Conductance analysis of (Co,Nb, Fe)-doped SnO<Subscript>2</Subscript> thick film gas sensors

Thick films prepared with undoped nanometric SnO₂ particles and with (Co, Nb, Fe)-doped SnO₂ were studied with the purpose of developing oxygen and carbon monoxide gas sensors. The ceramic powders were obtained through the Pechini method. The morphological characteristics were studied with SEM and TEM, after which, they were subjected to sensitivity tests under different atmospheres. A correlation was established between the microstructure of the material, the effects of the additives, and the electrical behavior. The response of the sensor could be explained as the result of the characteristics of the intergranular potential barriers developed at intergrains. It was determined that the SnO₂-doped films have a greater sensitivity between 200 °C and 350 °C.     

Predicting acute denervation in carpal tunnel syndrome

OBJECTIVE: Defects of the cochlear modiolus have been found to be associated with most cases of large vestibular aqueduct. The clinical significance of these modiolar defects has not been studied previously. The purpose of this article is to correlate clinical (functional) parameters, such as hearing outcomes, with the severity of the radiographic findings in these dysplastic inner ears. STUDY DESIGN: The study design was a retrospective chart review, supplemented with telephone interviews and clinic visits. SETTING: The study was conducted at an academic, tertiary care center. PATIENTS: Thirty consecutive patients with large vestibular aqueducts participated. RESULTS: Scores of modiolar deficiencies yielded inconsistent correlations with hearing loss. Vestibular aqueduct morphology and thickness correlated very strongly with the severity of hearing loss. CONCLUSIONS: These observations support the hypothesis that large vestibular aqueduct-related hearing loss may be caused by transmission of subarachnoid pressure forces into the inner ear. However, the thickness and morphology of the vestibular aqueduct may simply be markers for more subtle cochlear dysplasia manifest by modiolar deficiency.     

<Emphasis Type="Italic">Trans</Emphasis> fatty acids and atopic eczema/dermatitis syndrome: The relationship with a free radical <Emphasis Type="Italic">cis-trans</Emphasis> isomerization of membrane lipids

The formation of trans FA residues in membrane phospholipids may be due to a free radical-catalyzed isomerization process occurring to the cis unsaturated FA moieties. Radical stress is well documented in inflammatory processes of atopic diseases, but no data are yet available about a possible association with trans FA detected in these patients. We investigated the presence of trans lipid isomers in the erythrocyte and T-lymphocyte membranes of 26 children affected by atopic eczema/dermatitis syndrome (AEDS). Trans lipid isomers were found in both cell membranes, up to a total content of 2.7 and 4.9% of the FA composition, respectively. By using the geometrical trans lipid library derived from in vitro models of thiyl radical-catalyzed isomerization, oleic and arachidonic acid isomers were detected. The statistical significance was evaluated by comparison with an age-matched control group. These results suggest the role of an endogenous free radical isomerization path occurring to membrane unsaturated lipids, complementary to the dietary contribution, which can be involved in the lipid impairment in AEDS. This study contributes to lipidomic research regarding the double bond structure and the influence of a geometrical change of membrane lipids in physiology and diseases.     

Morbidity and mortality in cystic fibrosis. Results of 20 years of experience

In this study the clinical data and treatment concept in 197 patients with cystic fibrosis, seen during the past 20 years at the University Children's Hospital of Berne (Switzerland), are presented. The results showed that during recent years the median age of survival, the mean age at death and the cumulative survival rates have improved. Furthermore, this study demonstrates that by forming groups of patients with similar age at diagnosis the cumulative survival rate declined in the group with early diagnosis much more markedly than in the group of patients with later diagnosis. Further evaluation of these data revealed that most patients of the former group had a more severe form of cystic fibrosis than the latter group. Since there are different patterns of severity in this disease, it will be necessary to develop staging for the purpose of statistical comparisons.     

Different risks of thrombosis in four coagulation defects associated with inherited thrombophilia: a study of 150 families

Deficiency of the naturally occurring anticoagulant proteins, such as antithrombin, protein C and protein S, and activated protein C resistance due to the factor V Leiden gene mutation is associated with inherited thrombophilia. So far, no direct comparison of the thrombotic risk associated with these genetic defects is available. In this study, we wish to compare the lifetime probability of developing thrombosis, the type of thrombotic symptoms, and the role of circumstantial triggering factors in 723 first- and second-degree relatives of 150 index patients with different thrombophilic defects. We found higher risks for thrombosis for subjects with antithrombin (risk ratio 8.1, 95% confidence interval [CI], 3.4 to 19.6), protein C (7.3, 95% CI, 2.9 to 18.4) or protein S deficiency (8.5, 95% CI, 3. 5 to 20.8), and factor V Leiden (2.2, 95% CI, 1.1 to 4.7) than for individuals with normal coagulation. The risk of thrombosis for subjects with factor V Leiden was lower than that for those with all three other coagulation defects (0.3, 95% CI, 0.1 to 1.6), even when arterial and superficial vein thromboses were excluded and the analysis was restricted to deep vein thrombosis (0.3, 95% CI, 0.2 to 0.5). No association between coagulation defects and arterial thrombosis was found. The most frequent venous thrombotic manifestation was deep vein thrombosis with or without pulmonary embolism (90% in antithrombin, 88% in protein C, 100% in protein S deficiency, and 57% in factor V Leiden), but a relatively mild manifestation such as superficial vein thrombosis was common in factor V Leiden (43%). There was a predisposing factor at the time of venous thromboembolism in approximately 50% of cases for each of the four defects. In conclusion, factor V Leiden is associated with a relatively small risk of thrombosis, lower than that for antithrombin, protein C, or protein S deficiency. In addition, individuals with factor V Leiden develop less severe thrombotic manifestations, such as superficial vein thrombosis.     

A resistive-gate In0.53Ga0.47As/InPheterostructure CCD

The first InGaAs/InP charge-coupled device (CCD) is demonstrated, exhibiting a charge transfer efficiency (CTE) of 0.98 at 13 MHz and 1 GHz. Cooling the device improves the CTE to greater than 0.99 at 13-MHz clock frequency. The 0.76-eV In_0.53Ga_0.47As bandgap makes this structure applicable to direct-detection short-wavelength infrared (SWIR) imagers     

Studies on the mechanism of metabolic stimulation in polymorphonuclear leukocytes during phagocytosis. Activators and inhibitors of the granule bound NADPH oxidase

The effects of several known inhibitors and activators of peroxidase-catalyzed reactions have been studied on the NADPH oxidase activity of granules isolated from polymorphonuclear leukocytes at rest or during phagocytosis. Redogenic substances, such as ascorbate or hydroquinone, and superoxide dismutase, which are known to inhibit peroxidase-catalyzed reactions, also inhibited the NADPH oxidase activity of granules. Oxidogenic substances, such as guaiacol or resorcinol, and manganese, which are known to stimulate peroxidase-catalyzed reactions, also activated the NADPH oxidase activity of granules. Cyanide, an inhibitor of peroxidase-catalyzed reactions, inhibited the NADPH oxidase activity of granules isolated from resting leukocytes but only slightly affected that of granules isolated from phagocytosing cells, as previously reported. A list of the properties of the NADPH oxidase activity of granules and of peroxidase oxidase activity is given. The arguments in favor of and those against a possible identity of the two activities are discussed.