Search results for "sensitive"
showing 10 items of 210 documents
On risk sensitive control of regular step Markov processes
2001
Ionic Transport through Chemically Functionalized Hydrogen Peroxide-Sensitive Asymmetric Nanopores
2015
We describe the fabrication of a chemical-sensitive nanofluidic device based on asymmetric nanopores whose transport characteristics can be modulated upon exposure to hydrogen peroxide (H2O2). We show experimentally and theoretically that the current-voltage curves provide a suitable method to monitor the H2O2-mediated change in pore surface characteristics from the electronic readouts. We demonstrate also that the single pore characteristics can be scaled to the case of a multipore membrane whose electric outputs can be readily controlled. Because H2O2 is an agent significant for medical diagnostics, the results should be useful for sensing nanofluidic devices.
Two Structurally Distinct Pathways for the Voltage-Sensing S4 Helices
2010
In voltage-dependent ion channels, the movement of the voltage-sensing S4 helices produces gating currents. The charge displaced as a function of the membrane potential (Q-V) is well described by a sequential two-state Boltzmann relation, indicating that there are at least two steps of gating charge movement from their Resting state to the Active state. In addition, it has been shown that at a maintained positive potential, the S4 helices of voltage-gated Na, Ca and K channels and the voltage sensitive phosphatase Ci-VSP, undergo a slower secondary conformational transition stabilizing the sensor in a Relaxed (inactivated) state. From the Relaxed state, the Q-V relation exhibits a strong sh…
G protein-coupled odorant receptors underlie mechanosensitivity in mammalian olfactory sensory neurons
2014
Mechanosensitive cells are essential for organisms to sense the external and internal environments, and a variety of molecules have been implicated as mechanical sensors. Here we report that odorant receptors (ORs), a large family of G protein-coupled receptors, underlie the responses to both chemical and mechanical stimuli in mouse olfactory sensory neurons (OSNs). Genetic ablation of key signaling proteins in odor transduction or disruption of OR–G protein coupling eliminates mechanical responses. Curiously, OSNs expressing different OR types display significantly different responses to mechanical stimuli. Genetic swap of putatively mechanosensitive ORs abolishes or reduces mechanical res…
Ensuring food safety using aptamer based assays: Electroanalytical approach
2020
Aptamers, are being increasingly employed as favorable receptors for constructing highly sensitive biosensors, for their remarkable affinities towards certain targets including a wide scope of biological or chemical substances, and their superiority over other biologic receptors. The selectivity and affinity of the aptamers have been integrated with the wise design of the assay, applying suitable modifications, such as nanomaterials on the electrode surface, employing oligonucleotide-specific amplification strategies or, their combinations. After successful performance of the electrochemical aptasensors for biomedical applications, the food sector with its direct implication for human healt…
A Portable Readout System for Microstrip Silicon Sensors (ALIBAVA)
2009
A readout system for microstrip silicon sensors has been developed. This system is able to measure the collected charge in one or two microstrip silicon sensors by reading out all the channels of the sensor(s), up to 256. The system can operate either with non-irradiated and irradiated sensors as well as with n-type and p-type microstrip silicon sensors. Heavily irradiated sensors will be used at the Super Large Hadron Collider, so this system can be used to research the performance of microstrip silicon sensors in conditions as similar as possible to the Super Large Hadron Collider operating conditions. The system has two main parts: a hardware part and a software part. The hardware part a…
Minimally invasive secondary cytoreduction plus HIPEC for recurrent ovarian cancer: a case series.
2014
Objective To analyze the feasibility of laparoscopic/robotic secondary cytoreductive surgery and hyperthermic intraperitoneal intra-operative chemotherapy (SCS + HIPEC) in a retrospective series of isolated platinum sensitive recurrent ovarian cancer. Methods We retrospectively evaluated a consecutive series of ovarian cancer patients with isolated platinum sensitive relapse. Isolated relapse was defined as the presence of a single nodule, in a single anatomic site. In all cases the presence of isolated relapse was assessed at pre-operative FDG-PET/CT scan, and confirmed with staging laparoscopy performed immediately before SCS + HIPEC. Results 84 women with platinum sensitive relapse recei…
Preparation of pH sensitive poly(vinilydenefluoride) porous membranes by grafting of acrylic acid assisted by supercritical carbon dioxide
2012
Free radical grafting of acrylic acid (AA) on poly(vinilydenefluoride) (PVDF) porous membranes was studied at 65°C using supercritical carbon dioxide (scCO 2) as a solvent and delivery agent. The process was initiated by the thermal decomposition of benzoylperoxide (BPO). Spectroscopic analyses confirmed the presence of poly(AA) chains linked to treated membranes. The mass fraction of grafted AA increased with grafting time and BPO concentration while it decreased when the density of the fluid phase was enhanced. A not-monotonic trend was obtained when the effect of the initial AA concentration was studied. The grafting process was accompanied by a reduction of the crystallinity of the PVDF…
Clever pH-Sensitive Drug-polymer Coniugates For Targeted Cancer Therapy
2014
Miniature Cavity-Enhanced Diamond Magnetometer
2017
We present a highly sensitive miniaturized cavity-enhanced room-temperature magnetic-field sensor based on nitrogen-vacancy (NV) centers in diamond. The magnetic resonance signal is detected by probing absorption on the 1042\,nm spin-singlet transition. To improve the absorptive signal the diamond is placed in an optical resonator. The device has a magnetic-field sensitivity of 28 pT/$\sqrt{\rm{Hz}}$, a projected photon shot-noise-limited sensitivity of 22 pT/$\sqrt{\rm{Hz}}$ and an estimated quantum projection-noise-limited sensitivity of 0.43 pT/$\sqrt{\rm{Hz}}$ with the sensing volume of $\sim$ 390 $\mu$m $\times$ 4500 $\mu$m$^{2}$. The presented miniaturized device is the basis for an e…