Temporal resolution of ultrafast compressive imaging using a single-chirped optical probe.

Ultrafast compressive imaging captures three-dimensional spatiotemporal information of transient events in a single shot. When a single-chirped optical probe is applied, the temporal information is obtained from the probe modulated in amplitude or phase using a direct frequency-time mapping method. Here, we extend the analysis of the temporal resolution of conventional one-dimensional ultrafast measurement techniques such as spectral interferometry to that in three-dimensional ultrafast compressive imaging. In this way, both the amplitude and phase of the probe are necessary for a full Fourier transform method, which obtains temporal information with an improved resolution determined by probe spectral bandwidth. The improved temporal resolution potentially enables ultrafast compressive imaging with an effective imaging speed at the quadrillion-frames-per-second level.

Generalized central slice theorem perspective on Fourier-transform spectral imaging at a sub-Nyquist sampling rate.

Fourier-transform spectral imaging captures frequency-resolved images with high spectral resolution, broad spectral range, high photon flux, and low stray light. In this technique, spectral information is resolved by taking Fourier transformation of the interference signals of two copies of the incident light at different time delays. The time delay should be scanned at a high sampling rate beyond the Nyquist limit to avoid aliasing, at the price of low measurement efficiency and stringent requirements on motion control for time delay scan. Here we propose, what we believe to be, a new perspective on Fourier-transform spectral imaging based on a generalized central slice theorem analogous to computerized tomography, using an angularly dispersive optics decouples measurements of the spectral envelope and the central frequency. Thus, as the central frequency is directly determined by the angular dispersion, the smooth spectral-spatial intensity envelope is reconstructed from interferograms measured at a sub-Nyquist time delay sampling rate. This perspective enables high-efficiency hyperspectral imaging and even spatiotemporal optical field characterization of femtosecond laser pulses without a loss of spectral and spatial resolutions.

Air Pollution Detection Using a Novel Snap-Shot Hyperspectral Imaging Technique.

Air pollution has emerged as a global problem in recent years. Particularly, particulate matter (PM2.5) with a diameter of less than 2.5 µm can move through the air and transfer dangerous compounds to the lungs through human breathing, thereby creating major health issues. This research proposes a large-scale, low-cost solution for detecting air pollution by combining hyperspectral imaging (HSI) technology and deep learning techniques. By modeling the visible-light HSI technology of the aerial camera, the image acquired by the drone camera is endowed with hyperspectral information. Two methods are used for the classification of the images. That is, 3D Convolutional Neural Network Auto Encoder and principal components analysis (PCA) are paired with VGG-16 (Visual Geometry Group) to find the optical properties of air pollution. The images are classified into good, moderate, and severe based on the concentration of PM2.5 particles in the images. The results suggest that the PCA + VGG-16 has the highest average classification accuracy of 85.93%.

Single-shot compressed optical field topography.

Femtosecond lasers are powerful in studying matter's ultrafast dynamics within femtosecond to attosecond time scales. Drawing a three-dimensional (3D) topological map of the optical field of a femtosecond laser pulse including its spatiotemporal amplitude and phase distributions, allows one to predict and understand the underlying physics of light interaction with matter, whose spatially resolved transient dielectric function experiences ultrafast evolution. However, such a task is technically challenging for two reasons: first, one has to capture in single-shot and squeeze the 3D information of an optical field profile into a two-dimensional (2D) detector; second, typical detectors are only sensitive to intensity or amplitude information rather than phase. Here we have demonstrated compressed optical field topography (COFT) drawing a 3D map for an ultrafast optical field in single-shot, by combining the coded aperture snapshot spectral imaging (CASSI) technique with a global 3D phase retrieval procedure. COFT can, in single-shot, fully characterize the spatiotemporal coupling of a femtosecond laser pulse, and live stream the light-speed propagation of an air plasma ionization front, unveiling its potential applications in ultrafast sciences.

Overexpressed COL5A1 is correlated with tumor progression, paclitaxel resistance, and tumor-infiltrating immune cells in ovarian cancer.

Ovarian cancer (OC) remains the leading cause of cancer-related death among gynecological cancers. The present study examined the role of collagen type V alpha 1 (COL5A1) and the characteristics of COL5A1 as an oncogenic protein in OC. The association of COL5A1 with paclitaxel (PTX)-resistance and stemness in OC was also studied and the multidatabase and big data analyses of the prognostic value, coexpression network, genetic alterations, and tumor-infiltrating immune cells of COL5A1 were elucidated. We found that COL5A1 expression was high in OC cells and tissues. Knockdown of COL5A1 inhibited the proliferation and migration of OC cells. Further study also showed that COL5A1 was overexpressed in PTX-resistant OC cells compared to respective PTX-sensitive cells. Additionally, COL5A1 was more enriched in OC stem cell-like cells. Silencing COL5A1 expression decreased the OC cell resistance to PTX and inhibited the ability of OC-spheroid formation. Survival analysis predicted that the elevated COL5A1 expression was associated with a worse survival outcome and correlated to the tumor stage of OC patients. The estimating relative subsets of RNA transcripts (CIBERSORT) algorithm analysis also unveiled the correlation of several tumor-infiltrating immune cells with the expression of COL5A1. Taken together, our data demonstrate that COL5A1 is a biomarker to predict OC progression and PTX-resistance and represents a promising target for OC treatment.

Abnormal Brain-Derived Neurotrophic Factor Exon IX Promoter Methylation, Protein, and mRNA Levels in Patients with Major Depressive Disorder.

Brain-derived neurotrophic factor (BDNF) exon IX promoter methylation levels, serum BDNF protein levels, and serum mRNA levels were investigated in patients with major depressive disorder (MDD) and healthy controls. Over two years, 51 patients with MDD and 62 healthy controls were recruited. Peripheral blood was drawn from all participants to analyze the BDNF exon IX promoter methylation levels as well as serum BDNF protein and mRNA levels, at baseline and after four weeks of antidepressant treatment. Methylation sequential analysis showed that patients with MDD (n = 39) had a higher methylation level at CpG site 217 and lower methylation levels at CpG site 327 and CpG site 362. Drug responders (n = 25) had a higher methylation level at CpG site 24 and CpG site 324 than the non-responders (n = 11). Patients with MDD had a lower serum BDNF protein and mRNA levels than the healthy controls. In conclusion, these results showed that BDNF exon IX promoter methylation levels, serum BDNF protein level, and serum BDNF mRNA level could contribute to the pathophysiology of a major depressive disorder.

Allergic rhinitis increases the risk of incident panic disorder among young individuals: A nationwide population-based cohort study in Taiwan.

BACKGROUND: Studies have reported an association between allergy and panic disorder. However, few studies have explored the relationship between allergic rhinitis and panic disorder. Previous studies were limited by cross-sectional study designs, self-reported symptoms, absence of matched controls, and lack of consideration of the influence of steroid and comorbidities. This study aimed to explore the longitudinal association between allergic rhinitis and panic disorder in a large population-based cohort of young people. METHODS: In this study, 79,917 new cases of allergic rhinitis between 1998 and 2012 in individuals younger than 20 years were identified from Taiwan's National Health Insurance Research Database. One control (nonallergic rhinitis) per case (allergic rhinitis) was randomly selected from the remaining sample, matching for age, sex, residence, and insurance premium. Both groups were followed until the end of 2013 for incidence of panic disorder. Cox regression analysis was performed, adjusting for sex, age, residence, insurance premium, systemic steroids, asthma, atopic dermatitis, allergic conjunctivitis, attention deficit hyperactivity disorder, depression, and Charlson index. RESULTS: Allergic rhinitis was associated with a 2-fold increase in risk for panic disorder after adjustment for other variables. Additional independent risk factor of panic disorders were female sex, older age group, and depression. LIMITATIONS: Lifestyle, substance use, smoking by the patient or family members, and psychosocial stressors were not evaluated. CONCLUSIONS: Allergic rhinitis was associated with increased risk of panic disorder. Assessment and intervention of allergy rhinitis among young people with panic disorder are critical.

Tardive akathisia related to the anti-hypertensive agent Sevikar-a case report.

BACKGROUND: Tardive akathisia (TA) is a subtype of tardive syndrome, and its etiology is still uncertain. Sevikar is an anti-hypertensive agent containing both amlodipine and olmesartan, and has never been reported to have an adverse reaction in patients with tardive syndrome. CASE PRESENTATION: A 57-year-old woman who took Sevikar for hypertension for 10 years developed TA one and a half years before receiving any psychiatric treatment. After switching from Sevikar to bisoprolol, she reported obvious improvement in her akathisia. CONCLUSIONS: It is noteworthy that her TA developed before receiving any antidepressant medication, and that her TA improved after discontinuation of Sevikar. In light of these pharmacodynamic properties, it is therefore concluded that use of amlodipine and olmesartan might have caused TA in this patient. We reported this rare case to remind clinicians to be aware of possible akathisia when using amlodipine and olmesartan in combination as anti-hypertensive agents.