Upconversion Plasmonic Lasing from an Organolead Trihalide Perovskite Nanocrystal with Low Threshold

The understanding of nonlinear light–matter interactions at the nanoscale has fueled worldwide interest in upconversion emission for imaging, lasing, and sensing. Upconversion lasers with anti-Stokes-type emission with various designs have been reported. However, reducing the volume and lasing threshold of such lasers to the nanoscale level is a fundamental photonics challenge. Here, we demonstrate that the upconversion efficiency can be improved by exploiting single-mode upconversion lasing from a single organo-lead halide perovskite nanocrystal in a resonance-adjustable plasmonic nanocavity. This upconversion plasmonic nanolaser has a very low lasing threshold (10 μJ cm⁻²) and a calculated ultrasmall mode volume (∼0.06 λ³) at 6 K. To provide the unique feature for lasing action, a temporal coherence signature of the upconversion plasmonic nanolasing was determined by measuring the second-order correlation function. The localized-electromagnetic-field confinement can be tailored in titanium nitride resonance-adjustable nanocavities, enhancing the pump-photon absorption and upconverted photon emission rate to achieve lasing. The proof-of-concept results significantly expand the performance of upconversion nanolasers, which are useful in applications such as on-chip, coherent, nonlinear optics, information processing, data storage, and sensing

Cell volume restriction by mercury chloride reduces M1-like inflammatory response of bone marrow-derived macrophages

Dysregulation of macrophages in the pro-inflammatory (M1) and anti-inflammatory (M2) sub-phenotypes is a crucial element in several inflammation-related diseases and injuries. We investigated the role of aquaporin (AQP) in macrophage polarization using AQP pan-inhibitor mercury chloride (HgCl2). Lipopolysaccharides (LPSs) induced the expression of AQP-1 and AQP-9 which increased the cell size of bone marrow-derived macrophages. The inhibition of AQPs by HgCl2 abolished cell size changes and significantly suppressed M1 polarization. HgCl2 significantly reduced the activation of the nuclear factor kappa B (NF-κB) and p38 mitogen-activated protein kinase (MAPK) pathways and inhibited the production of IL-1β. HgCl2 attenuated LPS-induced activation of mitochondria and reactive oxygen species production and autophagy was promoted by HgCl2. The increase in the light chain three II/light chain three I ratio and the reduction in PTEN-induced kinase one expression suggests the recycling of damaged mitochondria and the restoration of mitochondrial activity by HgCl2. In summary, the present study demonstrates a possible mechanism of the AQP inhibitor HgCl2 in macrophage M1 polarization through the restriction of cell volume change, suppression of the p38 MAPK/NFκB pathway, and promotion of autophagy

Twisting of the DNA-binding surface by a β-strand-bearing proline modulates DNA gyrase activity

DNA gyrase is the only topoisomerase capable of introducing (−) supercoils into relaxed DNA. The C-terminal domain of the gyrase A subunit (GyrA-CTD) and the presence of a gyrase-specific ‘GyrA-box’ motif within this domain are essential for this unique (−) supercoiling activity by allowing gyrase to wrap DNA around itself. Here we report the crystal structure of Xanthomonas campestris GyrA-CTD and provide the first view of a canonical GyrA-box motif. This structure resembles the GyrA-box-disordered Escherichia coli GyrA-CTD, both adopting a non-planar β-pinwheel fold composed of six seemingly spirally arranged β-sheet blades. Interestingly, structural analysis revealed that the non-planar architecture mainly stems from the tilted packing seen between blades 1 and 2, with the packing geometry likely being defined by a conserved and unusual β-strand-bearing proline. Consequently, the GyrA-box-containing blade 1 is placed at an angled spatial position relative to the other DNA-binding blades, and an abrupt bend is introduced into the otherwise flat DNA-binding surface. Mutagenesis studies support that the proline-induced structural twist contributes directly to gyrase’s (−) supercoiling activity. To our knowledge, this is the first demonstration that a β-strand-bearing proline may impact protein function. Potential relevance of β-strand-bearing proline to disease phenylketonuria is also noted

Cross-National Differences in Victimization : Disentangling the Impact of Composition and Context

Varying rates of criminal victimization across countries are assumed to be the outcome of countrylevel structural constraints that determine the supply ofmotivated o¡enders, as well as the differential composition within countries of suitable targets and capable guardianship. However, previous empirical tests of these ‘compositional’ and ‘contextual’ explanations of cross-national di¡erences have been performed upon macro-level crime data due to the unavailability of comparable individual-level data across countries. This limitation has had two important consequences for cross-national crime research. First, micro-/meso-level mechanisms underlying cross-national differences cannot be truly inferred from macro-level data. Secondly, the e¡ects of contextual measures (e.g. income inequality) on crime are uncontrolled for compositional heterogeneity. In this paper, these limitations are overcome by analysing individual-level victimization data across 18 countries from the International CrimeVictims Survey. Results from multi-level analyses on theft and violent victimization indicate that the national level of income inequality is positively related to risk, independent of compositional (i.e. micro- and meso-level) di¡erences. Furthermore, crossnational variation in victimization rates is not only shaped by di¡erences in national context, but also by varying composition. More speci¢cally, countries had higher crime rates the more they consisted of urban residents and regions with lowaverage social cohesion.

Male Germ Cell-Specific RNA Binding Protein RBMY: A New Oncogene Explaining Male Predominance in Liver Cancer

Male gender is a risk factor for the development of hepatocellular carcinoma (HCC) but the mechanisms are not fully understood. The RNA binding motif gene on the Y chromosome (RBMY), encoding a male germ cell-specific RNA splicing regulator during spermatogenesis, is aberrantly activated in human male liver cancers. This study investigated the in vitro oncogenic effect and the possible mechanism of RBMY in human hepatoma cell line HepG2 and its in vivo effect with regards to the livers of human and transgenic mice. RBMY expression in HepG2 cells was knocked down by RNA interference and the cancer cell phenotype was characterized by soft-agar colony formation and sensitivity to hydrogen-peroxide-induced apoptosis. The results revealed that RBMY knockdown reduced the transformation and anti-apoptotic efficiency of HepG2 cells. The expression of RBMY, androgen receptor (AR) and its inhibitory variant AR45, AR-targeted genes insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP-3) was analyzed by quantitative RT-PCR. Up-regulation of AR45 variant and reduction of IGF-1 and IGFBP-3 expression was only detected in RBMY knockdown cells. Moreover, RBMY positive human male HCC expressed lower level of AR45 as compared to RBMY negative HCC tissues. The oncogenic properties of RBMY were further assessed in a transgenic mouse model. Liver-specific RBMY transgenic mice developed hepatic pre-cancerous lesions, adenoma, and HCC. RBMY also accelerated chemical carcinogen-induced hepatocarcinogenesis in transgenic mice. Collectively, these findings suggest that Y chromosome-specific RBMY is likely involved in the regulation of androgen receptor activity and contributes to male predominance of HCC

A novel role of CPEB3 in regulating EGFR gene transcription via association with Stat5b in neurons

CPEB3 is a sequence-specific RNA-binding protein and represses translation of its target mRNAs in neurons. Here, we have identified a novel function of CPEB3 as to interact with Stat5b and inhibit its transcription activity in the nucleus without disrupting dimerization, DNA binding and nuclear localization of Stat5b. Moreover, CPEB3 is a nucleocytoplasm-shuttling protein with predominant residence in the cytoplasm; whereas activation of NMDA receptors accumulates CPEB3 in the nucleus. Using the knockdown approach, we have found the receptor tyrosine kinase, EGFR, is a target gene transcriptionally activated by Stat5b and downregulated by CPEB3 in neurons. The increased EGFR expression in CPEB3 knockdown neurons, when stimulated with EGF, alters the kinetics of downstream signaling. Taken together, CPEB3 has a novel function in the nucleus as to suppress Stat5b-dependent EGFR gene transcription. Consequently, EGFR signaling is negatively regulated by CPEB3 in neurons

Incorporating Distant Sequence Features and Radial Basis Function Networks to Identify Ubiquitin Conjugation Sites

Ubiquitin (Ub) is a small protein that consists of 76 amino acids about 8.5 kDa. In ubiquitin conjugation, the ubiquitin is majorly conjugated on the lysine residue of protein by Ub-ligating (E3) enzymes. Three major enzymes participate in ubiquitin conjugation. They are – E1, E2 and E3 which are responsible for activating, conjugating and ligating ubiquitin, respectively. Ubiquitin conjugation in eukaryotes is an important mechanism of the proteasome-mediated degradation of a protein and regulating the activity of transcription factors. Motivated by the importance of ubiquitin conjugation in biological processes, this investigation develops a method, UbSite, which uses utilizes an efficient radial basis function (RBF) network to identify protein ubiquitin conjugation (ubiquitylation) sites. This work not only investigates the amino acid composition but also the structural characteristics, physicochemical properties, and evolutionary information of amino acids around ubiquitylation (Ub) sites. With reference to the pathway of ubiquitin conjugation, the substrate sites for E3 recognition, which are distant from ubiquitylation sites, are investigated. The measurement of F-score in a large window size (−20∼+20) revealed a statistically significant amino acid composition and position-specific scoring matrix (evolutionary information), which are mainly located distant from Ub sites. The distant information can be used effectively to differentiate Ub sites from non-Ub sites. As determined by five-fold cross-validation, the model that was trained using the combination of amino acid composition and evolutionary information performs best in identifying ubiquitin conjugation sites. The prediction sensitivity, specificity, and accuracy are 65.5%, 74.8%, and 74.5%, respectively. Although the amino acid sequences around the ubiquitin conjugation sites do not contain conserved motifs, the cross-validation result indicates that the integration of distant sequence features of Ub sites can improve predictive performance. Additionally, the independent test demonstrates that the proposed method can outperform other ubiquitylation prediction tools

Association of maternal Vitamin D status with glucose tolerance and caesarean section in a multi-ethnic Asian cohort: the growing up in Singapore towards healthy outcomes study

10.1371/journal.pone.0142239PLoS ONE10111-16GUSTO (Growing up towards Healthy Outcomes