Biosensors and Bioelectronics最新文献_第10页

Quantification of Pectobacterium carotovorum subsp. carotovorum in kimchi cabbage using a surface-enhanced Raman scattering platform with silver nanostructures 利用银纳米结构表面增强拉曼散射平台定量检测泡菜中的果胶杆菌亚种（Pectobacterium carotovorum subsp.

IF 10.7 1区生物学

Biosensors and Bioelectronics Pub Date : 2024-09-07 DOI: 10.1016/j.bios.2024.116766

{"title":"Quantification of Pectobacterium carotovorum subsp. carotovorum in kimchi cabbage using a surface-enhanced Raman scattering platform with silver nanostructures","authors":"","doi":"10.1016/j.bios.2024.116766","DOIUrl":"10.1016/j.bios.2024.116766","url":null,"abstract":"<div><p><em>Pectobacterium carotovorum</em> subsp. <em>carotovorum</em> (PCC) is a notorious plant pathogen responsible for severe soft rot in kimchi cabbage, which results in significant economic losses. To detect PCC rapidly and accurately in kimchi cabbage, we developed a surface-enhanced Raman scattering (SERS) substrate on which silver nanospheres (AgNSs), nanowires (AgNWs), and nanoseeds are combined on a polydimethylsiloxane (PDMS) platform. The incorporation of Ag nanoseeds creates a higher density of hotspots, which ensures a low detection limit of 1.001 CFU/mL. Electron microscopy and spectroscopic analyses confirmed the successful fabrication of the substrate and its enhanced sensitivity. The SERS substrate exhibits excellent selectivity by effectively distinguishing PCC from other bacteria commonly found in kimchi cabbage. The substrate gives rise to strong Raman signals across PCC concentrations ranging from 10<sup>1</sup> to 10<sup>6</sup> CFU/mL. Additionally, a predictive model was developed for accurately detecting PCC in real kimchi cabbage samples, and the results were validated by polymerase chain reaction measurements. A sensitive, selective, and rapid approach for PCC detection in kimchi cabbage that offers a promising improvement over existing methodologies is presented.</p></div>","PeriodicalId":259,"journal":{"name":"Biosensors and Bioelectronics","volume":null,"pages":null},"PeriodicalIF":10.7,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142168344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Redox interference-free bimodal paraoxon sensing enabled by an aggregation-induced emission nanozyme catalytically hydrolyzing phosphoesters specifically 通过聚合诱导发射纳米酶催化特异性水解磷酸酯，实现无氧化还原干扰的双模对氧磷传感

IF 10.7 1区生物学

Biosensors and Bioelectronics Pub Date : 2024-09-06 DOI: 10.1016/j.bios.2024.116756

{"title":"Redox interference-free bimodal paraoxon sensing enabled by an aggregation-induced emission nanozyme catalytically hydrolyzing phosphoesters specifically","authors":"","doi":"10.1016/j.bios.2024.116756","DOIUrl":"10.1016/j.bios.2024.116756","url":null,"abstract":"<div><p>In view of the current serious situation of organophosphorus pesticides (OPs) residue contamination, developing rapid and accurate OPs sensors is a matter of urgency. Redox-nanozyme based colorimetric sensors have been widely researched and utilized in OPs residue determination, but overcoming the interference of external redox substances and the effect of single-signal modes on detection performance is still a challenge. Here we fabricated a Zr-based metal–organic framework (MOF) featuring specific phosphatase-like activity and strong aggregation-induced emission (AIE) fluorescence for redox interference-free bimodal pesticide sensing. In the MOF, the activity-tunable Zr<sup>4+</sup> node offered high hydrolytic activity and affinity toward P–O containing substrates, and the rigid framework structure effectively enhanced the fluorescence emission of the ligand 1,1,2,2-tetra(4-carboxylphenyl)ethylene. The developed AIEzyme could efficiently catalyze the hydrolysis of paraoxon to yellow <em>p</em>-nitrophenol, which further reduced the intrinsic AIE fluorescence of AIEzyme through internal filtration effect. Thereby, a natural enzyme-free dual-mode colorimetric/fluorescence approach was established for paraoxon detection with no interference from redox substances, and a smartphone-assisted portable platform was further developed to enable the facile, rapid, and high-performance sensing of the pesticide in complex practical matrices.</p></div>","PeriodicalId":259,"journal":{"name":"Biosensors and Bioelectronics","volume":null,"pages":null},"PeriodicalIF":10.7,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142151968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Recent advances of electrochemical and optical point-of-care biosensors for detecting neurotransmitter serotonin biomarkers 用于检测神经递质血清素生物标记物的电化学和光学床旁生物传感器的最新进展

IF 10.7 1区生物学

Biosensors and Bioelectronics Pub Date : 2024-09-06 DOI: 10.1016/j.bios.2024.116743

{"title":"Recent advances of electrochemical and optical point-of-care biosensors for detecting neurotransmitter serotonin biomarkers","authors":"","doi":"10.1016/j.bios.2024.116743","DOIUrl":"10.1016/j.bios.2024.116743","url":null,"abstract":"<div><p>Since its discovery in 1984, the monoamine serotonin (5-HT) has been recognized for its critical role as a neuromodulator in both the central and peripheral nervous systems. Recent research reveals that serotonin also significantly influences various neuronal activities. Historically, it was believed that peripheral serotonin, produced by tryptophan hydroxylase in intestinal cells, functioned primarily as a hormone. However, new insights have expanded its known roles, necessitating advanced detection methods.</p><p>Biosensors have emerged as indispensable tools in biomedical diagnostics, enabling the rapid and minimally invasive detection of target analytes with high spatial and temporal resolution. This review summarizes the progress made in the past decade in developing optical and electrochemical biosensors for serotonin detection. We evaluate various sensing strategies that optimize performance in terms of detection limits, sensitivity, and specificity. The study also explores recent innovations in biosensing technologies utilizing surface-modified electrodes with nanomaterials, including gold, graphite, carbon nanotubes, and metal oxide particles. Applications range from in vivo studies to chemical imaging and diagnostics, highlighting future prospects in the field.</p></div>","PeriodicalId":259,"journal":{"name":"Biosensors and Bioelectronics","volume":null,"pages":null},"PeriodicalIF":10.7,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0956566324007498/pdfft?md5=97dcadfac7e82b6f0c8f768b7a83e7e9&pid=1-s2.0-S0956566324007498-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142173246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

NIR-photoactivatable DNA nanomachines for spatiotemporally controllable monitoring of microRNA-21 in living cells based on signal amplification strategy 基于信号放大策略的近红外光激活 DNA 纳米机械用于活细胞中 microRNA-21 的时空可控监测

IF 10.7 1区生物学

Biosensors and Bioelectronics Pub Date : 2024-09-06 DOI: 10.1016/j.bios.2024.116755

{"title":"NIR-photoactivatable DNA nanomachines for spatiotemporally controllable monitoring of microRNA-21 in living cells based on signal amplification strategy","authors":"","doi":"10.1016/j.bios.2024.116755","DOIUrl":"10.1016/j.bios.2024.116755","url":null,"abstract":"<div><p>Precise and spatiotemporally controllable analysis of microRNA-21 in living cells is crucial for accurate diagnosis and effective treatment of related diseases. Herein, a near-infrared (NIR)-photoactivatable DNA nanomachine (PUCNPs-NH<sub>2</sub>/PEG-ZL-DNA) was constructed for the precise analysis and diagnosis of microRNA-21 in tumor cells. Peanut-shaped upconversion nanoparticles (PUCNPs) were employed as the carriers and activators for the intelligent DNA probe, specifically enabling the cleavage of the photocleavable linker (PC-linker) from the hairpin DNA probe (Hp-Dzy) upon exposure to 808 nm irradiation. In the presence of the target microRNA-21, the locker DNA hybridized with microRNA-21 and the DNAzymes was freed to hybridize with the looped portion of the hairpin DNA (Hp-1). Mg<sup>2+</sup> was employed as the cofactor, facilitating the precise cleavage of Hp-1, which triggered the restoration of fluorescence signals. Subsequently, DNAzymes exhibited the competency to selectively recognize and engage with additional Hp-1, and the fluorescence signals were effectively amplified by the recycling process. Consequently, the DNA nanomachine exhibited a linear response to microRNA-21 concentrations ranging from 0.5 nM to 1.0 μM, achieving a remarkable detection limit (LOD) of 1.19 nM under the optimal conditions. This strategy is realized through the integration of photocontrollable upconversion nanotechnology with the signal amplification approach, showing feasible prospects for spatiotemporally precise and highly sensitive monitoring of microRNA in tumor cells.</p></div>","PeriodicalId":259,"journal":{"name":"Biosensors and Bioelectronics","volume":null,"pages":null},"PeriodicalIF":10.7,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142152037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Early wound infection monitoring via headspace O2 micro-respirometry 通过顶空氧气微呼吸监测早期伤口感染。

IF 10.7 1区生物学

Biosensors and Bioelectronics Pub Date : 2024-09-05 DOI: 10.1016/j.bios.2024.116751

{"title":"Early wound infection monitoring via headspace O2 micro-respirometry","authors":"","doi":"10.1016/j.bios.2024.116751","DOIUrl":"10.1016/j.bios.2024.116751","url":null,"abstract":"<div><p>A luminescence based, inexpensive, 3D printed O<sub>2</sub> indicator is incorporated into a commercial, clear, occlusive wound dressing, which allows the %O<sub>2</sub> in the headspace above a simulated wound to be monitored. Two wound models are used to evaluate this micro-respirometry-based system for monitoring wound infection namely, a simple ‘agar plug’ model and a wounded porcine skin model. Inoculation of either wound model with <em>E. coli</em>, <em>E. cloacae</em>, or <em>A. baumannii</em>, produces the typical ‘S’-shaped, τ vs incubation time, <em>t</em>, profiles, associated with micro-respirometry, due to the decrease in %O<sub>2</sub> in the headspace above the wound. A threshold value for the lifetime, τ<sub>TT</sub>, of 21.1 μs, is identified at which the bacterial load is equal to the critical colonization threshold, CCT, ca. 10<sup>6</sup> colony forming units, CFU/mL, above which infection is highly likely. The agar plug wound model/O<sub>2</sub> indicator combination is used to identify when the CCT is reached for a wide range of inoculant concentrations, spanning the range 10<sup>8</sup>–10<sup>1</sup> CFU/mL, for all three microbial species. The O<sub>2</sub> indicator is also successfully evaluated using a porcine skin wound model inoculated with <em>E. coli</em>. The results of this work are compared to other reported, usually invasive, smart wound monitoring systems. The possible use of this new, non-invasive smart-wound dressing technology, both at the point of care and at home, are discussed briefly.</p></div>","PeriodicalId":259,"journal":{"name":"Biosensors and Bioelectronics","volume":null,"pages":null},"PeriodicalIF":10.7,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0956566324007577/pdfft?md5=cce9236f09e3fc8645f131c7de07319e&pid=1-s2.0-S0956566324007577-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142144594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An extraction-free one-pot assay for rapid detection of Klebsiella pneumoniae by combining RPA and CRISPR/Cas12a 结合 RPA 和 CRISPR/Cas12a 快速检测肺炎克雷伯氏菌的免提取一次检测法

IF 10.7 1区生物学

Biosensors and Bioelectronics Pub Date : 2024-09-05 DOI: 10.1016/j.bios.2024.116740

引用次数: 0

Smartphone-based point-of-care photoelectrochemical immunoassay coupling with ascorbic acid-triggered photocurrent-polarity conversion switching 基于智能手机的护理点光电化学免疫测定与抗坏血酸触发的光电流-极性转换耦合。

IF 10.7 1区生物学

Biosensors and Bioelectronics Pub Date : 2024-09-05 DOI: 10.1016/j.bios.2024.116749

{"title":"Smartphone-based point-of-care photoelectrochemical immunoassay coupling with ascorbic acid-triggered photocurrent-polarity conversion switching","authors":"","doi":"10.1016/j.bios.2024.116749","DOIUrl":"10.1016/j.bios.2024.116749","url":null,"abstract":"<div><p>Photocurrent-polarity conversion strategies are typically realized by constructing complex photovoltaic electrodes or changing the relevant conditions, but most involve poor photogenerated carrier transfer efficiency and cumbersome experimental steps. To this end, a photoelectrochemical (PEC) biosensor by utilizing ascorbic acid (AA)-induced photocurrent-polarity-switching was proposed for the detection of carcinoembryonic antigen (CEA). Under light excitation, the electron donor AA was oxidized by the photogenerated holes of photoactive material Co-NC/CdS, resulting in the conversion of cathodic photocurrent to the anodic direction. In the presence of the target CEA, alkaline phosphatase (ALP) was introduced into the microplates by the sandwiched immunoreaction, which then catalyzed the production of AA from ascorbic acid-2-phosphate (AAP). Finally, the catalytic product AA was transferred onto Co-NC/CdS-modified screen-printed carbon electrode, thus activating photocurrent-polarity-switching platform. The anodic photocurrent values gradually increased with increasing CEA concentration in the range of 0.02–80 ng mL<sup>−1</sup> and reached a limit of detection (LOD) of 8.47 pg mL<sup>−1</sup> (S/N = 3). In addition, the results of actual sample detection prove the reliability of the constructed PEC biosensor. Importantly, this work relies on a mobile smartphone wireless Bluetooth device coupled with the PEC biosensor for immediate detection, providing another idea for detecting CEA in clinical diagnosis.</p></div>","PeriodicalId":259,"journal":{"name":"Biosensors and Bioelectronics","volume":null,"pages":null},"PeriodicalIF":10.7,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142144519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Electronic detection of apoptotic cells on a microchip 在微芯片上对凋亡细胞进行电子检测

IF 10.7 1区生物学

Biosensors and Bioelectronics Pub Date : 2024-09-05 DOI: 10.1016/j.bios.2024.116750

{"title":"Electronic detection of apoptotic cells on a microchip","authors":"","doi":"10.1016/j.bios.2024.116750","DOIUrl":"10.1016/j.bios.2024.116750","url":null,"abstract":"<div><p>Robust and rapid detection of apoptosis in cells is crucially needed for diagnostics, drug discovery, studying pathogenic mechanisms and tracking patient response to medical interventions and treatments. Traditionally, the methods employed to detect apoptosis rely on complex instrumentation like flow cytometers and fluorescence microscopes, which are both expensive and complex-to-operate except in centralized laboratories with trained labor. In this work, we introduce a microfluidic device that can screen cells in a suspension for apoptosis markers and report the assays results as electronic data. Specifically, our device identifies apoptotic cells by detecting externalized phosphatidylserine on a cell membrane – a well-established biomarker that is also targeted by fluorophore-based labeling in conventional assays. In our device, apoptotic cells are discriminated from others through biochemical capture followed by transduction of individual capture events into electrical signals via integrated electrical sensors. The developed technology was tested on simulated samples containing controlled amounts of cells with artificially-induced apoptosis and validated by benchmarking against conventional flow cytometry. Combining sample manipulation and electronic detection on a disposable microfluidic chip, our cell apoptosis assay is amenable to be implemented in a variety of settings and therefore has the potential to create new opportunities for cell-based diagnostics and therapeutics and contribute to improved healthcare outcomes on a large scale.</p></div>","PeriodicalId":259,"journal":{"name":"Biosensors and Bioelectronics","volume":null,"pages":null},"PeriodicalIF":10.7,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142225431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Machine learning-assisted melamine-Cu nanozyme and cholinesterase integrated array for multi-category pesticide intelligent recognition 机器学习辅助三聚氰胺-铜纳米酶和胆碱酯酶集成阵列用于多类农药智能识别。

IF 10.7 1区生物学

Biosensors and Bioelectronics Pub Date : 2024-09-04 DOI: 10.1016/j.bios.2024.116747

{"title":"Machine learning-assisted melamine-Cu nanozyme and cholinesterase integrated array for multi-category pesticide intelligent recognition","authors":"","doi":"10.1016/j.bios.2024.116747","DOIUrl":"10.1016/j.bios.2024.116747","url":null,"abstract":"<div><p>Expanding target pesticide species and intelligent pesticide recognition were formidable challenges for existing cholinesterase inhibition methods. To improve this status, multi-active Mel-Cu nanozyme with mimetic Cu-N sites was prepared for the first time. It exhibited excellent laccase-like and peroxidase-like activities, and can respond to some pesticides beyond the detected range of enzyme inhibition methods, such as glyphosate, carbendazim, fumonisulfuron, etc., through coordination and hydrogen bonding. Inspired by the signal complementarity of Mel-Cu and cholinesterase, an integrated sensor array based on the Mel-Cu laccase-like activity, Mel-Cu peroxidase-like activity, acetylcholinesterase, and butyrylcholinesterase was creatively constructed. And it could successfully discriminate 12 pesticides at 0.5–50 μg/mL, which was significantly superior to traditional enzyme inhibition methods. Moreover, on the basis of above array, a unified stepwise prediction model was built using classification and regression algorithms in machine learning, which enabled concentration-independent qualitative identification as well as precise quantitative determination of multiple pesticide targets, simultaneously. The sensing accuracy was verified by blind sample analysis, in which the species was correctly identified and the concentration was predicted within 10% error, suggesting great intelligent recognition ability. Further, the proposed method also demonstrated significant immunity to interference and practical application feasibility, providing powerful means for pesticide residue analysis.</p></div>","PeriodicalId":259,"journal":{"name":"Biosensors and Bioelectronics","volume":null,"pages":null},"PeriodicalIF":10.7,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142144589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A ferrous fluorescence lifetime response probe for monitoring changes in lipid droplets during ferroptosis and imaging in liver disease model 亚铁荧光寿命响应探针，用于监测铁突变过程中脂滴的变化和肝病模型成像。

IF 10.7 1区生物学

Biosensors and Bioelectronics Pub Date : 2024-09-04 DOI: 10.1016/j.bios.2024.116742

{"title":"A ferrous fluorescence lifetime response probe for monitoring changes in lipid droplets during ferroptosis and imaging in liver disease model","authors":"","doi":"10.1016/j.bios.2024.116742","DOIUrl":"10.1016/j.bios.2024.116742","url":null,"abstract":"<div><p>Ferrous ions (Fe<sup>2</sup>⁺) accumulation and abnormal alterations in lipid droplets (LDs) are closely associated with ferroptosis. In the liver, excessive iron accumulation promotes oxidative stress and exacerbates lipid droplet accumulation, while the disruption of iron homeostasis may also affect the formation and size of lipid droplets, their increased number and size can exacerbate the severity of disease under fatty liver conditions. The leads to hepatocyte damage, further triggering liver inflammation, fibrosis, and ultimately resulting in cirrhosis and hepatocellular carcinoma. Therefore, real-time monitoring of iron ion and lipid droplet changes is crucial for assessing the severity of liver disease, disease progression, and understanding the mechanisms of ferroptosis. We have developed a fluorescent probe, NRFep, for real-time monitoring of iron ion fluctuations and visualization of lipid droplet changes in ferroptosis and liver disease models. NRFep is specific and sensitive to iron ions and exhibits excellent stability in both cells and animal models. In addition, NRFep can be used to monitor changes in iron ions and lipid droplets in mouse liver injury and fatty liver models. Through fluorescence lifetime imaging technology, NRFep can also study the dynamic changes of intracellular iron ion content. NRFep provides a powerful tool for studying ferroptosis and related diseases, and its unique dual-monitoring function opens up new possibilities for developing new diagnostic and therapeutic strategies.</p></div>","PeriodicalId":259,"journal":{"name":"Biosensors and Bioelectronics","volume":null,"pages":null},"PeriodicalIF":10.7,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142144592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0