Swim pressure: stress generation in active matter

We discover a new contribution to the pressure (or stress) exerted by a suspension of self-propelled bodies. Through their self-motion, all active matter systems generate a unique swim pressure that is entirely athermal in origin. The origin of the swim pressure is based upon the notion that an active body would swim away in space unless confined by boundaries-this confinement pressure is precisely the swim pressure. Here we give the micromechanical basis for the swim stress and use this new perspective to study self-assembly and phase separation in active soft matter. The swim pressure gives rise to a nonequilibrium equation of state for active matter with pressure-volume phase diagrams that resemble a van der Waals loop from equilibrium gas-liquid coexistence. Theoretical predictions are corroborated by Brownian dynamics simulations. Our new swim stress perspective can help analyze and exploit a wide class of active soft matter, from swimming bacteria to catalytic nanobots to molecular motors that activate the cellular cytoskeleton.

Dielectron mass spectra from Au+Au collisions at √[s(NN)]=200 GeV

We report the STAR measurements of dielectron (e(+)e(-)) production at midrapidity (|y(ee)|<1) in Au+Au collisions at √[s(NN)]=200  GeV. The measurements are evaluated in different invariant mass regions with a focus on 0.30-0.76 (ρ-like), 0.76-0.80 (ω-like), and 0.98-1.05 (ϕ-like)   GeV/c(2). The spectrum in the ω-like and ϕ-like regions can be well described by the hadronic cocktail simulation. In the ρ-like region, however, the vacuum ρ spectral function cannot describe the shape of the dielectron excess. In this range, an enhancement of 1.77±0.11(stat)±0.24(syst)±0.33(cocktail) is determined with respect to the hadronic cocktail simulation that excludes the ρ meson. The excess yield in the ρ-like region increases with the number of collision participants faster than the ω and ϕ yields. Theoretical models with broadened ρ contributions through interactions with constituents in the hot QCD medium provide a consistent description of the dilepton mass spectra for the measurement presented here and the earlier data at the Super Proton Synchrotron energies.

Probing the repulsive core of the nucleon-nucleon interaction via the (4)He(e,e'pN) triple-coincidence reaction

We studied simultaneously the (4)He(e,e'p), (4)He(e,e'pp), and (4)He(e,e'pn) reactions at Q(2)=2(GeV/c)(2) and x(B)>1, for an (e,e'p) missing-momentum range of 400 to 830  MeV/c. The knocked-out proton was detected in coincidence with a proton or neutron recoiling almost back to back to the missing momentum, leaving the residual A=2 system at low excitation energy. These data were used to identify two-nucleon short-range correlated pairs and to deduce their isospin structure as a function of missing momentum, in a region where the nucleon-nucleon (NN) force is expected to change from predominantly tensor to repulsive. The abundance of neutron-proton pairs is reduced as the nucleon momentum increases beyond ∼500  MeV/c. The extracted fraction of proton-proton pairs is small and almost independent of the missing momentum. Our data are compared with calculations of two-nucleon momentum distributions in (4)He and discussed in the context of probing the elusive repulsive component of the NN force.

Amelioration of Muc5b mucin hypersecretion is enhanced by IL-33 after 2-APB administration in a murine model of allergic rhinitis

We attempted to clarify whether hypersecretion of Muc5b mucin from mouse nasal submucosal glands that is enhanced by interleukin (IL)-33 under allergic conditions can be ameliorated by administration of 2-APB. Immunohistochemistry was used to examine both the distribution of T cells in the nasal mucosa of an allergic rhinitis mouse model and expressions of IL-33 receptor ST2 and Muc5b protein in mouse submucosal gland cells. The amounts of protein and mRNA of Orai1, Muc5b, IL-4, IL-5, IL-13 and IL-33 in mouse nasal lavage fluid (NLF) and nasal mucosa were determined using enzyme-linked immunosorbent assay and real-time reverse transcription-polymerase chain reaction. Expressions of Orai1, Muc5b, IL-4, IL-5, IL-13 and IL-33 were up-regulated in the allergic state and IL-33 increased the levels of Muc5b, IL-4, IL-5 and IL-13, but did not influence proliferation of T cells; however, ST2 was diminished in nasal submucosal gland cells. 2-APB reduced proliferation of T cells and the Orai1 level in the nasal mucosa. It also reduced the concentrations of IL-4, IL-5 and IL-13 in NLF and nasal mucosa, and hypersecretion of Muc5b from glandular cells that was enhanced by IL-33, but did not affect IL-33 production. 2-APB decreased Muc5b mucin hypersecretion from submucosal gland that was enhanced by IL-33 in allergic mice by limiting Ca(2+) release-activated Ca(2+) channel activity in which Orai1 plays a crucial role in the gland cells and/or by controlling channel activation in T cells and proliferation of these cells.

Beam-energy dependence of the directed flow of protons, antiprotons, and pions in Au+Au collisions

Rapidity-odd directed flow (v1) measurements for charged pions, protons, and antiprotons near midrapidity (y=0) are reported in sNN=7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV Au+Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider. At intermediate impact parameters, the proton and net-proton slope parameter dv1/dy|y=0 shows a minimum between 11.5 and 19.6 GeV. In addition, the net-proton dv1/dy|y=0 changes sign twice between 7.7 and 39 GeV. The proton and net-proton results qualitatively resemble predictions of a hydrodynamic model with a first-order phase transition from hadronic matter to deconfined matter, and differ from hadronic transport calculations.

Jet-hadron correlations in √[s(NN)]=200 GeV p+p and central Au+Au collisions

Azimuthal angular correlations of charged hadrons with respect to the axis of a reconstructed (trigger) jet in Au+Au and p+p collisions at √[s(NN)]=200  GeV in STAR are presented. The trigger jet population in Au+Au collisions is biased toward jets that have not interacted with the medium, allowing easier matching of jet energies between Au+Au and p+p collisions while enhancing medium effects on the recoil jet. The associated hadron yield of the recoil jet is significantly suppressed at high transverse momentum (pTassoc) and enhanced at low pTassoc in 0%-20% central Au+Au collisions compared to p+p collisions, which is indicative of medium-induced parton energy loss in ultrarelativistic heavy-ion collisions.

PTGS2 gene polymorphism -765G>C is associated with coronary artery disease: a meta-analysis

Previous studies focusing on the association of PTGS2 polymorphism -765G>C with coronary artery disease (CAD) have failed to reach the same conclusion. In the present study, we performed a meta-analysis to systematically summarize the possible association between PTGS2 polymorphism -765G>C and the risk of CAD. We conducted a search of case-control studies on the associations of PTGS2 with susceptibility to CAD in PubMed, EMBASE, and Chinese National Knowledge Infrastructure databases. Data from eligible studies were extracted for meta-analysis. CAD risk associated with PTGS2 -765G>C was estimated by pooled odds ratios (ORs) and 95% confidence intervals (95%CI) with the RevMan 5.2 software. Eleven independent case-control studies on PTGS2 -765G>C were included in our meta-analysis. Our results showed that PTGS2 -765G>C was associated with a decreased risk of CAD (OR = 0.66, 95%CI = 0.56-0.79; P < 0.001). This meta-analysis suggests that PTGS2 -765G>C is associated with a decreased risk of CAD.

Upgraded high time-resolved x-ray imaging crystal spectroscopy system for J-TEXT ohmic plasmas

This paper presents the upgraded x-ray imaging crystal spectrometer (XICS) system on Joint Texas Experimental Tokamak (J-TEXT) tokamak and the latest experimental results obtained in last campaign. With 500 Hz frame rate of the new Pilatus detector and 5 cm × 10 cm spherically bent crystal, the XICS system can provide core electron temperature (Te), core ion temperature (Ti), and plasma toroidal rotation (VΦ) with a maximum temporal resolution of 2 ms for J-TEXT pure ohmic plasmas. These parameters with high temporal resolution are very useful in tokamak plasma research, especially for rapidly changed physical processes. The experimental results from the upgraded XICS system are presented.

Energy dependence of moments of net-proton multiplicity distributions at RHIC

We report the beam energy (sqrt[sNN]=7.7-200  GeV) and collision centrality dependence of the mean (M), standard deviation (σ), skewness (S), and kurtosis (κ) of the net-proton multiplicity distributions in Au+Au collisions. The measurements are carried out by the STAR experiment at midrapidity (|y|<0.5) and within the transverse momentum range 0.4<pT<0.8  GeV/c in the first phase of the Beam Energy Scan program at the Relativistic Heavy Ion Collider. These measurements are important for understanding the quantum chromodynamic phase diagram. The products of the moments, Sσ and κσ2, are sensitive to the correlation length of the hot and dense medium created in the collisions and are related to the ratios of baryon number susceptibilities of corresponding orders. The products of moments are found to have values significantly below the Skellam expectation and close to expectations based on independent proton and antiproton production. The measurements are compared to a transport model calculation to understand the effect of acceptance and baryon number conservation and also to a hadron resonance gas model.

Overall codon usage pattern of enterovirus 71

Hand, foot, and mouth disease (HFMD) is a systemic illness in children and is usually caused by enterovirus 71 (EV71). To provide new insights into the genetic features of EV71 and the relationship between the overall codon usage pattern of this virus and that of humans, values for relative synonymous codon usage (RSCU), effective number of codons (ENC), codon adaptation index (CAI), and nucleotide composition were calculated and analyzed. The relationship between ENC values and (G+C)₃% suggests that, although nucleotide composition plays an important role in shaping the overall codon usage pattern of this virus, other factors also affect this pattern. In addition, the negative correlation between the CAI value and (G+C)₃% suggests that the secondary structure of the EV71 coding sequence caused by its nucleotide composition can affect gene expression. Moreover, there was no significant correlation between ENC and CAI, suggesting that gene expression does not play a role in shaping the overall codon usage pattern of EV71. The overall codon usage pattern of the EV71 virus is only partly similar to the general codon pattern of human, suggesting that, although EV71 has co-evolved with humans for extended periods, mutation pressure played an important role in shaping the virus's overall codon usage pattern. These results revealed that the EV71 virus has developed a subtle strategy during evolution for adapting to environmental changes in its host cells solely by means of mutation pressure.

Natriorexigenic effect of DAMGO is decreased by blocking AT1 receptors in the central nucleus of the amygdala

μ-Opioid receptor (μ-OR) activation with agonist [D-Ala², N-Me-Phe⁴, Gly⁵-ol]-enkephalin (DAMGO) in the central nucleus of the amygdala (CeA) induces sodium (0.3M NaCl) intake in rats. The purpose of this study was to examine the effects of pre-injections of losartan (AT1 angiotensin receptor antagonist) into the CeA on 0.3 M NaCl and water intake induced by DAMGO injected bilaterally in the same area in rats submitted to water deprivation-partial rehydration (WD-PR) and in rats treated with the diuretic furosemide (FURO) combined with a low dose of the angiotensin-converting enzyme inhibitor captopril (CAP) injected subcutaneously (FURO/CAP). Male Sprague-Dawley rats with stainless steel cannulas implanted bilaterally into the CeA were used. In WD-PR rats, bilateral injections of DAMGO (2 nmol in 0.5 μL) into the CeA induced 0.3 M NaCl and water intake, and pre-treatment with losartan (108 nmol in 0.5 μL) injected into the CeA reduced 0.3 M NaCl and water intake induced by DAMGO. In FURO/CAP rats, pre-treatment with losartan (108 nmol in 0.5 μL) injected into the CeA attenuated the increase in 0.3M NaCl and water intake induced by DAMGO (2 nmol in 0.5 μL) injected into the same site. The results suggest that the natriorexigenic effect of DAMGO injected into the CeA is facilitated by endogenous angiotensin II acting on AT1 receptors in the CeA, which drives rats to ingest large amounts of hypertonic NaCl.

Differences in frequencies of UGT1A9, 1A7, and 1A1 genetic polymorphisms in Chinese Tibetan versus Han Chinese populations

As part of a series of pharmacogenomics studies of the Chinese population, we investigated genetic polymorphisms of some UGT1A regions. The three genes that were analyzed were UGT1A9, 1A7, and 1A1; we sequenced their exons, together with promoters, surrounding introns and 3'-untranslated regions (3'UTR) in 100 unrelated-healthy Chinese Tibetan individuals. We compared the data with information on Han Chinese of the same region, which we downloaded from the HapMap database. We identified 40 polymorphisms; 16 of them were shared by the two populations. We then analyzed their linkage disequilibrium map. The UGT1As cluster can be divided into two linkage blocks in the Tibetan population: Block 1 (UGT1A9, UGT1A7), Block 2 (3'-UTR). Furthermore, we identified haplotypes and selected their tagSNPs. In exon 1 of UGT1A7 gene, 393G>A (Arg131Gln, rs17868324) was found at a frequency of 44.4% in the Tibetan population, compared to only 0.7% in the Han population. The linkage blocks in the Han Chinese sample differed from that of the Chinese Tibetan group; the former had Block 1 (UGT1A9, UGT1A7), Block 2 (UGT1A7), and Block 3 (3'-UTR). These findings provide fundamental information for future molecular genetic studies of the UGT1A gene cluster as well as for personalized medicine in Chinese.

Identification of CHIP as a novel causative gene for autosomal recessive cerebellar ataxia

Autosomal recessive cerebellar ataxias are a group of neurodegenerative disorders that are characterized by complex clinical and genetic heterogeneity. Although more than 20 disease-causing genes have been identified, many patients are still currently without a molecular diagnosis. In a two-generation autosomal recessive cerebellar ataxia family, we mapped a linkage to a minimal candidate region on chromosome 16p13.3 flanked by single-nucleotide polymorphism markers rs11248850 and rs1218762. By combining the defined linkage region with the whole-exome sequencing results, we identified a homozygous mutation (c.493CT) in CHIP (NM_005861) in this family. Using Sanger sequencing, we also identified two compound heterozygous mutations (c.389AT/c.441GT; c.621C>G/c.707GC) in CHIP gene in two additional kindreds. These mutations co-segregated exactly with the disease in these families and were not observed in 500 control subjects with matched ancestry. CHIP colocalized with NR2A, a subunit of the N-methyl-D-aspartate receptor, in the cerebellum, pons, medulla oblongata, hippocampus and cerebral cortex. Wild-type, but not disease-associated mutant CHIPs promoted the degradation of NR2A, which may underlie the pathogenesis of ataxia. In conclusion, using a combination of whole-exome sequencing and linkage analysis, we identified CHIP, encoding a U-box containing ubiquitin E3 ligase, as a novel causative gene for autosomal recessive cerebellar ataxia.

Chinese urban-rural disparity in pandemic (H1N1) 2009 vaccination coverage rate and associated determinants: a cross-sectional telephone survey

OBJECTIVES

The present study aimed to examine the differences in pandemic (H1N1) 2009 vaccination coverage rate between urban and rural areas in China, and to explore factors associated with any urban-rural differences.

STUDY DESIGN

Cross-sectional study.

METHODS

Data were derived from a cross-sectional telephone survey performed in seven urban and two rural areas soon after the pandemic peak in China, concerning pandemic (H1N1) 2009 vaccination and associated knowledge, attitudes and practices among the general population in China. A total of 10 669 participants aged 18 years and above participated in the study.

RESULTS

Vaccination amongst rural residents was less than urban residents (8.9% vs 11.2%, P = 0.002). Among those who have not been immunized, 82.2% of rural respondents showed a willingness to get vaccinated against A/H1N1, significantly higher than that of urban respondents (55.3%). The major barrier to vaccination was reported as 'not being informed to get vaccination', of which there was a greater proportion in rural than urban population (71.9% vs 68.8%, P = 0.009). The analysis revealed a number of factors which contribute to this disparity: previous experience of vaccination against flu, degree of awareness of the free vaccination policy, and sociodemographic differences between urban and rural areas.

CONCLUSIONS

Significant discrepancies existed in the pandemic (H1N1) 2009 vaccination coverage rate and associated determinants, as well as the intention to get vaccinated between urban and rural residents. To improve the effectiveness of similar vaccination programmes in the future, campaigns for rural people need to be specifically tailored to address disparities in uptake.

Tumor-derived mural-like cells coordinate with endothelial cells: role of YKL-40 in mural cell-mediated angiogenesis

Tumor neo-vasculature is characterized by spatial coordination of endothelial cells with mural cells, which delivers oxygen and nutrients. Here, we explored a key role of the secreted glycoprotein YKL-40, a mesenchymal marker, in the interaction between endothelial cells and mesenchymal mural-like cells for tumor angiogenesis. Xenotransplantation of tumor-derived mural-like cells (GSDCs) expressing YKL-40 in mice developed extensive and stable blood vessels covered with more GSDCs than those in YKL-40 gene knockdown tumors. YKL-40 expressed by GSDCs was associated with increased interaction of neural cadherin/β-catenin/smooth muscle alpha actin; thus, mediating cell-cell adhesion and permeability. YKL-40 also induced the interaction of vascular endothelial cadherin/β-catenin/actin in endothelial cells (HMVECs). In cell co-culture systems, YKL-40 enhanced both GSDC and HMVEC contacts, restricted vascular leakage, and stabilized vascular networks. Collectively, the data inform new mechanistic insights into the cooperation of mural cells with endothelial cells induced by YKL-40 during tumor angiogenesis, and also enhance our understanding of YKL-40 in both mural and endothelial cell biology.

P63 regulates tubular formation via epithelial-to-mesenchymal transition

P63, a p53 family member, is expressed as TA and ΔN isoforms. Interestingly, both TAp63 and ΔNp63 are transcription factors, and regulate both common and distinct sets of target genes. p63 is required for survival of some epithelial cell lineages, and lack of p63 leads to loss of epidermis and other epithelia in humans and mice. Here, we explored the role of p63 isoforms in cell proliferation, migration and tubulogenesis by using Madin-Darby Canine Kidney (MDCK) tubular epithelial cells in two- or three-dimensional (2-D or 3-D) culture. We found that like downregulation of p53, downregulation of p63 and TAp63 decreases expression of growth-suppressing genes, including p21, PUMA and MIC-1, and consequently promotes cell proliferation and migration in 2-D culture. However, in 3-D culture, downregulation of p63, especially TAp63, but not p53, decapacitates MDCK cells to form a cyst structure through enhanced epithelial-to-mesenchymal transition (EMT). In contrast, downregulation of ΔNp63 inhibits MDCK cell proliferation and migration in 2-D culture, and delays but does not block MDCK cell cyst formation and tubulogenesis in 3-D culture. Consistent with this, downregulation of ΔNp63 markedly upregulates growth-suppressing genes, including p21, PUMA and MIC-1. Taken together, these data suggest that TAp63 is the major isoform required for tubulogenesis by maintaining an appropriate level of EMT, whereas ΔNp63 fine-tunes the rate of cyst formation and tubulogenesis by maintaining an appropriate expression level of genes involved in cell cycle arrest and apoptosis.

miR-200b inhibits TGF-β1-induced epithelial-mesenchymal transition and promotes growth of intestinal epithelial cells

Inflammatory bowel disease (IBD), which consists of Crohn's disease (CD) and ulcerative colitis (UC), is a chronic, inflammatory disorder of the gastro-intestinal tract with unknown etiology. Current evidence suggests that intestinal epithelial cells (IECs) is prominently linked to the pathogenesis of IBD. Therefore, maintaining the intact of epithelium has potential roles in improving pathophysiology and clinical outcomes of IBD. MicroRNAs (miRNAs) act as post-transcriptional gene regulators and regulate many biological processes, including embryonal development, cell differentiation, apoptosis and proliferation. In this study, we found that miR-200b decreased significantly in inflamed mucosa of IBD, especially for UC, when compared with their adjacent normal tissue. Simultaneously, we also found that the genes of E-cadherin and cyclin D1 were reduced significantly and correlated positively to the miR-200b. In addition, the upregulation of transforming growth factor-beta 1 (TGF-β1) was inversely correlated to the miR-200b in IBD. To investigate the possible roles of miR-200b in IECs maintaining, we used TGF-β1 to induce epithelial-mesenchymal transition (EMT) in IEC-6 initially. After sustained over-expressing miR-200b in IEC-6, the EMT was inhibited significantly that was characterized by downregulation of vimentin and upregulation of E-cadherin. Furthermore, we found that miR-200b enhanced E-cadherin expression through targeting of ZEB1, which encode transcriptional repressors of E-cadherin. SMAD2 was found to act as a target of miR-200b with direct evidence that miR-200b binding to the 3′ UTR of SAMD2 and the ability of miR-200b to repress SMAD2 protein expression. With SMAD2 depletion, the expression of vimentin decreased correspondingly, which suggested miR-200b might reduce vimentin through regulating the SMAD2. With endogenous over-expression of miR-200b, the proliferation of IEC-6 cells increased significantly by increasing S-phase entry and promoting expression of the protein cyclin D1. Summarily, our study suggested a potential role for mir-200b in maintaining intact of intestinal epithelium through inhibiting EMT and promoting proliferation of IECs.

Upregulation of DLX2 confers a poor prognosis in glioblastoma patients by inducing a proliferative phenotype

The human Distal-less Homeobox (DLX) gene family encodes homeobox transcription factors involved in the control of morphogenesis and tissue homeostasis, which is primarily expressed in embryonic development. Recently, DLX gene family was reported to have essential roles in carcinogenesis. We have profiled whole genome expressed genes in 83 glioblastoma multiforme (GBM) patients from the Chinese Glioma Genome Atlas (CGGA) Group. Two major groups of samples were identified in mRNA expression profiles (referred to as Cluster 1 (C1) and Cluster 2 (C2)). We identified 7 out of the top 10 Gene Ontology terms in the C1 group were associated with differentiation and development of neuronal cell. The most significant prognostic gene was DLX2 (P < 0.001, OR = 1.744); overexpression of DLX2 indicated poor survival in the 83 GBM patients (low DLX2 vs high DLX2, 77.6 vs 44.7 weeks, P < 0.001). Annotation of mRNA profiling data on GBM from The Cancer Genome Atlas and MD Anderson Cancer Center showed the proneural and neural subtypes highly correlated with low and high DLX2 expression, respectively. Knocking down of DLX2 in GBM cell line-LN229 results in decreased cyclin D1 expression and cell proliferation. Collectively, these data identified high expression of DLX2 as a poor prognostic marker to GBM patients.

Histone deacetylase inhibitors suppress mutant p53 transcription via histone deacetylase 8

Mutation of the p53 gene is the most common genetic alteration in human cancer and contributes to malignant process by enhancing transformed properties of cells and resistance to anticancer therapy. Mutant p53 is often highly expressed in tumor cells at least, in part, due to its increased half-life. However, whether mutant p53 expression is regulated by other mechanisms in tumors is unclear. Here we found that histone deacetylase (HDAC) inhibitors suppress both wild-type and mutant p53 transcription in time- and dose-dependent manners. Consistent with this, the levels of wild-type and mutant p53 proteins are decreased upon treatment with HDAC inhibitors. Importantly, we found that upon knockdown of each class I HDAC, only HDAC8 knockdown leads to decreased expression of wild-type and mutant p53 proteins and transcripts. Conversely, we found that ectopic expression of wild-type, but not mutant HDAC8, leads to increased transcription of p53. Furthermore, we found that knockdown of HDAC8 results in reduced expression of HoxA5 and consequently, attenuated ability of HoxA5 to activate p53 transcription, which can be rescued by ectopic expression of HoxA5. Because of the fact that HDAC8 is required for expression of both wild-type and mutant p53, we found that targeted disruption of HDAC8 expression remarkably triggers proliferative defect in cells with a mutant, but not wild-type, p53. Together, our data uncover a regulatory mechanism of mutant p53 transcription via HDAC8 and suggest that HDAC inhibitors and especially HDAC8-targeting agents might be explored as an adjuvant for tumors carrying a mutant p53.