64 research outputs found

    Modulated Self-Assembly of Catalytically Active Metal–Organic Nanosheets Containing Zr6 Clusters and Dicarboxylate Ligands

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    Two-dimensional metal–organic nanosheets (MONs) have emerged as attractive alternatives to their three-dimensional metal–organic framework (MOF) counterparts for heterogeneous catalysis due to their greater external surface areas and higher accessibility of catalytically active sites. Zr MONs are particularly prized because of their chemical stability and high Lewis and Brønsted acidities of the Zr clusters. Herein, we show that careful control over modulated self-assembly and exfoliation conditions allows the isolation of the first example of a two-dimensional nanosheet wherein Zr6 clusters are linked by dicarboxylate ligands. The hxl topology MOF, termed GUF-14 (GUF = Glasgow University Framework), can be exfoliated into monolayer thickness hns topology MONs, and acid-induced removal of capping modulator units yields MONs with enhanced catalytic activity toward the formation of imines and the hydrolysis of an organophosphate nerve agent mimic. The discovery of GUF-14 serves as a valuable example of the undiscovered MOF/MON structural diversity extant in established metal–ligand systems that can be accessed by harnessing the power of modulated self-assembly protocols

    Compositional analysis of the associations between 24-h movement behaviours and cardio-metabolic risk factors in overweight and obese adults with pre-diabetes from the PREVIEW study: cross-sectional baseline analysis

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    Background: Physical activity, sedentary time and sleep have been shown to be associated with cardio-metabolic health. However, these associations are typically studied in isolation or without accounting for the effect of all movement behaviours and the constrained nature of data that comprise a finite whole such as a 24 h day. The aim of this study was to examine the associations between the composition of daily movement behaviours (including sleep, sedentary time (ST), light intensity physical activity (LIPA) and moderate-to-vigorous activity (MVPA)) and cardio-metabolic health, in a cross-sectional analysis of adults with pre-diabetes. Further, we quantified the predicted differences following reallocation of time between behaviours. Methods: Accelerometers were used to quantify daily movement behaviours in 1462 adults from eight countries with a body mass index (BMI) ≥25 kg·m− 2 , impaired fasting glucose (IFG; 5.6–6.9 mmol·l − 1 ) and/or impaired glucose tolerance (IGT; 7.8–11.0 mmol•l − 1 2 h following oral glucose tolerance test, OGTT). Compositional isotemporal substitution was used to estimate the association of reallocating time between behaviours. Results: Replacing MVPA with any other behaviour around the mean composition was associated with a poorer cardio-metabolic risk profile. Conversely, when MVPA was increased, the relationships with cardiometabolic risk markers was favourable but with smaller predicted changes than when MVPA was replaced. Further, substituting ST with LIPA predicted improvements in cardio-metabolic risk markers, most notably insulin and HOMA-IR. Conclusions: This is the first study to use compositional analysis of the 24 h movement composition in adults with overweight/obesity and pre-diabetes. These findings build on previous literature that suggest replacing ST with LIPA may produce metabolic benefits that contribute to the prevention and management of type 2 diabetes. Furthermore, the asymmetry in the predicted change in risk markers following the reallocation of time to/from MVPA highlights the importance of maintaining existing levels of MVPA. Trial registration: ClinicalTrials.gov (NCT01777893)

    Epigenetic regulation of fetal bone development and placental transfer of nutrients: progress for osteoporosis

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    Osteoporosis is a common age-related disorder and causes acute and long-term disability and economic cost. Many factors influence the accumulation of bone minerals, including heredity, diet, physical activity, gender, endocrine functions, and risk factors such as alcohol, drug abuse, some pharmacological drugs or cigarette smoking. The pathology of bone development during intrauterine life is a factor for osteoporosis. Moreover, the placental transfer of nutrients plays an important role in the building of bones of fetuses. The importance of maternal calcium intake and vitamin D status are highlighted in this review. Various environmental factors including nutrition state or maternal stress may affect the epigenetic state of a number of genes during fetal development of bones. Histone modifications as histone hypomethylation, histone hypermethylation, hypoacetylation, etc. are involved in chromatin remodeling, known to contribute to the epigenetic landscape of chromosomes, and play roles in both fetal bone development and osteoporosis. This review will give an overview of epigenetic modulation of bone development and placental transfer of nutrients. In addition, the data from animal and human studies support the role of epigenetic modulation of calcium and vitamin D in the pathogenesis of osteoporosis. We review the evidence suggesting that various genes are involved in regulation of osteoclast formation and differentiation by osteoblasts and stem cells. Epigenetic changes in growth factors as well as cytokines play a rol in fetal bone development. On balance, the data suggest that there is a link between epigenetic changes in placental transfer of nutrients, including calcium and vitamin D, abnormal intrauterine bone development and pathogenesis of osteoporosis

    The Outcome of Adolescent Anorexia Nervosa: Findings from Berlin and Sofia

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    As part of a multisite collaborative outcome study of eating disorders in adolescence, two samples from West Berlin and Sofia were compared. The study was based on a systematic evaluation of the clinical status during the first inpatient treatment after onset of the disorder, and personal interviews with the former patients at follow-up. Despite the differences in the cultural background, the clinical features, the diagnostic pattern, the developmental histories, the family background, and the follow-up findings were remarkably similar. The mortality rate was higher in the West Berlin than in the Sofia sample. However, the outcome in terms of the distribution of eating disorders was similar in the surviving patients of the two samples . Received M.D. and Ph.D. in psychology at the University of Hamburg, Germany. Major research interests are eating disorders, developmental psychopathology, and neuropsychiatry. Received M.D. at the University of Sofia. Major research interest is in eating disorder

    The outcome of adolescent eating disorders : findings from an international collaborative study

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    Within the International Collaborative Outcome Study of Eating Disorders in Adolescence (ICOSEDA) we studied the clinical features, treatment, and outcome in consecutive cohorts of adolescent patients at five sites in former West Berlin and East Berlin, Zurich, Sofia and Bucharest. A total of N = 242 patients were followed up after a mean interval of 6.4 years in young adulthood. Using semi-structured interviews it was found that on average the patients were in either inpatient or outpatient treatment for 30% of the entire period between first admission and follow-up. Across the five sites 70% recovered from the eating disorder and a similar rate showed good or fair psychosocial functioning and no other psychiatric disorder. However, the combination of these three criteria showed that at follow-up only every second former patient was a mentally healthy and psychosocially well functioning person. The univariate and joint consideration of a large list of predictors lead to the conclusion that individual prognosis of the course of adolescent eating disorders is a hazardous undertaking

    2D networks of metallo-capsules and other coordination polymers from a hexapodal ligand

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    The hexapodal ligand hexakis(isonicotinoyl)cyclotricatechylene (L1) belonging to the cyclotriveratrylene family of host-molecules has been synthesised and used in the assembly of a series of coordination polymer materials with Re(I), Co(II), Cu(II), Ni(II) and Ag(I) salts. Single crystal structures of the coordination polymers [Re3(L1)2Br3(CO)3] 1, and an isomorphic [M3L2] series where M = Co, Cu or Ni, reveal 2D framework structures with a simplified topology of 36 or hxl. These are composed of M6(L1)2 metallo-cages linked together in a pair-wise fashion through each metal centre. Compound 1 is a rare example of a rhenium coordination polymer and was investigated for guest uptake from solution, complexing I2. The mixed-ligand species [Cu2(L1)(CF3CO2)3(isonicotinate)] forms a (3,4,5)-connected 2D coordination polymer, while [Ag2(L1)(DMF)2]·2BF4·2(H2O)·6(DMF) features a 2D network of (3,6)-connectivity and with kagome dual (kgd) topology

    A transcultural outcome study of adolescent eating disorders

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    OBJECTIVE: The aim of the study was to assess the treatment and outcome of adolescent eating disorders in an international study including Western and Eastern European clinical and research centres. METHOD: A total of 138 patients with adolescent onset of an eating disorder (primarily anorexia nervosa) were followed-up after a mean interval of 5 years after first admission. RESULTS: On average, the patients had spent 25% of the total follow-up period in either in-patient or out-patient treatment. Half of them required a second hospitalization and a quarter required a third hospitalization for the eating disorder. At follow-up, 68% of the total sample did not have an eating disorder. The prediction of outcome revealed different patterns of risk variables depending on the type of criterion. CONCLUSION: The outcome of adolescent eating disorders is relatively similar across cultures, and better than in patients with later onset of the disorder

    Wilson disease associated with mesangiocapillary glomerulonephritis. A Case Report

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    Wilson`s disease (hepatolenticular degeneration) is an autosomal recessive dis or der of copper transport. It is characterized by the accumulation of copper in the liver and subsequently other organs, mainly the central nervous system and the kidneys because of a deficiency of the copper-binding protein ceruloplasmin. The gene for Wilson`s disease has been mapped to chromosome 13 at the q14 region. The approximate homozygote prevalence of 1 in 30,000 (13,16).Scripta Scientifica Medica 2007; 39(2):143-14

    Inorganic materials in drug delivery

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    Drug delivery systems are used to carry an active pharmaceutical ingredient (API) in order to improve its properties, for instance enhancing the precision of targeting, protecting it from degradation, or controlling the rate of release. A wide range of inorganic materials can be used to achieve these goals. This chapter will review the key recent developments in this field, with a focus on the four families of materials which have attracted most attention: 3D metal organic frameworks (MOFs), 3D mesoporous silicas (MSNs), 2D layered materials, and 0D inorganic nanoparticles (MNPs). These systems can have a very wide range of physical properties and chemical functionalities. For instance, MOFs and MSNs are porous and thus can offer high drug loadings, while stability varies significantly. MOFs often require functionalisation and protection from rapid degradation prior to cargo delivery, while MSNs and MNPs can persist in vivo. Layered materials also vary widely in stability but can result in effective targeting and extended release profiles. In all cases, the presence of an inorganic species in addition to the API can aid targeting and permit imaging to be performed concomitantly with drug delivery. Post-fabrication functionalisation is also possible, allowing further augmentation of tuning of properties. Inorganic systems thus have huge potential in drug delivery, but there are also very significant barriers to clinical adoption which need to be overcome to allow them to reach their full potential
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