Precise Assignment Research Articles

Assembly-free design for additive manufacturing of articulated components based on layered precision assignment

ABSTRACT This paper presents an assembly-free design method for additive manufacturing (AM) of articulated components based on layered precision assignment (LPA). The articulated components are top-down decomposed into physically separated or nearly disconnected entities in different types of fit with specific clearance, for layered slicing hereafter. The forward design method sequentially integrates build orientation, adaptive slicing, trajectory optimization, in conjunction with machine uncertainty of 3D printing (3DP). Besides geometric analysis, the machine uncertainty owing to vibration and thermal coupling is considered by establishing general precision model of kinematic chain errors. By utilizing integrated digital twins (DT), the material extruding process can be visualized synchronously during fabrication process, with the support of a series of online sensor metadata. The manufacturing precision at each layer can be allocated and assigned with accurate distribution, on the basis of trajectory error assessment. The physical experiment of human lumbar vertebrae is carried out to verify the proposed method. The experiment proves that the proposed LPA is fundamentally adaptive to non-assembly 3DP of a variety of even alternative processes with multi-materials under machine uncertainty.

Unravelling the ultrafast dynamics of a N-BODIPY compound

Although the photophysics of BODIPY compounds has been widely investigated in the last few years, their analogues N-BODIPY, with nitrogen substitution at the boron center, did not receive comparable attention. In this work we report the synthesis and photochemical characterization of a substituted N-BODIPY compound, by means of a combined theoretical and spectroscopic approach. Compared to a standard BODIPY, the compound under investigation presents a lower fluorescence quantum yield (QY) in the visible region. The excited state relaxation dynamics of the dye was studied in different solvents, showing further fluorescence quenching in polar solvents, and excited state decay rates strongly dependent on the environment polarity. The role of the pendant moieties and the involvement of charge transfer states in the excited state dynamics was experimentally addressed by transient absorption spectroscopy, and further analyzed with TD-DFT calculations, which allowed precise assignment of the transient signals to the correspondent electronic configuration. The complete picture of the N-BODIPY behavior shows the presence of both charge transfer and localized states, influencing the observed photophysics to different amounts, depending on the excitation conditions and the surrounding environment.

Ro-vibrational spectral features and pressure broadening dynamics of dideutero-methane (12CH2D2) in the ν9(B2) fundamental band

Dideutero-methane 12CH2D2 is unique among all the methane isotopomers because of its asymmetric-top nature. Here, we first report the fine ro-vibrational gas-phase spectra of 12CH2D2 isotopomer in the a-type ν9 (B2-symmetry) fundamental band near 7.8 µm using ultra-sensitive cavity ring-down spectroscopy (CRDS) instrument in the mid-infrared spectral region. We utilized Gaussian 16 to calculate the relevant spectroscopic parameters of 12CH2D2 and subsequently performed the PGOPHER simulation for precise assignments of the fine ro-vibrational lines of 12CH2D2. Further, we conducted the pressure broadening dynamics of 12CH2D2 isotopomer with various foreign gases and accurately determined the pressure broadening coefficients, γi in cm−1 atm−1 [i = He, Ar, N2, Hydrogen mixture(H2 + N2) and zero air] of various transition lines of 12CH2D2.

Complete rotational assignment of the (0,0) vibrational band of the A1Π–X1Σ+ transition of carbon monosulfide

Carbon monosulfide (CS) generated in the S(1D) + CS2 → CS(X1Σ+) + S2 reaction was detected with the laser-induced fluorescence via the A1Π–X1Σ+ transition. The rotational structure of the (0,0) vibrational band is considerably deformed by the perturbation between the vibrational levels v = 0 of A1Π and v = 10 of a'3Σ+ states. Both the appearance wavelengths and peak intensities of many rotational lines are varied by the size of the perturbation. The precise assignment of the rotational lines of the spin-forbidden transition a'3Σ+−X1Σ+ (10,0) bands has been given. The observed spectrum was well-reproduced with higher accuracy than any previous analysis.

Ligand-protected gold nanoclusters probed by IRMPD spectroscopy and quantum chemistry calculations

This paper reports an attempt to structurally characterize isolated ligand-protected gold nanoclusters by means of gas-phase InfraRed Multiple Photon Dissociation (IRMPD) spectroscopy compared to quantum chemistry Density Functional Theory (DFT) calculations. The mass-selected kilodalton nanocluster complexes consist of ten or eleven gold atoms that are bound to glutathione or phosphine ligands and are produced by ElectroSpray Ionization (ESI) in the form of multiply charged anions or cations. This study allows us to build some methodology benchmarks for species that are large for IRMPD experiments and that are used for biochemistry applications. These gas-phase results on isolated ions are compared to condensed phase data from Fourier-Transform InfraRed (FTIR) spectroscopy and to theoretical IR spectra that are calculated with two different functional/basis sets, namely B3LYP/6-31G* and M06L/LanL2DZ, at the scaled static harmonic level. Although theoretical calculations are able to reproduce well the experimental IR spectra, the size of such species and the presence of many possible interactions between ligands make difficult a precise assignment among the many possible molecular arrangements.

Bakta: rapid and standardized annotation of bacterial genomes via alignment-free sequence identification.

Command-line annotation software tools have continuously gained popularity compared to centralized online services due to the worldwide increase of sequenced bacterial genomes. However, results of existing command-line software pipelines heavily depend on taxon-specific databases or sufficiently well annotated reference genomes. Here, we introduce Bakta, a new command-line software tool for the robust, taxon-independent, thorough and, nonetheless, fast annotation of bacterial genomes. Bakta conducts a comprehensive annotation workflow including the detection of small proteins taking into account replicon metadata. The annotation of coding sequences is accelerated via an alignment-free sequence identification approach that in addition facilitates the precise assignment of public database cross-references. Annotation results are exported in GFF3 and International Nucleotide Sequence Database Collaboration (INSDC)-compliant flat files, as well as comprehensive JSON files, facilitating automated downstream analysis. We compared Bakta to other rapid contemporary command-line annotation software tools in both targeted and taxonomically broad benchmarks including isolates and metagenomic-assembled genomes. We demonstrated that Bakta outperforms other tools in terms of functional annotations, the assignment of functional categories and database cross-references, whilst providing comparable wall-clock runtimes. Bakta is implemented in Python 3 and runs on MacOS and Linux systems. It is freely available under a GPLv3 license at https://github.com/oschwengers/bakta. An accompanying web version is available at https://bakta.computational.bio.

Unveiling bonding states and roles of edges in nitrogen-doped graphene nanoribbon by X-ray photoelectron spectroscopy

X-ray photoelectron spectroscopy (XPS) is among the most utilized analytical methods for nitrogen-doped carbon materials. Clarifying the assignments of nitrogen-doped carbon materials with different degrees of carbonization, which relates to conjugated systems, is essential to correlate structures with the performance of various applications, but such precise assignments were challenging. In this work, precise analyses were conducted to overcome the difficulty to assign the peaks of carbon materials with different degrees of carbonization, different edges, and various nitrogen-containing functional groups in graphene nanoribbons (GNRs), such as nitrile, pyridinic, primary with/without charges, secondary with/without charge, tertiary without charges (graphitic nitrogen), and quaternary nitrogen. Electrons donated from hydrogen and Madelung potentials showed a higher correlation to the peak shift of C1s and N1s XPS spectra than Mulliken charges on nitrogen. Zigzag edges showed a greater influence on the peak shift of tertiary amine (graphitic nitrogen) than armchair edges on XPS spectra. Besides, as the degree of carbonization is increased from aromatic compound-like structures to GNRs, the peak positions of C–N in C1s and N1s XPS spectra shifted to higher binding energies. This research proved that XPS could be applied to the precise structural analyses of nitrogen-containing carbon materials.

Guessing the outcome of separate and joint quantum measurements of noncommuting observables

According to Heisenberg's uncertainty relation, there is an ultimate limit to how precisely we may predict the outcome of position and momentum measurements on a quantum system. We show that this limit may be violated by an arbitrarily large factor if one aims, instead, to guess the unknown value of a past measurement. For experiments on a single quantum system, the precise assignment of past position and momentum measurement outcomes is accompanied by large uncertainty about their linear combinations, while we show that entanglement with an ancillary system permits accurate retrodiction of any such linear combination. Finally, we show that the outcomes of experiments that jointly measure multiple linear combinations of position and momentum observables by means of ancillary probe particles can also be guessed with no formal lower limit. We present quantitative results for projective measurements and for generalized measurements where all components are prepared in Gaussian states.

Cell of Origin and Genomic Profile of Primary Central Nervous System Lymphoma Determined Using the Nanostring Lst Assay and Ultra Deep Targeted Next Generation Sequencing

Introduction: Primary central nervous system lymphoma (PCNSL) is characterized by a consistently inferior outcome compared to systemic diffuse large B-cell lymphoma (DLBCL) with a median overall survival of 2-4 years. Therefore, PCNSL represents a significant clinical challenge with an urgent need for better biomarkers and novel therapeutic targets. The distinction of DLBCL into cell of origin (COO) categories based on patterns of gene expression reminiscent of germinal center B-cell (GC-) type, activated B-cell (ABC-) type, with a small number of “unclassified” cases, has profound prognostic and potential therapeutic implications with many novel therapies displaying differential efficacy between the GC and ABC groups. Therefore, the precise determination of COO is becoming increasingly important for the appropriate patient stratification for novel targeted therapies. The NanoString LST assay is a digital gene-expression based test for COO assignment, representing a more accurate means of COO determination compared to standard immunohistochemistry (IHC) based algorithms, and was recently successfully applied in nodal DLBCLs. In the present study, we tested the LST assay on a cohort of PCNSL patients and performed a complementary targeted genomic profiling on a subset of these patients.Methods: The COO of 77 PCNSL patients was determined with the NanoString LST assay using RNAs extracted from FFPE samples and compared with the results obtained by the Hans IHC algorithm. The genomic profiles of 62 PCNSL cases were determined using ultra-deep targeted next generation sequencing (NGS) of 13 recurrently mutated target genes, including CARD11, CCND3, CD79B, CSMD2, CSMD3, IRF4, C-MYC, MYD88, PAX5, PIM1, PRDM1, PTPRD and TP53 using the TruSeq Custom Amplicon approach (dual strand workflow) on a HiSeq4000 Instrument (Illumina) to an average depth of 30.000x. Only variants supported by more than 100 mutant reads with an allele frequency (VAF) of >5% were considered.Results: The LST assay resulted in the following subtype calls: 80.5% ABC, 12.9% GC and 6.5% unclassified (UC). Using the Hans IHC algorithm, 94.8% (73/77) of the PCNSL cases were classified as ABC subtype with 5.2% (4/77) representing the GC subtype. Interestingly, the COO classification obtained using the LST assay showed a different outcome in 16.9% (13/77) of the cases: Out of the 12 cases classified as ABC subtype with the IHC algorithm, 7 cases presented as GC subtype and 5 showed an UC profile using the LST assay. On the other hand, one case characterized as GC subtype with the IHC assay was classified as ABC when analyzed using the LST assay. As for the mutation analysis, we detected a total of 402 somatic mutations in the 62 PCNSL cases across the 13 genes analyzed with individual cases harboring mutations in 4 genes on average (range: 1-11). The most frequently mutated genes were MYD88 (76%), PIM1 (55%) and PRMD1 (50%). The mutation frequencies in the remaining genes were as follows: CD79B (40%), PTPRD (32%), MYC (31%), PAX-5 (31%), CARD11 (26%), TP53 (26%), IRF4 (23%), CCND3 (19%), CSMD2 (19%) and CSMD3 (18%). Analyzing the mutation profiles of the ABC and GC subtypes, we observed an enrichment of CD79B (47% vs 20%) and PIM1 (59% vs 20%) in cases with ABC subtype, with IRF4 mutations being present in ABC cases only (29% vs 0%). None of the other genes demonstrated a considerable difference between the GC and ABC subtypes with regards to the mutation frequency.Conclusions: We successfully applied, for the first time, the NanoString LST assay for COO determination using FFPE derived RNA samples from a cohort of 77 PCNSL patients. Interestingly, the LST assay revealed a lower proportion of patients with ABC subtype compared our IHC findings (80.5% vs 94.8%). This may reflect the genuine biology of these cases, as the NanoString LST assay represents the most reliable COO determination approach compared to the original gold standard GEP method. The frequent mutations revealed in components of different actionable pathways including the BCR pathway, cell cycle regulation and CNS development highlights the role of these variants in the pathogenesis of PCNSL. Considering the emergence of novel therapies with selective activity in the GC and ABC patient groups the precise assignment of COO and the complementary mutation analysis will most likely have an important role in guiding the appropriate patient management in PCNSL. DisclosuresStorhoff:NanoString Technologies: Employment, Equity Ownership. Ghali:NanoString Technoliges: Employment.

18F-Choline PET/CT, MRI, and Software-Based Image Fusion Analysis in Patients With Primary Hyperparathyroidism.

The aim of this study was to evaluate the diagnostic performance of 18F-choline PET and MRI in patients with primary hyperparathyroidism. Furthermore, the additional value of software-based PET/MRI scan fusion was analyzed. This retrospective study includes 42 patients (38 women) with an age between 32.5 and 79.1 years. PET/CT scans were performed on a dedicated system after injection of 250 to 350 MBq 18F-choline. For the MRI examination, T1-weighted images of the cervical region were used. The image fusion was made by anatomical coregistration using an automated algorithm based on mutual information. A total of 46 lesions were discovered and histologically confirmed in 42 patients. Histopathological examination revealed 38 adenomas and 8 hyperplasias. This means that, in 4 of these 42 patients, 2 lesions per patient were discovered. PET/CT also detected 46 abnormal findings, but only 43 were correctly recognized, whereas the other 3 were false-positive (FP). Six lesions could not be detected correctly: 3 were FP and 3 false-negative, which resulted in a sensitivity of 93.5% and a specificity of 97.5%. The site-specific evaluation showed 18 true-positive enlarged parathyroid glands with MRI, but also produced 13 FP findings and failed to detect 28 lesions; the sensitivity and specificity are thus 39.1% and 89.3%, respectively. The difference in detection rate between 18F-choline PET/CT and MRI was statistically significant (P < 0.001). 18F-choline PET/CT is clearly superior to MRI for localization diagnostics in primary hyperparathyroidism. Image fusion of both modalities can be helpful for more precise anatomical assignment.

Chemical Bonding and Electronic Structure of the Early Transition Metal Borides: ScB, TiB, VB, YB, ZrB, NbB, LaB, HfB, TaB, and WB.

The predissociation thresholds of the early transition metal boride diatomics (MB, M = Sc, Ti, V, Y, Zr, Nb, La, Hf, Ta, W) have been measured using resonant two-photon ionization (R2PI) spectroscopy, allowing for a precise assignment of the bond dissociation energy (BDE). No previous experimental measurements of the BDE exist in the literature for these species. Owing to the high density of electronic states arising from the ground and low-lying separated atom limits in these open d-subshell species, a congested spectrum of vibronic transitions is observed as the energy of the ground separated atom limit is approached. Nonadiabatic and spin-orbit interactions among these states, however, provide a pathway for rapid predissociation as soon as the ground separated atom limit is reached, leading to a sharp decrease in signal to background levels when this limit is reached. Accordingly, the BDEs of the early transition metal borides have been assigned as D0(ScB) 1.72(6) eV, D0(TiB) 1.956(16) eV, D0(VB) 2.150(16) eV, D0(YB) 2.057(3) eV, D0(ZrB) 2.573(5) eV, D0(NbB) 2.989(12) eV, D0(LaB) 2.086(18) eV, D0(HfB) 2.593(3) eV, D0(TaB) 2.700(3) eV, and D0(WB) 2.730(4) eV. Additional insight into the chemical bonding and electronic structures of these species has been achieved by quantum chemical calculations.

Unravelling the Fast Alkali-Ion Dynamics in Paramagnetic Battery Materials Combined with NMR and Deep-Potential Molecular Dynamics Simulation.

Solid-state nuclear magnetic resonance (ssNMR) has received extensive attention in characterizing alkali-ion battery materials because it is highly sensitive for probing the local environment and dynamic information of atoms/ions. However, precise spectral assignment cannot be carried out by conventional DFT for high-rate battery materials at room temperature. Herein, combining DFT calculation of paramagnetic shift and deep potential molecular dynamics (DPMD) simulation to achieve the converged Na+ distribution at hundreds of nanoseconds, we obtain the statistically averaged paramagnetic shift, which is in excellent agreement with ssNMR measurements. Two 23 Na shifts induced by different stacking sequences of transition metal layers are revealed in the fast chemically exchanged NMR spectra of P2-type Na2/3 (Mg1/3 Mn2/3 )O2 for the first time. This DPMD simulation auxiliary protocol can be beneficial to a wide range of ssNMR analysis in fast chemically exchanged material systems.

Unravelling the Fast Alkali‐Ion Dynamics in Paramagnetic Battery Materials Combined with NMR and Deep‐Potential Molecular Dynamics Simulation

AbstractSolid‐state nuclear magnetic resonance (ssNMR) has received extensive attention in characterizing alkali‐ion battery materials because it is highly sensitive for probing the local environment and dynamic information of atoms/ions. However, precise spectral assignment cannot be carried out by conventional DFT for high‐rate battery materials at room temperature. Herein, combining DFT calculation of paramagnetic shift and deep potential molecular dynamics (DPMD) simulation to achieve the converged Na+ distribution at hundreds of nanoseconds, we obtain the statistically averaged paramagnetic shift, which is in excellent agreement with ssNMR measurements. Two 23Na shifts induced by different stacking sequences of transition metal layers are revealed in the fast chemically exchanged NMR spectra of P2‐type Na2/3(Mg1/3Mn2/3)O2 for the first time. This DPMD simulation auxiliary protocol can be beneficial to a wide range of ssNMR analysis in fast chemically exchanged material systems.

&lt;strong&gt;Amphipoda from the Late Neogene of Shanxi, China&lt;/strong&gt;

Amphipods are extremely diverse malacostracan crustaceans that have conquered many environments from oceanic abysses to the terrestrial realm. Despite their impressive modern diversity and abundance, they are particularly rare in the fossil record. Herein, we describe the exceptionally preserved Gammaroidorum yooling sp. nov. from the Late Neogene of Xiaobai Formation near Pandao village, Shanxi, China. Due to the limitation of the preservation, namely the non-preservation of setae, we could not establish a precise generic assignment, so used the collective group Gammaroidorum Jarzembowski, Chény, Fang &amp; Wang, 2020. Although there are still doubts on the precise placement of this new species within amphipods, these fossils are important since they represent the first known fossil occurrence of an amphipod in China. Besides, these fossils have an unusual preservation, being almost transparent in most cases, and being most easily seen by reflecting light on the fossil.

Uppermost Jurassic to Lower Cretaceous benthic foraminiferal faunas of the Weimei and the Bandingsi localities of northern and southern parts of South Tibet – A preliminary analysis

Diverse foraminiferal assemblages from the Weimei–Gyabula, and the Menkadun–Gucuo formations have been recorded based on the study of two Upper Jurassic to Lower Cretaceous successions, respectively located in the northern and southern parts of South Tibet. Each section contains three different foraminiferal assemblages. Due to the poor state of preservation and the occurrence of long-ranged cosmopolitan species, these foraminiferal assemblages do not allow a precise age assignment for the fossil bearing strata. However, the identification of the Globulina prisca assemblage indicates a Cretaceous age for the Shale Unit of the Gucuo Formation, although the Jurassic/Cretaceous (J/K) boundary was traditionally delineated above this unit. On the other hand, the occurrence of Dorothia oxycona indicates that the uppermost Gyabula and Gucuo formations cannot be older than Aptian and middle Albian age, respectively.During the Late Jurassic to Early Cretaceous, the northern part of South Tibet was located in a deep marine environment, probably at bathyal to abyssal depths, whereas the southern part of South Tibet was part of the outer neritic shelf environment. Typical foraminiferal associations of mildly oxygen-deficient deep-water environment and increased surface productivity have been recorded during the late Early Cretaceous. The biofacies succession indicates that the late Early Cretaceous was associated with a deepening of the palaeobasin, probably associated with a global Albian transgression.

Periodontal Treatment Needs of Hemodialized Patients.

End-stage renal failure is the reason for complications in many systems and organs, and the applied pharmacotherapy often causes the deepening of already existing pathologies within the oral cavity, such as: caries, periodontal diseases, mucosal lesions or reduced saliva secretion. Reduced saliva secretion results in an increased accumulation of dental plaque, its mineralization and prolonged retention, which leads to the development of gingival and periodontal inflammation. There is some evidence that chronic kidney diseases are influenced by periodontal health. The aim of the work was to evaluate the dental needs by the usage of clinical assessment of periodontal tissues of patients suffering from end-stage chronic kidney disease, arterial hypertension or/and diabetes mellitus. Material and methods: 228 patients underwent the research. 180 patients were hemodialized in Diaverum dialysis stations (42 of them were diagnosed with end stage chronic disease, 79 with the end stage chronic disease and arterial hypertension, 16 with end stage chronic kidney disease and diabetes, 43 with end-stage chronic disease, arterial hypertension and diabetes) and 48 patients of the Conservative Dentistry with Endodontics Clinic of Academic Centre of Dentistry of Silesian Medical University in Bytom and patients of the dentistry division of Arnika Clinic in Zabrze not diagnosed with any of the aforementioned diseases. The scheme of the research comprised 2 parts: analysis of the general health and assessment of the periodontal status which contain the following indices: Periodontal Probing Depth (PPD), Clinical Attachment Lost (CAL), Bleeding Index or Bleeding on Probing Index (BI or BOP), Community Periodontal Index for Treatment Needs (CPITN). Results: Significantly lower percentage of patients with healthy periodontal tissues and higher percentage with periodontal pockets deeper than 3.5 mm and the loss of trainers connective of 5 mm or higher were in the examined group. The values of the bleeding index were significantly lower in control group. The analysis of the CPITN index indicates higher percentage of patients qualified as CPI 1 or 2 in the control group while in the examined one most of the patients turned out to require specialist periodontal treatment. Conclusions: there is a direct relationship between periodontal status and end-stage renal disease which typically includes other chronical civilization ailments. It is important to develop a scheme for the easy and rapid examination of periodontal status, to determine the treatment needs in this area, which will allow precise assignment of long-term dialyzed patients to the range of prophylactic and therapeutic procedures.

ABO B gene is associated with introversion personality tendancies through linkage with dopamine beta hydroxylase gene

Although personality is thought to be 50% heritable, consensus has not been reached about the specific genes involved, interest in genes affecting personality and behavior continues because of the linkage of personality traits with both physical and mental illness. One hundred and twenty years of study of the ABO blood types and the genes causing them has led to more precise assignment of genotype-phenotype linkage. Countries like Japan and Korea with 100years history of study of ABO blood groups and personality as well as other countries have published research with no consensus. Introversion is a well-studied personality trait with 50% genetic causation. Dopamine system has been linked to the introversion-extroversion spectrum with high dopamine linked to introversion. Dopamine beta hydroxylase determines the ratio of dopamine to norepinephrine. Dopamine beta hydroxylase gene, DBH, is in linkage disequilibrium with ABO gene thus offering insight into the ABO findings related to personality traits. ABO blood groups have been studied with some but not all studies finding type AB associated with introversion. One explanation for the inconsistent replication of findings could be that genotypes would show more differences than phenotypes. ABO A allele, ABO B allele or the synergism of both alleles could be the driver of introversion trait in ABO AB. Patients in an obstetric gynecology practice appeared to demonstrate a tendancy to introversion in phenotype ABO B. Since we had access to ABO blood phenotypes instead of genotypes of our obstetric gynecology office patients, we hypothesized that phenotype ABO AB when compared with ABO O would be associated with higher introversion since these phenotypes were also genotypes and since ABO O unlike ABO AB is not found associated with introversion in extant research. Though ABO B allele was observed to be the likely cause of introversion in patients and since we had available only phenotypes of ABO to use in search of genetic allele that causes introversion trait, ABO AB needs to be dissected to see whether ABO A allele or ABO B allele is the driver of the introspective trait. Based on the literature and on observation, the hypothesis was that ABO B is the driver of introversion trait. A pilot student of 225 obstetric gynecology patients using the online NPA personality test showed higher scores for introversion tendancies in ABO AB compared to ABO O and when ABO AB was compared to ABO A. This supports ABO B as the driver of introversion tendancies in the ABO gene. Studies using ABO genotypes instead of ABO phenotypes should provide further support for this hypothesis. Given the support for introversion tendancies in personality caused by higher dopamine genetically with dopamine beta hydroxylase low activity and this dopamine state being common mechanism for such conditions as schizophrenia and autism, continued discoveries of genes that impact this state will lead to many health implications.

Conformational analysis by UV spectroscopy: the decisive contribution of environment-induced electronic Stark effects.

UV chromophores are frequently used as probes of the molecular structure. In particular, they are sensitive to the electric field generated by the molecular environment, resulting in the observation of Stark effects on UV spectra. While these environment-induced electronic Stark effects (EI-ESE) are already used for conformational analysis in the condensed phase, this work explores the potential of such an approach when performed at much higher conformational resolution in the gas phase. By investigating model alkali benzylacetate and 4-phenylbutyrate ion pairs, where the electric field applied to the phenyl ring is chemically tuned by changing the nature of the alkali cation, this work demonstrates that precise conformational assignments can be proposed based on the correlation between the conformation-dependent calculated electric fields and the frequency of the electronic transitions observed in the experimental UV spectra. Remarkably, the sole analysis of Stark effects and fragmentation patterns in mass-selected UV spectra provided an accurate and complete conformational analysis, where spectral differences as small as a few cm−1 between electronic transitions were rationalized. This case study illustrates that the identification of EI-ESE together with their interpretation at the modest cost of a ground state electric field calculation qualify UV spectroscopy as a powerful tool for conformational analysis.

Singpuria, a new genus of Eudicot flower from the latest Cretaceous Deccan Intertrappean Beds of India

A new bisexual flower, Singpuria kapgatei, gen. et sp. nov., is described from chert of latest Cretaceous age from the Deccan Intertrappean Beds at Singpur, Madhya Pradesh, in central India. The hypogynous, actinomorphic flower is ~1.6 mm wide, with distinct sepals and petals. The androecium consists of 18 tetrasporangiate, dithecal, basifixed anthers borne in radial pairs on nine bifurcate filaments. The gynoecium is superior and syncarpous, with pentagonal symmetry. Pollen from the stamens is tricolporate and microreticulate. The combined morphological features of this flower indicate that Singpuria is a eudicot with affinities in the Pentapetalae, but we have been unable to make a more precise assignment. Nevertheless, we consider it useful to place this rare fossil flower on record as an exemplary extinct member of the Deccan biota. Singpuria may represent a clade that was isolated on the Indian subcontinent and became extinct in response to environmental changes at the K/Pg boundary, or later in the Cenozoic as the land mass moved northward through new climate zones and collided with Eurasia.

Acidity-Driven Bidirectional Room-Temperature Spin-State Switch and Fluorescence Modulation of a Mononuclear Fe(II) Complex

Room-temperature switchable materials showing multiple responses toward external stimuli are highly desired. Herein, we report bidirectional spin-state switch and fluorescence modulation of an Fe(I...