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1.
Annu Rev Immunol ; 42(1): 647-677, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38424658

RESUMEN

Lymphocytes spanning the entire innate-adaptive spectrum can stably reside in tissues and constitute an integral component of the local defense network against immunological challenges. In tight interactions with the epithelium and endothelium, tissue-resident lymphocytes sense antigens and alarmins elicited by infectious microbes and abiotic stresses at barrier sites and mount effector responses to restore tissue homeostasis. Of note, such a host cell-directed immune defense system has been recently demonstrated to surveil epithelial cell transformation and carcinoma development, as well as cancer cell metastasis at selected distant organs, and thus represents a primordial cancer immune defense module. Here we review how distinct lineages of tissue-resident innate lymphoid cells, innate-like T cells, and adaptive T cells participate in a form of multilayered cancer immunity in murine models and patients, and how their convergent effector programs may be targeted through both shared and private regulatory pathways for cancer immunotherapy.


Asunto(s)
Inmunidad Innata , Neoplasias , Humanos , Animales , Neoplasias/inmunología , Neoplasias/terapia , Linfocitos/inmunología , Linfocitos/metabolismo , Microambiente Tumoral/inmunología , Inmunidad Adaptativa , Inmunoterapia/métodos
2.
Nature ; 601(7891): 118-124, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34912121

RESUMEN

The skin serves as a physical barrier and an immunological interface that protects the body from the external environment1-3. Aberrant activation of immune cells can induce common skin autoimmune diseases such as vitiligo, which are often characterized by bilateral symmetric lesions in certain anatomic regions of the body4-6. Understanding what orchestrates the activities of cutaneous immune cells at an organ level is necessary for the treatment of autoimmune diseases. Here we identify subsets of dermal fibroblasts that are responsible for driving patterned autoimmune activity, by using a robust mouse model of vitiligo that is based on the activation of endogenous auto-reactive CD8+ T cells that target epidermal melanocytes. Using a combination of single-cell analysis of skin samples from patients with vitiligo, cell-type-specific genetic knockouts and engraftment experiments, we find that among multiple interferon-γ (IFNγ)-responsive cell types in vitiligo-affected skin, dermal fibroblasts are uniquely required to recruit and activate CD8+ cytotoxic T cells through secreted chemokines. Anatomically distinct human dermal fibroblasts exhibit intrinsic differences in the expression of chemokines in response to IFNγ. In mouse models of vitiligo, regional IFNγ-resistant fibroblasts determine the autoimmune pattern of depigmentation in the skin. Our study identifies anatomically distinct fibroblasts with permissive or repressive IFNγ responses as the key determinant of body-level patterns of lesions in vitiligo, and highlights mesenchymal subpopulations as therapeutic targets for treating autoimmune diseases.


Asunto(s)
Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/patología , Fibroblastos/inmunología , Piel/inmunología , Piel/patología , Vitíligo/inmunología , Vitíligo/patología , Adolescente , Adulto , Animales , Linfocitos T CD8-positivos/inmunología , Quimiocina CXCL10/inmunología , Quimiocina CXCL9/inmunología , Niño , Modelos Animales de Enfermedad , Femenino , Fibroblastos/patología , Humanos , Interferón gamma/inmunología , Masculino , Melanocitos/inmunología , Melanocitos/patología , Ratones , Persona de Mediana Edad , Comunicación Paracrina , RNA-Seq , Análisis de la Célula Individual , Células del Estroma/inmunología , Linfocitos T Citotóxicos/inmunología , Adulto Joven
3.
Plant J ; 115(1): 205-219, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36999610

RESUMEN

Low temperature and abscisic acid (ABA) are the two main factors that induce anthocyanin synthesis; however, their potential relationships in governing anthocyanin biosynthesis in Solanum lycopersicum (tomato) seedlings remains unclear. Our study revealed the involvement of the transcription factor SlAREB1 in the low-temperature response of tomato seedlings via the ABA-dependent pathway, for a specific temperature range. The overexpression of SlAREB1 enhanced the expression of anthocyanin-related genes and the accumulation of anthocyanins, especially under low-temperature conditions, whereas silencing SlAREB1 dramatically reduced gene expression and anthocyanin accumulation. There is a direct interaction between SlAREB1 and the promoters of SlDFR and SlF3'5'H, which are structural genes that impact anthocyanin biosynthesis. SlAREB1 can regulate anthocyanins through controlling SlDFR and SlF3'5'H expression. Accordingly, SlAREB1 takes charge of regulating anthocyanin biosynthesis in tomato seedlings via the ABA-dependent pathway at low temperatures.


Asunto(s)
Solanum lycopersicum , Solanum lycopersicum/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Antocianinas , Temperatura , Ácido Abscísico/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
4.
J Nutr ; 154(2): 369-380, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38122845

RESUMEN

BACKGROUND: There is a U-shaped relationship between dietary selenium (Se) ingestion and optimal sperm quality. OBJECTIVES: This study aimed to investigate the optimal dietary dose and forms of Se for sperm quality of breeder roosters and the relevant mechanisms. METHODS: In experiment 1, 18-wk-old Jingbai laying breeder roosters were fed a Se-deficient base diet (BD, 0.06 mg Se/kg), or the BD + 0.1, 0.2, 0.3, 0.4, 0.5, or 1.0 mg Se/kg for 9 wk. In experiment 2, the roosters were fed the BD or the BD + sodium selenite (SeNa), seleno-yeast (SeY), or Se-nanoparticles (SeNPs) at 0.2 mg Se/kg for 9 wk. RESULTS: In experiment 1, added dietary 0.2 and 0.3 mg Se/kg led to higher sperm motility and lower sperm mortality than the other groups at weeks 5, 7, and/or 9. Furthermore, added dietary 0.2-0.4 mg Se/kg produced better testicular histology and/or lower testicular 8-hydroxy-deoxyguanosine than the other groups. Moreover, integrated testicular transcriptomic and cecal microbiomic analysis revealed that inflammation, cell proliferation, and apoptosis-related genes and bacteria were dysregulated by Se deficiency or excess. In experiment 2, compared with SeNa, SeNPs slightly increased sperm motility throughout the experiment, whereas SeNPs slightly reduced sperm mortality compared with SeY at week 9. Both SeY and SeNPs decreased malondialdehyde in the serum than those of SeNa, and SeNPs led to higher glutathione peroxidase (GPX) and thioredoxin reductase activities and GPX1 and B-cell lymphoma 2 protein concentrations in the testis compared with SeY and SeNa. CONCLUSIONS: The optimal dietary Se dose for reproductive health of breeder roosters is 0.25-0.35 mg Se/kg, and SeNPs displayed better effects on reproductive health than SeNa and SeY in laying breeder roosters. The optimal doses and forms of Se maintain reproductive health of roosters associated with regulation intestinal microbiota homeostasis and/or testicular redox balance, inflammation, cell proliferation, and apoptosis.


Asunto(s)
Microbioma Gastrointestinal , Selenio , Masculino , Animales , Testículo/metabolismo , Selenio/metabolismo , Pollos/metabolismo , Salud Reproductiva , Motilidad Espermática , Semillas , Oxidación-Reducción , Dieta , Inflamación/metabolismo , Apoptosis , Proliferación Celular , Suplementos Dietéticos
5.
J Synchrotron Radiat ; 30(Pt 2): 319-326, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36891845

RESUMEN

With fast advances in enhancing the focusing/imaging resolution of Fresnel zone plate lenses toward sub-10 nm, low diffraction efficiency in connection with their rectangular zone shape still remains a big issue in both soft and hard X-ray microscopy. In hard X-ray optics, encouraging progress has recently been reported in our earlier attempts of high focusing efficiency by 3D kinoform shaped metallic zone plates, formed by greyscale electron beam lithography. This paper addresses our efforts towards high focusing/imaging efficiency by developing a novel dielectric kinoform zone plate lens for soft X-rays. The effects of the zone materials and zone shapes on the focusing/imaging quality were first theoretically investigated by a modified thin-grating-approximation method, revealing superior efficiencies of dielectric kinoform zone plates over rectangular ones in metals. Optical characterizations of replicated dielectric kinoform zone plates by greyscale electron beam lithography demonstrate a focusing efficiency of 15.5% with a resolution of 110 nm in the water window of X-rays. Apart from high efficiency, the novel kinoform zone plate lenses developed in this work exhibit significant advantages over conventional zone plates, i.e. simplified process, low cost and no need for a beamstop.

6.
Nanotechnology ; 34(21)2023 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-36745920

RESUMEN

X-ray microscope as an important nanoprobing tool plays a prevailing role in nano-inspections of materials. Despite the fast advances of high resolution focusing/imaging reported, the efficiency of existing high-resolution zone plates is mostly around 5% in soft x-ray and rapidly goes down to 1%-2% when the resolution approaches 10 nm. It is well known that the rectangular zone shape, beamstop, limited height/width ratios, material absorption of light and structural defects are likely responsible for the limited efficiency. Although zone plates with Kinoform profile are supposed to be efficient, progress for achieving both high resolution (<30 nm) and high efficiency (>5%) have hardly been addressed in soft x-ray. In this work, we propose a compound Kinoform/Fresnel zone plate (CKZP) by combing a dielectric Kinoform zone plate with a 15 nm resolution zone plate. Greyscale electron beam lithography was applied to form the 3D Kinoform zone plate and atomic layer deposition was carried out to form the binary zone plate. Optical characterizations demonstrated 15 nm resolution focusing/imaging with over 7.8% efficiency in soft x-ray. The origin of the efficiency improvement behind the proposed compound lens is theoretically analyzed and discussed.

7.
Appl Opt ; 62(14): 3542-3550, 2023 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-37706967

RESUMEN

X-ray ptychography is a popular variant of coherent diffraction imaging that offers ultrahigh resolution for extended samples. In x-ray ptychography instruments, the Fresnel zone-plate (FZP) is the most commonly used optical probe system for both soft x-ray and hard x-ray. In FZP-based ptychography with a highly curved defocus probe wavefront, the reconstructed image quality can be significantly impacted by the initial probe function form, necessitating the construction of a suitable initial probe for successful reconstruction. To investigate the effects of initial probe forms on FZP-based ptychography reconstruction, we constructed four single-mode initial probe models (IPMs) and three multi-mode IPMs in this study, and systematically compared their corresponding simulated and experimental reconstructions. The results show that the Fresnel IPM, spherical IPM, and Fresnel-based multi-mode IPMs can result in successful reconstructions for both near-focus and defocus cases, while random IPMs and constant IPMs work only for near-focus cases. Consequently, for FZP-based ptychography, the elaborately constructed IPMs that closely resemble real probes in wavefront phase form are more advantageous than natural IPMs such as the random or constant model. Furthermore, these IPMs with high phase similarity to the high-curvature large-sized probe adopted in experiments can help greatly improve ptychography experiment efficiency and decrease radiation damage to samples.

8.
Int J Mol Sci ; 24(13)2023 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-37445959

RESUMEN

Previous studies found that 5-aminolevulinic acid (ALA) and abscisic acid (ABA) can mitigate damage from adversity by enhancing photosynthesis. However, it is not clear whether they have positive effects on iron utilization and chlorophyll synthesis of tomato seedlings under low-temperature stress. To investigate the possible functional relationship between ABA and ALA and elucidate the possible mechanisms of action of ALA to alleviate low-temperature stress in tomato seedlings, this experiment analyzed the effects of ALA and ABA on chlorophyll synthesis in tomato seedling leaves sprayed with exogenous of ALA (25 mg·L-1) or ABA (100 µM) under low-temperature stress (8-18 °C/8-12 °C, day/night). The results show that exogenous ALA increased the Fv/Fm of tomato leaves by 5.31% and increased the accumulation of iron and chlorophyll by 101.15% and 15.18%, respectively, compared to the low-temperature treatment alone, and tomato resistance of low-temperature stress was enhanced. Meanwhile, exogenous application of ALA increased the ABA content by 39.43%, and subsequent application of exogenous ABA revealed that tomato seedlings showed similar effects to exogenous ALA under low-temperature stress, with increased accumulation of iron and chlorophyll in tomato seedlings, which eventually increased the maximum photochemical efficiency of PS II. Under low-temperature stress, application of exogenous ABA significantly reduced ALA content, but the expression of key enzyme genes (PPGD, HEMB1, HEME1, and HEMF1), precursors of chlorophyll synthesis by ALA, was significantly elevated, presumably because the increased activity of these enzymes after external application of ABA accelerated ALA consumption. In conclusion, ABA may crosstalk with ALA to improve the photochemical efficiency and low temperature resistance of tomatoes by regulating chlorophyll synthesis and iron accumulation.


Asunto(s)
Ácido Abscísico , Solanum lycopersicum , Ácido Abscísico/metabolismo , Ácido Aminolevulínico/farmacología , Ácido Aminolevulínico/metabolismo , Plantones/metabolismo , Clorofila/metabolismo , Hojas de la Planta/metabolismo
9.
Crit Rev Eukaryot Gene Expr ; 32(6): 21-31, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35997115

RESUMEN

The objective of the study was to explore the role of SDC1 in breast cancer cells. Our study also investigated the regulatory relationship between SDC1 and the microRNA (miRNA) miR-335-5p as well as the impact of these two genes on the progression of breast cancer. Bioinformatic approaches were employed to analyze the differentially expressed messenger RNAs (mRNAs) and miRNAs (DE-mRNAs and DE-miRNAs) in breast cancer tissue. Then mRNA SC1 was obtained. Differentially downregulated mRNAs were intersected with target miRNAs predicted by databases, and miR-335-5p was determined as the study object. Quantitative reverse transcription polymerase chain reaction was applied to assess the expressions of SDC1 and miR-335-5p in each cell line. Next, Western blot assay was conducted to detect the protein level of SDC1 and dual-luciferase assay was performed to verify the binding relationship between miR-335-5p and SDC1. Finally, we conducted methyl thiazolyl tetrazolium (MTT), colony formation, and Transwell assays and flow cytometry to further investigate the impacts of SDC1 and miR-335-5p on the progression of breast cancer. SDC1 was significantly highly expressed while miR-335-5p was remarkably lowly expressed in human breast cancer. Silencing SDC1 in breast cancer blocked the proliferation, migration and invasion of the cells. In breast cancer, SDC1 was a target gene of miR-335-5p and silencing miR-335-5p notably increased SDC1 expression. Compared with the silence of miR-335-5p, simultaneous silences of miR-335-5p and SDC1 significantly reduced the proliferative, migratory and invasive abilities of breast cancer cells. The result revealed the interaction between miR-335-5p and SDC1 in the progression of breast cancer, which may contribute to the treatments for this cancer.


Asunto(s)
Neoplasias de la Mama , MicroARNs , Sindecano-1 , Neoplasias de la Mama/genética , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Femenino , Humanos , MicroARNs/genética , Invasividad Neoplásica/genética , Sindecano-1/genética
10.
J Synchrotron Radiat ; 29(Pt 2): 386-392, 2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-35254301

RESUMEN

X-ray microscopes are powerful tools in the nano-inspection of materials owing to their ultra-high resolution at the molecular level. However, the focusing efficiency of binary zone plate lenses as key components in such probes is merely 5% in practice, hindering their application in advanced scientific research. Although kinoform zone plate lenses are in principle supposed to possess high efficiency beyond binary ones, little progress has been reported so far due to the shortage of both a theoretical calculation approach and greyscale lithography for generating fine three-dimensional (3D) kinoform zones of the lenses. This paper reports our theoretical work for a modified beam propagation method to compute the focusing performance and state-of-the-art 3D greyscale electron beam lithography for kinoform zone plate lenses. Three different zone shapes - binary, kinoform and top-flat kinoform (nicknamed the trapezoid-kinoform) - were compared both theoretically and experimentally. Theoretical calculations suggest, for the first time, that the trapezoid-kinoform zone plate gives rise to the highest focusing efficiency among the three lenses, which was proved by optical characterization of the fabricated lens with hard X-rays. As high as 40% of the focusing efficiency by Au trapezoid-kinoform lenses with resolution of 250 nm at 8 keV has been achieved, which is two times higher than that of binary zone plate lenses. The origin of the enhanced efficiency in the trapezoid-kinoform zone plate lens was explained by the joint contributions from both the refraction through the kinoform slope and the diffraction through the top flat part of the trapezoid-kinoform zone plate. Such a breakthrough in focusing efficiency sheds light on the further development of X-ray lenses with both high resolution and high efficiency.

11.
Ecotoxicol Environ Saf ; 231: 113173, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35007830

RESUMEN

A growing body of evidence associated particulate matter (PM) exposure with lipid metabolism disorders, yet, the underlying mechanism remains to be elucidated. Among the major lipid metabolism modulators, peroxisome proliferator-activated receptor (PPAR) alpha plays an important role. In the current study, an individually ventilated cage (IVC) system was used to expose C57/B6 mice to real-ambient PM for six weeks, with or without co-treatment of PPAR alpha agonist WY14,643. The general parameters, liver and adipose tissue pathology, serum lipids, metal deposition and lipid profile of liver were assessed. The results indicated that six weeks of real-ambient PM exposure induced dyslipidemia, including increased serum triglycerides (TG) and decreased high density lipoprotein cholesterol (HDL-C) level, along with steatosis in liver, increased size of adipocytes in white adipose tissue (WAT) and whitening of brown adipose tissue (BAT). ICP-MS results indicated increased Cr and As deposition in liver. Lipidomics analysis revealed that glycerophospholipids and cytochrome P450 pathway were most significantly affected by PM exposure. Several lipid metabolism-related genes, including CYP4A14 in liver and UCP1 in BAT were downregulated following PM exposure. WY14,643 treatment alleviated PM-induced dyslipidemia, liver steatosis and whitening of BAT, while enhancing CD36, SLC27A1, CYP4A14 and UCP1 expression. In conclusion, PPAR alpha pathway participates in PM-induced lipid metabolism disorder, PPAR alpha agonist WY14,643 treatment exerted protective effects on PM-induced dyslipidemia, liver steatosis and whitening of BAT, but not on increased adipocyte size of WAT.


Asunto(s)
Trastornos del Metabolismo de los Lípidos , PPAR alfa , Tejido Adiposo Pardo/metabolismo , Animales , Metabolismo de los Lípidos , Trastornos del Metabolismo de los Lípidos/metabolismo , Ratones , PPAR alfa/genética , PPAR alfa/metabolismo , Material Particulado/metabolismo , Proliferadores de Peroxisomas/metabolismo , Proliferadores de Peroxisomas/farmacología
12.
Angew Chem Int Ed Engl ; 61(16): e202115552, 2022 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-35112438

RESUMEN

Improving the reversibility of oxygen redox is quite significant for layered oxides cathodes in sodium-ion batteries. Herein, we for the first time simultaneously tune bulk O2 and nonbonding oxygen state for reversible oxygen redox chemistry in P2-Na0.67 Mn0.5 Fe0.5 O2 through a synergy of Li2 TiO3 coating and Li/Ti co-doping. O2- is oxidized to molecular O2 and peroxide (O2 )n- (n<2) during charging. Molecular O2 derived from transition metal (TM) migration is related to the superstructure ordering induced by Li doping. The synergy mechanism of Li2 TiO3 coating and Li/Ti co-doping on the two O-redox modes is revealed. Firstly, Li2 TiO3 coating restrains the surface O2 and inhibits O2 loss. Secondly, nonbonding Li-O-Na enhances the reversibility of O2- →(O2 )n- . Thirdly, Ti doping strengthens the TM-O bond which fixes lattice oxygen. The cationic redox reversibility is also enhanced by Li/Ti co-doping. The proposed insights into the oxygen redox reversibility are insightful for other oxide cathodes.

13.
J Synchrotron Radiat ; 28(Pt 2): 512-517, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33650564

RESUMEN

Scanning mode is a key factor for the comprehensive performance, including imaging efficiency, of scanning transmission X-ray microscopy (STXM). Herein is presented a bidirectional scanning method designed for STXM with an S-shaped moving track. In this method, artificially designed ramp waves are generated by a piezo-stage controller to control the two-dimensional scanning of the sample. The sample position information is measured using laser interferometric sensors and sent to a field-programmable gate array (FPGA) board which also acquires the X-ray signals simultaneously from the detector. Since the data recorded by the FPGA contain the real position of each scanned point, the influence of the backlash caused by the back-turning movement on the STXM image can be eliminated. By employing an adapted post-processing program, a re-meshed high-resolution STXM image can be obtained. This S-track bidirectional scanning method in fly-scan mode has been implemented on the STXM endstation at the Shanghai Synchrotron Radiation Facility (SSRF), and successfully resolved the ∼30 nm interval between the innermost strips of a Siemens star. This work removes the limitation on bidirectional scanning caused by motor backlash and vibration, and significantly improves the efficiency of STXM experiments.

14.
J Synchrotron Radiat ; 28(Pt 3): 924-929, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33950000

RESUMEN

The three-dimensional (3D) dual-energy focal stacks (FS) imaging method has been developed to quickly obtain the spatial distribution of an element of interest in a sample; it is a combination of the 3D FS imaging method and two-dimensional (2D) dual-energy contrast imaging based on scanning transmission soft X-ray microscopy (STXM). A simulation was firstly performed to verify the feasibility of the 3D elemental reconstruction method. Then, a sample of composite nanofibers, polystyrene doped with ferric acetylacetonate [Fe(acac)3], was further investigated to quickly reveal the spatial distribution of Fe(acac)3 in the sample. Furthermore, the data acquisition time was less than that for STXM nanotomography under similar resolution conditions and did not require any complicated sample preparation. The novel approach of 3D dual-energy FS imaging, which allows fast 3D elemental mapping, is expected to provide invaluable information for biomedicine and materials science.

15.
Opt Express ; 29(11): 16214-16227, 2021 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-34154189

RESUMEN

Multi-slice ptychography (MSP) is a fast three-dimensional ptychography technology developed on the basis of conventional ptychography. With this method, three-dimensional imaging can be achieved without rotating the sample. The prototype multi-slice algorithm can only reconstruct three-dimensional samples with a limited number of slices, which greatly limits the depth range and resolution of sample imaging. Here we reported a virtual depth-scan scheme of MSP in which a thick sample is scanned virtually in the depth direction across its whole thickness range within the reconstruction process, thereby eliminating the restriction on slice number and potentially improving the depth resolution of MSP. This new approach also improves the flexibility of multi-slice ptychography. Both the simulation and experimental results validate the feasibility of our new approach.

16.
Proc Natl Acad Sci U S A ; 115(29): E6880-E6889, 2018 07 17.
Artículo en Inglés | MEDLINE | ID: mdl-29959210

RESUMEN

Changes in external light patterns can alter cell activities in peripheral tissues through slow entrainment of the central clock in suprachiasmatic nucleus (SCN). It remains unclear whether cells in otherwise photo-insensitive tissues can achieve rapid responses to changes in external light. Here we show that light stimulation of animals' eyes results in rapid activation of hair follicle stem cells with prominent hair regeneration. Mechanistically, light signals are interpreted by M1-type intrinsically photosensitive retinal ganglion cells (ipRGCs), which signal to the SCN via melanopsin. Subsequently, efferent sympathetic nerves are immediately activated. Increased norepinephrine release in skin promotes hedgehog signaling to activate hair follicle stem cells. Thus, external light can directly regulate tissue stem cells via an ipRGC-SCN autonomic nervous system circuit. Since activation of sympathetic nerves is not limited to skin, this circuit can also facilitate rapid adaptive responses to external light in other homeostatic tissues.


Asunto(s)
Folículo Piloso/metabolismo , Luz , Vías Nerviosas/metabolismo , Células Ganglionares de la Retina/metabolismo , Células Madre/metabolismo , Núcleo Supraquiasmático/metabolismo , Animales , Folículo Piloso/citología , Ratones , Ratones Transgénicos , Vías Nerviosas/citología , Células Ganglionares de la Retina/citología , Células Madre/citología , Núcleo Supraquiasmático/citología
17.
Opt Express ; 27(26): 37667-37679, 2019 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-31878544

RESUMEN

A novel membrane-based tunable liquid aspherical lens design capable of dynamically reducing spherical aberration over certain focal length tuning range is presented. Different from conventional treatment using elastic membrane with uniform thickness, in current case, the membrane's cross-section is designed to be a plano-convex shape with well-defined aspherical contour. A brand new design flow combining optical ray-tracing and mechanical finite element analysis is especially developed, in which through properly selecting the initial focal length and the center membrane thickness with respect to particularly designed figure of merit (FOM), the membrane can be flexibly optimized to achieve dynamic spherical aberration correction capability over the desired focal length range. For proof of concept demonstration, a tunable aspherical lens with clear aperture of 4 mm is designed. Compared with conventional counterpart, after being individually optimized using current design strategy, lenses with distinctly reduced spherical aberration have been successfully achieved over different focal length tuning ranges. Besides, no special refractive index matching between the filling liquid and the membrane is required, making current design more practical in real applications.

18.
Opt Express ; 27(5): 7787-7802, 2019 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-30876336

RESUMEN

Focal stack (FS) is an effective technique for fast 3D imaging in high-resolution scanning transmission X-ray microscopy. Its crucial issue is to assign each object within the sample to the correct position along the optical axis according to a proper focus measure. There is probably information loss with previous algorithms for FS reconstruction because the old algorithms can only detect one focused object along each optical-axial pixel line (OAPL). In this study, we present an improved FS algorithm, which utilizes an elaborately calculated threshold for normalized local variances to extract multiple focused objects in each OAPL. Simulation and experimental results show its feasibility and high efficiency for 3D imaging of high contrast, sparse samples. It is expected that our advanced approach has potential applications in 3D X-ray microscopy for more complex samples.

19.
Appl Opt ; 57(22): 6527-6533, 2018 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-30117891

RESUMEN

Coherent diffractive imaging (CDI) is a lensless, high-resolution imaging method that is currently under rapid development by using X-rays, visible light, or electrons. However, its inherent ambiguities and the need of a priori knowledge about objects are limiting applications based on this method. By combining a conventional CDI method with the basic idea of ptychography, the method of spatially correlated CDI, a method fit for multiple sample imaging in single-shot mode, is proposed to enhance the robustness of CDI. In this method, a strong spatial relevancy is built by introducing the same region into each sample, which establishes a strong real-space constraint for image reconstruction. Both simulations and visible-light experiments demonstrated the good imaging quality and robustness of this method, which does not need tight supports.

20.
Plant Cell ; 26(8): 3387-402, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25096783

RESUMEN

Potassium (K(+)) is one of the essential nutrient elements for plant growth and development. Plants absorb K(+) ions from the environment via root cell K(+) channels and/or transporters. In this study, the Shaker K(+) channel Os-AKT1 was characterized for its function in K(+) uptake in rice (Oryza sativa) roots, and its regulation by Os-CBL1 (Calcineurin B-Like protein1) and Os-CIPK23 (CBL-Interacting Protein Kinase23) was investigated. As an inward K(+) channel, Os-AKT1 could carry out K(+) uptake and rescue the low-K(+)-sensitive phenotype of Arabidopsis thaliana akt1 mutant plants. Rice Os-akt1 mutant plants showed decreased K(+) uptake and displayed an obvious low-K(+)-sensitive phenotype. Disruption of Os-AKT1 significantly reduced the K(+) content, which resulted in inhibition of plant growth and development. Similar to the AKT1 regulation in Arabidopsis, Os-CBL1 and Os-CIPK23 were identified as the upstream regulators of Os-AKT1 in rice. The Os-CBL1-Os-CIPK23 complex could enhance Os-AKT1-mediated K(+) uptake. A phenotype test confirmed that Os-CIPK23 RNAi lines exhibited similar K(+)-deficient symptoms as the Os-akt1 mutant under low K(+) conditions. These findings demonstrate that Os-AKT1-mediated K(+) uptake in rice roots is modulated by the Os-CBL1-Os-CIPK23 complex.


Asunto(s)
Proteínas de Unión al Calcio/fisiología , Oryza/metabolismo , Proteínas de Plantas/fisiología , Canales de Potasio/fisiología , Potasio/metabolismo , Proteínas Serina-Treonina Quinasas/fisiología , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/fisiología , Proteínas de Unión al Calcio/genética , Proteínas de Unión al Calcio/metabolismo , Prueba de Complementación Genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raíces de Plantas/metabolismo , Canales de Potasio/química , Canales de Potasio/genética , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/genética , Interferencia de ARN , Nicotiana/genética , Levaduras/genética
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