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Objective To investigate the clinical characteristics of neonatal acute respiratory distress syndrome (ARDS), and the factors influencing its prognosis. Methods Clinical data of 1 018 cases suffering from respiratory failure admitted to the neonatal intensive care unit (NICU) of our hospital during the year of 2017 were collected and retrospectively analyzed. Among them, 204 cases were diagnosed as neonatal ARDS according to the Montreux definition. The clinical data of these 204 neonatal ARDS patients were retrospectively analyzed. Results ① There were 12 preterm infants (5.9%) with gestational age of 24 weeks to 27 weeks + 6 d, 49 preterm infants (24.0%) with gestational age of 28 weeks to 31 weeks + 6 d, 70 preterm infants (34.3%) with gestational age of 32 weeks to 36 weeks + 6 d, and 73 full-term infants (35.8%). The infants had an average birth weight of 2 260±898 g, with the male ratio of 62.3% (127 cases). Among them, 42 cases (20.7%) got 5 min Apgar score≤7 points. There were 94 cases (46.1%) suffering from sepsis, including 85 cases with early-onset sepsis. According to oxygen index, the 204 ARDS infants were assigned into mild (n=137, 67.2%), moderate (n=49, 24.0%) and severe (n=18, 8.8%) groups, and significant differences were seen in the ratio of non-invasive ventilation, time of assisted ventilation and length of hospital stay among the groups (P < 0.05). ② Among the 204 cases, 163 cases (79.9%) got improved or cured, and 41 cases (20.1%) were abandoned or dead. For different prognosis groups, univariate analysis found that gestational age, birth weight, and 5 min Apgar score were related to prognosis (P < 0.05). Multivariate logistic regression analysis showed that gestational age was an independent influencing factor for neonatal ARDS prognosis. Conclusion Gestational age, birth weight and 5 min Apgar score are pivotal factors for the prognosis of neonatal ARDS.

The salivary pellicle plays an important role in oral physiology, yet noninvasive in situ characterization and mapping of this layer remains elusive. The goal of this study is to develop an optical approach for the real-time, noninvasive mapping and characterization of salivary pellicles using optical coherence tomography (OCT) and optical coherence microscopy (OCM). The long-term goals are to improve diagnostic capabilities in the oral cavity, gain a better understanding of physiological and pathological processes related to the oral hard tissues, and monitor treatment responses. A salivary pellicle is incubated on small enamel cubes using human whole saliva. OCT and OCM imaging occurs at 0, 10, 30, 60 min, and 24 h. For some imaging, spherical gold nanoparticles (15 nm) are added to determine whether this would increase the optical signal from the pellicle. Multiphoton microscopy (MPM) provides the baseline information. In the saliva-incubated samples, a surface signal from the developing pellicle is visible in OCT images. Pellicle "islands" form, which increase in complexity over time until they merge to form a continuous layer over the enamel surface. Noninvasive, in situ time-based pellicle formation on the enamel surface is visualized and characterized using optical imaging.

A multiphoton endoscopy system has been developed using a two-axis microelectromechanical systems (MEMS) mirror and double-cladding photonic crystal fiber (DCPCF). The MEMS mirror has a 2-mm-diam, 20-deg optical scanning angle, and 1.26-kHz and 780-Hz resonance frequencies on the x and y axes. The maximum number of resolvable focal spots of the MEMS scanner is 720 x 720 on the x and y axes, which indicates that the MEMS scanner can potentially support high-resolution multiphoton imaging. The DCPCF is compared with standard single-mode fiber and hollow-core photonic bandgap fiber on the basis of dispersion, attenuation, and coupling efficiency properties. The DCPCF has high collection efficiency, and its dispersion can be compensated by grating pairs. Three configurations of probe design are investigated, and their imaging quality and field of view are compared. A two-lens configuration with a collimation and a focusing lens provides the optimum imaging performance and packaging flexibility. The endoscope is applied to image fluorescent microspheres and bovine knee joint cartilage.

We implement a fiber-delivered compact femtosecond fiber laser at 1,030-nm wavelength in multiphoton imaging. The laser pulse duration is 150 fs, the average power is 200 mW, and the repetition rate is 40 MHz. The laser measures 200 x 160 x 45 mm in size and its output is delivered through a photonic bandgap fiber. Intrinsic second-harmonic generation signal is excited from rat tail tendon and human skin samples. Two-photon excited fluorescence signal is obtained from human skin tissues stained with exogenous fluorophore. Our results show that femtosecond fiber lasers at 1030-nm wavelength have significant potential in developing compact, all-fiber-based, portable multiphoton systems and endoscopes.

The structural origin of scattering contrast from single cells is examined by using a combined optical coherence and multiphoton microscope based on a 12 fs Ti:sapphire source and a 0.95 NA objective. High-resolution coherence-gated scattering images from single cells are coregistered and compared with two-photon-excited fluorescence images. Scattering contrast is observed from mitochondria, plasma membrane, actin filaments, and the boundary between cytoplasm and nucleus. There is little contribution to scattering from regions inside the nuclear core. These results confirm that light scattering signals from specific subcellular structures can be visualized by using coherent reflectance geometry.

In this paper, we used the liquid phase stripping method to manufacture MoS2–SnSe2 heterojunction saturable absorber (SA). The scanning electron microscope, the atomic force microscope, and the Raman spectrometer were used to characterize the MoS2–SnSe2 heterojunction SA. The Q‐switched mode‐locked (QSML) Nd:GGG laser with MoS2–SnSe2 heterojunction SA was presented. The maximum output power of the QSML Nd:GGG laser was 236.4 mW with a repetition rate of 83.3 MHz and pulse width of 447 ps. In short, the MoS2–SnSe2 heterojunction nanosheets present excellent saturable absorption characteristics. [ABSTRACT FROM AUTHOR]

A 12-fs broadband (100-nm) source is used to combine multiphoton microscopy (MPM) and optical coherence tomography (OCT) in a single platform. An ultrafast Ti:sapphire laser simultaneously provides short pulses necessary for efficient MPM excitation and the broad bandwidth required for high-resolution OCT. Using 0.3-microm microspheres and a 63x, 0.95 numerical aperture objective, we demonstrate that MPM and OCT channels are coregistered with lateral resolution of approximately 0.5 microm and axial resolution of approximately 1.5 microm. Preliminary studies of a 3-D organotypic epithelial tissue model show that multiphoton images of fluorescence and second harmonic signals are derived from cellular and extracellular matrix structures, respectively, while OCT images are generated from scattering interfaces due to tissue variations in refractive index. The combined MPM/OCT microscope is capable of providing simultaneous functional and structural information from cells and extracellular matrix and is potentially a powerful tool for studying biological processes in thick tissues.

We have developed a multiphoton microscopy (MPM) system using a 12-fs Ti:sapphire laser with adjustable dispersion precompensation in order to examine the impact of pulse duration on nonlinear optical signals. The efficiencies of two-photon-excited fluorescence (TPEF) and second harmonic generation (SHG) were studied for various pulse durations, measured at the sample, ranging from approximately 400 fs to sub-20 fs. Both TPEF and SHG increased proportionally to the inverse of the pulse duration for the entire tested range. Because of improved signal-to-noise ratio, sub-20-fs pulses were used to enhance MPM imaging depth by approximately 160%, compared to 120-fs pulses, in human skin.