Now showing 1 - 10 of 295
- ItemCalculation of the net tunneling electric current in S'-I-S junction(Mahidol University. Mahidol University Library and Knowledge Center, 2023) Mukda Siribangphae; Rassmidara Hoonsawat; Tang, I. Ming; Sukajit LeelapruteThe transmission coefficients for the S-I-S system are calculated by using the boundary value treatment. It is assumed that the carriers are both electrons and holes. The calculated coefficients is found to be related to the BSC density of states. Since these coefficients appear in the integral expression for the net tunneling current, the tunneling currents for the S-I-S system are also related to the BSC density of states. The integrals are evaluated numerically to yield a "predicted" net electric current for the S-I-S junctions. The "predicted" current-voltage curves are in very good agreement with experimental results found in the literature. The only adjustments needed for the curve fitting are the values of the wave vector within the insulator layer in the junction. The order of magnitude of the tunneling current for applied voltages in the millivolt range are in exact agreement with the observed magnitudes. The agreement appears for S and S being either high T. superconductors or being conventional superconductors. The calculated tunneling currents for S-I-S and S-I-S systems are also analyses as a function of the imaginary part of the insulator wave vector k, the insulator thickness L, the energy gaps and the critical temperatures of S and S.
- ItemBiological and genetic characteristics of vibrio parahaemolyticus isolated from raw seafoods in Thailand(Mahidol University. Mahidol University Library and Knowledge Center, 2023) Jutamas Pumiprapat; Orasa Suthienkul; Kanokrat Siripanichgon; Boonchuay Eampokalap; Saovanee C. Dharmsthiti
- ItemAssessment of the effectiveness of oral rehydration therapy (ORT) against severe dehydration in diarrhea : case-control study(Mahidol University. Mahidol University Library and Knowledge Center, 2023) Pulungsih, Sri Pandam, 1951-; Amphorn Ittiravivongs; Junya Pattaraarchachai; Wandee Varavithya
- ItemBrain growth in rats fed essential fatty acid deficient diet since neonatal period(Mahidol University. Mahidol University Library and Knowledge Center, 2023) Uraiwan Wutisilp; Phienvit Tantibhedhangkul; Sakorn Dhanamitta; Naiphinich Kotchabhakdi
- ItemArtificial insemination in cows : estrous and pregnancy detection by measurement of reproductive hormones(Mahidol University. Mahidol University Library and Knowledge Center, 2023) Wunnee Buaboocha; Kanok Pavasuthipaisit; Puthipongse Varavudhi; Manit Panprapa
- ItemBifurcation analysis of a product inhibition model of a continuous fermentation process(Mahidol University. Mahidol University Library and Knowledge Center, 2023) Chalard Chiaranai; Yongwimon Lenbury; Rassmidara Hoonsawat; Tang, I. Ming; Nardtida Tumrasvin
- ItemBiomechanics of the snatch technique of Thai weightlifters(Mahidol University. Mahidol University Library and Knowledge Center, 2023) Patraporn Tepjitra; Thyon Chentanez; Sommart Keorochana; Sirirat Hirunrat
- ItemStudy of acute and subacute toxicity of 2,4,6-trihydroxyacetophenone and its effect on hepatic excretory function(Mahidol University. Mahidol University Library and Knowledge Center, 2023) Chatsuda Tubtim; Prayad Komaratat; Pawinee Piyachaturawat; Chaivat ToskulkaoToxicity of phloracetophenone (2,4,6-trihydroxyacetophenone, THA), the aglycone part of phloracetophenone glucoside from Curcuma comosa (family Zingiberaceae), which has previously been reported to stimulate bile secretion and lower plasma lipids, was evaluated. Acute toxicity of a single dose of THA was studied in mice (weanlings and adults), hamsters, and rats of both sexes, by oral and intraperitoneal administration. LD50 values were dependent on species, sex of animals and routes of administration, but was not age dependent. THA was practically classified as a non-toxic compound when it was given to rats by an oral route (i.g.). The LD50 value in adult male and female rats was higher than 6 g/kg BW. Hamsters and mice appeared to be the more sensitive to THA than rats. LD50 value via intraperitoneal (i.p.) route in adult males were 338 and 365 mg/kg BW, respectively. At lethal doses, the animals became excited, with ataxia and hypersensitivity to noise, followed by convulsions and death with respiratory paralysis. Subacute toxicity was studied in adult male mice, by giving a daily sublethal dose of THA (37-300 mg/kg BW, i.g.) for 30 consecutive days. A high dose of THA (150 mg/kg BW) induced marked changes of hepatocytes at periportal area including vacuolization of hepatocyte and nuclear degeneration. In severe cases, the affected area was expanded from the periportal area into the central area. Plasma concentrations of liver enzymes, alanine and aspartate aminotransferases and other biochemical parameters including bilirubin, BUN and hepatic triglyceride content were slightly increased. The content of liver glutathione varied but remained within the normal range. It is suggested that THA, particularly at high dose, partially induced subacute toxicities in mice and probably, those toxic effects can be attributed to THA itself, not its metabolite. Furthermore, hepatic excretory function, after THA treatment, was evaluated by using the sulfobromophthalein (BSP) clearance method. Plasma disappearance and biliary excretion of an intravenous BSP injection were assessed in bile duct-cannulated controls and 17 α-ethinylestradiol (EE)-induced cholestatic rats. A single intraduodenal administration of THA at a dose of 50 or 100 mg/kg BW immediately increased bile flow rate, which peaked at 15 min. The acute increase of bile flow rate by THA enhanced hepatic clearance of BSP and decreased plasma alkaline phosphatase in EE-cholestatic rats to normal levels but did not affect bilirubin. Prolonged treatment with THA for 5 days increased basal bile flow rate and BSP clearance in EE-cholestatic rats. These results suggest that THA at a biologically active dose had low toxicity and might be safe for further development as a therapeutic agent for a short treatment in some hepatic disorders.
- ItemMicroangioarchitecture of seminal vesicle and prostate gland in common tree shrew (Tupaia glis)(Mahidol University. Mahidol University Library and Knowledge Center, 2023) Koumkrit Pisetpaisan; Reon Somana; Panjit Chunhabundit; Wisuit Pradidarcheep; Wichai EkataksinThis study was aimed at elucidating the blood supply system to the seminal vesicle and the prostate gland in the common tree shrew (Tupaia glis.). Eighteen male common tree shrews weighing between 110-190 g were used. Their seminal vesicles and prostate glands were prepared for studying with LM and with corrosion cast technique. It was found that the seminal vesicle and prostate glands were supplied by branches of the anterior division of the internal iliac artery. This artery also supplies the pelvic visceral organs. The anterior division of internal iliac artery gives off three main branches. The first one is the superior vesical artery which gives off five branches to supply urinary bladder, ureter, vas deferens, urethra and finally it courses to the medial side of the seminal vesicle to become the seminal vesicle artery. The second branch of anterior division of internal iliac artery is the inferior vesical artery which gives off five to seven branches. Five to six branches supply the dorsal and ventral surfaces of the distal portion (glandular acini region) of the gland and continue to the intermediate section of the ducts and finally supply the proximal portion of tile prostatic ducts adjacent to the prostatic urethra. The remaining branches supply tile prostatic urethra and membranous urethra. The third branch of the anterior division of internal iliac artery is internal pudendal artery. The first and the second branches from the anterior division of the internal iliac artery, usually anastomoses with one another, are called the marginal branch of superior vesical artery. This branch gives off several arterioles to supply the greater curvature and the posteromedial side of the seminal vesicle and the rostral region of the anteroventral lobe of the prostate eland The penetrating arterioles terminate as capillary network. The capillaries supplying the seminal vesicle and prostate gland are without fenestration. The veins from the two glands usually accompany the arteries. The interconnections between veins are usually found in both of seminal vesicle and prostate gland. These veins open into tile internal iliac vein before joining the external iliac artery to form the inferior vena cava. The pattern of blood supply of the prostate gland in the common tree shrew is quite similar to that of human but somewhat different from that of rat. The blood supply to the ventral prostate in rats appears as a single trunk with the base near the proximal portion of the prostatic duct adjacent to the prostatic urethra. These vessels eventually branch out into smaller vessels, at the intermediate section of the duct most of which continue to the distal part (the glandular acini) where they supply tilt distal region of the prostatic duct and the glandular portion.
- ItemTissue preservation of plastinated brain slices : a comparison between two types of dehydration methods, lyophilization followed by acetone and lyophilization alone(Mahidol University. Mahidol University Library and Knowledge Center, 2023) Thanitsara Weachateng; Sukumal Chongthammakun; Boonsirm Withyachumnarnkul; Wantane TrakulrungsiThe Conventional method for brain slice plastination has been improved by adding a staining procedure and changing the dehydration method, from acetone dehydration to lyophilization. The improved technique still has some drawbacks; flaking occurs on the brain surface after being platinated. This study was aimed at the further improvement of the technique, which could eliminate the flaking. The brain slices were platinated through the standard procedure for S10 plastination. The only difference was in the dehydration process. After fixation and sectioning at 4 mm thick in coronal sections, and at 6 mm thick in horizontal and sagittal sections, the brains were dehydrated through lyophilization for 48 hours, followed by acetone immersion for 8 hours. The specimens were subsequently processed by forced impregnation and curing. The final products were platinated brain slices, with brownish color of the gray matter and cellular components (nuclei) and whitish of the white matters and neuronal fibers or nerve tracts. The degree of shrinkage was 5% in average, which was less than that that of the brains dehydrated by lyophilization only (6% shrinkage). The surface of the brain slices were glistening and smooth, no flaking was observed. Compared to the brain slices that were dehydrated through lyophilization alone, the newly developed brain slices were more flexible and show higher contrast between the gray and white matter. The degree of brightness of the brain surfaces, termed the integrated density, was quantified by computerized software Image Tool. It was found that the platinated brain slices that were dehydrated through lyophilization, and acetone immersion had significantly higher contrast than that of the brains dehydrated by lyophilization alone or those dehydrated by acetone alone and stained with Alston's method.