Revealing critical mechanisms in determining sorghum resistance to drought and salt using mRNA, small RNA and degradome sequencing.

BACKGROUND: Plant growth and development are severely threatened by drought and salt stresses. Compared with structural genes, transcription factors (TFs) play more pivotal roles in plant growth and stress adaptation. However, the underlying mechanisms of sorghum adapting to drought and salt are insufficient, and systematic analysis of TFs in response to the above stresses is lacking. RESULTS: In this study, TFs were identified in sorghum and model plants (Arabidopsis thaliana and rice), and gene number and conserved domain were compared between sorghum and model plants. According to syntenic analysis, the expansion of sorghum and rice TFs may be due to whole-genome duplications. Between sorghum and model plants TFs, specific conserved domains were identified and they may be related to functional diversification of TFs. Forty-five key genes in sorghum, including four TFs, were likely responsible for drought adaption based on differently expression analysis. MiR5072 and its target gene (Sobic.001G449600) may refer to the determination of sorghum drought resistance according to small RNA and degradome analysis. Six genes were associated with drought adaptation of sorghum based on weighted gene co-expression network analysis (WGCNA). Similarly, the core genes in response to salt were also characterized using the above methods. Finally, 15 candidate genes, particularly two TFs (Sobic.004G300300, HD-ZIP; Sobic.003G244100, bZIP), involved in combined drought and salt resistance of sorghum were identified. CONCLUSIONS: In summary, the findings in this study help clarify the molecular mechanisms of sorghum responding to drought and salt. We identified candidate genes and provide important genetic resource for potential development of drought-tolerant and salt-tolerant sorghum plants.

Breaking the symmetric spiral spectrum distribution of a Laguerre-Gaussian beam propagating in moderate-to-strong isotropic atmospheric turbulence.

We demonstrate that the spiral spectrum (also known as orbital angular momentum spectrum) of a Laguerre-Gaussian (LG) beam with topological charge (TC) l is asymmetrically broadened propagating through moderate-to-strong atmospheric turbulence, even the statistics of turbulence is isotropic. This phenomenon is quite different from that predicted in weak turbulence where the spiral spectrum of a disturbed LG beam is symmetric with respect to its TC number l. An explicit analytical expression of the spiral spectrum of the LG beam with l = 1 is derived based on the extend Huygens-Fresnel integral and quadratic approximation, which is used to illustrate the transition scenarios of the spiral spectrum from symmetry to asymmetry in weak-to-strong turbulence. The physical mechanism for the asymmetric spiral spectrum in moderate-to-strong turbulence is thoroughly discussed. Our results are confirmed by the multi-phase screen numerical simulations and are consistent with the experimental results reported in Phys. Rev. A105, 053513 (2022)10.1103/PhysRevA.105.053513 and Opt. Lett.38, 4062 (2013)10.1364/OL.38.004062.

Recalled age of myopia onset may predict risk of high adult myopia in Chinese adults.

INTRODUCTION: This study aimed to investigate the relationship between age of myopia onset and high myopia and to explore if age of onset mediated the associations of high myopia with parental myopia and time spent on electronics. METHODS: This cross-sectional study enrolled 1118 myopic patients aged 18 to 40. Information was obtained via a detailed questionnaire. Multivariable logistic regression and linear regression models were utilized to assess age of onset in relation to high myopia and spherical equivalent refractive error, respectively. Structural equation models examined the mediated effect of onset age on the association between parental myopia, time spent on electronics and high myopia. RESULTS: An early age at myopia onset was negatively correlated with spherical equivalent refractive power. Subjects who developed myopia before the age of 12 were more likely to suffer from high myopia than those who developed myopia after the age of 15. Age of myopia onset was the strongest predictor of high myopia, with an area under the curve (AUC) in Receiver Operator Characteristic (ROC) analysis of 0.80. Additionally, age of myopia onset served as a mediator in the relationships between parental myopia, electronic device usage duration, and the onset of high myopia in adulthood. CONCLUSIONS: Age of myopia onset might be the single best predictor for high myopia, and age at onset appeared to mediate the associations of high myopia with parental myopia and time spent on electronics.

Genome-wide identification of Brassicaceae histone modification genes and their responses to abiotic stresses in allotetraploid rapeseed.

BACKGROUND: Histone modification is an important epigenetic regulatory mechanism and essential for stress adaptation in plants. However, systematic analysis of histone modification genes (HMs) in Brassicaceae species is lacking, and their roles in response to abiotic stress have not yet been identified. RESULTS: In this study, we identified 102 AtHMs, 280 BnaHMs, 251 BcHMs, 251 BjHMs, 144 BnHMs, 155 BoHMs, 137 BrHMs, 122 CrHMs, and 356 CsHMs in nine Brassicaceae species, respectively. Their chromosomal locations, protein/gene structures, phylogenetic trees, and syntenies were determined. Specific domains were identified in several Brassicaceae HMs, indicating an association with diverse functions. Syntenic analysis showed that the expansion of Brassicaceae HMs may be due to segmental and whole-genome duplications. Nine key BnaHMs in allotetraploid rapeseed may be responsible for ammonium, salt, boron, cadmium, nitrate, and potassium stress based on co-expression network analysis. According to weighted gene co-expression network analysis (WGCNA), 12 BnaHMs were associated with stress adaptation. Among the above genes, BnaPRMT11 simultaneously responded to four different stresses based on differential expression analysis, while BnaSDG46, BnaHDT10, and BnaHDA1 participated in five stresses. BnaSDG46 was also involved in four different stresses based on WGCNA, while BnaSDG10 and BnaJMJ58 were differentially expressed in response to six different stresses. In summary, six candidate genes for stress resistance (BnaPRMT11, BnaSDG46, BnaSDG10, BnaJMJ58, BnaHDT10, and BnaHDA1) were identified. CONCLUSIONS: Taken together, these findings help clarify the biological roles of Brassicaceae HMs. The identified candidate genes provide an important reference for the potential development of stress-tolerant oilseed plants.

Enhancing fiber-coupling efficiency of beam-to-fiber links in turbulence by spatial non-uniform coherence engineering.

We present a general formula for the fiber-coupling efficiency of various types of non-uniformly correlated beams propagating in a turbulent atmosphere. With it, we calculate the fiber-coupling efficiency of a specific type of non-uniformly correlated beams, Laguerre non-uniformly correlated (LNUC) beams, to investigate how the non-uniform correlation structure plays a role in enhancing the fiber-coupling efficiency. Compared with conventional Gaussian Schell-model beams, the LNUC beams possess better coupling behavior, and the initial coherence length and beam order of such beams can be adjusted to further improve the fiber-coupling efficiency in turbulence. Our results demonstrate how non-uniformly correlated beams can be used for fiber-coupling applications, and demonstrate their intriguing potential for free-space optical communications.

Synthesis of partially coherent beams with a prescribed conjugate-model correlation structure.

Using the sum of two mutually complex conjugate functions as the integral kernel of the necessary and sufficient condition derived by Gori et al., the conjugate-model correlation structure can be constructed. Here, we introduced a general strategy for the synthesis of partially coherent beams with such correlation structures. With it, we described a specific family of such beams, called Hermite conjugate-model beams. Their focusing properties were investigated numerically and experimentally. The experimental results are consistent with the theoretical predictions, and show that the proposed beams possess novel physical features compared with well-known Schell-model beams, such as controllable intensity distributions both at the source and focal plane, which may prove useful in free-space optical communications and optical trapping.

Generating multi-focus beams with a spatial non-uniform coherence structure.

We introduce a class of structured light beams, named multi-focus beams, which exhibit self-focusing at multiple propagation distances. We show that the proposed beams not only have the ability to produce multiple longitudinal focal spots, but also that the number, intensity, and position of the foci can be controlled by adjusting the initial beam parameters. Furthermore, we demonstrate that these beams still exhibit self-focusing in the shadow of an obstacle. We have experimentally generated such beams and the results are consistent with the theoretical predictions. Our studies may find application where fine control of the longitudinal spectral density is needed, such as longitudinal optical trapping and manipulation of multiple particles, and transparent material cutting.

Genome-Wide Profiling of Exosomal Long Noncoding RNAs Following Air Pollution Exposure: A Randomized, Crossover Trial.

Changes in human genome-wide long noncoding RNAs (lncRNAs) associated with air pollution are unknown. This study aimed to investigate the effect of air pollution on human exosomal lncRNAs. A randomized, crossover trial was conducted among 35 healthy adults. Participants were allocated to 4 h exposure in road (high air pollution) and park (low air pollution) sessions in random order with a 2 week washout period. RNA sequencing was performed to measure lncRNAs. Differential lncRNAs were identified using a linear mixed-effect model. Mean concentrations of air pollutants such as ultrafine particles (UFP), black carbon (BC), carbon monoxide (CO), and nitrogen dioxide (NO2) were 2-3 times higher in the road than those in the park. Fifty-five lncRNAs [false discovery rate (FDR) < 0.05] including lncRNA NORAD, MALAT1, and H19 were changed in response to air pollution exposure. We found that 54 lncRNAs were associated with CO, 49 lncRNAs with UFP, 49 lncRNAs with BC, 48 lncRNAs with NO2, and 4 lncRNAs with PM2.5 (FDR < 0.05). These differential lncRNAs participated in dozens of pathways including cardiovascular signaling, epithelial cell proliferation, inflammation, and transforming growth factor. This trial for the first time profiled changes of human exosomal lncRNAs following air pollution. Our findings revealed multiple biological processes moderated by lncRNAs and provided epigenetic insights into cardiovascular effects of air pollution.

Super cosh-Gauss nonuniformly correlated radially polarized beam and its propagation characteristics.

In this paper, a new kind of partially coherent vector beam termed as super cosh-Gauss nonuniformly correlated radially polarized (SCNRP) beam is introduced. Such beam source exhibits almost perfect coherence between two points that are within the beam center region or located on a ring concentric with the beam center. However, the coherence drops or even vanishes when the two points leave the central region and are located on the concentric rings with different radii. The second-order statistical properties, such as the spectral density, the state of polarization (SOP), and the degree of polarization (DOP) of such beam upon free-space propagation are studied through numerical examples. Our results reveal that the beam displays a self-focusing property during propagation. The focusing ability can be enhanced with increasing the beam index and decreasing the beam's spatial coherence width, whereas the DOP and SOP remain unchanged on propagation. Meanwhile, we establish an experimental system with the use of a radial polarization converter and a digital micro-mirror device to synthesize the SCNRP beam with controllable beam index and spatial coherence width. The spectral density and polarization properties of the synthesized beam during propagation are measured and analyzed in the experiment. The experimental results agree well with our theoretical predictions.

Analysis and experimental demonstration of propagation features of radially polarized specific non-uniformly correlated beams.

With the development of the unified theory of coherence and polarization, the novel physical properties generated by different correlation structures of vector partially coherent beams (PCBs) have attracted much attention. Recently, a new class of structured beams have been proposed [Opt. Lett.45, 3824 (2020)10.1364/OL.397316], called vector specific non-uniformly correlated beams. These beams combine non-uniform polarization and non-uniform correlation, and they exhibit propagation features not seen in conventional vector PCBs. In this Letter, we continue the analysis of the previous work, taking radially polarized Hermite non-uniformly correlated (RPHNUC) beams as an example, and focus on the physical interpretation of the peculiar propagation features of such beams. We verify the predicted behavior of RPHNUC beams through experiment.

Synthesis of vector nonuniformly correlated light beams by a single digital mirror device.

We present a stable and flexible way to generate the vector nonuniformly correlated (NUC) beams with a compact optical system that involves only a single digital mirror device and a common-path interferometer. The system provides near real-time generation and accurate control of the phase difference between the orthogonal field components of the vector NUC beams. We discuss the methodology based on the vectorial pseudo-mode decomposition of the cross-spectral density matrix of the beam. The method is validated by experimentally generating a class of vector NUC beams, named electromagnetic cosh-Gauss NUC beams, which have not been previously synthesized. Such beams display self-focusing feature on propagation and can reduce to different types of scalar NUC beams by selecting out the linearly polarized components at different polarization angles.

On-field test and data calibration of a low-cost sensor for fine particles exposure assessment.

BACKGROUND: Accurate individual exposure assessment is crucial for evaluating the health effects of particulate matter (PM). Various portable monitors built upon low-cost optical sensors have emerged. However, the main challenge for their application is to guarantee accuracy of measurements. OBJECTIVE: To assess the performance of a newly developed PM sensor, and to develop methods for post-hoc data calibration to optimize its data quality. METHOD: We conducted a series of laboratory experiments and field evaluations to quantify the reproducibility within Plantower PM sensors 7003 (PMS 7003) and the consistency between sensors and two established PM2.5 measurement methods [tapered element oscillating microbalances (TEOM) and gravimetric method (GM)]. Post-hoc data calibration methods for sensors were based on a multiple linear regression model (MLRM) and a random forest model (RFM). Ratios of raw and calibrated readings over the data of reference methods were calculated to examine the improvement after calibration. RESULTS: Strong correlations (≥0.82) and relatively small relative standard deviations (16-21%) between sensors were found during the laboratory and the field sampling. Compared with the reference methods, moderate to strong coefficients of determination (0.56-0.83) were observed; however, significant deviations were presented. After calibration, the ratios of PMS measurements over that of two reference methods both became convergent. CONCLUSIONS: Our study validated low-cost optical PM sensors under a wide range of PM2.5 concentrations (8-167 µg/m3). Our findings indicated potential applicability of PM sensors in PM2.5 exposure assessment, and confirmed a need of calibration. Linear calibration methods may be sufficient for ambient monitoring using TEOM as a reference, while nonlinear calibration methods may be more appropriate for indoor monitoring using GM as a reference.

Propagation of radially polarized Hermite non-uniformly correlated beams in a turbulent atmosphere.

We study the propagation properties of a recently introduced class of structured beams, radially polarized Hermite non-uniformly correlated (RPHNUC) beams, in a turbulent atmosphere using the extended Huygens-Fresnel integral and investigate how the mode order and coherence width play a role in resisting the degradation and depolarization effects of the turbulence. In contrast with conventional vector partially coherent beams (PCBs) with uniform (Schell-model) correlation structure, the interaction of the non-uniform correlation structure and non-uniform polarization gives these beams the ability to self-heal their intensity distribution and polarization over certain propagation ranges in turbulence. These properties suggest that RPHNUC beams may be useful in a number of applications, in particular optical trapping and free-space optical communications.

The evolution of spectral intensity and orbital angular momentum of twisted Hermite Gaussian Schell model beams in turbulence.

We introduce a new class of twisted partially coherent beams with a non-uniform correlation structure. These beams, called twisted Hermite Gaussian Schell model (THGSM) beams, have a correlation structure related to Hermite functions and a twist factor in their degree of coherence. The spectral density and total average orbital angular momentum per photon of these beams strongly depend on the distortions applied to their degree of coherence. On propagation through free space, they exhibit both self-splitting and rotation of their spectral density profile, combining the interesting effects of twisted beams and non-uniformly correlated beams. We demonstrate that we can adjust both the beam order and the twist factor of THGSM beams to improve their resistance to turbulence.

Random source for generating Airy-like spectral density in the far field.

A stationary beam forming an Airy-like spectral density in the far field is analyzed theoretically and experimentally. The Schell-model source that radiates such a beam is an extended version of a recently introduced source [O. Korotkova, et al., Opt. Lett.43, 4727 (2018)10.1364/OL.43.004727; X. Chen, et al., Opt. Lett.44, 2470 (2019)10.1364/OL.44.002470, in 1D and 2D, respectively]. We show, in particular, that the source degree of coherence, being the fourth-order root of a Lorentz-Gaussian function and having linear and cubic phase terms, may be either obtained from the Fourier transform of the far-field Airy-like pattern or at the source using the sliding function method. The spectral density of the beam is analyzed on propagation through paraxial ABCD optical systems, on the basis of the generalized Collins integral, by means of the derived closed-form expression. We show that the distribution of the side lobes in the Airy beam spectral density can be controlled by the parameters of the source degree of coherence. Further, an experiment involving a spatial light modulator (SLM) is carried out for generation of such a beam. We experimentally measure the complex degree of coherence of the source and observe the gradual formation of a high-quality Airy-like spectral density towards the far field. In addition, the trajectory of the intensity maxima of the beam after a thin lens is studied both theoretically and experimentally. The random counterpart of the classic, deterministic Airy beam may find applications in directed energy, imaging, beam shaping, and optical trapping.

Vector partially coherent beams with prescribed non-uniform correlation structure.

We introduce a general strategy for the synthesis of vector partially coherent beams (PCBs) with a prescribed non-uniform correlation structure. With it, we characterize a specific family of such beams, termed radially polarized Hermite non-uniformly correlated (RPHNUC) beams. These beams possess unusual propagation properties compared to vector PCBs with uniform correlation structure; for example, they maintain their dark hollow core and evolve multi-ring structures. These beams may prove useful in free-space optical communications, optical trapping, and polarization-sensitive imaging.

Inverse design of a spatial filter in edge enhanced imaging.

A spatial filter, as a key element in edge enhanced imaging, determines the resolution and the contrast of imaging. However, the conventional spiral phase filter (SPF) results in background noise near the edges of objects in the formed images due to the fact that the point spread function (PSF) of the SPF has sub-oscillations that decrease the edge resolution. In this Letter, we propose a method for inversely designing the spatial filter, aiming to achieve high-resolution images. We show that the sub-oscillations in the PSF of the filter can be, in principle, completely suppressed. Further, we experimentally demonstrate the edge enhancement, with high resolution, for both amplitude and phase objects by using our own designed filter. Our method may find potential applications in fingerprint identification and image processing.

FeCl3-Promoted Annulation of 2-Haloindoles: Switchable Synthesis of Spirooxindole-chromeno[2,3-b]indoles and Spirooxindole-chromeno[3,2-b]indoles.

Electrophilic indoles bearing a leaving group at C2 undergo C3-regioselective dearomative hydroaryloxylation and subsequent 1,2-tertiary alkyl migration/aromatization. This is the first ring-opening migration of the spiroindolenine intermediate formed by the C3 nucleophilic addition reaction. Various spiro-oxindole-chromeno[3,2-b]/[2,3-b]indoles were successfully synthesized in excellent yields (up to 98%). This reaction features selective ring-opening migration (C-C/C-O) of the tertiary alkyl group from the indole C3 position to the C2 position stereoselectively, providing a unique synthetic method for constructing novel polycyclic indole skeletons.

Loss of Lgr4 inhibits differentiation, migration and apoptosis, and promotes proliferation in bone mesenchymal stem cells.

The key signaling networks regulating bone marrow mesenchymal stem cells (BMSCs) are poorly defined. Lgr4, which belongs to the leucine-rich repeat-containing G protein-coupled receptor (LGR) family, is widely expressed in multiple tissues from early embryogenesis to adulthood. We investigated whether Lgr4 functions in BMSCs and in osteogenesis, adipogenesis, and skeletal myoblasts, using mice with a ß-geo gene trap inserted into the Lgr4 gene. Abundant Lgr4 expression was detected in skeletal, adipose and muscular tissue of Lgr4+/- mice at E16.5 by ß-gal staining, and Lgr4-deficiency promoted BMSC proliferation (16 ± 4 in wild-type [WT] and 28 ± 2 in Lgr4-/- ) using colony forming units-fibroblast assay, while suppressing BMSC migration (from 103 ± 18 in WT to 57 ± 10 in Lgr4-/- ) by transwell migration assay and apoptosis ratio (from 0.0720 ± 0.0123 to 0.0189 ± 0.0051) by annexin V staining assay. Deletion of Lgr4 decreased bone mass (BV/TV from 19.16 ± 2.14 in WT mice to 10.36 ± 1.96 in KO) and fat mass through inhibiting BMSC differentiation to osteoblasts or adipocytes. Furthermore, LGR4-regulated osteogenic, adipogenic, and myogenic gene expression. Importantly, our data showed that loss of Lgr4-inhibited fracture healing by suppressing osteoblast differentiation. Moreover, deletion of Lgr4 in BMSCs-delayed fracture healing following stem cell therapy by BMSC transplantation. Together, our results demonstrated that LGR4 is essential for mesoderm-derived tissue development and BMSC differentiation, demonstrating that LGR4 could be a promising drug target for related diseases and a critical protein for stem cell therapy.

Experimental realization of dark and antidark diffraction-free beams.

We report the first, to the best of our knowledge, experimental realization of high-quality dark and antidark diffraction-free beams, first theoretically proposed by Ponomarenko et al. [Opt. Lett.32, 2508 (2007)OPLEDP0146-959210.1364/OL.32.002508]. Our method employs a single spatial light modulator (SLM) and is based on superposing mutually uncorrelated but spatially coherent in the time domain Bessel modes with modal weights proportional to the SLM display times of the corresponding modes. We also experimentally verify diffraction-free properties of the generated beams upon their free space propagation.