scholarly journals Experimental studies on preparation of the porous and small-diameter poly(ε-caprolactone) external vascular scaffold and its degradability and biocompatibility

2018 ◽  
Vol 6 ◽  
pp. 2
Author(s):  
Qingyun Chen ◽  
Xia Jiang ◽  
Li Feng
Keyword(s):  
Mechanical Property ◽  
Raw Materials ◽  
Degradation Mechanism ◽  
Experimental Studies ◽  
Small Diameter ◽  
Thermomyces Lanuginosus ◽  
Control Group ◽  
Vascular Scaffold ◽  
The Media ◽  
Form Stability

Aim: This study was aim to prepare a porous poly(ε-caprolactone) (PCL) biodegradable external vascular scaffold by dipping and leaching method, and to assess its mechanical property, degradability and biocompatibility. Methods: We used the PCL-1, PCL-2 as the raw materials and NaCl particles as the pore-forming agents to construct a porous PCL external vascular scaffold. We tested the mechanical property of the porous PCL external vascular scaffold. The degradability of the scaffold was studied in the presence of thermomyces lanuginosus lipase (TL lipase). After 1, 3, and 5, 7 days, the samples were taken out, and the pH of the media was measured. The form-stability of the scaffold was investigated by macroscopic observation and the microstructure of it was observed by SEM. The cytotoxicity of the scaffold was evaluated by CCK-8 assay. Results: PCL-1 could make a white integrated external vascular scaffold with uniform texture. When the concentration of NaCl was less than or equal to 50%, the tensile strength of the porous PCL-1 external vascular scaffolds were higher than 4.2 Mpa, which meet the demand of clinical vascular transplantation. With the degradation of the scaffold in the lipase media, the form-stability of the scaffold was seriously destroyed, the surface of the scaffold began to degrade with some honeycomb holes, and the pH of the media values were lower than the initial reading of 7.4. Rat adipose-derived stem cells (rADSCs) cultured in the extractions of the porous PCL external vascular scaffold had good proliferation and cell morphology compared to the control group. Conclusion: The porous PCL-1-50 external vascular scaffold, with the 50% concentration of NaCl, had the maximum porosity on the basis of enough mechanical strength which meets the demand of clinical vascular transplantation. Moreover, it had good biocompatibility with rADSCs and the degradation mechanism of the scaffold was surface degradation.

scholarly journals PHYSICOCHEMICAL AND ELECTROCHEMICAL METHODS FOR MODIFYING THE PROPERTIES OF DIAMONDS AND ORE PULP COMPONENTS DURING THE SEPARATION OF DIAMOND-BEARING KIMBERLITES

2021 ◽  
Vol 13 (2) ◽  
pp. 238-247
Author(s):  
Galina DVOICHENKOVA ◽  
◽  
Elena CHANTURIA ◽  
Alexander TIMOFEEV ◽  
Elena CHERNYSHEVA ◽  
...  
Keyword(s):  
Raw Materials ◽  
Experimental Studies ◽  
Dense Medium ◽  
Protective Shell ◽  
Foam Separation ◽  
Industrial Enterprises ◽  
Diamond Crystals ◽  
Heavy Medium ◽  
The Media ◽  
The Stability

The main deposits of kimberlite ores located in the regions of Western Yakutia are enriched at the ALROSA diamond extraction factories using a similar technology, in which the maximum completeness of extraction and safety of diamond crystals is ensured by the stages of schemes. The bulk of diamond crystals is extracted in the processes of heavy medium, sticky and foam separation, the effectiveness of which is determined by the properties of diamonds, kimberlite minerals and the media separating them. The article presents the results of theoretical and experimental studies carried out by ICEMR RAS together with the largest universities in Russia, scientific and industrial enterprises of ALROSA. It is shown that the use of combined energy methods of destruction and removal of hydrophilizing formations on diamond crystals provides hydrophobization of their surface in the processes of sticky and foam separation. It has been established that the efficiency and economic indicators of the process of dense medium separation of diamond-containing raw materials are due to the stability of the technological properties of the weighting agent of the ferrosilicon medium and the suspension prepared on its basis. The method for modifying the corrosion resistance of ferrosilicon by nitriding its surface has been substantiated and tested. The proposed method makes it possible to create a protective shell on the surface of the granules, preventing their destruction upon contact with corrosive components of the water-air environment. Semi-industrial tests have established the possibility of increasing the extraction of diamonds into concentrates for sticky and foam separation by 4 and 5.2%, respectively. The results of laboratory tests have confirmed the possibility of reducing the corrosion rate of ferrosilicon by 5-6 times in the process of dense medium separation.

Biodegradation mechanism of biogas production by modified rice straw fermentation

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8862-8882
Author(s):  
Enhai Liu ◽  
Baozhong Zhu ◽  
Shengyong Liu ◽  
Hailong Yu ◽  
Zhiping Zhang ◽  
...  
Keyword(s):  
Rice Straw ◽  
Biogas Production ◽  
Raw Materials ◽  
Degradation Mechanism ◽  
Raw Material ◽  
White Rot ◽  
Control Group ◽  
Biogas Yield ◽  
Optimal Ratio ◽  
Pre Treatment

Based on the literature on the degradation mechanism and the change of micro-functional groups in the fermentation process of modified rice straw, this study aimed to solve the problems of low biogas production rate and poor stability of the biogas production system. In this work, mathematical equations were developed and combined with duck dung and rice straw mixed raw material to perform a fermentation test. The molecular micro-functional group changes of cellulose, hemicellulose, and lignin were studied to obtain the optimal ratio of mixed raw materials for fermentation and to explore the optimization mechanism of its fermentation biogas production. Experimental results showed that the optimal ratio of mixed raw materials was 2.8:1, and the inclusion of a suitable amount of Mn2+(concentration of 2 mol × L-1) was able to strengthen MnP activity and improve the ability of white-rot fungi to rupture β-O-4 bonds. A modification pre-treatment via activated carbon-based solid acid was performed, and the experimental group generated 15.8% more cumulative biogas than the control group. The biogas yield reached its peak when 300 g of inoculum was added to the pre-treatment at a concentration of 30%.

A possibility of using nickel concentrate, obtained as a result of hydrometallurgical enrichment of manganese-containing raw materials, at steel alloying

2020 ◽  
Vol 76 (7) ◽  
pp. 709-715
Author(s):  
O. Yu. Kichigina
Keyword(s):  
Raw Materials ◽  
Experimental Studies ◽  
Selective Extraction ◽  
Technological Parameters ◽  
Nickel Iron ◽  
Nickel Recovery ◽  
Nickel Concentrate ◽  
Steel Alloying ◽  
High Degree ◽  
Comprehensive Processing

At production of stainless steel expensive alloying elements, containing nickel, are used. To decrease the steel cost, substitution of nickel during steel alloying process by its oxides is an actual task. Results of analysis of thermodynamic and experimental studies of nickel reducing from its oxide presented, as well as methods of nickel oxide obtaining at manganese bearing complex raw materials enrichment and practice of its application during steel alloying. Technology of comprehensive processing of complex manganese-containing raw materials considered, including leaching and selective extraction out of the solution valuable components: manganese, nickel, iron, cobalt and copper. Based on theoretical and experiment studies, a possibility of substitution of metal nickel by concentrates, obtained as a result of hydrometallurgical enrichment, was confirmed. Optimal technological parameters, ensuring high degree of nickel recovery out of the initial raw materials were determined. It was established, that for direct steel alloying it is reasonable to add into the charge pellets, consisting of nickel concentrate and coke fines, that enables to reach the through nickel recovery at a level of 90%. The proposed method of alloying steel by nickel gives a possibility to decrease considerably steel cost at the expense of application of nickel concentrate, obtained out of tails of hydrometallurgical enrichment of manganese-bearing raw materials, which is much cheaper comparing with the metal nickel.

The influence of probiotic drug Biolax-U on morphological and biochemical parameters of blood in cows

2020 ◽  
pp. 70-76
Author(s):  
A. Farkhutdinova
Keyword(s):  
Biochemical Parameters ◽  
Hematological Parameters ◽  
Experimental Studies ◽  
Positive Influence ◽  
Biologically Active ◽  
Feed Consumption ◽  
Control Group ◽  
Animal Blood ◽  
Black And White ◽  
White Breed

The expediency of using the probiotic drug Biolax-U in the rations of lactating and dry cows of Black-and-White breed has been studied and scientifically proved. The influence of this drug on the morphological and biochemical parameters of animal blood has been determined. The composition of the probiotic drug Biolax-U consists of eight strains of a balanced complex of living lactic acid bacteria, yeast and actinomycetes, as well as biologically active substances. For experimental studies conducted on 2 groups of cows have been selected by the method of pairs-analogs, the influence of feeding of feed have been prepared with the use of the microbiological drug with probiotic action Biolax-U on feed consumption, morphological and biochemical changes in blood has been studied. Analysis of the rations of cows indicates that the content of calcium, phosphorus, magnesium, sulfur and trace elements such as manganese, copper, zinc and cobalt in the feed has been reduced. It has been found by studies that the use of probiotic drug Biolax-U had the positive influence on the feed intake, digestibility and better assimilation of feed nutrients and contributed to the improvement of blood morphological and biochemical parameters. For example, in animals of the experimental group hemoglobin has increased by 3,6 % (Р < 0,05), red blood cells by 10,1 (P ≤ 0,05), the content of leukocytes by 4,43, carotene by 9,6, glucose by 3,4; reserve alkalinity by 15,6, calcium by 19,4 (P ≤ 0,01), and phosphorus by 18,4 % compared with the control group of animals. During the lactation significantly improved hematological parameters including alkalinity reserve by 5,11 %, calcium level by 11,1, phosphorus by 8,6, hemoglobin by 14,2 %, the content of erythrocytes by 12,3, leukocyte by 3,86, and carotene 11,1 % against the parameters of animals of control group. The improvement of morphological and biochemical parameters of blood of cows indicates about stimulating effect on hematopoiesis and the general clinical condition of animals that contributes to the improvement of metabolic processes when using feed prepared with the use of microbiological drug with probiotic action Biolax-U.

The effectiveness of use RUSMA additive in the rations of lactating cows

2020 ◽  
pp. 28-37
Author(s):  
S. Sukhanova ◽  
N. Pozdnyakova ◽  
F. Yaroslavtsev
Keyword(s):  
Milk Fat ◽  
Raw Materials ◽  
Fat Content ◽  
Feed Additives ◽  
Control Group ◽  
New Mineral ◽  
Milk Productivity ◽  
Black And White ◽  
Lactating Cows ◽  
Experimental Group

The results of researches on the development of new mineral feed additives based on raw materials produced by Uralchem and the study of the eff ectiveness of their use in the rations of lactating cows have been presented in the article. The experiment has been carried out in the conditions of LLC “PF Barabinskoe” in the Dalmatovsky area in the Kurgan region where 3 groups of lactating cows of Black-and-White breed have been formed. Animals in the control group have been received the ration adopted in the farm, the 1st experimental group with the additive RusMA No. 1 at a dose of 150 g, the 2nd experimental group– with the additive RusMA No. 2 at the dose of 350 g. The use of experimental mineral additives in feeding lactating cows allowed us to increase their milk productivity and profi tability of production. At the same time, the best eff ectiveness was shown by the additive RusMA No. 2 at the dose of 350 g/head/day. The use of RusMA additives during the experiment period (105 days) allowed to increase the milk productivity of cows in the 1st experimental group by 6,03 % and in the 2nd experimental group by 8,24 %. Taking into account the fat content in milk, this diff erence was 6,31 and 8,53 %, respectively. The energy value of milk from cows of the experimental groups was higher compared to the control group by 2,45 and 1,76 %, respectively. According to the content of dry matter in milk, cows of the 2nd experimental group exceeded the control and 1st experimental group by 0,39 and 0,12 abs.%, respectively. The maximum milk fat content has been observed in the milk of cows of the 1st experimental group by 0,03 and 0,01 abs.% more than in the control and 2nd experimental groups, respectively. In terms of protein content, the cows of the 2nd experimental group signifi cantly exceeded the control group by 0,10 abs.% and the 1st experimental by 0,04 abs.%. The content of milk sugar in the 2nd experimental group was higher than in the control by 0,30 abs.% and compared to the 1st experimental by 0,11 %. Signifi cantly more calcium and phosphorus were contained in the milk of cows of the 2nd experimental group by 4,58 % (Р ≤ 0,001) and 2,86 % (Р ≤ 0,05), compared with the control group. The expenditures of feed in the EFU for the production of 1 kg of milk in animals of the 2nd experimental group was less by 5,13 % than in control cows and by 2,63 % compared to the 1st experimental group. The prime cost of 1 centner of milk was lower in the 2nd experimental group by 3,94 %, in the 1st experimental group by 2,65 % compared to the control group. The level of profi tability of milk production in the 2nd experimental group was higher by 9,0 and 1,0 abs.% in comparison with the control and 1st experimental groups, respectively.

Arthrophytum scoparium Extract Improves Memory Impairment and Affects Acetylcholinesterase Activity In Mice Brain

2020 ◽  
Vol 21 (6) ◽  
pp. 480-487
Author(s):  
Med A. Smach ◽  
Jawhar Hafsa ◽  
Bassem Charfeddine ◽  
Hedi Dridi ◽  
Khalifa Limem ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Saline Water ◽  
Experimental Studies ◽  
Chronic Administration ◽  
Acetylcholinesterase Activity ◽  
Control Group ◽  
Pharmacological Activities ◽  
Oxidative Damages ◽  
Y Maze ◽  
Mice Brain

Background: Arthrophytum scoparium (Pomel) Iljin (Amaranthaceae family) has been widely used in traditional Tunisian medicine to treat many disorders such as migraine, headache, and neurological disorders. This study investigates the effect of Arthrophytum scoparium Aqueous Extract (ASAE) on cognitive impairments and oxidative injury induced by galactose (10%) in a mouse model. Materials and Methods: The mice were divided randomly into 4 experimental groups, including the control group (saline water 9 ‰), Galactose group, Scop group (300 mg/kg/d), and Scop+Gal group (300 mg/kg/d). Mice received the corresponding solutions by intraperitoneal injection (i.p.) for 7 days before the Y-maze active tests. Galactose 10% was given to all groups except control and Scop groups, 30 min before the trial. Levels of Acetylcholinesterase Activity (AChE), Ascorbic Acid (AA), Gluthatione (GSH) and Malondialdehyde (MDA) in mice brains were examined. Results: Chronic administration of galactose significantly impaired cognitive performance in Y maze, caused marked oxidative damages and a significant increase in the acetylcholinesterase activity as compared to other groups. On the contrary, ASAE (300 mg/kg) treatment suppressed galactoseinduced oxidative damage by ameliorating the increased levels of GSH and AA. Moreover, ASAE treatment reduced brain AChE activities in the galactose-induced model. Conclusion: These findings suggest that ASAE exerts potent anti-amnesic effects via the modulation of cholinergic and antioxidant activities. The observed pharmacological activities should be further evaluated by detailed experimental studies and validated by clinical trials.

An intervention study on the effectiveness of an anti-stress-app on psychophysiological acute and chronic stress (Preprint)

2018 ◽  
Author(s):  
Franziska Lautenbach
Keyword(s):  
Chronic Stress ◽  
Acute Stress ◽  
Physiological Stress ◽  
Stress Test ◽  
Experimental Studies ◽  
Trier Social Stress Test ◽  
Control Group ◽  
Subjective Perception ◽  
Face To Face ◽  
Acute And Chronic Stress

BACKGROUND Dealing with stress is of central importance. Lately, smartphone applications (apps) are deployed in stress interventions as they offer maximal flexibility for users. First results of experimental studies show that anti-stress apps effect subjective perception of stress positively (Ly et al., 2014). However, current literature lacks studies on physiological stress reactions (e.g., cortisol), although they are of special interest to health issues. OBJECTIVE Therefore, the aim of this study was to investigate the effectiveness of an anti-stress app in chronic and acute stress reduction on a physiological (cortisol) and psychological level (subjective perception of stress) in comparison to a face-to-face and a control group in a pre-post design, for the first time. METHODS Sixty-two participants took part in the pretesting procedure (drop-out of 53 %). Based on age, gender, physical activity and subjectively perceived acute stress due to the Trier Social Stress Test for groups (TSST-G; von Dawans et al., 2011) as well as based on subjectively chronic stress assessed during the pretest, participants were parallelized in three groups (anti-stress-app: n = 10, face-to-face: n = 11, control group: n = 9). RESULTS After six weeks of the cognitive-based resource-oriented intervention, participants were exposed to the TSST-G for post testing. Results did not show a change of cortisol secretion or cognitive appraisal of the acute stressor. Further, no changes were detected in the chronic physiological stress reaction. CONCLUSIONS Possible causes are discussed extensively. CLINICALTRIAL no

How negative mood hinders belief updating in depression: results from two experimental studies

2021 ◽  
pp. 1-14
Author(s):  
Tobias Kube ◽  
Lukas Kirchner ◽  
Thomas Gärtner ◽  
Julia Anna Glombiewski
Keyword(s):  
Performance Feedback ◽  
Negative Mood ◽  
Experimental Studies ◽  
Positive Mood ◽  
Control Group ◽  
Belief Updating ◽  
Significant Group ◽  
Negative Beliefs ◽  
Clinically Depressed ◽  
Happy Mood

Abstract Background In two experimental studies, we tested the hypothesis that negative mood would hinder the revision of negative beliefs in response to unexpectedly positive information in depression, whereas positive mood was expected to enhance belief updating. Methods In study 1 (N = 101), we used a subclinical sample to compare the film-based induction of sad v. happy mood with a distraction control group. Subsequently, participants underwent a well-established paradigm to examine intra-individual changes in performance-related expectations after unexpectedly positive performance feedback. In study 2, we applied the belief-updating task from study 1 to an inpatient sample (N = 81) and induced sad v. happy mood via film-clips v. recall of autobiographic events. Results The results of study 1 showed no significant group differences in belief updating; the severity of depressive symptoms was a negative predictor of belief revision, though, and there was a non-significant trend suggesting that the presence of sad mood hindered belief updating in the subgroup of participants with a diagnosed depressive episode. Study 2 revealed that participants updated their expectations significantly less in line with positive feedback when they underwent the induction of negative mood prior to feedback, relative to positive mood. Conclusions By indicating that the presence of negative mood can hinder the revision of negative beliefs in clinically depressed people, our findings suggest that learning from new experiences can be hampered if state negative mood is activated. Thus, interventions relying on learning from novel positive experiences should aim at reducing state negative mood in depression.

scholarly journals Effect of Pork Meat Replacement by Fish Products on Fatty Acid Content, Physicochemical, and Sensory Properties of Pork Pâtés

2020 ◽  
Vol 11 (1) ◽  
pp. 188
Author(s):  
Piotr Skałecki ◽  
Agnieszka Kaliniak-Dziura ◽  
Piotr Domaradzki ◽  
Mariusz Florek ◽  
Ewa Poleszak ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Acid Content ◽  
Raw Materials ◽  
Fatty Acid Content ◽  
Calorific Value ◽  
Thiobarbituric Acid ◽  
Acid Value ◽  
Sensory Properties ◽  
Control Group

The aim of the study was to assess the influence of the addition of fish raw materials (roe or fish meat) on the quality and nutritional value of pork pâtés. The control group (n = 4) consisted of pork pâtés, I experimental group (n = 6) of pâtés with 20% addition of roe (perch and pike), and II group of pâtés with 20% addition of fish (perch and pike meat) (n = 6). The pâtés’ pH, color, and profiled texture analysis were instrumentally measured and water, protein, fat, ash, and fatty acid content were determined by reference methods. To assess the oxidative stability of lipids the measurement of peroxide number, thiobarbituric acid reactive substances and content of conjugated dienes and trienes was used. The degree of fat hydrolysis was determined on the basis of acid value. Sensory analysis was carried out using the scaling method, taking into account 12 unit quality characteristics. Products with roe and meat contained less fat (accordingly 15.9% and 14.1%) and showed lower calorific value (accordingly 225.6 and 208.6 kcal/100 g) compared to pork pâtés (20.2% of lipids, 267 kcal/100 g). Moreover, the addition of fish raw materials improved the index of nutritional quality for protein (from 3.2 to 3.9) and beneficially reduced the nutritional index for fat (from 2.2 to 1.9). Fish constituents modified, to a certain extent, the color, texture, and sensory properties of pâtés, while maintaining full acceptability in consumer assessment. The addition of fish roe significantly increased the healthful quality by improving the fatty acid profile of pâtés, in which the significantly highest content of n-3 fatty acids, including eicosapentaenoic and docosahexaenoic acids (accordingly 252.21, 43.17, and 107.94 mg/100 g product), as well the highest concentration of saturated branched chain fatty acids were determined (18.75 mg/100 g product).

scholarly journals Degradation Mechanism of Porous Metal-Organic Frameworks by In Situ Atomic Force Microscopy

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 722
Author(s):  
Ioanna Christodoulou ◽  
Tom Bourguignon ◽  
Xue Li ◽  
Gilles Patriarche ◽  
Christian Serre ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Degradation Mechanism ◽  
Metal Organic Frameworks ◽  
Porous Metal ◽  
Force Microscopy ◽  
Atomic Force ◽  
Metal Organic ◽  
The Media ◽  
Ph Conditions

In recent years, Metal-Organic Frameworks (MOFs) have attracted a growing interest for biomedical applications. The design of MOFs should take into consideration the subtle balance between stability and biodegradability. However, only few studies have focused on the MOFs’ stability in physiological media and their degradation mechanism. Here, we investigate the degradation of mesoporous iron (III) carboxylate MOFs, which are among the most employed MOFs for drug delivery, by a set of complementary methods. In situ AFM allowed monitoring with nanoscale resolution the morphological, dimensional, and mechanical properties of a series of MOFs in phosphate buffer saline and in real time. Depending on the synthetic route, the external surface presented either well-defined crystalline planes or initial defects, which influenced the degradation mechanism of the particles. Moreover, MOF stability was investigated under different pH conditions, from acidic to neutral. Interestingly, despite pronounced erosion, especially at neutral pH, the dimensions of the crystals were unchanged. It was revealed that the external surfaces of MOF crystals rapidly respond to in situ changes of the composition of the media they are in contact with. These observations are of a crucial importance for the design of nanosized MOFs for drug delivery applications.

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