The electrocatalytic activity for the hydrogen evolution reaction on alloys is determined by element-specific adsorption sites rather than d-band properties.

Trends of the electrocatalytic activities for the hydrogen evolution reaction (HER) across transition metals are typically explained by d-band properties such as center or upper edge positions in relation to Fermi levels. Here, the universality of this relation is questioned for alloys, exemplified for the AuPt system which is examined with electrocatalytic measurements and density functional theory (DFT) calculations. At small overpotentials, linear combinations of the pure-metals' Tafel kinetics normalized to the alloy compositions are found to precisely resemble the measured HER activities. DFT calculations show almost neighbor-independent adsorption energies on Au and Pt surface-sites, respectively, as the adsorbed hydrogen influences the electron density mostly locally at the adsorption site itself. In contrast, the density of states of the d-band describe the delocalized conduction electrons in the alloys, which are unable to portray the local electronic environments at adsorption sites and related bonding strengths. The adsorption energies at element-specific surface sites are related to overpotential-dependent reaction mechanisms in a multidimensional reinterpretation of the volcano plot for alloys, which bridges the found inconsistencies between activity and bonding strength descriptors of the common electrocatalytic theory for alloys.

A radiochemical lab-on-a-chip paired with computer vision to unlock the crystallization kinetics of (Ba,Ra)SO4.

(Ra,Ba)SO4 solid solutions are commonly encountered as problematic scales in subsurface energy-related applications, e.g., geothermal systems, hydraulic fracturing, conventional oil and gas, etc. Despite its relevance, its crystallization kinetics were never determined because of radium (226), high radioactivity (3.7 × 1010 Bq g-1), and utilization in contemporary research, therefore constrained to trace amounts (< 10-8 M) with the composition of BaxRa1-xSO4 commonly restricted to x > 0.99. What if lab-on-a-chip technology could create new opportunities, enabling the study of highly radioactive radium beyond traces to access new information? In this work, we developed a lab-on-a-chip experiment paired with computer vision to evaluate the crystal growth rate of (Ba,Ra)SO4 solid solutions. The computer vision algorithm enhances experimental throughput, yielding robust statistical insights and further advancing the efficiency of such experiments. The 3D analysis results of the precipitated crystals using confocal Raman spectroscopy suggested that {210} faces grew twice as fast as {001} faces, mirroring a common observation reported for pure barite. The crystal growth rate of (Ba0.5Ra0.5)SO4 follows a second-order reaction with a kinetic constant equal to (1.23 ± 0.09) × 10-10 mol m-2 s-1.

The Influence of Increased Pedicle Screw Diameter and Thicker Rods on Surgical Results in Adolescents Undergoing Posterior Spinal Fusion for Idiopathic Scoliosis.

Background: Modern surgical techniques allow for the correction of spinal deformity, stopping its progression and improving pain relief and social and physical functioning. These instruments have different implant designs, screws, and rod diameters and can be composed of different metal alloys with different hardnesses, which can have a significant impact on the effect of correcting spinal deformities. We designed a retrospective cohort study based on the same surgical technique and spine system using different implant sizes, and compared the results across them. Methods: This is a retrospective review of adolescent idiopathic scoliosis (AIS) patients who underwent posterior spinal fusion (PSF) between 2016 and 2022 with a minimum two-year follow-up (FU) using two spinal implant systems: 5.5 and 6.0 mm diameter screws with double 5.5 mm titanium rods (Group 1 (G1)), and 6.0 and 6.5 mm diameter pedicle screws with double 6.0 mm cobalt-chromium rods (Group 2 (G2)). The evaluated data were as follows: preoperative personal data, radiographic outcomes, complications, and health-related quality of life questionnaire (HRQoL). The parameters were reviewed preoperatively, after the final fusion, and during the FU. Results: The mean age of all 260 patients at surgery was 14.8 years. The average BMI was also similar in both groups and was noted as 21. The mean levels of fusion and screw density were similar in both groups. The mean preoperative major curves (MCs) were 57.6° and 62.5° in G1 and G2, respectively. The mean flexibility of the curves was noted as 35% in G1 and 33% in G2. After definitive surgery, the mean percentage correction of the MC was better in G2 vs. G1, with 74.5% vs. 69.8%, respectively (p < 0.001). At the final FU, the average loss of correction was 5.9° for G1 and 3.2° for G2 (p < 0.001). The mean preoperative (TK) thoracic kyphosis (T2-T5) was 12.2° in G1 and 10.8° in G2. It was corrected to 15.2° in G1 and to 13° in G2. At the FFU, we noted a significant difference in the TK (T2-T5) between the groups, with 16.7° vs. 9.6° for G1 vs. G2, respectively (p < 0.001). Statistical significance was observed between the preoperative sagittal balance and the final follow-up for both groups (p < 0.001). Conclusions: AIS patients surgically treated with screws with a larger diameter and thicker and stiffer rods showed greater correction and postoperative thoracic kyphosis without implant failure. The complication rates, implant density, and clinical outcomes remained similar. The radiographic benefits reported in this cohort study suggest that large-sized screws and stiffer rods for the correction of pediatric spinal deformities are safe and very effective.

Entropy-Mediated Stable Structural Evolution of Prussian White Cathodes for Long-Life Na-Ion Batteries.

The high-entropy approach is applied to monoclinic Prussian White (PW) Na-ion cathodes to address the issue of unfavorable multilevel phase transitions upon electrochemical cycling, leading to poor stability and capacity decay. A series of Mn-based samples with up to six metal species sharing the N-coordinated positions was synthesized. The material of composition Na1.65 Mn0.4 Fe0.12 Ni0.12 Cu0.12 Co0.12 Cd0.12 [Fe(CN)6 ]0.92 □0.08 ⋅ 1.09H2 O was found to exhibit superior cyclability over medium/low-entropy and conventional single-metal PWs. We also report, to our knowledge for the first time, that a high-symmetry crystal structure may be advantageous for high-entropy PWs during battery operation. Computational comparisons of the formation enthalpy demonstrate that the compositionally less complex materials are prone to phase transitions, which negatively affect cycling performance. Based on data from complementary characterization techniques, an intrinsic mechanism for the stability improvement of the disordered PW structure upon Na+ insertion/extraction is proposed, namely the dual effect of suppression of phase transitions and mitigation of gas evolution.

Nebulised delivery of RNA formulations to the lungs: From aerosol to cytosol.

In the past decade RNA-based therapies such as small interfering RNA (siRNA) and messenger RNA (mRNA) have emerged as new and ground-breaking therapeutic agents for the treatment and prevention of many conditions from viral infection to cancer. Most clinically approved RNA therapies are parenterally administered which impacts patient compliance and adds to healthcare costs. Pulmonary administration via inhalation is a non-invasive means to deliver RNA and offers an attractive alternative to injection. Nebulisation is a particularly appealing method due to the capacity to deliver large RNA doses during tidal breathing. In this review, we discuss the unique physiological barriers presented by the lung to efficient nebulised RNA delivery and approaches adopted to circumvent this problem. Additionally, the different types of nebulisers are evaluated from the perspective of their suitability for RNA delivery. Furthermore, we discuss recent preclinical studies involving nebulisation of RNA and analysis in in vitro and in vivo settings. Several studies have also demonstrated the importance of an effective delivery vector in RNA nebulisation therefore we assess the variety of lipid, polymeric and hybrid-based delivery systems utilised to date. We also consider the outlook for nebulised RNA medicinal products and the hurdles which must be overcome for successful clinical translation. In summary, nebulised RNA delivery has demonstrated promising potential for the treatment of several lung-related conditions such as asthma, COPD and cystic fibrosis, to which the mode of delivery is of crucial importance for clinical success.

The Child's Age and the Size of the Curvature Do Not Affect the Accuracy of Screw Placement with the Free-Hand Technique in Spinal Deformities in Children and Adolescents.

BACKGROUND: The current method of treatment of spinal deformities would be almost impossible without pedicle screws (PS) placement. There are only a few studies evaluating the safety of PS placement and possible complications in children during growth. The present study was carried out to evaluate the safety and accuracy of PS placement in children with spinal deformities at any age using postoperative computed tomography (CT) scans. METHODS: 318 patients (34 males and 284 females) who underwent 6358 PS fixations for pediatric spinal deformities were enrolled in this multi-center study. The patients were divided into three age groups: less than 10 years old, 11-13 years old, and 14-18 years old. These patients underwent postoperative CT scans and were analyzed for pedicle screw malposition (anterior, superior, inferior, medial, and lateral breaches). RESULTS: The breach rate was 5.92% for all pedicles. There were 1.47% lateral and 3.12% medial breaches for all pedicles with tapping canals, and 2.66% lateral and 3.84% medial breaches for all pedicles without a tapping canal for the screw. Of the 6358 screws placed in the thoracic, lumbar, and sacral spine, 98% of the screws were accurately placed (grade 0, 1, and juxta pedicular). A total of 56 screws (0.88%) breached more than 4 mm (grade 3), and 17 (0.26%) screws were replaced. No new and permanent neurological, vascular, or visceral complications were encountered. CONCLUSIONS: The free-hand technique for pedicle screw placement in the acceptable and safety zone in pedicles and vertebral bodies was 98%. No complications associated with screw insertion in growth were noted. The free-hand technique for pedicle screw placement can be safely used in patients at any age. The screw accuracy does not depend on the child's age nor the size of the deformity curve. Segmental instrumentation with posterior fixation in children with spinal deformities can be performed with a very low complication rate. Navigation of the robot is only an auxiliary tool in the hands of the surgeons, and the result of the work ultimately depends on the surgeons.

Artificial Intelligence in the Intensive Care Unit: Present and Future in the COVID-19 Era.

The development of artificial intelligence (AI) allows for the construction of technologies capable of implementing functions that represent the human mind, senses, and problem-solving skills, leading to automation, rapid data analysis, and acceleration of tasks. These solutions has been initially implemented in medical fields relying on image analysis; however, technological development and interdisciplinary collaboration allows for the introduction of AI-based enhancements to further medical specialties. During the COVID-19 pandemic, novel technologies established on big data analysis experienced a rapid expansion. Yet, despite the possibilities of advancements with these AI technologies, there are number of shortcomings that need to be resolved to assert the highest and the safest level of performance, especially in the setting of the intensive care unit (ICU). Within the ICU, numerous factors and data affect clinical decision making and work management that could be managed by AI-based technologies. Early detection of a patient's deterioration, identification of unknown prognostic parameters, or even improvement of work organization are a few of many areas where patients and medical personnel can benefit from solutions developed with AI.

Low-spin state of Fe in Fe-doped NiOOH electrocatalysts.

Doping with Fe boosts the electrocatalytic performance of NiOOH for the oxygen evolution reaction (OER). To understand this effect, we have employed state-of-the-art electronic structure calculations and thermodynamic modeling. Our study reveals that at low concentrations Fe exists in a low-spin state. Only this spin state explains the large solubility limit of Fe and similarity of Fe-O and Ni-O bond lengths measured in the Fe-doped NiOOH phase. The low-spin state renders the surface Fe sites highly active for the OER. The low-to-high spin transition at the Fe concentration of ~ 25% is consistent with the experimentally determined solubility limit of Fe in NiOOH. The thermodynamic overpotentials computed for doped and pure materials, η = 0.42 V and 0.77 V, agree well with the measured values. Our results indicate a key role of the low-spin state of Fe for the OER activity of Fe-doped NiOOH electrocatalysts.

Proximal ulna morphology in various pediatric population age groups: proximal ulna dorsal angulation (PUDA) and olecranon tip-to-apex (TTA) distance.

PURPOSE: To measure proximal ulna dorsal angulation (PUDA) and olecranon tip-to-apex distance (TTA) in pediatric population to aid surgeons with data for proximal ulna fractures fixation. METHODS: Retrospective review of the hospital radiographic database. All elbow radiographs were identified and after implementing exclusion criteria, included were 95 patients aged 0-10; 53 patients aged 11-14; and 53 patients aged 15-18. PUDA was defined as the angle between lines placed on the "flat spot" of the olecranon and the dorsal edge of the ulnar shaft and TTA as the distance between the tip of the olecranon to the apex of angulation. Two evaluators performed measurements independently. RESULTS: In age group 0-10, mean PUDA was 7.53°, range 3.8-13.7, 95% CI 7.16-7.91, while mean TTA was 22.04 mm, range 8.8-50.5, 95% CI 19.92-24.17. In age group 11-14, mean PUDA was 4.99°, range 2.5-9.3, 95% CI (4.61-5.37), while mean TTA was 37.41 mm, range 16.5-66.6, 95% CI (34.91-39.90). In age group 15-18, mean PUDA was 5.18°, range 2.9-8.1, 95% CI (4.75-5.61), while mean TTA was 43.79 mm, range 24.5-79.4, 95% CI (41.38-46.19). PUDA was negatively correlated with age (r = - 0.56, p < 0.001), while TTA was positively correlated with age (r = 0.77, p < 0.001). Reliability levels of 0.81-1 or 0.61-0.80 were achieved for most of intra- and inter-rater reliabilities besides two levels of 0.41-60 and one of 0.21-0.40. CONCLUSION: The main study finding is that in most cases mean age-group values may serve as a template for proximal ulna fixation. There are some cases in which X-ray of contralateral elbow may provide surgeon with a better template. LEVEL OF EVIDENCE: II.

Profiling Docetaxel in Plasma and Urine Samples from a Pediatric Cancer Patient Using Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction Combined with LC-MS/MS.

In recent years, therapeutic drug monitoring (TDM) has been applied in docetaxel (DOC)-based anticancer therapy to precisely control various pharmacokinetic parameters, including the concentration of DOC in biofluids (e.g., plasma or urine), its clearance, and its area under the curve (AUC). The ability to determine these values and to monitor DOC levels in biological samples depends on the availability of precise and accurate analytical methods that both enable fast and sensitive analysis and can be implemented in routine clinical practice. This paper presents a new method for isolating DOC from plasma and urine samples based on the coupling of microextraction and advanced liquid chromatography with tandem mass spectrometry (LC-MS/MS). In the proposed method, biological samples are prepared via ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) using ethanol (EtOH) and chloroform (Chl) as the desorption and extraction solvents, respectively. The proposed protocol was fully validated according to the Food and Drug Administration (FDA) and the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) requirements. The developed method was then applied to monitor the DOC profile in plasma and urine samples collected from a pediatric patient suffering from cardiac angiosarcoma (AS) with metastasis to lungs and mediastinal lymph nodes, who was receiving treatment with DOC at a dose of 30 mg/m2 body surface area. Due to the rarity of this disease, TDM was carried out to determine the exact levels of DOC at particular time points to ascertain which levels were conducive to maximizing the treatment's effectiveness while minimizing the drug's toxicity. To this end, the concentration-time profiles of DOC in the plasma and urine samples were determined, and the levels of DOC at specific time intervals up to 3 days after administration were measured. The results showed that DOC was present at higher concentrations in the plasma than in the urine samples, which is due to the fact that this drug is primarily metabolized in the liver and then eliminated with the bile. The obtained data provided information about the pharmacokinetic profile of DOC in pediatric patients with cardiac AS, which enabled the dose to be adjusted to achieve the optimal therapeutic regimen. The findings of this work demonstrate that the optimized method can be applied for the routine monitoring of DOC levels in plasma and urine samples as a part of pharmacotherapy in oncological patients.

Monitoring of sirolimus in the whole blood samples from pediatric patients with lymphatic anomalies.

In recent years, off-label use of sirolimus (SIR) has been gaining attention in the clinical practice. However, since it is critical to achieve and maintain therapeutic blood levels of SIR during treatment, the regular monitoring of this drug in individual patients must be implemented, especially in off-label indications of this drug. In this article, a fast, simple, and reliable analytical method for determining SIR levels in whole blood samples is proposed. Sample preparation based on dispersive liquid-liquid microextraction (DLLME) followed by liquid chromatography-mass spectrometry (LC-MS/MS) was fully optimized toward the analysis of SIR and proposed as a fast, simple, and reliable analytical method for determining the pharmacokinetic profile of SIR in whole-blood samples. In addition, the practical applicability of the proposed DLLME-LC-MS/MS method was evaluated by analyzing the pharmacokinetic profile of SIR in whole blood samples obtained from two pediatric patients suffering from lymphatic anomalies, receiving this drug as off-label clinical indication. The proposed methodology can be successfully applied in routine clinical practice for the fast and precise assessment of SIR levels in biological samples, thus allowing SIR dosages to be adjusted in real time during pharmacotherapy. Moreover, the measured SIR levels in the patients indicate the need for monitoring between doses to ensure the optimal pharmacotherapy of patients.

Design of lipid-based nanoparticles for delivery of therapeutic nucleic acids.

The successful development of nonviral delivery systems for nucleic acids has been reported extensively over the past number of years. Among them, lipid-based nanoparticles (LNPs) represent the most advanced platform. This review provides an overview of the state-of-the-art in LNP technology, focusing on the delivery of a range of nucleic acids. Recent advances in the development of an efficient and safe lipid-based system are critically analyzed with a particular emphasis on the rationale behind the design of LNPs and on attempts to elucidate the resulting molecular assembly and structure, their interactions with cellular proteins and biodistribution. In addition, manufacturing methods including microfluidics and their potential to influence stability and scale-up are summarized.

BMPR1A promotes ID2-ZEB1 interaction to suppress excessive endothelial to mesenchymal transition.

AIMS: Components of bone morphogenetic protein (BMP) signalling have been implicated in both pathogenesis of pulmonary arterial hypertension (PAH) and endothelial-mesenchymal transition (EndoMT). In particular, the importance of BMP type 2 receptor in these processes has been extensively analysed. However, the contribution of BMP type 1 receptors (BMPR1s) to the onset of PAH and EndoMT remains poorly understood. BMPR1A, one of BMPR1s, was recently implicated in the pathogenesis of PAH, and was found to be down-regulated in the lungs of PAH patients, neither the downstream mechanism nor its contribution to EndoMT has been described. Therefore, we aim to delineate the role of endothelial BMPR1A in modulating EndoMT and pathogenesis of PAH. METHODS AND RESULTS: We find that BMPR1A knockdown in endothelial cells (ECs) induces hallmarks of EndoMT, and deletion of endothelial Bmpr1a in adult mice (Bmpr1aiECKO) leads to development of PAH-like symptoms due to excessive EndoMT. By lineage tracing, we show that endothelial-derived smooth muscle cells are increased in endothelial Bmpr1a-deleted mice. Mechanistically, we identify ZEB1 as a primary target for BMPR1A in this setting; upon BMPR1A activation, ID2 physically interacts and sequesters ZEB1 to attenuate transcription of Tgfbr2, which in turn lowers the responses of ECs towards transforming growth factor beta (TGFß) stimulation and prevents excessive EndoMT. In Bmpr1aiECKO mice, administering endothelial targeting lipid nanoparticles containing siRNA against Tgfbr2 effectively ameliorate PAH, reiterating the importance of BMPR1A-ID2/ZEB1-TGFBR2 axis in modulating progression of EndoMT and pathogenesis of PAH. CONCLUSIONS: We demonstrate that BMPR1A is key to maintain endothelial identity and to prevent excessive EndoMT. We identify BMPR1A-induced interaction between ID2 and ZEB1 is the key regulatory step for onset of EndoMT and pathogenesis of PAH. Our findings indicate that BMPR1A-ID2/ZEB1-TGFBR2 signalling axis could serve as a potential novel therapeutic target for PAH and other EndoMT-related vascular disorders.

Understanding the role of flux, pressure and temperature on polymorphism in ThB2O5.

A novel polymorph of ThB2O5, denoted as ß-ThB2O5, was synthesised under high-temperature high-pressure (HT/HP) conditions. Via single crystal X-ray diffraction measurements, ß-ThB2O5 was found to form a three-dimensional (3D) framework structure where thorium atoms are ten-fold oxygen coordinated forming tetra-capped trigonal prisms. The only other known polymorph of ThB2O5, denoted α, synthesised herein using a known borax, B2O3-Na2B4O7, high temperature solid method, was found to transform to the ß polymorph when exposed to conditions of 4 GPa and ∼900 °C. Compared to the α polymorph, ß-ThB2O5 has smaller molar volume by approximately 12%. Exposing a mixture of the α and ß polymorphs to HT/HP conditions ex situ further demonstrated the preferred higher-pressure phase being ß, with no α phase material being observed via Rietveld refinements against laboratory X-ray powder diffraction (PXRD) measurements. In situ heating PXRD measurements on α-ThB2O5 from RT to 1030 °C indicated that α-ThB2O5 transforms to the ß variant at approximately 900 °C via a 1st order mechanism. ß-ThB2O5 was found to exist only over a narrow temperature range, decomposing above 1050 °C. Ab initio calculations using density functional theory (DFT) with the Hubbard U parameter indicated, consistent with experimental observations, that ß is both the preferred phase at higher temperatures and high pressures. Interestingly, it was found by switching from B2O3-Na2B4O7 to H3BO3-Li2CO3 flux using consistent high temperature solid state conditions for the synthesis of the α variant, ß-ThB2O5 could be generated. Comparison of their single crystal measurements showed this was identical to that obtained from HT/HP conditions.

Nanoemulsion supported microemulsion electrokinetic chromatography coupled with selected preconcentration techniques as an approach for analysis of highly hydrophobic compounds.

In this paper, an oil-in-water (O/W) nanoemulsion (NE) prepared by water cold dilution of an O/W microemulsion (ME) was introduced as a sample matrix in microemulsion electrokinetic capillary chromatography (MEEKC) for the highly hydrophobic compounds analysis. Several model compounds with log PO/W values in the 4.1-10.9 range, from different chemical groups, including retinol, α-tocopherol, cholecalciferol, phylloquinone, menaquinone-7, dichlorodiphenyltrichloroethane, ivermectin have been tested. As a proof of the concept of NE formation, a dynamic light scattering technique was employed to determine the size distribution profile of NE particles. Moreover, due to relatively low conductivity of the NE matrix (50-100 times lower in comparison to the separation buffer) and a negative electric charge provided to hydrophobic compounds through NE dispersed phase, NE matrices have been combined with preconcentration techniques based on electrokinetic dosing, namely field amplified sample injection (FASI) and pressure assisted electrokinetic injection (PAEKI). The detection limits for vitamin K1 and K2-MK7 in the NE matrix in combination with FASI (NE-MEEKC-FASI) as well as PAEKI (NE-MEEKC-PAEKI) were up to 42.9 and 12.1 ng mL-1, respectively. In comparison to standard hydrodynamic injection for microemulsion sample matrix NE-MEEKC-PAEKI grant 45-fold improvement in signal sensitivity. The study presents an innovative approach, as it enables the use of preconcentration techniques for highly hydrophobic compounds (log PO/W > 4), which was not previously possible for implementation in the electromigration techniques. Likewise, the use of organic solvents has been reduced by using ME as a solvent for stock solutions and diluting with water prior to the analysis. The application to real samples was investigated using a dietary supplement containing vitamin K2-MK7 obtained from the fermentation product of soybeans.

Self-Medication with Drotaverine among Patients with Common Abdominal Symptoms and Treatment Efficacy from the Perspectives of Patients and General Practitioners-An Observational, Retrospective, Cross-Sectional Study Using Real-World Data.

In Poland, drotaverine is the most frequently purchased antispasmodic, yet there is a paucity of real-world data on its use. We evaluated the profiles of patients who used drotaverine, and we investigated prescription patterns among general practitioners (GPs). In this cross-sectional, questionnaire-based study, we asked patients who purchased drotaverine about their reasons for using it, its perceived efficacy, satisfaction with treatment, and physician consultation. We also asked GPs about the status of drotaverine in their practice. Among 650 recruited patients, 74% used drotaverine for pain, 67% for cramps, and 19% for abdominal discomfort. Approximately 83% of patients purchased drotaverine without a physician's advice. Patients who used it after a physician's advice were more frequently female, older, and less educated. For all symptoms, mean severity scores decreased by ~5 points (0-10 scale) after the first dose. Ninety-eight percent of patients were satisfied with drotaverine. Among 210 GPs, the percentages prescribing drotaverine were: 42% for irritable bowel syndrome, 89% for cholelithiasis, 60% as supportive therapy for urinary infections, 89% for nephrolithiasis, and 75% for menstruation pain. The GPs perceived drotaverine as more useful, effective, and tolerable than other drugs for abdominal pain or cramps. Drotaverine significantly reduced the severity of all symptoms for which it was taken, and it was perceived as effective and tolerable.

Monazite-Type SmPO4 as Potential Nuclear Waste Form: Insights into Radiation Effects from Ion-Beam Irradiation and Atomistic Simulations.

Single-phase monazite-type ceramics are considered as potential host matrices for the conditioning of separated plutonium and minor actinides. Sm-orthophosphates were synthesised and their behaviour under irradiation was investigated with respect to their long-term performance in the repository environment. Sintered SmPO4 pellets and thin lamellae were irradiated with 1, 3.5, and 7 MeV Au ions, up to fluences of 5.1 × 1014 ions cm-2 to simulate ballistic effects of recoiling nuclei resulting from α-decay of incorporated actinides. Threshold displacement energies for monazite-type SmPO4 subsequently used in SRIM/TRIM simulations were derived from atomistic simulations. Raman spectra obtained from irradiated lamellae revealed vast amorphisation at the highest fluence used, although local annealing effects were observed. The broadened, but still discernible, band of the symmetrical stretching vibration in SmPO4 and the negligible increase in P-O bond lengths suggest that amorphisation of monazite is mainly due to a breaking of Ln-O bonds. PO4 groups show structural disorder in the local environment but seem to behave as tight units. Annealing effects observed during the irradiation experiment and the distinctively lower dose rates incurred in actinide bearing waste forms and potential α-radiation-induced annealing effects indicate that SmPO4-based waste forms have a high potential for withstanding amorphisation.

Gamma radiolytic stability of the novel modified diglycolamide 2,2'-oxybis(N,N-didecylpropanamide) (mTDDGA) for grouped actinide extraction.

Reprocessing of spent nuclear fuel aims at improving resource efficiency and reducing its radiotoxicity and heat production in the long term. The necessary separation of certain metal ions from the spent fuel solutions can be achieved using different solvent extraction processes. For the scenario of the EURO-GANEX process, the use of the new, modified diglycolamide 2,2'-oxybis(N,N-didecylpropanamide) (mTDDGA) was recently proposed to simplify the current solvent composition and reduce extraction of fission products. Before further developing the process based on this new ligand, its stability under ionizing radiation conditions needs to be studied. For this reason, gamma irradiation experiments were conducted followed by analyses with high performance liquid chromatography coupled to a mass spectrometer (HPLC-MS). The determined degradation rate of mTDDGA was found to be lower than that of the reference molecule N,N,N',N'-tetra-n-octyl-diglycolamide (TODGA). Many identified degradation compounds of both molecules are analogues showing the same bond breaking, although also unreported de-methylation, double/triple de-alkylation and n-dodecane addition products were observed.

Dispersion Interactions between Molecules in and out of Equilibrium Geometry: Visualization and Analysis.

The London dispersion interactions between systems undergoing bond breaking, twisting, or compression are not well studied due to the scarcity and the high computational cost of methods being able to describe both the dynamic correlation and the multireference character of the system. Recently developed methods based on the Generalized Valence Bond wave function, such as EERPA-GVB and SAPT(GVB) (SAPT = symmetry-adapted perturbation theory), allow one to accurately compute and analyze noncovalent interactions between multireference systems. Here, we augment this analysis by introducing a local indicator for dispersion interactions inspired by Mata and Wuttke's Dispersion Interaction Density [ J. Comput. Chem. 2017, 38, 15-23] applied on top of an EERPA-GVB computation. Using a few model systems, we show what insights into the nature and evolution of the dispersion interaction during bond breaking and twisting such an approach is able to offer. The new indicator can be used at a minimal cost additional to an EERPA-GVB computation and can be complemented by an energy decomposition employing the SAPT(GVB) method. We explain the physics behind the initial increase, followed by a decrease in the interaction of linear molecules upon bond stretching. Namely, the elongation of covalent bonds leads to the enhancement of attractive dispersion interactions. For even larger bond lengths, this effect is canceled by the increase of the repulsive exchange forces resulting in a suppression of the interaction and finally leading to repulsion between monomers.

Simultaneous determination of mitotane, its metabolite, and five steroid hormones in urine samples by capillary electrophoresis using ß-CD2 SDS1 complexes as hydrophobic compounds solubilizers.

Mitotane is a cytotoxic drug used in the treatment of inoperable adrenocortical carcinoma, it inhibits steroidogenesis as well, and therefore monitoring the level of steroid hormones in patients treated with mitotane is a crucial point of therapy. Hence, we have developed a simple, fast, and efficient electrophoretic method combined with reverse polarity sweeping as online preconcentration technique and dispersive liquid-liquid microextraction for the simultaneous determination of mitotane, its main metabolite DDA, and five steroid hormones (progesterone, testosterone, epitestosterone, cortisol, and corticosterone) in urine samples. In addition, a new sample matrix consisting of ß-CD2 SDS1 complexes for a high hydrophobic compounds solubilization was developed. Approach based on the application of ß-cyclodextrin and SDS complex of a ratio 2:1 allowed for hydrodynamic injection into the capillary of a solution containing both mitotane and other analytes. The detection limits of the analytes for the reverse polarity sweeping-dispersive liquid-liquid microextraction method were found to be in the range of 1.5-3 ng/mL, which were approximately 1000 times lower than in the conventional hydrodynamic injection (5 s, 0.5 psi) without any preconcentration procedure. All analytes were completely resolved in less than 13 min by uncoated silica capillary with an inner diameter of 75 µm (ID) × 60 cm. Electrophoretic separation was performed in reverse polarity with a voltage of -25 kV with a background electrolyte (BGE) consisting of 100 mM SDS, 25% ACN, 25 mM phosphate buffer (pH 2.5), and 7 mM ß-cyclodextrin.