bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on failure criteria and collapse height of roadway roof strata based on energy accumulation and dissipation characteristics
Authors: Li Zhu , Zhang Hong , Jiang Ze , Feng Guorui , Cui Jiaqing , Ma Jingkai 
Published: May 2021

AbstractRoof collapse is a form of rock failure driven by energy release. The rectangular elastic thin plate (RETP) model, widely used in coal mining engineering research, reflects the law of the movement of overlying strata of a coal seam. The stress distribution regularity of each delamination can be analyzed using the theoretical model of RETPs. In this study, a new method for determining both the height of the caving zone and the damaged area of the roadway roof is developed based on the energy evolution law. The damaged area and the oval‐shaped boundary of each stratum are determined using the damage criterion deduced by calculating the strain energy of the elementary volume. As a case study, the collapse height was obtained by accumulating the thickness of damaged strata, and the length of bolts was increased from 2.2 m to 2.8 m, effectively preventing the reoccurrence of a roof collapse for the No. 30102 working face in Nanliang Coal Mine. In addition, the vertical boundary of the caved zone can be outlined by connecting and fitting the end vertexes of the minor axis in the oval‐shaped damaged area of the RETPs. The supporting angle of the bolts in two side walls of the roadway was decreased from 75° to 70°. This method was verified and applied in a roof collapse investigation by determining the length and drilling angle of the anchor rod and anchor cable required to develop reasonable support schemes. The results of this research can be used for ensuring safety in coal mining and subway or tunnel construction in China.
A comparative study of phytochemical investigation and antioxidative activities of six citrus peel species
Authors: Olfa Taktak , Gargouri Manel , Akrouti Amel , Brits Maxime , Gargouri Mahmoud , Ben Ameur Raoudha , Pieters Luc , Foubert Kenn , Magné Christian , Soussi Ahlem , Allouche Noureddine 
Published: May 2021

AbstractOver the past few decades, much effort has been devoted to the study of known food products for medicinal applications. Among these, citrus fruits play a key role in providing a wide range of health‐beneficial effects but it generates a huge amount of waste products. In an attempt to recover those wastes, peel of six citrus species (C aurantium, C limetta,C limon, C reticulata, C Sinensis osbeck, and C Sinensis thomson) was evaluated for yield, physicochemical properties, phenolic constituents and antioxidant activities. LC‐MS/MS analysis showed that the flavonoids neoeriocitrin, luteolin‐7‐O‐neohesperidoside, scoparin and neohesperidin were chemical markers for C limetta, whereas apigenin‐6,8‐di‐C‐glycoside was only detected in C Sinensis Osbeck. PCA analysis revealed signiﬁcant correlations between antioxidant activities and phenolic contents, highlighting a large interspecific variability. These results suggest that Citrus peel by‐products may be valuably recycled by industries due to their high yield and transformed into value‐added products, with potential interest for the development of functional foods, cosmetics or preventive therapies for some diseases.
Numerical study on filtration law of supercritical carbon dioxide fracturing in shale gas reservoirs
Authors: Luo Zhifeng , Wu Lin , Zhao Liqiang , Zhang Nanlin , Chen Weihua , Liang Chong 
Published: May 2021

AbstractSupercritical carbon dioxide (SC‐CO2) fracturing can form more complex fracture network and avoid reservoir damage, making it a lucrative alternative to hydraulic fracturing in shale gas reservoirs. This study establishes a two‐dimensional dynamic filtration model of SC‐CO2 fracturing, which considers stress sensitivity, fluid adsorption, dynamic changes of fluid physical parameters, and coupled fracture propagation. According to the established model, the dynamic filtration of fracture elements and matrix pressure variation in fracture propagation are simulated and analyzed. And the influence of dynamic and static filtration model, constant and variable SC‐CO2 physical parameters, and fluid types in the filtration areas on the calculation results, as well as the effects of stress sensitivity and fluid adsorption on the filtration process are analyzed. The results show that during the fracturing process, fracture elements’ average filtration rate gradually drops and finally becomes stable, while the cumulative filtration volume increases nearly linearly. The static filtration model of uncoupled fracture propagation or the simplification of fluid in the filtration areas to SC‐CO2 single phase provides the reduction of calculation results, while constant SC‐CO2 physical parameters or the fluid simplification to the methane (CH4) single phase have the opposite effect. Stress sensitivity can accelerate the filtration, while fluid adsorption can slow down the filtration. The influence of stress sensitivity is maximal at the middle stage of fracturing, while the influence of fluid adsorption weakens with time. This study's findings have important guiding significance for the optimal design and field application of SC‐CO2 fracturing in shale gas reservoirs. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd.
Differences in risk factors for molecular subtypes of clear cell renal cell carcinoma
Authors: Purdue Mark P. , Rhee Jongeun , Moore Lee , Gao Xiaohua , Sun Xuezheng , Kirk Erin , Bencko Vladimir , Janout Vladimir , Mates Dana , Zaridze David , Petruzella Stacey , Hakimi Abraham Ari , Linehan William Marston , Chanock Stephen J. , Brennan Paul , Furberg Helena , Troester Melissa , Rothman Nathaniel 
Published: May 2021

AbstractThe ccA and ccB molecular subtypes of clear cell renal cell carcinoma (ccRCC) have well‐characterized prognostic relevance. However, it is not known whether they possess distinct etiologies. We investigated the relationships between these subtypes and RCC risk factors within a case‐control study conducted in Eastern Europe. We analyzed risk factor data for ccA (n = 144) and ccB (n = 106) cases and 1476 controls through case‐only and case‐control comparisons to assess risk factor differences across subtypes using logistic and polytomous regression models. We also performed a meta‐analysis summarizing case‐only results from our study and three patient cohorts. Patients with ccB tumors had poorer survival than those with ccA tumors and were more likely to be male (case‐only odds ratio [OR] 2.68, 95% confidence interval [CI] 1.43‐5.03). In case‐control analyses, body mass index was significantly associated with ccA tumors (OR 2.45, 95% CI 1.18‐5.10 for ≥35 vs <25 kg/m2) but not with ccB tumors (1.52, 0.56‐4.12), while trichloroethylene was associated with ccB but not ccA (OR 3.09, 95% CI 1.11‐8.65 and 1.25, 0.36‐4.39 respectively for ≥1.58 ppm‐years vs unexposed). A polygenic risk score of genetic variants identified from genome‐wide association studies was associated with both ccA and, in particular, ccB (OR 1.82, 1.11‐2.99 and 2.87, 95% CI 1.64‐5.01 respectively for 90th vs 10th percentile). In a meta‐analysis of case‐only results including three patient cohorts, we still observed the ccB excess for male sex and the ccA excess for obesity. In conclusion, our findings suggest the existence of etiologic heterogeneity across ccRCC molecular subtypes for several risk factors.
Acute and subacute toxicity evaluation of Houttuynia cordata ethanol extract and plasma metabolic profiling analysis in both male and female rats
Authors: Chen Hongjiang , Sha Xiuxiu , Luo Yiyuan , Chen Jianwei , Li Xiang , Wang Juan , Cao Gang , Peng Xin 
Published: May 2021

AbstractHouttuynia cordata has been used as a traditional medicine for more than 1500 years. It has aroused wide public concern about its safety in the past few years, for it contains various aristolactams. However, the safety of H. cordata extract remains unclear. In the present study, single dose (2000 mg/kg) and subacute (250, 500, and 1000 mg/kg/day for 28 days) oral toxicity studies of the 95% ethanol extract of H. cordata (HCE) were performed in both male and female Sprague–Dawley (SD) rats. Hematological, biochemical, histopathological parameters, and plasma metabolic profiling were assessed. The single‐dose toxicity of HCE was more than 2000 mg/kg. The subacute toxicity results showed that no significant adverse effect of HCE was observed at 250 mg/kg/day. However, five rats died in 500 and 1000 mg/kg/day groups and exhibited toxicities to liver and kidney. Plasma metabolic profiling analysis suggested that a number of metabolic disturbances were induced by oral administration of HCE, focusing on energy metabolism, amino acid metabolism, and lipids metabolism. Moreover, it appeared that male rats were more susceptible to the toxic effects of HCE than female rats. Therefore, in this preliminary study, oral administration of HCE 250 mg/kg/day can be regarded as the no observed adverse effect level in rats over 28 days. However, long‐term use of HCE with large doses exhibited some hepatotoxicity and nephrotoxicity in rats.
Cr(VI)‐induced DNA damage is lessened by the modulation of hsp70 via increased GSH de novo synthesis in Drosophila melanogaster
Authors: Chaouhan Hitesh S. , Jha Rakesh R. , Patel Devendra K. , Kar Chowdhuri Debapratim 
Published: May 2021

AbstractHexavalent chromium [Cr(VI)] is a genotoxic chemical, and in the chemical‐exposed organism, oxidative stress is one of the leading causative mechanisms of genotoxicity. Heat shock protein‐70 (Hsp70) is reported to be modulated in environmental chemical exposed organisms. Inadequate information on the protective role of Hsp70 in chemical‐induced DNA lesions prompted us to investigate this possibility in a well‐studied genetically tractable in vivo model Drosophila melanogaster. In the midgut cells of Cr(VI)‐exposed hsp70‐knockout (KO), ‐knockdown (KD), and ‐overexpression Drosophila strains, no significant change in double‐strand breaks generation was observed in comparison to similarly exposed w

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and the respective genetic control strain after 48 h. Therefore, the role of hsp70 was investigated on oxidative DNA damage induction in the exposed organisms after 24 h. Oxidized DNA lesions (particularly oxidized purine‐based lesions), 8‐oxo‐dG level, and oxidative stress endpoints were found to be significantly elevated in hsp70‐KO and ‐KD strains in comparison to similarly exposed w

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and respective genetic control strain. On the contrary, in ubiquitous hsp70‐overexpression strain exposed to Cr(VI), these endpoints were significantly lowered concurrently with increased GSH level through elevated gclc, and gclm expression, Gclc level, and GCL activity. The study suggests that as a consequence of hsp70 overexpression, the augmented GSH level in cells vis‐a‐vis GSH de novo synthesis can counteract Cr(VI)‐induced oxidized DNA lesions.
On the performance of the Black and Scholes options pricing formulas during the subprime and Covid‐19 crises
Authors: Redroban Shirley , Cifuentes Arturo 
Published: May 2021

AbstractWe examine the performance of the Black‐Scholes (B‐S) formulas around (i.e., before, during and after) two periods of market stress: the subprime crisis (October, 2008) and the onset of the Covid‐19 pandemic (March, 2020). This is interesting for two reasons. First, most studies regarding the accuracy of the B‐S formulas have been done under regular or normal market conditions (granted, a fuzzy concept), not under conditions of severe market stress. And second, these two crises are quite different in nature. The subprime crisis was generated within a specific segment of the capital markets and affected only some sectors of the economy; the Covid‐19 crisis was due to an external shock and still continues to have a much wider impact. We find, in agreement with previous studies under different circumstances, that the accuracy of these formulas is very poor. Moreover, we find that the degree of mispricing, which is significant and in many cases exceed 100%, is manifest in both crises, and in all scenarios analyzed.
Unsulfated biotechnological chondroitin by itself as well as in combination with high molecular weight hyaluronan improves the inflammation profile in osteoarthritis in vitro model
Authors: Vassallo Valentina , Stellavato Antonietta , Cimini Donatella , Pirozzi Anna V. A. , Alfano Alberto , Cammarota Marcella , Balato Giovanni , D'Addona Alessio , Ruosi Carlo , Schiraldi Chiara 
Published: May 2021

AbstractSeveral studies suggest that inflammation has a pivotal role during the progression of osteoarthritis (OA) and cytokines have been identified as the main process mediators. This study aimed to explore the ability to modulate the main OA pro‐inflammatory biomarkers of novel gels (H‐HA/BC) based on high molecular weight hyaluronan (H‐HA) and unsulfated biotechnological chondroitin (BC). For the first time, BC was tested also in combination with H‐HA on human primary cells isolated from pathological knee joints. Specifically, the experiments were performed using an OA in vitro model based on human chondrocytes and synoviocytes. To evaluate the anti‐inflammatory effects of H‐HA/BC in comparison with H‐HA and BC single gels, NF‐kB, COMP‐2, MyD88, MMP‐13 and a wide range of cytokines, known to be specific biomarkers in OA (e.g., IL‐6, IL‐8, and TNF‐α), were evaluated. In addition, cell morphology and proliferation occurring in the presence of either H‐HA/BC or single components were assessed using time‐lapse video microscopy. It was shown that synovial fluids and cells isolated from OA suffering patients, presented a cytokine pattern respondent to an ongoing inflammation status. H‐HA and BC significantly reduced the levels of 23 biomarkers associated with cartilage damage. However, H‐HA/BC decreased significantly 24 biological mediators and downregulated 19 of them more efficiently than the single components. In synoviocytes cultures, cytokine analyses proved that H‐HA/BC gels re‐established an extracellular environment more similar to a healthy condition reducing considerably the concentration of 11 analytes. Instead, H‐HA and BC significantly modulated 7 (5 only with a longer treatment) and 8 biological cytokines, respectively. Our results suggest that H‐HA/BC beyond the viscosupplementation effect typical for HA‐based gels, can improve the inflammation status in joints and thus could be introduced as a valid protective and anti‐inflammatory intraarticular device in the field of Class III medical devices for OA treatments.
Novel nanocomposite of biochar‐zerovalent copper for lead adsorption
Authors: Din Salah Ud , Awan Junaid Murtaza , Imran Muhammad , Zain‐Ul‐Abdin  , Haq Sirajul , Hafeez Muhammad , Hussain Sajjad , Khan Muhammad Sarfraz 
Published: May 2021

AbstractIn this study, a composite of zerovalent copper‐biochar was investigated for its ability to remove lead from water. The prepared material was characterized by using scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), X‐ray diffractomter (XRD), and X‐ray photoelectron spectroscopy (XPS). The pH effect on adsorption of lead was investigated within the range of 2–8 and the effect of temperature was studied at 303, 308, 313, and 318 K. The kinetics of lead adsorption on biochar composite was evaluated and the equilibrium time of 12 hr was established. To further evaluate the nature of adsorption, Langmuir model was tested and the adsorption capacities were evaluated for lead adsorption on the surface of copper biochar composite. The activation energy, entropy, and enthalpy values indicated the adsorption phenomenon to be chemisorptive and spontaneous in nature. Comparison of adsorption capacities with the reported adsorbents in the literature concluded zerovalent copper‐biochar composite to be an efficient adsorbent for the removal of lead in the experimental conditions under study.Research Highlights
Highly efficient composite of zerovalent copper with biochar was synthesized for lead adsorption.
XPS and XRD shows the presence of zerovalent copper in the biochar composite.
pH and temperature were the main governing factors in the adsorption process.
Adsorption capacity for lead is higher than many of the reported adsorbents.
VEGF165 gene‐modified human umbilical cord blood mesenchymal stem cells protect against acute liver failure in rats
Authors: Chen Haiou , Tang Shigang , Liao Jinmao , Liu Meng , Lin Yihe 
Published: May 2021

AbstractBackgroundHuman umbilical cord blood mesenchymal stem cells (HUCB‐MSCs) can exert a protective effect in rat models of acute liver failure (ALF). Vascular endothelial growth factor 165 (VEGF165) is the predominant VEGF isoform and possesses a strong pro‐angiogenic function. In the present study, HUCB‐MSC served as the gene delivery vehicle for the VEGF165 gene, and we explored the therapeutic effects of this system on ALF.MethodsHUCB‐MSCs were infected with an adenovirus expressing green fluorescent protein (GFP)‐VEFG fusion protein (Ad‐VEGF165) to overexpress VEGF165 or an adenovirus expressing GFP (Ad‐GFP) as control. The control and modified HUCB‐MSCs were then transplanted into ALF model rats. Liver function and liver pathological changes were assessed by biochemical tests and liver histology. Immunohistochemistry was carried out to determine the expression of, CD34, Ki67 and VEGF.ResultsVEGF165 overexpression enhanced the multipotency of HUCB‐MSCs and promoted the homing and colonization of HUCB‐MSC in the liver tissues of ALF rats. Furthermore, although HUCB‐MSC transplantation ameliorated liver damage and promoted liver regeneration to some extent in ALF rats, Ad‐VEGF165‐HUCB‐MSC transplantation showed stronger therapeutic effects on ALF.ConclusionsIn summary, transplantation of VEGF165‐modified HUCB‐MSCs exert stronger therapeutic effects on ALF than HUCB‐MSCs. The present study provides a novel therapeutic approach for ALF.
Longitudinal analysis of microfinance borrowers in Brazil: A dynamic market segmentation
Authors: de Souza Lucas Lopes Ferreira , Bassi Francesca , de Freitas Ana Augusta Ferreira 
Published: May 2021

AbstractThis study uses a dynamic modelling approach to group clients of a microcredit programme in Brazil and follows them over time. Five segments are identified based on variables related to business, owners, families and operations performed within the programme. Results show that borrowers' circumstances are diverse and different actions are needed for each group. Many customers remained in the same segment; some moved to segments with worse conditions. However, the fact that one fourth of borrowers improved conditions is promising, considering the risky nature of entrepreneurial activity and the Brazilian economic context. Our analyses show that mission drift does not occur.
Porphyromonas gingivalisinduces periodontitis, causes immune imbalance, and promotes rheumatoid arthritis
Authors: Zhou Niu , Zou Fagui , Cheng Xiao , Huang Yilian , Zou Hang , Niu Qingru , Qiu Yi , Shan Fen , Luo Aoxiang , Teng Wei , Sun Jianbo 
Published: May 2021

AbstractPeriodontitis induced by bacteria especially Porphyromonas gingivalis (P. gingivalis) is the most prevalent microbial disease worldwide and is a significant risk factor for systemic diseases such as rheumatoid arthritis (RA). RA and periodontitis share similar clinical and pathologic features. Moreover, the prevalence of RA is much higher in patients with periodontitis than in those without periodontitis. To explore the immunologic mechanism of periodontitis involved in RA, we established a mouse model of periodontitis and then induced RA. According to the results of paw thickness, arthritis clinical score, arthritis incidence, microscopic lesion using H&E staining, and micro-CT analysis, periodontitis induced by P. gingivalis promoted the occurrence and development of collagen-induced arthritis (CIA) in mice. Furthermore, periodontitis enhanced the frequency of CD19+ B cells, Th17, Treg, gMDSCs, and mMDSCs, whereas down-regulated IL-10 producing regulatory B cells (B10) in CIA mice preinduced for periodontitis with P. gingivalis. In vitro stimulation with splenic cells revealed that P. gingivalis directly enhanced differentiation of Th17, Treg, and mMDSCs but inhibited the process of B cell differentiation into B10 cells. Considering that adoptive transfer of B10 cells prevent RA development, our study, although preliminary, suggests that down-regulation of B10 cells may be the key mechanism that periodontitis promotes RA as the other main immune suppressive cells such as Treg and MDSCs are up-regulated other than down-regulated in group of P. gingivalis plus CIA.
Severe COVID-19 is marked by dysregulated serum levels of carboxypeptidase A3 and serotonin
Authors: Soria-Castro Rodolfo , Meneses-Preza Yatsiri G , Rodríguez-López Gloria M , Romero-Ramírez Sandra , Sosa-Hernández Víctor A , Cervantes-Díaz Rodrigo , Pérez-Fragoso Alfredo , Torres-Ruíz José J , Gómez-Martín Diana , Campillo-Navarro Marcia , Álvarez-Jiménez Violeta D , Pérez-Tapia Sonia M , Chávez-Blanco Alma D , Estrada-Parra Sergio , Maravillas-Montero José L , Chacón-Salinas Rommel 
Published: May 2021

AbstractThe immune response plays a critical role in the pathophysiology of SARS-CoV-2 infection ranging from protection to tissue damage and all occur in the development of acute respiratory distress syndrome (ARDS). ARDS patients display elevated levels of inflammatory cytokines and innate immune cells, and T and B cell lymphocytes have been implicated in this dysregulated immune response. Mast cells are abundant resident cells of the respiratory tract and are able to release different inflammatory mediators rapidly following stimulation. Recently, mast cells have been associated with tissue damage during viral infections, but their role in SARS-CoV-2 infection remains unclear. In this study, we examined the profile of mast cell activation markers in the serum of COVID-19 patients. We noticed that SARS-CoV-2-infected patients showed increased carboxypeptidase A3 (CPA3) and decreased serotonin levels in their serum when compared with symptomatic SARS-CoV-2-negative patients. CPA3 levels correlated with C-reactive protein, the number of circulating neutrophils, and quick SOFA. CPA3 in serum was a good biomarker for identifying severe COVID-19 patients, whereas serotonin was a good predictor of SARS-CoV-2 infection. In summary, our results show that serum CPA3 and serotonin levels are relevant biomarkers during SARS-CoV-2 infection. This suggests that mast cells and basophils are relevant players in the inflammatory response in COVID-19 and may represent targets for therapeutic intervention.