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BACKGROUND: Immune checkpoint inhibitors (ICIs) are commonly used to treat lung cancer patients, but their use can lead to immune-related adverse events (irAEs), which pose a challenge for treatment strategies. The impact of irAEs on the incidence of COVID-19 pneumonia in lung cancer patients during the ongoing COVID-19 pandemic is unclear. This study aims to investigate the association between irAEs and COVID-19 pneumonia in lung cancer patients receiving ICIs. METHODS: We conducted a cross-sectional study of lung cancer patients who received ICIs and were infected with COVID-19 due to the Omicron variant between December 2022 and February 2023 in China. We collected data on irAEs and COVID-19 outcomes. Logistic regression analyses were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between irAEs and the incidence of COVID-19 pneumonia. RESULTS: A total of 193 patients were enrolled, with 72 patients (37.30%) in the irAEs group and 121 patients (62.70%) in the non-irAEs group. Twenty-six patients (13.47%) developed COVID-19 pneumonia and 6 patients (3.11%) progressed to severe cases after COVID-19 infection. Multivariate logistic regression showed that the lung cancer patients who experienced irAEs was significantly associated with a higher incidence rate of COVID-19 pneumonia (OR = 9.56, 95%CI: 2.21-41.33; P = 0.0025). CONCLUSION: Our study suggests that lung cancer patients receiving ICIs and experiencing irAEs may have a higher risk of developing COVID-19 pneumonia due to the Omicron variant. Therefore, close monitoring of these patients during the COVID-19 pandemic is necessary to mitigate this risk.
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COVID-19 , Neoplasias Pulmonares , Humanos , Estudios Transversales , Inhibidores de Puntos de Control Inmunológico , Pandemias , SARS-CoV-2 , China , Estudios RetrospectivosRESUMEN
A fiber laser with strong spontaneous emission and high signal-to-noise ratio is proposed and experimentally demonstrated for simultaneous measurement of temperature and refractive index (RI). By cascading a single MZ interferometer, the power and the emission spectrum of the fiber laser are modulated by surrounding temperature and RI. The dual parameters are determined from the measured power change and interference dip shift. A temperature sensitivity of 0.146 dB/°C (-0.06n m/∘ C) in the range from 20°C to 90°C at an RI of 1.3910 and an RI sensitivity of -156.07d B/R I U (153.70 nm/RIU) in the range from 1.3333 to 1.3910 at 20°C are achieved.
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Mid-infrared (mid-IR) lasers have great applications in bio-molecular sensing due to strong vibrational fingerprints in this wavelength range. However, it is a huge challenge to realize mid-IR lasers in conventional silica materials. Here, we demonstrate the generation of mid-IR Raman lasers and Kerr-frequency combs from an all-silica microresonator/fiber laser system. A single wavelength narrow-linewidth laser at â¼2 µm is first realized by using an ultrahigh Q-factor silica whispering-gallery-mode (WGM) microresonator as mode-selection mirror, and thulium-doped silica fiber as gain medium. Due to the strong intensity enhancement in the microresonator itself, multiple third-order nonlinear optical effects are observed, which include stimulated Stokes and anti-Stokes Raman scattering, and (cascaded) four-wave-mixing (FWM). The stimulated Stokes and anti-Stokes Raman scattering shift the initial 2 µm narrow-linewidth laser to as far as â¼2.75 µm and â¼1.56 µm, respectively. While the cascaded FWM helps to form a Kerr-frequency comb with a broad bandwidth of â¼900â nm and a mode spacing of twice of the microresonator free-spectral-range. This work offers a simple and effective route to realize all-silica mid-IR lasers based on enhanced optical nonlinearity in WGM microresonators.
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Stimulated Brillouin scattering (SBS) in a microcavity is usually realized by employing a wavelength tunable external cavity diode laser (TECDL) as the pump source. In this Letter, we report the observation of SBS in a high Q microcavity based on a TECDL-free scheme. The microcavity is employed as a mode-reflecting mirror for constructing a fiber-ring laser and, simultaneously, pumped by the fiber-ring lasing with intrinsic resonance latching. Several regimes are observed in a microcavity with a diameter of â¼215 µm, such as single lasing pumped SBS and multiple regular lasing pumped SBSs (single or cascaded). The microwave signals from the beat notes of the composite output lasing are measured with full-width at half-maximum on the scale of kilohertz at â¼11 and â¼22 GHz, indicating the high coherence between the pump and the Brillouin lasing.
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We propose and experimentally demonstrate a simple scheme for generating optical frequency combs (OFCs) in a fiber-ring/microresonator laser system. The ultrahigh Q whispering gallery mode microresonator is employed both as a mode reflection mirror to generate erbium lasing and as a Kerr-nonlinearity initiator that introduces optical parametric oscillation signals to form OFCs. By controlling the coupling position between the fiber taper and microresonator, optimizing the fiber polarization, as well as the pump power from a 974 nm laser diode (LD), versatile OFCs can be tuned out from single-wavelength states. The OFCs have single, multiple, or combined free spectral ranges. In addition, a Raman-gain-assisted OFC is also observed with a bandwidth of â¼230 nm. This LD-pumped and multifunctional laser system could find applications in precision spectroscopy, biochemical sensing, and optical fiber communication systems.
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We demonstrate the first observation of stimulated Brillouin scattering (SBS) in a high-Q whispering gallery mode tellurite microsphere. Tellurite glass with composition of 70TeO2-20ZnO-5Na2O-5La2O3 (molar ratio) was prepared in-house using a melt-quenching technique. Moreover, tellurite microspheres with Q in excess of 13 millions at 1550 nm were fabricated by melting tellurite microwires using a CO2 laser. By pumping the tellurite microspheres with a tunable single frequency laser, SBS is further realized with a threshold as low as 0.58 mW. At last, the beat notes between the pump and the Stokes signals were measured, which indicated the Brillouin frequency shift is at the 8.2 GHz band for our tellurite glass. Our results could propel significant applications utilizing SBS by employing tellurite microspheres.
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We experimentally demonstrate an ultralow-threshold cascaded Brillouin microlaser for tunable microwave generation in a high-Q silica microsphere resonator. The threshold of the Brillouin microlaser is as low as 8 µW, which is close to the theoretical prediction. Moreover, the fifth-order Stokes line with a frequency shift up to 55 GHz is achieved with a coupled pump power of less than 0.6 mW. Benefiting from resonant wavelength shifts driven by thermal dynamics in the microsphere, we further realized tunable microwave signals with tuning ranges of 40 MHz at an 11 GHz band and 20 MHz at a 22 GHz band. To the best of our knowledge, it was the first attempt for tunable microwave source based on the whispering-gallery-mode Brillouin microlaser. Such a tunable microwave source from a cascaded Brillouin microlaser could find significant applications in aerospace, communication engineering, and metrology.
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Plasmonic whispering gallery (WG) modes confined in metal-coated resonators are theoretically investigated by electromagnetic analyses. The resonance can be tuned from internal surface plasmonic WG modes to the hybrid state of the plasmonic mode by an introduced isolation layer. As the coated metal is reduced in size, the optical resonance is shifted out by the mode coupling of the internal and external surface plasmonic WG modes. Based on the optical leak of the plasmonic WG mode, the optical influences led by the surroundings with a variable refractive index are considered. Device performance criteria such as optical power leak, resonant wavelength shift, and threshold gain are studied. Full wave simulations are also employed and the results present good consistency with analytic solutions. The metal-coated resonator assisted by an active material is expected to provide promising performance as a refractometric sensor.
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The double transfer matrix method (DTMM) is proposed for calculating the eigenvalues of the resonant mode of a metallically coated dielectric rectangle resonator. Two-dimensional electromagnetic analyses are performed to investigate the optical influences induced by planar structure parameters. The results show that there theoretically exists a highest Q-factor resonance for both TE and TM modes at a certain length-width ratio with fixed resonant wavelength and resonator area. Due to the influence of surface plasma polaritons (SPPs) trapped at the corners of the resonator which is not considered in DTMM, the TM mode resonances are deformed and deviate severely from that of the analytical model. The geometric deformation on the resonator is introduced by replacing the four right angles with circular boundaries, and the SPP accompanied mode behaviors are corrected to the standing waves.
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We propose and demonstrate a MoS2-based passively Q-switched Er-doped fiber laser with a wide tuning range of 1519.6-1567.7 nm. The few-layer MoS2 nano-platelets are prepared by the liquid-phase exfoliation method, and are then made into polymer-composite film to construct the fiber-compatible MoS2 saturable absorber (SA). It is measured at 1560 nm wavelength, that such MoS2 SA has the modulation depth of â¼ 2% and the saturable optical intensity of â¼ 10 MW/cm(2). By further inserting the filmy MoS2-SA into an Er-doped fiber laser, stable Q-switching operation with a 48.1 nm continuous tuning from S- to C-waveband is successfully achieved. The shortest pulse duration and the maximum pulse energy are 3.3 µs and 160 nJ, respectively. The repetition rate and the pulse duration under different operation conditions have been also characterized. To the best of our knowledge, it is the first demonstration of MoS2 Q-switched, widely-tunable fiber laser.
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Absorción de Radiación , Disulfuros/química , Erbio/química , Rayos Láser , Molibdeno/química , Fibras Ópticas , Electricidad , Soluciones , Sonicación , Difracción de Rayos XRESUMEN
This work presents a remarkably simple method for the fabrication of ultraviolet (UV)-curable adhesive bottle-like microresonators (BLMRs). The main fabrication process involves two steps: (1) creating liquid bottle-like microcavities along the taper waist of an optical fiber taper under interfacial tension and (2) curing the liquids into solids by UV light irradiation. The shape of the BLMRs can be fitted with a truncated harmonic-oscillator profile. Whispering gallery mode resonances of the bottle-like microcavity were excited via a tapered fiber at different positions along its axis. A cleaner spectrum with identifiable and traceable features over a broad wavelength range at the center excitation position and the estimated Q factors close to 105 around 1.55 µm are observed. The shifts of resonance frequency by the input light power change demonstrate the potential applications of thermo-optic sensing and frequency tuning.
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We demonstrate a large-energy, wavelength-tunable, all-fiber passively Q-switched Er:Yb-codoped laser using a mono-layer chemical vapor deposition (CVD) graphene saturable absorber (SA). By exploiting the large laser gain of Er:Yb double-clad fiber and optimizing the coupling ratio of the output coupler, not only can the mono-layer CVD graphene SA be protected from oversaturation and thermal damage, but also a large pulse energy up to 1.05 µJ (corresponding to the average output power of 25.6 mW) is thus achieved. Using a tunable fiber Fabry-Perot filter, stable Q-switched pulses can operate with a tunable range from 1530.97 to 1546.92 nm, covering a wavelength range of â¼16 nm. The Q-switching states at the different lasing wavelengths have been observed and recorded. The Q-switched repetition rate and the pulse duration (with the minimum one of 2.6 µs) have been characterized as well. This is, to the best of our knowledge, the largest pulse energy from an all-fiber graphene Q-switched laser.
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Cancer patients with COVID-19 have a higher infection rate and mortality rate than non-cancer patients. However, there are few studies on the correlation between the serum C-reactive protein (CRP) and cancer patients with COVID-19. This study aims to investigate the association between serum CRP and the incidence of COVID-19 pneumonia in cancer patients at the end of 2022 in China. This cross-sectional study with a retrospective cohort between December 2022 and February 2023 assessed cancer patients complicated with COVID-19 infection in 2 Chinese institutions. Logistic regression analyses were used to compute Odds ratio (OR) and 95%CIs for the association between serum CRP and the incidence of COVID-19 pneumonia in cancer patients. A total of 213 cancer patients with COVID-19 were enrolled. Eighty-six patients (40.4%) developed COVID-19 pneumonia, among which 23 patients (10.8%) progressed to severe cases. Univariate Logistic regression showed that high CRP levels were found to be an unfavorable predictor of COVID-19 outcomes (ORâ =â 17.9, 95%CI: 7.3, 43.6; P < .001). In the multivariate analysis, high CRP levels were associated with a higher incidence rate of COVID-19 pneumonia (ORâ =â 9.8, 95%CI: 2.2, 43.8; Pâ =â .003). In the multivariate logistic regression model and smooth curve fitting, we found a correlation between CRP and COVID-19 pneumonia. The serum CRP was associated with the incidence of Omicron variant COVID- 19 pneumonia in cancer patients. Hence, cancer patients with high CRP level maybe need for timely computer tomography examination and more aggressive treatment.
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Proteína C-Reactiva , COVID-19 , Neoplasias , Humanos , Proteína C-Reactiva/química , China/epidemiología , COVID-19/diagnóstico , COVID-19/metabolismo , Estudios Transversales , Neoplasias/complicaciones , Neoplasias/epidemiología , Pronóstico , Estudios Retrospectivos , SARS-CoV-2/metabolismoRESUMEN
We numerically investigate the direct and indirect optical interactions of pair circular resonators laterally confined by metal-insulator waveguide. The direct optical interaction shows the split of quality (Q) factors of bonding and antibonding states only happens for thick insulator. The indirect optical interaction through a waveguide is proposed to control the modes resonance and collect the output emissions. The Q factors of resonant modes versus the coupling distance (width of waveguide) are studied. The results show whispering gallery modes(WGMs) engaged into interaction are strongly coupled with the guided waves of waveguide once its width is close to the cut-off width of guided waves, while the coupled mode of two WGMs is not limited by this condition. High Q factor mode, combined with a robust wide emission waveguide(close to the cut-off width of second-order guided waves), can be realized from the bonding states of WGM and coupled WGM with an added wave envelope in waveguide. In addition to the pair resonators, the studies on four resonators interacted with each other through waveguide are also addressed and wide waveguide output is anticipated.
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Diseño Asistido por Computadora , Metales/química , Modelos Teóricos , Dispositivos Ópticos , Refractometría/instrumentación , Resonancia por Plasmón de Superficie/instrumentación , Simulación por Computador , Diseño de Equipo , Análisis de Falla de Equipo , Luz , Dispersión de RadiaciónRESUMEN
A waveguide is bridged between two metallically hybrid microdisks for achieving nonlocal optical processing. The whispering gallery mode (WGM) is split into two modes, one is intrinsic WGM and the other is oscillating mode (OM) whose photons oscillate between two microdisks through the waveguide. The characteristics of OM on the waveguide's width and length are studied. The results show the fundamental WGM oscillation only happens at certain lengths and widths of the waveguide, and strong optical interaction between two microdisks is accompanied by a high-loss waveguide. The optical processing through a waveguide between two individual resonators or photon producers may be applied to dynamic control on the photon states.
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Because breast cancer cells such as MCF-7, exhibit vital and developmental signs by exosome secretion, diagnosing them in the blood can provide a good index of the presence of breast cancer. However, accurate and inexpensive detection of exosomes in clinical practice faces challenges. Therefore, in the presents study, an aptasensor based on CD63 aptameriron oxide-copper ion nanozymes (Fe3O4-Cu2+-NZs) was designed with the ability of the CD63 aptamer to interact with the exosome and the release of the Fe3O4-Cu2+-NZs for peroxidase-like activity on the tetramethylbenzidine (TMB). After fabrication of CD63 aptamer-Fe3O4-Cu2+-NZs based on hydrothermal method, their physicochemical properties were investigated with the SEM, TEM, DLS, Zeta, XRD and magnetization. To investigate the interaction of CD63 aptamer-Fe3O4-Cu2+-NZs with exosomes, the required exosomes were extracted from cultured MCF-7 cells. The performance of CD63 aptamer-Fe3O4-Cu2+-NZs on TMB degradation in the presence and absence of exosomes was investigated through UV-vis adsorption and ocular observations based on colour changes on laboratory and real samples. The results show that the absence of exosomes significantly inhibited the peroxidase-like activity of CD63 aptamer-Fe3O4-Cu2+-NZs due to the aptamer coating. Under optimal conditions, the designed CD63 aptamer-Fe3O4-Cu2+-NZs is capable of detecting exosomes in the range of 1.4 × 104-5.6 × 105 particles/µL with a detection limit of 5.91 × 10³ particles/µL. Also, this method showed a satisfactory outcome in detection of cancer cells in real samples. Overall, this colorimetric aptasensor can be used to diagnose breast cancer cells based on a simple and inexpensive approach.
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Aptámeros de Nucleótidos , Técnicas Biosensibles , Neoplasias de la Mama , Exosomas , Aptámeros de Nucleótidos/química , Técnicas Biosensibles/métodos , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/metabolismo , Colorimetría/métodos , Exosomas/química , Exosomas/metabolismo , Femenino , Humanos , Peroxidasas/análisis , Peroxidasas/metabolismoRESUMEN
We theoretically present in-plane multiple guided emissions of metallically confined microdisk lasers which can be applied to drive multiple elements in compact photonic integration at the same time. Two to four-port microdisks with transverse magnetic and electric polarizations are investigated based on finite difference time domain simulation and padé approximation. Modes filtering of coupling ports are verified by the calculated mode quality factors (Q) which are decided by the matching of coupling ports with the energy density distribution of corresponding modes. Single mode lasing operation of semiconductor microdisk with guided emissions is possibly realized by selectively pumping.
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Port output of metallo-dielectric confined circular microlasers directly connected with a coupling waveguide in radial direction is presented and numerically investigated by the finite-difference time-domain method and the Padé approximation. The quality factors of fundamental whispering-gallery modes confined in microlasers with dimensions of around 1 µm do not deteriorate until the output waveguide can support a one-order guided wave. The port-output metallo-dielectric microlasers with low threshold are expected. In addition, the mode characteristics of port-output metallo-dielectric microlasers are studied based on ample modes of larger cavity, where coupled modes and standing-wave-like modes dominate in the cavity with a wide output port.
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The integration of one more gain media in droplet microlasers with morphology-dependent modes, which can be employed in optofluidic systems as multi-wavelength lasing sources, is highly attractive and demands new cavity design and fabrication approaches. Here, cholesteric liquid crystal (CLC) droplets with an integrative triple-emulsion cavity are fabricated via glass-capillary-based microfluidic technologies and dual-gain lasing with variable modes, flexibly configured by the combination and incorporation of gain dyes and CLCs into both the core and shell. The distributed feedback (DFB) mode, formed by the feedback from the self-assembled helix periodic structure of CLCs, the whispering gallery (WG) mode, and the hybrid, is selectively excited by controlling the spatial coupling between the pump beam and the droplet with gain. With the merits of dual-gain and controllable lasing, a prototype dual-wavelength-ratiometric thermometer with self-calibration capability is expected to be developed. Furthermore, the anisotropic CLC core is substituted with an isotropic fluid and the gain from the CLC shell is additionally removed, DFB lasings in both shell and core are absent, and only Bragg-shell reflection-based hybrid modes are excited for lasing. The CLC droplet microlasers with an integrative cavity are expected to provide a new route to future lab-on-chip (LOC) applications.
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Colesterol/química , Cristales Líquidos/química , Técnicas Analíticas Microfluídicas , Técnicas Analíticas Microfluídicas/instrumentación , Tamaño de la PartículaRESUMEN
We report a magnetically transportable microlaser with cholesteric liquid crystal (CLC) core-shell structure, operating in band-edge mode. The dye doped CLC shells as a water-in-oil-in-water (W/O/W) double emulsion were fabricated by microfluidics. Water-dispersible Fe3O4 magnetic nanoparticles were incorporated in the inner aqueous phase by taking advantage of the immiscibility with the middle CLC oil phase. The influence of temperature and shell thickness on laser properties was discussed in detail. The non-invasive manipulation of microlasers was realized under a magnetic field. The dependence of velocity on the viscosity of the carrying fluid and size of the core-shell structure was theoretically analyzed and experimentally investigated using a prototype electromagnetic platform. We also discussed the design principles for this type of DDCLC core-shell structure. Such magnetically transportable microlasers offer promise in in-channel illumination applications requiring active control inside micro-channels.