Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 58
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Plant Cell ; 35(10): 3697-3711, 2023 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-37378548

RESUMEN

FLOWERING PROMOTING FACTOR1 (FPF1), a small protein without any known domains, promotes flowering in several plants; however, its functional mechanism remains unknown. Here, we characterized 2 FPF1-like proteins, FPL1 and FPL7, which, in contrast, function as flowering repressors in Brachypodium distachyon. FPL1 and FPL7 interact with the components of the florigen activation complex (FAC) and inhibit FAC activity to restrict expression of its critical target, VERNALIZATION1 (VRN1), in leaves, thereby preventing overaccumulation of FLOWERING LOCUS T1 (FT1) at the juvenile stage. Further, VRN1 can directly bind to the FPL1 promoter and repress FPL1 expression; hence, as VRN1 gradually accumulates during the late vegetative stage, FAC is released. This accurate feedback regulation of FPL1 by VRN1 allows proper FT1 expression in leaves and ensures sufficient FAC formation in shoot apical meristems to trigger timely flowering. Overall, we define a sophisticated modulatory loop for flowering initiation in a temperate grass, providing insights toward resolving the molecular basis underlying fine-tuning flowering time in plants.

2.
J Cell Sci ; 135(16)2022 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-35892293

RESUMEN

Stereocilia are F-actin-based protrusions on the apical surface of inner-ear hair cells and are indispensable for hearing and balance perception. The stereocilia of each hair cell are organized into rows of increasing heights, forming a staircase-like pattern. The development and maintenance of stereocilia are tightly regulated, and deficits in these processes lead to stereocilia disorganization and hearing loss. Previously, we showed that the F-BAR protein FCHSD2 is localized along the stereocilia of cochlear hair cells and cooperates with CDC42 to regulate F-actin polymerization and cell protrusion formation in cultured COS-7 cells. In the present work, Fchsd2 knockout mice were established to investigate the role of FCHSD2 in hearing. Our data show that stereocilia maintenance is severely affected in cochlear hair cells of Fchsd2 knockout mice, which leads to progressive hearing loss. Moreover, Fchsd2 knockout mice show increased acoustic vulnerability. Noise exposure causes robust stereocilia degeneration as well as enhanced hearing threshold elevation in Fchsd2 knockout mice. Lastly, Fchsd2/Cdc42 double knockout mice show more severe stereocilia deficits and hearing loss, suggesting that FCHSD2 and CDC42 cooperatively regulate stereocilia maintenance.


Asunto(s)
Proteínas Portadoras , Pérdida Auditiva , Proteínas de la Membrana , Estereocilios , Animales , Ratones , Actinas/metabolismo , Proteínas Portadoras/metabolismo , Células Ciliadas Auditivas/metabolismo , Pérdida Auditiva/metabolismo , Proteínas de la Membrana/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Estereocilios/metabolismo
3.
Plant Physiol ; 192(4): 2703-2722, 2023 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-37067917

RESUMEN

Alternative splicing (AS) is a gene regulatory mechanism that generates multiple transcripts of the same gene precursor by the spliceosome complex, promoting messenger RNA complexity, and proteome diversity. Although AS is extensively studied in response to environmental stresses, whether it mediates age-dependent development and how it is adjusted by growth transitions are largely unknown. Here, we comprehensively explored the AS landscape at different developmental stages in the grass model plant Brachypodium (Brachypodium distachyon). We identified abundant coding genes and noncoding transcripts subject to dynamic AS regulation during juvenile, adult, and reproductive transitions. Moreover, we revealed that SC35-LIKE SPLICING FACTOR 33 (SCL33), a serine/arginine-rich splicing factor in spliceosomes, plays a redundant and antagonistic role with its putative paralog, SCL33L, in regulating intron assembly across distinct developmental stages. In addition, we determined global AS variations in microRNA156 (miR156)-overproducing plants, in which growth transitions are delayed, and found that SPLs were regulated by miR156 in intron retention alteration in addition to mRNA clearance and translation inhibition manners. Finally, we demonstrated a complex regulatory process of age-dependent AS events in B. distachyon that was coincidently or separately regulated by miR156 and SCL33/SCL33L. These results illustrate a substantial machinery of AS that mediates phase transitions in plants.


Asunto(s)
Brachypodium , Brachypodium/genética , Empalme Alternativo/genética , Intrones , Factores de Empalme de ARN/genética , Regulación de la Expresión Génica de las Plantas
4.
Toxicol Appl Pharmacol ; 486: 116934, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38663673

RESUMEN

The development of diabetes mellitus (DM) is generally accompanied by erectile dysfunction (ED) and pulmonary arterial hypertension (PAH), which increases the use of combination drug therapy and the risk of drug-drug interactions. Saxagliptin for the treatment of DM, sildenafil for the treatment of ED and PAH, and macitentan for the treatment of PAH are all substrates of CYP3A4, which indicates their potential involvement in drug-drug interactions. Therefore, we investigated potential pharmacokinetic interactions between saxagliptin and sildenafil/macitentan. We investigated this speculation both in vitro and in vivo, and explored the underlying mechanism using in vitro hepatic metabolic models and molecular docking assays. The results showed that sildenafil substantially inhibited the metabolism of saxagliptin by occupying the catalytic site of CYP3A4 in a competitive manner, leading to the alterations in the pharmacokinetic properties of saxagliptin in terms of increased maximum plasma concentration (Cmax), area under the plasma concentration-time curve from time 0 to 24 h (AUC(0-t)), area under the plasma concentration-time curve from time 0 extrapolated to infinite time (AUC(0-∞)), decreased clearance rate (CLz/F), and prolonged terminal half-life (t1/2). In contrast, a slight inhibition was observed in saxagliptin metabolism when concomitantly used with macitentan, as no pharmacokinetic parameters were altered, except for CLz/F. Thus, dosage adjustment of saxagliptin may be required in combination with sildenafil to achieve safe therapeutic plasma concentrations and reduce the risk of potential toxicity, but it is not necessary for co-administration with macitentan.


Asunto(s)
Adamantano , Dipéptidos , Interacciones Farmacológicas , Pirimidinas , Citrato de Sildenafil , Sulfonamidas , Citrato de Sildenafil/farmacocinética , Citrato de Sildenafil/farmacología , Sulfonamidas/farmacocinética , Sulfonamidas/farmacología , Dipéptidos/farmacocinética , Dipéptidos/farmacología , Pirimidinas/farmacocinética , Pirimidinas/farmacología , Humanos , Adamantano/análogos & derivados , Adamantano/farmacocinética , Adamantano/farmacología , Masculino , Animales , Citocromo P-450 CYP3A/metabolismo , Simulación del Acoplamiento Molecular , Microsomas Hepáticos/metabolismo , Microsomas Hepáticos/efectos de los fármacos , Inhibidores de la Dipeptidil-Peptidasa IV/farmacocinética , Inhibidores de la Dipeptidil-Peptidasa IV/farmacología
5.
Chem Res Toxicol ; 37(7): 1171-1186, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38870402

RESUMEN

Exposure to anthropogenic aerosols has been associated with a variety of adverse health effects, increased morbidity, and premature death. Although cigarette smoke poses one of the most significant public health threats, the cellular toxicity of particulate matter contained in cigarette smoke has not been systematically interrogated in a size-segregated manner. In this study, we employed a refined particle size classification to collect cigarette aerosols, enabling a comprehensive assessment and comparison of the impacts exerted by cigarette aerosol extract (CAE) on SH-SY5Y, HEK293T, and A549 cells. Exposure to CAE reduced cell viability in a dose-dependent manner, with organic components having a greater impact and SH-SY5Y cells displaying lower tolerance compared to HEK293T and A549 cells. Moreover, CAE was found to cause increased oxidative stress, mitochondrial dysfunction, and increased levels of apoptosis, pyroptosis, and autophagy, leading to increased cell death. Furthermore, we found that rutin, a phytocompound with antioxidant potential, could reduce intracellular reactive oxygen species and protect against CAE-triggered cell death. These findings underscore the therapeutic potential of antioxidant drugs in mitigating the adverse effects of cigarette aerosol exposure for better public health outcomes.


Asunto(s)
Aerosoles , Supervivencia Celular , Tamaño de la Partícula , Material Particulado , Humanos , Material Particulado/toxicidad , Supervivencia Celular/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Nicotiana/química , Nicotiana/efectos adversos , Estrés Oxidativo/efectos de los fármacos , Productos de Tabaco/efectos adversos , Contaminación del Aire Interior/efectos adversos , Apoptosis/efectos de los fármacos
6.
Artículo en Inglés | MEDLINE | ID: mdl-38607209

RESUMEN

Background: Currently, there is a lot of discussion in clinical and scientific research over the best ways to delay meniscal degeneration and speed up its healing. Meniscal injury and degeneration are significant contributors to the development of knee osteoarthritis in a pathological state. Objective: To isolate, culture and characterize rat meniscal fibrochondrocytes in vitro, and to provide a simple and feasible cell culture method for the study of damage repair of rat meniscal fibrochondrocytes. Methods: The rat medial and lateral meniscus of both knees was surgically isolated. Trypsin and type II collagenase were used to remove the cells, and toluidine blue staining and type II collagen immunofluorescence were used to identify the cells. The cells were then routinely cultured in low-sugar DMEM complete culture medium. Results: At different time points, cells showed different physiological shapes, from polygonal or short spindle to spindle shape, and finally to triangle or ellipse, and cell proliferation ability gradually increased with time. The OD values of cells cultured at 48h and 72h were higher than those at 24h. Comparing OD values of cells cultured for 48h and 72h, although OD value of 72h increased. Toluidine blue staining and type I collagen immunofluorescence staining were positive. Conclusion: A more dependable technique for fibrochondrocyte isolation and culture is offered for the study of meniscus in molecular biology and tissue engineering. The cells cultured using this method are morphologically stable, have a strong proliferation ability, and possess the fundamental biological properties of fibrochondrocytes in vivo.

7.
J Opt Soc Am A Opt Image Sci Vis ; 40(12): 2146-2155, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-38086023

RESUMEN

In this paper, an optical color single-channel asymmetric cryptosystem based on the non-negative matrix factorization (NMF) and a face biometric in cyan-magenta-yellow-black (CMYK) space is proposed. To the best of our knowledge, this is the first time that NMF has been introduced into optical color image encryption. In the proposed cryptosystem, the color image in CMYK space is first decomposed into four color channels: C, M, Y, and K. By performing NMF operations on the four color channels, the four basic and sparse matrices can be obtained, respectively, which achieves asymmetry and saves computational resources. The four basis matrices can be used as private keys, and the four coefficient matrices are synthesized by the inverse discrete wavelet transform for subsequent encryption. Finally, the synthesized image is encoded with double random phase encoding based on phase truncation (PT). Compared with the existing PT-based cryptosystems, our cryptosystem can improve security against a special attack. In addition, the chaotic random phase mask is generated by a face biometric, which is noncontact and unique. Numerical simulation results are shown to verify the feasibility and robustness of our cryptosystem. Further, the proposed cryptosystem can be extended to encrypt multiple images conveniently.

8.
Appl Opt ; 62(3): 665-674, 2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36821270

RESUMEN

In this paper, we propose an asymmetric optical double-image cryptosystem based on generalized singular value decomposition (GSVD) and five-dimensional (5D) hyperchaotic maps. In the proposed cryptosystem, the two plain images are first decomposed into five components by the GSVD operation. The two unitary matrices obtained by GSVD are encoded as a complex function, which is then modulated by the chaotic random phase masks (CRPMs). The private key and the final encryption result are generated by phase-truncation and amplitude-truncation operations. The GSVD operation can decompose two images at the same time and is used to generate the private key that enables the encryption process to be asymmetric. Compared with the existing phase-truncated-based cryptosystems, our cryptosystem can improve security against a special attack. In addition, the CRPMs are generated by 5D hyperchaotic maps, which have a larger parameter space and better randomness. Numerical simulation results are shown to verify the feasibility and robustness of our cryptosystem. Furthermore, the proposed cryptosystem can be extended to encrypt multiple images conveniently.

9.
BMC Nephrol ; 24(1): 350, 2023 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-38031052

RESUMEN

BACKGROUND: Disability in activities of daily living (ADL) significantly increases the risk of mortality among patients undergoing hemodialysis. Malnutrition and decreased exercise capacity are closely correlated with ADL disability. Phase angle (PhA) has been proposed as a measure of nutritional status and exercise capacity. This study aims to investigate the prevalence of ADL disability in hemodialysis patients and its association with PhA. METHODS: A prospective, observational study was conducted, involving hemodialysis patients treated between November 2019 and January 2020 in an affiliated hospital of Chinese university. ADL was measured using both basic ADL (BADL) scales and instrumental ADL (IADL) scales. PhA measurements were obtained using a BIA device while the patients were in the supine position after dialysis. RESULTS: A total of 237 hemodialysis patients with a mean age of 60.01 ± 13.55 years were included in this study. The prevalence of disability in ADL was 43.5%. Multivariable analysis results showed a robust association between low PhA and disability in both BADL and IADL (for each unit decrease in PhA: odds ratio 4.83 [95% CI: 2.56-9.0], and 3.57 [95% CI: 2.14-5.95], respectively). The optimal cut-off values of PhA for disability in BADL and IADL were 4.8 and 5.4, with the area under the ROC curve (AUC) were 0.783 (0.727, 0.835) and 0.799 (0.743, 0.848), respectively. CONCLUSIONS: Low PhA is strongly associated with disability in ADL in hemodialysis patients. These findings suggest that PhA may serve as a potentially objective measure of ADL disability in hemodialysis patients.


Asunto(s)
Actividades Cotidianas , Personas con Discapacidad , Diálisis Renal , Anciano , Humanos , Persona de Mediana Edad , Estudios Prospectivos
10.
World Wide Web ; 26(1): 207-232, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35440889

RESUMEN

In recent years, artificial intelligence technologies have been successfully applied in time series prediction and analytic tasks. At the same time, a lot of attention has been paid to financial time series prediction, which targets the development of novel deep learning models or optimize the forecasting results. To optimize the accuracy of stock price prediction, in this paper, we propose a clustering-enhanced deep learning framework to predict stock prices with three matured deep learning forecasting models, such as Long Short-Term Memory (LSTM), Recurrent Neural Network (RNN) and Gated Recurrent Unit (GRU). The proposed framework considers the clustering as the forecasting pre-processing, which can improve the quality of the training models. To achieve the effective clustering, we propose a new similarity measure, called Logistic Weighted Dynamic Time Warping (LWDTW), by extending a Weighted Dynamic Time Warping (WDTW) method to capture the relative importance of return observations when calculating distance matrices. Especially, based on the empirical distributions of stock returns, the cost weight function of WDTW is modified with logistic probability density distribution function. In addition, we further implement the clustering-based forecasting framework with the above three deep learning models. Finally, extensive experiments on daily US stock price data sets show that our framework has achieved excellent forecasting performance with overall best results for the combination of Logistic WDTW clustering and LSTM model using 5 different evaluation metrics.

11.
Cancer Sci ; 112(1): 287-295, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32418280

RESUMEN

This study aims to identify postoperative recurrence patterns of pancreatic cancer with different molecular profiles, which provides evidence for personalized target volumes of adjuvant radiotherapy. Patients with pathologically confirmed resectable pancreatic ductal adenocarcinoma were included. Recurrences were treated with stereotactic body radiation therapy. Immunohistochemical staining of Ki-67, P53, and programmed cell death-ligand 1 (PD-L1) was carried out. Both of the intensities of Ki-67 and P53 were classified as 10% or less, 11%-49%, and 50% or more. Eighty-nine patients had PD-L1 tested, stratified as TC0 and IC0, and TC1/2 or IC1/2. Distances with significant differences among different levels or beyond 10 mm were of interest. With the increasing intensity of Ki-67, the distance from the superior and posterior border of 80% recurrences to the celiac axis (CA) ranged from 10.1 to 13.8 mm and 9.2 to 11.0 mm. The distance from the inferior and posterior border of 80% recurrences to the superior mesenteric artery (SMA) ranged from 9.4 to 9.9 mm and 9.4 to 11.0 mm. Similarly, with the increasing intensity of P53, the distance from the superior and posterior border of 80% recurrences to the CA ranged from 9.7 to 13.2 mm and 10.1 to 10.6 mm. The distance from the inferior and anterior border of 80% recurrences to the SMA ranged from 9.5 to 9.9 mm and 8.6 to 9.4 mm. Regarding the increasing level of PD-L1, the distance from the superior border of 80% recurrences to the CA ranged from 10.9 to 13.5 mm. A biologically effective dose of more than 65 Gy to local recurrences was predictive of favorable outcomes in all levels of Ki-67, P53, and PD-L1. Nonuniform expansions of regions of interest based on different levels of molecular profiles to form target volumes could cover most recurrences, which might be feasible for adjuvant radiotherapy.


Asunto(s)
Carcinoma Ductal Pancreático/radioterapia , Recurrencia Local de Neoplasia/patología , Neoplasias Pancreáticas/radioterapia , Medicina de Precisión/métodos , Radioterapia Adyuvante/métodos , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/análisis , Carcinoma Ductal Pancreático/mortalidad , Carcinoma Ductal Pancreático/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/mortalidad , Neoplasias Pancreáticas/mortalidad , Neoplasias Pancreáticas/patología , Radiocirugia/métodos , Efectividad Biológica Relativa , Neoplasias Pancreáticas
12.
Semin Dial ; 34(2): 137-146, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33210365

RESUMEN

The predictors of weaning time of renal replacement therapy (RRT) remain controversial for special patients suffering from acute kidney injury (AKI). The present work aims to perform a meta-analysis to evaluate proper predictors of RRT weaning in AKI patients. We systematically searched EMBASE, PubMed, and Cochrane Central Register of Controlled trials for literatures between 1984 and June 2019. Studies evaluating predictors of weaning success of RRT in patients of AKI were included. Random-effects model or fixed-effects model meta-analyses were performed to compute a standard mean difference (SMD). Newcastle-Ottawa Scale was employed to assess the risk of bias. We included 10 observational trials including 1453 patients. Twelve predictors including urine output, serum creatinine, serum urea, mean arterial pressure, central venous pressure, lactate, serum potassium, serum bicarbonate, pH value, SOFA score, urinary urea, and urinary creatinine were identified, showing urine output (p = 0.0000), serum creatinine (p = 0.008), serum potassium (p = 0.02), serum bicarbonate (p = 0.01), pH value (p = 0.03), urinary urea (p = 0.002), and urinary creatinine (p = 0.02) were significantly associated with weaning success. With the limited evidence, we speculate that urine output, serum creatinine, serum potassium, serum bicarbonate, pH value, urinary urea, and urinary creatinine might be associated with successful weaning.


Asunto(s)
Lesión Renal Aguda , Diálisis Renal , Lesión Renal Aguda/terapia , Creatinina , Humanos , Pruebas de Función Renal , Terapia de Reemplazo Renal
13.
Appl Opt ; 60(2): 239-249, 2021 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-33448945

RESUMEN

The segmentation of blood vessels in retinal images is crucial to the diagnosis of many diseases. We propose a deep learning method for vessel segmentation based on an encoder-decoder network combined with squeeze-and-excitation connection and atrous spatial pyramid pooling. In our implementation, the atrous spatial pyramid pooling allows the network to capture features at multiple scales, and the high-level semantic information is combined with low-level features through the encoder-decoder architecture to generate segmentations. Meanwhile, the squeeze-and-excitation connections in the proposed network can adaptively recalibrate features according to the relationship between different channels of features. The proposed network can achieve precise segmentation of retinal vessels without hand-crafted features or specific post-processing. The performance of our model is evaluated in terms of visual effects and quantitative evaluation metrics on two publicly available datasets of retinal images, the Digital Retinal Images for Vessel Extraction and Structured Analysis of the Retina datasets, with comparison to 12 representative methods. Furthermore, the proposed network is applied to vessel segmentation on local retinal images, which demonstrates promising application prospect in medical practices.


Asunto(s)
Algoritmos , Procesamiento de Imagen Asistido por Computador , Vasos Retinianos/diagnóstico por imagen , Humanos , Modelos Teóricos , Curva ROC
14.
Appl Opt ; 59(30): 9558-9567, 2020 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-33104677

RESUMEN

In this paper, an optical single-channel asymmetric cryptosystem based on the inverse discrete wavelet transform (IDWT) and chaotic standard map for multi-image in cyan-magenta-yellow-black (CMYK) mode is proposed. To the best of our knowledge, this is the first time that the color image in CMYK format is encoded into a real-valued two-dimensional (2D) format by the IDWT; thus, our scheme can be implemented in a single-channel step. In addition, we propose to generate the random phase mask based on the chaotic standard map. Due to the large key space and high efficiency of the chaotic standard map, the security level of the proposed scheme can be improved. The chaotic standard map is employed to generate the chaotic standard phase mask (CSPM). Then the encoded 2D image can be encrypted in the linear canonical transform domain based on the CSPM. Numerical simulation results are shown to verify the feasibility and effectiveness of our cryptosystem. In addition, our approach outperforms other relevant cryptosystems and can be extended to encrypt multiple color images directly.

15.
Appl Opt ; 59(35): 11087-11097, 2020 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-33361937

RESUMEN

Optical coherence tomography (OCT) image enhancement is a challenging task because speckle reduction and contrast enhancement need to be addressed simultaneously and effectively. We present a refined Retinex model for guidance in improving the performance of enhancing OCT images accompanied by speckle noise; a physical explanation is provided. Based on this model, we establish two sequential optimization functions in the logarithmic domain for speckle reduction and contrast enhancement, respectively. More specifically, we obtain the despeckled image of an entire OCT image by solving the first optimization function. Incidentally, we can recover the speckle noise map through removing the despeckle component directly. Then, we estimate the illumination and reflectance by solving the second optimization function. Further, we apply the contrast-limited adaptive histogram equalization algorithm to adjust the illumination, and project it back to the reflectance for achieving contrast enhancement. Experimental results demonstrate the robustness and effectiveness of our proposed method. It performs well in both speckle reduction and contrast enhancement and is superior to the other two methods both in terms of qualitative analysis and quantitative assessment. Our method has the practical potential to improve the accuracy of manual screening and computer-aided diagnosis for retinal diseases.


Asunto(s)
Diagnóstico por Computador/métodos , Aumento de la Imagen/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Enfermedades de la Retina/diagnóstico por imagen , Tomografía de Coherencia Óptica/métodos , Algoritmos , Sensibilidad de Contraste/fisiología , Humanos , Modelos Teóricos
16.
Appl Opt ; 59(7): 1854-1863, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-32225701

RESUMEN

In this paper, we propose an optical single-channel asymmetric cryptosystem for multi-image in cyan-magenta-yellow-black (CMYK) color space. To the best of our knowledge, this is the first time that multiple images in CMYK color space have been directly encrypted. The proposed optical asymmetric cryptosystem is based on the quick response (QR) encoding process and the designed Fresnel-linear canonical-fractional Fourier transform (FLFT) encryption process. Each FLFT encryption process consists of phase-truncated FLFT and random amplitude phase masks. The proposed cryptosystem without color space conversion can improve the quality of the decrypted images and avoid the loss of information. In addition, by utilizing the QR codes, the cross talk and quality-loss problems can be reduced efficiently. Numerical simulation results demonstrate that the proposed cryptosystem possesses high robustness against various types of attacks, high security for encrypting multiple color images, and fast encryption efficiency. Furthermore, the proposed cryptosystem outperforms the other relevant cryptosystems and can be extended to encrypt multiple color images in a straightforward way.

17.
Appl Opt ; 59(8): 2422-2430, 2020 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-32225778

RESUMEN

We propose an asymmetric optical image cryptosystem based on biometric keys and singular value decomposition (SVD) in the Fresnel transform domain. In the proposed cryptosystem, the biometric keys are palmprint phase mask generated by a palmprint, a chaotic phase mask, and an amplitude truncated Fourier transform, which can provide the cryptosystem with more data security due to the uniqueness of the palmprint. Two images are first encoded into a complex function, which then is modulated by the palmprint phase mask. A Fresnel transform and then an SVD operation are performed on the modulated result. The SVD operation is used to generate private secret keys, which makes the encryption secret keys and decryption secret keys different, and thus the encryption process and decryption process are different. In addition, multiple images are encrypted into a real-valued ciphertext, making it convenient to transport and record. Numerical simulation results have demonstrated that our proposed encryption system has robustness against statistical, occlusion, noise, and chosen-plaintext attacks.

18.
Phys Chem Chem Phys ; 18(12): 8401-11, 2016 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-26931147

RESUMEN

The electronic structure and charge transport properties of thieno[2,3-b]benzothiophene (TBT) and its eight derivatives are investigated via density functional theory (DFT). The impact of different π-bridge spacers (1, the dimer of TBT; 2, vinyl; 3, phenyl; and 4, tetrafluorophenyl) and substituents (5, phenyl; 6, biphenyl; 7, naphthalenyl; and 8, benzothiophenyl) on the geometric structures, reorganization energy, absorption spectra, frontier orbitals, ionization potentials (IPs) and electron affinities (EAs) of all the compounds is explored to establish the relationship between the structure and properties. All the compounds show wide band gaps and low-lying HOMOs, and the IPs of all the TBT derivatives are higher than that of pentacene. The crystal packing interactions, transfer integrals and charge carrier mobilities of compounds 1, 2, 4 and 6 are also calculated. The calculated results demonstrated that these kinds of materials may exhibit good environmental stability and high charge mobility due to their large conjugated planar structure, close π-stacking arrangement, and multiple intermolecular interactions. For compounds 1 and 4, the predicted hole mobility is as high as 0.28 and 0.17 cm(2) V(-1) s(-1), respectively, indicating that both of them benefit hole transport, while compounds 2 and 6 exhibit balanced charge transport properties with the hole and electron mobilities of 0.012 and 0.013 cm(2) V(-1) s(-1), respectively, for compound 2. Compound 6 shows a relatively lower charge mobilities of 10(-3) order of magnitude for both holes and electrons due to the larger reorganization energy and lower transfer integrals.

19.
Chin J Cancer Res ; 27(2): 172-80, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25937779

RESUMEN

OBJECTIVE: In recent years, the combination of cetuximab and chemoradiotherapy (CRT) has been used to treat stage III non-small cell lung cancer (NSCLC); however, limited data are available for Chinese patients. Herein, we report preliminary data from a phase I/II study testing the combination of cetuximab with inductive chemotherapy, followed by concurrent CRT (CCRT) in Chinese patients with stage III NSCLC. METHODS: Eligibility criteria were Zubrod performance status (PS) 0-1, forced expiratory volume in 1 second (FEV1) ≥1.2 L and adequate organ function. Enrolled patients received weekly cetuximab (initial dose of 400 mg/m(2) on day 1 of week 1 and a maintenance dose of 250 mg/m(2) on week 2 to the end of CCRT) with cisplatin/vinorelbine (NP) chemotherapy (every 3 weeks for 2 cycles from week 2, followed by two cycles of concomitant NP chemotherapy and intensity-modulated thoracic radiotherapy (TRT) (60-66 Gy/2 Gy). The primary endpoints were toxicity and feasibility. All patients received positron emission tomography-computerized tomography (PET-CT) scans within the 2 weeks prior to enrollment. Univariate analyses were used to assess the correlation between SUV-T, SUV-N, SUV-TOTAL, gender, age, histology, tumor-node-metastasis (TNM) stage, PS and smoking status and survival. Survival curves were generated for different populations using the Kaplan-Meier method and compared using a log-rank test. RESULTS: Seventeen patients were enrolled and 16 completed the full regime. The overall response rate (ORR) was 58.8% and 82.3% after the induction and CCRT phases, respectively. With a median follow-up duration of 27.6 months, the median survival was 27.6 months [95% confidence interval (CI): 11.3-43.9 months] with 1- and 2-year survival rates of 88.2% (95% CI, 60.6-96.9%) and 58.8% (95% CI, 60.6-77.8%), respectively. Three patients remain progression-free to date, and the median progression-free survival (PFS) was 13.5 months (95% CI, 6.8-20.2 months). No treatment-related death occurred; however, 76% of the patients experienced grade 3+ adverse events (AEs), including nausea/vomiting, intestinal obstruction, and esophagitis (<6%), while other AEs were mostly of hematological nature (71%). The cut-off values for SUV-T and SUV-TOTAL were 11 and 20, respectively. Univariate analyses revealed SUV-TOTAL (P=0.027), SUV-T (P=0.025), and PS (P=0.006) as potential survival predictors, with a hazard ratio (HR) of 3.4, 3.7, and 9.9, respectively. CONCLUSIONS: The combination of cetuximab with induction chemotherapy followed by CCRT appears feasible and promising. Local and locoregional maximal SUVs, defined by (18)F-FDG PET-CT scanning, may represent a prognostic indicator for long-term survival for these patients, which warrants further study.

20.
Chem Biol Interact ; 399: 111146, 2024 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-39002878

RESUMEN

Apixaban is an oral anticoagulant that directly inhibits the target Factor Xa (FXa). In this study, we focused on the in vivo and in vitro effects of adagrasib and asciminib on apixaban metabolism, to discover potential drug-drug interactions (DDI) and explore their inhibitory mechanisms. The levels of apixaban and its metabolite, O-desmethyl-apixaban (M2), were determined by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). In vitro evaluation, the maximum half inhibitory concentration (IC50) of adagrasib in rat liver microsomes (RLM) and human liver microsomes (HLM) against apixaban was 7.99 µM and 117.40 µM, respectively. The IC50 value of asciminib against apixaban in RLM and HLM was 4.28 µM and 18.42 µM, respectively. The results of the analysis on inhibition mechanisms showed that adagrasib inhibited the metabolism of apixaban through a non-competitive mechanism, while asciminib inhibited the metabolism of apixaban through a mixed mechanism. Moreover, the interaction of apixaban with adagrasib and asciminib in Sprague-Dawley (SD) rats was also investigated. It was found that the pharmacokinetic characteristics of apixaban were significantly changed when combined with these two antitumor drugs, where AUC(0-t), AUC(0-∞), t1/2, Tmax, and Cmax were increased, while CLz/F was significantly decreased. But both drugs did not appear to affect the metabolism of M2 in a significant way. Consistent results from in vitro and in vivo demonstrated that both adagrasib and asciminib inhibited the metabolism of apixaban. It provided reference data for the future clinical individualization of apixaban.


Asunto(s)
Antineoplásicos , Microsomas Hepáticos , Pirazoles , Piridonas , Ratas Sprague-Dawley , Animales , Pirazoles/farmacología , Pirazoles/metabolismo , Piridonas/farmacología , Piridonas/farmacocinética , Humanos , Microsomas Hepáticos/metabolismo , Ratas , Masculino , Antineoplásicos/farmacología , Interacciones Farmacológicas , Espectrometría de Masas en Tándem , Inhibidores del Factor Xa/farmacología , Inhibidores del Factor Xa/farmacocinética , Fenilacetatos , Tiofenos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA