97 research outputs found

    Passive Testing of Electrically Small Antennas in Electronic Systems

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    In This Paper, a Measurement Scheme, Which Eliminates the Interference of the Common Mode Current, for Electrically Small Antennas is Proposed. Firstly, the Causes and Effects of Common Mode Currents Appearing in Passive Testing Are Analyzed. Then, the Influence of Different Outlet Points of Coaxial Cable on the Passive Testing of Antenna is Studied Experimentally and Numerically. According to the Distribution of the Common Mode Currents on the Ground Plane When the Coaxial Cable Feeds the Antenna, the Minimum Current Point is Selected as the Outlet Point of the Coaxial Cable to Reduce the Influence of Common Mode Current. Additionally, the Influence of the Coaxial Cable\u27s Arrangement and the Soldering Area between Coaxial Cable and Ground Plane on the Antenna under Test is Studied. Finally, Considering the Output Point, Arrangement and Soldering Area of the Coaxial Cable, a Measurement Scheme to Improve the Passive Measurement Accuracy of the Electrically Small Antenna is Proposed

    Influence of isoniazid on T lymphocytes, cytokines, and macrophages in rats

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    T lymphocytes, cytokines, and macrophages play important roles in the clearance of Mycobacterium tuberculosis (Mtb) by the immune system. This study aimed to investigate the effects of isoniazid on the functions of both innate and adaptive immune cells. Healthy rats were randomly divided into experimental and control groups. Each group was randomly divided into three subgroups and named according to the duration of drug feeding, 1, 3, and 3 months followed by drug withdrawal for 1 month. The experimental groups were fed with isoniazid (12 mg/mL) and the control groups with normal saline. The percentage of CD4+ and CD8+ T lymphocytes, level of interleukin (IL)-12 and interferon (IFN)-Ī³, and function of macrophages were determined at these three time points. Isoniazid significantly increased the percentage of CD4+ T lymphocytes and the CD4+/CD8+ T lymphocyte cell ratio (P < 0.05). It transiently (<1 month) enhanced the functions of rat macrophages significantly (P < 0.05). In summary, isoniazid could increase the percentage of CD4+ T lymphocytes, CD4+/CD8+ T lymphocyte cell ratio, and enhance macrophage function in healthy rats

    A Planar Low-Profile Meander Antenna Design for Wireless Terminal Achieving Low RF Interference and High Isolation in Multi-Antenna Systems

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    In this article, a meander line internal antenna used for wireless terminal is proposed. The current of this antenna is mostly distributed on the antenna radiator itself, rather than on the main board of the wireless device. As a result, the chance of having radiofrequency (RF) interference issues, which usually result in receiver desensitization in wireless radios, can be significantly reduced. The antenna has good radiation performance in the vertical polarization with a low physical profile, compared with the existing antenna designs for typical wireless terminals. The antenna has efficiency similar to the monopole antenna with much less reference/ground plane dependence, achieving lower RF interference, which is demonstrated by the noise coupling measurements in a predefined digital clock - antenna configuration. Furthermore, the mutual coupling (i.e., isolation) between two such antennas is studied and the envelope correlation coefficient between the two antennas is found to be low. A router assembled with the two proposed antennas is tested, and the total isotropic sensitivity is found lower compared with monopole antennas, due to the characteristics of low RF interference and high isolation of the proposed antenna

    Deep Learning Based Segmentation of Various Brain Lesions for Radiosurgery

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    Semantic segmentation of medical images with deep learning models is rapidly developed. In this study, we benchmarked state-of-the-art deep learning segmentation algorithms on our clinical stereotactic radiosurgery dataset, demonstrating the strengths and weaknesses of these algorithms in a fairly practical scenario. In particular, we compared the model performances with respect to their sampling method, model architecture, and the choice of loss functions, identifying the suitable settings for their applications and shedding light on the possible improvements

    Identification of CD8+ cytotoxic T lymphocyte epitopes from porcine reproductive and respiratory syndrome virus matrix protein in BALB/c mice

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    Twenty-seven nanopeptides derived from the matrix (M) protein of porcine reproductive and respiratory syndrome virus (PRRSV) were screened for their ability to elicit a recall interferon-Ī³ (IFN-Ī³) response from the splenocytes of BALB/c mice following DNA vaccination and a booster vaccination with recombinant vaccinia virus rWR-PRRSV-M. We identified two peptides (amino acid residues K93FITSRCRL and F57GYMTFVHF) as CD8+ cytotoxic T lymphocyte (CTL) epitopes. These peptides elicited significant numbers of IFN-Ī³ secreting cells, compared with other M nonapeptides and one irrelevant nonapeptide. Bioinformatics analysis showed that the former is an H-2Kd-restricted CTL epitope, and the latter is an H-2Dd-restricted CTL epitope. Multiple amino acid sequence alignment among different PRRSV M sequences submitted to GenBank indicated that these two CTL epitopes are strongly conserved, and they should therefore be considered for further research on the mechanisms of cellular immune responses to PRRSV

    MYH9 is an Essential Factor for Porcine Reproductive and Respiratory Syndrome Virus Infection

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    Porcine reproductive and respiratory syndrome (PRRS) caused by the PRRS virus (PRRSV) is an important swine disease worldwide. PRRSV has a limited tropism for certain cells, which may at least in part be attributed to the expression of the necessary cellular molecules serving as the virus receptors or factors on host cells for virus binding or entry. However, these molecules conferring PRRSV infection have not been fully characterized. Here we show the identification of non-muscle myosin heavy chain 9 (MYH9) as an essential factor for PRRSV infection using the anti-idiotypic antibody specific to the PRRSV glycoprotein GP5. MYH9 physically interacts with the PRRSV GP5 protein via its C-terminal domain and confers susceptibility of cells to PRRSV infection. These findings indicate that MYH9 is an essential factor for PRRSV infection and provide new insights into PRRSV-host interactions and viral entry, potentially facilitating development of control strategies for this important swine disease

    Feasibility of delta radiomicsā€“based pCR prediction for rectal cancer patients treated with magnetic resonanceā€“guided adaptive radiotherapy

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    Magnetic resonanceā€“guided adaptive radiotherapy (MRgART) represents the latest frontier in precision radiotherapy. It is distinguished from other modalities by the possibility of acquiring high-contrast soft tissue images, combined with the ability to recalculate and re-optimize the plan on the daily anatomy. The extensive database of available images offers ample scope for using disciplines such as radiomics to try to correlate features and outcomes. This study aimed to correlate the change of radiomics feature along the treatment to pathological complete response (pCR) for locally advanced rectal cancer (LARC) patients. Twenty-eight LARC patients undergoing neoadjuvant chemoradiotherapy (nCRT) with a short course (25 Gy, 5 Gy Ɨ 5f) MRgART at 1.5 Tesla MR-Linac were enrolled. The T2-weighted images acquired at each fraction, corresponding target delineation, pCR result of the surgical specimen, and clinical variables were collected. Seven families of features [First Order, Shape, Gray-level Co-occurrence Matrix (GLCM), Gray-level Dependence Matrix (GLDM), Gray-level Run Length Matrix (GLRLM), Gray-level Size Zone Matrix (GLSZM), and Neighborhood Gray Tone Difference Matrix (NGTDM)] were extracted, and delta features were calculated from the ratio of features of each successive fraction to those of the first fraction. Mann-Whitney U test and LASSO were utilized to reduce the dimension of features and select those features that are most significant to pCR. At last, the radiomics signatures were established by linear regression with the final set of features and their coefficients. A total of 581 radiomics features were extracted, and 2,324 delta features were calculated for each patient. Nineteen features and delta features, and one clinical variable (cN) were significant (p< 0.05) to pCR; seven predictive features were further selected and included in the linear regression to construct the radiomics signature significantly discriminating pCR and non-pCR groups (p< 0.05). Delta features based on MRI images acquired during a short course MRgART could potentially be used to predict treatment response in LARC patients undergoing nCRT

    Effect of Ultrasonic Treatment on Vitis vinifera L. Cell Wall Pectin Components

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    In order to clarify the content and structural changes of different pectin fractions in grape cell walls under ultrasonic treatment, the grapes were treated with different ultrasonic time and ultrasonic power in this study, and the content of pectin fractions, composition of monosaccharides and structural changes of grape cell walls were analyzed by means of carbazole sulfuric acid method, PMP pre-column derivatization, high-performance liquid gel chromatography , scanning electron microscopy, Fourier transform infrared spectroscopy and circular dichroism. Results showed that the highest and the lowest contents in fresh grape cell walls were alkali-soluble pectin (NSP) and chelate pectin (CSP), respectively, and they were 27.41 mg/g AIR and 8.25 mg/g AIR. The total pectin decreased after ultrasonic treatments, in which the water-soluble pectin (WSP) increased and the CSP and NSP decreased. A total of six monosaccharides were detected in three pectins, and the monosaccharides of different pectin were not the same. The galactose and arabinose were high in WSP, the glucuronic acid was the most abundant of CSP and the rhamnose were the highest in NSP. After ultrasonic treatment, the contents of monosaccharides decreased, while the composition did not change, and the main chain structure of pectin was no change, but the linear structure and the degree of branch chain were changed. With the increase of ultrasonic times and powers, the molecular weight of different pectins declined gradually. And in the microstructure showed a more loose morphology. In addition, ultrasonic treatment had an effect on the structure and chain conformation of CSP and NSP, which made their maximum response values shift, and the effect of ultrasonic power was more significant. In conclusion, ultrasonic treatment could reduce the pectin and monosaccharide contents in grape cell walls, and affect the molecular linear structure and molecular chain conformation of pectin. These results can provide theoretical basis for the quality change of grape products under ultrasonic treatment

    Personalized connectivity-based network targeting model of transcranial magnetic stimulation for treatment of psychiatric disorders: computational feasibility and reproducibility

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    Repetitive transcranial magnetic stimulation (rTMS) holds promise for treating psychiatric disorders; however, the variability in treatment efficacy among individuals underscores the need for further improvement. Growing evidence has shown that TMS induces a broad network modulatory effect, and its effectiveness may rely on accurate modulation of the pathological network specific to each disorder. Therefore, determining the optimal TMS coil setting that will engage the functional pathway delivering the stimulation is crucial. Compared to group-averaged functional connectivity (FC), individual FC provides specific information about a personā€™s brain functional architecture, offering the potential for more accurate network targeting for personalized TMS. However, the low signal-to-noise ratio (SNR) of FC poses a challenge when utilizing individual resting-state FC. To overcome this challenge, the proposed solutions include increasing the scan duration and employing the cluster method to enhance the stability of FC. This study aimed to evaluate the stability of a personalized FC-based network targeting model in individuals with major depressive disorder or schizophrenia with auditory verbal hallucinations. Using resting-state functional magnetic resonance imaging data from the Human Connectome Project, we assessed the modelā€™s stability. We employed longer scan durations and cluster methodologies to improve the precision in identifying optimal individual sites. Our findings demonstrate that a scan duration of 28 minutes and the utilization of the cluster method achieved stable identification of individual sites, as evidenced by the intraindividual distance falling below the ~1cm spatial resolution of TMS. The current model provides a feasible approach to obtaining stable personalized TMS targets from the scalp, offering a more accurate method of TMS targeting in clinical applications
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