Special Probe Research Articles

Selective and visual detection of triphosgene by a red turn-on fluorescent probe

Triphosgene has been successfully and widely applied in many fields such as medicine, pesticides, spices, dyes and polymer materials. Though triphosgene itself is low toxic, the potential presence of nucleophiles would lead to the release of cracked gas phosgene which is highly toxic and irritant if triphosgene was inhaled into the lungs, resulting in more serious and sustained respiratory distress. The risk of inhalation poisoning is especially acute, because phosgene content can be mortal prior to its smell being recognizable. Hence, triphosgene may pose a threat to public health and security due to its intentional use in terrorist activities and accidental leakage in industrial accidents. There have been few special fluorescent probe developed specifically for triphosgene. Therefore, it is urgent to develop an efficient and reliable method to detect and identify triphosgene. The macroscopical red color has the function of stimulating people's senses and emotions. A visual red colour and fluorescent assay method based on a rhodamine dye for triphosgene was developed with high selectivity and sensitivity. Furthermore, the probe RDM-670 loaded test strips are prepared and display practical utility in sensitive fluorescent detection of triphosgene.

Multi-frequency imaging with non-linear calibration of magnetoresistance sensors for surface and buried defects inspection

Timely inspecting defects has both safety and economic significance in industry. Eddy current testing (ECT) probes with array sensors are widely used for metal structures inspection. However, the sensitivities of array sensors are typically not consistent, resulting in different responses when measuring the same defect signal. Therefore, the array sensors of an array probe are desired to be calibrated. This paper proposes an ECT probe with an array of tunnel magnetoresistance (TMR) sensors and two excitation coils for surface and buried defects inspection. Alternating currents with different frequencies and amplitudes are driven through the two coils simultaneously. The TMR sensors have non-linear resistance vs. magnetic field curves. A non-linear calibration method based on the non-linear characteristic is proposed to calibrate the high frequency signals of the sensors. This calibration method does not need any extra equipment and takes account of the effect of the non-uniformity of the excitation magnetic field to some extent. Experimental result shows that the signal becomes much flatter after the calibration. The relative flat index is reduced from 38.6% to 11% by the calibration process. To validate the detectability of the proposed probe for different kinds of defects, surface and buried defects in aluminum samples are tested by the probe. It is seen that a small surface defect with sizes 1 mm (length) x 0.5 mm (width) x 0.5 mm (height) can be clearly identified from the high-frequency image. Two defects buried 3 mm below the top surface are also inspected. The peak signal values of the two defects are 0.69 V and 0.97 V, respectively, demonstrating that the probe can distinguish the 0.1 mm height difference of the two defects. In addition, a defect buried 10 mm under the surface is imaged by the probe. Thanks to the special probe design and excellent sensitivity of the TMR sensors, the probe has good sensitivity for both surface and buried defects.

Highly Sensitive Imaging Spectrometer System Based on Areal Array to Linear Array Optical Fiber Probe for Biological Spectral Detection

Noninvasive bio-molecular spectral sensing method for scattered tissue can be utilized to accurately obtain and analyze bio-molecular information. Propagation of light in biological tissues will gradually present diffusive feature and results in severe attenuation of detection light intensity and deteriorating the signal-to-noise ratio of detection system. In our work, we built a three-channel imaging spectrometer system and designed a compatible special fiber bundle probe for diffusive spectral detection. The system can synchronously collect the spectral signals from 270 fibers in the fiber bundles then convert them into electrical signal. Aiming at the aberration in the system, we also designed a corresponding data processing method to effectively realize the wavelength calibration of spectral signals. Finally, the system was applied to the nondestructive detection of human tissues and mouse with the <inline-formula> <tex-math notation="LaTeX">$15 ~ \mu \text{W}$ </tex-math></inline-formula> white light and 4.05 mw 405 nm laser. For the above extremely weak excitation light source, our system can still obtain the high signal-to-noise ratio diffusive spectra with less than 1 s integration time. Experiments were conducted to obtain spectra of back-scattering and autofluorescence of biological tissue. Experimental results show that the system has certain advantages in biological tissue scattering spectroscopy detection and autofluorescence detection.

Abstract 5761: Validation of TMB (tumor mutational burden) quantification using putative driver mutations in customized targeted sequencing platform

Abstract Next generation sequencing has revolutionised genomic studies of cancer, having facilitated the development of precision oncology treatments based on a tumour’s molecular profile. Tumor mutational burden (TMB) measurements aid in identifying patients who are likely to benefit from immunotherapy. In most cases, there is no result of a paired normal tissues. Therefore, it is difficult to effectively exclude germline mutations, so it does not effectively reflect the TMB of cancer driver mutation. We aimed to modify the TMB analysis pipeline to reflect the germline and multi-nucleotide variants (MNVs), specifically for Korean solid tumors. “CancerMaster” is custom RNA probes for target enrichment sequencing. It consists of all unions (7,811 regions, 2.5Mb) of reported exons of 524 tumor and immune related genes. The panel contains special RNA probes, which enables detection of microsatellite instability, Epstein-Barr virus and Human papillomavirus. This Panel sensitivity, precision, and TMB were assessed using immunohistochemistry and TruSight Oncology 500 for well-characterized samples (cellularity ≤ 20% and sequencing QC passed, n = 415). We achieved a mean coverage of 1,183x, with sensitivity and specificity of &amp;gt;99% and precision of &amp;gt;97% in alteration. We performed MNV analysis for more accurate mutation analysis. We used WhatsHap for haplotype phasing and the bcftools to call the MNV. The MNV-rich genes were HLA-A (2019 sites), HLA-B (1284 sites), and HLA-C (825 sites), and BRCA2, BRCA1, ATM and ATR, a DNA repair-related genes, was also identified at more than 30 sites. In addition, up to 14 MNVs were detected in one sample. In this study, we analyzed putative driver mutations that removed germline mutations, referring to the ACMG guidelines for sequence variant interpretation based on the Korean genome database (KOVA and KRGDB) and gnomAD. The TMB was recalculated by reflecting the MNV and the putative driver mutation. As a result, it was confirmed that this upgraded TMB analysis was similar to TMB calculated through actual somatic mutation through comparison with normal tissues. The TMB-high (20≤) sample was 8.4% (36/415) for pan-cancer, but 6.9% (20/289) for gastric cancer and 25% (12/48) for colorectal cancer showed differences by cancer type. In addition, it was confirmed that there is a correlation between TMB-high and MSI-H (sensitivity : 70.0%, specificity 99.5%, accuracy 95.9%) In conclusion, we validated TMB analysis pipeline for the expansion of immunotherapeutic applications in treatment-refractory Korean solid cancers. Citation Format: Woo Sun Kwon, Jingmin Che, Sun Young Rha, Hyun Cheol Chung. Validation of TMB (tumor mutational burden) quantification using putative driver mutations in customized targeted sequencing platform [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5761.

Preliminary flow measurements of a small-scale, vertical axis wind turbine for the analysis of blockage influence in wind tunnels

Abstract The development of competitive lift vertical axis wind turbines (VAWTs) is yet a challenge in wind power research. New designs typically require wind tunnel testing before in site implementation. One of the major problems at the laboratory stage is the appearance of a significant flow blockage for small scale models, which affects the performance of the tested wind turbines and prevents the direct extrapolation of results to open field conditions without previous correction. Unfortunately, a suitable blockage correction for lift VAWTs has not been achieved yet, so more studies are needed in this research field to fill the gap. As part of preliminary work with this aim, a small scale VAWT prototype has been designed, constructed, and tested in a 1.15×1 m2 test section wind tunnel with a semi-closed chamber, featuring a blockage ratio of 0.37. Preliminary aerodynamic measurements were performed for different tip speed ratios on the downstream near wake using a special 3-hole pressure probe. Results show that the wake velocity profiles present a velocity increase around the prototype with a low velocity region in the windward quadrant of the turbine, indicating an important influence of the tunnel boundaries. These preliminary measurements have given an initial insight on the aerodynamic relationships between turbine performance and flow patterns. Additionally, they will help to devise an appropriate strategy for the following experiments, with the final objective of developing a blockage correction for small scaled VAWTs.

RF and microwave diagnostics for compact plasma traps and possible perspectives for fusion devices

Plasma diagnostics is a topic having a great impact on R&D in compact ion sources as well as in large fusion reactors. Towards this aim, non-invasive microwave diagnostics approaches, such as interferometric, polarimetric and microwave imaging profilometric techniques can allow obtaining volumetric, line-integrated or even space-resolved information about plasma electron density. Special probes can be also designed and implemented in order to characterize external and/or self-generated radio-waves in the plasmas. In particular, the design, construction and operation of a K-band microwave interferometry/polarimetry setup based on the Frequency-Modulated Continuous-Wave (FMCW) method at INFN-LNS will be described: this tool provides reliable measurements of the plasma density even in the extreme unfavorable wavelength-to-plasma scale ratio in plasma-based ion sources. A “frequency sweep” and a post-processing filtering method (for interferometry and polarimetry, respectively) were used to filter out the multipath contributions or cavity induced depolarizations in the detected signals. Besides this, the use of the aforementioned RF plasma-immersed probes will also be discussed, which allow measuring local E-fields and fast temporal response in order to characterize turbulent (through kinetic instabilities, cyclotron maser emission, etc.) vs. stable plasma regimes. An analysis based on wavelet transform applied to measurements of plasma radio self-emission in B-minimum and simple mirror traps will be presented. These tools and methods have the potential to be applied to plasma machines both in compact traps and large-size reactors with a proper scaling.

Determination of probe non-linearity and error due to measurement position for direct measurement type of gauge block comparator and its measurement uncertainty

The non-linearity of probes is one of the important components in gauge block calibration by the mechanical comparative method of two gauges blocks at the same nominal length. However, an advanced method for gauge block calibration is a mechanical direct measurement method of two gauge blocks showing the greatest difference in nominal length of 25 mm. This method uses a special probe based on the interferential scanning principle to produce the signals to measure the displacement. In this paper, non-linearity and error due to measurement position were investigated as they related to the accuracy of measurement results. The differences in central length of pairs of standard gauge blocks made of steel were measured by optical interferometry with the measurement uncertainty (k=2) 23 nm. Length in the range of 5 μm to 25 mm was used in the experiment. Non-linearity of the probe was evaluated by the simple linear regression model. Various factors such as origin setting point, temperature, and vibration have been analysed. In the preliminary experiment, the non-linearity, position error, repeatability and retrace error over the measuring range 25 mm are 13 nm, -18 nm, 15 nm, and 10 nm respectively. The standard uncertainty of direct measurement type caused by non-linearity is 4 nm.

Design of thermoelectric devices for extracting foreign objects from the human body by freezing

Objectives.The purpose of the article is to consider the designs of thermoelectric devices (TEC) for extracting foreign objects (IO) from the human body by freezing with various options for removing heat from the hot junctions of the thermoelectric module (TEM).Method. Modifications of thermoelectric devices are described for extracting the IO from the human body by freezing it to a special probe. Their technical design differs in the way of heat removal from the TEM hot junctions, for which air heat removal, melting working substances and preliminary cooling of the radiator are used. The basic relationships for calculating the technical means intended for the removal of heat from the hot junctions of the TEM are presented.Result. The graphs of the dependence of the temperature change of the TEM hot junctions in time are obtained for different values of its heat output when using an air heat removal system and the time of complete penetration of various working substances used in the device.Conclusion. The data obtained show that for the operating conditions of the TEC, the temperature of the hot junctions of the TEM with an air heat sink does not go beyond the permissible limits. With a module power of 8 W, 12 W and 16 W, the temperature of the hot junctions of thermoelements stabilizes rather quickly and takes the value of 308 K, 313 K and 318 K. maintaining their stable temperature is most preferred is nickel nitrate, less - elaidic acid and paraffin. Calculations of the design of a device with a pre-cooled radiator system also show the efficiency of heat removal from the hot junctions of the TEM for the duration of the entire procedure for removing the IO from the human body.

Detecting the defects of warm-sprayed Ti-6Al-4V coating using Eddy current testing method

Thermal spay coatings have been widely used to provide structural components with protection from harsh environments such as corrosion, heat, and wear resistance. However, delamination, pores or peeling defects may exist in an as-fabricated coating which influence the mechanical properties of the coating. We developed an eddy current testing (ECT) system using a special ECT probe. The ECT probe was composed of one detection coil and two excitation coils. The lower excitation coil was used to produce the excitation magnetic field in the specimen and the upper excitation coil was used to compensate the background signal. In this study, the feasibility of our ECT system to inspect the Ti-6Al-4V warm spray (WS) coatings were investigated. The artificial defects embedded between the Ti-6Al-4V coating and the substrate were successfully detected using the ECT system.

Intergenerational Aspirations Across the Life Course in Asia

Articles in this special issue probe the relationships between strategies for upward socio-economic mobility and intergenerational aspirations in Asia. With capitalism, urbanisation, mass media, education and migration increasing throughout Asia, now is a time of flux in opportunities and subjectivities. Such changes are lived as deeply personal and relational. Young people are often instrumental to familial ‘development’ strategies, and this effects divisions of labour, norms of moral economy, life course ideals and distributions of power. At the same time, media, education and development discourses often exhort people to author autonomous destinies through entrepreneurialism, career and consumerism. Contributors to this issue, ‘Development, Gender and Intergenerational Aspirations in Asia’, ethnographically explore how old and new dreams—some emphasising autonomy, while others stress familial obligation—conjoin, elide and compete, and how people negotiate associated life course expectations. We also show how dreams find limits, requiring redreaming and rerouting.

Low-intensity extracorporeal shock wave therapy promotes recovery of sciatic nerve injury and the role of mechanical sensitive YAP/TAZ signaling pathway for nerve regeneration.

Background:Histological and functional recovery after peripheral nerve injury (PNI) is of significant clinical value as delayed surgical repair and longer distances to innervate terminal organs may account for poor outcomes. Low-intensity extracorporeal shock wave therapy (LiESWT) has already been proven to be beneficial for injured tissue recovery on various pathological conditions. The objective of this study was to explore the potential effect and mechanism of LiESWT on PNI recovery.Methods:In this project, we explored LiESWT's role using an animal model of sciatic nerve injury (SNI). Shockwave was delivered to the region of the SNI site with a special probe at 3 Hz, 500 shocks each time, and 3 times a week for 3 weeks. Rat Schwann cells (SCs) and rat perineurial fibroblasts (PNFs) cells, the two main compositional cell types in peripheral nerve tissue, were cultured in vitro, and LiESWT was applied through the cultured dish to the adherent cells. Tissues and cell cultures were harvested at corresponding time points for a reverse transcription-polymerase chain reaction, Western blotting, and immunofluorescence staining. Multiple groups were compared by using one-way analysis of variance followed by the Tukey-Kramer test for post hoc comparisons.Results:LiESWT treatment promoted the functional recovery of lower extremities with SNI. More nerve fibers and myelin sheath were found after LiESWT treatment associated with local upregulation of mechanical sensitive yes-associated protein (YAP)/transcriptional co-activator with a PDZ-binding domain (TAZ) signaling pathway. In vitro results showed that SCs were more sensitive to LiESWT than PNFs. LiESWT promoted SCs activation with more expression of p75 (a SCs dedifferentiation marker) and Ki67 (a SCs proliferation marker). The SCs activation process was dependent on the intact YAP/TAZ signaling pathway as knockdown of TAZ by TAZ small interfering RNA significantly attenuated this process.Conclusion:The LiESWT mechanical signal perception and YAP/TAZ upregulation in SCs might be one of the underlying mechanisms for SCs activation and injured nerve axon regeneration.

ИССЛЕДОВАНИЕ ДРАГОЦЕННЫХ КАМНЕЙ ИЗ КОЛЛЕКЦИИ МУЗЕЯ ЗЕМЛЕВЕДЕНИЯ МЕТОДАМИ ОПТИЧЕСКОЙ И СКАНИРУЮЩЕЙ ЭЛЕКТРОННОЙ МИКРОСКОПИИ. ПЕРВЫЕ РЕЗУЛЬТАТЫ

For the first time, a study of the chemical composition and diagnostic properties of gemstones of the main collection of the Earth Science Museum at Moscow State University has been carried out. The modern non-destructive analytical methods were used. These were the optical and scanning electron microscopy, which make it possible to study material composition without special sampling or probing, the latter fact being highly relevant in the museum field. Optical microscopy data showed that the majority of the studied gems contain a lot of fluid and solid inclusions of other minerals, indicating the natural origin of the examined samples. Typomorphic features of emerald crystals show a shale genetic type of this species. Data from scanning electron microscopy revealed the presence of boron impurity in the composition of diamond single crystals.

Facile design of multifunction-integrated linear oligonucleotide probe with multiplex amplification effect for label-free and highly sensitive GMO biosensing

Well-defined structures and compositions of nucleic acids afford oligonucleotide probes with unique chemical properties and biological functions for various biosensing applications. Herein, a unique and special oligonucleotide probe, named multifunction-integrated linear oligonucleotide probe (MI-LOP), was facile designed and reported for label-free and turn-on fluorescent detection of the codon component of genetically modified organisms (GMOs). The MI-LOP contains four different functional regions including recognition of target, serving as polymerization template, and creating polymerization primer-linked G-quadruplex (PP-G-quadruplex). Without the aid of any other oligonucleotides, the introduction of target DNA can make each function of the MI-LOP executed one-by-one, during which the species of target DNA, target analogue, and PP-G-quadruplex can be cyclically utilized and in turn induce a multiplex signal amplification responsible for substantial collection of the G-quadruplex moieties under isothermal conditions. The stable G-quadruplexes can combine with N-methyl mesoporphyrin IX (NMM) and function as efficient fluorescence light-up probes, rapidly leading to a dramatic increase in the fluorescence intensity for the amplified detection of the target codon component. Our results strongly demonstrate that the developed MI-LOP with multiplex amplification effect confers the sensing strategy a high sensitivity and specificity for quantitative and qualitative detection of the target codon. And it has also been successfully applied for analyzing target codon in the complex extractions of soybean. The achievements highlight the significance of using oligonucleotide probes as promising analytical tools to promote the basic biochemical research and help in food and environmental analysis.

Speaker Abstracts Plenary Lectures (PL) PL1. Face Perception in Infants Using Near-Infrared Spectroscopy (NIRS)

We have been studying the underlying mechanisms of face perception in humans using magneto-(MEG), electroencephalography (EEG) and near-infrared spectroscopy (NIRS). In this lecture, I will mainly focus on the development of face perception in infants. NIRS is a spectroscopic method using the near-infrared region of the electromagnetic spectrum (from 780 nm to 2500 nm). The biggest advantages of NIRS compared with functional magnetic resonance imaging (fMRI) are as follows: (1) NIRS can be used when subjects are moving, for example, during walking and cooking. Therefore, NIRS can be used to measure brain activity of infants and children who cannot help moving; (2) It is much cheaper. We recently made a special light probe of NIRS for studying infants. I will mainly introduce our basic studies of face perception in infants using NIRS. In addition, I will introduce our latest clinical studies in patients with attention deficit hyperactivity disorder (ADHD) and anorexia nervosa.

Modeling the Depth of Surface Cracks in Brake Disc

The article presents the state of knowledge and research in the field of surface cracks occurring in disc braking systems of rail and car vehicles. The craze formed during the operation of vehicles is particularly dangerous and leads to breaking the disc into several pieces. It may lead to a loss of braking force and damage to the entire disc brake caliper. The main aim of the research is to identify surface cracks in brake discs made of cast iron and use experimental methods to estimate their depth. Research were conducted on the disc braking system developed by the authors. In examining the location and depth of cracks, the penetration method, ultrasound, as well as a special probe were used. This device measures the crack depth based on the electrical resistance between two points on the surface of the metallic object. The tests showed that the first microcracks on the brake discs appeared after 309 braking tests on the test stand. In addition, it was observed that the surface cracks length of the disc increased linearly to depth until they reached about 11.5–12 mm with corresponded to crack lengths in the range of 65–70 mm. However, determination of the regression functions presented in the article allows to estimate the depth of surface cracks up to 70 mm long on cast iron brake discs by measuring their length.

A special o-dialdehyde fluorescent probe simultaneously sensing Hcy, GSH and its application in living cells and zebrafish imaging

The development of fluorescent probes enabling to distinguish Cys, Hcy and GSH has always been a considerable challenge, in particular the distinction of Hcy and other two biothiols, because Hcy has a very similar structure with Cys and a relatively lower concentration in living organisms. In this work, a special o-dialdehyde fluorescent probe, quinoline-2,3-dicarboxaldehyde (QDA), has been synthesized and demonstrated superior performance in differentiating detection of Hcy and GSH, which is different from the previous reported o-dialdehyde probes specifically detecting GSH. Furthermore, the probe can selectively distinguish Hcy and GSH from different signal channels in living cells and zebrafish, meaning it has great potential in biological applications. This finding will provide a novel idea for the design of fluorescent probes to distinguish biothiols.

Ways to Increase the Efficiency of Thermopressiometry

Purpose. The purpose of the work is to identify the ways to increase the efficiency of engineering research, based on the significant amount of exploration work required in the creation of modern man-made objects, taking into account the shortcomings of existing instruments and equipment used to measure soil stress, and in relation to the need to improve the design of thermopressiometers, which are aimed to facilitate the study of frozen soils. Methodology. The ways to improve the blade thermopressiometer for the study of frozen soils with different aggregates were selected by the comparative-analytical method and the method of analogy. Thawing depth, absolute soil sediment, deformation modulus etc. were determined by thermal-technical calculations. Findings. The application issues of concern of the existing thermopressiometers (limited research of soils of a certain type, complexity and insufficient accuracy of readings) identified can be overcome by the proposed improved design of a blade thermopressiometer for testing frozen sandy-clay soils. It is based on the improved heating circuit, the applicationd of quality materials and changing the form of the blades and body. The device is intented for use on permafrost and natural frozen soils of the world, including Ukraine. Originality. For the first time we offered a model of an advanced thermopressiometer with an improved body shape made of high-quality corrosion-resistant materials, including non-metallic ones. It has the reduced number of blades to one retractable sector blade-stamp (square or round) and one heating blade-stamp. A special probe design with mechanical/hydraulical sensor drive with a thermocouple (or with two fork probes to improve the measurements) was proposed. It was also recommended to introduce an electric conductive system designed for thawed soils, with a rod for measuring the retractable blade-stamp. The possibility of using a thermopressiometer during the study of seasonally frozen soils is established. Practical value. Improving the device model should facilitate its application in engineering and geological research for various types of construction, including transport, hydraulic engineering, which use the methods of deep freezing of weak and unstable soils.

EFFECT OF DENTAL RESTORATIVE MATERIALS ON LOCAL ORAL MICROBIOCENOSIS IN PATIENTS WITH FRONT TOOTH RESTORATIONS

The aim of this study is determine the changes in the local microbiocenosis of the oral cavity in patients with direct composite and indirect ceramic restorations within 12 months after the treatment completion. Materials and methods. The assessment of changes in the local microbiocenosis was performed on 18 individuals. The species and quantitative composition of the microflora was determined before the treatment and in 1 year after the treatment. To collect biomaterial samples (oral fluid) we used special probe with hygroscopic cotton swabs, then placed into test tubes with Amies transport solution. Results. The general assessment of the microbiological condition of the oral cavity of the patients with restorations of anterior teeth performed with different materials did not reveal a statistical difference in the change of microbiocenosis before the treatment and one year after the treatment. When identifying the relationship between microbiological changes in the oral cavity, depending on age in the group, where light curing composite resin was used, a statistically significant difference was found out in the indicator of opportunistic microflora (in particular Candida albicans) ranging from the "normal" values to the "above normal" values (&lt;102 ) in the middle-aged patients. Conclusions. Restoration material, age and sex of the patient do not have a significant effect on the change of the local microbiocenosis of the oral cavity. However, the use of ceramic restorations in some individual cases may improve the state of the microbiocenosis, as dental ceramics is a worse substrate for microbial plaque adhesion and microorganism development compared with composite materials.

Does Neurally Adjusted Ventilatory Assist Compared to Pressure Support Ventilation Decrease Patient Ventilator Asynchrony?

BACKGROUND: Patient-mechanical ventilator (MV) asynchrony despite optimal adjustment of MV parameters is a common problem that is partly associated with difficult weaning of MV. Neurally adjusted ventilatory assist (NAVA) is a mode of proportional ventilation that count on diaphragmatic activity (measured by special esophageal probe and expressed as diaphragm electrical [Edi]) to provide proportional support to patient effort which differs from one breath to another according to Edi signal. AIM: The purpose of this trial is to determine the impact of NAVA compared to pressure support ventilation (PSV) mode in decreasing patient-MV asynchrony and hemodynamic effect in patients on MV with expected difficult weaning. MATERIALS AND METHODS: This prospective interventional trial was conducted on 30 critically ill on MV with expected difficult weaning. First, patients were put on PSV mode for 24 h. Then, patients were put on NAVA mode (for weaning) for the next 24 h. The incidence of different types of asynchrony in both modes was investigated. RESULTS: NAVA mode significantly reduced the asynchrony index when compared to PSV (1.1 ± 0.39% vs. 2.8 ± 1.1, respectively, p &lt; 0.001), P/F ratio was significantly higher during NAVA (250 in NAVA vs. 210 in PSV, p &lt; 0.001), heart rate, and mean arterial blood pressure were significantly reduced during NAVA (p &lt; 0.001 and 0.015, respectively). CONCLUSIONS: Compared to PSV, NAVA-reduced patient-MV asynchrony significantly and increased the P/F ratio significantly with better hemodynamics.

Development and validation of a targeted sequencing panel for application to treatment-refractory solid tumor.

245 Background: Next generation sequencing has revolutionised genomic studies of cancer, having facilitated the development of precision oncology treatments based on a tumour’s molecular profile. We aimed to develop a targeted sequencing panel for application to treatment-refractory solid tumor types with particular focus on tumours of the stomach cancer, plus test for utility in FFPE, fluid sample and cancer cell lines. Methods: “CancerMaster” is custom RNA probes for target enrichment sequencing. It consists of all unions (7,811 regions, 2.5Mb) of reported exons of 524 tumor and immune related genes. The panel contains special RNA probes, which enables detection of microsatellite instability, Epstein-Barr virus and Human papillomavirus. Also, the CancerMaster panel analyzes 524 genes as well as genomic signatures including microsatellite instability (MSI), tumor mutational burden (TMB) and HLA allele. FFPE samples and 49 gastric cancer (GC) cell lines were collected for performance and application testing. Panel sensitivity and precision were measured using well-characterised DNA controls (n = 117), and specificity by Sanger sequencing, pyrosequencing, FoundationOne CDx. Results: We achieved a mean coverage of 1,032x, with sensitivity and specificity of &gt;99% and precision of &gt;97%. In this study, we evaluated 26 Yonsei Cancer Center (YCC) GC cell lines and 23 GC cell lines from other sources (ATCC, KCLB, and JCRB). Application to 49 gastric cancers cell lines resulted in detection of copy number variant (CNV), single number variant (SNV) and small InDel aligned to whole exome sequencing data. In addition to previous novel EBV infected cell line (YCCEL1/YCC-10, J Gen Virol. 2013), we observed amplification and overexpression of receptor tyrosine kinase (RTK) including HER2 (YCC-19, 32, 33, 38), EGFR (YCC-11, 21), Met (YCC-31, 34), and FGFR2 (YCC-28, 30) in YCC GC cell lines; confirming that protein was overexpression by Western blot or Flow cytometry in 19/49 (38.8%). Interestingly, amplification of RTKs was detected mutually exclusive pattern with other RTK amplification. Conclusions: We have developed and validated an analytically-validated panel for application to cancers of treatment-refractory types.