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1.
Opt Express ; 32(9): 16455-16466, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38859271

RESUMEN

Novel evanescently coupled waveguide modified uni-traveling carrier photodiodes (MUTC-PDs) employing a thick multi-layer coupling waveguide are reported. To improve the optical-to-electrical (O/E) conversion efficiency, a thick multi-layer coupling waveguide with a gradually increased refractive index from the bottom layer to the absorption layer is utilized. The refractive index profile facilitates the upward transmission of incident light into the absorption region, thereby enhancing the evanescent coupling efficiency. Meanwhile, the coupling waveguide, with a total thickness of 1.75 µm, expands the mode field diameter, thereby reducing the input coupling loss. Additionally, the top layer of the coupling waveguide also serves as the drift layer. This configuration facilitates efficient light absorption within a short PD length, thus ensuring ultrawide bandwidth and high O/E conversion efficiency simultaneously. Without an additional spot size coupler or anti-reflection coating, the measured responsivity is as high as 0.38 A/W for the PD with an active area of 5 × 6 µm2. Meanwhile, an ultrawide 3-dB bandwidth of 153 GHz has been demonstrated.

2.
Opt Express ; 31(19): 30066-30078, 2023 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-37710557

RESUMEN

The ray-mapping method has been widely used for designing freeform illumination lenses. However, in non-paraxial or off-axis situations, it remains challenging to obtain an integrable ray-mapping, often requiring a complex iterative correction process for the initial mapping. To address this challenge, we propose an extended ray-mapping method that incorporates differentiable ray-tracing into the design pipeline of the ray-mapping method. This enables accurate surface construction according to ray-mapping and efficient shape correction based on irradiance distribution. The proposed method involves two optimization stages. In the first stage, the freeform surface is preliminarily optimized to closely match the optimal transport mapping. The obtained freeform surface is then further optimized in the second stage to minimize the divergence between the target and simulated irradiance distributions. Additionally, the mean curvature of the freeform surface is also constrained in the second stage to facilitate the fabrication of the final freeform surface. Non-paraxial illumination lenses and off-axis illumination lenses have been designed using the proposed method within ten minutes, and simulations demonstrate that the approach is effective and robust.

3.
J Opt Soc Am A Opt Image Sci Vis ; 40(6): 1107-1115, 2023 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-37706764

RESUMEN

Surface defect identification plays a vital role in defective component rapid screening tasks in optics-related industries. However, the weakness and complexity of optical surface defects pose considerable challenges to their effective identification. To this end, a deep network based on multi-scale mixed kernels and structural re-parameterization is proposed to identify four manufacturing and two non-manufacturing optical surface defects. First, we design a multi-size mixed convolutional kernel with multiple receptive fields to extract rich shallow features for characterizing the defects with varying scales and irregular shapes. Then, we design an asymmetric mixed kernel integrating square, horizontal, vertical, and point convolutions to capture rotationally robust middle-and-deep features. Moreover, a structural re-parameterization strategy is introduced to equivalently convert the multi-branch architecture in the training phase into a deploy-friendly single-branch architecture in the inference phase, so that the model can obtain higher inference speed without losing any performance. Experiments on an optical surface defect dataset demonstrate that the proposed method is efficient and effective. It achieves a remarkable accuracy of 97.39% and an ultra-fast inference speed of 201.76 frames/second with only 5.23M parameters. Such a favorable accuracy-speed trade-off is capable of meeting the requirements of real-world optical surface defect identification applications.

4.
Opt Express ; 31(15): 23790-23800, 2023 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-37475221

RESUMEN

Novel back-illuminated modified uni-traveling-carrier photodiodes (MUTC-PDs) with wide bandwidth and high saturation power are demonstrated. The effect of cliff layer doping on the electric field distribution is investigated to achieve fast carrier transport. MUTC-PDs with miniaturized device diameter and low contact resistance are fabricated to improve the RC-limited bandwidth. Meanwhile, inductive peaking is implemented to further extend the bandwidth. PDs with 3-µm and 3.6-µm-diameter exhibit a ultrawide bandwidth of 230 GHz and 200 GHz, together with -4.94 dBm and -2.14 dBm saturation power at 220 GHz and 200 GHz, respectively.

5.
Biomark Med ; 17(8): 407-415, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37522177

RESUMEN

Aim: To explore the clinical implication of serum CDC42 in asthmatic children. Materials & methods: Serum CDC42 from 80 asthmatic children experiencing exacerbation, 80 asthmatic children in remission and 40 healthy controls was detected by ELISA. Results: CDC42 was highest in asthmatic children experiencing exacerbation followed by asthmatic children in remission and healthy controls (p < 0.001). Among asthmatic children experiencing exacerbation, CDC42 positively correlated with exacerbation severity (p = 0.011), Th2 (p = 0.017), TNF-α (p < 0.001), IL-6 (p = 0.009) and IL-8 (p = 0.008) and negatively correlated with Th1/Th2 ratio (p = 0.028). In asthmatic children in remission, CDC42 correlated with lower Th1/Th2 ratio (p = 0.028) and higher TNF-α (p = 0.026). In healthy controls, CDC42 showed no correlation with Th1/2 or inflammatory cytokines. Conclusion: Circulating CDC42 reflects exacerbation risk, Th1/2 imbalance and inflammation in asthmatic children.


Asunto(s)
Asma , Células Th2 , Humanos , Niño , Factor de Necrosis Tumoral alfa , Células TH1 , Citocinas , Inflamación
6.
Opt Lett ; 48(8): 2182-2185, 2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-37058672

RESUMEN

The dispersion characteristics of a microresonator are important for applications in nonlinear optics, and precise measurement of the dispersion profile is crucial to device design and optimization. Here we demonstrate the dispersion measurement of high-quality-factor gallium nitride (GaN) microrings by a single-mode fiber ring, which is simple and convenient to access. Once the dispersion parameters of the fiber ring have been determined by the opto-electric modulation method, the dispersion can be obtained from the microresonator dispersion profile by polynomial fitting. To further verify the accuracy of the proposed method, the dispersion of the GaN microrings is also evaluated with frequency comb-based spectroscopy. Dispersion profiles obtained with both methods are in good agreement with simulations based on the finite element method.

7.
Opt Express ; 30(13): 23260-23269, 2022 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-36225010

RESUMEN

A membrane multiple quantum well (MQW) electro-optical (EO) modulator exploiting low loss high-k radio-frequency (RF) slot waveguides is proposed for sub-terahertz bandwidth. By employing high-k barium titanate (BTO) claddings in place of doped InP cladding layers in traditional InP-based MQW modulators, the proposed modulator exhibits enhanced modulation efficiency and bandwidth as well as reduced insertion loss. A low half-wave voltage-length product of 0.24 V·cm is estimated, together with over 240 GHz bandwidth for a 2-mm-long modulation region, thus allowing sub-terahertz operation.

8.
Opt Express ; 30(16): 29216-29233, 2022 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-36299101

RESUMEN

Mid-spatial-frequency (MSF) errors seriously damages the imaging performance of optical components. Path pattern is an important factor that affects the generation of MSF waviness in polishing. This paper proposes a versatile pseudo random tree-shaped path (RTSP) generation method imitating the growth rules of tree branch in nature, which can efficiently generate continuous, uniformly distributed and multi-directional paths on a specified surface. Furthermore, the effectiveness of RTSP to suppress MSF waviness is verified by numerical simulation and experimental results. Finally, the RTSP is applied to the polishing of Ti-6Al-4V titanium alloy mirror. Results indicate that grinding marks have been significantly removed, while no obvious MSF waviness is introduced.

9.
J Healthc Eng ; 2022: 6220774, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35463694

RESUMEN

Children are the reserve force for national construction, and children's health is now being paid more and more attention. In today's childhood asthma treatment, many are based on the treatment of common cough, and there is no strict division with asthma. Importantly, the efficacy of inhaled corticosteroids in the treatment of childhood asthma has been extensively studied in the medical community. However, there is no clear explanation for its specific efficacy and role. Research on childhood asthma has always been a key topic in medicine. This article aims to conduct a meta-analysis of the correlation between inhaled corticosteroids and asthma in children. This article proposes a more scientific literature screening strategy, which can achieve a higher accuracy rate for meta-analysis. It combines the intelligent medical health system in the analysis of children's asthma to assist in the analysis of curative effects. Such analysis also provides reference significance for related research. The experimental results indicate that inhaled corticosteroids have a good effect on childhood asthma. As the concentration of inhaled glucocorticoid increases, the effect will be better. Specifically, if the concentration is increased by 10%, the effect will be about 15% better, but there are corresponding side effects.


Asunto(s)
Antiasmáticos , Asma , Administración por Inhalación , Corticoesteroides/uso terapéutico , Antiasmáticos/uso terapéutico , Asma/tratamiento farmacológico , Niño , Humanos
10.
Artículo en Inglés | MEDLINE | ID: mdl-34463232

RESUMEN

BACKGROUND: Premature ovarian failure (POF) refers to pathological amenorrhea before 40 years. OBJECTIVE: To explore the regulatory effect of Rg1 on POF and clarify associated mechanisms. MATERIALS AND METHODS: POF mice were induced by injecting with D-galactose (D-gal, 200 mg/kg/- day). Mice were divided into phosphate buffered saline (PBS), D-gal (POF mice), D-gal/Rg1 group (POF mice administrating D-gal/Rg1). Weight growth rate and ovarian weight coefficient were measured. Serum estradiol (E2), follicle stimulating hormone (FSH), luteinizing hormone (LH), superoxide dismutase (SOD), catalase (CAT) levels were examined using ELISA. The status of follicle and corpus luteum was determined using hematoxylin-eosin (HE) staining. P16INK4a and silent- mating type information regulation-2 homolog-1 (SIRT1) were determined using western blotting and RT-PCR. RESULTS: Weight growth rate and ovarian weight coefficient of mice in D-gal group were significantly decreased than PBS group (p<0.05). Serum E2, LH, SOD, CAT levels were significantly decreased, FSH levels were remarkably increased in D-gal group than PBS group (p<0.05). Rg1 (D-- gal/Rg1 group) significantly increased weight growth rate and ovarian weight coefficient, enhanced E2, LH, SOD, CAT levels and decreased FSH levels than D-gal group (p<0.05). HE staining demonstrated normal follicle morphology/structure of mice in PBS group and decreased the number of follicles, obvious vacuolation of corpus luteum and increased atretic follicles of mice in D-gal group. Compared with D-gal group, the number of follicles was increased, luteal follicles were decreased in mice in D-gal/Rg1 group (p<0.05). Rg1 significantly (D-gal/Rg1) downregulated p16INK4a and upregulated SIRT1 expression in ovarian tissues of mice compared to the D-gal group (p<0.05). CONCLUSION: Rg1 could delay premature ovarian failure in D-gal induced POF mouse model through downregulating p16INK4a and upregulating SIRT1 expression.


Asunto(s)
Insuficiencia Ovárica Primaria , Animales , Femenino , Hormona Folículo Estimulante , Ginsenósidos , Humanos , Hormona Luteinizante , Ratones , Insuficiencia Ovárica Primaria/inducido químicamente , Insuficiencia Ovárica Primaria/tratamiento farmacológico , Insuficiencia Ovárica Primaria/metabolismo , Sirtuina 1 , Superóxido Dismutasa
11.
J Healthc Eng ; 2021: 5317403, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34721824

RESUMEN

CT image information data under deep learning algorithms was adopted to evaluate small airway function and analyze the clinical efficacy of different glucocorticoid administration ways in asthmatic children with small airway obstruction. The Res-NET in the deep learning algorithm was used to perform feature extraction, summary classification, and other reconstruction of CT images. A deep learning network model Mask-R-CNN was constructed to enhance the ability of image reconstruction. A total of 118 children hospitalized with acute exacerbation of asthma in the hospital were recruited. After acute exacerbation treatment, 96 children with asthma were screened out for small airway obstruction, which were divided into glucocorticoid aerosol inhalation group (group A, 32 cases), glucocorticoid combined with bronchodilator aerosol inhalation group (group B, 32 cases), and oral hormone therapy group (group C, 32 cases). Asthmatic children with small airway obstruction were screened after acute exacerbation treatment and were rolled into glucocorticoid aerosol inhalation group (group A), glucocorticoid combined with bronchodilators aerosol inhalation group (group B), and oral hormone therapy group (group C). Lung function indicators (maximal mid-expiratory flow (MMEF75 and 25), 50% forced expiratory flow (FEF50), and 75% forced expiratory flow (FEF75)), FeNO level, and airway inflammation indicators (IL-6, IL-35, and eosinophilic (EOS)) were compared before and one month after treatment. The ratio of airway wall thickness to outer diameter (T/D) and the percentage of airway wall area to total airway area (WA%) were measured by e-Health high-resolution CT (HRCT). The constructed network model was used to measure the patient's coronary artery plaque and blood vessel volume, and the image was reconstructed on the Res-Net network. It was found that the MSE value of the Res-Net network was the lowest, and the efficiency was very high during the training process. T/D and WA (%) of asthmatic children with small airway obstruction after treatment were significantly lower than those before treatment (P < 0.01). After treatment, MMEF75/25 and FEF75 were significantly higher than those before treatment (P < 0.05). Lung function-related indicator FEF50 was significantly higher than that before treatment (P < 0.01). FeNO level after treatment was remarkably lower than that before treatment (P < 0.01). In addition, lung function-related indicators, airway inflammation indicators, and FeNO level improved the most in group C, followed by group B, and those improvements in group A were the least obvious, with great differences among groups (P < 0.05). In summary, the Res-Net model proposed was of certain feasibility and effectiveness for CT image segmentation and can effectively improve the clinical evaluation of patient CT image information. Glucocorticoids could improve small airway function and airway inflammation in asthmatic children with small airway obstruction, and oral corticosteroids were more effective than aerosol inhalation therapy.


Asunto(s)
Obstrucción de las Vías Aéreas , Asma , Aprendizaje Profundo , Obstrucción de las Vías Aéreas/diagnóstico por imagen , Obstrucción de las Vías Aéreas/tratamiento farmacológico , Algoritmos , Asma/diagnóstico por imagen , Asma/tratamiento farmacológico , Niño , Glucocorticoides , Humanos , Tomografía Computarizada por Rayos X
12.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 43(5): 706-715, 2021 Oct.
Artículo en Chino | MEDLINE | ID: mdl-34728031

RESUMEN

Objective To establish a human colon cancer cell line HCT-116/5-FU resistant to 5-fluorouracil(5-FU)and explore the relationship between runt-related transcription factor 3(RUNX3)and drug resistance of colorectal cancer.Methods The human colon cancer cell line HCT-116/5-FU with resistance to 5-FU was established by low concentration gradient increment combined with high-dose intermittent shock.CCK-8 method was used to determine the half maximal inhibitory concentration(IC50)of 5-FU on the parent line HCT-116 and drug-resistant line HCT-116/5-FU.The cell growth curve was established for the calculation of population doubling time(TD).The mRNA levels and protein levels of RUNX3,P-glycoprotein(P-gp),multidrug resistance-associated protein 1(MRP1),and lung resistance-related protein(LRP)in HCT-116 and HCT-116/5-FU cells were determined by qRT-PCR and Western blotting,respectively.The RUNX3 expression in HCT-116 cells was knocked down by siRNA technique,and the cells were divided into RUNX3 knockdown groups(si-RUNX3-1 group and si-RUNX3-2 group)and negative control group(si-NC group).The knockdown efficiency was verified by qRT-PCR at the mRNA level and Western blotting at the protein level.The IC50 in si-RUNX3 groups and si-NC group was determined with CCK-8 method,and the expression of P-gp,MRP1,and LRP in the two groups was detected by Western blotting.Results A stable human colon cancer drug-resistant cell line HCT-116/5-FU was successfully constructed.HCT-116/5-FU showed the TD 1.38 times as long as that of HCT-116(P=0.002)and changed morphology.The mRNA level of RUNX3 in HCT-116/5-FU cells was significantly lower than that in HCT-116 cells(P=0.048),and those of P-gp(P=0.008),MRP1(P=0.001),and LRP(P=0.001)showed the opposite trend.The protein level of RUNX3 in HCT-116/5-FU cells was significantly lower than that in HCT-116(P<0.001),and those of P-gp,MRP1,and LRP presented the opposite trend(all P<0.001).The HCT-116 cell model with low expression of RUNX3 was successfully established.The mRNA level of RUNX3 had no significant difference between si-RUNX3-1 group and si-NC group(P=0.064),while the level in si-RUNX3-2 group was significantly lower than that in si-NC group(P=0.034).The protein levels of RUNX3 in si-RUNX3-1 group and si-RUNX3-2 group were lower than that in si-NC group(both P<0.001).The results demonstrated higher knocking efficiency in si-RUNX3-2 group,which was thus selected to complete the follow-up test.The IC50 of si-RUNX3 group was significantly higher than that of si-NC group(P<0.001),which indicated that the down-regulated expression of RUNX3 could reduce the sensitivity of HCT-116 cells to 5-FU.The relative protein levels of P-gp,MRP1,and LRP in si-RUNX3 group were significantly higher than those in si-NC group(all P<0.001).Conclusion The down-regulation of RUNX3 expression can reduce the sensitivity of HCT-116 cells to 5-FU,which is considered to be related to the up-regulated expression of P-gp,MRP1,and LRP.


Asunto(s)
Neoplasias del Colon , Factor de Transcripción 3 , Línea Celular Tumoral , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/genética , Subunidad alfa 3 del Factor de Unión al Sitio Principal , Resistencia a Antineoplásicos , Fluorouracilo/farmacología , Humanos
13.
Opt Express ; 29(19): 29802-29812, 2021 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-34614718

RESUMEN

Pseudo-random paths are a useful tool to reduce mid-spatial frequency errors created in the processing of optical surfaces by sub-aperture polishing tools. Several types of patterns have been proposed, including hexagonal, square and circular, but prior literature has largely focused on flat and gently curved surfaces. Here, an extension of the circular-random path to strongly curved aspheric and freeform surfaces is proposed. The main feature of the algorithm is to cover the entire surface to be polished with a uniformly distributed tool path. Aspheric condenser lenses are then polished with a regular raster and circular-random path. Analysis of the optical performance shows that the random path can reduce the amplitude of mid-spatial frequency errors and relative intensity of satellite images. These features are particularly desirable in short wavelength applications, such as mirrors for EUV and X-ray.

14.
Proc Natl Acad Sci U S A ; 118(18)2021 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-33903240

RESUMEN

Inorganic semiconductor-based microscale light-emitting diodes (micro-LEDs) have been widely considered the key solution to next-generation, ubiquitous lighting and display systems, with their efficiency, brightness, contrast, stability, and dynamic response superior to liquid crystal or organic-based counterparts. However, the reduction of micro-LED sizes leads to the deteriorated device performance and increased difficulties in manufacturing. Here, we report a tandem device scheme based on stacked red, green, and blue (RGB) micro-LEDs, for the realization of full-color lighting and displays. Thin-film micro-LEDs (size ∼100 µm, thickness ∼5 µm) based on III-V compound semiconductors are vertically assembled via epitaxial liftoff and transfer printing. A thin-film dielectric-based optical filter serves as a wavelength-selective interface for performance enhancement. Furthermore, we prototype arrays of tandem RGB micro-LEDs and demonstrate display capabilities. These materials and device strategies provide a viable path to advanced lighting and display systems.

15.
Appl Opt ; 60(8): 2177-2189, 2021 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-33690313

RESUMEN

Nonmechanical beam-steering devices are of importance to achieve fast, compact, and reliable LiDAR. We propose a 2D nonmechanical beam-steering device based on a virtually imaged phased array (VIPA) for frequency-modulated continuous-wave (FMCW) LiDAR. In the design, 2D nonmechanical beam steering and high-resolution FMCW ranging can be achieved at the same time by wavelength tuning. The design formulas of the VIPA-based 2D disperser are greatly simplified by introducing appropriate approximation, and a feasible design procedure is proposed for the first time, to the best of our knowledge. Based on the proposed method, several design examples with different optimal properties are exhibited.

16.
Opt Express ; 29(5): 7049-7059, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33726213

RESUMEN

A waveguide-based multi-beam steering device is proposed for light detection and ranging (LIDAR). The device integrates binary gratings with an optical phased array (OPA), thus enabling a single-chip LIDAR system. The device can provide an N×M beam array that covers a wide angular range while phase shifters help realize steering over a narrow angle range between the beams. The antenna structure for 1D beam splitting is realized by combining the design of a grating coupler and a beam splitter grating, and a uniform beam splitting is achieved along the other dimension using non-uniformly distributed antennas. To illustrate the design, an OPA with an 11×11 beam array is designed at a wavelength of 905 nm. The OPA achieves a wide total field of view (FOV) of 68.8° × 77° with a narrow beam-array-steering angle of 6.5°, enabling a wide-FOV 3D sensing with a high frame rate.

17.
Ir J Med Sci ; 190(3): 1079-1085, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33156444

RESUMEN

BACKGROUND: This study aimed to investigate the correlation of JNK pathway-associated phosphatase (JKAP) with clinical features, inflammation, exacerbation risk, and severity in asthmatic children. METHODS: Asthmatic exacerbation children (N = 90), asthmatic remission children (N = 90), and healthy controls (N = 90) were enrolled in this case-control study, whose venous blood samples were collected after enrollment for routine blood test, JKAP, and inflammatory cytokines detection by enzyme-linked immune sorbent assay. The clinical features included demographic data, family history of asthma, and pulmonary ventilation function. RESULTS: JKAP level was the lowest in asthmatic exacerbation children, followed by asthmatic remission children and healthy controls. ROC curve revealed good ability of JKAP in distinguishing three groups from each other, especially in telling asthmatic exacerbation children from healthy controls (AUC: 0.926; 95%CI: 0.887-0.965). In addition, JKAP was negatively correlated with eosinophil count, immunoglobulin E (IgE), tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1ß), interleukin-6 (IL-6), and interleukin-17 (IL-17), positively correlated with forced expiratory volume in 1 sec/forced vital capacity (FEV1/FVC) and FEV1 (%predicted) in asthmatic exacerbation children. Whereas in asthmatic remission children, JKAP was negatively correlated with eosinophil count, TNF-α, IL-1ß, IL-6, and IL-17 and positively correlated with FEV1 (%predicted), but not with IgE or FEV1/FVC. In healthy controls, the correlation of JKAP with clinical features and inflammatory cytokines was non-obvious. For exacerbation severity, JKAP was the highest in mild exacerbation children, followed by moderate exacerbation children, and severe exacerbation children. CONCLUSION: JKAP serves as a potential biomarker for asthmatic susceptibility, inflammation, exacerbation risk, and severity in children.


Asunto(s)
Asma , Sistema de Señalización de MAP Quinasas , Estudios de Casos y Controles , Niño , Humanos , Inflamación , Monoéster Fosfórico Hidrolasas
18.
Nanomaterials (Basel) ; 10(11)2020 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-33233685

RESUMEN

GaN quantum dots embedded in nanowires have attracted much attention due to their superior optical properties. However, due to the large surface-to-volume ratio of the nanowire, the impacts of surface states are the primary issue responsible for the degradation of internal quantum efficiency (IQE) in heterostructured dot-in-nanowires. In this paper, we investigate the carrier recombination mechanism of GaN/AlN dot-in-nanowires with an in situ grown AlN shell structure. Ultraviolet photoelectron spectroscopy (UPS) measurements were performed to describe the band bending effect on samples with different shell thicknesses. Temperature-dependent photoluminescence (TDPL) data support that increasing the AlN shell thickness is an efficient way to improve internal quantum efficiency. Detailed carrier dynamics was analyzed and combined with time-resolved photoluminescence (TRPL). The experimental data are consistent with our physical model that the AlN shell can effectively flatten the band bending near the surface and isolate the surface non-radiative recombination center. Our systematic research on GaN/AlN quantum dots in nanowires with a core-shell structure may significantly advance the development of a broad range of nanowire-based optoelectronic devices.

19.
Opt Express ; 28(16): 24123-24135, 2020 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-32752398

RESUMEN

CCD arrays encode color information via uniformly distributed red, green and blue pixels. Therefore, even a perfectly achromatic system projecting an image onto a CCD plane cannot possibly associate a single object point with the 3 or more discrete pixels encoding color content. Here, we propose and demonstrate a micro-lens array (MLA) design that simultaneously corrects chromatic aberrations and separates color channels to spatially distinct pixels. Starting from a commercially available aspheric condenser lens, methods to design and assess the performance of a few microns deep MLA etched on the convex optical surface are detailed. Actual fabrication is carried out by fluid jet polishing, with an optical form deviation of 0.24 µm rms. Finally, the MLA is assessed with a narrowly collimated beam containing two wavelengths, which produces distinct spots of diameter 10-15 µm as expected.

20.
Med Sci Monit ; 26: e918207, 2020 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-32037392

RESUMEN

BACKGROUND Clinical relapse in acute myeloid leukemia (AML) is associated with the reduced treatment response of leukemia stem cells (LSCs). This study aimed to investigate the effects of the ginseng derivative, ginsenoside Rg1 (Rg1), on CD34+CD38- LSCs derived from KG1a human acute myeloid leukemia cells. MATERIAL AND METHODS CD34+CD38- LSCs were isolated from KG1a human acute myeloid leukemia cells by cell sorting. CD34+CD38- KG1alpha LSCs were divided into the control group and the Rg1 group (treated with Rg1). The cell counting kit-8 (CCK-8) assay evaluated the proliferation of CD34+CD38- KG1alpha LSCs and flow cytometry studied the cell cycle. The mixed colony-forming unit (CFU-Mix) assay and staining for senescence-associated beta-galactosidase (SA-ß-Gal) evaluated cell senescence. Expression of sirtuin 1 (SIRT1) and tuberous sclerosis complex 2 (TSC2) were evaluated using Western blot and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS CD34+CD38- KG1alpha LSCs were isolated at 98.72%. Rg1 significantly reduced the proliferation of CD34+CD38- KG1alpha LSCs compared with the control group (p<0.05). Cells in the G0/G1 phase were significantly increased, and cells in the G2/M and S phase were significantly reduced compared with the control group (p<0.05). Rg1 significantly increased SA-ß-Gal and reduced CFU-Mix formation compared with the control group (p<0.05), significantly down-regulated SIRT1 expression in CD34+CD38- KG1alpha LSCs compared with the control group (p<0.05), and significantly reduced TSC2 expression in CD34+CD38- KG1alpha LSCs compared with the control group (p<0.05). CONCLUSIONS Rg1 inhibited cell proliferation and induced cell senescence markers in CD34+CD38- KG1alpha LSCs by activating the SIRT1/TSC2 signaling pathway.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Senescencia Celular/efectos de los fármacos , Ginsenósidos/farmacología , Leucemia Mieloide Aguda/patología , Células Madre Neoplásicas/metabolismo , Transducción de Señal , Sirtuina 1/metabolismo , Esclerosis Tuberosa/metabolismo , ADP-Ribosil Ciclasa 1/metabolismo , Antígenos CD34/metabolismo , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Regulación hacia Abajo/efectos de los fármacos , Humanos , Leucemia Mieloide Aguda/metabolismo , Células Madre Neoplásicas/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , beta-Glucosidasa/metabolismo
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