Chemical sensor platform for non-invasive monitoring of activity and dehydration.

A non-invasive solution for monitoring of the activity and dehydration of organisms is proposed in the work. For this purpose, a wireless standalone chemical sensor platform using two separate measurement techniques has been developed. The first approach for activity monitoring is based on humidity measurement. Our solution uses new humidity sensor based on a nanostructured TiO2 surface for sweat rate monitoring. The second technique is based on monitoring of potassium concentration in urine. High level of potassium concentration denotes clear occurrence of dehydration. Furthermore, a Wireless Body Area Network (WBAN) was developed for this sensor platform to manage data transfer among devices and the internet. The WBAN coordinator controls the sensor devices and collects and stores the measured data. The collected data is particular to individuals and can be shared with physicians, emergency systems or athletes' coaches. Long-time monitoring of activity and potassium concentration in urine can help maintain the appropriate water intake of elderly people or athletes and to send warning signals in the case of near dehydration. The created sensor system was calibrated and tested in laboratory and real conditions as well. The measurement results are discussed.

Sensing properties of multiwalled carbon nanotubes grown in MW plasma torch: electronic and electrochemical behavior, gas sensing, field emission, IR absorption.

Vertically aligned multi-walled carbon nanotubes (VA-MWCNTs) with an average diameter below 80 nm and a thickness of the uniform VA-MWCNT layer of about 16 µm were grown in microwave plasma torch and tested for selected functional properties. IR absorption important for a construction of bolometers was studied by Fourier transform infrared spectroscopy. Basic electrochemical characterization was performed by cyclic voltammetry. Comparing the obtained results with the standard or MWCNT­modified screen-printed electrodes, the prepared VA-MWCNT electrodes indicated their high potential for the construction of electrochemical sensors. Resistive CNT gas sensor revealed a good sensitivity to ammonia taking into account room temperature operation. Field emission detected from CNTs was suitable for the pressure sensing application based on the measurement of emission current in the diode structure with bending diaphragm. The advantages of microwave plasma torch growth of CNTs, i.e., fast processing and versatility of the process, can be therefore fully exploited for the integration of surface-bound grown CNTs into various sensing structures.

Integrated chip electrophoresis and magnetic particle isolation used for detection of hepatitis B virus oligonucleotides.

Rapid and sensitive detection is a key step in the effective and early response to the global hazard of various viral diseases. In this study, an integrated isolation of hepatitis B virus (HBV)-specific DNA fragment by magnetic nanoparticles (MNPs) and its immediate analysis by microchip CGE was performed. Microfluidic CE chip was used to accommodate the complete process of viral DNA isolation by MNPs including hybridization and thermal denaturation followed by CE separation. Beforehand, calibration curves of HBV fragments were constructed. For isolation by MNPs, specific streptavidin-biotin interaction was used to bind complementary HBV fragment to magnetic particles. After analysis of isolated HBV by regular MNPs method, innovative approach was performed. The commercial CE chip (Bio-rad) was successfully used to execute HBV fragment isolation. Detection using LIF with detection limit of 1 ng/mL was accomplished.

Lipoxygenase inhibitors enhance tumor suppressive effects of jun proteins on v-myb-transformed monoblasts BM2.

Inhibitors of arachidonic acid (AA) conversion were described as suppressors of proliferation and inducers of differentiation of various leukemic cells. Certain AA metabolites have been shown to cooperate with Jun proteins that are important factors controlling cell proliferation, differentiation and apoptosis. Using lipoxygenase (LOX) inhibitors of various specifity we studied possible participation of lipoxygenase pathway in regulation of proliferation and apoptosis of v-myb-transformed chicken monoblasts BM2 and its functional interaction with Jun proteins. We found that nordihydroguaiaretic acid (NDGA) and esculetin (Esc) negatively regulate proliferation of BM2 cells causing accumulation in either G0/G1-phase (nordihydroguaiaretic acid) or S-phase (esculetin) of the cell cycle. BM2 cells can be also induced to undergo growth arrest and partial differentiation by ectopic expression of Jun proteins. We demonstrated that lipoxygenase inhibitors further enforce tumor suppressive capabilities of Jun proteins by inducing either more efficient cell cycle block and/or apoptosis in BM2 cells. This suggests that there is a cross-talk between the lipoxygenase- and Jun-directed pathways in regulation of differentiation and proliferation of monoblastic cells. Thus pharmacologic agents that specifically block lipoxygenase-catalyzed activity and enforce the effects of differentiation-inducers may be important components in anti-tumor therapies.

Anesthesia management of a patient with a ventricular assist device for noncardiac surgery.

Congestive heart failure represents a severe health condition with unfavourable long-term prognosis despite all the progress in pharmacological therapy of heart failure. Another therapeutic option is represented by mechanical cardiac support devices. Ventricular assist devices (VAD) constitute largest subgroup of these devices. Patients supported with VAD carry many considerations which are important for successful perioperative management of these patients for noncardiac surgery. The general perioperative considerations include consultation with VAD management personnel, detailed assessment of end-organ dysfunction before surgery, appropriate antibiotic prophylaxis, deactivation of implantable cardioverter-defibrillator for the time of surgical procedure, and the choice between general and regional anesthesia. Intraoperative monitoring depends primarily on the type of blood flow generated by VAD. For devices generating pulsatile blood flow, standard monitoring arrangements are needed. In the patients supported by devices which provide nonpulsatile blood flow, pulse oximetry and noninvasive blood pressure measurement are not reliable monitoring methods, and placement of intra-arterial catheter is warranted. In all the patients supported with VAD, transesophageal echocardiography is extremely useful method for monitoring the function of VAD itself, and in the case of univentricular VAD for monitoring the function of nonsupported cardiac ventricle. The most important issue in hemodynamic management of the patients with VAD is avoiding hypovolemia because it can cause inadequate VAD output with resulting low cardiac output and hypotension. All the patients with VAD need some degree of anticoagulation, and for noncardiac surgery the question of interrupting or decreasing the level of anticoagulation should be discussed among members of the caring team.