bluuebunny/crossref_metadata_2025_split huggingface dataset:
From a P‐Bridging Phosphaketene to μ‐Phosphinidenide and μ‐Diphosphaurea Units at a Dinickel Core
Authors: Schulz Roland A. , Karaca Uhut S. , Diefenbach Martin , Werthmann Niclas J. A. , Dechert Sebastian , Hansmann Max M. , Holthausen Max C. , Meyer Franc 
Published: November 2024

AbstractSalt metathesis of dinickel(II) complex LNi2Br (1; L is a dinucleating pyrazolate ligand with two β‐diketiminato chelate arms) with Na(OCP) ⋅ (dioxane)2.5 yielded LNi2(PCO) (2) with a P‐bridging phosphaethynolate. Further reaction of 2 with benzyl isocyanide or with an N‐heterocyclic carbene (NHC) triggered decarbonylation and gave LNi2(PCN‐CH2Ph) (3) and LNi2P(NHC) (4) with P‐bridging cyanophosphide and NHC‐phosphinidenide, respectively. Electronic structure analysis indicated a μ2‐η2 : η1 binding mode of the PCO− anion between the two NiII ions in 2, which is even more pronounced for the [PCN(−CH2Ph)]− anion in 3. DFT assessment of the formation mechanism of 4 showed that attack at the phosphaketene‐C atom is kinetically preferred but reversible and unproductive, while kinetically more demanding back‐side SN2 attack at the phosphaketene‐P atom triggers CO release with 4 as thermodynamic product. Nucleophilic addition at the phosphaketene‐C could be demonstrated by the strongly exergonic reaction of 2 with KPPh2, giving unstable K[LNi2(P(O)CPPh2)] (5) with a P‐bridging and K+‐stabilized diphosphaurea derivative. All new complexes 2–5 have been comprehensively characterized, including by X‐ray diffraction.
Temperature‐Driven Axial‐Equatorial Isomerism and Magnetic Relaxation on Low‐Spin Co(II) Borohydride Complexes
Authors: Wang Jing‐Yu , Li Zhen , Zhang Lu , Chen Yan‐Cong , Ruan Ze‐Yu , Du Shan‐Nan , Deng Wei , Wu Si‐Guo , Liu Jun‐Liang , Tong Ming‐Liang 
Published: November 2024

Comprehensive SummaryCrystalline materials with diastereomerism serve as ideal prototypes for investigating the influence of coordination environments on chemophysical properties. In this study, we synthesized a pair of axial‐equatorial isomers [Co(II)(HB(timtBu)3)(cis‐dppen)](BF4)·solv ([HB(timtBu)3]− = hydrotris(3‐tertbutyl‐2‐thioxoimidazol‐1‐yl)borate; cis‐dppen = cis‐1,2‐bis(diphenylphosphino)ethene; solv = 0.5THF·2H2O and 2H2O for ax‐CoHS2P2 and eq‐CoHS2P2, respectively), by varying the crystallization temperatures. Despite both diastereoisomers adopting distorted square pyramidal geometries, the bidentate cis‐dppen ligand chelates to the central Co(II) either in an axial‐equatorial or equatorial‐equatorial manner, with a boron‐hydrogen binding to the metal center. Magnetic studies reveal differences in g‐values between these axial‐equatorial isomers. X‐band electron paramagnetic resonance spectra suggest rapid equilibrium and potential conformational interconversion in response to temperature changes in solution. Magnetic measurements indicate field‐induced slow relaxation of magnetization in this low‐spin S = 1/2 system, with spin‐lattice relaxations dominated by Raman and quantum tunneling of magnetization mechanisms due to the absence of thermally populated excited states.
Long‐term follow‐up of a phase 2 study of all‐trans retinoic acid, arsenic trioxide, and gemtuzumab ozogamicin in acute promyelocytic leukemia
Authors: Jen Wei‐Ying , Marvin‐Peek Jennifer , Kantarjian Hagop M. , Alvarado Yesid , Borthakur Gautam , Jabbour Elias , Wierda William , Kadia Tapan M. , Daver Naval G. , DiNardo Courtney D. , Short Nicholas J. , Jain Nitin , Ferrajoli Alessandra , Kornblau Steven , Yilmaz Musa , Ohanian Maro , McCue David , Burger Jan , Hammond Danielle , Patel Keyur , Issa Ghayas C. , Pemmaraju Naveen , Sasaki Koji , Maiti Abhishek , Abbas Hussein A. , Chien Kelly , Takahashi Koichi , Haddad Fadi , Bose Prithviraj , Masarova Lucia , Montalban‐Bravo Guillermo , Swaminathan Mahesh , Brandt Mark , Pierce Sherry , Garcia‐Manero Guillermo , Ravandi Farhad 
Published: November 2024

AbstractBackgroundAll‐trans retinoic acid (ATRA) and arsenic trioxide (ATO) combinations have produced excellent outcomes in patients with standard‐risk acute promyelocytic leukemia (APL). Herein, the authors update their long‐term results with the regimen of ATO‐ATRA and gemtuzumab ozogamicin (GO) in standard‐risk and high‐risk APL.MethodsThis was a phase 2 trial of patients with newly diagnosed APL. Induction comprised ATRA 45 mg/m2 and ATO 0.15 mg/kg daily. GO 6–9 mg/m2 was added for high‐risk patients and for standard‐risk patients who developed leukocytosis >10 × 109/L. Consolidation consisted of four courses of ATO‐ATRA, with GO for patients who had PML::RARA persistence.ResultsOne hundred forty‐six patients (median age, 53.0 years; range, 19.3–83.9 years) were treated, including 106 patients (72.6%) with standard‐risk APL and 40 (27.4%) with high‐risk APL. GO was administered to 68 standard‐risk patients (64.2%) for leukocytosis. The complete remission rate was 93.8% (95% confidence interval [CI], 92.2%–98.5%). Negative measurable residual disease status was achieved in 97.1% of patients who attained complete remission. At a median follow‐up of 61.8 months (95% CI, 4.7–128.4 months), the 5‐year event‐free survival, disease‐free survival, and overall survival rates were 92.4% (95% CI, 87.9%–97.1%), 93.6% (95% CI, 89.5%–97.8%), and 93.1% (95% CI, 88.9%–97.7%), respectively. Induction mortality was 2.7%. The most common severe adverse events were elevated transaminases in 41.0% of patients and infection in 13.7%. There were no cases of veno‐occlusive disease.ConclusionsThe combination of ATO‐ATRA and GO was curative in 94% of patients who had APL with a favorable safety profile (ClinicalTrials.gov identifier NCT01409161).
Understanding Ion‐specific “Hofmeister” Effects in Enzyme Catalysis through using RNase A as a Paradigm Model
Authors: Taghavi Shahraki Bahareh , Khajehpour Mazdak 
Published: November 2024

AbstractBiophysical studies in the last two decades have clearly demonstrated that salts affect biomolecules in an ion‐specific manner (i. e., Hofmeister Effects). Studies performed upon such diverse biological processes such as protein folding, protein precipitation, protein coacervation and phase separation, and protein oligomerization, have all shown that this ion specificity is directly related to how individual ions interact with biomolecular surfaces. Interestingly, although ion‐specific effects upon enzyme catalytic processes are well‐known in the literature, a molecular level description of these effects has not yet been made available. For example, it is not clear whether ion‐specific effects observed in enzyme catalysis are directly related to how ions modulate the enzyme's folding free energy, or not. This work attempts to address this need by investigating ion‐specific effects upon the enzymatic activity and folding free energy of a well‐characterized enzyme system, Ribonuclease A (RNase A). To this end we have developed a robust framework to analyze and quantify ion‐specific effects upon the RNase A catalyzed phosphate ring opening reaction of cCMP (Cytidine 2′:3′‐cyclic monophosphate monosodium salt). Our studies show that both the folding thermodynamics and the Michaelis‐Menten kinetic parameters of this enzyme show ion‐specific salt dependence. However, even through salt addition affects the folding free energy and enzyme catalysis of RNase A in an ion‐specific manner, these effects are not necessarily directly related to each other. Ion‐specific effects observed in protein folding reflects mostly how an individual ion interacts with the overall protein surface; while alternatively, ion‐specific effects on enzyme activity indicate how a given ion interacts with the enzyme active site surface or alternatively, how ions interact with the substrate molecule as represented by changes in the substrate thermodynamic activity coefficient.
Understanding the Reactivity and Selectivity of Oxazaborolidium Ion‐Catalyzed Diels‐Alder Reactions Involving Cyclobutenones as Dienophiles
Authors: Portela Susana , Fernández Israel 
Published: November 2024

AbstractThe poorly understood factors controlling the reactivity and selectivity (both stereo‐ and enantioselectivity) of catalyzed Diels‐Alder reactions involving cyclobutenones as dienophiles have been analyzed in detail by means of Density Functional Theory calculations. To this end, the reactions with cyclopentadiene and furan as dienes and 3‐(methoxycarbonyl)cyclobutenone catalyzed by Corey's chiral oxazaborolidium ion (COBI) have been selected and compared to their analogous uncatalyzed transformations. The combined Activation Strain Model of reactivity and Energy Decomposition Analysis methods have been used to quantitatively understand the acceleration and selectivity induced by the catalyst in this reaction.
Molecular Engineering for Future Thermoelectric Materials: The Role of Electrode and Metal Components in Molecular Junctions
Authors: Park Jiwoo , Park Sohyun 
Published: November 2024

AbstractAs global temperatures increase due to climate change, the accumulation of excess heat on Earth presents a valuable resource that can be harnessed for electricity generation using thermoelectric materials. However, the intricate structures of bulk thermoelectric materials pose significant challenges to their comprehensive understanding and limit performance. Additionally, their relatively high production costs present practical obstacles. A promising solution to these issues lies in molecular control and the use of molecular junctions. Molecules are predicted to surpass the performance of existing bulk materials in energy conversion because they can be chemically tuned to achieve high thermoelectric efficiencies. This review identifies the thermoelectric parameters that affect the performance of molecular junctions. It also explores various experimental platforms for measuring thermoelectric performance from single molecules to assemblies of hundreds of molecules. Finally, it highlights recent advancements in thermoelectric molecular junctions, focusing on the crucial roles of electrodes and metal components within the molecules, such as Ru complexes, metalloporphyrins, metallocenes, conjugated silane wires, and endohedral metallofullerenes. Ultimately, our review provides a comprehensive analysis of strategies to enhance the thermoelectric efficiency of molecular junctions.
CircSpna2 attenuates cuproptosis by mediating ubiquitin ligase Keap1 to regulate the Nrf2‐Atp7b signalling axis in depression after traumatic brain injury in a mouse model
Authors: Du Mengran , Fu Jiayuanyuan , Zhang Jie , Zhu Ziyu , Huang Xuekang , Tan Weilin , Liu Lian , Huang Zhijian , Liu Xin , Tan Qiuhao , Liao ZhengBu , Cheng Yuan 
Published: November 2024

AbstractBackgroundDepression is a common but often overlooked consequence in individuals with post‐traumatic brain injury (TBI). Circular RNAs (circRNAs) play essential roles in the nervous system, yet their involvement in the cell death mechanism known as cuproptosis and in TBI‐related depression remains unclear.ObjectivesThis study aimed to investigate the role of circRNA, specifically circSpna2, in the regulation of cuproptosis and its association with depression in TBI patients.MethodsRNA sequencing (RNA‐Seq) was used to assess the differential expression of circRNAs. Depression was evaluated using subjective and objective rating scales, and circSpna2 expression levels in plasma were measured. Further functional experiments were conducted in TBI mouse models, including knockdown and overexpression of circSpna2, to explore its impact on the Keap1‐Nrf2‐Atp7b pathway and cuproptosis.ResultsTBI patients exhibited decreased levels of circSpna2, which correlated with depression (p < 0.0001). Knocking down circSpna2 in TBI mice aggravated depression‐like symptoms (p < 0.0001). Mechanistically, circSpna2 was found to bind ubiquitin ligase Keap1, modulating the Nrf2‐Atp7b signaling pathway and influencing cuproptosis (docking score: −331.88). Overexpression of circSpna2 alleviated cuproptosis after TBI through the Keap1/Nrf2/Atp7b axis.ConclusionsCircSpna2 plays a regulatory role in cuproptosis and may serve as a novel biomarker and therapeutic target for depression following TBI. Enhancing circSpna2 expression could mitigate depression after TBI by modulating the Keap1/Nrf2/Atp7b pathway.Key pointsThis study explores the role of circSpna2 in depression following traumatic brain injury (TBI). It was found that circSpna2 is significantly downregulated in TBI patients, and its expression levels correlate with depressive symptoms. In TBI mouse models, overexpression of circSpna2 alleviated depression‐like behaviours, while its knockdown exacerbated these symptoms, suggesting its potential as both a biomarker and a therapeutic target for post‐TBI depression. Mechanistically, circSpna2 regulates the Nrf2‐Atp7b signalling pathway by binding to the DGR domain of Keap1, which prevents Nrf2 ubiquitination and enhances Nrf2 activity. This in turn promotes the transcription of Atp7b, a copper transport protein, helping to maintain copper homeostasis and mitigate copper‐induced oxidative stress, a key protein of cell death (cuproptosis). The overexpression of circSpna2 also improved mitochondrial function and synaptic integrity, which are typically impaired by copper dysregulation. These findings highlight the therapeutic potential of circSpna2 in managing TBI‐related depression through the regulation of oxidative stress and copper homeostasis.
A Serial Sampling Closed‐Loop System for Transceiver Beam Nulling
Authors: Yang Lei , Yang Dongdong , Wang Yuexian 
Published: November 2024

ABSTRACTConsidering the limited space, power of the unmanned platform, and the inconsistency of the antenna array transceiver beam pattern, we design a serial sampling closed‐loop system for transceiver beam nulling, which has a strong robustness and global convergence. It is mathematically proved that the serial sampling closed‐loop system is capable of adaptively nulling jamming signals by analyzing the system mathematical model for the first time. Our work addresses the issue that the existing transceiver system on unmanned platforms cannot estimate the directions of arrival (DOAs) of jamming signals causing the transmit beam not to be nulled in the DOAs of jammers. Simulation results show that the proposed system can be applied in scenarios with strictly limitations on space, weight, and power (SWaP) to suppress jamming signals when receiving desired signals while covering the transmissions.
Compact UWB Slot Antenna With Dual‐Circular Polarization and Improvement of CP Performance
Authors: Soleimani Leili , Zehforoosh Yashar , Asadpor Loghman 
Published: November 2024

ABSTRACTThis study presents an ultrawideband (UWB) slot antenna with a dual‐circular (left‐ and right‐hand) circular polarization. The presented circularly polarized (CP) antenna involves 45° oriented patches cooperating with I‐ and L‐shaped stubs fed by a directional coupler. Using a directional coupler produces orthogonal electric fields to generate CP operation, and as a result of the cooperation between patches and stubs, antenna CP performance is improved. The fabricated antenna, including two microstrip ports, occupies an area of 50 × 50 × 1.016 mm3. By stimulating each antenna port independently, it is possible to obtain right‐hand circular polarization (RHCP) and left‐hand circular polarization (LHCP). The experiments show that the antenna being presented has an operating frequency of 116.14% (2.87–10.82 GHz) and an axial ratio bandwidth of 33.97% (7.11–10.02 GHz). Furthermore, a stable radiation pattern was also measured for the antenna, which had a maximum gain of 2.77 dBic in the operating frequency band.
Adaptative Variation in a Neotropical Dung Beetle: Females and Gamma Males Present Tunneler Morphology, While Beta and Alpha Males Present Wing Morphology for Velocity
Authors: de Oliveira Ribeiro Pedro Henrique , Camargo Nicholas Ferreira , Frizzas Marina Regina 
Published: November 2024

ABSTRACTIn evolutionary terms, plastic traits can covary, providing adaptive value by compensating for certain characteristic costs or enhancing fitness. This combination of traits is expected in species with significant intrapopulation ecological variation, like insects. In the Phanaeini tribe, males and females have distinct nesting behaviors, and the alpha, beta, and gamma morphotypes of trimorphic males display different reproductive strategies. Although phenotypic integration of wings and protibiae associated with horn size occurs in dung beetles, this study focuses on the morphological and functional variation of these and other structures due to behavioral differences and reproductive strategies between sexes and male morphotypes. We used a geometric and functional morphometric approach to investigate the variation in plasticity of structures (clypeus, protibia, elytra, and membranous wing), their integration with horn size in males, and flight biomechanics in the trimorphic dung beetle Oxysternon palemo (Scarabaeinae: Phanaeini). Comparing different sexes and morphotypes, we tested for significant differences associated with various reproductive and behavioral strategies. Adaptive morphological differences were found in all structures in at least three of the four groups (females and alpha, beta, and gamma males), along with clear sexual dimorphism in the protibia. In alpha males, fossorial structures enhance resource partitioning and confrontations, whereas in females and gamma males, these structures optimize digging and tunnel mobility. We also found integration between the size of pronotal horns and clypeus shape, and between head horn size and wing shape. The variation in elytra morphology, covariation between membranous wings and horns, and flight biomechanics results suggests different reproductive investment and foraging strategies among groups. Alpha and beta males invest in intense flights and rapid resource colonization, whereas gamma males exhibit slower, low‐energy flights with greater reproductive investment. We discuss how trade‐offs between dispersal and reproduction in polyphenic insects shape adaptive variation through plasticity in dung beetle morphotypes.
Levels of Sex Steroids in Plethodontid Salamanders: A Comparative Study Within the Genus Aneides
Authors: Staub Nancy L. , Hayes Stephen G. , Mendonca Mary T. 
Published: November 2024

ABSTRACTDerived monomorphism is a condition in which males and females are phenotypically similar, but the similarity is derived. Derived monomorphism typically evolves from sexual dimorphism or from a different monomorphic state. We examined the hormonal basis of derived monomorphism in the salamander genus Aneides (Plethodontidae). We reject our hypothesis that circulating levels of androgens explain the derived traits, such as enlarged jaw musculature, in females (some would call them “male‐like traits”). There was no clear pattern of differences in androgen levels or degree of dimorphism in androgen levels, between the sexually dimorphic Aneides hardii and the other, derived monomorphic, species studied. Concentrations of testosterone and dihydrotestosterone were higher in males than in females in all species examined. The degree of sexual dimorphism in androgen level was also consistent among the species studied. Levels of androgens in female plethodontids have not been previously reported.
Parent‐Specific Transgenerational Immune Priming Enhances Offspring Defense—Unless Heat Stress Negates It All
Authors: Schneider Ralf F. , Dubin Arseny , Marten Silke‐Mareike , Roth Olivia 
Published: November 2024

ABSTRACTTransgenerational immune priming (TGIP) adjusts offspring's immune responses based on parental immunological experiences. It is predicted to be adaptive when parent–offspring environmental conditions match, while mismatches negate those advantages, rendering TGIP potentially costly. We tested these cost–benefit dynamics in the pipefish Syngnathus typhle (Syngnathidae). Because of their unique male pregnancy, egg production and rearing occur in different sexes, providing both parents multiple avenues for TGIP. Parental bacteria exposure in our pipefish was simulated through vaccinations with heat‐killed Vibrio aestuarianus before mating the fish to each other or to controls. The resulting offspring were exposed to V. aestuarianus in control or heat stress environments, after which transcriptome and microbiome compositions were investigated. Transcriptomic TGIP effects were only observed in Vibrio‐exposed offspring at control temperatures, arguing for low costs of TGIP in non‐matching microbiota environments. Transcriptomic phenotypes elicited by maternal and paternal TGIP had limited overlap and were not additive. Parentally induced transcriptomic responses were associated with immune functions, and specifically, the paternal response to the innate immune branch, possibly hinting at trained immunity. TGIP of both parents reduced the relative abundance of the experimental Vibrio in exposed offspring, showcasing its ecological benefits. Despite TGIP's significance in matching biotic environments, no TGIP‐associated phenotypes were observed for heat‐treated offspring, illustrating its limitations. Heat spikes caused by climate change thus threaten TGIP benefits, potentially increasing susceptibility to emerging marine diseases. We demonstrate the urgent need to understand how animals cope with climate‐induced changes in microbial assemblages to assess their vulnerability in light of climate change.
The Cost of Self‐Defense: Browsing Effects in the Rare Plant Species Salix arizonica
Authors: Lencioni Shannon J. , Massatti Rob , Keefover‐Ring Ken , Holeski Liza M. 
Published: November 2024

ABSTRACTCoevolution between plants and their animal predators has led to diverse defensive adaptations. Multiple theories of defense propose that there are resource allocation costs associated with producing chemical defenses. One leading hypothesis, optimal defense theory (ODT), suggests that natural selection will result in the allocation of resources to defenses that optimize the cost‐to‐benefit ratio between defense and other functional processes. The population decline of the rare subalpine wetland species, Arizona willow (Salix arizonica), has been attributed to various biotic and abiotic factors, with browsing from wild and domestic ungulates as a significant concern for at least three decades. In a field experiment using natural populations, we compare the relationship between phytochemical defense and height in Arizona willows with and without long‐term protection from browsing via browse exclosures. Consistent with the predictions of ODT, individuals with physical protection from ungulate browsing for multiple years had significantly lower phenolic glycoside (PG) concentrations and increased plant height compared to unprotected individuals. A similar pattern was found across all individuals, whereby total PG concentration and height were negatively correlated. In a short‐term experiment in natural populations, changes in levels of defense were not observed when plants received protection for only one growing season. The contrasting pattern of defense plasticity in response to long‐term versus short‐term physical protection suggests a differential plastic response in this long‐lived species. Delayed reduction in PG concentration may serve as a benefit to avoid mismatches between environmental cues and responses. Our research sheds light on the intricate dynamics between plant‐defense strategies, environmental pressures, and evolutionary adaptations in shaping plant–browser interactions.