Experimental and theoretical screening of nanoscale oxide reactivity with LiBH4

Experimentation, thermodynamic modeling, and atomic modeling were combined to screen the reactivity of SiO2, Al2O3, and ZrO2 nanoscale oxides with LiBH4. Equilibrium thermodynamic modeling showed that the reactions of oxides with LiBH4 could lead to formation of stable Li-bearing oxide and metal boride phases. Experimentation was conducted to evaluate the discharge/recharge reaction products of nanoscale oxide-LiBH4 mixtures. Thermal gravimetric analyses-mass spectroscopy and x-ray diffraction revealed significant SiO2 destabilization of LiBH4 dehydrogenation, resulting in the formation of lithium silicate and boric acid. A smaller amount of lithium metaborate and boric acid was formed with Al2O3. No destabilization products were observed with ZrO2. Density functional theory atomic modeling predicted much stronger LiBH4 interfacial adsorption on the SiO2 and Al2O3 surfaces than on the ZrO2 surface, which was consistent with the experimental findings. Following dehydrogenation, interfacial Li atoms were predicted to strongly adsorb on the oxide surfaces effectively competing with LiH formation. The interfacial Li interactions with Al2O3 and ZrO2 were equal in strength in the fully hydrided and dehydrided states, so that their predicted net effect on LiBH4 dehydrogenation was insignificant. Zirconia was selected for nanoframework development based on the combined observations of compatibility and weaker associative interactions with LiBH4.

Phase II study of dasatinib in non-small cell lung cancer (NSCLC)

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Background: Lung cancer is the leading cause of cancer-related deaths. Better systemic therapies are needed. One potential therapeutic target is c-Src which is expressed and activated in NSCLC patient tumors where it can mediate invasion, angiogenesis, and proliferation. Additionally, epidermal growth factor receptor (EGFR) and c-Src cooperate to promote NSCLC survival. We are conducting a phase II study of dasatinib, a tyrosine kinase inhibitor of c-Src, Abl, c-Kit, PDGFR, Btk, and EphA2. The primary objective is to determine the rate of progression free survival at 12 weeks in patients with metastatic NSCLC treated with dasatinib as front line therapy. Methods: Patients with metastatic NSCLC were treated with dasatinib (100 mg BID), with PET/CT scans every 6 weeks. KRAS and EGFR mutations, EGFR copy number, and pSrc expression were measured in pre-treatment biopsies. Blood was collected pretreatment and on day 21 to measure drug exposure (PK), pharmacodynamics (PD), and serum cytokine levels. Results: Twenty five patients have enrolled on study. Of the 16 patients evaluable for response: 1 had a partial response (PR) with no evidence of recurrence for at least 18 months (male smoker with adenocarcinoma and KRAS mutation); 6 patients had stable disease (SD) which includes 3 patients with prolonged stable disease for 4, 6, and 18 months; 9 had progressive disease (PD). Only 4 patients had a significant change in SUV (>25%): decreased in 2 with PR and SD and increased in 2 with PD and SD. There is currently no clear association between EGFR and KRAS mutational analysis and response, although the sample number is small. Only 2 patients have activating EGFR mutations: one with SD and one with PD. PK, PD, and cytokine data will be presented. The most common grade 3/4 toxicity is dyspnea/pleural effusion that has led to a reduced dasatinib starting dose in subsequent patients. Conclusions: Dasatinib as a single agent has activity in a subset of patients with NSCLC. Planned correlative studies may lead to the discovery of biomarkers that predict response. Toxicities observed were consistent with prior dasatinib phase I studies in solid tumor patients. Supported by NCI/CTEP (NIH contract N01-CM-62202), The Commonwealth Foundation for Cancer Research and Bristol-Myers Squibb.

[Table: see text]

The clinical pathogensis significance associated with mutation of APC MCR in colorectal neoplasms

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Background: To explore the clinical pathogensis evalution of codon 1493,1367 and 1328 mutations in MCR (mutation cluster region) of exon 15 of APC (Adenomatous polyposis coli) gene in cases of colorectal neoplasm and the family history. Methods: The specimens from 21 colorectal adenoma specimens groups,16 colorectal carcinoma groups, 20 healthy germline groups with positive familial history and 8 healthy germline groups without familial history. MCR of APC gene were extracted and specificly amplified, then sequenced by sequencer, the codon mutations were analyzed between the 4 groups and various genotypes tested with Chi-square. Results: The codon mutations were three variations: 1493(ACG > ACA), 63/69(91.3%); 1367(CAG > TAG), 1/69(1.4%) and 1328(CAG>TAG), 5/69(7.2%). The allele mutations were checked out four genotypes such as 4478(G→A), 41/69(59.4%); 4478(G/A), 22/69(31.9%); 4096(C/T), 1/69 (1.4%) and 3979(C/T), 5/69(7.2%); but the significant groups status (P<0.05) were shown between the adenoma and nonfamily history group on the analysis of 4478(G→A) and (G/A), also the significant differences were tested between the with and without family history on the analysis of 4478(G→A). The significant differences (P<0.05) in pathogensis mutant phenotypes were involved between 4478(G→A) with 4478(G/A), 4096(C/T) and 3979(C/T), respectively; also showed between 4478(G/A) with 4096(C/T) and 3979(C/T); but not between 4096(C/T) and 3979(C/T) (P>0.05). Conclusions: In our data, the highest mutant frequency 4478(G→A) of 1493(ACG>ACA) presented to the significant phenotype of positive history and adenoma, but 4478 (G/A) were associated with colorectal adenocancer, which was discovered in the different effect to candidators despite the same synonymous mutation. In researches, APC MCR codon 1367 and 1328 genotyping were significantly presented in the colorectal cancergenetic phenotypes in somatic cells only.

No significant financial relationships to disclose.

Correlation between K-ras mutations status and benefit from cetuximab treatment in advanced colorectal cancer

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Background: Cetuximab is a monoclonal antibody that specifically blocks the EGFR. We follow -up study the efficacy and toxicity of cetuximab with chemotherapy in the treatment of advanced colorectal cancer from Chinese in East China. Methods: We analyzed tumor samples from 120 patients with advanced colorectal cancer by direct sequencing, to observe the mutations status in exon 2,3 of K-ras gene. And 30 patients were followed up according the RECIST standard for their treatment outcome of cetuximab plus chemotherapy at 2 -12 months. Results: K-ras mutations were identified in 48 of 120(40%) patients with colorectal cancer in exon2, which including 8 mutation types; 38/48(79.2%) mutations in 12 codon(G12D 43.7%,G12V 25%,G12C 10.4%,G12R 6%,G12S 4%,G12A 2%) and 10/48(18.7%) in 13 codon(G13D 18.7%,G13C 2%). None mutation was found in 61codon of exon3. we observed the clinical efficacy of 30 patients treated by cetuximab plus chemotherapy, of 21 patients with wild-type K-ras tumors as compared with 9 patients with mutated K-ras significantly improved the response rate (5/21 21.8% vs 1/9 11.1%,P<0.01)and the disease control rate (19/21 90.4% vs,2/9 22.2%,P<0.01). There were a few patients with mutated K-ras tumors benefit from cetuximab, in which the fluorescence intensity of mutation cells of all detected tumor tissue approach to 1:3 status by sequencing analysis. The major toxicities of treatment were acne-like rash, which were found in 14/21(66.6%)of patients with wild-type K- ras, and 5/9(55.5%)of patients with mutated K-ras . Conclusions: The East-China patients share the same (40%) mutation frequency and type of k-ras gene with other races . Patients with wild type K-ras mutation have significantly higher Response rate and disease control rate on cetuximab plus chemotherapy treatment .Our results once again show that somatic mutations status of k-ras is a major determinant of cetuximab response in advanced colorectal cancer. There was no statistical correlation between acne-like rash of the major toxicities and mutations status of k-ras. There were a few patients bearing mutated k-ras did benefit from cetuximab, that would need to be validation between Chinese or Ethnicity association phenotype by a large numbers of samples.

No significant financial relationships to disclose.

Endoprosthetic replacement for primary tumours around the knee: experience from Peking University

In developing countries locally-made low-cost prostheses are mainly used in limb-salvage surgery to alleviate the economic burden. We retrospectively collected data on 104 patients treated by limb-salvage surgery between July 1997 and July 2005. We used a locally-designed and fabricated stainless-steel endoprosthesis in each case. Oncological and functional outcomes were evaluated at a mean follow-up of 47 months (12 to 118). A total of 73 patients (70.2%) were free from disease, nine (8.7%) were alive with disease, 19 (18.2%) had died from their disease and three (2.9%) from unrelated causes. According to the Musculoskeletal Tumor Society scoring system, the mean functional score was 76.3% (SD 17.8). The five-year survival for the implant was 70.5%. There were nine cases (8.7%) of infection, seven early and two late, seven (6.7%) of breakage of the prosthesis, three (2.9%) of aseptic loosening and two (1.9%) of failure of the polyethylene bushing. Multivariate analysis showed that a proximal tibial prosthesis and a resection length of 14 cm or more were significant negative prognostic factors. Our survival rates and Musculoskeletal Tumor Society functional scores are similar to those reported in the literature. Although longer follow-up is needed to confirm our results, we believe that a low-cost custom-made endoprosthesis is a cost-effective and reliable reconstructive option for limb salvage in developing countries.

Anomalous line shape of the cross section for e{+}e{-}--> hadrons in the center-of-mass energy region between 3.650 and 3.872 GeV

We observe an obvious anomalous line shape of the e;{+}e;{-}--> hadrons total cross sections in the energy region between 3.700 and 3.872 GeV. It is inconsistent with the explanation for only one simple psi(3770) resonance with a statistical significance of 7sigma. The anomalous line shape may be explained by two possible enhancements of the inclusive hadron production near the center-of-mass energies of 3.764 and 3.779 GeV, indicating that either there is likely a new structure in addition to the psi(3770) resonance around 3.773 GeV, or there are some physics effects reflecting the DD[over ] production dynamics.

Genetic susceptibility and haplotype analysis between Fcγ receptor IIB and IIIA gene with systemic lupus erythematosus in Chinese population

The objective of this study is to understand the role of FcγRIIB and FcγRIIIA gene in susceptibility to systemic lupus erythematosus (SLE), and to examine possible susceptible haplotypes between two genes. A total of 119 patients with SLE from 95 nuclear families, aged from 14 to 78 years, were selected according to 1997 criteria of American College of Rheumatology. In addition, 316 family members of these patients were also genotyped. A family-based association study was used to explore the relationship between gene polymorphism and SLE. We studied 13 single-nucleotide polymorphisms (SNPs) encoding non-synonymous substitution in the FcγRIIB and FcγRIIIA gene (four SNPs in the FcγRIIB gene and nine SNPs in the FcγRIIIA gene) with respect to genetic susceptibility to SLE. All SNPs were genotyped by restriction fragment length polymorphism method. Among 13 SNPs, univariate (single-marker) family-based association tests showed that variant alleles at only four SNPs (rs10917661 and rs1050501, in exon 2 and exon 5 of FcγRIIB gene, rs403016 and rs428888, in exon3 of FcγRIIIA gene respectively) were significantly associated with genetic susceptibility to SLE. Furthermore, the haplotype-specific FBATs showed 50Ter-225Thr (34.1%, in FcγRIIB gene) and 72Arg-118Asn (40%, in the FcγRIIIA gene) haplotype were more frequently transmitted in SLE than other haplotypes ( Z = 3.539, P = 0.00042; Z = 2.678, P = 0.007412 respectively). But haplotypes were not found between FcγRIIB and FcγRIIIA gene Our results suggest that there were meaningful haplotype in FcγRIIIA and FcγRIIB gene respectively. FcγRIIIA and FcγRIIB genes in the pathogenesis of SLE may play an independent role in Chinese population.

Validation of the simplified Chinese version of EORTC QLQ-C30 from the measurements of five types of inpatients with cancer

BACKGROUND

European Organization for Research and Treatment quality of life (QOL) questionnaire (QLQ-C30) has been used frequently and many language versions have been developed, including the simplified Chinese version. It is important to study psychometric properties of the simplified Chinese version from the clinical standpoint.

PATIENTS AND METHODS

The simplified Chinese version of the QLQ-C30 was used in a longitudinal study of 600 patients with five types of cancer: lung, breast, head and neck, colorectal, and stomach. The psychometric properties of the scale were evaluated by indicators of validity and reliability coefficients such as Cronbach's alpha and Pearson's correlation coefficient r, standardized response mean (SRM), correlational analysis, t-tests, and structural equation models.

RESULTS

Correlation and structural equation model analyses confirmed good construct validity with root mean square error of approximation 0.054, standardized root mean square residual 0.037, non-normed fit index 0.972, and comparative fit index 0.980. The alpha coefficients for all domains are >0.7 except for cognitive functioning (0.49). The test-retest reliability coefficients for most domains are >0.80 except for appetite loss (0.77) and diarrhea (0.75). The QOL score changes after treatments were of statistical significance with higher or moderate SRM in most domains.

CONCLUSION

The simplified Chinese version of QLQ-C30 has good validity, reliability, and responsiveness and can be used to measure QOL for Chinese cancer patients.

Perpendicular spin torques in magnetic tunnel junctions

We quantitatively determine a perpendicular spin torque in magnetic tunnel junctions by measuring the room-temperature critical switching current at various magnetic fields and current pulse widths. We find that the magnitude of the torque is proportional to the product of the current density and the bias voltage, and the direction of the torque reverses as the polarity of the voltage changes. By taking into account the energy-dependent inelastic scattering of tunnel electrons, we formulate the bias dependence of the perpendicular spin torque which is in qualitative agreement with the experimental results.

Search for the invisible decay of J/psi in psi(2S) --> pi(+)pi(-) J/psi

Using psi(2S) --> pi(+)pi(-) J/psi events in a sample of 14.0 x 10(6) psi(2S) decays collected with the BES-II detector, a search for the decay of the J/psi to invisible final states is performed. No signal is found, and an upper limit at the 90% confidence level is determined to be 1.2 x 10(-2) for the ratio B(J/psi --> invisible)/B(J/psi-->mu(+)mu(-)). This is the first search for J/psi decays to invisible final states.