Utilization of Matrix Effect for Enhancing Resolution in Cation Exchange Chromatography.

In ion chromatography studies, the matrix effect of other inorganic ions present in the sample is a well-known phenomenon. In this work, the behavior of inorganic and organic ions was studied in a system overloaded with ammonium ions. The ammonium ions came from a solution of ammonium hydroxide in various concentrations (0.25-1.25%). In this system, which was significantly overloaded with ammonium ions, the behavior of three ions were tested (lithium, tris, and sodium cations). The measurements were performed at different eluent concentrations (6-17 mM), chromatographic column temperatures (25-40 °C), and injected volumes (15-40 µL). The retention times of sodium and lithium ions increased with increasing amounts of injected ammonium, while tris remained essentially unchanged, indicating that the resolution of these ions can be influenced by varying the concentration of the matrix. The results suggested that the observed effect was due to a combination of the pH change caused by the injected matrix, the dissociation of tris ions, the dissociation of the carbocylic ion-exchange groups of stationary phase, the change in buffer capacity, and the amount of ammonium ion introduced. It has been shown that in a well-designed experiment, the addition of ammonium hydroxide to the sample at concentrations greater than 1% can improve the efficiency of organic and inorganic cation separation. It was found that 8 mM methanesulfonic acid eluent, 30 °C, 1% ammonium hydroxide matrix concentration, and 25 µL injection were optimal for the baseline separation of tris and sodium ions on the high-capacity Dionex CS16 column. These ions could not be separated on this column without the presence of the ammonium matrix.

Unbiased Determination of Adsorption Isotherms by Inverse Method in Liquid Chromatography.

The Inverse Method is a widely used technique for the determination of adsorption isotherms in liquid chromatography. In this method, isotherm is determined from the overloaded peak profile of the component by the iterative solution of the mass balance equation of liquid chromatography. Successful use of this method requires a prior assumption of equation of isotherm (Langmuir, BET etc.). In this work, we have developed an inverse method that gives results of similar accuracy to the frontal analysis without assuming the equation of the isotherm. The oversaturated peaks were calculated using a spline fitted to data points instead of the derivative of the isotherm. The distribution of the isotherm points were optimized for minimizing the difference between the measured and calculated overloaded peaks. The accuracy of the developed method was verified with synthetic benchmark peaks and by the determination of isotherm of buthyl-benzoate under real conditions. The results confirmed that the accuracy of the developed method is similar to that of Frontal Analysis.

Fluorescence Quenching of Tyrosine-Ag Nanoclusters by Metal Ions: Analytical and Physicochemical Assessment.

A new synthesis method is described for the first time to produce silver nanoclusters (AgNCs) by using the tyrosine (Tyr) amino acid. Several important parameters (e.g., molar ratios, initial pH, reaction time etc.) were optimized to reach the highest yield. The formed Tyr-AgNCs show characteristic blue emission at λem = 410 nm, and two dominant fluorescence lifetime components were deconvoluted (τ1 ~ 3.7 and τ2 ~ 4.9 ns). The NCs contained metallic cores stabilized by dityrosine. For possible application, the interactions with several metal ions from the tap water and wastewater were investigated. Among the studied cations, four different ions (Cu2+, Ni2+, Fe3+, and Rh3+) had a dominant effect on the fluorescence of NCs. Based on the detected quenching processes, the limit of detection of the metal ions was determined. Static quenching (formation of a non-luminescent complex) was observed in all cases by temperature-dependent measurements. The calculated thermodynamic parameters showed that the interactions are spontaneous ranked in the following order of strength: Cu2+ > Fe3+ > Rh3+ > Ni2+. Based on the sign and relations of the standard enthalpy (ΔH°) and entropy changes (ΔS°), the dominant forces were also identified.

Development of a Fast and Robust UHPLC Method for Apixaban In-Process Control Analysis.

In-process control (IPC) is an important task during chemical syntheses in pharmaceutical industry. Despite the fact that each chemical reaction is unique, the most common analytical technique used for IPC analysis is high performance liquid chromatography (HPLC). Today, the so-called "Quality by Design" (QbD) principle is often being applied rather than "Trial and Error" approach for HPLC method development. The QbD approach requires only for a very few experimental measurements to find the appropriate stationary phase and optimal chromatographic conditions such as the composition of mobile phase, gradient steepness or time (tG), temperature (T), and mobile phase pH. In this study, the applicability of a multifactorial liquid chromatographic optimization software was studied in an extended knowledge space. Using state-of-the-art ultra-high performance liquid chromatography (UHPLC), the analysis time can significantly be shortened. By using UHPLC, it is possible to analyse the composition of the reaction mixture within few minutes. In this work, a mixture of route of synthesis of apixaban was analysed on short narrow bore column (50 × 2.1 mm, packed with sub-2 µm particles) resulting in short analysis time. The aim of the study was to cover a relatively narrow range of method parameters (tG, T, pH) in order to find a robust working point (zone). The results of the virtual (modeled) robustness testing were systematically compared to experimental measurements and Design of Experiments (DoE) based predictions.

Theoretical Analysis of Efficiency of Multi-Layer Core-Shell Stationary Phases in the High Performance Liquid Chromatography of Large Biomolecules.

Modern analytical applications of liquid chromatography require columns with higher and higher efficiencies. In this work, the general rate model (GRM) of chromatography is used for the analysis of the efficiency of core-shell phases having two porous layers with different structures and/or surface chemistries. The solution of the GRM in the Laplace domain allows for the calculation of moments of elution curves (retention time and peak width), which are used for the analysis of the efficiency of bi-layer particles with and without a non-porous core. The results demonstrate that bi-layer structures can offer higher separation power than that of the two layers alone if the inner layer has smaller surface coverage (retentivity) and the pore size and pore diffusion of the outer layer is either equal to or higher than that of the inner layer. Even in the case of core-shell phases, there is an increase in resolution by applying the bi-layer structure; however, we can always find a mono-layer core-shell particle structure with a larger core size that provides better resolution. At the optimal core size, the resolution cannot be further improved by applying a bi-layer structure. However, in case of the most widely produced general-purpose core-shell particles, where the core is ∼70% of the particle diameter, a 15-20% gain of resolution can be obtained by using well-designed and optimized bi-layer core-shell phases.

Analysis of Non-Ionic Surfactant Triton X-100 Using Hydrophilic Interaction Liquid Chromatography and Mass Spectrometry.

It is well known that surfactants increase the solubility of hydrophobic organic compounds and cause adverse environmental effects. The removal of these compounds from the contaminated soil or ground-water is particularly difficult due to their water soluble feature. In this work, an ultra-high performance hydrophilic interaction liquid chromatographic method was developed for the separation of oligomers of Triton X-100 octylphenol-polyethoxylate non-ionic surfactant. Liquid chromatography-mass spectrometry (LC-MS) was used to identify the Triton X-100 compounds. There was a 44 mass unit difference between two adjacent peaks that is the molar mass of one ethylene oxide group (⁻CH 2 CH 2 O⁻). A quadratic retention model was applied for the estimation of retention of the examined non-ionic surfactant and the optimization of gradient elution conditions. The optimized method was suitable for the baseline separation of 28 Triton X-100 oligomers in five minutes.

Linear solvent strength model on porous graphitic carbon stationary phase using high temperature liquid chromatographic method for allopurinol related substances analysis.

A high-performance liquid chromatography (HPLC) method was developed for the analysis of Allopurinol and its Ph.Eur. impurities using a porous graphitic carbon (PGC) stationary phase. Retention behavior of solutes was studied across a wide temperature range (30-90 °C) and various gradient times (5-20 min). Analysis of the data revealed distinct retention mechanisms between reversed-phase and PGC phases. However, it was proved that the retention of Allopurinol and its Ph.Eur. impurities on PGC stationary phase can be effectively modeled using the linear solvent strength (LSS) theory. This allows for the utilization of LSS-based method development software to optimize methods under these conditions. By using commercial chromatographic modeling software, separation of Allopurinol and Ph.Eur. impurities was optimized within a large design space. At the optimized operating conditions (pH = 2.0, tG = 6 min, T = 60 °C), all solutes were separated within 6 min with baseline resolution. Comparison between predicted and experimentally measured chromatograms further confirmed the applicability of LSS theory in developing analytical methods for PGC-based HPLC systems. The presented approach offers a general framework for method development on PGC phases.

Revisiting column selectivity choices in ultra-high performance liquid chromatography-Using multidimensional analytical Design Spaces to identify column equivalency.

Current guides and column selection system (CSS) platforms can provide some helpful insights with regard to the selection of alternative phases. Their practical reliability however, can also turn out to be questionable, especially considering the lack of detailed specifics, such as a clear definition of points of equivalence-appropriate running conditions under which the given analytical mixture can be satisfactorily resolved on various stationary phases. In this context, the use of multivariate modeling tools can be highly beneficial. These tools, when applied systematically, are ideal for uniquely characterizing complex LC-separation systems, a fact supported by numerous peer-reviewed papers. Revisiting our earlier work [1] and the applied systematic workflow [2], we used a Design Space modeling software (DryLab), with the main focus on building and comparing 3-dimensional separation models of amlodipine and its related impurities to identify shared method conditions under which columns are conveniently interchangeable. Our study comprised 5, C18-modified ultra-high performance liquid chromatography (UHPLC) columns in total, in some cases with surprising results. We identified several equivalences between the Design Spaces (DSs) of markedly different columns. Conversely, there were cases where, despite the predicted similarities in column data, the modeled DSs demonstrated clear differences between the selected stationary phases.

Prospects of Food Taxes for Planetary Health: A Systematic Review of Modeling Studies.

OBJECTIVES: The aim of this study was to analyze the modeling methodologies of fiscal policies on food with health or environmental outcomes. BACKGROUND: Evidence suggests that fiscal policies on food can contribute to addressing the growing burden of noncommunicable diseases and climate change. These policies should be modeled in advance to see the implications for the environment and health. METHODS: A systematic review was conducted of studies that modeled fiscal policies on the food groups targeted by the EAT-Lancet Commission and examined their health or environmental outcomes. The Scopus and PubMed databases were searched on November 30, 2021. The records were double-screened and data on modeling methods were extracted from the included studies. RESULTS: A total of 55 studies were included in the review. The most frequently modeled interventions were fruit and vegetable subsidies (n = 19) and carbon taxes on food (n = 17). One study also included a consumer education campaign to enhance the effect of fiscal policy. The outcomes are highly sensitive to consumption change and price elasticities. None of the studies modeled the health effects of environmental outcomes. CONCLUSIONS: A model that covered all the relevant aspects of the issue was not found. Some parts were missing from all the included models. It is advisable to model the stability of the amount of diet consumed, either by keeping the amount of food in the diet stable or by taking a more conservative approach and keeping the consumed calories stable. It is preferable to keep the included diseases and environmental boundaries broad to have more valid outcome estimates on this complex issue. A more comprehensive understanding of fiscal policies would allow us to better anticipate the impact of our actions and inactions and thus could lead to more sophisticated measures taken by policymakers. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. 2022 CRD42022291945/.

Academic education in environmental chemistry in Europe-addressing future challenges in research and regulation.

Following the tradition of the 16th International Conference on Chemistry and the Environment (ICCE) in Oslo, Norway (2017), and the subsequent 17th ICCE in Thessaloniki, Greece (2019), a follow-up session on higher education in environmental science was organized at the 18th ICCE in Venice, Italy (June 2023). The aim of the session was to stimulate the exchange of experiences and knowledge on graduate and post-graduate level educational programmes, including their development, prioritization, and implementation. The session discussed the integration of practical training activities, which included the integration of environmental chemistry in various bachelor's and master's programmes. The aim was to demonstrate the versatility of environmental chemistry as an interdisciplinary scientific discipline that allows the development of essential green skills for developing sustainable strategies for the environmental experts of tomorrow. Furthermore, during the session, a survey was conducted among the conference participants to collect attitudes and reflections from the audience on the education of environmental chemistry (and related fields).

The Semmelweis Study: a longitudinal occupational cohort study within the framework of the Semmelweis Caring University Model Program for supporting healthy aging.

The Semmelweis Study is a prospective occupational cohort study that seeks to enroll all employees of Semmelweis University (Budapest, Hungary) aged 25 years and older, with a population of 8866 people, 70.5% of whom are women. The study builds on the successful experiences of the Whitehall II study and aims to investigate the complex relationships between lifestyle, environmental, and occupational risk factors, and the development and progression of chronic age-associated diseases. An important goal of the Semmelweis Study is to identify groups of people who are aging unsuccessfully and therefore have an increased risk of developing age-associated diseases. To achieve this, the study takes a multidisciplinary approach, collecting economic, social, psychological, cognitive, health, and biological data. The Semmelweis Study comprises a baseline data collection with open healthcare data linkage, followed by repeated data collection waves every 5 years. Data are collected through computer-assisted self-completed questionnaires, followed by a physical health examination, physiological measurements, and the assessment of biomarkers. This article provides a comprehensive overview of the Semmelweis Study, including its origin, context, objectives, design, relevance, and expected contributions.

Effect of time-invariant pressure gradients on peak formation and efficiency in ultrahigh-pressure liquid chromatography.

In chromatography, pressure can affect the retention factors of compounds significantly. In liquid chromatography, this effect is primarily related to the change in the molecular volume of solute during adsorption that is remarkably high for large biomolecules such as peptides and proteins. As a result, the migration velocities of chromatographic bands vary spatially through the column affecting the degree of band broadening. In this work, based on theoretical considerations, chromatographic efficiencies are studied under pressure-induced gradient conditions. The retention factor and migration velocity of different components are examined, and it is shown that components with the same retention time can have different migration patterns. The width of the initial band after injection is affected by the pressure gradient, providing significantly thinner initial bands for compounds with higher pressure sensitivity. In addition to classical band broadening phenomena, the influence of pressure gradients on band broadening is remarkable. The positive velocity gradient leads to extra band broadening. Our results clearly demonstrate that the zones are significantly wider at the end of the column if the change of molar volume of solute during adsorption is large. If the pressure drop is increasing, this effect becomes more significant. In the same time, the high release velocity of the bands somewhat counteracts the extra band broadening effect, however, it can not offset it perfectly. As a result, the separation efficiency of large biomolecules is decreased significantly due to the chromatographic pressure gradient. Under UHPLC conditions, the extent of apparent efficiency loss can reach up to 50% compared to the intrinsic efficiency of the column.

Challenges and opportunities for improvement in the management and financing system of Health Promotion Offices in Hungary.

Background: One hundred ten Health Promotion Offices (HPOs) have started operating in Hungary in response to public health challenges. Many of them have been active for almost 10 years, yet their operational experience has not been evaluated. The specific objectives of our study were: (1) to describe the current operational and funding system of HPOs, (2) to identify challenges related to the current management and funding practices, and (3) to formulate recommendations for improvement based on gathered experience and international experience. Design: In order to gain a deeper insight into the operational experience of HPOs, an online survey was conducted with the professional or economic managers of HPOs. A scoping review was carried out to gather international experiences about best practices to formulate recommendations for improvement in developing the operational and financing scheme for HPOs. Results: We found that current HPO network in Hungary faces three main challenges: a deficient management system, inflexible financing scheme, and unequal ability to purchase or provide services for the population. Conclusions: Based on the survey complemented by international experiences, we propose the overhaul of the professional management system and switching toa combination of fixed and performance-based financing scheme for the HPOs in Hungary.

International practices in health technology assessment and public financing of digital health technologies: recommendations for Hungary.

Background: Evaluating and integrating digital health technologies is a critical component of a national healthcare ecosystem in the 2020s and is expected to even increase in significance. Design: The paper gives an overview of international practices on public financing and health technology assessment of digital health technologies (DHTs) in five European Union (EU) countries and outlines recommendations for country-level action that relevant stakeholders can consider in order to support uptake of digital health solutions in Hungary. A scoping review was carried out to identify and gather country-specific classifications and international practices on the financing DHTs in five pioneering EU countries: Germany, France, Belgium, the United Kingdom and Finland. Results: Several frameworks have been developed for DHTs, however there is no single, unified framework or method for classification, evaluation, and financing of digital health technologies in European context. European countries apply different taxonomy, use different assessment domains and regulations for the reimbursement of DHTs. The Working Group of the Hungarian Health Economic Society recommends eight specific points for stakeholders, importantly taking active role in shaping common clinical evidence standards and technical quality criteria across in order for common standards to be developed in the European Union single market. Conclusion: Specificities of national healthcare contexts must be taken into account in decisions to allocate public funds to certain therapies rather than others.

The Effectiveness of Supplementation with Key Vitamins, Minerals, Antioxidants and Specific Nutritional Supplements in COPD-A Review.

Currently, an increasing amount of evidence supports the notion that vitamins C, D and E, carotenoids, and omega-3 fatty acids may protect against the progression of chronic respiratory diseases. Although chronic obstructive pulmonary disease (COPD) primarily affects the lung, it is often accompanied by extrapulmonary manifestations such as weight loss and malnutrition, skeletal muscle dysfunction, and an excess of harmful oxidants, which can lead to a decline in quality of life and possible death. Recently, the role of various vitamins, minerals, and antioxidants in mitigating the effects of environmental pollution and smoking has received significant attention. Therefore, this review evaluates the most relevant and up-to-date evidence on this topic. We conducted a literature review between 15 May 2018 and 15 May 2023, using the electronic database PubMed. Our search keywords included COPD, chronic obstructive pulmonary disease, FEV1, supplementation: vitamin A, vitamin D, vitamin E, vitamin C, vitamin B, omega-3, minerals, antioxidants, specific nutrient supplementations, clinical trials, and randomized controlled trials (RCTs). We focused on studies that measured the serum levels of vitamins, as these are a more objective measure than patient self-reports. Our findings suggest that the role of appropriate dietary supplements needs to be reconsidered for individuals who are predisposed to or at risk of these conditions.

Roadmap for large-scale implementation of point-of-care testing in primary care in Central and Eastern European countries: the Hungarian experience.

OBJECTIVE: The aim of this study is to give a broad overview of the international best practices regarding the implementation of point-of-care testing (POCT) in primary care (PC) setting and to highlight the facilitators and barriers for widespread national uptake. The study focuses on the managerial and organizational side of POCT, offering a roadmap for implementation as well as highlighting the most important requirements needed to unlock the clinical and economical potential of POCT in the Hungarian healthcare system. METHODS: We conducted an English language scoping literature review between January 2012 and June 2021 to assess the recent trends of POCT implementation in developed countries. Our research focuses on the recent publications of several European and Anglo-Saxon countries where POCT utilization is common. In parallel, we reviewed the Hungarian regulatory framework, ongoing governmental legislation, and strategies influencing the POCT dissemination in the Hungarian PC sector. RESULTS: Among the possible POCT usage in PC, we identified several clinically relevant devices and tests (C-reactive protein, urine, blood glucose, D-dimer, prothrombin time) important in screening and early detection of morbidities representing high disease burden. Based on international literature, general practitioners (GPs) are interested in the shortened diagnostic times, portable devices, and better doctor-patient relations made possible by POCT. There are several concerns, however, regarding initial and operational costs and reimbursement, limited scientific evidence about quality and safety, unclear regulations on quality validation of tests, as well as managerial aspects like PC staff training and IT integration at the GP level. CONCLUSION: As our review highlights, there is considerable interest among GPs to implement POCT as it has the potential to improve quality of care; however, there are many obstacles to overcome before widespread uptake. Further investigation is recommended to elaborate management and quality insurance background and to develop appropriate regulatory framework and financial scheme for GP practices. Preferably this work should involve the local practicing GPs to better tailor the implementation roadmap to country-specific details.

Riding the Pandemic Waves-Lessons to Be Learned from the COVID-19 Crisis Management in Romania.

In our analysis, we assessed how Romania dealt with the numerous challenges presented by the COVID-19 pandemic during 2021. In that year, the government had to deal with two waves of COVID-19 pandemics caused by the new variants, the low vaccination rate of the population, the overload of the healthcare system and political instability at the same time. Based on publicly available databases and international literature, we evaluated government measures aimed at reducing the spread of the pandemic and ensure the operation of the healthcare workforce and infrastructure. In addition, we evaluated measures to provide health services effectively and the government's pandemic responses regarding excess mortality in 2021. In the absence of a complex monitoring system, limited information was available on the spread of the pandemic or the various risk factors at play. Due to incomplete and inadequate management systems, the government was unable to implement timely and adequate measures. Our analysis concludes that the management of a pandemic can only be successful if data are collected and evaluated using complex systems in a timely manner, and if members of society adhere to clearly communicated government measures due to high levels of trust in the government.

Theoretical study of the efficiency of liquid chromatography columns with particle size gradient.

Modern analytical applications of liquid chromatography require more and more efficient columns. In this work, the possibility of utilizing particle size gradient in the chromatographic column was studied by a theoretical approach. In the course of our work three different scenarios of particle size gradients were considered with different shapes (linear, convex and concave). The evolution of bandwidth inside the column was plotted for each scenario. As a reference point, the bandwidth of the uniform column was used, which had the same pressure drop as the non-uniform column. According to our calculations, in isocratic elution mode, the non-uniform column does not offer any advantage compared to the uniform column, regardless the type of the particle size gradient. In gradient elution mode, however, extra band compression occurs was found. For negative particle size gradients, the final physical bandwidth was found to be approximately 1-4 % smaller than for uniform columns. This slight gain in efficiency in terms of bandwidth compression can be expanded to 5-8 % by the optimization of the limiting particle sizes. These optimized results are obtained when the final particle size is approximately 40% of the initial particle diameter.

Age and Gender Specific Lung Cancer Incidence and Mortality in Hungary: Trends from 2011 Through 2016.

Objective: No assessment was conducted describing the age and gender specific epidemiology of lung cancer (LC) prior to 2018 in Hungary, thus the objective of this study was to appraise the detailed epidemiology of lung cancer (ICD-10 C34) in Hungary based on a retrospective analysis of the National Health Insurance Fund database. Methods: This longitudinal study included patients aged ≥20 years with LC diagnosis (ICD-10 C34) between January 1, 2011 and December 31, 2016. Patients with different cancer-related codes 6 months before or 12 months after LC diagnosis or having any cancer treatment other than lung cancer protocols were excluded. Results: Lung cancer incidence and mortality increased with age, peaking in the 70-79 age group (375.0/100,000 person-years) among males, while at 60-69 age group for females (148.1/100,000 person-years). The male-to-female incidence rate ratio reached 2.46-3.01 (p < 0.0001) among the 70-79 age group. We found 2-11% decrease in male incidence rate at most age groups, while a significant 1-3% increase was observed in older females (>60) annually during the study period. Conclusion: This nationwide epidemiology study demonstrated that LC incidence and mortality in Hungary decreased in younger male and female population, however we found significant increase of incidence in older female population, similar to international trends. Incidence rates peaked in younger age-groups compared to Western countries, most likely due to higher smoking prevalence in these cohorts, while lower age LC incidence could be attributed to higher competing cardiovascular risk resulting in earlier mortality in smoking population.

Improvement in Lung Cancer Survival: 6-Year Trends of Overall Survival at Hungarian Patients Diagnosed in 2011-2016.

Objective: Lung cancer is one of the most common cancers worldwide and its survival is still poor. The objective of our study was to estimate long-term survival of Hungarian lung cancer patients at first time based on a nationwide review of the National Health Insurance Fund database. Methods: Our retrospective, longitudinal study included patients aged ≥20 years who were diagnosed with lung cancer (ICD-10 C34) between January 1, 2011 and December 31, 2016. Survival rates were evaluated by year of diagnosis, patient gender and age, and morphology of lung cancer. Results: 41,854 newly diagnosed lung cancer patients were recorded. Mean age at diagnosis varied between 64.7 and 65.9 years during study period. One- and 5-year overall survival rates for the total population were 42.2 and 17.9%, respectively. Survival was statistically associated with gender, age and type of lung cancer. Female patients (n = 16,362) had 23% better survival (HR: 0.77, 95% confidence interval (CI): 0.75-0.79; p < 0.001) than males (n = 25,492). The highest survival rates were found in the 20-49 age cohort (5Y = 31.3%) and if the cancer type was adenocarcinoma (5Y = 20.5%). We measured 5.3% improvement (9.2% adjusted) in lung cancer survival comparing the period 2015-2016 to 2011-2012 (HR: 0.95 95% CI: 0.92-0.97; p = 0.003), the highest at females <60 year (0.86 (adjusted HR was 0.79), interaction analysis was significant for age and histology types. Conclusion: Our study provided long-term Lung cancer survival data in Hungary for the first time. We found a 5.3% improvement in 5-year survival in 4 years. Women and young patients had better survival. Survival rates were comparable to-and at the higher end of-rates registered in other East-Central European countries (7.7%-15.7%).