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BACKGROUND Metabolic syndrome (MetS) is a complex group of metabolic disorder syndromes that are risk factors for diabetes and cardiovascular disease. The main aims of this study were to: (1) to establish a MetS risk prediction model based on a routine health checkup cohort using the RSF algorithm, (2) to compare the prediction performance between the model established by the RSF algorithm and cox regression, and (3) visualize predictive models as a nomogram, which can be adapted for web-based use. OBJECTIVE The main aims of this study were to: (1) to establish a MetS risk prediction model based on a routine health checkup cohort using the RSF algorithm, (2) to compare the prediction performance between the model established by the RSF algorithm and cox regression, and (3) visualize predictive models as a nomogram, which can be adapted for web-based use. METHODS The model was based on data from 14,496 subjects aged≥18 years who had a comprehensive health examination and did not have MetS at baseline (2016), with a maximum follow-up of 5 years. A risk prediction model based on the RSF algorithm was developed by applying the physical examination data and compared with the Cox proportional hazards model. The Harrell consistency index (C-index) was used to discriminate the ability of the prediction model, and the Brier score (BS) was used to measure the accuracy of the model prediction results. A nomogram and a web-based application were constructed to vividly demonstrate the prediction model. RESULTS During the 5-year follow-up, 593 (4.09%) participants were diagnosed with MetS. In the RSF prediction model, 15 predictors were identified and then based on the Akaike information criterion strategy. we filtered the set of variables with the lowest OOB error rate (OOB=0.130) among the 15 predictors, ultimately containing seven predictors of WC, GLU, HDL-C, BMI, TG, SBP, and Age. In the testing dataset, the C-index scores of the RSF model, the simplified RSF model, and the Cox model were 0.984, 0.978, and 0.875, and the brier scores were 0.046,0.048 and 0.305, respectively, showing that the discriminatory ability and the accuracy of the prediction results of the RSF model were superior compared with the cox model. CONCLUSIONS We developed a MetS prediction model using the RSF algorithm, which was validated to outperform the cox model, and we constructed a nomogram that can be effectively used for the initial risk prediction of MetS. It is useful for the early identification and prediction of people at high risk of developing MetS.

Introduction The aggregation of lifestyle behaviors and their association with metabolic associated fatty liver disease (MAFLD) remains unclear. We identified lifestyle patterns and investigated their association with MAFLD in a sample of Chinese adults who underwent annual physical examinations. Methods Annual physical examination data of Chinese adults from January 2016 to December 2020 was used in this study. We created a scoring system for lifestyle items combining statistical method (Multivariate analysis of variance) and clinical expertise’s opinion (Delphi method). Subsequently, principal components analysis and two-step cluster analysis were implemented to derive lifestyle patterns of men and women. Binary logistic regression analysis was used to explore the prevalence risk of MAFLD among lifestyle patterns stratified by gender. Results A total of 196,515 subjects were included in the analysis. Based on the defined lifestyle scoring system, nine and four lifestyle patterns were identified for men and women, respectively, which included “healthy or unhealthy” patterns and mixed patterns containing a combination of healthy and risky lifestyle behaviors. This study showed that subjects with an unhealthy or mixed pattern had a differentially higher risk of developing MAFLD than subjects with a relatively healthy pattern, especially among men. Conclusions Clusters of unfavorable behaviors are more prominent in men when compared to women. Lifestyle patterns, as the important factors influencing the development of MAFLD, show significant gender differences in the risk of MAFLD. There is a strong need for future research to develop targeted MAFLD interventions based on the identified behavioral clusters by gender stratification.

Semiconductor nanocrystals (NCs) are emerging luminescent materials with superior optical properties. However, the light-conversion application of NCs is restricted by reabsorption-induced fluorescent quenching. Here, a NC-NC Forster resonance energy transfer (FRET) system is developed by employing large CsPbBr3 NCs as donors and CdSe/CdS NCs as acceptors. The FRET systems using toluene and octadecene as solvents show decreases of 10% and 14%, respectively, in the integrated photoluminescence (PL) intensity, far below the reabsorption loss observed in concentrated CdSe/CdS NCs (>30%) at the same color purity. Notably, we demonstrate by transient absorption measurements that the styrene-mediated FRET system involves a Dexter energy transfer process, which enables the harvesting of triplet excitons and leads to an additional PL enhancement at system level by a maximum of 40% instead of fluorescence quenching. The remarkably improved light-conversion efficiency and antiquenching property make the proposed NC-NC system superior in light down-conversion applications.

A high temporal waveform fidelity stimulated Brillouin scattering phase conjugate mirror (SBS-PCM) with high energy efficiency, based on a novel medium, Novec-7500, is proposed and practically achieved in this study. A theoretical analysis reveals that the temporal-domain waveform distortion is caused by the inherent pulse duration compression effect of the SBS, and this undesirable phenomenon can be significantly suppressed by decreasing the compression coefficient (CC afterwards), which is defined as the gain coefficient divided by the phonon lifetime, which coefficient and is identified as the key parameter for high waveform-fidelity in SBS-PCM. The feasibility of this approach was demonstrated experimentally, in which a reflected pulse with waveform symmetry equals to the pump and an average pulse duration of 0.974 τp (τp is the duration of pump) with an energy efficiency of over 90% was achieved using Novec-7500.

Semiconductor nanocrystals (NCs) are emerging luminescent materials with superior optical properties. However, the light-conversion application of NCs is restricted by reabsorption-induced fluorescent quenching. Here, a NC-NC Förster resonance energy transfer (FRET) system is developed by employing large CsPbBr

Physical vapor deposition has emerged as a promising strategy for efficient and stable all-inorganic perovskite light-emitting devices (PeLEDs). However, the thermally evaporated PeLEDs still suffer from unsatisfactory optoelectrical performance because of the massive nonradiative defects. Herein, we demonstrate an efficient bilateral interfacial defect-passivation strategy toward high-performance PeLEDs with a thermally deposited CsPbBr3 emissive layer (EML). Specifically, the nonradiative defects from the bulk as well as the EML/charge transport layer (CTL) interface are significantly suppressed by implementing the 3-amino-1-propanol (3AP)-modified PEDOT:PSS and introducing ammonium salts, respectively. Simultaneously, both the 3AP induced less-conductive Cs4PbBr6 and ammonium salts can balance the charge injection into the EML effectively. As a result, we achieved efficient PeLEDs based on thermally evaporated CsPbBr3 with a luminance of 15745 cd/m2, current efficiency of 32 cd/A, external quantum efficiency of 8.86%, and lifetime of 3.74 h. The strategy proposed here may shed light on the development of highly efficient thermally evaporated PeLEDs.

We demonstrate a label-free imaging system capable of generating two-photon fluorescence (TPF) and second-harmonic generation (SHG) signals simultaneously, using a wavelength-tunable mode-locked Ti:Sapphire laser. TPF and SHG images are acquired at two wavelength ranges. One is between 415 nm and 455 nm, and the other is between 495 nm and 635 nm. The capability of the imaging system is demonstrated by performing simultaneous TPF and SHG imaging of freshly excised mouse lung lobes. At 870 nm excitation, the microenvironment of pulmonary alveoli is revealed by TPF from elastin fibers and SHG from collagen fibers. Macrophages residing inside apparent alveolar lumens are also identified by autofluorescence.

Multiphoton microscopy is a well-established technique for biomedical applications, but real-time multidepth multimodal multiphoton microscopy using non-imaging detection has barely been discussed. We demonstrate a novel label-free imaging system capable of generating multimodal multiphoton signals at different focal planes simultaneously. Two spatially overlapped and temporally interlaced beams are obtained by applying cost-effective electro-optic modulator (EOM)-based fast-switching light paths. The switching beams have different divergence properties, enabling imaging at different depths into samples. The EOM is synchronized to the pixel clock from the microscope, achieving pixel-to-pixel focus-switching. The capability of the imaging system is demonstrated by performing real-time multidepth two-photon fluorescence (TPF) and second-harmonic generation (SHG) imaging of freshly excised mouse lung lobes. TPF and SHG images are acquired at two wavelength ranges. One is between 415 and 455 nm, and the other is between 495 and 635 nm. The microenvironment of pulmonary alveoli is depicted by the distributions of both elastin fibers visualized by TPF and collagen fibers illustrated by SHG. Macrophages residing inside apparent alveolar lumens are also identified by TPF, which shows that the imaging system is capable of localizing biological objects in three dimensions and has the potential of monitoring in vivo cellular dynamics in the axial direction.

We propose a terahertz surface plasmon biosensor based on MoS 2 for detecting blood components. The change of the thickness of MoS 2 has a great influence on the amount of resonance peak drift. The ultra-high wavelength sensitivity and resolution ratio of the biosensor are 715.59 μ m/RIU and 1.40 × 10−7 RIU, respectively. When the overall structure of the sensor changes by ± 0.4%, the maximum relative error of the resonance frequency is 1.3699%, and the maximum relative error of the peak loss is 1.5327%, which are all within a reasonable range and will not affect the sensor’ performance.

An ultraviolet (UV) detector on single crystal chemical vapor deposition (CVD) diamond with three-dimensional (3D) metal electrodes, is designed, and fabricated with the aim to improve collection efficiency of photo-induced carriers. Interdigitated Ti/Au electrodes were formed within 10 μm deep groove etched in diamond to ensure a more uniform field pattern in the diamond bulk. In the preliminary tests the groove-shaped 3D device performance was compared to a detector with a conventional planar structure on the same material at applied electric field of 1 V/μm. It is found that the responsivity of the 3D electrode structure in the spectral range of 220–280 nm is up to 50% higher than that for the planar structure.

We demonstrate a multi-color background-free coherent anti-Stokes Raman scattering (CARS) imaging system, using a low-cost, all-fiber, energetic, multi-wavelength time-lens source. The time-lens source generates picosecond pulse trains at three different wavelengths. The first is 1064.3 nm, the second is tunable between 1052 nm and 1055 nm, and the third is tunable between 1040 nm and 1050 nm. When the time-lens source is synchronized with a mode-locked Ti:Sa laser, two of the three wavelengths are used to detect different Raman frequencies for two-color on-resonance imaging, whereas the third wavelength is used to obtain the off-resonance image for nonresonant background subtraction. Mixed poly(methyl methacrylate) (PMMA) and polystyrene (PS) beads are used to demonstrate two-color background-free CARS imaging. Synchronization of the multi-wavelength time-lens source with a microscope enables pixel-to-pixel wavelength-switching. Simultaneous two-color CARS imaging of CH2 and CH3 stretching vibration modes with realtime background subtraction is demonstrated in ex vivo mouse tissue.

We propose a new method capable of precise Rhodamine B distribution mapping with two-photon fluorescence (TPF) microscopy. Both epi-detection TPF (E-TPF) and forward TPF (F-TPF) is used for TPF imaging.

Two-photon fluorescence (TPF) imaging system with dual-axis galvo mirror as scanning unit is built. Based on the optical path of imaging system built, mechanism of how intensity distortion generating in dual-axis galvo mirror scanning TPF imaging system is theoretically analyzed. In experiment, TPF imaging is realized with Rhodamine B sample through detecting TPF signal generated from Rhodamine B molecule at excitation of broadband femtosecond pulses. The imaging result verifies the existence of intensity distortion with distribution agreeing well with the theoretical analyzation. To eliminate the intensity distortion in TPF imaging result, a mathematical method is proposed in which a calibration matrix is calculated, As the calibration matrix is applied to the distorted imaging result of Rhodamine B sample, intensity distortion is relieved effectively and precise imaging result is achieved.

Highly lignified vascular plant cell walls represent the majority of cellulosic biomass. Complete release of the biomass to deliver renewable energy by physical, chemical, and biological pretreatments is challenging due to the "protection" provided by polymerized lignin, and as such, additional tools to monitor lignin deposition and removal during plant growth and biomass deconstruction would be of great value. We developed a hyperspectral stimulated Raman scattering microscope with 9 cm(-1) spectral resolution and submicrometer spatial resolution. Using this platform, we mapped the aromatic ring of lignin, aldehyde, and alcohol groups in lignified plant cell walls. By multivariate curve resolution of the hyperspectral images, we uncovered a spatially distinct distribution of aldehyde and alcohol groups in the thickened secondary cell wall. These results collectively contribute to a deeper understanding of lignin chemical composition in the plant cell wall.

Femtosecond time-resolved coherent anti-Stokes Raman spectroscopy (CARS) is utilized to study the ultrafast vibrational dynamics in ethanol at room temperature. The beat wavenumbers between Raman modes of C H stretch modes (from 2800 cm−1 to 3000 cm−1) in ethanol are excited and detected by varying wavelengths of the laser pulses and detection window. The coherence relaxation times of the C H stretch mode in ethanol are measured.

Femtosecond time-resolved coherent anti-Stokes Raman spectroscopy is utilized to study the ultrafast vibrational dynamics in BBO crystals at room temperature. The beat wavenumbers between Raman modes and coherence decay rates of Raman modes (at 1214 cm −1 and 1437 cm −1 ) in BBO crystals are excited and detected. The intensities of vibrational modes in BBO crystals are found that they can be controlled by geometrical configuration.

A high speed two-photon fluorescence microscopy system based on 2D galvanometer scanning is developed, and imaging of Rhodamine B samples and labeled Caski cells is performed. Coherent Micra-5 femtosecond laser is used as the light source, which has 82 MHz frequency, 45 fs pulse width and 400 mW average power. Galvo mirrors and prism pairs are applied in order to obtain higher imaging speed and better imaging resolution respectively. To prove the ability of system, two-photon imaging of Rhodamine B samples and Caski cells labeled by Rhodamine-dyed phalloidin are performed. The results show that the system imaging speed is greatly improved from previous work. The acquisition time reaches the order of 1frame/s, which makes up imprecision of mechanical translation platform and reduces photobleaching and structure damage. By measuring FWHM of lined region of image, lateral resolution is confirmed to be 1.05μm; the vertical resolution of the system can reach 3μm, which is restricted by Z-axis step motor. What’s more, images of different frames are reconstructed to perform three-dimensional imaging. The ability of the phalloidin’s specific binding to the cell is also verified by observing obtained two-photon image.

In this letter, a high pulse energy and high beam quality 819.7 nm Ti:sapphire laser pumped by a frequency-doubled Nd:YAG laser is demonstrated. At incident pump energy of 774 mJ, the maximum output energy of 89 mJ at 819.7 nm with a pulse width of 100 μs is achieved at a repetition rate of 5 Hz. To the best of our knowledge, this is the highest pulse energy at 819.7 nm with pulse width of hundred microseconds for a Ti:sapphire laser. The beam quality factor M 2 is measured to be 1.18. This specific wavelength with the high pulse energy and high beam quality at 819.7 nm is a promising light source to create a polychromatic laser guide star together with a home-made 589 nm laser via exciting the sodium atoms in the mesospheric atmosphere.

We utilized femtosecond time-resolved coherent anti-Stokes Raman spectroscopy (CARS) to study the ultrafast vibrational dynamics in distilled water at room temperature. The CARS signals from the broad OH-stretching modes between 3100 cm−1 and 3700 cm−1 were obtained and analyzed. The dephasing times of four Raman modes in water were detected and compared.

Spectrally dispersed femtosecond time-resolved coherent anti-Stokes Raman spectroscopy is applied to study the ultrafast vibrational dynamics in ethanol at room temperature. The anti-Stokes intensities were monitored as a function of delay time and wavenumber. By simply changing the timing of the laser pulses, the vibrational dynamics between the excited Raman transitions in ethanol molecules can be tracked and detected. Copyright © 2014 John Wiley & Sons, Ltd.

Spectrally dispersed femtosecond time-resolved coherent anti-Stokes Raman spectroscopy is utilized to study the ultrafast vibrational dynamics in rhodamine B dye in solution at room temperature. The anti-Stokes intensities are monitored as a function of time and wavenumber. By simply changing the timing of laser pulses, the vibrational dynamics of excited Raman transitions in rhodamine B molecules can be tracked and detected.

We report on the harmonics radiation and spectrum properties in the Xe–Ar gas mixture by using tight focusing laser pulses. The cutoff position is extended from the harmonic H33–H37 in mixed gases. The extended orders are attributed to the harmonic radiation from Xe+. We observe that the harmonics are decreased in the plateau region. The result is attributed to the destructive interference of the harmonics generated from the different atoms. Our results suggest that using the Xe–Ar mixture as nonlinear can obtain the coherent XUV source.

We experimentally study the harmonics from a Xe-He gas mixture using tight-focusing femtosecond laser pulses. The spectrum in the mixed gases exhibits an extended cutoff region from the harmonic H21 to H27. The potential explanation is that the harmonics photons from Xe contribute the electrons of He atoms to transmit into the excited-state. Therefore, the harmonics are emitted from He atoms easily. Furthermore, we show that there are the suppressed harmonics H15 and H17 in the mixed gases. The underlying mechanism is the destructive interference between harmonics generated from different atoms. Our results indicate that HHG from Xe-He gas mixture is an efficient method of obtaining the coherent soft X-ray source.

Broadband two-photon fluorescence (TPF) imaging system based on femtosecond oscillator is built. Broadband TPF signal generated from Rhodamine B molecule is detected at different detection windows. Both TPF signals detected at short wavelength detection window of 545–615 nm and long wavelength detection window of 642–708 nm are used for TPF imaging. Through switching detection window from short wavelength to long wavelength, deepened imaging depth is achieved. The TPF imaging results, with single [Formula: see text] pixels frame taking time of 4–8 s, demonstrate high performance and the good reliability of the imaging system.

We demonstrate a multi-color background-free coherent anti-Stokes Raman scattering (CARS) imaging system, using a robust, all-fiber, low-cost, multi-wavelength time-lens source. The time-lens source generates picosecond pulse trains at three different wavelengths. The first is 1064.3 nm, the second is tunable between 1052 nm and 1055 nm, and the third is tunable between 1040 nm and 1050 nm. When the time-lens source is synchronized with a mode-locked Ti:Sa laser, two of the three wavelengths are used to detect different Raman frequencies for two-color on-resonance imaging, whereas the third wavelength is used to obtain the off-resonance image for nonresonant background subtraction. Mixed poly(methyl methacrylate) (PMMA) and polystyrene (PS) beads are used to demonstrate two-color background-free CARS imaging. The synchronized multi-wavelength time-lens source enables pixel-to-pixel wavelength-switching. We demonstrate simultaneous two-color CARS imaging of CH(2) and CH(3) stretching vibration modes with real-time background subtraction in ex vivo mouse tissue.

The S-tapered PCF interferometer for refractive index sensing was demonstrated in this letter. The whole fabrication process was carried out using a standard splicing machine. It has a compact and stable structure since the S-shape assumes the same function with elongating taper. The sensor exhibits highly SRI sensitivity, which is found to be 8.0 10-5 RIU in 1.38-1.44 and the temperature dependence is only 4.2 pm/°C low 100°C.

Based on ultrafast laser pulses, time-resolved resonance enhancement coherent anti-Stokes Raman scattering (RE-CARS) is applied to investigate wave-packet dynamics in gaseous iodine. The effects of air pressure on the wave-packet dynamics of iodine molecules are studied at pressures ranging from 1.5 Torr to 750 Torr. The RE-CARS signals are recorded in a gas cell filled with a mixture of about 0.3 Torr iodine in air buffer gas at room temperature. The revivals and fractional revival structures in the wave-packet signal are found to gradually disappear with rising air pressure up to 750 Torr, and the decay behaviors of the excited B-state and ground X-state become faster with increasing air pressure, which is due to the collision effects of the molecules and the growing complexity of the spectra at high pressures.

A recently developed time-resolved coherent anti-Stokes Raman scattering (tr-CARS) technique allows the measurement of vibrational coherences with high frequency differences with the ambient environment. The method is based on the short spatial extension of femtosecond pulses with a broadband tunable nonlinear optical parametric amplifier (NOPA) and an internal time delay between the probe and pump/Stokes pulse pair in the CARS process. The different beat frequencies between Raman modes can be selectively detected as oscillations in the tr-CARS transient signal with the broadband tunable NOPA. In this work, we aim at the Raman C—H stretching vibrations from 2800 cm−1 to 3000 cm−1, within which the different vibrational modes in both ethanol and methanol are selectively excited and simultaneously detected. The high time resolution of the experimental set-up allows one to monitor the vibrational coherence dynamics and to observe the quantum beat phenomena on a terahertz scale. This investigation indicates that the femtosecond tr-CARS technique is a powerful tool for the real-time monitoring and detection of molecular and biological agents, including airborne contaminants such as bacterial spores, viruses and their toxins.

Femtosecond time-resolved coherent anti-Stokes Raman spectroscopy (CARS) is utilized to study the ultrafast vibrational dynamics in BBO crystals at room temperature. Time-resolved two-beam and three-beam CARS are detected. The vibrational dephasing time is analyzed and the changes of vibrational mode intensities with the polarization of pump pulses are observed.

We utilize femtosecond time-resolved electronic resonance-enhanced coherent anti-Stokes Raman scattering (ERE-CARS) to investigate new information for pyrromethene 650 (PM650) dye molecules. For this purpose, the vibrational properties of PM650 are registered in diluted solutions of several organisms. We observe a strong Raman vibrational mode with a wavenumber difference of about 48 cm − 1 in its organic solutions. This may be linked to the intramolecular electron transfer (ICT) process from the aromatic ring to the cyano group in PM650. The influence of the solvent effects on the vibrational dynamics of PM650 is also investigated. The vibrational properties of PM650 dye molecules diluted in polar organic solutions are light solvent-dependent.

We utilize femtosecond time-resolved electronic resonance-enhanced coherent anti-Stokes Raman scattering (ERE-CARS) to study the vibrational dynamics of cresyl violet 670 (CV670) dye molecules. For this purpose, the vibrational properties of CV670 are registered in diluted solutions of ethanol and methanol. By changing the timing (Δt > 0) of the laser pulses of this nondegenerate four wave mixing technique, the wavepacket dynamics on the electronically ground state can be detected as oscillations in the ERE-CARS signal. Two strong Raman vibrational modes with an average period of 0.401 and 0.423 ps in CV670–ethanol solutions are obtained simultaneously, and we observe a qualitative vibrational dephasing time difference of the Raman vibrational modes of CV670 in ethanol and methanol solvents (5 × 10–5 mol/L), which may be due to the influence of the formation of the supramolecular structures in CV670–ethanol and CV670–methanol mixtures on the Raman modes of CV670.

Time-resolved femtosecond coherent anti-Stokes Raman spectroscopy (fs-CARS) is utilized to measure the methane/oxygen/nitrogen flame temperature at atmospheric-pressure. The measurements are performed using the CARS signal of N2 with 40-fs laser pulses in the first few picoseconds after the initial in-phase excitation. Flame temperatures at 300 and 1 325 K are measured, the experimental results show good agreements with theoretical ones and present a good repeatability.

In this paper, ultrafast time-resolved coherent degenerate four-wave-mixing (DFWM) spectroscopy is performed to investigate molecular dynamics in the gaseous phase. Laser pulses lasting for 40 fs are used to create and monitor different vibrational eigenstates of iodine at room temperature (corresponding to a low saturation pressure of about 35 Pa). Using an internal time delay in the DFWM process resonant with the transition between the ground X-state and the excited B-state, the vibrational states of both the electronically excited and the ground states are detected as oscillations in the DFWM transient signal. The dynamics of either the electronically excited or ground state of iodine molecules obtained are consistent with the previous high temperature studies on the femtosecond time-resolved DWFM spectroscopy.

LC cell injected the mixture of dye pyrromethene 567 (PM567) and nematic liquid crystal (NLC) by capillary action was prepared. Holographic pumping with a Nd:YAG laser (532 nm, 1 Hz, 10 ns) to form gain distributed feedback in the cell, tunable laser output from the cell was investigated. Through changing the intersection angles of the two coherent light beams from 46° to 50°, the tuning range we obtained is about 37 nm (550–587 nm). Additionally, the FWHM of the laser under such experimental setup was less than 0.1 nm even without the resonant cavity, and the threshold of the laser was about 26 μJ, which was very low as we known.

The molecular dynamics process is investigated in this paper using a broadband fs time-resolved coherent anti-Stokes Raman spectroscopy (CARS) technique. By varying the timing of laser pulses, low vibrational states are started and studied on both the electronically excited B ( 3 Π 0 u + ) state and ground X ( 1 Σ 0 g + ) state of iodine in the gas phase at room temperature. According to change the pump wavelength or Stokes pulse as well as the wavelength of the detection window for the CARS signal, dynamics on different potential-energy surfaces can be accessed and detected by the CARS spectroscopy. Results show that the period of the oscillation is decreased for the excited B ( 3 Π 0 u + ) state as the wavelength of the pump pulses is increased, while it is increased for the ground X ( 1 Σ 0 g + ) state with the increase of the Stokes wavelength.