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1.
Nature ; 583(7817): 533-536, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32699400

RESUMO

The quantum-level interplay between geometry, topology and correlation is at the forefront of fundamental physics1-15. Kagome magnets are predicted to support intrinsic Chern quantum phases owing to their unusual lattice geometry and breaking of time-reversal symmetry14,15. However, quantum materials hosting ideal spin-orbit-coupled kagome lattices with strong out-of-plane magnetization are lacking16-21. Here, using scanning tunnelling microscopy, we identify a new topological kagome magnet, TbMn6Sn6, that is close to satisfying these criteria. We visualize its effectively defect-free, purely manganese-based ferromagnetic kagome lattice with atomic resolution. Remarkably, its electronic state shows distinct Landau quantization on application of a magnetic field, and the quantized Landau fan structure features spin-polarized Dirac dispersion with a large Chern gap. We further demonstrate the bulk-boundary correspondence between the Chern gap and the topological edge state, as well as the Berry curvature field correspondence of Chern gapped Dirac fermions. Our results point to the realization of a quantum-limit Chern phase in TbMn6Sn6, and may enable the observation of topological quantum phenomena in the RMn6Sn6 (where R is a rare earth element) family with a variety of magnetic structures. Our visualization of the magnetic bulk-boundary-Berry correspondence covering real space and momentum space demonstrates a proof-of-principle method for revealing topological magnets.

2.
Nature ; 567(7749): 500-505, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30894753

RESUMO

The quantum behaviour of electrons in materials is the foundation of modern electronics and information technology1-11, and quantum materials with topological electronic and optical properties are essential for realizing quantized electronic responses that can be used for next generation technology. Here we report the first observation of topological quantum properties of chiral crystals6,7 in the RhSi family. We find that this material class hosts a quantum phase of matter that exhibits nearly ideal topological surface properties originating from the crystals' structural chirality. Electrons on the surface of these crystals show a highly unusual helicoid fermionic structure that spirals around two high-symmetry momenta, indicating electronic topological chirality. The existence of bulk multiply degenerate band fermions is guaranteed by the crystal symmetries; however, to determine the topological invariant or charge in these chiral crystals, it is essential to identify and study the helicoid topology of the arc states. The helicoid arcs that we observe on the surface characterize the topological charges of ±2, which arise from bulk higher-spin chiral fermions. These topological conductors exhibit giant Fermi arcs of maximum length (π), which are orders of magnitude larger than those found in known chiral Weyl fermion semimetals5,8-11. Our results demonstrate an electronic topological state of matter on structurally chiral crystals featuring helicoid-arc quantum states. Such exotic multifold chiral fermion semimetal states could be used to detect a quantized photogalvanic optical response, the chiral magnetic effect and other optoelectronic phenomena predicted for this class of materials6.

3.
Am J Respir Cell Mol Biol ; 70(2): 94-109, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37874230

RESUMO

Oxidative stress, inflammation, and endoplasmic reticulum (ER) stress sequentially occur in bronchopulmonary dysplasia (BPD), and all result in DNA damage. When DNA damage becomes irreparable, tumor suppressors increase, followed by apoptosis or senescence. Although cellular senescence contributes to wound healing, its persistence inhibits growth. Therefore, we hypothesized that cellular senescence contributes to BPD progression. Human autopsy lungs were obtained. Sprague-Dawley rat pups exposed to 95% oxygen between Postnatal Day 1 (P1) and P10 were used as the BPD phenotype. N-acetyl-lysyltyrosylcysteine-amide (KYC), tauroursodeoxycholic acid (TUDCA), and Foxo4 dri were administered intraperitoneally to mitigate myeloperoxidase oxidant generation, ER stress, and cellular senescence, respectively. Lungs were examined by histology, transcriptomics, and immunoblotting. Cellular senescence increased in rat and human BPD lungs, as evidenced by increased oxidative DNA damage, tumor suppressors, GL-13 stain, and inflammatory cytokines with decreased cell proliferation and lamin B expression. Cellular senescence-related transcripts in BPD rat lungs were enriched at P10 and P21. Single-cell RNA sequencing showed increased cellular senescence in several cell types, including type 2 alveolar cells. In addition, Foxo4-p53 binding increased in BPD rat lungs. Daily TUDCA or KYC, administered intraperitoneally, effectively decreased cellular senescence, improved alveolar complexity, and partially maintained the numbers of type 2 alveolar cells. Foxo4 dri administered at P4, P6, P8, and P10 led to outcomes similar to TUDCA and KYC. Our data suggest that cellular senescence plays an essential role in BPD after initial inducement by hyperoxia. Reducing myeloperoxidase toxic oxidant production, ER stress, and attenuating cellular senescence are potential therapeutic strategies for halting BPD progression.


Assuntos
Displasia Broncopulmonar , Hiperóxia , Ácido Tauroquenodesoxicólico , Recém-Nascido , Animais , Ratos , Humanos , Displasia Broncopulmonar/patologia , Hiperóxia/metabolismo , Ratos Sprague-Dawley , Pulmão/patologia , Senescência Celular , Peroxidase/metabolismo , Oxidantes , Animais Recém-Nascidos , Modelos Animais de Doenças
4.
Nature ; 562(7725): 91-95, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30209398

RESUMO

Owing to the unusual geometry of kagome lattices-lattices made of corner-sharing triangles-their electrons are useful for studying the physics of frustrated, correlated and topological quantum electronic states1-9. In the presence of strong spin-orbit coupling, the magnetic and electronic structures of kagome lattices are further entangled, which can lead to hitherto unknown spin-orbit phenomena. Here we use a combination of vector-magnetic-field capability and scanning tunnelling microscopy to elucidate the spin-orbit nature of the kagome ferromagnet Fe3Sn2 and explore the associated exotic correlated phenomena. We discover that a many-body electronic state from the kagome lattice couples strongly to the vector field with three-dimensional anisotropy, exhibiting a magnetization-driven giant nematic (two-fold-symmetric) energy shift. Probing the fermionic quasi-particle interference reveals consistent spontaneous nematicity-a clear indication of electron correlation-and vector magnetization is capable of altering this state, thus controlling the many-body electronic symmetry. These spin-driven giant electronic responses go well beyond Zeeman physics and point to the realization of an underlying correlated magnetic topological phase. The tunability of this kagome magnet reveals a strong interplay between an externally applied field, electronic excitations and nematicity, providing new ways of controlling spin-orbit properties and exploring emergent phenomena in topological or quantum materials10-12.

5.
Ecotoxicol Environ Saf ; 269: 115810, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38100849

RESUMO

BACKGROUND: Jujuboside B (JuB) is the main bioactive saponin component of Chinese anti-insomnia herbal medicine Ziziphi Spinosae Semen, which has been reported to possess varied pharmacological functions. Even though it has been traditionally used to treat inflammation- and toxicity-related diseases, the effects of JuB on acetaminophen (APAP) overdose-induced hepatotoxicity have not been determined yet. METHODS: C57BL/6 J mice were pre-treated with JuB (20 or 40 mg/kg) for seven days before APAP (400 mg/kg) injection. After 24 h of APAP treatment, serum, and liver tissues were collected to evaluate the therapeutic effects. To investigate whether the Nrf2-STING signaling pathway is involved in the protective effects of JuB against APAP-induced hepatotoxicity, the mice received the DMXAA (the specific STING agonist) or ML385 (the specific Nrf2 inhibitor) during the administration of JuB, and Hematoxylin-eosin staining, Real-time PCR, immunohistochemical, and western blot were performed. RESULTS: JuB pretreatment reversed APAP-induced CYP2E1 accumulations and alleviated APAP-induced acute liver injury. Furthermore, JuB treatment significantly inhibited oxidative stress and the pro-inflammatory cytokines, as well as alleviated hepatocyte apoptosis induced by APAP. Besides, our result also demonstrated that JuB treatment upregulated the levels of total Nrf2, facilitated its nuclear translocation, upregulated the expression of HO-1 and NQO-1, and inhibited the APAP-induced STING pathway activation. Finally, we verified that the beneficial effects of JuB were weakened by DMXAA and ML385. CONCLUSION: Our study suggested that JuB could ameliorate APAP-induced hepatic damage and verified a previously unrecognized mechanism by which JuB prevented APAP-induced hepatotoxicity through adjusting the Nrf2-STING pathway.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Saponinas , Animais , Camundongos , Acetaminofen/toxicidade , Acetaminofen/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Substâncias Protetoras/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Camundongos Endogâmicos C57BL , Transdução de Sinais , Estresse Oxidativo , Fígado , Saponinas/farmacologia , Saponinas/uso terapêutico
6.
Rep Prog Phys ; 86(11)2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37751734

RESUMO

Kagome magnet has been found to be a fertile ground for the search of exotic quantum states in condensed matter. Arising from the unusual geometry, the quantum interactions in the kagome lattice give rise to various quantum states, including the Chern-gapped Dirac fermion, Weyl fermion, flat band and van Hove singularity. Here we review recent advances in the study of the R166 kagome magnet (RT6E6, R = rare earths; T = transition metals; and E = Sn, Ge, etc) whose crystal structure highlights the transition-metal-based kagome lattice and rare-earth sublattice. Compared with other kagome magnets, the R166 family owns the particularly strong interplays between thedelectrons on the kagome site and the localizedfelectrons on the rare-earth site. In the form of spin-orbital coupling, exchange interaction and many-body effect, the quantum interactions play an essential role in the Berry curvature in both the reciprocal and real spaces of R166 family. We discuss the spectroscopic and transport visualization of the topological electrons hosted in the Mn kagome layer of RMn6Sn6and the various topological effects due to the quantum interactions, including the Chern-gap opening, the exchange-biased effect, the topological Hall effect and the emergent inductance. We hope this work serves as a guide for future explorations of quantum magnets.

7.
Nat Mater ; 21(10): 1111-1115, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35835819

RESUMO

Room-temperature realization of macroscopic quantum phases is one of the major pursuits in fundamental physics1,2. The quantum spin Hall phase3-6 is a topological quantum phase that features a two-dimensional insulating bulk and a helical edge state. Here we use vector magnetic field and variable temperature based scanning tunnelling microscopy to provide micro-spectroscopic evidence for a room-temperature quantum spin Hall edge state on the surface of the higher-order topological insulator Bi4Br4. We find that the atomically resolved lattice exhibits a large insulating gap of over 200 meV, and an atomically sharp monolayer step edge hosts an in-gap gapless state, suggesting topological bulk-boundary correspondence. An external magnetic field can gap the edge state, consistent with the time-reversal symmetry protection inherent in the underlying band topology. We further identify the geometrical hybridization of such edge states, which not only supports the Z2 topology of the quantum spin Hall state but also visualizes the building blocks of the higher-order topological insulator phase. Our results further encourage the exploration of high-temperature transport quantization of the putative topological phase reported here.

8.
Phys Rev Lett ; 130(6): 066402, 2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36827563

RESUMO

Novel topological phases of matter are fruitful platforms for the discovery of unconventional electromagnetic phenomena. Higher-fold topology is one example, where the low-energy description goes beyond standard model analogs. Despite intensive experimental studies, conclusive evidence remains elusive for the multigap topological nature of higher-fold chiral fermions. In this Letter, we leverage a combination of fine-tuned chemical engineering and photoemission spectroscopy with photon energy contrast to discover the higher-fold topology of a chiral crystal. We identify all bulk branches of a higher-fold chiral fermion for the first time, critically important for allowing us to explore unique Fermi arc surface states in multiple interband gaps, which exhibit an emergent ladder structure. Through designer chemical gating of the samples in combination with our measurements, we uncover an unprecedented multigap bulk boundary correspondence. Our demonstration of multigap electronic topology will propel future research on unconventional topological responses.

9.
Oral Dis ; 29(7): 2865-2877, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36076344

RESUMO

In this study, we explored the suspected pathogens of chronic periodontitis at different stages of occurrence and development. We collected 100 gingival crevicular fluid samples, 27, 27, and 26 from patients with mild, moderate, and severe chronic periodontitis, respectively, and 20 from healthy individuals. Pathogens were detected using a 16S rRNA metagenomic approach. Quantitative Insights in Microbial Ecology, Mothur, and other software were used to analyze the original data, draw relative abundance histograms and heat maps, and calculate flora abundance and diversity indexes. We identified 429 operational taxonomic units, covering 13 phyla, 20 classes, 32 orders, 66 families, and 123 genera from the four groups of samples. Each group showed microbial diversity, and the number of new species of bacterial flora in the gingival crevicular fluid samples gradually increased from the healthy to the severe chronic periodontitis group. There was a significant difference in the relative abundance of the core flora at the phylum, class, order, family, and genus classification levels. Our data indicated a certain correlation between the changes in the subgingival microbial structure and the occurrence and development of chronic periodontitis, which might be able to provide a reference for the diagnosis, treatment and prevention of chronic periodontitis.


Assuntos
Periodontite Crônica , Microbiota , Humanos , Periodontite Crônica/terapia , RNA Ribossômico 16S/genética , Bactérias/genética , Líquido do Sulco Gengival , Microbiota/genética
10.
Proc Natl Acad Sci U S A ; 117(27): 15517-15523, 2020 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-32554603

RESUMO

Topological electrons in semimetals are usually vulnerable to chemical doping and environment change, which restricts their potential application in future electronic devices. In this paper, we report that the type-II Dirac semimetal [Formula: see text] hosts exceptional, robust topological electrons which can tolerate extreme change of chemical composition. The Dirac electrons remain intact, even after a substantial part of V atoms have been replaced in the [Formula: see text] solid solutions. This Dirac semimetal state ends at [Formula: see text], where a Lifshitz transition to p-type trivial metal occurs. The V-Al bond is completely broken in this transition as long as the bonding orbitals are fully depopulated by the holes donated from Ti substitution. In other words, the Dirac electrons in [Formula: see text] are protected by the V-Al bond, whose molecular orbital is their bonding gravity center. Our understanding on the interrelations among electron count, chemical bond, and electronic properties in topological semimetals suggests a rational approach to search robust, chemical-bond-protected topological materials.

11.
J Sci Food Agric ; 103(5): 2459-2472, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36588174

RESUMO

BACKGROUND: As a traditional Chinese condiment, douchi has attracted attention in Asian and European countries because of its high nutrient content and unique flavors. Douchi is currently produced mostly by natural fermentation. The quality of douchi produced in this way is affected by microbial species, temperature, humidity, and season, so the physical and chemical properties of the product, the content of flavor substances, and its safety vary. In this study, four safe strains with high protease activity, screened previously, namely Bacillus velezensis, Bacillus amyloliquefaciens, Lichtheimia ramosa, and Lichtheimia corymbifera, were used as starter cultures for douchi fermentation. RESULTS: After 35 days, the results showed that the pH, titratable acids, free amino-type nitrogen, amino acids, the total number of colonies, and neutral protease activity of all samples had reached an average level. Through gas chromatography-mass spectrometry (GC-MS), the content of key aroma substances aldehydes and esters was higher than in commercial douchi and the free amino acid content of douchi fermented by the four strains was three to five times that of commercial douchi. Douchi fermented by Bacillus amyloliquefaciens had more flavor substances and the highest 2, 2-diphenyl-1-(2, 4, 6-trinitrophenyl) hydrazyl (DPPH) free radical scavenging rates of 92.4%. Four samples yielded total phenolic content and soy isoflavones in the range of 0.98-1.93 g kg-1 and 0.58-0.89 g kg-1 , respectively. CONCLUSION: These findings indicate that the use of a high-protease activity starter to produce douchi can improve the quality of douchi to a certain extent. The douchi obtained using Bacillus amyloliquefaciens not only has a good flavor but also has a high level of antioxidant activity. © 2023 Society of Chemical Industry.


Assuntos
Antioxidantes , Peptídeo Hidrolases , Antioxidantes/metabolismo , Fermentação , Peptídeo Hidrolases/metabolismo , Aminoácidos/metabolismo , Endopeptidases/metabolismo
12.
J Am Chem Soc ; 144(4): 1700-1708, 2022 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-35041406

RESUMO

The benefits of excess PbI2 on perovskite crystal nucleation and growth are countered by the photoinstability of interfacial PbI2 in perovskite solar cells (PSCs). Here we report a simple chemical polishing strategy to rip PbI2 crystals off the perovskite surface to decouple these two opposing effects. The chemical polishing results in a favorable perovskite surface exhibiting enhanced luminescence, prolonged carrier lifetimes, suppressed ion migration, and better energy level alignment. These desired benefits translate into increased photovoltages and fill factors, leading to high-performance mesostructured formamidinium lead iodide-based PSCs with a champion efficiency of 24.50%. As the interfacial ion migration paths and photodegradation triggers, dominated by PbI2 crystals, were eliminated, the hysteresis of the PSCs was suppressed and the device stability under illumination or humidity stress was significantly improved. Moreover, this new surface polishing strategy can be universally applicable to other typical perovskite compositions.

13.
Pestic Biochem Physiol ; 188: 105261, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36464366

RESUMO

Based on the previous finding that a substitution at 5-position of the benzene ring is favorable to enhance the degradation rates of sulfonylurea herbicides, a total of 16 novel 2,5-disubsituted sulfonylurea compounds were chemically synthesized and fully characterized by means of 1H NMR, 13C NMR, HRMS and X-ray diffraction. By using HPLC analysis, the degradation behavior of M03, a compound belonging to this family, was studied and confirmed that chlorsulfuron itself is not a degraded product of the 2,5-disubstituted sulfonylureas. Inhibition constants against plant acetohydroxyacid synthase (AHAS) were determined for selected compounds, among which SU3 showed seven times stronger activity against the mutant W574L enzyme than chlorsulfuron. Molecular docking suggested that the substituted group at 5-position of benzene ring is likely to interact with the surrounding residues Met200 and Asp376 of AtAHAS. From the greenhouse herbicidal assay and crop safety test, SU5 and SU6 are considered as herbicide candidates to control dicotyledon weeds in corn, while SU3 is likely to be a promising candidate to control dicotyledon weed species and barnyard grass in wheat. The present research has therefore provided some new insights to understand the structure-activity relationships of herbicidal sulfonylureas with di-substitutions at benzene ring.


Assuntos
Benzeno , Herbicidas , Simulação de Acoplamento Molecular , Compostos de Sulfonilureia/farmacologia , Sulfonamidas , Herbicidas/farmacologia
14.
Anal Chem ; 93(46): 15493-15500, 2021 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-34752060

RESUMO

Depending on the reaction between walkers and tracks, DNA walker is able to output signals continuously, which has attracted great attention from the bioanalytical community. Therefore, how to improve its reaction kinetics for efficient signal readout is of great significance. Herein, a quadrilateral DNAzyme walker was fabricated by colocalizing one walker and three DNA tracks in the quadrilateral nucleic acid frame to form a reaction unit (abbreviated as qDNA walker). Impressively, in contrast to the common free DNAzyme walker, the reaction kinetics of the qDNA walker was 2.3 times faster, which could achieve microRNA detection within 30 min. Meanwhile, an electrochemiluminescence (ECL) emitter of anthracene-cucurbituril supramolecular nanocrystals (Ant-CB SNCs) was obtained based on the self-assembly of cucurbituril (CB, host molecule) and anthracene (Ant, guest molecule). Benefiting from the host-guest recognition effect, the prepared Ant-CB SNCs exhibited enhanced ECL efficiency due to the supramolecular interaction between CB and Ant, which could inhibit vibration and rotation of the Ant molecules. We defined this new enhanced ECL phenomenon as "host-guest recognition-enhanced ECL." As a proof of concept, an ECL biosensor for microRNA-21 (miRNA-21) was constructed by combining the high-efficiency DNAzyme walker and the advanced ECL emitter of Ant-CB SNCs, which showed a linear range from 50 aM to 50 pM with a low limit of detection (11 aM), highlighting the great potential in clinical diagnosis.


Assuntos
Técnicas Biossensoriais , DNA Catalítico , MicroRNAs , DNA , Técnicas Eletroquímicas , Cinética , Limite de Detecção , Medições Luminescentes
15.
Phys Rev Lett ; 126(24): 246602, 2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34213939

RESUMO

Exploration of the topological quantum materials with electron correlation is at the frontier of physics, as the strong interaction may give rise to new topological phases and transitions. Here we report that a family of kagome magnets RMn_{6}Sn_{6} manifest the quantum transport properties analogical to those in the quantum-limit Chern magnet TbMn_{6}Sn_{6}. The topological transport in the family, including quantum oscillations with nontrivial Berry phase and large anomalous Hall effect arising from Berry curvature field, points to the existence of Chern gapped Dirac fermions. Our observation demonstrates a close relationship between rare-earth magnetism and topological electron structure, indicating the rare-earth elements can effectively engineer the Chern quantum phase in kagome magnets.

16.
Arch Gynecol Obstet ; 303(2): 533-539, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33104866

RESUMO

PURPOSE: Here, we compared endometrioma recurrence rates in patients who have undergone a laparoscopic cystectomy and treated with a gonadotropin-releasing hormone agonist (GnRHa) alone or a GnRHa combined with a levonogestrel intrauterine system (LND-IUS). METHODS: We enrolled endometrioma patients who underwent laparoscopic cyst enucleation and divided them into two groups according to postoperative management: GnRHa alone and GnRHa in combination with LND-IUS. We compared preoperative history, perioperative parameters, postoperative endometrioma recurrence, and symptoms between these two groups. RESULTS: A total of 320 patients were included in the final analysis. With a median 84.6 months of follow-up, we detected significant differences between the two groups with respect to age at surgery (31.6 ± 4.8 vs. 37.6 ± 4.2 years, χ2 = 1.978, p < 0.001), gravida (0 vs. 2, χ2 = 4.391, p < 0.001), parity (0 vs. 1, χ2 = 0.035, p < 0.001), body mass index (21.0 ± 2.5 vs. 21.9 ± 2.4, χ2 = 0.0096, p = 0.009), r-AFS score (48 vs. 64, χ2 = 4.888, p = 0.001), and operation time (60 vs. 75 min, χ2 = 9.119, p = 0.003). Patients treated with both GnRHa and LND-IUS achieved significantly less endometrioma recurrence (23.6 vs. 11.5%, χ2 = 5.202, p = 0.023) and higher rates of pain remission (92.1 vs. 100%, χ2 = 6.511, p = 0.011), while those with GnRHa alone suffered more recurrent and painful symptoms (χ2 = 9.280, p = 0.026). Multivariate analysis using a Cox regression demonstrated that combined GnRHa and LNG-IUS treatment correlated with a decreased endometrioma recurrence rate after laparoscopic cystectomy (RR 0.369, 95% CI 0.182-0.749, p = 0.006). CONCLUSIONS: Combination treatment of GnRHa and LNG-IUS exhibited superior pain relief and recurrence prevention among endometrioma patients after fertility-sparing surgery. Thus, combination treatment is a preferable long-term option for patients without intent for pregnancy in the near future.


Assuntos
Anticoncepcionais Femininos/administração & dosagem , Endometriose/cirurgia , Hormônio Liberador de Gonadotropina/administração & dosagem , Dispositivos Intrauterinos Medicados , Levanogestrel/administração & dosagem , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/prevenção & controle , Adulto , Terapia Combinada , Anticoncepcionais Femininos/uso terapêutico , Endometriose/patologia , Feminino , Hormônio Liberador de Gonadotropina/agonistas , Hormônio Liberador de Gonadotropina/uso terapêutico , Humanos , Levanogestrel/uso terapêutico , Recidiva Local de Neoplasia/patologia , Período Pós-Operatório , Prevenção Secundária , Resultado do Tratamento
17.
Biol Reprod ; 103(5): 918-926, 2020 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-32697306

RESUMO

An ideal research model plays a vital role in studying the pathogenesis of a disease. At present, the most widely used endometrial disease models are cell lines and animal models. As a novel studying model, organoids have already been applied for the study of various diseases, such as disorders related to the liver, small intestine, colon, and pancreas, and have been extended to the endometrium. After a long period of exploration by predecessors, endometrial organoids (EOs) technology has gradually matured and maintained genetic and phenotypic stability after long-term expansion. Compared with cell lines and animal models, EOs have high stability and patient specificity. These not only effectively and veritably reflects the pathophysiology of a disease, but also can be used in preclinical drug screening, combined with patient derived xenografts (PDXs). Indeed, there are still many limitations for EOs. For example, the co-culture system of EOs with stromal cells, immune cell, or vascular cells is not mature, and endometrial cancer organoids have a lower success rate, which should be improved in the future. The investigators predict that EOs will play a significant role in the study of endometrium-related diseases.


Assuntos
Endométrio/patologia , Organoides/patologia , Doenças Uterinas/patologia , Técnicas de Cultura de Células , Meios de Cultura , Feminino , Humanos
18.
Hum Reprod ; 35(2): 328-339, 2020 02 29.
Artigo em Inglês | MEDLINE | ID: mdl-32048711

RESUMO

STUDY QUESTION: What are the oncofertility outcomes of young women (≤40 years old) with bilateral serous borderline ovarian tumors (SBOTs) after fertility-sparing surgery? SUMMARY ANSWER: Fertility preservation with the bilateral ovarian cystectomy procedure is feasible for bilateral SBOTs, with an acceptable oncological outcome and worthwhile pregnancy rates. WHAT IS KNOWN ALREADY: Fertility-sparing approaches are becoming the standard management of young patients with unilateral SBOTs and other borderline histological subtypes. However, there is a paucity of evidence to dictate the best management in bilateral SBOTs. STUDY DESIGN, SIZE, DURATION: This was a retrospective observational study performed at the Peking Union Medical College Hospital in Beijing, China, between January 1999 and January 2019. PARTICIPANTS/MATERIALS, SETTING, METHODS: Ninety-four women (≤40 years old) with pathologically confirmed bilateral SBOTs were included. Following preoperative counseling, patients self-selected into one of three treatment modalities: bilateral ovarian cystectomy (n = 48), unilateral adnexectomy plus contralateral cystectomy (UAC; n = 31), and radical surgery (n = 15). Univariate and multivariate analyses were used to determine the clinical and pathological features associated with disease-free survival and reproductive outcomes. MAIN RESULTS AND THE ROLE OF CHANCE: During the median follow-up of 64 months (range, 4-243 months), 61 patients (65%) developed relapse, including 3 (20%) in the radical group, 26 (84%) in the UAC group and 32 (67%) in the bilateral cystectomy group. In the multivariate analyses, preoperative CA-125>300 U/mL, fertility preservation and micropapillary pattern were independently associated with adverse disease-free survival (P = 0.001, 0.03 and 0.026, respectively). Fourteen patients (15%) experienced invasive recurrence, and three (3%) died of progressive disease. The micropapillary pattern was significantly associated with invasive evolution risk (P = 0.006). Of the 49 patients who attempted to conceive, 23 (47%) achieved 27 pregnancies (24 spontaneous and three after IVF-ET), resulting in 19 live births. There was no significant difference in disease-free survival (P = 0.13) or pregnancy rate (41 vs. 50%, P = 0.56) between the UAC and bilateral procedures. LIMITATIONS, REASONS FOR CAUTION: As a retrospective study conducted in a referral center, inherent biases exist. The nonrandom allocation to treatment groups and relatively small number of patients attempt to conceive might limit the statistical power of our findings. Only 41 patients (43.6%) received complete staging during their initial surgeries, so an underestimation bias in terms of the FIGO stage and extraovarian implants might have occurred. WIDER IMPLICATIONS OF THE FINDINGS: The ultraconservative bilateral ovarian cystectomy procedure should be proposed in bilateral SBOTs when technically feasible. Invasive evolution occurs frequently in these women, and intense follow-up and oncofertility counseling are warranted, especially for those with micropapillary patterns. STUDY FUNDING/COMPETING INTEREST(S): No external funding was used for this study. There are no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.


Assuntos
Preservação da Fertilidade , Neoplasias Ovarianas , Adulto , China , Feminino , Humanos , Recidiva Local de Neoplasia , Neoplasias Ovarianas/cirurgia , Gravidez , Estudos Retrospectivos
19.
Immunity ; 35(1): 109-22, 2011 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-21723159

RESUMO

Although both natural and induced regulatory T (nTreg and iTreg) cells can enforce tolerance, the mechanisms underlying their synergistic actions have not been established. We examined the functions of nTreg and iTreg cells by adoptive transfer immunotherapy of newborn Foxp3-deficient mice. As monotherapy, only nTreg cells prevented disease lethality, but did not suppress chronic inflammation and autoimmunity. Provision of Foxp3-sufficient conventional T cells with nTreg cells reconstituted the iTreg pool and established tolerance. In turn, acute depletion of iTreg cells in rescued mice resulted in weight loss and inflammation. Whereas the transcriptional signatures of nTreg and in vivo-derived iTreg cells were closely matched, there was minimal overlap in their T cell receptor (TCR) repertoires. Thus, iTreg cells are an essential nonredundant regulatory subset that supplements nTreg cells, in part by expanding TCR diversity within regulatory responses.


Assuntos
Fatores de Transcrição Forkhead/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Especificidade do Receptor de Antígeno de Linfócitos T , Subpopulações de Linfócitos T/metabolismo , Linfócitos T Reguladores/metabolismo , Transferência Adotiva , Animais , Animais Recém-Nascidos , Autoimunidade/genética , Células Cultivadas , Fatores de Transcrição Forkhead/genética , Tolerância Imunológica , Inflamação , Depleção Linfocítica , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Mutantes , Mutação/genética , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Especificidade do Receptor de Antígeno de Linfócitos T/genética , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/patologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/patologia
20.
Nano Lett ; 19(4): 2397-2403, 2019 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-30823703

RESUMO

Two-dimensional ferromagnet Cr2Ge2Te6 (CGT) is so resistive below its Curie temperature that probing its magnetism by electrical transport becomes extremely difficult. By forming heterostructures with Pt, however, we observe clear anomalous Hall effect (AHE) in 5 nm thick Pt deposited on thin (<50 nm) exfoliated flakes of CGT. The AHE hysteresis loops persist to ∼60 K, which matches well to the Curie temperature of CGT obtained from the bulk magnetization measurements. The slanted AHE loops with a narrow opening indicate magnetic domain formation, which is confirmed by low-temperature magnetic force microscopy (MFM) imaging. These results clearly demonstrate that CGT imprints its magnetization in the AHE signal of the Pt layer. Density functional theory calculations of CGT/Pt heterostructures suggest that the induced ferromagnetism in Pt may be primarily responsible for the observed AHE. Our results establish a powerful way of investigating magnetism in 2D insulating ferromagnets, which can potentially work for monolayer devices.

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