393 research outputs found
Hexa-peri-hexabenzocoronenes – Controlling their Self-Assembly by Engineering the Lateral Substituents
Polycondensed aromatic hydrocarbons (PAH), which can be regarded as two-dimensional subsections of graphite, have begun to attract increasing interest in supramolecular chemistry. Substituted hexa-peri-hexabenzocoronenes (HBC), an outstanding class of PAH, are well-known to self-organize
in solution into highly ordered columnar molecular stacks. The formed structures are very sensitive to any variation of the medium as well as the lateral substituents of the HBC derivatives. Various perfluoroalkylated HBC compounds have been prepared and investigated by powder XRD, DSC, fluorescence
and cryo-SEM in order to gain certain control over the self-assembling behavior of this class of compounds
Synthesis of perfluoroalkylated bulky triarylamines
The synthesis of two new triarylamine compounds bearing perfluoroalkylated side chains is described. Good thermal stabilities combined with a blue emission make these compounds promising candidates for materials applications
Disaster waste management challenges and enabling factors for strategic planning:the case of the Beirut Port explosion
The cardiovascular effects of salidroside in the Goto-Kakizaki diabetic rat model
Many factors, including hyperglycemia, hypertension, obesity, dyslipidemia, and a sedentary lifestyle, contribute to a high prevalence of cardiovascular disease. Specific vascular impairment treatments in the context of diabetes and vascular risk need to be improved. Salidroside is the primary active component of Rhodiola rosea and has documented antioxidative, cardioprotective, and vasculoprotective properties. The aim of this study was to test the hypothesis that salidroside has protective effects against hyperglycemia, hypertension, and vasodilation impairment in the Goto-Kakizaki (GK) rat model of diabetes. We evaluated cardiovascular parameters (e.g., daytime/nighttime systolic and diastolic blood pressure, heart rate, and activity), metabolic parameters (e.g., body weight, food and water consumption, serum fructosamine level, glucose tolerance), eNOS / phospho-eNOS expression level and in vitro vascular reactivity of aorta and second-order mesenteric arteries in Wistar-Kyoto (control) and GK (diabetic) rats treated with salidroside (40 mg/kg) or placebo (water) for 5 weeks. GK rats showed hypertension, marked glucose intolerance, and impaired endothelium-dependent and endothelium-independent vasodilation capacity. Salidroside showed beneficial effects on endothelial and non-endothelial vasodilation and likely acts on the endothelium and smooth muscle cells through the soluble guanylyl cyclase pathway. Despite its vascular effects, salidroside had no effect on blood pressure and heart rate in GK and control rats, it did not improve glucose metabolism or limit hypertension in the GK model of type 2 diabetes
Effect of Polarization and Chronic Inflammation on Macrophage Expression of Heparan Sulfate Proteoglycans and Biosynthesis Enzymes
Heparan sulfate (HS) proteoglycans on immune cells have the ability to bind to and regulate the bioactivity more than 400 bioactive protein ligands, including many chemokines, cytokines, and growth factors. This makes them important regulators of the phenotype and behavior of immune cells. Here we review how HS biosynthesis in macrophages is regulated during polarization and in chronic inflammatory diseases such as rheumatoid arthritis, atherosclerosis, asthma, chronic obstructive pulmonary disease and obesity, by analyzing published micro-array data and mechanistic studies in this area. We describe that macrophage expression of many HS biosynthesis and core proteins is strongly regulated by macrophage polarization, and that these expression patterns are recapitulated in chronic inflammation. Such changes in HS biosynthetic enzyme expression are likely to have a significant impact on the phenotype of macrophages in chronic inflammatory diseases by altering their interactions with chemokines, cytokines, and growth factors
Trees with Given Stability Number and Minimum Number of Stable Sets
We study the structure of trees minimizing their number of stable sets for
given order and stability number . Our main result is that the
edges of a non-trivial extremal tree can be partitioned into stars,
each of size or , so that every vertex is included in at most two
distinct stars, and the centers of these stars form a stable set of the tree.Comment: v2: Referees' comments incorporate
Tribenzopentaphene derivatives with lateral aromatic groups: the effect of the nature and position of substituents on emission properties
Nine new derivatives of the trapezoidal tribenzopentaphene (TBP) polycyclic aromatic hydrocarbon (PAH) were synthesized via the Suzuki–Miyaura palladium catalyzed cross-coupling reaction. The novel TBP derivatives, which bear various rigid and flexible aromatic groups either at their more accessible (R1) or congested (R2) bases, were fully characterized using high resolution mass spectrometry (HR-MS), nuclear magnetic resonance (NMR), UV-Vis absorption and emission spectroscopy. Our investigation reveals that extended conjugation between TBP and the aromatic side groups is possible when the latter are carefully selected and attached at the TBP wide base (R1), which causes an emission red-shift of the resulting target compounds. On the other hand, emission properties and density functional calculations suggest that attaching side groups at the sterically demanding base position (R2) induces a pronounced distortion from the planarity of the TBP central core structure
Whole exome sequencing in fetuses with isolated increased nuchal translucency: a systematic review and meta-analysis.
OBJECTIVE: To estimate the incremental yield of detecting pathogenic or likely pathogenic diagnostic genetic variants (DGV) by whole exome sequencing (WES) over standard karyotype and chromosomal microarray (CMA) analyses in fetuses with isolated increased nuchal translucency (NT) and normal fetal anatomy at the time of 11-14 weeks scan. MATERIALS AND METHODS: Medline and Embase databases were searched. Inclusion criteria were fetuses with NT >95th percentile, normal karyotype and CMA and no associated structural anomalies at the time of the 11-14 weeks scan. The primary outcome was to estimate the incremental yield of detecting pathogenic or likely pathogenic genetic variants by WES over standard karyotype and CMA analyses in fetuses with isolated increased nuchal translucency. The secondary outcomes were the detection of a genetic variant of unknown significance. Sub-analysis according to different NT cutoffs (between 3.0 and 5.5 mm and > 5.5 mm) and considering fetuses with isolated NT in which fetal anatomy was confirmed to be normal at the anomaly scan were also performed. Random effects model meta-analyses of proportion were used to analyze the data. RESULTS: Eight articles (324 fetuses) were included in the systematic review. Of the fetuses with negative standard karyotype and CMA analysis, the 8.07% (95% CI 5.4-11.3) had pathogenic or likely pathogenic genetic variants detected exclusively by WES. When stratifying the analysis according to NT cutoffs, genetic anomalies detected exclusively at WES analysis were found in 44.70% (95% CI 26.8-63.4) of fetuses with NT between 3.0 mm and 5.5 mm and 55.3% (95% CI 36.6-73.2) in those fetuses with NT >5.5 mm and positive WES results. The 7.84% (95% CI 1.6-18.2) had variants of unknown significance identified by WES. When considering fetuses with isolated increased NT and normal fetal anatomy at the anomaly scan, the rate of pathogenic or likely pathogenic genetic variants detected by WES was 3.87% (95% CI 1.6-7.1), while variants of unknown significance were detected in 4.27% (95% CI 2.2-7.0) of cases. CONCLUSIONS: Pathogenic and likely pathogenic genetic variants detected by WES are present in a significant proportion of fetuses with increased NT but normal standard karyotype and CMA analysis, also when no anomalies are detected at the anomaly scan. Further large studies sharing objective protocols of imaging assessment are needed to confirm these findings and to elucidate which gene panels should be assessed in fetuses with isolated increased NT to rule out associated genetic anomalies, which may potentially impact post-natal outcomes
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