Synthesis of nanomaterials for biomedical applications

The field of nanotechnology is growing vastly, both as a field of research and in commercial applications. This rapid growth calls for synthesis methods which can produce high quality nanomaterials, while being scalable. This thesis describes an investigation into the use of a continuous hydrothermal reactor for the synthesis of nanomaterials, with potential use in three different biomedical applications – bone scaffolds, fluorescent biomarkers, and MRI contrast agents. The first chapter of this thesis provides an overview of nanotechnology: the advantages of nanoscale, the commercial industries which can benefit, and the predominant methods currently used to produce nanomaterials. Some advantages and drawbacks of each synthesis route are given, concluding with a description of the Nozzle reactor – the patented technology used for nanomaterial synthesis in this Thesis. Chapter 2 then focusses on the characterisation techniques used in this thesis, detailing the principles of how data is obtained, as well as highlighting the limitations of each method. With the background information in place, chapters 3, 4 and 5 describe more specific nanomaterials and how they can be applied to each of the aforementioned biomedical fields. These chapters provide the technical details of how various nanomaterials can be synthesised using the Nozzle reactor, and the structural data (crystallinity, particle size) obtained from these samples. Furthermore, the functional properties of these nanomaterials are tested and the results, along with a discussion of any trends, are presented. Finally, this thesis concludes with a summary of the results described and emphasises the key areas where further work can be conducted

Synthesis of nanomaterials for biomedical applications

The field of nanotechnology is growing vastly, both as a field of research and in commercial applications. This rapid growth calls for synthesis methods which can produce high quality nanomaterials, while being scalable. This thesis describes an investigation into the use of a continuous hydrothermal reactor for the synthesis of nanomaterials, with potential use in three different biomedical applications – bone scaffolds, fluorescent biomarkers, and MRI contrast agents. The first chapter of this thesis provides an overview of nanotechnology: the advantages of nanoscale, the commercial industries which can benefit, and the predominant methods currently used to produce nanomaterials. Some advantages and drawbacks of each synthesis route are given, concluding with a description of the Nozzle reactor – the patented technology used for nanomaterial synthesis in this Thesis. Chapter 2 then focusses on the characterisation techniques used in this thesis, detailing the principles of how data is obtained, as well as highlighting the limitations of each method. With the background information in place, chapters 3, 4 and 5 describe more specific nanomaterials and how they can be applied to each of the aforementioned biomedical fields. These chapters provide the technical details of how various nanomaterials can be synthesised using the Nozzle reactor, and the structural data (crystallinity, particle size) obtained from these samples. Furthermore, the functional properties of these nanomaterials are tested and the results, along with a discussion of any trends, are presented. Finally, this thesis concludes with a summary of the results described and emphasises the key areas where further work can be conducted

Sex-related differences in extracranial complications in patients with traumatic brain injury

Background: Extracranial complications after traumatic brain injury (TBI) are common. Their influence on outcome is uncertain. Furthermore, the role of sex on the development of extracranial complications following TBI remains poorly investigated. We aimed to investigate the incidence of extracranial complications after TBI with particular focus on sex-related differences with regard to complications and their influence on outcome. Methods: This retrospective, observational study was conducted in a level I universitary swiss trauma center. Consecutive patients with TBI admitted to the intensive care unit (ICU) between 2018 and 2021 were included. Patients' and trauma characteristics, in-hospital complications (i.e., cardiovascular, respiratory, renal, metabolic, gastrointestinal, hematological, and infectious) as well as functional outcome 3 months after trauma were analyzed. Data was dichotomized by sex or by outcome. Univariate as well as multivariate logistic regression was performed to reveal possible associations between sex, outcome and complications. Results: Overall, 608 patients were included (male n = 447, 73.5%). Extracranial complications occurred most frequently in cardiovascular, renal, hematological and infectious systems. Men and women suffered similarly from extracranial complications. While men needed correction of coagulopathies more often (p = 0.029), women suffered more frequently from urogenital infections (p = 0.001). Similar results were found in a subgroup of patients (n = 193) with isolated TBI. A multivariate analysis did not show extracranial complications to be independent predictors of unfavorable outcome. Conclusion: Extracranial complications following TBI occur frequently during the ICU-stay, can affect almost all organ systems but are not independent predictors of unfavorable outcome. The results suggest that sex-specific strategies for early recognition of extracranial complications might not be needed in patients with TBI

Effects of Foliar-Applied Mixed Mineral Fertilizers and Organic Biostimulants on the Growth and Hybrid Seed Production of a Male-Sterile Inbred Maize Line

Plants of inbred maize lines are characterized by low vigor due to their high rates of homozygosity and may, therefore, benefit from additional nutrients and biostimulants supplied via foliar spraying. The present study innovatively investigated the effects of foliar treatment with three commercial organic-mineral fertilizers/biostimulants on a male-sterile inbred line of maize at the five-leaf stage. The three fertilizers were characterized by their following content: (i) NPK + hydrolyzed animal epithelium + micronutrients (named 'NPK + Hae + micro'), (ii) NK + humified peat (named 'NK + Hp'), and (iii) PK + Ascophyllum nodosum extracts (named 'PK + An'). The resulting shoot and root growth and seed yield and quality were compared to a control (C). Both NPK + Hae + micro and PK + An treatments enhanced root growth in the top 20 cm soil layer at the ten-leaf stage: root dry biomass increased by 80 and 24%, respectively, and the volumetric root length density by 61 and 17%. The two treatments also allowed for a larger number of commercial seeds to be produced (on average +16 bags per gross hectare vs. C) owing to a better seed caliber, which consequently reduced rates of seed disposal (-11 and -20% for PK + An and NPK + Hae + micro, respectively) and, in the case of NPK + Hae + micro, due to an increment in the number of kernels per ear (+5% vs. C). These effects were not associated with any significant changes in shoot growth, height, or leaf net CO2 assimilation. In this preliminary trial, peak commercial benefit was obtained with the use of hydrolyzed epithelium together with macro- and micronutrients. Further investigation into application timing and dose, and the means by which these products alleviate the effects of low vigor and stress conditions observed particularly under mechanical emasculation is, however, necessary for their full exploitation in the production of hybrid maize seeds

Evaluation of extraction methods for untargeted metabolomic studies for future applications in zebrafish larvae infection models

Sample preparation in untargeted metabolomics should allow reproducible extractions of as many molecules as possible. Thus, optimizing sample preparation is crucial. This study compared six diferent extraction procedures to fnd the most suitable for extracting zebrafsh larvae in the context of an infection model. Two one-phase extractions employing methanol (I) and a single miscible phase of methanol/acetonitrile/water (II) and two two-phase methods using phase separation between chloroform and methanol/water combinations (III and IV) were tested. Additional bead homogenization was used for methods III and IV (III_B and IV_B). Nine internal standards and 59 molecules of interest (MoInt) related to mycobacterial infection were used for method evaluation. Two-phase methods (III and IV) led to a lower feature count, higher peak areas of MoInt, especially amino acids, and higher coefcients of variation in comparison to one-phase extractions. Adding bead homogenization increased feature count, peak areas, and CVs. Extraction I showed higher peak areas and lower CVs than extraction II, thus being the most suited one-phase method. Extraction III and IV showed similar results, with III being easier to execute and less prone to imprecisions. Thus, for future applications in zebrafsh larvae metabolomics and infection models, extractions I and III might be chosen

Sex-related differences in extracranial complications in patients with traumatic brain injury

BackgroundExtracranial complications after traumatic brain injury (TBI) are common. Their influence on outcome is uncertain. Furthermore, the role of sex on the development of extracranial complications following TBI remains poorly investigated. We aimed to investigate the incidence of extracranial complications after TBI with particular focus on sex-related differences with regard to complications and their influence on outcome.MethodsThis retrospective, observational study was conducted in a level I universitary swiss trauma center. Consecutive patients with TBI admitted to the intensive care unit (ICU) between 2018 and 2021 were included. Patients’ and trauma characteristics, in-hospital complications (i.e., cardiovascular, respiratory, renal, metabolic, gastrointestinal, hematological, and infectious) as well as functional outcome 3 months after trauma were analyzed. Data was dichotomized by sex or by outcome. Univariate as well as multivariate logistic regression was performed to reveal possible associations between sex, outcome and complications.ResultsOverall, 608 patients were included (male n = 447, 73.5%). Extracranial complications occurred most frequently in cardiovascular, renal, hematological and infectious systems. Men and women suffered similarly from extracranial complications. While men needed correction of coagulopathies more often (p = 0.029), women suffered more frequently from urogenital infections (p = 0.001). Similar results were found in a subgroup of patients (n = 193) with isolated TBI. A multivariate analysis did not show extracranial complications to be independent predictors of unfavorable outcome.ConclusionExtracranial complications following TBI occur frequently during the ICU-stay, can affect almost all organ systems but are not independent predictors of unfavorable outcome. The results suggest that sex-specific strategies for early recognition of extracranial complications might not be needed in patients with TBI

О рецептуростроении клеев с постоянной «липкостью» на основе бутадиен-нитрильных каучуков

The optimal set of the properties of elastomeric glues can be achieved by the right ratio of components. The combined influence of resins, plasticizers and agents of tackiness on the properties of adhesive compositions was studied.Оптимального комплекса свойств эластомерных клеев можно достигнуть благодаря правильному соотношению компонентов. Изучено совместное влияние на свойства клеевых композиций смол , пластификатора и агента липкости

Highly Crystalline and Semiconducting Imine-Based Two-Dimensional Polymers Enabled by Interfacial Synthesis

Single-layer and multi-layer 2D polyimine films have been achieved through interfacial synthesis methods. However, it remains a great challenge to achieve the maximum degree of crystallinity in the 2D polyimines, which largely limits the long-range transport properties. Here we employ a surfactant-monolayer-assisted interfacial synthesis (SMAIS) method for the successful preparation of porphyrin and triazine containing polyimine-based 2D polymer (PI-2DP) films with square and hexagonal lattices, respectively. The synthetic PI-2DP films are featured with polycrystalline multilayers with tunable thickness from 6 to 200 nm and large crystalline domains (100–150 nm in size). Intrigued by high crystallinity and the presence of electroactive porphyrin moieties, the optoelectronic properties of PI-2DP are investigated by time-resolved terahertz spectroscopy. Typically, the porphyrin-based PI-2DP 1 film exhibits a p-type semiconductor behavior with a band gap of 1.38 eV and hole mobility as high as 0.01 cm2 V−1 s−1, superior to the previously reported polyimine based materials. © 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

Communication: Light driven remote control of microgels’ size in the presence of photosensitive surfactant: Complete phase diagram

Here we report on a light triggered remote control of microgel size in the presence of photosensitive surfactant. The hydrophobic tail of the cationic surfactant contains azobenzene group that undergoes a reversible photo-isomerization reaction from a trans- to a cis-state accompanied by a change in the hydrophobicity of the surfactant. We have investigated light assisted behaviour and the complex formation of the microgels with azobenzene containing surfactant over the broad concentrational range starting far below and exceeding several times of the critical micelle concentration (CMC). At small surfactant concentration in solution (far below CMC), the surfactant in the trans-state accommodates within the microgel causing its compaction, while the cis-isomer desorbs out of microgel resulting in its swelling. The process of the microgel size change can be described as swelling on UV irradiation (trans-cis isomerization) and shrinking on irradiation with blue light (cis-trans isomerization). However, at the surfactant concentrations larger than CMC, the opposite behaviour is observed: the microgel swells on blue irradiation and shrinks during exposure to UV light. We explain this behaviour theoretically taking into account isomer dependent micellization of surfactant within the microgels