207 research outputs found

    The durability of basalt-fiber-reinforced cement mortar under exposure to unilateral salt freezing cycles

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    Basalt fiber and cement-based materials have been widely applied in engineering structures. In this context, the durability of basalt-fiber-reinforced ordinary silicate mortar was systematically studied under exposure to unilateral salt freezing. The mechanical durability, chloride ion diffusion characteristics, and microscopic pore characteristics of cement mortar with basalt fiber content levels in the range of 0 kg/m3–1.5 kg/m3 were tested under exposure to 0–40 freeze–thaw cycles. The relationships of changes in the internal pore structure with mass loss, mechanical damage, and the physical properties of the material were also analyzed under exposure to salt freezing cycles. The results demonstrated that even a small amount of basalt fiber could significantly improve the mechanical properties of cement mortar under unilateral salt freezing and its resistance to salt freezing erosion. In particular, cement mortar with 1.2 kg/m3 basalt fiber content exhibited good durability of compressive and flexural strength, while the specimens with no basalt fibers exhibited a relatively large degree of internal porosity under exposure to unilateral salt freezing. Our work provides concrete evidence for changes in the porosity of mortar under exposure to unilateral salt freezing, with these changes showing an exponential relationship with mortar mass loss and a strong linear correlation with changes in the compressive strength, flexural strength, and chloride ion diffusion coefficient of the material

    Diaqua­bis­[4-(4H-1,2,4-triazol-4-yl)benzoato-κ2 O,O′]nickel(II)

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    In the title compound, [Ni(C9H6N3O2)2(H2O)2], the NiII atom lies on a twofold rotation axis and is six-coordinated by two bidentate chelating 4-(1,2,4-triazol-4-yl)benzoate ligands and two water mol­ecules in a distorted octa­hedral geometry. Inter­molecular O—H⋯N hydrogen bonds link the complex mol­ecules into a two-dimensional network parallel to (010)

    Co-delivery of Cisplatin(IV) and Capecitabine as an Effective and Non-toxic Cancer Treatment

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    A strategy for preparing composite micelles (CM) containing both cisplatin(IV) [CisPt(IV)] prodrug and capecitabine using a co-assembly method is described in this study. The CM are capable of an effective release of the anticancer drug cisplatin(II) [CisPt(II)] and capecitabine via acid hydrolysis once they are internalized by cancer cells. Moreover, the CM display a synergistic effect in vitro and the combination therapy in the micellar dosage form leads to reduced systemic toxicity and enhanced antitumor efficacy in vivo

    Biogeography and Virulence of Staphylococcus aureus

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    Staphylococcus aureus is commonly carried asymptomatically in the human anterior nares and occasionally enters the bloodstream to cause invasive disease. Much of the global diversity of S. aureus remains uncharacterised, and is not clear how disease propensity varies between strains, and between host populations.We compared 147 isolates recovered from five kindergartens in Chengdu, China, with 51 isolates contemporaneously recovered from cases of pediatric infection from the main hospital serving this community. The samples were characterised by MLST, the presence/absence of PVL, and antibiotic resistance profiling.Genotype frequencies within individual kindergartens differ, but the sample recovered from cases of disease shows a general enrichment of certain MLST genotypes and PVL positive isolates. Genotypes under-represented in the disease sample tend to correspond to a single sequence cluster, and this cluster is more common in China than in other parts of the world.Virulence propensity likely reflects a synergy between variation in the core genome (MLST) and accessory genome (PVL). By combining evidence form biogeography and virulence we demonstrate the existence of a "native" clade in West China which has lowered virulence, possibility due to acquired host immunity

    Transgenic studies reveal the positive role of LeEIL-1 in regulating shikonin biosynthesis in Lithospermum erythrorhizon hairy roots

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    Time-course accumulation of shikonin in four typical hairy root lines. Value of Ei-19 or EO-13 is significantly different from that of the control line WT-1 or EV-9 at each time point from 3 to 12 days, respectively (Student’s t-test, P < 0.05). (TIF 125 kb

    Current situation and factors influencing elderly care in community day care centers: a cross-sectional study

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    BackgroundThe latest census data show that people over 60 years of age account for about 18.7% of the total population in China, and the aging of the population has become an irreversible trend in the 21st century. This study aimed to investigate the current status and factors influencing the care of the elderly in community day care centers in order to lay the foundation for the development of better services in community day care centers.MethodsThis study was a cross-sectional survey using convenience sampling in Nanjing, China. The survey instrument was the Day care and Elderly Care Service Needs Questionnaire, which included the Ability of Daily Living Assessment (ADL), the Xiao Shuiyuan Social Support Rating Scale (SSRS) and the Day care Elderly Care Service Needs Survey Form, and a general information survey.ResultsA total of 450 elderly people in day care centers were surveyed. The elderly had different levels of demand for day care services, especially regarding daily care. Correlation analyses indicated that age (r = 0.619), education level (r = 0.616), source of income (r = 0.582), caregiver (r = 0.557), satisfaction with care service (r = 0.603), and degree of ADL (r = 0.629) were correlated with the need for elderly day care services (all p &lt; 0.05). The factors influencing the demand for day care services encompassed age, education level, income source, caregiver, satisfaction with service, and ADL (all p &lt; 0.05).ConclusionElderly care services in community day care centers are mainly based on daily and spiritual comfort, and the needs of the elderly are influenced by many factors. Timely nursing care policies and measures that target these factors are needed to improve elderly care

    Physical Characterization and Volatile Organic Compound Monitoring of Recycled Polyethylene Terephthalate under Mechanical Recycling

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    In this study, physical characterization and monitoring of volatile organic compounds (VOCs) were investigated on recycled polyethylene terephthalate (rPET) from a mechanical recycling process and rPET bottles made with different rPET contents, with the aim of tracing the source of rPET and assessing its safety when use as a food contact material. It was found that rPET had a similar thermal stability to that of virgin PET (vPET). rPET bottles did not show any significant changes in groups or structure and exhibit similar crystallization and melting behaviors to vPET. However, there were minor mechanical scratches in the surface micromorphology of rPET bottles, and the color of rPET bottles became darker, greener and yellower as the content of recycled material increased. The solid-state polycondensation process was found to play an important role in the removal of VOCs, as detected by headspace gas chromatography-mass spectrometry (HS-GC-MS), resulting in a very small amount of residual VOCs in rPET. Four VOCs (acetaldehyde, glycol and nonanal at levels less than 1.00 mg/kg; 2-methyl-1,3 dioxolane at levels of 1.72-5.76 mg/kg) were detected in the rPET bottles. This study shows that rPET bottles are qualified for reuse in food contact in terms of thermal properties, structure, morphology and VOC residues, although there is variability in color

    H5N1 avian influenza re-emergence of Lake Qinghai: phylogenetic and antigenic analyses of the newly isolated viruses and roles of migratory birds in virus circulation

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    Highly pathogenic avian influenza H5N1 virus has swept west across the globe and caused serious debates on the roles of migratory birds in virus circulation since the first large-scale outbreak in migratory birds of Lake Qinghai, 2005. In May 2006, another outbreak struck Lake Qinghai and six novel strains were isolated. To elucidate these QH06 viruses, the six isolates were subjected to whole-genome sequencing. Phylogenetic analyses show that QH06 viruses are derived from the lineages of Lake Qinghai, 2005. Five of the six novel isolates are adjacent to the strain A/Cygnus olor/Croatia/1/05, and the last one is related to the strain A/duck/Novosibirsk/02/05, an isolate of the flyway. Antigenic analyses suggest that QH06 and QH05 viruses are similar to each other. These findings implicate that QH06 viruses of Lake Qinghai may travel back via migratory birds, though not ruling out the possibility of local circulation of viruses of Lake Qinghai
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