Status of Aluminum Oxide Gate Dielectric Technology for Insulated-Gate GaN-Based Devices.

Insulated-gate GaN-based transistors can fulfill the emerging demands for the future generation of highly efficient electronics for high-frequency, high-power and high-temperature applications. However, in contrast to Si-based devices, the introduction of an insulator on (Al)GaN is complicated by the absence of a high-quality native oxide for GaN. Trap states located at the insulator/(Al)GaN interface and within the dielectric can strongly affect the device performance.

SDVSRM - a new SSRM based technique featuring dynamically adjusted, scanner synchronized sample voltages for measurement of actively operated devices.

Scanning spreading resistance microscopy (SSRM) with its high spatial resolution and high dynamic signal range is a powerful tool for two-dimensional characterization of semiconductor dopant areas. However, the application of the method is limited to devices in equilibrium condition, as the investigation of actively operated devices would imply potential differences within the device, whereas SSRM relies on a constant voltage difference between sample surface and probe tip. Furthermore, the standard preparation includes short circuiting of all device components, limiting applications to devices in equilibrium condition.

[Valproic acid concentration in the blood serum of pregnant women and umbilical cord blood in relation to the condition of the newborn--case studies].

Epilepsy is one of the most common neurological diseases in the world. One of the most difficult clinical problems associated with the disease is to treat pregnant women because the use of antiepileptic drugs increase the risk of birth defects in the fetus. The second most common use in pregnant women is an antiepileptic drug valproic acid.

[Electronic cigarettes - effects on health. Previous reports].

Currently very popular in the market of tobacco products have gained electronic cigarettes (ang. E-cigarettes). These products are considered to be potentially less harmful in compared to traditional tobacco products.

[Artichoke--untapped potential of herbal medicine in the treatment of atherosclerosis and liver diseases].

Substances of natural origin are the subject of growing interest on the part of both researchers and doctors. One of the well known herbal medicines extensively examined in terms of clinical and pharmacological is artichoke (Cynara scolymus L.), which was used in European medicine from the 18th century.

[Artichoke--herbal drug].

The liver is the gland most vulnerable to the toxic effects of xenobiotics, as responsible for their metabolism. Significant impact on the functioning of this gland has a style of life: alcohol consumption, diet with high fats ingredients and prooxidative substances and synthetic drugs. Very improtant aspect in herbal medicaments is protective properties on parenchymal organ-damaging.

Tuning fulleride electronic structure and molecular ordering via variable layer index.

C60 fullerides are uniquely flexible molecular materials that exhibit a rich variety of behaviour, including superconductivity and magnetism in bulk compounds, novel electronic and orientational phases in thin films and quantum transport in a single-C60 transistor. The complexity of fulleride properties stems from the existence of many competing interactions, such as electron-electron correlations, electron-vibration coupling and intermolecular hopping. The exact role of each interaction is controversial owing to the difficulty of experimentally isolating the effects of a single interaction in the intricate fulleride materials.

Novel orientational ordering and reentrant metallicity in K(x)C(60) monolayers for 3 < or = x < or = 5.

STM studies on K(x)C(60) monolayers reveal new behavior over a wide range of the phase diagram. As x increases from 3 to 5 K(x)C(60) monolayers undergo metal-insulator-metal reentrant phase transitions and exhibit a variety of novel orientational orderings, including a complex 7-molecule, pinwheel-like structure. The proposed driving mechanism for the orientational ordering is the lowering of electron kinetic energy by maximizing the overlap of neighboring molecular orbitals.

[Cotinine in urine of mother and their newborn and in cord serum and placenta as a biomarker of foetal exposure to tobacco smoke].

In Poland, tobacco smoking by women in a procreational age as well as the pregnant women is a common phenomenon. The aim of the conducted research was to assess the usefulness of cotinine markers in different biological materials--mother and newborn's urine, cord blood se. rum, placenta--as a biomarker of tobacco smoking by delivering women, and dependence between these biomarkers and the newborn's health state.

[Effect of tobacco smoke on permeability of capillary of pregnant and non-pregnant rats].

From among 4200 chemical compounds contained in the tobacco smoke, nicotine and carbon monoxide are responsible for changes in the heart-vessel system to the greatest extent. Additionally, other toxic compounds, including the carcinogenic ones, have a significant impact on the biological activity in the tissues of blood vessels. A particularly complex picture of the detrimental impact of the tobacco smoke is presented in case of pregnant women, fetuses and newborns.

Visualization of the molecular Jahn-Teller effect in an insulating K4C60 monolayer.

We present a low-temperature scanning tunneling microscopy (STM) study of K(x)C60 monolayers on Au(111) for 3 < or = x < or = 4. The STM spectrum evolves from one that is characteristic of a metal at x = 3 to one that is characteristic of an insulator at x = 4. This electronic transition is accompanied by a dramatic structural rearrangement of the C60 molecules.

[Tobacco smoke effects the activity of superoxide dismutase, glutathione peroxidase and total antioxidant status in pregnant and non-pregnant animals].

Total antioxidant status was measured as the reduction of the ABTS radical cation as well as the activities of SOD and GPx in female rats exposed and non-exposed to the cigarette smoke, pregnant and non-pregnant. The assessment was done in lungs, plasma, kidneys, liver and placenta of Wistar rats exposed to the cigarette smoke (1500 mg CO/m3 air) for 21 days. Total antioxidant status was significantly elevated in lungs and plasma of smoke-exposed animals, pregnant and non-pregnant, when compared to the matched controls.

Controlled atomic doping of a single C60 molecule.

We report a method for controllably attaching an arbitrary number of charge dopant atoms directly to a single, isolated molecule. Charge-donating K atoms adsorbed on a silver surface were reversibly attached to a C60 molecule by moving it over K atoms with a scanning tunneling microscope tip. Spectroscopic measurements reveal that each attached K atom donates a constant amount of charge (approximately 0.

Direct observation of internal spin structure of magnetic vortex cores.

Thin film nanoscale elements with a curling magnetic structure (vortex) are a promising candidate for future nonvolatile data storage devices. Their properties are strongly influenced by the spin structure in the vortex core. We have used spin-polarized scanning tunneling microscopy on nanoscale iron islands to probe for the first time the internal spin structure of magnetic vortex cores.

[Epidemiology of proximal femur fracture and results of therapy in patients treated at the Orthopedic-Trauma Ward of the Railway Hospital in Warsaw in the years 1986-1990].

A retrospective analysis included 441 hospitalized patients with fractures of the proximal femoral bone, treated at the orthopedic-traumatology ward in 1986-1990. Such patients constituted 9.12% of all patients treated during those years.