Final Preparation Step Research Articles

Reliable N-Glycan Analysis–Removal of Frequently Occurring Oligosaccharide Impurities by Enzymatic Degradation

Glycosylation, especially N-glycosylation, is one of the most common protein modifications, with immense importance at the molecular, cellular, and organismal level. Thus, accurate and reliable N-glycan analysis is essential in many areas of pharmaceutical and food industry, medicine, and science. However, due to the complexity of the cellular glycosylation process, in-depth glycoanalysis is still a highly challenging endeavor. Contamination of samples with oligosaccharide impurities (OSIs), typically linear glucose homo-oligomers, can cause further complications. Due to their physicochemical similarity to N-glycans, OSIs produce potentially overlapping signals, which can remain unnoticed. If recognized, suspected OSI signals are usually excluded in data evaluation. However, in both cases, interpretation of results can be impaired. Alternatively, sample preparation can be repeated to include an OSI removal step from samples. However, this significantly increases sample amount, time, and effort necessary. To overcome these issues, we investigated the option to enzymatically degrade and thereby remove interfering OSIs as a final sample preparation step. Therefore, we screened ten commercially available enzymes concerning their potential to efficiently degrade maltodextrins and dextrans as most frequently found OSIs. Of these enzymes, only dextranase from Chaetomium erraticum and glucoamylase P from Hormoconis resinae enabled a degradation of OSIs within only 30 min that is free of side reactions with N-glycans. Finally, we applied the straightforward enzymatic degradation of OSIs to N-glycan samples derived from different standard glycoproteins and various stem cell lysates.

Impact of surface preparation on the formation of deformation-induced α‘-martensite in a metastable austenitic steel

Abstract The metastable austenitic steel X6CrNi-Nb18-10 (AISI 347) will partly transform to α‘-martensite under mechanical loading at room temperature. In order to determine the influence of loading conditions on deformation-induced martensitic transformation, a thorough surface preparation is required for the samples to be analyzed, ensuring that a martensite-free sample surface is achieved prior to mechanical loading. In this paper, two preparation techniques were compared, focusing in particular on the final preparation step, which is polishing. Measurements using electron backscatter diffraction (EBSD) have revealed that large α‘-martensite volume fractions of more than 20 % are present on the prepared sample surface after vibratory polishing. However, they can be removed almost completely by electrolytic polishing and chemical etching respectively.

Peer review declaration

All papers published in this volume of IOP Conference Series: Earth and Environmental Science have been peer reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.• Type of peer review: Single-blind• Conference submission management system: via e-mail ns_ran@mail.ru • Number of submissions received: 39• Number of submissions sent for review: 39• Number of submissions accepted: 34• Acceptance Rate (Number of Submissions Accepted/Number of Submissions Received X 100): 87.2• Average number of reviews per paper: 2• Total number of reviewers involved: 37• Any additional info on review process: The review process was organized by the next way:➢ All the participants who presented their reports on Symposium sections (virtually, via Zoom) were invited to submit their papers to be published in “IOP Conference Series: Earth and Environmental Science”.➢ Submission of papers was carried out by the Organizing Committee’s e-mail ns_ran@mail.ru. ➢ The secretary of the Organizing Committee made all the materials formal verification and redirected the needed quality submissions to corresponding editors with respect to six thematic sections (one executive editor for each section).➢ The section executive editor provided at least two reviews for each paper from his section. The reviewers were selected from the list of high quality experts who are world-known specialists in geology, geophysics and geoecology from Russia, Kyrgyzstan, Uzbekistan and Kazakhstan.➢ With respect to review results all the submissions were divided into three groups:1) The manuscript is recommended for publication2) The manuscript is recommended for publication after revision (for these type of submissions the revision process was continued by communication between authors and reviewers via the executive editor in hidden form)3) The manuscript is not recommended for publication➢ The final step of papers preparation was related to accepted submissions verification with respect to the IOP:EES format requirements; checking of scientific style and the English language spelling and punctuation correctness.• Contact person for queries: Name: Olga Zabinyakova Affiliation: Research station of Russian Academy of Sciences in Bishkek city, Bishkek, Kyrgyzstan Email: ns_ran@mail.ru

New concept of fortified yogurt formulation with encapsulated carrot waste extract

High yogurt consumption worldwide has opened the opportunity for designing a new concept of this fermented dairy product as an extremely valuable functional food item, fortified with bioactive components such as carotenoids. In this way, daily diets can become more effective in reducing diseases associated with nutritional deficiencies as well as alleviate the problem of accumulation of food by-products that are rich in bioactive components. In this study, after the extraction of carotenoids from carrot waste (CW) and complete characterization, the encapsulation process was carried out by electrostatic extrusion. Two concentrations of completely characterized CW beads (2.5 and 5 g/100g) were added to yogurt during the final step of yogurt preparation. Comparative studies of control and fortified yogurts were executed during a storage period of 28 d at 4 °C. Yogurt fortification with both concentrations provides a part of β-carotene recommended daily intake. Overall, microbiological and physico-chemical properties of the fortified yogurts were well-maintained during the storage period. The encapsulated carotenoids considerably improved the antioxidant activity of the yogurt; therefore, it can be used for the development of fortified yogurt with high nutritional properties.

Polymer-assisted TEM specimen preparation method for oxidation-sensitive 2D materials

By structural and analytical TEM and scanning electron microscopy experiments we show that atomically-resolved structural characterization of oxidation-sensitive two-dimensional material is strongly hindered when the final step of the preparation process, the transfer to the TEM grid, is performed with a wet etching method involving bases or acids, interacting with the highly reactive sample surface. Here we present an alternative polymer-assisted and mechanical-exfoliation-based sample preparation method and demonstrate it on selected oxidation-sensitive transition metal phosphorus trisulfides and transition metal dichalcogenides. The analysis, obtained from the samples prepared with both of the methods clearly show that oxidation is the origin of discrepancy, the oxidation during the final preparation step is strongly reduced only when the new method is applied, and atomically-resolved structural characterization of the pristine structures is now possible.

Contribution of Foods and Poor Food-Handling Practices to the Burden of Foodborne Infectious Diseases in France.

The foodborne disease burden (FBDB) related to 26 major biological hazards in France was attributed to foods and poor food-handling practices at the final food preparation step, in order to develop effective intervention strategies, especially food safety campaigns. Campylobacter spp. and non-typhoidal Salmonella accounted for more than 60% of the FBDB. Approximately 30% of the FBDB were attributed to 11 other hazards including bacteria, viruses and parasites. Meats were estimated as the main contributing food category causing (50–69%) (CI90) of the FBDB with (33–44%), (9–21%), (4–20%) (CI90) of the FBDB for poultry, pork and beef, respectively. Dairy products, eggs, raw produce and complex foods caused each approximately (5–20%) (CI90) of the FBDB. When foods are contaminated before the final preparation step, we estimated that inadequate cooking, cross-contamination and inadequate storage contribute for (19–49%), (7–34%) and (9–23%) (CI90) of the FBDB, respectively; (15–33%) (CI90) of the FBDB were attributed to the initial contamination of ready-to-eat foods—without any contribution from final food handlers. The thorough implementation of good hygienic practices (GHPs) at the final food preparation step could potentially reduce the FBDB by (67–85%) (CI90) (mainly with the prevention of cross-contamination and adequate cooking and storage).

Structural equation modelling of food safety knowledge, attitude and practices among consumers in Malaysia

Factors contributing to foodborne illnesses in Malaysia were identified as insanitary food handling procedures and lack of hygiene in food preparation area. Food safety at home is a critical point as consumers represent the final step in food preparation and prevention of foodborne diseases. This study aims to investigate the food safety knowledge, attitude and self-reported practices among consumers in Malaysia. An online survey was conducted, and data were analysed using descriptive statistics and exploratory factor analysis. A model linking food safety knowledge and attitude and their direct effects on practices were confirmed using structural equation modelling (SEM). The proposed model fulfilled the goodness of fit indices and is deemed acceptable. Respondents demonstrate good level of food safety knowledge and positive attitudes and self-reported practices. Food safety knowledge has a negative and insignificant relationship with food safety practices (β1 = -0.284, p>0.05) while attitude significantly affects food safety practices (β1 = 0.534, p<0.05). The findings clearly indicate that food safety knowledge does not directly affect food safety practices This is also the first study to provide new empirical findings on thermometer usage among consumers in Malaysia. This study establishes an important point of reference where consumers use visual appearances to determine if food is thoroughly cooked and practice washing raw chicken prior to cooking. Food safety practices at home play a critical role in protecting consumers in reducing risks of foodborne illnesses.

Verification of nitrous oxide primary standard gas mixtures by gas chromatography and cavity ring-down spectroscopy for ambient measurements in South Africa

Nitrous oxide (N2O) is an important greenhouse gas and is the third-largest contributor to global warming with a global warming potential (GWP) higher than that of carbon dioxide. Ambient N2O is monitored globally and described at nanomole per mole (nmol mol−1) levels. Metrologically traceable and highly accurate N2O gas standards are required to understand the behaviour of the greenhouse gases in the atmosphere and GWP. A group of primary standard gas mixtures (PSGMs) in aluminium cylinder material has been prepared in synthetic air for the calibration of analytical instruments for measurement of N2O at an ambient level. An automatic weighing system with a mass comparator and a fully automated circular rotary plate, as well as a gas filling station, was used in the preparation of the gas mixtures. Analytical methods such as gas chromatography coupled with micro-electron capture detector and cavity ring-down spectroscopy were adopted in the verification process. Four PSGMs in the final preparation step were used to analyse unknown background and filtered air samples at the ambient level. An expanded uncertainty relative to the gravimetric amount fraction was found to be 0.02 %. Results show that the background air samples lie within the calibration range with 329 to 330 nmol mol−1 obtained and 135 nmol mol−1 obtained for filtered air sample.

Couscous: Ethnic making and consumption patterns in the Northeast of Algeria

Couscous is an ancient dish that is nearly ubiquitous throughout the North African countries. It is well known as a staple dish in Algeria as many differences can be found concerning its ethnic preparation and making. The present work, based on a survey, aimed to identify the traditional making diagram of couscous and to describe how couscous-based dishes are prepared. The consumption patterns were also identified in the Northeastern localities of Algeria. This study was undertaken through direct interviews with 517 persons who prepared Couscous using the traditional practices in the regions of Bejaia, Jijel, Constantine, Guelma, Oum El bouaghi, Khenchela, and Batna. From the survey, it seems that the first step of couscous making is a size classification of durum wheat semolina into coarse semolina (> 500 μm) and fine semolina (< 500 μm). The second step consists in steaming of coarse semolina before its hydration with salted water. The rolling calibration includes three substeps: nucleation, shaping, and finishing. The addition of cornstarch or wheat flour is performed during the finishing substep. After wet couscous steaming, the precooked couscous is dried under the shade followed by their exposure to the sun. The final step of couscous preparation is the packaging of dried couscous by adding some preservative and flavoring products. Couscous is prepared for several local events, family celebrations, or religious feasts with vegetable sauces and different meat sources such as red meat, chicken meat, fish, or ethnic meat-based products such as guedid, douara, bouzelouf, or merguez. Another variant of couscous, mesfouf, is further prepared with finely rolled semolina and some butter.

Adsorbent-Based Downstream-Processing of the Decarboxylase-Based Synthesis of 2,6-Dihydroxy-4-methylbenzoic Acid

In this case study the regioselective enzymatic carboxylation of 3,5-dihydroxytoluene (orcinol) using the nonoxidative 2,3-dihydroxybenzoic acid decarboxylase from Aspergillus oryzae (2,3-DHBD_Ao), followed by an adsorbent-based downstream approach, has been investigated. The product 2,6-dihydroxy-4-methylbenzoic acid (DHMBA) was herein purified by an adsorption–desorption cycle and subsequently obtained with purities >99% without a full elimination of the excess bicarbonate from its reaction solution. Ten adsorbent resins were studied in respect of their ability to recover the product from the reaction solution, whereas the strong anion exchange resin Dowex 1x2 in its chloride form showed affinities >99%, even at bicarbonate concentrations of >3 mol·L–1. Desorption from loaded resin was carried out by a 2 mol·L–1 HCl/acetone mixture, followed by product crystallization during acetone evaporation. This presented concept does not require a final column preparation step and improves the overall atom efficie...

Development of a borreliosis assay: Mannan coated polyethylene sinter bodies as a new platform technology

Rapid diagnosis of Lyme borreliosis has been carried out on chemically modified porous polyethylene sinter bodies. Photografting of 2-propenol on sinter body's surface was performed as a first step, introducing active hydroxyl groups as a result of polyalcohol formation. The hydroxyl groups were used for further immobilization and could be linked via 3-aminopropyltriethoxysilane (APTES) to polysaccharides like mannan. Prone to coupling, mannan was activated using N, N'-disuccinimidyl carbonate (DSC) to allow smooth reaction with the primary amine groups of the silane layer. In a final preparation step, a recombinant fusion protein consisting of the mannan-binding domain of the lectin Concanavalin A (ConA) and a specific Borrelia surface antigen was immobilized by self-organization on the mannan surface. The fusion protein was used as biological interface structure. This strategy is highly efficient and resulted in a defined orientation of the antigen part of the fusion protein. Rapid and convenient differentiation could be then established between Borrelia-negative and a -positive serum even in 1000-fold diluted samples and detection of Lyme borreliosis in a rather early stage is likely. Furthermore, this generic strategy can be easily transferred to other bacterial or viral antigen structures.

AMP-activated protein kinase is involved in induction of protective autophagy in astrocytes exposed to oxygen-glucose deprivation.

In the paper by Gabryel et al. (2014), there were errors in Figures 1, 4, and 5. The authors regret that the Figures no. 1, 4 and 5 containing representative western blots should be replaced. Upon inspection of published images and original data, the corresponding author (B.G.) found that on the final step of figure preparation she made a procedural errors in representative image choice and an incorrect attachment of images into Figure 1, 4 and 5. The correct figures are reproduced here. The authors apologize for any confusion caused by these mistakes and thank the readers for alerting them to these issues.

Novel Budesonide Particles for Dry Powder Inhalation Prepared Using a Microfluidic Reactor Coupled With Ultrasonic Spray Freeze Drying

Budesonide (BDS) is a potent active pharmaceutical ingredient, often administered using respiratory devices such as metered dose inhalers, nebulizers, and dry powder inhalers. Inhalable drug particles are conventionally produced by crystallization followed by milling. This approach tends to generate partially amorphous materials that require post-processing to improve the formulations’ stability. Other methods involve homogenization or precipitation and often require the use of stabilizers, mostly surfactants. The purpose of this study was therefore to develop a novel method for preparation of fine BDS particles using a microfluidic reactor coupled with ultrasonic spray freeze drying, and hence avoiding the need of additional homogenization or stabilizer use. A T-junction microfluidic reactor was employed to produce particle suspension (using an ethanol-water, methanol-water, and an acetone-water system), which was directly fed into an ultrasonic atomization probe, followed by direct feeding to liquid nitrogen. Freeze drying was the final preparation step. The result was fine crystalline BDS powders which, when blended with lactose and dispersed in an Aerolizer at 100 L/min, generated fine particle fraction in the range 47.6% ± 2.8% to 54.9% ± 1.8%, thus exhibiting a good aerosol performance. Subsequent sample analysis confirmed the suitability of the developed method to produce inhalable drug particles without additional homogenization or stabilizers. The developed method provides a viable solution for particle isolation in microfluidics in general.

Assessment of critical steps of a GC/MS based indirect analytical method for the determination of fatty acid esters of monochloropropanediols (MCPDEs) and of glycidol (GEs)

Fatty acid esters of 2- and 3-chloropropanediol (MCPDEs) and fatty acid esters of glycidol (GEs) are commonly monitored in edible fats and oils. A recommendation issued by the European Commission emphasizes the need of generating data on the occurrence of these substances in a broad range of different foods. So far, analytical methods for the determination of MCPDEs and GEs are fully validated only for oils, fats and margarine. This manuscript presents the assessment of critical steps in the AOCS Cd 29a-13 method for the simultaneous determination of MCPDEs and GEs in the fat phase obtained from bakery and potato products, smoked and fried fish and meat, and other cereal products. The trueness of the method is affected by the additional formation of 3-MBPD esters from monoacylglycerols (MAGs), which are frequently present in food. The overestimation of GE contents for some samples was confirmed by the comparison of results with results obtained by an independent analytical method (direct analysis of GE by HPLC-MS/MS). An additional sample pre-treatment by SPE was introduced to remove MAGs from fat prior to the GEs conversion, while the overall method sensitivity was not significantly affected. Trueness of the determination of GEs by the modified analytical procedure was confirmed by comparison with a direct analysis of GEs. The potential impact on accuracy of results of the final sample preparation step of the analytical procedure, the derivatization of free forms MCPD and MBPD with PBA, was evaluated as well. Different commercial batches of PBA showed differences in solubility in a non-polar organic solvent. The PBA derivatization in organic solvent did not affect precision and trueness of the method due to the isotopic standard dilution. However, method sensitivity might be significantly compromised.

Synthesis, characterization and cytotoxicity of Chitosan/Polyvinyl Alcohol/Bioactive Glass hybrid scaffolds obtained by lyophilization

One of the important research topics in tissue engineering is the development of optimum three-dimensional scaffolds for regeneration and growth of bone tissue. The scaffold developed should promote an initial biomechanical support, provide the formation, deposition and organization of the new organic matrix generated, and degrade proportionally to the growth of the new tissue. In this study hybrid scaffolds based on the blend Chitosan (CHI)/Poly (vinyl alcohol) (PVA), with two different CHI:PVA molar ratios (1:1, and 3:1), and Bioactive Glass as the inorganic phase, were developed by a sol-gel route, followed by lyophilization. The materials were cross-linked with Glutaraldehyde. The obtained porous scaffolds were characterized by SEM, FTIR, porosity measurements by Archimedes method, and compression test. The in vitro degradation was studied by immersion in simulated body fluid for several time periods and evaluation of mass loss. Citotoxicity analysis was carried out on samples as prepared and after immersion in PBS solution for 24hrs, using human fibroblast cells and MTT method to evaluate cell viability. The matrices obtained showed promising results, presenting about 96% porosity, pore size varying in the range 20-300 µm, and interconnected pores. The mass loss presented by the matrices with CHI/PVA ratios 3:1 and 1:1 during the degradation test in vitro, was around 10% after a week of testing, with macroscopic preservation of their physical structure. Cytotoxicity tests showed that the samples were toxic as produced and not toxic after treatment with PBS, showing this approach was suitable as a final preparation step of these samples. Keywords: Chitosan, PVA, bioactive glass, lyophilization, porosity, scaffolds

&lt;italic&gt;Ushoi kangshu&lt;/italic&gt; -A traditional bamboo shoot salad of the &lt;italic&gt;Meiteis&lt;/italic&gt; of Manipur

&lt;italic&gt;Ushoi kangshu&lt;/italic&gt; is a fiery traditional seasonal delicacy of the &lt;italic&gt;Meiteis&lt;/italic&gt; of Manipur, India prepared from fresh bamboo shoot. The main ingredients being fermented fish, chillies and peas. The preparation method is a traditional art which is handed over from generation to generation. Bamboo shoots are low in calories, high in dietary fiber and rich in various nutrients like protein, carbohydrates, amino acids, minerals, fat, sugar and inorganic salts, however, bamboo shoots are known to contain plant toxins (cyanogenic glycosides) which are harmful to human health. Studies on the cyanogenic content shows that the toxin is present in high concentration (600mg/kg) in the fresh bamboo shoot however, the concentration of the toxic compound is decreased step wise (400mg/kg to 160mg/kg) during the preparation of &lt;italic&gt;ushoi kangshu&lt;/italic&gt; and is completely removed at the final step of preparation. More over it was observed that this ethnic bamboo shoot salad is highly nutritious due to its garnishing with locally available herbs which has medicinal and therapeutic values.

Furan formation during storage and reheating of sterilised vegetable purées

To this day, research for furan mitigation has mostly targeted the levels of food production and handling of prepared foods by the consumer. However, part of the furan concentrations found in commercially available food products might originate from chemical deterioration reactions during storage. A range of individual vegetable purées was stored at two different temperatures to investigate the effects of storage on the furan concentrations of shelf-stable, vegetable-based foods. After 5 months of storage at 35°C (temperature-abuse conditions), a general increase in furan concentrations was observed. The furan formation during storage could be reduced by storing the vegetable purées at a refrigerated temperature of 4°C, at which the furan concentrations remained approximately constant for at least 5 months. Following storage, the vegetable purées were briefly reheated to 90°C to simulate the effect of the final preparation step before consumption. Contrary to storage, furan concentrations decreased as a result of evaporative losses. Both refrigerated storage and the reheating step prior to consumption showed the potential of mitigation measures for furan formation in vegetable-based foods (e.g. canned vegetables, ready-to-eat soups, sauces or baby foods). Next to furan, the vegetable purées were analysed for 2- and 3-methylfuran. Tomato was very susceptible to the formation of both alkylated derivatives of furan, as opposed to the other vegetables in this study. Methylfuran concentrations rapidly decreased during storage, which was contrary to the results observed for furan.

A convenient synthesis of new NSAID esters containing amino acid, urea and amide moieties

Abstract A convenient synthetic method for the preparation of novel NSAID twin esters 6a-i containing amino acid residue, urea and amide moieties has been developed. The synthetic pathway applied for the preparation of target compounds and key intermediates 1-benzotriazolecarboxylic acid chloride (1), NSAID benzotriazolides 2a-c and N-(1-benzotriazolecarbonyl)-amino acids 3a-d involved benzotriazole as a synthetic auxiliary. The final preparation step of esters 6a-i included the solvent-free reaction of compounds 2a-c with amino acid derivatives 5a-g, bearing two hydroxyl groups, one at each terminal, beside urea and amide functionalities.

Optical clearing of archive-compatible paraffin embedded tissue for multiphoton microscopy: erratum

We correct an error in the methods reported in our previous paper [Biomed. Opt. Express 3, 2752 (2012)]; the liquid used for the final step of specimen preparation was 100% mineral oil, not a mixture of oil and glycerol.

Vibratory Polishing of a Nickel-Based Superalloy (MAR 247) Using VibroMet 2

Abstract Preparation artifacts such as scratches, surface deformation and smearing are often difficult to remove by conventional grinding and polishing. Vibratory polishing is a mechanical process. It provides a very gentle polishing treatment. This final preparation step provides for a removal of ground specimen surfaces without causing deformations. The sample surface was examined on the basis of different mechanical and chemical/mechanical preparation steps with regard to its suitability for subsequent examinations using a scanning electron microscope (for example EBSD measurements).