New Membrane-Forming Aromatic Co-Poly(amide-imide)s: Influence of the Chemical Structure on the Morphological, Thermal and Transport Properties

Polymer film membranes are used to solve specific separation problems that dictate structural requirements. Structural and morphological parameters of film membranes based on glassy polyheteroarylenes can be controlled in the process of preparation from solutions that opens up prospects for obtaining structured membranes required for targeted separation. In the case of aromatic poly(amide-imide)s, the possibility of controlling film formation and structure virtually has not been studied. In the present work, a series of homologous co-poly(amide-imide)s differing in the number of repeating units with carboxyl-substituted aromatic fragments was synthesized by polycondensation. Comparative analysis of the processes of formation of membranes with different morphologies based on these polymers under equal conditions was performed. New information was obtained about the influence of the amounts of carboxyl groups and the residual solvent on structural properties of asymmetric membranes. The influence of these factors on transport properties of dense membranes under pervaporation conditions was studied. It was demonstrated that in the case of carboxyl-containing poly(amide-imide)s, the domains formed during film preparation had a significant effect on membrane properties.

The correlation between volumetric bone mineral density and morphological parameters of the proximal femur and clinical outcomes in ankylosing spondylitis patients with hip involvement

Background To measure volumetric bone mineral density (vBMD) with quantitative computed tomography (QCT) in the proximal femur of ankylosing spondylitis (AS) patients with hip involvement and analyze their correlations with radiographic and clinical parameters. Methods Sixty-five AS inpatients were enrolled in this study. The bone mineral density was measured by QCT and dual-energy x-ray absorptiometry (DXA), respectively. The morphological parameters of the proximal femur were measured on digital anteroposterior (AP) radiographs of the pelvis. The correlations between them were analyzed by SPSS software. Results The average trabecular vBMD measured at the femoral neck was 136.38 ± 25.58 mg/cm3. According to the BASRI-Hip score, group A consisted of 39 hips (0–2 score) and group B consisted of 26 hips (3–4 score). There were significant differences regarding trabecular CTXA equivalent T-score between group A and B at the femoral neck (p = 0.004); intertrochanteric region (p < 0.001) and greater trochanter (p = 0.001). The trabecular CTXA equivalent T-score at femoral neck had a negative correlation with disease duration (r = − 0.311, p = 0.012) and with CBR (r = − 0.319, p = 0.010). Conclusions The low trabecular bone density at the site of the hip was associated with the duration of disease progression and degree of hip involvement. Meanwhile, it had a correlation with hip function status although we failed to confirm a significant relationship between hip vBMD and disease activity.

INFLUENCE OF COVID 19 ON MORPHOLOGICAL AND CARDIOVASCULAR STATUS OF PROFESSIONAL HANDBALL PLAYERS

Handball is one of the very popular sports games in the world. The current COVID 19 pandemic directly affects handball players in the training and competition processes from all age categories but professional players seem to be at a higher risk of contracting the disease. This study aimed to assess morphological and cardiovascular status of 20 participants, professional handball players who compete at elite competition rank, and therewith to adjust their training process and to test the differences between COVID 19 positive and COVID 19 negative participants. Testing included measurements of basic morphological parameters while the function of the cardiovascular system (CVS) was assessed at rest and effort - exercise stress test with Vita Maxima protocol. The results of t-test did not show a statistically significant difference in morphological and cardiovascular characteristics of participants who had COVID 19 infection (with a positive PCR test), who had symptoms of infection but no PCR test for the virus, and those who did not contract COVID 19.

The effect of prebiotic with bifidogenic properties on morphometric parameters of rabbits

The research was aimed at study of the potential and effectiveness of lactulose use in rabbit breeding. Lactulose is an isomer of milk sugar (disaccharide), it serves as a nutrient substrate for saccharolytic bacteria. The latter decompose it into short-chain fatty acids - lactic, acetic, propionic, butyric. At that time, the pH of the contents of the colon decreases. The microbiocenosis uses lactulose as a source of carbohydrates and energy. In this work, the optimal dosage and method of introducing lactulose into the diet of young rabbits of the California breed are calculated and determined experimentally. The experiment (2013-2016) involved male rabbits at the age of 45 days. The duration of the experiment was 60 days. The control group and two experimental groups of 20 heads each were formed by the method of analog pairs. The dry type of feeding was used using full-grain granular compound feed KK-92. Lactulose concentrate "Lactusan" was used, being added to drinking water. As the basic value of the norm for the introduction of lactulose into the diet of rabbits for further planned experiments, 0.06 g/kg of live weight per day was taken. As a result of the conducted studies, some responses of the rabbit body were revealed when they were raised using the lactulose prebiotic, which has bifidogenic properties. The influence of different dosages of lactulose on some morphological parameters and meat productivity of rabbits was established. The mass of the examined internal organs did not undergo critical changes. The introduction of lactulose into the diet of California rabbits for 60 days at a dosage of 0.06 g/kg of live weight per day increased the slaughter yield by 3.1 %, and at a dosage of 0.12 g/kg ‒by 0.5 %.

Does Conventional Morphological Evaluation Still Play a Role in Predicting Blastocyst Formation?

BackgroundAdvanced models including time-lapse imaging and artificial intelligence technologies have been used to predict blastocyst formation. However, the conventional morphological evaluation of embryos is still widely used. The purpose of the present study was to evaluate the predictive power of conventional morphological evaluation regarding blastocyst formation.MethodsRetrospective evaluation of data from 15613 patients receiving blastocyst culture from January 2013 through December 2020 in our institution were reviewed. Generalized estimating equations (GEE) were used to establish the morphology-based model. To estimate whether including more features regarding patient characteristics and cycle parameters improve the predicting power, we also establish models including 27 more features with either LASSO regression or XGbosst. The predicted number of blastocyst were associated with the observed number of the blastocyst and were used to predict the blastocyst transfer cancellation either in fresh or frozen cycles. ResultsBased on early cleavage and routine observed morphological parameters (cell number, fragmentation, and symmetry), the GEE model predicted blastocyst formation with an AUC of 0.779(95%CI: 0.77-0.787) and an accuracy of 74.7%(95%CI: 73.9%-75.5%) in the validation set. LASSO regression model and XGboost model based on the combination of cycle characteristics and embryo morphology yielded similar predicting power with AUCs of 0.78(95%CI: 0.771-0.789) and 0.754(95%CI: 0.745-0.763), respectively. For per-cycle blastocyst yield, the predicted number of blastocysts using morphological parameters alone strongly correlated with observed blastocyst number (r=0.897, P<0.0001) and predicted blastocyst transfer cancel with an AUC of 0.926((95%CI: 0.911-0.94). ConclusionThe data suggested that routine morphology observation remained a feasible tool to support an informed decision regarding the day of transfer. However, models based on the combination of cycle characteristics and embryo morphology do not increase the predicting power significantly.

Contralateral Eye Study On The Characteristics of Corneal Aberration In Patients With Bilateral Keratoconus And Unilateral Corneal Vogt’s Striae

Purpose: To assess the corneal high-order aberration(HOA) and its correlation with corneal morphological parameters in patients with bilateral keratoconus (KCN) and unilateral Vogt’s striae.Methods: A total of 168 eyes of 84 patients with KCN, whose corneas had definite signs of unilateral Vogt’s striae were enrolled. Corneal HOA and morphological parameters were measured using Pentacam HR.Results: The corneal morphological parameters between KCN eyes with and without Vogt’s striae were evidently different (P < 0.001). The 3rd coma 90°, 4th spherical aberration, 5th coma 90°, RMS (total), and RMS (HOA) in the front, back surfaces and total cornea in KCN eyes with Vogt’s striae were significantly higher than those in KCN eyes without Vogt’s striae (P < 0.001). In KCN eyes with Vogt’s striae, the 3rd coma 90° and 4th spherical aberration in the front surface and total cornea were negatively correlated with K1, K2, Km, Kmax, ACE, and PCE (P < 0.05). The 3rd coma 90° , 4th spherical aberration in back surface and RMS (total), RMS (HOA) in the front, back surfaces, total cornea were positively correlated with K1, K2, Km, Kmax, ACE, and PCE (P < 0.05).Conclusions: Corneal HOA especially vertical coma and spherical aberration may increase when Vogt’s striae appeared in KCN eyes. The scale of increase was significantly related with changes in corneal shapes.