bluuebunny/crossref_metadata_2025 huggingface dataset:
An Intelligent Optimization Method for Preliminary Design of Lead-Bismuth Reactor Core Based on Kriging Surrogate Model
Authors: Li Qiong , Liu Zijing , Xiao Yingjie , Zhao Pengcheng , Zhao Yanan , Yang Tao , Yu Tao
Published: March 2022

To meet the numerous application demands of lead-bismuth reactors, different design optimization tasks need to be conducted on these reactors based on the existing reactor core solutions. However, the design optimization of lead-bismuth reactors is a challenging task because it is a complex, multi-dimensional, and nonlinear constrained problem. To resolve these issues and improve the efficiency of design optimization, a new method, called the KSM-OLHS-SEUMRE method, based on the Kriging surrogate model (KSM), orthogonal Latin hypercube sampling (OLHS), and space exploration and unimodal region elimination (SEUMRE) algorithm is proposed in this study. Based on this method, a design optimization program of lead-bismuth reactors (DOPPLER-K) is developed, which realizes functions like sample point generation, optimization analysis, pre-post processing of reactor calculation, coupling of the Reactor Monte Carlo (RMC) calculation code and the Steady-state Thermal-hydraulic Analysis Code (STAC). Further, taking lead-bismuth reactors SPALLER-4 and URANUS as prototypes, the proposed intelligent optimization method for preliminary design of lead-bismuth reactor core is verified. The results show that this method can rapidly and accurately find the target scheme satisfying the optimization conditions, and it is three orders of magnitude faster than pure Monte Carlo calculation. Compared with the initial core scheme of URANUS, the optimization rates of fuel loading, total core mass, active zone volume, and total core volume are reduced by 10.8, 11.5, 18.1, and 17.1%, respectively. These results validate the feasibility and efficacy of the proposed method for design optimization of lead-bismuth reactor core.
Dynamic Heat Transfer Analysis on the New U-type Medium-Deep Borehole Ground Heat Exchanger
Authors: Guan Chunmin , Fang Zhaohong , Zhang Wenke , Yao Haiqing , Man Yi , Yu Mingzhi
Published: March 2022

The U-type medium-deep borehole ground heat exchanger BGHE is a new form of utilization of geothermal energy and there has been relatively little research on it. This paper introduces the structure and working principle of the BGHE. The energy control equations based on the characteristics of the heat transfer model are established creatively. The initial and boundary conditions of the circulating fluid and rock soil are determined. And the reliability of the simulation is verified through comparing the simulated results with the engineering data. Based on the above theoretical foundation, the effects of the circulating fluid flow rate, geothermal gradient and thermal conductivity of different soil layers on the nominal heat extraction and the outlet temperature of the U-type BGHE are examined. The temperature changes in the soil surrounding the vertical pipe and the temperature of circulating fluid at the inlet and outlet of the BGHE are analysed. The corresponding reasons of these changes are revealed. It is shown from simulation results that the circulating fluid flow rate has opposite influence on the nominal heat extraction and outlet temperature. The increasing terrestrial heat flow is conducive to heat transfer, but the reverse heat transfer occurs during the heat transfer process. The influence of the BGHE on the surrounding rock soil will hardly affect the continuous use of the buried ground heat exchanger. The results of the study are beneficial to better understand the heat transfer characteristics of the U-type medium-deep BGHE and its impact on the surrounding soil. It will promote the popularization and application of medium-deep geothermal energy.
Plasma Donor-Derived Cell-Free DNA Levels Are Associated With the Inflammatory Burden and Macrophage Extracellular Trap Activity in Renal Allografts
Authors: Guo Luying , Shen Jia , Lei Wenhua , Yan Pengpeng , Wang Meifang , Zhou Qin , Wang Huiping , Wu Jianyong , Chen Jianghua , Wang Rending
Published: March 2022

Recent studies have confirmed the role of plasma donor-derived cell-free DNA (ddcfDNA) as a reliable non-invasive biomarker for allograft injury after kidney transplantation. Whereas the variability of plasma ddcfDNA levels among recipients has limited their clinical use. This study aimed to explore the intrinsic factors associated with plasma ddcfDNA elevation by investigating the impact of Banff lesions and inflammatory infiltrates on ddcfDNA levels in kidney transplant recipients. From March 2017 to September 2019, a total of 106 kidney transplant recipients with matched allograft biopsies were included, consisting of 13 recipients with normal/nonspecific changes, 13 recipients with borderline changes, 60 with T cell-mediated rejection, and 20 with antibody-mediated rejection. Histologic classification was performed according to the Banff 2017 criteria by two experienced pathologists. Plasma ddcfDNA fractions ranged from 0.12% to 10.22%, with a median level of 0.91%. Banff histology subelements including glomerulitis, intimal arteritis, and severe interstitial inflammation were correlated with increased plasma ddcfDNA levels. The inflammatory cell infiltrate in the allografts was phenotyped by immunochemistry and automatically counted by digital image recognition. Pearson correlation analysis revealed a significant positive correlation between macrophage infiltrations in allografts and plasma ddcfDNA levels. Additionally, macrophage extracellular trap (MET) activity was significantly associated with the rise in plasma ddcfDNA levels. Our findings demonstrated that plasma ddcfDNA could reflect the inflammatory state in renal allografts and suggested the potential role of METs in the pathogenesis of allograft injury.
Parasitomimetics: Can We Utilize Parasite-Derived Immunomodulatory Molecules for Interventions to Immunological Disorders?
Authors: Nagai Kazuki , Goto Yasuyuki
Published: March 2022

Because our immune system has ability to expel microorganisms invading our body, parasites need evolution to maintain their symbiosis with the hosts. One such strategy of the parasites is to manipulate host immunity by producing immunomodulatory molecules and the ability of parasites to regulate host immunity has long been a target of research. Parasites can not only manipulate host immune response specific to them, but also influence the host’s entire immune system. Such ability of the parasites may sometimes bring benefit to the hosts as many studies have indicated the “hygiene hypothesis” that a decreased opportunity of parasitic infections is associated with an increased incidence of allergy and autoimmune diseases. In other words, elucidating the mechanisms of parasites to regulate host immunity could be applied not only to resolution of parasitic infections but also to treatment of non-parasitic immunological disorders. In this review, we show how much progress has been made in the research on immunomodulation of host immunity by parasites. Here, we define the word ‘parasitomimetics’ as emulation of parasites’ immunomodulatory systems to solve immunological problems in humans and discuss potential applications of parasite-derived molecules to other diseases.
The Role of microRNA in the Inflammatory Response of Wound Healing
Authors: Jiang Yuanyuan , Xu Xiang , Xiao Long , Wang Lihong , Qiang Sheng
Published: March 2022

Wound healing, a highly complex pathophysiological response to injury, includes four overlapping phases of hemostasis, inflammation, proliferation, and remodeling. Initiation and resolution of the inflammatory response are the primary requirements for wound healing, and are also key events that determines wound quality and healing time. Currently, the number of patients with persistent chronic wounds has generally increased, which imposes health and economic burden on patients and society. Recent studies have found that microRNA(miRNA) plays an essential role in the inflammation involved in wound healing and may provide a new therapeutic direction for wound treatment. Therefore, this review focused on the role and significance of miRNA in the inflammation phase of wound healing.
Application of Artificial Neural Networks for Corrosion Behavior of Ni–Zn Electrophosphate Coating on Galvanized Steel and Gene Expression Programming Models
Authors: Zeraati Malihe , Abbasi Hossein , Ghaffarzadeh Parvin , Chauhan Narendra Pal Singh , Sargazi Ghasem
Published: March 2022

Zn–Ni electrophosphate coating is one of the most commonly used materials in industrial applications. The corrosion resistance of this coating is very important in order to achieve the minimum corrosion current of the Zn–Ni electrophosphate coating. This study described a new reliability simulation framework to determine the corrosion behavior of coating using a gene artificial neural network (ANN) to estimate the corrosion current of the coating. The input parameters of the model are temperature, pH of electroplating bath, current density, and Ni2+ concentration, and corrosion current defined as output. The effectiveness and accuracy of the model were checked by utilizing the absolute fraction of variance (R2 = 0.9999), mean absolute percentage error (MAPE = 0.0171), and root mean square error (RMSE= 0.0002). This is determined using the genetic algorithm (GA) and the optimum practice condition.
Factors Contributing to Persistent Frequent Attendance in Primary Care Among the Oldest Old: Longitudinal Evidence From the AgeCoDe-AgeQualiDe Study
Authors: Buczak-Stec Elżbieta W. , Hajek André , van den Bussche Hendrik , Eisele Marion , Oey Anke , Wiese Birgitt , Weyerer Siegfried , Werle Jochen , Fuchs Angela , Pentzek Michael , Luppa Melanie , Löbner Margit , Weeg Dagmar , Mösch Edelgard , Heser Kathrin , Wagner Michael , Riedel-Heller Steffi G. , Maier Wolfgang , Scherer Martin , König Hans-Helmut
Published: March 2022

Objective

Since there is a lack of longitudinal studies in this area, our aim was to identify the determinants of persistent frequent attendance in primary care among the oldest old in Germany.

Methods

Longitudinal data (follow-up wave 7–9) were taken from the multicenter prospective cohort “Study on needs, health service use, costs, and health-related quality of life in a large sample of oldest-old primary care patients (85+)” (AgeQualiDe), covering primary care patients ≥ 85 years (FU7 n = 741, mean age 88.9 years (SD 2.9; 85–100)). Persistent frequent attenders of general practitioner (GP) services (the patients in the top decile of the number of GP consultations in two or more consecutive waves) were our main outcome of interest. Logistic random-effects models were used.

Results

Our analysis included 1,891 observations (766 individuals). Across three waves, we identified 56 persistent frequent attenders. Results of random-effects logistic regressions showed that the odds of being persistent frequent attender were higher for widowed individuals (OR = 4.57; 95% CI [1.07–19.45]). Moreover, a one-point increase in the frailty score and having one more chronic condition increased the odds of being a persistent frequent attender by 68% (OR =1.68; 95% CI [1.05–2.69]) and 23% (OR=1.23, 95% CI [1.05–1.44]), respectively.

Conclusion

Our study stressed the longitudinal association between frailty and widowhood as well as chronic diseases and persistent frequent attendance among the oldest old in Germany.
Mesenchymal Stem Cell-Derived Exosomes: Toward Cell-Free Therapeutic Strategies in Chronic Kidney Disease
Authors: Cao Qinghua , Huang Chunling , Chen Xin-Ming , Pollock Carol A.
Published: March 2022

Chronic kidney disease (CKD) is rising in global prevalence and has become a worldwide public health problem, with adverse outcomes of kidney failure, cardiovascular disease, and premature death. However, current treatments are limited to slowing rather than reversing disease progression or restoring functional nephrons. Hence, innovative strategies aimed at kidney tissue recovery hold promise for CKD therapy. Mesenchymal stem cells (MSCs) are commonly used for regenerative therapy due to their potential for proliferation, differentiation, and immunomodulation. Accumulating evidence suggests that the therapeutic effects of MSCs are largely mediated by paracrine secretion of extracellular vesicles (EVs), predominantly exosomes. MSC-derived exosomes (MSC-Exos) replicate the functions of their originator MSCs via delivery of various genetic and protein cargos to target cells. More recently, MSC-Exos have also been utilized as natural carriers for targeted drug delivery. Therapeutics can be effectively incorporated into exosomes and then delivered to diseased tissue. Thus, MSC-Exos have emerged as a promising cell-free therapy in CKD. In this paper, we describe the characteristics of MSC-Exos and summarize their therapeutic efficacy in preclinical animal models of CKD. We also discuss the potential challenges and strategies in the use of MSC-Exos-based therapies for CKD in the future.
Acceleration of pCASL-Based Cerebral 4D MR Angiography Using Compressed SENSE: A Comparison With SENSE
Authors: Wang Maoxue , Ma Yiming , Chen Fei , Zhou Fei , Zhang Jilei , Zhang Bing
Published: March 2022

Objectives

The objectives of this study were to accelerate the non-contrast-enhanced four-dimensional magnetic resonance angiography (4D MRA) based on pseudocontinuous arterial spin labeling combined with the Keyhole and View-sharing (4D-PACK) procedure using the Compressed SENSE (C-SENSE) and to improve intracranial vasculopathy evaluations for clinical purposes.

Methods

4D-PACK acquisition with different C-SENSE and SENSE acceleration factors was performed on 29 healthy volunteers and six patients by means of a 3.0 T MR system. Two radiologists used a 4-grade scale to qualitatively assess the vessel visualization of the middle cerebral artery (MCA) and used a 5-grade scale to qualitatively examine the image quality of 4D-PACK axial source images. Interobserver agreement was assessed by determining the weighted kappa statistic. The contrast-to-noise ratio (CNR) and arterial transmit time (ATT) were calculated in four segments of the MCA. The repeated measures one-way ANOVA for CNR and the Friedman test for source images and vessel visualization were used to analyse the differences in five sequences.

Results

(1) At the M4 segment, C-SENSE5 acquisition (scores, 2.72 ± 0.53) and C-SENSE6.5 (scores, 2.55 ± 0.57) provided similar vessel visualization compared with SENSE4.5 (scores, 2.72 ± 0.46); however, C-SENSE8 (scores, 1.79 ± 0.49) and C-SENSE10 (scores, 1.52 ± 0.51) had lower scores (P < 0.050). (2) The source image quality of C-SENSE5 (scores, 4.55 ± 0.51), C-SENSE6.5 (scores, 4.03 ± 0.33), and C-SENSE8 (scores, 3.48 ± 0.51) acquisition was higher than that of SENSE4.5 (scores, 3.07 ± 0.26) (P < 0.001). (3) CNRs of different MCA segments for C-SENSE5 and C-SENSE6.5 acquisitions were not significantly different compared with that of SENSE4.5 acquisition. However, the CNRs were significantly lower for C-SENSE8 (M1: 45.85 ± 13.91, M2: 27.08 ± 9.92, M4: 7.93 ± 4.49) and C-SENSE10 (M1: 37.94 ± 9.92, M2: 23.51 ± 9.0, M4: 6.78 ± 4.12) than for SENSE4.5 (M1: 55.49 ± 13.39, M2: 36.94 ± 11.02, M4: 10.18 ± 5.15) in each corresponding segment (P < 0.050). ATTs in all MCA segments within different accelerating C-SENSE factors were obviously correlated with SENSE4.5.

Conclusion

C-SENSE6.5 acquisition could be used to evaluate both the intracranial macrovascular and distal arteries, which could reduce the acquisition time by 18% (5 min 5 s) compared with SENSE4.5. Moreover, C-SENSE8 acquisition (37% acceleration, 3 min 54 s) could be used for routine screening and clinical diagnosis of intracranial macrovascular disease with balanced image quality.
Saliva Based Liquid Biopsies in Head and Neck Cancer: How Far Are We From the Clinic?
Authors: Patel Aditi , Patel Shanaya , Patel Parina , Tanavde Vivek
Published: March 2022

Head and neck cancer (HNC) remains to be a major cause of mortality worldwide because of confounding factors such as late-stage tumor diagnosis, loco-regional aggressiveness and distant metastasis. The current standardized diagnostic regime for HNC is tissue biopsy which fails to determine the thorough tumor dynamics. Therefore, due to the ease of collection, recent studies have focused on the utility of saliva based liquid biopsy approach for serial sampling, early diagnosis, prognosis, longitudinal monitoring of disease progression and treatment response in HNC patients. Saliva collection is convenient, non-invasive, and pain-free and offers repetitive sampling along with real time monitoring of the disease. Moreover, the detection, isolation and analysis of tumor-derived components such as Circulating Tumor Nucleic Acids (CTNAs), Extracellular Vesicles (EVs), Circulating Tumor Cells (CTCs) and metabolites from saliva can be used for genomic and proteomic examination of HNC patients. Although, these circulatory biomarkers have a wide range of applications in clinical settings, no validated data has yet been established for their usage in clinical practice for HNC. Improvements in isolation and detection technologies and next-generation sequencing analysis have resolved many technological hurdles, allowing a wide range of saliva based liquid biopsy application in clinical backgrounds. Thus, in this review, we discussed the rationality of saliva as plausible biofluid and clinical sample for diagnosis, prognosis and therapeutics of HNC. We have described the molecular components of saliva that could mirror the disease status, recent outcomes of salivaomics associated with HNC and current technologies which have the potential to improve the clinical value of saliva in HNC.
Economic Burden Conferred by Population-Level Cancer Screening on Resource-Limited Communities: Lessons From the ESECC Trial
Authors: Li Fuxiao , Hu Yanjun , Guo Chuanhai , Lei Liang , Li Fenglei , Liu Mengfei , Liu Zhen , Pan Yaqi , Liu Fangfang , Liu Ying , Hu Zhe , Chen Huanyu , He Zhonghu , Ke Yang
Published: March 2022

Objectives

Upper gastrointestinal (G.I.) cancer screening has been conducted in China for decades. However, the economic burden for treatment “intensively” occurred in advance due to screening in resource-limited communities remain unclear.

Methods

We compared the treatment costs for upper G.I. cancers from the screening and control arms of a population-based randomized trial in a high-risk area for esophageal cancer (EC) in China based on claims data from the health insurance system in the local area which included whole population coverage.

Results

The average out-of-pocket cost per treatment of EC in the screening arm was lower than that in the control arm ($5,972vs.$7,557). This difference was a consequence of down-staging from screening which resulted in lower cost therapy for earlier stage cancers. Moreover, this result is similar for cardial and non-cardial gastric cancer in the two study arms ($7,933vs.$10,605). However, three times as many (103vs.36) families in the screening arm suffered catastrophic health expenditure for all cancer types. The overall treatment cost for all EC patients in the screening arm ($1,045,119) was 2.44 times that in the control arm ($428,292), and the ratio for cardial and non-cardial gastric cancer was 1.12 ($393,261vs.$351,557).

Conclusion

Cancer treatment secondary to screening may triple the likelihood of catastrophic patient medical expenditure, and sharply increase the economic pressure on the local community, particularly for cancer types which are of high prevalence. Financial support for patients and the health insurance system should be taken into consideration when planning budgets for cancer screening programs in communities which are resource-limited.
Efficacy and Pharmacological Mechanism of Poria cocos-Based Formulas Combined With Chemotherapy for Ovarian Cancer: A Integrated Systems Pharmacology Study
Authors: Peng Xinya , Jia Congchao , Chi Hao , Wang Pengyu , Fu Hu , Li Yunyue , Wang Qin
Published: March 2022

Previous studies have shown that Poria cocos-based formulas combined with chemotherapy can improve the quality of life of ovarian cancer patients. However, the results are still controversial. We systematically searched the literature from eight databases to evaluate the efficacy and safety of Poria cocos-based formulas in combination with paclitaxel-carboplatin in treating ovarian cancer (OC). Subsequently, network pharmacology, molecular docking and cell experiments were performed to further verify the underlying molecular mechanism. Thirteen randomized controlled trials, including 922 patients with OC, were enrolled in the study. The results indicated that Poria cocos-based compounds combined with paclitaxel-carboplatin significantly improved patients’ tumor response rate, traditional Chinese medicine syndrome score, Karnofsky Performance Scale, physical and social function, and reduced side effects of chemotherapy compared to the paclitaxel-carboplatin alone. According to the network pharmacological analysis, tumulosic acid were the most bioactive compounds of Poria cocos. BCL2L1 is highly expressed in OC and is associated with a worse prognosis which could become potential drug target. Functional enrichment analysis suggested that the anti-OC effect of Poria cocos may be related to PI3K-Akt signaling pathway. The molecular docking results indicated that tumulosic acid might inhibit OC by regulating BCL2L1. Vitro experiment confirmed tumulosic acid that induced cell apoptosis by modulating PI3K/AKT signaling and BCL2L1. Our study may provide a clinical basis and theoretical rationale for combining Poria cocos-based formulas with chemotherapy for OC. In addition, the integrated pharmacological strategy proposed in our study provides an excellent example for exploring the mechanism of complex formulas.
Australian Sea Snake Envenoming Causes Myotoxicity and Non-Specific Systemic Symptoms - Australian Snakebite Project (ASP-24)
Authors: Johnston Christopher I. , Tasoulis Theo , Isbister Geoffrey K.
Published: March 2022

Background:Sea snakes are venomous snakes found in the warm parts of the Indo-Pacific, including around Australia. Most sea snake envenoming causes myotoxicity, but previous Australian case reports describe neurotoxicity. We aimed to describe the epidemiology and clinical presentation of Australian sea snake envenoming and the effectiveness of antivenom.

Methods:Patients were recruited to the Australian Snakebite Project (ASP), an Australia-wide prospective observational study recruiting all patients with suspected or confirmed snakebite >2 years. Information about demographics, bite circumstances, species involved, clinical and laboratory features of envenoming, and treatment is collected and entered into a purpose-built database.

Results:Between January 2002 and August 2020, 13 patients with suspected sea snake bite were recruited to ASP, 11 were male; median age was 30 years. Bites occurred in Queensland and Western Australia. All patients were in or around, coastal waters at the time of bite. The species involved was identified in two cases (bothHydrophis zweifeli).Local effects occurred in 9 patients: pain (5), swelling (5), bleeding (2), bruising (1). Envenoming occurred in eight patients and was characterised by non-specific systemic features (6) and myotoxicity (2). Myotoxicity was severe (peak CK 28200 and 48100 U/L) and rapid in onset (time to peak CK 13.5 and 15.1 h) in these two patients. Non-specific systemic features included nausea (6), headache (6), abdominal pain (3), and diaphoresis (2). Leukocytosis, neutrophilia, and lymphopenia occurred in both patients with myotoxicity and was evident on the first blood test. No patients developed neurotoxicity or coagulopathy. Early Seqirus antivenom therapy was associated with a lower peak creatine kinase.

Conclusion:While relatively rare, sea snake envenoming is associated with significant morbidity and risk of mortality. Early antivenom appears to have a role in preventing severe myotoxicity and should be a goal of therapy.
Applications and Mechanisms of Tripterygium Wilfordii Hook. F. and its Preparations in Kidney Diseases
Authors: Tong Xue , Qiao Yanheng , Yang Yuanjian , Liu Haizhao , Cao Zhiyong , Yang Bo , Wei Lijuan , Yang Hongtao
Published: March 2022

Tripterygium wilfordii Hook. f. (TwHF) is a Chinese botanical drug containing a large number of metabolites. The discovered and recognized anti-inflammatory and immune-regulating effects have made it attract more and more attentions in trials and clinical researches. The extraction and processing of TwHF for pharmaceuticals is a manifestation of the role of traditional Chinese medicine. However, TwHF is toxic. Optimization of TwHF preparations has become a requirement for the development of TwHF pharmaceuticals. Our article introduces the main preparations of TwHF on the Chinese market and their characteristics. In particular, we summarize the clinical applications and influential mechanisms of TwHF and its preparations in kidney diseases. Considering that nephropathy is closely related to immune inflammation and TwHF is a botanical drug with a high number of metabolites, the application of TwHF in kidney diseases may be much more complicated. By revealing the role and mechanisms of TwHF in kidney diseases, this study aims to provide more insights to basic and clinical studies about nephropathy.
Bubble Dynamics in Stationary Two-phase Flow Through Disordered Porous Media
Authors: Sales J. M. A. , Seybold H. J. , Oliveira C. L. N. , Andrade J. S.
Published: March 2022

Two-phase flow through porous media leads to the formation of drops and fingers, which eventually break and merge or may be trapped behind obstacles. This complex dynamical behavior highly influences macroscopic properties such as the effective permeability and it also creates characteristic fluctuations in the velocity fields of the two phases, as well as in their relative permeability curves. In order to better understand how the microscopic behavior of the flow affects macroscopic properties of two phases, we simulate the velocity fields of two immiscible fluids flowing through a two-dimensional porous medium. By analyzing the fluctuations in the velocity fields of the two phases, we find that the system is ergodic for large volume fractions of the less viscous phase and high capillary numbers Ca. We also see that the distribution of drop sizes m follows a power-law scaling, P(m)∝m−ξ. The exponent ξ depends on the capillary number. Below a characteristic capillary number, namely Ca* ≈ 0.046, the drops are large and cohesive with a constant scaling exponent ξ ≈ 1.23 ± 0.03. Above the characteristic capillary number Ca*, the flow is dominated by many small droplets and few finger-like spanning clusters. In this regime the exponent ξ increases approaching 2.05 ± 0.03 in the limit of infinite capillary number. Our analysis also shows that the temporal mean velocity of the entire mixture can be described by a generalization of Darcy’s law of the form v̄(m)∝(∇P)β where the exponent β is sensitive to the surface tension between the two phases. In the limit of infinite capillary numbers the mobility term increases exponentially with the saturation of the less viscous phase. This result agrees with previous observations for effective permeabilities found in dissolved-gas-driven reservoirs.
Post-traumatic Growth and Psychological Resilience During the COVID-19 Pandemic: A Serial Mediation Model
Authors: Li Qi , Hu Jinsheng
Published: March 2022

Although the World Health Organization (WHO) has issued guidelines for managing to contain, mitigate, and limit of the COVID-19. However, it is more essential to highlight the urgency and importance of evaluating social functioning and mental health status during the pandemic. College students have experienced serious problems and have had to overcome many negative situations brought about by the pandemic. Accordingly, the present study intended to use Chinese college students as sample to examine the positive adoption and changes during the ongoing COVID-19. Guided by literatures in this filed, we explored the internal mechanism of post-traumatic growth affecting psychological resilience, and considered about mediation roles of positive coping styles and cognitive reappraisal. A total of 463 college students from universities in China effectively completed online questionnaires. The result indicated that these four variables were positively correlated with each other (ps < 0.001). More importantly, our findings proved a direct and positive effect on psychological resilience. Positive coping styles and cognitive reappraisal, respectively, mediated the relationship between post-traumatic growth and psychological resilience. Over all, the hypothesized serial model conclusively fits the data: students with high-level post-traumatic growth tended to report increased use of positive coping strategies, which further facilitated their cognitive reappraisal, and subsequently, promoted their psychological resilience. The findings obtained in this study will provide a theoretical basis and possible viable strategies for both targeted crisis intervention and psychological trauma recovery plans.
The Assessment of Dual-Cycle Identity Models Among Secondary School Students: The Hungarian Adaptation of DIDS and U-MICS
Authors: Rivnyák Adrienn , Járdaházi Evelyn , Arató Nikolett , Péley Bernadette , Láng András
Published: March 2022

The aim of the present study was to evaluate the factor structure and validity of the Hungarian versions of the Dimensions for Identity Development Scale (DIDS) and Utrecht-Management of Identity Commitments Scale (U-MICS). Both models assume that the iterative process of exploring and evolving commitments occurs in two distinct cycles. The sample for testing the factor structure of DIDS consisted of 808 adolescents (357 boys and 451 girls) aged between 14 and 21 years (Mage = 16.86; SD = 1.35). The sample for testing the factor structure of U-MICS consisted of 803 adolescents (353 boys and 450 girls) aged between 14 and 21 years (Mage = 16.88; SD = 1.34). Results indicated a five factor model of DIDS in the present sample. All the five dimensions correlated as hypothesized both internally and externally. In line with previous research, six clusters emerged based on the dimensions of DIDS, including ruminative moratorium. Regarding U-MICS, results indicated a three factor model in the present sample. All the three dimensions were internally and externally correlated as hypothesized regarding both ideological and interpersonal identity domains. With regard to the identity status cluster solution, five clusters emerged in both the educational and friendship domains. We found specific variation regarding identity clusters in the two identity domains. Our results support the use of these two measurements in Hungarian context. Further, our results confirm the divergent developmental dynamics of ideological and interpersonal identity domains.
Prevalence and Associated Factors of Depression, Anxiety and Insomnia Symptoms Among Patients Receiving Ophthalmic Consultation Online During the COVID-2019 Pandemic
Authors: Ding Lin , Guo Ni , Zhu Jianing , Tuxunjiang Dilinuer , Abudoukeremuahong Aierxiding , Zuo Chengguo , Lin Mingkai
Published: March 2022

Objective

This study aims to assess the prevalence and associated factors of depression, anxiety and insomnia symptoms among patients undergoing ophthalmic consultation online during the coronavirus disease 2019 (COVID-2019) pandemic.

Methods

We reviewed the data of patients who received online ophthalmic consultations during the lockdown period from February to August 2020, and an online survey was conducted among them. We collected the respondents' demographic data and their attitudes toward the online consultation, assessed the depression, anxiety and insomnia symptoms and estimated associated factors by logistic regression analysis.

Results

The online service provided 425 consultations during the COVID-19 lockdown period. Of these eligible subjects, 139 patients responded to an invitation to participant in the study (105/75.5% were females, and 40/28.8% were health care workers). More than half of the participants reported that they trusted and were satisfied with the online consultation (109/78.4% and 82/59%, respectively). Fifty-two (37.4%), 32 (23.0%), and 53 (38.1%) patients showed symptoms of depression, anxiety, and insomnia, respectively. Depression was found to be significantly more common in health care workers (P = 0.019) and those who were basically satisfied with online consultation (P = 0.024). Anxiety was more common among participants who had used electronics for a long time (P = 0.038). Binary logistic regression showed health care work as a risk factor for depressive symptoms (odds ratio [OR]: 2.424; 95% CI: 1.143–5.143; P = 0.021).

Conclusion

Psychological distress is highly prevalent among patients who were involved in online consultation for ocular manifestations during the COVID-19 lockdown period. In the context of a major public health event, ophthalmologists should focus not only on ocular symptoms but also on the mental health of their patients, and appropriate psychological support should be given.
Description of Symptoms Caused by the Infection of the SARS-CoV-2 B.1.621 (Mu) Variant in Patients With Complete CoronaVac Vaccination Scheme: First Case Report From Santiago of Chile
Authors: Barrera-Avalos Carlos , Luraschi Roberto , Acuña-Castillo Claudio , Vidal Mabel , Mella-Torres Andrea , Inostroza-Molina Ailen , Vera Rodrigo , Vargas Sergio , Hernández Iván , Perez Christian , Vallejos-Vidal Eva , Valdés Daniel , Imarai Mónica , Reyes-López Felipe E. , Sandino Ana María
Published: March 2022

Vaccine administration is one of the most efficient ways to control the current coronavirus disease 2019 (COVID-19) pandemic. However, the appearance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants can avoid the immunity generated by vaccines. Thus, in patients with a complete vaccine schedule, the infection by SARS-CoV-2 may cause severe, mild, and asymptomatic manifestations of the disease. In this case report, we describe for the first time the clinical symptoms of four patients (three symptomatic; one asymptomatic) from Santiago of Chile, with a complete vaccination schedule with two doses of CoronaVac (Sinovac Life Science) infected with the variant of interest (VOI) B.1.621 (Mu). They were compared with four unvaccinated patients, who had a higher prevalence of symptoms after infection compared to vaccinated patients. In the CoronaVac-vaccinated group, an 80-year-old patient who registered various comorbidities required Invasive mechanical ventilation for 28 days with current home medical recovery discharge. By contrast, in the unvaccinated group, a 71-year-old presented more symptoms with more than 45 days of Invasive mechanical ventilation, which continues to date, presenting greater lung damage than the vaccinated hospitalized patient. This first report evidence differences in the clinical symptomatology of patients vaccinated and non-vaccinated infected with the VOI B.1.621 (Mu) and suggest the protective effects of CoronaVac against this variant.
Acoustical Treatments on Ventilation Ducts through Walls: Experimental Results and Novel Models
Authors: Nilsson Erik , Ménard Sylvain , Bard Hagberg Delphine , Vardaxis Nikolaos-Georgios
Published: March 2022

Sound reduction is complex to estimate for acoustical treatments on ventilation ducts through walls. Various acoustical treatments are available for ventilation ducts, including internal lining (absorption along the inner perimeter), external lagging (external sound insulation), silencer, and suspended ceilings. Previous studies have examined how silencers and the internal lining affect the sound transmission of ventilation ducts. However, there are few theories to predict the effect of external lagging in combination with ventilation ducts and how the total sound reduction is affected. This article aims to investigate different acoustical treatments and develop theoretical models when external lagging with stone wool is used to reduce flanking sound transmission via the surface area of ventilation ducts. Theoretical models are developed for external lagging and compared with measurement data. Measurements and theory are generally in good agreement over the third-octave band range of 100–5000 Hz. The developed models clarify that the distance closest to the wall has the main impact on sound reduction for a combined system with a wall and a ventilation duct. Suspended ceilings and silencers are found to be enough as acoustical treatments for certain combinations of ventilation ducts and walls. However, external lagging seems to be the only effective solution in offices and schools when a large ventilation duct passes through a wall with high sound reduction.
A Compound Scheme Based on Improved ADRC and Nonlinear Compensation for Electromechanical Actuator
Authors: Zhang Mingyue , Li Qingdang
Published: March 2022

A compound scheme, based on an improved active disturbance rejection controller (ADRC) and nonlinear compensation, is developed for the electromechanical actuator (EMA) system in this paper. First, considering the influences of backlash, friction on the EMA system, a model for the EMA system is presented. The LuGre model and Hysteresis inverse model are used to compensate for the friction and backlash phenomenon. Then, the method of improved ADRC, based on the Fal function filter and a Linear extended state observer (LESO), is investigated. Simultaneously, since the controller parameters of the improved ADRC are complicated, the non-dominated sorting genetic algorithm II (NSGA-II) is presented to optimize the controller parameters, to achieve the best dynamic response. Finally, simulation and experiment are presented to validate the effectiveness of the proposed method. Under the nonlinear compensation, the performance of the proposed compound scheme is compared with the conventional proportional integral (PI) controller, in terms of step response analysis and sine wave response analysis. Simulation and experiments show that the proposed controller provides high-performance dynamic characteristics.
Constrained Motion Planning of 7-DOF Space Manipulator via Deep Reinforcement Learning Combined with Artificial Potential Field
Authors: Li Yinkang , Li Danyi , Zhu Wenshan , Sun Jun , Zhang Xiaolong , Li Shuang
Published: March 2022

During the on-orbit operation task of the space manipulator, some specific scenarios require strict constraints on both the position and orientation of the end-effector, such as refueling and auxiliary docking. To this end, a novel motion planning approach for a space manipulator is proposed in this paper. Firstly, a kinematic model of the 7-DOF free-floating space manipulator is established by introducing the generalized Jacobian matrix. On this basis, a planning approach is proposed to realize the motion planning of the 7-DOF free-floating space manipulator. Considering that the on-orbit environment is dynamical, the robustness of the motion planning approach is required, thus the deep reinforcement learning algorithm is introduced to design the motion planning approach. Meanwhile, the deep reinforcement learning algorithm is combined with artificial potential field to improve the convergence. Besides, the self-collision avoidance constraint is considered during planning to ensure the operational security. Finally, comparative simulations are conducted to demonstrate the performance of the proposed planning method.
Approach for Cost Functions for the Use in Trade-Off Investigations Assessing the Environmental Impact of a Future Energy Efficient European Aviation
Authors: Förster Peter , Yildiz Bekir , Feuerle Thomas , Hecker Peter
Published: March 2022

Aircraft emissions represent a relevant amount of human induced CO2. Globally, up to 2.5 per cent of such emissions stem from the aviation industry. In order to investigate the effects within the atmosphere, realistic flight profiles are necessary to provide quantitatively tangible values of emissions. The flight profiles and the according fuel consumption can be calculated by using waypoints from flight plans and Base of Aircraft Data (BADA). This paper presents an approach to refine the fuel consumption by integrating the passenger load into the calculation. Since effects of emissions have to be assessed on a greater scale, such as on the European air traffic network, the presented approach provides cost functions for CO2 emissions for different aircraft types and load factors. The cost functions were derived by means of regression analyses of BADA based calculated flight profiles with a step size of one second. The calculations are based on real historic traffic scenarios over several days. The derived aircraft specific fuel burn coefficients enable a simple and efficient integration of CO2 estimations depending on the flight distance, load factor and aircraft type. This can be applied to large traffic scenarios to also study different set-ups such as travel restrictions, other disruptions or an alteration in the traffic system as a whole. In order to enable the assessment of further aspects of such changes to the European air traffic system at large and to foster reproducibility and comparability of related studies, we provide further general-purpose cost estimation functions for several important key characteristics. Besides fuel consumption, we develop cost estimations for air navigation fees and maintenance for conventional aircraft. Those functions are also provided for the design concept of a short-range all-electric aircraft. This propeller aircraft features game-changing technologies such as active laminar flow control, active load alleviation and advanced materials and structure concepts. The approaches discussed in this paper will focus on the generic aspects of aircraft related costs, which can be derived from general available data. For the sake of reproducibility, the results will be made publicly available.
A Coupled LES-Synthetic Turbulence Method for Jet Noise Prediction
Authors: Blake Joshua D. , Sescu Adrian , Thompson David , Hattori Yuji
Published: March 2022

Large-eddy simulation (LES)-based jet noise predictions do not resolve the entire broadband noise spectra, often under-predicting high frequencies that correspond to un-resolved small-scale turbulence. The coupled LES-synthetic turbulence (CLST) model is presented which aims to model the missing high frequencies. The CLST method resolves large-scale turbulent fluctuations from coarse-grid large-eddy simulations (CLES) and models small-scale fluctuations generated by a synthetic eddy method (SEM). Noise is predicted using a formulation of the linearized Euler equations (LEE), where the acoustic waves are generated by source terms from the combined fluctuations of the CLES and the stochastic fields. Sweeping and straining of the synthetic eddies are accounted for by convecting eddies with the large turbulent scales from the CLES flow field. The near-field noise of a Mach 0.9 jet at a Reynolds number of 100,000 is predicted with LES. A high-order numerical algorithm, involving a dispersion relation preserving scheme for spatial discretization and an Adams–Bashforth scheme for time marching, is used for both LES and LEE solvers. Near-field noise spectra from the LES solver are compared to published results. Filtering is applied to the LES flow field to produce an under-resolved CLES flow field, and a comparison to the un-filtered LES spectra reveals the missing noise for this case. The CLST method recovers the filtered high-frequency content, agreeing well with the spectra from LES and showing promise at modeling the high-frequency range in the acoustic noise spectrum at a reasonable expense.
The Control of Corner Separation with Parametric Suction Side Corner Profiling on a High-Load Compressor Cascade
Authors: Li Xiangjun , Dong Jiezhong , Chen Hua , Lu Huawei
Published: March 2022

Nowadays, with the increase of the thrust-to-weight ratio of the aero engines, the high aerodynamic load has made corner separation an issue for axial compressors. The complex three-dimensional flow field makes it challenging to suppress the corner separation, especially considering the performance at multi-working conditions. To suppress the corner separation and reduce loss, the investigation in this paper proposed a new parametric suction side corner profiling method, which includes few variables but enables the flexible variation of the shape. A bi-objective auto-optimization design process for the corner profiling was carried out on a high-load linear compressor cascade, with the companion of end wall and blade profiling. The aim was to investigate the effective flow control rules for the corner separation and practical design guidelines for its geometry under multiple working conditions. The numerical results identified that the suction side corner profiling brings a much more dominant effect to corner separation than end wall profiling and blade profiling. The most critical flow control rule is to accelerate the climbing second flow on the bottom of the suction surface to suppress the reverse trend of the boundary layer and further relieve the corner separation. In addition, the design point and near-stall point have different well-fitting thicknesses and axial positions. A medium value between the design and near-stall well-fitting parameters will make the suction side corner profiling a best-matching case for a medium inflow condition and adequate performance at a range of conditions.
Evaluation of the Antagonistic Effect of Pseudomonas Rhizobacteria on Fusarium Wilt of Chickpea
Authors: Khalifa Meriem Wafaa , Rouag Noureddine , Bouhadida Mariem
Published: March 2022

This study aimed to isolate rhizobacteria belonging to the genus Pseudomonas with plant-growth-promoting properties that can be used in the control of chickpea wilt disease caused by Fusarium oxysporum f. sp. ciceris (Foc). The production of antifungal compounds by the isolated rhizobacteria was assessed against two Foc isolates, coded Foc-S1 and Foc-S2. Strains E1FP13, E1FP4, and E1PP7 were the most effective against Foc-S1, with percentages of 52.77%, 48.37%, and 47.97%, respectively, while E1PP6, E1FP13, and E1PP15 were the most effective against Foc-S2 with percentages of 52.20%, 52.09%, and 45.38%, respectively. All five isolates were identified as Pseudomonas species using 16S rRNA sequencing. The microscopic examination of the impact of the Pseudomonas strains on Foc revealed that all five strains caused morphological changes in Foc, such as granulation and condensation of the cytoplasm, fragmentation, and deformation of the hyphae. The strains produced several plant-growth-promoting compounds, such as cellulase, hydrogen cyanide, indole acetic acid, ammonia, siderophores, lipase, protease, and solubilized phosphate. They were also able to significantly increase chickpea growth and reduce wilt disease, with E1FP13 resulting in the highest disease reductions of 55.77% (Foc-S1) and 53.33% (Foc-S2). The results revealed that our isolates can make promising biocontrol agents for controlling chickpea wilt disease.