Dynamic and Polarization-Independent Wavefront Control Based on Hybrid Topological Metasurfaces.

Exceptional points (EPs), known as non-Hermitian singularities, have been observed and investigated in parity-time symmetric metasurfaces. However, the chirality and tunability in non-Hermitian metasurfaces still need to be explored. Here, we propose a dynamic topological metasurface with the meta-atom consisting of two orthogonally oriented nanorods, which are placed on the phase change material Ge2Sb2Te5 (GST) and SiO2 dielectric layer, respectively. When GST is converted from the amorphous state (a-GST) to the crystalline state (c-GST), an EP can be dynamically switched from the "ON" state to the "OFF" state in a parameter space. Moreover, based on the topologically protected phase and amplitude modulations of the cross-polarization component, the phase-only hologram and amplitude-only hologram are engineered in the a-GST case and concealed in the c-GST case. Finally, we explore the 2D-chiral symmetry of meta-atoms and further propose two spin-selective meta-deflectors and a hybrid meta-deflector operating with arbitrary polarizations. The GST-based hybrid metasurface offers richer possibilities to realize various wavefront controls.

Challenging pitfalls in frozen section pathology: a case of mandible ghost cell odontogenic carcinoma and the literature review.

BACKGROUND: Ghost cell odontogenic carcinoma (GCOC) is a rare malignancy characterized by the presence of ghost cells, preferably in the maxilla. Only slightly more than 50 case reports of GCOC have been documented to date. Due to the rarity of this tumor and its nonspecific clinical criteria, there is a heightened risk of misdiagnosis in clinical examination, imaging findings, and pathology interpretation. CASE PRESENTATION: A 50-year-old male patient presented to the hospital due to experiencing pain in his lower front teeth while eating for the past 2 months. Upon examination, a red, hard, painless mass was found in his left lower jaw, measuring approximately 4.0 cm × 3.5 cm. Based on the malignant histological morphology of the tumor and the abundant red-stained keratinized material, the preoperative frozen section pathology misdiagnosed it as squamous cell carcinoma (SCC). The surgical resection specimen pathology via paraffin section revealed that the tumor was characterized by round-like epithelial islands within the fibrous interstitium, accompanied by a large number of ghost cells and some dysplastic dentin with infiltrative growth. The malignant components displayed marked heterogeneity and mitotic activity. Additionally, a calcified cystic tumor component of odontogenic origin was observed. Hemorrhage, necrosis, and calcifications were present, with a foreign body reaction around ghost cells. Immunoreactivity for ß-catenin showed strong nuclear positivity in tumor cells, while immunostaining was completely negative for p53. The Ki67 proliferation index was approximately 30-40%. The tumor cells exhibited diffuse CK5/6, p63, and p40 immunoreactivity, with varying immunopositivity for EMA. Furthermore, no BRAFV600E mutation was identified by ARMS-PCR. The final pathology confirmed that the tumor was a mandible GCOC. CONCLUSION: We have reported and summarized for the first time the specific manifestations of GCOC in frozen section pathology and possible pitfalls in misdiagnosis. We also reviewed and summarized the etiology, pathological features, molecular characteristics, differential diagnosis, imaging features, and current main treatment options for GCOC. Due to its rarity, the diagnosis and treatment of this disease still face certain challenges. A correct understanding of the pathological morphology of GCOC, distinguishing the ghost cells and the secondary stromal reaction around them, is crucial for reducing misdiagnosis rates.

Tripartite motif 38 alleviates the pathological process of NAFLD-NASH by promoting TAB2 degradation.

Nonalcoholic fatty liver disease (NAFLD) has become the most prevalent chronic liver disease worldwide, without any Food and Drug Administration-approved pharmacological intervention in clinic. Trim38, as an important member of the TRIM (tripartite motif-containing) family, was largely reported to be involved in the regulation of innate immune and inflammatory responses. However, the functional roles of TRIM38 in NAFLD remain largely unknown. Here, the expression of TRIM38 was first detected in liver samples of both NAFLD mice model and patients diagnosed with NAFLD. We found that TRIM38 expression was downregulated in NAFLD liver tissues compared with normal liver tissues. Genetic Trim38-KO in vivo showed that TRIM38 depletion deteriorated the high-fat diet and high fat and high cholesterol diet-induced hepatic steatosis and high fat and high cholesterol diet-induced liver inflammation and fibrosis. In particular, we found that the effects of hepatocellular lipid accumulation and inflammation induced by palmitic acid and oleic acid were aggravated by TRIM38 depletion but mitigated by TRIM38 overexpression in vitro. Mechanically, RNA-Seq analysis demonstrated that TRIM38 ameliorated nonalcoholic steatohepatitis progression by attenuating the activation of MAPK signaling pathway. We further found that TRIM38 interacted with transforming growth factor-ß-activated kinase 1 binding protein 2 and promoted its protein degradation, thus inhibiting the transforming growth factor-ß-activated kinase 1-MAPK signal cascades. In summary, our study revealed that TRIM38 could suppress hepatic steatosis, inflammatory, and fibrosis in NAFLD via promoting transforming growth factor-ß-activated kinase 1 binding protein 2 degradation. TRIM38 could be a potential target for NAFLD treatment.

Melanoma differentiation-Associated gene 5 protects against NASH in mice.

BACKGROUND AND AIMS: NASH is a complicated disease characterized by hepatocyte steatosis, inflammation infiltration, and liver fibrosis. Accumulating evidence suggests that the innate immunity plays a key role in NASH progression. Here, we aimed to reveal the role of melanoma differentiation-associated gene 5 (MDA5, also known as Ifih1), a conventional innate immune regulator following viral infection, in the progression of NASH and investigate its underlying mechanism. APPROACH AND RESULTS: We first examined the expression of MDA5 and found that MDA5 was markedly down-regulated in the livers with NASH in human individuals and mice models. MDA5 overexpression significantly inhibits the free fatty acid-induced lipid accumulation and inflammation in hepatocyte in vitro, whereas MDA5 knockdown promotes hepatocyte lipotoxicity. Using hepatocyte-specific Mda5 gene knockout and transgenic mice, we found that diet-induced hepatic steatosis, inflammation, and liver fibrosis were markedly exacerbated by Mda5 deficiency but suppressed by Mda5 overexpression. Mechanistically, we found that the activation of apoptosis signal-regulating kinase 1 (ASK1)-mitogen-activated protein kinase pathway was significantly inhibited by MDA5 but enhanced by MDA5 deletion. We further validated that MDA5 directly interacted with ASK1 and suppressed its N-terminal dimerization. Importantly, blockage of ASK1 with adenovirus-expressing dominant negative ASK1 obviously reversed the lipid accumulation and ASK1 pathway activation when Mda5 was knocked out. CONCLUSIONS: These data indicate that MDA5 is an essential suppressor in NASH. The findings support MDA5 as a regulator of ASK1 and a promising therapeutic target for NASH.

Breviscapine alleviates NASH by inhibiting TGF-ß-activated kinase 1-dependent signaling.

BACKGROUND AND AIMS: NAFLD is a key component of metabolic syndrome, ranging from nonalcoholic fatty liver to NASH, and is now becoming the leading cause of cirrhosis and HCC worldwide. However, due to the complex and unclear pathophysiological mechanism, there are no specific approved agents for treating NASH. Breviscapine, a natural flavonoid prescription drug isolated from the traditional Chinese herb Erigeron breviscapus, exhibits a wide range of pharmacological properties, including effects on metabolism. However, the anti-NASH efficacy and mechanisms of breviscapine have not yet been characterized. APPROACH AND RESULTS: We evaluated the effects of breviscapine on the development of hepatic steatosis, inflammation, and fibrosis in vivo and in vitro under metabolic stress. Breviscapine treatment significantly reduced lipid accumulation, inflammatory cell infiltration, liver injury, and fibrosis in mice fed a high-fat diet, a high-fat/high-cholesterol diet, or a methionine- and choline-deficient diet. In addition, breviscapine attenuated lipid accumulation, inflammation, and lipotoxicity in hepatocytes undergoing metabolic stress. RNA-sequencing and multiomics analyses further indicated that the key mechanism linking the anti-NASH effects of breviscapine was inhibition of TGF-ß-activated kinase 1 (TAK1) phosphorylation and the subsequent mitogen-activated protein kinase signaling cascade. Treatment with the TAK1 inhibitor 5Z-7-oxozeaenol abrogated breviscapine-mediated hepatoprotection under metabolic stress. Molecular docking illustrated that breviscapine directly bound to TAK1. CONCLUSION: Breviscapine prevents metabolic stress-induced NASH progression through direct inhibition of TAK1 signaling. Breviscapine might be a therapeutic candidate for the treatment of NASH.

Energy-efficient Preparation of Amino and Sulfhydryl Functionalized Biomass Carbon Dots via a Reverse Microemulsion for Specific Recognition of Fe3+ and L-cysteine.

Amino- and sulfhydryl- functionalized biomass carbon dots (BCDs) were prepared by one-pot reverse microemulsion for specific recognition of ferric ions (Fe3+) and L-cysteine (L-Cys). Green grapefruit peel was used as the carbon source while aminosilane and mercaptosilane were used as N- and S-supplier. Following the adsorption of Fe3+ on the surfaces of BCDs-NH2 and BCDs-SH, the fluorescence responses was quenched step by step, while adding L-Cys to the BCDs-NH2/Fe3+ system restored the fluorescence. The BCDs-NH2 and BCDs-SH system exhibited extremely low limits of detection for Fe3+ of 3.2 and 3.0 nM, respectively, within a wide linear ranges of 0.006-200 µM and 0.004-200 µM, respectively. The BCDs-NH2/Fe3+ systems were used as an optosensor for L-Cys in the concentration ranges of 0.08-30 and 30-1000 µM with a detection limit of 65 nM. Developed BCDs-NH2 and BCDs-SH were able to respond to Fe3+ in water samples with satisfactory recoveries of 100.1%-103.1% and 94.6%-108.5%, respectively, and the BCDs-NH2/Fe3+ system was also able to respond to BCDs-NH2/Fe3+ in actual lake water samples with recoveries from 87.3% to 98.8%. Meanwhile, The BCDs-NH2 exhibited good photoluminescence and stability, and the with a fluorescence quantum yield was as high as 25%. This work demonstrates the feasibility of using such materials to remove hazardous ions from water and employing the resulting complexes for optosensing in a sustainable manner.

Quinolines and isoquinolines as HIV-1 inhibitors: Chemical structures, action targets, and biological activities.

Human immunodeficiency virus type 1 (HIV-1), a lentivirus that causes acquired immunodeficiency syndrome (AIDS), poses a serious threat to global public health. Since the advent of the first drug zidovudine, a number of anti-HIV agents acting on different targets have been approved to combat HIV/AIDS. Among the abundant heterocyclic families, quinoline and isoquinoline moieties are recognized as promising scaffolds for HIV inhibition. This review intends to highlight the advances in diverse chemical structures and abundant biological activity of quinolines and isoquinolines as anti-HIV agents acting on different targets, which aims to provide useful references and inspirations to design and develop novel HIV inhibitors for medicinal chemists.

An S=1 Iron(IV) Intermediate Revealed in a Non-Heme Iron Enzyme-Catalyzed Oxidative C-S Bond Formation.

Ergothioneine (ESH) and ovothiol A (OSHA) are two natural thiol-histidine derivatives. ESH has been implicated as a longevity vitamin and OSHA inhibits the proliferation of hepatocarcinoma. The key biosynthetic step of ESH and OSHA in the aerobic pathways is the O2 -dependent C-S bond formation catalyzed by non-heme iron enzymes (e.g., OvoA in ovothiol biosynthesis), but due to the lack of identification of key reactive intermediate the mechanism of this novel reaction is unresolved. In this study, we report the identification and characterization of a kinetically competent S=1 iron(IV) intermediate supported by a four-histidine ligand environment (three from the protein residues and one from the substrate) in enabling C-S bond formation in OvoA from Methyloversatilis thermotoleran, which represents the first experimentally observed intermediate spin iron(IV) species in non-heme iron enzymes. Results reported in this study thus set the stage to further dissect the mechanism of enzymatic oxidative C-S bond formation in the OSHA biosynthesis pathway. They also afford new opportunities to study the structure-function relationship of high-valent iron intermediates supported by a histidine rich ligand environment.

Gastrodin Improves Nonalcoholic Fatty Liver Disease Through Activation of the Adenosine Monophosphate-Activated Protein Kinase Signaling Pathway.

BACKGROUND AND AIMS: NASH is currently one of the most common causes of liver transplantation and hepatocellular carcinoma. Thus far, there is still no effective pharmacological therapy for this disease. Recently, Gastrodin has demonstrated hepatoprotective effects in a variety of liver diseases. The aim of this study is to investigate the function of Gastrodin in NASH. APPROACH AND RESULTS: In our study, Gastrodin showed potent therapeutic effects on NASH both in vivo and in vitro. In high-fat diet or high-fat and high-cholesterol diet-fed mice, the liver weight, hepatic and serum triglyceride and cholesterol contents, and serum alanine aminotransferase and aspartate aminotransferase activity levels were markedly reduced by Gastrodin treatment as compared with the corresponding vehicle groups. Notably, Gastrodin showed minimal effects on the function and histological characteristics of other major organs in mice. We further examined the effects of Gastrodin on lipid accumulation in primary mouse hepatocytes and human hepatocyte cell line and observed that Gastrodin showed a significant decrease in lipid accumulation and inflammatory response in hepatocytes under metabolic stress. Furthermore, RNA-sequencing analysis systemically indicated that Gastrodin suppressed the pathway and key regulators related to lipid accumulation, inflammation, and fibrosis in the pathogenesis of NASH. Mechanistically, we found that Gastrodin protected against NASH by activating the adenosine monophosphate-activated protein kinase (AMPK) pathway, which was supported by the result that the AMPK inhibitor Compound C or AMPK knockdown blocked the Gastrodin-mediated hepatoprotective effect. CONCLUSIONS: Gastrodin attenuates steatohepatitis by activating the AMPK pathway and represents a therapeutic for the treatment of NASH.

SIMPLE Is an Endosomal Regulator That Protects Against NAFLD by Targeting the Lysosomal Degradation of EGFR.

BACKGROUND AND AIMS: NAFLD has become a tremendous burden for public health; however, there is no drug for NAFLD therapy at present. Impaired endo-lysosome-mediated protein degradation is observed in a variety of metabolic disorders, such as atherosclerosis, type 2 diabetes mellitus, and NAFLD. Small integral membrane protein of lysosome/late endosome (SIMPLE) is a regulator of endosome-to-lysosome trafficking and cell signaling, but the role that SIMPLE plays in NAFLD progression remains unknown. Here we investigated SIMPLE function in NAFLD development and sophisticated mechanism therein. APPROACH AND RESULTS: This study found that in vitro knockdown of SIMPLE significantly aggravated lipid accumulation and inflammation in hepatocytes treated with metabolic stimulation. Consistently, in vivo experiments showed that liver-specific Simple-knockout (Simple-HKO) mice exhibited more severe high-fat diet (HFD)-induced, high-fat-high-cholesterol diet (HFHC)-induced, and methionine-choline-deficient diet (MCD)-induced steatosis, glucose intolerance, inflammation, and fibrosis than those fed with normal chow (NC) diet. Meanwhile, RNA-sequencing demonstrated the up-regulated signaling pathways and signature genes involved in lipid metabolism, inflammation, and fibrosis in Simple-HKO mice compared with control mice under metabolic stress. Mechanically, we found SIMPLE directly interact with epidermal growth factor receptor (EGFR). SIMPLE deficiency results in dysregulated degradation of EGFR, subsequently hyperactivated EGFR phosphorylation, thus exaggerating NAFLD development. Moreover, we demonstrated that using EGFR inhibitor or silencing EGFR expression could ameliorate lipid accumulation induced by the knockdown of SIMPLE. CONCLUSIONS: SIMPLE ameliorated NASH by prompting EGFR degradation and can be a potential therapeutic candidate for NASH.

Cordycepin Ameliorates Nonalcoholic Steatohepatitis by Activation of the AMP-Activated Protein Kinase Signaling Pathway.

BACKGROUND AND AIMS: Nonalcoholic fatty liver disease, especially nonalcoholic steatohepatitis (NASH), has become a major cause of liver transplantation and liver-associated death. NASH is the hepatic manifestation of metabolic syndrome and is characterized by hepatic steatosis, inflammation, hepatocellular injury, and different degrees of fibrosis. However, there is no US Food and Drug Administration-approved medication to treat this devastating disease. Therapeutic activators of the AMP-activated protein kinase (AMPK) have been proposed as a potential treatment for metabolic diseases such as NASH. Cordycepin, a natural product isolated from the traditional Chinese medicine Cordyceps militaris, has recently emerged as a promising drug candidate for metabolic diseases. APPROACH AND RESULTS: We evaluated the effects of cordycepin on lipid storage in hepatocytes, inflammation, and fibrosis development in mice with NASH. Cordycepin attenuated lipid accumulation, inflammation, and lipotoxicity in hepatocytes subjected to metabolic stress. In addition, cordycepin treatment significantly and dose-dependently decreased the elevated levels of serum aminotransferases in mice with diet-induced NASH. Furthermore, cordycepin treatment significantly reduced hepatic triglyceride accumulation, inflammatory cell infiltration, and hepatic fibrosis in mice. In vitro and in vivo mechanistic studies revealed that a key mechanism linking the protective effects of cordycepin were AMPK phosphorylation-dependent, as indicated by the finding that treatment with the AMPK inhibitor Compound C abrogated cordycepin-induced hepatoprotection in hepatocytes and mice with NASH. CONCLUSION: Cordycepin exerts significant protective effects against hepatic steatosis, inflammation, liver injury, and fibrosis in mice under metabolic stress through activation of the AMPK signaling pathway. Cordycepin might be an AMPK activator that can be used for the treatment of NASH.

The E3 Ubiquitin Ligase Ring Finger Protein 5 Ameliorates NASH Through Ubiquitin-Mediated Degradation of 3-Hydroxy-3-Methylglutaryl CoA Reductase Degradation Protein 1.

BACKGROUND AND AIMS: NAFLD is the most prevalent chronic liver disease worldwide, but no effective pharmacological therapeutics are available for clinical use. NASH is the more severe stage of NAFLD. During this progress, dysregulation of endoplasmic reticulum (ER)-related pathways and proteins is one of the predominant hallmarks. We aimed to reveal the role of ring finger protein 5 (RNF5), an ER-localized E3 ubiquitin-protein ligase, in NASH and to explore its underlying mechanism. APPROACH AND RESULTS: We first inspected the expression level of RNF5 and found that it was markedly decreased in livers with NASH in multiple species including humans. We then introduced adenoviruses for Rnf5 overexpression or knockdown into primary mouse hepatocytes and found that palmitic acid/oleic acid (PAOA)-induced lipid accumulation and inflammation in hepatocytes were markedly attenuated by Rnf5 overexpression but exacerbated by Rnf5 gene silencing. Hepatocyte-specific Rnf5 knockout significantly exacerbated hepatic steatosis, inflammatory response, and fibrosis in mice challenged with diet-induced NASH. Mechanistically, we identified 3-hydroxy-3-methylglutaryl CoA reductase degradation protein 1 (HRD1) as a binding partner of RNF5 by systematic interactomics analysis. RNF5 directly bound to HRD1 and promoted its lysine 48 (K48)-linked and K33-linked ubiquitination and subsequent proteasomal degradation. Furthermore, Hrd1 overexpression significantly exacerbated PAOA-induced lipid accumulation and inflammation, and short hairpin RNA-mediated Hrd1 knockdown exerted the opposite effects. Notably, Hrd1 knockdown significantly diminished PAOA-induced lipid deposition, and up-regulation of related genes resulted from Rnf5 ablation in hepatocytes. CONCLUSIONS: These data indicate that RNF5 inhibits NASH progression by targeting HRD1 in the ubiquitin-mediated proteasomal pathway. Targeting the RNF5-HRD1 axis may provide insights into the pathogenesis of NASH and pave the way for developing strategies for NASH prevention and treatment.

Multidimensional Image and Beam Splitter Based on Hyperbolic Metamaterials.

Recently, multidimensional metasurfaces, which can modulate multiple optical parameters of input and output lights simultaneously, have aroused intensive interest. Here, we demonstrate multidimensional switchable images and 3D integrated beam splitters based on hyperbolic metamaterials (HMMs). On one hand, a switchable image controlled by output helicity and input wavelengths is achieved by arranging HMMs with different polarization conversion performance. On the other hand, polarization-multiplexed broadband beam splitter is generated by spatially engineering the subunit with broadband half-plate performance. By integrating the multiplexed beam splitter with a filter metamaterial, this multidimensional beam splitter can further realize the separation of output light by space and wavelength. This cascaded multilayer metamaterial achieves a brand new optical functionality and offers more inspiring possibilities for the design of multifunctional optical devices in the future.

TfOH-Catalyzed [4 + 1] Annulation of p-Quinone Methides with α-Aryl Diazoacetates: Straightforward Access to Highly Functionalized 2,3-Dihydrobenzofurans.

We have developed a methodology for the greatly efficient construction of significant 2,3-dihydrobenzofuran scaffolds bearing a quaternary carbon center at the C2 position by means of [4 + 1] annulation reactions between p-quinone methides and α-aryl diazoacetates as C1 synthons through organocatalysis by readily accessible TfOH catalyst under mild and transition metal-free conditions. This metal-free protocol furnishes an operationally simple and swift process for the free assembly of diverse highly functionalized 2,3-dihydrobenzofurans and also features broad substrate scope, excellent functional group compatibility, and environmental friendliness. Mechanistic investigation suggested that the reaction undergoes a rapid cascade protonation/intermolecular Michael addition/intramolecular substitution process.

TfOH-Catalyzed N-H Insertion of α-Substituted-α-Diazoesters with Anilines Provides Access to Unnatural α-Amino Esters.

A time-economical TfOH-catalyzed N-H insertion between anilines and α-alkyl and α-aryl-α-diazoacetates provides a straightforward approach to access unnatural α-amino esters, which readily undergo various transformations and can thus be used for the synthesis of pharmaceutically relevant molecules. The α-amino esters were obtained in moderate to excellent yields.

[The Ultrasonographic Features of Female Reproductive System Extraosseous Ewing's Sarcoma].

OBJECTIVE: This study investigated the clinicopathological traits and ultrasound features of female reproductive system extraosseous Ewing's sarcoma (EES) and explored the diagnostic value of ultrasonography for this condition. METHODS: Cases of female pelvic EES diagnosed and treated at our hospital between June 2009 and June 2019 were included in this study. Pathology data and ultrasound manifestations were assessed retrospectively to summarize the clinical traits and ultrasound features of female reproductive system EES. Based on the results, recommendations for the ultrasonography-based diagnosis of this disease were proposed. RESULTS: During the 10-year study period, 13 female patients were diagnosed with EES in the pelvic cavity based on the results of postoperative pathology tests. The age of the patients ranged from 8 mouth to 40 years, and no patients demonstrated specific clinical symptoms. However, an examination of tumor biomarkers revealed that certain patients had elevated levels of CA125. In the 13 patients, 19 lesions were identified, including 16 that involved the reproductive system. The primary ultrasound manifestation was uneven, low-echo solidity or cystic solidity, exhibiting large size, irregular shape, and unclear boundary. A few patients had concurrent ascites. Although some lesions lacked blood supply, the blood supply of most lesions was medium to abundant, and the blood flow was mostly characterized by low resistant. Almost none of the lesions were definitively diagnosed preoperatively. CONCLUSIONS: Preoperative definitive diagnosis of EES in the female reproductive system remains a great clinical challenge. Although certain clinical traits and ultrasound features are associated with this disease, and color Doppler ultrasonography might provide vital information indicating the presence of EES, the final diagnosis still depends on the pathological test results of the patients.

TfOH-Catalyzed Cascade C-H Activation/Lactonization of Phenols with α-Aryl-α-diazoesters: Rapid Access to α-Aryl Benzofuranones.

Aryl benzofuranones are privileged structural units present in natural products and pharmaceutically relevant compounds with high bioactivity and therapeutic value; synthetic access to these scaffolds remains an area of intensive interest. A new and efficient TfOH-catalyzed cascade ortho C-H activation/lactonization of phenols with α-aryl-α-diazoacetates is reported. This metal-free protocol provides an operationally simple and rapid method for the one-pot assembly of diverse α-aryl benzofuranones in high yields with broad substrate scope, a readily starting material, good chemo-regioselectivity, and excellent functional group compatibility.

Organocatalytic Asymmetric Domino Oxa-Michael-Mannich-[1,3]-Amino Rearrangement Reaction of N-Tosylsalicylimines to α,ß-Unsaturated Aldehydes by Diarylprolinol Silyl Ethers.

An organocatalytic asymmetric enantioselective domino oxa-Michael-Mannich-[1,3]-amino rearrangement reaction of N-tosylsalicylimines with a wide range of α,ß-unsaturated aldehydes utilizing diarylprolinol silyl ether catalysis is described. The catalytic reactions proceed with excellent enantioselectivity (up to 99% ee) to produce the corresponding chair N-tosylimines-chromenes with a yield of up to 99%, tolerating a range of functional groups. This methodology offers a new method with great potential to further extend the synthetic power and versatility of chiral aminocatalysis.

Spin-Selective Transmission in Chiral Folded Metasurfaces.

Controlling the spin angular momentum of light (or circular polarization state) plays a crucial role in the modern photonic applications such as optical communication, circular dichroism spectroscopy, and quantum information processing. However, the conventional approaches to manipulate the spin of light require naturally occurring chiral or birefringent materials of bulky sizes due to the weak light-matter interactions. Here we experimentally demonstrate an approach to implement spin-selective transmission in the infrared region based on chiral folded metasurfaces that are capable of transmitting one spin state of light while largely prohibiting the other. Due to the intrinsic chirality of the folded metasurface, a remarkable circular dichroism as large as 0.7 with the maximum transmittance exceeding 92% is experimentally demonstrated. The giant circular dichroism is interpreted within the framework of charge-current multipole expansion. Moreover, the intrinsic chirality can be readily controlled by manipulating the folding angle of the metasurface with respect to the cardinal plane. Benefiting from its strong chirality and spin-dependent transmission characteristics, the proposed folded metasurface may be applied to a range of novel photon-spin selective devices for optical communication technologies and biophotonics.

Nuclear lncRNA HOXD-AS1 suppresses colorectal carcinoma growth and metastasis via inhibiting HOXD3-induced integrin ß3 transcriptional activating and MAPK/AKT signalling.

BACKGROUND: Long noncoding RNAs (lncRNAs) have been indicated to play critical roles in cancer development and progression. LncRNA HOXD cluster antisense RNA1 (HOXD-AS1) has recently been found to be dysregulated in several cancers. However, the expression levels, cellular localization, precise function and mechanism of HOXD-AS1 in colorectal carcinoma (CRC) are largely unknown. METHODS: Real-time PCR and in situ hybridization were used to detect the expression of HOXD-AS1 in CRC tissue samples and cell lines. Gain- and loss-of-function experiments were performed to investigate the biological roles of HOXD-AS1 in CRC cell line. RNA pull down, RNA immunoprecipitation and chromatin immunoprecipitation assays were conducted to investigate the mechanisms underlying the functions of HOXD-AS1 in CRC. RESULTS: We observed that HOXD-AS1 was located in the nucleus of CRC cells and that nuclear HOXD-AS1 was downregulated in most CRC specimens and cell lines. Lower levels of nuclear HOXD-AS1 expression were associated with poor outcomes of CRC patients. HOXD-AS1 downregulation enhanced proliferation and migration of CRC cells in vitro and facilitated CRC tumourigenesis and metastasis in vivo. Mechanistic investigations revealed that HOXD-AS1 could suppress HOXD3 transcription by recruiting PRC2 to induce the accumulation of the repressive marker H3K27me3 at the HOXD3 promoter. Subsequently, HOXD3, as a transcriptional activator, promoted Integrin ß3 transcription, thereby activating the MAPK/AKT signalling pathways. CONCLUSION: Our results reveal a previously unrecognized HOXD-AS1-HOXD3-Integrin ß3 regulatory axis involving in epigenetic and transcriptional regulation constitutes to CRC carcinogenesis and progression.