27 research outputs found
Effect of Temperature on Solid-state Hydride Metal Synthesis According to Thermodynamic Modeling
Thermodynamic modeling of the reduction of copper dichloride in the media of various gaseous hydrides (ammonia, monosilane, methane) in the temperature range 273-1000 K was carried out. Calculations show that in narrower temperature ranges corresponding to the reactions of solid-state hydride synthesis (SHS) of metal sub- stances metal formation is usually supported by theoretical propositions. As a result of thermodynamic modeling, a principal result was obtained on the suppression ofΒ competing processes of nitriding, siliconizing and carbonizationΒ of metal under SHS conditions, which is important for metallurgical production. This additionally substantiates the correctness of previous experimental studies of SHS metals with modified surface and improved properties. By mod- eling, it was found that the reduction of solid copper dichloride to metal in ammonia or methane occurs stepwise (se- quentially, according to the Baykov rule) through the intermediate stages of the formation of a compound of low- valent copper β copper (I)chloride
Transrectal ultrasound-integrated spectral optical tomography of hypoxic progression of a regressing tumor in a canine prostate
The objective of this study was to evaluate if transrectal optical tomography implemented at three wavelength bands for spectral detection could monitor changes of the hemoglobin oxygen saturation (SβOβ) in addition to those of the total hemoglobin concentration ([HbT]) in lesions of a canine prostate, including an induced tumor modeling canine prostate cancer. Near-infrared (NIR) optical tomography was integrated with ultrasound (US) for transrectal imaging. Multi-spectral detection at 705 nm, 785 nm and 808 nm rendered measurements of [HbT] and SβOβ. Canine transmissible venereal tumor (TVT) cells were injected into the right lobe of a dog's prostate gland, which had a pre-existing cyst in the left lobe. Longitudinal assessments of the prostate were performed weekly over a 63-day duration by NIR imaging concurrent with grey-scale and Doppler US. Ultrasonography revealed a bi-lobular tumor-mass regressing from day-49 to day-63. At day-49 this tumor-mass developed a hypoxic core that became larger and more intense by day-56 and expanded further by day-63. The tumor-mass presented a strong hyper-[HbT] feature on day-56 that was inconsistent with US-visualized blood flow. Histology confirmed two necrotic TVT foci within this tumor-mass. The cyst appeared to have a large anoxic-like interior that was greater in size than its ultrasonographically delineated lesion, and a weak lesional elevation of [HbT]. On day-56, the cyst presented a strong hyper-[HbT] feature consistent with US-resolved blood flow. Histology revealed acute and chronic hemorrhage in the periphery of the cyst. The NIR imaging features of two other TVT nodules and a metastatic lymph node were evaluated retrospectively. Transrectal US-integrated spectral optical tomography seems to enable longitudinal monitoring of intra-lesional oxygenation dynamics in addition to the hemoglobin content of lesions in the canine prostate.Electrical & Computer EngineeringVeterinary Clinical Science
In vivo trans-rectal ultrasound-coupled near-infrared optical tomography of intact normal canine prostate
This is the first tomography-presentation of the optical properties of a normal canine prostate, in vivo, in its native intact environment in the pelvic canal. The imaging was performed by trans-rectal near-infrared (NIR) optical tomography in steady-state measurement at 840 nm on three sagittal planes across the right lobe, middle-line, and left lobe, respectively, of the prostate gland. The NIR imaging planes were position-correlated with concurrently applied trans-rectal ultrasound, albeit there was no spatial prior employed in the NIR tomography reconstruction. The reconstructed peak absorption coefficients of the prostate on the three planes were 0.014, 0.012, and 0.014 mm-1. The peak reduced scattering coefficients were 5.28, 5.56, and 6.53 mm-1. The peak effective attenuation coefficients were 0.45, 0.43, and 0.50 mm -1. The absorption and effective attenuation coefficients were within the ranges predictable at 840 nm by literature values which clustered sparsely from 355 nm to 1064 nm, none of which were performed on a canine prostate with similar conditions. The effective attenuation coefficients of the gland were shown to be generally higher in the internal aspects than in the peripheral aspects, which is consistent with the previous findings that the urethral regions were statistically more attenuating than the capsular regions.Electrical and Computer EngineeringVeterinary Clinical Science
In vivo trans-rectal ultrasound-coupled optical tomography of a transmissible venereal tumor model in the canine pelvic canal
In vivo trans-rectal near-infrared (NIR) optical tomography was performed concurrently with, albeit reconstructed without spatial a prior of, trans-rectal ultrasound (US) on transmissible venereal tumor (TVT) developed as a model in the canine pelvic canal. Studies were taken longitudinally at prior to, 14 days after, and 35 days after the TVT injection. As the tumor grew, the nodules became increasingly hyperabsorptive and moderately hyperscattering on NIR. The regions of strong NIR contrast, especially on absorption images, correlated well with those of US hypoechoic masses indicative of tumors. Combining the information of trans-rectal NIR and US detected the tumor more accurately than did the US alone at 14 days postinjection.Veterinary Clinical SciencesElectrical and Computer Engineerin
Trans-rectal ultrasound-coupled near-infrared optical tomography of the prostate. Part II: Experimental demonstration
We demonstrate trans-rectal optical tomography of the prostate using an endo-rectal near-infrared (NIR) applicator integrated with a transrectal ultrasound (TRUS) probe. The endo-rectal NIR applicator incorporated a design presented in our previously reported work. A continuous-wave NIR optical tomography system is combined with a commercial US scanner to form the dual-modality imager. Sagittal transrectal imaging is performed concurrently by endo-rectal NIR and TRUS. The TRUS ensures accurate positioning of the NIR applicator as well as guides NIR image reconstruction using the spatial prior of the target. The use of a condom, which is standard for TRUS, is found to have minimal effect on trans-rectal NIR imaging. Tests on avian tissues validates that NIR imaging can recover the absorption contrast of a target, and its accuracy is improved when the TRUS spatial prior is incorporated. Trans-rectal NIR/US imaging of a healthy canine prostate in situ is reported.Electrical and Computer EngineeringVeterinary Clinical Science
Exogenous glycosaminoglycans coat damaged bladder surfaces in experimentally damaged mouse bladder
BACKGROUND: Interstital cystitis is often treated with exogenous glycosaminoglycans such as heparin, chondroitin sulphate (Uracyst), hyaluronate (Cystistat) or the semi-synthetic pentosan polysulphate (Elmiron). The mechanism of action is presumed to be due to a coating of the bladder surface to replace the normally present chondroitin sulphate and heparan sulphate lost as a result of the disease. This study used fluorescent labelled chondroitin sulphate to track the distribution of glycosaminoglycans administered intravesically to mouse bladder that had been damaged on the surface. METHODS: The surfaces of mouse bladders were damaged by 3 mechanisms β trypsin, 10 mM HCl, and protamine sulphate. Texas Red-labeled chondroitin sulphate was instilled into the bladders of animals with damaged bladders and controls instilled only with saline. Bladders were harvested, frozen, and sectioned for examination by fluorescence. RESULTS: The normal mouse bladder bound a very thin layer of the labelled chondroitin sulphate on the luminal surface. Trypsin- and HCl-damaged bladders bound the labelled chondroitin sulphate extensively on the surface with little penetration into the bladder muscle. Protamine produced less overt damage, and much less labelling was seen, presumably due to loss of the label as it complexed with the protamine intercalated into the bladder surface. CONCLUSION: Glycosaminoglycan administered intravesically does bind to damaged bladder. Given that the changes seen following bladder damage resemble those seen naturally in interstitial cystitis, the mechanisms proposed for the action of these agents is consistent with a coating of damaged bladder
Effect of Temperature on Solid-state Hydride Metal Synthesis According to Thermodynamic Modeling
Π’Π΅ΡΠΌΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΠΌΠΎΠ΄Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ Π²ΠΎΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈΡ Π΄ΠΈΡ
Π»ΠΎΡΠΈΠ΄Π° ΠΌΠ΅Π΄ΠΈ Π² ΡΡΠ΅Π΄Π°Ρ
ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ
Π³Π°Π·ΠΎΠΎΠ±ΡΠ°Π·Π½ΡΡ
Π³ΠΈΠ΄ΡΠΈΠ΄ΠΎΠ² (Π°ΠΌΠΌΠΈΠ°ΠΊ, ΠΌΠΎΠ½ΠΎΡΠΈΠ»Π°Π½, ΠΌΠ΅ΡΠ°Π½) Π² ΠΈΠ½ΡΠ΅ΡΠ²Π°Π»Π΅ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡ 273-1000 Π. Π Π°ΡΡΠ΅ΡΡ ΠΏΠΎΠΊΠ°Π·ΡΠ²Π°ΡΡ, ΡΡΠΎ Π²
Π±ΠΎΠ»Π΅Π΅ ΡΠ·ΠΊΠΈΡ
ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ½ΡΡ
Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½Π°Ρ
, ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΡΡΡΠΈΡ
ΡΠ΅Π°ΠΊΡΠΈΡΠΌ ΡΠ²Π΅ΡΠ΄ΠΎΡΠ°Π·Π½ΠΎΠ³ΠΎ Π³ΠΈΠ΄ΡΠΈΠ΄Π½ΠΎΠ³ΠΎ ΡΠΈΠ½ΡΠ΅Π·Π° (Π‘ΠΠ‘) ΠΌΠ΅ΡΠ°Π»Π»ΠΈΡΠ΅ΡΠΊΠΈΡ
Π²Π΅ΡΠ΅ΡΡΠ², ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΠ΅ ΠΌΠ΅ΡΠ°Π»Π»ΠΎΠ² ΠΎΠ±ΡΡΠ½ΠΎ ΠΏΠΎΠ΄ΡΠ²Π΅ΡΠΆΠ΄Π°Π΅ΡΡΡ ΡΠ΅ΠΎΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΈΠΌΠΈ ΠΏΠΎΠ»ΠΎΠΆΠ΅Π½ΠΈΡΠΌΠΈ. Π ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ΅ ΡΠ΅ΡΠΌΠΎΠ΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΌΠΎΠ΄Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΎΡΠ½ΠΎΠ²Π½ΠΎΠΉ ΡΠ΅Π·ΡΠ»ΡΡΠ°Ρ Π±ΡΠ» ΠΏΠΎΠ»ΡΡΠ΅Π½ ΠΏΠΎ ΠΏΠΎΠ΄Π°Π²Π»Π΅Π½ΠΈΡ ΠΊΠΎΠ½ΠΊΡΡΠΈΡΡΡΡΠΈΡ
ΠΏΡΠΎΡΠ΅ΡΡΠΎΠ² Π°Π·ΠΎΡΠΈΡΠΎΠ²Π°Π½ΠΈΡ, ΡΠΈΠ»ΠΈΡΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΈ ΠΊΠ°ΡΠ±ΠΎΠ½ΠΈΠ·Π°ΡΠΈΠΈ ΠΌΠ΅ΡΠ°Π»Π»Π° Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ
Π‘ΠΠ‘, ΡΡΠΎ Π²Π°ΠΆΠ½ΠΎ Π΄Π»Ρ ΠΌΠ΅ΡΠ°Π»Π»ΡΡΠ³ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΡΡΠ²Π°