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Comparative electrochemical study of oxidative nicarbazin determination in non-aqueous media: Differential pulse voltammetry vs. capillary electrophoresis with amperometric detection
Get PDFBackground
Electrochemistry offers a range of powerful techniques for solving analytical problems, each with its own advantages and limitations that can significantly affect the information obtained. These variations lead to diverse requirements for newly developed methods. Applying multiple electrochemical techniques simultaneously can optimize information extraction from a sample, aiding in the selection of the best analytical approach.
Results
In this study, we present the first investigation of the oxidation of the coccidiostat nicarbazin, along with a comparative evaluation of two established electrochemical methods with complementary strengths: differential pulse voltammetry (DPV) and capillary electrophoresis coupled with amperometric detection (CE-AD). We thoroughly examine the oxidative determination of nicarbazin in poultry feed samples using acetonitrile based media. DPV allows for rapid and efficient analysis, while CE-AD excels in handling complex samples with electrochemically active species due to its high separation efficiency. Both methods exhibit limits of detection (LODs) in the low micromolar range. To provide a comprehensive understanding of the nicarbazin oxidation process, the final reaction products were analyzed by mass spectrometry, identifying 4-nitroaniline and (4-nitrophenyl)formamide as key product compounds.
Significance and novelty
This pioneering research on the anodic detection of nicarbazin includes a detailed analysis of the components in the studied equimolar mixture. The developed protocols, combined with straightforward sample preparation, enable the successful determination of nicarbazin levels below those allowed by EU regulations
Immobilienfinanzierung durch Markt und Regulierung belastet
No full textDie aktuellen Verwerfungen auf den deutschen Immobilienmärkten sind in erster Linie durch die Zinswende und die steigenden Baukosten begründet: nach über zehn Jahren positiver Preisentwicklung sind Transaktions- und Finanzierungsvolumina seit dem zweiten Quartal 2022 rückläufig. Banken reagieren vorsichtig, die Beleihungsquoten bleiben trotz sinkender Preise niedrig, der Fokus verschiebt sich auf vermietete Objekte in innerstädtischen Lagen. Ermutigend sind die bislang anhaltend niedrigen Ausfallquoten bei Immobiliendarlehen, v. a. im Vergleich zu der Zeit nach der Finanz- und Wirtschaftskrise 2007/2008. Dies gilt insbesondere für Wohnimmobilien, doch für Gewerbeimmobilien nur mit leichten Einschränkungen ebenfalls. Der Neubausektor ist jedoch massiv belastet, da viel Fremdkapital benötigt wird und sowohl von Banken ausgegebenes Fremdkapital als auch Mezzanine-Kapital nicht in ausreichendem Umfang und nicht zu darstellbaren Kosten zur Verfügung steht. Besserung ist kurzfristig nicht in Sicht. Es stellt sich angesichts dieses Marktumfeldes die Frage, ob jüngste Regulierungsmaßnahmen für eine weitere Verschärfung der Situation sorgen könnten. Zu nennen sind hierbei die Kapitalunterlegung von 150 % für Projektentwicklungen und die Einführung eines sektoralen Systemrisikopuffers für die Finanzierung von Wohnimmobilien in Höhe von 2 % ab dem 01. Februar 2023. Da der Immobilienmarkt seinen zyklischen Höhepunkt bereits überschritten hatte, werden diese Maßnahmen wohl nicht die primär beabsichtigte antizyklische, sondern eine prozyklische Wirkung entfalten
Robotic reconstruction of complex bladder neck stenosis: Single‐centre experience with three techniques
Get PDFObjectives
To evaluate and compare surgical techniques for robot-assisted reconstruction of recurrent bladder neck stenosis (BNS). BNS following a simple prostatectomy represents a rare but challenging condition in operative urology. Various robotic reconstructive techniques have been described, showing differing success rates. This monocentric case series reports on three distinct robotic surgical approaches for managing recurrent BNS.
Patients and methods
A retrospective analysis was conducted on patients undergoing robot-assisted surgical repair for recurrent BNS at our institution. Clinical data, including patient history, comorbidities (Charlson Comorbidity Index), surgical treatment, complications (Clavien-Dindo classification) and follow-up outcomes, were analysed.
Results
A total of 27 patients underwent robotic bladder neck reconstruction for recurrent BNS. Twelve patients were treated with YV plasty, 12 with stricture resection and end-to-end anastomosis and 3 with reconstruction using a buccal mucosa graft (BMG). At a median follow-up of 18 months, therapy failure occurred in 9 patients (33.3%), with failure rates of 25.0% for YV plasty, 33.3% for stricture resection and 66.7% for BMG plasty. Nine patients (33.3%) experienced surgery-related complications, including 7 minor complications (5 in the stricture resection group, 1 in the YV plasty group and 1 in the BMG group) and 2 major complications (1 in the stricture resection group and 1 in the YV plasty group). De novo incontinence occurred in five patients (19.2%), all of whom had undergone stricture resection with end-to-end anastomosis.
Conclusions
Recurrent BNS poses a significant surgical challenge. Based on our experience, BMG reconstruction demonstrated suboptimal outcomes, while stricture resection was associated with the highest complication rate and the most frequent occurrence of de novo incontinence. YV plasty, with its relatively low morbidity and minimally invasive nature, has become the preferred technique in our institution for managing this condition. Prospective studies with larger cohorts are warranted to confirm these findings and further refine surgical approaches
Geschlechterspezifische Unterschiede in der Lebensqualität von Lungenkrebspatienten in Stadium IV
Get PDFDie Lebensqualität (LQ) von Lungenkrebspatienten gewinnt zunehmend an Bedeutung in onkologischen Studien. Ziel dieser Arbeit war es, männliche und weibliche Lungenkrebspatienten im metastasierten Stadium auf Geschlechterunterschiede in ihrer LQ mittels der EORTC (European Organisation for Research and Treatment of Cancer) Fragebögen QLQ-C30 (Core Quality of Life Questionnaire) und QLQ-LC29 (Lung Cancer Quality of Life Questionnaire) zu untersuchen.
Es handelt sich um eine prospektive Querschnittstudie, für die Patienten am Universitätsklinikum Regensburg sowie am Krankenhaus Barmherzige Brüder Regensburg mittels der EORTC Fragebögen QLQ-C30 und QLQ-LC29 befragt wurden. Weitere Daten sind den Arztbriefen der jeweiligen Patienten entnommen worden. Die Subgruppenanalyse erfolgte mit dem Programm SPSS (Statistical Package für Social Sciences). Es wurde eine ANCOVA (Kovarianzanalyse) erstellt, bei welcher die LQ als abhängige Variable und das Alter als Kovariable gewählt wurden. Adjustiert wurde zudem für Geschlecht, Komorbiditäten, Histologie und Karnofsky Performance Status (KPS). Das Signifikanzniveau wurde auf p=0,05 festgelegt. Für die einzelnen Aspekte der LQ wurden jeweils die separaten Mittelwerte männlicher und weiblicher Patienten aus den gewonnenen Daten berechnet.
Insgesamt konnten 201 Patienten mit Lungenkrebs rekrutiert werden. Davon befanden sich 131 Patienten im UICC (Union internationale contre le cancer) Stadium IV und waren somit geeignet für diese Studie. Es ergibt sich ein signifikanter Unterschied für Haarausfall (w=42,499 vs. m=25,560; p=0,011), welcher die Frauen stärker in ihrer LQ beeinflusst als die Männer. Für die einzelnen Werte der LQ ist ein klinisch relevanter Unterschied (MCID) definiert ab einer Differenz der Mittelwerte von über 5. Dies findet sich bei Rollenfunktionalität, soziale Funktionalität, Fatigue, Dyspnoe und Übelkeit und Erbrechen zum Nachteil für die weiblichen Patienten. Ein MCID in finanziellen Problemen betrifft die Männer stärker. Die am stärksten gewertete Aspekte sind für beide Geschlechter annähernd dieselben: für die Funktionalitäten hat sich die Rollenfunktionalität am stärksten verschlechtert (w=50,573 vs. m=57,734). In den Symptomskalen des QLQ-C30 sind es Fatigue (w=53,250 vs. m=43,581), Dyspnoe (w=52,306 vs. m=46,741) und Schlafstörungen (w=28,880 vs. m=35,546). In den Einzelskalen des QLQ-LC29 sind es existentielle Ängste (w=67,617 vs. m=61,462) und Abnahme körperlicher Fähigkeiten (w=62,436 vs. m=58,431). Darauf folgt bei Frauen Haarausfall (w=42,499) und bei Männern Husten (m=35,997).
Es lässt sich tendenziell eine schlechtere LQ für Frauen mit metastasiertem Lungenkrebs zeigen. Jedoch haben beide Geschlechter eine insgesamt eingeschränkte LQ im Vergleich zur Normalbevölkerung.
Haarausfall ist für die Frauen ein stark belastender Aspekt während der Erkrankung.
Insgesamt sollte die Aufmerksamkeit im Rahmen einer Behandlung vermehrt auf den am stärksten gewerteten Faktoren liegen, wobei sich ein geschlechterspezifischer Behandlungsansatz als nützlich erweisen kann, hinsichtlich des besseren oder schlechteren Ansprechens auf bestimmte Therapieformen sowie unterschiedlichen Bedürfnissen von männlichen und weiblichen Patienten
Meglumine-enhanced water solubility and stability of quercetin at moderate pH via liposome encapsulation
Get PDFIn the present work, the flavonoid quercetin was encapsulated into liposomes from an aqueous solution using meglumine as solubility enhancer and stabilizer for quercetin. This study was a proof of principle to demonstrate the feasibility of the pH-driven (or pH jump) method even with very oxidation-sensitive polyphenols. We thus investigated meglumine addition together with the standard thin-film hydration method to prepare liposomes. Furthermore, the pH was initially set at 9 to enhance the water-solubility of quercetin and was lowered to 7 after encapsulation. The liposomes were prepared using DPPC, DPPG, cholesterol and DMPE lipids and two different saline buffer solutions containing either sucrose or meglumine. Successful encapsulation of quercetin was confirmed by Differential Pulse Voltammetry. The estimation of the degree of oxidation of quercetin inside the liposomes was performed by High-Performance Liquid Chromatography. It was found that a significant amount of unoxidized quercetin was encapsulated in the liposomes from an aqueous solution, notably in the liposomes prepared with meglumine buffer solution
Metabolomic profiling of renal cyst fluid in advanced ADPKD: insights from dialysis and transplantation cohorts
No full textBackground
Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disorder characterized by progressive renal cyst formation, often leading to end-stage kidney disease (ESKD). In contrast to the urinary metabolome in ADPKD, the composition of renal cyst fluid remains largely unexplored.
Methods
We conducted a comprehensive metabolomic analysis of renal cyst fluid from 26 ADPKD patients (20 on dialysis, six with kidney transplants) using ¹H-NMR spectroscopy and liquid chromatography-mass spectrometry (LC-MS). Cysts were clustered based on metabolite profiles, and differences were analyzed across groups defined by renal function status (dialysis vs. transplant), cyst volume, and cyst fluid sodium concentrations.
Results
Dialysis patients and transplant recipients differed significantly in their renal cyst fluid metabolomes. The former exhibited higher concentrations of myoinositol, creatinine, sucrose, τ-methylhistidine, trigonelline, and sarcosine, while the latter showed increased levels of leucine, isoleucine, valine and alanine. Remarkably, metabolites of the immunosuppressive prodrug mycophenolate mofetil were detected in renal cyst fluids after kidney transplantation. Despite intra- and interindividual variability, cyst fluid from the same patient displayed greater homogeneity. Interestingly, metabolomic profiles were not altered by cyst size.
Conclusion
This first systematic metabolomic analysis of renal cyst fluid in advanced ADPKD reveals distinct metabolic signatures linked to renal function status. The data provides novel insights into the pathophysiology of ADPKD and highlight the potentials of renal cyst fluid metabolomics for identifying biomarkers and therapeutic targets
Additive effect between maltodextrins and short food agreed organic acids for rutin and quercetin solubilization in aqueous solutions
No full textThe aim of this study was to achieve an efficient, cost effective and food compatible solubilization of antioxidants by combining two solubilization mechanisms. For this purpose, a complexing agent (polysaccharide molecules) and a small molecule (short organic acids) were combined. Solubilization experiments of rutin and quercetin (two hydrophobic polyphenols) were performed using maltodextrins, cyclodextrins, citric acid and malic acid. We were able to show that maltodextrins at high concentrations are able to solubilize the polyphenols in a similar way to cyclodextrin and thus represent inexpensive and readily available alternatives. Due to their salting-out character we assume a solubilization mechanism via specific interactions, probably complexation. Adding citric or malic acids to maltodextrin solution further increased solubility via additive effects, though the low pH and the salting-out effects of their salts limit practical applications
HSN—helping in mental distress: a new emotion focused psychological first aid program
No full textPsychological first aid programs aim to train lay people to help others who are
experiencing a mental health crisis or developing mental health problems. The
current article introduces the new German psychological first aid training program HSN. The acronym HSN stands for “Helfen in Seelischer Not” (helping in mental distress) but also for the action chain “hear, speak, network.” The HSN program differs from other well-examined mental health first aid programs by (1) focusing primarily on emotions instead of disorders, (2) using a blended approach, combining face-to-face and online elements right from the start of the project and (3) a low-threshold approach with a course duration of two hours. Here we specify the HSN concept and report first results from a sample of 150 students. The participating students completed a self-report questionnaire before and after the course regarding their “confidence to help.” The program demonstrated good feasibility without any relevant side effects. On a descriptive level we observed an improvement of the averaged values of all questionnaire items after the course. These positive initial results merit the further development of HSN as a lowthreshold psychological first aid program
Instantly Reversible Enzyme Regulation via Dichromatic Irradiation of Incorporated Azobenzene
No full textAzobenzene is a widely recognized tool for achieving artificial spatiotemporal control of enzyme activity using light. Photocontrol reversibility is typically based on photostationary states with varying E and Z isomer compositions achieved through irradiation at specific wavelengths. Here, we report an alternative mechanism for azobenzene based enzyme regulation, discovered through simultaneous irradiation with two wavelengths. Using two engineered variants of imidazole glycerol phosphate synthase, in which azobenzene was incorporated as an unnatural amino acid to enable reversible control under monochromatic irradiation, we uncovered unique behavior under dichromatic irradiation. Notably, a distinct spectroscopic signal from the azobenzene moiety emerged during simultaneous irradiation at 365 nm and 420 nm and vanished upon return to the dark. Intriguingly, dichromatic irradiation triggered a reproducible two-fold increase in catalytic activity and an instantaneous return to baseline activity in the dark for one variant. In contrast, the other variant and the wild-type enzyme maintained their baseline activity under the same conditions. These findings reveal an unexplored avenue for azobenzene photoswitching, offering a novel approach to photocontrol with potential applications in sequentially regulating multiple enzymes, especially when combined with monochromatic irradiation strategies
Domain-incremental white blood cell classification with privacy-aware continual learning
Get PDFWhite blood cell (WBC) classification plays a vital role in hematology for diagnosing various medical conditions. However, it faces significant challenges due to domain shifts caused by variations in sample sources (e.g., blood or bone marrow) and differing imaging conditions across hospitals. Traditional deep learning models often suffer from catastrophic forgetting in such dynamic environments, while foundation models, though generally robust, experience performance degradation when the distribution of inference data differs from that of the training data. To address these challenges, we propose a generative replay-based Continual Learning (CL) strategy designed to prevent forgetting in foundation models for WBC classification. Our method employs lightweight generators to mimic past data with a synthetic latent representation to enable privacy-preserving replay. To showcase the effectiveness, we carry out extensive experiments with a total of four datasets with different task ordering and four backbone models including ResNet50, RetCCL, CTransPath, and UNI. Experimental results demonstrate that conventional fine-tuning methods degrade performance on previously learned tasks and struggle with domain shifts. In contrast, our continual learning strategy effectively mitigates catastrophic forgetting, preserving model performance across varying domains. This work presents a practical solution for maintaining reliable WBC classification in real-world clinical settings, where data distributions frequently evolve