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1.
Mol Cell ; 75(3): 644-660.e5, 2019 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-31398325

RESUMEN

Cell-cell communication via ligand-receptor signaling is a fundamental feature of complex organs. Despite this, the global landscape of intercellular signaling in mammalian liver has not been elucidated. Here we perform single-cell RNA sequencing on non-parenchymal cells isolated from healthy and NASH mouse livers. Secretome gene analysis revealed a highly connected network of intrahepatic signaling and disruption of vascular signaling in NASH. We uncovered the emergence of NASH-associated macrophages (NAMs), which are marked by high expression of triggering receptors expressed on myeloid cells 2 (Trem2), as a feature of mouse and human NASH that is linked to disease severity and highly responsive to pharmacological and dietary interventions. Finally, hepatic stellate cells (HSCs) serve as a hub of intrahepatic signaling via HSC-derived stellakines and their responsiveness to vasoactive hormones. These results provide unprecedented insights into the landscape of intercellular crosstalk and reprogramming of liver cells in health and disease.


Asunto(s)
Comunicación Celular/genética , Hígado/metabolismo , Enfermedad del Hígado Graso no Alcohólico/genética , Análisis de Secuencia de ARN , Animales , Reprogramación Celular/genética , Modelos Animales de Enfermedad , Células Estrelladas Hepáticas/metabolismo , Células Estrelladas Hepáticas/patología , Humanos , Ligandos , Hígado/patología , Macrófagos/metabolismo , Macrófagos/patología , Ratones , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/patología , Transducción de Señal/genética , Análisis de la Célula Individual
2.
Hepatology ; 79(2): 409-424, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-37505219

RESUMEN

BACKGROUND AND AIMS: NASH represents a severe stage of fatty liver disease characterized by hepatocyte injury, inflammation, and liver fibrosis. Myeloid-derived innate immune cells, such as macrophages and dendritic cells, play an important role in host defense and disease pathogenesis. Despite this, the nature of transcriptomic reprogramming of myeloid cells in NASH liver and its contribution to disease progression remain incompletely defined. APPROACH AND RESULTS: In this study, we performed bulk and single-cell RNA sequencing (sc-RNA seq) analysis to delineate the landscape of macrophage and dendritic cell transcriptomes in healthy and NASH livers. Our analysis uncovered cell type-specific patterns of transcriptomic reprogramming on diet-induced NASH. We identified brain-abundant membrane-attached signal protein 1 (Basp1) as a myeloid-enriched gene that is markedly induced in mouse and human NASH liver. Myeloid-specific inactivation of Basp1 attenuates the severity of diet-induced NASH pathologies, as shown by reduced hepatocyte injury and liver fibrosis in mice. Mechanistically, cultured macrophages lacking Basp1 exhibited a diminished response to pro-inflammatory stimuli, impaired NLRP3 inflammasome activation, and reduced cytokine secretion. CONCLUSIONS: Together, these findings uncover Basp1 as a critical regulator of myeloid inflammatory signaling that underlies NASH pathogenesis.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Ratones , Humanos , Animales , Enfermedad del Hígado Graso no Alcohólico/patología , Hígado/patología , Hepatocitos/metabolismo , Dieta , Cirrosis Hepática/patología , Ratones Endogámicos C57BL , Modelos Animales de Enfermedad
3.
J Am Chem Soc ; 146(14): 9721-9727, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38556809

RESUMEN

The volumetric density of the metal atomic site is decisive to the operating efficiency of the photosynthetic nanoreactor, yet its rational design and synthesis remain a grand challenge. Herein, we report a shell-regulating approach to enhance the volumetric density of Co atomic sites onto/into multishell ZnxCd1-xS for greatly improving CO2 photoreduction activity. We first establish a quantitative relation between the number of shell layers, specific surface areas, and volumetric density of atomic sites on multishell ZnxCd1-xS and conclude a positive relation between photosynthetic performance and the number of shell layers. The triple-shell ZnxCd1-xS-Co1 achieves the highest CO yield rate of 7629.7 µmol g-1 h-1, superior to those of the double-shell ZnxCd1-xS-Co1 (5882.2 µmol g-1 h-1) and single-shell ZnxCd1-xS-Co1 (4724.2 µmol g-1 h-1). Density functional theory calculations suggest that high-density Co atomic sites can promote the mobility of photogenerated electrons and enhance the adsorption of Co(bpy)32+ to increase CO2 activation (CO2 → CO2* → COOH* → CO* → CO) via the S-Co-bpy interaction, thereby enhancing the efficiency of photocatalytic CO2 reduction.

4.
Hepatology ; 78(5): 1478-1491, 2023 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-35950514

RESUMEN

BACKGROUND AND AIMS: The mammalian liver harbors heterogeneous cell types that communicate via local paracrine signaling. Recent studies have delineated the transcriptomic landscape of the liver in NASH that provides insights into liver cell heterogeneity, intercellular crosstalk, and disease-associated reprogramming. However, the nature of intrahepatic signaling and its role in NASH progression remain obscure. APPROACH AND RESULTS: Here, we performed transcriptomic analyses and identified cardiotrophin-like cytokine factor 1 (CLCF1), a member of the IL-6 family cytokines, as a cholangiocyte-derived paracrine factor that was elevated in the liver from diet-induced NASH mice and patients with NASH. Adenovirus-associated virus-mediated overexpression of CLCF1 in the liver ameliorated NASH pathologies in two diet-induced NASH models in mice, illustrating that CLCF1 induction may serve an adaptive and protective role during NASH pathogenesis. Unexpectedly, messenger RNA and protein levels of leukemia inhibitory factor receptor (LIFR), a subunit of the receptor complex for CLCF1, were markedly downregulated in NASH liver. Hepatocyte-specific inactivation of LIFR accelerated NASH progression in mice, supporting an important role of intrahepatic cytokine signaling in maintaining tissue homeostasis under metabolic stress conditions. CONCLUSIONS: Together, this study sheds light on the molecular nature of intrahepatic paracrine signaling during NASH pathogenesis and uncovers potential targets for therapeutic intervention.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Comunicación Paracrina , Animales , Humanos , Ratones , Citocinas/genética , Citocinas/metabolismo , Dieta/efectos adversos , Modelos Animales de Enfermedad , Interleucinas/metabolismo , Hígado/metabolismo , Mamíferos , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/etiología , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Comunicación Paracrina/genética , Comunicación Paracrina/fisiología
5.
Mol Carcinog ; 62(10): 1474-1486, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37283234

RESUMEN

Since chemotherapy's therapeutic impact is diminished by drug resistance, treating ovarian cancer is notably challenging. Thereafter, it is critical to develop cutting-edge approaches to treating ovarian cancer. Baohuoside I (derived from Herba Epimedii) is reported to have antitumor properties in various malignancies. It is unknown, however, what role Baohuoside I plays in cisplatin (DDP)-resistant ovarian cancer cells. 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT), colony formation, and flow cytometry assay were used to investigate the impact of Baohuoside I on ovarian cancer A2780 cells and DDP-resistant A2780 (A2780/DDP) cells. The level of microtubule associated protein 1 light chain 3 (LC3) was determined using immunofluorescence staining. Utilizing the mRFP-GFP-LC3B tandem fluorescent probe allowed us to analyse the autophagy flux. Analysis of mRNA and protein level was performed using RT-qPCR and Western blot analysis, respectively. The interaction between hypoxia inducible factor 1 subunit alpha (HIF-1α) and autophagy related 5 (ATG5) promoter was investigated by dual luciferase and ChIP assay. Additionally, evaluation of Baohuoside I's role in ovarian cancer was performed using a nude mouse xenograft model. Baohuoside I decreased the viability and proliferation and triggered the apoptosis of both A2780 and A2780/DDP cells in a concentration-dependent manner. Baohuoside I also increased the sensitivity of A2780/DDP cells to DDP. Concurrently, HIF-1α could promote A2780/DDP cells resistance to DDP. In addition, HIF-1α could induce the autophagy of A2780/DDP cells through transcriptionally activating ATG5, and Baohuoside I imporved the chemosensitivity of A2780/DDP cells to DDP by downregulating HIF-1α. Moreover, Baohuoside I could inhibit the chemoresistance to DDP in ovarian cancer in vivo. Baohuoside I sensitizes ovarian cancer cells to DDP by suppressing autophagy via downregulating the HIF-1α/ATG5 axis. Consequently, Baohuoside I might be evaluated as a new agent for enhancing the chemotherapeutic efficacy of drug treatment for ovarian cancer.


Asunto(s)
Antineoplásicos , Neoplasias Ováricas , Animales , Ratones , Humanos , Femenino , Cisplatino/farmacología , Cisplatino/uso terapéutico , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Línea Celular Tumoral , Resistencia a Antineoplásicos/genética , Autofagia , Apoptosis , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Proliferación Celular , Proteína 5 Relacionada con la Autofagia
6.
Appl Opt ; 62(17): 4409-4414, 2023 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-37707131

RESUMEN

A highly sensitive and reliable tunable diode laser absorption spectroscopy gas detection system with a temperature-pressure compensation algorithm is demonstrated for detecting C H 4 concentrations in near space. Near space generally refers to the airspace 20-100 km away from the ground, where temperature and pressure changes are complex. Since the gas absorption spectrum is easily affected by temperature and pressure, a temperature-pressure compensation algorithm is proposed and used in the C H 4 sensor to improve the detection accuracy of the sensor. First, we measured the basic characteristics of the sensor in the laboratory, such as linearity and long-term stability. Experimental results showed that the linear correlation coefficient R-square can reach 0.999, and the concentration fluctuation of C H 4 is less than 0.17 ppm within 3.5 h. Then the sensor was applied to a research activity in Qinghai Province, China, in September, and the results show that the sensor can effectively monitor the C H 4 concentration in near space.

7.
J Am Chem Soc ; 144(27): 12381-12389, 2022 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-35767839

RESUMEN

Metallic-state gold nanorods are well known to exhibit strong longitudinal plasmon excitations in the near-infrared region (NIR) suitable for photothermal conversion. However, when the size decreases below ∼2 nm, Au nanostructures become nonmetallic, and whether the longitudinal excitation in plasmonic nanorods can be inherited is unknown. Here, we report atomically precise rod-shaped Au42(SCH2Ph)32 with a hexagonal-close-packed Au20 kernel of aspect ratio as high as 6.2, which exhibits an intense absorption at 815 nm with a high molar absorption coefficient of 1.4 × 105 M-1 cm-1. Compared to other rod-shaped nanoclusters, Au42 possesses a much more effective photothermal conversion with a large temperature increase of ∼27 °C within 5 min (λex = 808 nm, 1 W cm-2) at an ultralow concentration of 50 µg mL-1 in toluene. Density functional theory calculations show that the NIR transition is mainly along the long axis of the Au20 kernel in Au42, i.e., a longitudinal excitonic oscillation, akin to the longitudinal plasmon in metallic-state nanorods. Transient absorption spectroscopy reveals that the fast decay in Au42 is similar to that of shorter-aspect-ratio nanorods but is followed by an additional slow decay with a long lifetime of 2400 ns for the Au42 nanorod. This work provides the first case that an intense longitudinal excitation is obtained in molecular-like nanorods, which can be used as photothermal converters and hold potential in biomedical therapy, photoacoustic imaging, and photocatalysis.


Asunto(s)
Nanoestructuras , Nanotubos , Oro/química , Nanoestructuras/química , Nanotubos/química
8.
Appl Opt ; 61(4): 919-924, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-35201060

RESUMEN

A linear self-reference spectral interferometry has been proposed to measure the distribution of polarization-maintaining photonic crystal fiber (PM-PCF) birefringence over a wide wavelength range combined with the soliton self-frequency shift and birefringence effect. The birefringence of PM-PCF is measured experimentally over the range of 800-970 nm, which is larger than 5×10-4 and shows a segmented change trend. The air micropore structure has a significant effect on the characteristics of PM-PCF, which makes it have a highly nonlinear coefficient, and at the same time, changes the dispersion and birefringence distributions of the PM-PCF. The distribution of PM-PCF birefringence, measured by experiment, provides a new dimension for the design of PM-PCF, which is helpful for a detailed fiber model and an iterative optimization of fiber structure.

9.
Hepatology ; 71(4): 1228-1246, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31469911

RESUMEN

BACKGROUND AND AIMS: Nonalcoholic steatohepatitis (NASH) is a progressive liver disease that is characterized by liver injury, inflammation, and fibrosis. NASH pathogenesis is linked to reprogramming of chromatin landscape in the liver that predisposes hepatocytes to stress-induced tissue injury. However, the molecular nature of the putative checkpoint that maintains chromatin architecture and preserves hepatocyte health remains elusive. APPROACH AND RESULTS: Here we show that heterogeneous nuclear ribonucleoprotein U (hnRNPU), a nuclear matrix protein that governs chromatin architecture and gene transcription, is a critical factor that couples chromatin disruption to NASH pathogenesis. RNA-seq and chromatin immunoprecipitation-seq studies revealed an extensive overlap between hnRNPU occupancy and altered gene expression during NASH. Hepatocyte-specific inactivation of hnRNPU disrupted liver chromatin accessibility, activated molecular signature of NASH, and sensitized mice to diet-induced NASH pathogenesis. Mechanistically, hnRNPU deficiency stimulated the expression of a truncated isoform of TrkB (TRKB-T1) that promotes inflammatory signaling in hepatocytes and stress-induced cell death. Brain-derived neurotrophic factor treatment reduced membrane TRKB-T1 protein and protected mice from diet-induced NASH. CONCLUSIONS: These findings illustrate a mechanism through which disruptions of chromatin architecture drive the emergence of disease-specific signaling patterns that promote liver injury and exacerbate NASH pathogenesis.


Asunto(s)
Ensamble y Desensamble de Cromatina , Ribonucleoproteína Heterogénea-Nuclear Grupo U/metabolismo , Glicoproteínas de Membrana/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Animales , Factor Neurotrófico Derivado del Encéfalo/uso terapéutico , Modelos Animales de Enfermedad , Hepatocitos/metabolismo , Ribonucleoproteína Heterogénea-Nuclear Grupo U/genética , Glicoproteínas de Membrana/genética , Ratones , Ratones Transgénicos , Enfermedad del Hígado Graso no Alcohólico/terapia , Proteínas Tirosina Quinasas/genética , Transcriptoma
10.
J Chem Phys ; 155(3): 034301, 2021 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-34293880

RESUMEN

Carboxylate groups have recently been explored as a new type of ligand to protect superatomic copper and silver nanoclusters, but little is known of the interfacial structure and bonding. Here, we employ density functional theory to investigate the interfaces of a model carboxylate group, CH3COO, on the coinage metal surfaces and clusters. We found that µ2-CH3COO is the most preferred binding mode on the three M(111) surfaces (M = Cu, Ag, and Au), while µ3-CH3COO is also stable on Cu(111) and Ag(111). The saturation coverage was found to be about seven CH3COO groups per nm2 for all surfaces. CH3COO has the strongest binding on Cu and weakest on Au. Moving from the flat surfaces to the icosahedral M13 clusters, we found that the eight-electron superatomic [M13(CH3COO)6]- nanoclusters also prefer the µ2-CH3COO mode on the surface. The icosahedral kernel in [Cu13(CH3COO)6]- and [Ag13(CH3COO)6]- was well maintained after geometry optimization, but a larger deformation was found in [Au13(CH3COO)6]-. Given the broad availability and variety of carboxylic acids including amino acids, our work suggests that carboxylate groups could be the next-generation ligands to further expand the universe of atomically precise metal clusters, especially for Cu and Ag.

11.
Sensors (Basel) ; 21(23)2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34884052

RESUMEN

Optical humidity sensors have evolved through decades of research and development, constantly adapting to new demands and challenges. The continuous growth is supported by the emergence of a variety of optical fibers and functional materials, in addition to the adaptation of different sensing mechanisms and optical techniques. This review attempts to cover the majority of optical humidity sensors reported to date, highlight trends in design and performance, and discuss the challenges of different applications.


Asunto(s)
Fibras Ópticas , Humedad
12.
J Am Chem Soc ; 142(40): 16905-16909, 2020 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-32941019

RESUMEN

We report the synthesis and structure of the first all-carboxylate-protected superatomic silver nanocluster. It was prepared by heating a dimethylformamide solution of perfluoroglutaric acid and AgNO3 under alkaline conditions, yielding a single crystal of [(CH3)2NH2]6[Ag8(pfga)6]. The [Ag8(pfga)6]6- cluster has a rhombohedral Ag86+ core, with each of its faces protected by one dianionic perfluoroglutarate (pfga) ligand. Electronic-structure analysis from density functional theory confirms the stability of this two-electron cluster due to the shell closing of the superatomic orbital in the (1S)2 configuration and explains the optical absorption of the cluster in the visible region as the transition from 1S to 1P orbital. The [Ag8(pfga)6]6- cluster emits bright green-yellow light in THF solution and bright orange light in the solid state. This work opens the door to using the widely available carboxylic acids to synthesize atomically precise Ag clusters of attractive properties.

13.
Proc Natl Acad Sci U S A ; 114(34): E7111-E7120, 2017 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-28784777

RESUMEN

Brown and beige adipocytes convert chemical energy into heat through uncoupled respiration to defend against cold stress. Beyond thermogenesis, brown and beige fats engage other metabolic tissues via secreted factors to influence systemic energy metabolism. How the protein and long noncoding RNA (lncRNA) regulatory networks act in concert to regulate key aspects of thermogenic adipocyte biology remains largely unknown. Here we developed a genome-wide functional screen to interrogate the transcription factors and cofactors in thermogenic gene activation and identified zinc finger and BTB domain-containing 7b (Zbtb7b) as a potent driver of brown fat development and thermogenesis and cold-induced beige fat formation. Zbtb7b is required for activation of the thermogenic gene program in brown and beige adipocytes. Genetic ablation of Zbtb7b impaired cold-induced transcriptional remodeling in brown fat, rendering mice sensitive to cold temperature, and diminished browning of inguinal white fat. Proteomic analysis revealed a mechanistic link between Zbtb7b and the lncRNA regulatory pathway through which Zbtb7b recruits the brown fat lncRNA 1 (Blnc1)/heterogeneous nuclear ribonucleoprotein U (hnRNPU) ribonucleoprotein complex to activate thermogenic gene expression in adipocytes. These findings illustrate the emerging concept of a protein-lncRNA regulatory network in the control of adipose tissue biology and energy metabolism.


Asunto(s)
Tejido Adiposo Beige/metabolismo , Tejido Adiposo Pardo/metabolismo , Proteínas de Unión al ADN/metabolismo , Termogénesis , Factores de Transcripción/metabolismo , Adipocitos/citología , Adipocitos/metabolismo , Tejido Adiposo Beige/crecimiento & desarrollo , Tejido Adiposo Pardo/crecimiento & desarrollo , Animales , Células Cultivadas , Proteínas de Unión al ADN/genética , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , ARN Largo no Codificante , Factores de Transcripción/genética
14.
J Biol Chem ; 290(52): 31003-12, 2015 Dec 25.
Artículo en Inglés | MEDLINE | ID: mdl-26547624

RESUMEN

Disruption of the body clock has been recognized as a risk factor for cardiovascular disease. How the circadian pacemaker interacts with the genetic factors associated with plasma lipid traits remains poorly understood. Recent genome-wide association studies have identified an expanding list of genetic variants that influence plasma cholesterol and triglyceride levels. Here we analyzed circadian regulation of lipid-associated candidate genes in the liver and identified two distinct groups exhibiting rhythmic and non-rhythmic patterns of expression during light-dark cycles. Liver-specific inactivation of Bmal1 led to elevated plasma LDL/VLDL cholesterol levels as a consequence of the disruption of the PCSK9/LDL receptor regulatory axis. Ablation of the liver clock perturbed diurnal regulation of lipid-associated genes in the liver and markedly reduced the expression of the non-rhythmically expressed gene Trib1. Adenovirus-mediated rescue of Trib1 expression lowered plasma PCSK9 levels, increased LDL receptor protein expression, and restored plasma cholesterol homeostasis in mice lacking a functional liver clock. These results illustrate an unexpected mechanism through which the biological clock regulates cholesterol homeostasis through its regulation of non-rhythmic genes in the liver.


Asunto(s)
Colesterol/metabolismo , Relojes Circadianos/fisiología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Hígado/metabolismo , Proproteína Convertasas/biosíntesis , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Receptores de LDL/biosíntesis , Serina Endopeptidasas/biosíntesis , Animales , Colesterol/genética , Regulación de la Expresión Génica/fisiología , Péptidos y Proteínas de Señalización Intracelular/genética , Lipoproteínas LDL/genética , Lipoproteínas LDL/metabolismo , Lipoproteínas VLDL/genética , Lipoproteínas VLDL/metabolismo , Ratones , Ratones Transgénicos , Proproteína Convertasa 9 , Proproteína Convertasas/genética , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Receptores de LDL/genética , Serina Endopeptidasas/genética
16.
J Neurosci Res ; 92(9): 1199-204, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24811319

RESUMEN

Ependymal cells are multiciliated epithelial cells that line the ventricles in the adult brain. Abnormal function or structure of ependymal cilia has been associated with various neurological deficits. For the first time, we report three distinct ependymal cell types, I, II, and III, based on their unique ciliary beating frequency and beating angle. These ependymal cells have specific localizations within the third ventricle of the mouse brain. Furthermore, neither ependymal cell types nor their localizations are altered by aging. Our high-speed fluorescence imaging analysis reveals that these ependymal cells have an intracellular pacing calcium oscillation property. Our study further shows that alcohol can significantly repress the amplitude of calcium oscillation and the frequency of ciliary beating, resulting in an overall decrease in volume replacement by the cilia. Furthermore, the pharmacological agent cilostazol could differentially increase cilia beating frequency in type II, but not in type I or type III, ependymal cells. In summary, we provide the first evidence of three distinct types of ependymal cells with calcium oscillation properties.


Asunto(s)
Señalización del Calcio/fisiología , Calcio/metabolismo , Cilios/fisiología , Epéndimo/citología , Células Epiteliales/clasificación , Espacio Intracelular/metabolismo , Alcoholes/farmacología , Animales , Señalización del Calcio/efectos de los fármacos , Ventrículos Cerebrales/anatomía & histología , Cilios/clasificación , Cilios/efectos de los fármacos , Cilostazol , Células Epiteliales/efectos de los fármacos , Técnicas In Vitro , Espacio Intracelular/efectos de los fármacos , Ratones , Microscopía de Interferencia , Fármacos Neuroprotectores/farmacología , Tetrazoles/farmacología
17.
Opt Express ; 22(9): 11244-53, 2014 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-24921822

RESUMEN

A novel active fiber loop ring-down gas sensor combined with dual wavelengths differential absorption method is proposed. Two Distributed Feedback Laser Diodes (DFB LDs) with different wavelengths are employed. One LD whose wavelength covered with the absorption line of target gas is used for sensing. Another LD whose wavelength is centered outside the absorption line is used for reference. The gas absorption loss can be obtained by differencing the reference signal and sensing signal. Compared with traditional method of one wavelength employed, it can eliminate the influence of the cavity loss variety and photoelectric device drift in the system efficiently. An Erbium Doped Fiber Amplifier (EDFA) with Automatic Gain Control (AGC) is used to compensate the loss of the light in the ring-down cavity, which will increase the cavity round trips and improve the precision of gas detection. And two fiber Bragg gratings (FBGs) are employed to get rid of amplified spontaneous emission (ASE) spectrum noise as filters. The calibrating ethyne samples of different concentrations are measured with a 65 mm long gas cell in order to evaluate the effect of reference. The results show the relative deviation is found to be less than ± 0.4% of 0.1% ethyne when a certain additional loss from 0 to 1.2dB is introduced to the cavity and the relative deviation of measured concentration is less than ± 0.5% over 24 hours.

18.
Zhonghua Yi Xue Za Zhi ; 94(43): 3432-5, 2014 Nov 25.
Artículo en Zh | MEDLINE | ID: mdl-25622677

RESUMEN

OBJECTIVE: To determine the performance of HR-HPV E6/E7 massager RNA (mRNA) test for detecting high-grade cervical intraepithelial neoplasia in cervical cancer screening and compare the clinical performance of HR-HPV E6/E7 mRNA test with HC-2 and Cervista HPV DNA tests for cross-sectional positivity in women with and without cervical neoplasia. METHODS: A total of 172 women underwent cytology, HR-HPV DNA test, HR-HPV E6/7 mRNA test, colposcopy and biopsy. We compared the clinical performance of HR-HPV E6/E7 mRNA test with Hybrid Capture 2 DNA test (HC-2) and Cervista HR-HPV DNA test on the cervical brush specimens during colposcopy and routine screening. The samples were histologically confirmed high-grade cervical intraepithelial neoplasia (CIN II) or worse (CIN II+) as an endpoint. RESULTS: HR-HPV E6/E7 mRNA positive rate was 37.9% in NILM, 67.9% in ASCUS and LSIL, 88.5% in ASC-H+. HR-HPV E6/E7 mRNA positive rate was 38.6% in CIN I, 77.4% in CIN II-3 and 92.5% in SCC. HR-HPV E6/E7 mRNA test showed a higher specificity than HC-2 and Cervista HPV DNA tests for high-grade lesions (61.4%, 54.3%, 55.7%, respectively, P < 0.05) and also a higher positive predictive value (75.9%, 74.8%, 74.6% respectively). Among three tests, HR-HPV E6/E7 mRNA had the largest area of ROC curve and the best diagnostic value. CONCLUSION: HR-HPV E6/E7 mRNA test has a performance more specific for detecting CIN II+ with the same sensitivity as HC-2 and Cervista HPV DNA tests. And it may serve as a more specific test for predicting the risk of progression and offer a viable tool for triage during cervical cancer screening.


Asunto(s)
Detección Precoz del Cáncer , Papillomaviridae , Biopsia , Colposcopía , Estudios Transversales , ADN Viral , Femenino , Humanos , Proteínas Oncogénicas Virales , Embarazo , ARN Mensajero , ARN Viral , Displasia del Cuello del Útero , Neoplasias del Cuello Uterino
19.
Food Chem X ; 21: 101232, 2024 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-38420507

RESUMEN

Sunlight exposure of grape clusters is frequently reported to influence grape aromas greatly. Among them, the effects of full shading (FS) of clusters on fruit quality and volatile compounds in grape berries has scarcely been investigated. In the present study, the effects of FS from véraison to ripeness on fruit quality and volatile compounds in Cabernet Sauvignon grapes were studied. The results showed that FS treatment reduced fruit size and berry weight, delayed fruit maturity, and decreased the contents of anthocyanins, phenols, and tannins in grape berries. In addition, volatile compounds in grape berries were analyzed, and 55 and 53 volatile compounds were detected in the control (CK) and FS groups, respectively. The results indicated that the concentrations of straight-chain fatty aldehydes, straight-chain fatty alcohols, straight-chain fatty acids, and branched-chain fatty acids, norisoprenoids, and total concentration of volatile compounds were all higher in FS group than in CK group. Specifically, FS treatment had significant promoting effects on the concentrations of ß-damascenone, terpineol, 2-ethyl-1-hexanol, and 2-hexenal, and remarkably decreased the concentrations of geranial, benzeneacetaldehyde, neral, and ethyl acetate. Partial least squares-discriminant analysis (PLS-DA) revealed a clear separation between the control (CK) and FS groups, and showed that 2-hexenal and hexanal were the main characteristic aroma compounds in the FS group. Moreover, an increase in the intensity of fruity, herbaceous, floral, and mushroom aromas was recorded in FS grapes. This study provides new insights into the effects of the exclusion of sunlight exposure on volatile compound accumulation in grape berries.

20.
JCI Insight ; 9(1)2024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38015639

RESUMEN

Interorgan crosstalk via secreted hormones and metabolites is a fundamental aspect of mammalian metabolic physiology. Beyond the highly specialized endocrine cells, peripheral tissues are emerging as an important source of metabolic hormones that influence energy and nutrient metabolism and contribute to disease pathogenesis. Neuregulin 4 (Nrg4) is a fat-derived hormone that protects mice from nonalcoholic steatohepatitis (NASH) and NASH-associated liver cancer by shaping hepatic lipid metabolism and the liver immune microenvironment. Despite its enriched expression in brown fat, whether NRG4 plays a role in thermogenic response and mediates the metabolic benefits of cold exposure are areas that remain unexplored. Here we show that Nrg4 expression in inguinal white adipose tissue (iWAT) is highly responsive to chronic cold exposure. Nrg4 deficiency impairs beige fat induction and renders mice more susceptible to diet-induced metabolic disorders under mild cold conditions. Using mice with adipocyte and hepatocyte-specific Nrg4 deletion, we reveal that adipose tissue-derived NRG4, but not hepatic NRG4, is essential for beige fat induction following cold acclimation. Furthermore, treatment with recombinant NRG4-Fc fusion protein promotes beige fat induction in iWAT and improves metabolic health in mice with diet-induced obesity. These findings highlight a critical role of NRG4 in mediating beige fat induction and preserving metabolic health under mild cold conditions.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Animales , Ratones , Tejido Adiposo Beige/metabolismo , Tejido Adiposo Pardo/metabolismo , Hormonas , Mamíferos , Neurregulinas/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Termogénesis
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