Template Selection Strategy for Synthesis of One-Dimensional CrSbSe3 Ferromagnetic Semiconductor Nanoribbons.

CrSbSe3─the only experimentally validated one-dimensional (1D) ferromagnetic semiconductor─has recently attracted significant attention. However, all reported synthesis methods for CrSbSe3 nanocrystals are based on top-down methods. Here we report a template selection strategy for the bottom-up synthesis of CrSbSe3 nanoribbons. This strategy relies on comparing the formation energies of potential binary templates to the ternary target product. It enables us to select Sb2Se3 with the highest formation energy, along with its 1D crystal structure, as the template instead of Cr2Se3 with the lowest formation energy, thereby facilitating the transformation from Sb2Se3 to CrSbSe3 by replacing half of the Sb atoms in Sb2Se3 with Cr atoms. The as-prepared CrSbSe3 nanoribbons exhibit a length of approximately 5 µm, a width ranging from 80 to 120 nm, and a thickness of about 5 nm. The single CrSbSe3 nanoribbon presents typical semiconductor behavior and ferromagnetism, confirming the intrinsic ferromagnetism in the 1D CrSbSe3 semiconductor.

miR-147a targets ZEB2 to regulate ox-LDL-induced monocyte adherence to HUVECs, atherosclerotic plaque formation, and stability in atherosclerosis.

The mechanisms underlying atherosclerosis (AS) that seriously affect human health, such as those involved in endothelial cell injury and monocyte/macrophage aggregation and infiltration, have not been fully elucidated. To investigate these processes, we established human umbilical vein endothelial cells (HUVECs) injured by oxidized low-density lipoprotein (ox-LDL) to mimic AS in vitro. Apolipoprotein E knockout (ApoE-/-) C57BL/6 mice were fed with a high-cholesterol diet to establish an AS model in vivo. We detected HUVEC apoptosis, and apoptosis-related proteins by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide and lactate dehydrogenase, flow cytometry, and Western blot assays, respectively, and we observed monocytes (THP-1 cells) adhering to HUVECs. Furthermore, miR-147a and its downstream target gene ZEB2 (zinc finger E-box binding homeobox 2) were predicted by bioinformatics analysis to be involved in AS, and their correlation was confirmed by several experiments. We determined the localization of miR-147a and ZEB2 within macrophages of AS mice by in situ hybridization and immunofluorescence. Atherosclerotic plaques in whole aortas were detected by histology observation. miR-147a attenuated adherence of monocytes to HUVECs and the upregulation of mononuclear chemotactic adhesion receptors in THP-1 cells induced by ox-LDL-injured HUVEC supernatants through directly downregulating ZEB2 levels. Moreover, miR-147a influenced M1/M2 macrophage polarization from THP-1 cells and the roles of their supernatants (THP-1 cells) in HUVEC apoptosis. miR-147a targeted ZEB2 to impact lipid accumulation and atherosclerotic plaque formation through regulating M1/M2 polarization and macrophage adhesion in AS mice. In summary, miR-147a attenuates ox-LDL-induced adherence of monocytes to HUVECs and modulates atherosclerotic plaque formation and stability through targeting ZEB2 during AS.

Enantioselective Glutamic Acid Discrimination and Nanobiological Imaging by Chiral Fluorescent Silicon Nanoparticles.

Enantioselective discrimination of chiral molecules is essential in chemistry, biology, and medical science due to the configuration-dependent activities of enantiomers. Therefore, identifying a specific amino acid and distinguishing it from its enantiomer by using nanomaterials with outstanding performance are of great significance. Herein, blue- and green-emitting chiral silicon nanoparticles named bSiNPs and gSiNPs, respectively, with excellent water solubility, salt resistance, pH stability, photobleaching resistance, biocompatibility, and ability to promote soybean germination, were fabricated in a facile one-step method. Especially, chiral gSiNPs presented excellent fluorescence recognition ability for glutamic acid enantiomers within 1 min, and the enantiomeric recognition difference factor was as high as 9.0. The mechanism for enantiomeric fluorescence recognition was systematically explored by combining the fluorescence spectra with density functional theory (DFT) calculation. Presumably, the different Gibbs free energy and hydrogen-bonding interaction of the chiral recognition module with glutamic acid enantiomers mainly contributed to the difference in the fluorescence signals. Most noteworthy was the fact that the chiral gSiNPs can showcase not only the ability to recognize l- and d-glutamic acids in living cells but also the test strips fabricated by soaking gSiNPs can be applied for d-glutamic acid visual detection. As a result, this study provided insights into the design of multifunctional chiral sensing nanoplatforms for enantiomeric detection and other applications.

Capsule type defines the capability of Klebsiella pneumoniae in evading Kupffer cell capture in the liver.

Polysaccharide capsule is the main virulence factor of K. pneumoniae, a major pathogen of bloodstream infections in humans. While more than 80 capsular serotypes have been identified in K. pneumoniae, only several serotypes are frequently identified in invasive infections. It is documented that the capsule enhances bacterial resistance to phagocytosis, antimicrobial peptides and complement deposition under in vitro conditions. However, the precise role of the capsule in the process of K. pneumoniae bloodstream infections remains to be elucidated. Here we show that the capsule promotes K. pneumoniae survival in the bloodstream by protecting bacteria from being captured by liver resident macrophage Kupffer cells (KCs). Our real-time in vivo imaging revealed that blood-borne acapsular K. pneumoniae mutant is rapidly captured and killed by KCs in the liver sinusoids of mice, whereas, to various extents, encapsulated strains bypass the anti-bacterial machinery in a serotype-dependent manner. Using capsule switched strains, we show that certain high-virulence (HV) capsular serotypes completely block KC's capture, whereas the low-virulence (LV) counterparts confer partial protection against KC's capture. Moreover, KC's capture of the LV K. pneumoniae could be in vivo neutralized by free capsular polysaccharides of homologous but not heterologous serotypes, indicating that KCs specifically recognize the LV capsules. Finally, immunization with inactivated K. pneumoniae enables KCs to capture the HV K. pneumoniae. Together, our findings have uncovered that KCs are the major target cells of K. pneumoniae capsule to promote bacterial survival and virulence, which can be reversed by vaccination.

Abnormal dermal microvascular endothelial cells in psoriatic excessive angiogenesis.

Psoriasis is characterized by excessive angiogenesis, with increased distortion and dilation of the dermal blood vessels. These vascular alterations are ascribed, at least in part, to the changes in dermal microvascular endothelial cell functions. However, despite the recognition of vascular normalization as an emerging strategy for the treatment of psoriasis, in-depth studies of human dermal microvascular endothelial cells (HDMECs) have been missing. The difficulty of isolation and culture of HDMECs has impeded the study of endothelial dysfunction in psoriasis. Researchers have done a great deal of work to study the abnormal characteristics of keratinocytes, fibroblasts, and leukocytes in psoriatic skin tissue. Recently, with successful isolation of HDMECs from psoriasis, great progress has been made in the elucidation of the pathogenic role of these cells in psoriasis. It is of great therapeutic significance to study the molecular mechanism of HDMECs in psoriasis. We review here the abnormalities of HDMECs in psoriasis.

The nearby atomic environment effect on an Fe-N-C catalyst for the oxygen reduction reaction: a density functional theory-based study.

Fe-N-C materials have emerged as highly promising non-noble metal catalysts for oxygen reduction reactions (ORRs) in polymer electrolyte membrane fuel cells. However, they still encounter several challenges that need to be addressed. One of these challenges is establishing an atomic environment near the Fe-N4 site, which can significantly affect catalyst activity. To investigate this, herein, we employed density functional theory (DFT). According to our computational analysis of the Gibbs free energy of the reaction based on the computational hydrogen electrode (CHE) model, we successfully determined two C-O-C structures near the Fe-N4 site (referred to as str-11) with the highest limiting potential (0.813 V). Specifically, in the case of O-doped structures, the neighboring eight carbon (C) atoms around nitrogen (N) can be categorized into two distinct types: four C atoms (type A) exhibiting high sensitivity to the limiting potential and the remaining four C atoms (type B) displaying inert behavior. Electronic structure analysis further elucidated that a structure will have strong activity if the valence band maximum (VBM) around its gamma point is mainly contributed by dxz, dyz or dz2 orbitals of Fe atoms. Constant-potential calculations showed that str-11 is suitable for the ORR under both acidic and alkaline conditions with a limiting potential of 0.695 V at pH = 1 and 0.926 V at pH = 14, respectively. Additionally, microkinetic simulations indicated the possibility of str-11 as the active site for the ORR under working potential at pH = 14.

The longitudinal relationship between leisure activities and depressive symptoms among older Chinese adults: an autoregressive cross-lagged analysis approach.

BACKGROUND: Existing studies have shown a correlation between leisure activities and depressive symptoms in older adults, but the direction of the longitudinal relationship is inconsistent. This study used an autoregressive cross-lagged model to examine the longitudinal relationship between leisure activity participation and geriatric depression. METHODS: A total of 7,138 participants aged 60 years or older from the 2nd to the 4th wave of the China Health and Retirement Longitudinal Study (CHARLS) were analysed. RESULTS: First, present depressive symptoms were significantly associated with future depressive symptoms (ß2013-2015 = .893, p < .001; ß2015-2018 = .946, p < .001), and the same rule applied to leisure activities (ß2013-2015 = .402, p < .001; ß2015-2018 = .404, p < .001). Second, current depressive symptoms negatively predicted future leisure activities (ß2013-2015 = -.071, p < .001; ß2015-2018 = -.085, p < .001), but the inverse relationship was not statistically significant (ß2013-2015 = -.003, p > .05; ß2015-2018 = -.003, p > .05). CONCLUSION: These findings underscore the importance of interventions targeting depressive symptoms to potentially enhance engagement in leisure activities among older adults. The results contribute to the understanding of the complex dynamics between mental health and lifestyle choices in older populations, highlighting the potential of proactive mental health interventions to improve overall well-being.

Chiral Cpx Rhodium(III)-Catalyzed Enantioselective Aziridination of Unactivated Terminal Alkenes.

Chiral cyclopentadienyl-rhodium(III) Cpx Rh(III) catalysis has been demonstrated to be competent for catalyzing highly enantioselective aziridination of challenging unactivated terminal alkenes and nitrene sources. The chiral Cpx Rh(III) catalysis system exhibited outstanding catalytic performance and wide functional group tolerance, yielding synthetically important and highly valuable chiral aziridines with good to excellent yields and enantioselectivities (up to 99 % yield, 93 % ee). This protocol presents a novel and effective strategy for synthesizing enantioenriched aziridines from simple alkenes. Various transformations were performed on the aziridine products, illustrating the versatility and synthetic potential of this protocol for constructing highly functionalized compounds.

The Cm14-3-3µ protein and CCT transcription factor CmNRRa delay flowering in chrysanthemum.

The floral transition from vegetative to reproductive growth is pivotal in the plant life cycle. NUTRITION RESPONSE AND ROOT GROWTH (OsNRRa), as a CONSTANS, CONSTANS-LIKE, TOC1 (CCT) domain protein, delays flowering in rice, and an orthologous protein, CmNRRa, inhibits flowering in chrysanthemum; however, the underlying mechanism remains unknown. In this study, using yeast two-hybrid screening, we identified the 14-3-3 protein family member Cm14-3-3µ as a CmNRRa-interacting protein. A combination of bimolecular fluorescence complementation, pull-down, and co-immunoprecipitation assays was performed to confirm the physical interaction between CmNRRa and Cm14-3-3µ. In addition, expression analysis showed that CmNRRa but not Cm14-3-3µ responded to the diurnal rhythm, whereas both genes were highly expressed in leaves. Moreover, the function of Cm14-3-3µ in flowering time regulation was similar to that of CmNRRa. Furthermore, CmNRRa repressed chrysanthemum FLOWERING LOCUS T-like 3 (CmFTL3) and an APETALA 1 (AP1)/FRUITFULL (FUL)-like gene (CmAFL1) but induced TERMINAL FLOWER1 (CmTFL1) directly by binding to their promoters. Cm14-3-3µ enhanced the ability of CmNRRa to regulate the expression of these genes. These findings suggest that there is a synergistic relationship between CmNRRa and Cm14-3-3µ in flowering repression in chrysanthemum.

An optimized method for retrograde labelling and quantification of rabbit retinal ganglion cells.

Rabbits are a commonly used animal model in glaucoma research, but their application has been limited by the techniques used to assess optic nerve injury (ONI). Our study devised an optimized method for retrograde labelling and analysing rabbit retinal ganglion cells (RGCs). This method involved improvements over the conventional method regarding the stereotaxic device, the positioning of superior colliculi, the target of axonal tracer delivery, and the visualization and analysis of labelled RGCs. To evaluate its efficacy, eight New Zealand White rabbits were divided into naïve and ONI groups. Unilateral limbal buckling surgery was performed in each animal of the ONI group to induce chronic ocular hypertension (OHT). The animals of both groups were injected with indocyanine green (ICG) into the interstice between the superior colliculus and occipital lobe on each side of the brain, and their eyes were examined by confocal scanning laser ophthalmoscopy (CSLO) after 48 h. The acquired images were then analysed to quantify the number of ICG-labelled RGCs in these eyes and their loss induced by OHT. To verify the identity and changes of the labelled RGCs, the retinas of the rabbits were subjected to immunofluorescence analyses. In addition, three animals were subjected to a second ICG labelling after 12 months to determine the influence of this procedure on the long-term viability of the labelled RGCs. Our results showed that ICG-labelled RGCs were detected by CSLO throughout the retinas of all animals. These RGCs showed a distinctly higher density below the ONH and were defective in sectorial areas in OHT eyes. Their average number in the cell counting area was 3989.2 ± 414.2 and 4023.3 ± 603.4 in the right and left eyes, respectively, of the naïve animals and 2590.9 ± 1474.2 and 3966.7 ± 24.0 in the OHT and non-OHT eyes, respectively, of the ONI animals. Immunofluorescence analyses showed positive staining with Brn3a and RBPMS in the ICG-labelled RGCs and sectorial defects of the cells in the OHT eyes, similarly as observed by CSLO. The second ICG labelling after 12 months in three animals showed no appreciable changes in RGC density compared with the first one. In summary, the optimized method of rabbit RGC retrograde labelling is reliable and accurate in both naïve and ONI animals and offers an approach for longitudinal observation of RGCs in the same eyes, which suggests its potential as a powerful tool for glaucoma and optic nerve research.

3ß-Hydroxy-12-oleanen-27-oic Acid Exerts an Antiproliferative Effect on Human Colon Carcinoma HCT116 Cells via Targeting FDFT1.

3ß-hydroxy-12-oleanen-27-oic acid (ATA), a cytotoxic oleanane triterpenoid with C14-COOH isolated from the rhizome of Astilbe chinensis, has been previously proven to possess antitumor activity and may be a promising antitumor agent. However, its molecular mechanisms of antitumor action were still unclear. This study explored the underlying mechanisms of cytotoxicity and potential target of ATA against human colorectal cancer HCT116 cells via integrative analysis of transcriptomics and network pharmacology in combination with in vitro and in vivo experimental validations. ATA significantly inhibited the proliferation of HCT116 cells in a concentration- and time-dependent manner and induced the cell cycle arrest at the G0/G1 phase, apoptosis, autophagy, and ferroptosis. Transcriptomic analysis manifested that ATA regulated mRNA expression of the genes related to cell proliferation, cell cycle, and cell death in HCT116 cells. The integrated analysis of transcriptomics, network pharmacology, and molecular docking revealed that ATA exerted cytotoxic activity via interactions with FDFT1, PPARA, and PPARG. Furthermore, FDFT1 was verified to be an upstream key target mediating the antiproliferative effect of ATA against HCT116 cells. Of note, ATA remarkably suppressed the growth of HCT116 xenografts in nude mice and displayed an apparent attenuation of FDFT1 in tumor tissues accompanied by the alteration of the biomarkers of autophagy, cell cycle, apoptosis, and ferroptosis. These results demonstrate that ATA exerted in vitro and in vivo antiproliferative effects against HCT116 cells through inducing cell apoptosis, autophagy, and ferroptosis via targeting FDFT1.

Effective Removal of Sulfonamides Using Recyclable MXene-Decorated Bismuth Ferrite Nanocomposites Prepared via Hydrothermal Method.

Developing a simple and efficient method for removing organic micropollutants from aqueous systems is crucial. The present study describes the preparation and application, for the first time, of novel MXene-decorated bismuth ferrite nanocomposites (BiFeO3/MXene) for the removal of six sulfonamides including sulfadiazine (SDZ), sulfathiazole (STZ), sulfamerazine (SMZ), sulfamethazine (SMTZ), sulfamethoxazole (SMXZ) and sulfisoxazole (SXZ). The properties of BiFeO3/MXene are enhanced by the presence of BiFeO3 nanoparticles, which provide a large surface area to facilitate the removal of sulfonamides. More importantly, BiFeO3/MXene composites demonstrated remarkable sulfonamide adsorption capabilities compared to pristine MXene, which is due to the synergistic effect between BiFeO3 and MXene. The kinetics and isotherm models of sulfonamide adsorption on BiFeO3/MXene are consistent with a pseudo-second-order kinetics and Langmuir model. BiFeO3/MXene had appreciable reusability after five adsorption-desorption cycles. Furthermore, BiFeO3/MXene is stable and retains its original properties upon desorption. The present work provides an effective method for eliminating sulfonamides from water by exploiting the excellent texture properties of BiFeO3/MXene.

Comparative Transcriptomic Analyses Propose the Molecular Regulatory Mechanisms Underlying 1,8-Cineole from Cinnamomum kanehirae Hay and Promote the Asexual Sporulation of Antrodia cinnamomea in Submerged Fermentation.

Antrodia cinnamomea is a valuable edible and medicinal mushroom with antitumor, hepatoprotective, and antiviral effects that play a role in intestinal flora regulation. Spore-inoculation submerged fermentation has become the most efficient and well-known artificial culture process for A. cinnamomea. In this study, a specific low-molecular compound named 1,8-cineole (cineole) from Cinnamomum kanehirae Hay was first reported to have remarkably promoted the asexual sporulation of A. cinnamomea in submerged fermentation (AcSmF). Then, RNA sequencing, real-time quantitative PCR, and a literature review were performed to predict the molecular regulatory mechanisms underlying the cineole-promoted sporulation of AcSmF. The available evidence supports the hypothesis that after receiving the signal of cineole through cell receptors Wsc1 and Mid2, Pkc1 promoted the expression levels of rlm1 and wetA and facilitated their transfer to the cell wall integrity (CWI) signal pathway, and wetA in turn promoted the sporulation of AcSmF. Moreover, cineole changed the membrane functional state of the A. cinnamomea cell and thus activated the heat stress response by the CWI pathway. Then, heat shock protein 90 and its chaperone Cdc37 promoted the expression of stuA and brlA, thus promoting sporulation of AcSmF. In addition, cineole promoted the expression of areA, flbA, and flbD through the transcription factor NCP1 and inhibited the expression of pkaA through the ammonium permease of MEP, finally promoting the sporulation of AcSmF. This study may improve the efficiency of the inoculum (spores) preparation of AcSmF and thereby enhance the production benefits of A. cinnamomea.

[Clinical feature and genetic analysis of a patient with Idiopathic hypogonadotropic hypogonadism due to a novel variant of CHD7 gene].

OBJECTIVE: To explore the clinical feature and genetic etiology of a patient with normosmic idiopathic hypogonadotropic hypogonadism (nIHH) due to variant of CHD7 gene. METHODS: A patient who had presented at Anhui Provincial Children's Hospital in October 2022 was selected as the study subject. Clinical data of the patient was collected. The patient and his parents were subjected to trio-whole exome sequencing. Candidate variant was verified by Sanger sequencing and bioinformatic analysis. RESULTS: The patient had featured delayed development of secondary sexual characteristics but normal olfactory function. Genetic testing revealed that he has harbored a c.3052C>T (p.Pro1018Ser) missense variant of the CHD7 gene, for which both of his parents were of the wild type. The variant has not been recorded in the PubMed and HGMD databases. Analysis of amino acid sequences suggested that the variant site is highly conserved, and the variant may affect the stability of protein structure. Based on the guidelines from the American College of Medical Genetics and Genomics, the c.3032C>T variant was classified as a likely pathogenic (PS2+PM2_Supporting+PP2+PP3+PP4). CONCLUSION: The delayed development of secondary sexual characteristics of the patient may be attributed to the c.3052C>T (p.Pro1018Ser) variant of the CHD7 gene. Above finding has expanded the variation spectrum of the CHD7 gene.

Cobalt-Catalyzed Nitrogen Atom Insertion in Arylcycloalkenes.

Developing strategies enabling the modification of underlying molecular frameworks facilitates access to underexplored chemical spaces. Skeletal editing is an emerging technology for late-stage diversification of bioactive molecules. However, the current state of this knowledge remains undeveloped. This work describes a simple protocol that "inserts" a nitrogen atom into arylcycloalkenes to form the corresponding N-heterocycles. The use of an inexpensive cobalt catalyst under aqueous and open-air conditions makes this protocol very practical. Examples of late-stage modification of compounds of pharmaceutical interest and complex fused ring compounds further demonstrated the potentially broad applicability of this methodology.

linc00174 deteriorates the pathogenesis of diabetic retinopathy via miR-26a-5p/PTEN/Akt signalling cascade-mediated pyroptosis.

PURPOSE: We aim to investigate the potential role and underlying mechanisms of linc00174 on pyroptosis in the pathogenesis of DR. METHODS: Expression patterns of linc00174, miR-26a-5p and PTEN in human retinal microvascular endothelial cells (hRMECs) were detected by quantitative real-time PCR (qRT-PCR) and Western blot, respectively. Biological functions of linc00174 on cell proliferation and pyroptosis were evaluated by CCK-8, flow cytometry, caspase-1 activity assays, respectively. Luciferase reporter assay was employed to verify the interaction between miR-26a-5p and linc00174/PTEN. Streptozotocin (STZ)-induced DR in mice was further constructed to verify the potential role of linc00174 in vivo. Hematoxylin and eosin (H&E) and immunohistochemical staining were performed to assess the pathological changes and caspase-1 expression in retinal tissues. RESULTS: Up-regulated linc00174 and PTEN and down-regulated miR-26a-5p were uncovered in hRMECs treated with high glucose (HG). Mechanistically, linc00174 served as a sponge of miR-26a-5p to facilitate PTEN expression. Functionally, knockdown of linc00174 inhibited HG-induced pyroptosis of hRMECs via targeting miR-26a-5p. Moreover, linc00174/miR-26a-5p axis participated in HG-induced pyroptosis via PTEN/Akt signaling cascade. Further, silencing of linc00174 attenuated pyroptosis via regulating miR-26a-5p/PETN axis in DR mice. CONCLUSIONS: Collectively, our study reveals that linc10074 deteriorates the pathogenesis of DR via miR-26a-5p/PTEN/Akt signalling cascade, which may shed light on the discovery of potential therapeutic agents for DR treatment.

Dysregulation of CXCL14 promotes malignant phenotypes of esophageal squamous carcinoma cells via regulating SRC and EGFR signaling.

The present study was to identify abnormal methylation genes implicated in esophageal squamous cell carcinoma (ESCC). Genomic methylation alterations in ESCC tissues were analyzed using laser-microdissection and whole-genome bisulfite sequencing. CXCL14 promoter was frequently hypermethylated in ESCC tissues. The correlation of CXCL14 hypermethylation status and the mRNA and protein expression levels were validated using nested methylation-specific PCR (nMS-PCR), RNAscope in situ hybridization (RISH) and Western blot. RISH results showed completely negative CXCL14 expression in 34.3% (34/99) ESCC, compared with those in the basal layer cells of normal epithelia. Low expression of CXCL14 was more present in patients with lower differentiation. The anticancer role of CXCL14 has been commonly associated with immune regulation in the literature. Here, we observed by functional analysis that CXCL14 can also act as a tumor suppressor in ESCC cells. 5-Aza-dC treatment suppressed CXCL14 methylation and up-regulated the expression of CXCL14. Ectopic expression of CXCL14 suppressed the proliferation, invasion, tumor growth, and lung metastasis of ESCC cells. Both ectopic expression and induction of CXCL14 with 5-Aza-dC inhibited the activity of SRC, MEK1/2 and STAT3 in ESCC cells, while activated EGFR. Importantly, a combination of CXCL14 expression and SRC or EGFR inhibitor dramatically repressed the proliferation of ESCC cells and the growth of xenografts. Our findings revealed a direct tumor suppressor role of CXCL14, but not through the immune system. The data suggest that for ESCC patients with low level CXCL14, increasing CXCL14 expression combined with inhibition of SRC or EGFR might be a promising therapeutic strategy.

Regulation of pneumococcal epigenetic and colony phases by multiple two-component regulatory systems.

Streptococcus pneumoniae is well known for phase variation between opaque (O) and transparent (T) colonies within clonal populations. While the O variant is specialized in invasive infection (with a thicker capsule and higher resistance to host clearance), the T counterpart possesses a relatively thinner capsule and thereby higher airway adherence and colonization. Our previous study found that phase variation is caused by reversible switches of the "opaque ON-or-OFF" methylomes or methylation patterns of pneumococcal genome, which is dominantly driven by the PsrA-catalyzed inversions of the DNA methyltransferase hsdS genes. This study revealed that switch frequency between the O and T variants is regulated by five transcriptional response regulators (rr) of the two-component systems (TCSs). The mutants of rr06, rr08, rr09, rr11 and rr14 produced significantly fewer O and more T colonies. Further mutagenesis revealed that RR06, RR08, RR09 and RR11 enrich the O variant by modulating the directions of the PsrA-catalyzed inversion reactions. In contrast, the impact of RR14 (RitR) on phase variation is independent of PsrA. Consistently, SMRT sequencing uncovered significantly diminished "opaque ON" methylome in the mutants of rr06, rr08, rr09 and rr11 but not that of rr14. Lastly, the phosphorylated form of RR11 was shown to activate the transcription of comW and two sugar utilization systems that are necessary for maintenance of the "opaque ON" genotype and phenotype. This work has thus uncovered multiple novel mechanisms that balance pneumococcal epigenetic status and physiology.

Grafting of Tetraphenylethylene on Silica Surface, Characterizations, and Their Chromatographic Performance as Reversed-Phase Stationary Phases.

Surface modification is an effective way to functionalize the materials so as to get some special properties. Tetraphenylethylene (TPE) has been widely investigated as a well-known reagent which has the nature of aggregation-induced emission (AIE), but has never been reported in the liquid chromatography stationary phase. In this work, TPE-grafted silica (Sil-TPE) was obtained successfully using the derivative of 1-(4-hydroxyphenyl)-1,2,2-triphenylethylene as a ligand, and then characterized by elemental analysis, Fourier transform infrared spectra, thermogravimetric analysis, and so forth. Laser scanning confocal microscopy images reflected the AIE phenomenon of grafted TPE because the internal vibration and rotation of TPE molecules were restrained in the confined silica space. The contact angle test showed superhydrophobic properties of Sil-TPE. In order to understand thoroughly the mechanism of chromatographic performance and retention behavior for Sil-TPE, Tanaka test mixture, alkylbenzenes, polycyclic aromatic hydrocarbons (PAHs), and phenols were separated. This reveals that Sil-TPE has strong aromaticity and certain shape selectivity, especially, has excellent separation performance for PAHs and phenols. The thermodynamic properties and repeatability of Sil-TPE were further studied, which showed the stability of Sil-TPE. This work shows that TPE can be successfully grafted on silica surface and it has the potential to be a new kind of promising stationary phases in the future.

Light-assisted anti-wrinkling on azobenzene-containing polyblend films.

Undesired surface wrinkling is a persistent issue far from being resolved. Here, we report a simple light-assisted strategy to prevent surface wrinkling on azobenzene-containing polyblend films, which is based on the unique photo-responsive behaviors of azobenzene moieties. Upon visible light irradiation, the mechanical strain-induced surface wrinkling of the azo-based polyblend film attached on a pre-strained compliant substrate can be effectively suppressed. The influence of light irradiation conditions and polyblend composition on the wrinkling resistance has been systematically investigated. Notably, empirical scaling laws that can quantify the connection of the critical wrinkling conditions with external and internal factors are derived. This spatiotemporal light-assisted strategy combined with the simple universal blending method would provide a general guideline for the anti-wrinkling purpose in diverse functional material systems/devices.