Suppression Of Recombination Research Articles

The joint evolution of separate sexes and sexual dimorphism.

Dioecious plants are frequently sexually dimorphic. Such dimorphism, which reflects responses to selection acting in opposite directions for male and female components of fitness, is commonly thought to emerge after separate sexes evolved from hermaphroditism. But associations between allocation to male and female function and traits under sexual conflict may well also develop in hermaphroditic ancestors. Here, we show that variation in sex allocation and a trait under sexual conflict inevitably generates an advantage to sexual specialisation, fueling the transition to dioecy. In the absence of constraints, this leads to the joint evolution of separate sexes and sexual dimorphism through the build-up of an association between sex allocation and the conflict trait, such that eventually the population consists of unisexuals expressing their sex-specific optima. We then investigate how such association might materialise genetically, either via recombination suppression or via sex-dependent expression, and show that the genetic architecture of sex alloca- tion and the conflict trait readily evolves to produce the association favoured by selection. Finally and in agreement with previous theory, we demonstrate that limited dispersal and self-fertilisation, which are pervasive ecological char- acteristics of flowering plants, can offset the advantage of sexual specialisation generated by sexual conflict and thus maintain hermaphroditism. Taken together, our results indicate that advantages to sexual specialisation are inevitable when there is conflict between sexual functions in hermaphrodites, but these advantages can be counterbalanced by ecological benefits of hermaphroditism.

Suppression of Class Switch Recombination to IgA by RASA2 and RASA3 through Inhibition of TGF-β Signaling.

Abs play a pivotal role in adaptive immunity by binding to pathogens and initiating immune responses against infections. Processes such as somatic hypermutation and class switch recombination (CSR) enhance Ab affinity and effector functions. We previously carried out a CRISPR/Cas9 screen in the CH12F3-2 (CH12) lymphoma B cell line to identify novel factors involved in CSR. The screen showed that guide RNAs targeting both Rasa2 and Rasa3 genes were decreased in IgA-negative CH12 B cells, implying that these genes might suppress CSR. Indeed, CSR was increased when either Rasa2 or Rasa3 were knocked out in CH12 cells. Compared to controls, Rasa2-/- and Rasa3-/- CH12 cells had increased expression of activation-induced cytidine deaminase (AID) and Iα transcripts, providing an explanation for the increased CSR. The increased CSR, AID, and Iα expression in Rasa2-/- or Rasa3-/- CH12F3-2 is mediated through TGF-β stimulation. Indeed, we found that deletion of RASA2 or RASA3 promotes a shift from noncanonical to canonical TGF-β signaling through SMAD3. These results show that RASA2 and RASA3 are both novel regulators of TGF-β signaling in B cells, a pathway known to be essential for CSR to IgA.

Fabrication of heterostructure multilayer devices through the optimization of Bi-metal sulfides for high-performance quantum dot-sensitized solar cells.

In this work, a titanium dioxide and lead sulfide (TiO2/PbS) nano-size heterostructure with tin sulfide was fabricated and coated via a two-step direct deposition process. Its microstructure, morphology, elemental composition, optical absorption, and photochemical activity were investigated. Linear sweep voltammetry and cyclic voltammetry curves substantiated its catalytic activity, indicating quantum dot effects of a well-developed space charge domain on the surface of the hybrid structure. These give rise to electron-hole recombination suppression and a high charge mobility rate. Moreover, direct stabilization was identified in current density, corresponding to the hybrid structures limiting the diffusion current process. Higher J SC values observed were substantiated by the role of quantum dot-size effects and enhanced crystalline structures, leading to a reduction in series resistance and an improved conversion efficiency of 10.05%. Overall, theoretical analyses and empirical findings indicated that the seamless migration of photoexcited electrons across the interfaces of SnS and PbS is linked to quantum dot effect synergy. This is facilitated by the space charge region, which serves as a conduit for efficient electron transfer between the respective materials.

Linker‐Mediated Delocalized Excited States in Dimeric Acceptors Enable Efficient Exciton Dissociation with Negligible Energy‐level Offsets

Efficient exciton dissociation at low energy offsets is key to overcoming voltage losses in organic solar cells. In this work, we developed two dimeric acceptors, i‐YT and o‐YT, by precisely controlling the position of an asymmetric electron‐donating linker. It induced the foldamer conformation of i‐YT with a para linkage (relative to the dicyano groups), while retaining the unfold conformation for o‐YT. This subtle structural modification influenced the molecular assembly properties, enabled near‐zero energy offset exciton dissociation and power conversion efficiencies exceeding 18% for i‐YT based organic solar cells. Detailed excitonic dynamics further revealed that the linker position critically influences three processes: the formation of delocalized singlet excited states, ultrafast charge transfer (~5 ps) in solid blends, and the suppression of exciton recombination. Additionally, devices based on i‐YT demonstrated outstanding long‐term stability, retaining over 85% of their initial efficiency after 1,400 hours of continuous illumination. These findings introduce a new class of dimeric acceptors that combine high efficiency with exceptional stability, offering a promising pathway toward low‐energy‐loss organic photovoltaics.

Linker-Mediated Delocalized Excited States in Dimeric Acceptors Enable Efficient Exciton Dissociation with Negligible Energy-level Offsets.

Efficient exciton dissociation at low energy offsets is key to overcoming voltage losses in organic solar cells. In this work, we developed two dimeric acceptors, i-YT and o-YT, by precisely controlling the position of an asymmetric electron-donating linker. It induced the foldamer conformation of i-YT with a para linkage (relative to the dicyano groups), while retaining the unfold conformation for o-YT. This subtle structural modification influenced the molecular assembly properties, enabled near-zero energy offset exciton dissociation and power conversion efficiencies exceeding 18% for i-YT based organic solar cells. Detailed excitonic dynamics further revealed that the linker position critically influences three processes: the formation of delocalized singlet excited states, ultrafast charge transfer (~5 ps) in solid blends, and the suppression of exciton recombination. Additionally, devices based on i-YT demonstrated outstanding long-term stability, retaining over 85% of their initial efficiency after 1,400 hours of continuous illumination. These findings introduce a new class of dimeric acceptors that combine high efficiency with exceptional stability, offering a promising pathway toward low-energy-loss organic photovoltaics.

Performance Enhancement of Hole Transport Layer-Free Carbon-Based CsPbIBr2 Solar Cells through the Application of Perovskite Quantum Dots.

CsPbIBr2, with its suitable bandgap, shows great potential as the top cell in tandem solar cells. Nonetheless, its further development is hindered by a high defect density, severe carrier recombination, and poor stability. In this study, CsPbI1.5Br1.5 quantum dots were utilized as an additive in the ethyl acetate anti-solvent, while a layer of CsPbBr3 QDs was introduced between the ETL and the CsPbIBr2 light-harvester film. The combined effect of these two QDs enhanced the nucleation, crystallization, and growth of CsPbIBr2 perovskite, yielding high-quality films characterized by an enlarged crystal size, reduced grain boundaries, and smooth surfaces. And a wider absorption range and better energy band alignment were achieved owing to the nano-size effect of QDs. These improvements led to a decreased defect density and the suppression of non-radiative recombination. Additionally, the presence of long-chain organic molecules in the QD solution promoted the formation of a hydrophobic surface, significantly enhancing the long-term stability of CsPbIBr2 PSCs. Consequently, the devices achieved a PCE of 9.20% and maintained an initial efficiency of 85% after 60 days of storage in air. Thus, this strategy proves to be an effective approach for the preparation of efficient and stable CsPbIBr2 PSCs.

11.88% Efficient Flexible Ag-Free CZTSSe Solar Cell: Spontaneously Tailoring the Alkali Metal Level.

Alkali metal is the requirement for highly efficient Cu2ZnSn(S, Se)4 (CZTSSe) solar cells, thus it is crucial to additionally incorporate alkali metal into the absorber layer for flexible solar cells. However, the efficiency of flexible CZTSSe devices reported to date, based on the conventional alkali incorporation strategies, still lags behind those made on rigid substrates. One of the main issues is the inability to control the alkali content and distribution in the absorber layer. Here, a facile alkaline incorporation approach is proposed, effectively regulating the content and distribution of alkali metals in the film. Such a method can spontaneously tailor the alkali metal content to a proper level, thus leading to the suppression of non-radiative recombination and a better carrier transport through the enhanced film quality and the optimized band binding structure. Finally, a champion flexible CZTSSe solar cell with an efficiency of 11.88% is achieved, the highest reported efficiency for a CZTSSe solar cell without noble Ag doping. This study affords an innovative spontaneous alkali-doping design for the preparation of high-performance flexible CZTSSe solar cells and provides a deeper insight into the extent of alkali metal doping.

Uniform Phase Permutation of Efficient Ruddlesden-Popper Perovskite Solar Cells via Binary Spacers and Single Crystal Coordination.

2D Ruddlesden-Popper perovskites (RPPs) have attracted extensive attention in recent years due to their excellent environmental stability. However, the power conversion efficiency (PCE) of RPP solar cells is much lower than that of 3D perovskite solar cells (PSCs), mainly attributed to their poor carrier transport performance and excessive heterogeneous phases. Herein, the binary spacers (n-butylammonium, BA and benzamidine, PFA) are introduced to regulate the crystallization kinetics and n-value phase distribution to form uniform phase permutation of RPP films. The study then incorporates n = 5 BA2MA4Pb5I16 memory single crystal to achieve ultrafast stepped-type carrier transport from the low n-value phases to the high n-value phases in the high-quality (BA0.75PFA0.25)2MA4Pb5I16 films. These binary spacers and single-crystal-assisted crystallization strategies produce high-quality films, leading to fast carrier extraction and significant nonradiative recombination suppression. The resulting PSC presents a champion PCE of 21.15% with an impressive open circuit voltage (VOC) of 1.26V, which is the record high efficiency and VOC for low n-value RPP solar cells (n ≤ 5).

DNA cytosine methylation suppresses meiotic recombination at the sex-determining region.

Meiotic recombination between homologous chromosomes is vital for maximizing genetic variation among offspring. However, sex-determining regions are often rearranged and blocked from recombination. It remains unclear whether rearrangements or other mechanisms might be responsible for recombination suppression. Here, we uncover that the deficiency of the DNA cytosine methyltransferase DNMT1 in the green alga Chlamydomonas reinhardtii causes anomalous meiotic recombination at the mating-type locus (MT), generating haploid progeny containing both plus and minus mating-type markers due to crossovers within MT. The deficiency of a histone methyltransferase for H3K9 methylation does not lead to anomalous recombination. These findings suggest that DNA methylation, rather than rearrangements or histone methylation, suppresses meiotic recombination, revealing an unappreciated biological function for DNA methylation in eukaryotes.

Hierarchical Nanostructures CuBi2O4 Integrated with Polyaniline Nanofibrous for Boosting Hole Extraction in Carbon-Based Perovskite Solar Cells.

Toward commercialization of carbon-based perovskite solar cells (C-PSCs), it is crucial to innovatively design inorganic hole transport layer materials that excel in extracting and transporting charge carriers to promote their photoelectric conversion efficiency (PCE). In this work, a novel and high-connectivity CuBi2O4-polyaniline nanofibrous (CuBi2O4-PN) reticular structure is created by integrating CuBi2O4 hierarchical microspheres (CuBi2O4 MS) with polyaniline nanofibrous. The introduction of CuBi2O4-PN as a hole transport layer (HTL) notably enhances the contact quality of the devices and substantially reduces the surface defects of C-PSCs. In a comparative analysis under identical experimental conditions, MAPbI3 devices incorporating CuBi2O4-PN HTL demonstrated a PCE of 14.79%, achieving a 44.3% increase over the reference device (10.25%). CuBi2O4-treated C-PSCs retained 89.9% of their original PCE after 45 days in storage, and they demonstrated improved stability over a longer time frame. This remarkable improvement in device performance can be attributed to the effective suppression of nonradiative recombination and the enhancement of the carrier transfer process in the device. Additionally, the unique interconnected reticular structure of CuBi2O4-PN provides efficient pathways for hole transfer, significantly contributing to the enhanced efficiency of the device.

Probing into the Low Efficiency of CdS/SnS-based Solar Cells and Remediation through Surface Treatments

Tin sulfide (SnS) is a highly promising photovoltaic absorption material in thin-film solar cells with abundant reserves, environmental friendliness, low cost and long-term stability. An efficiency of up to 4.8% has been achieved for SnS absorber/CdS heterojunction solar cells where the CdS buffer layer is usually obtained by chemical bath deposition. However, current CdS/SnS devices often suffer from severe interface recombination loss, which deteriorates device performance. This report focuses on the CdS film surface to identify performance-degrading factors for CdS/SnS-based solar cells. XRD and XPS reveal numerous oxides on freshly fabricated CdS films increasing surface roughness and reducing conductivity. Herein, a method based on ammonium sulfide (AS) chemical treatment is proposed, which can effectively reduce the oxide content on the surface of CdS and optimize the band alignment, leading to the facilitation of charge carrier transport and the suppression of interface recombination. Consequently, the PCE of the FTO/CdS/SnS/Ag device is enhanced about three times (from 0.18% to 0.47%) with excellent moisture stability.

Light harvesting S-scheme g-C3N4/TiO2/M photocatalysts for efficient removal of hazardous moxifloxacin

The development of advanced photocatalysts with enhanced efficiency for environmental remediation is critical for addressing persistent organic pollutants like Moxifloxacin. In this study, we present a novel S-scheme heterojunction g-C3N4/TiO2/M photocatalyst designed to optimize light harvesting and charge separation for the effective degradation of Moxifloxacin. The innovative S-scheme configuration enables superior charge transfer dynamics by retaining potent photogenerated electrons in the conduction band of TiO2 and holes in the valence band of g-C3N4, significantly improving photocatalytic performance compared to conventional Type-II systems. Heterogeneous photocatalysis, particularly using TiO2-based materials, offers a promising approach. Here, we synthesized TiO2 hybridized with metal-doped g-C3N4 (GCNTM) via a simple hydrothermal method. The fabricated nanocomposites were characterized using SEM, XRD, FTIR, and UV–Vis (DRS). These GCNTM nanocomposites were employed for the degradation of hazardous Moxifloxacin (MXF) under visible light. Detailed analysis of the photocatalytic mechanism reveals that the synergistic interaction between g-C3N4, TiO2, and the co-catalyst M not only broadens the light absorption spectrum but also enhances the separation and lifespan of charge carriers. Among the synthesized materials, GCNTLa demonstrated the highest degradation efficiency, achieving 96 % removal of MXF. This enhanced activity is attributed to the effective suppression of charge recombination, leading to the generation of reactive species responsible for MXF degradation. Additionally, GCNTM showed remarkable stability and reusability, with only a 6 % reduction in efficiency after five cycles, confirming its high reusability and mechanical stability. Our S-scheme photocatalyst demonstrates a marked increase in the degradation rate of Moxifloxacin under visible light irradiation, highlighting its potential for practical environmental applications.

Enhanced tetracycline degradation using UV/Fenton/titanium dioxide (TiO2) hybrid process

TiO2 was synthesized using neem leaf extract as soft bio template and Titanium (IV) isopropoxide (C12H28O4Ti) as a precursor. Morphological properties revealed well crystalline anatase phase of 19.8 nm size for the biotemplated TiO2 (B-TiO2) compared to 24.2 nm of the non-templated TiO2 (N-TiO2). TEM revealed a nano sheet-like structure for the B-TiO2 and it exhibited a larger SBET surface area (35.45 m2/g) and average pore diameter (5.74 nm) compared to the N-TiO2 (19.72 m2/g) and (2.028 nm) respectively. XPS results showed carbon peaks indicating small bio-carbon doping on the lattice of the TiO2, which can promote charge transfer upon light excitation during photocatalyst reactions. The results of the photoluminescence study indicate reduced PL intensity of the B-TiO2 which signifies the suppression of recombination of charge carriers or electron-hole pairs in the B-TiO2. The photocatalytic activity was assessed by the photodegradation of tetracycline (TC: 50 mg/L) under UV irradiation and the B-TiO2 was employed as a photocatalyst. In the absence of UV light, B-TiO2 catalyst slightly removed TC due to limited active species. However, the degradation of TC increases significantly due to the synergetic effect of the UV/Fenton/B-TiO2 hybrid system. Moreover, the biotemplate exposes the surface of the B-TiO2 which permits improved utilization of all surface-active sites. Quenching experiments were also performed via scavengers, results confirmed that hydroxyl radicals, superoxide radicals and electrons are the key reactive species in the TC degradation. The effects of influential parameters such as B-TiO2 dosage, TC concentration, pH, and Fe2+ to H2O2 molar ratio were also investigated, in addition, the catalyst is stable, as it achieved > 80 % TC degradation efficiency after five reuse cycles.

Versatile Bi2MoO6/Prussian Blue-Au nanoplatform for oxygen-self-produced and GSH-depleted enhanced sonodynamic efficacy

Deprivation of oxygen and scavenging of reactive oxygen species (ROS) severely restrict the antitumor efficiency of sonodynamic therapy (SDT). To address these challs, we report the Bi2MoO6/Prussian Blue-Au (BMO/PB-Au) nanosystem as piezoelectric sonosensitiser for highly efficient ROS production under ultrasonic irradiation. In this system, the nanosystem has catalase-like (CAT) and glutathione oxidase (GSHOD) catalytic activity, which can enhance SDT effectively by producing reactive oxygen species and consuming glutathione (GSH). While the narrow bandgap and heterojunctions contribute to the improved charge separation and charge recombination suppression of the piezoelectric semiconductor BMO, accelerating ROS generation. Packaging MCF-7 cancer cell membranes (CM) on the surface of BMO/PB-Au will effectively improve the enrichment of nanoparticles in tumor tissue. The in vivo results showed that the BMO/PB-Au@CM nanoplatform can effectively inhibit tumor growth through the enhanced SDT effect. Our findings provide a paradigm to rationally design hypoxia-relieve and GSH-depleted SDT platform to for promoting cancer therapy efficiency.

Long‐Term Maintenance of Complex Chromosomal Inversion Polymorphism in Drosophila mediopunctata

ABSTRACTNatural selection is known to favor specific gene combinations, thereby shaping the evolution of recombination rates, often through epistatic interactions. However, the dynamics of these interacting factors within natural populations remain poorly understood. In this study, we investigate the long‐term maintenance of a complex polymorphism involving linked, nonoverlapping chromosomal inversions in a natural population of Drosophila mediopunctata. Remarkably, even after 30 years—equivalent to roughly 340 generations—two major features have remained unexpectedly stable: the linkage disequilibrium (LD) between inversions, which deviates significantly from the theoretical prediction of decay, and a consistent seasonal cycle pattern of heterozygous excess and homozygous deficiencies. We explored the roles of recombination suppression, epistatic selection, and overdominance in maintaining this stability, examining their alignment with previously described patterns. Our findings reveal that moderate selection coefficients, such as s = 0.0407, are sufficient to maintain the observed LD for the most common haplotypes, albeit leading to an unstable equilibrium. Simulations further reveal that the introduction of overdominance stabilizes the system, enabling the long‐term persistence of this complex inversion polymorphism across various frequency scenarios. The stability of this system appears to hinge on a delicate balance between LD, recombination rates, and selective pressures, with overdominance playing a critical role. Our findings highlight the significance of epistatic interactions and selective pressures in shaping evolutionary pathways in natural populations and offer a compelling example of natural selection acting on a complex inversion polymorphism, providing valuable insights into the evolutionary dynamics governing inversion systems.

Identification of Genomic Regions Associated with Differences in Flowering Time and Inflorescence Architecture between Melastoma candidum and M. normale.

Understanding the genetic basis of species differences in flowering time and inflorescence architecture can shed light on speciation and molecular breeding. Melastoma shows rapid speciation, with about 100 species formed in the past few million years, and, meanwhile, possesses high ornamental values. Two largely sympatric and closely related species of this genus, M. candidum and M. normale, differ markedly in flowering time and flower number per inflorescence. Here, we constructed an F2 population between M. candidum and M. normale, and used extreme bulks for flowering time and flower number per inflorescence in this population to identify genomic regions underlying the two traits. We found high differentiation on nearly the whole chromosome 7 plus a few regions on other chromosomes between the two extreme bulks for flowering time. Large chromosomal inversions on chromosome 7 between the two species, which contain flowering-related genes, can explain recombinational suppression on the chromosome. We identified 1872 genes with one or more highly differentiated SNPs between the two bulks for flowering time, including CSTF77, FY, SPA3, CDF3, AGL8, AGL15, FHY1, COL9, CIB1, FKF1 and FAR1, known to be related to flowering. We also identified 680 genes with one or more highly differentiated SNPs between the two bulks for flower number per inflorescence, including PNF, FIL and LAS, knows to play important roles in inflorescence development. These large inversions on chromosome 7 prevent us from narrowing down the genomic region(s) associated with flowering time differences between the two species. Flower number per inflorescence in Melastoma appears to be controlled by multiple genes, without any gene of major effect. Our study indicates that large chromosomal inversions can hamper the identification of the genetic basis of important traits, and the inflorescence architecture of Melastoma species may have a complex genetic basis.

Synergistic anti-solvent engineering with piperizium salts for highly efficient inverted perovskite solar cells exceeding 25 %

Trap-assisted non-radiative recombination in the perovskite (PVK) film is a primary limitation in further enhancing the performance of inverted perovskite solar cells (PSCs). Herein, an effective anti-solvent additive strategy is proposed, employing 1-(2-Methoxyphenyl)piperazine hydrochloride (2MPCl) as a multifunctional anti-solvent additive to passivate defects in PVK. The introduction of 2MPCl effectively passivate Pb2+ and halide vacancies through ion bonds and hydrogen bonds, thereby obtaining high-quality PVK films. Besides, the multifunctional 2MPCl can effectively modulate the energy level structure of PVK, resulting in a more n-type PVK surface, thereby facilitating electron transfer between PVK and PCBM. Consequently, the optimization of energy levels and suppression of trap-assisted recombination elevate the efficiency of devices with 2MPCl to 25.02 %, with significantly enhanced stability compared to control devices. This novel anti-solvent additive strategy aims to address the challenge of trap-assisted non-radiative recombination in PVK film, which is important for enhancing the performance of inverted PSCs.

Abstract C046: Targeting wild-type IDH1 sensitizes homologous recombination proficient pancreatic cancer to PARP inhibition

Abstract Introduction: Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer-related mortality in the United States. While Poly (ADP-ribose) polymerase (PARP) inhibitors show promise for PDAC with Homologous Recombination Deficiency (HRD), this mutation is present in less than 10% of cases. Our research focuses on exploiting a vulnerability in the remaining 90% of HR proficient (HRP) tumors. We identified that wild-type isocitrate dehydrogenase 1 (IDH1) plays a critical role in HR repair. By inhibiting IDH1, we discovered suppression of the homologous recombination (HR) pathway, leading to compromised genomic integrity. This renders cancer cells more susceptible to PARP inhibitor therapy, offering a novel therapeutic approach for HRP PDAC. Methods:We assessed the impact of IDH1 inhibition on HR pathway activity using Western blotting to measure HR repair protein levels and HR reporter assays. The effect of IDH1 inhibition (Ivosidenib) combined with PARP inhibition (Olaparib) on in vitro growth inhibition was assessed through drug combination assays. Additionally, we investigated the molecular mechanisms underlying the synergistic effects of the drug combination. To further evaluate the therapeutic potential of IDH1 inhibition in combination with PARP inhibitors, we examined tumor growth in xenograft models of PDAC in athymic nude mice and survival studies were performed in C57BL/6J mice transplanted with orthotopic murine pancreatic cancer. Results:Wild-type IDH1 blockade induces a BRCA-like phenotype by decreasing α-ketoglutarate (αKG) levels and causing histone hypermethylation. This leads to decreased HR repair efficiency in HRP pancreatic cancer cells (MiaPaCa-2 and Panc-1), resulting in a strong synergistic effect when combined with the DNA-damaging agent Olaparib. The combination treatment significantly reduced cell survival in both short and long-term assays. Furthermore, we discovered that these compounds complemented each other in the DNA damage response, leading to increased γ-H2AX (DNA damage marker) and apoptosis. In vivo studies using murine PDAC models demonstrated that the combination of ivosidenib and olaparib synergistically enhanced anti-tumor activity compared to either single agent alone. Conclusion:These data provide novel insight into the mechanisms underlying in the context of HRP cancer susceptibility to a dual treatment approach involving an IDH1 inhibitor and a PARP inhibitor. This approach holds promise for precision medicine in pancreatic cancer treatment, although further pre- clinical studies are needed for validation and refinement. Citation Format: Mehrdad Zarei, Omid Hajihassani, Hallie J. Graor, Soubhi Tahhan, Alexander W. Loftus, Faith Nakazzi, Semmer A. Ali, Parnian Naji, Luke D. Rothermel, Jonothan R. Brody, Jordan M. Winter. Targeting wild-type IDH1 sensitizes homologous recombination proficient pancreatic cancer to PARP inhibition [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C046.

Influence of gadolinium substitution on the crystal structure of NiO and its maximized photocatalytic degradation activity on tetracycline and direct yellow pollutants

Gadolinium-substituted NiO crystal structures with excellent stability were utilized for the first time to degrade antibiotic and organic dye pollutants. A simple hydrothermal technique was used to synthesize different concentrations of Gd3+ substituted NiO, and the catalysts were thoroughly characterized using sophisticated techniques to explore the influence of Gd3+ on the crystal structure and optical characteristics of NiO. The 1.5% Gd3+ substituted NiO showed outstanding photocatalytic activity on tetracycline and direct yellow degradation, with percentages of 90.72 and 95.5%, respectively. The improvement of photocatalytic degradation efficiency is primarily due to the suppression of photoinduced electron and hole recombination via the creation of Gd3+ as the inner energy band state below the conduction band. The recycling experiments revealed that the catalyst is more stable, with no indication of loss after ten cycles. Scavenging investigations also demonstrated that superoxide and holes were responsible for the efficient degradation of pollutants.

A sex chromosome polymorphism maintains divergent plumage phenotypes between extensively hybridizing yellowhammers (Emberiza citrinella) and pine buntings (E. leucocephalos).

Under allopatric speciation, populations of a species become isolated by a geographic barrier and develop reproductive isolation through genetic differentiation. When populations meet in secondary contact, the strength of evolved reproductive barriers determines the extent of hybridization and whether the populations will continue to diverge or merge together. The yellowhammer (Emberiza citrinella) and pine bunting (E. leucocephalos) are avian sister species that diverged in allopatry on either side of Eurasia during the Pleistocene glaciations. Though they differ greatly in plumage and form distinct genetic clusters in allopatry, these taxa show negligible mitochondrial DNA differentiation and hybridize extensively where they overlap in central Siberia, lending uncertainty to the state of reproductive isolation in the system. To assess the strength of reproductive barriers between taxa, we examined genomic differentiation across the system. We found that extensive admixture has occurred in sympatry, indicating that reproductive barriers between taxa are weak. We also identified a putative Z chromosome inversion region that underlies plumage variation in the system, with the 'pine bunting' haplotype showing dominance over the 'yellowhammer' haplotype. Our results suggest that yellowhammers and pine buntings are currently at a crossroads and that evolutionary forces may push this system towards either continued differentiation or population merging. However, even if these taxa merge, recombination suppression between putative chromosome Z inversion haplotypes may maintain divergent plumage phenotypes within the system. In this way, our findings highlight the important role hybridization plays in increasing the genetic and phenotypic variation as well as the evolvability of a system.