Transition finite element families for adaptive analysis of axisymmetric elasticity problems

In this paper, four transition element families that comprise five- to seven-node quadrilateral elements are developed based on the hybrid-stress and enhanced assumed strain (EAS) formulations for adaptive analyses of axisymmetric elasticity problems. For members in the first hybrid-stress family, a quasi-linear stress field with ten equilibrating stress modes is derived and employed. To study the effect of including more stress modes in the assumed stress field, another family with two additional stress modes is implemented. On the other hand, two EAS element families are constructed with respect to the incompatible displacement modes of two existing incompatible displacement transition element families. Several numerical examples are exercised. It can be seen that the first hybrid-stress family is the most accurate one among the proposed families. Moreover, the EAS families are close to the respective incompatible families in accuracy yet the former families are not only more efficient in computation but also more concise in formulation. © 2010 Elsevier B.V. All rights reserved.postprin

Numerical solutions on fracture of piezoelectric materials by hybrid element

The cracked piezoelectric problem is observed numerically. To simulate the characteristic singularity at the crack tip, a plane piezoelectric hybrid element is derived. The new model involves displacement u, stress σo, electric displacement D and electric potential p as independent variables. The electromechanical coupling behavior of the cracked piezoelectric ceramics PZT-4 and PZT-5 is investigated. Under impermeable crack condition, the 1/√r-singularity at the crack-tip zone is exactly represented for σ and D. The efficiency of implementing the permeable crack condition is also inspected. To examine current energy release rate formulas, the path-independent integral is computed, and then a fitting formula for the energy release rate is obtained. In this paper, all the numerical results are compared with the previously reported theoretical solutions. © 2001 Elsevier Science Ltd. All rights reserved.postprin

Monitoring the fitness of antiviral-resistant influenza strains during an epidemic: a mathematical modelling study

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Liquid-crystal alignment on a-C : H films by nitrogen plasma beam scanning

[[abstract]]A plasma beam scanning treatment has been developed to modify the surface of the hydrogenated amorphous carbon (a-C:H) film on the indium tin oxide glass. The plasma beam scanning treatment makes the a-C:H film an excellent layer for liquid-crystal alignment. The qualities of a-C:H films were characterized by using atomic force microscope, micro-Raman spectroscopy, and field-emission scanning electron microscope. The ultrathin a-C:H films were deposited at 50% CH4/(H-2+CH4) gas ratio, 100 W radio-frequency power, and a gas pressure of 10 mtorr for 15 min by capacitive-coupled plasma chemical-vapor deposition method. The twist nematic cells were filled with liquid crystal (ZLI-2293) on the a-C:H film treated with different nitrogen plasma beam scanning time. The grooving mechanism is considered not responsible for the liquid-crystal (LC) alignment. Raman spectra suggest that a bond-breaking process of aromatic rings occurs in the a-C:H film. The O-1s, C-1s, and N-1s core-level spectra support that the nitrogen plasma beam scanning treatment induces a bond-breaking process of aromatic rings to create available carbon dangling bonds for the formation of C-O bonds. The newly formed C-O bonds are "directional," which favor the LC alignment on the a-C:H film.[[fileno]]2010137010005[[department]]物理

Medical treatment of viral pneumonia including SARS in immunocompetent adult

Since no randomized controlled trials have been conducted on the treatment of viral pneumonia by antivirals or immunomodulators in immunocompetent adults, a review of such anecdotal experience are needed for the more rational use of such agents. Case reports (single or case series) with details on their treatment and outcome in the English literature can be reviewed for pneumonia caused by human or avian influenza A virus (50 patients), varicella zoster virus (120), adenovirus (29), hantavirus (100) and SARS coronavirus (SARS-CoV) (841). Even with steroid therapy alone, the mortality rate appeared to be lower when compared with conservative treatment for pneumonia caused by human influenza virus (12.5% vs. 42.1%) and hantavirus (13.3% vs. 63.4%). Combination of an effective antiviral, acyclovir, with steroid in the treatment of varicella zoster virus may be associated with a lower mortality than acyclovir alone (0% vs. 10.3%). Combination of interferon alfacon-1 plus steroid, or lopinavir/ritonavir, ribavirin plus steroid were associated with a better outcome than ribavirin plus steroid (0% vs. 2.3% vs. 7.7%, respectively). Combination of lopinavir/ritonavir plus ribavirin significantly reduced the virus load of SARS-CoV in nasopharyngeal, serum, stool and urine specimens taken between day 10 and 15 after symptom onset when compared with the historical control group treated with ribavirin. It appears that the combination of an effective antiviral and steroid was associated with a better outcome. Randomized therapeutic trial should be conducted to ascertain the relative usefulness of antiviral alone or in combination with steroid. © 2004 The British Society. Published by Elsevier Ltd. All rights reserved.postprin

High folic acid consumption leads to pseudo-MTHFR deficiency, altered lipid metabolism, and liver injury in mice.

Increased consumption of folic acid is prevalent, leading to concerns about negative consequences. The effects of folic acid on the liver, the primary organ for folate metabolism, are largely unknown. Methylenetetrahydrofolate reductase (MTHFR) provides methyl donors for S-adenosylmethionine (SAM) synthesis and methylation reactions

Differentiation Therapy Targeting the β-Catenin/CBP Interaction in Pancreatic Cancer.

BACKGROUND:Although canonical Wnt signaling is known to promote tumorigenesis in pancreatic ductal adenocarcinoma (PDAC), a cancer driven principally by mutant K-Ras, the detailed molecular mechanisms by which the Wnt effector β-catenin regulates such tumorigenesis are largely unknown. We have previously demonstrated that β-catenin's differential usage of the Kat3 transcriptional coactivator cyclic AMP-response element binding protein-binding protein (CBP) over its highly homologous coactivator p300 increases self-renewal and suppresses differentiation in other types of cancer. AIM/METHODS:To investigate Wnt-mediated carcinogenesis in PDAC, we have used the specific small molecule CBP/β-catenin antagonist, ICG-001, which our lab identified and has extensively characterized, to examine its effects in human pancreatic cancer cells and in both an orthotopic mouse model and a human patient-derived xenograft (PDX) model of PDAC. RESULTS/CONCLUSION:We report for the first time that K-Ras activation increases the CBP/β-catenin interaction in pancreatic cancer; and that ICG-001 specific antagonism of the CBP/β-catenin interaction sensitizes pancreatic cancer cells and tumors to gemcitabine treatment. These effects were associated with increases in the expression of let-7a microRNA; suppression of K-Ras and survivin; and the elimination of drug-resistant cancer stem/tumor-initiating cells

Adipocyte Fatty Acid Binding Protein Potentiates Toxic Lipids-Induced Endoplasmic Reticulum Stress in Macrophages via Inhibition of Janus Kinase 2-dependent Autophagy

Lipotoxicity is implicated in the pathogenesis of obesity-related inflammatory complications by promoting macrophage infiltration and activation. Endoplasmic reticulum (ER) stress and adipocyte fatty acid binding protein (A-FABP) play key roles in obesity and mediate inflammatory activity through similar signaling pathways. However, little is known about their interplay in lipid-induced inflammatory responses. Here, we showed that prolonged treatment of palmitic acid (PA) increased ER stress and expression of A-FABP, which was accompanied by reduced autophagic flux in macrophages. Over-expression of A-FABP impaired PA-induced autophagy associating with enhanced ER stress and pro-inflammatory cytokine production, while genetic ablation or pharmacological inhibition of A-FABP reversed the conditions. PA-induced expression of autophagy-related protein (Atg)7 was attenuated in A-FABP over-expressed macrophages, but was elevated in A-FABP-deficient macrophages. Mechanistically, A-FABP potentiated the effects of PA by inhibition of Janus Kinase (JAK)2 activity, thus diminished PA-induced Atg7 expression contributing to impaired autophagy and further augmentation of ER stress. These findings suggest that A-FABP acts as autophagy inhibitor to instigate toxic lipids-induced ER stress through inhibition of JAK2-dependent autophagy, which in turn triggers inflammatory responses in macrophages. A-FABP-JAK2 axis may represent an important pathological pathway contributing to obesity-related inflammatory diseases.published_or_final_versio

Lymphocyte surge as a marker for immunorestitution disease due to Pneumocystis in jiroveci HIV-negative immunosuppressed hosts

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Surveillance and Genome Analysis of Human Bocavirus in Patients with Respiratory Infection in Guangzhou, China.

Human bocavirus (HBoV) is a novel parvovirus associated with respiratory tract diseases and gastrointestinal illness in adult and pediatric patients throughout the world. To investigate the epidemiological and genetic variation of HBoV in Guangzhou, South China, we screened 3460 throat swab samples from 1686 children and 1774 adults with acute respiratory infection symptoms for HBoV between March 2010 and February 2011, and analyzed the complete genome sequence of 2 HBoV strains. Specimens were screened for HBoV by real-time PCR and other 6 common respiratory viruses by RT-PCR or PCR. HBoV was detected in 58 (1.68%) out of 3460 samples, mostly from pediatric patients (52/58) and inpatient children (47/58). Six adult patients were detected as HBoV positive and 5 were emergency cases. Of these HBoV positive cases, 19 (32.76%) had co-pathogens including influenza virus (n = 5), RSV (n = 5), parainfluenza (n = 4), adenovirus (n = 1), coronavirus (n = 7). The complete genome sequences of 2 HBoVs strains (Genbank no. JN794565 and JN794566) were analyzed. Phylogenetic analysis showed that the 2 HBoV strains were HBoV1, and were most genetically close to ST2 (GenBank accession number DQ0000496). Recombination analysis confirmed that HBoV strain GZ9081 was an intra-genotype recombinant strain among HBoV1 variants.published_or_final_versio