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1.
Mol Cell ; 81(12): 2533-2548.e9, 2021 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-33857403

RESUMO

From biosynthesis to assembly into nucleosomes, histones are handed through a cascade of histone chaperones, which shield histones from non-specific interactions. Whether mechanisms exist to safeguard the histone fold during histone chaperone handover events or to release trapped intermediates is unclear. Using structure-guided and functional proteomics, we identify and characterize a histone chaperone function of DNAJC9, a heat shock co-chaperone that promotes HSP70-mediated catalysis. We elucidate the structure of DNAJC9, in a histone H3-H4 co-chaperone complex with MCM2, revealing how this dual histone and heat shock co-chaperone binds histone substrates. We show that DNAJC9 recruits HSP70-type enzymes via its J domain to fold histone H3-H4 substrates: upstream in the histone supply chain, during replication- and transcription-coupled nucleosome assembly, and to clean up spurious interactions. With its dual functionality, DNAJC9 integrates ATP-resourced protein folding into the histone supply pathway to resolve aberrant intermediates throughout the dynamic lives of histones.


Assuntos
Proteínas de Choque Térmico HSP40/metabolismo , Chaperonas de Histonas/metabolismo , Linhagem Celular Tumoral , Cromatina , Montagem e Desmontagem da Cromatina , Replicação do DNA , Proteínas de Choque Térmico HSP40/fisiologia , Proteínas de Choque Térmico HSP70/metabolismo , Células HeLa , Chaperonas de Histonas/fisiologia , Histonas/metabolismo , Humanos , Componente 2 do Complexo de Manutenção de Minicromossomo/metabolismo , Modelos Moleculares , Chaperonas Moleculares/metabolismo , Nucleossomos , Ligação Proteica , Proteômica/métodos
2.
Small ; 20(10): e2306095, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37903361

RESUMO

Seasonal influenza still greatly threatens public health worldwide, leading to significant morbidity and mortality. Antiviral medications for influenza treatment are limited and accompanied by increased drug resistance. In severe influenza virus infection, hyperinflammation and hypoxia may be the significant threats associated with mortality, so the development of effective therapeutic methods to alleviate excessive inflammation while reducing viral damage is highly pursued. Here, a multifunctional MOF-based nanohybrid of Cu─TCPP@Mn3 O4 as a novel drug against influenza A virus infection (MOF = metal-organic framework; TCPP = tetrakis (4-carboxyphenyl) porphyrin) is designed. Cu─TCPP@Mn3 O4 exhibits potent inhibitory capability against influenza A virus infection in vitro and in vivo. The mechanism study reveals that Cu─TCPP@Mn3 O4 inhibits the virus entry by binding to the HA2 subunit of influenza A virus hemagglutinin. In addition, the nanoparticles of Mn3 O4 in Cu─TCPP@Mn3 O4 can scavenge intracellular ROS with O2 generation to downregulate inflammatory factors and effectively inhibit cytokines production. By reconstructing the antioxidant microenvironment, Cu─TCPP@Mn3 O4 features as a promising nanomedicine with anti-inflammatory and anti-viral synergistic effects.


Assuntos
Influenza Humana , Nanopartículas , Humanos , Espécies Reativas de Oxigênio , Inflamação/tratamento farmacológico , Antivirais/farmacologia , Antivirais/uso terapêutico
3.
Mol Phylogenet Evol ; 197: 108113, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38796071

RESUMO

A robust and stable phylogenetic framework is a fundamental goal of evolutionary biology. As the third largest insect order in the world following Coleoptera and Diptera, Lepidoptera (butterflies and moths) play a central role in almost every terrestrial ecosystem as indicators of environmental change and serve as important models for biologists exploring questions related to ecology and evolutionary biology. However, for such a charismatic insect group, the higher-level phylogenetic relationships among its superfamilies are still poorly resolved. Compared to earlier phylogenomic studies, we increased taxon sampling among Lepidoptera (37 superfamilies and 68 families containing 263 taxa) and acquired a series of large amino-acid datasets from 69,680 to 400,330 for phylogenomic reconstructions. Using these datasets, we explored the effect of different taxon sampling with significant increases in the number of included genes on tree topology by considering a series of systematic errors using maximum-likelihood (ML) and Bayesian inference (BI) methods. Moreover, we also tested the effectiveness in topology robustness among the three ML-based models. The results showed that taxon sampling is an important determinant in tree robustness of accurate lepidopteran phylogenetic estimation. Long-branch attraction (LBA) caused by site-wise heterogeneity is a significant source of bias giving rise to unstable positions of ditrysian groups in phylogenomic reconstruction. Phylogenetic inference showed the most comprehensive framework to reveal the relationships among lepidopteran superfamilies, and presented some newly relationships with strong supports (Papilionoidea was sister to Gelechioidea and Immoidea was sister to Galacticoidea, respectively), but limited by taxon sampling, the relationships within the species-rich and relatively rapid radiation Ditrysia and especially Apoditrysia remain poorly resolved, which need to increase taxon sampling for further phylogenomic reconstruction. The present study demonstrates that taxon sampling is an important determinant for an accurate lepidopteran tree of life and provides some essential insights for future lepidopteran phylogenomic studies.


Assuntos
Teorema de Bayes , Borboletas , Mariposas , Filogenia , Animais , Mariposas/genética , Mariposas/classificação , Funções Verossimilhança , Borboletas/genética , Borboletas/classificação , Modelos Genéticos
4.
Phys Rev Lett ; 132(21): 215101, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38856257

RESUMO

Polarization of drift-Alfvén waves, defined as the ratio of electrostatic to electromagnetic fluctuations, has remained unmeasurable in fusion plasmas for decades, despite its pivotal role in understanding wave dynamics and their impact on plasmas. We report the first measurements of drift-Alfvén wave polarization in a hot, magnetically confined plasma. The breakthrough is enabled by a novel methodology developed from gyrokinetic theory, utilizing fluctuations of electron temperature and density. Analysis of data from the DIII-D tokamak reveals that the waves above the geodesic acoustic mode frequency exhibit dominant electromagnetic polarization, whereas lower-frequency waves show a mix of electromagnetic and electrostatic polarization, indicating a strong coupling between shear Alfvén waves and drift-acoustic waves.

5.
Eur J Haematol ; 112(2): 257-265, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37698159

RESUMO

OBJECTIVES: We aim to analyze the predictive value of thromboelastography on bleeding severity of patients with chimeric antigen receptor (CAR)-T cell therapy. METHODS: A total of 80 patients with refractory/relapsed hematological malignancy were enrolled and divided into two groups: the severe bleeding group and the non-severe bleeding group. The thromboelastography data was collected on the day of CAR-T infusion and the 3rd, 7th, 10th, 13th, 17th, and 20th day after CAR-T cell infusion. RESULTS: The patients of the severe bleeding group had lower platelet (p < .007), maximum amplitude (p = .002), coagulation index (p = .005), and longer coagulation time (p = .019). Increasing trend in reaction time and coagulation time and decreasing trend in Alpha, maximum amplitude, and coagulation index on Days 0-10, opposite on Days 10-20. Univariate logistic regression analysis and multivariable logistic regression analysis showed maximum amplitude on the 3rd day after CAR-T cell infusion (MA3) (OR = 0.9; 95% CI = 0.84-0.95; p < .001) and cytokine release syndrome grade (OR = 2.57; 95% CI = 1.35-5.32; p = .006) were significantly associated with high bleeding severity. CONCLUSIONS: Thromboelastography was considered to be a good predictor of bleeding severity.


Assuntos
Neoplasias Hematológicas , Receptores de Antígenos Quiméricos , Humanos , Tromboelastografia , Imunoterapia Adotiva/efeitos adversos , Neoplasias Hematológicas/diagnóstico , Neoplasias Hematológicas/terapia , Hemorragia/diagnóstico , Hemorragia/etiologia , Hemorragia/terapia , Terapia Baseada em Transplante de Células e Tecidos
6.
Nucleic Acids Res ; 50(9): 5349-5368, 2022 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-35489058

RESUMO

Histone chaperones regulate all aspects of histone metabolism. NASP is a major histone chaperone for H3-H4 dimers critical for preventing histone degradation. Here, we identify two distinct histone binding modes of NASP and reveal how they cooperate to ensure histone H3-H4 supply. We determine the structures of a sNASP dimer, a complex of a sNASP dimer with two H3 α3 peptides, and the sNASP-H3-H4-ASF1b co-chaperone complex. This captures distinct functionalities of NASP and identifies two distinct binding modes involving the H3 α3 helix and the H3 αN region, respectively. Functional studies demonstrate the H3 αN-interaction represents the major binding mode of NASP in cells and shielding of the H3 αN region by NASP is essential in maintaining the H3-H4 histone soluble pool. In conclusion, our studies uncover the molecular basis of NASP as a major H3-H4 chaperone in guarding histone homeostasis.


Assuntos
Chaperonas de Histonas , Histonas , Chaperonas de Histonas/metabolismo , Histonas/metabolismo , Homeostase , Chaperonas Moleculares/metabolismo , Ligação Proteica
7.
Nucleic Acids Res ; 50(12): e67, 2022 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-35288754

RESUMO

DNA-encoded library (DEL) technology is a powerful tool for small molecule identification in drug discovery, yet the reported DEL selection strategies were applied primarily on protein targets in either purified form or in cellular context. To expand the application of this technology, we employed DEL selection on an RNA target HIV-1 TAR (trans-acting responsive region), but found that the majority of signals were resulted from false positive DNA-RNA binding. We thus developed an optimized selection strategy utilizing RNA patches and competitive elution to minimize unwanted DNA binding, followed by k-mer analysis and motif search to differentiate false positive signal. This optimized strategy resulted in a very clean background in a DEL selection against Escherichia coli FMN Riboswitch, and the enriched compounds were determined with double digit nanomolar binding affinity, as well as similar potency in functional FMN competition assay. These results demonstrated the feasibility of small molecule identification against RNA targets using DEL selection. The developed experimental and computational strategy provided a promising opportunity for RNA ligand screening and expanded the application of DEL selection to a much wider context in drug discovery.


Assuntos
RNA , Bibliotecas de Moléculas Pequenas , DNA/química , Escherichia coli/metabolismo , Mononucleotídeo de Flavina , Ligantes , RNA/antagonistas & inibidores , RNA/química , Riboswitch , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia
8.
BMC Nurs ; 23(1): 392, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849821

RESUMO

AIM: To explore the views and experiences of formal caregivers caring for older inpatients with physical disabilities. METHODS: It was a qualitative phenomenological study. Using purposive sampling, twelve formal caregivers were chosen in a tertiary comprehensive hospital in Hangzhou, China. Semi-structured, face-to-face interviews were conducted, guided by open-ended questions that focused on gaining rich insights into participants' views and experiences. Coding reliability thematic analysis was used to guide data analysis and categorize, based on Lazarus and Folkman's theory of transactional coping. RESULTS: Four themes emerged from the data analysis: (1) Caregiving Threats. (2) motivations. (3) Responsibility Management. (4) Fear. CONCLUSION: Despite facing significant pressure at work, formal caregivers of elderly inpatients with physical disabilities possess the drive and various coping strategies to excel in their role. Identifying caregivers' experiences of care can be helpful in improving resilience to stress and maintaining stability in formal caregivers.

9.
J Environ Sci (China) ; 139: 527-542, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38105074

RESUMO

Lessening energy-related carbon emissions has become a crucial measure to achieve Chinese carbon neutrality. This study is the first to construct a Difference in Carbon pressures-adjusted Human Development Index (DCHDI) model for the purpose of exploring the coupling effect between carbon emissions and human development variety from 2000 to 2019 in Chinese provinces. We demonstrate the following. (1) The total energy-related carbon footprint of 30 provinces in China reached 10.2 billion tons in 2019, with an average annual growth rate of 6.93% over the past two decades; and the provinces with the highest carbon emissions per capita are InnerMongolia, Ningxia, and Shanxi. (2) At the provincial level, we observed that the Human Development Index (HDI), which includes life expectancy, education, and income, has been rising, while Beijing, Shanghai, and Tianjin entered the super-high HDI level before 2008. (3) The entire coupling effect of 30 Chinese provinces has been broadly fortified in the last 20 years, but the growth rate of DCHDI values in 2011-2019 has slowed down compared with that in 2000-2010; the clustering phenomenon demonstrated that this discovery is associated with historical peaks in total carbon emissions. (4) The coordination degree of carbon emissions per capita and HDI was verified, and 96% of the data points were found in the range of super high coupling coordination degree. Overall, this study provides the government with worthwhile guidance for decision-making and carbon reduction strategies for other countries struggling to advance human sustainable development.


Assuntos
Carbono , Desenvolvimento Econômico , Humanos , China , Carbono/análise , Pequim , Dióxido de Carbono/análise
10.
Anal Chem ; 95(12): 5331-5339, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-36926822

RESUMO

As an enzyme-free exponential nucleic acid amplification method, the click chemistry-mediated ligation chain reaction (ccLCR) has shown great prospects in the molecular diagnosis. However, the current optics-based ccLCR is challenged by remarkable nonspecific amplification, severely hindering its future application. This study demonstrated that the severe nonspecific amplification was generated probably due to high random collision in the high DNA probe concentration (µM level). To solve this hurdle, a nucleic acid template-dominated ccLCR was constructed using nM-level DNA probes and read on an electrochemical platform (cc-eLCR). Under the optimal conditions, the proposed cc-eLCR detected a low-level nucleic acid target (1 fM) with a single-base resolution. Furthermore, this assay was applied to detect the target of interest in cell extracts with a satisfactory result. The proposed cc-eLCR offers huge possibility for click chemistry-mediated enzyme-free exponential nucleic acid amplification in the application of medical diagnosis and biomedical research.


Assuntos
Técnicas Biossensoriais , RNA , Química Click/métodos , Técnicas Biossensoriais/métodos , DNA/química , Sondas de DNA/genética , Sondas de DNA/química , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas Eletroquímicas/métodos , Limite de Detecção , Hibridização de Ácido Nucleico
11.
J Transl Med ; 21(1): 113, 2023 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-36765369

RESUMO

BACKGROUND: Cell-cell communications of various cell populations within tumor microenvironment play an essential role in primary tumor growth, metastasis evolution, and immune escape. Nevertheless, comprehensive investigation of cell-cell communications in the ccRCC (Clear cell renal carcinoma) microenvironment and how this interplay affects prognosis still remains limited. METHODS: Intercellular communications were characterized by single-cell data. Firstly, we employed "CellChat" package to characterize intercellular communications across all types of cells in microenvironment in VHL mutated and non-mutated samples from 8 patients, respectively. And pseudotime trajectory analyses were performed with monocle analyses. Finally clinical prognosis and immunotherapy efficacy with different landscapes of intercellular interplay are evaluated by TCGA-KIRC and immunotherapy cohort. RESULTS: Firstly, the VHL phenotype may be related to the intercellular communication landscape. And trajectory analysis reveals the potential relationship of cell-cell communication molecules with T cells and Myeloid cells differentiation. Furthermore, those molecules also correlate with the infiltration of T cells and Myeloid cells. A tumor cluster with highly expressed ligands was defined by quantitative analysis and transcription factor enrichment analysis, which was identified to be pivotal for intercellular communications in tumor microenvironment. Finally, bulk data indicates bulk that different clusters with different intercellular communications have significant predictive value for prognosis and distinguished immunotherapy efficiency. CONCLUSIONS: The intercellular communication landscapes of VHL wild and VHL mutant ccRCC vary. Intercellular communications within the tumor microenvironment also influence T cell and myeloid cell development and infiltration, as well as predict clinical prognosis and immunotherapy efficacy in ccRCC.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Carcinoma de Células Renais/terapia , Microambiente Tumoral , Comunicação Celular , Análise Fatorial , Prognóstico
12.
Neurol Sci ; 44(7): 2431-2442, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36808310

RESUMO

PURPOSE: This study aimed at the population receiving thrombolytic therapy and to explore the optimal time point for neutrophil-to-lymphocyte ratio (NLR) in predicting stroke-associated pneumonia (SAP). METHODS: We assessed patients undergoing intravenous thrombolysis (IVT) for acute ischemic stroke. Blood parameters were sampled before thrombolysis (within 30 min after admission) and within 24-36 h after thrombolysis, respectively. The primary outcome measure was the occurrence of SAP. Multivariate logistic regression analysis was performed to analyze the association between admission blood parameters and the event of SAP. We also used receiver operating characteristic (ROC) curve analysis to assess the discriminative ability of blood parameters measured at different times in predicting SAP. RESULTS: Among the 388 patients, SAP occurred in 60 (15%) patients. Multivariate logistic regression analysis showed that NLR was significantly associated with SAP (NLR before IVT: aOR = 1.288; 95%CI = 1.123-1.476; p < 0.001; NLR after IVT: (aOR = 1.127, 95%CI = 1.017-1.249; p = 0.023). The ROC curve showed that the predictive ability of NLR after IVT was better than NLR before IVT, not only in predicting the occurrence of SAP but also in predicting short-term and long-term functional outcomes, hemorrhagic transformation, and 1-year mortality. CONCLUSION: Increased NLR measured within 24-36 h after IVT has a significant predictive effect on the occurrence of SAP and can be used to predict short-term and long-term poor functional outcomes, hemorrhagic transformation, and 1-year mortality.


Assuntos
AVC Isquêmico , Pneumonia , Acidente Vascular Cerebral , Humanos , Neutrófilos , Estudos Retrospectivos , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/tratamento farmacológico , Linfócitos
13.
BMC Surg ; 23(1): 105, 2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37118712

RESUMO

OBJECTIVE: The objective of this study was to evaluate the safety and efficacy of pneumovesicoscopic Cohen surgery with an adjustable suspension technique through the urethra for the treatment of primary vesicoureteral reflux disease in infants. METHODS: This study retrospectively analysed the clinical data of 31 infants who underwent pneumovesicoscopic Cohen surgery with an adjustable suspension technique through the urethra in our hospital from January 2019 to December 2020. We also collected the clinical data of 29 infants who underwent open Cohen surgery in our hospital from January 2015 to December 2018 as a control variable. The clinical efficacy of the two groups was compared. RESULT: All pneumovesicoscopic Cohen surgeries were successfully completed and no patients were converted to open surgery. The amount of bleeding, duration of postoperative analgesia, duration of postoperative haematuria, incision size and length of hospital stay in the pneumovesicoscopic surgery group were significantly lower than those in the open surgery group (P < 0.05). The operation time of the pneumovesicoscopic surgery group was significantly longer than that of the open surgery group (P < 0.05). Both groups were followed for six months after surgery. At the 6-month follow-up time, there were no significant differences in the degree of hydronephrosis, renal scarring, renal atrophy, glomerular filtration rate, or KIM-1 and MCP-1 expression between the two groups (P > 0.05). CONCLUSION: Pneumovesicoscopic Cohen surgery with an adjustable suspension technique through the urethra for the treatment of primary vesicoureteral reflux disease in infants was safe and effective. This procedure had the advantages of less trauma, quick recovery and good cosmetic effects.


Assuntos
Refluxo Vesicoureteral , Humanos , Lactente , Refluxo Vesicoureteral/cirurgia , Uretra/cirurgia , Estudos Retrospectivos , Reimplante/métodos , Resultado do Tratamento
14.
BMC Surg ; 23(1): 382, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38114974

RESUMO

AIM: Splenic vessel-preserving spleen-preserving distal pancreatectomy (SVP-SPDP) has a lower risk of splenic infarction than the splenicvessel-sacrificing SPDP, but it is more technically demanding. Learning curve of robotic-assisted SVP-SPDP (RSVP-SPDP) remains unreported. This study sought to analyze the perioperative outcomes and learning curve of RSVP-SPDP by one single surgeon. METHODS: Seventy-four patients who were intended to receive RSVP-SPDP at the First Affiliated Hospital of Sun Yat-sen University between May 2015 and January 2023 were included. The learning curve were retrospectively analyzed by using cumulative sum (CUSUM) analyses. RESULTS: Sixty-two patients underwent RSVP-SPDP (spleen preservation rate: 83.8%). According to CUSUM curve, the operation time (median, 318 vs. 220 min; P < 0.001) and intraoperative blood loss (median, 50 vs. 50 mL; P = 0.012) was improved significantly after 16 cases. Blood transfusion rate (12.5% vs. 3.4%; P = 0.202), postoperative major morbidity rate (6.3% vs. 3.4%; P = 0.524), and postoperative length-of-stay (median, 10 vs. 8 days; P = 0.120) improved after 16 cases but did not reach statistical difference. None of the patients had splenic infarction or abscess postoperatively. CONCLUSION: RSVP-SPDP was a safe and feasible approach for selected patients after learning curve. The improvement of operation time and intraoperative blood loss was achieved after 16 cases.


Assuntos
Laparoscopia , Neoplasias Pancreáticas , Procedimentos Cirúrgicos Robóticos , Infarto do Baço , Cirurgiões , Humanos , Pancreatectomia , Estudos Retrospectivos , Perda Sanguínea Cirúrgica , Infarto do Baço/etiologia , Infarto do Baço/cirurgia , Curva de Aprendizado , Resultado do Tratamento , Artéria Esplênica/cirurgia , Neoplasias Pancreáticas/cirurgia
15.
J Biol Chem ; 297(6): 101357, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34756887

RESUMO

It has been shown that phages have evolved anti-CRISPR (Acr) proteins to inhibit host CRISPR-Cas systems. Most acr genes are located upstream of anti-CRISPR-associated (aca) genes, which is instrumental for identifying these acr genes. Thus far, eight Aca families (Aca1-Aca8) have been identified, all proteins of which share low sequence homology and bind to different target DNA sequences. Recently, Aca1 and Aca2 proteins were discovered to function as repressors by binding to acr-aca promoters, thus implying a potential anti-anti-CRISPR mechanism. However, the structural basis for the repression roles of Aca proteins is still unknown. Here, we elucidated apo-structures of Aca1 and Aca2 proteins and their complex structures with their cognate operator DNA in two model systems, the Pseudomonas phage JBD30 and the Pectobacterium carotovorum template phage ZF40. In combination with biochemical and cellular assays, our study unveils dimerization and DNA-recognition mechanisms of Aca1 and Aca2 family proteins, thus revealing the molecular basis for Aca1-and Aca2-mediated anti-CRISPR repression. Our results also shed light on understanding the repression roles of other Aca family proteins and autoregulation roles of acr-aca operons.


Assuntos
Bacteriófagos/metabolismo , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Óperon , Pectobacterium carotovorum/virologia , Pseudomonas aeruginosa/virologia , Proteínas Virais/metabolismo , Bacteriófagos/química , Bacteriófagos/genética , Modelos Moleculares , Pectobacterium carotovorum/genética , Pectobacterium carotovorum/metabolismo , Conformação Proteica , Multimerização Proteica , Fagos de Pseudomonas/química , Fagos de Pseudomonas/genética , Fagos de Pseudomonas/metabolismo , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , Proteínas Virais/química , Proteínas Virais/genética
16.
J Am Chem Soc ; 144(12): 5653-5660, 2022 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-35315276

RESUMO

The understanding of the hydrolysis mechanism of lanthanide ions is limited by their elusive coordination configuration and undeveloped technology. A potential solution by high-resolution mass spectroscopy studies is hindered by the lack of a stable model under electrospray ionization (ESI) conditions and the complexity of the spectra. Herein, it is demonstrated that diketonate ligands can efficiently stabilize the hydrolyzed intermediate cluster of Ln3+ under ESI conditions, and an effective mass difference fingerprint of isomorphism (MDFI) method is proposed, which can allow the determination of the nuclearity-number of the species without depth resolution. Thus, the hydrolysis of Ln3+ into an atomically precise hydroxide cluster is observed at the level of precise formulae. The species evolution upon hydrolysis is along the dominant path of {Eu3}-{Eu4}-{Eu9}-{Eu10}-{Eu11}-{Eu15}-{Eu16} and a nondominant path of {Eu3}-{Eu4}-{Eu8-1}-{Eu8-2} under the investigated conditions. The crystal of the {Eu16} species was obtained via low-temperature crystallization, and single-crystal X-ray diffraction studies show that its structure contains three octahedral {o-Ln6} units. The contradiction between multiple {o-Ln6} units in the structure and the absence in the formation process indicates that the repetitive subunit observed in the structure does not necessarily correspond to the construction units of high-nuclearity clusters. Photophysical measurements indicate that Eu16 cluster has a high total emission quantum efficacy of 12.8% in the solid state. This study provides fundamental insights into the formation, evolution, and assembly of small lanthanide hydroxide units upon hydrolysis, which is vital for the goal of directional synthesis of lanthanide hydroxide clusters.


Assuntos
Elementos da Série dos Lantanídeos , Cristalografia por Raios X , Hidrólise , Hidróxidos , Elementos da Série dos Lantanídeos/química , Ligantes
17.
Opt Express ; 30(4): 6248-6257, 2022 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-35209564

RESUMO

By the method of singular-valued decomposition (SVD), ghost imaging (GI) reconstructs the images with high efficiency. However, a small amount of noise can greatly degrade or even destroy the object information. In this paper, we experimentally investigate the method of truncated SVD (TSVD) by selecting the first few largest singular values to enhance the image quality. The contrast-to-noise ratio and structural similarity of the images are improved with appropriate truncation ratios. To further improve the image quality, we analyze the noise effects on TSVD-based GI and introduce additional filters. TSVD-based GI may find its applications in rapid imaging under complicated environment conditions.

18.
Phys Rev Lett ; 128(2): 025003, 2022 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-35089750

RESUMO

The role of self-generated zonal flows in the collisionless trapped-electron-mode (CTEM) turbulence is a long-standing open issue in tokamak plasmas. Here, we show, for the first time, that the zonal flow excitation in the CTEM turbulence is formally isomorphic to that in the ion temperature gradient turbulence. Trapped electrons contribute implicitly only via linear dynamics. Theoretical analyses further suggest that, for short wavelength CTEMs, the zonal flow excitation is weak and, more importantly, not an effective saturation mechanism. Corresponding controlling parameters are also identified theoretically. These findings not only offer a plausible explanation for previous seemingly contradictory simulation results, but can also facilitate controlling the CTEM instability and transport with experimentally accessible parameters.

19.
Acta Pharmacol Sin ; 43(5): 1311-1323, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34462564

RESUMO

N6-methyladenosine (m6A) is the most abundant posttranscriptional methylation modification that occurs in mRNA and modulates the fine-tuning of various biological processes in mammalian development and human diseases. In this study we investigated the role of m6A modification in the osteogenesis of mesenchymal stem cells (MSCs), and the possible mechanisms by which m6A modification regulated the processes of osteoporosis and bone necrosis. We performed systematic analysis of the differential gene signatures in patients with osteoporosis and bone necrosis and conducted m6A-RNA immunoprecipitation (m6A-RIP) sequencing to identify the potential regulatory genes involved in osteogenesis. We showed that fat mass and obesity (FTO), a primary m6A demethylase, was significantly downregulated in patients with osteoporosis and osteonecrosis. During the differentiation of human MSCs into osteoblasts, FTO was markedly upregulated. Both depletion of FTO and application of the FTO inhibitor FB23 or FB23-2 impaired osteogenic differentiation of human MSCs. Knockout of FTO in mice resulted in decreased bone mineral density and impaired bone formation. PPARG, a biomarker for osteoporosis, was identified as a critical downstream target of FTO. We further revealed that FTO mediated m6A demethylation in the 3'UTR of PPARG mRNA, and reduced PPARG mRNA stability in an YTHDF1-dependent manner. Overexpression of PPARG alleviated FTO-mediated osteogenic differentiation of MSCs, whereas knockdown of PPARG promoted FTO-induced expression of the osteoblast biomarkers ALPL and OPN during osteogenic differentiation. Taken together, this study demonstrates the functional significance of the FTO-PPARG axis in promoting the osteogenesis of human MSCs and sheds light on the role of m6A modification in mediating osteoporosis and osteonecrosis.


Assuntos
Células-Tronco Mesenquimais , Osteonecrose , Osteoporose , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Animais , Diferenciação Celular , Humanos , Mamíferos/genética , Mamíferos/metabolismo , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Knockout , Osteogênese , Osteonecrose/metabolismo , Osteoporose/genética , PPAR gama/metabolismo , RNA Mensageiro/metabolismo
20.
BMC Surg ; 22(1): 72, 2022 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-35219304

RESUMO

BACKGROUND: The purpose of this study was to summarize the clinical experience and 10 year follow-up results of laparoscopic assisted Soave procedure for the treatment of long-segment Hirschsprung disease (HD). METHODS: From January 2010 to February 2020, 106 children with long-segment HD participated in this study. The laparoscopic-assisted Soave procedure was performed for the treatment of long-segment HD. The follow-up time was two weeks, one month, and three months after the operation, and then every six months to one year. RESULTS: The operation was successful for all 106 children. All patients were discharged 5-7 days after the operation. The median time in surgery was 150 (100-190) minutes, and the median volume of bleeding was 6 (3-10) ml. The short-term postoperative daily defecation frequency was 4-11 times, 3-7 times within 6 months, and 2-3 times after 6-12 months. Postoperative complications included anastomotic leakage in two cases, perianal dermatitis in 13 cases, anastomotic stenosis in four cases, adhesive bowel obstruction in two cases, enterocolitis in 16 cases, soiling in 11 cases, and constipation recurrence in three cases. CONCLUSIONS: The laparoscopic-assisted Soave procedure is a safe and effective surgical method for treating long-segment HD, and it causes little trauma or bleeding and has a fast postoperative recovery. Yet some complications may occur. Preoperative diagnosis, intraoperative and postoperative standardized processing can reduce the postoperative complications.


Assuntos
Procedimentos Cirúrgicos do Sistema Digestório , Doença de Hirschsprung , Laparoscopia , Anastomose Cirúrgica , Criança , Constipação Intestinal , Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Doença de Hirschsprung/complicações , Doença de Hirschsprung/cirurgia , Humanos , Lactente , Laparoscopia/métodos , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Resultado do Tratamento
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