1A1 State Research Articles

Impact of primary aldosteronism on kidney function: results from the SPAIN-ALDO registry.

To evaluate the impact of aldosterone excess on renal function in individuals with primary aldosteronism and to compare its evolution after surgery or mineralocorticoid receptor antagonist (MRA) treatment. A multicentre, retrospective cohort study of primary aldosteronism patients in follow-up in 36 Spanish tertiary hospitals, who underwent specific treatment for primary aldosteronism (MRA or adrenalectomy). A total of 789 patients with primary aldosteronism were included, with a median age of 57.5 years and 41.8% being women. At primary aldosteronism diagnosis, the prevalence of chronic kidney disease (CKD) was 10.7% ( n = 84), with 75% of cases classified as state 3a ( n = 63). Primary aldosteronism patients with CKD had a longer duration of hypertension, a higher prevalence of type 2 diabetes, dyslipidaemia, cardiovascular events, hypokalaemia, and albuminuria. Unilateral adrenalectomy was performed in 41.8% of cases ( n = 330), and 459 patients were treated with MRA. After a median follow-up of 30.7 months (range 13.3-68.4), there was a significant decline in the estimated glomerular filtration rate (eGFR) in operated patients and those receiving MRA. During follow-up, 24.4% of patients with CKD at the time of primary aldosteronism diagnosis had normalized renal function, and 39% of those with albuminuria had albuminuria remission. There were no differences in renal function or albuminuria regression between the two therapy groups. However, development of albuminuria was less common in operated than in medically treated patients (0 vs. 6.0%, P = 0.009). CKD affects around 10% of the patients with primary aldosteronism, with a higher risk in individuals with long-term hypertension, type 2 diabetes, dyslipidaemia, cardiovascular events, hypokalaemia, and albuminuria. At short-term, both MRA and surgical treatment lead to a reduction of renal function, but adrenalectomy led to higher renal protection.

Evaluation of Science Implementation in Mechanical Engineering Design Curriculum Class 2A State Polytechnic of Jakarta Pekalongan City Campus Academic Year 2023/2024

Evaluation of Science Implementation in Mechanical Engineering Design Curriculum Class 2A State Polytechnic of Jakarta Pekalongan City Campus Academic Year 2023/2024

Relaxation of the 2a1 ionized water dimer: An interplay of intermolecular Coulombic decay (ICD) and proton transfer processes.

This article investigates the relaxation dynamics of the ionized 2a1 state of a water molecule within a water dimer. The study was motivated by findings from two previous pieces of research that focused on the relaxation behaviors of the inner-valence ionized water dimer. The present study discloses an observation indicating that water dimers display specific fragmentation patterns following inner-valence ionization, depending on the position of the vacancy. Vacancies were created in the 2a1 state of the proton-donating water molecule (PDWM) and proton-accepting water molecule (PAWM). Utilizing Born-Oppenheimer molecular dynamics simulations, the propagation of the 2a1 ionized state was carried out for both scenarios. The results revealed proton transfer occurred when the vacancy resided in the PDWM, accompanied by the closing of decay channels for O-H bond distance (RO-H) > 1.187Å (matching Richter et al.'s findings). Conversely, when vacancy was on PAWM, we observed no closing of decay channels (aligning with Jahnke et al.'s findings). This difference translates to distinct fragmentation pathways. In PDWM cases, 2a1 state ionization leads to H3O+ -OH• formation. In contrast, PAWM vacancies result in decay pathways leading to H2O+-H2O+ products.

Interaction-driven first-order and higher-order topological superconductivity

We investigate topological superconductivity in the Rashba-Hubbard model, describing heavy-atom superlattice and van der Waals materials with broken inversion. We focus in particular on fillings close to the van Hove singularities, where a large density of states enhances the superconducting transition temperature. To determine the topology of the superconducting gaps and to analyze the stability of their surface states in the presence of disorder and residual interactions, we employ an fRG+MFT approach, which combines the unbiased functional renormalization group (fRG) with a real-space mean-field theory (MFT). Our approach uncovers a cascade of topological superconducting states, including A1 and B1 pairings, whose wave functions are of dominant p- and d-wave character, respectively, as well as a time-reversal breaking A1+iB1 pairing. While the A1 and B1 states have first-order topology with helical and flat-band Majorana edge states, respectively, the A1+iB1 pairing exhibits second-order topology with Majorana corner modes. We investigate the disorder stability of the bulk superconducting states, analyze interaction-induced instabilities of the edge states, and discuss implications for experimental systems. Published by the American Physical Society 2024

Newly observed low-lying Ω = 1 state of PbO.

High-resolution spectroscopy of lead monoxide was performed in a range of 22 400-25 300 cm-1. A new Ω = 1 state located between the a1 and A0+ states was observed, and it is labeled c1. Spectroscopic constants, including the hyperfine interaction coefficient, were determined for the a1 and c1 states. The vibrational levels of these two electronic states are located closely to each other, and the interaction between them causes gradual exchange of electronic state properties in our observation wave number range. Our observation poses a question for the band assignment for the b0- state, which has some resemblance with this c1 state.

Theoretical study of valence excitations in fluoromethanes by high energy electron impact

We report a theoretical study of the electron-impact electronic excitation of fluoromethanes. Generalized oscillator strengths (GOSs) are calculated for the molecules at the equation-of-motion coupled-cluster singles and doubles level. To clarify the influence of nuclear dynamics on the electronic excitations, the effects of internal molecular vibrations are included in the calculation. Comparison with experimental data resolves some inconsistencies in the assignment of the transition bands. Furthermore, it is shown that the lengthening of the CH bond enhances the excitation from the highest occupied orbital to the 3s Rydberg orbital for CHF3, CH2F2, and CH3F, and that the CH stretching vibrations thus have a significant influence, especially at small momentum transfer where electric dipole transitions are dominant. Since the 2 1A1 state of CHF3 dissociates into CF3 + H, the result indicates that the CH stretching vibration causes an increase in the production of CF3 by electron collision and by photoabsorption.

Unveiling geometric and electronic structures of NbSi4−/0 clusters and electron detachments of the anionic cluster: A quantum chemical investigation

AbstractThis article presents computational insights into the geometric and electronic structures of NbSi4−/0 clusters using density functional theory and the CASSCF/CASPT2 method. The anionic and neutral ground states are identified as the 1A′ and 2A′ states, respectively, within a trigonal bipyramidal isomer where the Nb atom occupies the equatorial position. The adiabatic detachment energy for the transition from the anionic ground state 1A′ to the neutral ground state 2A′ is estimated to be 2.30 eV. Additionally, an evaluation of the vertical detachment energies for transitions to the neutral states 12A′, 12A″, 22A′, 22A″, 32A′, 32A″, and 42A′ yields respective values of 2.42, 2.78, 2.94, 3.34, 3.86, 4.08, and 4.28 eV. These computed electron detachment energies successfully account for all five bands observed in the photoelectron spectrum of the anionic cluster. Furthermore, the Franck–Condon factor simulations reveal extensive vibrational progressions associated with the transition to the neutral ground state 12A′, manifesting as an unresolved broad band at 2.41 eV in the spectrum.

Vibronic effect study of 1A2 state of H2O and D2O

The generalized oscillator strengths of the dipole-forbidden excitations of the 1A2 of H2O and D2O were calculated with the time dependent density functional theory, by taking into account the vibronic effect. It is found that the vibronic effect converts the dipole-forbidden excitation of the 1A2 into a dipole-allowed one, which enhances the intensities of the corresponding generalized oscillator strength in the small squared momentum transfer region. The present investigation shows that the vibronic effect of H2O is slightly stronger than that of D2O, which exhibits a clear isotopic effect.

IR spectroscopic characterization of [M,C,2H]+ (M = Ru and Rh) products formed by reacting 4d transition metal cations with oxirane: Spectroscopic evidence for multireference character in RhCH2.

A combination of infrared multiple-photon dissociation (IRMPD) action spectroscopy and quantum chemical calculations was employed to investigate the [M,C,2H]+ (M = Ru and Rh) species. These ions were formed by reacting laser ablated M+ ions with oxirane (ethylene oxide, c-C2H4O) in a room-temperature ion trap. IRMPD spectra for the Ru species exhibit one major band and two side bands, whereas spectra for the Rh species contain more distinct bands. Comparison with density functional theory (DFT), coupled-cluster (CCSD), and equation-of-motion spin-flip CCSD (EOM-SF-CCSD) calculations allows assignment of the [M,C,2H]+ structures. For the spectrum of [Ru,C,2H]+, a combination of HRuCH+ and RuCH2+ structures reproduces the observed spectrum at all levels of theory. The well-resolved spectrum of [Rh,C,2H]+ could not be assigned unambiguously to any calculated structure using DFT approaches. The EOM-SF-CCSD calculations showed that the ground-state surface has multireference electronic character, and symmetric carbenes in both the 1A1 and 3A2 states are needed to reproduce the observed spectrum.

The elusive phenylethynyl radical and its cation: synthesis, electronic structure, and reactivity.

Alkynyl radicals and cations are crucial reactive intermediates in chemistry, but often evade direct detection. Herein, we report the direct observation of the phenylethynyl radical (C6H5CC˙) and its cation (C6H5CC+), which are two of the most reactive intermediates in organic chemistry. The radical is generated via pyrolysis of (bromoethynyl)benzene at temperatures above 1500 K and is characterized by photoion mass-selected threshold photoelectron spectroscopy (ms-TPES). Photoionization of the phenylethynyl radical yields the phenylethynyl cation, which has never been synthesized due to its extreme electrophilicity. Vibrationally-resolved ms-TPES assisted by ab initio calculations unveiled the complex electronic structure of the phenylethynyl cation, which appears at an adiabatic ionization energy (AIE) of 8.90 ± 0.05 eV and exhibits an uncommon triplet (3B1) ground state, while the closed-shell singlet (1A1) state lies just 2.8 kcal mol-1 (0.12 eV) higher in energy. The reactive phenylethynyl radical abstracts hydrogen to form ethynylbenzene (C6H5CCH) but also isomerizes via H-shift to the o-, m-, and p-ethynylphenyl isomers (C6H4CCH). These radicals are very reactive and undergo ring-opening followed by H-loss to form a mixture of C8H4 triynes, along with low yields of cyclic 3- and 4-ethynylbenzynes (C6H3CCH). At higher temperatures, dehydrogenation from the unbranched C8H4 triynes forms the linear tetraacetylene (C8H2), an astrochemically relevant polyyne.

Pressure‐Induced Dual‐Emission of Mn‐Based Metal Halides (C5H6N)2MnBr4

AbstractRegulating the crystal structure of metal halides is important to tune their photoluminescence (PL) or govern the potential emergence of diverse physical properties. Here, an exceptional PL phenomenon characterized by dual‐emission bands in the Mn‐based metal halides (C5H6N)2MnBr4 is observed through hydrostatic pressure measurements. The results have confirmed that the dual‐emission bands centered at ≈518 and 650 nm arise from isolated Mn2+ ions and super‐exchange within Mn2+–Mn2+ dimers, respectively. (C5H6N)2MnBr4 displays remarkable piezochromic luminescence, accompanied by a red shift in dual‐emission. This phenomenon can be attributed to the enhancement of crystal‐field splitting energy and the reduction of relaxation from the low‐energy excited state 4T1 to the ground state 6A1. Meanwhile, the dual‐emission exhibits an anomalous increase ≈1.5–3.9 GPa, which is associated with reduced nonradiative losses during energy migration due to the decreased distance between the luminescent centers as a consequence of lattice contraction. Moreover, (C5H6N)2MnBr4 undergoes a phase transition at ≈1.5 GPa, and upon decompression, the high‐pressure phase partially recovers. This study not only provides insights into the luminescent properties of Mn‐based metal halides but also presents a novel approach to the design of multifunctional photoluminescent materials.

Effect of NM (B, C, N, O and F) doping and Fe[sbnd]NM co-doping on structure, electronic and magnetic properties of monolayer 2H[sbnd]MoTe[formula omitted] : A first principle investigation

Exploring magnetism in two-dimensional transition-metal dichalcogenides (TMDs) has gained a plethora of interest in recent times. Herein, employing spin-polarized density functional theory, we looked into the effect of non-metal doping (B, C, N, O, and F) and Fe-non metal co-doping on structure, electronic, and magnetic properties of 2HMoTe2 to identify new promising configurations for spin-based device applications. For non-metal doping, the results depict that B, N, and F-doped systems are magnetic, and the N-doped system shows magnetic-semiconducting behavior. The half-metallic Fe-doped MoTe2 transforms into a magnetic semiconductor upon co-doping. The structural distortion around the Fe atoms modifies the crystal field splitting, resulting in triply degenerate a1 and singly degenerate a2 and a3 states. Uncompensated electrons in the co-doped system and hybridization between Fe and NM atom modifies the magnetic properties of monolayer MoTe2. Competition between crystal field splitting and intra-atomic Hund’s exchange splitting determines the magnetic moment. Due to charge compensation, C-doped and FeC co-doped systems are non-magnetic. N-doped and FeN co-doped MoTe2 exhibit long-range magnetic ordering. Formation energy calculations revealed that the co-doped configurations are easily attainable in experiments compared to non-metal doped systems. The results open up a robust way to realize 2HMoTe2 based spintronic devices.

Accurate absolute absorption cross-sections of the ozone Wulf bands at 1 µm range: measurements with high-resolution cw-CRDS laser techniques

Ozone plays a major role in atmospheric chemistry and radiative processes with an impact on climate and ecosystems being also considered as a possible biosignature species in exoplanetary observations. This makes important an extension of accurate laboratory data to various spectral ranges. The present work provides absolute absorption cross-sections of ozone accurate to about 3% in the near-IR range around 1 µm using for the first time a continuous-wave cavity-ring-down spectrometer (cw-CRDS) for recording the transitions above the first dissociation threshold of O3. This has permitted high-sensitivity and high-resolution measurements covering the region from 9745 to 10850 cm−1 corresponding to the transitions from the electronic ground state to spin-rovibronic levels of excited triplet electronic states 3A2 and 3B2 that form the Wulf band system. Two complementary methods based on the stationary recording with the quasi-continuous laser tuning and on the pressure ramp measurements at carefully chosen grids of wavenumbers were implemented and provided very well consistent results within 2% on average. The experimental integrated absorption intensity in the range under the study is evaluated as 1.393×10−20 (± 2%) cm/molecule. The comparison with the available published data of continuous recordings shows that our absorption cross-sections are much more accurate, particularly in the region with complex partly resolved spin-rovibronic spectral patterns. This region corresponds to a transparency near-IR window of the water vapor and is thus well suited for atmospheric applications. The theoretical modeling of the measured spectra using eight rovibronic bands is discussed. The experimental absorption cross-sections at the dense grid of wavenumbers are provided in the electronic supplementary files, which could be used as new reference data in the 9745 to 10850 cm−1 range.

First-principles study of geometric and electronic structures, and optical transition energies of Mn4+ impurity ions: K2SiF6 as a prototype

In this study, we present the results of first-principles calculations conducted within the density functional theory to investigate the geometric and electronic structures of the ground 4A2 and excited 2E and 4T2 states, as well as the optical transition energies between these states, in the prototype system of K2SiF6:Mn4+. To achieve this, we employed a comprehensive evaluation of the five representative exchange-correlation functionals, enabling the development of a state-of-art calculation scheme that effectively describes the geometric and electronic structures of the excited 2E and 4T2 states. The calculated excitation, emission and zero-phonon line energies of the optical transitions between the ground 4A2 state and the excited 2E and 4T2 states demonstrate a better agreement with experimental results. However, we observed that the conventional and widely-used approach based on the analysis of the electronic density of states diagrams derived from the ground state calculations failed to accurately evaluate the vertical optical transition energies from the 4A2 ground state to the excited 2E and 4T2 states when compared to experimental data. The calculation technique developed in this study holds the potential for widespread application to other combinations of host materials and impurity ion, which is of great importance for future developments in the field of optical materials.

Diabatic Potential Energy Surfaces of the Interacting Triplet States 3A2 and 3B1 of the Ozone Molecule

Diabatic Potential Energy Surfaces of the Interacting Triplet States 3A2 and 3B1 of the Ozone Molecule

Cadmium Transforms Astrocytes into the A1 Subtype via Inducing Gap Junction Protein Connexin 43 into the Nucleus.

Cadmium is highly toxic and present in the environment and can be accumulated among various levels of the food chain. Both humans and animals are at risk from toxicity associated with cadmium. However, the neurological endpoint caused by cadmium has not been revealed. The aim of our research is to explore the potential target of cadmium attack when causing neurotoxicity. 80 male chickens (one day old, weighing 36.49 ± 2.88 g) were randomly divided into four groups and independently treated with 0, 35, 70, or 140 mg/kg CdCl2 in diet for 90 days. The result showed that the striatum was damaged due to a high dose of cadmium in the brain, which was characterized by degeneration of neurons and astrocyte dysfunction. Transcriptome analysis demonstrated that striatal astrocytes were transformed into the A1 state under cadmium exposure. Deeper investigation revealed that the internalization of gap junction protein connexin 43 was responsible for this transformation. Eventually, we can conclude that the internalized gap junction protein connexin 43 of astrocytes is the target of cadmium anchoring, and this process was accompanied by the transformation of astrocytes into the A1 subtype. This study provides a new direction for exploring the effects of cadmium on the nervous system and the treatment of subsequent nervous system diseases.

Experimental and Theoretical Studies of the HeICl Van der Waals Complexes in the Valence and Ion-pair States.

The article presents results of experimental and theoretical analysis of the T-shaped and linear HeICl van der Waals complexes in the valence A1 and ion-pair β1 states as well as the HeICl(A1,vA ,nA ←X0+ ,vX =0,nx and β1,vβ ,nβ ←A1,vA ,nA ) optical transitions (ni are quantum numbers of the vdW) modes). The HeICl(β1,vβ ,nβ )→He+ICl(E0+ , , β1) decay are also studied. Luminescence spectra of the HeICl(β1,vβ =0-3,nβ ) complex electronic (ICl(E0+ ,vE , ) and vibrational ICl(β1,vβ ) predissociation products are measured, and branching ratios of decay channels are determined. To construct potential energy surfaces for the HeICl(A1, β1) states, we utilized the intermolecular diatomic-in-molecule perturbation theory first order method. Experimental and calculated spectroscopic characteristics of the A1 and β1 states agree well. Comparison of the experimental and calculated pump-probe, action and excitation spectra shows that the calculated spectra describe the experimental spectra adequately.

High-level studies of the singlet states of quadricyclane, including analysis of a new experimental vacuum ultraviolet absorption spectrum by configuration interaction and density functional calculations.

A synchrotron-based vacuum ultraviolet absorption spectrum (VUV) of quadricyclane (QC) is reported with energies up to 10.8eV. Extensive vibrational structure has been extracted from the broad maxima by fitting short energy ranges of the VUV spectrum to high level polynomial functions and processing the regular residuals. Comparison of these data with our recent high-resolution photoelectron spectral of QC showed that this structure must be attributed to Rydberg states (RS). Several of these appear before the valence states at higher energies. Both types of states have been calculated by configuration interaction, including symmetry-adapted cluster studies (SAC-CI) and time dependent density functional theoretical methods (TDDFT). There is a close correlation between the SAC-CI vertical excitation energies (VEE) and both Becke 3-parameter hybrid functional (B3LYP), especially Coulomb-attenuating method-B3LYP determined ones. The VEE for several low-lying s-, p, d-, and f-RS have been determined by SAC-CI and adiabatic excitation energies by TDDFT methods. Searches for equilibrium structures for 11,3A2 and 11B1 states for QC led to rearrangement to a norbornadiene structure. Determination of the experimental 00 band positions, which show extremely low cross-sections, has been assisted by matching features in the spectra with Franck-Condon (FC) fits. Herzberg-Teller (HT) vibrational profiles for the RS are more intense than the FC ones, but only at high energy, and are attributed to up to ten quanta. The vibrational fine structure of the RS calculated by both FC and HT procedures gives an easy route to generating HT profiles for ionic states, which usually require non-standard procedures.

Threshold Photoelectron Spectrum of the Phenoxy Radical.

The high-resolution photoion mass-selected threshold photoelectron spectrum (ms-TPES) of the phenoxy radical (C6H5O•), produced by pyrolysis of anisole, was investigated at the VUV beamline of the Swiss Light Source. Adiabatic ionization energies have been determined to be 8.56, 9.42, 9.76, and 9.94 eV to the X̃+1A1, ã+3A2, Ã+1A2, and b̃+3B2 cation states, respectively, supported by DFT, WFT, and composite-method calculations. A ring deformation mode was found to be active upon ionization by Franck-Condon analysis and responsible for the vibrational structure of the TPES in all four ion states. While the X̃+1A1 and ã+3A2 states' assignment agrees with the literature, we revise the energetic order of the Ã+1A2 and b̃+3B2 cation states in the ms-TPES, based on a pronounced lifetime broadening of the excited triplet state. This is rationalized by strong coupling between the triplet states as confirmed by EOM-EE-CCSD calculations indicating a conical intersection with a low-lying seam to the ã+3A2 state. Our study provides a well-resolved spectrum, to be used for the isomer-selective assignment of reactive species in combustion and catalysis and also serves as benchmark to evaluate theoretical methods to address closed- and open-shell singlet and triplet cation intermediates.

Collisional excitation of hyperfine levels of OH by hydrogen atoms

ABSTRACT Observations of transitions between the hyperfine levels of the hydroxyl radical (OH) can provide crucial information on the physical conditions in interstellar clouds. Accurate modelling of the spectra requires calculated rate coefficients for the excitation of OH by H atoms, which is often present in molecular clouds in addition to the dominant H2 molecule. In this work, rate coefficients for the (de-)excitation of hyperfine levels of OH through collisions with hydrogen atoms are presented. In previous work, nuclear-spin-free scattering calculations were carried out; these took account of the fact that four electronic states (1A′, 1A″, 3A′, and 3A″) arise from the interaction of OH(X2Π) with H(2S). Because of the deep H2O($\tilde{X}^1A^{\prime }$) well, inelastic transitions can occur through direct collisions or by formation and decay of a collision complex. The rates of collision-induced hyperfine transitions were computed by the recoupling method and the MJ randomization approximations, respectively. These data will be useful in astrophysical models of OH excitation.