The relationship of structure,thermal and water vapor permeability barrier properties of poly(butylene succinate)/organomodified beidellite clay bionanocomposites prepared by in situ polycondensation

The exploitation of beidellite clay (BDT), used as a nanofiller in the preparation of poly(butylene succinate) (PBS)/organoclay biodegradable nanocomposites, was investigated. A series of bionanocomposites with various loadings of the organoclay (3CTA-BDT) were prepared by in situ polycondensation reaction between succinic anhydride (SuAh) and 1,4-butanediol (1,4-BD) at atmospheric pressure in refluxing decalin with azeotropic removal of water, and the reaction was catalyzed by non-toxic bismuth chloride (BiCl₃). X-ray diffraction (XRD) and scanning electron microscopy (SEM) results showed that 3CTA-BDT was likely exfoliated and well dispersed in PBS matrix. Thermal properties (TGA, DSC and thermal conductivity), contact angle measurements and water vapor sorption behavior of the corresponding nanocomposites were also discussed. Compared to pure PBS, a significant reduction of the diffusion coefficient and the water vapor permeability (WVP) by 44 and 37%, respectively, was observed by adding only 5 wt% of 3CTA-BDT. These results could make these bionanocomposites suitable materials for food packaging application.

The exploitation of beidellite clay (BDT), used as a nanofiller in the preparation of poly(butylene succinate) (PBS)/organoclay biodegradable nanocomposites, was investigated. Their thermal and water vapor barrier properties were also studied.     

Evaluation of the antiparasitic activities of imidazol-2-ylidene–gold(I) complexes

A series of cationic gold(I)–carbene complexes with various 4,5-diarylimidazolylidene ligands were either newly prepared or repurposed for testing against protozoal Leishmania major, Toxoplasma gondii, and Trypanosoma brucei parasites. The syntheses of the new complexes 1b and 1c were described. Ferrocene compound 1a showed the highest activities against L. major amastigotes and T. gondii and distinct selectivity for T. gondii cells when compared with the activity against nonmalignant Vero cells. The ferrocene derivatives 1a–c are generally more active against the L. major amastigotes and the T. gondii tachyzoites than the other tested anisyl gold complexes and the approved drugs atovaquone and amphotericin B. Compounds 1a and 1e showed the highest selectivities for L. major amastigotes. Compounds 1d and 1f showed the highest selectivities for L. major promastigotes; 1f was the most active compound against L. major promastigotes of this series of compounds. The 3,4,5-trimethoxyphenyl analog 1b also exhibited a much greater selectivity for T. b. brucei cells when compared with its activity against human HeLa cells.     

Effects of resistance training of moderate intensity on heart rate variability,body composition,and muscle strength in healthy elderly women

Purpose

The practice of resistance training is recommended as non-pharmacological strategy during aging. In this study, we propose training composed of exercises, leg 180° press, seated row, leg curl, bench press, abduction machine, push down, adduction machine, and curl biceps. Accordingly, this study aimed to determine the effects of dynamic resistance training on autonomic response, muscle strength, and body composition of elderly women without comorbidities.

Methods

Twenty-six healthy older women (65 ± 3 years) were randomly divided into two groups. The Control Group (CG) consisted of 13 subjects not engaged in any physical exercise, while the Training Group (GT) (n = 13) performed 8 strength training exercises with 3 sets of 8 maximum repetitions. Heart rate variability, body composition, and muscle strength were assessed before and after the 12 weeks in both groups.

Results

No significant difference was found in body composition, muscle strength, and heart rate variability between CG and TG before (baseline) 12 weeks of training. Significant differences between pre- and post-training moments were found only in training group. In this sense, results demonstrated improvement (p < 0.05) in body fat mass (23.0 ± 1.2 vs. 20.0 ± 1.1 kg), fat-free mass (38.0 ± 1.5 vs. 42.0 ± 1.4 kg), strength of upper (17.8 ± 1.0 vs. 22.2 ± 1.1 kgf) and lower limbs (27.1 ± 2.4 vs. 34.1 ± 2.5 kgf), and in time and frequency domain measures of heart rate variability, highlighting the indices LF/HF (1.2 ± 0.4 vs. 0.7 ± 0.1).

Conclusions

The dynamic resistance training protocol presented in this study may be regarded as an effective approach to prevent cardiovascular morbidity and mortality in elderly women.

     

Decline of Systolic and Diastolic 2D Strain Rate During Follow-Up of HLHS Patients After Fontan Palliation

Accurate assessment of ventricular function is particularly important in children with hypoplastic left heart syndrome (HLHS) after completion of the total cavopulmonary connection (TCPC). For this purpose, two-dimensional speckle tracking (2DST) is a promising technique as it does not depend on the angle of insonation or the geometry of the ventricle. The objective of this study was to assess changes in systolic and diastolic right ventricular (RV) function within a 5-year follow-up period of HLHS patients after TCPC using conventional and 2DST echocardiography. RV fractional area change (RVFAC), tricuspid annular plane systolic excursion (TAPSE), E/A, E/e′ and 2DST parameters [global longitudinal peak systolic strain (GS) and strain rate (GSRs), global strain rate in early (GSRe) and late (GSRa) diastole] of 40 HLHS patients were compared at 1.6 and at 5.1 years after TCPC. RVFAC, E/A, E/e′ and GS did not change, whereas TAPSE (13.7 ± 3.2 vs. 10.5 ± 2.4 mm/m², p < 0.001), GSRs (?1.56 ± 0.28 vs. ?1.35 ± 0.31 1/s, p < 0.001), GSRe (2.22 ± 0.49 vs. 1.96 ± 0.44 1/s, p = 0.004) and GSRa (1.19 ± 0.39 vs. 0.92 ± 0.39 1/s, p < 0.001) decreased significantly. Systolic and diastolic RV function parameters of HLHS patients decreased from 1.6 to 5.1 years after TCPC in our patients. Changes in global strain rate parameters may be signaling early RV dysfunction that is not detectable by traditional echocardiography. Further study is needed to verify this and to determine whether these changes are clinically relevant.     

Human mesenchymal stem cells at the single-cell level: simultaneous seven-colour immunofluorescence

Extracellular, intracellular or surface proteins can be used as putative markers to characterize human mesenchymal stem cells (hMSC). However, these markers are also expressed by other cell types and primary cell pools reveal considerable heterogeneity. Therefore, the simultaneous detection of several markers on a single cell appears to be an attractive approach to identify hMSC. Here we demonstrate the specific distinction of human MSC from human osteoblasts via seven-colour fluorescence on the single cell level with simultaneous marker detection of CD44, CD105/endoglin, CD106/VCAM-1, collagen-IV, fibronectin, actin and DAPI nuclear staining. We performed spectral image acquisition using a Sagnac-type interferometer. Subsequent linear unmixing allowed for decomposition of each pixel in its spectral components. Our approach reveals a typical expression profile of the adherent singular cells, allowing the specific distinction between hMSC and osteoblasts on the single cell level.     

Expression of merozoite surface protein markers by Plasmodium falciparum-infected erythrocytes in peripheral blood and tissues of children with fatal malaria

Sequestration of Plasmodium falciparum-infected erythrocytes is a pathological feature of fatal cerebral malaria. P. falciparum is genetically diverse among, and often within, patients. Preferential sequestration of certain genotypes might be important in pathogenesis. We compared circulating parasites with parasites sequestered in the brain, spleen, liver, and lung in the same Malawian children with fatal malaria, classifying serotypes using antibodies to merozoite surface proteins 1 and 2 and immunofluorescence in order to differentiate parasites and to quantify the proportions of each serotype. We found (i) similar distributions of various serotypes in different tissues and (ii) concordance between parasite serotypes in peripheral blood and parasite serotypes in tissues. No serotypes predominated in the brain in cerebral malaria, and parasites belonging to a single serotype did not cluster within individual vessels or within single tissues. These findings do not support the hypothesis that cerebral malaria is caused by cerebral sequestration of certain virulent types.     

Molecular cytogenetic analysis of complex karyotypes with derivative chromosome der(1)t(1;5) found in two patients with myeloid leukemia

Dedifferentiated liposarcoma of the pleura is an extremely rare malignancy mimicking a variety of tumors, such as other sarcomas, mesothelioma, and malignant solitary fibrous tumor of the pleura. Liposarcoma of the pleura can be combined with mediastinal involvement, and in most cases it may be impossible to be certain where the primary tumor originated. In this report, we describe a very rare occurence of a dedifferentiated liposarcoma of the pleura in a 76-year-old woman associated with a distinct second dedifferentiated liposarcoma of the mediastinum. Histologically, the pleural tumor demonstrated spindle cells arranged in a fascicular pattern, whereas the mediastinal tumor was mostly adipocytic with small areas of spindle cells. Vimentin and protein S100 were focally expressed by the tumor cells. The differential diagnosis of the pleural mass included malignant solitary fibrous tumor. Cytogenetic analysis showed supernumerary ring chromosomes in the pleural tumor, as well as strong amplification of MDM2 and CDK4 genes in both tumors. Array comparative genomic hybridization showed amplifications of chromosome arms 6q, 12q, and 15q, shared by both tumors and strongly pointing to a common origin.