scholarly journals Biocompatible and Thermoresistant Hydrogels Based on Collagen and Chitosan

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 272
Author(s):  
Pablo Sánchez-Cid ◽  
Mercedes Jiménez-Rosado ◽  
José Fernando Rubio-Valle ◽  
Alberto Romero ◽  
Francisco J. Ostos ◽  
...  
Keyword(s):  
Temperature Drop ◽  
Thermomechanical Properties ◽  
Raw Material ◽  
Mechanical Resistance ◽  
Microstructural Properties ◽  
Ph Change ◽  
Soft Tissue Regeneration ◽  
Hybrid Hydrogels ◽  
Two Stages ◽  
Similar Intensity

Hydrogels are considered good biomaterials for soft tissue regeneration. In this sense, collagen is the most used raw material to develop hydrogels, due to its high biocompatibility. However, its low mechanical resistance, thermal stability and pH instability have generated the need to look for alternatives to its use. In this sense, the combination of collagen with another raw material (i.e., polysaccharides) can improve the final properties of hydrogels. For this reason, the main objective of this work was the development of hydrogels based on collagen and chitosan. The mechanical, thermal and microstructural properties of the hydrogels formed with different ratios of collagen/chitosan (100/0, 75/25, 50/50, 25/75 and 0/100) were evaluated after being processed by two variants of a protocol consisting in two stages: a pH change towards pH 7 and a temperature drop towards 4 °C. The main results showed that depending on the protocol, the physicochemical and microstructural properties of the hybrid hydrogels were similar to the unitary system depending on the stage carried out in first place, obtaining FTIR peaks with similar intensity or a more porous structure when chitosan was first gelled, instead of collagen. As a conclusion, the synergy between collagen and chitosan improved the properties of the hydrogels, showing good thermomechanical properties and cell viability to be used as potential biomaterials for Tissue Engineering.

scholarly journals Automatic Evaluation of the Mechanical Properties of Steels Maraging using Digital Image Processing Techniques

2020 ◽  
Author(s):  
Angélica Alves Viana ◽  
Savio Lopes Rabelo ◽  
José Daniel de Alencar Santos ◽  
Venceslau Xavier de Lima Filho ◽  
Douglas De Araújo Rodrigues ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Maraging Steel ◽  
Raw Material ◽  
High Fracture Toughness ◽  
Mechanical Resistance ◽  
High Fracture ◽  
Traditional System ◽  
Transformation Methods ◽  
Processing Techniques

Some strategic sectors of the economy require that the raw material of their machines and equipment have mechanical properties that satisfy their use. Maraging steel is a material of great concern since it is necessary to have a high mechanical resistance associated with high fracture toughness. The traditional tests to determine the fracture toughness of this material before use in applications are the Charpy and KIC tests. However, this process is characterized by being exhaustive and requiring specialized and trained professionals. Thus, to reverse this situation, this work proposes a new approach to determine the mechanical properties of maraging steel. For this, initially, the method removes any artifacts present in the image resulting from the mode of acquisition. In sequence, this works tested the method Extended Minimum Transformation (EMT) and mathematical morphology to find these markers of the regions of the dimples. Then, the Adaptive Thresholding, Optimal Global Thresholdusing the Otsu Method and Watershed transformation methods were used to segment the dimples. In the end, the diameter of the dimples and the toughness of the material were calculated. Tests are carried out and compared with the result obtained by specialists using the traditional system to evaluate the proposed approach. The results obtained were satisfactory for the application because the proposed approach presented speed and precision to the conventional methods.

scholarly journals Diatoms - nature materials with great potential for bioapplications

2016 ◽  
Vol 70 (6) ◽  
pp. 613-627 ◽  
Author(s):  
Djordje Medarevic ◽  
Dusan Losic ◽  
Svetlana Ibric
Keyword(s):  
Drug Delivery ◽  
Gas Sensing ◽  
High Surface ◽  
High Surface Area ◽  
Raw Material ◽  
Nanoporous Structure ◽  
Mechanical Resistance ◽  
Diatom Frustule ◽  
Wide Availability ◽  
Made In

Diatoms are widespread unicellular photosynthetic algae that produce unique highly ordered siliceous cell wall, called frustule. Micro- to nanoporous structure with high surface area that can be easily modified, high mechanical resistance, unique optical features (light focusing and luminescence) and biocompatibility make diatom frustule as a suitable raw material for the development of devices such as bio- and gas sensors, microfluidic particle sorting devices, supercapacitors, batteries, solar cells, electroluminescent devices and drug delivery systems. Their wide availability in the form of fossil remains (diatomite or diatomaceous earth) as well as easy cultivation in the artificial conditions further supports use of diatoms in many different fields of application. This review focused on the recent achievements in the diatom bioapplications such as drug delivery, biomolecules immobilization, bio- and gas sensing, since great progress was made in this field over the last several years.

HEMATOPOETIC STEM CELL RESPONSE TO STIMULATION OF EXTRACTS FROM ANIMAL MATERIALS

2016 ◽  
Vol 78 (5-6) ◽  
Author(s):  
Ivan Smirnov ◽  
Victor Keino ◽  
Ksenia Goryacheva ◽  
Alexander Shunk ◽  
Alexander Bondarev ◽  
...  
Keyword(s):  
Raw Materials ◽  
Raw Material ◽  
Animal Origin ◽  
Aqueous Extracts ◽  
Second Stage ◽  
Hematopoetic Stem Cell ◽  
Two Stages ◽  
Stimulation Of

The article presents the results of the research hemostimulating activity of aqueous extracts of antler young Siberean stag and drone larvae homogenate. These substrates were obtained from raw materials of animal origin. Altai Krai andAltaiRepublicare subjects of theRussian Federationwhich is the place of production of the raw material. Experiments were conducted in two stages. The first stage - in vitro, which included a research of experimental substrates on the culture of mouse marrow cells. During the experiments were obtained different results. We counted the number of colonies grown in cell culture for this. The second stage of experimenters - in vivo. It included an assessment of the myeloprotector on model of cytostatic myelosuppression of mice and analysis of bone marrow and peripheral blood.

scholarly journals Laser-based additively manufactured polymers: a review on processes and mechanical models

2020 ◽  
Vol 56 (2) ◽  
pp. 961-998
Author(s):  
Roberto Brighenti ◽  
Mattia Pancrazio Cosma ◽  
Liviu Marsavina ◽  
Andrea Spagnoli ◽  
Michele Terzano
Keyword(s):  
Process Parameters ◽  
Mechanical Performance ◽  
Selective Laser Sintering ◽  
Theoretical Models ◽  
Raw Material ◽  
Laser Source ◽  
Mechanical Resistance ◽  
Layer By Layer ◽  
Influence Of Process Parameters ◽  
Mechanical Models

Abstract Additive manufacturing (AM) is a broad definition of various techniques to produce layer-by-layer objects made of different materials. In this paper, a comprehensive review of laser-based technologies for polymers, including powder bed fusion processes [e.g. selective laser sintering (SLS)] and vat photopolymerisation [e.g. stereolithography (SLA)], is presented, where both the techniques employ a laser source to either melt or cure a raw polymeric material. The aim of the review is twofold: (1) to present the principal theoretical models adopted in the literature to simulate the complex physical phenomena involved in the transformation of the raw material into AM objects and (2) to discuss the influence of process parameters on the physical final properties of the printed objects and in turn on their mechanical performance. The models being presented simulate: the thermal problem along with the thermally activated bonding through sintering of the polymeric powder in SLS; the binding induced by the curing mechanisms of light-induced polymerisation of the liquid material in SLA. Key physical variables in AM objects, such as porosity and degree of cure in SLS and SLA respectively, are discussed in relation to the manufacturing process parameters, as well as to the mechanical resistance and deformability of the objects themselves. Graphic abstract

Effect of unrefined crude glycerol composition on the properties of polyurethane foams

2017 ◽  
Vol 54 (3) ◽  
pp. 633-649 ◽  
Author(s):  
Nuno V Gama ◽  
Belinda Soares ◽  
Carmen SR Freire ◽  
Rui Silva ◽  
Artur Ferreira ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Crude Glycerol ◽  
Mechanical Performance ◽  
Methyl Esters ◽  
Thermomechanical Properties ◽  
Polyurethane Foams ◽  
Raw Material ◽  
Two Samples ◽  
Pre Treatment ◽  
The Impact

The aim of this study is to evaluate the possibility of using unrefined crude glycerol (CG), a byproduct of the biodiesel industry, in the production of polyurethane foams. In order to assess the suitability of this raw material for the production of polyurethane foams, two samples of crude glycerol with different compositions in glycerol, fatty acids, and methyl esters were used directly, without any pretreatment or purification. Additionally, one of these samples was also submitted to a pre-treatment step in order to evaluate the advantage of purifying the raw material and, for comparison, pure glycerol was also used to prepare polyurethane foams. Both chemical and structural characterizations of the produced foams, as well as the thermomechanical properties determined, showed that unrefined crude glycerol is a suitable ecopolyol for the production of polyurethane foams. Although the presence of fatty acids and esters affects their mechanical performance, this issue can be explored to tune the properties of the ensuing polyurethane foams. Furthermore, the evaluation of the impact of using unrefined CG on the sustainability of polyurethane foams production yielded promising results.

scholarly journals Description And Composition Chemistry of Meat and Carapace (Thalasina Anomala)

2020 ◽  
Vol 25 (2) ◽  
pp. 138
Author(s):  
Tengku Muhammad Ghazali ◽  
Fillia R.G Sitinjak ◽  
Wahdi Simanullang
Keyword(s):  
Research Method ◽  
Mineral Content ◽  
Dry Weight ◽  
Proximate Analysis ◽  
Ash Content ◽  
Raw Material ◽  
Body Parts ◽  
Test Results ◽  
Mangrove Area ◽  
Two Stages

Thalasina anomala is a type of shrimp that is generally found in the muddy areas of the mangrove area on the coast of the Selat Panjang. The purpose of this study was to obtain the chemical composition of meat and carapace and the rendemen of T. Anoma. Meat and carapace as raw material. This research method description and data analyzed statistically. In this study, there are two stages, namely preparation and rendement of body parts of rama shrimp and then proximate analysis of meat and carapace. Proximate test results from meat and carapace of successive shrimp are water content 76.58 %, 38.93 % gross weight (gw), protein content 81, 46 %, 10.12 % dry weight (dw) , fat content of 5.01% (dw), 2.36% (dw), ash content of 3.93% (bk), 73.96% (dw) and Carbohydrates 9.61% (dw), 14.62% (dw). This value shows that protein in meat is beneficial in food, while carapaces ash content shows the high mineral content

scholarly journals Seed development in Paeonia ostii (Paeoniaceae), with particular reference to embryogeny

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Keliang Zhang ◽  
Weizhang Cao ◽  
Jerry M. Baskin ◽  
Carol C. Baskin ◽  
Jing Sun ◽  
...  
Keyword(s):  
Seed Development ◽  
Seed Coat ◽  
Soluble Sugars ◽  
Outer Integument ◽  
Dry Mass ◽  
Endosperm Development ◽  
Raw Material ◽  
Lack Of Information ◽  
Two Stages ◽  
Peripheral Cells

Abstract Background Seeds of Paeonia ostii have been proposed as a source of raw material for the production of edible oil; however, lack of information about the developmental biology of the seeds hampers our ability to use them. Our aim was to investigate development of the seed coat, endosperm and embryo of P. ostii in relation to timing of accumulation of nutrient reserves from pollination to seed maturity. Ovules and developing seeds of P. ostii were collected at various stages of development from zygote to maturity. Seed fresh mass, dry mass, germination, moisture, soluble sugars, starch, protein and oil content were determined. Ontogeny of seeds including embryo, endosperm and seed coat were analyzed histologically. Results The ovule of P. ostii is anatropous, crassinucellate and bitegmic. The zygote begins to divide at about 5 days after pollination (DAP), and the division is not accompanied by cell wall formation. By 25 DAP, the proembryo begins to cellularize. Thereafter, several embryo primordia appear at the surface of the cellularized proembryo, but only one matures. Endosperm development follows the typical nuclear type. The seed coat is derived from the outer integument. During seed development, soluble sugars, starch and crude fat content increased and then decreased, with maximum contents at 60, 80 and 100 DAP, respectively. Protein content was relatively low compared with soluble sugars and crude fat, but it increased throughout seed development. Conclusions During seed development in P. ostii, the seed coat acts as a temporary storage tissue. Embryo development of P. ostii can be divided into two stages: a coenocytic proembryo from zygote (n + n) that degenerates and a somatic embryo from peripheral cells of the proembryo (2n → 2n). This pattern of embryogeny differs from that of all other angiosperms, but it is similar to that of gymnosperms.

scholarly journals HIDROLISIS ASAM PADA TEPUNG PATI UBI JALAR PUTIH (Ipomoea batatas L.) DALAM PEMBUATAN GULA CAIR

2018 ◽  
Vol 6 (2) ◽  
pp. 77
Author(s):  
RTM Sutamihardja ◽  
Nia Yuliani ◽  
Hana Laelasari ◽  
Devy Susanty
Keyword(s):  
Sweet Potato ◽  
Ipomoea Batatas ◽  
Potato Starch ◽  
Raw Material ◽  
Hydrolysis Time ◽  
Hydrolysis Process ◽  
Sweet Potato Starch ◽  
Hcl Concentration ◽  
Two Stages ◽  
Industrial Needs

Acid Hydrolysis on The Starch Flour of white sweet potato (Ipomoea batatas L.) in Making of Liquid SugarNational sugar needs for both direct consumption and for industrial needs will continue to increase as the population increases. According to Dirjenbun, in 2014 the national sugar demand reaches 5.7 million tons. Consisting of 2.8 million tons of white crystalline sugar for direct community consumption and 2.9 million tons of refined crystal sugar to meet industrial needs. White sweet potato can be used as raw material for making liquid glucose through hydrolysis process with acid (HCl). The preparation of liquid glucose consists of two stages: gelatinization stage and hydrolysis stage. Optimum hydrolysis was determined by variations in HCl concentration of 0.25; 0.5; and 0.75 N and time variations of 30, 60, and 90 minutes. The yield of sweet potato starch was 28.82% and the highest yield of hydrolysis result of white sweet potato starch was 94.07% at acid concentration 0.75 N with hydrolysis time 90 minutes.Keywords: white sweet potato, Flour of white sweet potato, liquid sugar, acid hydrolysisABSTRAKKebutuhan gula nasional baik untuk konsumsi langsung maupun untuk kebutuhan industri akan terus meningkat sejalan dengan meningkatnya jumlah penduduk. Menurut Dirjenbun, pada tahun 2014 kebutuhan gula nasional mencapai 5,7 juta ton yang terdiri dari 2,8 juta ton gula kristal putih untuk konsumsi masyarakat langsung dan 2,9 juta ton gula kristal rafinasi untuk memenuhi kebutuhan industri. Ubi jalar putih dapat dijadikan bahan baku pembuatan glukosa cair melalui proses hidrolisis dengan asam (HCl). Pembuatan glukosa cair terdiri dari dua tahap yaitu tahap gelatinisasi dan tahap hidrolisis. Hidrolisis optimum ditentukan dengan variasi konsentrasi HCl yaitu 0,25; 0,5; dan 0,75 N dan variasi waktu 30, 60, dan 90 menit. Rendemen pati ubi jalar didapatkan sebesar 28,82% dan rendemen glukosa tertinggi hasil hidrolisis pati ubi jalar putih sebesar 94,07% pada konsentrasi asam 0,75 N dengan waktu hidrolisis 90 menit.Kata kunci: Ubi jalar putih, Tepung Pati Ubi Jalar Putih, Gula cair, hidrolisis asam

scholarly journals Functional Microbiota for Polypeptide Degradation during Hypertonic Moromi-Fermentation of Pixian Broad Bean Paste

Foods ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 930
Author(s):  
Lijie Zhang ◽  
Yida Bao ◽  
Haifeng Chen ◽  
Jiaquan Huang ◽  
Yan Xu
Keyword(s):  
Amino Acid ◽  
High Throughput Sequencing ◽  
Raw Material ◽  
Asian Countries ◽  
Spontaneous Fermentation ◽  
Second Stage ◽  
Extracellular Proteome ◽  
Acid Accumulation ◽  
Two Stages ◽  
Candida Zeylanoides

Traditional fermented bean pastes are indispensable seasonings in many East Asian countries. They are produced via hypertonic solutions by spontaneous fermentation. Functional, unknown microbiota carry great risks for food safety and stable quality. Thus, analysis and subsequent utilization of functional microbiota will be a good strategy to resolve these problems. During bean fermentation, the microbial functions were divided into two stages, including first stage-raw material (polypeptide) degradation and second stage-amino acid catabolism. In this study, we aimed to analyze the functional microbiota of first stage. Omics-studies, including high-throughput sequencing, correlation analysis and extracellular proteome, were used to generate candidate functional microbes for polypeptide degradation in this study. Then, we cultured the candidate functional microbes. After the batch fermentation and enzymatic analysis, we found three strains secreted peptidase and resulted amino acid accumulation, involving Aspergillus niger, Candida zeylanoides and Bacillus licheniformis. Thus, A. niger, C. zeylanoides and B. licheniformis conducted the functional microbiota for polypeptide degrading during hypertonic moromi fermentation. This study supplies a strategy for functional microbiota analysis. In addition, this is the first report that C. zeylanoides can secrete proteome and produce amino acids from polypeptide.

Gelatinization Technique Applied to the Processing of Porous Clay Bodies

2018 ◽  
Vol 930 ◽  
pp. 8-13
Author(s):  
Ana Gabriele Storion ◽  
Maria Gabriela Nogueira Campos ◽  
Neide Aparecida Mariano ◽  
Walter Aparecido Mariano ◽  
Sylma Carvalho Maestrelli
Keyword(s):  
Initial Temperature ◽  
Porous Ceramic ◽  
Clay Content ◽  
Linear Shrinkage ◽  
Solid Content ◽  
Raw Material ◽  
Processing Route ◽  
Mechanical Resistance ◽  
Cold Forming

Conventional processes for manufacturing porous ceramic sometimes provide bodies with low mechanical strength in addition to the high complexity or cost. This work proposes a new porous ceramic processing route: gelatinization, using as raw material clay with low plasticity, water and gelatin. The characterization of the clay was carried out and specimens of various compositions were produced by varying clay content (40, 50, 55 and 60% of solids) and keeping the water and gelatin content constant in the formulation. After cold forming the samples were fired under various conditions: initial temperature of 300 or 600 °C; maximum firing temperature of 800, 900, 1000, 1100 or 1350 °C. After firing, it was obtained the values of the water absorption, bulk density, apparent porosity, linear shrinkage and mechanical resistance. The best results were for samples fired in temperatures lower than 1100 °C and 50% and 55 % of solid content.

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