Compact and Versatile QEPAS-Based Sensor Box for Simultaneous Detection of Methane and Infrared Absorber Gas Molecules in Ambient Air

In this work we report on an innovative sensor box employing two acoustic detection modules connected in series for quartz-enhanced photoacoustic multi-gas detection. One detection module is coupled with an internal distributed-feedback quantum cascade laser (DFB-QCL) emitting at ∼7.719 µm for methane (CH4) sensing, while the second module has been designed to be coupled with an external laser source targeting the absorption features of a specific gas molecule Mx in the infrared spectral range. The sensor box can thus be employed for any application, depending on the CH4/Mx gas combination to be detected. The ∼7.719 µm DFB-QCL also allowed water vapor monitoring. To demonstrate the sensor versatility, we report on the QEPAS-box environmental monitoring application by simultaneously detecting in air methane, which is a greenhouse gas, nitric oxide (NO), an ozone depleting substance, and water vapor. Sensitivity levels of 4.30 mV ppm−1 and 17.51 mV ppm−1 and minimum detection limits of 48 ppb and 11 ppb for methane and nitric oxide detection were achieved, respectively. The sensor box operation was tested by analysing ambient air. Average concentrations of ∼1.73 ppm of CH4, ∼0.134 ppm of NO and 1.8% of H2O were measured

Real-life disease monitoring in follicular lymphoma patients using liquid biopsy ultra-deep sequencing and PET/CT

In the present study, we screened 84 Follicular Lymphoma patients for somatic mutations suitable as liquid biopsy MRD biomarkers using a targeted next-generation sequencing (NGS) panel. We found trackable mutations in 95% of the lymph node samples and 80% of the liquid biopsy baseline samples. Then, we used an ultra-deep sequencing approach with 2 · 10−4 sensitivity (LiqBio-MRD) to track those mutations on 151 follow-up liquid biopsy samples from 54 treated patients. Positive LiqBio-MRD at first-line therapy correlated with a higher risk of progression both at the interim evaluation (HRINT 11.0, 95% CI 2.10–57.7, p = 0.005) and at the end of treatment (HREOT, HR 19.1, 95% CI 4.10–89.4, p < 0.001). Similar results were observed by PET/CT Deauville score, with a median PFS of 19 months vs. NR (p < 0.001) at the interim and 13 months vs. NR (p < 0.001) at EOT. LiqBio-MRD and PET/CT combined identified the patients that progressed in less than two years with 88% sensitivity and 100% specificity. Our results demonstrate that LiqBio-MRD is a robust and non-invasive approach, complementary to metabolic imaging, for identifying FL patients at high risk of failure during the treatment and should be considered in future response-adapted clinical trials.This study has been funded by Instituto de Salud Carlos III (ISCIII) and co-funded by the European Union through the projects PI21/00314, PI19/01430, PI19/01518 and PI18/00295, PTQ2020-011372, CP19/00140, CP22/00082, Doctorado industrial CAM IND2020/TIC-17402 and CRIS cancer foundation

Detection of kinase domain mutations in BCR::ABL1 leukemia by ultra-deep sequencing of genomic DNA

The screening of the BCR::ABL1 kinase domain (KD) mutation has become a routine analysis in case of warning/failure for chronic myeloid leukemia (CML) and B-cell precursor acute lymphoblastic leukemia (ALL) Philadelphia (Ph)-positive patients. In this study, we present a novel DNA-based next-generation sequencing (NGS) methodology for KD ABL1 mutation detection and monitoring with a 1.0E-4 sensitivity. This approach was validated with a well-stablished RNA-based nested NGS method. The correlation of both techniques for the quantification of ABL1 mutations was high (Pearson r = 0.858, p < 0.001), offering DNA-DeepNGS a sensitivity of 92% and specificity of 82%. The clinical impact was studied in a cohort of 129 patients (n = 67 for CML and n = 62 for B-ALL patients). A total of 162 samples (n = 86 CML and n = 76 B-ALL) were studied. Of them, 27 out of 86 harbored mutations (6 in warning and 21 in failure) for CML, and 13 out of 76 (2 diagnostic and 11 relapse samples) did in B-ALL patients. In addition, in four cases were detected mutation despite BCR::ABL1 < 1%. In conclusion, we were able to detect KD ABL1 mutations with a 1.0E-4 sensitivity by NGS using DNA as starting material even in patients with low levels of disease

Personalized monitoring of circulating tumor DNA with a specific signature of trackable mutations after chimeric antigen receptor T-cell therapy in follicular lymphoma patients

BackgroundCART therapy has produced a paradigm shift in the treatment of relapsing FL patients. Strategies to optimize disease surveillance after these therapies are increasingly necessary. This study explores the potential value of ctDNA monitoring with an innovative signature of personalized trackable mutations.MethodEleven FL patients treated with anti-CD19 CAR T-cell therapy were included. One did not respond and was excluded. Genomic profiling was performed before starting lymphodepleting chemotherapy to identify somatic mutations suitable for LiqBio-MRD monitoring. The dynamics of the baseline mutations (4.5 per patient) were further analyzed on 59 cfDNA follow-up samples. PET/CT examinations were performed on days +90, +180, +365, and every six months until disease progression or death.ResultsAfter a median follow-up of 36 months, all patients achieved a CR as the best response. Two patients progressed. The most frequently mutated genes were CREBBP, KMT2D and EP300. Simultaneous analysis of ctDNA and PET/CT was available for 18 time-points. When PET/CT was positive, two out of four ctDNA samples were LiqBio-MRD negative. These two negative samples corresponded to women with a unique mesenteric mass in two evaluations and never relapsed. Meanwhile, 14 PET/CT negative images were mutation-free based on our LiqBio-MRD analysis (100%). None of the patients had a negative LiqBio-MRD test by day +7. Interestingly, all durably responding patients had undetectable ctDNA at or around three months after infusion. Two patients presented discordant results by PET/CT and ctDNA levels. No progression was confirmed in these cases. All the progressing patients were LiqBio-MRD positive before progression.ConclusionThis is a proof-of-principle for using ctDNA to monitor response to CAR T-cell therapy in FL. Our results confirm that a non-invasive liquid biopsy MRD analysis may correlate with response and could be used to monitor response. Harmonized definitions of ctDNA molecular response and pinpointing the optimal timing for assessing ctDNA responses are necessary for this setting. If using ctDNA analysis, we suggest restricting follow-up PET/CT in CR patients to a clinical suspicion of relapse, to avoid false-positive results

Research on the development and application of museum cultural Resources display based on virtual reality technology

The development of museum cultural industry, as the key content of the development of national cultural industry, affects the inheritance of national culture and history. Due to the constant update of hightech, new media and other technologies, the display of cultural resources in museums is becoming more and more diversified. The application of virtual reality technology, digital interaction technology, new media and other technologies brings new vitality to the display design of modern museums. Under the background of this era, the exhibition of museum cultural resources is researched and explored. At present, virtual reality technology is gradually applied in the display and dissemination of cultural resources. This paper discusses how to realize the application of this technology in the display of cultural resources in museums

Rigid/Flexible Transparent Electronics Based on Separated Carbon Nanotube Thin-Film Transistors and Their Application in Display Electronics

Transparent electronics has attracted numerous research efforts in recent years because of its promising commercial impact in a wide variety of areas such as transparent displays. High optical transparency as well as good electrical performance is required for transparent electronics. Preseparated, semiconducting enriched carbon nanotubes are excellent candidates for this purpose due to their excellent mobility, high percentage of semiconducting nanotubes, and room-temperature processing compatibility. Here we report fully transparent transistors based on separated carbon nanotube networks. Using a very thin metal layer together with indium tin oxide as source and drain contacts, excellent electrical performance as well as high transparency (∼82%) has been achieved (350–800 nm). Also, devices on flexible substrates are fabricated, and only a very small variation in electric characteristics is observed during a flexibility test. Furthermore, an organic light-emitting diode control circuit with significant output light intensity modulation has been demonstrated with transparent, separated nanotube thin-film transistors. Our results suggest the promising future of separated carbon nanotube based transparent electronics, which can serve as the critical foundation for next-generation transparent display applications

Incoherent broadband mid-infrared detection with lanthanide nanotransducers

Spectral conversion of mid-infrared (MIR) radiation to visible (VIS) and near-infrared (NIR) wavelengths is a fundamental technology for spectroscopy and imaging; however, current MIR-to-VIS/NIR conversion technology is limited to nonlinear optics with bulky crystals or resonant nanocavities. Here we report lanthanide-based MIR-to-NIR nanotransducers that enable broadband MIR sensing at room temperature by harnessing ratiometric luminescence changes. The ratiometric luminescence of lanthanide nanotransducers in the NIR region can be incoherently modulated by MIR radiation in the 4.5–10.8 µm wavelength range. Ratiometric modulation of luminescence enables a detection limit of ~0.3 nW × µm−2 with an internal quantum efficiency on the order of 3 × 10−3. The ratiometric sensor based on lanthanide nanotransducers does not require cryogenic cooling, polarization control, phase matching or nanoantenna design for light confinement. We also developed a camera with lanthanide nanotransducers, which enable room-temperature MIR imaging. We anticipate that these lanthanide nanotransducers can be extended to MIR light manipulation at the microscale for chip-integrated device applications.Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)National Research Foundation (NRF)Submitted/Accepted versionThis work was supported by the Singapore Ministry of Education (grant nos. MOE2017-T2-2-110 and MOE2016-T3-1-006(S)), the Agency for Science, Technology and Research (A*STAR) (grant nos. A1983c0038 and A2090b0144), and National Research Foundation, Prime Minister’s Office, Singapore (award nos. NRF-NRFI05-2019-003, NRF-CRP18-2017-02, NRF-CRP22-2019-0002 and NRF-CRP19-2017-01)

Mid-infrared photonics and optoelectronics in 2D materials

With intriguing properties that are different from the conventional bulk materials, two-dimensional (2D) materials have attracted numerous and widespread research interests, including its applications in photonics and optoelectronics. Devices based on 2D materials have been demonstrated in a wide spectral range, from the ultraviolet to the terahertz, and the microwave wavelength range. The mid-infrared (MIR) region (about 2–20 μm) bears a particular scientific and technological significance because, for instance, many molecules have their spectral fingerprints and there are atmosphere transparent windows in this region. Nevertheless, the MIR region remains underdeveloped compared to the visible and the near-infrared telecommunication regimes, mainly due to the lack of suitable materials, such as narrow bandgap materials, and proper photonic designs for building high performance optoelectronic devices in this wavelength regime. Therefore, researchers have been exploring the possibility and opportunity of 2D materials to fill up the gap. Here, we review the key recent developments of 2D materials in the MIR photonic and optoelectronic applications, including photodetection, light modulation, surface plasmon polaritons, phonon polaritons, and their nonlinearities and provide an outlook on the challenges and opportunities that lie ahead for MIR optoelectronic research fields with 2D materials.Ministry of Education (MOE)National Research Foundation (NRF)Published versionG. Liang and X. Yu contribute equally to this work. This work is support by funding from the Ministry of Education, Singapore grant (MOE2018-T2-1-176), A*Star AME programmatic grant under grant no. A18A7b0058, and National Research Foundation Competitive Research Program (NRF-CRP18-2017-02 and NRFCRP22-2019-0007)