Physical Properties and Durability of Lime-Cement Mortars Prepared with Water Containing Micro-Nano Bubbles of Various Gases

The paper presents the experimental studies on the effect of the water containing micro-nano bubbles of various gases on the physico-mechanical properties of lime-cement mortars. In total, 7 types of mortars were prepared: with water containing the micro-nano bubbles of O₂, O₃ or CO₂ as 50% or 100% substitute of ordinary mixing water (tap water) and the reference mortar prepared using tap water. In order to determine the influence of water with micro-nano bubbles of gases, the consistency of fresh mortar and the physical properties of hardened mortar, i.e., specific and apparent density, total porosity, water absorption by weight and capillary absorption, were established. The mechanical strength of the considered mortars was studied as well by conducting the tests for flexural and compressive strengths following 14, 28 and 56 days. Reduced workability and capillary absorption were observed in the modified mortars within the range of 0.9–8.5%. The mortars indicated an increase in the flexural strength after 28 days ranging from 3.4% to 23.5% and improved compressive strength in 1.2–31%, in comparison to the reference mortar. The conducted studies indicated increased flexural and compressive strengths along with the share of micro-nano bubbles of gases in the mixing water.     

Impact of Coronary Artery Disease Burden on 12‐Month Mortality of Patients After Transcatheter Aortic Valve Implantation

Objectives

The aim of the study was to compare 12‐month mortality rate of patients with and without complete coronary revascularization before transcatheter aortic valve implantation (TAVI).

Background

There are limited data on the impact of coronary artery disease burden in patients with severe aortic stenosis undergoing TAVI.

Methods

One hundred and one consecutive patients undergoing TAVI were enrolled. Of them 16 (15.8%) had an incomplete coronary revascularization. The primary endpoint was 12‐month all‐cause mortality.

Results

Twelve‐month all‐cause mortality was higher in patients with incomplete coronary revascularization than in patients with complete coronary revascularization or without significant lesions (75.0% vs 7.1%; P < 0.001). Importantly, incomplete coronary revascularization was an independent predictor of higher mortality rate after 12 months (hazard ratio (HR) for incomplete coronary revascularization 10.86, 95% CI 3.72–31.73; P < 0.001; HR for a history of stroke/TIA 3.93, 95% confidence interval (CI) 1.39–11.07; P < 0.001; HR for blood transfusion 2.84 95% CI (1.06–7.63); P = 0.039). In 9 of 16 (56.3%) patients, incomplete revascularization was related to the presence of chronic total occlusions (CTO). Patients with CTO had an increased mortality rate after 12 months (55.6% vs 14.1%; P = 0.008) as compared to patients without the CTO.

Conclusions

Incomplete coronary revascularization and a history of stroke or TIA may be independent predictors of all‐cause mortality in patients undergoing TAVI. However, further studies are recommended to confirm the results, especially in terms of the impact of CTO presence on long‐term mortality after TAVI.

     

Neuroimmunomodulatory effect of highly toxic organophosphorus compound on the development of Trichinella spiralis infection

The highly toxic organophosphorus compound (isopropylmethylphosphonofluoridate--IMPF) belonging to the group of the so called toxic of warfare agents can impair immune effector mechanisms determining the development of parasitic infection. Preliminary studies have demonstrated that IMPF delays elimination of adults Trichinella spiralis forms from the intestine of C57B1/6 mice and B6C3F1 hybrids. Besides, the studied compound modifies the proliferative activity of T-cells in the above mentioned mice and reduces the production of anti-SRBC antibodies in C57B1/6 strain. The mechanisms are discussed of the organophosphorus compound effect on neuroimmunological processes connected with antiparasitic immunity, paying attention also to the function of these processes by the parasitic infection itself, in host-parasite relationship. The probability is also considered of increased sensitivity to Leishmania infection in humans poisoned with IMPF and/or other organophosphorus compounds.     

Multifocal atrophic gastritis: pathogenesis and therapeutic implications

OBJECTIVE: This study, carried out on 51 patients with multifocal atrophic gastritis (MAG) and 92 age and sex-matched dyspeptic controls, was designed to examine both exocrine (gastric acid) and endocrine (gastrin) gastric secretion before and after therapeutic intervention including Helicobacter pylori eradication and vitamin C treatment. METHODS: Fasting and gastrin-releasing peptide-induced gastric acid secretion, serum levels of gastrin and proinflammatory (IL-1beta, IL-8, TNF-alpha) as well as gastric mucosal gene expression of ornithine decarboxylase (ODC), cyclooxygenase 2 (COX-2) and growth factors (epidermal growth factor and transforming growth factor alpha) were determined before and after the eradication of Helicobacter pylori and therapy with large doses (1 g/d) of vitamin C for 3 months. RESULTS: The H. pylori eradication, assessed by C-urea breath test, and vitamin C therapy failed to reverse the histological atrophy of the gastric mucosa but improved significantly the functional status of the atrophied mucosa, especially its exocrine and endocrine secretory activities, attenuated the expression of premalignant markers such as ODC and COX-2, raised the production of growth factors and diminished the release of proinflammatory cytokines. CONCLUSIONS: These results indicate that MAG may be considered as an environmental disease of the gastric mucosa, whose functional status can be improved by the eradication of H. pylori combined with antioxidant therapy with large doses of vitamin C.     

Do alcohol restrictions reduce suicide mortality?

AIM: Blood alcohol concentration (BAC) at the time of suicide was examined in relation to the marked falls in suicide rates and per capita alcohol consumption in Estonia during the major Soviet anti-alcohol campaign from 1 June 1985. DESIGN AND PARTICIPANTS: In all, 5054 suicide cases (76% males, 24% females) were examined with respect to the official autopsy reports of the Estonian Bureau of Forensic Medicine (autopsy rates: 95% of males, 88% of females) before (1981-84), during (1986-88) and after (1989-92) the campaign. Cases were divided by gender and BAC level (0.5-1.49, 1.5-2.49 and > 2.5 per thousand). FINDINGS: During the campaign, annual per capita alcohol consumption in Estonia fell from 10.9 to 6.6 l. Alcohol in blood was found in 47.9% before, 35.1% during and 40.9% after the campaign. During the intervention, BAC-positive, i.e. alcohol-positive, suicides decreased by 39.2% for males and 41.4% for females, with the largest fall occurring at the BAC 2.5 per thousand + level for both sexes. Changes in BAC-negative suicides were modest. When the campaign ended suicide rates started to rise. CONCLUSIONS: Investigation on an individual level showed that alcohol consumption was a common precursor to suicide and that rigorous alcohol restrictions were accompanied particularly by a decrease in BAC-positive suicide mortality among both sexes. However, the 'natural experiment' does not, in terms of study design, demonstrate convincingly that the fall in the suicide rate was due specifically to the decrease in alcohol use as such.     

In‐hospital and long‐term outcomes of percutaneous balloon aortic valvuloplasty with concomitant percutaneous coronary intervention in patients with severe aortic stenosis

Background

Severe aortic stenosis (AS) often coexists with significant coronary artery disease.

Objective

To evaluate procedural complications and long‐term outcomes of patients with severe AS undergoing balloon aortic valvuloplasty (BAV) and percutaneous coronary intervention (PCI).

Methods

A total of 97 patients with severe AS underwent 104 BAVs as palliative procedure, bridge to definitive treatment, or before urgent non‐cardiac surgery. Patients were followed‐up for at least 12 months.

Results

Of the 97 patients, 34 (35.0%) underwent standalone BAV, 45 (46.4%) underwent BAV with coronary angiography, and 18 (18.6%) BAV with PCI. There were no differences in baseline characteristics and indications for BAV among the groups (P > 0.05). No higher risk of complications after BAV performed with concomitant coronary angiography/PCI was observed. Transcatheter aortic valve implantation was performed after BAV in 13 (13.4%) patients and surgical aortic valve replacement in three (3.1%) patients. In spite of no difference in in‐hospital mortality (5.6% vs. 8.9%; P = 0.76), patients with BAV and concomitant PCI had lower long‐term mortality than patients with BAV and concomitant coronary angiography (28.5% vs. 51.0%; P = 0.03). In multivariable Cox analysis adjusted for age, sex, and body mass index, the Society of Thoracic Surgeons Predicted Risk of Mortality score was identified as the only independent predictor of long‐term mortality for all patients (HR: 1.09, 95%CI: 1.04‐1.15, P = 0.0006).

Conclusions

Concomitant PCI or coronary angiography performed with BAV may not increase the risk of major and vascular complications. Patients with BAV and concomitant PCI may have better survival than patients with BAV and concomitant coronary angiography.     

Durability of Hydrophobic/Icephobic Coatings in Protection of Lightweight Concrete with Waste Aggregate

The aim of the research presented in this paper is to evaluate the feasibility of using hydrophobic agents based on organosilicon compounds for surface protection of lightweight concrete modified with waste polystyrene. The experimental part pertains to the physical and mechanical properties of polystyrene-modified lightweight concrete. The concrete samples were prepared with the following ingredients: CEM I 42.5 R cement, recycled polystyrene (0–2 mm), quartz sand (0–2 mm), coarse river aggregate (2–16 mm), and water. Silane and tetramethoxysilane were employed for surface hydrophobization. Concrete with 20% polystyrene exhibits high porosity (25.22%), which is related to an increase in absorptivity (14.75%) compared to the reference concrete. The hydrophobized concrete is characterized by the lowest surface free energy (SFE) value, which is 7 or 11 times lower than the value of reference concrete, depending on the agents. The test on the contact angle (CA) was performed before and after the frost-resistance test (F–T test). Lower SFE translates into lower adhesive properties, higher resistance of the material to the infiltration of water and corrosive compounds, e.g., salts, and higher resistance to freezing and thawing cycles. Silane and tetramethoxysilane coating raised frost resistance by 54–58% compared to the reference samples. This agent reduced absorptivity by 30%. Recycled polystyrene can be successfully used to produce lightweight concrete (LC) with high durability provided by hydrophobic/icephobic coatings.     

Presence of hepatitis C virus (HCV)-RNA in peripheral blood mononuclear cells in HCV serum negative patients during interferon and ribavirin therapy

Identification of hepatitis C virus (HCV)-RNA in blood serum is crucial for hepatitis C diagnosis and for appropriate treatment. Detection of HCV-RNA in blood serum is used for therapy monitoring of patients with hepatitis C. Despite HCV-RNA elimination from blood serum during treatment in some patients, HCV viremia appears again after the completion of therapy. The aim of this study was to assess HCV-RNA in peripheral blood mononuclear cells (PBMCs) of hepatitis C patients in relation to HCV-RNA and antibodies to HCV in the serum. The study involved 71 patients undergoing anti-viral therapy (interferon and ribavirin). RNA isolated from serum and PBMCs was examined for the presence of HCV-RNA by an RT-PCR technique using specific oligonucleotide primers or by commercially available kits. In order to show the possible presence of HCV sequences in PBMCs, molecular DNA probes were constructed with a PCR amplicon and biotin-labelled by nick translation, and FISH and extended chromatin fibers in situ hybridization (ECFs-FISH) techniques were used. A 24-month follow-up study revealed that 34 out of 59 patients (58%) eliminated HCV-RNA from their sera. In the serum negative group, HCV-RNA was detected in PBMCs of 2 patients. The presence of HCV-RNA in PBMCs was confirmed by the FISH technique. In the ECFs-FISH procedure, no signal was found in all examined patients. Our data suggest that PBMCs infected with HCV can serve as a virus reservoir. HCV-RNA serum negative patients who have HCV-RNA in their leukocytes after completion of anti-viral therapy would be at great risk of hepatitis C recurrence. These HCV-RNA serum negative but PBMCs positive patients would be a potential source of HCV spread.     

Diet and nutritional factors in inflammatory bowel diseases

Inflammatory bowel disease(IBD) development is affected by complex interactions between environmental factors, changes in intestinal flora, various predisposing genetic properties and changes in the immune system. Dietary factors seem to play an underestimated role in the etiopathogenesis and course of the disease. However, research about food and IBD is conflicting. An excessive consumption of sugar, animal fat and linoleic acid is considered a risk factor for IBD development, whereas a high fiber diet and citrus fruit consumption may play a protective role. Also, appropriate nutrition in particular periods of the disease may facilitate achieving or prolonging remissions and most of all, improve the quality of life for patients. During disease exacerbation, a low fiber diet is recommended for most patients. In the remission time, an excessive consumption of alcohol and sulfur products may have a negative effect on the disease course. Attempts are also made at employing diets composed in detail in order to supplement IBD therapy. A diet with a modified carbohydrate composition, a semi-vegetarian diet and a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols are under investigation. Due to chronic inflammation as well as side effects of chronically used medications, patients with IBD are also at increased risk of nutritional factor deficiencies, including iron, calcium, vitamin D, vitamin B12, folic acid, zinc, magnesium and vitamin A. It should also be remembered that there is no single common diet suitable for all IBD patients; each of them is unique and dietary recommendations must be individually developed for each patient, depending on the course of the disease, past surgical procedures and type of pharmacotherapy.