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1.
Mol Med ; 30(1): 81, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862942

RESUMO

BACKGROUND: Studies have highlighted a possible crosstalk between the pathogeneses of COVID-19 and systemic lupus erythematosus (SLE); however, the interactive mechanisms remain unclear. We aimed to elucidate the impact of COVID-19 on SLE using clinical information and the underlying mechanisms of both diseases. METHODS: RNA-seq datasets were used to identify shared hub gene signatures between COVID-19 and SLE, while genome-wide association study datasets were used to delineate the interaction mechanisms of the key signaling pathways. Finally, single-cell RNA-seq datasets were used to determine the primary target cells expressing the shared hub genes and key signaling pathways. RESULTS: COVID-19 may affect patients with SLE through hematologic involvement and exacerbated inflammatory responses. We identified 14 shared hub genes between COVID-19 and SLE that were significantly associated with interferon (IFN)-I/II. We also screened and obtained four core transcription factors related to these hub genes, confirming the regulatory role of the IFN-I/II-mediated Janus kinase/signal transducers and activators of transcription (JAK-STAT) signaling pathway on these hub genes. Further, SLE and COVID-19 can interact via IFN-I/II and IFN-I/II receptors, promoting the levels of monokines, including interleukin (IL)-6/10, tumor necrosis factor-α, and IFN-γ, and elevating the incidence rate and risk of cytokine release syndrome. Therefore, in SLE and COVID-19, both hub genes and core TFs are enriched within monocytes/macrophages. CONCLUSIONS: The interaction between SLE and COVID-19 promotes the activation of the IFN-I/II-triggered JAK-STAT signaling pathway in monocytes/macrophages. These findings provide a new direction and rationale for diagnosing and treating patients with SLE-COVID-19 comorbidity.


Assuntos
COVID-19 , Estudo de Associação Genômica Ampla , Lúpus Eritematoso Sistêmico , SARS-CoV-2 , Transdução de Sinais , Humanos , COVID-19/genética , Lúpus Eritematoso Sistêmico/genética , SARS-CoV-2/fisiologia , Feminino , Janus Quinases/metabolismo , Fatores de Transcrição STAT/metabolismo , Fatores de Transcrição STAT/genética , Masculino , Transcriptoma , Perfilação da Expressão Gênica , Multiômica
2.
Exp Eye Res ; 227: 109350, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36566010

RESUMO

Elevation of intraocular pressure (IOP) is a major, controllable risk factor of primary open-angle glaucoma (POAG). Transforming growth factor-ß2 (TGF-ß2)-induced excessive accumulation of extracellular matrix (ECM) in the trabecular meshwork (TM) has been demonstrated to contribute significantly to the development of high IOP. We previously showed that treatment with salidroside (Sal), a plant-derived glucoside, can ameliorate the TGF-ß2-induced ECM expression in cultured human TM cells and reduce TGF-ß2-induced ocular hypertension in mice. In the current study, its underlying molecular mechanism associated with microRNA-210-3p (miR-210-3p) was characterized. We discovered that, in TM tissues of POAG patients, there was an increase in miR-210-3p. And miR-210-3p mediated a portion of the pathological effects of TGF-ß2 in vitro (excessive accumulation of ECM in cultured human TM cells) and in vivo (mouse ocular hypertension and ECM accumulation in the TM). Most interestingly, miR-210-3p was down-regulated by Sal, which appeared to mediate a significant portion of its IOP-lowering effect. Thus, these results shed light on the probable molecular mechanisms of TGF-ß2 and Sal and indicate that manipulation of miR-210-3p level/activity represents a potential new therapeutic strategy for POAG.


Assuntos
Glaucoma de Ângulo Aberto , MicroRNAs , Hipertensão Ocular , Humanos , Animais , Camundongos , Fator de Crescimento Transformador beta2/metabolismo , Malha Trabecular/metabolismo , Glaucoma de Ângulo Aberto/metabolismo , Matriz Extracelular/metabolismo , Hipertensão Ocular/metabolismo , Pressão Intraocular , Células Cultivadas , MicroRNAs/metabolismo
3.
Phys Chem Chem Phys ; 25(3): 2043-2049, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36546549

RESUMO

Electronic states are significantly correlated with chemical compositions, and the information related to these factors is especially crucial for the manipulation of the properties of matter. However, this key information is usually verified by after-validation methods, which could not be obtained during material processing, for example, in the field of femtosecond laser direct writing inside materials. Here, critical evolution stages of electronic states for monolayer tungsten diselenide (WSe2) around the modification threshold (at a Mott density of ∼1013 cm-2) are observed by broadband femtosecond transient absorption spectroscopy, which is associated with the intense femtosecond-laser-assisted oxygen-doping mechanism. First-principles calculations and control experiments on graphene-covered monolayer WSe2 further confirm this modification mechanism. Our findings reveal a photochemical reaction for monolayer WSe2 under the Mott density condition and provide an electronic state criterion to in situ monitor the degrees of modification in monolayer transition metal dichalcogenides during the femtosecond laser modification.

4.
Ann Vasc Surg ; 92: 285-293, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36739079

RESUMO

BACKGROUND: We sought to find new biomarkers for abdominal aortic aneurysms (AAA) caused by chronic intermittent hypoxia (CIH). METHODS: The AAA mice model was created using Ang II. The mice were divided into normoxic and CIH groups. The structure of AAA was observed using abdominal ultrasonography, Elastica van Gieson (EVG), and hematoxylin and eosin (HE) staining. The expression of ɑ-SMA was investigated using immunohistochemistry. The novel biomarkers were screened using bioinformatics analysis. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to verify the expression of novel genes in both normal oxygen and CIH. RESULTS: CIH appears to cause greater aortic dilation, higher AAA incidence, lower survival rate, thicker vessel wall, and more brittle elastic lamellae when compared to controls. The immunohistochemistry results showed that the expression of ɑ-SMA in the CIH group was reduced significantly. Four novel genes, including Homer2, Robo2, Ehf, and Asic1, were found to be differentially expressed between normal oxygen and CIH using qRT-PCR, indicating the same trend as bioinformatics analysis. CONCLUSIONS: We discovered that CIH could hasten the occurrence and progression of AAA. Four genes (Homer2, Robo2, Ehf, and Asic1) may be novel biomarkers for AAA, which could aid in the search for new therapies for patients with AAA caused by CIH.


Assuntos
Aneurisma da Aorta Abdominal , Apneia Obstrutiva do Sono , Camundongos , Animais , Resultado do Tratamento , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/genética , Aneurisma da Aorta Abdominal/metabolismo , Imuno-Histoquímica , Oxigênio , Apneia Obstrutiva do Sono/genética , Apneia Obstrutiva do Sono/metabolismo , Modelos Animais de Doenças , Hipóxia/genética , Proteínas de Arcabouço Homer
5.
Int J Mol Sci ; 24(2)2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36674790

RESUMO

Mesenchymal stem cells (MSCs) with self-renewing, multilineage differentiation and immunomodulatory properties, have been extensively studied in the field of regenerative medicine and proved to have significant therapeutic potential in many different pathological conditions. The role of MSCs mainly depends on their paracrine components, namely secretome. However, the components of MSC-derived secretome are not constant and are affected by the stimulation MSCs are exposed to. Therefore, the content and composition of secretome can be regulated by the pretreatment of MSCs. We summarize the effects of different pretreatments on MSCs and their secretome, focusing on their immunomodulatory properties, in order to provide new insights for the therapeutic application of MSCs and their secretome in inflammatory immune diseases.


Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Secretoma , Medicina Regenerativa , Imunoterapia
6.
Int J Mol Sci ; 24(8)2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-37108145

RESUMO

Phenotypic transformation of macrophages plays important immune response roles in the occurrence, development and regression of periodontitis. Under inflammation or other environmental stimulation, mesenchymal stem cells (MSCs) exert immunomodulatory effects through their secretome. It has been found that secretome derived from lipopolysaccharide (LPS)-pretreated or three-dimensional (3D)-cultured MSCs significantly reduced inflammatory responses in inflammatory diseases, including periodontitis, by inducing M2 macrophage polarization. In this study, periodontal ligament stem cells (PDLSCs) pretreated with LPS were 3D cultured in hydrogel (termed SupraGel) for a certain period of time and the secretome was collected to explore its regulatory effects on macrophages. Expression changes of immune cytokines in the secretome were also examined to speculate on the regulatory mechanisms in macrophages. The results indicated that PDLSCs showed good viability in SupraGel and could be separated from the gel by adding PBS and centrifuging. The secretome derived from LPS-pretreated and/or 3D-cultured PDLSCs all inhibited the polarization of M1 macrophages, while the secretome derived from LPS-pretreated PDLSCs (regardless of 3D culture) had the ability to promote the polarization of M1 to M2 macrophages and the migration of macrophages. Cytokines involved in the production, migration and polarization of macrophages, as well as multiple growth factors, increased in the PDLSC-derived secretome after LPS pretreatment and/or 3D culture, which suggested that the secretome had the potential to regulate macrophages and promote tissue regeneration, and that it could be used in the treatment of inflammation-related diseases such as periodontitis in the future.


Assuntos
Ligamento Periodontal , Periodontite , Humanos , Lipopolissacarídeos/farmacologia , Lipopolissacarídeos/metabolismo , Secretoma , Células Cultivadas , Citocinas/metabolismo , Células-Tronco/metabolismo , Macrófagos/metabolismo , Periodontite/terapia , Periodontite/metabolismo , Inflamação/metabolismo , Diferenciação Celular
7.
Plant J ; 108(3): 781-792, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34492144

RESUMO

The cotton (Gossypium hirsutum) pigment gland is a distinctive structure that functions as the main deposit organ of gossypol and its derivatives. It is also an ideal system in which to study cell differentiation and organogenesis. However, only a few genes that determine the process of gland formation have been reported, including GoPGF, CGP1, and CGFs; the molecular mechanisms underlying gland initiation are still largely unclear. Here, we report the discovery of the novel stem pigment gland-forming gene GoSPGF by map-based cloning; annotated as a GRAS transcription factor, this gene is responsible for the glandless trait specifically on the stem. In the stem glandless mutant T582, a point mutation (C to A) was found to create a premature stop codon and truncate the protein. Similarly, virus-induced gene silencing of GoSPGF resulted in glandless stems and dramatically reduced gossypol content. Comparative transcriptomic data showed that loss of GoSPGF significantly suppressed expression of many genes involved in gossypol biosynthesis and altered expression of genes involved in gibberellic acid signaling/biosynthesis. Overall, these findings provide more insight into the networks regulating glandular structure differentiation and formation in cotton, which will be helpful for understanding other plants bearing special gland structures such as tobacco (Nicotiana benthamiana), artemisia annua, mint (Mentha spp.), and rubber (Hevea brasiliensis).


Assuntos
Gossypium/genética , Proteínas de Plantas/genética , Clonagem Molecular , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Giberelinas/metabolismo , Gossypium/crescimento & desenvolvimento , Gossypium/metabolismo , Gossipol/metabolismo , Proteínas de Plantas/metabolismo , Caules de Planta/genética , Caules de Planta/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Transdução de Sinais , Nicotiana/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
8.
Small ; 18(1): e2105682, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34786849

RESUMO

Electrochemical CO2 reduction reaction (CO2 RR) is a promising approach to convert CO2 to carbon-neutral fuels using external electric powers. Here, the Bi2 S3 -Bi2 O3 nanosheets possessing substantial interface being exposed between the connection of Bi2 S3 and Bi2 O3 are prepared and subsequently demonstrate to improve CO2 RR performance. The electrocatalyst shows formate Faradaic efficiency (FE) of over 90% in a wide potential window. A high partial current density of about 200 mA cm-2 at -1.1 V and an ultralow onset potential with formate FE of 90% are achieved in a flow cell. The excellent electrocatalytic activity is attributed to the fast-interfacial charge transfer induced by the electronic interaction at the interface, the increased number of active sites, and the improved CO2 adsorption ability. These collectively contribute to the faster reaction kinetics and improved selectivity and consequently, guarantee the superb CO2 RR performance. This study provides an appealing strategy for the rational design of electrocatalysts to enhance catalytic performance by improving the charge transfer ability through constructing a functional heterostructure, which enables interface engineering toward more efficient CO2 RR.

9.
Chemistry ; 28(24): e202104490, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35236006

RESUMO

Ga2 O3 -decorated and -defective surface models based on anatase TiO2 have been established. The thermodynamic reaction pathways, including protonation, deoxygenation and hydroxylation steps, during CO2 conversion with H2 O to C1 products were calculated. The calculation results demonstrate that a Ga2 O3 cocatalyst enhances the selective adsorption of CO2 and slightly weakens the competitive adsorption of H2 O. The promotion effect of Ga2 O3 on the subsequent reaction depends on the availability of protons and electrons. Free-energy calculations revealed that the basic functional site generated by Ga2 O3 not only suppresses the back reaction of the OH group after H2 O directly provides protons but also maintains the surface defect oxygen vacancy (VO ), which promotes the reaction thermodynamics but tends to be consumed in the process. Additionally, Ga2 O3 decoration promotes VO formation, and the coexistence of Ga2 O3 and VO further decreases the reaction rate-determining step energy barrier, promoting C1 production.

10.
Clin Infect Dis ; 73(9): e3317-e3323, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-32634824

RESUMO

BACKGROUND: Passive-active immunoprophylaxis against mother-to-child transmission (MTCT) of hepatitis B virus (HBV) recommends administering hepatitis B immunoglobulin (HBIG) and birth-dose hepatitis B vaccine in infants within 12 or 24 hours after birth. With this protocol, MTCT of HBV still occurs in 5-10% infants of HBV-infected mothers with positive hepatitis B e antigen (HBeAg). The present study aimed to investigate whether earlier administration of HBIG and hepatitis B vaccine after birth can further increase protection efficacy. METHODS: We conducted a prospective, multi-center observational study in infants born to mothers with HBV infection, in whom neonatal HBIG and birth dose hepatitis B vaccine were administered within one hour after birth. The infants were followed up for HBV markers at 7-14 months of age. RESULTS: A total of 1140 pregnant women with HBV were enrolled, and 982 infants (9 twins) of 973 mothers were followed up at 9.6 ± 1.9 months of age. HBIG and birth-dose vaccine were administered in newborn infants within a median of 0.17 (0.02-1.0) hours after birth. The overall rate of MTCT was 0.9% (9/982), with none (0%) of the 607 infants of HBeAg-negative mothers and 9 (2.4%) of 375 infants of HBeAg-positive mothers acquiring HBV. All 9 HBV-infected infants were born to mothers with HBV DNA >2.75 × 106 IU/mL. Maternal HBV DNA levels >2 × 106 IU/mL were an independent risk factor (odds ratio, 10.627; 95% confidence interval, 2.135-∞) for immunoprophylaxis failure. CONCLUSIONS: Earlier use (within 1 hour after birth) of HBIG and hepatitis B vaccine can provide better protection efficacy against MTCT of HBV.


Assuntos
Hepatite B , Complicações Infecciosas na Gravidez , Feminino , Hepatite B/prevenção & controle , Antígenos de Superfície da Hepatite B , Vacinas contra Hepatite B , Antígenos E da Hepatite B , Vírus da Hepatite B , Humanos , Lactente , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Gravidez , Complicações Infecciosas na Gravidez/prevenção & controle , Estudos Prospectivos
11.
Plant Biotechnol J ; 18(10): 2002-2014, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32030869

RESUMO

Xinjiang has been the largest and highest yield cotton production region not only in China, but also in the world. Improvements in Upland cotton cultivars in Xinjiang have occurred via pedigree selection and/or crossing of elite alleles from the former Soviet Union and other cotton producing regions of China. But it is unclear how genomic constitutions from foundation parents have been selected and inherited. Here, we deep-sequenced seven historic foundation parents, comprising four cultivars introduced from the former Soviet Union (108Ф, C1470, 611Б and KK1543) and three from United States and Africa (DPL15, STV2B and UGDM), and re-sequenced sixty-nine Xinjiang modern cultivars. Phylogenetic analysis of more than 2 million high-quality single nucleotide polymorphisms allowed their classification two groups, suggesting that Xinjiang Upland cotton cultivars were not only spawned from 108Ф, C1470, 611Б and KK1543, but also had a close kinship with DPL15, STV2B and UGDM. Notably, identity-by-descent (IBD) tracking demonstrated that the former Soviet Union cultivars have made a huge contribution to modern cultivar improvement in Xinjiang. A total of 156 selective sweeps were identified. Among them, apoptosis-antagonizing transcription factor gene (GhAATF1) and mitochondrial transcription termination factor family protein gene (GhmTERF1) were highly involved in the determination of lint percentage. Additionally, the auxin response factor gene (GhARF3) located in inherited IBD segments from 108Ф and 611Б was highly correlated with fibre quality. These results provide an insight into the genomics of artificial selection for improving cotton production and facilitate next-generation precision breeding of cotton and other crops.

12.
Environ Sci Technol ; 53(20): 12091-12100, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31524383

RESUMO

In this work, to achieve both clean energy production and carbon emission reduction, a united conversion to couple CO2 mineralization with thermochemical hydrogen production is proposed. Natural magnesium silicate minerals are used to fix CO2 in the form of carbonate minerals, whereas H2O is dissociated to produce H2 in the thermochemical cycle. The integration provides a new solution to the challenges of the high energy consumption and poor economic value of conventional CO2 mineralization processes, and the technical feasibility has been proven. Moreover, the energy economy and CO2 conversion capacity were investigated. Hydrolyzation and carbonation experiments were performed in a homemade reactor, and it was found that an optimal MgI2 hydrolyzation rate of 75% could be achieved without alkali consumption. A detailed simulation of the whole system was also developed. The optimal energy conversion efficiency of the cycle reached 47.6%, which is higher than most of the published theoretical energy efficiency values for sulfur-iodine thermochemical cycles. A modified calculation of the net energy requirement for CO2 mineralization was carried out. Finally, a comparison and an evaluation of the energy efficiencies were made based on the calculation. In the optimal case, the modified net energy requirement is 1.4 MJ/kg CO2, which means that this method is competitive compared to those of previous works.


Assuntos
Dióxido de Carbono , Carbonatos , Carbono , Hidrogênio , Minerais
13.
BMC Pregnancy Childbirth ; 18(1): 292, 2018 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-29980185

RESUMO

BACKGROUND: Pregnancy is a unique physiological condition with the cellular immune functions compromised at some extents to allow the mature of growing fetus. Whether pregnancy may influence the replication of hepatitis B virus (HBV) is less studied. The present study aimed to investigate the influence of pregnancy on the replication of HBV and expression of viral antigens by comparing the levels of HBV DNA and viral antigens in pregnant and non-pregnant women. METHODS: A total of 727 HBsAg-positive serum samples, collected from 214 pregnant women and 513 non-pregnant women of childbearing age, were included. Based on the pregnancy status, subjects were divided into four groups: nulliparous (n = 158), pregnant (n = 214), 7-12 months postpartum (n = 170), and 2-5 years postpartum (n = 185). The levels of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) were quantitatively measured with microparticle enzyme immunoassay. HBV DNA levels were detected by fluorescent real-time PCR. RESULTS: The median ages of four groups were 25.0, 25.3, 26.2 and 29.3 years, respectively (p < 0.01). HBeAg-positive proportions were 34.2, 33.6, 35.3 and 29.2%, respectively (p = 0.624). HBV DNA levels in HBeAg-positive women were higher than those in HBeAg-negative women (7.88 vs 2.62 log IU/ml, p < 0.001). HBV DNA levels in the four groups with positive HBeAg were 7.8, 7.7, 8.0 and 8.0 log IU/ml, respectively (p = 0.057), while HBsAg titers were 4.4, 4.5, 4.6 and 4.8 log IU/ml (p = 0.086) and HBeAg titers were 3.1, 3.0, 3.1 and 3.0 log S/CO (p = 0.198). In the four groups with negative HBeAg, HBV DNA levels were 2.3, 2.6, 2.5 and 2.8 log IU/ml, respectively (p = 0.085), while HBsAg titers were 3.1, 3.3, 3.3 and 3.0 log IU/ml (p = 0.06). CONCLUSIONS: Serum levels of HBV DNA and viral antigens showed no significant changes in nulliparous, pregnant, and postpartum women, regardless of the HBeAg status. The results indicate that pregnancy has little influence on the replication of HBV and the expression of viral antigens.


Assuntos
Antígenos de Superfície da Hepatite B/sangue , Antígenos E da Hepatite B/sangue , Vírus da Hepatite B/fisiologia , Hepatite B , Período Pós-Parto/sangue , Complicações Infecciosas na Gravidez , Carga Viral/métodos , Adulto , China/epidemiologia , DNA Viral/sangue , Feminino , Hepatite B/diagnóstico , Hepatite B/epidemiologia , Hepatite B/imunologia , Humanos , Avaliação de Resultados em Cuidados de Saúde , Paridade/imunologia , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/imunologia , Replicação Viral/imunologia
14.
J Exp Bot ; 68(15): 4125-4135, 2017 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-28922761

RESUMO

Map-based gene cloning is a vital strategy for the identification of the quantitative trait loci or genes underlying important agronomic traits. The conventional map-based cloning method is powerful but generally time-consuming and labor-intensive. In this context, we introduce an improved bulked segregant analysis method in combination with a virus-induced gene silencing (VIGS) strategy for rapid and reliable gene mapping, identification and functional verification. This method was applied to a multiple recessive marker line of upland cotton, Texas 582 (T582), and identified unique genomic positions harboring mutant loci, showing the reliability and efficacy of this method. The v1 locus was further fine-mapped. Only one gene, GhCHLI, which encodes one of the subunits of Mg chelatase, was differentially down-regulated in T582 compared with TM-1. A point mutation occurred in the AAA+ conserved region of GhCHLI and led to an amino acid substitution. Suppression of its expression by VIGS in TM-1 resulted in a yellow blade phenotype that was similar to T582. This integrated approach provides a paradigm for the rapid mapping and identification of the candidate genes underlying the genetic traits in plants with large and complex genomes in the future.


Assuntos
Inativação Gênica , Gossypium/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Proteínas de Plantas/genética , Mapeamento Cromossômico , Clonagem Molecular , Vírus/genética
15.
Clin Infect Dis ; 73(1): 166-167, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32818227
16.
Small ; 11(32): 3903-8, 2015 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-25918861

RESUMO

By utilizing the dual roles of the erasable promoter (pyrrole), "clean", highly conductive, and nitrogen-doped CNT aerogels are derived from a promoter-assisted hydrothermal reaction (HTR) coupling with pyrolysis. The resulting materials show an excellent performance towards oxygen reduction reaction (ORR).

17.
Opt Lett ; 40(19): 4492-5, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26421564

RESUMO

This article describes a laser-shared photothermal system that achieves tight temperature regulation by frequency-domain photoacoustic (FD-PA) feedback. To this end, a continuous-wave laser system was designed with arbitrarily modulatable laser intensity. And, by fast alternating in the time domain between a constant laser intensity for photothermal heating and a modulated laser intensity for FD-PA temperature measurement, photothermal temperature variations are captured by FD-PA in real time. A proportional-integral-derivative (PID) controller monitors the feedback from FD-PA measurements and controls photothermal heating dose accordingly, thus stabilizing the temperature at preset values. The proposed system is demonstrated to achieve ultrafast temperature measurement at a 4 kHz rate, and with proper averaging, the measurement and regulation accuracy are 0.75 deg and 0.9 deg respectively.


Assuntos
Retroalimentação , Lasers , Técnicas Fotoacústicas , Fototerapia/métodos , Temperatura
18.
Phys Rev Lett ; 115(15): 155301, 2015 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-26550731

RESUMO

Optical control of atomic interactions in quantum gases is a long-sought goal of cold atom research. Previous experiments have been hindered by rapid decay of the quantum gas and parasitic deformation of the trap potential. We develop and implement a generic scheme for optical control of Feshbach resonances which yields long quantum gas lifetimes and a negligible parasitic dipole force. We show that fast and local control of interactions leads to intriguing quantum dynamics in new regimes, highlighted by the formation of van der Waals molecules and localized collapse of a Bose condensate.

19.
Angew Chem Int Ed Engl ; 53(50): 13934-9, 2014 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-25381722

RESUMO

The development of new promising metal-free catalysts is of great significance for the electrocatalytic hydrogen evolution reaction (HER). Herein, a rationally assembled three-dimensional (3D) architecture of 1D graphitic carbon nitride (g-C3N4) nanoribbons with 2D graphene sheets has been developed by a one-step hydrothermal method. Because of the multipathway of charge and mass transport, the hierarchically structured g-C3N4 nanoribbon-graphene hybrids lead to a high electrocatalytic ability for HER with a Tafel slope of 54 mV decade(-1), a low onset overpotential of 80 mV and overpotential of 207 mV to approach a current of 10 mA cm(-2), superior to those non-metal materials and well-developed metallic catalysts reported previously. This work presents a great advance for designing and developing highly efficient metal-free catalyst for hydrogen evolution.

20.
Heliyon ; 10(7): e28913, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38596064

RESUMO

Magnesium phosphate cement (MPC) is a high-performance repairing material suitable for the interfacial disease of slab track. In this study, the early properties of MPC were optimized using central composite design (CCD) approach based on response surface methodology (RSM). Three factors with five levels and three responses were considered. The significance of the factors and their interactions were verified by using analysis of variance (ANOVA). The result show that the mass ratio of water-to-binder (W/b) affects fluidity, while the mass ratio of magnesia-to-phosphate (M/P) and borax-to-magnesia (B/M) impact the setting time of MPC. Higher W/b results in higher fluidity, while an increase in M/P reduces the setting time by increasing the neutralization reaction. Borax addition retards the reaction, prolonging the setting time. The three factors significantly affect the early compressive strength of MPC. At M/P = 3.5, the interweaving of MgO and K-struvite (MKP) forms a dense network structure, enhancing the strength. Borax and W/b interact to affect compressive strength, with borax retarding MKP crystal growth and higher W/b reducing compactness. Combined with microscopic property test, the strength generation mechanism of MPC with optimized mixing ratio was revealed, And the feasibility of field application of MPC was verified by strength test.

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