Growth of optical-quality anthracene crystals doped with dibenzoterrylene for controlled single photon production

Dibenzoterrylene (DBT) molecules within a crystalline anthracene matrix show promise as quantum emitters for controlled, single photon production. We present the design and construction of a chamber in which we reproducibly grow doped anthracene crystals of optical quality that are several mm across and a few μm thick. We demonstrate control of the DBT concentration over the range 6-300 parts per trillion and show that these DBT molecules are stable single-photon emitters. We interpret our data with a simple model that provides some information on the vapour pressure of DBT.

The combination of axitinib followed by paclitaxel/carboplatin yields extended survival in advanced BRAF wild-type melanoma: results of a clinical/correlative prospective phase II clinical trial

BACKGROUND

Simultaneous chemotherapy with vascular endothelial growth factor (VEGF) inhibition has not shown additional benefit over chemotherapy alone in advanced melanoma. We tested administration of the potent VEGF inhibitor axitinib followed by paclitaxel/carboplatin to determine whether enhanced tumour proliferation during axitinib withdrawal leads to sustained chemosensitivity.

METHODS

We conducted a prospective phase II trial in metastatic melanoma patients with ECOG performance status 0-1 and normal organ function. Axitinib 5 mg PO b.i.d. was taken on days 1-14 of each 21-day treatment cycle, and carboplatin (AUC=5) with paclitaxel (175 mg m(-2)) was administered on day 1 starting with cycle 2. 3'-Deoxy-3'-(18)F-fluorothymidine ((18)F-FLT)-PET scans were performed in five patients to assess tumour proliferation on days 1, 14, 17, and 20 of cycle 1. Molecular profiling for BRAF was performed for all patients with cutaneous, acral, or mucosal melanoma.

RESULTS

The treatment was well tolerated. The most common grade 3 AEs were hypertension, neutropenia, and anaemia. Grade 4 non-haematologic AEs were not observed. Four of five patients completing (18)F-FLT-PET scans showed increases (23-92%) in SUV values during the axitinib holiday. Of 36 evaluable patients, there were 8 confirmed PRs by Response Evaluation Criteria in Solid Tumors. Overall, 20 patients had SD and 8 had PD as the best response. The median PFS was 8.7 months and the median overall survival was 14.0 months. Five BRAF(V600E/K) patients had significantly worse PFS than patients without these mutations.

CONCLUSIONS

Axitinib followed by carboplatin and paclitaxel was well tolerated and effective in BRAF wild-type metastatic melanoma. 3'-Deoxy-3'-(18)F-fluorothymidine-PET scans showed increased proliferation during axitinib withdrawal.

Electron-boson spectral density of LiFeAs obtained from optical data

We analyze existing optical data in the superconducting state of LiFeAs at T = 4 K, to recover its electron-boson spectral density. A maximum entropy technique is employed to extract the spectral density I(2)χ(ω) from the optical scattering rate. Care is taken to properly account for elastic impurity scattering which can importantly affect the optics in an s-wave superconductor, but does not eliminate the boson structure. We find a robust peak in I(2)χ(ω) centered about Ω(R) ≅ 8.0 meV or 5.3 k(B)Tc (with Tc = 17.6 K). Its position in energy agrees well with a similar structure seen in scanning tunneling spectroscopy (STS). There is also a peak in the inelastic neutron scattering (INS) data at this same energy. This peak is found to persist in the normal state at T = 23 K. There is evidence that the superconducting gap is anisotropic as was also found in low temperature angular resolved photoemission (ARPES) data.

Delayed hematopoietic recovery after auto-SCT in patients receiving arsenic trioxide-based therapy for acute promyelocytic leukemia: a multi-center analysis

A potential link between arsenic (ATO)-based therapy and delayed hematopoietic recovery after autologous hematopoietic SCT (HSCT) for acute promyelocytic leukemia (APL) has previously been reported. We retrospectively reviewed the clinical histories of 58 patients undergoing autologous HSCT for APL at 21 institutions in the United States and Japan. Thirty-three (56%) of the patients received ATO-based therapy prior to stem cell collection. Delayed neutrophil engraftment occurred in 10 patients (17%): 9 of the 10 patients (90%) received prior ATO (representing 27% of all ATO-treated patients), compared with 1 of the 10 patients (10%) not previously treated with ATO (representing 4% of all ATO-naïve patients; P<0.001). Compared with ATO-naïve patients, ATO-treated patients experienced significantly longer times to ANC recovery (median 12 days vs 9 days, P<0.001). In multivariate analysis, the only significant independent predictor of delayed neutrophil engraftment was prior treatment with ATO (hazard ratio 4.87; P<0.001). Of the available stem cell aliquots from APL patients, the median viable post-thaw CD34+ cell recovery was significantly lower than that of cryopreserved autologous stem cell products from patients with non-APL AML. Our findings suggest that ATO exposure prior to CD34+ cell harvest has deleterious effects on hematopoietic recovery after autologous HSCT.

Single dipole evanescently coupled to a multimode waveguide

We consider a single dipole evanescently coupled to a cylindrical multimode waveguide. The emission rate into the waveguide is calculated as a function of the waveguide diameter and the dipole orientations, and the result is confirmed by finite-difference-time-domain simulations. We show that as the guide radius increases, the coupling to a given mode decreases but new decay channels to higher order modes open up to increase the density of states. This study gives insight for designing waveguide-based single photon sources that exploit superposition of transverse modes.

Physical activity and its related motivational attributes in adolescents with different BMI

BACKGROUND

A number of obesity studies have been focused on identifying the relationships between socioeconomic status and physical activity involvement. In behavioral medicine, the limited data are available on obese people's physical activity and its related psychological predictors based on psychological theories.

PURPOSE

To identify the differences in physical activity and its related motivational attributes among normal weight, overweight, and obese adolescents and to find the effect of body mass index (BMI) and the Self-Determination Theory (SDT) constructs in predicting physical activity.

METHOD

One thousand seventy-one students ranging from seventh to ninth grades were randomly selected from three junior high schools in Seoul (359 normal weight students, 468 overweight students, and 244 obese students). A Korean version of Behavioral Regulation in Exercise Questionnaire-2 and Leisure Time Exercise Questionnaire were applied to measure the participants' motivational attributes and physical activity.

RESULTS

Overweight and obese adolescents showed higher scores on amotivation and externally motivated regulations for physical activity than their normal weight counterparts. Internal regulation was more significant for physical activity in normal weight adolescent. However, there was no difference in physical activity among the three groups. Additionally, the findings identified that BMI and the SDT constructs were significant to explain physical activity.

CONCLUSION

This study offers fundamental knowledge in gaining a clearer understanding of the types of motivation most likely to contribute to the initiation and promotion of physical activity in overweight and obese adolescents.

Deriving the electron-phonon spectral density of MgB2 from optical data, using maximum entropy techniques

We use maximum entropy techniques to extract an electron-phonon density from optical data for the normal state at T = 45 K of MgB2. Limiting the analysis to a range of phonon energies below 110 meV, which is sufficient for capturing all phonon structures, we find a spectral function that is in good agreement with that calculated for the quasi-two-dimensional σ-band. Extending the analysis to higher energies, up to 160 meV, we find no evidence for any additional contributions to the fluctuation spectrum, but find that the data can only be understood if the density of states is taken to decrease with increasing energy.

Abstract P3-14-12: Risk factors for local regional recurrence in patients undergoing breast conserving surgery following neoadjuvant chemotherapy and validation of the MD Anderson prognostic index

Background: Breast conserving surgery (BCS) is a primary goal of neoadjuvant chemotherapy (NAC) in patients with locally advanced breast cancer, especially with recent improvements in tumor response. Patient selection for BCS following NAC may be different than classic local regional recurrence (LRR) risk factors. Here we investigate risk factors for LRR and attempt to validate the MD Anderson Prognostic Index (MDAPI) for LRR in a single institution series.

Methods: Data were analyzed for 178 consecutive patients treated at one institution who underwent NAC followed by BCS and whole breast radiotherapy between the years 1999 and 2011. Using univariate and multivariate analysis, multiple clinicopathologic factors were investigated, as well as the subgroups of the MDAPI. Chi-square tests were used to compare the LRR-free survival rates between subgroups.

Results: The median follow-up was 70.33 months and the 5-year LRR-free survival was 93.18%. Multivariate analysis demonstrated that clinical stage and pathologic stage were both statistically significant for LRR-free survival, while pattern of residual disease was of borderline statistical significance. The MDAPI was not significantly associated with LRR-free survival (MDAPI low 93.80%, Intermediate 88.23%, High 88.89%).

Five-Year Local Regional Recurrence -Free Survival According to Clinicopathologic Factors # Patients5yr LRR-Free SurvivalPathologic Stage p = 0.03301580.0%14292.5%27692.5%3994.6%pCR38100%Clinical Stage p = 0.0291580.0%213796.3%33883.8%MDAPI Score P = 0.506Low (0 or 1)12993.80%Int (2)3488.23%High (3)988.89%*MDAPI Score Factors  cN Stage P = 0.305cN0-N116593.3%cN2-N31070%LVI P = 0.453No-LVI15793.5%Yes-LVI2390.9%pT&gt;2cm P = 0.158Residual Tumor Morphology P = 0.055Multifocal Resid Tumor5996.5%Solitary Mass6690.6%No Resid Tumor5394.3%*These factors make up the MDA Prognostic Index

Conclusion: Overall the 5-year LRR-free survival was high at 93.18%, which compares favorably to similar neoadjuvant patient cohorts who receive mastectomy instead of BCS. Our analysis indicates clinical stage and pathologic stage are significant in predicting LRR. Of the four predictive factors utilized by the MDAPI, only multifocal residual disease showed weak predictive power (p = 0.055) in our population; however, it correlated with higher LRR-free survival, the opposite of its indication in the MDAPI. The MDAPI was not useful in our patient population; the risk groups did not significantly correlate with LRR-free survival. This may be secondary to low total number of recurrence events and also the small number of patients in the MDAPI-high group (9 patients had an MDAPI score of 3, and none had a score of 4). As further data emerge regarding biology of tumors and recurrence, it may be a combination of molecular profiling and residual cancer burden that is a better predictor for LRR.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-14-12.

Risk factors for anemia in children under 6 years of age in Ethiopia: analysis of the data from the cross-sectional Malaria IndicatorSurvey, 2007

BACKGROUND

Malaria is a leading cause of morbidity in Ethiopia. However, its transmission varies in both space and time, and large areas of the country are hypoendemic and epidemic-prone. The Ethiopia National Malaria Indicator Survey 2007 is a cross-sectional, nationally-representative household survey. The objective of the analyses presented here were to use the survey's data to identify factors associated with anemia presence in children under 6 years of age (U6); specifically, investigate the association between malaria and anemia; and discuss using anemia as a malaria proxy biomarker in the Ethiopian hypo-endemic transmission setting.

METHODS

The survey sampled 4185 households in 347 enumeration areas ≤2500 m above sea level. Primary outcome was increasing anemia severity in sampled children: no anemia (Hb: ≥11g/dl); mild anemia (Hb: ≥8g/dl and <11g/dl); and moderate-severe anemia (Hb: <8g/dl). Secondary outcomes were positive malaria rapid diagnostic test (RDT) or blood slide microscopy.

RESULTS

The analysis included 6054 (92.0%) children U6 in 3962 households. The proportion of children with no anemia, mild anemia, and moderate-severe anemia was 63.6%, 31.3%, and 5.1%, respectively. The overall prevalence of anemia (Hb <11g/dl) was 36.4% (95% CI 34.4-38.4). Factors independently associated with reduced relative odds of anemia categories were age (OR=0.7, 95% CI 0.7-0.7) and female sex (OR=0.9, 95% CI 0.8-1.0); malaria RDT positivity was associated with increased relative odds of a more severe anemia category (OR=5.8, 95% CI 3.7-9.2).

CONCLUSIONS

We conclude that at altitudes ≤2500 m malaria appears to be a significant risk factor for anemia; potentially anemia could be used as a useful proxy biomarker for malaria and its control in Ethiopia.

Gadoxetic acid-enhanced MRI for T-staging of gallbladder carcinoma: emphasis on liver invasion

OBJECTIVE

To evaluate the diagnostic performance of gadoxetic acid-enhanced MRI with an emphasis on the usefulness of the hepatobiliary phase (HBP) in T-staging of gallbladder carcinoma.

METHODS

66 patients with surgically confirmed gallbladder carcinoma underwent MRI. Two radiologists independently reviewed two sets of gadoxetic acid-enhanced MRI without and with the HBP. Local tumour spread was evaluated according to T-staging, and the results were compared with pathological findings. The diagnostic performance of two image sets to differentiate each T-stage was compared.

RESULTS

The sensitivities of MRI with the HBP to differentiate T1 vs ≥ T2 lesions, ≤ T2 vs ≥ T3 lesions and ≤ T3 vs T4 lesions were 96.3%, 85.7% and 100% for Observer 1 and 92.6%, 95.2% and 100% for Observer 2, respectively (p<0.0001). By adding the HBP, the sensitivities to differentiate ≤ T2 vs ≥ T3 lesions were increased from 66.7% to 85.7% for Observer 1 and from 81.0% to 95.2% for Observer 2, although there was no significant difference (p>0.05). The overall accuracies for T-staging were increased from 80.3% to 86.4% for Observer 1, a statistically significant degree (p=0.046), and from 83.8% to 87.9% for Observer 2 (p>0.05). The k-value for the two observers indicated excellent agreement.

CONCLUSION

Gadoxetic acid-enhanced MRI provided acceptable diagnostic performance for T-staging of gallbladder carcinoma. Addition of the HBP aids in the detection of liver invasion.

ADVANCES IN KNOWLEDGE

In the T-staging of gallbladder carcinoma, gadoxetic acid-enhanced MRI with the HBP may enhance detection of liver invasion.

A phase 1 trial of imatinib, bevacizumab, and metronomic cyclophosphamide in advanced colorectal cancer

Background:

This phase 1 clinical trial was conducted to determine the safety, maximum-tolerated dose (MTD), and pharmacokinetics of imatinib, bevacizumab, and metronomic cyclophosphamide in patients with advanced colorectal cancer (CRC).

Methods:

Patients with refractory stage IV CRC were treated with bevacizumab 5 mg kg⁻¹ i.v. every 2 weeks (fixed dose) plus oral cyclophosphamide q.d. and imatinib q.d. or b.i.d. in 28-day cycles with 3+3 dose escalation. Response was assessed every two cycles. Pharmacokinetics of imatinib and cyclophosphamide and circulating tumour, endothelial, and immune cell subsets were measured.

Results:

Thirty-five patients were enrolled. Maximum-tolerated doses were cyclophosphamide 50 mg q.d., imatinib 400 mg q.d., and bevacizumab 5 mg kg⁻¹ i.v. every 2 weeks. Dose-limiting toxicities (DLTs) included nausea/vomiting, neutropaenia, hyponatraemia, fistula, and haematuria. The DLT window required expansion to 42 days (1.5 cycles) to capture delayed toxicities. Imatinib exposure increased insignificantly after adding cyclophosphamide. Seven patients (20%) experienced stable disease for >6 months. Circulating tumour, endothelial, or immune cells were not associated with progression-free survival.

Conclusion:

The combination of metronomic cyclophosphamide, imatinib, and bevacizumab is safe and tolerable without significant drug interactions. A subset of patients experienced prolonged stable disease independent of dose level.