Removing 65 Years of Approximation in Rotating Ring Disk Electrode Theory with Physics-Informed Neural Networks.

The rotating Ring Disk Electrode (RRDE), since its introduction in 1959 by Frumkin and Nekrasov, has become indispensable with diverse applications in electrochemistry, catalysis, and material science. The collection efficiency (N) is an important parameter extracted from the ring and disk currents of the RRDE, providing valuable information about reaction mechanism, kinetics, and pathways. The theoretical prediction of N is a challenging task: requiring solution of the complete convective diffusion mass transport equation with complex velocity profiles. Previous efforts, including by Albery and Bruckenstein who developed the most widely used analytical equations, heavily relied on approximations by removing radial diffusion and using approximate velocity profiles. 65 years after the introduction of RRDE, we employ a physics-informed neural network to solve the complete convective diffusion mass transport equation, to reveal the formerly neglected edge effects and velocity corrections on N, and to provide a guideline where conventional approximation is applicable.

Comparative study of photocatalysis with bulk and nanosheet graphitic carbon nitrides enhanced with silver.

The main goal of this research is to investigate the effectiveness of graphitic carbon nitride (g-C3N4, g-CN) in both bulk and nanosheet forms, which have been surface-modified with silver nanoparticles (Ag NPs), as photocatalysts for the degradation of acid orange 7 (AO7), a model dye. The photodegradation of AO7 dye molecules in water was used to test the potential photocatalytic properties of these powder materials under two different lamps with wavelengths of 368 nm (UV light) and 420 nm (VIS light). To produce Ag NPs (Ag content 0.5, 1.5, and 3 wt%) on the g-CN materials, a new synthesis route based on a wet and low-temperature method was proposed, eliminating the need for reducing agents. The photodegradation activity of the samples increased with increasing silver content, with the best photocatalytic performances achieved for bulk g-CN samples and nanosheet silver-modified samples (with the highest content of 3 wt% Ag) under UV light, i.e., more than 75% and 78%, respectively. The VIS-induced photocatalytic activity of both examined series was higher than that of UV. The highest activities of 92% and 98% were achieved for the 1.5% Ag-modified g-CN bulk and nanosheet materials. This research presents an innovative, affordable, and environmentally friendly chemical approach to synthesizing photocatalysts that can be used for degrading organic pollutants in wastewater treatment.

Reproducible growth of Brachypodium in EcoFAB 2.0 reveals that nitrogen form and starvation modulate root exudation.

Understanding plant-microbe interactions requires examination of root exudation under nutrient stress using standardized and reproducible experimental systems. We grew Brachypodium distachyon hydroponically in fabricated ecosystem devices (EcoFAB 2.0) under three inorganic nitrogen forms (nitrate, ammonium, and ammonium nitrate), followed by nitrogen starvation. Analyses of exudates with liquid chromatography-tandem mass spectrometry, biomass, medium pH, and nitrogen uptake showed EcoFAB 2.0's low intratreatment data variability. Furthermore, the three inorganic nitrogen forms caused differential exudation, generalized by abundant amino acids-peptides and alkaloids. Comparatively, nitrogen deficiency decreased nitrogen-containing compounds but increased shikimates-phenylpropanoids. Subsequent bioassays with two shikimates-phenylpropanoids (shikimic and p-coumaric acids) on soil bacteria or Brachypodium seedlings revealed their distinct capacity to regulate both bacterial and plant growth. Our results suggest that (i) Brachypodium alters exudation in response to nitrogen status, which can affect rhizobacterial growth, and (ii) EcoFAB 2.0 is a valuable standardized plant research tool.

Cynipid wasps systematically reprogram host metabolism and restructure cell walls in developing galls.

Many insects have evolved the ability to manipulate plant growth to generate extraordinary structures called galls, in which insect larva can develop while being sheltered and feeding on the plant. In particular, cynipid (Hymenoptera: Cynipidae) wasps have evolved to form morphologically complex galls and generate an astonishing array of gall shapes, colors, and sizes. However, the biochemical basis underlying these remarkable cellular and developmental transformations remains poorly understood. A key determinant in plant cellular development is cell wall deposition that dictates the physical form and physiological function of newly developing cells, tissues, and organs. However, it is unclear to what degree cell walls are restructured to initiate and support the formation of new gall tissue. Here, we characterize the molecular alterations underlying gall development using a combination of metabolomic, histological, and biochemical techniques to elucidate how valley oak (Quercus lobata) leaf cells are reprogrammed to form galls. Strikingly, gall development involves an exceptionally coordinated spatial deposition of lignin and xylan to form de novo gall vasculature. Our results highlight how cynipid wasps can radically change the metabolite profile and restructure the cell wall to enable the formation of galls, providing insights into the mechanism of gall induction and the extent to which plants can be entirely reprogrammed to form unique structures and organs.

Discovering Electrochemistry with an Electrochemistry-Informed Neural Network (ECINN).

Machine learning is increasingly integrated into chemistry research by guiding experimental procedures, correlating structure and function, interpreting large experimental datasets, to distill scientific insights that might be challenging with traditional methods. Such applications, however, largely focus on gaining insights via big data and/or big computation, while neglecting the valuable chemical prior knowledge dwelling in chemists' minds. In this paper, we introduce an Electrochemistry-Informed Neural Network (ECINN) by explicitly embedding electrochemistry priors including the Butler-Volmer (BV), Nernst and diffusion equations on the backbone of neural networks for multi-task discovery of electrochemistry parameters. We applied the ECINN to voltammetry experiments of F e 2 + / F e 3 + ${{\rm F}{{\rm e}}^{2+}/{\rm F}{{\rm e}}^{3+}}$ and R u N H 3 6 2 + / R u N H 3 6 3 + ${{\rm R}{\rm u}{\left({\rm N}{{\rm H}}_{3}\right)}_{6}^{2+{\rm \ }}/{\rm R}{\rm u}{\left({\rm N}{{\rm H}}_{3}\right)}_{6}^{3+{\rm \ }}}$ redox couples to discover electrode kinetics and mass transport parameters. Notably, ECINN seamlessly integrated mass transport with BV to analyze the entire voltammogram to infer transfer coefficients directly, so offering a new approach to Tafel analysis by outdating various mass transport correction methods. In addition, ECINN can help discover the nature of electron transfer and is shown to refute incorrect physics if imposed. This work encourages chemists to embed their domain knowledge into machine learning models to start a new paradigm of chemistry-informed machine learning for better accountability, interpretability, and generalization.

Results of surgical therapy of functioning pituitary adenomas.

INTRODUCTION: Functioning pituitary adenomas lead to substantial morbidity and increased mortality associated with typical endocrine syndromes. Surgical therapy is an integral part of the management of these tumours. The aim of this study was to evaluate the results of surgical transnasal procedures in patients with functioning pituitary adenomas who underwent the surgery at the Department of Neurosurgery, University Hospital Olomouc. METHODS: Patients with functioning pituitary adenoma (ACTH, GH, PRL) were indicated for surgery. All patients underwent preoperative and postoperative endocrinological examination and laboratory tests to assess excessive or deficient hormonal production and imaging examination. RESULTS: The cohort consisted of 58 patients, 33 of whom were women and 25 men. The age range was 12-77 years (mean age 47.6 years). Microadenoma was diagnosed in 58.6% of patients and macroadenoma in 41.4% of patients. The most common hypersecretory syndrome was excessive production of growth hormone (56.9%), followed by excessive production of adrenocorticotropic hormone (24.1%) and prolactin (12.1%). In the group with excessive production of ACTH, complete remission was achieved after the first surgery in 78.6% of cases (72.8% for microadenomas (8) and 100% (3) cases in macroadenomas); in the group with excessive GH production in 51.4% (63.2% (7) in microadenomas and 46.2% (12) cases in macroadenomas). In the group with excessive production of PRL, it was 57.1% (100% (2) in microadenomas and 40% (2) cases in macroadenomas). CONCLUSION: Surgical therapy in the presented cohort led to the normalisation of hormonal excessive production in 58.6% of cases. A combination of drug therapy and radiotherapeutic methods was necessary in the remaining cases to achieve hormonal remission.

Rheological Characteristics of Fe-C-Cr(Ni) Alloys.

The principal objective of this project was to investigate the rheological properties of Fe-C-Cr and Fe-C-Ni-based low-alloy steels using an Anton Paar high-temperature rotational viscometer up to 1550 °C. The emphasis was placed on determining the liquidus temperatures and evaluating the flow and viscosity curves and the temperature dependence of dynamic viscosity. All were studied depending on the change in the content of chromium (0.010-4.863 wt%), nickel (0.001-4.495 wt%), and carbon (0.043-1.563 wt%). It was shown that the dynamic viscosity decreases with increasing nickel content and increases with increasing carbon and chromium content. The experimental data of the flow curves were fitted using the Herschel-Bulkley model with a good agreement between the measured and calculated values. Characterization of the internal structure was performed by SEM and EDX analyses, confirming non-significant changes in the microstructure of the original and remelted samples. The phase composition of the selected samples was also determined using JMatPro 12.0 simulation software (Sente Software Ltd., Guildford, UK).

Gibberellin and abscisic acid transporters facilitate endodermal suberin formation in Arabidopsis.

The plant hormone gibberellin (GA) regulates multiple developmental processes. It accumulates in the root elongating endodermis, but how it moves into this cell file and the significance of this accumulation are unclear. Here we identify three NITRATE TRANSPORTER1/PEPTIDE TRANSPORTER (NPF) transporters required for GA and abscisic acid (ABA) translocation. We demonstrate that NPF2.14 is a subcellular GA/ABA transporter, presumably the first to be identified in plants, facilitating GA and ABA accumulation in the root endodermis to regulate suberization. Further, NPF2.12 and NPF2.13, closely related proteins, are plasma membrane-localized GA and ABA importers that facilitate shoot-to-root GA12 translocation, regulating endodermal hormone accumulation. This work reveals that GA is required for root suberization and that GA and ABA can act non-antagonistically. We demonstrate how the clade of transporters mediates hormone flow with cell-file-specific vacuolar storage at the phloem unloading zone, and slow release of hormone to induce suberin formation in the maturation zone.

Electrochemical characterization of leached steel-making sludge.

In this work, the electrochemical properties of the leached sludge, magnetite and zinc ferrite were studied. Acetic acid was used as a leaching reagent because, in recent years, there has been a surge of interest in using zinc-containing materials as photocatalysts, with acetic acid finding application in their preparation. Various methodological approaches were used, but the best results were achieved with a combination of 1-3 h leaching in 0.01 M acetic acid with a solid/liquid ratio of 500. In this arrangement, zincite was almost completely removed from the sludge, while zinc ferrite and magnetite remained in the solid residue. Ex situ analyses of the main leaching products were performed by X-ray diffraction, infrared spectroscopy, and thermogravimetry. The electrochemical behaviour of solid residue and model systems, that are micromagnetite and zinc ferrite, was studied in alkaline media by means of modified carbon paste electrodes, cyclic voltammetry, and chronocoulometry, with a suitable potential window ranging from 0 to 1.5 V. In summary, a linear dependence of the anodic and cathodic peak height on the square root of the scan rate was found. The position of the anodic and cathodic peaks shifted slightly with scan rate, only at low rates, up to 25 mV/s, the individual peaks coincided. The electrochemical response suggested a quasireversible process.

Fertilizer Type Affects Stable Isotope Ratios of Nitrogen in Human Blood Plasma─Results from Two-Year Controlled Agricultural Field Trials and a Randomized Crossover Dietary Intervention Study.

The stable nitrogen isotope ratio δ15N is used as a marker of dietary protein sources in blood. Crop fertilization strategies affect δ15N in plant foods. In a double-blinded randomized cross-over dietary intervention trial with 33 participants, we quantified the effect of fertilizer type (conventional: synthetic fertilizer and organic: animal or green manure) on δ15N in blood plasma. At study baseline, plasma δ15N was +9.34 ± 0.29‰ (mean ± standard deviation). After 12 days intervention with a diet based on crops fertilized with animal manure, plasma δ15N was shifted by +0.27 ± 0.04‰ (mean ± standard error) compared to synthetic fertilization and by +0.22 ± 0.04‰ compared to fertilization with green manure (both p < 0.0001). Accordingly, differences in the δ15N values between fertilizers are propagated to the blood plasma of human consumers. The results indicate a need to consider agricultural practices when using δ15N as a dietary biomarker.

The Effect of Trace Oxygen Addition on the Interface Behavior of Low-Alloy Steel.

This work aims to assess the effect of an oxygen content graded in minimal quantities, on the order of hundreds of ppms, on the determination of surface tension of low-alloy FeCOCr and FeCONi steels in contact with a corundum substrate. Oxygen, as a surface-active element, was segregated at the surface where it interacted with the major components of the alloys, leading to a reduction in surface tension. The sessile drop method was used for wetting tests in the temperature range from steel liquidus temperatures to 1600 °C under nonoxidizing conditions. The effect of oxygen on surface tension and wetting angles was verified by statistical analysis using the Kruskal-Wallis test, which supported the results stating that the values of these quantities decreased with increasing oxygen content. Furthermore, liquidus temperatures, which are of practical importance, were determined by the optical and DTA methods and then compared with theoretically calculated temperature values. It turned out that the increased chromium content causes difficulties in determining surface tension up to 1550 °C due to the formation of a thin Cr2O3 layer. In addition, SEM and XRD analyses accompanied by calculations in the FactSage oxide database were performed to better understand the wetting mechanism.

Transnasal endoscopic surgery of sphenoid meningocele associated with pituitary adenoma. A case report.

BACKGROUND: Transsphenoid meningoencephalocele is a congenital anomaly formed by herniation of an ependyma delimited sac through a bony defect into the sphenoid sinus. The sac contains cerebrospinal fluid and neurovascular structures. The prevalence of transsphenoid meningoencephalocele in the adult population is rare. It usually manifests as nasal liquorrhoea. METHODS AND RESULTS: This case report presents an adult male who underwent surgery due to suspected pituitary macroadenoma. The surgery was performed endoscopically via the transnasal approach with a surprising finding of true transsphenoid meningoencephalocele. Ectopic solid tissue was found in the sphenoid sinus in which pituitary adenoma was histologically confirmed. CONCLUSION: This paper presents a previously unpublished combination of true transsphenoid meningoencephalocele and pituitary adenoma in an adult individual.

Sinonasal quality of life in patients after an endoscopic endonasal surgery of a sellar tumour.

Endoscopic endonasal approach uses the nasal cavity and paranasal sinuses to access the cranial base and may be a source of post-surgical morbidity in many patients with a sellar tumour. The objective of the presented study was to evaluate sinonasal quality of life and assess the effect of chosen reconstruction of the cranial base on the final condition. 65 patients, 33 male and 32 female who underwent an endoscopic endonasal surgery due to sellar expansion, were included into this prospective study. Sinonasal quality of life was evaluated using the Sinonasal Outcome Test-22 (SNOT-22) questionnaire before the surgery and six months after the surgery. Sinonasal quality of life was evaluated for the total cohort of patients and for patients after reconstruction (fascia lata, muscle) and without reconstruction. The minimum follow-up period was one year. There was no significant difference between the score (SNOT-22) before the surgery (average 14.4 points) and after the surgery (average 17.5 points), p = 0.067 in the whole cohort. Statistically significant differences were found in the following items-the need to blow nose, nasal congestion, loss of smell and taste, and thick discharge from the nose. The comparison of subgroups with and without the reconstruction yielded statistically significant differences in favour of patients with reconstruction in the following items-lack of high-quality sleep and feeling exhaustion. The endoscopic endonasal approach in patients with a sellar tumour is a gentle method with minimal effects on sinonasal quality of life over a period longer than six months. The most common complaints are the need to blow nose, nasal congestion, loss of smell and taste, and thick discharge from the nose. Cranial base reconstruction using the muscle and fascia lata seems to be a potential factor positively influencing sinonasal quality of life.

The use of an O-arm in endonasal endoscopic operations of the skull base.

BACKGROUND: Endoscopic endonasal transsphenoidal approaches are broadly used nowadays for a vast spectrum of pathologies sited in the anterior and middle cranial fossa. The usage of neuronavigation systems (neuronavigation) in these surgeries is crucial for improving orientations deeply inside the skull and increasing patient safety. METHODS: The aim of this study was to assess the use of optical neuronavigation, together with an intraoperative O-arm O2 imaging system, in a group of patients with hypophyseal adenoma that underwent a transnasal transsphenoidal surgery, and correlate the accuracy and its deviation during the navigational process against the use of conventional neuronavigation that uses preoperative MRI and CT scans. The overall group consisted of six patients, between 39 and 78 years old, with a diagnosis of hypophyseal adenoma. Patients were treated with an endoscopic transsphenoidal technique and all of them underwent preoperative MRI and CT scans of the brain. These images were used in the neuronavigation system StealthStation S7® during the surgery, where we defined two bony anatomical landmarks, such as a vomer or the origin of an intrasphenoidal septum, in each operated patient. The tip of the navigational instrument, under endoscopic control, pointed to these landmarks and the distance between the tip and the bony structure was measured on the neuronavigation system. Afterwards, intraoperative 3D x-ray imaging was performed via the mobile system O-arm O2® system with automatic transfer into the navigational system. Under endoscopic guidance, we localized the identical bony anatomical landmarks used in the previous measurement and re-measured the distance between the tip and bony landmark in images acquired by the O-arm. The results of both measurements were statistically compared. RESULTS: The mean error of accuracy during conventional neuronavigation with usage of preoperative CT and MRI scans was 2.65 mm. During the neuronavigation, with utilization of intraoperative 3D O-arm images, the mean error of accuracy 0 mm. These mean errors of accuracy (both measurement methods were compared by nonparametric Wilcoxon test) had a statistically significant difference (p = 0.043). CONCLUSIONS: Based on this preliminary clinical study, we conclude that the O-arm is capable of providing intraoperative x-ray 3D images in sufficient spatial resolution in a clinically feasible acquisition. The mean error of accuracy during intraoperative navigation, based on 3D O-arm scans at the skull base, is significantly lower compared to the usage of navigation using conventional presurgical CT and MRI images. This suggests the suitability of this method for utilization during endoscopic endonasal skull base approaches.

The oxygen isotopic signature of soil- and plant-derived sulphate is controlled by fertilizer type and water source.

The oxygen isotope signature of sulphate (δ18 Osulphate ) is increasingly used to study nutritional fluxes and sulphur transformation processes in a variety of natural environments. However, mechanisms controlling the δ18 Osulphate signature in soil-plant systems are largely unknown. The objective of this study was to determine key factors, which affect δ18 Osulphate values in soil and plants. The impact of an 18 O-water isotopic gradient and different types of fertilizers was investigated in a soil incubation study and a radish (Raphanus sativus L.) greenhouse growth experiment. Water provided 31-64% of oxygen atoms in soil sulphate formed via mineralization of organic residues (green and chicken manures) while 49% of oxygen atoms were derived from water during oxidation of elemental sulphur. In contrast, δ18 Osulphate values of synthetic fertilizer were not affected by soil water. Correlations between soil and plant δ18 Osulphate values were controlled by water δ18 O values and fertilizer treatments. Additionally, plant δ34 S data showed that the sulphate isotopic composition of plants is a function of S assimilation. This study documents the potential of using compound-specific isotope ratio analysis for investigating and tracing fertilization strategies in agricultural and environmental studies.

Authenticity testing of organically grown vegetables by stable isotope ratio analysis of oxygen in plant-derived sulphate.

Analytical methods for authenticity testing of organically grown vegetables are urgently needed. Here we present a novel method for organic authentication based on stable isotope ratio analysis of oxygen in plant-derived sulphate. We combined this method with stable isotope ratio analysis of bulk plant tissue and plant-derived nitrate to discriminate organic and conventional potato, carrot, and cabbage from rigidly controlled long-term field trials and from a case study using retail potatoes. It was shown that oxygen isotope ratios of sulphate from organic vegetables were significantly lower compared to their conventional counterparts and the values were directly linked to the fertilisation strategy. The classification power of sulphate isotope analysis was superior compared to known bulk tissue isotope markers and nitrate isotope values. In conclusion, oxygen isotope analysis of plant-derived sulphate represents a promising new method for authentication of organic vegetables.

Mastoid foramen, mastoid emissary vein and clinical implications in neurosurgery.

BACKGROUND: Mastoid emissary vein is especially important from the neurosurgical point of view, because it is located in variable number in the area of the occipitomastoid suture and it can become a source of significant bleeding in surgical approaches through the mastoid process, especially in retrosigmoid craniotomy, which is used for approaches to pathologies localized in the cerebellopontine angle. Ideal imaging method for diagnosis of these neglected structures when planning a surgical approach is high-resolution computed tomography. The aim of this work was to provide detailed information about this issue. METHODS: We studied a group of 295 skulls obtained from collections of five anatomy departments and the National Museum. Both quantitative and qualitative parameters of the mastoid foramen were evaluated depending on side of appearance and gender. Individual distances of the mastoid foramen from clearly defined surface landmarks (asterion, apex of mastoid process, foramen magnum) and other anatomical structures closely related to this issue (width of groove for sigmoid sinus, diameters of internal and external openings of mastoid foramen) were statistically processed. RESULTS: The most frequently represented type of the mastoid foramen is type II by Louis (41.2%). The differences between right and left sides were not statistically significant. In men there was a higher number of openings on the right side and in qualitative parameters the type III and IV predominated, whereas in women the types I and II were more frequent. In men, greater distances from the mastoid foramen were observed when evaluating qualitative parameters for defined surface landmarks. Mean size of the external opening diameter was 1.3 mm; however, several openings measured up to 7 mm. CONCLUSIONS: Despite excellent knowledge of anatomy, however, good pre-operative examination using imaging methods and mastering of microsurgical techniques create the base for successful treatment of pathological structures in these anatomically complex areas.

An NPF transporter exports a central monoterpene indole alkaloid intermediate from the vacuole.

Plants sequester intermediates of metabolic pathways into different cellular compartments, but the mechanisms by which these molecules are transported remain poorly understood. Monoterpene indole alkaloids, a class of specialized metabolites that includes the anticancer agent vincristine, antimalarial quinine and neurotoxin strychnine, are synthesized in several different cellular locations. However, the transporters that control the movement of these biosynthetic intermediates within cellular compartments have not been discovered. Here we present the discovery of a tonoplast localized nitrate/peptide family (NPF) transporter from Catharanthus roseus, CrNPF2.9, that exports strictosidine, the central intermediate of this pathway, into the cytosol from the vacuole. This discovery highlights the role that intracellular localization plays in specialized metabolism, and sets the stage for understanding and controlling the central branch point of this pharmacologically important group of compounds.

Resection versus biopsy of glioblastomas in eloquent brain areas.

AIM: The aim of this study was to compare resection and biopsy of glioblastoma (GBM) in eloquent brain areas (EBA). METHODS: This was a prospective evaluation of 38 patients with GBM in EBA. 22 were treated by surgical resection and 16 by biopsy. Preoperative KPS, neurological status and size of lesion on MRI were assessed. One week and three months postoperatively KPS, neurological status and Performance Status (PS) WHO were evaluated. Extent of resection (EOR) and overall survival (OS) were described. Overall mean age of the patients was 64.3 years, the mean lesion size in the resection group was 47.7 mm and in the biopsy group 51.0 mm. RESULTS: Worsening or development of permanent neurological deficits 3 months after surgery were significantly lower in the resection group (23%), than the biopsy group (94%). In the resection group the median pre and postoperative KPS three months after surgery was 80.0. In the biopsy group the median pre and postoperative KPS was 68.1 one week after the procedure. In the resection group, 3 months after surgery, the median PS was 1, in the biopsy group one week after surgery the median PS was 2. The difference was statistically insignificant. The mean OS after resection was 12.2 months, and after biopsy 3.5 months. The difference was highly statistically significant. The mean EOR was 90%. CONCLUSION: This is the first prospective study, to our knowledge, that compares the results of resection and biopsy of primary GBM in EBA. For patients in good clinical condition with tumors in or near EBA, recommended is as radical resection of GBM as possible.