Precise Assignment Research Articles

Periodic and non-periodic DFT studies of an organic semiconductor material: Structural, electronic, optical, and vibrational properties of ninhydrin

The main purpose of the present study is to explore details of the structural, electronic, optical and vibrational properties of ninhydrin. To achieve this aim, the results of extensive DFT calculations have been employed. Because the accuracy of the results is essential in this study, some periodic DFT approximations have first been subjected to rigorous computational tests, and the RPBE-TS functional is finally selected. Then, the analysis of the RPBE-TS results has revealed that the studied crystal is a semiconductor with a direct band gap of 2.17 eV. The variation of some optical properties (dielectric constant, absorption coefficient, and refractive index) as a function of the polarization directions of the incident electromagnetic wave has also been presented. In addition, the complementarity of anharmonic isolated molecule and harmonic solid-state calculations is exploited in order to give precise assignments of the experimental IR spectrum in the region 400–3800 cm−1. The combination of these two theoretical approaches allows the precise identification of the four red-shifted OH-stretching bands based on the periodic DFT-calculations, and also to attribute, by using the isolated molecule model, some anharmonic bands in the CH/OH stretching regions 2700–3800 cm−1.

Hierarchical Interdisciplinary Topic Detection Model for Research Proposal Classification

The peer merit review of research proposals has been the major mechanism to decide grant awards. However, research proposals have become increasingly interdisciplinary. It has been a longstanding challenge to assign interdisciplinary proposals to appropriate reviewers so proposals are fairly evaluated. One of the critical steps in reviewer assignment is to generate accurate interdisciplinary topic labels for proposal-reviewer matching. Existing systems mainly collect topic labels manually generated by principle investigators. However, such human-reported labels can be non-accurate, incomplete, labor intensive, and time costly. What role can AI play in developing a fair and precise proposal reviewer assignment system? In this study, we collaborate with the National Science Foundation of China to address the task of automated interdisciplinary topic path detection. For this purpose, we develop a deep Hierarchical Interdisciplinary Research Proposal Classification Network (HIRPCN). Specifically, we first propose a hierarchical transformer to extract the textual semantic information of proposals. We then design an interdisciplinary graph and leverage GNNs to learn representations of each discipline in order to extract interdisciplinary knowledge. After extracting the semantic and interdisciplinary knowledge, we design a level-wise prediction component to fuse the two types of knowledge representations and detect interdisciplinary topic paths for each proposal. We conduct extensive experiments and expert evaluations on three real-world datasets to demonstrate the effectiveness of our proposed model.

DNA metabarcoding of mock communities highlights potential biases when assessing Neotropical fish diversity

AbstractDespite the increasing popularity of DNA metabarcoding in the assessment of aquatic ecosystems using fish eDNA or ichthyoplankton, challenges have hampered its broader application in the Neotropical freshwaters. Using five mock communities composed of fish species from two Neotropical River basins, we evaluated the influence of DNA concentration and choice of mitochondrial 12S molecular markers (MiFish, NeoFish, and Teleo) on species detection and relative read abundance (RRA) using DNA metabarcoding. Of the three 12S markers analyzed, only MiFish detected all species from all mock communities. The performance of a taxonomy‐free approach using ASV/MOTUs was not as precise as assigning DNA reads to species using a curated 12S library that includes approximately 100 fish species since more than one ASV/MOTU was observed for the same specimen. Thus, here we showcase the importance of a custom reference database to allow precise assignment of Neotropical fish species in metabarcoding studies and that the RRA is dependent on community composition, marker, and DNA concentration. We highlight the importance of controlled experiments using known species communities before large investments are made in assessing biodiversity using non‐invasive methods that apply DNA metabarcoding.

Species-Level Taxonomic Characterization of Uncultured Core Gut Microbiota of Plateau Pika.

Rarely has the vast diversity of bacteria on Earth been profiled, particularly on inaccessible plateaus. These uncultured microbes, which are also known as "microbial dark matter," may play crucial roles in maintaining the ecosystem and are linked to human health, regarding pathogenicity and prebioticity. The plateau pika (Ochotona curzoniae) is a small burrowing steppe lagomorph that is endemic to the Qinghai-Tibetan Plateau and is a keystone species in the maintenance of ecological balance. We used a combination of full-length 16S rRNA amplicon sequencing, shotgun metagenomics, and metabolomics to elucidate the species-level community structure and the metabolic potential of the gut microbiota of the plateau pika. Using a full-length 16S rRNA metataxonomic approach, we clustered 618 (166 ± 35 per sample) operational phylogenetic units (OPUs) from 105 plateau pika samples and assigned them to 215 known species, 226 potentially new species, and 177 higher hierarchical taxa. Notably, 39 abundant OPUs (over 60% total relative abundance) are found in over 90% of the samples, thereby representing a "core microbiota." They are all classified as novel microbial lineages, from the class to the species level. Using metagenomic reads, we independently assembled and binned 109 high-quality, species-level genome bins (SGBs). Then, a precise taxonomic assignment was performed to clarify the phylogenetic consistency of the SGBs and the 16S rRNA amplicons. Thus, the majority of the core microbes possess their genomes. SGBs belonging to the genus Treponema, the families Muribaculaceae, Lachnospiraceae, and Oscillospiraceae, and the order Eubacteriales are abundant in the metagenomic samples. In addition, multiple CAZymes are detected in these SGBs, indicating their efficient utilization of plant biomass. As the most widely connected metabolite with the core microbiota, tryptophan may relate to host environmental adaptation. Our investigation allows for a greater comprehension of the composition and functional capacity of the gut microbiota of the plateau pika. IMPORTANCE The great majority of microbial species remain uncultured, severely limiting their taxonomic characterization and biological understanding. The plateau pika (Ochotona curzoniae) is a small burrowing steppe lagomorph that is endemic to the Qinghai-Tibetan Plateau and is considered to be the keystone species in the maintenance of ecological stability. We comprehensively investigated the gut microbiota of the plateau pika via a multiomics endeavor. Combining full-length 16S rRNA metataxonomics, shotgun metagenomics, and metabolomics, we elucidated the species-level taxonomic assignment of the core uncultured intestinal microbiota of the plateau pika and revealed their correlation to host nutritional metabolism and adaptation. Our findings provide insights into the microbial diversity and biological significance of alpine animals.

#4876 CLASSIFICATION OF BIOPSY FINDINGS IN INDIVIDUALS WITH NEPHROPATHIES USING MOLECULAR GENETIC TESTING AND PROTEOMICS

Abstract Background and Aims In approximately 10% of adults with chronic kidney disease, a hereditary cause can be identified. Important representatives are Alport syndrome and inherited podocytopathies, which often show the histological picture of focal segmental glomerulosclerosis (FSGS). FSGS is a histological finding of various etiologies (primary, hereditary, secondary). Especially in suspected glomerular kidney disease, kidney biopsy is the diagnostic gold standard. The aim of this study was to evaluate a cohort of individuals with genetically confirmed inherited nephropathy and previous kidney biopsy to determine whether the histological examination can provide a clue to the underlying inherited kidney disease. Biopsies were further investigated by proteomics via liquid-chromatography-mass spectrometry (LC-MS) to potentially elucidate the underlying protein defect. Method The cohort for this retrospective study consisted of 23 individuals with a genetically confirmed inherited nephropathy and a previously performed kidney biopsy. A systematic pathological secondary review of the 23 biopsies was carried out (genetic diagnosis unknown at secondary review). The findings of the biopsies were compared with the molecular genetic results. 9 proband and 9 control biopsies were additionally evaluated through LC-MS. Laser capture microdissection was used to extract glomeruli from the tissue samples, which were then further analyzed on alterations in protein expression secondary to the respective disease-causing variants. Results In the cohort, disease-causing variants were identified in the following genes: COL4A3 (n = 3), COL4A5 (n = 4), WT1 (n = 3), UMOD (n = 3), and each n = 1 for the genes INF2, DAAM2, MUC1, COQ8B, NPHP4, TRIM8, CD2AP, NPHS2, CLCN5, and PAX2. The biopsies showed predominantly segmental glomerulosclerosis and parenchymal scarring, as well as podocyte damage. Four individuals with the histological diagnosis of Alport syndrome were genetically confirmed as having X-chromosomal (n = 2; including one female carrier) and autosomal-recessive (n = 2) Alport syndrome. Proteomics showed heterogeneous results. Proband samples carried variants in COL4A3 (n = 3), COL4A5 (n = 3), ADCK4, NPHP4, and WT1 (the last three each n = 1). COL4A3 was detected in 6/9 of control samples and in 0/9 of proband samples; COL4A5 was detected in 5/9 of control samples and in 0/9 of proband samples. ADCK4, NPHP4, and WT1 could not be detected in this analysis, neither in control, nor in proband samples. Conclusion In this study, molecular genetic diagnostics allowed a more precise disease assignment and thus provided information on therapy, prognosis, recurrence in the transplant, possible extrarenal phenotypes, and inheritance. Histological findings can indicate an inherited disease and help to trigger genetic testing (e.g., Alport syndrome). However, genetic diagnostics can also classify cases for which there are no typical morphological criteria described or if severe scarring impairs morphological diagnosis. Numerous cases of a respective monogenic disease would have to be analyzed in order to establish common histopathological criteria, if present. This is a challenge due to the rapid discovery of new disease-associated genes and the rarity of the respective diseases. LC-MS-based proteomics from kidney biopsy samples showed to be of limited value in further characterizing changes associated with specific variants. Unlike the genome, which is consistent due to the stability of DNA, the proteome is influenced by various effects: Different stages of fibrosis depending on the time of biopsy and other factors like coexistent disease lead to varying protein intensities even in two separate samples that present identical genetic variants. The detected protein intensity patterns could not be sufficiently correlated with the genetic findings. Despite the detection of certain proteins of interest like type IV collagens, their intensity variation due to advanced tissue damage did not allow reliable conclusions on the underlying cause. Alternatively, molecular methods such as MALDI imaging could further visualize these changes.

Synthesis, Isolation, and Characterization of Two Cationic Organobismuth(II) Pincer Complexes Relevant in Radical Redox Chemistry.

Herein, we report the synthesis, isolation, and characterization of two cationic organobismuth(II) compounds bearing N,C,N pincer frameworks, which model crucial intermediates in bismuth radical processes. X-ray crystallography uncovered a monomeric Bi(II) structure, while SQUID magnetometry in combination with NMR and EPR spectroscopy provides evidence for a paramagnetic S = 1/2 state. High-resolution multifrequency EPR at the X-, Q-, and W-band enable the precise assignment of the full g- and 209Bi A-tensors. Experimental data and DFT calculations reveal both complexes are metal-centered radicals with little delocalization onto the ligands.

A Wireless Rowing Measurement System for Improving the Rowing Performance of Athletes.

The rowing technique is a key factor in the overall rowing performance. Nowadays the athletes' performance is so advanced that even small differences in technique can have an impact on sport competitions. To further improve the athletes' performance, individualized rowing is necessary. This can be achieved by intelligent measurement technology that provides direct feedback. To address this issue, we developed a novel wireless rowing measurement system (WiRMS) that acquires rowing movement and measures muscle activity using electromyography (EMG). Our measurement system is able to measure several parameters simultaneously: the rowing forces, the pressure distribution on the scull, the oar angles, the seat displacement and the boat acceleration. WiRMS was evaluated in a proof-of-concept study with seven experienced athletes performing a training on water. Evaluation results showed that WiRMS is able to assess the rower's performance by recording the rower's movement and force applied to the scull. We found significant correlations (p < 0.001) between stroke rate and drive-to-recovery ratio. By incorporating EMG data, a precise temporal assignment of the activated muscles and their contribution to the rowing motion was possible. Furthermore, we were able to show that the rower applies the force to the scull mainly with the index and middle fingers.

Devonian palynoevents in the circum-Arctic region

Devonian strata of the present-day Arctic contain abundant and diverse assemblages of terrestrial palynomorphs, particularly from Middle and Upper Devonian sections; few intervals of Lower Devonian and Silurian strata have been palynologically studied, and these demonstrate strong palynofloral similarities across the region. Based on published records, we present a compilation of six last occurrence events (LOs), 44 first occurrence events (FOs) and one acme event that have proven of value in correlation in the present-day Arctic. Although their chronostratigraphic resolution is relatively low, and a scarcity of independent age control hampers precise age assignments, palynology is the only biostratigraphic discipline available for confident chronostratigraphic correlation of most Arctic Devonian strata.

Soft-x-ray spectroscopy of coronene+ and (coronene+H)+ cations: The influence of hydrogenation on electronic structure and photofragmentation

We have studied soft-x-ray absorption in coronene and in singly hydrogenated coronene cations. Hydrogenation on the one hand closes the singly occupied molecular orbital of the coronene radical cation and thus decreases the reactivity of the molecule. On the other hand, the additional H atom breaks the coronene ${D}_{6h}$ symmetry and exhibits a comparably small binding energy. The effect of single hydrogenation on soft-x-ray photoionization is therefore hard to predict. In our experiments, the mass selected polycyclic aromatic hydrocarbons' cations were stored in a cryogenic radio-frequency ion trap and exposed to monochromatic x rays with energies around the carbon $K$ edge. The partial photoion yields were recorded as a function of photon energy by means of time-of-flight mass spectrometry. The experimental data was compared to time-dependent density-functional theory calculations based on a short-range corrected functional. The combination of experiment and theory allowed for precise assignment of $1s$ excitations to the resonances in the spectra. We found that these resonant transitions as well as direct $1s$ ionization into the continuum could induce nondissociative ionization, H/${\mathrm{H}}_{2}$ loss, as well as fragmentation of the carbon backbone. For multiple ionization, neutral hydrogen loss was found to compete with fission reactions where ${\mathrm{H}}^{+}$ or ${\mathrm{H}}_{2}{}^{+}$ is released. H attachment was found to substantially decrease backbone fragmentation.

Link assignment of time-reference transfer from the space station to the BeiDou satellite constellation

With the successful in-orbit operation of the cold atomic optical clock in the Mengtian laboratory cabin, a highly precise space time-reference will be formed. The BeiDou navigation satellite constellation has the ability of global coverage. By establishing time-transfer links with BeiDou satellites, the space station can realize precise transfer of its time-reference to wide area users. Aiming at the problem of highly precise and robust time-transfer link assignment from the space station to the BeiDou constellation, a link assignment model was established with taking the maximum hop and the connectivity as the evaluation indexes respectively of the accuracy and robustness of the time-transfer network. A topology optimization algorithm based on the genetic algorithm (GA) was further designed. Taking the time-reference transfer from the space station to the BeiDou Walker constellation as an example, the link assignment simulation was implemented in a minimum common orbit period. The precise time-reference transfer was realized using about 30% of inter-satellite link (ISL) timeslots. The maximum hop of the time-transfer links reached the theoretical optimal value, and the network connectivity was not less than 3. It was demonstrated that with the complex constraints of the ISL system, the payload quantity and visibility, the proposed assignment method could realize highly precise and robust time-reference transfer from the space station to the BeiDou constellation in any operation period.

Advanced characterization of organic–metal and organic–organic interfaces: from photoelectron spectroscopy data to energy-level diagrams

Organic–metal and organic–organic interfaces account for the functionality of virtually all organic optoelectronic applications and the energy-level alignment is of particular importance for device performance. Often the energy-level alignment is simply estimated by metal work functions and ionization energies and electron affinities of the organic materials. However, various interfacial effects such as push back, mirror forces (also known as screening), electronic polarization or charge transfer affect the energy-level alignment. We perform x-ray and ultraviolet photoelectron spectroscopy (XPS and UPS) measurements on copper-hexadecafluorophthalocyanine (F16CuPc) and titanyl-phthalocyanine (TiOPc) thin films on Ag(111) and use TiOPc bilayers to decouple F16CuPc layers from the metal substrate. Even for our structurally well-characterized model interfaces and by stepwise preparation of vacuum-sublimed samples, a precise assignment of vacuum-level and energy-level shifts remains challenging. Nevertheless, our results provide guidelines for the interpretation of XPS and UPS data of organic–metal and organic–organic interfaces.

Competitor hydrogen-bond acceptors in the SP(NH)3-based structures: Comparison of structural features – Computational/database and experimental

The phosphorothioic triamides (4-Cl-C6H4CH2NH)3P(S) (I) and (4-CH3-C6H4CH2NH)3P(S) (II) were synthesized to study their coordination behaviors towards Hg(II) cation. The resulting complexes, [(4-Cl-C6H4CH2NH)3P(S)]2Hg2Cl4 (III) and [(4-CH3-C6H4CH2NH)3P(S)]2Hg2Cl4 (IV), are the first examples of mercury complexes with SP(NHR)3 ligands characterized by X-ray crystallography. The presence of NH/CH units and some potential competitor acceptors with moderate/weak acceptor capabilities (sulfur, chlorine and π system) provides the opportunity to study the hydrogen bond elements of (I), (III) and (IV), structurally and of all four compounds theoretically. The strengths of inter- and intramolecular hydrogen bonds were assessed by quantum chemical calculations (Atoms In Molecules (AIM), and Natural Bond Orbital (NBO)), and the internal interactions were further examined by reduced density gradient (RDG) analysis. The differences/similarities of structures were addressed in the view point of geometry, conformations related to flexible substituted benzyl moieties, crowding in the structures and non-bonded contacts, stabilization of four-membered Hg2Cl2 rings and some topics related to solution nuclear magnetic resonance studies (chemical shifts and coupling constants). The similarity of structures investigated allowed for a precise assignment of vibrational frequencies. A survey of the Hg—SP segment in the Cambridge Structural Database shows that the Hg—S bond lengths in (III) and (IV) are among the smallest Hg—S bonds in the structures with the thiophosphoryl-holding ligands.

Adaptive mutant particle swarm optimization based precise cargo airdrop of unmanned aerial vehicles

Emerging unmanned system technologies and smart logistics have motivated logistics enterprises to use unmanned aerial vehicles (UAVs) for last-mile cargo delivery through the air so as to benefit from its flexibility and low cost. It is useful to deliver cargoes by airdrops from fixed-wing UAVs. However, wind and parameter errors of the UAV could make the cargo deviate from the desired landing point. To improve the accuracy of airdrop methods, this paper presents the Continuously Computed Release Point under conditions of strong wind (SW-CCRP) airdrop strategy to transport the cargo to a given position by a fixed-wing UAV. In this strategy, a set of differential equations are used to model the cargo motion and wind perturbations are considered. Based on the established motion model and the kinematic relationships between the cargo and the target position, the expected release point can be accurately predicted in real time. In order to satisfy the precision requirement, the precision assignment is studied to determine the permissible parameter error ranges. In view of that the conventional precision assignment methods are difficult to be applied in the airdrop system because of its complexity and strong nonlinearity, an adaptive mutant particle swarm optimization (AMPSO) algorithm is proposed to solve this problem, in which the adaptive inertia weight can balance the global and local search. In addition, the mutation factor of the AMPSO is able to avoid premature convergence and stagnation. Finally, two specific test scenarios are designed to validate the effectiveness of the proposed approaches.

(Digital Presentation) Mass Spectroscopic Products Analysis during Charging of Li-O2 Cell with Tegdme Based Electrolyte

Rechargeable lithium-air battery (LAB) is considered to be one of the most promising energy storage devices because of its large theoretical energy density. Despite significant efforts by many research groups, LAB is still far from practical use and many problems must be overcome [1]. The first problem is associated with the use of air as it contains many components other than oxygen including N2, water, and CO2, which interfere battery reactions. Thus, most of the fundamental studies are not on LAB but on Lithium-oxygen battery (LOB), which uses pure oxygen as an active material. Even LOB has many serious problems, including low cyclability caused by (1) high charging overpotential, which induces degradation of positive electrode (carbon) and electrolyte solution, and (2) degradation/dendrite formation of negative Li metal electrode. To improve the cyclability, it is essential to clarify the mechanism of degradation of electrodes and electrolyte.Here we employed mass spectroscopy to follow products generation during charging so that we can clarify the degradation mechanisms of electrodes and electrolyte. Porous carbon sheet (KJCNT from KJ Specialty Paper), lithium metal (Honjo Metal), 1 M LiTFSI TEGDME (both from Sigma-Aldrich) solution, PE separator (W-Scope), and stainless steel mesh (Hohsen) were used as positive electrode, negative electrode, electrolyte, separator, and gas diffusion layer, respectively. Isotope exchanged TEGDME, i.e., 13CH3-TEGDME and CD3-TEGDME, which were synthesized in our laboratory, and 18O2 (Taiyo Nippon Sanso) were used for mass spectroscopy for precise products assignments. Details of set-up for mass analysis have been reported elsewhere [2]. We carried out online QMS (Quadrupole Mass Spectrometer) measurement for mass numbers of decomposition products between 12-90 during the potential sweep from OCP to 4.8 V (0.05 mV/s).Figure 1 shows the current and mass signals of m/z = 18 (H2O), 32 (O2), and 44 (CO2) as a function of potential. It is clear that current increased immediately as potential was scanned from OCP (~2.8 V ), reached a maximum at 3.3 V, decreased gradually, reached a minimum at 4.0 V, increased again to reach a maximum at 4.4 V, decreased to reach a minimum at 4.6 V and increased again. The potential dependence of O2 signal is very similar to that of current as the main battery reaction is Li2O2 → 2Li+ + O2 + 2e-. Two clear peaks were observed at around 3.3 V and 4.4V, showing the presence of two kinds of Li2O2 [3]. The H2O signal started to increase just after the 1st current/O2 peaks where the current efficiency for O2 generation current efficiency started to decrease, suggesting the H2O formation is related to the decrease of the current efficiency. The CO2 signal started to be significant at 4.1 V where current and the O2 signals started to increase again and reached a maximum at ca. 4.5 V, which is more positive than those of current and O2 signal but equal to H2O peak. Although current increased again significantly at potentials more positive than 4.65 V, no mass signals of O2, H2O and CO2 increased. Instead signals such as m/z = 15, 29, 31, 45, and 60, which are related to organic molecules derived from TEGDME, became significant. Figure 2 shows the online QMS results at 4.65 V. We can see that various mass signals such as 15, 29, etc. were observed at this potential. By careful analysis of the results with the assistance of isotopes 18O2, 13CH3-TEGDME, and CD3-TEGDME, presence of CH3OH, HCHO and other organic molecules with high vapor pressure originated from TEGDME were confirmed. Additionally, we detected molecules with low vapor pressure such as CH3O(CH2)2OH, CH3OCH2COCH3, etc., which were derived from TEGDME by GC/MS analysis of samples collected every 1hr. Based on the products detected by online QMS and GC/MS, possible degradation mechanism of electrolyte can be deduced. I will discuss the degradation mechanism of electrolyte based on the above results.[1] Liu T., et al. Current challenges and routes forward for nonaqueous lithium–air batteries. Chemical reviews, 2020, 120(14): 6558-6625.[2] Ue, M., et al. Material balance in the O2 electrode of Li–O2 cells with a porous carbon electrode and TEGDME-based electrolytes, RSC Advances, 2020, 10(70): 42971 - 42982.[3] Nishioka K, et al. Isotopic depth profiling of discharge products identifies reactive interfaces in an aprotic Li–O2 battery with a redox mediator. Journal of the American Chemical Society, 2021, 143(19): 7394-7401. Figure 1

A Straightforward HPV16 Lineage Classification Based on Machine Learning.

Human Papillomavirus (HPV) is the causal agent of 5% of cancers worldwide and the main cause of cervical cancer and it is also associated with a significant percentage of oropharyngeal and anogenital cancers. More than 60% of cervical cancers are caused by HPV16 genotype, which has been classified into lineages (A, B, C, and D). Lineages are related to the progression of cervical cancer and the current method to assess lineages is by building a Maximum Likelihood Tree (MLT); which is slow, it cannot assess poor sequenced samples, and annotation is done manually. In this study, we have developed a new model to assess HPV16 lineage using machine learning tools. A total of 645 HPV16 genomes were analyzed using Genome-Wide Association Study (GWAS), which identified 56 lineage-specific Single Nucleotide Polymorphisms (SNPs). From the SNPs found, training-test models were constructed using different algorithms such as Random Forest (RF), Support Vector Machine (SVM), and K-nearest neighbor (KNN). A distinct set of HPV16 sequences (n = 1,028), whose lineage was previously determined by MLT, was used for validation. The RF-based model allowed a precise assignment of HPV16 lineage, showing an accuracy of 99.5% in the known lineage samples. Moreover, the RF model could assess lineage to 273 samples that MLT could not determine. In terms of computer consuming time, the RF-based model was almost 40 times faster than MLT. Having a fast and efficient method for assigning HPV16 lineages, could facilitate the implementation of lineage classification as a triage or prognostic marker in the clinical setting.

UPS, XPS, NEXAFS and Computational Investigation of Acrylamide Monomer

Acrylamide is a small conjugated organic compound widely used in industrial processes and agriculture, generally in the form of a polymer. It can also be formed from food and tobacco as a result of Maillard reaction from reducing sugars and asparagine during heat treatment. Due to its toxicity and possible carcinogenicity, there is a risk in its release into the environment or human intake. In order to provide molecular and energetic information, we use synchrotron radiation to record the UV and X-ray photoelectron and photoabsorption spectra of acrylamide. The data are rationalized with the support of density functional theory and ab initio calculations, providing precise assignment of the observed features.

SMART: An Open-Source Extension of WholeBrain for Intact Mouse Brain Registration and Segmentation.

Mapping immediate early gene (IEG) expression across intact mouse brains allows for unbiased identification of brain-wide activity patterns underlying complex behaviors. Accurate registration of sample brains to a common anatomic reference is critical for precise assignment of IEG-positive (“active”) neurons to known brain regions of interest (ROIs). While existing automated voxel-based registration methods provide a high-throughput solution, they require substantial computing power, can be difficult to implement and fail when brains are damaged or only partially imaged. Additionally, it is challenging to cross-validate these approaches or compare them to any preexisting literature based on serial coronal sectioning. Here, we present the open-source R package SMART (Semi-Manual Alignment to Reference Templates) that extends the WholeBrain R package framework to automated segmentation and semi-automated registration of intact mouse brain light-sheet fluorescence microscopy (LSFM) datasets. The SMART package was created for novice programmers and introduces a streamlined pipeline for aligning, registering, and segmenting LSFM volumetric datasets across the anterior-posterior (AP) axis, using a simple “choice game” and interactive menus. SMART provides the flexibility to register whole brains, partial brains or discrete user-chosen images, and is fully compatible with traditional sectioned coronal slice-based analyses. We demonstrate SMART’s core functions using example datasets and provide step-by-step video tutorials for installation and implementation of the package. We also present a modified iDISCO+ tissue clearing procedure for uniform immunohistochemical labeling of the activity marker Fos across intact mouse brains. The SMART pipeline, in conjunction with the modified iDISCO+ Fos procedure, is ideally suited for examination and orthogonal cross-validation of brain-wide neuronal activation datasets.

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.