Identification of preferentially exposed crystal facets by X-ray diffraction

Crystals with exposed facets are popular materials in many catalytic applications due to their high reactivity. Facet identification is often conducted by transmission electron microscopy (TEM). In this work, we analyze the effects of doping, vacancy creation, anisotropic broadening, and preferred orientation on the intensity of X-ray diffraction (XRD) peaks by using tetragonal bismuth oxyhalides (BiOX, X = Cl, Br, and I) as examples. The differences in these effects were successfully used to identify the preferentially exposed (001) facets of BiOX nanoplates synthesized by a polymer-assisted precipitation method. In comparison to TEM, the XRD analysis is not only cheaper and easier to perform, but also it gives results representative for the sample. This work aims to provide further justification for the use of XRD as a powerful and handy characterization technique in the field of crystal facet engineering.

Intensification of X-ray diffraction peaks can be used to get information about doping, presence of vacancies, anisotropic nanostructures, or preferred orientation of crystals with largely exposed facets.     

Pitfalls in endosonographic imaging of suspected insulinomas: pancreatic nodules of unknown dignity

OBJECTIVE: Endosonography enables localization and characterization of gastroenteropancreatic neuroendocrine tumors. We have studied the problem of misleading abnormalities of pancreatic morphology as obtained by endosonographic imaging. DESIGN AND METHODS: A total of 438 endosonographies performed for known or suspected diseases of the adrenal glands and/or the pancreas and/or suspected metastases in the neighboring tissues were analyzed. RESULTS: In the pancreas, nine benign insulinomas, four non-metastatic islet cell carcinomas, and multiple benign neuroendocrine tumors in one patient with multiple-endocrine neoplasia-1 (MEN-1) disease were detected and correctly localized as proven by postoperative histology. In three further patients with genetic diagnosis of MEN-1, asymptomatic tumors were detected and are under observation. However, we also found an 8 x 4 mm hypoechoic tumor in the cauda pancreatis of a patient with severe factitial hypoglycemia (glimepiride). In another patient suffering from severe hypoglycemia, a hypoechoic area of 24 x 10 mm in the processus uncinatus/caput pancreatis was found. Although organic hyperinsulinism was excluded, this patient underwent surgery because of suspected pancreatic carcinoma. There was normal pancreatic tissue in the abnormal region, which was also localized by intraoperative sonography. In a third patient with an adrenal carcinoma, a 6 x 3 mm hypoechoic nodule in the cauda pancreatis did not change its morphology over an observation period of 13 months, its clinical relevance is completely unclear. CONCLUSIONS: Pancreatic nodules of unknown dignity were detected in nearly 1% of our patients and must be considered to be a diagnostic problem. These experiences clearly show, on the one hand, that pancreatic endosonography is a very useful diagnostic support in the management of endocrine tumor patients. However, on the other hand, endosonography of endocrine organs is not a substitute for careful endocrinological examination and testing and must be considered in the context of endocrinological findings.     

Einfluss visueller Rehabilitation auf sekundäre depressive Störungen bei altersabhängiger Makuladegeneration

Background

Age-related macular degeneration (AMD) often leads to visual impairment, loss of reading ability, reduced quality of life and secondary depression. The present study examined if visual rehabilitation has a preventive effect on secondary depression in these patients.

Material and methods

In a controlled pilot study 20 patients were randomized into 2 groups whereby 9 underwent visual rehabilitation at first examination and 11 received magnifying visual aids only after 3 months. Psychosocial status was assessed by the geriatric depression scale (GDS) and the German version of the Centre for Epidemiologic Studies depression (CES-D) scale (main outcome parameter), cognitive status by the dementia detection test (DemTecT), minimental status (MMS) and quality of life by the National Eye Institute visual function questionnaire (NEI-VFQ 25). Ophthalmological examination included reading speed measurement by standardized texts (International Reading Speed Texts; IReST).

Results

Parameters of the CES-D scale, DemTect and the subitem exercise of social roles of the NEI-VFQ 25 emerged in a divergent manner. Patients of the rehabilitation group became less depressive and improved in cognitive and social abilities and in the control group vice versa. The interactive effect of group and time was statistically significant for all three tests.

Conclusions

Visual rehabilitation has a positive impact on depression as well as cognitive status and quality of life in patients with AMD. The effects have to be confirmed in future studies with more patients and a longer observation period.     

Particulate air pollution and vascular reactivity: the bus stop study

Objective Particulate air pollution is associated with cardiovascular morbidity but mechanisms are not well understood. We tested the effects on vascular reactivity of exposure to fine particulates matter mass (PM_2.5), number of particles ≤1 μm/m³ (PM_1.0) and nitrogen dioxide concentration (NO₂). Method About 39 healthy volunteers sat outside for 2 h at two different Ottawa bus stops. Flow-mediated vasodilation (FMD) of the brachial artery was then measured by ultrasound and expressed as: (maximum artery diameter after release of a blood pressure cuff inflated above systolic pressure—baseline resting diameter)/baseline resting diameter. Results A 30 μg/m³ increase in PM_2.5 exposure corresponded to a 0.48% reduction in FMD, P = 0.05 representing a 5% relative change in the maximum ability to dilate. Results were consistent between the two bus stops and not sensitive to type of analysis. No significant association was found between FMD and NO₂, PM_1.0 or traffic density. Conclusion PM_2.5 may reduce the capacity to vasodilate, a potential explanation for the documented association with cardiovascular morbidity.     

Catalytic role of metals supported on SBA-16 in hydrodeoxygenation of chemical compounds derived from biomass processing

Hydrodeoxygenation (HDO) carried out at high temperatures and high hydrogen pressures is one of the alternative methods of upgrading pyrolytic oils from biomass, leading to high quality biofuels. To save energy, it is important to carry out catalytic processes under the mildest possible experimental conditions. The aim of our research was the synthesis of ordered mesoporous SBA-16 type silica materials modified with transition metal atoms (Ir, Ru, Pd, Pt), their physicochemical characterization and use as catalysts in hydrodeoxygenation of model chemicals (guaiacol, syringol, creosol). The HDO process was carried out under mild experimental conditions at temperatures in the range from 90 to 130 °C and hydrogen pressures in the range from 25 to 60 bar. The catalytic tests revealed differences in the catalytic properties of the samples studied. The catalytic systems used assured highly efficient transformations of the examined molecules as well as high selectivity towards chemical compounds with lower O/C ratio and higher H/C ratio as compared to those in the initial substrates. High activity of the catalysts containing precious metals in the experimental conditions applied suggests their potential to improve bio-oil production for biofuels.

Hydrodeoxygenation (HDO) carried out under mildest possible experimental conditions (temperatures and hydrogen pressures) is one of the alternative methods of upgrading pyrolytic oils from biomass, leading to high quality biofuels.     

Modification and Functionalization of Zeolites for Curcumin Uptake

This work shows that hierarchical zeolites are promising systems for the delivery of biologically relevant hydrophobic substances, such as curcumin. The validity of using piperine as a promoter of curcumin adsorption was also evaluated. The use of pure curcumin is not medically applicable due to its low bioavailability and poor water solubility. To improve the undesirable properties of curcumin, special carriers are used to overcome these shortcomings. Hierarchical zeolites possessing secondary mesoporosity are used as pharmaceutical carrier systems for encapsulating active substances with low water solubility. This porosity facilitates access of larger reagent molecules to the active sites of the material, preserving desirable adsorption properties, acidity, and crystallinity of zeolites. In this work, methods are proposed to synthesize hierarchical zeolites based on a commercial FAU-type zeolite. Studies on the application and adsorption kinetics of curcumin using commercial FAU-type zeolite and hierarchical zeolites based on commercial FAU-type zeolite are also included.     

Biphenylcarboxamide derivatives as antagonists of platelet-activating factor

A series of N-[4-(3-pyridinyl)butyl]-1,1'-biphenyl-4-carboxamides was prepared, and the compounds were evaluated for platelet-activating factor (PAF) antagonist activity in a binding assay employing washed, whole dog platelets and in vivo for their ability to inhibit PAF-induced bronchoconstriction in the guinea pig. The inclusion of a methyl group in the R configuration on the side-chain carbon adjacent to the carboxamide nitrogen atom of these derivatives resulted in a marked enhancement of potency in the binding assay for compounds unsubstituted in the biphenyl 2-position and, more importantly, in improved oral bioavailability. Previous work with related pyrido[2,1-b]-quinazoline-8-carboxamides suggests that the presence of such an alkyl group improves bioavailability by rendering the resulting compounds resistant to degradation by liver amidases. The most interesting compounds to emerge from this work are (R)-2-bromo-3',4'-dimethoxy-N-[1-methyl-4-(3-pyridinyl)butyl]-1,1'-bi phe nyl- 4-carboxamide (33) and (R)-2-butyl-3',4'-dimethoxy-N-[1-methyl-4-(3-pyridinyl)butyl]- 1,1'-biphenyl-4-carboxamide (40) each of which inhibits PAF-induced bronchoconstriction in the guinea pig by greater than 55%. 6 h after an oral dose of 50 mg/kg.     

Association of interleukin-8 receptor alpha polymorphisms with chronic obstructive pulmonary disease and asthma

Chronic obstructive pulmonary disease (COPD) and asthma are common complex diseases characterized by airflow obstruction and inflammatory processes in the small airways. lnterleukin 8 (IL-8) is a potent proinflammatory cytokine which interacts with the IL-8 receptor alpha (IL8RA, CXCR1) and beta (IL8RB, CXCR2), leading to activation and migration of leukocytes. In order to evaluate the role of the IL8RA gene in the pathogenesis of COPD and asthma, we screened the coding region of IL8RA for mutations by means of single-strand conformation polymorphism analysis in 50 COPD patients and identified three exchanges (M31R, S276T and R335C). These three polymorphisms were subsequently genotyped in 182 adult patients with COPD, 68 adult patients and 130 children with asthma as well as 454 healthy controls. The frequencies of the IL8RA 31R and 335C alleles were significantly increased in patients with COPD and in children with asthma compared to healthy controls (P=0.0073 and 0.023, respectively). Thus, these polymorphisms may play a role in the pathogenesis of COPD and asthma.     

A polymorphism in the macrophage migration inhibitory factor gene is involved in the genetic predisposition of Crohn's disease and associated with cumulative steroid doses

BACKGROUND/AIMS: Macrophage migration inhibitory factor (MIF) is an important cytokine involved in the regulation of the innate immune system in IBD. Secreted MIF is able to induce the production of pro-inflammatory cytokines and counteracts anti-inflammatory effects of steroids. We evaluated whether the single nucleotide polymorphism (SNP) G/C at position -173 of the MIF gene contributes to the predisposition to IBD and higher amounts of steroid therapy. METHODOLOGY: We genotyped the SNP G/C at position -173 of the MIF gene in 157 patients with Crohn's disease (CD), 102 patients with ulcerative colitis (UC) and 489 healthy controls. Allele frequencies and cumulative steroid doses were compared. RESULTS: C allele and CC genotype frequencies were significantly decreased in CD patients compared to controls (p < 0.012 and p < 0.022, respectively). No significant differences were found in UC patients compared to controls. Cumulative corticosteroid dose was significantly higher in CD patients with the CC genotype [12300mg/yr (0-40000mg/yr), p < 0.021] compared with the GC genotype [220mg/yr (0-450mg/yr) and the GG genotype (310mg/yr (100-500mg/yr)]. In contrast, there were no significant differences between the genotypes in UC patients. CONCLUSIONS: Our data demonstrate the counterregulatory effects of MIF in CD patients and indicate the important role of the SNP G/C at position -173 of the MIF gene for the anti-inflammatory therapy with glucocorticoids.