bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mapping the Ultrafast Mechanistic Pathways of Co Photocatalysts in Pure Water through Time‐Resolved X‐ray Spectroscopy
Authors: Velasco Lucia , Liu Cunming , Zhang Xiaoyi , Grau Sergi , Gil‐Sepulcre Marcos , Gimbert‐Suriñach Carolina , Picón Antonio , Llobet Antoni , DeBeer Serena , Moonshiram Dooshaye 
Published: August 2023

AbstractNanosecond time‐resolved X‐ray (tr‐XAS) and optical transient absorption spectroscopy (OTA) are applied to study 3 multimolecular photocatalytic systems with [Ru(bpy)3]2+photoabsorber, ascorbic acid electron donor and Co catalysts with methylene (1), hydroxomethylene (2) and methyl (3) amine substituents in pure water. OTA and tr‐XAS of 1 and 2 show that the favored catalytic pathway involves reductive quenching of the excited photosensitizer and electron transfer to the catalyst to form a CoII square pyramidal intermediate with a bonded aqua molecule followed by a CoI square planar derivative that decays within ≈8 μs. By contrast, a CoI square pyramidal intermediate with a longer decay lifetime of ≈35 μs is formed from an analogous CoII geometry for 3 in H2O. These results highlight the protonation of CoI to form the elusive hydride species to be the rate limiting step and show that the catalytic rate can be enhanced through hydrogen containing pendant amines that act as H−H bond formation proton relays.
Mechanistic Insights into Formation of Residual Solid in Lignin Depolymerization
Authors: Lv Kaiqi , Chen Zhengjian , Zhang Jiaheng , Liu Yong , Long Jinxing 
Published: August 2023

AbstractCurrent techniques of lignin conversion are challenged by the low carbon utilization efficiency resulting from the severe generation of residual solid (char). Therefore, a better understanding of pathway for char formation is significant and highly desired for lignin valorization. In this work, we propose a fundamental mechanistic insight into char formation in lignin depolymerization, using hydrothermal decomposition as model reaction. The results demonstrate that the char featuring a multi‐layer construction of coke and oligomer contains mainly G units, primarily generated from native G‐lignin and demethoxylation of S‐lignin. Instead, H‐lignin contributes to the formation of volatile monophenols. Furthermore, new methylene bridges form between the benzene rings in lignin, which consequently results in the formation of recalcitrant char. Based on these observations, a plausible mechanism for char formation is proposed and verified by the density functional theory calculation.
A new continuous Class‐E mode based on the general theory of high‐efficiency continuous power amplifier
Authors: Wei Xuepeng , Luo Yonglun , Wu Yulan , Yuan Guoqing , Chang Rong , Hong Guoping 
Published: August 2023

SummaryBy multiplying with the continuous factor (CF), the conventional Class‐
, Class‐J power amplifier (PA) can be expanded to their corresponding continuous modes, resulting in a great degree of freedom for broadband design. However, this method can hardly apply to other types of PAs. In view of this problem, the continuous mode is deeply analyzed from the perspective of equation solving for the first time, and a general theory for high‐efficiency broadband continuous PA design is proposed. In this theory, the continuous impedance space does not rely on a mapping relationship achieved by multiplying with the CF, but on a direct solution of the high‐efficiency equations to obtain the broadband design space. This approach is simpler and has the potential to provide greater design space. As a validation, this theory is used for the analysis of Class‐E PAs and a new continuous Class‐E (NC‐E) PA is presented. With knee‐point voltage and finite harmonics taken into account, this type of PA greatly expands the broadband design space of Class‐E PAs and also has the advantage of harmonic matching. The NC‐E PA is designed and manufactured using GaN HEMT CGH40010F, which achieves 40.6–41.6 dBm output power and 66.2%–74.2% drain efficiency (DE) in the frequency band of 2.5–3.8 GHz.
Role of cytoblock on pleural effusion for diagnosis of malignant disease
Authors: Shahini Labinot , Hoxha Musa , Marku Flamur , Morina Besim , Cena Valon , Kabashi Klodete , Mustafa Luan 
Published: August 2023

AbstractBackgroundThoracocentesis of pleural effusion is a simple technique for pleural fluid examination through cytology. In addition to cytological examination to assess the nature of pleural fluid content, we can also perform more detailed examinations through cytoblocks of residual fluid. These paraffin‐embedded cytoblock samples are important because we can perform examinations as in other bioptic samples. In these samples, immunohistochemical and molecular analyses can be performed.MethodsTwo hundred fifty‐five cytological samples from patients with pleural effusion were examined. In cases in which the presence of malignant cells was identified in the cytological examination, as well as cases that were suspicious but not definitive for the presence of a malignant effusion, a cytoblock was prepared. Histological examination and immunohistochemical analysis were performed.ResultsAmong 255 cases with pleural effusion, 152 had the presence of malignant cells and 6 cases were suspicious, but uncertain for the presence of malignant cells, while 86 cases had inflammatory pleural effusion or other pathologies but were not malignant. After histological analysis of the cytoblock and immunohistochemical analysis, we identified 82 malignant tumors of the lung, 8 malignant tumors of the gastrointestinal tract, 15 malignant tumors of the breast, and 6 malignant tumors of the female genital tract, as well as 24 tumors of undetermined origin.ConclusionsCytoblocks are important for the diagnosis of the primary nature of malignant pleural effusions. The highest importance is primary lung tumors, as well as those tumors in which the primary site of the tumor cannot be determined clinically.
Detection of doping peptides and basic drugs in equine urine using liquid chromatography–mass spectrometry
Authors: Flores Luis , Hargrave Sabine , Clifford Amel , Alarcio Gwendolyne , Moeller Benjamin C. 
Published: August 2023

AbstractThe abuse of prohibited agents including peptides and basic small‐molecule drugs is an area of great concern in horseracing due to their high potential to act as doping agents. These compound classes include agents such as growth hormone‐releasing peptides, peptide analgesics, beta‐2‐adrenergic receptor agonists, and quaternary ammonium drugs that can be challenging to detect and regulate because of their chemical properties and potential rapid elimination following administration. The use of highly sensitive and selective analytical techniques such as liquid chromatography–mass spectrometry (LC–MS) is necessary to provide coverage of these substances and their potential metabolites. This study describes the development and validation of methodology capable of the detection of over 50 different peptide‐based doping agents, related secretagogues, quaternary ammonium drugs, and other challenging small molecules in equine urine following solid‐phase extraction using a mixed mode weak cation exchange sorbent. Following sample extraction, the compounds were analyzed using LC–MS with chromatographic separation via a reverse phase gradient and detection via selective reaction monitoring following introduction to a triple‐stage quadrupole mass spectrometer using positive mode electrospray ionization. Validation parameters including limits of detection and quantitation, accuracy, precision, linear range, recovery, stability, and matrix effects were determined. Briefly, the limits of detection for most compounds were in the sub‐ng/mL ranges with adequate precision and accuracy sufficient for an initial testing procedure. Stability studies indicated that most compounds were sufficiently stable to allow for effective screening using conditions commonly utilized in drug testing laboratories.
Fission–fusion dynamics in the social networks of a North American pitviper
Authors: Tetzlaff Sasha J. , Vizentin‐Bugoni Jeferson , Sperry Jinelle H. , Davis Mark A. , Clark Rulon W. , Repp Roger A. , Schuett Gordon W. 
Published: August 2023

AbstractMany animal species exist in fission–fusion societies, where the size and composition of conspecific groups change spatially and temporally. To help investigate such phenomena, social network analysis (SNA) has emerged as a powerful conceptual and analytical framework for assessing patterns of interconnectedness and quantifying group‐level interactions. We leveraged behavioral observations via radiotelemetry and genotypic data from a long‐term (>10 years) study on the pitviper Crotalus atrox (western diamondback rattlesnake) and used SNA to quantify the first robust demonstration of social network structures for any free‐living snake. Group‐level interactions among adults in this population resulted in structurally modular networks (i.e., distinct clusters of interacting individuals) for fidelis use of communal winter dens (denning network), mating behaviors (pairing network), and offspring production (parentage network). Although the structure of each network was similar, the size and composition of groups varied among them. Specifically, adults associated with moderately sized social groups at winter dens but often engaged in reproductive behaviors—both at and away from dens—with different and fewer partners. Additionally, modules formed by individuals in the pairing network were frequently different from those in the parentage network, likely due to multiple mating, long‐term sperm storage by females, and resultant multiple paternity. Further evidence for fission–fusion dynamics exhibited by this population—interactions were rare when snakes were dispersing to and traversing their spring–summer home ranges (to which individuals show high fidelity), despite ample opportunities to associate with numerous conspecifics that had highly overlapping ranges. Taken together, we show that long‐term datasets incorporating SNA with spatial and genetic information provide robust and unique insights to understanding the social structure of cryptic taxa that are understudied.
Can Bengal Tiger (Panthera tigris tigris) endure the future climate and land use change scenario in the East Himalayan Region? Perspective from a multiple model framework
Authors: Deka Jyotish Ranjan , Ali Sk. Zeeshan , Ahamad Mujahid , Borah Priyanka , Gopi Govindan Veeraswami , Badola Ruchi , Sharma Rabindra , Hussain Syed Ainul 
Published: August 2023

AbstractLarge mammals are susceptible to land use and climate change, unless they are safeguarded within large, protected areas. It is crucial to comprehend the effects of these changes on mammals to develop a conservation plan. We identified ecological hotspots that can sustain an ecosystem for the endangered Bengal tiger (Panthera tigris tigris), an umbrella species. We developed three distinct ensemble species distribution models (SDMs) for the Bengal tiger in the Indian East Himalayan Region (IEHR). The first model served as the baseline and considered habitat type, climate, land cover, and anthropogenic threats. The second model focused on climate, land use, and anthropogenic threats, the third model focused on climate variables. We projected the second and third models onto two future climate scenarios: RCP 4.5 and RCP 8.5. We evaluated the threats possess to protected areas within eco‐sensitive zone based on the potential tiger habitat. Finally, we compared the potential habitat with the IUCN tiger range. Our study revealed that the Brahmaputra valley will serve as the primary habitat for tigers in the future. However, considering the projected severe climate scenarios, it is anticipated that tigers will undergo a range shift towards the north and east, especially in high‐altitude regions. Very high conservation priority areas, which make up 3.4% of the total area, are predominantly located in the riverine corridor of Assam. High conservation priority areas, which make up 5.5% of total area are located in Assam and Arunachal Pradesh. It is important to note that conservation priority areas outside of protected areas pose a greater threat to tigers. We recommend reassessing the IUCN Red List's assigned range map for tigers in the IEHR, as it is over‐predicted. Our study has led us to conclude both land use and climate change possess threats to the future habitat of tigers. The outcomes of our study will provide crucial information on identifying habitat hotspots and facilitate appropriate conservation planning efforts.
Ecogroups and maternal haplogroups reveal the ancestral origin of native Chinese goat populations based on the variation of mtDNA D‐loop sequences
Authors: Qin Wenjuan , Chen Daosong , Guo Panpan , Hu Lixing , Zheng Xiaodong , Cheng Jin , Chen Hongquan 
Published: August 2023

AbstractChina is rich in goat breeding resources. Officially recognized local goat breeds are mainly distributed in agro‐ecological regions. The population structure and matrilineal origin of native Chinese goats can be used to formulate protection and utilization strategies for these genetic resources. In this study, the genetic structure and maternal origin of native Chinese goats were investigated using mtDNA D‐loop sequences. A total of 329 goat samples from 25 Chinese indigenous goat populations and five introduced goat breeds from abroad were collected; these populations were distributed in four ecogroups designated as Southwest, South‐central, the North China Plain, and Foreign‐ecogroup. A larger average number of nucleotide differences and richer nucleotide diversity were observed in South‐central and Foreign‐ecogroup, whereas these were lower in Southwest. The 216 haplotypes divided into several haplogroups, of which HapA contained 99 haplotypes distributed in Southwest, the North China Plain, and Foreign‐ecogroup with high frequency (0.53–0.77), whereas the frequency of HapA in South‐central was <0.09. HapB was mostly found in South‐central (0.5538) and was distributed to the North China Plain (0.2667), while it was rare in Southwest (<0.08) and Foreign‐ecogroup (<0.07). According to the estimation of kinship and ancestry, HapA had five ancestors (A2, A3, A5, A10, and A12), HapB had a single maternal ancestor (A8), and HapC had two maternal ancestors (A1 and A4). This study showed that native Chinese goat breeds were mainly divided into three haplogroups (HapA, HapB, and HapC) and goat populations have expanded in the ecological regions.
Erosion regime controls sediment environmental DNA‐based community reconstruction
Authors: Morlock Marina A. , Rodriguez‐Martinez Saúl , Huang Doreen Yu‐Tuan , Klaminder Jonatan 
Published: August 2023

AbstractAnalysis of environmental DNA detected in lake sediments shows promise to become a great paleoecological technique that can provide detailed information about organism communities living in past environments. However, when interpreting sedimentary environmental DNA records, it is of crucial importance to separate ecosystem responses to large‐scale environmental change from “noise” caused by changes in sediment provenance or potential post‐depositional DNA mobility. In this study, we show that plant and mammalian communities reconstructed from sediments are strongly affected by sediment provenance, but unaffected by vertical mobility of DNA after sediment deposition. We observe that DNA from aquatic plants was abundant in background sediment, while embedded detrital event layers (sediment deposited under erosion events) primarily contained terrestrial plants; hence, vertical mobility of aquatic plant DNA across sediment layers was negligible within our studied lakes. About 33% of the identified terrestrial plant genera were only found in detrital sediment, suggesting that sediment origin had a strong impact on the reconstructed plant community. Similarly, DNA of some mammalian taxa (Capra hircus, Ursus arctos, Lepus, and Felis) were only or preferentially found in detrital event layers. Temporal changes across the Holocene were the main drivers of change for reconstructed plant communities, but sediment type was the second most important factor of variance. Our results highlight that erosion and sediment provenance need to be considered when reconstructing past mammalian and plant communities using environmental DNA from lake sediments.
Regioselective Rhodium‐Catalyzed 1,2‐Hydroboration of Pyridines and Quinolines Enabled by the Tris(8‐quinolinyl)phosphite Ligand**
Authors: Chacón‐Terán Miguel A. , Landaeta Vanessa R. , Wolf Robert , Rodríguez‐Lugo Rafael E. 
Published: August 2023

AbstractA Rh(I) complex [κ2(P,N)‐{P(Oquin)3}RhCl(PPh3)] (1) bearing the P,N ligand tris(8‐quinolinyl)phosphite, P(Oquin)3, has been synthesized and structurally characterized. The molecular structure of complex 1 shows that P(Oquin)3 acts as a bidentate P,N chelate ligand. Reactivity studies of 1 reveal that the triphenylphosphine ligand can be replaced by Pcy3 or removed upon oxidation with concomitant coordination of a second 8‐quinolyl unit of P(Oquin)3. In addition, the Rh(III) complex [RhCl2{OP(Oquin)2}] (3), resulting from treating 1 with either wet CDCl3 or, sequentially, with HCl and water, was identified by X‐ray diffraction analysis. Complex 1 catalyzes the 1,2‐regioselective hydroboration of pyridines and quinolines, affording N‐boryl‐1,2‐dihydropyridines (1,2‐BDHP) and N‐boryl‐1,2‐hydroquinolines (1,2‐BDHQ) in high yield (up to >95 %) with turnover numbers (TONs) of up to 130. The system tolerates a variety of substrates of different electronic and steric nature. In comparison with other transition‐metal‐based hydroboration catalysts, this system is efficient at a low catalyst loading without the requirement of base or other additives.
Multienzymatic Synthesis of γ‐Lactam Building Blocks from Unsaturated Esters and Hydroxylamine
Authors: Jäger Christina , Nieger Martin , Rissanen Kari , Deska Jan 
Published: August 2023

AbstractThe assembly of enzymatic cascades and multi‐step reaction sequences represents an attractive alternative to traditional synthetic‐organic approaches. The biocatalytic reaction mediators offer not only mild conditions and permit the use of environmentally benign reagents, but the high compatibility of different enzymes promises more streamlined reaction setups. In this study, a triple‐enzymatic strategy was developed that enables the direct conversion of γ,δ‐unsaturated esters to N‐hydroxy‐γ‐lactam building blocks. Hereby, a lipase‐catalyzed hydroxylaminolysis generates hydroxamic acid intermediates that are subsequently aerobically activated by horseradish peroxidase and glucose oxidase to cyclize in an intramolecular nitroso ene reaction. Utilizing the hydroxylaminolysis/ene‐cyclization sequence for the preparation of an aza‐spirocyclic lactam, the multi‐enzymatic methodology was successfully employed in the synthesis of key intermediates en route to alkaloids of the Cephalotaxus family.
A review of the zone broadening contributions in free‐flow electrophoresis
Authors: Mahmud Sakur , Ramproshad Sarker , Deb Rajesh , Dutta Debashis 
Published: August 2023

AbstractThe broadening of analyte streams, as they migrate through a free‐flow electrophoresis (FFE) channel, often limits the resolving power of FFE separations. Under laminar flow conditions, such zonal spreading occurs due to analyte diffusion perpendicular to the direction of streamflow and variations in the lateral distance electrokinetically migrated by the analyte molecules. Although some of the factors that give rise to these contributions are inherent to the FFE method, others originate from non‐idealities in the system, such as Joule heating, pressure‐driven crossflows, and a difference between the electrical conductivities of the sample stream and background electrolyte. The injection process can further increase the stream width in FFE separations but normally influencing all analyte zones to an equal extent. Recently, several experimental and theoretical works have been reported that thoroughly investigate the various contributions to stream variance in an FFE device for better understanding, and potentially minimizing their magnitudes. In this review article, we carefully examine the findings from these studies and discuss areas in which more work is needed to advance our comprehension of the zone broadening contributions in FFE assays.
Improved method for positioning crane grab boom corner points using Hough transform and k‐means clustering
Authors: Wang Min , Wan Longkun , Zhao Chengli , Zhao Zhangyan 
Published: August 2023

AbstractIn the process of automatic grabbing of bridge segment beams, it is crucial to accurately locate and align the corner points of the crane's boom with the beam's lifting holes. This requires the utilization of image processing techniques to precisely detect and locate the corner points of the crane's boom. Existing feature matching methods face challenges such as low detection accuracy and unsuitability for this specific scenario. This article proposes a novel approach for corner point localization by using the intersection points of lines, facilitating the matching of feature points between left and right images. The method consists of three steps: first, a grayscale difference map is constructed by utilizing the R and G channels of the RGB color space. This enhances the bimodal characteristics of the grayscale histograms between the foreground and background, which facilitates the subsequent binarization process. Additionally, opening and closing operations are employed to remove small artifacts from the Canny edge detection results, effectively reducing noise. Second, an adaptive thresholding method based on the mean and variance of Hough transform voting scores is proposed. This method filters out interference lines from the clustering results by selecting appropriate voting scores. Furthermore, an improved centroid calculation method is introduced, which utilizes weighted formulas based on different proportions of voting scores. These weighted formulas replace the original clustering centroids as the basis for line fitting. Finally, the corner coordinates of the crane's boom are computed based on the line fitting results, and the recognition accuracy is compared under different lighting conditions. Experimental results demonstrate that the proposed algorithm exhibits smaller detection errors and higher robustness compared to other corner detection algorithms, particularly when there are numerous interference edge points in the edge detection results. The computed corner coordinates achieve pixel‐level accuracy. The algorithm performs optimally under strong supplementary lighting conditions, with an average detection error percentage of 97.1% within 0–2 pixels and a recognition accuracy of 98.6%. The recognition success rates under different lighting conditions are all above 92.9%. This method is superior to traditional corner detection methods, meets the requirements for automatic grabbing of the boom, and holds practical engineering value. It provides a basis for addressing the accuracy and robustness challenges of crane algorithms influenced by multiple environmental factors.