Synthesis of vertically aligned ultra-long ZnO nanowires on heterogeneous substrates with catalyst at the root

The synthesis of ultra-long high-quality ZnO nanowires with uniform size and orientation on heterogeneous substrates is highly desirable, not only for investigating the fundamental properties of ZnO nanowires, but also for fabricating integrated functional nanodevices. Here we present a novel and general technique for growing vertically aligned ultra-long ZnO nanowires on various substrates. More importantly, the metal catalyst is experimentally determined not at the tip ends of the nanowires but at the junction area between the nanowires and the underlying substrate. Based on detailed analysis and control group results, we then propose a three-stage growth mechanism, in which vapor-liquid-solid growth and vapor-solid growth compete with each other to become dominant.

Aspirin Resistance: Clinical Significance and Genetic Polymorphism

OBJECTIVE: To determine the prevalence, clinical implications and underlying mechanism of aspirin resistance in Chinese patients. METHODS: Platelet aggregation was determined by light transmission aggregometry (LTA) using four different inducers. Patients were divided into aspirin-resistant (AR), aspirin semi responder (ASR) and aspirin-sensitive (AS) groups, according to their LTA results. Aspirin resistance was assessed by thromboelastography (TEG, with arachidonic acid [AA] or adenosine diphosphate as inducers), serum/urinary 11-dehydrothromboxane B2 (11-DH-TXB2) assay, platelet function analyser-100 assay and P-selectin assay. Polymorphisms in the prostaglandin endoperoxide synthase 1 ( PTGS1) gene (A842G, C50T, C22T, G128A, C644A and C714A), the PTGS2 gene (G765C) and the integrin β3 ( ITGB3) gene (C196T) were examined. RESULTS: The study included 360 aspirin-treated patients and 314 healthy controls. AS patients had significantly lower levels of 11-DH-TXB2 than AR and ASR patients, and significantly lower levels of P-selectin than AR patients. TEG-AA was more sensitive, specific and consistent than P-selectin in detecting aspirin resistance. The frequency of the PTGS2 G765C mutation was significantly higher in the AR/ASR groups versus the AS group. CONCLUSIONS: TEG-AA was more sensitive, specific and consistent than the P-selectin assay for detecting aspirin resistance, and the PTGS2 G765C mutation may be related to aspirin resistance.

Socioeconomic status and children with intellectual disability in China

BACKGROUND

Intellectual disability (ID) accounts for 70% of all disabilities among children in China's Second National Sampling Survey on Disability. Although studies have shown a relationship between social class and ID in children, none have investigated the association of socioeconomic variables in Chinese children with mild or severe ID.

METHODS

Data for children aged 0-6 years with and without ID were abstracted from the Second National Sampling Survey on Disability in China, conducted in 2006. Crude odds ratios showed the effect of sociodemographic factors on mild and severe ID. Adjusted odds ratios (OR(a) ) (95% confidence intervals) estimated the independent effects of these factors.

RESULTS

For both mild and severe ID, risk of having ID increased with male sex, birth to a woman aged 35 years and older, lower maternal education, mother's older age at delivery, lower income and rural residence. After age, gender and parent disability were controlled, mothers aged 35 years and older were more likely to have a child with ID: mild ID, OR(a) 1.47 (1.15-1.88); severe ID, OR(a) 1.32 (1.00-1.73). There was an approximate increasing monotonic risk of severe ID with increasing socioeconomic disadvantage: lowest income, OR(a) 3.00 (2.19-4.12); low income, OR(a) 2.28 (1.63-3.19); lower middle income, OR(a) 1.72 (1.27-2.33); middle income, OR(a) 1.73 (1.28-2.36).

CONCLUSIONS

There is a significant relationship between sociodemographic factors and ID. Similar patterns were found for both mild and severe ID. Recommendations are given for preventing ID in Chinese children.

Measurements of higher order flow harmonics in Au+Au collisions at √s(NN)=200 GeV

Flow coefficients ν(n) for n=2, 3, 4, characterizing the anisotropic collective flow in Au+Au collisions at √s(NN)=200 GeV, are measured relative to event planes Ψ(n), determined at large rapidity. We report ν(n) as a function of transverse momentum and collision centrality, and study the correlations among the event planes of different order n. The ν(n) are well described by hydrodynamic models which employ a Glauber Monte Carlo initial state geometry with fluctuations, providing additional constraining power on the interplay between initial conditions and the effects of viscosity as the system evolves. This new constraint can serve to improve the precision of the extracted shear viscosity to entropy density ratio η/s.

Basic fibroblast growth factor inhibits osteogenic differentiation of stem cells from human exfoliated deciduous teeth through ERK signaling

OBJECTIVE

Stem cells from human exfoliated deciduous teeth (SHED) are a unique postnatal stem cell population capable of regenerating mineralized tissue and treating immune disorders. However, the mechanism that controls SHED differentiation is not fully understood. Here, we showed that basic fibroblast growth factor (bFGF) treatment attenuated SHED-mediated mineralized tissue regeneration through activation of the extracellular signal-regulated kinase (ERK) 1/2 pathway.

MATERIAL AND METHOD

The level of mineralized nodule formation was assessed by alizarin red staining. Expression levels of osteogenic genes, osteocalcin and runt-related transcription factor 2, were examined by RT-PCR. Subcutaneous implantation approach was used to assess in vivo bone formation. Downstream signaling pathways of bFGF were examined by Western blotting.

RESULT

Activation of ERK1/2 signaling by bFGF treatment inhibited WNT/β-catenin pathway, leading to osteogenic deficiency of SHED. ERK1/2 inhibitor treatment rescued bFGF-induced osteogenic differentiation deficiency.

CONCLUSION

These data suggest that bFGF inhibits osteogenic differentiation of SHED via ERK1/2 pathway. Blockade ERK1/2 signaling by small molecular inhibitor treatment improves bone formation of SHED after bFGF treatment.

Synthesis of BaCO3 nanowires and their humidity sensitive property

Barium carbonate (BaCO3) nanowires have been synthesized for the first time by using the composite hydroxide mediated (CHM) method. The products are characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). Humidity sensors based on BaCO3 nanowires have been fabricated. The response to humidity in static and dynamic measurement proves the ultrasensitive property of the sensors. The resistance changes from 386 M(omega) to 7.1 M(omega) as the relative humidity (RH) increases from 20% to 95%. The response and recovery time of the resistance is 16 s and 56 s versus the changes of relative humidity from 25% to 85%. These results indicate promising applications of BaCO3 nanowires in a highly sensitive environmental monitoring and humidity control electronic device.

Suppression of back-to-back hadron pairs at forward rapidity in d+Au collisions at √s(NN)=200 GeV

Back-to-back hadron pair yields in d+Au and p+p collisions at √s(NN)=200 GeV were measured with the PHENIX detector at the Relativistic Heavy Ion Collider. Rapidity separated hadron pairs were detected with the trigger hadron at pseudorapidity |η|<0.35 and the associated hadron at forward rapidity (deuteron direction, 3.0<η<3.8). Pairs were also detected with both hadrons measured at forward rapidity; in this case, the yield of back-to-back hadron pairs in d+Au collisions with small impact parameters is observed to be suppressed by a factor of 10 relative to p+p collisions. The kinematics of these pairs is expected to probe partons in the Au nucleus with a low fraction x of the nucleon momenta, where the gluon densities rise sharply. The observed suppression as a function of nuclear thickness, p(T), and η points to cold nuclear matter effects arising at high parton densities.

Cold nuclear matter effects on J/ψ yields as a function of rapidity and nuclear geometry in d+A collisions at sqrt[s(NN)]=200 GeV

We present measurements of J/ψ yields in d+Au collisions at sqrt[s(NN)]=200  GeV recorded by the PHENIX experiment and compare them with yields in p+p collisions at the same energy per nucleon-nucleon collision. The measurements cover a large kinematic range in J/ψ rapidity (-2.2<y<2.4) with high statistical precision and are compared with two theoretical models: one with nuclear shadowing combined with final state breakup and one with coherent gluon saturation effects. In order to remove model dependent systematic uncertainties we also compare the data to a simple geometric model. The forward rapidity data are inconsistent with nuclear modifications that are linear or exponential in the density weighted longitudinal thickness, such as those from the final state breakup of the bound state.

Abstract 869: Characterization of malignant melanoma families with CDK4 germ-line mutation

Background: CDKN2A (p16) and CDK4 are high-risk susceptibility genes for cutaneous melanoma. CDKN2A is the major identified high-risk gene and CDKN2A-mutated families have been extensively characterized. Melanoma families with CDK4 mutation are very rare. Only 10 such families have been published and a systematic investigation of their phenotype is lacking.

Aim of study: We evaluated all known CDK4-mutated families with regard to phenotypic features of their melanocytic disease. We also examined if common variants of the melanocortin-1 receptor (MC1R) gene had an effect on age of melanoma onset.

Methods: CDK4-melanoma families, previously ascertained by different research groups, were selected for this study either by contacting the authors of published papers or by requests via the GenoMEL Melanoma Genetics Consortium. Phenotypic data related to melanoma and pigmentation were collected via a standardized form. For all family members with available DNA, exon 2 of CDK4 and the complete coding region of the MC1R gene were sequenced.

Results: Thirteen CDK4 families (including three unpublished) were enrolled in the study. Altogether, 83 subjects with malignant melanoma, having a total of 125 melanomas, were verified in the pedigrees. The mean and median age of melanoma diagnosis was 38.5 years and 36.5 years, respectively. Of the 83 melanoma-positive subjects, 29 (34.9%) had multiple primary melanoma. Superficially spreading melanoma was the most common histological diagnosis (52.2%). DNA was available from 198 members of the pedigrees, and 81 tested positive for either the CDK4 R24H or R24C mutation; 117 subjects including 39 spouses tested negative. Subjects with the CDK4 mutation or with verified melanoma had a much higher prevalence of atypical nevi (79.5% and 77.2%, respectively) than CDK4-negative family members (26.0%; p&lt;0.001 for both groups). The pedigrees included only one verified case of pancreatic cancer, occurring in a non-tested subject with melanoma. There did not appear to be evidence for a predisposition to other non-melanoma cancers. The analysis of MC1R gene variants is ongoing.

Conclusion: CDK4-positive melanoma families are phenotypically similar to families with a CDKN2A mutation with regard to age of melanoma diagnosis, histological tumor type and the presence of atypical nevi/multiple melanomas. In a clinical setting, the CDK4 gene should therefore be examined if a melanoma family is negative for a CDKN2A mutation. Although based on only 13 CDK4 families, mutation carriers do not appear to have an increased predisposition to pancreatic cancer as noted in some pedigrees with CDKN2A mutations.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 869. doi:10.1158/1538-7445.AM2011-869

LeERF-1, a novel AP2/ERF family gene within the B3 subcluster, is down-regulated by light signals in Lithospermum erythrorhizon

We previously showed that ethylene might be involved in the process of shikonin biosynthesis regulated by light signals. Here, we cloned a full-length cDNA of LeERF-1, a putative ethylene response factor gene, from Lithospermum erythrorhizon using the RACE (rapid amplification of cDNA ends) method. Phylogenetic analysis revealed that LeERF-1 was classified in the B3 subfamily, together with ERF1 and ORA59 of Arabidopsis. Heterologous expression of LeERF-1 in Arabidopsis showed that LeERF-1:eGFP fusion protein was precisely localised to the nucleus, implying that it might function as a transcription factor. Detailed expression analysis with real-time PCR showed that LeERF-1 was significantly down-regulated by white, blue and red light, although the inhibitory effect of red light was relatively weak compared to other light conditions. Tissue-specific expression analysis also indicated that LeERF-1 was dominantly expressed in the roots, which grow in soil in darkness. These patterns are all consistent with the effects of different light signals on regulating formation of shikonin and its derivatives, indicating that LeERF-1 might be a crucial positive regulator, like other B3 subfamily proteins (such as ORCA3 and ORA59), in regulating biosynthesis of secondary metabolites.

Thermal Oxidation of Amorphous Silicon-Boron Alloy

The thermal oxidation of amorphous silicon-boron alloy (prepared by low pressure chemical vapor deposition) with boron contents ranged from 0–40% at a temperature range of 25- 700 °C has been carried out. Crystalline silicon and polycrystalline boron have also been studied for comparison purposes. The resultant thin oxide overlayers were characterized by X-ray photoelectron spectroscopy. It was found that both the oxidation of Si and of B are enhanced by mixing of the two elements. The oxidation of boron is significantly slower than silicon. During oxidation of silicon-boron alloy, preferential oxidation of silicon occurs at the oxide/bulk interface and the silicon oxide overlayer advances into the bulk faster than the boron oxide.

Cross section and parity-violating spin asymmetries of W± boson production in polarized p + p collisions at sqrt[s] = 500 GeV

Large parity-violating longitudinal single-spin asymmetries A(L)(e+) = -0.86(-0.14) (+0.30) and A(L)(e-) = 0.88(-0.71) (+0.12) are observed for inclusive high transverse momentum electrons and positrons in polarized p+p collisions at a center-of-mass energy of sqrt[s] = 500 GeV with the PHENIX detector at RHIC. These e± come mainly from the decay of W± and Z0 bosons, and their asymmetries directly demonstrate parity violation in the couplings of the W± to the light quarks. The observed electron and positron yields were used to estimate W± boson production cross sections for the e± channels of σ(pp → W+ X) × BR(W+ → e+ ν(e)) = 144.1 ± 21.2(stat)(-10.3) (+3.4) (syst) ± 21.6(norm)  pb, and σ(pp → W- X) × BR(W- → e- ν[over ¯](e)) = 31.7 ± 12.1(stat)(-8.2) (+10.1) (syst) ± 4.8(norm)  pb.