ABSTRACT
We report on our design of a scanning gate microscope housed in a cryogen-free dilution refrigerator with a base temperature of 15 mK. The recent increase in efficiency of pulse tube cryocoolers has made cryogen-free systems popular in recent years. However, this new style of cryostat presents challenges for performing scanning probe measurements, mainly as a result of the vibrations introduced by the cryocooler. We demonstrate scanning with root-mean-square vibrations of 0.8 nm at 3 K and 2.1 nm at 15 mK in a 1 kHz bandwidth with our design. Using Coulomb blockade thermometry on a GaAs/AlGaAs gate-defined quantum dot, we demonstrate an electron temperature of 45 mK.
Subject(s)
Microscopy, Electron, Scanning/instrumentation , Microscopy, Scanning Tunneling/instrumentation , Cryopreservation , Electrons , Equipment Design , Freezing , Magnetics , Microscopy, Atomic Force/instrumentation , Microscopy, Atomic Force/methods , Microscopy, Electron, Scanning/methods , Microscopy, Scanning Tunneling/methods , Oscillometry/methods , TemperatureABSTRACT
A weekly administration of alternating irinotecan or oxaliplatin associated to 5-Fluorouracil in advanced colorectal cancer was planned in order to evaluate a new schedule maintaining dose intensities of each drug as in double combinations and tolerability of the triplet association. The following weekly schedule was administered: irinotecan, days 1 and 15; oxaliplatin, days 8 and 22; 5-fluorouracil (5-FU) over 12-h (from 10:00 p.m. to 10:00 a.m.) timed flat infusion, days 1-2, 8-9, 15-16 and 22-23, every 4 weeks. Dose- finding and phase II study were planned. Thirteen patients were enrolled in the dose-finding study and 23 in the phase II study. The recommended doses of our study are: irinotecan 160 mg/m(2); oxaliplatin 80 mg/m(2); 5-FU 900 mg/m(2). The dose-limiting toxicity was diarrhea (35% of patients) but no cases of febrile neutropenia were observed. In 30 patients assessable for response two complete (6.7%) and 18 partial (60%) responses were observed, for an overall response rate of 66.7% (alpha 0.05, CI+/-17). The triplet association using this weekly alternating schedule is an active and well-tolerated outpatient regimen. Surgical removal of residual disease was considered in 5 patients and a radical resection was performed in 5 patients (147 %).
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Colorectal Neoplasms/drug therapy , Liver Neoplasms/drug therapy , Lung Neoplasms/drug therapy , Adult , Aged , Camptothecin/administration & dosage , Camptothecin/analogs & derivatives , Colorectal Neoplasms/pathology , Dose-Response Relationship, Drug , Female , Fluorouracil/administration & dosage , Humans , Irinotecan , Liver Neoplasms/secondary , Lung Neoplasms/secondary , Lymphatic Metastasis , Male , Maximum Tolerated Dose , Middle Aged , Organoplatinum Compounds/administration & dosage , Oxaliplatin , Survival Rate , Treatment OutcomeABSTRACT
Using Monte Carlo simulations and experimental results, we show that for common thin film deposition techniques, such as sputter deposition and chemical vapor deposition, a mound structure can be formed with a characteristic length scale, or "wavelength" lambda, that describes the separation of the mounds. We show that the temporal evolution of lambda is distinctly different from that of the mound size, or lateral correlation length xi. The formation of a mound structure is due to nonlocal growth effects, such as shadowing, that lead to the breakdown of the self-affinity of the morphology described by the well-established dynamic scaling theory. We show that the wavelength grows as a function of time in a power law form, lambda approximately t(p), where p approximately equals 0.5 for a wide range of growth conditions, while the mound size grows as xi approximately t(1-z), where 1/z varies depending on growth conditions.
