Experimental Taenia solium cysticercosis in pigs: characteristics of the infection and antibody response

The biology of aging is reviewed from the perspective of a medical geneticist. This was the perspective of the late Sam Goldstein, and this article is, therefore, dedicated to his memory. Aging can be defined as the set of phenotypes that escape the force of natural selection. These phenotypes can be modulated by mutation or polymorphism at numerous genetic loci. Given the remarkable genetic and environmental heterogeneity that characterizes our species, it is understandable that there should be considerable variation in patterns of aging. A genetic approach involving the mapping and positional cloning of major loci could provide basic understanding of the mechanisms underlying such variability. Prototypic examples being investigated by the author and his colleagues are the Werner syndrome and dementias of the Alzheimer type. The biochemical genetic analysis of these and other disorders could lead to a new style of medicine based upon preventive approaches tailored to the needs of individuals. Such interventions should ideally involve pediatricians.     

Low-frequency noise in submicrometer MOSFETs with HfO/sub 2/, HfO/sub 2//Al/sub 2/O/sub 3/ and HfAlO/sub x/ gate stacks

Low-frequency noise measurements were performed on p- and n-channel MOSFETs with HfO/sub 2/, HfAlO/sub x/ and HfO/sub 2//Al/sub 2/O/sub 3/ as the gate dielectric materials. The gate length varied from 0.135 to 0.36 /spl mu/m with 10.02 /spl mu/m gate width. The equivalent oxide thicknesses were: HfO/sub 2/ 23 /spl Aring/, HfAlO/sub x/ 28.5 /spl Aring/ and HfO/sub 2//Al/sub 2/O/sub 3/ 33 /spl Aring/. In addition to the core structures with only about 10 /spl Aring/ of oxide between the high-K dielectric and silicon substrate, there were "double-gate oxide" structures where an interfacial oxide layer of 40 /spl Aring/ was grown between the high-K dielectric and Si. DC analysis showed low gate leakage currents in the order of 10/sup -12/ A(2-5 /spl times/ 10/sup -5/ A/cm/sup 2/) for the devices and, in general, yielded higher threshold voltages and lower mobility values when compared to the corresponding SiO/sub 2/ devices. The unified number-mobility fluctuation model was used to account for the observed 1/f noise and to extract the oxide trap density, which ranged from 1.8 /spl times/ 10/sup 17/ cm/sup -3/ eV/sup -1/ to 1, 3 /spl times/ 10/sup 19/ cm/sup -3/ eV/sup -1/ somewhat higher compared to conventional SiO/sub 2/ MOSFETs with the similar device dimensions. There was no evidence of single electron switching events or random telegraph signals. The aim of this paper is to present a general discussion on low-frequency noise characteristics of the three different high-K/gate stacks, relative comparison among them and to the Si-SiO/sub 2/ system.     

Histamine H3 receptor desensitization in the guinea-pig ileum

Histamine H3 receptor ligands are usually tested in guinea-pig intestine preparations. A possible desensitization of agonist-induced twitch inhibition was studied in longitudinal muscle-myenteric plexus from ileal segments. A cumulative concentration-response curve for R-alpha-methylhistamine was made; when a second curve was made 30 min afterwards, a marked decrease of pD2 and a more modest decrease of Emax were observed without changes in tissue sensitivity to electrical stimulation or morphine inhibition. At 120 min, pD2 and Emax were not different from those for the first curve. Receptor desensitization seems homologous and reversible and could interfere with repetitive testing of histamine H3 receptor ligands.     

Procedural results and late clinical outcomes after placement of three or more stents in single coronary lesions

BACKGROUND: Previous reports have suggested higher procedural and long-term complications among patients treated with multiple stents for diffuse lesions and/or long dissections. METHODS AND RESULTS: To evaluate procedural success, major complications, and clinical outcomes (> or = 1 year) in a consecutive series of patients treated with multiple (> or = 3) contiguous stents in single lesions, we evaluated in-hospital and long-term (1-year) clinical outcomes in 117 consecutive patients treated with > or = 3 coronary stents compared with a concurrent series of patients treated with 1 or 2 stents (n=1673) between January 1, 1994, and December 31, 1995. Multiple stents were implanted more often in larger vessels, in the right coronary artery or saphenous vein grafts, and for unfavorable lesion characteristics, including long (>20 mm), calcified, ulcerated, thrombotic, and/or flow-obstructing lesions. Overall procedural success was obtained in 97.4% of patients and was similar whether 1 or 2 versus > or = 3 stents were used. Non-Q-wave MI (CK-MB > or = 5 times normal) was more frequent after > or = 3 stents (22.8% versus 13.4%, P=.005). Target lesion revascularization (TLR) was 14.6% for 1 or 2 stents and 13.3% for > or = 3 stents (P=.70). There was no difference in death (2.2% versus 0.9%, P=.34) or Q-wave MI (1.4% versus 0.9%, P=.64) between the two groups (1 or 2 stents versus > or = 3 stents, respectively), and overall cardiac event-free survival was similar during follow-up (P=.70). CONCLUSIONS: Patients treated with multiple (> or = 3) contiguous stents compared with 1 or 2 stents have (1) similar in-hospital procedural success and major complications despite having more unfavorable lesion characteristics, (2) a higher rate of procedural non-Q-wave MI, and (3) similar TLR and overall major cardiac event rates during 1 year of follow-up.     

Formation of High-Tc Superconducting Bi-Pb-Sr-Ca-Cu Oxide Films by Spray Pyrolysis of an Oxalate Suspension

A Bi-Pb-Sr-Ca-Cu oxide superconducting thick film, exhibiting T_c(onset) = 120 K and T_c(zero) = 100 K, can be obtained by spray pyrolysis of oxalate suspension on the (100) MgO substrate, using the partial-melting state at 860°C for 15 h, a rapid-quenching process to 500°C, and a postannealing treatment for 1 h at 835°C. These processes are believed to enhance the volume fraction of 2223 phase and increase the T_c(zero) . The films show preferred orientation and adhere well to the substrate.