18 research outputs found

    Combined Effect of Dietary Cadmium and Benzo(a)pyrene on Metallothionein Induction and Apoptosis in the Liver and Kidneys of Bank Voles

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    Bank voles free living in a contaminated environment have been shown to be more sensitive to cadmium (Cd) toxicity than the rodents exposed to Cd under laboratory conditions. The objective of this study was to find out whether benzo(a)pyrene (BaP), a common environmental co-contaminant, increases Cd toxicity through inhibition of metallothionein (MT) synthesis—a low molecular weight protein that is considered to be primary intracellular component of the protective mechanism. For 6 weeks, the female bank voles were provided with diet containing Cd [less than 0.1 μg/g (control) and 60 μg/g dry wt.] and BaP (0, 5, and 10 μg/g dry wt.) alone or in combination. At the end of exposure period, apoptosis and analyses of MT, Cd, and zinc (Zn) in the liver and kidneys were carried out. Dietary BaP 5 μg/g did not affect but BaP 10 μg/g potentiated rather than inhibited induction of hepatic and renal MT by Cd, and diminished Cd-induced apoptosis in both organs. The hepatic and renal Zn followed a pattern similar to that of MT, attaining the highest level in the Cd + BaP 10-μg/g group. These data indicate that dietary BaP attenuates rather than exacerbates Cd toxicity in bank voles, probably by potentiating MT synthesis and increasing Zn concentration in the liver and kidneys

    Spatial Random Slope Multilevel Modeling Using Multivariate Conditional Autoregressive Models: A Case Study of Subjective Travel Satisfaction in Beijing

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    This article explores how to incorporate a spatial dependence effect into the standard multilevel modeling (MLM). The proposed method is particularly well suited to the analysis of geographically clustered survey data where individuals are nested in geographical areas. Drawing on multivariate conditional autoregressive models, we develop a spatial random slope MLM approach to account for the within-group dependence among individuals in the same area and the spatial dependence between areas simultaneously. Our approach improves on recent methodological advances in the integrated spatial and MLM literature, offering greater flexibility in terms of model specification by allowing regression coefficients to be spatially varied. Bayesian Markov chain Monte Carlo (MCMC) algorithms are derived to implement the proposed model. Using two-level travel satisfaction data in Beijing, we apply the proposed approach as well as the standard nonspatial random slope MLM to investigate subjective travel satisfaction of residents and its determinants. Model comparison results show strong evidence that the proposed method produces a significant improvement against a nonspatial random slope MLM. A fairly large spatial correlation parameter suggests strong spatial dependence in district-level random effects. Moreover, spatial patterns of district-level random effects of locational variables have been identified, with high and low values clustering together

    An international cohort study of autosomal dominant tubulointerstitial kidney disease due to REN mutations identifies distinct clinical subtypes

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    There have been few clinical or scientific reports of autosomal dominant tubulointerstitial kidney disease due to REN mutations (ADTKD-REN), limiting characterization. To further study this, we formed an international cohort characterizing 111 individuals from 30 families with both clinical and laboratory findings. Sixty-nine individuals had a REN mutation in the signal peptide region (signal group), 27 in the prosegment (prosegment group), and 15 in the mature renin peptide (mature group). Signal group patients were most severely affected, presenting at a mean age of 19.7 years, with the prosegment group presenting at 22.4 years, and the mature group at 37 years. Anemia was present in childhood in 91% in the signal group, 69% prosegment, and none of the mature group. REN signal peptide mutations reduced hydrophobicity of the signal peptide, which is necessary for recognition and translocation across the endoplasmic reticulum, leading to aberrant delivery of preprorenin into the cytoplasm. REN mutations in the prosegment led to deposition of prorenin and renin in the endoplasmic reticulum Golgi intermediate compartment and decreased prorenin secretion. Mutations in mature renin led to deposition of the mutant prorenin in the endoplasmic reticulum, similar to patients with ADTKD-UMOD, with a rate of progression to end stage kidney disease (63.6 years) that was significantly slower vs. the signal (53.1 years) and prosegment groups (50.8 years) (significant hazard ratio 0.367). Thus, clinical and laboratory studies revealed subtypes of ADTKD-REN that are pathophysiologically, diagnostically, and clinically distinct

    Ocena rozcieńczonych roztworów celulozy pod kątem ich przydatności do formowania nanowłókien metodą elektroprzędzenia

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    This paper discusses the possibility of nanofibre formation in an electrostatic field from cellulose solutions in different solvent systems. Additionally when investigating solutions of various cellulose content, an attempt was made to evaluate these solutions from the viewpoint of their usability for nanofibre formation. The spinnability of the solutions examined was assessed based on observation of the stability of nanofibre formation by the simplest single needle spinning device. The morphology of the samples obtained by electrospinning was studied by Scanning Electron Microscopy (SEM). Spinning dopes were obtained using well-known technologies for cellulose solution preparation applied in the cellulose fibre industry, namely N-Methylmorpholine N-oxide (NMMO) and viscose methods, as well as a mixture of phosphoric acids, which is relatively cheap, easily available and yet not used in industry. Based on the research conducted, it may be concluded that the cellulose solutions in NMMO proved to be the best system for exceptionally stable formation of nanofibres in an electrostatic field.W pracy przedstawiono próbę otrzymania nanowłókien w polu elektrostatycznym wykorzystując do tego celu roztwory celulozy w różnych układach rozpuszczalnikowych. Podjęto również próbę oceny tych roztworów pod kątem ich zdolności do tworzenia nanowłókien badając roztwory o różnych stężeniach celulozy. Oceny przędliwości roztworów dokonano na podstawie obserwacji stabilności formowania nanowłókien, wykorzystując do tego celu najprostszy, jedno-igłowy układ formujący. Uzyskane podczas procesu elektroprzędzenia próbki analizowane były pod kątem ich morfologii z wykorzystaniem skaningowej mikroskopii elektronowej (SEM). Do sporządzenia roztworów przędzalniczych wykorzystano znane i stosowane w przemyśle włókien celulozowych techniki otrzymania roztworów celulozy tj. N-tlenek N-metylomorfoliny (NMMO), metodę wiskozową oraz stosunkowo tani i łatwo dostępny, ale niestosowany w przemyśle kwas ortofosforowy. Na podstawie przeprowadzonych badań stwierdzono, iż optymalnym układem pozwalającym na bardzo stabilne formowanie nanowłókien w polu elektrostatycznym są roztwory celulozy w NMMO

    Integrating space syntax with field observations to understand the spatial logic of park infrastructure

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    Park pathway characteristics can influence the movement of visitors and the functional usage of space. This article aims to assess the design of different types of public parks in Cairo, Egypt, through the lens of space syntax, which identifies spatial layout as a primary factor that determines pedestrian movement. We integrate space syntax metrics with field observations to examine the underlying spatial logic of small, medium and large public parks, and compare their three structures based on form and function. The results indicated that the degree of spatial accessibility and degree of control over accessing adjacent walkways were positively associated with movement flows on each walkway segment. However, many park facilities, such as wedding halls and theatres, tended to be randomly distributed due to the heavy commercialisation of the parks, which places facilities based on land availability. Our findings provide insights into the design and management of park environments. Overall, leisure facilities should be provided based on community needs. Noisy activities should be placed in isolated zones to attenuate noise. In addition, activities that serve various people groups should be located along highly accessible pathways to encourage their use

    SCALING EFFECTS IN THE PENNA AGEING MODEL

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    Thermal properties of cellulose carbamate

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