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Discontinuity layout optimization (DLO) is a relatively new upper bound limit analysis method. Compared to classic topology optimization methods, aimed at obtaining the optimum design of a structure by considering its self-weight, building cost or bearing capacity, DLO optimizes the failure pattern of the structure under specific loading conditions and constraints by minimizing the dissipation energy. In this work, we present a modified DLO algorithm that contains all of the advantages of DLO. It is referred to virtual displacement-based discontinuity layout optimization (VDLO). VDLO takes the stress state of a loaded structure as a snapshot and correspondingly provides the optimum failure pattern, which greatly extends the application potential of DLO. Numerical examples indicate the effectiveness and flexibility of VDLO. It is regarded as a highly promising supplemental tool for other numerical methods in element-/node-based frameworks.

Tannic acid (TA) is a natural phenolic compound abundant in plants. Its characteristics of low combustion and good absorption make it useful in the flame retardant field. On this basis, a new expansive flame retardant system (ACT) composed of ammonium polyphosphate (APP)/TA functional clay (CT) was used to study the synergistic flame retardancy and smoke suppression of natural rubber (NR). Because of their unique flame retardancy and better mechanical properties compared with the traditional expansive flame retardant system (IFR), new flame retardants have attracted much attention in various fields. The results of the cone calorimeter showed that the ACT system can significantly influence the decomposition behavior of NR and form a highly graphitized and phosphorous carbon layer to protect the composite material, thus a synergistic effect is produced on the flame retardancy and smoke suppression performance of the composite material. In addition, within the effective additive quality range of the ACT system, TC can give the NR composite excellent mechanical properties.

Nanomaterials allow designing targeted therapies, facilitate molecular diagnostics, and are therefore enabling platforms for personalized medicine. A systematic science and a predictive understanding of molecular/supramolecular structure relationships and nanoparticle structure/biological property relationships are needed for rational design and clinical progress but are hampered by the anecdotal nature, nonsystematic and nonrepresentative nanomaterial assortment, and oligo-disciplinary approach of many publications. Here, we find that a systematic and comprehensive multidisciplinary approach to production and exploration of molecular-structure/nanostructure relationship and nano-bio structure/function relationship of medical nanomaterials can be achieved by combining systematic chemical synthesis, thorough physicochemical analysis, computer modeling, and biological experiments, as shown in a nanomaterial family of amphiphilic, micelle-forming oxazoline/siloxane block copolymers suited for the clinical application. This comprehensive interdisciplinary approach leads to improved understanding of nanomaterial structures, allows good insights into binding modes for the nanomaterial protein corona, induces the design of minimal cell-binding materials, and yields rational strategies to avoid toxicity. Thus, this work contributes to a systematic and scientific basis for rational design of medical nanomaterials.

SUMMARYWe performed a proteogenomic analysis of hepatocellular carcinomas (HCCs) across clinical stages and etiologies. We identified pathways differentially regulated on the genomic, transcriptomic, proteomic and phosphoproteomic levels. These pathways are involved in the organization of cellular components, cell cycle control, signaling pathways, transcriptional and translational control and metabolism. Analyses of CNA-mRNA and mRNA-protein correlations identified candidate driver genes involved in epithelial-to-mesenchymal transition, the Wnt-β-catenin pathway, transcriptional control, cholesterol biosynthesis and sphingolipid metabolism. The activity of targetable kinases aurora kinase A and CDKs was upregulated. We found that CTNNB1 mutations are associated with altered phosphorylation of proteins involved in actin filament organization, whereas TP53 mutations are associated with elevated CDK1/2/5 activity and altered phosphorylation of proteins involved in lipid and mRNA metabolism. Integrative clustering identified HCC subgroups with distinct regulation of biological processes, metabolic reprogramming and kinase activation. Our analysis provides insights into the molecular processes underlying HCCs.

Understanding the mechanisms underlying evasive resistance in cancer is an unmet medical need to improve the efficacy of current therapies. In hepatocellular carcinoma (HCC), aberrant expression of hypoxia-inducible factor 1 α (HIF1α) and increased aerobic glycolysis metabolism are drivers of resistance to therapy with the multi-kinase inhibitor Sorafenib. However, it has remained unknown how HIF1α is activated and how its activity and the subsequent induction of aerobic glycolysis promote Sorafenib resistance in HCC. Here, we report the ubiquitin-specific peptidase USP29 as a new regulator of HIF1α and of aerobic glycolysis during the development of Sorafenib resistance in HCC. In particular, we identified USP29 as a critical deubiquitylase (DUB) of HIF1α, which directly deubiquitylates and stabilizes HIF1α and, thus, promotes its transcriptional activity. Among the transcriptional targets of HIF1α is the gene encoding hexokinase 2 (HK2), a key enzyme of the glycolytic pathway. The absence of USP29, and thus of HIF1α transcriptional activity, reduces the levels of aerobic glycolysis and restores sensitivity to Sorafenib in Sorafenib-resistant HCC cells in vitro and in xenograft transplantation mouse models in vivo. Notably, the absence of USP29 and high HK2 expression levels correlate with the response of HCC patients to Sorafenib therapy. Together, the data demonstrate that, as a DUB of HIF1α, USP29 promotes Sorafenib resistance in HCC cells, in parts by upregulating glycolysis, thereby opening new avenues for therapeutically targeting Sorafenib-resistant HCC in patients.

Background & Aims HBeAg seroconversion during the natural history of chronic hepatitis B (CHB) is associated with a strong drop in serum HBV DNA levels and a reduction of intrahepatic covalently closed circular DNA (cccDNA) content. Of particular interest is the transition to HBeAg-negative chronic infection (ENCI). ENCI, previously known as inactive carrier state, is characterized by very low or negative viremia and the absence of liver disease. The molecular mechanisms responsible for the transition to ENCI and for the control of viral replication in ENCI are still poorly understood. Methods To identify which step(s) in the viral life cycle are controlled during the transition to ENCI, we quantified cccDNA, pre-genomic RNA (pgRNA), total HBV RNA and DNA replicative intermediates in 68 biopsies from patients in different phases of CHB. Results HBeAg seroconversion is associated with a reduction of cccDNA amounts as well as transcriptional activity. Silencing of cccDNA is particularly pronounced in ENCI, where there was ~46 times less pgRNA per cccDNA compared to HBeAg-negative CHB. Furthermore, a subgroup of patients with HBeAg-negative CHB can be characterized by reduced replication efficiency downstream of pgRNA. Conclusions The reduction in serum viral load during the transition to ENCI seems to primarily result from strong inhibition of the transcriptional activity of cccDNA which can be maintained in the absence of liver disease. Lay summary During the natural course of chronic hepatitis B virus infections, the immune response can gain control of viral replication. Quantification of viral DNA and RNA in liver biopsies of patients in different stages of chronic hepatitis B allowed us to identify the steps in the viral life cycle that are affected during the transition from active to inactive disease. Therapeutic targeting of these steps might induce sustained inhibition of viral transcription.

Background & Aims Most viruses are detected at early stages of cell infection and induce an innate immune response mediated by production of interferons (IFNs). IFNs induce expression of hundreds of IFN-stimulated genes (ISGs). Infection of chimpanzees with hepatitis C virus, but not hepatitis B virus (HBV), induces ISG expression in the liver. HBV might not induce an innate immune response because it is not detected by pattern recognition receptors (the stealth properties of HBV) or because HBV suppresses IFN production or signaling despite detection by pattern recognition receptors. We studied innate immune signaling in liver biopsies from patients with different stages of chronic HBV infection and uninfected individuals (controls). Methods We obtained liver within 10 minutes after collection from 30 patients with chronic HBV infection (hepatitis B e antigen-positive or -negative, with or without hepatitis) and 42 controls (most with fatty liver disease). The liver tissues were analyzed by histology, immunohistochemistry, quantitative reverse-transcription polymerase chain reaction, in situ hybridization, HBV RNA quantification, and HBV genotyping; some specimens were incubated with toll-like receptor (TLR) ligands (polyinosinic-polycytidylic acid) or infected with Sendai virus and then analyzed. Results Liver specimens from patients with HBV infection were not expressing more IFN or ISGs than those from control patients, indicating that chronic HBV infection did not activate an innate immune response. However, liver specimens from patients with HBV infection did produce IFN and induce expression of ISGs following activation of TLR3 with poly(I:C) or Sendai virus infections, so the innate immune response is not suppressed in these tissues. Conclusion Liver tissues from patients with chronic HBV infection do not have induction of an innate immune response, but this response can be activated by other factors (TLR3 binding, Sendai virus infection) in HBV-infected liver tissue. These findings support the hypothesis that HBV is invisible to pattern recognition receptors.

Photoacoustic imaging (PAI) is a new biomedical imaging modality based on light-triggered ultrasound emission. For in vivo application, materials with good photoacustic response to illumination in the near-infrared spectrum and suited tissue delivery strategies are needed. We developed polymeric, near-infrared responsive nanomaterials tuned for in vivo application based on oxazoline block copolymer chemistry by living cationic polymerization and a related functional transformation, loaded with a new photonic material, hydrophobized phthalocyanine Zinc complex (H-PcZn), that was efficiently encapsulated into the nanoparticles by self-assembly. The resulting nanoparticles P-NPs and N-NPs bear positive, and negative surface charge, respectively. After physicochemical characterization, applicability of the two nanoparticles as photoacoustic contrast agents was evaluated in vitro and in phantom experiments, where they exhibited excellent PAI contrast. In vivo distribution and visualization of P-NPs and N-NPs following i.v. injection imaged by PAI was confirmed by cryosection fluorescence analysis and showed that the materials accumulated in tissues within 1 h with differential tissue distribution. This pilot study thus describes synthesis of a novel polymeric photoacoustic nanosystem and demonstrates its potential for multimodal, photoacoustic in vivo imaging and for fluorescence imaging.

Web has been one of the major information sources in people’s daily life. However, a majority of Web information are regarded as incredible, as most Web information are not well evaluated before they are posted online. This eventually has a substantial impact on Web information utilization. For example, faked Web information will lead to wrong decision in business areas. In addition, the development of Web 2.0 makes people more convenient in producing and spreading information on the Web, which even worsens the information credibility problem on the Web. Thus, in this paper we review the current advances in the researches on Web information credibility, including related systems and methods for Web 1.0 information as well as existing studies on microblog information credibility. Finally, we propose a future research framework focusing on microblog information credibility.

In order to search for alternative agents to overcome chemoresistance during the treatment of ovarian cancer, this study aimed to examine the anticancer effects and action mechanism of salinomycin, a selective inhibitor of cancer stem cells, on cisplatin-resistant human ovarian cancer cell lines in vitro and in vivo. The concentration- (0.01-200 µM) and time‑dependent (24-72 h) growth inhibitory effects of salinomycin were observed in the ovarian cancer cell lines OV2008, C13, A2780, A2780-cp, SKOV3 and OVCAR3, by measuring cell viability using the resazurin reduction assay. The IC50 (24 h) range of salinomycin on the six cell lines was found to be 1.7-7.4 µM. After cisplatin-resistant C13 cells were treated with salinomycin, the percentage of apoptotic cells determined by flow cytometry was significantly increased, in a concentration- and time‑dependent manner. However, no cell cycle arrest was detected in the G1/G0, S and G2/M phases in the salinomycin‑treated and control cells. The Bio-Plex phosphoprotein 5-plex assay (Akt, IκB-α, ERK1/2, JNK and p38 MAPK) demonstrated a marked time- and concentration‑dependent increase in the phosphorylation of p38 MAPK, subsequent to salinomycin treatment. Moreover, salinomycin significantly suppressed tumor growth in a tumor xenograft model. These findings suggested that salinomycin efficiently inhibits the cisplatin-resistant human ovarian cancer cell line growth through the induction of apoptosis, potentially associated with the p38 MAPK activation.

This study investigated the anticancer effect and mechanism of salinomycin, a selective inhibitor of cancer stem cell, on human ovarian cancer cell line OV2008 in vitro and in vivo. The growth inhibitory effect of salinomycin on ovarian cancer cell line OV2008 was determined by measuring cell viability using the resazurin reduction assay. Apoptotic nuclear morphology was visualized by 4,6-diamino-2-phenylindole staining technique. The percentages of apoptotic cells and cell cycle parameters were detected by flow cytometry. The activity of p38 mitogen-activated protein kinase (p38 MAPK) was analyzed by Bio-Plex phosphoprotein assay. In vivo activity of salinomycin was assayed through tumor growth. Salinomycin caused concentration- (0.01-200 μM) and time-dependent (24-72 h) growth inhibitory effects in OV2008. Cell nuclear morphology observations showed that salinomycin-treated OV2008 cells displayed typical apoptotic characteristics. Salinomycin significantly increased the percentages of apoptotic cells in OV2008, showing a concentration- and time-dependent manner. There was no cell cycle arrest in the G1/G0, S, and G2/M phases between salinomycin-treated cells and control cells. Salinomycin also enhanced the phosphorylation of p38 MAPK. Moreover, salinomycin significantly inhibited the growth of the ovarian xenograft tumors. Salinomycin exhibited significant growth inhibition and induction of apoptosis in the human ovarian cancer cell line OV2008. The data suggested that salinomycin-induced apoptosis in OV2008 might be associated with activating p38 MAPK and merits further investigations.

Recombinant alpha interferon (IFN-alpha) is used for the treatment of viral hepatitis and some forms of cancer. During these therapies IFN-alpha is injected once daily or every second day for several months. Recently, the long-acting pegylated IFN-alpha (pegIFN-alpha) has replaced standard IFN-alpha in therapies of chronic hepatitis C because it is more effective, supposedly by inducing a long-lasting activation of IFN signaling pathways. IFN signaling in cultured cells, however, becomes refractory within hours, and little is known about the pharmacodynamic effects of continuously high IFN-alpha serum concentrations. To investigate the behavior of the IFN system in vivo, we repeatedly injected mice with IFN-alpha and analyzed its effects in the liver. Within hours after the first injection, IFN-alpha signaling became refractory to further stimulation. The negative regulator SOCS1 was rapidly upregulated and likely responsible for early termination of IFN-alpha signaling. For long-lasting refractoriness, neither SOCS1 nor SOCS3 were instrumental. Instead, we identified the inhibitor USP18/UBP43 as the key mediator. Our results indicate that the current therapeutic practice using long-lasting pegIFN-alpha is not well adapted to the intrinsic properties of the IFN system. Targeting USP18 expression may allow to exploit the full therapeutic potential of recombinant IFN-alpha.

The discovery that the human Jagged1 gene (JAG1) is the Alagille syndrome disease gene indicated that Notch signaling has an important role in bile duct homeostasis. The functional study of this signaling pathway has been difficult because mice with targeted mutations in Jagged1, Notch1, or Notch2 have an embryonic lethal phenotype. We have previously generated mice with inducible Notch1 disruption using an interferon-inducible Cre-recombinase transgene in combination with the loxP flanked Notch1 gene. We used this conditional Notch1 knockout mouse model to investigate the role of Notch1 signaling in liver cell proliferation and differentiation. Deletion of Notch1 did not result in bile duct paucity, but, surprisingly, resulted in a continuous proliferation of hepatocytes. In conclusion, within weeks after Notch1 inactivation, the mice developed nodular regenerative hyperplasia without vascular changes in the liver.

Vascular endothelial cells (EC) are an exposed tissue with intimate contact with circulating Ag-specific CTL. Experimental in vitro and clinical data suggested that endothelial cells present a different repertoire of MHC class I-restricted peptides compared with syngeneic leukocytes or epithelial cells. This endothelial-specific peptide repertoire might protect EC from CTL-mediated cell death. The HLA-A*02-restricted peptide profile of human EC and syngeneic B lymphoblastoid cells was biochemically analyzed and compared. For EC selective peptides, source protein expression, peptide binding affinity, and peptide–HLA-A*02 turnover were measured. The significance of abundant peptide presentation for target cell recognition by immunodominant CTL was tested by small interfering RNA treatment of EC to knock down the source proteins. High amounts of two peptides, PTRF56–64 and CD59106–114, were consistently detected in EC. This predominance of two endothelial peptides was explained by cell type-specific source protein expression that compensated for poor HLA-A*02 binding affinity and short half-live of peptide/HLA-A*02 complexes. Knocking down the source proteins containing the abundant endothelial peptide motifs led to a nearly 100-fold increase of surface expression of SMCY311–319, an immunodominant minor histocompatibility Ag, as detected by cytotoxicity assays using SMCY311–319-specific CTL. We conclude that EC express and present preferentially two distinct HLA-A*02-restricted peptides at extraordinary high levels. These abundant self-peptides may protect EC from CTL-mediated lysis by competing for HLA-A*02 binding sites with immunodominant scarcely expressed antigenic peptides.

Background & aims Hepatitis C virus (HCV) is a major cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma worldwide. The majority of patients treated with interferon alpha do not have a sustained response with clearance of the virus. The molecular mechanisms underlying interferon resistance are poorly understood. Interferon-induced activation of the Jak-STAT (signal transducer and activator of transcription) signal transduction pathway is essential for the induction of an antiviral state. Interference of viral proteins with the Jak-STAT pathway could be responsible for interferon resistance in patients with chronic HCV. Methods We have analyzed interferon-induced signal transduction through the Jak-STAT pathway in transgenic mice that express HCV proteins in their liver cells. STAT activation was investigated with Western blots, immunofluorescence, and electrophoretic mobility shift assays. Virus challenge experiments with lymphocytic choriomeningitis virus were used to demonstrate the functional importance of Jak-STAT inhibition. Results STAT signaling was found to be strongly inhibited in liver cells of HCV transgenic mice. The inhibition occurred in the nucleus and blocked binding of STAT transcription factors to the promoters of interferon-stimulated genes. Tyrosine phosphorylation of STAT proteins by Janus kinases at the interferon receptor was not inhibited. This lack in interferon response resulted in an enhanced susceptibility of the transgenic mice to infection with a hepatotropic strain of lymphocytic choriomeningitis virus. Conclusions Interferon-induced intracellular signaling is impaired in HCV transgenic mice. Interference of HCV proteins with interferon-induced intracellular signaling could be an important mechanism of viral persistence and treatment resistance.