BATF2 inhibits PD-L1 expression and regulates CD8+ T-cell infiltration in non-small cell lung cancer.

Immune checkpoint blockades have made huge breakthrough among some cancer types including lung cancer. However, only a small proportion of patients will benefit from immune checkpoint blockades; other patients have no or minor response to immunotherapy. The underlying mechanisms and efficient biomarkers to predict immunotherapy resistances remain unclear and lacking. In this study, BATF2 knockout mice, human xenograft mice, were used for in vivo studies. Relevant RNA and protein levels were analyzed by RT-quantitative PCR and Western blotting. As a result, we found that the expression of BATF2 is negatively correlated with expression of programmed death-ligand 1 in the plasma of patients. Mechanically, we showed that BATF2 inhibits programmed death-ligand 1 expression in cancer cells by inhibiting the PI3K-AKT pathway where ZEB2 plays an important role in this process. Based on bioinformatics analysis, we found that the function of BATF2 in promoting antitumor immune response in patients with non-small cell lung cancer, which is mediated by BATF2, enhances CD8+ T-cell infiltration as well as activation. The expression of BATF2 from circulating tumor cells and tissues can be serve as an efficient biomarker to predict diagnosis, prognosis, and immunotherapy efficacy.

Irradiated microparticles suppress prostate cancer by tumor microenvironment reprogramming and ferroptosis.

Immunogenic cell death (ICD) plays a crucial role in triggering the antitumor immune response in the tumor microenvironment (TME). Recently, considerable attention has been dedicated to ferroptosis, a type of ICD that is induced by intracellular iron and has been demonstrated to change the immune desert status of the TME. However, among cancers that are characterized by an immune desert, such as prostate cancer, strategies for inducing high levels of ferroptosis remain limited. Radiated tumor cell-derived microparticles (RMPs) are radiotherapy mimetics that have been shown to activate the cGAS-STING pathway, induce tumor cell ferroptosis, and inhibit M2 macrophage polarization. RMPs can also act as carriers of agents with biocompatibility. In the present study, we designed a therapeutic system wherein the ferroptosis inducer RSL-3 was loaded into RMPs, which were tested in in vitro and in vivo prostate carcinoma models established using RM-1 cells. The apoptosis inducer CT20 peptide (CT20p) was also added to the RMPs to aggravate ferroptosis. Our results showed that RSL-3- and CT20p-loaded RMPs (RC@RMPs) led to ferroptosis and apoptosis of RM-1 cells. Moreover, CT20p had a synergistic effect on ferroptosis by promoting reactive oxygen species (ROS) production, lipid hydroperoxide production, and mitochondrial instability. RC@RMPs elevated dendritic cell (DC) expression of MHCII, CD80, and CD86 and facilitated M1 macrophage polarization. In a subcutaneously transplanted RM-1 tumor model in mice, RC@RMPs inhibited tumor growth and prolonged survival time via DC activation, macrophage reprogramming, enhancement of CD8+ T cell infiltration, and proinflammatory cytokine production in the tumor. Moreover, combination treatment with anti-PD-1 improved RM-1 tumor inhibition. This study provides a strategy for the synergistic enhancement of ferroptosis for prostate cancer immunotherapies.

18F-FDG PET/CT characterization and response evaluation in a case of lymphomatoid granulomatosis involving the main pulmonary artery.

Main pulmonary artery (MPA) involvement of lymphomatoid granulomatosis (LYG) is extremely rare. We described fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) findings in a case with LYG originated from the MPA. Fluorine-18-FDG PET/CT demonstrated nodular hypermetabolic foci in the MPA, corresponding well to the intraluminal filling defects on CT pulmonary angiography, and the secondary right heart dysfunction was observed. Final diagnosis was made after transcatheter MPA biopsies and multi-disciplinary consultation. The patient recovered completely following the steroid therapy and MPA stenting, which was illustrated on the second 18F-FDG PET/CT.

170†GHz quasi-optical sub-harmonic mixer with a back-to-back lenses packaging based on HDI.

The paper presents a 170 GHz quasi-optical sub-harmonic mixer with a 3D-printed back-to-back lenses packaging. The quasi-optical mixer is comprised by a pair of antiparallel GaAs Schottky diodes, a patch antenna for receiving local oscillator (LO) pump signal, a symmetric-slit patch antenna for receiving radio frequency (RF) signal, dual 3D-printed lenses and a matching network. The quasi-optical mixer with a pair of antiparallel GaAs Schottky diodes is designed on a multilayer build-up printed circuit board (PCB) utilizing commercially low-cost and high-density interconnect (HDI) technology. The LO and RF antennas are placed on the front and back of the multilayer build-up substrate, respectively, thus significantly simplifying the quasi-optical design. Furthermore, dual 3D-printed lenses placed back-to-back are proposed for LO and RF antennas radiation gain enhancement and mechanical robustness. Additionally, the buried planar reflectors in the substrate maintain effective radiation isolation between the antennas. For facilitating coupling efficiency of signal power into the Schottky diodes and signal isolation between the LO pump signal and RF signal, a compact matching network with low-loss quasi-coaxial via transition structure is integrated in the mixer circuit. The measured single-sideband conversion loss is from 11.3 to 15.4 dB in an operation range of 160 to 180 GHz. The measured radiation patterns agree well with the simulated results.

Integrated plasma and exosome long noncoding RNA profiling is promising for diagnosing non-small cell lung cancer.

OBJECTIVES: Non-small cell lung cancer (NSCLC) accounts for more than 80 % of all lung cancers, and its 5-year survival rate can be greatly improved by early diagnosis. However, early diagnosis remains elusive because of the lack of effective biomarkers. In this study, we aimed to develop an effective diagnostic model for NSCLC based on a combination of circulating biomarkers. METHODS: Tissue-deregulated long noncoding RNAs (lncRNAs) in NSCLC were identified in datasets retrieved from the Gene Expression Omnibus (GEO, n=727) and The Cancer Genome Atlas (TCGA, n=1,135) databases, and their differential expression was verified in paired local plasma and exosome samples from NSCLC patients. Subsequently, LASSO regression was used to screen for biomarkers in a large clinical population, and a logistic regression model was used to establish a multi-marker diagnostic model. The area under the receiver operating characteristic (ROC) curve (AUC), calibration plots, decision curve analysis (DCA), clinical impact curves, and integrated discrimination improvement (IDI) were used to evaluate the efficiency of the diagnostic model. RESULTS: Three lncRNAs-PGM5-AS1, SFTA1P, and CTA-384D8.35 were consistently expressed in online tissue datasets, plasma, and exosomes from local patients. LASSO regression identified nine variables (Plasma CTA-384D8.35, Plasma PGM5-AS1, Exosome CTA-384D8.35, Exosome PGM5-AS1, Exosome SFTA1P, Log10CEA, Log10CA125, SCC, and NSE) in clinical samples that were eventually included in the multi-marker diagnostic model. Logistic regression analysis revealed that Plasma CTA-384D8.35, exosome SFTA1P, Log10CEA, Exosome CTA-384D8.35, SCC, and NSE were independent risk factors for NSCLC (p<0.01), and their results were visualized using a nomogram to obtain personalized prediction outcomes. The constructed diagnostic model demonstrated good NSCLC prediction ability in both the training and validation sets (AUC=0.97). CONCLUSIONS: In summary, the constructed circulating lncRNA-based diagnostic model has good NSCLC prediction ability in clinical samples and provides a potential diagnostic tool for NSCLC.

Mean platelet volume modifies the contribution of homocysteine to cardiovascular disease: A real-world study.

BACKGROUND AND AIMS: The effect of reductions in homocysteine (Hcy) on cardiovascular disease (CVD) was suggested to be modified by platelet activation, but the interaction between Hcy and platelet activation on CVD events is not well studied. Here, we aimed to examine the interaction between Hcy and platelet activation on CVD in a large, real-world population. METHODS AND RESULTS: A total of 27,234 patients with hypertension (mean 63 years, 48% male) who were registered in Taicang city and free of CVD were prospectively followed up for new CVD events from 2017 to 2020. Hcy and platelet indices including mean platelet volume (MPV) were assayed at baseline. A total of 1063 CVD events were recorded during follow-up. Hcy at baseline was significantly associated with a higher risk of CVD (HR = 1.85, P < 0.001 for log-transformed Hcy). MPV showed a significant interaction effect with Hcy on CVD (HR = 1.20, P = 0.030 for the interaction term). The association between Hcy and CVD was significantly stronger in participants with a large (vs. small) MPV (HR = 2.71 vs. 1.32, P = 0.029 for log-transformed Hcy). For participants with both elevated Hcy and a large MPV, the attributable proportion of CVD events due to their interaction was 0.26 (95% CI: 0.06-0.45). CONCLUSIONS: The association between Hcy and CVD was significantly stronger in patients with hypertension with a larger MPV. MPV may modify the contribution of Hcy to CVD events through synergistic interactions with Hcy. These findings suggest that MPV could be monitored and controlled in the prevention of CVD.

Image restoration algorithm for terahertz FMCW radar imaging.

The terahertz frequency modulation continuous-wave (THz FMCW) imaging technology has been widely used in non-destructive testing applications. However, THz FMCW real-aperture radar usually has a small depth of field and poor lateral resolution, thus restricting the high-precision imaging application. This paper proposes a 150-220 GHz FMCW Bessel beam imaging system, effectively doubling the depth of field and unifying the lateral resolution compared to the Gaussian beam quasi-optical system. Moreover, a THz image restoration algorithm based on local gradients and convolution kernel priors is proposed to eliminate further the convolution effect introduced by the Bessel beam, thereby enhancing the lateral resolution to 2 mm. It effectively improves the image under-restoration or over-restoration caused by the mismatch between the ideal and actual point spread function. The imaging results of the resolution test target and semiconductor device verify the advantages of the proposed system and algorithm.

Synchronous pulmonary MALT lymphoma and squamous cell lung cancer: a case report.

Pulmonary B-cell lymphoma in the extranodal marginal zone of mucosa-associated lymphoid tissue (MALT), a rare tumor originating from bronchial mucosa-associated lymphoid tissue, is the major histologic type of primary pulmonary lymphoma. Combined lung squamous cell carcinoma with pulmonary MALT lymphoma is rare. A 63-year-old male patient presented to the hospital because of a dry cough, and chest CT showed soft tissue density nodules in the upper lobe of the right lung, the boundary was visible lobulation and spiculation, and the middle lobe of the right lung showed patchy shadow, moderate enhancement, associated with bronchial traction. After a multidisciplinary diagnosis and treatment (MDT) discussion, surgical resection was done for the patient, and postoperative pathological results showed pulmonary MALT lymphoma combined with lung squamous carcinoma. For complex pulmonary multiple lesions, judgment needs to be made after MDT discussion, and timely intervention is required for lesions suspicious of malignancy. There are no uniform recommendations for the management of mixed tumors of the lung, and an individualized treatment plan needs to be developed based on the patient's actual condition.

Biomarkers of oxidative stress in broiler chickens attacked by lipopolysaccharide: A systematic review and meta-analysis.

Oxidative stress (OS) constitutes a pivotal factor in the initiation and progression of lipopolysaccharide (LPS) challenges in broiler chickens. Increasing studies have demonstrated that Alleviation of oxidative stress seems to be a reasonable strategy to alleviate LPS-mediated afflictions in broilers. Nonetheless, the relationship between OS-related indicators and exposure to LPS remains a topic of debate. The aim of this investigation was to precisely and holistically evaluate the effect of LPS exposure on OS-associated markers. We conducted a systematic search of four electronic databases-PubMed, Web of Science, Scopus, and Cochrane for relevant studies, and a total of 31 studies were included. The overall results showed that the LPS treatment significantly increased the levels of oxygen radicals and their products, such as malondialdehydes (MDA), reactive oxygen species (ROS), and 8-hydroxy-2-deoxyguanosine (8-OHdG), while significantly reduced the levels of antioxidants, such as total antioxidative capacity (T-AOC), total superoxide dismutase (T-SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and glutathione (GSH), in the chickens. Intriguingly, though the observed trends in alterations were not strictly correlated with LPS concentrations, the enzyme activity levels were indeed influenced by the concentration of LPS. This observation highlights the complex relationship between LPS exposure and the body's antioxidant response. Despite some limitations, all the included studies were deemed credible. Subgroup evaluations revealed that the jejunum and duodenum has demonstrated stronger antioxidant capability compared to other tissues. Overall, our study presents compelling evidence that exposure to LPS induces significant OS in chickens. And we also found that the extent of OS was related to LPS doses, target tissues, and dietary ingredients.

Prognostic significance of serum globulin in patients with acute ischemic stroke.

BACKGROUND AND PURPOSE: We investigated the association between serum globulin levels upon hospital admission and in-hospital short-term outcomes in acute ischemic stroke (AIS) patients. METHODS: A total of 3,127 AIS patients enrolled from December 2013 to May 2014 across 22 hospitals in Suzhou city were included in the present study. We divided patients into 4 groups according to their level of admission serum globulin: Q1 (<23.5 g/L), Q2 (23.5-26.4 g/L), Q3 (26.4-29.9 g/L), and Q4 (≥29.9 g/L). Logistic regression models were used to estimate the effect of serum globulin on the short-term outcomes, including all cause in-hospital mortality, poor outcome upon discharge (modified Rankin Scale score ≥3) and in-hospital pneumonia in AIS patients. RESULTS: The median National Institutes of Health Stroke Scale (NIHSS) score was 4.0 (IQR, 2.0-7.0). The risk of in-hospital mortality was significantly higher in patients with highest serum globulin level (Q4) compared to those with lowest (Q1) (adjusted odds ratio [OR] 2.30; 95% confidence interval [CI], 1.12-4.70; P-trend =0.026). The highest serum globulin level (Q4) was associated with a 1.32-fold and 1.62-fold increase in the risk of poor outcome upon discharge (adjusted OR 1.32; 95% CI, 1.00-1.75; P-trend = 0.070) and in-hospital pneumonia (adjusted OR 1.62; 95% CI, 1.18-2.23; P-trend = 0.001) in comparison to Q1 after adjustment for potential covariates. CONCLUSIONS: A high level of serum globulin upon hospital admission was independently associated with all cause in-hospital mortality, poor outcome upon discharge and in-hospital pneumonia in relative mild AIS patients.

Targeting disordered-structured domain interactions in Galectin-3 based on NMR and enhanced MD.

Intrinsically disordered regions (IDRs) are common and important functional domains in many proteins. However, IDRs are difficult to target for drug development due to the lack of defined structures that would facilitate the identification of possible drug-binding pockets. Galectin-3 is a carbohydrate-binding protein of which overexpression has been implicated in a wide variety of disorders, including cancer and inflammation. Apart from its carbohydrate-recognition/binding domain (CRD), Galectin-3 also contains a functionally important disordered N-terminal domain (NTD) that contacts the C-terminal domain (CTD) and could be a target for drug development. To overcome challenges involved in inhibitor design due to lack of structure and the highly dynamic nature of the NTD, we used a protocol combining nuclear magnetic resonance data from recombinant Galectin-3 with accelerated molecular dynamics (MD) simulations. This approach identified a pocket in the CTD with which the NTD makes frequent contact. In accordance with this model, mutation of residues L131 and L203 in this pocket caused loss of Galectin-3 agglutination ability, signifying the functional relevance of the cavity. In silico screening was used to design candidate inhibitory peptides targeting the newly discovered cavity, and experimental testing of only three of these yielded one peptide that inhibits the agglutination promoted by wild-type Galectin-3. NMR experiments further confirmed that this peptide indeed binds to a cavity in the CTD, not within the actual CRD. Our results show that it is possible to apply a combination of MD simulations and NMR experiments to precisely predict the binding interface of a disordered domain with a structured domain, and furthermore use this predicted interface for designing inhibitors. This procedure can potentially be extended to many other targets in which similar IDR interactions play a vital functional role.

Phosphorylation of human CEACAM1-LF by PKA and GSK3ß promotes its interaction with ß-catenin.

CEACAM1-LF, a homotypic cell adhesion adhesion molecule, transduces intracellular signals via a 72 amino acid cytoplasmic domain that contains two immunoreceptor tyrosine-based inhibitory motifs (ITIMs) and a binding site for ß-catenin. Phosphorylation of Ser503 by PKC in rodent CEACAM1 was shown to affect bile acid transport or hepatosteatosis via the level of ITIM phosphorylation, but the phosphorylation of the equivalent residue in human CEACAM1 (Ser508) was unclear. Here we studied this analogous phosphorylation by NMR analysis of the 15N labeled cytoplasmic domain peptide. Incubation with a variety of Ser/Thr kinases revealed phosphorylation of Ser508 by GSK3bß but not by PKC. The lack of phosphorylation by PKC is likely due to evolutionary sequence changes between the rodent and human genes. Phosphorylation site assignment by mass spectrometry and NMR revealed phosphorylation of Ser472, Ser461 and Ser512 by PKA, of which Ser512 is part of a conserved consensus site for GSK3ß binding. We showed here that only after phosphorylation of Ser512 by PKA was GSK3ß able to phosphorylate Ser508. Phosphorylation of Ser512 by PKA promoted a tight association with the armadillo repeat domain of ß-catenin at an extended region spanning the ITIMs of CEACAM1. The kinetics of phosphorylation of the ITIMs by Src, as well dephosphorylation by SHP2, were affected by the presence of Ser508/512 phosphorylation, suggesting that PKA and GSK3ß may regulate the signal transduction activity of human CEACAM1-LF. The interaction of CEACAM1-LF with ß-catenin promoted by PKA is suggestive of a tight association between the two ITIMs of CEACAM1-LF.

Selection criteria of image reconstruction algorithms for terahertz short-range imaging applications.

Terahertz (THz) imaging has been regarded as cutting-edge technology in a wide range of applications due to its ability to penetrate through opaque materials, non-invasive nature, and its increased bandwidth capacity. Recently, THz imaging has been extensively researched in security, driver assistance technology, non-destructive testing, and medical applications. The objective of this review is to summarize the selection criteria for current state-of-the-art THz image reconstruction algorithms developed for short-range imaging applications over the last two decades. Moreover, we summarize the selected algorithms' performance and their implementation process. This study provides an in-depth understanding of the fundamentals of image reconstruction algorithms related to THz short-range imaging and future aspects of algorithm processing and selection.

Ultra-wideband signal generation and fusion algorithm for high-resolution terahertz FMCW radar imaging.

The terahertz frequency modulated continuous wave (THz FMCW) imaging has proved to be a novel nondestructive testing (NDT) technology for non-metal materials, and the large bandwidth is usually required to meet high range resolution demands in many applications such as multilayer sample under test (SUT). However, broadband THz hardware is difficult to design. In this paper, an ultra-wideband THz FMCW generation method is proposed, which provides frequency modulation bandwidths of up to 386 GHz by time-division multiplexing. Furthermore, an ultra-wideband signal fusion algorithm (USFA) is also proposed and significantly improves the range resolution to 0.46 mm in air. Results from the artificially constructed multilayer structure demonstrate the superiority and effectiveness of our method quantitatively.

Efficiency improvement of inverted perovskite solar cells enabled by PTAA/MoS2double hole transporters.

Hole transport layer (HTL) plays a critical role in perovskite solar cells (PSCs). We focus on the improvement of PSCs performance with MoS2nanosheets as the anode buffer layer in the inverted photovoltaic structure. PSC with single MoS2buffer layer shows poor performance in power conversion efficiency (PCE) and the long-term stability. By combination of MoS2and Poly[bis(4-phenyl) (2,4,6-trimethylphenyl) amine] (PTAA) as double-layer HTL, the PCE is improved to 18.47%, while the control device with PTAA alone shows a PCE of 14.48%. The same phenomenon is also found in 2D PSCs. For double-layer HTL devices, the PCE reaches 13.19%, and the corresponding PCE of the control group using PTAA alone is 10.13%. This significant improvement is attributed to the reduced interface resistance and improved hole extraction ability as shown by the electric impedance spectroscopy and fluorescence spectroscopy. In addition, the improved device exhibits better stability because the PCE still maintains 66% of the initial value after 500 h of storage, which is higher than the 47% of the remaining PCE from device based on single PTAA or MoS2. Our results demonstrate the potential of polymer/inorganic nanomaterial as a double-layer buffer material for PSCs.

High range resolution wideband terahertz FMCW radar with a large depth of field.

Terahertz frequency modulation continuous wave (THz FMCW) imaging technology has been widely used in non-destructive testing (NDT) applications of non-metallic materials. However, THz FMCW real-aperture radar usually has a narrow bandwidth and small depth of field, thus restricting the application of THz FMCW NDT. In this paper, a wideband THz signal (220-500 GHz) generation method is proposed by time-division multiplexing. Moreover, a dual-band quasi-optical design with a large depth of field is proposed based on the THz Bessel beam, and a high-quality range profile is obtained. Especially, a signal fusion extended Fourier analysis algorithm without prior knowledge is proposed to further enhance the range profile accuracy, which improves the range resolution to 0.28 mm (λ/3, center frequency 360 GHz). The effectiveness and advantages of the proposed system are verified by artificially constructing composite materials.

Sedative effect and safety of different doses of S-ketamine in combination with propofol during gastro-duodenoscopy in school-aged children: a prospective, randomized study.

BACKGROUND: Propofol combined with opioids can reduce the dosage of propofol and improve the safety of endoscopy. However, there are few studies on propofol combined with S-ketamine in children undergoing gastro-duodenoscopy. We aim to determine the sedative effect and safety of different doses of S-ketamine in combination with propofol in school-aged children undergoing gastro-duodenoscopy. METHODS: This is a prospective, randomized trial. Totally, 120 school-aged children who underwent gastro-duodenoscopy were randomly allocated into Group P, Group S0.3, Group S0.5 and Group S0.7. During induction, children in Group P, Group S0.3, Group S0.5 and Group S0.7 received 0, 0.3 mg.kg-1, 0.5 mg.kg-1 and 0.7 mg.kg-1 S-ketamine, respectively, following 3 mg.kg-1 propofol injection. During gastro-duodenoscopy, 1 mg.kg-1 of propofol was added according to the condition of the children and the BIS (bispectral index) value. The primary outcome was smooth placement rate of the first endoscope insertion. The secondary outcome was the times of additional propofol, the total amount of propofol, adverse events, recovery time, length of PACU (post anesthesia care unit) stay and endoscopist satisfaction. RESULTS: The smooth placement rate of the first endoscope insertion in Group P, Group S0.3 and Group S0.5 was significantly lower than that in Group S0.7 (16.70%, 34.50%, 50.00% vs. 83.30%, respectively, P < 0.001). The times of additional propofol in Group S0.3 (P = 0.018), Group S0.5 (P = 0.014) and Group S0.7 (P = 0.001) were significantly less than Group P. The total amount of propofol in Group S0.7 was significantly less than Group P (P < 0.001). The incidence of intraoperative hypotension in Group S0.5 and Group S0.7 was low. Group S0.7 had significantly higher incidence of postoperative dizziness (P = 0.003), longer PACU stay (P = 0.018) and higher endoscopist satisfaction (P = 0.001) than Group P. There was no difference in the recovery time among groups. CONCLUSION: S-ketamine (0.7 mg.kg-1) in combination with propofol can provide satisfactory sedative effect and reduce the dosage of propofol in school-aged children undergoing gastro-duodenoscopy, but there are higher incidence of postoperative dizziness and longer PACU stay.

Association between CORIN methylation and hypertension in Chinese adults.

BACKGROUND: Corin, a physical activator of atrial natriuretic peptide, has been associated with hypertension with unclear mechanisms. Here, we aimed to examine whether CORIN gene methylation was involved in the underlying molecular mechanisms. METHODS: DNA methylation levels of CORIN were measured by target bisulfite sequencing using genomic DNA isolated from peripheral blood mononuclear cells in 2498 participants in the Gusu cohort (discovery sample) and 1771 independent participants (replication sample). We constructed a mediation model with DNA methylation as the predictor, serum corin as the mediator, and hypertension as the outcome, adjusting for covariates. Multiple testing was controlled by false discovery rate (FDR) approach. RESULTS: Of the 9 CpGs assayed, hypermethylation at all CpGs were significantly associated with a lower level of blood pressure in the discovery sample and eight associations were also significant in the replication sample (all FDR-adjusted p<0.05). Serum corin mediated approximately 3.07% (p=0.004), 6.25% (p=0.002) and 10.11% (p=0.034) of the associations of hypermethylation at one CpG (Chr4:47840096) with systolic and diastolic blood pressure, and hypertension, respectively. All these mediations passed the causal inference test. CONCLUSIONS: These results suggest that hypermethylation in the CORIN gene is associated with a lower odds of prevalent hypertension and may be involved in the role of corin in blood pressure regulation.

A Low-Cost Metamaterial Sensor Based on DS-CSRR for Material Characterization Applications.

This paper presents a metamaterial sensor using a double slit complementary square ring resonator (DS-CSRR) that has been utilized for the measurement of dielectric materials, especially coal powder. The design is optimized for best performance of deep notch depth in transmission coefficient (Magnitude of S21). Sensitivity analysis of transmission coefficient with respect to structure dimensions has been carried out. Metamaterial properties of double negative permitivity and permeability were extracted from the S-parameters of this sensor. The optimized structure is fabricated using low cost FR-4 PCB board. Measured result shows resonance frequency of 4.75 GHz with a deep notch up to -41 dB. Simulated and measured results show good agreement in desired frequency band. For material characterization, first, two known materials are characterized using this metamaterial sensor. Their respective resonances and dielectric constants are known, so the transcendental equation of the sensor is formulated. Afterwards, the proposed sensor is used for dielectric measurement of two types of coal powder, i.e., Anthracite and Bituminous. The measured value of dielectric constant of Anthracite coal is 3.5 and of Bituminous coal is 2.52. This is a simple and effective nondestructive measurement technique for material testing applications.

Point-of-care ultrasound to confirm the position of bronchial blockers in children.

PURPOSE: We described the accuracy of ultrasound in determining the position of bronchial blockers (BBs) in children underwent thoracoscopic surgery. METHODS: We enrolled 52 children with ASA grade I-III who received thoracoscopic surgery with placement of BBs. Point-of-care ultrasound was performed according to the BLUE protocol. The ultrasound-guided lung sliding sign and curtain sign were used to assess the position of BBs. The accuracy of ultrasound in evaluating the position of BBs, as well as the accuracy and operating time of sliding sign and curtain sign at each examination point were recorded and compared. RESULTS: The accuracy of ultrasound in evaluating the position of BBs was 88% (46/52, 95% CI 0.69-0.97). When using the curtain sign to assess the position of BBs, the accuracy was 90% (94/104, 95% CI 0.78-0.96), which was significantly higher than when using the sliding sign (65% (136/208), 95% CI 0.55-0.74) (p = 0.002). The accuracy of curtain sign at the left mid-axillary line-diaphragm and the right mid-axillary line-diaphragm was respectively 96% (50/52, 95% CI 0.80-0.99) and 84% (44/52, 95% CI 0.65-0.95), which were higher than that of sliding sign at upper blue points and lower blue points. There was no significant difference in the operating time between two ultrasound signs (the curtain sign, 13.4 ± 8.2 s vs. the lung sliding sign, 16.2 ± 10.0 s, p = 0.065). CONCLUSION: Point-of-care ultrasound can effectively assess the position of BBs. The accuracy of using the curtain sign at the mid-axillary line-diaphragm is higher than that of using the lung sliding sign at the anterior chest wall.