ZnO Thin Film, Device, and Circuit Fabrication using Low-Temperature PECVD Processes

We report undoped ZnO films deposited at low temperature (200°C) using plasma-enhanced chemical vapor deposition (PECVD). ZnO thin-film transistors (TFTs) fabricated using ZnO and Al₂O₃ deposited in situ by PECVD with moderate gate leakage show a field-effect mobility of 10 cm²/V s, threshold voltage of 7.5 V, subthreshold slope <1 V/dec, and current on/off ratios >10⁴. Inverter circuits fabricated using these ZnO TFTs show peak gain magnitude (dV _out/dV _in) ~5. These devices appear to be strongly limited by interface states and reducing the gate leakage results in TFTs with lower mobility. For example, ZnO TFTs fabricated with low-leakage Al₂O₃ have mobility near 0.05 cm²/V s, and five-stage ring-oscillator integrated circuits fabricated using these TFTs have a 1.2 kHz oscillation frequency at 60 V, likely limited by interface states.     

Probability of malignant degeneration of ovarian tumors. Clinical study on the probability of malignant degeneration

More than 600 cases of ovarian tumors were analyzed for histological type, age of patient, bilateral occurrence, mobility and malignant degeneration in restant ovaries. Tumors of germinal epithelial origin show the highest incidence (24%) of malignant degeneration, tumors of germ cells the lowest (3,5%). Incidence of malignant degeneration increases in relation to the age of the patient from 2% (and under 30 years) to 36,5% (60-70 years). Each form of tumor has its typical age peak, which is about 20 years higher for carcinomas than for their benign counterpart. Bilateral ovarian tumors are malignant in 29%, one-sided only in 13%. Among freely movable ovarian tumors, only 6% enclose a malignant tumor, among adhaerent ones 34%. The examination of the prognosis of granulosacell-tumors, dysgerminomas and teratoblastomas is based on a larger material.     

The cardiovascular effects of diazepam and of diazepam and pancuronium during fentanyl and oxygen anaesthesia

A study of the physiological behaviour of the synthetic compound Orthonil (alpha-chloro-beta-(3-chloro-o-tolyl)-propionitrile revealed a strong auxin activity in higher plants. Otherwise, Orthonil appeared not to be a herbicide-auxin. It is metabolized intensively in plant tissues. Among the identified metabolites, two compounds were detected which also exert a high auxin activity. It is concluded that at least a part of the apparent auxin activity of Orthonil may be due to alpha-(3-chloro-o-tolyl) acetic acid, one metabolite of Orthonil. Although Orthonil strongly stimulates elongation growth, this growth is not accompanied by a stimulated ethylene evolution as is the case with other auxins. A possible metabolic pathway of Orthonil is discussed.     

A method for studying glyoxylic acid induced fluorescence and ultrastructure of monoamine neurons

Inasmuch as precise correlations of light- and electronmicroscopy are crucial for understanding biostructure, it seemed necessary to bring together the advantages of the glyoxylic acid (GA) method (for inducing monoamine fluorescence) and electron microscopy. A combined fluorescence and electron microscope method using GA is introduced. The brain is perfused by 2% GA in Krebs-Ringer bicarbonate buffer (pH 7.0) and this solution is followed by 4% paraformaldehyde containing 0.5% glutaraldehyde in Sorensen's phosphate buffer (pH 7.4). Sections are cut by cryostat or by vitratome and incubated in 2% GA in phosphate buffer (pH 7.0). Using fluorescence microscopy, features of interest are sketched and/or photographed. Afterwards, the same or subsequent section is processed for electron microscopy. Since axons of catecholamine-containing neurons (as well as their perikarya and terminals) are visualized by GA, the recommended procedure expands the range of studies concerning monoamine neurons that can now be carried out effectively.     

Renal transport of urate during diuretic-induced hypouricemia

The effect of two weeks administration of a uricosuric diuretic (SKF-62698) on renal urate handling has been examined in 11 normal men. Plasma urate concentrations had declined by more than 60 per cent after two weeks. Urate excretion per unit of glomerular filtration rate and urate clearance (Curate) per unit of glomerular filtration rate were increased after the administration of SKF-62698. The importance of intact tubular secretion of urate in producing these changes was assessed by administering pyrazinamide, an agent that curtails urate secretion, to each participant. The decrements in urate excretion and clearance produced by pyrazinamide both increased significantly, whereas the residual urate excretion rates and clearances not suppressible by pyrazinamide were only minimally altered by SKF-62698 treatment. These results suggest that the excretion of secreted urate was enhanced by prolonged administration of SKF-62698, probably secondary to the inhibition of postsecretory urate reabsorption. In addition, because the nonsuppressible urate excretion did not decline despite a 63 per cent reduction in the plasma urate, it is likely that the reabsorption of filtered urate also was impaired by SKF-62698.     

Emulsification by the phase inversion temperature method: the role of self-bodying agents and the influence of oil polarity

Oil-in-water emulsions stabilized with nonionic emulsifiers change to water-in-oil emulsions as the temperature rises when the hydrophilic and lipophilic properties of the mixed emulsifier are just balanced. Preparation above the phase inversion temperature followed by rapid cooling yields emulsions that exhibit very fine droplet size and extreme long-term stability. Cosmetic emulsions were prepared by this phase inversion temperature (PIT) method using typical raw materials such as polar oils, e.g. decyl oleate, 2-octyl dodecanol or isopropyl myristate, and nonionic emulsifiers, e.g. ceteareth-12 or polyoxyethylene eicosyl/docosyl ether combined with cetostearyl alcohol as a co-emulsifier. The phase inversion temperature was measured as a function of the oil polarity and the concentration of mixed emulsifier. The relationship between phase inversion temperature, droplet size and emulsion stability was investigated. In addition, self-bodying agents such as cetostearyl alcohol or monoglycerides were added to these thin, fine disperse emulsions to adjust the consistency. The influence of these ingredients on phase inversion temperature, droplet size, yield value and emulsion stability was studied.     

Starch derivatives with high degree of functionalization. III. Influence of reaction conditions and starting materials on molecular structure of carboxymethyl starch

Carboxymethyl starch (CMS) was prepared in a completely heterogeneous procedure in a methanol/water slurry activated with aqueous sodium hydroxide (45%, w/v) using monochloroacetic acid as the etherifying agent. The influence of the reaction conditions and the type of starting starch (amylose content and preactivation) was evaluated in regard to the formation of the main repeating units (i.e., unfunctionalized and mono‐, di‐, tri‐, and tetra‐O‐carboxymethylated) and the pattern of functionalization within the anhydroglucose units (AGU). The reproducible synthesis gave products with a maximal degree of substitution of CM groups (DS_CM) of 0.66, which was reached in a one‐step synthesis. Repeated carboxymethylation led to products with a DS_CM of 0.88. As revealed by means of HPLC analysis after complete acidic depolymerization, in any sample the mono‐O‐carboxymethylated glucose (mono‐O‐CMglc) was preferably present while the di‐O‐CMglc was formed to a very low extent only. The tri‐O‐CMglc was found in some samples while tetra‐O‐CMglc was not detected. The mole fractions determined did not follow the simple Spurlin statistic as shown for CM cellulose synthesized under comparable conditions. Within the carboxymethylated AGUs a preferred functionalization at position 2 was analyzed by means of ¹H‐NMR spectroscopy after hydrolytic chain degradation. Consequently, the CMS samples synthesized contained mainly 2‐mono‐O‐CM‐AGU. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2036–2044, 2001     

Environmental and operational stability of solution-processed 6,13-bis(triisopropyl-silylethynyl) pentacene thin film transistors

We report operational and environmental stability of solution-processed organic thin film transistors (OTFTs) using the small molecule organic semiconductor 6,13-bis(triisopropyl-silylethynyl) pentacene (TIPS-pentacene). Typical drop-cast TIPS-pentacene OTFTs show strong molecular ordering and relatively stable characteristics with air and illumination compared to vapor-deposited pentacene OTFTs. For short channel length devices, TIPS-pentacene OTFTs undergo significant degradation with bias-stress, possibly due to operation at large drive currents and large local power dissipation as well as built-in charges in the channel area.