Material Strength Effect in the Shock Compression of Alumina

The Hugoniot elastic limits (HEL) of a high-density aluminum oxide ceramic (Lucalox) and a slightly lower-density ceramic (porosity approximately 4%) were determined to be 112±13 and 83±5 kbar, respectively. Above the HEL, the shock-stress-volume Hugoniot curves for both materials are offset by 40 kbar or more above their hydrostatic-pressure-volume curves. These results indicate that shear stresses with magnitudes of about 30–40 kbar persist in aluminum oxide to shock-pressure levels of at least 300 kbar

A molecule-based 1 : 2 digital demultiplexer

A trichromophoric molecule consisting of a porphyrin linked to both a dihydropyrene and a dihydroindolizine-type photochrome, in combination with a third harmonic generating crystal, functions as a 1:2 digital demultiplexer with photonic inputs and outputs. Each of the two photochromes may be cycled independently between two metastable forms, leading to four photoisomers, three of which are used in the demultiplexer. These isomers interact photochemically with the porphyrin in order to yield the demultiplexer function. With the address input (1064-nm light) turned off, one Output of the device (porphyrin fluorescence) tracks the state of the data input (532-nm light). When the address input is turned on, the second output (absorbance at 572 nm) tracks the state of the data input, while the first output remains off. The demultiplexer does not require chemical or electrical inputs, and can cycle through its operational sequences multiple times

Adult Pancreatic Hemangioma: Case Report and Literature Review

We report an adult pancreatic hemangioma diagnosed on pathological specimen review following pylorus preserving pancreaticoduodenectomy for a symptomatic cystic mass in the head of the pancreas. Eight cases of adult pancreatic hemangioma have been reported in literature since 1939. Presenting symptoms, radiographic diagnosis, pathologic characteristics, and treatment of adult pancreatic hemagiomas are discussed following review of all published cases

Dog Owners\u27 Perspectives on Canine Dental Health : A Questionnaire Study in Sweden

Periodontal disease is one of the most common diseases affecting dogs, with a reported prevalence of at least 80% in dogs over 3 years of age. However, there is a lack of studies regarding dog owners\u27 assessment of their dog\u27s dental health, and whether they perceive clinical signs often associated with periodontal disease, i.e., dental calculus, halitosis or mobile or lost teeth. A validated questionnaire survey was distributed to all Swedish dog owners with email addresses in the national registry (n = 209,263). The response rate was 32%. The survey questions concerned opinions and practices regarding canine dental health, including assessment of dental health parameters and dog owners\u27 ability to examine their dog\u27s mouth. A construct (α = 0.76) was used to investigate dog owners\u27 assessed symptoms of their dog\u27s dental health in relation to background factors. Half of the respondents rated their dog\u27s dental health as very good. However, one in four dog owners experienced difficulties when inspecting the dog\u27s teeth. The most common reason for this difficulty was stated to be an uncooperative dog. Almost half of the dog owners reported halitosis to some degree in their dog, and almost four in ten owners reported dental calculus. One in eight dogs had been previously anesthetized for dental cleaning, and one in 12 dogs had experienced problems with gum disease, according to the owners. Owners\u27 assessment varied significantly with the dog\u27s age, weight, breed, breed group, sex, and concurrent disease. Owner-related factors that influenced the assessment of the dog\u27s dental health were age, gender, education, county (urban/rural), and whether they were breeders or not. Dog owners with smaller dogs, older dogs and certain breeds predisposed to periodontal disease assessed their dog\u27s dental health as worse than their counterparts, which is in agreement with previously reported higher prevalence of dental disease in these groups. This indicates that dog owners are able to perform relative assessment of their dog\u27s dental health status. Our results also highlight the need for routine professional assessment of periodontal health, as well as education of dog owners and training of dogs to accept dental care procedures

Algorithmic aspects of theory blending

In Cognitive Science, conceptual blending has been proposed as an important cognitive mechanism that facilitates the creation of new concepts and ideas by constrained combination of available knowledge. It thereby provides a possible theoretical foundation for modeling high-level cognitive faculties such as the ability to understand, learn, and create new concepts and theories. This paper describes a logic-based framework which allows a formal treatment of theory blending, discusses algorithmic aspects of blending within the framework, and provides an illustrating worked out example from mathematics

Laser-induced fluorescence studies of the biodistribution of carotenoporphyrins in mice.

The biodistribution of two recently developed tumour markers, trimethylated (CP(Me)3) and trimethoxylated (CP(OMe)3) carotenoporphyrin, was investigated by means of laser-induced fluorescence (LIF) after i.v. injection into 38 tumour-bearing (MS-2 fibrosarcoma) female Balb/c mice. At 3, 24, 48 or 96 h after administration, the carotenoporphyrin fluorescence was measured in tumoral and peritumoral tissue, as well as in the abdominal, thoracic and cranial cavities. The fluorescence was induced by a nitrogen laser-pumped dye laser, emitting light at 425 nm, and analysed by a polychromator equipped with an image-intensified CCD camera. The fluorescence was evaluated at 490, 655 and 720 nm: the second and third wavelengths represent the carotenoporphyrin (CP)-related peaks, whereas the first one is close to the peak of the tissue autofluorescence. The tumour and the liver were the two tissue types showing the strongest carotenoporphyrin-related fluorescence, whereas the cerebral cortex and muscle consistently exhibited weak substance-related fluorescence. In most tissue types, the fluorescence intensities decreased over time. A few exceptions were observed, notably the liver, in which the intensity remained remarkably constant over the time period investigated

Laser-induced fluorescence in malignant and normal tissue in mice injected with two different carotenoporphyrins.

Laser-induced fluorescence (LIF) was used to characterise the localisation of an intravenously administered trimethylated carotenoporphyrin [CP(Me)3] and a trimethoxylated carotenoporphyrin [CP(OMe)3] in an intramuscularly transplanted malignant tumour (MS-2 fibrosarcoma) and healthy muscle in female Balb/c mice, 3, 24, 48 and 96 h post injection. The fluorescence was induced with a dye laser pumped by a nitrogen laser, emitting light at 425 nm. The fluorescence spectra were recorded in the region 455-760 nm using a polychromator equipped with an image-intensified CCD camera. The tumour/peritumoral muscle ratio was about 5:1 for CP(Me)3 and about 6:1 for CP(OMe)3 in terms of the background-free fluorescence intensity, which peaked at about 655 nm. By including the endogenous tissue fluorescence, the contrast was further enhanced by a factor of approximately 2