Effects of fictive temperature on the leaching of soda lime silica glass surfaces

The fictive temperature of glass characterizes the glass network structure and its thermal history, and thereby can influence ion and water transport in the glass surface. In this study, IR specular reflectance (SR), refractive index, and density measurements were used to characterize and confirm the effects of glass sample processing, especially the fictive temperature/thermal‐history variations. The subsequent acid leaching of these glasses created leached surface layers due to interdiffusion and reaction of hydrous species in the surface; the hydrogen depth profiles obtained with secondary ion mass spectrometry (SIMS) confirmed enhanced leaching with increasing fictive temperature. Attenuated total reflectance (ATR) in the mid‐ and near‐IR indicated increases in both SiOH and H₂O species with increasing fictive temperature. The relative intensities and shapes of the ATR peaks were found to vary between the samples suggesting that speciation of the hydrous reaction products (eg, strong and weakly hydrogen‐bonded OH) is also influenced by the original fictive temperature of the glass, but could not be quantitatively determined.     

Ionic Conductivity in Sodium–Alkaline Earth–Aluminosilicate Glasses

The effect of alkaline‐earth ions on Na transport in aluminosilicate glasses was studied by measuring ionic conductivity for a systematic compositional series of Na₂O–RO–Al₂O₃–SiO₂ glasses (R=Mg, Ca, Sr, Ba). The Na transport in aluminosilicate glass could be affected by compositional changes in aluminum coordination and nonbridging oxygen as well as physical properties such as dielectric constant, shear modulus, and ionic packing factor. Through careful experimental designs and measurements, the main determinants among these parameters were identified. ²⁷Al MAS‐NMR indicated that all aluminum species contained in these glasses are four‐coordinated. The activation energy for ion conductivity decreased with increasing aluminum content and decreasing ionic radii of the alkaline‐earth ion in the region where [Al] < [Na]. When the aluminum content exceeded the sodium content ([Al] > [Na]), the composition dependence of the activation energy depended on the specific alkaline earth. These results are explained based on variations in free volume and dielectric constant caused by structural changes around the AlO₄ charge compensation sites. These structure changes occur in response to the smaller size and higher field strength of the alkaline‐earth ions, and are most prevalent in the compositions which require bridging of two AlO₄ sites by the alkaline‐earth ion for charge compensation.     

Visual inspection of the uterine cervix after the application of acetic acid in the detection of cervical carcinoma and its precursors

BACKGROUND: Organized cervical cytology screening programs are not feasible in many developing countries where cervical carcinoma is an important cause of mortality among adult women. This study compared visual inspection of the cervix after application of 3-4% acetic acid (VIA, or cervicoscopy) with cytology as methods for the detection of cervical carcinoma and its precursors. METHODS: Three thousand women were examined by both VIA and cytology. Those positive on one or both of the screening tests (n = 423) or those who had clinically suspicious lesions even if the tests were negative (n = 215) were invited for colposcopy. Directed biopsies were obtained from 277 of 573 women at colposcopy. Those with moderate dysplasia or worse lesions diagnosed by histology were considered true-positives. Those with no lesions or with reactive or reparative changes at colposcopy and those for whom histology revealed no pathology, reactive or reparative changes, atypia, or mild dysplasia were considered false-positives. The detection rate of true-positive cases and the approximate specificity of the two tests were compared. RESULTS: VIA was positive in 298 women (9.8%), and cytology was positive (for atypia or worse lesions) in 307 women (10.2%). Of the 51 true-positive cases (20 cases of moderate dysplasia, 7 of severe dysplasia, 12 of carcinoma in situ, and 12 of invasive carcinoma), VIA detected 46 (90.1%) and cytology 44 (86.2%), yielding a sensitivity ratio of 1.05. VIA detected five lesions missed by cytology, and cytology detected three missed by VIA; both missed two lesions. The approximate specificities were 92.2% for VIA and 91.3% for cytology. The positive predictive value of VIA was 17.0%, and that of cytology was 17.2%. CONCLUSIONS: These results indicate that VIA and cytology had very similar performance in detecting moderate dysplasia or more severe lesions in this study. VIA merits further evaluation as a primary screening test in low-resource settings.     

Cytodiagnosis of primary malignant melanoma of the female urethra--a case report

Clinical course of multiple myeloma in patients under 40 years of age was analysed. In all cases diagnosis was established in III stage of the disease according to Durie and Salmon. In 4 cases good response to treatment (partial remission or stabilisation of proliferative process) was achieved. Survival time of 2 dead patients was 5 and 74 months, and that of 3 still alive patients is 41, 53, and 59 months and tends to be longer than median survival time of general population of patients with multiple myeloma.     

Total Antioxidant Capacity and Change in Phytochemicals of Four Major Varieties of Cardamom Oils During Decortication

The oil content and chemical composition of the volatiles from whole capsule, decorticated seed and husk of four varieties of cardamom viz. Malabar, Mysore, Vazhukka, and Guatemala were studied. The differences in the aroma of cardamom from different sources were attributed to the ratio of esters and 1,8-cineole in the oil. The main constituents of the oils were found to be terpinylacetate and 1,8-cineol. The study revealed that the oil obtained from a whole capsule of the Malabar variety was superior in quality compared to the oil from other varieties. The in vitro total antioxidant capacity of the oils from whole capsules by two different methods was also carried out, and it was found that the Malabar variety has the highest antioxidant activity compared to other varieties.     

A specific antidote for the treatment of digitalis poisoning in uremic patients

Two chronic haemodialyzed patients with digitalis intoxication are reported. One of them took digoxin 0.25 mg three times daily for an unknown period and the other took digitoxin 0.1 mg twice daily for two weeks. The symptoms of intoxication were mainly concealed by uremic syndrome. The diagnosis was established by noticed sinus bradycardia, first- and second-degree atrioventricular block in ECG and the determination of sera levels of glycosides (serum digoxin concentration was 7.36 ng/ml, serum digitoxin concentration was 46.5 ng/ml) in both cases. Considering the probable long elimination period of digitalis and the potentially life-threatening situation the patients were given digoxin-specific antibody (Fab) fragments with potassium replacement therapy. The symptoms disappeared within a few hours after therapy, side effects and rebound toxicity did not develop. In connection with these cases the aim of this report is to publish a method which can reverse the life-threatening digitalis intoxication in patients suffering from renal failure as well. As to the above method, the authors have not found any similar case reports in the Hungarian medical literature.     

Airwriting: a wearable handwriting recognition system

We present a wearable input system which enables interaction through 3D handwriting recognition. Users can write text in the air as if they were using an imaginary blackboard. The handwriting gestures are captured wirelessly by motion sensors applying accelerometers and gyroscopes which are attached to the back of the hand. We propose a two-stage approach for spotting and recognition of handwriting gestures. The spotting stage uses a support vector machine to identify those data segments which contain handwriting. The recognition stage uses hidden Markov models (HMMs) to generate a text representation from the motion sensor data. Individual characters are modeled by HMMs and concatenated to word models. Our system can continuously recognize arbitrary sentences, based on a freely definable vocabulary. A statistical language model is used to enhance recognition performance and to restrict the search space. We show that continuous gesture recognition with inertial sensors is feasible for gesture vocabularies that are several orders of magnitude larger than traditional vocabularies for known systems. In a first experiment, we evaluate the spotting algorithm on a realistic data set including everyday activities. In a second experiment, we report the results from a nine-user experiment on handwritten sentence recognition. Finally, we evaluate the end-to-end system on a small but realistic data set.     

Effect of fillers in the binary systems containing TMTD–amidinothiourea and MBTS–amidinothiourea in NR vulcanization

In earlier studies,^1,2 we have shown that in MBTS–amidinothiourea and TMTD–amidinothiourea binary system of rubber vulcanization, amidinothiourea functions effectively as a secondary accelerator and improves the accelerator activity of these systems. These secondary accelerators enhance the physical properties of the vulcanizates and show better cure characteristics of the mixes compared to the reference systems studied. In this paper, we present the results of our study on the effect of various fillers in the sulfur vulcanization of natural rubber using amidinothiourea as the secondary accelerator. We have taken MBTS–amidinothiourea and TMTD–amidinothiourea binary accelerator systems and vulcanizates were prepared with carbon black, precipitated silica, and china clay as fillers. Different compositions of amidinothiourea were used in various mixes using standard recipes. Reference mixes were also studied. Curing characteristics of the mixes and various physical properties of the vulcanizates were evaluated. Optimum dosage of amidinothiourea required has also been derived. Among the different secondary accelerators tried including amidinothiourea, it may be stated generally that the more nucleophilic the secondary accelerator, the less the optimum cure times. This fact points to a nucleophilic reaction mechanism in the systems under review. In the evaluation of tensile and other physical properties of the vulcanizates, some of the systems containing amidinothiourea show better properties while others give comparable values with the reference mixes. Estimation of crosslink density also supports the above conclusion. © 1996 John Wiley & Sons, Inc.     

Comparison of various organic stabilizers as capping agents for CdS nanoparticles synthesis

Results of the studies on the preparation and characterization of CdS nanoparticles capped with various organic stabilizers are presented in this article. Solutions of Cadmium acetate and Sodium sulphide were taken as the precursors. CdS nanoparticles were synthesized in an aqueous medium with Mercaptopropionic acid (MPA) as the stabilizer and non-aqueous methods were used for the synthesis of Polyvinyl Pyrrolidone (PVP) and thiophenol-capped CdS nanoparticles. The synthesized CdS nanoparticles were characterized by the optical absorption and X-ray diffraction (XRD) studies. Particle sizes estimated from the band gap values using Effective Mass Approximation (EMA) agreed fairly well with those calculated from the XRD using Scherrer formula. The quantity and the concentration of the stabilizers needed for effective capping of the CdS nanoparticles were different in the three cases considered. Stability of the synthesized CdS nanoparticles was studied at different intervals of time for 10 days. A change in particle size was observed at lower stabilizer concentrations for the first few days. But at higher stabilizer concentrations there was no change in particle size with time.