedad y severa.
Análisis de la violencia de género en la universidad. Propuesta de intervención cualitativa
Authors: Loayza-Maturrano Edward Faustino , Vásquez León Shirley Mirella , Flores de la Cruz Heyden Neil
Published: July 2021

La situación de violencia de género que muestra nuestra sociedad se refleja también en nuestras instituciones como es el caso de la universidad. Las instituciones de educación superior universitaria no escapan a este fenómeno. Este problema puede ocurrir en la relación entre estudiantes (varón y mujer) y la relación docente-estudiante. El presente estudio tiene como propósito analizar la violencia que se suscita contra la mujer en las universidades. La investigación es de tipo cualitativa y de diseño fenomenológico desarrollado, metodológicamente, mediante un instrumento del tipo entrevista validada a través de una triangulación previa, la cual fue aplicada a grupos focales de estudiantes de ambos géneros en tres universidades. El tipo de muestreo fue por conveniencia y estuvo representado por 107 estudiantes. Los resultados muestran que existe incidencia no generalizada de la violencia de género ejercida por estudiantes varones y docentes, la cual es más significativa en los indicadores: coacción indirecta y coacción encubierta; que se sustenta en el ejercicio del poder de parte del estudiante varón de ciclos superiores y de docentes. Las conclusiones corroboran la existencia de violencia de género, cuya ocurrencia está determinada por el ejercicio de poder de estudiantes varones y docentes.
La Teleorientación: estrategia costo efectiva para la atención de personas con Hipertensión Arterial en el contexto COVID-19, Perú, 2020
Authors: Bautista Aida , Coronel Chafloque Frank Anthony , Zegarra  Chapoñan Roberto
Published: July 2021

RESUMEN

Objetivo: Analizar la Teleorientación como una estrategia costo efectivo para la atención de personas con Hipertensión Arterial (HTA) en el contexto Covid -19.

Materiales y Métodos: Artículo de reflexión sobre el análisis crítico de la teleorientación de personas con hipertensión arterial en contexto COVID-19, que resalta aspectos del marco normativo, ventajas y beneficios para los usuarios y los servicios de salud.Resultados: La teleorientación representó una estrategia costo efectiva beneficiosa en países de Sudamérica ya que permitió brindar educación, seguimiento y atención de salud oportuna al paciente con HTA, disminuyó el costo farmacológico mensual de S/. 5.76, mejoraría la calidad de vida al identificar signos y síntomas de alerta de la HTA, disminuyó la demanda laboral y costos en hospitales para el personal de salud reduciendo tiempo de espera y riesgos de contagio con enfermedades concomitantes Conclusión: Resulta adecuado considerar a la teleorientación como una medida costo efectiva en el seguimiento, tratamiento, atención y educación de las personas con HTA, debido a que podría incrementar la esperanza de vida de estos pacientes, evitar la exposición innecesaria a otras enfermedades durante la asistencia a los establecimientos de salud, disminuir la carga laboral del profesional de salud y reduciría costos del sistema de atención en salud orientados a gastos farmacológicos y horarios prolongados de espera; asimismo, constituye uno de los primeros pasos hacia la transformación digital en salud, en la cual Sudamérica aún se encuentra en proceso de desarrollo.

 

Palabras Claves: Teleorientación; hipertensión arterial, COVID-19.
Competências docentes e aprendizagem em controladoria em programas de mestrado: uma investigação da percepção discente
Authors: Walter Silvana Anita , Kremer Jhessica Tamara , De Oliveira Gomes Jéssica Karine , Priebe Anna Caroline
Published: July 2021

Objetivo: Compreender a percepção dos discentes sobre a relação entre competências docentes e aprendizado de controladoria em programas de mestrado em contabilidade no sul e sudeste do Brasil.

Metodologia: Estudo qualitativo com caráter descritivo-exploratório realizado por meio de entrevistas em profundidade. Foram entrevistados 19 alunos que concluíram a disciplina de controladoria em 9 programas de mestrado em contabilidade no sul e sudeste do Brasil. Empregou-se análise de conteúdo.

Resultados: Os alunos indicaram que a percepção sobre conhecimentos (domínio de conteúdo, experiência prática sobre organizações e experiência acadêmica), habilidades (prática pedagógica, incluindo comunicação, estratégias de ensino e método de avaliação) e atitudes (preparação das aulas; escolha dos materiais da disciplina; e relacionamento interpessoal) dos professores se relacionam com seu processo de aprendizagem. Esta diferenciação é apenas didática, pois tanto a teoria sobre competências quanto os resultados obtidos a partir das entrevistas demonstram que esses aspectos se inter-relacionam no processo de aprendizagem.

Contribuições do Estudo: Essa pesquisa pode trazer contribuições relevantes para professores e instituições avaliarem e promoverem mudanças no processo de ensino em controladoria nos programas de mestrado.
Gerenciamento de resultados e governança corporativa: uma análise a partir da adoção das IFRS no Brasil
Authors: Chacon Prata Bruno , Flach Leonardo
Published: July 2021

Objetivo: O artigo tem por objetivo analisar se a adoção das International Financial Reporting Standards (IFRS) fortaleceu a relação negativa entre gerenciamento de resultados e boas práticas de governança corporativa, sendo elas: os níveis diferenciados de governança corporativa da B3, a presença de um conselho de administração independente e se a companhia é auditada por uma Big Four.

Metodologia: Utilizou-se uma amostra de 92 empresas listadas na B3 no período de 2002-2007 para anteriormente as IFRS e 2010-2015 para o posteriormente as IFRS, sendo os dados coletados nas notas explicativas, formulário de referência e na base de dados Economática®. Para a mensuração da variável dependente gerenciamento de resultados, foi utilizado o modelo proposto por Dechow, Hutton, Kim e Sloan (2012).

Resultados: Os resultados da pesquisa sugerem que quando há a presença de um comitê administrativo independente, os níveis de gerenciamento de resultados são menores, sendo essa relação impulsionada pela adoção das IFRS. Não podemos afirmar que as empresas nos níveis mais altos de governança corporativa e auditadas por uma Big Four possuem menor incidência de gerenciamento de resultados após a aplicação das IFRS.

Contribuições do Estudo: O trabalho contribui para um melhor entendimento de como variáveis relacionadas com governança podem sim influenciar na qualidade da informação contábil-financeira. Também contribui para a literatura que investiga se as Normas Internacionais de Contabilidade influenciam ou não a qualidade da informação contábil.
As competências do contador sob a ótica dos profissionais atuantes da cidade de Vitória de Santo Antão – PE
Authors: Moura dos Santos Andreza , Nobre Gonçalves Ferreira Amorim Tania , Marques da Cunha Tácio
Published: July 2021

Objetivo: A presente pesquisa objetivou identificar quais são as competências desejáveis ao contador sob a ótica dos profissionais contábeis, que trabalham nos escritórios da cidade de Vitória de Santo Antão, em Pernambuco.

Metodologia: Realizou-se uma pesquisa de campo levantamento (survey), descritiva, com abordagem quantitativa e utilização de um questionário específico, aplicados a uma amostra de 26 escritórios de contabilidade. O estudo considerou a classificação de competências da norma estabelecida pelo IFAC International Federation of Accountants (2012), categorizadas como: intelectuais; técnicas e funcionais; pessoais; interpessoais e de comunicação; e organizacionais e de gerenciamento de negócio, bem como a utilização do conjunto de competências definidos pelos estudos de Cardoso (2006), Callado e Amorim (2017). Os dados da pesquisa foram coletados pessoalmente e por e-mail, sendo tratados com o auxílio do software Microsoft Excel, possibilitando a construção de tabelas para análise.

Resultados: As competências do contador indicadas pelos profissionais da área atuantes nos escritórios localizados na cidade de Vitória de Santo Antão, em Pernambuco, foram consoantes com aquelas previstas pelo IFAC (IES 3), destacando-as com maior nível de importância, entre as cinco categorias classificadas na referida norma: capacidade para identificar problemas, atuação em conformidade com a legislação, agir com ética e integridade, trabalhar em equipe, saber administrar e organizar bem o tempo. Repara-se uma tendência voltada para o novo papel do contador, deixando de ser visto como um mero “contador de feijão” para um “parceiro de negócio”.

Contribuições do Estudo: Identificar e compreender quais são as competências requeridas ao profissional contábil pode auxiliar no crescimento e no desenvolvimento do mesmo nas organizações, visto que ainda que existem diversas investigações sobre esta temática, é consensual o entendimento de que a competência do contador é um construto em formação, sendo assim não consolidado. Outra contribuição é apresentar para os cursos de ciências contábeis da região o que o mercado espera dos discentes, podendo estes organizar um projeto político pedagógico. Ao reconhecer quais as competências consideradas relevantes nas perspectivas dos próprios profissionais atuantes, possibilita-se discussões que busquem encontrar sugestões de melhorias para sua formação, e ainda sobre o seu papel social, ponderando mudanças no âmbito político, econômico e tecnológico.
O efeito da introdução de market makers na liquidez das ações: evidências no mercado acionário brasileiro
Authors: Carvalho Gabriel Augusto de , Eduardo Ribeiro João , Correia Laíse Ferraz
Published: July 2021

Objetivo: Este estudo teve por objetivo analisar se a introdução de market makers nas negociações das ações de empresas brasileiras listadas na bolsa de valores brasileira, é uma medida válida para a elevação da liquidez de mercado desses ativos.

Metodologia: Foi realizado o teste de quebra estrutural de Chow nas séries temporais das proxies de liquidez spread médio, índice turnover e volume financeiro, em uma amostra de 55 ativos. Optou-se por considerar dados na janela de 260 dias antes e 260 dias após o início da atuação do market maker, por representar o número aproximado de pregões em um ano, e por evitar conclusões errôneas devido à volatilidade do mercado brasileiro.

Resultados: Os resultados evidenciaram que após a introdução dos market makers e considerado um nível de confiança de 99%, 67% dos ativos estudados tiveram mudanças abruptas e estatisticamente significativas no spread médio, 47% apresentaram mudanças abruptas no turnover e 60% tiveram mudanças no volume de negociação. Flexibilizando o nível de confiança para 95%, 76% dos ativos estudados apresentaram mudanças abruptas no spread médio, 65% tiveram mudanças no turnover e 69% apresentaram mudanças no volume de negociações. Ao nível de confiança de 90%, os resultados encontrados foram de 85% dos ativos apresentando mudanças abruptas no spread médio, 78% apresentando mudanças no turnover e 73% apresentando mudanças abruptas e estatisticamente significativas no volume negociado.

Contribuições do Estudo: Esse quadro fornece portanto, fortes evidências sobre a atuação dos market makers e a influência que esses agentes exercem na liquidez de mercado dos ativos negociados pela bolsa de valores brasileira, ao demostrar que, a sua contratação pode aumentar a liquidez e contribuir de forma significativa com as negociações dos ativos.