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1.
Nature ; 628(8008): 515-521, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38509374

RESUMO

The convergence of topology and correlations represents a highly coveted realm in the pursuit of new quantum states of matter1. Introducing electron correlations to a quantum spin Hall (QSH) insulator can lead to the emergence of a fractional topological insulator and other exotic time-reversal-symmetric topological order2-8, not possible in quantum Hall and Chern insulator systems. Here we report a new dual QSH insulator within the intrinsic monolayer crystal of TaIrTe4, arising from the interplay of its single-particle topology and density-tuned electron correlations. At charge neutrality, monolayer TaIrTe4 demonstrates the QSH insulator, manifesting enhanced nonlocal transport and quantized helical edge conductance. After introducing electrons from charge neutrality, TaIrTe4 shows metallic behaviour in only a small range of charge densities but quickly goes into a new insulating state, entirely unexpected on the basis of the single-particle band structure of TaIrTe4. This insulating state could arise from a strong electronic instability near the van Hove singularities, probably leading to a charge density wave (CDW). Remarkably, within this correlated insulating gap, we observe a resurgence of the QSH state. The observation of helical edge conduction in a CDW gap could bridge spin physics and charge orders. The discovery of a dual QSH insulator introduces a new method for creating topological flat minibands through CDW superlattices, which offer a promising platform for exploring time-reversal-symmetric fractional phases and electromagnetism2-4,9,10.

2.
Nature ; 595(7868): 521-525, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34290425

RESUMO

Whereas ferromagnets have been known and used for millennia, antiferromagnets were only discovered in the 1930s1. At large scale, because of the absence of global magnetization, antiferromagnets may seem to behave like any non-magnetic material. At the microscopic level, however, the opposite alignment of spins forms a rich internal structure. In topological antiferromagnets, this internal structure leads to the possibility that the property known as the Berry phase can acquire distinct spatial textures2,3. Here we study this possibility in an antiferromagnetic axion insulator-even-layered, two-dimensional MnBi2Te4-in which spatial degrees of freedom correspond to different layers. We observe a type of Hall effect-the layer Hall effect-in which electrons from the top and bottom layers spontaneously deflect in opposite directions. Specifically, under zero electric field, even-layered MnBi2Te4 shows no anomalous Hall effect. However, applying an electric field leads to the emergence of a large, layer-polarized anomalous Hall effect of about 0.5e2/h (where e is the electron charge and h is Planck's constant). This layer Hall effect uncovers an unusual layer-locked Berry curvature, which serves to characterize the axion insulator state. Moreover, we find that the layer-locked Berry curvature can be manipulated by the axion field formed from the dot product of the electric and magnetic field vectors. Our results offer new pathways to detect and manipulate the internal spatial structure of fully compensated topological antiferromagnets4-9. The layer-locked Berry curvature represents a first step towards spatial engineering of the Berry phase through effects such as layer-specific moiré potential.

3.
Nat Mater ; 22(5): 583-590, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36894774

RESUMO

Using circularly polarized light to control quantum matter is a highly intriguing topic in physics, chemistry and biology. Previous studies have demonstrated helicity-dependent optical control of chirality and magnetization, with important implications in asymmetric synthesis in chemistry; homochirality in biomolecules; and ferromagnetic spintronics. We report the surprising observation of helicity-dependent optical control of fully compensated antiferromagnetic order in two-dimensional even-layered MnBi2Te4, a topological axion insulator with neither chirality nor magnetization. To understand this control, we study an antiferromagnetic circular dichroism, which appears only in reflection but is absent in transmission. We show that the optical control and circular dichroism both arise from the optical axion electrodynamics. Our axion induction provides the possibility to optically control a family of [Formula: see text]-symmetric antiferromagnets ([Formula: see text], inversion; [Formula: see text], time-reversal) such as Cr2O3, even-layered CrI3 and possibly the pseudo-gap state in cuprates. In MnBi2Te4, this further opens the door for optical writing of a dissipationless circuit formed by topological edge states.

4.
J Org Chem ; 89(3): 1633-1647, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38235569

RESUMO

A metal-free and atom-economic route for the synthesis of naphtho[1,2-b]furan-3-ones has been realized via p-TsOH·H2O-catalyzed intramolecular tandem double cyclization of γ-hydroxy acetylenic ketones with alkynes in formic acid. The benzene-linked furanonyl-ynes are the key intermediates obtained by the scission/recombination of C-O double bonds. Further, the structural modifications of the representative product were implemented by reduction, demethylation, substitution, and [5 + 2]-cycloaddition.

5.
Proc Natl Acad Sci U S A ; 118(48)2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34819380

RESUMO

Chiral Weyl fermions with linear energy-momentum dispersion in the bulk accompanied by Fermi-arc states on the surfaces prompt a host of enticing optical effects. While new Weyl semimetal materials keep emerging, the available optical probes are limited. In particular, isolating bulk and surface electrodynamics in Weyl conductors remains a challenge. We devised an approach to the problem based on near-field photocurrent imaging at the nanoscale and applied this technique to a prototypical Weyl semimetal TaIrTe4 As a first step, we visualized nano-photocurrent patterns in real space and demonstrated their connection to bulk nonlinear conductivity tensors through extensive modeling augmented with density functional theory calculations. Notably, our nanoscale probe gives access to not only the in-plane but also the out-of-plane electric fields so that it is feasible to interrogate all allowed nonlinear tensors including those that remained dormant in conventional far-field optics. Surface- and bulk-related nonlinear contributions are distinguished through their "symmetry fingerprints" in the photocurrent maps. Robust photocurrents also appear at mirror-symmetry breaking edges of TaIrTe4 single crystals that we assign to nonlinear conductivity tensors forbidden in the bulk. Nano-photocurrent spectroscopy at the boundary reveals a strong resonance structure absent in the interior of the sample, providing evidence for elusive surface states.

6.
Nano Lett ; 23(17): 8099-8105, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37656017

RESUMO

van der Waals (vdW) magnets, an emerging family of two-dimensional (2D) materials, have received tremendous attention due to their rich fundamental physics and significant potential for cutting-edge technological applications. In contrast to the conventional bulk counterparts, vdW magnets exhibit significant tunability of local material properties, such as stacking engineered interlayer coupling and layer-number dependent magnetic and electronic interactions, which promise to deliver previously unavailable merits to develop multifunctional microelectronic devices. As a further ingredient of this emerging topic, here we report nanoscale quantum sensing and imaging of the atomically thin vdW magnet chromium thiophosphate CrPS4, revealing its characteristic layer-dependent 2D static magnetism and dynamic spin fluctuations. We also show a large tunneling magnetoresistance in CrPS4-based spin filter vdW heterostructures. The excellent material stability and robust strategy against environmental degradation in combination with tailored magnetic properties highlight the potential of CrPS4 in developing state-of-the-art 2D spintronic devices for next-generation information technologies.

7.
J Org Chem ; 88(6): 3409-3423, 2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36847758

RESUMO

A one-pot step-economic tandem process involving (5 + 2)-cycloaddition and Nazarov cyclization reactions has been reported for the facile synthesis of indanone-fused benzo[cd]azulenes from (E)-2-arylidene-3-hydroxyindanones and conjugated eneynes. This highly regio- and stereoselective bisannulation reaction is enabled by dual silver and Brønsted acid catalysis and opens up a new avenue for the construction of important bicyclo[5.3.0]decane skeletons.

8.
Biosci Biotechnol Biochem ; 87(5): 516-524, 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-36822622

RESUMO

3-(4-hydroxy-3-methoxyphenyl)propionic acid (HMPA) is one of the end-products from gut microbiota from dietary polyphenols, which might contribute to their health benefits. This study aims to investigate the absorption, metabolism, and tissue accumulation of HMPA in Sprague-Dawley (SD) rats. After HMPA (10 mg/kg body weight) was orally administered, intact and conjugated HMPAs in the bloodstream were detected and reached the maximum concentration in 15 min (HMPA, 2.6 ± 0.4 nmol/mL; sulfated HMPA, 3.6 ± 0.9 nmol/mL; glucuronidated HMPA, 0.55 ± 0.09 nmol/mL). HMPA and its conjugates were also detected in the target organs 6 h postadministration, indicating that HMPA undergoes rapid conversion into conjugates, and they broadly distribute to organs with similar profiles (kidneys > liver > thoracic aorta > heart > soleus muscle > lungs). This study demonstrated that orally administered HMPA (10 mg/kg) in SD rats undergoes rapid metabolism and wide tissue distribution with ≥1.2% absorption ratio.


Assuntos
Hempa , Propionatos , Ratos , Animais , Ratos Sprague-Dawley , Hempa/metabolismo , Fígado/metabolismo
9.
AIDS Res Ther ; 20(1): 45, 2023 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-37452359

RESUMO

BACKGROUND: This study conducted a survey of men who have sex with men (MSM) in Maanshan City of Anhui Province to assess the risk behaviors related to human immunodeficiency virus (HIV) infection. METHODS: A cross-sectional survey was conducted from June 2016 to June 2019. The MSM were recruited by a peer-driven sampling method. A face-to-face interview with anonymous questionnaire was used for data collection. The information collected by the survey was summarized and epidemiology described the basic characteristics of MSM, and then the related factors were statistically analyzed. RESULTS: A total of 934 MSM were recruited with a average age was 30.5 (SD = 8.90) years old, including 816 (87.4%) HIV negative participants and 118 (12.6%) HIV positive ones. This study showed that freelancer (OR = 4.02, 95% CI: 1.96-8.23), scope of sexual partners distribution (OR = 1.78, 95% CI: 1.36-2.33), number of male sexual partners (OR = 2.11, 95% CI: 1.47-3.02), role of anal sex with men was receptive (OR = 2.54, 95% CI: 1.25-5.13) and versatile (OR = 2.34, 95% CI: 1.31-4.19) and non-steady sex partners (OR = 2.14, 95% CI: 1.56-2.93) were risk factors for HIV infection, while monthly income (OR = 0.68, 95% CI: 0.57-0.82), education level (OR = 0.79, 95% CI: 0.66-0.95), frequency of condom use (OR = 0.53, 95% CI: 0.35-0.81) and number of oral sex partners (OR = 0.35, 95% CI: 0.24-0.51) in the past 6 months were protective factors for HIV infection. CONCLUSION: Risk behaviors were common in MSM, and urgent need for targeted and comprehensive interventions to reduce risky sexual behaviour and to prevent HIV infection in MSM.


Assuntos
Infecções por HIV , Minorias Sexuais e de Gênero , Masculino , Humanos , Adulto , Criança , Estudos Transversais , Infecções por HIV/prevenção & controle , Homossexualidade Masculina , Comportamento Sexual , Fatores de Risco , China/epidemiologia
10.
Proc Natl Acad Sci U S A ; 117(27): 15573-15580, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32571944

RESUMO

Cyanobacteriochromes (CBCRs) are small, bistable linear tetrapyrrole (bilin)-binding light sensors which are typically found as modular components in multidomain cyanobacterial signaling proteins. The CBCR family has been categorized into many lineages that roughly correlate with their spectral diversity, but CBCRs possessing a conserved DXCF motif are found in multiple lineages. DXCF CBCRs typically possess two conserved Cys residues: a first Cys that remains ligated to the bilin chromophore and a second Cys found in the DXCF motif. The second Cys often forms a second thioether linkage, providing a mechanism to sense blue and violet light. DXCF CBCRs have been described with blue/green, blue/orange, blue/teal, and green/teal photocycles, and the molecular basis for some of this spectral diversity has been well established. We here characterize AM1_1499g1, an atypical DXCF CBCR that lacks the second cysteine residue and exhibits an orange/green photocycle. Based on prior studies of CBCR spectral tuning, we have successfully engineered seven AM1_1499g1 variants that exhibit robust yellow/teal, green/teal, blue/teal, orange/yellow, yellow/green, green/green, and blue/green photocycles. The remarkable spectral diversity generated by modification of a single CBCR provides a good template for multiplexing synthetic photobiology systems within the same cellular context, thereby bypassing the time-consuming empirical optimization process needed for multiple probes with different protein scaffolds.


Assuntos
Proteínas de Bactérias/metabolismo , Evolução Molecular , Luz , Fotorreceptores Microbianos/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/efeitos da radiação , Cor , Cianobactérias/genética , Cianobactérias/metabolismo , Cianobactérias/efeitos da radiação , Mutagênese Sítio-Dirigida , Nostoc/genética , Nostoc/metabolismo , Nostoc/efeitos da radiação , Fotobiologia/métodos , Fotorreceptores Microbianos/efeitos da radiação , Biologia Sintética/métodos , Tetrapirróis/metabolismo
11.
Sensors (Basel) ; 23(12)2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37420795

RESUMO

In this study, we utilized a sapphire substrate with a matrix protrusion structure as a template. We employed a ZnO gel as a precursor and deposited it onto the substrate using the spin coating method. After undergoing six cycles of deposition and baking, a ZnO seed layer with a thickness of 170 nm was formed. Subsequently, we used a hydrothermal method to grow ZnO nanorods (NRs) on the aforementioned ZnO seed layer for different durations. ZnO NRs exhibited a uniform outward growth rate in various directions, resulting in a hexagonal and floral morphology when observed from above. This morphology was particularly evident in ZnO NRs synthesized for 30 and 45 min. Due to the protrusion structure of ZnO seed layer, the resulting ZnO nanorods (NRs) displayed a floral and matrix morphology on the protrusion ZnO seed layer. To further enhance their properties, we utilized Al nanomaterial to decorate the ZnO nanoflower matrix (NFM) using a deposition method. Subsequently, we fabricated devices using both undecorated and Al-decorated ZnO NFMs and deposited an upper electrode using an interdigital mask. We then compared the gas-sensing performance of these two types of sensors towards CO and H2 gases. The research findings indicate that sensors based on Al-decorated ZnO NFM exhibit superior gas-sensing properties compared to undecorated ZnO NFM for both CO and H2 gases. These Al-decorated sensors demonstrate faster response times and higher response rates during the sensing processes.


Assuntos
Nanoestruturas , Óxido de Zinco , Óxido de Alumínio , Eletrodos , Gases
12.
Nano Lett ; 22(13): 5523-5529, 2022 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-35731986

RESUMO

Activating metamagnetic transitions between ordered states in van der Waals magnets and devices bring great opportunities in spintronics. We show that external pressure, which enhances the interlayer hopping without introducing chemical disorders, triggers multiple metamagnetic transitions upon cooling in the topological van der Waals magnets Mn(Bi1-xSbx)4Te7, where the antiferromagnetic interlayer superexchange coupling competes with the ferromagnetic interlayer coupling mediated by the antisite Mn spins. The temperature-pressure phase diagrams reveal that while the ordering temperature from the paramagnetic to ordered states is almost pressure-independent, the metamagnetic transitions show nontrivial pressure and temperature dependence, even re-entrance. For these highly anisotropic magnets, we attribute the former to the ordering temperature being only weakly dependent on the intralayer parameters and the latter to the parametrically different pressure and temperature dependence of the two interlayer couplings. Our independent probing of these disparate magnetic interactions paves an avenue for efficient magnetic manipulations in van der Waals magnets.

13.
Nano Lett ; 22(14): 5810-5817, 2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35816128

RESUMO

Topological materials featuring exotic band structures, unconventional current flow patterns, and emergent organizing principles offer attractive platforms for the development of next-generation transformative quantum electronic technologies. The family of MnBi2Te4 (Bi2Te3)n materials is naturally relevant in this context due to their nontrivial band topology, tunable magnetism, and recently discovered extraordinary quantum transport behaviors. Despite numerous pioneering studies to date, the local magnetic properties of MnBi2Te4 (Bi2Te3)n remain an open question, hindering a comprehensive understanding of their fundamental material properties. Exploiting nitrogen-vacancy (NV) centers in diamond, we report nanoscale quantum imaging of the magnetic phase transitions and spin fluctuations in exfoliated MnBi4Te7 flakes, revealing the underlying spin transport physics and magnetic domains at the nanoscale. Our results highlight the unique advantage of NV centers in exploring the magnetic properties of emergent quantum materials, opening new opportunities for investigating the interplay between topology and magnetism.

14.
Int J Mol Sci ; 24(7)2023 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-37047211

RESUMO

E3 ubiquitin ligases play important roles in plant immunity, but their role in soybean has not been investigated previously. Here, we used Bean pod mottle virus (BPMV)-mediated virus-induced gene silencing (VIGS) to investigate the function of GmSAUL1 (Senescence-Associated E3 Ubiquitin Ligase 1) homologs in soybean. When two closely related SAUL1 homologs were silenced simultaneously, the soybean plants displayed autoimmune phenotypes, which were significantly alleviated by high temperature, suggesting that GmSAUL1a/1b might be guarded by an R protein. Interestingly, silencing GmSAUL1a/1b resulted in the decreased activation of GmMPK6, but increased activation of GmMPK3 in response to flg22, suggesting that the activation of GmMPK3 is most likely responsible for the activated immunity observed in the GmSAUL1a/1b-silenced plants. Furthermore, we provided evidence that GmSAUL1a is a bona fide E3 ligase. Collectively, our results indicated that GmSAUL1 plays a negative role in regulating cell death and immunity in soybean.


Assuntos
Glycine max , Ubiquitina-Proteína Ligases , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Glycine max/fisiologia , Fenótipo , Imunidade Vegetal/genética , Regulação da Expressão Gênica de Plantas
15.
J Environ Manage ; 326(Pt B): 116776, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36435122

RESUMO

Antibiotics are emerging pollutants largely considered to have a lower risk based on persistent, bioaccumulative, toxic (PBT) risk assessments. However, an increasing number of studies have illustrated that antibiotics are responsible for the global increase in antimicrobial resistance (AMR), which suggests that the risk of antibiotics has been largely underestimated by using PBT risk assessment. Here, we designed an integrated innovation risk assessment framework of persistent, bioaccumulative, toxic, and resistance (PBTR) that accounts for antibiotic resistance to better represent the antibiotic environmental risk. This novel antibiotic risk assessment framework was further verified via application to 39 target antibiotics in the 23 drinking water sources of the lower Yangtze River (LYR), China, during the normal and flood seasons. In contrast with the PBT assessment, single toxicity assessment and single resistance assessment, in the PBTR assessment, 7 of 39 target antibiotics with bacterial insensitivity were observed to represent a more prominent risk, as were the sites sampled during the flood season with low concentrations but high pollution loads, which confirmed that the sensitivity of PBTR risk assessment was instructive. The PBTR risk assessment for the screened priority antibiotics contributes not only representative data but also an innovative approach for identifying resistance risks. Using the positive matrix factorization (PMF) model, the sources of priority antibiotics can be predicted and thus supported the corresponding policy. Overall, this study first constructed a PBTR risk assessment framework, then applied it to facilitate the accurate management of antibiotic pollution at the basin level.


Assuntos
Água Potável , Poluentes Químicos da Água , Água Potável/análise , Monitoramento Ambiental , Antibacterianos/farmacologia , Antibacterianos/análise , Poluentes Químicos da Água/análise , Rios , Medição de Risco , China
16.
Zhongguo Zhong Yao Za Zhi ; 48(2): 517-524, 2023 Jan.
Artigo em Zh | MEDLINE | ID: mdl-36725241

RESUMO

In recent years, the clinical treatment of colorectal cancer(CRC) has made great progress, but chemoresistance is still one of the main reasons for reducing the survival rate of patients with colorectal cancer. Therefore, ameliorating chemotherapy resis-tance is an urgent problem to be solved. The purpose of this study was to investigate the regulatory role and related molecular mechanisms of hydroxysafflor yellow A(HSYA) in colorectal cancer cell proliferation, migration, and 5-fluorouracil(5-FU) chemoresistance. In this study, HCT116 and HT-29 cells were used as research subjects. Firstly, methyl thiazolyl tetrazolium(MTT) assay and colony formation assay were used to detect and analyze the effect of HSYA on the proliferation of CRC cells. Secondly, the effect of HSYA on the cell cycle in CRC cells was analyzed by cell cycle assay. Furthermore, the effect of HSYA on the migration of CRC cells was analyzed by wound-healing assay and Transwell assay. Based on the above, the influences of HSYA on 5-FU chemoresistance of CRC cells and related molecular mechanisms were explored and analyzed. The results showed that HSYA significantly inhibited the proliferation and migration of CRC cells, and arrested the cell cycle in G_0/G_1 phase. In addition, HSYA significantly ameliorated the chemoresistance of CRC cells to 5-FU. The results of acridine orange staining and Western blot showed that the autophagy activity of CRC cells in the HSYA and 5-FU combined treatment group was significantly higher than that in the 5-FU single drug treatment group. As compared with the 5-FU single drug treatment group, the phosphorylation levels of protein kinase B(Akt) and mammalian target of rapamycin(mTOR) in the HSYA and 5-FU combined treatment group were significantly reduced, indicating that the Akt/mTOR signaling pathway in the combined treatment group was down-regulated in CRC cells. In conclusion, HSYA may upregulate autophagy activity through the Akt/mTOR signaling pathway, thereby inhibiting the proliferation and migration of CRC cells and ameliorating the chemoresistance to 5-FU.


Assuntos
Neoplasias Colorretais , Proteínas Proto-Oncogênicas c-akt , Humanos , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Resistencia a Medicamentos Antineoplásicos , Linhagem Celular Tumoral , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Fluoruracila/farmacologia , Proliferação de Células , Autofagia , Neoplasias Colorretais/tratamento farmacológico
17.
BMC Cancer ; 22(1): 307, 2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35317758

RESUMO

BACKGROUND: The tumorigenesis of infused umbilical cord mesenchymal stem cells (UC-MSCs) is being preclinically evaluated. METHODS: We observed tumor formation in NOD SCID mice after a single subcutaneous injection of hUC-MSCs and the effect of these cells on tumor growth in tumor-bearing mice. Three generations (P5, P7, and P10) of hUC-MSCs (1 × 107) from two donors (hUC-MSC1 and hUC-MSC2) were inoculated subcutaneously into NOD SCID mice. Subcutaneous transplantation models were established in NOD SCID mice with human cervical cancer HeLa cells (solid tumor) and human B cell lymphoma Raji cells (hematological tumor). Then, the animals were euthanized, gross dissection was performed, and tissues were collected. Various organs were observed microscopically to identify pathological changes and tumor metastasis. RESULTS: In the tumorigenesis experiment, no general anatomical abnormalities were observed. In the tumor promotion experiment, some animals in the HeLa groups experienced tumor rupture, and one animal died in each of the low- and medium-dose hUC-MSC groups. The results may have occurred due to the longer feeding time, and the tumor may have caused spontaneous infection and death. Pathological examination revealed no metastasis to distant organs in any group. In the Raji tumor model, some animals in each group experienced tumor rupture, and one animal in the medium-dose hUC-MSC group died, perhaps due to increased tumor malignancy. Thus, hUC-MSCs neither promoted nor inhibited tumor growth. No cancer cell metastasis was observed in the heart, liver, spleen, lungs, kidneys or other important organs, except that pulmonary venule metastasis was observed in 1 animal in the model group. CONCLUSIONS: Injected hUC-MSCs were not tumorigenic and did not significantly promote or inhibit solid or hematological tumor growth or metastasis in NOD SCID mice.


Assuntos
Carcinogênese/patologia , Células-Tronco Mesenquimais/fisiologia , Cordão Umbilical/citologia , Animais , Feminino , Células HeLa , Humanos , Linfoma de Células B/patologia , Masculino , Camundongos Endogâmicos NOD , Camundongos SCID , Modelos Animais , Metástase Neoplásica , Células Tumorais Cultivadas
18.
Oral Dis ; 2022 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-36546840

RESUMO

OBJECTIVE: To explore the protective effect of human urine-derived stem cell exosomes (hUSC-Exos) on radiation-induced salivary gland (SG) injuries in Sprague Dawley rats. METHODS: Fresh adult urine was collected, and primary hUSCs were isolated and identified. The hUSCs were hypoxia-pretreated with 1% oxygen for 24 h and then transferred to a normoxic culture environment for 24 h. The hUSC-Exos were collected and identified for exosomes. A radiation-induced injury model was established in the rats, and exosomes were introduced by local injection in the SG and tail vein. The submandibular gland was excised for morphological observation 1 week later. Immunohistochemical detection of the glandular tissue was conducted by α-smooth muscle actin (a-SMA), stem cell growth factor receptor (c-Kit) staining, and periodic acid-Schiff staining. Qualitative polymerase chain reaction and western blot analysis were adopted to detect the gene and protein expression of Wnt3a, GSK3ß, and Axin. RESULTS: In both the normoxic and hypoxic hUSC-Exo groups, microvesicular structures with bilayer membranes of approximately 80 nm in diameter were detected, and the expressions of CD9 and CD63 were detected by nanoflow cytometry. Compared with the control group, in the radiation-induced injury model group, the expression of a-SMA was significantly higher, the expression of c-Kit was significantly lower, and the expressions of Wnt3a, GSK3ß, and Axin were significantly upregulated; the differences were statistically significant (p < 0.05). Compared with the model group, in the normoxic and hypoxic hUSC-Exo groups, the expression of a-SMA was significantly decreased, the expression of c-Kit was significantly increased, and the expressions of Wnt3a, GSK3ß, and Axin were significantly upregulated; the differences were statistically significant (p < 0.05). CONCLUSION: Hypoxia-pretreated hUSC-Exos could repair radiation-induced SG injuries by activating the Wnt3a/GSK3ß pathway to suppress the expressions of a-SMA and c-Kit.

19.
BMC Palliat Care ; 21(1): 30, 2022 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-35255876

RESUMO

BACKGROUND: Anticipatory grief has been shown to be highly prevalent among family caregivers of patients with advanced illness. Qualitative study suggests that illness uncertainty may be one of the core characteristics of anticipatory grief, but it has not been confirmed in quantitative studies. Therefore, the purpose of this study was to explore the relationship between anticipatory grief and illness uncertainty among Chinese family caregivers of patients with advanced lung cancer and to determine the factors influencing anticipatory grief. METHODS: This descriptive cross-sectional study used a convenience sampling method and recruited 254 inpatient family caregivers from the thoracic medicine ward of Liaoning Cancer Hospital & Institute in Shenyang, mainland China. Anticipatory grief (Anticipatory Grief Scale (AGS), illness uncertainty (Uncertainty in Illness Scale Family Caregiver Version) and sociodemographic information (Self-compiled general information questionnaire) were measured using validated self-report measures. RESULTS: Chinese family caregivers of patients with advanced lung cancer had high levels of anticipatory grief (73.5 ± 16.1). The results of the correlation analysis showed a positive association between anticipatory grief and illness uncertainty (r = 0.580, P < 0.001). The final linear regression model with anticipatory grief as the dependent variable included four variables: illness uncertainty (ß = 0.674, P < 0.001), lack of informativeness (ß = - 0.168, P = 0.08), monthly income (ß = 0.139, P = 0.006), and caregiving burden (ß = - 0.196, P < 0.001). CONCLUSIONS: Illness uncertainty is probably an important factor affecting anticipatory grief. Excessive caregiving burden is associated with high levels of anticipatory grief. Improving illness uncertainty and caregiving burden may effectively reduce anticipatory grief among Chinese family caregivers.


Assuntos
Cuidadores , Neoplasias Pulmonares , Estudos Transversais , Pesar , Humanos , Inquéritos e Questionários , Incerteza
20.
Phytother Res ; 2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36250265

RESUMO

AMP-activated protein kinase (AMPK) regulates overall energy consumption and energy intake through cytokines. Ligusticum striatum DC (CX) combined with Gastrodia elata Blume (TM) has been used for migraine treatment for millennia. When used alone in clinical practice, CX causes symptoms of thirst, irritability, and yellow urine and has influenced the levels of cytokines such as AMP that activate the AMPK pathway of energy metabolism. However, relationships between this compatibility prescription, integral biological energy metabolism, and the AMPK pathway remain unclear. Studies were performed by treating normal rats with physiological saline, CX extract, CX coupled TM extract, and TM extracts separately for 4 weeks. Food intake, water intake, urine output, stool output, and body weight were monitored once a week by the metabolic cage method. Values of FBG, BUN, TP, TC and TG in blood samples were detected approaching the whole blood automatic detector from 1 to 4 weeks. Na+ -K+ -ATPase, Ca2+ -Mg2+ -ATPase, cAMP, and cGMP activity were determined by the enzyme-linked immunosorbent assay (ELISA); the biological samples that were obtained at 1, 2, 3, and 4 weeks after drug administration were tested by GC-TOF-MS. Then real-time PCR and Western Blot were applied to detect changes in expression of some substances involved in energy metabolism. The results demonstrated that administering CX alone increased energy input, mobility, and respiratory exchange ratio, accelerated energy consumption, and caused inflammatory infiltration in the liver. CX coupled with TM led to lower energy metabolism and liver damage in comparison with CX used alone. Moreover, CX-treated rats harbored higher levels of differential metabolites (including pyrophosphate, oxaloacetic acid, and galactinol). Glycerophospholipid metabolism and the citrate cycle are closely related to the differential metabolites above. In addition, CX-induced unbalanced energy metabolism depends on cAMP activation mediated by the AMPK/PGC-1α pathway in rats. Our findings suggest that CX-induced energy metabolism imbalance was corrected after coupling with TM by mediating the AMPK/PGC-1α pathway.

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