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1.
EMBO J ; 42(1): e111703, 2023 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-36326837

RESUMEN

EXD2 is a recently identified exonuclease that cleaves RNA and DNA in double-stranded (ds) forms. It thus serves as a model system for investigating the similarities and discrepancies between exoribonuclease and exodeoxyribonuclease activities and for understanding the nucleic acid (NA) unwinding-degradation coordination of an exonuclease. Here, using a single-molecule fluorescence resonance energy transfer (smFRET) approach, we show that despite stable binding to both substrates, EXD2 barely cleaves dsDNA and yet displays both exoribonuclease and exodeoxyribonuclease activities toward RNA-DNA hybrids with a cleavage preference for RNA. Unexpectedly, EXD2-mediated hybrid cleavage proceeds in a discrete stepwise pattern, wherein a sudden 4-bp duplex unwinding increment and the subsequent dwell constitute a complete hydrolysis cycle. The relatively weak exodeoxyribonuclease activity of EXD2 partially originates from frequent hybrid rewinding. Importantly, kinetic analysis and comparison of the dwell times under varied conditions reveal two rate-limiting steps of hybrid unwinding and nucleotide excision. Overall, our findings help better understand the cellular functions of EXD2, and the cyclic coupling between duplex unwinding and exonucleolytic degradation may be generalizable to other exonucleases.


Asunto(s)
Exorribonucleasas , ARN , ARN/metabolismo , Exorribonucleasas/genética , Exorribonucleasas/metabolismo , Cinética , ADN/metabolismo , Exodesoxirribonucleasas/metabolismo
2.
Proc Natl Acad Sci U S A ; 121(17): e2318380121, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38635629

RESUMEN

The gene content in a metagenomic pool defines the function potential of a microbial community. Natural selection, operating on the level of genomes or genes, shapes the evolution of community functions by enriching some genes while depriving the others. Despite the importance of microbiomes in the environment and health, a general metric to evaluate the community-wide fitness of microbial genes remains lacking. In this work, we adapt the classic neutral model of species and use it to predict how the abundances of different genes will be shaped by selection, regardless of at which level the selection acts. We establish a simple metric that quantitatively infers the average survival capability of each gene in a microbiome. We then experimentally validate the predictions using synthetic communities of barcoded Escherichia coli strains undergoing neutral assembly and competition. We further show that this approach can be applied to publicly available metagenomic datasets to gain insights into the environment-function interplay of natural microbiomes.


Asunto(s)
Microbiota , Microbiota/genética , Metagenoma/genética , Selección Genética , Genes Microbianos
3.
Nucleic Acids Res ; 52(11): 6269-6284, 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38634789

RESUMEN

Telomeres, TTAGGGn DNA repeat sequences located at the ends of eukaryotic chromosomes, play a pivotal role in aging and are targets of DNA damage response. Although we and others have demonstrated presence of short telomeres in genetic cardiomyopathic and heart failure cardiomyocytes, little is known about the role of telomere lengths in cardiomyocyte. Here, we demonstrate that in heart failure patient cardiomyocytes, telomeres are shortened compared to healthy controls. We generated isogenic human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) with short telomeres (sTL-CMs) and normal telomeres (nTL-CMs) as model. Compared to nTL-CMs, short telomeres result in cardiac dysfunction and expression of senescent markers. Using Hi-C and RNASeq, we observe that short telomeres induced TAD insulation decrease near telomeric ends and this correlated with a transcription upregulation in sTL-CMs. FOXC1, a key transcription factor involved in early cardiogenesis, was upregulated in sTL-CMs and its protein levels were negatively correlated with telomere lengths in heart failure patients. Overexpression of FOXC1 induced hiPSC-CM aging, mitochondrial and contractile dysfunction; knockdown of FOXC1 rescued these phenotypes. Overall, the work presented demonstrate that increased chromatin accessibility due to telomere shortening resulted in the induction of FOXC1-dependent expression network responsible for contractile dysfunction and myocardial senescence.


Asunto(s)
Senescencia Celular , Factores de Transcripción Forkhead , Insuficiencia Cardíaca , Células Madre Pluripotentes Inducidas , Miocitos Cardíacos , Acortamiento del Telómero , Telómero , Humanos , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , Miocitos Cardíacos/metabolismo , Senescencia Celular/genética , Acortamiento del Telómero/genética , Telómero/genética , Telómero/metabolismo , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/metabolismo , Miocardio/metabolismo , Miocardio/patología
4.
Brief Bioinform ; 24(3)2023 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-37141141

RESUMEN

Microbiome-based diagnosis of cancer is an increasingly important supplement for the genomics approach in cancer diagnosis, yet current models for microbiome-based diagnosis of cancer face difficulties in generality: not only diagnosis models could not be adapted from one cancer to another, but models built based on microbes from tissues could not be adapted for diagnosis based on microbes from blood. Therefore, a microbiome-based model suitable for a broad spectrum of cancer types is urgently needed. Here we have introduced DeepMicroCancer, a diagnosis model using artificial intelligence techniques for a broad spectrum of cancer types. Built based on the random forest models it has enabled superior performances on more than twenty types of cancers' tissue samples. And by using the transfer learning techniques, improved accuracies could be obtained, especially for cancer types with only a few samples, which could satisfy the requirement in clinical scenarios. Moreover, transfer learning techniques have enabled high diagnosis accuracy that could also be achieved for blood samples. These results indicated that certain sets of microbes could, if excavated using advanced artificial techniques, reveal the intricate differences among cancers and healthy individuals. Collectively, DeepMicroCancer has provided a new venue for accurate diagnosis of cancer based on tissue and blood materials, which could potentially be used in clinics.


Asunto(s)
Líquidos Corporales , Microbiota , Neoplasias , Humanos , Inteligencia Artificial , Neoplasias/diagnóstico , Genómica
5.
Brain ; 147(4): 1294-1311, 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38289861

RESUMEN

Ischaemic stroke causes neuron loss and long-term functional deficits. Unfortunately, effective approaches to preserving neurons and promoting functional recovery remain unavailable. Oligodendrocytes, the myelinating cells in the CNS, are susceptible to oxygen and nutrition deprivation and undergo degeneration after ischaemic stroke. Technically, new oligodendrocytes and myelin can be generated by the differentiation of oligodendrocyte precursor cells (OPCs). However, myelin dynamics and their functional significance after ischaemic stroke remain poorly understood. Here, we report numerous denuded axons accompanied by decreased neuron density in sections from ischaemic stroke lesions in human brain, suggesting that neuron loss correlates with myelin deficits in these lesions. To investigate the longitudinal changes in myelin dynamics after stroke, we labelled and traced pre-existing and newly-formed myelin, respectively, using cell-specific genetic approaches. Our results indicated massive oligodendrocyte death and myelin loss 2 weeks after stroke in the transient middle cerebral artery occlusion (tMCAO) mouse model. In contrast, myelin regeneration remained insufficient 4 and 8 weeks post-stroke. Notably, neuronal loss and functional impairments worsened in aged brains, and new myelin generation was diminished. To analyse the causal relationship between remyelination and neuron survival, we manipulated myelinogenesis by conditional deletion of Olig2 (a positive regulator) or muscarinic receptor 1 (M1R, a negative regulator) in OPCs. Deleting Olig2 inhibited remyelination, reducing neuron survival and functional recovery after tMCAO. Conversely, enhancing remyelination by M1R conditional knockout or treatment with the pro-myelination drug clemastine after tMCAO preserved white matter integrity and neuronal survival, accelerating functional recovery. Together, our findings demonstrate that enhancing myelinogenesis is a promising strategy to preserve neurons and promote functional recovery after ischaemic stroke.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Ratones , Animales , Humanos , Anciano , Vaina de Mielina/patología , Isquemia Encefálica/complicaciones , Isquemia Encefálica/patología , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/patología , Oligodendroglía/patología , Neuronas , Diferenciación Celular/fisiología
6.
Cereb Cortex ; 34(4)2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38602742

RESUMEN

Prior investigations have established that the manipulation of neural activity has the potential to influence both rapid eye movement and non-rapid eye movement sleep. Low-intensity retinal ultrasound stimulation has shown effectiveness in the modulation of neural activity. Nevertheless, the specific effects of retinal ultrasound stimulation on rapid eye movement and non-rapid eye movement sleep, as well as its potential to enhance overall sleep quality, remain to be elucidated. Here, we found that: In healthy mice, retinal ultrasound stimulation: (i) reduced total sleep time and non-rapid eye movement sleep ratio; (ii) changed relative power and sample entropy of the delta (0.5-4 Hz) in non-rapid eye movement sleep; and (iii) enhanced relative power of the theta (4-8 Hz) and reduced theta-gamma coupling strength in rapid eye movement sleep. In Alzheimer's disease mice with sleep disturbances, retinal ultrasound stimulation: (i) reduced the total sleep time; (ii) altered the relative power of the gamma band during rapid eye movement sleep; and (iii) enhanced the coupling strength of delta-gamma in non-rapid eye movement sleep and weakened the coupling strength of theta-fast gamma. The results indicate that retinal ultrasound stimulation can modulate rapid eye movement and non-rapid eye movement-related neural activity; however, it is not beneficial to the sleep quality of healthy and Alzheimer's disease mice.


Asunto(s)
Enfermedad de Alzheimer , Animales , Ratones , Entropía , Estado de Salud , Luz , Calidad del Sueño
7.
Nucleic Acids Res ; 51(14): 7357-7375, 2023 08 11.
Artículo en Inglés | MEDLINE | ID: mdl-37378420

RESUMEN

DNA-RNA hybrids play various roles in many physiological progresses, but how this chromatin structure is dynamically regulated during spermatogenesis remains largely unknown. Here, we show that germ cell-specific knockout of Rnaseh1, a specialized enzyme that degrades the RNA within DNA-RNA hybrids, impairs spermatogenesis and causes male infertility. Notably, Rnaseh1 knockout results in incomplete DNA repair and meiotic prophase I arrest. These defects arise from the altered RAD51 and DMC1 recruitment in zygotene spermatocytes. Furthermore, single-molecule experiments show that RNase H1 promotes recombinase recruitment to DNA by degrading RNA within DNA-RNA hybrids and allows nucleoprotein filaments formation. Overall, we uncover a function of RNase H1 in meiotic recombination, during which it processes DNA-RNA hybrids and facilitates recombinase recruitment.


Asunto(s)
Meiosis , Ribonucleasa H , Humanos , Masculino , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , ADN/genética , ADN/metabolismo , Recombinasa Rad51/genética , Recombinasa Rad51/metabolismo , Recombinasas/genética , Espermatocitos/metabolismo , Ribonucleasa H/metabolismo
8.
Proc Natl Acad Sci U S A ; 119(23): e2116462119, 2022 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-35658074

RESUMEN

Helicases are multifunctional motor proteins with the primary task of separating nucleic acid duplexes. These enzymes often exist in distinct oligomeric forms and play essential roles during nucleic acid metabolism. Whether there is a correlation between their oligomeric state and cellular function, and how helicases effectively perform functional switching remains enigmatic. Here, we address these questions using a combined single-molecule approach and Bloom syndrome helicase (BLM). By examining the head-on collision of two BLM-mediated DNA unwinding forks, we find that two groups of BLM, upon fork convergence, promptly oligomerize across the fork junctions and tightly bridge two independent single-stranded (ss) DNA molecules that were newly generated by the unwinding BLMs. This protein oligomerization is mediated by the helicase and RNase D C-terminal (HRDC) domain of BLM and can sustain a disruptive force of up to 300 pN. Strikingly, onsite BLM oligomerization gives rise to an immediate transition of their helicase activities, from unwinding dsDNA to translocating along ssDNA at exceedingly fast rates, thus allowing for the efficient displacement of ssDNA-binding proteins, such as RPA and RAD51. These findings uncover an activity transition pathway for helicases and help to explain how BLM plays both pro- and anti-recombination roles in the maintenance of genome stability.


Asunto(s)
ADN de Cadena Simple , RecQ Helicasas , ADN/metabolismo , ADN de Cadena Simple/genética , Recombinación Homóloga , Microscopía Confocal , Pinzas Ópticas , RecQ Helicasas/metabolismo
9.
Proc Natl Acad Sci U S A ; 119(23): e2116445119, 2022 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-35658079

RESUMEN

The deformation mode of the Tibetan Plateau is of crucial importance for understanding its construction and extrusion processes, as well as for the assessment of regional earthquake potential. Block motion and viscous flow models have been proposed to describe the deformation field but are not fully supported by modern geophysical observations. The 2021 Mw 7.4 Maduo earthquake, which occurred inside the Songpan-Ganzi terrane (SGT) in central-east Tibet, provides a chance to evaluate the associated deformation mode of the region. We conduct a joint inversion for this earthquake and resolve a bilateral rupture process, which is characterized by super- and subshear rupture velocities, respectively. We interpret this distinct rupture behavior to be the result of the respective slip concentration depths of the two ruptured segments. We analyze geological, seismic, and geodetic evidence and find that the SGT upper crust shows distributed shear deformation and distinct transverse anisotropy, which are associated with folded structures originating from compression of the paleo-Tethys ocean accretional prism realigned by following shear deformation. The SGT receives lateral shear loading from its NS boundary and accommodates a right-step sinistral motion across the terrane boundary faults. The unique tectonic setting of the SGT defines locations and behaviors of internal faulting and strong earthquakes such as the 2021 Maduo earthquake, with the latter occurring on slow-moving faults at intervals of several thousands of years.

10.
Nano Lett ; 24(37): 11648-11653, 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39225486

RESUMEN

Energetic carriers generated by localized surface plasmon resonance (LSPR) provide an efficient way to drive chemical reactions. However, their dynamics and impact on surface reactions remain unknown due to the challenge in observing hot holes. This makes it difficult to correlate the reduction and oxidation half-reactions involving hot electrons and holes, respectively. Here we detect hot holes in their chemical form, Ag(I), on a Ag surface using surface-enhanced Raman scattering (SERS) of SO32- as a hole-specific label. It allows us to determine the dynamic correlations of hot electrons and holes. We find that the equilibrium of holes is the key factor of the surface chemistry, and the wavelength-dependent plasmonic chemical anode refilling (PCAR) effect plays an important role, in addition to the LSPR, in promoting the electron transfer. This method paves the way for visualizing hot holes with nanoscale spatial resolution toward the rational design of a plasmonic catalytic platform.

11.
Nano Lett ; 24(8): 2444-2450, 2024 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-38363218

RESUMEN

Quantum Griffiths phase (QGP) is a novel quantum phenomenon of quantum phase transition in two-dimensional (2D) superconductors, and the emergence of inhomogeneous superconducting rare regions immersed in a metallic matrix is theoretically related to the quantum Griffiths singularity (QGS). However, the theoretical proposal of superconducting rare regions still lacks intuitive experimental verification. Here, we construct an artificial ordered superconducting-islands-array on monolayer graphene with the aid of an anodic aluminum oxide (AAO) membrane. The QGS under both in-plane and out-of-plane magnetic fields is evidenced by the divergent dynamical critical exponent and is in compliance with the direct activated scaling behavior. The phase diagram clearly shows that the QGP is indeed bred in the rare superconducting regions within isolated superconducting islands with a vanished quantum coherence. Our results reveal the universal features of QGP in artificial heterostructured systems and provide a visualized platform for the theoretical proposal of QGS.

12.
Gut ; 2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39216984

RESUMEN

OBJECTIVE: Pancreatic ductal adenocarcinoma (PDAC) stands as one of the most lethal cancers, marked by its lethality and limited treatment options, including the utilisation of checkpoint blockade (ICB) immunotherapy. Epigenetic dysregulation is a defining feature of tumourigenesis that is implicated in immune surveillance, but remains elusive in PDAC. DESIGN: To identify the factors that modulate immune surveillance, we employed in vivo epigenetic-focused CRISPR-Cas9 screen in mouse PDAC tumour models engrafted in either immunocompetent or immunodeficient mice. RESULTS: Here, we identified MED12 as a top hit, emerging as a potent negative modulator of immune tumour microenviroment (TME) in PDAC. Loss of Med12 significantly promoted infiltration and cytotoxicity of immune cells including CD8+ T cells, natural killer (NK) and NK1.1+ T cells in tumours, thereby heightening the sensitivity of ICB treatment in a mouse model of PDAC. Mechanistically, MED12 stabilised heterochromatin protein HP1A to repress H3K9me3-marked endogenous retroelements. The derepression of retrotransposons induced by MED12 loss triggered cytosolic nucleic acid sensing and subsequent activation of type I interferon pathways, ultimately leading to robust inflamed TME . Moreover, we uncovered a negative correlation between MED12 expression and immune resposne pathways, retrotransposon levels as well as the prognosis of patients with PDAC undergoing ICB therapy. CONCLUSION: In summary, our findings underscore the pivotal role of MED12 in remodelling immnue TME through the epigenetic silencing of retrotransposons, offering a potential therapeutic target for enhancing tumour immunogenicity and overcoming immunotherapy resistance in PDAC.

13.
Plant J ; 113(4): 698-715, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36564995

RESUMEN

Carnation (Dianthus caryophyllus L.) is one of the most famous and ethylene-sensitive cut flowers worldwide, but how ethylene interacts with other plant hormones and factors to regulate petal senescence in carnation is largely unknown. Here we found that a gene encoding WRKY family transcription factor, DcWRKY33, was significantly upregulated upon ethylene treatment. Silencing and overexpression of DcWRKY33 could delay and accelerate the senescence of carnation petals, respectively. Abscisic acid (ABA) and H2 O2 treatments could also accelerate the senescence of carnation petals by inducing the expression of DcWRKY33. Further, DcWRKY33 can bind directly to the promoters of ethylene biosynthesis genes (DcACS1 and DcACO1), ABA biosynthesis genes (DcNCED2 and DcNCED5), and the reactive oxygen species (ROS) generation gene DcRBOHB to activate their expression. Lastly, relationships are existed between ethylene, ABA and ROS. This study elucidated that DcWRKY33 promotes petal senescence by activating genes involved in the biosynthesis of ethylene and ABA and accumulation of ROS in carnation, supporting the development of new strategies to prolong the vase life of cut carnation.


Asunto(s)
Dianthus , Syzygium , Ácido Abscísico/metabolismo , Dianthus/genética , Especies Reactivas de Oxígeno/metabolismo , Syzygium/metabolismo , Etilenos/metabolismo , Flores , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
14.
Plant J ; 114(3): 636-650, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36808165

RESUMEN

Carnation (Dianthus caryophyllus L.) is a respiratory climacteric flower, comprising one of the most important cut flowers that is extremely sensitive to plant hormone ethylene. Ethylene signaling core transcription factor DcEIL3-1 plays a key role in ethylene induced petal senescence in carnation. However, how the dose of DcEIL3-1 is regulated in the carnation petal senescence process is still not clear. Here, we screened out two EBF (EIN3 Binding F-box) genes, DcEBF1 and DcEBF2, which showed quick elevation by ethylene treatment according to the ethylene induced carnation petal senescence transcriptome. Silencing of DcEBF1 and DcEBF2 accelerated, whereas overexpression of DcEBF1 and DcEBF2 delayed, ethylene induced petal senescence in carnation by influencing DcEIL3-1 downstream target genes but not DcEIL3-1 itself. Furthermore, DcEBF1 and DcEBF2 interact with DcEIL3-1 to degrade DcEIL3-1 via an ubiquitination pathway in vitro and in vivo. Finally, DcEIL3-1 binds to the promoter regions of DcEBF1 and DcEBF2 to activate their expression. In conclusion, the present study reveals the mutual regulation between DcEBF1/2 and DcEIL3-1 during ethylene induced petal senescence in carnation, which not only expands our understanding about ethylene signal regulation network in the carnation petal senescence process, but also provides potential targets with respect to breeding a cultivar of long-lived cut carnation.


Asunto(s)
Dianthus , Syzygium , Dianthus/genética , Syzygium/metabolismo , Fitomejoramiento , Etilenos/metabolismo , Flores/genética , Flores/metabolismo
15.
Neuroimage ; 299: 120841, 2024 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-39244077

RESUMEN

Working memory in attention deficit hyperactivity disorder (ADHD) is closely related to cortical functional network connectivity (CFNC), such as abnormal connections between the frontal, temporal, occipital cortices and with other brain regions. Low-intensity transcranial ultrasound stimulation (TUS) has the advantages of non-invasiveness, high spatial resolution, and high penetration depth and can improve ADHD memory behavior. However, how it modulates CFNC in ADHD and the CFNC mechanism that improves working memory behavior in ADHD remain unclear. In this study, we observed working memory impairment in ADHD rats, establishing a corresponding relationship between changes in CFNCs and the behavioral state during the working memory task. Specifically, we noted abnormalities in the information transmission and processing capabilities of CFNC in ADHD rats while performing working memory tasks. These abnormalities manifested in the network integration ability of specific areas, as well as the information flow and functional differentiation of CFNC. Furthermore, our findings indicate that TUS effectively enhances the working memory ability of ADHD rats by modulating information transmission, processing, and integration capabilities, along with adjusting the information flow and functional differentiation of CFNC. Additionally, we explain the CFNC mechanism through which TUS improves working memory in ADHD. In summary, these findings suggest that CFNCs are important in working memory behaviors in ADHD.

16.
J Am Chem Soc ; 2024 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-39241040

RESUMEN

The selective upcycling of polyolefins to create products of increased value has emerged as an innovative approach to carbon resource stewardship, drawing significant scientific and industrial interest. Although recent advancements in recycling technology have facilitated the direct conversion of polyolefins to hydrocarbons or oxygenated compounds, the synthesis of nitrogenated compounds from such waste polyolefins has not yet been disclosed. Herein, we demonstrate a novel approach for the upcycling of waste polyolefins by efficiently transforming a range of postconsumer plastic products into nitriles and amides. This process leverages the catalytic properties of manganese dioxide in combination with an inexpensive nitrogen source, urea, to make it both practical and economically viable. Our approach not only opens new avenues for the creation of nitrogenated chemicals from polyolefin waste but also underscores the critical importance of recycling and valorizing carbon resources originally derived from fossil fuels. This study provides a new upcycling strategy for the sustainable conversion of waste polyolefins.

17.
J Am Chem Soc ; 146(31): 21922-21931, 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39052980

RESUMEN

Donor-acceptor (D-A) conjugated systems have been extensively investigated and play important roles in organic electronics. Incorporating D-A structures into (hetero)cycloarenes endows them tunable electronic properties, while the well-defined cavity remains. However, the synthetic complexity of introducing electron-acceptor moieties into (hetero)cycloarenes limits their development and applications. In this paper, the first family of electronically tunable D-A heterocycloarenes (DAHCn, n = 1-5) based on pyrazine derivatives was facilely synthesized through cyclocondensation reaction from a tetraketone-functionalized heterocycloarene precursor prepared using the ketal-protection strategy. The effect of expanded conjugation and the inserted electron-withdrawing group on the electronic structures of the D-A heterocycloarenes was studied systematically by X-ray crystallographic analysis, various spectroscopic measurements, and theoretical calculations. Interestingly, the presence of an electron-withdrawing group polarizes the inner C(sp2)-H and significantly increases the binding affinities of D-A heterocycloarenes to the iodide anion. Meanwhile, the anion affinity can be further modulated by the type of attached substituents and the distance of polarization. More importantly, the dicyanopyrazine derivative DAHC3 shows the highest binding strength to the iodide ion as a 2:1 sandwich complex (log ß2 = 12.3 and ΔG = -69.1 kJ mol-1), which is the strongest iodide receptor using C(sp2)-H hydrogen bonding interactions reported to date. Our finding provides a new strategy to design and synthesize D-A heterocycloarenes and strong anion receptors.

18.
Small ; 20(5): e2305728, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37752692

RESUMEN

Immunotherapy is regarded as a prospective strategy against metastatic cancer. However, tumor-associated macrophages (TAMs), which accumulate in hypoxic tumor microenvironment, reduce the effectiveness of immunotherapy by blocking or "hijacking" the initiation of the immune response. Here, a novel tumor-targeted nanoplatform loaded with hypoxia-pathway-intervened docosahexaenoic acid (DHA) and chemotherapeutic drug carfilzomib (CFZ) is developed, which realizes the rescue of TAM-hijacked immune response and effective metastatic cancer immunotherapy. DHA is conjugated to fucoidan (Fuc) via a reduction cleavable selenylsulfide bond (SSe) for micelle preparation, and CFZ is encapsulated in the hydrophobic cores of micelles. The functionalized nanoplatforms (Fuc─SSe─DHA (FSSeD)-CFZs) induce immunogenic cell death, inhibit hypoxia-inducible factor-1α expression, and improve immunosuppression by TAM suppression. FSSeD-CFZs enhance immune response against primary tumor development and metastasis formation. In brief, the novel rescue strategy for TAM-hijacked immunoreaction by inhibiting hypoxia pathway has the potential and clinically translational significance for enhanced metastatic cancer immunotherapy.


Asunto(s)
Macrófagos , Neoplasias , Humanos , Macrófagos/metabolismo , Neoplasias/patología , Inmunoterapia , Hipoxia/metabolismo , Hipoxia/patología , Micelas , Inmunidad , Microambiente Tumoral , Línea Celular Tumoral
19.
Small ; : e2402998, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38716678

RESUMEN

Aqueous zinc-based batteries (AZBs) are promising energy storage solutions with remarkable safety, abundant Zn reserve, cost-effectiveness, and relatively high energy density. However, AZBs still face challenges such as anode dendrite formation that reduces cycling stability and limited cathode capacity. Recently, low-dimensional metal-organic frameworks (LD MOFs) and their derivatives have emerged as promising candidates for improving the electrochemical performance of AZBs owing to their unique morphologies, high structure tunability, high surface areas, and high porosity. However, clear guidelines for developing LD MOF-based materials for high-performance AZBs are scarce. In this review, the recent progress of LD MOF-based materials for AZBs is critically examined. The typical synthesis methods and structural design strategies for improving the electrochemical performance of LD MOF-based materials for AZBs are first introduced. The recent noteworthy research achievements are systematically discussed and categorized based on their applications in different AZB components, including cathodes, anodes, separators, and electrolytes. Finally, the limitations are addressed and the future perspectives are outlined for LD MOFs and their derivatives in AZB applications. This review provides clear guidance for designing high-performance LD MOF-based materials for advanced AZBs.

20.
Opt Express ; 32(6): 10527-10534, 2024 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-38571261

RESUMEN

In the traditional dry etching process for photonic device fabrication, the etching effect is influenced in many ways, usually resulting in relatively large sidewall roughness and high transmission loss. In this study, an effective method, namely the secondary coating method, is proposed to reduce the transmission loss of a Ge-Sb-Se chalcogenide waveguide and increase the quality factor (Q-factor) of a Ge-Sb-Se chalcogenide micro-ring resonator. The Ge-Sb-Se waveguide and micro-ring resonator are fabricated by ultraviolet exposure/electron beam lithography and inductively coupled plasma etching technology. Afterward, a 10 nm-thick Ge-Sb-Se thin film is deposited by thermal evaporation. The measurements show that after secondary coating, the sidewall roughness of the waveguide is reduced from 11.96 nm to 6.52 nm, with the transmission loss reduced from 2.63± 0.19 dB/cm to 1.86± 0.11 dB/cm at 1.55 µm wavelength. Keeping an equal coupling condition with equal radius and coupling distance, the Q-factor of the micro-ring resonator is improved by 47.5% after secondary coating. All results indicate that the secondary coating method is a feasible way to generate low-loss and high Q-factor integrated chalcogenide photonic devices.

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