Detection of the CD8+ T cell immune response in mice infected with OVA-Listeria monocytogenes

Summary: T cells are able to recognize and kill pathogens that infect host cells, including bacteria, viruses, and tumor cells. Here, we present a protocol to detect T cell function and bacterial load in OVA-Listeria monocytogenes-infected mice. We provide a detailed description of the steps for detecting OVA-specific CD8+ T cells and their cytokine expression levels in splenocytes using flow cytometry on day 7 after infecting mice with OVA-Listeria monocytogenes. Additionally, we describe the steps for detecting the OVA-Listeria monocytogenes load in the mouse liver.For complete details on the use and execution of this protocol, please refer to Chen et al.1 : Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics

Rational molecular design for isoindigo-based polymer semiconductors with high ductility and high electrical performance

Achieving good electrical properties and ductility of polymer semiconductors has always been challenging. In this work, a series of isoindigo derivative-based conjugated polymers was studied in an effort to gain a better understanding of the influence of polymer main and side chain structures on their electrical and mechanical properties. The results suggested that the introduction of alkyl side chains onto the donors can significantly enhance the mechanical properties of isoindigo-based polymers; however, the electrical properties of the films greatly deteriorated due to the large steric hindrance by the chain. The insertion of strong electron-withdrawing units, such as benzodifurandione, into the isoindigo chain during the synthesis of a bis(2-oxoindolin-3-ylidene)-benzodifuran-dione (BIBDF)-based polymer (PBIBDF-BT) significantly boosted the electrical properties of the films without decreasing their mechanical properties. The crack onset in PBIBDF-BT thin films was observed at 50% tensile strain. In addition, PBIBDF-BT thin films exhibited bipolar transport properties with both electron and hole mobilities greater than 0.1 cm(2) V-1 s(-1) at 100% strain. It is found that the improvement of PBIBDF-BT performance is attributed to its proper molecular structure. The long alkyl side chains significantly increase the ductility of PBIBDF-BT thin films, and the strong electron-withdrawing BIBDF unit in the main chains enhances the local aggregation, resulting in a significant increase in mobility. These results indicate that the mechanical and electrical properties of conjugated polymers could simultaneously be improved through reasonable molecular design.11Nsciescopu

Violence detection from ECG signals:a preliminary study

Abstract This research studied violence detection from less than 6-second ECG signals. Features were calculated based on the Bivariate Empirical Mode Decomposition (BEMD) and the Recurrence Quantification Analysis (RQA) applied to ECG signals from violence simulation in a primary school, involving 12 pupils from two grades. The feature sets were fed to a kNN classifier and tested using 10-fold cross validation and leave-one-subject-out (LOSO) validation in subject-dependent and subject-independent training models respectively. Features from BEMD outperformed the ones from RQA in both 10-fold cross validation, i.e. 88% vs. 73% (2nd grade pupils) and 87% vs. 81% (5th grade pupils), and LOSO validation, i.e. 77% vs. 75% (2nd grade pupils) and 80% vs. 76% (5th grade pupils), but have larger variation than the ones from RQA in both validations. Average performances for subject-specific system in 10-fold cross validation were 100% vs. 93% (2nd grade pupils) and 100% vs. 97% (5th grade pupils) for features from the BEMD and the RQA respectively. The results indicate that ECG signals as short as 6 seconds can be used successfully to detect violent events using subject-specific classifiers

Newcastle Disease Virus-Based Live Attenuated Vaccine Completely Protects Chickens and Mice from Lethal Challenge of Homologous and Heterologous H5N1 Avian Influenza Viruses

H5N1 highly pathogenic avian influenza virus (HPAIV) has continued to spread and poses a significant threat to both animal and human health. Current influenza vaccine strategies have limitations that prevent their effective use for widespread inoculation of animals in the field. Vaccine strains of Newcastle disease virus (NDV), however, have been used successfully to easily vaccinate large numbers of animals. In this study, we used reverse genetics to construct a NDV that expressed an H5 subtype avian influenza virus (AIV) hemagglutinin (HA). Both a wild-type and a mutated HA open reading frame (ORF) from the HPAIV wild bird isolate, A/Bar-headed goose/Qinghai/3/2005 (H5N1), were inserted into the intergenic region between the P and M genes of the LaSota NDV vaccine strain. The recombinant viruses stably expressing the wild-type and mutant HA genes were found to be innocuous after intracerebral inoculation of 1-day-old chickens. A single dose of the recombinant viruses in chickens induced both NDV- and AIV H5-specific antibodies and completely protected chickens from challenge with a lethal dose of both velogenic NDV and homologous and heterologous H5N1 HPAIV. In addition, BALB/c mice immunized with the recombinant NDV-based vaccine produced H5 AIV-specific antibodies and were completely protected from homologous and heterologous lethal virus challenge. Our results indicate that recombinant NDV is suitable as a bivalent live attenuated vaccine against both NDV and AIV infection in poultry. The recombinant NDV vaccine may also have potential use in high-risk human individuals to control the pandemic spread of lethal avian influenza

Emotion recognition and school violence detection from children speech

Abstract School violence is a serious problem all over the world, and violence detection is significant to protect juveniles. School violence can be detected from the biological signals of victims, and emotion recognition is an important way to detect violence events. In this research, a violence simulation experiment was designed and performed for school violence detection system. Emotional voice from the experiment was extracted and analyzed. Consecutive elimination process (CEP) algorithm was proposed for emotion recognition in this paper. After parameters optimization, SVM was chosen as the classifier and the algorithm was validated by Berlin database which is an emotional speech database of adults, and the mean accuracy for seven emotions was 79.05%. The emotional speech database of children extracted in violence simulation was also classified by SVM classifier with proposed CEP algorithm, and the mean accuracy was 66.13%. The results showed that high classification performance could be achieved with the CEP algorithm. The classification result was also compared with database of adults, and the results indicated that children and adults’ voice should be treated differently in speech emotion recognition researches. The accuracy of children database is lower than adult database; the accuracy of violence detection will be improved by other signals in the system

Helical Nanofibrils of Block Copolymer for High-Performance Ammonia Sensors

Conjugated polymers with a helical structure have been in rapid development in recent years because of their potential applications in chemical and biological sensors. We demonstrate the fabrication and characterization of helical nanofibrils of block copolymer poly­(4-iso-cyano-benzoic acid 5-(2-dimethylamino-ethoxy)-2-nitro-benzylester)-<i>b</i>-poly­(3-hexylthiophene) (PPI­(-DMAENBA)-<i>b</i>-P3HT) via a transfer-etching method. The density and lateral length of nanofibrils can be facilely controlled by regulating the process conditions, which, in turn, directly determine the electronic property. Organic field effect transistors based on helical nanofibrils were successfully fabricated with the highest mobility of 9.1 × 10^–3 cm²/(V s)⁻¹, an on/off ratio of 3.4 × 10⁵, and high bias stability. The helical nanofibrils were proved to be beneficial for obtaining a highly sensitive and selective chemical sensor. And, the transistor based on helical nanofibrils exhibits a relative response of 28.6% to 100 ppb ammonia, which is even much higher than the responses to 1 ppm ammonia for homo poly­(3-hexylthiophene) nanofibrils (7%) and block copolymer nanofibrils without helical structure (0.9%). The combination of helical structure with nanofibrils may provide a new strategy to fabricate high-performance chemical sensors suitable for use in environmental monitoring, industrial and agricultural production, health care, and foodsafety