43 research outputs found

    New Type of Soft (Prime) Ideals in Commutative BCK-Algebras

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    The soft set theory is an important mathematical tool for dealing with uncertainty. By endowing a par-ameter set as a commutative BCK-algebra (that is commutative weak-BCI-algebra), the notions of a new type of soft prime ideals, annihilators of soft sets and new type of involutory soft ideals in commutative BCK-algebras are introduced. Two new compositional operations are defined and used to characterize the new type of soft ideals in commutative BCK-algebras. By using partial ordering on commutative BCK-algebras, some properties of the new type of soft ideals are studied. Properties of annihilators of soft sets and new type of involutory soft ideals are obtained. The existence of a new type of soft prime ideals in commutative BCK-algebras and its difference from the standard soft prime ideals are illustrated with examples. It is shown that a soft set is a new type of soft prime ideals in commutative BCK-algebras and its level set is a prime ideal is not a necessary and sufficient condition, which is different from the results of the usual fuzzy algebra. Some equivalent characterizations of the new type of soft prime ideals in commutative BCK-algebras are given. Furthermore, the properties of its homomorphism image and inverse image are discussed

    Detection of malignant lesions in cytologically indeterminate thyroid nodules using a dual-layer spectral detector CT-clinical nomogram

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    PurposeTo evaluate the capability of dual-layer detector spectral CT (DLCT) quantitative parameters in conjunction with clinical variables to detect malignant lesions in cytologically indeterminate thyroid nodules (TNs).Materials and methodsData from 107 patients with cytologically indeterminate TNs who underwent DLCT scans were retrospectively reviewed and randomly divided into training and validation sets (7:3 ratio). DLCT quantitative parameters (iodine concentration (IC), NICP (IC nodule/IC thyroid parenchyma), NICA (IC nodule/IC ipsilateral carotid artery), attenuation on the slope of spectral HU curve and effective atomic number), along with clinical variables, were compared between benign and malignant cohorts through univariate analysis. Multivariable logistic regression analysis was employed to identify independent predictors which were used to construct the clinical model, DLCT model, and combined model. A nomogram was formulated based on optimal performing model, and its performance was assessed using receiver operating characteristic curve, calibration curve, and decision curve analysis. The nomogram was subsequently tested in the validation set.ResultsIndependent predictors associated with malignant TNs with indeterminate cytology included NICP in the arterial phase, Hashimoto’s Thyroiditis (HT), and BRAF V600E (all p < 0.05). The DLCT-clinical nomogram, incorporating the aforementioned variables, exhibited superior performance than the clinical model or DLCT model in both training set (AUC: 0.875 vs 0.792 vs 0.824) and validation set (AUC: 0.874 vs 0.792 vs 0.779). The DLCT-clinical nomogram demonstrated satisfactory calibration and clinical utility in both training set and validation set.ConclusionThe DLCT-clinical nomogram emerges as an effective tool to detect malignant lesions in cytologically indeterminate TNs

    A COVID-19 Risk Score Combining Chest CT Radiomics and Clinical Characteristics to Differentiate COVID-19 Pneumonia From Other Viral Pneumonias

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    With the continued transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) throughout the world, identification of highly suspected COVID-19 patients remains an urgent priority. In this study, we developed and validated COVID-19 risk scores to identify patients with COVID-19. In this study, for patient-wise analysis, three signatures, including the risk score using radiomic features only, the risk score using clinical factors only, and the risk score combining radiomic features and clinical variables, show an excellent performance in differentiating COVID-19 from other viral-induced pneumonias in the validation set. For lesion-wise analysis, the risk score using three radiomic features only also achieved an excellent AUC value. In contrast, the performance of 130 radiologists based on the chest CT images alone without the clinical characteristics included was moderate as compared to the risk scores developed. The risk scores depicting the correlation of CT radiomics and clinical factors with COVID-19 could be used to accurately identify patients with COVID-19, which would have clinically translatable diagnostic and therapeutic implications from a precision medicine perspective

    Towards molecular breeding of reproductive traits in cereal crops

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    The transition from vegetative to reproductive phase, flowering per se, floral organ development, panicle structure and morphology, meiosis, pollination and fertilization, cytoplasmic male sterility (CMS) and fertility restoration, and grain development are the main reproductive traits. Unlocking their genetic insights will enable plant breeders to manipulate these traits in cereal germplasm enhancement. Multiple genes or quantitative trait loci (QTLs) affecting flowering (phase transition, photoperiod and vernalization, flowering per se), panicle morphology and grain development have been cloned, and gene expression research has provided new information about the nature of complex genetic networks involved in the expression of these traits. Molecular biology is also facilitating the identification of diverse CMS sources in hybrid breeding. Few Rf (fertility restorer) genes have been cloned in maize, rice and sorghum. DNA markers are now used to assess the genetic purity of hybrids and their parental lines, and to pyramid Rf or tms (thermosensitive male sterility) genes in rice. Transgene(s) can be used to create de novo CMS trait in cereals. The understanding of reproductive biology facilitated by functional genomics will allow a better manipulation of genes by crop breeders and their potential use across species through genetic transformation

    Pollution and health risk assessment of heavy metals in soils of Guizhou, China

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    Mining of minerals in Guizhou, China, where it is enriched with reserves, may lead to soil contamination with heavy metals. We assessed the risk of eight typical heavy metals in Guizhou soils by collecting province-wide data available in the literature and using the geo-accumulation index method, the ecological risk assessment method, and the USEPA health risk assessment model. The concentrations of eight heavy metals, except for Pb and Cr, were above the background levels. Soil heavy metal pollution evaluation results showed that As, Cu, Zn, Pb, Cr, Cd, and Ni reached the pollution levels, while Hg fell into the category of moderate contamination. As, Cu, Zn, Pb, Cr, and Ni posed low potential ecological risk, while Cd and Hg demonstrated a considerable or a very high potential ecological risk. Totally, the integrated potential ecological risk was ranked “very high” . Regarding to health risk, the non-carcinogenic risks caused by heavy metals were insigniïŹcant, but the carcinogenic risk caused by As was signiïŹcant. Consequently, there appeared serious soil contamination of Hg and As, with the latter also being the greatest potential risk to human health. Both Hg and As should stay at the highest priory for remediation efforts in Guizhou soils

    Development of a new calcium sulfoaluminate (synthetic ye'elimite) blended PII 52.5 cement

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    The aim of this paper is to examine the effect of a blending dose of calcium sulfoaluminate (synthetic ye'elimite, C4A3)andgypsumonthehydrationandhardeningpropertiesofanewyeâ€Čelimite(C4A3) and gypsum on the hydration and hardening properties of a new ye'elimite (C4A3) blended PII 52.5 cement. By using X-ray diffractometry, mercury intrusion porosimetry, thermogravimetry and scanning electron microscopy, it was revealed that the hydration of tricalcium silicate (C3S) is significantly retarded by the lack of gypsum; the renewed hydration of tricalcium aluminate (C3A) was retarded in cement pastes containing a high amount of C4A3.ThedosageofC4A3. The dosage of C4A3 and the ratio of gypsum/C4A3bothhaveanotableinfluenceonthehydrationheat,hydrationproductsandthecompressivestrengthandlinearexpansion.Thecementpastecontaining3 both have a notable influence on the hydration heat, hydration products and the compressive strength and linear expansion. The cement paste containing 3% C4A3 at gypsum/C4A3$ ratio of 2 exhibited the best performance, in terms of both high early and long-term compressive strength and acceptable linear expansion (0·04% on 300 d); the cement can therefore be adopted in industrial structures

    Impact of micromechanics on dynamic compressive behavior of ultra-high performance concrete containing limestone powder

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    To improve sustainability and reduce costs, interest in using limestone powder (LP) in ultra-high performance concrete (UHPC) has been increasing in recent years. Incorporating LP changes packing, characteristics of C–S–H and pore structure of interfacial transition zone (ITZ) and matrix by physical and chemical effects. However, the influences of LP replacement on the mechanical properties of UHPC, from micromechanics to macroscopic impact behaviors, have not been well understood. Herein, mercury intrusion porosimetry (MIP), thermal gravimetric (TG), nanoindentation test and Split Hopkinson pressure bar (SHPB) test are performed to reveal the relationships between the micromechanical properties and the dynamic performances of UHPC. Results show that appropriate amount of LP incorporation optimizes the packing, leading to a narrower space and more densely compacted C–S–H that improves the percentages of high-density C–S–H and ultra-high density C–S–H in ITZ. The higher density of C–S–H results in a higher steel fiber-matrix bond strength, which benefits a higher dynamic compressive strength and energy absorption while a lower dynamic increase factor. More low-density C–S–H are generated due to the dilution effect of excessive LP, leading to a weak steel fiber-matrix bond strength that deteriorates the impact resistance. Additionally, the mechanism of LP enhancing the quality of C–S–H in ITZ is proposed, which favors understanding the relation between macro dynamic performance and interfacial behavior at the micro and nanoscale

    Welan gum retards the hydration of calcium sulfoaluminate

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    This paper illustrates the retarding effects of welan gum on the hydration of C4A3bothintheabsenceandpresenceofgypsum.Byusingthemethodsofisothermalcalorimetry,X−raydiffractometry,mercuryinstructionporosimetry,thermogravimetryandscanningelectronmicroscopy,itrevealsthatthehydrationofC4A3 both in the absence and presence of gypsum. By using the methods of isothermal calorimetry, X-ray diffractometry, mercury instruction porosimetry, thermogravimetry and scanning electron microscopy, it reveals that the hydration of C4A3 is significantly retarded and reduced in the presence of welan gum, while the total hydration heat of C4A3isreducedwiththeriseofdoseofwelangum.TheretardingeffectofwelangumonthehydrationofC4A3 is reduced with the rise of dose of welan gum. The retarding effect of welan gum on the hydration of C4A3 in the absence of gypsum is much stronger than that in the presence of gypsum. The hydration product of AFm is AFm-12 at curing time longer than 1 d at the w/c ratio of 1. As a whole, welan gum will not affect the composition of hydration products of C4A3$, even though the AFm phase grains grown well and are better shaped with addition of 0.50% welan gum

    Effect of welan gum on the hydration and hardening of Portland cement

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    This paper reports the effects of welan gum on the hydration and hardening behaviors of Portland cement (PC) by using X-ray diffractometry, mercury instruction porosimetry, thermogravimetry, differential scanning calorimetry and scanning electron microscopy. Results show that welan gum has notable influence on the setting time of PC paste and the formation of calcium hydroxide (Ca(OH)2); welan gum has little impact on the total hydration heat, AFt content and/or the morphologies of hydration products even though it delays the induction period of hydration and the second reaction of the aluminate phase. Welan gum retards the early hydration of C3S and accelerates the early hydration of C4AF. The compressive strength is improved, and pore size of hardened cement paste is reduced with at the studied period when welan gum is no more than 0.05%. In this research, the cement paste with 0.05% welan gum exhibits the highest long-term (90 d) compressive strength and lowest porosity
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