Molecular mechanism of alkene epoxidation: A model study with 3,3-dimethyl-1-butene on Ag(111)

On chlorine-promoted Ag(111) oxygen adatoms selectively oxidise 3,3-dimethyl-1-butene (DMB) to the corresponding epoxide with very high selectivity providing direct verification of the mechanism advanced earlier for alkene epoxidation over single crystal silver and silver catalysts.     

Melatonin and Female Hormone Secretion in Postmenopausal Overweight Women

Estrogen deficiency is considered to be the main cause of increased appetite and increased weight in postmenopausal women. In this period, reduced secretion of melatonin (MEL) was also observed. The aim of the study was to evaluate the secretion of melatonin, 17-β estradiol and follicle-stimulating hormone (FSH) in relation to body mass index (BMI) in pre- and postmenopausal women. The study included 90 women divided into three equal groups: group I (control)—women without menstrual disorders, group II—postmenopausal women without change in appetite and body weight, group III—postmenopausal women experiencing increased appetite and weight gain. In each patient, serum melatonin, 17-β-estradiol, FSH and urine a 6-sulfatoxymelatonin (aMT6s) were determined. Compared to the control group, the level of melatonin and estradiol was statistically lower. The FSH level was higher than in the groups of postmenopausal women. No significant correlation was found in all groups between the level of melatonin and the levels of estradiol and FSH. A negative correlation was found between aMT6s excretion and BMI, and a positive correlation between the level of FSH and BMI, mainly in overweight women. The obtained results indicate a significant effect of melatonin deficiency on the process of weight gain in postmenopausal women and justify its use in treatment of these disorders.     

Renovation of brick interceptor sewers

Brick interceptor sewers began to be built in Europe (London, Paris, Hamburg) in the 18th century. The sewers were built from solid ceramic brick (so called sewer brick) or clinker brick. This paper presents a study of damage to brick interceptor sewers built in the 19th century and at beginning of the 20th century in Poland. Damage to the sewer structure and to the surrounding ground and its causes are identified. On the basis of results of in situ investigations, laboratory tests and structural and strength analyses, the condition of sewer structures in Poland was assessed as a pre-failure one. Underground infrastructure pipes of urban areas can be repaired in trenches or using trenchless techniques. Although trenchless technologies have been known in Poland for more than 25 years, there is still the lack of knowledge and imagination on the part of designers – so different problems in renovating process of brick interceptor sewers are described.     

Forensic investigations of buried utilities failures in Poland

This paper discusses the problem of failures of sewerage and water-supply systems. Typical kinds of damage to pipelines are described and classified according to reliability theory and their causes. Results of the author’s examination of damaged sewerage and water-supply pipelines, including the causes of four failures, are presented. In the conclusion, the principal hazards to failure-free operation of underground infrastructure are indicated.     

Interactions Via α2β1 Cell Integrin May Protect against the Progression of Airway Structural Changes in Asthma

Increased airway wall thickness and remodeling of bronchial mucosa are characteristic of asthma and may arise from altered integrin signaling on airway cells. Here, we analyzed the expression of β₁-subfamily integrins on blood and airway cells (flow cytometry), inflammatory biomarkers in serum and bronchoalveolar lavage, reticular basement membrane (RBM) thickness and collagen deposits in the mucosa (histology), and airway geometry (CT-imaging) in 92 asthma patients (persistent airflow limitation subtype: n = 47) and 36 controls. Persistent airflow limitation was associated with type-2 inflammation, elevated soluble α₂ integrin chain, and changes in the bronchial wall geometry. Both subtypes of asthma showed thicker RBM than control, but collagen deposition and epithelial α₁ and α₂ integrins staining were similar. Type-I collagen accumulation and RBM thickness were inversely related to the epithelial expression of the α₂ integrin chain. Expression of α₂β₁ integrin on T-cells and eosinophils was not altered in asthma. Collagen I deposits were, however, more abundant in patients with lower α₂β₁ integrin on blood and airway CD8⁺ T-cells. Thicker airway walls in CT were associated with lower α₂ integrin chain on blood CD4⁺ T-cells and airway eosinophils. Our data suggest that α₂β₁ integrin on inflammatory and epithelial cells may protect against airway remodeling advancement in asthma.     

Beyond the Mind—Serum Trace Element Levels in Schizophrenic Patients: A Systematic Review

The alterations in serum trace element levels are common phenomena observed in patients with different psychiatric conditions such as schizophrenia, autism spectrum disorder, or major depressive disorder. The fluctuations in the trace element concentrations might act as potential diagnostic and prognostic biomarkers of many psychiatric and neurological disorders. This paper aimed to assess the alterations in serum trace element concentrations in patients with a diagnosed schizophrenia. The authors made a systematic review, extracting papers from the PubMed, Web of Science, and Scopus databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Among 5009 articles identified through database searching, 59 of them were assessed for eligibility. Ultimately, 33 articles were included in the qualitative synthesis. This review includes the analysis of serum levels of the following trace elements: iron, nickel, molybdenum, phosphorus, lead, chromium, antimony, uranium, magnesium, aluminum, zinc, copper, selenium, calcium, and manganese. Currently, there is no consistency regarding serum trace element levels in schizophrenic patients. Thus, it cannot be considered as a reliable prognostic or diagnostic marker of schizophrenia. However, it can be assumed that altered concentrations of those elements are crucial regarding the onset and exaggeration of either psychotic or negative symptoms or cognitive dysfunctions.     

Application of Cr(VI) transport across the polymer inclusion membrane with calixresorcin[4]arene derivative as ion carrier

ABSTRACT

In this study, the experiments were performed to evaluate the Cr(VI) removal efficiency by transport across the polymer inclusion membrane with calixresorcin[4]arene derivative as ion carrier. The several influence factors such as carrier concentration, the amount of plasticizer in the membrane as well the effect of acid type and its concentration in source phase and the membrane stability were investigated. It was found that the immobilized calixresorcin[4]arene derivative in membranes effectively extracted chromium from acidic media. Under optimized conditions, the Cr(VI) removal efficiency was 98.4%.     

A maximum-likelihood estimator for trial-to-trial variations in noisy MEG/EEG data sets

The standard procedure to determine the brain response from a multitrial evoked magnetoencephalography (MEG) or electroencephalography (EEG) data set is to average the individual trials of these data, time locked to the stimulus onset. When the brain responses vary from trial-to-trial this approach is false. In this paper, a maximum-likelihood estimator is derived for the case that the recorded data contain amplitude variations. The estimator accounts for spatially and temporally correlated background noise that is superimposed on the brain response. The model is applied to a series of 17 MEG data sets of normal subjects, obtained during median nerve stimulation. It appears that the amplitude of late component (30-120 ms) shows a systematic negative trend indicating a weakening response during stimulation time. For the early components (20-35 ms) no such a systematic effect was found. The model is furthermore applied on a MEG data set consisting of epileptic spikes of constant spatial distribution but varying polarity. For these data, the advantage of applying the model is that positive and negative spikes can be processed with a single model, thereby reducing the number of degrees of freedom and increasing the signal-to-noise ratio.