Non-isotopic in situ hybridization of HPV types in cervical intraepithelial lesions in patients with AIDS

Naturally produced methane shows different delta 13C-values with respect to its origin, e.g., geological or biological. Methane-production of ruminants is considered to be the dominant source from the animal kingdom. Isotopic values of rumen methane--given in literature--range between -80/1000 and -50/1000 and are related to feed composition and also sampling techniques. Keeping cows, camels and sheep under identical feed conditions and sampling rumen gases via implanted fistuale we compared delta PDB 13C-values of methane and CO2 between the species. Referring to mean values obtained from 4 or 5 samples at different times of 11 animals (n = 47) we calculated delta PDB 13C-medians resulting in small but not significant differences within and significant differences between the species for CO2 and methane. The delta PDB 13C-differences between methane and CO2 were statistically equal within and also between the species. Therefore a linear regression of methane values on CO2 is appropriate and leads to: delta PDB 13C(methane)/1000 = 1.57 * delta PDB 13C(CO2)/1000 - 47/1000 with a correlation coefficient of r = 0.87.     

Experimental occlusal interferences. Part IV. Mandibular rotations induced by a pliable interference

In 12 subjects, a pliable, yet unbreakable, intercuspal interference (aluminum shim onlay splint; uniform height of 0.25 mm) was placed between either the right or left maxillary and mandibular second premolars and first molars. During brief and forceful biting (dynamic chewing stroke of about 20 kg force) the interference emulated a semisoft food bolus, and at the end of biting (subsequent static clenching stroke of about 20 kg force) it emulated a rigid metal interference. During dynamic/static biting, rotational electrognathography measured maximum frontal and horizontal plane torque of the right and left mandibular condyles. Eleven subjects (92%) showed frontal plane upward rotation (mean of 1.0 degree) of the condyle contralateral to the interference, and one subject (8%) showed frontal plane upward rotation (0.4 degree) of the condyle ipsilateral to the interference. Two subjects (17%) showed no horizontal plane rotation; seven subjects (58%) showed backward rotation (mean of 0.4 degree) of the condyle contralateral to the interference; and three subjects (25%) showed backward rotation (mean of 0.3 degree) of the condyle ipsilateral to the interference. It is suggested that, in the presence of an occlusal interference, mastication may have both short- and long-term detrimental effects.     

CHL1 encodes a component of the low-affinity nitrate uptake system in Arabidopsis and shows cell type-specific expression in roots

The Arabidopsis CHL1 (AtNRT1) gene confers sensitivity to the herbicide chlorate and encodes a nitrate-regulated nitrate transporter. However, how CHL1 participates in nitrate uptake in plants is not yet clear. In this study, we examined the in vivo function of CHL1 with in vivo uptake measurements and in situ hybridization experiments. Under most conditions tested, the amount of nitrate uptake by a chl1 deletion mutant was found to be significantly less than that of the wild type. This uptake deficiency was reversed when a CHL1 cDNA clone driven by the cauliflower mosaic virus 35S promoter was expressed in transgenic chl1 plants. Furthermore, tissue-specific expression patterns showed that near the root tip, CHL1 mRNA is found primarily in the epidermis, but further from the root tip, the mRNA is found in the cortex or endodermis. These results are consistent with the involvement of CHL1 in nitrate uptake at different stages of root cell development. A functional analysis in Xenopus oocytes indicated that CHL1 is a low-affinity nitrate transporter with a K(m) value of approximately 8.5 mM for nitrate. This finding is consistent with the chlorate resistance phenotype of chl1 mutants. However, these results do not fit the current model of a single, constitutive component for the low-affinity uptake system. To reconcile this discrepancy and the complex uptake behavior observed, we propose a "two-gene" model for the low-affinity nitrate uptake system of Arabidopsis.     

Film thickness in point contacts under generalized Newtonian EHL conditions: Numerical and experimental analysis

The current paper contributes to the understanding of the behaviour of a smooth point EHL contact with a generalized Newtonian lubricant under pure rolling. The film thickness distribution was computed using a numerical simulation with measured rheological lubricant properties. The numerical predictions, obtained solving the generalized Reynolds equation were compared with film thicknesses measured in an optical ball-on-disc device. The numerical results correctly predict the absolute film thickness and the film thickness increase with rolling speed.     

Thermal Oxidation Mechanism of Polyalphaolefin Greases with Lithium Soap and Diurea Thickeners: Effects of the Thickener

In this work, lithium and diurea greases formulated by poly-alpha-olefin were aged up to 1,200 h in an oven at 120°C and periodically taken out for testing. Scanning electron microscopy (SEM) and infrared (IR) spectra proved that both physical and chemical degradation occurred during the thermal aging process, such as a decrease in apparent viscosity, thickener destruction, and change in chemical species. Diurea grease showed much better anti-oxidation performance during thermal aging than lithium grease. A dual effect of thermal aging on the grease lubricity was observed and analyzed. Results showed that early oxidation might reduce grease lubricity due to the formation of ketones and aldehydes, and the decrease in grease viscosity and oil bleeding due to thickener destruction would contribute to better replenishment.     

Fundamentals of Materials Science: The Microstructure-Property Relationship Using Metals as Model Systems, 2nd Edition,by Eric J. Mittemeijer,Springer Nature Switzerland AG 2021

Journal of Materials Science -     

Current Understanding of Structure–Processing–Property Relationships in BaTiO3–Bi(M)O3 Dielectrics

As part of a continued push for high permittivity dielectrics suitable for use at elevated operating temperatures and/or large electric fields, modifications of BaTiO₃ with Bi(M)O₃, where M represents a net‐trivalent B‐site occupied by one or more species, have received a great deal of recent attention. Materials in this composition family exhibit weakly coupled relaxor behavior that is not only remarkably stable at high temperatures and under large electric fields, but is also quite similar across various identities of M. Moderate levels of Bi content (as much as 50 mol%) appear to be crucial to the stability of the dielectric response. In addition, the presence of significant Bi reduces the processing temperatures required for densification and increases the required oxygen content in processing atmospheres relative to traditional X7R‐type BaTiO₃‐based dielectrics. Although detailed understanding of the structure–processing–property relationships in this class of materials is still in its infancy, this article reviews the current state of understanding of the mechanisms underlying the high and stable values of both relative permittivity and resistivity that are characteristic of BaTiO₃‐Bi(M)O₃ dielectrics as well as the processing challenges and opportunities associated with these materials.     

The Development of a Spacer Layer Imaging Method (SLIM) for Mapping Elastohydrodynamic Contacts

Optical interferometry has proved to be a valuable experimental tool in the study of elastohydrodynamic lubrication (EHD). It is a technique that gives detailed information on the lubricant film distribution within the contact; however, the sensitivity is limited and it is only recently, with the development of the spacer layer optical technique, that the study of the thin film lubrication regime has been possible. The limitation of the spacer layer technique is that generally only one measurement is taken from the center of the contact. The next logical step in the development of this technique is, therefore, a system that combines the mapping capabilities of the original optical method with the thin film capabilities of the spacer layer approach.

This paper describes the development of a contact mapping technique that uses the spacer layer approach to visualize, and measure, thin lubricant films in concentrated contacts. The development of the technique is described and its application to both static and moving contacts reported. Thin EHD films (down to 10 nm) have been measured and mapped.