Spatial-temporal optical vortex pendulum on a curved surface.

Spatial-temporal optical vortices (STOVs) have recently become the focus of newly structured optical fields. In this paper, their propagation on a 2D curved surface named the constant Gaussian curvature surface (CGCS) is studied. Using the matrix optics approach, we provide the analytical solution of the STOV propagation under the paraxial approximation on the CGCS with positive curvature. One method of creating timers is made possible by the spatiotemporal distribution direction of STOV light intensity, which swings like a pendulum throughout the evolution, in contrast to propagation on a flat surface. This swing, however, stops when the curved surface's curvature radius matches the light's Rayleigh distance. Besides, the transverse orbital angular momentum of STOV is deduced, and we find that the intrinsic and extrinsic OAM periodically exchange, but the total transverse OAM is always zero during the propagation on CGCS. It aids in controlling the transverse extrinsic orbital angular momentum of STOV in nontrivial space.

Mapping of Fatty Aldehydes in the Diabetic Rat Brain Using On-Tissue Chemical Derivatization and Air-Flow-Assisted Desorption Electrospray Ionization-Mass Spectrometry Imaging.

Fatty aldehydes (FALs) are involved in various biological processes, and their abnormal metabolism is related to the occurrence and development of neurological diseases. Because of their low ionization efficiency, methods for in situ detection and mass spectrometry imaging (MSI) analysis of FALs remain underreported. On-tissue chemical tagging of hardly ionizable target analytes with easily ionized moieties can improve ionization efficiency and detection sensitivity in MSI experiments. In this study, an on-tissue chemical derivatization-air-flow-assisted desorption electrospray ionization-MSI method was developed to visualize FALs in the rat brain. The method showed high sensitivity and specificity, allowing the use of in situ high-resolution MS3 to identify FALs. The methodology was applied to investigate the region-specific distribution of FALs in the brains of control and diabetic encephalopathy (DE) rats. In DE rats, FALs were found to be significantly enriched in various brain regions, especially in the cerebral cortex, hippocampus, and amygdala. Thus, increased FAL levels and oxidative stress occurred in a region-dependent manner, which may contribute to cognitive function deficits in DE. In summary, we provide a novel method for the in situ detection of FALs in biological tissues as well as new insights into the potential pathogenesis of DE.

Opto-magnetic resonance single-beam magnetometer driven by vector polarized light.

In this paper, we present an analysis of the amplitude variations of the opto-magnetic resonance absorption signals obtained in a single-beam magnetometer driven by radially or azimuthally polarized light (RPL/APL). It is shown that optically polarized atoms driven by cylindrical vector beams obtained only the alignment of atomic multipole moments but not the orientation, which is in good agreement with our simulation and experimental results. In comparison with the plane polarized pump light fields, cylindrical vector beams with much more complete electric vector polarization distribution in the transverse plane, make it unlikely to create the "emptying state " (no-atom populated) among the ground-state Zeeman sublevels for any possible orientation of the applied static magnetic field. These characteristics of the RPL/APL lead to generally smaller atomic population difference and lower response intensity of the transmitted signal. The tensor decomposition of atomic polarized states and the evolution of atomic multipole moments with the sweeping radio frequency (RF) field offer the way to show the magnetic orientation sensitivity of the radially or azimuthally polarized probe light, which possess similar profiles as that of the linearly polarized light, only with a constant phase lag of about π/2 and obvious amplitude differences.

Optically polarized selective transmission of a fractional vector vortex beam by the polarized atoms with external magnetic fields.

We investigate the role of external magnetic fields and linearly polarized pump light, especially when their directions are parallel or vertical, on the propagation of the fractional vector vortex beams (FVVBs) through a polarized atomic system. Herein, the different configurations of external magnetic fields lead to various optically polarized selective transmissions of FVVBs with different fractional topological charge α caused by the polarized atoms, which is theoretically demonstrated by the atomic density matrix visualization analysis and experimentally explored by Cesium atom vapor. Meanwhile, we find that the FVVBs-atom interaction is a vectorial process due to the different optical vector polarized states. In this interaction process, the atomic optically polarized selection property provides potential for the realization of the magnetic compass based on warm atoms. For the FVVBs, due to the rotational asymmetry of the intensity distribution, we can observe some transmitted light spots with unequal energy. Compared with the integer vector vortex beam, it is possible to obtain a more precise magnetic field direction by fitting the different "petal" spots of the FVVBs.

NFIC1 inhibits the migration and invasion of MDA-MB-231 cells through S100A2-mediated inactivation of MEK/ERK pathway.

NFIC is a potent transcriptional factor involved in many physiological and pathological processes, including tumorigenesis. However, the role of NFIC1, the longest isoform of NFIC, in the progression of triple negative breast cancer (TNBC) remains elusive. Our study demonstrates that overexpression of NFIC1 inhibits the migration and invasion of TNBC MDA-MB-231 cells. NFIC1 regulates the expression of S100A2, and knockdown of S100A2 reverses the inhibitive effects of NFIC1 on the migration and invasion of MDA-MB-231 cells. Furthermore, knockdown of S100A2 activates the MEK/ERK signaling transduction pathway that is inhibited by NFIC1 overexperssion. Treatment with MEK/ERK pathway inhibitor, U0126, abolishes the effects of S100A2 knockdown. In addition, overexpression of NFIC1 in MDA-MB-231 cells increases the expression of epithelial markers and decreases the expression of mesenchymal markers, and these effects could also be reversed by knockdown of S100A2. Collectively, these results demonstrate that NFIC1 inhibits the Epithelial-mesenchymal transition (EMT) of MDA-MB-231 cells by regulating S100A2 expression, which suppress the activation of MEK/ERK pathway. Therefore, our study confirms the role of NFIC1 as a tumor repressor in TNBC, and reveals the molecular mechanism through which NFIC1 inhibits the migration and invasion of MDA-MB-231 cells.

Measurement and multiplexing of ultra-low duty cycle Nyquist pulse sequences.

In this paper, we propose a novel, to the best of our knowledge, method to our knowledge for generating and accurately measuring Nyquist pulse sequences with an ultra-low duty cycle of only 0.037, which breaks the limitations caused by the noise and bandwidth of the optical sampling oscilloscope (OSO) by using a narrow-bandwidth real-time oscilloscope (OSC) and an electrical spectrum analyzer (ESA). By this method, it is found that the bias point drift of the dual parallel Mach-Zehnder modulator (DPMZM) is the main cause of the distortion of the waveform. In addition, we increase the repetition rate of Nyquist pulse sequences by a factor of 16 by multiplexing the unmodulated Nyquist pulse sequences.

Ultra-flat multicarrier light source based on recirculating frequency shift loop driven by a parity-time symmetric optoelectronic oscillator.

A multicarrier light source based on a recirculating frequency shift loop (RFSL) driven by a parity-time (PT)-symmetric optoelectronic oscillator (OEO) is proposed and experimentally demonstrated. The impact of the side-mode suppression ratio (SMSR) of the radio frequency (RF) signal on the multicarrier is studied for the first time, to our knowledge. The RFSL driven by PT-symmetric OEO significantly optimizes the phase noise and flatness of the multicarrier, facilitating the system miniaturization. In the experiment, a 10.019 GHz RF signal with a SMSR of 42 dB is generated with -98.63d B c/H z measured phase noise at 10 kHz offset frequency (actual phase noise should be lower than -122.87d B c/H z). Up to 120 subcarriers with 2.32 dB flatness are obtained successfully, covering the overall bandwidth of approximately 1.2 THz.

Propagation properties of finite Airy beams on curved surfaces.

Airy beams have provided exciting inspiration in the field of optical communication, particle manipulation, and imaging. We investigate the propagation properties of the exponential truncation Airy beams (ETABs) on constant Gaussian curvature surfaces (CGCSs) in this paper. The analytical expression of the electric field of ETABs propagating on the CGCSs is derived. It shows that the equivalent periodical accelerations of the trajectories of ETABs on the curved surface are always larger than the constant one on the flat surface because the CGCSs have a strong focusing ability. For the same reason, the non-diffraction propagation of ETABs is found when the focusing ability of the CGCSs is strong enough. Moreover, we investigate the self-healing length of ETABs on CGCSs and explore that the ability of self-healing is related to the geometry of CGCSs besides the width of the block and the size of the beam. The self-healing length gets larger with the increase of radius of CGCSs and finally consists with that on the flat surface. These propagation characteristics are different from those in the flat space and are useful for the future applications of ETABs in particle manipulation on waveguides, light-sheet fluorescence microscopy, curved nanophotonics, and so on.

Spatial filtering of Zeeman sub-states in an atomic fountain.

In an atomic fountain, atoms in motion can be spatially separated into discrete Zeeman sub-states by magnetically induced Stern-Gerlach effect. With resonant light pulses acting as a shutter, specific states are selected for subsequent experiments. Such separation-selection process in atomic optics is the analogue of a spatial filter in physical optics which selects and purifies the modes of light. This technique is demonstrated by injecting a pulsed current in a circular coil around a vertical atomic fountain, separating the pre-cooled Rubidium atoms by a distance of centimeters in between, and filtering each single sub-state with block pulses. The filtered atoms after the process is highly purified in the desired sub-state. The apparatus of the atomic spatial filter is adaptable in atomic optics and can be integrated into the high-vacuum chamber of an atomic fountain.

NFIC1 suppresses migration and invasion of breast cancer cells through interferon-mediated Jak-STAT pathway.

NFIC1, the longest isoform of NFIC, is essential for the regulation on spatiotemporal expression of drug-metabolizing genes in liver. However, the role of NFIC1 in breast cancer is not clear. Here we showed that increased expression of NFIC1 suppressed the migration and invasion of MCF-7 cells. NFIC1 overexpression increased the expression of IFNB1, IFNL1, IFNL2 and IFNL3, and the activation of interferon-mediated Jak-STAT pathway was enhanced by NFIC1 overexpression. Treatment with Jak-STAT pathway inhibitors, Filgotinib or Ruxolitinib, reversed the suppressive effects of NFIC1 overexpression on migration and invasion of MCF-7 cells. In addition, we found that MX1 and MX2, two target genes of Jak-STAT pathway, mediated the migration and invasion of MCF-7 cells. These results demonstrated that NFIC1 inhibited the migration and invasion in MCF-7 cells through interferon-mediated activation of Jak-STAT pathway, indicating that Jak-STAT pathway might be a potential therapeutic target for preventing breast cancer metastasis.

Novel piRNA MW557525 regulates the growth of Piwil2-iCSCs and maintains their stem cell pluripotency.

BACKGROUND: CSCs play an important role in tumor development. Some studies have demonstrated that piRNAs participate in the progression of various cancers. However, the detailed function of piRNAs in CSCs requires further investigation. This study aimed to investigate the significance of novel piRNA MW557525, one of the top five up-regulated piRNAs screened by gene chip and it has been verified by RT-q-PCR that it is indeed the most obvious up-regulated expression in Piwil2-iCSCs. METHODS AND RESULTS: Differentially expressed piRNAs in Piwil2-iCSCs were screened by gene chip. Target genes were predicted by the miRanda algorithm and subjected to GO and KEGG analysis. One of the differential piRNAs, novel piRNA MW557525, was transfected and its target gene NOP56 was silenced in Piwil2-iCSCs, respectively. RT-qPCR, western blot (WB) and dual luciferase reporter assay were used to investigate the interaction of piRNA MW557525 and NOP56. We identified the effect of piRNA MW557525 and NOP56 knockdown on cell proliferation, migration, invasion, and apoptosis via CCK-8, transwell assay, and flow cytometry. The expressions of CD24, CD133, KLF4, and SOX2 were detected via WB. The results showed that piRNA MW557525 was negatively correlated with NOP56, and it promoted the proliferation, migration, invasion, and inhibited apoptosis in Piwil2-iCSCs, and it also promoted the expressions of CD24, CD133, KLF4, and SOX2, while NOP56 showed the opposite effect. CONCLUSIONS: These findings suggested that novel piRNA MW557525 might be a novel therapeutic target in Piwil2-iCSCs.

Antitumor effect of Escherichia coli-derived outer membrane vesicles on neuroblastoma in vitro and in vivo.

Bacterial outer membrane vesicles (OMVs) are spherical microbubbles that contain biological content and are produced by gram-negative bacteria. The use of OMVs as adjuvants for cancer immunotherapy or as drug carriers for targeted therapies has attracted the interest of many scholars. However, it is unclear whether OMVs can exert direct antitumor effects and whether OMVs can inhibit pediatric tumors. Here, we explore the potential of Escherichia coli-derived OMVs to directly suppress neuroblastoma. Our results demonstrate the antitumor effects of OMVs in vitro and in vivo, and no serious adverse reactions were observed. OMV uptake into the cytoplasm and nucleus directly decreases cell stemness, DNA damage, apoptosis and cell cycle arrest, which may be the mechanisms by which OMVs suppress tumors. Our results demonstrate the potential of bacterial OMVs to be used as antitumor adjuvant therapies, increasing the number of candidates for the development of cancer therapies in the future. More relevant studies are urgently needed to demonstrate the efficacy and safety of OMVs.

Single medium-sized hepatocellular carcinoma treated with sequential conventional transarterial chemoembolization (cTACE) and microwave ablation at 4 weeks versus cTACE alone: a propensity score.

BACKGROUND: Microwave ablation (MWA) is a potentially curative treatment for unresectable patients with hepatocellular carcinoma (HCC) ≤ 3 cm, while its therapeutic efficacy decreases significantly for HCC > 3cm. Previous studies have demonstrated that conventional transarterial chemoembolization (cTACE) combined with MWA (cTACE-MWA) may improve local tumor control rate and reduce the recurrence rate for HCC > 3cm. However, there have been few study designs to analyze the clinical efficacy of cTACE-MWA for medium-sized HCC (3-5cm). Therefore, this study aims to compare the clinical efficacy and safety of cTACE-MWA with cTACE alone for a single medium-sized HCC of 3-5 cm in diameter. METHODS: We retrospectively investigate the data of 90 patients with a single medium-sized HCC who were referred to our hospital and underwent cTACE-MWA or cTACE alone from December 2017 to March 2020. Then, patients were identified with propensity score-matched (1:1). The local tumor response to treatment and time to progression (TTP) were compared using mRECIST criteria between the cTACE-MWA group and the cTACE group. RESULTS: A total of 42 patients were included after matching (cTACE-MWA: 21; cTACE: 21). Comparing with cTACE, cTACE-MWA demonstrate significantly better local tumor control (ORR: 95.2% vs 61.9%, p = 0.02; DCR: 95.2% vs 66.7%, p = 0.045) and TTP (median 19.8 months vs 6.8 months, p < 0.001). The 1- and 2-year cumulative probabilities of OS were 100% and 95% in the cTACE-MWA group, which were significantly higher than those in the cTACE group (95% and 76%) (p = 0.032). Multivariate Cox regression analysis illustrates that cTACE-MWA was associated with better TTP (hazard ratio, 0.28; 95% CI: 0.1, 0.76; p = 0.012), but tumor size was associated with worse TTP (hazard ratio, 1.71; 95% CI: 1.01, 2.89; p = 0.045). CONCLUSIONS: cTACE followed by MWA improved TTP and OS in patients with a single medium-sized HCC, and no major complication was observed in this study.

A review of different ventilation modes on thermal comfort, air quality and virus spread control.

In the era of Corona Virus Disease 2019 (COVID-19), inappropriate indoor ventilation may turn out to be the culprit of microbial contamination in enclosed spaces and deteriorate the environment. To collaboratively improve the thermal comfort, air quality and virus spread control effect, it was essential to have an overall understanding of different ventilation modes. Hence, this study reviewed the latest scientific literature on indoor ventilation modes and manuals of various countries, identified characteristics of different ventilation modes and evaluated effects in different application occasions, wherefore to further propose their main limitations and solutions in the epidemic era. For thermal comfort, various non-uniform ventilation modes could decrease the floor-to-ceiling temperature difference, draft rate or PPD by 60%, 80% or 33% respectively, or increase the PMV by 45%. Unsteady ventilation modes (including intermittent ventilation and pulsating ventilation) could lower PPD values by 12%-37.8%. While for air quality and virus spread control, non-uniform ventilation modes could lower the mean age of air or contaminants concentration by 28.3%-47% or 15%-47% respectively, increase the air change efficiency, contaminant removal effectiveness or protection efficiency by 6.6%-10.4%, 22.6% or 14%-50% respectively. Unsteady ventilation mode (pulsating ventilation) could reduce the peak pollutant concentration and exposure time to undesirable concentrations by 31% and 48% respectively. Non-uniform modes and unsteady modes presented better performance in thermal comfort, air quality and virus spread control, whereas relevant performance evaluation indexes were still imperfect and the application scenarios were also limited.

Propagation and transformation of a light beam on a curved surface.

Starting from the wave equation with a non-zero space curvature, a generalized coordinate-independent expression for the evolution of a light beam on a curved space is derived. By defining the propagation axes, the expression reduces to integrable Green functions without an inevitable singular point. With a Gaussian incident field, the stationary status and refocusing effect of the light field on different shapes of curved surfaces are discussed. Different from a constant diffusion behavior in a flat space, the field experiences a periodical diffraction and refocusing spontaneously with no additional optical elements. To be more specific, we noticed that the laser field on a curved surface experiences a fractional Fourier transform, with a propagation angle to be the transform order. We hope our theoretical results can provide some references for the practical application in a curved surface space.

Angular momentum of the vortex ultrashort pulsed beam with a smaller beam waist.

The angular momentum (AM) of light has important implications for many fields of optics research, such as optics communication, quantum information and laser-scan microscopy. Thus, in this paper, we intend to investigate the average AM of the vortex ultrashort pulsed beam (VUPB), which is generated and widely applied in the field of high-intensity and ultrafast regimes. According to the vector potential, we firstly derive the electromagnetic field of the VUPB, then analyze the spatial intensity, the phase profile and the polarization state of the beam. We explore that the total AM per photon of VUPB is not n ℏ value when the beam waist w0 is of wavelength or sub-wavelength order, since the polarization of VUPB is changed from linear to circular polarization with the decrease of beam waist, which introduces the conversion of the orbital AM to the spin AM. Moreover, based on the conservation of the total AM, the minimum waist of VUPB can be obtained, which is dependent on the pulse duration time α and topological charge n. Finally, the average AM of the fractional VUPB expressed by the superposition of the integer VUPB with different weights, is analyzed, which is not equal to the AM of fractional CW beam µ - sin (2µπ)/2π (µ is the fractional topological charge), but is associated with the beam waist w0 and α. Therefore, we think that the AM of VUPB can be controlled by adjusting the α and w0.

Laser propagation in a Rindler accelerated reference frame based on matrix optics.

The Rindler space-time describing a series of accelerating observers is Ricci flat, but it still has novel optical effects. In the case of Wenzel, Kramers, and Brillouin (WKB) approximation, we derive the light paths in the Rindler frame based on the covariant wave equation and geodesic equations. Then, we use ABCD matrix optics method to explore the propagation characteristics of Rindler frame, thus link three different optical transformation scenes (geometry, gravity, and vacuum refractive index) together. Moreover, the propagation characteristics of hollow beam in Rindler space-time are described analytically. In the longitudinal direction, we demonstrate the shift and stretch effects of the dark spot of a beam, while the transverse spot size is proved to be convergence in the accelerated system, and the wavefront curvature can tend a constant twice the acceleration at the far field. Those characteristics are quite different from the ones in the flat space-time. Based on these calculations, we simply demonstrate the position uncertain relationship between the transverse beam size and the momentum, which surprisingly coincides with the derivation of quantization. We hope that we can provide one simple method to analyze the beam propagation in the accelerated frame.

Observation of square- and h-shaped pulse from a mode-locked erbium-doped fiber laser.

We demonstrate the generation of a type of square-shaped pulse in a passively mode-locked erbium-doped fiber laser based on the nonlinear optical loop mirror technique. Through adjusting the pump power and polarization state, square-shaped pulses are generated. Furthermore, we investigate the pulse profile in relation to the optical spectrum. By filtering out short-wavelength spectrum components gradually, pulse shaping is achieved, and the top of the square-shaped pulse becomes flat. Subsequently, by filtering out long-wavelength spectrum components, a type of h-shaped pulse is obtained and the formation reason is also investigated.

[Establishment of an Animal Model of Vesicoureteral Reflux Renal Injury through Partial Bladder Outlet Obstruction].

OBJECTIVE: To establish an animal model of reflux renal damage through bladder outlet obstruction. METHODS: Sixty male C57BL/6 mice aged 6-8 weeks were randomly assigned to a control group, a sham operation group, and a partial bladder outlet obstruction (PBOO) group, with 20 mice in each group. Laparotomy were performed on the PBOO mice under anesthesia in order to separate the bladder necks and to perform guided partial ligation of the bladder neck with a metal rod of 0.3 mm diameter. Mice in the sham operation group had laparotomy and had their bladder necks separated without ligation. The control group did not receive any treatment. 7 days after the surgery, 12 surviving mice were randomly selected from each group to observe the general changes of the bladder, ureter, renal pelvis and kidney. Retrograde urography was performed through the bladder. Kidney tissues were extracted for histopathological analysis. The expression levels of Vimentin, proliferating cell nuclear antigen (PCNA) and α-smooth muscle actin (α-SMA) were examined with Western blot, immunohistochemistry and immunofluorescence staining tests, respectively. RESULTS: Compared with the control and sham operation group, the bladder, ureter, and renal pelvis of the mice in the PBOO group were significantly enlarged, vesicoureteral reflux was more obvious, the kidney volume and mass increased ( P<0.001), and renal parenchyma became thinner ( P<0.000 1). Histopathological staining showed glomerular atrophy, renal tubule expansion, tubulointerstitial inflammatory cell infiltration, glomerular basement membrane hyperplasia and obvious interstitial fibrosis. Western blot, immunofluorescence and immunohistochemistry staining showed that the expression levels of Vimentin, PCNA and α-SMA in kidney tissue were elevated ( P<0.000 1). CONCLUSION: After PBOO, the bladder, ureter, and kidney of the mice showed obvious morphological alteration and presented reflux renal fibrosis-like damage. This can be used as an animal model to study the pathological alteration mechanism and therapeutic measures of renal fibrosis caused by bladder outlet obstruction.

Metabolic fingerprinting of cell types in mouse skeletal muscle by combining TOF-SIMS with immunofluorescence staining.

Skeletal muscle tissue is composed of various muscle cell types which differ in physiological functions. Changes in cell type composition of skeletal muscle are associated with the development of metabolic diseases. Skeletal muscle cell types are currently distinguished by immunofluorescence (IF) staining based on myosin heavy chain (MHC) isoform difference. However, it remains a challenge to provide metabolic fingerprints of different muscle cell types by IF staining. Therefore, in this study, we proposed a method to examine metabolite distribution within different cell types by time-of-flight secondary ion mass spectrometry (TOF-SIMS) with high spatial resolution. Skeletal muscle samples from C57/BL6 mice were obtained by slicing. Cell types in TOF-SIMS images were labelled corresponding to IF images from the same region of serially cut sections. Mass spectra corresponding to individual muscle cells were extracted to compare metabolic fingerprints among cell types. Skeletal muscle cells were classified into two clusters based on the mass spectra of individual cells. Unsaturated diacylglycerol (DG) and fatty acid (FA) species were found to be distributed in a cell-type dependent manner. Moreover, relative quantification showed that the content of unsaturated DGs, oleic acid and linoleic acid was higher in type I and type IIA cells than in type IIB cells. TOF-SIMS in combination with IF enables us to directly visualize metabolite distribution in different cell types, to find potential biomarkers for cell type classification. TOF-SIMS imaging coupled with IF staining has been proved to be a promising tool for metabolic fingerprinting of different skeletal muscle cell types.