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1.
Small ; : e2400013, 2024 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-38433394

RESUMO

Ruddlesden-Popper (RP) interface with defined stacking structure will fundamentally influence the optoelectronic performances of lead-halide perovskite (LHP) materials and devices. However, it remains challenging to observe the atomic local structures in LHPs, especially for multi-dimensional RP interface hidden inside the nanocrystal. In this work, the advantages of two imaging modes in scanning transmission electron microscopy (STEM), including high-angle annular dark field (HAADF) and integrated differential phase contrast (iDPC) STEM, are successfully combined to study the bulk and local structures of inorganic and organic/inorganic hybrid LHP nanocrystals. Then, the multi-dimensional RP interfaces in these LHPs are atomically resolved with clear gap and blurred transition region, respectively. In particular, the complex interface by the RP stacking in 3D directions can be analyzed in 2D projected image. Finally, the phase transition, ion missing, and electronic structures related to this interface are investigated. These results provide real-space evidence for observing and analyzing atomic multi-dimensional RP interfaces, which may help to better understand the structure-property relation of LHPs, especially their complex local structures.

2.
Small ; 20(25): e2309331, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38213019

RESUMO

The ß-relaxation is one of the major dynamic behaviors in metallic glasses (MGs) and exhibits diverse features. Despite decades of efforts, the understanding of its structural origin and contribution to the overall dynamics of MG systems is still unclear. Here two palladium-based Pd─Cu─P and Pd─Ni─P MGs are reported with distinct different ß-relaxation behaviors and reveal the structural origins for the difference using the advanced X-ray photon correlation spectroscopy and absorption fine structure techniques together with the first-principles calculations. The pronounced ß-relaxation and fast atomic dynamics in the Pd─Cu─P MG mainly come from the strong mobility of Cu atoms and their locally favored structures. In contrast, the motion of Ni atoms is constrained by P atoms in the Pd─Ni─P MG, leading to the weakened ß-relaxation peak and sluggish dynamics. The correlation of atomic dynamics with microscopic structures provides a way to understand the structural origins of different dynamic behaviors as well as the nature of aging in disordered materials.

3.
Ecotoxicol Environ Saf ; 274: 116191, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38460408

RESUMO

The reproduction toxicity of pubertal exposure to Microcystin-LR (MC-LR) and the underlying mechanism needs to be further investigated. In the current study, pubertal male ICR mice were intraperitoneally injected with 2 µg/kg MC-LR for four weeks. Pubertal exposure to MC-LR decreased epididymal sperm concentration and blocked spermatogonia proliferation. In-vitro studies found MC-LR inhibited cell proliferation of GC-1 cells and arrested cell cycle in G2/M phase. Mechanistically, MC-LR exposure evoked excessive reactive oxygen species (ROS) and induced DNA double-strand break in GC-1 cells. Besides, MC-LR inhibited DNA repair by reducing PolyADP-ribosylation (PARylation) activity of PARP1. Further study found MC-LR caused proteasomal degradation of SIRT6, a monoADP-ribosylation enzyme which is essential for PARP1 PARylation activity, due to destruction of SIRT6-USP10 interaction. Additionally, MG132 pretreatment alleviated MC-LR-induced SIRT6 degradation and promoted DNA repair, leading to the restoration of cell proliferation inhibition. Correspondingly, N-Acetylcysteine (NAC) pre-treatment mitigated the disturbed SIRT6-USP10 interaction and SIRT6 degradation, causing recovered DNA repair and subsequently restoration of cell proliferation inhibition in MC-LR treated GC-1 cells. Together, pubertal exposure to MC-LR induced spermatogonia cell cycle arrest and sperm count reduction by oxidative DNA damage and simultaneous SIRT6-mediated DNA repair failing. This study reports the effect of pubertal exposure to MC-LR on spermatogenesis and complex mechanism how MC-LR induces spermatogonia cell proliferation inhibition.


Assuntos
Toxinas Marinhas , Microcistinas , Sirtuínas , Espermatogônias , Animais , Masculino , Camundongos , Apoptose , Proliferação de Células , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Reparo do DNA , Toxinas Marinhas/metabolismo , Toxinas Marinhas/toxicidade , Camundongos Endogâmicos ICR , Microcistinas/metabolismo , Microcistinas/toxicidade , Sêmen , Sirtuínas/efeitos dos fármacos , Sirtuínas/metabolismo , Espermatogônias/efeitos dos fármacos , Espermatogônias/metabolismo
4.
Anal Chem ; 95(19): 7458-7467, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37146167

RESUMO

Herein, we report a novel liquid chromatography coupled with tandem mass spectrometry method to characterize N-acetylneuraminic acid (Neu5Ac, Sa) linkage in N-linked glycans in glycopeptides with no sialic acid derivatization. First, we established a separation in reversed-phase high-performance liquid chromatography (HPLC) using a higher formic acid concentration in the mobile phases, which separated the N-glycopeptides depending on the Sa linkage. We also demonstrated a novel characterization method of Sa linkages in N-glycopeptides using electron-activated dissociation. We found that hot electron capture dissociation using an electron beam energy higher than 5 eV cleaved glycosidic bonds in glycopeptides, resulting in each glycosidic bond in the antennas being broken on both sides of the oxygen atom. Such glycosidic bond cleavage at the reducing end (C-type ion) showed the difference in Sa linkages between Sa-Gal, Gal-GlcNAc, and GlcNAc-Man. We proposed a rule to characterize the Sa linkages using the Sa-Gal products. This method was applied to N-glycopeptides in tryptic fetuin digest separated by an optimized reversed-phase HPLC. We successfully identified a number of isomeric glycoforms in the glycopeptides with different Sa links, whose peptide backbones were also simultaneously sequenced by hot ECD.


Assuntos
Glicopeptídeos , Ácido N-Acetilneuramínico , Humanos , Ácido N-Acetilneuramínico/química , Glicopeptídeos/análise , Elétrons , Cromatografia Líquida/métodos , Espectrometria de Massas em Tandem/métodos
5.
J Proteome Res ; 21(10): 2462-2471, 2022 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-36074808

RESUMO

We describe a method to obtain a comprehensive profile of multiple glycosylations in glycopeptide isoforms. We detected a wide range of abundances of various O-glycoforms in isomeric glycopeptides using hot electron capture dissociation (hot ECD) in liquid chromatography-tandem mass spectrometry. To capture low abundant glycosylated species, a prototype of a ZenoTOF 7600 system incorporating an efficient electron-activated dissociation device to perform hot ECD was operated in targeted or scheduled high-resolution multiple reaction monitoring workflows. In addition, Zeno trap pulsing was activated to enhance the sensitivity of the time-of-flight mass spectrometer. Sixty-nine O-glycopeptides of the long O-glycopeptides in tryptic bovine fetuin digest were obtained with a relative abundance range from 100 to 0.2%, which included sialylated glycans with Neu5Ac and Neu5Gc.


Assuntos
Glicopeptídeos , Espectrometria de Massas em Tandem , Animais , Bovinos , Elétrons , Fetuínas , Glicopeptídeos/análise , Polissacarídeos/química , Isoformas de Proteínas , Espectrometria de Massas em Tandem/métodos
6.
Int J Mol Sci ; 23(24)2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36555689

RESUMO

Melon (Cucumis melo) is an important economic crop cultivated worldwide. A unique SUN gene family plays a crucial role in regulating plant growth and fruit development, but many SUN family genes and their function have not been well-characterized in melon. In the present study, we performed genome-wide identification and bioinformatics analysis and identified 24 CmSUN family genes that contain integrated and conserved IQ67 domain in the melon genome. Transcriptome data analysis and qRT-PCR results showed that most CmSUNs are specifically enriched in melon reproductive organs, such as young flowers and ovaries. Through genetic transformation in melons, we found that overexpression of CmSUN23-24 and CmSUN25-26-27c led to an increased fruit shape index, suggesting that they act as essential regulators in melon fruit shape variation. Subcellular localization revealed that the CmSUN23-24 protein is located in the cytoplasmic membrane. A direct interaction between CmSUN23-24 and a Calmodulin protein CmCaM5 was found by yeast two-hybrid assay, which indicated their participation in the calcium signal transduction pathway in regulating plant growth. These findings revealed the molecular characteristics, expression profile, and functional pattern of the CmSUN genes, and may provide the theoretical basis for the genetic improvement of melon fruit breeding.


Assuntos
Cucumis melo , Cucurbitaceae , Cucumis melo/genética , Frutas/genética , Cucurbitaceae/genética , Melhoramento Vegetal , Perfilação da Expressão Gênica
7.
Inorg Chem ; 58(4): 2444-2453, 2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30702275

RESUMO

Five new metal-organic frameworks, [Zn2L2]·2DMF·2MeOH (1), [Zn2L2(py)2] (2), [Cd2L2]·Diox·MeOH·6H2O (3), [Mn2L2]·2DMF·2MeOH (4), and [Co2L2]·2DMF·4H2O (5), were assembled by using a novel 8-hydroxyquinolinate derivative H2L with different metal ions. Complex 1 features a 3D porous network consisting of meso-helical chains ( P + M) built from metal-ligand coordination bonds. The adjacent dinuclear ZnII building blocks in 2 are connected together to generate a 2D grid network. In complex 3, each binuclear motif is bound to four ZnII ions to produce a 2D layer structure that stacks into a 3D porous structure. The framework of complex 4 is isostructural to 5, featuring a 21 helical chain built from [M2L2] units (M = Mn or Co). The adjacent meso-helices associated in parallel are interconnected by the phenolate µ2-O atoms of H2L to give rise to a 2D network. Distinct solid-state luminescence properties of 1-3 were observed, arising from their different metal nodes and frameworks. In particular, complex 1 exhibited excellent stability in both common organic solvents and H2O, thus facilitating its utility as a chemical sensor. Remarkably, luminescent 1 showed highly sensitive detection for nitroaromatic molecules in methanol and Fe3+ ion in H2O even in the presence of other interfering metal cations.

8.
Int J Mol Sci ; 20(8)2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-31018553

RESUMO

Dehydrins (DHNs), as a sub-family of group two late embryogenesis-abundant (LEA) proteins, have attracted considerable interest owing to their functions in enhancing abiotic stress tolerance in plants. Our previous study showed that the expression of CaDHN5 (a dehydrin gene from pepper) is strongly induced by salt and osmotic stresses, but its function was not clear. To understand the function of CaDHN5 in the abiotic stress responses, we produced pepper (Capsicum annuum L.) plants, in which CaDHN5 expression was down-regulated using VIGS (Virus-induced Gene Silencing), and transgenic Arabidopsis plants overexpressing CaDHN5. We found that knock-down of CaDHN5 suppressed the expression of manganese superoxide dismutase (MnSOD) and peroxidase (POD) genes. These changes caused more reactive oxygen species accumulation in the VIGS lines than control pepper plants under stress conditions. CaDHN5-overexpressing plants exhibited enhanced tolerance to salt and osmotic stresses as compared to the wild type and also showed increased expression of salt and osmotic stress-related genes. Interestingly, our results showed that many salt-related genes were upregulated in our transgenic Arabidopsis lines under salt or osmotic stress. Taken together, our results suggest that CaDHN5 functions as a positive regulator in the salt and osmotic stress signaling pathways.


Assuntos
Capsicum/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Estresse Fisiológico , Arabidopsis/genética , Arabidopsis/fisiologia , Capsicum/fisiologia , Secas , Genes de Plantas , Osmorregulação , Pressão Osmótica , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/fisiologia , Tolerância ao Sal
9.
Int J Mol Sci ; 21(1)2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31861623

RESUMO

Dehydrins play an important role in improving plant resistance to abiotic stresses. In this study, we isolated a dehydrin gene from pepper (Capsicum annuum L.) leaves, designated as CaDHN4. Sub-cellular localization of CaDHN4 was to be found in the nucleus and membrane. To authenticate the function of CaDHN4 in cold- and salt-stress responses and abscisic acid (ABA) sensitivity, we reduced the CaDHN4 expression using virus-induced gene silencing (VIGS), and overexpressed the CaDHN4 in Arabidopsis. We found that silencing of CaDHN4 reduced the growth of pepper seedlings and CaDHN4-silenced plants exhibited more serious wilting, higher electrolyte leakage, and more accumulation of ROS in the leaves compared to pTRV2:00 plants after cold stress, and lower chlorophyll contents and higher electrolyte leakage compared to pTRV2:00 plants under salt stress. However, CaDHN4-overexpressing Arabidopsis plants had higher seed germination rates and post-germination primary root growth, compared to WT plants under salt stress. In response to cold and salt stresses, the CaDHN4-overexpressed Arabidopsis exhibited lower MDA content, and lower relative electrolyte leakage compared to the WT plants. Under ABA treatments, the fresh weight and germination rates of transgenic plants were higher than WT plants. The transgenic Arabidopsis expressing a CaDHN4 promoter displayed a more intense GUS staining than the normal growth conditions under treatment with hormones including ABA, methyl jasmonate (MeJA), and salicylic acid (SA). Our results suggest that CaDHN4 can protect against cold and salt stresses and decrease ABA sensitivity in Arabidopsis.


Assuntos
Ácido Abscísico/farmacologia , Arabidopsis/crescimento & desenvolvimento , Capsicum/metabolismo , Proteínas de Plantas/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Capsicum/genética , Núcleo Celular/metabolismo , Resposta ao Choque Frio , Citoplasma/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Germinação/efeitos dos fármacos , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Espécies Reativas de Oxigênio/metabolismo , Estresse Salino
10.
Genes Dev ; 23(23): 2711-6, 2009 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-19952106

RESUMO

Cholesterol homeostasis is required to maintain normal cellular function and avoid the deleterious effects of hypercholesterolemia. Here we show that the Drosophila DHR96 nuclear receptor binds cholesterol and is required for the coordinate transcriptional response of genes that are regulated by cholesterol and involved in cholesterol uptake, trafficking, and storage. DHR96 mutants die when grown on low levels of cholesterol and accumulate excess cholesterol when maintained on a high-cholesterol diet. The cholesterol accumulation phenotype can be attributed to misregulation of npc1b, an ortholog of the mammalian Niemann-Pick C1-like 1 gene NPC1L1, which is essential for dietary cholesterol uptake. These studies define DHR96 as a central regulator of cholesterol homeostasis.


Assuntos
Colesterol/metabolismo , Drosophila melanogaster/metabolismo , Regulação da Expressão Gênica , Homeostase/fisiologia , Receptores Citoplasmáticos e Nucleares/metabolismo , Animais , Colesterol na Dieta/metabolismo , Dieta , Gorduras na Dieta/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Homeostase/genética , Modelos Animais , Mutação/genética , Mutação/imunologia , Receptores Citoplasmáticos e Nucleares/genética , Análise de Sobrevida
11.
Small Methods ; 8(1): e2300871, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37800990

RESUMO

Internal strain and its distribution within the crystal lattice play crucial roles in modulating dislocation activities, thereby affecting mechanical properties of materials. Through the synergistic application of integrated differential phase contrast, in situ transmission electron microscopy characterizations, and computational simulations, a method is unveiled for homogenizing dislocation pinning in NiCoCr multi-principal element alloy (MPEA) through the introduction of a high concentration of oxygen atoms with high diffusion mobility. The doping of massive oxygen atoms creates a high density of strong local pinning points for dislocation motion. Notably, oxygen interstitials exhibit remarkable diffusion and mobility across different octahedral and tetrahedral sites within the distorted crystal lattice of NiCoCrO alloy, even at room temperature. The capability allows for the release of severe stress concentrations arising from dislocation entanglement and the establishment of new strong local pinning points at alternative locations in a uniform way, enabling the material with high strength and outstanding deformability. These findings suggest that interstitial atoms can exhibit significant mobility, even at ambient temperature, in complex MPEAs with spreading lattice distortion, opening new possibilities for dislocation engineering.

12.
Adv Mater ; 36(28): e2312566, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38630368

RESUMO

Transition metal oxides (TMOs) are widely studied for loading of various catalysts due to their low cost and high structure flexibility. However, the prevailing close-packed nature of most TMOs crystals has restricted the available loading sites to surface only, while their internal bulk lattice remains unactuated due to the inaccessible narrow space that blocks out most key reactants and/or particulate catalysts. Herein, using tunnel-structured MnO2, this study demonstrates how TMO's internal lattice space can be activated as extra loading sites for atomic Ag in addition to the conventional surface-only loading, via which a dual-form Ag catalyst within MnO2 skeleton is established. In this design, not only faceted Ag nanoparticles are confined onto MnO2 surface by coherent lattice-sharing, Ag atomic strings are also seeded deep into the sub-nanoscale MnO2 tunnel lattice, enriching the catalytically active sites. Tested for electrochemical CO2 reduction reaction (eCO2RR), such dual-form catalyst exhibits a high Faradaic efficiency (94%), yield (67.3 mol g-1 h-1) and durability (≈48 h) for CO production, exceeding commercial Ag nanoparticles and most Ag-based electrocatalysts. Theoretical calculations further reveal the concurrent effect of such dual-form catalyst featuring facet-dependent eCO2RR for Ag nanoparticles and lattice-confined eCO2RR for Ag atomic strings, inspiring the future design of catalyst-substrate configuration.

13.
J Neuroinflammation ; 9: 153, 2012 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-22747852

RESUMO

Gastrointestinal symptoms and altered blood phospholipid profiles have been reported in patients with autism spectrum disorders (ASD). Most of the phospholipid analyses have been conducted on the fatty acid composition of isolated phospholipid classes following hydrolysis. A paucity of information exists on how the intact phospholipid molecular species are altered in ASD. We applied ESI/MS to determine how brain and blood intact phospholipid species were altered during the induction of ASD-like behaviors in rats following intraventricular infusions with the enteric bacterial metabolite propionic acid. Animals were infused daily for 8 days, locomotor activity assessed, and animals killed during the induced behaviors. Propionic acid infusions increased locomotor activity. Lipid analysis revealed treatment altered 21 brain and 30 blood phospholipid molecular species. Notable alterations were observed in the composition of brain SM, diacyl mono and polyunsaturated PC, PI, PS, PE, and plasmalogen PC and PE molecular species. These alterations suggest that the propionic acid rat model is a useful tool to study aberrations in lipid metabolism known to affect membrane fluidity, peroxisomal function, gap junction coupling capacity, signaling, and neuroinflammation, all of which may be associated with the pathogenesis of ASD.


Assuntos
Encéfalo/metabolismo , Transtornos Globais do Desenvolvimento Infantil/metabolismo , Modelos Animais de Doenças , Enterobacteriaceae , Fosfolipídeos/sangue , Propionatos/toxicidade , Animais , Biomarcadores/sangue , Biomarcadores/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Transtornos Globais do Desenvolvimento Infantil/induzido quimicamente , Transtornos Globais do Desenvolvimento Infantil/patologia , Pré-Escolar , Enterobacteriaceae/metabolismo , Humanos , Infusões Intraventriculares , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Propionatos/administração & dosagem , Ratos , Ratos Long-Evans
14.
PLoS Biol ; 7(2): e43, 2009 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-19243223

RESUMO

Heme is a ligand for the human nuclear receptors (NR) REV-ERBalpha and REV-ERBbeta, which are transcriptional repressors that play important roles in circadian rhythm, lipid and glucose metabolism, and diseases such as diabetes, atherosclerosis, inflammation, and cancer. Here we show that transcription repression mediated by heme-bound REV-ERBs is reversed by the addition of nitric oxide (NO), and that the heme and NO effects are mediated by the C-terminal ligand-binding domain (LBD). A 1.9 A crystal structure of the REV-ERBbeta LBD, in complex with the oxidized Fe(III) form of heme, shows that heme binds in a prototypical NR ligand-binding pocket, where the heme iron is coordinately bound by histidine 568 and cysteine 384. Under reducing conditions, spectroscopic studies of the heme-REV-ERBbeta complex reveal that the Fe(II) form of the LBD transitions between penta-coordinated and hexa-coordinated structural states, neither of which possess the Cys384 bond observed in the oxidized state. In addition, the Fe(II) LBD is also able to bind either NO or CO, revealing a total of at least six structural states of the protein. The binding of known co-repressors is shown to be highly dependent upon these various liganded states. REV-ERBs are thus highly dynamic receptors that are responsive not only to heme, but also to redox and gas. Taken together, these findings suggest new mechanisms for the systemic coordination of molecular clocks and metabolism. They also raise the possibility for gas-based therapies for the many disorders associated with REV-ERB biological functions.


Assuntos
Heme/metabolismo , Óxido Nítrico/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Sítios de Ligação , Linhagem Celular Tumoral , Ritmo Circadiano , Proteínas de Ligação a DNA , Humanos , Ligantes , Óxido Nítrico/farmacologia , Oxirredução , Domínios e Motivos de Interação entre Proteínas , Estrutura Terciária de Proteína , Receptores Citoplasmáticos e Nucleares/química , Proteínas Repressoras/química , Transcrição Gênica/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos
15.
Nat Commun ; 13(1): 951, 2022 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-35177632

RESUMO

Crystallization of biomacromolecules-metal-organic frameworks (BMOFs) allows for orderly assemble of symbiotic hybrids with desirable biological and chemical functions in one voxel. The structure-activity relationship of this symbiotic crystal, however, is still blurred. Here, we directly identify the atomic-level structure of BMOFs, using the integrated differential phase contrast-scanning transmission electron microscopy, cryo-electron microscopy and x-ray absorption fine structure techniques. We discover an obvious difference in the nanoarchitecture of BMOFs under different crystallization pathways that was previously not seen. In addition, we find the nanoarchitecture significantly affects the bioactivity of the BMOFs. This work gives an important insight into the structure-activity relationship of BMOFs synthesized in different scenarios, and may act as a guide to engineer next-generation materials with excellent biological and chemical functions.


Assuntos
Estruturas Metalorgânicas/ultraestrutura , Microscopia Crioeletrônica , Cristalização , Estruturas Metalorgânicas/química , Microscopia Eletrônica de Transmissão e Varredura , Relação Estrutura-Atividade , Espectroscopia por Absorção de Raios X
16.
ACS Nano ; 16(12): 21618-21625, 2022 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-36521057

RESUMO

Octahedral molecular sieves (OMSs) based on MnO2 have been widely studied in the fields of deionization, geochemistry, and energy storage due to their microporous tunnel framework capable of adsorbing and exchanging various ions, particularly cations. The understanding of cation adsorption/exchange within OMS tunnels demands atomic-scale exploration, which has been scarcely reported. Here, we disclose how various cations (K+/Ag+/Na+) interplay within the OMS tunnel space on an atomic scale. Not only are the lattice sites for each adsorbed cation species pinpointed but the scenario of dual-cation adsorption within single tunnels is also demonstrated, together with the discovery of characteristic concentration-dependent cation ordering. Moreover, compared with the theoretical parent tunnel phase, the heterogeneous tunnels, though sparsely distributed, exhibit a distinct yet orderly cationic accommodation, highlighting the non-negligible role of tunnel heterogeneity in regulating OMS physiochemistry. Our findings clarify the long-existing ambiguities in nano- and atomic-scale science of the ion adsorption process in OMS materials and are expected to inspire their structural/compositional engineering toward functionality enhancement in various fields.

17.
Front Genet ; 13: 1000448, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36160021

RESUMO

Purpose: This study aimed to compare the clinical outcomes of camrelizumab in hepatitis B virus-related hepatocellular carcinoma (HBV-HCC) patients and non-HBV, non-HCV hepatocellular carcinoma (NBNC-HCC) patients in China. Materials and methods: A total of 54 patients with hepatocellular carcinoma who received camrelizumab were included in this retrospective study from January 2019 to December 2021. The patients were assigned to the HBV-HCC group (n = 28) and the NBNC-HCC group (n = 26). The primary endpoints were overall survival (OS) and progression-free survival (PFS), and the secondary endpoints were the objective response rate (ORR), disease control rate (DCR), and adverse events (AEs). Multivariate analysis using Cox proportional hazard regression was used to identify independent prognostic factors. A nomogram model was subsequently established based on independent prognostic factors. Results: The mean duration of follow-up was 12.7 ± 3.6 months. The median OS was not determined. The median PFS in the HBV-HCC group was significantly longer than that in the NBNC-HCC group (9.2 vs. 6.7 months, p = 0.003). The ORR and DCR in the HBV-HCC group were significantly higher than those in the NBNC-HCC group (ORR, 28.6% vs. 7.7%, p = 0.048; DCR, 71.4% vs. 42.3%, p = 0.031). No significant differences in the total incidence of AEs were found between the HBV-HCC group and the NBNC-HCC group (75.0% vs. 69.2%, p = 0.224). Multivariate regression analysis identified etiology, AFP level, and vascular invasion as independent prognostic factors (all p < 0.05). Conclusion: Our findings demonstrate that camrelizumab is more effective in HBV-HCC patients than in NBNC-HCC patients, with manageable safety.

18.
J Am Soc Mass Spectrom ; 33(9): 1723-1732, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-35948044

RESUMO

We report on the dissociation of singly protonated peptides by electrons using electron-activated dissociation (EAD), which comprises electron impact excitation of ions from organics (EIEIO), electronic-excitation dissociation (EED), and electron ionization dissociation (EIoD). Various singly protonated peptides were dissociated using a recently reported fast EAD device. The dissociation can be induced through two pathways: (i) vibrational dissociation similar to collision-activated dissociation (CAD, or collision-induced dissociation, CID) by relaxation from a molecular electronic excited state to high vibrational states; and (ii) radical-induced dissociation where molecular electronic excitation is followed by homolytic cleavage. EAD is complementary to CAD as additional molecular information can be obtained; e.g., fragile PTM moieties, such as glycosylation and sulfation, can be localized. Simultaneously, the energetic production of radical z• fragments enables Leu and Ile discrimination, like in a hot ECD process. Using the fast EAD device, LC-EIEIO-time-of-flight mass spectrometry was applied to a tryptic monoclonal antibody digest containing short singly protonated peptides.


Assuntos
Elétrons , Peptídeos , Íons/química , Espectrometria de Massas/métodos , Peptídeos/química , Processamento de Proteína Pós-Traducional
19.
Front Oncol ; 12: 997030, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36568251

RESUMO

Objective: This study aimed to assess the efficacy and safety of adjuvant chemotherapy (ACT) after concurrent chemoradiation (CCRT) in patients with locally advanced cervical cancer (LACC) via meta-analysis. Methods: A systematic literature search of MEDLINE, PubMed, Web of Science, EMBASE, and the Cochrane Central Register of Controlled Trials was conducted from January 10, 1966 to May 20, 2022. Randomized controlled trials and observational studies comparing the CCRT alone with CCRT plus ACT were included. The literature search, quality assessment, and data extraction were conducted by two reviewers independently. The primary endpoints were 3-year rates of overall survival (OS) and progression-free survival (PFS). Complete response rate, local recurrence, distant metastasis, and adverse events were secondary outcomes. The hazard ratios (HRs) and relative risk (RR) were pooled. Results: Nine studies with a total of 2732 patients were included in this meta-analysis, including 1411 patients in the CCRT group and 1321 in the CCRT plus ACT group. The HR for 3-year rates of OS and PFS of the CCRT group compared with the CCRT plus ACT group was 0.72 [95%confidence interval (CI) = 0.44-1.17] and 0.78 (95%CI = 0.5-1.75), respectively. No significant differences were observed between the two groups in the complete response rate (RR = 1.06, 95%CI = 0.96-1.16). However, local recurrence and distant metastasis were significantly lower in the CCRT plus ACT group than in the CCRT group (RR = 0.63, 95%CI = 0.44 -0.91 and RR = 0.64, 95%CI = 0.47-0.88). Grade 3-4 acute toxicities were more frequent in the CCRT plus ACT group (RR = 1.73, 95%CI =1.19-2.52). Conclusion: Although associated with a decreased risk of local recurrence and distant metastasis, ACT did not significantly improve the survival rate and the complete response rate with increasing grade 3-4 acute toxicities in patients with LACC. Thus, this ACT regimen cannot be recommended for patients with LACC. Systematic review registration: https://inplasy.com/inplasy-2022-9-0089/, identifier INPLASY202290089.

20.
Mol Cell Proteomics ; 8(3): 421-32, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18936058

RESUMO

The derivation and long-term maintenance of human embryonic stem cells (hESCs) has been established in culture formats that are both dependent and independent of support (feeder) cells. However, the factors responsible for preserving the viability of hESCs in a nascent state remain unknown. We describe a mass spectrometry-based method for probing the secretome of the hESC culture microenvironment to identify potential regulating protein factors that are in low abundance. Individual samples were analyzed several times, using successive mass (m/z) and retention time-directed exclusion, without sampling the same peptide ion twice. This iterative exclusion -mass spectrometry (IE-MS) approach more than doubled protein and peptide metrics in comparison to a simple repeat analysis method on the same instrument, even after extensive sample pre-fractionation. Furthermore, implementation of the IE-MS approach was shown to enhance the performance of an older quadrupole time of flight (Q-ToF) MS. The resulting number of identified peptides approached that of a parallel repeat analysis on a newer LTQ-Orbitrap MS. The combination of the results of both instruments proved to be superior to that achieved by a single instrument in the identification of additional proteins. Using the IE-MS strategy, combined with complementary gel- and solution-based fractionation methods, the hESC culture microenvironment was extensively probed. Over 10 to 12 times more extracellular proteins were observed compared with previously published surveys. The detection of previously undetectable growth factors, present at concentrations ranging from 10(-9) to 10(-11) g/ml, highlights the depth of our profiling. The IE-MS approach provides a simple and reliable technique that greatly enhances instrument performance by increasing the effective depth of MS-based proteomic profiling. This approach should be widely applicable to any LC-MS/MS instrument platform or biological system.


Assuntos
Meios de Cultivo Condicionados/química , Células-Tronco Embrionárias/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/análise , Espectrometria de Massas/métodos , Animais , Fracionamento Celular , Células Cultivadas , Cromatografia Líquida , Misturas Complexas , Meios de Cultura Livres de Soro , Espaço Extracelular/metabolismo , Humanos , Camundongos , Peptídeos/análise , Proteínas/análise
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