Epitaxial highly ordered Sb:SnO2 nanowires grown by the vapor liquid solid mechanism on m-, r- and a-Al2O3

Epitaxial, highly ordered Sb:SnO2 nanowires were grown by the vapor-liquid-solid mechanism on m-, r- and a-Al2O3 between 700 °C and 1000 °C using metallic Sn and Sb with a mass ratio of Sn/Sb = 0.15 ± 0.05 under a flow of Ar and O2 at 1 ± 0.5 mbar. We find that effective doping and ordering can only be achieved inside this narrow window of growth conditions. The Sb:SnO2 nanowires have the tetragonal rutile crystal structure and are inclined along two mutually perpendicular directions forming a rectangular mesh on m-Al2O3 while those on r-Al2O3 are oriented in one direction. The growth directions do not change by varying the growth temperature between 700 °C and 1000 °C but the carrier density decreased from 8 × 1019 cm-3 to 4 × 1017 cm-3 due to the re-evaporation and limited incorporation of Sb donor impurities in SnO2. The Sb:SnO2 nanowires on r-Al2O3 had an optical transmission of 80% above 800 nm and displayed very long photoluminescence lifetimes of 0.2 ms at 300 K. We show that selective area location growth of highly ordered Sb:SnO2 nanowires is possible by patterning the catalyst which is important for the realization of novel nanoscale devices such as nanowire solar cells.

Bone metastases in biliary cancers: A multicenter retrospective survey

•Natural history of biliary cancers metastatic to bone•The role of skeletal events in patients with biliary cancer•Biliary cancer and bone metastases: role of bisphosphonates.

HER2 loss in HER2-positive gastric or gastroesophageal cancer after trastuzumab therapy: Implication for further clinical research

Mechanisms of acquired resistance to trastuzumab-based treatment in gastric cancer are largely unknown. In this study, we analyzed 22 pairs of tumor samples taken at baseline and post-progression in patients receiving chemotherapy and trastuzumab for advanced HER2-positive [immunohistochemistry (IHC) 3+ or 2+ with in-situ hybridization (ISH) amplification] gastric or gastroesophageal cancers. Strict clinical criteria for defining acquired trastuzumab resistance were adopted. Loss of HER2 positivity and loss of HER2 over-expression were defined as post-trastuzumab IHC score <3+ and absence of ISH amplification, and IHC "downscoring" from 2+/3+ to 0/1+, respectively. HER2 IHC was always performed, while ISH was missing in 3 post-progression samples. Patients with initial HER2 IHC score 3+ and 2+ were 14 (64%) and 8 (36%), respectively. Loss of HER2 positivity and HER2 over-expression was observed in 32 and 32% samples, respectively. The chance of HER2 loss was not associated with any of the baseline clinicopathological variables. The only exception was in patients with initial IHC score 2+ versus 3+, for both endpoints of HER2 positivity (80 vs. 14%; p = 0.008) and HER2 over-expression (63 vs. 14%; p = 0.025). As already shown in breast cancer, loss of HER2 may be observed also in gastric cancers patients treated with trastuzumab-based chemotherapy in the clinical practice. This phenomenon may be one of the biological reasons explaining the failure of anti-HER2 second-line strategies in initially HER2-positive disease.

Mesostructured silica and aluminosilicate carriers for oxytetracycline delivery systems

Oxytetracycline delivery systems containing various MCM-type silica and aluminosilicate with different antibiotic content were developed in order to establish the influence of the support structural and textural properties and aluminum content on the drug release profile. The antibiotic molecules were loaded into the support mesochannels by incipient wetness impregnation method using a drug concentrated aqueous solution. The carriers and drug-loaded materials were investigated by small- and wide-angle XRD, FTIR spectroscopy, TEM and N2 adsorption-desorption isotherms. Faster release kinetics of oxytetracycline from uncalcined silica and aluminosilicate supports was observed, whereas higher drug content led to lower delivery rate. The presence of aluminum into the silica network also slowed down the release rate. The antimicrobial assays performed on Staphylococcus aureus clinical isolates showed that the oxytetracycline-loaded materials containing MCM-41-type mesoporous silica or aluminosilicate carriers inhibited the bacterial development.

Gelatin–poly(vinyl alcohol) porous biocomposites reinforced with graphene oxide as biomaterials

The present work aims to develop new biocomposites based on gelatin (Gel) and poly(vinyl alcohol) (PVA) reinforced with graphene oxide (GO).

Capecitabine with/without mitomycin C: results of a randomized phase II trial of second-line therapy in advanced biliary tract adenocarcinoma

PURPOSE

Advanced biliary tract adenocarcinoma (BTA) is a rare tumor with a poor prognosis. Since no standard salvage chemotherapy regimen exists, we explored the activity of capecitabine alone or combined with mitomycin C.

METHODS

Patients aged 18-75 years and with KPS >50, with pathological diagnosis of BTA stratified based on site and stage of disease, were randomized to receive capecitabine 2000 mg/m(2) day 1-14 alone (ARM A) or in combination with mitomycin C 6 mg/m(2) day 1 (ARM B) as second-line therapy. Cycles were repeated in both arms every 3 weeks. Tumor assessment was performed every 2 months. The primary endpoint was the probability of being progression free at 6 months (PFS-6) from treatment start. According to the Fleming design, the study aimed to enroll 26 pts per arm. An exploratory endpoint was to assess thymidylate synthase (TS) and thymidine phosphorylase (TP) expression, as biomarkers predictive for clinical outcomes of capecitabine treatment.

RESULTS

Between October 2011 and 2013, 57 metastatic pts were enrolled: ARM A/B 28/29. Accordingly, 55 (26/29) pts were assessable for the primary endpoint: 2 (8%) ARM A and 3 (10%) ARM B pts were PFS-6. Main G3-4 toxicities were: hand-foot syndrome and transaminitis in 4/0%, and thrombocytopenia, diarrhea and fatigue in 0/3% of pts. No statistically significant correlation was found between TS or TP expression and pts' outcome.

CONCLUSIONS

Since capecitabine yielded a disappointing outcome and the addition of mitomycin C did not improve the results, new therapeutic strategies need to be explored to improve survival in this disease setting.