Performance Evaluation for Medium Voltage MIMO-OFDM Power Line Communication System

Power line communication(PLC)provides intelligent electrical functions such as power quality measurement,fault surveys,and remote control of electrical network.Most of research works have been done in low voltage(LV)scenario due to the fast development of in-home PLC.The aim of this paper is to evaluate the link-level performance of a medium voltage(MV)MIMO-OFDM communication system based on transmission link under underground power line channel.The MIMO channel is modeled as a modified multipath model in the presence of impulsive noise and background noise.We first perform a measurement on the practical MV MIMO channel parameters for a section of buried cable of 1 km long in Ganzhou city,Jiangxi province,China.Based on the measured channel,we design the frame structure based on an IEEE standard for broadband over power line networks[1]to support MV MIMO-OFDM transmission.According to designed frame structure,we design an encoder and a decoder for a dual binary tail-biting turbo code and optimize some key decoder parameters for low bit error rate performance.Finally,the link-level performance for both spatial multiplexing and spatial diversity are evaluated.Numeral results show that MV MIMO-OFDM is a promising approach to provide both high data rate and link reliability for PLC.

An Algorithm Based on Markov Chain to Improve Edge Cache Hit Ratio for Blockchain-Enabled IoT

Reasonable allocation of storage and computing resources is the basis of building big data system.With the development of IoT(Internet of Things),more data will be brought.A three-layer architecture includes smart devices layer,edge cloud layer and blockchain-based distributed cloud layer.Blockchain is used in IoT for building a distributed decentralize P2P architecture to deal with the secure issue while edge computing deals with increasing volume of data.Edge caching is one of the important application scenarios.In order to allocate edge cache resources reasonably,to improve the quality of service and to reduce the waste of bandwidth resources,this paper proposes a content selection algorithm of edge cache nodes.The algorithm adopts markov chain model,improves the utilization of cache space and reduces the content transmission delay.The hierarchical caching strategy is adopted and the secondary cache stores slides of contents to expand the coverage of cached content and to reduce user waiting time.Regional node cooperation is adopted to expand the cache space and to support the regional preference of cache content.Compared with the classical substitution algorithm,simulation results show that the algorithm in this paper has higher cache hit ratio and higher space utilization.

C_(12-14)仲醇乙氧基化物的合成与性能研究

以KOH、CH_(3)OK为催化剂催化C_(12-14)仲醇乙氧基化反应合成了环氧乙烷加合数为3的仲醇聚氧乙烯醚表面活性剂SAEO_(3)。评价了两种催化剂的催化C_(12-14)仲醇乙氧基化反应活性。系统考察了催化剂的变化对SAEO_(3)性能(包括表面性能、物化性能和应用性能等)的影响。并将实验室合成的SAEO_(3)与市售Secol-30产品的各项性能进行对比。得出的结论如下:相比于KOH催化剂,利用CH_(3)OK催化仲醇乙氧基化反应时,该催化剂反应活性和产物选择性较高。SAEO_(3)与市售Secol-30产品物化性能比较接近,CH_(3)OK催化得到的仲醇醚的浊点高于其他产品。SAEO_(3)的cmc低于市售Secol-30产品。但Secol-30降低表面张力的能力更加优越些,在较低浓度下可将水溶液的表面张力降低至28.25 mN/m。SAEO_(3)产品的应用性能润湿、乳化、泡沫,去污能力均优于Secol-30。该类仲醇聚氧乙烯醚属于低泡表面活性剂,无凝胶相区且去污能力优越,因此可将其应用于浓缩洗涤剂产品中。

Background-free latent fingerprint imaging based on nanocrystals with long-lived luminescence and pH-guided recognition

Latent fingerprints (LFPs)are highly specific to individuals,and LFP imaging has played an important role in areas such as forensic investigation and law enforcement.Presently,LFP imaging still faces considerable problems,including background interference and destructive and complex operations.Herein,we have designed a background-free,nondestructive,and easy-to-perform method for LFP imaging based on pH-mediated recognition of LFPs by carboxyl group- functionalized Zn2GeO4:Mn (ZGO:Mn-COOH)persistent luminescence nanorods (PLNRs).By simply adjusting the pH of the ZGO:Mn-COOH colloid dispersion to a certain acidic range,the negatively charged ZGO:Mn-COOH readily binds to protonated fingerprint ridges via electrostatic attraction.The ZGO:Mn-COOH colloid dispersion can be stored in portable commercial spray bottles,and the LFPs have been easily detected in situ by simply dropping the colloid dispersion on the LFPs.Moreover,since the ZGO:Mn-COOH can remain luminescent after excitation ceases,background color and background fluorescence interference were efficiently removed by simply capturing the luminescent LFP images after the excitation ceased.The entire LFP imaging process can be easily conducted without any destructive or complex operations.Due to the great versatility of the developed method for LFP imaging,clear LFP images with well-resolved ridge patterns were obtained.The designed background-free,nondestructive,and easy-to-perform LFP imaging strategy has great potential for future applications, such as forensic investigations and law enforcement.

Correction to:Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In the original version of this article,the legend to Figure 1 was incorrect.The corrected legend is given below.Fig.1 A Location of the primers in SARS-CoV-2 genome.B Sequence comparison among seven human coronaviruses(SARS-CoV-2,SARS-CoV,MERS-CoV,HCoVOC43,HCoV-HKU-1,HCoV-NL63 and HCoV-229E).C Cross-reactivity test of the novel SARS-CoV-2 RTLAMP assay to other common respiratory viruses.Tested common respiratory viruses include HCoV-HKU-1,HCoV-NL63,HCoV-OC43,HCoV-229E,influenza A,B,and C viruses,parainfluenza viruses type 1-3,enterovirus,respiratory syncytial virus A and B groups,human rhinovirus,human metapneumovirus,adenovirus and bocavirus.

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

Dear Editor,Since early December 2019, a large outbreak of pneumonia caused by a novel coronavirus(COVID-19) had emerged in Wuhan, China(Wu et al. 2020 a, b;Zhou et al. 2020;Zhu et al. 2020;Jiang and Shi 2020). Similar to severe acute respiratory syndrome coronavirus(SARS-CoV) and Middle East respiratory syndrome coronavirus(MERS-CoV),the new coronavirus also belongs to Betacoronavirus。

Design of high stability thin-film transistor biosensor for the diagnosis of bladder cancer

Bladder cancer is the most common malignant tumor in the urinary system,with high morbidity,mortality and recurrence after surgery.However,current bladder cancer urine diagnosis methods are limited by the low accuracy and specificity due to the low abundance of bladder cancer biomarkers in the urine with complex biological environments.Herein,we present a high stability indium gallium zinc oxide field effect transistor(IGZO-FET)biosensor for efficient identification of bladder cancer biomarkers from human urine samples.The recognition molecular functionalized IGZO-FET biosensor exhibits stable electronic and sensing performance due to the large-area fabrication of IGZO thin-film FET.Owing to the excellent electrical performance of IGZO-FET,the IGZO-FET biosensor exhibits high sensitivity and extremely low detection limit(2.7 amol/L)towards bladder cancer biomarkers.The IGZO-FET biosensor is also able to directly detect bladder tumor biomarker in human urine with high sensitivity and specificity,and could differentiate bladder cancer patients’urine samples from healthy donors effectively.These results indicate that our designed high-performance biosensor shows great potential in the application of portable digital bladder cancer diagnosis devices.

Self-assembled nanozyme complexes with enhanced cascade activity and high stability for colorimetric detection of glucose

Construction of multi-enzyme complexes not only can help expand the understanding of biological mechanisms, but also holds great promise in biosynthesis, biosensing and biomedicine. Herein, a hybrid multi-enzyme system, CeO2/glucose oxidase(GOx) nanocomplex was developed via self-assembly and exhibited excellent catalytic activity toward cascade reactions. Compared to mixed GOx and CeO2, the nanocomplexes displayed enhanced efficiency, mainly attributed to the minimal diffusion of intermediate in the nanocomplexes system. Moreover, the nanocomplexes exhibited outstanding long-term stability and excellent recyclability. Benefiting from these merits, a highly sensitive and selective biosensor for colorimetric detection of glucose was constructed based on CeO2/GOx nanocomplexes. Such a self-assembled nanozyme complex offers a simple and efficient example to build spatially confined multi-enzyme systems to potentiate their applications in energy conversion,detoxification and bioanalysis.

Tongue coating microbiome as a potential biomarker for gastritis including precancerous cascade

The development of gastritis is associated with an increased risk of gastric cancer. Current invasive gastritis diagnostic methods are not suitable for monitoring progressIn this work based on 78 gastritis patients and 50 healthy individuals, we observed that the variation of tongue-coating microbiota was associated with the occurrenee and development of gastritis. Twenty-one microbial species were identified for differentiating tongue-coating microbiomes of gastritis and healthy individuals. Pathways such as microbial metabolism in diverse environments, biosynthesis of antibiotics and bacterial chemotaxis were up-regulated in gastritis patients. The abundance of Campylobacter concisus was found associated with the gastric precancerous cascade. Furthermore, Campylobacter concisus could be detected in tongue coating and gastric fluid in a validation cohort containing 38 gastritis patients. These observations provided biological evidence of tongue diagnosis in traditional Chinese medicine, and indicated that tongue-coating microbiome could be a potential non-invasive biomarker, which might be suitable for long-term monitoring of gastritis.

Construction of MoS2 field effect transistor sensor array for the detection of bladder cancer biomarkers

Bladder cancer is one of the commonest malignant tumors of urinary system with high recurrence. However, currently developed bladder cancer urine diagnosis methods are hindered by the low detection sensitivity and accuracy. Herein, a molybdenum disulfide(MoS2) nanosheets-based field effect transistor(FET) sensor array was constructed for simultaneous detection of multiple bladder cancer biomarkers in human urine. With the excellent electronic property of MoS2 and the high specific identification capability of recognition molecules, the proposed biosensor array could simultaneously detect nuclear matrix protein 22(NMP22) and cytokeratin 8(CK8) with a wide linear range of 10-6–10-1 pg mL-1 and an ultra-low detection limit of 0.027 and 0.019 aM, respectively. Furthermore, this highly sensitive and specific MoS2 FET sensor array could be used to identify bladder cancer biomarkers from human urine samples. This designed high-performance biosensor array shows great potential in the future diagnosis of bladder cancer.

Ferriporphyrin-inspired MOFs as an artificial metalloenzyme for highly sensitive detection of H2O2 and glucose

Metalloenzymes which employ metal species and organic ligands as central active sites play significant roles in various biological activities.Development of artificial metalloenzymes can help to understand the related physiological mechanism and promote the applications of metalloenzymes in biosynthesis,energy conversion and biosensing.In this work,inspired by the active sites of ferriporphyrin-based metalloenzymes,Fe-MOFs by using ferric as the metal center and a porphyrin analog as the organic liga nd were developed as an artificial metalloenzyme.The Fe-MOFs exhibit high peroxidase-like catalytic activity with excellent long-term stability.Moreover,highly sensitive biosensors were built to detect H2 O2 and glucose based on the Fe-MOFs.Such MOFs-based artificial metalloenzyme offers an efficient strategy for the development of highly stable and efficient metalloenzymes,showing great potential in catalysis,energy transfer,biosensing and medical diagnosis.

A Novel 2-dimensional Multiplex qPCR Assay for Single-Tube Detection of Nine Human Herpesviruses

Human herpesviruses are double-stranded DNA viruses that are classified into nine species.More than 90%of adults are ever infected with one or more herpesviruses.The symptoms of infection with different herpesviruses are diverse ranging from mild or asymptomatic infections to deadly diseases such as aggressive lymphomas and sarcomas.Timely and accurate detection of herpesvirus infection is critical for clinical management and treatment.In this study,we established a single-tube nonuple qPCR assay for detection of all nine herpesviruses using a 2-D multiplex qPCR method with a house-keeping gene as the internal control.The novel assay can detect and distinguish different herpesviruses with 30 to 300 copies per 25µL single-tube reaction,and does not cross-react with 20 other human viruses,including DNA and RNA viruses.The robustness of the novel assay was evaluated using 170 clinical samples.The novel assay showed a high consistency(100%)with the single qPCR assay for HHVs detection.The features of simple,rapid,high sensitivity,specificity,and low cost make this assay a high potential to be widely used in clinical diagnosis and patient treatment.