Microfluidic devices for photo-and spectroelectrochemical applications

The review presents recent developments in electrochemical devices for photo- and spectroelectrochemical investigations, with the emphasis on miniaturization (i.e., nanointerdigitated complementary metal-oxide-semiconductor devices, micro- and nano-porous silicon membranes or microoptoelectromechanical systems), silica glass/microreactors (i.e., plasmonic, Raman spectroscopy or optical microcavities) or polymer-based devices (i.e., 3D-printed, laser-engraved channels). Furthermore, we have evaluated inter alia the efficiency of various fabrication approaches for bioelectrochemical systems, biocatalysis, photochemical synthesis, or single nanoparticle spectroelectrochemistry. We envisioned the miniaturization of applied techniques such as cathodoluminescence, surface plasmon resonance, surface-enhanced Raman spectroscopy, voltametric and amperometric methods in the spectroelectrochemical microdevices. The research challenges and development perspectives of microfluidic, and spectroelectrochemical devices were also elaborated on.publishedVersio

A closed bipolar electrochemical cell for the interrogation of BDD single particles : electrochemical advanced oxidation

A closed bipolar electrochemical cell containing two conductive boron-doped diamond (BDD) particles of size ∼ 250 – 350 μm, produced by high-pressure high-temperature (HPHT) synthesis, has been used to demonstrate the applicability of single BDD particles for electrochemical oxidative degradation of the dye, methylene blue (MB). The cell is fabricated using stereolithography 3D printing and the BDD particles are located at either end of a solution excluded central channel. Platinum wire electrodes placed in each of the two outer solution compartments are used to drive electrochemical reactions at the two BDD particles, which, under bipolar conditions do not require direct electrical connection to a potential source. Experiments using ultra high-performance liquid chromatography coupled with mass spectrometry (UHPLC-MS) show that the anodic pole BDD particle is able to electrochemically remove > 99 % of the dye (originally present at 1 × 10−4 M) to undetectable UHPLC-MS products in 600 s. Monitoring of the time dependant change in MB peak area, from the UHPLC chromatograms, enables a pseudo first order rate constant of 0.54 min−1 to be determined for MB removal. Given the large scale at which such particles can be produced (tonnes), such data bodes well for scale up opportunities using HPHT-grown BDD particles, where the particles can be assembled into high surface area electrode formats

Global urban environmental change drives adaptation in white clover

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale

Stress in the teaching profession

Stres zawodowy związany z pracą nauczyciela jest nieunikniony. Jest szczególnym rodzajem stresu, związanym z sytuacją, warunkami i wymaganiami stawianymi przez społeczeństwo. Celem pracy jest zobrazowanie zjawiska stresu w zawodzie nauczyciela. Ponadto zaprezentowanie specyfiki zawodu nauczyciela, jego ról społecznych i zawodowych oraz cech charakteru niezbędnych do pracy na stanowisku pedagoga. Istotne jest także przedstawienie wyników ankiety dotyczącej stresu przeprowadzonej w Zespole Szkół Hotelarsko-Turystycznych w Zakopanem oraz zaprezentowanie możliwości wykorzystania uzyskanych wyników w doskonaleniu praktyk w zarządzaniu zasobami ludzkimi w badanej placówce.Stress in the profession of teaching is inevitable. It is a specific kind of a stress connected with situations, conditions and society’s requirements. The aim of the thesis is to illustrate the stress phenomenon which occurs during the process of teaching. Moreover, it is vital to present the importance of the roles of a school teacher and his/her detailed characteristics. Additionally, the thesis shows the analysis of the poll relating to stress, which was distributed in Zespół Szkół Hotelarsko – Turystycznych in Zakopane. At the end of the thesis, there are some hints showing how to improve the management of people in chosen school

p53 codon 72 polymorphism in cervical cancer patients and healthy women from Poland.

A polymorphism at codon 72 of gene p53 results in the presence of either arginine or proline at this position. We investigated the distribution of p53 codon 72 polymorphism in cervical cancer patients and a control group of healthy women from Poland. Our results do not confirm the hypothesis that the p53 codon polymorphism could play a role as a factor for squamous carcinoma of the cervix

Clinical Nutrition of Critically Ill Patients in the Context of the Latest ESPEN Guidelines

The group of patients most frequently in need of nutritional support are intensive care patients. This year (i.e., 2019), new European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines of clinical nutrition in intensive care were published, updating and gathering current knowledge on the subject of this group of patients. Planning the right nutritional intervention is often a challenging task involving the necessity of the choice of the enteral nutrition (EN) or parenteral nutrition (PN) route of administration, time of initiation, energy demand, amino acid content and demand as well as the use of immunomodulatory nutrition. The aim of this study was to specify and discuss the basic aspects of the clinical nutrition of critically ill patients recommended by ESPEN guidelines. Clinical nutrition in intensive care seems to be the best-studied type of nutritional intervention. However, meta-analyses and clinical studies comparing EN and PN and their impact on the prognosis of the intensive care patients showed ambiguous results. The nutritional interventions, starting with EN, should be initiated within 24–48 h whereas PN, if recommended, should be implemented within 3–7 days. The recommended method of calculation of the energy demand is indirect calorimetry, however, there are also validated equations used worldwide in everyday practice. The recommended protein intake in this group of patients and the results of insufficient or too high supply was addressed. In light of the concept of immunomodulatory nutrition, the use of appropriate amino acid solutions and lipid emulsion that can bring a positive effect on the modulation of the immune response was discussed

Physicochemical Compatibility and Stability of Linezolid with Parenteral Nutrition

Patients referred to intensive care units (ICU) require special care due to their life-threatening condition, diseases and, frequently, malnutrition. Critically ill patients manifest a range of typical physiological changes caused by predominantly catabolic reactions in the body. It is necessary to provide the patients with proper nutrition, for example by administering total parenteral nutrition (TPN). The addition of linezolid to TPN mixtures for patients treated for linezolid-sensitive infections may reduce the extent of vascular access handling, resulting in a diminished risk of unwanted catheter-related infections. The compatibility and stability studies were conducted of linezolid in parenteral nutrition mixtures of basic, high- and low-electrolytic, high- and low-energetic and immunomodulatory composition. Mixtures containing linezolid were stored at 4–6 °C and 25 °C with light protection and at 25 °C without light protection for 168 h. In order to evaluate changes in the concentration of linezolid a previously validated reversed-phase HPLC method with UV detection was used. It was found that linezolid was stable at 4–6 °C in the whole course of the study whereas at 25 °C it proved stable over a period of 24 h required for administration of parenteral nutrition mixtures. The TPN mixtures demonstrated compatibility with linezolid and suitable stability, which were not affected by time or storage conditions

Development, Validation, and Stability Assessment Application of RP-HPLC-DAD Method for Quantification of Ampicillin in Total Parenteral Nutrition Admixtures

Background: The administration of total parenteral nutrition (TPN) is a common procedure in intensive care units, where the concomitant use of other intravenous medication is frequently needed. One of the particularly dangerous complications for neurosurgical patients is meningitis, for which high doses of ampicillin (AMP) are used. In such cases, the addition of AMP to TPN admixtures would be a desirable procedure. Thus, the AMP determination method in TPN admixture was developed and validated. Methods: An isocratic HPLC analysis was performed on a LiChrospher C18 end-capped column (250 mm, 4.6 mm, 5 µm) with a C18 pre-column (LiChrospher 100, 4 mm, 5 µm). The flow rate was 1.0 mL min−1 and the detection wavelength was 230 nm. System suitability parameters, such as capacity factor, numbers of the theoretical plate, asymmetry factor, as well as validation parameters, including method precision, accuracy, linearity, selectivity, and robustness, were set up. Results: The method was shown to be linear, precise, accurate, specific, and robust, and it can be used for the quantitative analysis of AMP in TPN admixtures. Conclusions: The degradation of AMP in the TPN admixtures occurred according to first order kinetics. The degradation rate was high and dependent on the composition of the mixture and the storage conditions (t0.5 varied from 142.44 h to 300.45 h)

Effect of Lipid Emulsion on Stability of Ampicillin in Total Parenteral Nutrition

Background: Ampicillin (AMP) is frequently administered parenterally in critically ill patients with meningitis or endocarditis. Many of them require parallel infusion of total parenteral nutrition (TPN) admixtures. The aim of the study was to determine the physicochemical stability of AMP in TPN admixtures. Methods: AMP was added to two formulations of TPN admixtures differing in the lipid emulsion (Lipofundin® MCT/LCT 20% or LIPIDem®). Samples were stored at 4 ± 1 °C with light protection, and at 25 ± 1 °C with and without light protection to assess the impact of temperature and light on formulation stability. Every 24 h the pH, zeta potential, mean droplet diameter (MDD) of a lipid emulsion, and AMP concentration using HPLC method were determined. The assessment of stability and compatibility of TPN admixtures with vitamins and trace elements was carried out immediately after preparation and after 24 h of storage. Results: The addition of AMP as well as vitamins and trace elements to the TPN admixtures did not affect their physical stability. An increase in the pH value of approx. 0.6 and reduction of zeta potential were observed. The MDD of the lipid emulsions was below the limit of 500 nm (dynamic light scattering (DLS) method) and no fat droplets greater than 525 nm were observed (light diffraction (LD) method). The content of AMP after the first 24 h was within the acceptable limit of 90% for TPN admixtures stored at 4 ± 1 °C and 25 ± 1 °C with light protection. Conclusions: The results showed that co-administration of AMP in the same bag with TPN admixture at the tested dose is possible when used ex tempore and with light protection