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1.
J Am Chem Soc ; 146(1): 319-329, 2024 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-38129955

RESUMO

Tumor invasion and metastasis are the main causes of tumor progression and are the leading causes of death among cancer patients. In the present study, we propose a strategy to regulate cellular signaling with a tumor metastasis-relevant cytoskeleton-associated protein 4 (CKAP4) specific aptamer for the achievement of tumor metastasis inhibition. The designed aptamer could specifically bind to CKAP4 in the cell membranes and cytoplasm to block the internalization and recycling of α5ß1 integrin, resulting in the disruption of the fibronectin-dependent cell adhesion and the weakening of the cell traction force. Moreover, the aptamer is able to impede the interaction between CKAP4 and Dickkopf1 (DKK1) to further block the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, which subsequently reduces AKT phosphorylation and inhibits the reorganization of the actin cytoskeleton in cell migration. The synergetic function of the designed aptamer in inhibiting cancer cell adhesion and blocking the PI3K signaling pathway enables efficient tumor cell metastasis suppression. The aptamer with specific targeting ability in regulating cellular signaling paves the way for cancer treatment and further provides a guiding ideology for inhibiting tumor metastasis.


Assuntos
Neoplasias , Proteínas Proto-Oncogênicas c-akt , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Linhagem Celular Tumoral , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais , Membrana Celular/metabolismo , Movimento Celular , Neoplasias/metabolismo
2.
Opt Lett ; 49(11): 2861-2864, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38824277

RESUMO

Inspired by the advanced integrated sensing and communication (ISAC), in this Letter, we explore the non-line-of-sight (NLoS) optical channels formed by reflections from the ground or objects to establish an integrated channel model for simultaneous communication and sensing. The integrated channel model can, on the one hand, perceive the changes in the surrounding environment and, on the other hand, determine whether these changes positively or negatively affect the quality of communication simultaneously. To validate the effectiveness of the proposed model, from sensing, we analyze the impact of various floor materials and visible light communication (VLC) users on the integrated channel; from communication, we characterize the influence of perceived environmental changes on communication performance by calculating throughput. Experimental results confirm the capability of the derived model, which can support the design and deployment of VL-based ISAC networks.

3.
Anal Chem ; 2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36607132

RESUMO

Portable point-of-care testing (POCT) is currently drawing enormous attention owing to its great potential for disease diagnosis and personal health management. Electrochemical biosensors, with the intrinsic advantages of cost-effectiveness, fast response, ease of miniaturization, and integration, are considered as one of the most promising candidates for POCT application. However, the clinical application of electrochemical biosensors-based POCT is hindered by the decreased detection sensitivity due to the low abundance of disease-relevant biomolecules in extremely complex biological samples. Herein, we construct a flexible electrochemical biosensor based on single-stranded DNA functionalized single-walled carbon nanotubes (ssDNA-SWNTs) for high sensitivity and stability detection of miRNA-21 in human urine to achieve bladder cancer (BCa) diagnosis and classification. The ssDNA-SWNT electrodes with a 2D interconnected network structure exhibit a high electrical conductivity, thus enabling the ultrasensitive detection of miRNA-21 with a detection limit of 3.0 fM. Additionally, the intrinsic flexibility of ssDNA-SWNT electrodes endows the biosensors with the capability to achieve high stability detection of miRNA-21 even under large bending deformations. In a cohort of 40 BCa patients at stages I-III and 44 negative control samples, the constructed ssDNA-SWNT biosensors could detect BCa with a 92.5% sensitivity, an 88.6% specificity, and classify the cancer stages with an overall accuracy of 81.0%. Additionally, the flexible ssDNA-SWNT biosensors could also be utilized for treatment efficiency assessment and cancer recurrence monitoring. Owing to their excellent sensitivity and stability, the designed flexible ssDNA-SWNT biosensors in this work propose a strategy to realize point-of-care detection of complex clinical samples to achieve personalized healthcare.

4.
J Nanobiotechnology ; 21(1): 412, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37936120

RESUMO

The immune system is closely associated with the pathogenesis of polycystic ovary syndrome (PCOS). Macrophages are one of the important immune cell types in the ovarian proinflammatory microenvironment, and ameliorate the inflammatory status mainly through M2 phenotype polarization during PCOS. Current therapeutic approaches lack efficacy and immunomodulatory capacity, and a new therapeutic method is needed to prevent inflammation and alleviate PCOS. Here, octahedral nanoceria nanoparticles with powerful antioxidative ability were bonded to the anti-inflammatory drug resveratrol (CeO2@RSV), which demonstrates a crucial strategy that involves anti-inflammatory and antioxidative efficacy, thereby facilitating the proliferation of granulosa cells during PCOS. Notably, our nanoparticles were demonstrated to possess potent therapeutic efficacy via anti-inflammatory activities and effectively alleviated endocrine dysfunction, inflammation and ovarian injury in a dehydroepiandrosterone (DHEA)-induced PCOS mouse model. Collectively, this study revealed the tremendous potential of the newly developed nanoparticles in ameliorating the proinflammatory microenvironment and promoting the function of granulosa cells, representing the first attempt to treat PCOS by using CeO2@RSV nanoparticles and providing new insights in combating clinical PCOS.


Assuntos
Nanocompostos , Síndrome do Ovário Policístico , Camundongos , Animais , Feminino , Humanos , Síndrome do Ovário Policístico/induzido quimicamente , Síndrome do Ovário Policístico/tratamento farmacológico , Síndrome do Ovário Policístico/metabolismo , Inflamação/tratamento farmacológico , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Microambiente Tumoral
5.
Int J Mol Sci ; 24(8)2023 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-37108376

RESUMO

Early maturity is an important agronomic trait in most crops, because it can solve the problem of planting in stubble for multiple cropping as well as make full use of light and temperature resources in alpine regions, thereby avoiding damage from low temperatures in the early growth period and early frost damage in the late growth period to improve crop yield and quality. The expression of genes that determine flowering affects flowering time, which directly affects crop maturity and indirectly affects crop yield and quality. Therefore, it is important to analyze the regulatory network of flowering for the cultivation of early-maturing varieties. Foxtail millet (Setaria italica) is a reserve crop for future extreme weather and is also a model crop for functional gene research in C4 crops. However, there are few reports on the molecular mechanism regulating flowering in foxtail millet. A putative candidate gene, SiNF-YC2, was isolated based on quantitative trait loci (QTL) mapping analysis. Bioinformatics analysis showed that SiNF-YC2 has a conserved HAP5 domain, which indicates that it is a member of the NF-YC transcription factor family. The promoter of SiNF-YC2 contains light-response-, hormone-, and stress-resistance-related elements. The expression of SiNF-YC2 was sensitive to the photoperiod and was related to the regulation of biological rhythm. Expression also varied in different tissues and in response to drought and salt stress. In a yeast two-hybrid assay, SiNF-YC2 interacted with SiCO in the nucleus. Functional analysis suggested that SiNF-YC2 promotes flowering and improves resistance to salt stress.


Assuntos
Setaria (Planta) , Setaria (Planta)/genética , Setaria (Planta)/metabolismo , Tolerância ao Sal/genética , Locos de Características Quantitativas , Fenótipo , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
6.
Int J Mol Sci ; 24(22)2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-38003509

RESUMO

Foxtail millet (Setaria italica (L.) P. Beauv) is an important food and forage crop that is well adapted to nutrient-poor soils. However, our understanding of how different LN-tolerant foxtail millet varieties adapt to long-term low nitrogen (LN) stress at the physiological and molecular levels remains limited. In this study, two foxtail millet varieties with contrasting LN tolerance properties were investigated through analyses of physiological parameters and transcriptomics. The physiological results indicate that JG20 (high tolerance to LN) exhibited superior biomass accumulation both in its shoots and roots, and higher nitrogen content, soluble sugar concentration, soluble protein concentration, zeatin concentration in shoot, and lower soluble sugar and soluble protein concentration in its roots compared to JG22 (sensitive to LN) under LN, this indicated that the LN-tolerant foxtail millet variety can allocate more functional substance to its shoots to sustain aboveground growth and maintain high root activity by utilizing low soluble sugar and protein under LN conditions. In the transcriptomics analysis, JG20 exhibited a greater number of differentially expressed genes (DEGs) compared to JG22 in both its shoots and roots in response to LN stress. These LN-responsive genes were enriched in glycolysis metabolism, photosynthesis, hormone metabolism, and nitrogen metabolism. Furthermore, in the shoots, the glutamine synthetase gene SiGS5, chlorophyll apoprotein of photosystem II gene SiPsbQ, ATP synthase subunit gene Sib, zeatin synthesis genes SiAHP1, and aldose 1-epimerase gene SiAEP, and, in the roots, the high-affinity nitrate transporter genes SiNRT2.3, SiNRT2.4, glutamate synthase gene SiGOGAT2, fructose-bisphosphate aldolase gene SiFBA5, were important genes involved in the LN tolerance of the foxtail millet variety. Hence, our study implies that the identified genes and metabolic pathways contribute valuable insights into the mechanisms underlying LN tolerance in foxtail millet.


Assuntos
Setaria (Planta) , Setaria (Planta)/genética , Setaria (Planta)/metabolismo , Proteínas de Plantas/metabolismo , Transcriptoma , Nitrogênio/metabolismo , Zeatina/metabolismo , Açúcares/metabolismo , Estresse Fisiológico/genética , Regulação da Expressão Gênica de Plantas
7.
Angew Chem Int Ed Engl ; 62(30): e202304298, 2023 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-37218113

RESUMO

Mass pathogen screening is critical to preventing the outbreaks and spread of infectious diseases. The large-scale epidemic of COVID-19 and the rapid mutation of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus have put forward new requirements for virus detection and identification techniques. Here, we report a CRISPR-based Amplification-free Viral RNA Electrical Detection platform (CAVRED) for the rapid detection and identification of SARS-CoV-2 variants. A series of CRISPR RNA assays were designed to amplify the CRISPR-Cas system's ability to discriminate between mutant and wild RNA genomes with a single-nucleotide difference. The identified viral RNA information was converted into readable electrical signals through field-effect transistor biosensors for the achievement of highly sensitive detection of single-base mutations. CAVRED can detect the SARS-CoV-2 virus genome as low as 1 cp µL-1 within 20 mins without amplification, and this value is comparable to the detection limit of real-time quantitative polymerase chain reaction. Based on the excellent RNA mutation detection ability, an 8-in-1 CAVRED array was constructed and realized the rapid identification of 40 simulated throat swab samples of SARS-CoV-2 variants with a 95.0 % accuracy. The advantages of accuracy, sensitivity, and fast speed of CAVRED promise its application in rapid and large-scale epidemic screening.


Assuntos
COVID-19 , RNA Viral , Humanos , RNA Viral/genética , SARS-CoV-2/genética , COVID-19/diagnóstico , Nucleotídeos , Sistemas CRISPR-Cas/genética , Técnicas de Amplificação de Ácido Nucleico
8.
Anal Chem ; 94(50): 17413-17421, 2022 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-36469021

RESUMO

Epidermal growth factor receptor (EGFR) nuclear translocation correlates with the abnormal proliferation, migration, and anti-apoptosis of tumor cells. Monitoring EGFR nuclear translocation provides insights into the molecular mechanisms underlying cancers. EGFR nuclear translocation includes two processes, EGFR phosphorylation and phosphorylated EGFR translocation to the nucleus. With the help of aptamers, probes that can achieve the first step of anchoring phosphorylated EGFR have been developed. However, the EGFR nuclear translocation can last for hours, posing a challenge to monitor the entire nuclear translocation in living cells. Herein, we designed a circular bivalent aptamer-functionalized optical probe with greatly enhanced stability for long-term visualization of EGFR nuclear translocation in situ. The results of cell experiments show that the probe could monitor the entire nuclear translocation of EGFR. The findings of tissue and in vivo experiments demonstrate that the probe can evaluate the development and progression of tumors by imaging EGFR nuclear translocation in situ. The proposed approach allows us to monitor EGFR nuclear translocation in the long term, indicating its great potential in investigating the mechanisms of cancers and guiding for tumor treatment.


Assuntos
Receptores ErbB , Neoplasias , Humanos , Receptores ErbB/metabolismo , Fosforilação , Neoplasias/metabolismo , Transporte Proteico , Oligonucleotídeos/metabolismo , Linhagem Celular Tumoral , Fator de Crescimento Epidérmico/metabolismo , Núcleo Celular/metabolismo
9.
Opt Express ; 30(20): 37026-37037, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36258621

RESUMO

As an important branch of visible light communication (VLC), optical camera communication (OCC) has received increasing attention recently, owing to its availability and low cost of deployment by re-using cameras as VLC receivers. However, cameras on popular smartphones and/or closed-circuit television systems have their primary function for taking pictures and recognizing objects, where the recorded images with objects are inevitable to be distorted by the coded light under OCC. To this end, we propose and experimentally demonstrate an improved OCC system which is able to achieve data communication and object recognition simultaneously. Basically, we devise an image restoration (IR) scheme to repair the pixels damaged by modulated light during data transmission, and it hence provides better image input to realize object recognition. Moreover, to maintain a reasonable data rate of OCC, we also engineer an object avoidance (OA) scheme to remove the negative effect caused by the object background in OCC frame. Finally, we implement a prototype of the proposed system to verify its performance on object recognition and communication, and experimental results show that the proposed IR can bring an improvement over 37% in terms of object recognition accuracy comparing to the baseline under a data rate of 5 kbps.

10.
J Clin Lab Anal ; 36(7): e24530, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35657116

RESUMO

It was known that mutations in the RT region were mainly related to nucleot(s)ide analogs resistance. Increasing studies indicated that RT mutations were related to advanced liver diseases (ALD) and had effects on HBV replication, but the distribution characteristics of mutations across RT region in the development of liver diseases and the effect of RT mutations on HBV replication were not fully clarified. HBV RT region was direct-sequenced in 1473 chronic HBV-infected patients. Mutation frequencies were analyzed to identify the specific mutations differing between groups classified by genotypes, loads of HBV DNA, or progression of liver diseases. In the range of rt145-rt290, rt145, rt221, rt222, rt267, and rt271 were the genotype-polymorphic sites, while rt238 was the genotype-specific sites. Mutations at rt163, rt173, rt180, rt181, rt184, rt191, rt199, and rt214 were more frequent among patients with C-genotype HBV, while those at rt220, rt225, rt226, rt269, and rt274 were more frequent among patients with B-genotype HBV. RtM204V/I could reduce the HBV DNA loads while rtQ/L267H/R could increase the HBV DNA loads. RtV214A/E/I (OR 3.94, 95% CI 1.09 to 14.26) was an independent risk factor for advanced liver diseases. In summary, the hotspots of mutations were different between B and C genotypes. Besides the effect on the S region, RT mutations had effects on HBV replication by other unknown ways. RtV214A/E/I was found to be an independent risk factor for ALD, suggesting that mutations at rt214 site could be used as a potential virological marker for the liver disease progression.


Assuntos
Vírus da Hepatite B , Hepatopatias , DNA Polimerase Dirigida por RNA , Antivirais , China/epidemiologia , DNA Viral/genética , Farmacorresistência Viral/genética , Genótipo , Vírus da Hepatite B/enzimologia , Vírus da Hepatite B/genética , Humanos , Hepatopatias/virologia , Mutação , DNA Polimerase Dirigida por RNA/genética
11.
Sensors (Basel) ; 22(21)2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36366071

RESUMO

Optical camera communication (OCC), enabled by light-emitting diodes (LEDs) and embedded cameras on smartphones, has drawn considerable attention thanks to the pervasive adoption of LED lighting and mobile devices. However, most existing studies do not consider the performance bottleneck of Region of Interest (RoI) extraction during decoding, making it challenging to improve communication capacity further. To this end, we propose a fast grid virtual division scheme based on pixel grayscale values, which extracts RoI quickly without sacrificing computational complexity, thereby reducing the decoding delay and improving the communication capacity of OCC. Essentially, the proposed scheme uses a grid division strategy to divide the received image into blocks and randomly sample several pixels within different blocks to quickly locate the RoI with high grayscale values in the original image. By implementing the lightweight RoI extraction algorithm, we experimentally verify its effectiveness in reducing decoding latency, demonstrating its superior performance in terms of communication capacity. The experimental results clearly show that the decoding delay of the proposed scheme is 70% lower than that provided by the Gaussian blur scheme for the iPhone receiver at a transmission frequency of 5 kHz.


Assuntos
Algoritmos , Iluminação , Sistemas Computacionais , Comunicação
12.
Sensors (Basel) ; 22(19)2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36236260

RESUMO

Visible light positioning (VLP) has attracted intensive attention from both academic and industrial communities thanks to its high accuracy, immunity to electromagnetic interference, and low deployment cost. In general, the receiver in a VLP system determines its own position by exploring the received signal strength (RSS) from the transmitter according to a pre-built RSS attenuation model. In such model-based methods, the LED's emission power and the receiver's height are usually required known and constant parameters to obtain reasonable positioning accuracy. However, the LED's emission power is normally time-varying due to the fact that the LED's optical output power is prone to changing with the LED's temperature, and the receiver's height is random in a realistic application scenario. To this end, we propose a height-independent three-dimensional (3D) VLP scheme based on the RSS ratio (RSSR), rather than only using RSS. Unlike existing RSS-based VLP methods, our method is able to independently find the horizontal coordinate, i.e., two-dimensional (2D) position, without a priori height information of the receiver, and also avoids the negative effect caused by fluctuation of the LED's emission power. Moreover, we can further infer the height of the receiver to achieve three-dimensional (3D) positioning by iterating the 2D results back into positioning equations. To quickly verify the proposed scheme, we conduct theoretical analysis with mathematical proof and experimental results with real data, which confirm that the proposed scheme can achieve high position accuracy without known information of the receiver's height and LED's emission power. We also implement a VLP prototype with five LED transmitters, and experimental results show that the proposed scheme can achieve very low average errors of 2.73 cm in 2D and 7.20 cm in 3D.

13.
Nano Lett ; 21(7): 2854-2860, 2021 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-33769062

RESUMO

Urinary tract infections (UTIs) caused by bacterial invasion can lead to life-threatening complications, posing a significant health threat to more than 150 million people worldwide. As a result, there is need for accurate and rapid diagnosis of UTIs to enable more effective treatment. Described here is an intelligent diagnostic system constructed for bacterial detection using an immunobiosensor, signal-amplification biochip, and image processing algorithm based on machine vision. This prototype can quickly detect bacteria by collection of enhanced luminescence enabled by the photonic crystals integrated into the biochip. By use of a machine vision algorithm, the very small luminescence signals are analyzed to provide a low detection limit and wide dynamic range. This sensor system can offer an affordable, accessible, and user-friendly digital diagnostic solution, possibly suitable for wearable technology, that could improve treatment of this challenging disease.


Assuntos
Sistemas Automatizados de Assistência Junto ao Leito , Infecções Urinárias , Humanos , Luminescência , Óptica e Fotônica , Infecções Urinárias/diagnóstico
14.
Angew Chem Int Ed Engl ; 61(18): e202115572, 2022 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-35212095

RESUMO

Monitoring microbial metabolism is vital for biomanufacturing processes optimization. However, it remains a grand challenge to offer insight into microbial metabolism due to particularly complex and dynamic processes. Here, we report an electron-sensing probe Zn2 GeO4 :Mn@Fe3+ for real-time and dynamic monitoring of Fe(III) respiration metabolism. The quenched persistent luminescence of Zn2 GeO4:Mn@Fe3+ is recovered when Fe3+ accepted electrons from the dynamic Fe(III) respiration metabolism, enabling the real-time monitoring of microbial metabolism. The probe shows the capability to verify the role of related biomolecules in microbial Fe(III) respiration metabolism, to track the dynamic Fe(III) respiration metabolic response to environmental stress and microbial co-culture interactions. Furthermore, the Zn2 GeO4 :Mn@Fe3+ probe provides guidance for improving biosynthesis efficiency by monitoring Fe redox recycling in microbial co-culture.


Assuntos
Elétrons , Compostos Férricos , Compostos Férricos/metabolismo , Oxirredução , Respiração
15.
Angew Chem Int Ed Engl ; 61(32): e202207132, 2022 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-35653160

RESUMO

Microbial cell factories reinvigorate current industries by producing complex fine chemicals at low costs. Reduced nicotinamide adenine dinucleotide phosphate (NADPH) is the main reducing power to drive the biosynthetic pathways in microorganisms. However, insufficient intrinsic NADPH limits the productivity of microorganisms. Here, we report that supplying microorganisms with long-lived electrons from persistent phosphor mesoporous Al2 O3 (meso-Al2 O3 ) can elevate the NADPH level to facilitate efficient fine chemical production. The defects in meso-Al2 O3 were demonstrated to be highly efficient in prolonging electrons' lifetime. The long-lived electrons in meso-Al2 O3 can pass the material-microorganism interface and power the biosynthetic pathways of E. coli to produce jet fuel farnesene. This work represents a reliable strategy to design photo-biosynthesis systems to improve the productivity of microorganisms with solar energy.


Assuntos
Biocombustíveis , Energia Solar , Escherichia coli , NADP , Luz Solar
16.
Opt Express ; 29(12): 19015-19023, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34154144

RESUMO

Deemed as a practical approach to realize Visible Light Communication on commercial-off-the-shelf devices, the Optical Camera Communication (OCC) is attracting increasing attention, thanks to its readiness to be built purely upon ubiquitous LED illuminating infrastructure and handy smartphones. However, limited by the low sampling ability of the built-in camera on a smartphone, the performance of existing OCC systems is still far away from the requirements of practical applications. To this end, we further investigate the reception ability of the smartphone's camera and propose an accumulative sampling scheme to improve the performance of the OCC system. Essentially, the proposed scheme can use all the grayscale information of the pixels projected by the LED transmitter, whereas the conventional ones normally use single row (or column) pixels for demodulating. By implementing the lightweight demodulation algorithm with accumulative sampling, we experimentally verify its effectiveness for supporting higher transmission frequency hence better performance in terms of data rate. Extensive evaluations have shown the BERs of the proposed method are over 87% and 96% lower than that provided by the baselines at a maximum transmission frequency of 5 kHz for the Samsung S8 and iPhone 8 Plus receivers, respectively.

17.
Opt Express ; 29(21): 34066-34076, 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34809204

RESUMO

Optical camera communication (OCC) systems, which utilize image sensors embedded in commercial-off-the-shelf devices to detect time and spatial variations in light intensity for enabling data communications, have stirred up researchers' interest. Compared to a direct OCC system whose maximum data rate is strongly determined by the LED source size, a reflected OCC system can break that limitation since the camera captures the light rays reflecting off an observation plane (e.g., a wall) instead of those light rays directly emanated from the light source. However, the low signal-to-noise ratio caused by the non-uniform irradiance distribution produced by LED luminaire on the observation plane in current reflected OCC systems cannot be avoided, hence low complexity and accurate demodulation are hard to achieve. In this paper, we present a FreeOCC system, which employs a dedicatedly tailored freeform lens to precisely control the propagation of modulated light. A desired uniform rectangular illumination is produced on the observation plane by the freeform lens, yielding a uniform grayscale distribution within the received frame captured by the camera in the proposed FreeOCC system. Then, the received signal can be easily demodulated with high accuracy by a simple thresholding scheme. A prototype of the FreeOCC system demonstrates the high performance of the proposed system, and two pulse amplitude modulation schemes (4-order and 8-order) are performed. By using the freeform lens, the packet reception rate is increased by 35% and 32%, respectively; the bit error rate is decreased by 72% and 59%, respectively, at a transmission frequency of 5 kHz. The results clearly show that the FreeOCC system outperforms the common reflected OCC system.

18.
Sensors (Basel) ; 21(10)2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34070024

RESUMO

In the Industrial Internet, computing- and power-limited mobile devices (MDs) in the production process can hardly support the computation-intensive or time-sensitive applications. As a new computing paradigm, mobile edge computing (MEC) can almost meet the requirements of latency and calculation by handling tasks approximately close to MDs. However, the limited battery capacity of MDs causes unreliable task offloading in MEC, which will increase the system overhead and reduce the economic efficiency of manufacturing in actual production. To make the offloading scheme adaptive to that uncertain mobile environment, this paper considers the reliability of MDs, which is defined as residual energy after completing a computation task. In more detail, we first investigate the task offloading in MEC and also consider reliability as an important criterion. To optimize the system overhead caused by task offloading, we then construct the mathematical models for two different computing modes, namely, local computing and remote computing, and formulate task offloading as a mixed integer non-linear programming (MINLP) problem. To effectively solve the optimization problem, we further propose a heuristic algorithm based on greedy policy (HAGP). The algorithm achieves the optimal CPU cycle frequency for local computing and the optimal transmission power for remote computing by alternating optimization (AP) methods. It then makes the optimal offloading decision for each MD with a minimal system overhead in both of these two modes by the greedy policy under the limited wireless channels constraint. Finally, multiple experiments are simulated to verify the advantages of HAGP, and the results strongly confirm that the considered task offloading reliability of MDs can reduce the system overhead and further save energy consumption to prolong the life of the battery and support more computation tasks.

19.
Anal Chem ; 92(14): 10162-10168, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32578424

RESUMO

Concurrent infection in cancer treatment is the leading cause of high cancer mortality that requires urgent action. Currently developed diagnostic methods are hindered by the difficulty of rapidly and reliably screening small amounts of pathogens in the blood and then release pathogens for downstream analysis, limiting the advance of cancer concurrent infection diseases diagnosis and targeted treatment. Herein, we present a near-infrared (NIR) light-responsive black phosphorus (BP)-based device that effectively captures and releases pathogen for downstream drug-resistance analysis. The aptamer-modified BP nanostructures exhibit enhanced topographical interactions and binding capabilities with pathogen, enabling highly efficient and selective capture of pathogen in serum. NIR light irradiation induces BP nanostructure to generate a local thermal effect, which regulates the three-dimensional structure of the aptamer and causes efficient release of pathogen from the substrate surface. The released pathogen is resistant to ampicillin as demonstrated by downstream genetic analysis. The design of the functionalized light-controlled device for monitoring pathogen behavior shows great potential for assisting in cancer therapy and promoting personalized healthcare.


Assuntos
Ampicilina/farmacologia , Antibacterianos/farmacologia , Infecções por Escherichia coli/tratamento farmacológico , Escherichia coli/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Aptâmeros de Nucleotídeos/química , Escherichia coli/patogenicidade , Humanos , Raios Infravermelhos , Testes de Sensibilidade Microbiana , Nanoestruturas/química , Neoplasias/microbiologia , Fósforo/química , Terapia Fototérmica , Staphylococcus aureus/patogenicidade
20.
Opt Lett ; 45(17): 4927-4930, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32870892

RESUMO

In this Letter, we propose and demonstrate a practical optical-spatial-summing-based non-orthogonal multiple access (OSS-NOMA) technique for visible light communication (VLC) systems. This technique is innovative in adopting OSS in that the transmitter of OSS-NOMA VLC can be built upon commercial illuminating light emitting diodes (LEDs), free of LEDs' harmful nonlinearity. Unlike conventional NOMA VLC using analog components such as digital-to-analog converters and bias-T in the transmitter side, OSS-NOMA exploits only digital control signals to drive a LED array in forming optical power superposition for NOMA signals. We demonstrate that by simply switching different amounts of LED chips on or off, the proposed OSS-NOMA transmitter can deliver a fine-grained power allocation ratio ranging from 0.01 to one for two users. The implemented OSS-NOMA VLC prototype leveraging commercial components can achieve low bit error rates of ≤3.1×10-3 for two users at a data rate of 800 kbps, confirming the promising potential of this novel OSS-NOMA VLC for Internet of Things (IoT) applications.

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