Ethanol Exposure in Rats and its Effect on Genetic Markers

Alcoholism is believed to affect an estimated 18 million people each year. The number of people abusing alcohol is three times the number of people abusing all other substances combined. (Institute for Health Policy, 2001) An estimated $276 billion per year(Institute for Health Policy, 2001)is spent to combat the influence of alcoholism in this country alone; more than cancer, heart disease, and diabetes, combined. A full understanding of the effects of alcohol on the developing nervous system and other organ systems, and knowing when and where that central or internal organ damage has occurred after a certain period of abuse will allow us to identify at risk individuals and allow for appropriate and efficient interventional strategies. The purpose of this study was to try and identify which peripheral biomarkers indicate when early evidence for central nervous system damage has occurred. We performed this using a well-established rat model of drinking with the intention of identifying genes in peripheral blood whose expression patterns are strongly correlated with damage to the brain but separate from changes produced by damage to the heart or liver. We found two genes that showed highly significant changes in all tissues, the Fos gene and the Hfrlike gene, although significant, they were not too interesting because they are known to fluctuate with other toxins. Further studies need to be done to pinpoint a specific biomarker for ethanol induced change

Microstructure Evolution and Mechanical Properties of Haynes 282

Precipitation-hardened nickel-based superalloys find wide applications in aero engines and land-based gas turbines due to a combination of properties such as high temperature strength, resistance to oxidation and corrosion, fabricability, and creep strength. Structural engine components are traditionally cast to achieve higher degree of geometrical design freedom. However, the latest fabrication strategy to achieve low cost and light weight structural components is by joining materials based on temperature needs. The challenge in this strategy is to tailor the heat treatment to suit the multi-material structures and still be able to meet the desired property requirements. This requires a profound understanding of the process-structure-property relationships in these complex alloys. The newly introduced Ni-base superalloy Haynes 282 has been attracting interest due to its high-temperature properties and excellent weldability. These properties are achieved due to the precipitation of strengthening phase (γʹ, Ni3 (Al,Ti)) and grain boundary carbides (mainly M23C6 and M6C) during heat treatment.As Haynes 282 has showed sensitivity to heat treatment temperatures within the typical tolerance limits around the conventional heat treatment, the main objective of this research was to understand the microstructural evolution and mechanical properties with changes in heat treatment conditions. The effect of heat treatment variations on microstructure and mechanical properties has been systematically studied. Its influence on microstructure and tensile properties between room temperature and 730 \ub0C are presented.The results show that γ׳ does not precipitate during rapid cooling but it precipitates as fine spherical particles during air cooling from the carbide stabilization temperature, and it changes to bimodal distribution with square and spherical morphology during slow cooling. During ageing, γ׳ is seen to precipitate intergranularly, as well as along the grain boundaries. The solvus temperature for this phase was above 1010 \ub0C (higher than previously suggested), and depending on the combination of temperatures and times of the heat treatments, the γ׳ morphology changes from spherical to bi-modal to cuboidal. The grain boundary carbide morphology depends strongly on heat treatment temperature and is seen to change from continuous film to brick wall structure and finally to discrete particles. These microstructural changes strongly affect both strength and ductility of the material. Furthermore, Haynes 282 forgings show ductility variations in short transverse direction. The lower limit of ductility in this direction is close to the design tolerance and thus creates a need to understand the underlying cause. In this part, the study is focused to understand ductility variation by microscopic investigations. Carbide segregation and banding is seen to influence the ductility when oriented perpendicular to the tensile axis. This influence is also qualitatively captured through micromechanical modelling. \ua0Haynes 282, gamma prime, carbides, isothermal transformation, anisotropy ductility, heat treatment, microstructure, solution treatment, carbide stabilization treatmen

Influence of heat treatment on the microstructure and tensile properties of Ni-base superalloy Haynes 282

The effect of heat treatment on the microstructure and mechanical properties of Ni-base superalloy Haynes 282 was investigated. Applying a standard two-step ageing (1010 °C/2 h +788 °C/8 h) to the as-received, mill annealed, material resulted in a the presence of discrete grain boundary carbides and finely dispersed intragranular γ′, with an average size of 43 nm. This condition showed excellent room temperature strength and ductility. The introduction of an additional solution treatment at 1120 °C resulted in grain growth, interconnected grain boundary carbides and coarse (100 nm) intragranular γ′. The coarser γ′ led to a significant reduction in the strength level, and the interconnected carbides resulted in quasi-brittle fracture with a 50% reduction in ductility. Reducing the temperature of the stabilization step to 996 °C during ageing of the mill annealed material produced a bi-modal γ′ distribution, and grain boundaries decorated by discrete carbides accompanied by γ′. This condition showed very similar strength and ductility levels as the standard ageing of mill-annealed material. This is promising since both grain boundary γ′ and a bi-modal intragranular γ′ distribution can be used to tailor the mechanical properties to suit specific applications. The yield strength of all three conditions could be accurately predicted by a unified precipitation strengthening model

Precipitation Kinetics and Morphology of Grain Boundary Carbides in Ni-Base Superalloy Haynes 282

Precipitation of grain boundary carbides in a mill-annealed Haynes 282 in the temperature range 650 degrees C to 1120 degrees C was investigated. The kinetics of M(23)C(6)was significantly faster than that of M6C. With increasing aging temperature, the morphology changes from continuous film to an interconnected brick wall structure and finally to discrete particles. No morphological changes were observed with aging time. Serrated grain boundaries formed during aging around 750 degrees C. The solvus temperature for both M(23)C(6)and M6C was approximately 1100 degrees C

METHODOLOGY FOR FLEET UNCERTAINTY REDUCTION WITH UNSUPERVISED LEARNING

Operational and environmental variance can skew reliability metrics and increase uncertainty around lifetime estimates. For this reason, fleet-wide analysis is often too general for accurate predictions on heterogeneous populations. Also, modern sensor based reliability and maintainability field and test data provide a higher level of specialization and disaggregation to relevant integrity metrics (e.g., amount of damage, remaining useful life). Modern advances, like Dynamic Bayesian Networks, reduce uncertainty on a unit-by-unit basis to apply condition-based maintenance. This thesis presents a methodology for leveraging covariate information to identify sub- populations. This population segmentation based methodology reduces fleet uncertainty for more practical resource allocation and scheduled maintenance. First, the author proposes, validates, and demonstrates a clustering based methodology. Afterwards, the author proposes the application of the Student-T Mixture Model (SMM) within the methodology as a versatile tool for modeling fleets with unclear sub-population boundaries. SMM’s fully Bayesian formulation, which is approximated with Variational Bayes (VB), is motivated and discussed. The scope of this research includes a new modeling approach, a proposed algorithm, and example applications

Precipitation of γ’ during cooling of nickel-base superalloy Haynes 282

Cooling-induced precipitation of the strengthening γ’ phase is commonly investigated in Ni-base superalloys with a high γ’ volume fraction, where it is used to control the final microstructure and properties. Less is known about the phase separation in low-volume-fraction alloys during cooling, although the microstructural state after cooling from solution treatment is known to affect subsequent heat-treatment steps. We use atomic-scale characterisation of Ni-base superalloy Haynes 282 (equilibrium γ’ volume fraction around 20%) to show that air cooling after solution or carbide stabilisation results in precipitation of nm-sized γ’ particles, whereas precipitation was suppressed during water quenching. The solution treatment has a significant effect on the hardness and γ’ precipitation during air cooling from the subsequent carbide stabilisation temperature. Also, the carbide-stabilisation treatment itself affects the γ’ precipitation during subsequent air cooling

Challenges in Early Diagnosis of Oral Cancer: Cases Series

Za oralni rak prosječna je stopa preživljavanja samo 50 %. Ta se prognoza može znatno poboljšati ako se bolest dijagnosticira i liječi u ranoj fazi, a obično se povezuje s klasičnim kliničkim karakteristikama povezanima s malignošću koje rezultiraju točnom dijagnozom. No, neki slučajevi, posebno u ranim fazama, mogu biti klinički varljivi pa se i pogrešno dijagnosticiraju. No postoji noviji trend u demografskim i etiološkim obilježjima koja se povezuju s oralnim karcinomom, a za kliničara su dijagnostički izazovi. Svjesnost o tim trendovima je potrebna kako bi se oralni rak rano dijagnosticirao. Ovdje su opisana tri takva izazovna slučaja.Oral cancer has an overall survival rate of only 50%. This prognosis is significantly improved when this disease is diagnosed and treated in its early stages. Oral cancer is usually associated with classical clinical features associated with malignancy resulting in accurate diagnosis. However, certain cases of oral cancer, especially in its early stages, can be clinically deceptive and can be misdiagnosed. There is a recent trend of changing demographics and etiology associated with oral cancer adding to the diagnostic challenges faced by the clinician. The awareness of these changing trends is needed to aid in early diagnosis of oral cancer. In this case series, we have presented three cases of patients with challenging aspects

Investigating the link between frontal sinus morphology and craniofacial characteristics with sex: A 3D CBCT study on the South Indian population [version 2; peer review: 2 approved]

Background: Measurement of craniofacial parameters plays an important role in sex determination in forensic science. The present study was done using cone beam computed tomography (CBCT) scans to evaluate the morphologic structure of the frontal sinuses and compare it with the width of nasal, cranial, maxillary and mandibular width which might help us in sex determination. Methods: A cross-sectional retrospective study was conducted using 142 full field of view (FOV) scans of patients archived from the department. The width of the nose, cranium, maxilla, and mandibular width was measured and compared with the frontal sinus between the two sexes. Results: A paired t-test was done to compare the linear measurements for both sexes' right and left frontal sinuses. The measurements were higher in males when compared to females. There was a statistically significant asymmetry (larger dimension on the left side) of the anterioposterior (p-value of 0.012) and superior-inferior dimensions in males (p-value of 0.135). Spearman's correlation showed that frontal sinus correlated with other craniofacial parameters like nasal, cranial, maxillary and mandibular width among both sexes. The frontal sinus, nasal, cranial, maxillary and mandibular widths were higher in males when compared to females (independent t-test). Discriminant function scores showed 66-68% accuracy to discriminate sex, using the anteroposterior dimension and mandibular width. Conclusions: The measurement of craniofacial parameters using CBCT can aid in determining the sex of unidentified and decomposed bodies