Propagation of integral and fractional perfect vortex beams in a gradient-index medium.

The analytical expressions for the complex amplitude of integral and fractional perfect vortex (PV) beams propagating in a gradient-index (GRIN) medium are derived. The intensity and phase distributions, propagation trajectories, Poynting vectors, and the effects of topological charge and refractive index at the medium axis on the intensity of both beams in the medium are numerically investigated. It is shown that both beams propagate periodically in the GRIN medium with alternating spot focusing and reconstruction. Unlike the integral PV beam, the fractional PV beam has a dark line in intensity profiles and a line edge dislocation in phase distributions along the positive x-axis. These properties persist during the beam propagation in the GRIN medium. Moreover, the topological charge and the refractive index at the medium axis have little effect on the intensity of the PV beam propagating in the GRIN medium. The results presented in this paper may be useful for the application of integral and fractional PV beams in optical guiding and optical communications.

Is it a normal phenomenon for pediatric patients to have brain leptomeningeal contrast enhancement on 3-tesla magnetic resonance imaging?

Determining whether sevoflurane sedation in children leads to "pseudo" prominent leptomeningeal contrast enhancement (pLMCE) on 3 Tesla magnetic resonance imaging will help reduce overdiagnosis by radiologists and clarify the pathophysiological changes of pLMCE.

Research advances in predicting the expansion of hypertensive intracerebral hemorrhage based on CT images: an overview.

Hematoma expansion (HE) is an important risk factor for death or poor prognosis in patients with hypertensive intracerebral hemorrhage (HICH). Accurately predicting the risk of HE in patients with HICH is of great clinical significance for timely intervention and improving patient prognosis. Many imaging signs reported in literatures showed the important clinical value for predicting HE. In recent years, the development of radiomics and artificial intelligence has provided new methods for HE prediction with high accuracy. Therefore, this article reviews the latest research progress in CT imaging, radiomics, and artificial intelligence of HE, in order to help identify high-risk patients for HE in clinical practice.

Roles of the APETALA3-3 ortholog in the petal identity specification and morphological differentiation in Delphinium anthriscifolium flowers.

The genus Delphinium (Ranunculaceae) with its unique and highly complex floral structure is an ideal system to address some key questions in terms of morphological and evolutionary studies in flowers. In D. anthriscifolium, for example, the original eight petal primordia differentiate into three types at maturity (i.e., two dorsal spurred, two lateral flat, and four ventral reduced petals). The mechanisms underlying their identity determination and morphological differentiation remain unclear. Here, through a comprehensive approach combining digital gene expression (DGE) profiles, in situ hybridization, and virus-induced gene silencing (VIGS), we explore the role of the APETALLATA3-3 (AP3-3) ortholog in D. anthriscifolium. Our findings reveal that the DeanAP3-3 not only functions as a traditionally known petal identity gene but also plays a critical role in petal morphological differentiation. The DeanAP3-3 gene is expressed in all the petal primordia before their morphological differentiation at earlier stages, but shows a gradient expression level difference along the dorsventral floral axis, with higher expression level in the dorsal spurred petals, intermediate level in the lateral flat petals and lower level in the ventral reduced petals. VIGS experiments revealed that flowers with strong phenotypic changes showed a complete transformation of all the three types of petals into non-spurred sepals. However, in the flowers with moderate phenotypic changes, the transformation of spurred petals into flat petals is associated with moderate silencing of the DeanAP3-3 gene, suggesting a significant impact of expression level on petal morphological differentiation. This research also shed some insights into the role of changes in gene expression levels on morphological differentiation in plants.

MC180295 is a highly potent and selective CDK9 inhibitor with preclinical in vitro and in vivo efficacy in cancer.

BACKGROUND: Inhibition of cyclin-dependent kinase 9 (CDK9), a novel epigenetic target in cancer, can reactivate epigenetically silenced genes in cancer by dephosphorylating the SWI/SNF chromatin remodeler BRG1. Here, we characterized the anti-tumor efficacy of MC180295, a newly developed CDK9 inhibitor. METHODS: In this study, we explored the pharmacokinetics of MC180295 in mice and rats, and tested the anti-tumor efficacy of MC180295, and its enantiomers, in multiple cancer cell lines and mouse models. We also combined CDK9 inhibition with a DNA methyltransferase (DNMT) inhibitor, decitabine, in multiple mouse models, and tested MC180295 dependence on T cells. Drug toxicity was measured by checking body weights and complete blood counts. RESULTS: MC180295 had high specificity for CDK9 and high potency against multiple neoplastic cell lines (median IC50 of 171 nM in 46 cell lines representing 6 different malignancies), with the highest potency seen in AML cell lines derived from patients with MLL translocations. MC180295 is a racemic mixture of two enantiomers, MC180379 and MC180380, with MC180380 showing higher potency in a live-cell epigenetic assay. Both MC180295 and MC180380 showed efficacy in in vivo AML and colon cancer xenograft models, and significant synergy with decitabine in both cancer models. Lastly, we found that CDK9 inhibition-mediated anti-tumoral effects were partially dependent on CD8 + T cells in vivo, indicating a significant immune component to the response. CONCLUSIONS: MC180380, an inhibitor of cyclin-dependent kinase 9 (CDK9), is an efficacious anti-cancer agent worth advancing further toward clinical use.

The mechanism underlying asymmetric bending of lateral petals in Delphinium (Ranunculaceae).

During the process of flower opening, most petals move downward in the direction of the pedicel (i.e., epinastic movement). In most Delphinium flowers, however, their two lateral petals display a very peculiar movement, the mirrored helical rotation, which requires the twist of the petal stalk. However, in some lineages, their lateral petals also exhibit asymmetric bending that increases the degree of mirrored helical rotation, facilitating the formation of a 3D final shape. Notably, petal asymmetric bending is a novel trait that has not been noticed yet, so its morphological nature, developmental process, and molecular mechanisms remain largely unknown. Here, by using D. anthriscifolium as a model, we determined that petal asymmetric bending was caused by the localized expansion of cell width, accompanied by the specialized array of cell wall nano-structure, on the adaxial epidermis. Digital gene analyses, gene expression, and functional studies revealed that a class I homeodomain-leucine zipper family transcription factor gene, DeanLATE MERISTEM IDENTITY1 (DeanLMI1), contributes to petal asymmetric bending; knockdown of it led to the formation of explanate 2D petals. Specifically, DeanLMI1 promotes cell expansion in width and influences the arrangement of cell wall nano-structure on the localized adaxial epidermis. These results not only provide a comprehensive portrait of petal asymmetric bending for the first time but also shed some new insights into the mechanisms of flower opening and helical movement in plants.