bluuebunny/crossref_metadata_2025 huggingface dataset:
What matters most and for whom? A cross-sectional study exploring goals of health professionals in German neonatal intensive care units
Authors: Mensen Anne , Roth Bernhard , Kuntz Ludwig , Wittland Michael , Glöckner Verena , Miedaner Felix
Published: March 2021

Objectives

Quality of care largely depends on successful teamwork, which in turn needs effective communication between health professionals. To communicate successfully in a team, health professionals need to strive for the same goals. However, it has been left largely unaddressed which goals professionals consider to be important. In this study, we aim to identify these goals and analyse whether differences between (1) personal and organisational goals, (2) different professions and (3) hierarchical levels exist in neonatal intensive care units (NICUs).

Design

Goals were identified based on a literature review and a workshop with health professionals and tested in a pilot study. Subsequently, in the main study, a cross-sectional employee survey was undertaken.

Setting and participants

1489 nurses and 537 physicians from 66 German NICUs completed the questionnaire regarding personal and organisational goal importance between May and July 2013. Answers were given based on a 7-point Likert scale varying between none and exceptionally high importance.

Results

Results show that the goals can be subdivided into three main goal dimensions: patients, parents and staff. Furthermore, our results reveal significant differences between different professions and different hierarchical level: physicians rated patient goals with a mean (95% CI) importance of 6.37 (6.32 to 6.43), which is significantly higher than nurses with a mean (95% CI) importance of 6.15 (6.12 to 6.19) (p<0.01). Otherwise, nurses classified parental goals as more important (p<0.01). Furthermore, professionals in leading positions rate patient goals significantly higher than professionals that are not in leading positions (6.36 (6.28 to 6.44) vs 6.19 (6.15 to 6.22), p<0.01).

Conclusions

Different employee goals need to be considered in decision-making processes to enhance employee motivation and the effectiveness of teamwork.

Trial registration number

DRKS00004589.
Decision Analysis in SHared decision making for Thromboprophylaxis during Pregnancy (DASH-TOP): a sequential explanatory mixed methods pilot study protocol
Authors: Humphries Brittany , León-García Montserrat , Bates Shannon , Guyatt Gordon , Eckman Mark , D"Souza Rohan , Shehata Nadine , Jack Susan , Alonso-Coello Pablo , Xie Feng
Published: March 2021

Introduction

Decision analysis is a quantitative approach to decision making that could bridge the gap between decisions based solely on evidence and the unique values and preferences of individual patients, a feature especially important when existing evidence cannot support clear recommendations and there is a close balance between harms and benefits for the treatments options under consideration. Low molecular weight heparin (LMWH) for the prevention of venous thromboembolism (VTE) during pregnancy represents one such situation. The objective of this paper is to describe the rationale and methodology of a pilot study that will explore the application of decision analysis to a shared decision-making process involving prophylactic LMWH for pregnant women or those considering pregnancy who have experienced a VTE.

Methods and analysis

We will conduct an international, mixed methods, explanatory, sequential study, including quantitative data collection and analysis followed by qualitative data collection and analysis. In step I, we will ask women who are pregnant or considering pregnancy and have experienced VTE to participate in a shared decision-making intervention for prophylactic LMWH. The intervention consists of three components: a direct choice exercise, a values elicitation exercise and a personalised decision analysis. After administration of the intervention, we will ask women to make a treatment decision and measure decisional conflict, self-efficacy and satisfaction. In step II, which follows the analysis of quantitative data, we will use the results to inform the qualitative interview. Step III will be a qualitative descriptive study that explores participants’ experiences and perceptions of the intervention. In step IV, we will integrate findings from the qualitative and quantitative analyses to obtain meta-inferences.

Ethics and dissemination

Site-specific ethics boards have approved the study. All participants will provide informed consent. The research team will take an integrated approach to knowledge translation.
Beyond PPE: a mixed qualitative–quantitative study capturing the wider issues affecting doctors’ well-being during the COVID-19 pandemic
Authors: Cubitt Lyndsey Jayne , Im Yu Ri , Scott Ciaran James , Jeynes Louise Claire , Molyneux Paul David
Published: March 2021

The COVID-19 pandemic has brought unprecedented challenges to the medical workforce. This has put them at increased risk of burnout at a time when levels are already worryingly high in the profession, with recent studies consistently showing that around half of doctors meet the validated criteria for burnout.

Objectives

To understand the wider factors influencing and impacting upon hospital doctors’ well-being during the COVID-19 pandemic in England.

Design

Cross-sectional survey and mixed quantitative–qualitative analysis.

Setting

Acute National Health Service (NHS) Foundation Trust in England.

Participants

An online survey was circulated in early June 2020 to all 449 doctors employed by the Trust. 242 doctors completed the survey (54% response rate).

Primary outcome measures

Questions assessed occupational details, self-reported changes in physical and mental health, satisfaction with working hours and patterns, availability of personal protective equipment (PPE), medication and facilities, communication and sought to identify areas seen as having a significant effect on doctors’ well-being.

Results

96% of respondents requiring PPE were able to access it. Nearly half of the respondents felt that their mental health had deteriorated since the start of the pandemic. Over a third stated that their physical health had also declined. Issues identified as having a negative impact on doctors included increased workload, redeployment, loss of autonomy, personal issues affecting family members, anxiety around recovery plans, inadequate access to changing and storage facilities and to rest areas that allow for social distancing. Doctors appreciated access to ‘calm rooms’ that were made available for staff, access to clinical psychology support, free drinks and free car parking on site.

Conclusion

The emerging themes are suggestive of increased burnout risk among doctors during the COVID-19 pandemic and encompass factors well beyond shortage of PPE. Small organisational initiatives and the implementation of changes suggested by survey respondents can have a positive impact on doctors’ well-being.
Regorafenib enhances antitumor immunity via inhibition of p38 kinase/Creb1/Klf4 axis in tumor-associated macrophages
Authors: Ou Da-Liang , Chen Chia-Wei , Hsu Chia-Lang , Chung Chih-Hung , Feng Zi-Rui , Lee Bin-Shyun , Cheng Ann-Lii , Yang Muh-Hwa , Hsu Chiun
Published: March 2021

Background

Regorafenib and other multikinase inhibitors may enhance antitumor efficacy of anti-program cell death-1 (anti-PD1) therapy in hepatocellular carcinoma (HCC). Its immunomodulatory effects, besides anti-angiogenesis, were not clearly defined.

Methods

In vivo antitumor efficacy was tested in multiple syngeneic liver cancer models. Murine bone marrow–derived macrophages (BMDMs) were tested in vitro for modulation of polarization by regorafenib and activation of cocultured T cells. Markers of M1/M2 polarization were measured by quantitative reverse transcription PCR (RT-PCR), arginase activity, flow cytometry, and ELISA. Knockdown of p38 kinase and downstream Creb1/Klf4 signaling on macrophage polarization were confirmed by using knockdown of the upstream MAPK14 kinase, chemical p38 kinase inhibitor, and chromatin immunoprecipitation.

Results

Regorafenib (5 mg/kg/day, corresponding to about half of human clinical dosage) inhibited tumor growth and angiogenesis in vivo similarly to DC-101 (anti-VEGFR2 antibody) but produced higher T cell activation and M1 macrophage polarization, increased the ratio of M1/M2 polarized BMDMs and proliferation/activation of cocultured T cells in vitro, indicating angiogenesis-independent immunomodulatory effects. Suppression of p38 kinase phosphorylation and downstream Creb1/Klf4 activity in BMDMs by regorafenib reversed M2 polarization. Regorafenib enhanced antitumor efficacy of adoptively transferred antigen-specific T cells. Synergistic antitumor efficacy between regorafenib and anti-PD1 was associated with multiple immune-related pathways in the tumor microenvironment.

Conclusion

Regorafenib may enhance antitumor immunity through modulation of macrophage polarization, independent of its anti-angiogenic effects. Optimization of regorafenib dosage for rational design of combination therapy regimen may improve the therapeutic index in the clinic.
Higher postoperative plasma EV PD-L1 predicts poor survival in patients with gastric cancer
Authors: Li Gaopeng , Wang Guoliang , Chi Fenqing , Jia Yuqi , Wang Xi , Mu Quankai , Qin Keru , Zhu Xiaoxia , Pang Jing , Xu Baixue , Feng Guangen , Niu Yuhu , Gong Tao , Zhang Hongwei , Dong Xiushan , Liu Ting , Ma Jinfeng , Gao Zefeng , Tao Kai , Li Feng , Xu Jun , Yu Baofeng
Published: March 2021

Background

The satisfactory prognostic indicator of gastric cancer (GC) patients after surgery is still lacking. Perioperative plasma extracellular vesicular programmed cell death ligand-1 (ePD-L1) has been demonstrated as a potential prognosis biomarker in many types of cancers. The prognostic value of postoperative plasma ePD-L1 has not been characterized.

Methods

We evaluated the prognostic value of preoperative, postoperative and change in plasma ePD-L1, as well as plasma soluble PD-L1, in short-term survival of GC patients after surgery. The Kaplan-Meier survival model and Cox proportional hazards models for both univariate and multivariate analyzes were used. And the comparison between postoperative ePD-L1 and conventional serum biomarkers (carcinoembryonic antigen (CEA), cancer antigen 19–9 (CA19-9) and CA72-4) in prognostic of GC patients was made.

Results

The prognostic value of postoperative ePD-L1 is superior to that of preoperative ePD-L1 on GC patients after resection, and also superior to that of conventional serum biomarkers (CEA, CA19-9 and CA72-4). The levels of postoperative ePD-L1 and ePD-L1 change are independent prognostic factors for overall survival and recurrence free survival of GC patients. High plasma level of postoperative ePD-L1 correlates significantly with poor survival, while high change in ePD-L1 level brings the significant survival benefit.

Conclusions

The level of plasma postoperative ePD-L1 could be considered as a candidate prognostic biomarker of GC patients after resection.
Breather degeneration and lump superposition for the (3 + 1)-dimensional nonlinear evolution equation
Authors: Tan Wei , Li Miao
Published: March 2021

This paper is devoted to the study of a (3 + 1)-dimensional generalized nonlinear evolution equation for the shallow-water waves. The breather solutions with different structures are obtained based on the bilinear form with perturbation parameters. Some new lump solitons are found in the process of studying the degradation behavior of breather solutions, and we also study general lump soliton, lumpoff solution and superposition phenomenon between lump soliton and breather solution. Besides, some theorems about the superposition between lump soliton and [Formula: see text]-soliton ([Formula: see text] is a nonnegative integer) are given. Some examples, including lump-[Formula: see text]-exponential type, lump-[Formula: see text]-logarithmic type, higher-order lump-type [Formula: see text]-soliton, are given to illustrate the correctness of the theorems and corollaries described. Finally, some novel nonlinear phenomena, such as emergence of lump soliton, degeneration of breathers, fission and fusion of lumpoff, superposition of lump-[Formula: see text]-solitons, etc., are analyzed and simulated.
The symplectic structure for renormalization of circle diffeomorphisms with breaks
Authors: Ghazouani S. , Khanin K.
Published: March 2021

The main goal of this paper is to reveal the symplectic structure related to renormalization of circle maps with breaks. We first show that iterated renormalizations of [Formula: see text] circle diffeomorphisms with [Formula: see text] breaks, [Formula: see text], with given size of breaks, converge to an invariant family of piecewise Möbius maps, of dimension [Formula: see text]. We prove that this invariant family identifies with a relative character variety [Formula: see text] where [Formula: see text] is a [Formula: see text]-holed torus, and that the renormalization operator identifies with a sub-action of the mapping class group [Formula: see text]. This action allows us to introduce the symplectic form which is preserved by renormalization. The invariant symplectic form is related to the symplectic form described by Guruprasad et al. [Group systems, groupoids, and moduli spaces of parabolic bundles, Duke Math. J. 89(2) (1997) 377–412], and goes back to the earlier work by Goldman [The symplectic nature of fundamental groups of surfaces, Adv. Math. 54(2) (1984) 200–225]. To the best of our knowledge the connection between renormalization in the nonlinear setting and symplectic dynamics had not been brought to light yet.
The Devonian landscape factory: plant–sediment interactions in the Old Red Sandstone of Svalbard and the rise of vegetation as a biogeomorphic agent
Authors: Davies Neil S. , Berry Christopher M. , Marshall John E.A. , Wellman Charles H. , Lindemann Franz-Josef
Published: March 2021

The Devonian Period was a crucial interval in the evolution of plants. During its 60 myr duration, it witnessed the successive evolution of roots, wood, trees and forests. In addition, many of the biogeomorphic phenomena that operate in modern terrestrial environments came online for the first time. The ‘Old Red Sandstone’ of Svalbard consists of a near-continuous Silurian to Late Devonian record of sedimentary environments colonized by land plants and provides a perfect natural laboratory to aid our understanding of the facies signatures and evolution of these phenomena. We describe and illustrate a catalogue of ‘Old Red Sandstone’ features that provide evidence for the stepwise appearance of novel plant–sediment interactions, including preserved plant material and rooting structures, early large woody debris accumulations, cannel coal deposits and the oldest known vegetation-induced sedimentary structures, in addition to vegetation-influenced motifs of elevated mudrock content and complex alluvial sand bodies. These characteristics are combined to reconstruct changes to non-marine environments in this Devonian ‘landscape factory’. In addition to tectonic and climate influences, plant evolution first served as a control on the construction of the sedimentary record during this period and has persisted as a fundamental influence on Earth surface processes and landforms ever since.
Identity-based Encryption from the Diffie-Hellman Assumption
Authors: Döttling Nico , Garg Sanjam
Published: March 2021

We provide the first constructions of identity-based encryption and hierarchical identity-based encryption based on the hardness of the (Computational) Diffie-Hellman Problem (without use of groups with pairings) or Factoring. Our construction achieves the standard notion of identity-based encryption as considered by Boneh and Franklin [CRYPTO 2001]. We bypass known impossibility results using garbled circuits that make a non-black-box use of the underlying cryptographic primitives.
Osteocyte- and late osteoblast-derived NOTUM reduces cortical bone mass in mice
Authors: Nilsson Karin H. , Henning Petra , El Shahawy Maha , Wu Jianyao , Koskela Antti , Tuukkanen Juha , Perret Christine , Lerner Ulf H. , Ohlsson Claes , Movérare-Skrtic Sofia
Published: March 2021

NOTUM produced by osteoblasts is known to regulate cortical bone mass. Our new findings show that NOTUM specifically derived by DMP1-expressing osteocytes and late osteoblasts regulates cortical bone mass and not trabecular bone mass.
Deep Neural Network for Somatic Mutation Classification
Authors: Wang Haifeng , Wang Chengche , Qu Hongchun
Published: March 2021

The detection and characterization of somatic mutations have become the important means to analyze the occurrence and development of cancer and, ultimately, will help to select effective and precise treatment for specific cancer patients. It is very difficult to detect somatic mutations accurately from the massive sequencing data. In this paper, a forest-graph-embedded deep feed-forward network (forgeNet) is utilized to detect somatic mutations from the sequencing data. In forgeNet, the random forest (RF) or Gradient Boosting Machine (GBM) and graph-embedded deep feed-forward network (GEDFN) are utilized to extract features and implement classification, respectively. Three real somatic mutation datasets collected from 48 triple-negative breast cancers are utilized to test the somatic mutation detection performances of forgeNet. The detection results show that forgeNet could make the 0.05%–0.424% improvements in terms of area under the curve (AUC) compared with support vector machines and random forest.
Production Constraints and Improvement Strategies of Cowpea (Vigna unguiculata L. Walp.) Genotypes for Drought Tolerance
Authors: Nkomo Gabriel V. , Sedibe Moosa M. , Mofokeng Maletsema A.
Published: March 2021

Cowpea (Vigna unguiculata L. Walp. L) is an important leguminous crop largely grown by smallholder farmers in sub-Saharan Africa for food security and animal feed. The objective of this study was to review the production constraints and improvement strategies of cowpea genotypes for drought tolerance. Data were analysed through use of literature review from various sources. In sub-Saharan Africa, cowpeas are produced mainly from West Africa, which accounts for 60% of worldwide production. A lot of pests and diseases affect cowpeas, and this often results in total crop loss. Through continuous improvement, many new cultivars are continually being identified and genetically characterised, and it is thus necessary to evaluate these new lines under different environments. There is a need for multidisciplinary collaborations among breeders and other relevant stakeholders such as farmer and extension workers because the improved cultivars must be according to the farmers preferred traits. Due to declining rainfall pattern in sub-Saharan Africa, there is an urgent requirement for cowpea breeding programmes that focus on developing varieties with short maturity, drought, pest, and disease tolerance. The present review discusses the constraints and improvement strategies of cowpea varieties for drought tolerance.
M-Polynomials and Topological Indices for Line Graphs of Chain Silicate Network and H-Naphtalenic Nanotubes
Authors: Irfan Muhammad , Rehman Hamood Ur , Almusawa Hassan , Rasheed Saffina , Baloch Imran Abbas
Published: March 2021

Graph theory has provided a very useful tool, called topological index, which is a number from the graph M with the property that every graph N isomorphic to M value of a topological index must be same for both M and N. Topological index is a descriptor in graph theory which is used to quantify the physio-chemical properties of the chemical graph. In this paper, we computed closed forms of M-polynomials for line graphs of H-naphtalenic nanotubes and chain silicate network. From M-polynomial, we obtained some topological indices based on degrees.
High-Frequency and Low-Intensity Patterned Transcranial Magnetic Stimulation over Left Dorsolateral Prefrontal Cortex as Treatment for Major Depressive Disorder: A Report of 3 Cases
Authors: Castillo-Aguilar Lizbeth , Ríos-Ponce Alma E. , Albano de Mendonca Edson , Villafuerte Gabriel
Published: March 2021

Current transcranial magnetic stimulation devices apply intense (near 1 tesla) repetitive magnetic pulses over a specific area of the skull at relatively lower frequencies (1-50 Hz). Nevertheless, different studies have shown that very small magnetic fields, at higher frequencies (50-1000 Hz.), produce therapeutic effects in major depressive disorder. We report the application of high-frequency and low-intensity patterned magnetic pulses over the left prefrontal dorsolateral cortex in three subjects diagnosed with clinical major depressive disorder. All three patients showed sharp changes in their self-reports as well as in the standardized clinical assessment. Hypothesized mechanisms of action of this new variant of magnetic stimulation are discussed.
Experimental Investigation into Compressive Behaviour and Preconsolidation Pressure of Structured Loess at Different Moisture Contents
Authors: Xu Yali , Guo Panpan , Zhu Chengwei , Lei Gang , Cheng Kang
Published: March 2021

This paper investigates the influence of the structured property of loess on its compressive behaviour and proposes a new method for determining the preconsolidation pressure of structured loess soil. A series of oedometer tests were carried out on undisturbed and remoulded loess samples prepared at various moisture contents. The effects of moisture content on the structured yield stress, the preconsolidation pressure, and the structural strength were also captured. It was found that the influence of the structured property of loess on the compression behaviour is divergent between undisturbed and remoulded loess samples. The discrepancy before and after structural yielding is more remarkable for the undisturbed soil. The Casagrande method realized through the MATLAB program can effectively eliminate human factors and accurately calculate the corresponding preconsolidation pressure for undisturbed soil. The effects of moisture content on the method for determining the preconsolidation pressure considering the structured property of loess were discussed. The determination method can accurately evaluate the loess consolidation state in loess regions. The influencing rules which the moisture content exerts on the structured yield stress, the preconsolidation pressure, and the structural strength all conform to exponential functions. The study is of great significance to correctly differentiating the foundation consolidation states and calculating the ground settlement in loess regions.
“Internet + Artificial Intelligence” Human Resource Information Management System Construction Innovation and Research
Authors: Zeng Zhen , Qi Longqi
Published: March 2021

Human resources are the cornerstone of operational operation. Good management of human resource information can enable businesses to operate effectively. However, for the time being, most enterprises still use traditional methods of allocating human resources, which are difficult to meet the development needs of enterprises. In order to find the optimal allocation of human resources in an enterprise, this article is based on “Internet + artificial intelligence,” using methods such as case analysis and literature analysis to collect data from databases such as CNKI, Wanfang Database, and SSCI, and uses fog computing to build a model for the optimal allocation of human resources which is proposed, and a large number of relevant literature studies are read and analyzed through the literature survey method. According to the research needs, through the research and summary of the content of the literature, the research structure found that there are many problems in the current human resource information management system. After the optimization of models and algorithms, the allocation of human resources has been greatly improved. The matching rate of personnel and job positions has increased by more than 50%. The operation efficiency index of the enterprise is above 0.8, an increase of about 30%. This shows that “Internet + artificial intelligence” can effectively optimize the enterprise human resource information management system, promote the greater use of its human resource value, bring higher economic returns to the enterprise, and provide assistance for the long-term stable and healthy development of the enterprise.
An Efficient Solid-Phase Extraction-Based Liquid Chromatography Method to Simultaneously Determine Diastereomers α-Tocopherol, Other Tocols, and Retinol Isomers in Infant Formula
Authors: Huang Baifen , Cai Zengxuan , Zhang Jingshun , Xu Jiaojiao
Published: March 2021

The separation and simultaneous quantitation of diastereomers of DL-α-tocopherol, eight tocol forms, and retinols (trans and cis) have been conducted by reversed-phase liquid chromatography followed by solid-phase extraction. A chiral silica stationary phase modified with polysaccharide derivative on the monodisperse macroporous silica gel (Unichiral OD-5H column, 150 mm × 4.6 mm, 5 μm, NanoMicro Technology Co., Ltd.) was employed for eluting each target compound. Instead of conventional solvent extract, a green and eco-friendly solid-phase extraction column, packing with nonpolar polystyrene divinylbenzene, was optimized in terms of capacity and solvent used in steps. Validation of the method was examined and confirmed to be satisfactory, with excellent linearity regression (r > 0.9999), acceptable accuracy (74.66%∼112.92%), and precision (0.20%∼10.52%) results. Limit of detection ranged from 0.05 mg·kg−1 (retinols) to 0.4 mg·kg−1 (tocols). The method was checked by infant formula reference material SRM 1849a as well, which illustrated good agreement of mass fraction with certified value and enriched the important isomer data.
Reliability Estimation under Scarcity of Data: A Comparison of Three Approaches
Authors: Leoni Leonardo , Cantini Alessandra , BahooToroody Farshad , Khalaj Saeed , De Carlo Filippo , Abaei Mohammad Mahdi , BahooToroody Ahmad
Published: March 2021

During the last decades, the optimization of the maintenance plan in process plants has lured the attention of many researchers due to its vital role in assuring the safety of operations. Within the process of scheduling maintenance activities, one of the most significant challenges is estimating the reliability of the involved systems, especially in case of data scarcity. Overestimating the average time between two consecutive failures of an individual component could compromise safety, while an underestimate leads to an increase of operational costs. Thus, a reliable tool able to determine the parameters of failure modelling with high accuracy when few data are available would be welcome. For this purpose, this paper aims at comparing the implementation of three practical estimation frameworks in case of sparse data to point out the most efficient approach. Hierarchical Bayesian modelling (HBM), maximum likelihood estimation (MLE), and least square estimation (LSE) are applied on data generated by a simulated stochastic process of a natural gas regulating and metering station (NGRMS), which was adopted as a case of study. The results identify the Bayesian methodology as the most accurate for predicting the failure rate of the considered devices, especially for the equipment characterized by less data available. The outcomes of this research will assist maintenance engineers and asset managers in choosing the optimal approach to conduct reliability analysis either when sufficient data or limited data are observed.
Experimental Investigation of Water‐Sand Mixed Fluid Initiation and Migration in Filling Fracture Network during Water Inrush
Authors: Yang Bin , Yang Tianhong
Published: March 2021

For water inrush induced by fracture network flow, the critical velocity of the incipient motion of sand particles was obtained, and the functional relation between critical velocity and particle size was established through a series of tests on the nonlinear flow characteristics of a filling fracture network. The influence of the particle size distribution, hydrodynamic force, and geometric features of the fracture network on the characteristics of particle loss; distribution laws; and water‐sand, two‐phase migration was also explored. Moreover, the interactions amongst water, movable particles, the surface of the skeleton, and fracture walls, and the formation mechanism of the flow channel were qualitatively analyzed. In addition, the change rules of the mass loss characteristics and porosity of the samples with time were tested successfully. The calculation methods of the permeability and non‐Darcy factor of the filling fracture network were also determined.
Research on the Progress of Interdigital Transducer (IDT) for Structural Damage Monitoring
Authors: Ziping Wang , Xiqiang Xiong , Lei Qian , Jiatao Wang , Yue Fei , Maoyuan Tian
Published: March 2021

In the application of Structural Health Monitoring (SHM) methods and related technologies, the transducer used for electroacoustic conversion has gradually become a key component of SHM systems because of its unique function of transmitting structural safety information. By comparing and analyzing the health and safety of large‐scale structures, the related theories and methods of Structural Health Monitoring (SHM) based on ultrasonic guided waves are studied. The key technologies and research status of the interdigital guided wave transducer arrays which used for structural damage detection are introduced. The application fields of interdigital transducers are summarized. The key technical and scientific problems solved by IDT for Structural Damage Monitoring (SHM) are presented. Finally, the development of IDT technology and this research project are summarised.
The Phase Shifting Soft Startup of L-LLC Resonant Bidirectional DC-DC Converter Based on Current-Limiting Curve
Authors: Lu Jing , Tong Xiangqian , Shen Ming , Yin Jun , Yuan Yongtao
Published: March 2021

The new L-LLC resonant bidirectional DC-DC converter (L-LLC-BDC) will produce a large resonance current and voltage inrush during the startup, posing a threat to the safe operation of the power device. Although a very high starting frequency can effectively suppress the inrush, it will also increase the output current demand of the driving ICs. This paper proposes a phase-shifting soft-start control strategy based on the current-limiting curve. Using operating mode analysis, the peak value of the resonant current is limited according to the output voltage and the phase shift angle of the switch, with the limit current curve at the startup stage drawn. By this current curve, a one-to-one correspondence between the output voltage and the phase shift angle of the switch is obtained. The phase-shifted soft-start control strategy can quickly establish the output voltage on the basis of a resonant frequency and can effectively suppress the resonance current inrush. An experimental prototype with a power of 6 kW and an input of 760 V and an output of 380 V is built. The experimental results prove the correctness and effectiveness of the soft start control strategy proposed in this paper.
Global Trends of Green Pesticide Research from 1994 to 2019: A Bibliometric Analysis
Authors: Smith Hein Hendrik , Idris Oladayo Amed , Maboeta Mark Steve
Published: March 2021

The fast-growing world population places food production under enormous pressure to ensure food security. One of the most common methods to increase food production is the use of pesticides, but the continuous use thereof has numerous detrimental effects on the environment. The interest in biopesticides for a possible substitute has grown over the past two decades. To determine the research evolution of biopesticides (green pesticides), a bibliometric analysis from 1994 to 2019 was carried out. A total of 580 documents were found eligible in the Scopus database for this analysis. Parameters such as the number of articles, article citations, keywords, source impact, and countries of publication were used to analyse the documents and rank countries based on authors, productivity, article citations, and co-authorship. The analysis reveals production increased significantly from 2009 and has the most published documents in 2019 with a total of 74 articles. Asia’s most populous countries, India and China, were ranked first and second, respectively, and the USA third in terms of the most productive countries in the field of plant biopesticides. Countries in Europe and Africa however have fewer publications than expected in this field, given the fact that they are high consumers of pesticides. India, China, and the USA have 4.08%, 2.94%, and 12.5% multiple country publications (MCPs), respectively, with the USA having a stronger collaboration. Finally, there is a clear indication in this study that India and China are taking the lead in substituting synthetic pesticides with the alternative natural plant biopesticide.
Coupling Coordination and Prediction Research of Tourism Industry Development and Ecological Environment in China
Authors: Yang Yun , Wang Rong , Tan Junlan
Published: March 2021

Based on the data relevant to China’s tourism industry and ecological environment from 2005 to 2018, the entropy method and the coupling coordination degree model were used to analyze the coupling degree and coupling coordination degree of the tourism industry’s development and the ecological environment, and the GM (1.1) gray model was used to predict these values in the future. The model provided predictions and illustrated the trend in the changes in the degree of coordination between the development of China’s tourism industry and the ecological environment for the next five years. The results show the following. (1) The coupling degree between China’s tourism industry and the ecological environment was between 0.3 and 0.5. It was in the low-level coupling stage in 2005 and 2006 and generally low in 2005–2009, lower than the average level of 0.4204. In 2018, the coupling degree between the development of China’s tourism industry and the ecological environment was mainly in a stage of antagonism, reaching a peak of 0.4998 in 2013. The coupling degree declined slightly from 2013 to 2015 and then began to show an upward trend again in 2016. (2) The average coupling coordination level of China’s tourism industry development and ecological environment was 0.4266, which is in the medium coupling coordination stage. From 2007 to 2013, it was mainly in the phase of moderate coupling and coordination and high coupling and coordination from 2014 to 2018. (3) From the prediction results, the coupling degree will enter the coupling degree running-in stage in 2021 and the extreme coordination stage in 2023, but the coupling growth level during the running-in period will be significantly lower than the coupling coordination degree. Coordinated development of the two systems will take a long time, and active economic policies need to be adopted to promote their coordinated development.
COPB2: A Novel Prognostic Biomarker That Affects Progression of HCC
Authors: Zhang Jiayao , Wang Xiaoyu , Li Guangbing , He Jingyi , Lu Ziwen , Yang Yang , Jiang Yong , Jiang Liyong , Li Feiyu , Liu Jun
Published: March 2021

Purpose. This study is aimed at investigating the expression, underlying biological function, and clinical significance of coatomer protein complex subunit beta 2 (COPB2) in hepatocellular carcinoma (HCC). Methods. HCC‐related data were extracted from The Cancer Genome Atlas (TCGA) database, International Cancer Genome Consortium (ICGC) database, and Gene Expression Omnibus (GEO) database. A logistic regression module was applied to analyze the relationship between the expression of COPB2 and clinicopathologic characteristics. The Cox proportional hazard regression model and Kaplan–Meier method were used for survival analysis. Gene set enrichment analysis (GSEA) was used to annotate the underlying biological functions. Loss‐of‐function experiments were conducted to determine the underlying mechanisms. Results. COPB2 was overexpressed in HCC, and high expression of COPB2 was significantly correlated with higher alpha fetoprotein (AFP) (odds ratio (OR) = 1.616, >20 vs. ≤20, p < 0.05), stage (OR = 1.744, III vs. I, p < 0.05), and grade (OR = 1.746, G4+G3 vs. G2+G1, p < 0.05). Kaplan–Meier survival analysis showed that HCC patients with high COPB2 expression had a worse prognosis than those with low COPB2 expression (p < 0.0001 for TCGA cohort, p < 0.05 for ICGC cohort). The univariate Cox (hazard ratio (HR) = 1.068, p < 0.0001) and multivariate Cox (HR = 2.011, p < 0.05) regression analyses suggested that COPB2 was an independent risk factor. GSEA showed that mTOR and other tumor‐related signaling pathways were differentially enriched in the high COPB2 expression phenotype. Silencing of COPB2 inhibited the proliferation, migration, and invasion abilities by suppressing epithelial‐mesenchymal transition and mTOR signaling. Conclusion. COPB2 is a novel prognostic biomarker and a promising therapeutic target for HCC.
Experimental Study on Reasonable Spacing after Carbon Dioxide Presplitting in Low‐Permeability Coal Seam
Authors: Wei Zongyong , Li Shugang , Lin Haifei , Li Botao , Ding Yang , Shuang Haiqing
Published: March 2021

Gas disasters have been always a major hidden danger that affects mining safety in coal mines. Gas drainage by drilling is the fundamental method of gas control in coal mines. In view of the low‐permeability coal seam, it is the basis of the safe and efficient production of the mine to take the measures of enhancing the permeability, improving the gas drainage efficiency, and shortening the drainage time. The 4−2 coal seam of the Jianxin coal mine in Shaanxi Province of China is a low‐permeability coal seam. In order to obtain the reasonable hole spacing and the reasonable extraction time after the penetration enhancement, the pressure drop method is used to investigate the extraction radius. The results show that the gas pressure around the test hole decreases with time as a negative exponential function, and the effective radius of extraction increases with the increase of extraction time as a logarithmic function. Through the comparative analysis and variance analysis of the test data of the two drilling fields, it is proved that the data of the drainage radius of the two drilling fields are accurate and reliable. It is obtained that the reasonable spacing of the gas drainage holes is 8.10 m and the reasonable drainage time is 180 days after CO2 presplitting and permeability increase in the 4−2 coal seam of the mine.
Dolichocolon Presenting with Bilateral Hydronephrosis in a Neonate
Authors: Gielen Laura , Raaijmakers Anke , De Groote Bert , ter Haar Eva
Published: March 2021

Background. Dolichocolon is an inborn anatomic variant of the colon with redundancies often causing constipation and/or volvulus presenting in childhood, adolescence, or adulthood. To the best of our knowledge, this is the first case of dolichocolon presenting in infancy with constipation and bilateral hydronephrosis. Case Presentation. A nineteen-day-old neonate presented to the emergency department with severe constipation and discomfort. During his admission, he developed pyelonephritis, and subsequent ultrasound of the kidneys and bladder showed bilateral hydroureteronephrosis. A barium enema was performed and it showed a dolichocolon. Enemas and lactulose were initiated with good effect on both the constipation as well as the hydronephrosis. Conclusions. Dolichocolon in a neonate can cause severe constipation which could also lead to an obstructive nephropathy if untreated. Monitoring of urine flow might be indicated when a neonate presents with severe constipation.
Statistical Modeling of Farmers’ Preference for Adaptation Strategies for Climate Change: The Case of Dera District, Oromia, Ethiopia
Authors: Belachew Tadesse Ayele , Ababu Dereje Gebeyehu
Published: March 2021

Climate change is primarily detrimental to the agriculture sector and the influence of climate change is decreased by using appropriate adaptation strategies. Studies on climate change adaptation recognize the importance of specific area-based research for designing policies to respond to climate change. This study, therefore, was applied at the district level to examine farmers’ preference for climate change adaptation strategies and the factors determining their preference. The objective of this study is to identify and model factors that influence farmers’ preference of adaptation strategies to counter the impacts of climate change in the case of Dera District, North Shoa, Oromia, Ethiopia. Cross-sectional study design was used with the questionnaire being administered on a multistage sample of 460 households from selected kebeles in the district. Descriptive statistics, multinomial logit, and count regression analysis were used to analyze the collected data. The study revealed that the farmers perceived that temperature had been increasing and rainfall had been decreasing over the last 10 years. The results also indicated that planting trees was the most preferred and frequently applied adaptation strategy to climate change while changing planting dates was the least. The results from the multinomial logit, Poisson regression, and negative binomial analysis showed that age, source of information, household size, education level of household head, distance to output market, distance to input market, agroecological locations of the farm, tropical livestock unit, size of the farm, tenure, grade of the farm, distance of the farm, formal extension service, farmer-to-farmer extension, credit service, rainfall expectation, and temperature expectations were significant factors in determining the adaptation strategies preferred by the farmers.
Analyzing and Estimating Thermal Conductivity of Sedimentary Rocks from Mineral Composition and Pore Property
Authors: Tang Boning , Zhu Chuanqing , Qiu Nansheng , Cui Yue , Guo Sasa , Luo Xin , Zhang Baoshou , Li Kunyu , Li Wenzheng , Fu Xiaodong
Published: March 2021

In this study, thermal conductivities of 128 rock samples located in the Xiong’an New Area and Tarim Basin were measured using the optical scanning and transient plane source methods. The thermal conductivities of the Xiong’an New Area samples range from 1.14 to 6.69 W/(m·K), in which the mean thermal conductivities of dolomite and sandstone are

4.95
±
1.19

and

1.80
±
0.44
 
W
/

m
·
K

, respectively. In the Tarim Basin, sandstone samples have thermal conductivities ranging from 1.21 to 3.56 W/(m·K) with a mean value of

2.51
±
0.66
 
W
/

m
·
K

. The results can provide helpful reference data for studies of geothermics and petroleum geology. Calculation correction and water-saturated measurements were conducted to acquire in situ rock thermal conductivity, and good consistency was found between both. Compaction diagenesis enhances bulk thermal conductivity of sedimentary rocks, particularly sandstones, by decreasing the rock porosity and mineral particle size. Finally, correction factors with respect to mineral grains were proposed to correct the thermal resistance of intergrain contacts and degree of intactness of crystals, and an optimized formula was adopted to calculate the thermal conductivity of sedimentary rock based on rock structure and mineral constituents.
A Robust Fault‐Tolerant Control for Quadrotor Helicopters against Sensor Faults and External Disturbances
Authors: Wang Ban , Huang Peng , Zhang Wei
Published: March 2021

This paper presents an active fault‐tolerant control strategy for quadrotor helicopters to simultaneously accommodate sensor faults and external disturbances. Unlike most of the existing fault diagnosis and fault‐tolerant control schemes for quadrotor helicopters, the proposed fault diagnosis scheme is able to estimate sensor faults while eliminating the effect of external disturbances. Moreover, the proposed fault‐tolerant control scheme is capable to eliminate the adverse effect of external disturbances as well by designing a disturbance observer to effectively estimate the unknown external disturbances and integrating with the designed integral sliding‐mode controller. In this case, the continuous operation of the quadrotor helicopter is ensured while avoiding the unexpected control chattering. In addition, the stability of the closed‐loop system is theoretically proved. Finally, the effectiveness and advantages of the proposed scheme are validated and demonstrated through comparative numerical simulations of the quadrotor helicopter under different faulty and uncertain scenarios.
Fatty Acid-Related Health Lipid Index of Raw and Fried Nile Tilapia (Oreochromis niloticus) Fish Muscle
Authors: Zula Aemiro Tadesse , Desta Derese Tamiru
Published: March 2021

Fried food consumption is popular in most parts of the world including Ethiopia. Among many fried products available in Ethiopia, fried fish is most commonly consumed in Hawassa Town due to the easy access to the fish from the lake. Recently, there is growing concern among fryers to recycle the oil while frying fish. However, there is limited evidence about the frying effect on the fatty-acid-related health lipid index of fried fish. Thus, the study was aimed to determine the fatty acid profile and the fatty-acid-related health lipid of raw and fried fish. Raw and fried fish were taken from the Hawassa open fish market. Fatty acid profiles were analyzed using a gas chromatography-mass spectrophotometer (GCMS), and the health lipid index was determined by calculation using the recommended formula. JMP pro 13 version software was used for data analysis. Our result showed that raw fish had a high amount of essential fatty acid, nutritive value index, hypocholesterolemic ratio, and peroxidizability index. In contrary to this, the fried fish had a high amount of trans-fatty acids, nonessential fatty acids, atherogenic index, and thrombogenic index. In conclusion, the fried fish loses its fatty-acid-related nutritional quality in uncontrolled frying conditions. Therefore, frying needs to be controlled, as it risks human health otherwise.
Working Capital Management and Its Impact on Firms’ Performance: An Empirical Analysis on Ethiopian Exporters
Authors: Wassie Fekadu Agmas
Published: March 2021

Companies may have their level of optimal working capital that maximizes their values through the effective management of current liabilities and assets. Previously, many studies were made on the impact of working capital management on the company’s performance in different sectors; however, its impact on the performance of firms that are engaged in export activities was not given any consideration and this particular study has attempted to investigate the fundamental impact of working capital management on the export firm’s performance in Ethiopia. To analyze this particular study, a total of 164 exporters operating in Ethiopia have been taken as a sample and both primary and secondary data collection methods were used. The data gathered from the sample of the study were analyzed using a multiple linear regression model and the result reveals that working capital management which was measured by account receivables period, cash conversion cycle, and accounts payable period has a statistically significant and positive correlation with the performance of exporting firms in Ethiopia which was measured by both return on assets and return on investment. However, working capital management which was measured by the inventory conversion period has a statistically significant and positive impact on return on investment, but it has an insignificant impact on the performance of sampled export firms in Ethiopia which was measured by return on assets. Based on the result of the study, firms may need to extend credit terms for customers, may prolong their cash conversion cycle, may need an extended payment period, and may or may not hold a high volume of inventory. All extending periods and cycles shall be made up to the extent of attaining an optimal level of working capital and better to implement a conservative policy of working capital management. Thus, it is advisable to consider the result of this study while making decisions regarding their working capital management to support their performance.