bluuebunny/crossref_metadata_2025 huggingface dataset:
Identifying the Impacts of Climate Change and Human Activities on Vegetation Cover Changes: A Case Study of the Yangtze River Basin, China
Authors: Yi Lang , Sun Ying , Ouyang Xiao , Yin Shaohua
Published: May 2022

The normalized difference vegetation index (NDVI) is a useful indicator to characterize vegetation development and land use which can effectively monitor changes in ecological environments. As an important area for ecological balance and safety in China, understanding the dynamic changes in land cover and vegetation of the Yangtze River Basin would be crucial in developing effective policies and strategies to protect its natural environment while promoting sustainable growth. Based on MODIS-NDVI data and meteorological data from 2000 to 2019, the temporal and spatial distribution of vegetation coverage in the Yangtze River Basin during the past 20 years were characterized, and the impacts of human activities and climate change were quantitatively evaluated. We drew the following research conclusions: (1) From 2000 to 2019, the vegetation cover of the Yangtze River Basin presented a fluctuating inter-annual growth trend. Except for the Taihu Lake sub-basin, the vegetation cover in other sub-basins showed an upward trend. (2) The vegetation cover exhibited a spatial distribution pattern of “high in the middle and low in the east and west”, with the multi-year average value of NDVI being 0.5153. (3) Areas with improved vegetation cover were significantly larger than the areas with degraded foliage. The central region has stronger overall trend of change than the east, and the east is stronger than the west. These vegetation cover changes are largely related to anthropogenic activities. (4) Vegetation cover changes due to precipitation and temperature exhibited significant spatial heterogeneity. While both temperature and precipitation influenced vegetation cover, the temperature was the leading climate factor in the area. (5) Anthropogenic and climate factors jointly promoted the change of vegetation cover in the Yangtze River Basin. Human activities contributed 79.29%, while climate change contributed 20.71%. This study could be used in subsequent studies analyzing the influencing factors affecting long-term vegetation cover in large-scale watersheds.
Mental and Physical Well-Being and Burden in Palliative Care Nursing: A Cross-Setting Mixed-Methods Study
Authors: May Susann , Gabb Franziska , Ignatyev Yuriy , Ehrlich-Repp Jana , Stahlhut Kerstin , Heinze Martin , Allsop Matthew , Stanze Henrikje , Muehlensiepen Felix
Published: May 2022

The working routines in palliative care nursing are associated with a variety of causes of stress with regional and setting-specific differences in Germany. This mixed-methods study aimed to investigate the mental and physical well-being among nurses in German palliative and hospice care and to gain a deeper understanding of procedural and structural aspects that may influence the mental and physical burden in palliative nursing care. The mixed-methods approach combined qualitative interviews, (n = 16) an online survey (n = 101), and subsequent data validation in a focus group (n = 6). Interview and focus group data were analysed using structured qualitative content analysis. Survey data were analysed using descriptive statistics and an explorative quantitative analysis. Moderate to very high levels of stress were reported across all settings, but were highest for nurses in specialized outpatient palliative care settings. Underlying causes of stress related to working conditions in the nursing profession across all palliative care settings were poor working hours, perceived inadequate remuneration, and high demands for documentation. To ensure sustainable high-quality palliative care, adaptations to working conditions that target causes of stress and burden in palliative care nurses are required.
Determinants of Differences in Health Service Utilization between Older Rural-to-Urban Migrant Workers and Older Rural Residents: Evidence from a Decomposition Approach
Authors: Li Li , Yang Jinjuan , Zhai Shaoguo , Li Dan
Published: May 2022

Background: The widening gap in health service utilization between different groups in mainland China has become an important issue that cannot be avoided. Our study explored the existence of differences and the causes of the differences in the health service utilization of older rural-to-urban migrant workers in comparison to older rural dwellers. Further, our study explored socioeconomic differences in health service utilization. Methods: The data from the China Labor-Force Dynamic Survey in 2016, the data from the Urban Statistical Yearbook in 2016, and the Statistical Bulletin were used. Our study applied the latest Andersen Model according to China’s current situation. Before we studied health service utilization, we used Coarsened Exact Matching to control the confounding factors. After matching, 2314 respondents were successfully matched (859 older rural-to-urban migrant workers and 1455 older rural dwellers). The Fairlie decomposition method was used to analyze the differences and the sources of health service utilization between older rural-to-urban migrant workers and their rural counterparts. Results: After matching, the probability two-weeks outpatient for older rural-to-urban migrant workers (5.59%) was significantly lower than older rural dwellers (7.57%). The probability of inpatient for older rural-to-urban migrant workers (5.59%) was significantly lower than older rural dwellers (9.07%). Overall, 17.98% of the total difference for two-week outpatient utilization was due to the observed influence factors. Moreover, 71.88% of total difference in inpatient utilization was due to the observed influence factors. Income quantiles (49.57%), health self-assessments (80.91%), and the sex ratio in the community (−102.29%) were significant in the differences in inpatient utilization. Conclusions: The findings provide important insights into the socioeconomic differences in health service utilization among older rural-to-urban migrant workers and older rural residents in China. These insights urge the government to take full account of the heterogeneity in designing health security system reform and public health interventions targeting vulnerable groups.
Validation of the COVID-19 Digital Health Literacy Instrument in the Italian Language: A Cross-Sectional Study of Italian University Students
Authors: Lorini Chiara , Velasco Veronica , Bonaccorsi Guglielmo , Dadaczynski Kevin , Okan Orkan , Zanobini Patrizio , Vecchio Luca P.
Published: May 2022

The Coronavirus Disease 19 (COVID-19) pandemic and the associated “infodemic” have shown the importance of surveillance and promotion of health literacy, especially for young adults such as university students who use digital media to a very high degree. This study aimed to assess the validity and reliability of the Italian version of the COVID-19 adapted version of the Digital Health Literacy Instrument (DHLI). This cross-sectional study is part of the COVID-19 University Students Survey involving 3985 students from two Italian universities. First, item analysis and internal consistency were assessed. Then, Principal Component Analysis (PCA) and Confirmatory Factor Analyses (CFA) were performed comparing different models. The Italian DHLI showed good psychometric characteristics. The protecting privacy subscale was excluded, given the criticalities presented in the validation process. CFA confirmed the four-factor structure, also including a high-order factor. This result allows using the scale to measure a global level of digital health literacy and consider its levels separately for each construct component: searching the web for information, evaluating reliability, determining personal relevance, and adding self-generated content.
Young Carer Perception of Control: Results of a Phenomenology with a Mixed Sample of Young Carers Accessing Support and Unknown to Services
Authors: Janes Ed
Published: May 2022

Identification challenges have resulted in young carers research largely being conducted with those who access support. Positive and negative impacts have been evidenced but there remains little consideration of the wider population. This phenomenology defines young carers as a spectrum of children with different experiences and aims to study the larger group. Participants were recruited from schools and projects, resulting in a mixed sample of young carers who were accessing support but also those who were unknown to services. Participants attended three interviews that initially gathered data on their caring role and family circumstances, before focusing on their health and well-being in the context of change. All interviews were transcribed and analysed at a whole-text and in-depth level to identify shared understanding. A study of the wider spectrum enabled the emergence of perception of control over their caring responsibilities as key to routine development. Although high levels of control helped some participants manage their roles, threats to control were identified, including instability in the care receiver’s condition, excessive caring and medical tasks. The original findings demonstrate how researching the wider spectrum can aid understanding of problematic care, and highlights the importance of recruiting young carers as a hard-to-reach group.
Brown Dog Tick (Rhipicephalus sanguineus Sensu Lato) Infection with Endosymbiont and Human Pathogenic Rickettsia spp., in Northeastern México
Authors: Salomon Jordan , Fernandez Santos Nadia Angelica , Zecca Italo B. , Estrada-Franco Jose G. , Davila Edward , Hamer Gabriel L. , Rodriguez Perez Mario Alberto , Hamer Sarah A.
Published: May 2022

Of the documented tick-borne diseases infecting humans in México, Rocky Mountain spotted fever (RMSF), caused by the Gram-negative bacterium Rickettsia rickettsii, is responsible for most fatalities. Given recent evidence of brown dog tick, Rhipicephalus sanguineus s.l., as an emerging vector of human RMSF, we aimed to evaluate dogs and their ticks for rickettsiae infections as an initial step in assessing the establishment of this pathosystem in a poorly studied region of northeastern México while evaluating the use of dogs as sentinels for transmission/human disease risk. We sampled owned dogs living in six disadvantaged neighborhoods of Reynosa, northeastern México to collect whole blood and ticks. Of 168 dogs assessed, tick infestation prevalence was 53%, composed of exclusively Rh. sanguineus s. l. (n = 2170 ticks). Using PCR and sequencing, we identified an overall rickettsiae infection prevalence of 4.1% (n = 12/292) in ticks, in which eight dogs harbored at least one infected tick. Rickettsiae infections included Rickettsia amblyommatis and Rickettsia parkeri, both of which are emerging human pathogens, as well as Candidatus Rickettsia andeanae. This is the first documentation of pathogenic Rickettsia species in Rh. sanguineus s.l. collected from dogs from northeastern México. Domestic dog infestation with Rickettsia-infected ticks indicates ongoing transmission; thus, humans are at risk for exposure, and this underscores the importance of public and veterinary health surveillance for these pathogens.
The Pathway to China’s Carbon Neutrality Based on an Endogenous Technology CGE Model
Authors: Liang Shuang , Lin Xinyue , Liu Xiaoxue , Pan Haoran
Published: May 2022

Global warming resulting from greenhouse gas emissions has been a worldwide issue facing humanity. Simultaneously, governments have the challenging task of striking a judicious balance between increased economic growth and decreased carbon emissions. Based on the energy-environment-economy triple coupling (3E-CGE) model, we endogenously integrate climate-friendly technologies into the model’s analysis framework through logic curves and refine and modify the CGE model’s energy use and carbon emission modules. We conduct a scenario simulation and sensitivity analysis on carbon tax, carbon-trading, and climate-friendly technological progress, respectively. The results reveal that carbon tax and carbon trading contribute to reducing carbon emissions in the short-term but achieving the goals of peak carbon and carbon neutrality will cause the collapse of the economic system. In the long-term, climate-friendly technologies are key to achieving the dual carbon goal; the development of such technologies can also stimulate economic development. The best path for China to achieve its dual carbon goals and economic development in the next 40 years involves effectively combining the carbon tax, carbon trading, and a climate-friendly technological progress. Specifically, China can begin trading carbon in high-emissions industries then impose industry-wide carbon taxes.
Research on the Influence of Education of Farmers’ Cooperatives on the Adoption of Green Prevention and Control Technologies by Members: Evidence from Rural China
Authors: Luo Lei , Qiao Dakuan , Zhang Ruixin , Luo Chenhao , Fu Xinhong , Liu Yuying
Published: May 2022

The study explores the impact of education of farmers’ cooperatives on members’ green production behavior. The Probit, Oprobit model and the mediation effect model are used to analyze the influence mechanism of the cooperative’s education on the members’ adoption of four types of green prevention and control technologies and the overall adoption rate, and the instrumental variable method is used for endogeneity treatment and robustness test. The results show that: (1) The education of cooperatives have a significant positive impact on the members’ physical pest control technology, biological pesticide application technology, water and fertilizer integration technology, scientific pesticides reduction technology, and the overall adoption rate plays a critical role. As a result, there is a certain degree of heterogeneity in different intergenerational member groups. (2) The education of cooperatives can significantly enhance members’ cognition of green prevention and control. (3) Through on-the-spot demonstration and general meetings of the members to carry out education, members are more likely to adopt green prevention and control technologies. These findings shed light on the mechanisms by which cooperative’s education affect the green production behavior of cooperative members and provide important policy implications for green agricultural development.
Rearrangement in the Hypervariable Region of JC Polyomavirus Genomes Isolated from Patient Samples and Impact on Transcription Factor-Binding Sites and Disease Outcomes
Authors: Wilczek Michael P. , Pike Aiden M. C. , Craig Sophie E. , Maginnis Melissa S. , King Benjamin L.
Published: May 2022

JC polyomavirus (JCPyV) is the causative agent of the fatal, incurable, neurological disease, progressive multifocal leukoencephalopathy (PML). The virus is present in most of the adult population as a persistent, asymptotic infection in the kidneys. During immunosuppression, JCPyV reactivates and invades the central nervous system. A main predictor of disease outcome is determined by mutations within the hypervariable region of the viral genome. In patients with PML, JCPyV undergoes genetic rearrangements in the noncoding control region (NCCR). The outcome of these rearrangements influences transcription factor binding to the NCCR, orchestrating viral gene transcription. This study examines 989 NCCR sequences from patient isolates deposited in GenBank to determine the frequency of mutations based on patient isolation site and disease status. The transcription factor binding sites (TFBS) were also analyzed to understand how these rearrangements could influence viral transcription. It was determined that the number of TFBS was significantly higher in PML samples compared to non-PML samples. Additionally, TFBS that could promote JCPyV infection were more prevalent in samples isolated from the cerebrospinal fluid compared to other locations. Collectively, this research describes the extent of mutations in the NCCR that alter TFBS and how they correlate with disease outcome.
Orphan G-Protein Coupled Receptor GPRC5B Is Critical for Lymphatic Development
Authors: Xu Wenjing , Nelson-Maney Nathan P. , Bálint László , Kwon Hyouk-Bum , Davis Reema B. , Dy Danielle C. M. , Dunleavey James M. , St. Croix Brad , Caron Kathleen M.
Published: May 2022

Numerous studies have focused on the molecular signaling pathways that govern the development and growth of lymphatics in the hopes of elucidating promising druggable targets. G protein-coupled receptors (GPCRs) are currently the largest family of membrane receptors targeted by FDA-approved drugs, but there remain many unexplored receptors, including orphan GPCRs with no known biological ligand or physiological function. Thus, we sought to illuminate the cadre of GPCRs expressed at high levels in lymphatic endothelial cells and identified four orphan receptors: GPRC5B, AGDRF5/GPR116, FZD8 and GPR61. Compared to blood endothelial cells, GPRC5B is the most abundant GPCR expressed in cultured human lymphatic endothelial cells (LECs), and in situ RNAscope shows high mRNA levels in lymphatics of mice. Using genetic engineering approaches in both zebrafish and mice, we characterized the function of GPRC5B in lymphatic development. Morphant gprc5b zebrafish exhibited failure of thoracic duct formation, and Gprc5b−/− mice suffered from embryonic hydrops fetalis and hemorrhage associated with subcutaneous edema and blood-filled lymphatic vessels. Compared to Gprc5+/+ littermate controls, Gprc5b−/− embryos exhibited attenuated developmental lymphangiogenesis. During the postnatal period, ~30% of Gprc5b−/− mice were growth-restricted or died prior to weaning, with associated attenuation of postnatal cardiac lymphatic growth. In cultured human primary LECs, expression of GPRC5B is required to maintain cell proliferation and viability. Collectively, we identify a novel role for the lymphatic-enriched orphan GPRC5B receptor in lymphangiogenesis of fish, mice and human cells. Elucidating the roles of orphan GPCRs in lymphatics provides new avenues for discovery of druggable targets to treat lymphatic-related conditions such as lymphedema and cancer.
IL-17A Is the Critical Cytokine for Liver and Spleen Amyloidosis in Inflammatory Skin Disease
Authors: Iida Shohei , Nakanishi Takehisa , Momose Fumiyasu , Ichishi Masako , Mizutani Kento , Matsushima Yoshiaki , Umaoka Ai , Kondo Makoto , Habe Koji , Hirokawa Yoshifumi , Watanabe Masatoshi , Iwakura Yoichiro , Miyahara Yoshihiro , Imai Yasutomo , Yamanaka Keiichi
Published: May 2022

Systemic amyloidosis is recognized as a serious complication of rheumatoid arthritis or inflammatory bowel disease, but also of inflammatory skin disease. However, the detailed molecular mechanism of amyloidosis associated with cutaneous inflammation remains unclear, and therapeutic approaches are limited. Here, we investigated the pathophysiology of amyloidosis secondary to cutaneous inflammation and the therapeutic effects of Janus kinase (JAK) inhibitors by examining a mouse model of spontaneous dermatitis (KCASP1Tg mice). Moreover, KCASP1Tg mice were crossed with interleukin-17A (IL-17A) knockout mice to generate IL-17A-/KCASP1Tg and examine the role of IL-17A in amyloidosis under cutaneous inflammation. KCASP1Tg mice showed severe amyloid deposition in the liver and spleen. Increased serum-neutral fat levels and decreased lymphocyte production were observed in the spleen. Overproduction of amyloidosis was partially ameliorated by the administration of JAK inhibitors and was further improved in IL-17A-/KCASP1Tg mice. IL-17A-producing cells included CD4, gamma delta, and CD8 T cells. In summary, our results from the analysis of a mouse model of dermatitis revealed that skin-derived inflammatory cytokines can induce amyloid deposition in the liver and spleen, and that the administration of JAK inhibitors and, even more, IL-17A ablation, reduced amyloidosis. This study demonstrates that active control of skin inflammation is essential to prevent internal organ amyloidosis.
Sulfated Phenolic Substances: Preparation and Optimized HPLC Analysis
Authors: Petrásková Lucie , Káňová Kristýna , Brodsky Katerina , Hetman Anastasiia , Petránková Barbora , Pelantová Helena , Křen Vladimír , Valentová Kateřina
Published: May 2022

Sulfation is an important reaction in nature, and sulfated phenolic compounds are of interest as standards of mammalian phase II metabolites or pro-drugs. Such standards can be prepared using chemoenzymatic methods with aryl sulfotransferases. The aim of the present work was to obtain a large library of sulfated phenols, phenolic acids, flavonoids, and flavonolignans and optimize their HPLC (high performance liquid chromatography) analysis. Four new sulfates of 2,3,4-trihydroxybenzoic acid, catechol, 4-methylcatechol, and phloroglucinol were prepared and fully characterized using MS (mass spectrometry), 1H, and 13C NMR. The separation was investigated using HPLC with PDA (photodiode-array) detection and a total of 38 standards of phenolics and their sulfates. Different stationary (monolithic C18, C18 Polar, pentafluorophenyl, ZICpHILIC) and mobile phases with or without ammonium acetate buffer were compared. The separation results were strongly dependent on the pH and buffer capacity of the mobile phase. The developed robust HPLC method is suitable for the separation of enzymatic sulfation reaction mixtures of flavonoids, flavonolignans, 2,3-dehydroflavonolignans, phenolic acids, and phenols with PDA detection. Moreover, the method is directly applicable in conjunction with mass detection due to the low flow rate and the absence of phosphate buffer and/or ion-pairing reagents in the mobile phase.
Vitamin K-Dependent Protein Activation: Normal Gamma-Glutamyl Carboxylation and Disruption in Disease
Authors: Berkner Kathleen L. , Runge Kurt W.
Published: May 2022

Vitamin K-dependent (VKD) proteins undergo an unusual post-translational modification, which is the conversion of specific Glu residues to carboxylated Glu (Gla). Gla generation is required for the activation of VKD proteins, and occurs in the endoplasmic reticulum during their secretion to either the cell surface or from the cell. The gamma-glutamyl carboxylase produces Gla using reduced vitamin K, which becomes oxygenated to vitamin K epoxide. Reduced vitamin K is then regenerated by a vitamin K oxidoreductase (VKORC1), and this interconversion of oxygenated and reduced vitamin K is referred to as the vitamin K cycle. Many of the VKD proteins support hemostasis, which is suppressed during therapy with warfarin that inhibits VKORC1 activity. VKD proteins also impact a broad range of physiologies beyond hemostasis, which includes regulation of calcification, apoptosis, complement, growth control, signal transduction and angiogenesis. The review covers the roles of VKD proteins, how they become activated, and how disruption of carboxylation can lead to disease. VKD proteins contain clusters of Gla residues that form a calcium-binding module important for activity, and carboxylase processivity allows the generation of multiple Glas. The review discusses how impaired carboxylase processivity results in the pseudoxanthoma elasticum-like disease.
Biomolecules under Pressure: Phase Diagrams, Volume Changes, and High Pressure Spectroscopic Techniques
Authors: Smeller László
Published: May 2022

Pressure is an equally important thermodynamical parameter as temperature. However, its importance is often overlooked in the biophysical and biochemical investigations of biomolecules and biological systems. This review focuses on the application of high pressure (>100 MPa = 1 kbar) in biology. Studies of high pressure can give insight into the volumetric aspects of various biological systems; this information cannot be obtained otherwise. High-pressure treatment is a potentially useful alternative method to heat-treatment in food science. Elevated pressure (up to 120 MPa) is present in the deep sea, which is a considerable part of the biosphere. From a basic scientific point of view, the application of the gamut of modern spectroscopic techniques provides information about the conformational changes of biomolecules, fluctuations, and flexibility. This paper reviews first the thermodynamic aspects of pressure science, the important parameters affecting the volume of a molecule. The technical aspects of high pressure production are briefly mentioned, and the most common high-pressure-compatible spectroscopic techniques are also discussed. The last part of this paper deals with the main biomolecules, lipids, proteins, and nucleic acids: how they are affected by pressure and what information can be gained about them using pressure. I I also briefly mention a few supramolecular structures such as viruses and bacteria. Finally, a subjective view of the most promising directions of high pressure bioscience is outlined.
upU-Net Approaches for Background Emission Removal in Fluorescence Microscopy
Authors: Benfenati Alessandro
Published: May 2022

The physical process underlying microscopy imaging suffers from several issues: some of them include the blurring effect due to the Point Spread Function, the presence of Gaussian or Poisson noise, or even a mixture of these two types of perturbation. Among them, auto–fluorescence presents other artifacts in the registered image, and such fluorescence may be an important obstacle in correctly recognizing objects and organisms in the image. For example, particle tracking may suffer from the presence of this kind of perturbation. The objective of this work is to employ Deep Learning techniques, in the form of U-Nets like architectures, for background emission removal. Such fluorescence is modeled by Perlin noise, which reveals to be a suitable candidate for simulating such a phenomenon. The proposed architecture succeeds in removing the fluorescence, and at the same time, it acts as a denoiser for both Gaussian and Poisson noise. The performance of this approach is furthermore assessed on actual microscopy images and by employing the restored images for particle recognition.
Volatile Characteristics of Apatite in Dacite from the Eastern Manus Basin and Their Geological Implications
Authors: Du Xiaoning , Zeng Zhigang , Chen Zuxing
Published: May 2022

As one of the youngest back-arc basins, the evolutionary behavior of magmatic volatiles in the Eastern Manus Basin has been poorly studied. Recently, apatite has received widespread attention for its powerful function in recording information on magmatic volatiles. In this paper, by determining the major element compositions and primary volatile abundances (F, Cl, SO3) of apatites in dacite, we analyze the compositions of volatiles before magma eruption in the Eastern Manus Basin, as well as their indications for magmatic oxygen fugacity and petrogenesis, so as to improve the study about the evolution of magmatic volatiles in this region. Experimental data indicate that apatite saturation temperatures range from 935 to 952 °C. All the apatites are magmatic apatites with F contents of 0.87−1.39 wt.%, Cl contents of 1.24−1.70 wt.%, and SO3 ≤ 0.06 wt.%. Analysis reveals that the apatites in this study crystallized from volatile-undersaturated melts, so their chemical compositions can be used as indicators of magmatic compositions. According to calculations, the minimum S concentrations of the host melts range from 2−65 ppm or 8−11 ppm. The crystallization and separation of magnetite caused the reduction state of melts, and the relatively low oxygen fugacity (ΔFMQ = −0.2 ± 0.9) caused low SO3 contents in apatites. In addition, F and Cl contents of the host melt were calculated to be 185−448 ppm and 1059−1588 ppm, corresponding to the H2O contents of 1.4−2.1% and 1.2−1.5% (error ± 30−40%), respectively. The high Cl/F ratio and H2O contents of samples indicate the addition of slab-derived fluids in the mantle source region of the Eastern Manus Basin. High F contents of the melts may be influenced by F-rich sediments, as well as the release of F from lawsonite and phengite decomposition. High Cl appears to originate from the dual influence of subduction-released fluids and Cl-rich seawater-derived components. Further, it is estimated that 14−21% of the total Cl concentrations in melts were added directly from subduction-released fluids, or higher.
Risk Assessment of Navigation Safety for Ferries
Authors: Hsu Wen-Kai K. , Chen Jun-Wen , Huynh Nguyen Tan , Lin Yan-You
Published: May 2022

This study aims to discuss a risk assessment of navigation safety for ferries. In this research, the risk factors (RFs) for the navigation safety of ferries are first investigated from relevant literature and ferry operational features. A fuzzy AHP (Analytic Hierarchical Process) approach is then proposed to weight those RFs, after which a continuous risk-matrix model is then developed to determine the RFs’ risk levels. Finally, to validate the practical application of the proposed model, ferries traveling across the Taiwan Strait were empirically investigated. The results may provide practical information for ferry operators to improve their safety performances. Further, the proposed risk assessment approach may provide references for related research in the safety management of short-distance passenger ships.
Sorbicillinoid Derivatives with the Radical Scavenging Activities from the Marine-Derived Fungus Acremonium chrysogenum C10
Authors: Duan Chengbao , Wang Shiyuan , Huo Ruiyun , Li Erwei , Wang Min , Ren Jinwei , Pan Yuanyuan , Liu Ling , Liu Gang
Published: May 2022

Sorbicillinoids are a class of structurally diverse hexaketide metabolites with good biological activities. To explore new structural sorbicillinoids and their bioactivities, the marine-derived fungus Acremonium chrysogenum C10 was studied. Three new sorbicillinoid derivatives, acresorbicillinols A–C (1–3), along with five known ones, trichotetronine (4), trichodimerol (5), demethyltrichodimerol (6), trichopyrone (7) and oxosorbicillinol (8), were isolated. The structures of new sorbicillinoids were elucidated by analysis of nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectroscopy (HRESIMS). The absolute configurations of compounds 1–3 were determined by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. Compound 3 exhibited a strong 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, with the IC50 value ranging from 11.53 ± 1.53 to 60.29 ± 6.28 μM in 24 h. Additionally, compounds 2 and 3 showed moderate activities against Staphylococcus aureus and Cryptococcus neoformans, with IC50 values of 86.93 ± 1.72 and 69.06 ± 10.50 μM, respectively. The boundary of sorbicillinoid biosynthetic gene cluster in A. chrysogenum was confirmed by transcriptional analysis, and the biosynthetic pathway of compounds 1–8 was also proposed. In summary, our results indicated that A. chrysogenum is an important reservoir of sorbicillinoid derivatives, and compound 3 has the potential for new natural agents in DPPH radical scavenging.
MAPK CcSakA of the HOG Pathway Is Involved in Stipe Elongation during Fruiting Body Development in Coprinopsis cinerea
Authors: Zhao Jing , Yuan Jing , Chen Yating , Wang Yu , Chen Jing , Bi Jingjing , Lyu Linna , Yu Cigang , Yuan Sheng , Liu Zhonghua
Published: May 2022

Mitogen-activated protein kinase (MAPK) pathways, such as the high-osmolarity glycerol mitogen-activated protein kinase (HOG) pathway, are evolutionarily conserved signaling modules responsible for transmitting environmental stress signals in eukaryotic organisms. Here, we identified the MAPK homologue in the HOG pathway of Coprinopsis cinerea, which was named CcSakA. Furthermore, during the development of the fruiting body, CcSakA was phosphorylated in the fast elongating apical part of the stipe, which meant that CcSakA was activated in the apical elongating stipe region of the fruiting body. The knockdown of CcSakA resulted in a shorter stipe of the fruiting body compared to the control strain, and the expression of phosphomimicking mutant CcSakA led to a longer stipe of the fruiting body compared to the control strain. The chitinase CcChiE1, which plays a key role during stipe elongation, was downregulated in the CcSakA knockdown strains and upregulated in the CcSakA phosphomimicking mutant strains. The results indicated that CcSakA participated in the elongation of stipes in the fruiting body development of C. cinerea by regulating the expression of CcChiE1. Analysis of the H2O2 concentration in different parts of the stipe showed that the oxidative stress in the elongating part of the stipe was higher than those in the non-elongating part. The results indicated that CcSakA of the HOG pathway may be activated by oxidative stress. Our results demonstrated that the HOG pathway transmits stress signals and regulates the expression of CcChiE1 during fruiting body development in C. cinerea.
Research on the Response of Ecosystem Service Function to Landscape Pattern Changes Caused by Land Use Transition: A Case Study of the Guangxi Zhuang Autonomous Region, China
Authors: Liu Yongqiang , Wang Shuang , Chen Zipeng , Tu Shuangshuang
Published: May 2022

Land use transitions cause reconfigurations of regional landscape patterns which can further change the regional ecosystem service functions and its values, especially in environmentally fragile regions. Firstly, this paper theoretically examines the relationships between land use transitions, landscape pattern evolution and the responses of ecosystem service functions in the Guangxi Zhuang Autonomous Region (Guangxi). Then, it explores the spatio-temporal evolution features of land use transition by using land use change matrices, examines landscape patterns by using the landscape pattern index, and studies ecosystem service value (ESV) by revising the coefficients of ESV per unit area. Finally, focus is placed on the empirical analysis of ESV responses to landscape pattern evolution caused by land use transitions in Guangxi. The results show that: (1) Guangxi has undergone an overall intensity-changing process of land use transition at a moderate rate during 1990–2010 and at a drastic rate during 2010–2018. In general, the area of construction land and waterbodies has increased, while forested land, grassland and farmland have decreased. Landscape fragmentation and heterogeneity are higher in the central area than that in the surrounding areas, while patch aggregation and connectivity show an opposite trend. Forested land patches are highly clustered, while grassland and farmland are fragmented and scattered and construction land patches tend to have aggregated. (2) The total loss of ESV has reached 20.56 billion RMB in Guangxi, and all areas’ single ESVs have decreased to different degrees during the past 28 years. Spatially, the ESV distribution shows a differentiated pattern of low in the central plain and high in the surrounding mountain regions which are mainly dominated by high-value zones. (3) The total ESV has significant positive correlations with the largest patch index (LPI), COHESION and the Aggregation Index (AI), and significant negative correlations with the Number of Patches (NP) and the Shannon Diversity Index (SHDI), while the correlation with the Landscape Shape Index (LSI) is not significant, indicating that the influence on ESV caused by landscape pattern evolution varies greatly. (4) The change of land area and multi-directional shifts among different land use types caused by land use transitions in Guangxi could both lead to the evolution of landscape patterns. Further, ecological service function responded obviously to the landscape pattern evolution in Guangxi, causing significant changes in strengthening or weakening of the ecological service function and its value. This systematic analysis should help coordinate the relationship of regional land use regulation, landscape pattern optimization and ecosystem operation in Guangxi or even China.
In Vitro Osteogenesis Stimulation via Nano-Hydroxyapatite/Carbon Nanotube Thin Films on Biomedical Stainless Steel
Authors: Martinelli Natalia M. , Ribeiro Maria Julia G. , Ricci Ritchelli , Marques Miller A. , Lobo Anderson Oliveira , Marciano Fernanda Roberta
Published: May 2022

We evaluated the electrophoretic deposition of nanohydroxyapatite/superhydrop hilic multiwalled carbon nanotube composites (nHAp/MWCNT) onto stainless steel biomedical alloys for applications in bone tissue engineering. First, nHAp/MWCNT composites were dispersed into 0.042 mol·L−1 of Ca(NO3)2·4H2O + 0.025 mol·L−1 NH4H2PO4 electrolytes (pH = 4.8) at two different concentrations. Next, a voltage of −2 V was applied using 316L stainless steel as a working electrode (0.27 cm2), a high-purity platinum coil wire was used as the auxiliary electrode, and an Ag/AgCl (3 M) electrode was used as the reference electrode. The nHAp/MWCNT composites were characterized by transmission electron microscopy. The deposited nHAp and nHAp/MWCNT films were characterized by profilometry, scanning electron microscopy, X-ray diffractometry and Raman spectroscopy. Human osteoblast cells were cultivated with the different materials and in vitro cytotoxicity was evaluated using lactate dehydrogenase (LDH) assay. The osteogenesis process was evaluated by mRNA levels of the three genes that are directly related to bone repair: Alkaline Phosphatase, Osteopontin and Osteocalcin. We showed that rough, crystalline apatite thin films containing phases of nHAp were successfully deposited onto 316L stainless steel alloys. Also, we noticed that nHAp/MWCNT thin films deposited onto 316L stainless steel alloys upregulated the expression of important genes related to bone mineralization and maturation. Our results strongly support the possibility of this new alternative to modify the surface of metallic biomedical alloys to promote bone tissue regeneration.
Synthesis of Honeycomb-Like Co3O4 Nanosheets with Excellent Supercapacitive Performance by Morphological Controlling Derived from the Alkaline Source Ratio
Authors: Jia Wanli , Li Jun , Lu Zhongjie , Juan Yongfei , Jiang Yunqiang
Published: May 2022

Honeycomb-like Co3O4 nanosheets with high specific surface area were successfully synthesized on porous nickel foam by the facile hydrothermal method followed by an annealing treatment (300 °C), which were used as high-performance supercapacitor electrodes. The effects of the mole ratio of hexamethylenetetramine (HMT) and Co(NO3)2 (1:1, 2:1, 3:1, 4:1, 5:1 and 6:1) as the reactants on the morphological evolution and electrochemical performance of the electrodes were investigated in detail. X-ray diffractometry (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) were applied to characterize the structure and morphology of the products. The electrochemical performance was measured by cyclic voltammetry (CV) and galvanostatic charge/discharge. The mole ratio of HMT and Co(NO3)2 produced a significant effect on the morphological evolution of Co3O4. The morphological evolution of Co3O4 with the increase in the mole ratio was followed: the nanosheets accompanied with a large number of spherical nanoparticles → the formation of some strip-like particles due to the agglomeration of spherical nanoparticles → the formation of new nanosheets resulting from the growth of strip-like particles → the formation of coarse flower-like particles owing to the connection among the nanosheets → the nanosheets gradually covered with flower-like particles. Accompanied with the change, the specific surface area was increased firstly, and then decreased. A maximum was obtained at a HMT and Co(NO3)2 mole ratio of 4:1. The evolution in morphology of Co3O4 was responsible for the change in electrochemical performance of the electrode. The specific capacitance value of the electrode prepared at a HMT and Co(NO3)2 mole ratio of 4:1 was highest (743.00 F·g−1 at 1 A·g−1 in the galvanostatic charge/discharge test). The similar result was also observed in the CV test with a scanning rate of 5 mV·s−1. Moreover, the electrode also demonstrated an excellent cyclic performance, in which about 97% of the initial specific capacitance remained at 1 A·g−1 for 500 cycles in the galvanostatic charge/discharge test. This excellent electrochemical performance was ascribed to high specific surface area of Co3O4 nanosheets that provide added channels and space for the ions transportation.
Elevated-Temperature Tensile Properties of Low-Temperature HIP-Treated EBM-Built Ti-6Al-4V
Authors: Thalavai Pandian Karthikeyan , Neikter Magnus , Bahbou Fouzi , Hansson Thomas , Pederson Robert
Published: May 2022

Evaluation of the high-temperature tensile properties of Ti-6Al-4V manufactured by electron beam melting (EBM) and subjected to a low-temperature hot isostatic pressing (HIP) treatment (800 °C) was performed in this study. The high-temperature tensile properties of as-built and standard HIP-treated (920 °C) materials were studied for comparison. Metallurgical characterization of the as-built, HIP-treated materials was carried out to understand the effect of temperature on the microstructure. As the HIP treatments were performed below the β-transus temperature (995 °C for Ti-6Al-4V), no significant difference was observed in β grain width between the as-built and HIP-treated samples. The standard HIP-treated material measured about 1.4×–1.7× wider α laths than those in the modified HIP (low-temperature HIP)-treated and as-built samples. The standard HIP-treated material showed about a 10–14% lower yield strength than other tested materials. At 350 °C, the yield strength decreased to about 65% compared to the room-temperature strength for all tested specimens. An increase in ductility was observed at 150 °C compared to that at room temperature, but the values decreased between 150 and 350 °C because of the activation of different slip systems.
Influence of the Milling Conditions of Aluminium Alloy 2017A on the Surface Roughness
Authors: Nowakowski Lukasz , Bartoszuk Marian , Skrzyniarz Michal , Blasiak Slawomir , Vasileva Dimka
Published: May 2022

The article presents the results and process analysis of the face milling of aluminium alloy 2017A with the CoroMill 490 tool on an AVIA VMC 800 vertical milling centre. The study analysed the effects of the cutting speed, the feed rate, the actual number of teeth involved in the process, the minimum thickness of the cut layer (hmin), and the relative displacement in the tool-workpiece system D(ξ) on the surface roughness parameter Ra. To measure relative displacement, an original bench was used with an XL-80 laser interferometer. The analysis of relative displacement and surface roughness allowed these factors to be correlated with each other. The purpose of this article is to determine the stable operating ranges of the CoroMill 490-050Q22-08M milling head with respect to the value of the generated relative displacement w during the face-milling process and to determine its influence on surface roughness. The research methodology presented in this paper and the cutting tests carried out allowed the determination of the optimum operating parameters of the CoroMill 490-050Q22-08M tool during the face milling of aluminium alloy 2017A, which are vc 300 m/m and fz—0.14 mm/tooth. Working with the defined cutting parameters allows all the cutting inserts in the tool body to be involved in shaping the geometrical structure of the surface, while maintaining a low vibration level D(ξ) > 1 µm, a low value of the parameter hmin > 1.5 µm, and the desired value of the parameter Ra > 0.2 µm
Influence of Different Welding Parameters on the Morphology, Microstructure, and Mechanical Properties of 780 Duplex-Phase Steel Laser Lap Welded Joint
Authors: Cui Shuwan , Pang Shuwen , Zhang Suojun , Liao Yong , Cai Hongfeng
Published: May 2022

This paper attempted to establish a relationship between the morphology, microstructure and mechanical properties of a laser lap welded joint (WJ) of 780 duplex-phase (DP) steel under different welding parameters. The experimental results showed that the microstructure of the heat-affected zone (HAZ) of all the WJs were tempered martensite and equiaxed ferrite. The microstructure at the fusion zone (FZ) in all the WJs was dominated by lath martensite and ferrite, and the grain size of the FZ was larger than that in the base materials (BMs). The mechanical properties of the welded joints were tested by a universal testing machine, and the changing law of lap tensile resistance with the laser-welding parameters was analyzed. The results show that there was a linear relationship between the width of the weld and the tensile-shear forces of the weld, and the penetration of the weld had no obvious effect on the tensile-shear forces of the weld. A binary linear-regression equation was established to reveal the degree of influence of welding speed and laser power on the mechanical properties of WJs. It was found that the laser power had a greater influence on the mechanical properties of WJs than the welding speed.
The Influence of Nanographite Addition on the Compaction Process and Properties of AISI 316L Sintered Stainless Steel
Authors: Kozub Barbara , Uthayakumar Marimuthu , Kazior Jan
Published: May 2022

This paper presents the effect of graphite addition on the pressing process and selected mechanical properties of AISI 316L austenitic stainless steel. The graphite powders used in this study differed in the value of the specific surface area of the particles, which were 15 (micropowder), 350, and 400 m2/g (nanopowder). Mixtures with the addition of lubricants—stearic acid and Kenolube—were also created, for comparison purposes. The scope of the tests included compressibility of blends, measurements of the ejection force while removing the compacts from the die, micro-structural studies, a static tensile test, a three-point bending test, a Kc impact test, Rockwell hardness, and Vickers microhardness measurements. The study demonstrated that the addition of graphite nanopowder to the studied steel acts as a lubricant, providing a significant improvement in lubricity during the pressing process. Moreover, the addition of nanographite allowed for a significant increase in the mechanical properties studied in this work; it was observed that, for the sinters made of mixtures with a higher graphite content and with a large specific surface area of its particles, better values for the tested properties were obtained.
Special Issue: Photocatalytic Materials for Environment Treatment and Energy Production
Authors: Isac Luminita
Published: May 2022

Nowadays, given the major problems facing humanity, the increasing environmental pollution and the need for sustainable and cheap energy sources represent important research issues [...]
Effect of Cell Morphology on Flexural Behavior of Injection-Molded Microcellular Polycarbonate
Authors: Güzel Kübra , Zarges Jan-Christoph , Heim Hans-Peter
Published: May 2022

The quantitative study of the structure and properties relationship in cellular materials is mostly limited to cell diameter, cell density, skin layer thickness, and cell size distribution. In addition, the investigation of the morphology is generally carried out in two dimensions. Therefore, the interrelation between morphological properties and mechanical characteristics of the foam structure has remained in an uncertain state. In this study, during the physical foaming process, a foam morphology is locally created by using a mold equipped with a core-back insert. The variation in morphology is obtained by modifying the mold temperature, injection flow rate, and blowing agent content in the polymer melt. X-ray microtomography (μCT) is used to acquire the 3D visualization of the cells structure. The Cell Distribution Index (CDI) is calculated to represent the polydispersity in cell size distribution. The relationship between the wide range of morphological qualities and relevant flexural properties is made explicit via a statistical model. According to the results, the morphology, particularly cell shape, characterizes the mechanism of the linear elastic deformation of the closed-cell foams. IR-thermography reveals the bending failure of cellular structures in the tensile region despite the differences in cell diameter.