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Notes: We have grown and characterized heteroepitaxial films of InP on GaAs. We demonstrate that by using flow-rate modulation epitaxy to grow the interface layer in a two-step process, we can improve the quality of heteroepitaxy films. The full widths at half maximum of the x-ray rocking curve and the 10 K photoluminescence spectrum for a 6.2-μm-thick InP/GaAs are 144 arcsec and 1.28 meV, respectively.

Notes: Iron containing diamond-like amorphous carbon (a-C:Fe) films were deposited by filtered cathodic vacuum arc technique. The influences of Fe content and substrate bias on the surface energy of the films were investigated. The surface energy of a-C:Fe films was determined by the contact angle measurement. Atomic force microscopy, Raman spectroscopy, and x-ray induced photoelectron spectroscopy were employed to analyze the origin of the variation of surface energy with various Fe content and substrate bias. It is found that the contact angle for water increases significantly after incorporating Fe into the films and the films become hydrophobic. The roughness of these films has no effect on the contact angle. The surface energy is reduced from 42.8 to 25 dyne/cm after incorporating Fe into the a-C film (10% Fe in the target), which is due to the reduction of both dispersive and polar component. The reduction in dispersive component is ascribed to the decrease of atomic density of the a-C:Fe films due to the increase in sp2 bonded carbon. When sp2 content increases to some extent, the atomic density remains constant and hence dispersive component does not change. The absorption of oxygen on the surface plays an important role in the reduction of the polar component for the a-C:Fe films. It is proposed that such network as (Cn–O–Fe)–O–(Fe–O–Cn) may be formed and responsible for the reduction of polar component. © 2001 American Institute of Physics.

Notes: The aim of glaucoma therapy is to preserve vision by reducing intraocular pressure (IOP). Following recent National Eye Institute sponsored studies, it is becoming increasingly apparent that every mmHg of extra IOP lowering counts.Bimatoprost is the newest and most effective addition to the physician's armamentarium of ocular hypotensive drugs. Direct clinical comparisons have demonstrated that it is more efficacious than the prostaglandin (PG) FP receptor agonist prodrugs, latanoprost and travoprost, as well as a β-adrenoceptor antagonist, timolol, alone or in fixed combination with the carbonic anhydrase inhibitor, dorzolamide. Moreover, patients that are refractory to latanoprost therapy may be successfully treated with bimatoprost. Such evidence provides support, at the clinical level, for the contention that bimatoprost is pharmacologically distinct from PG FP receptor agonist prodrugs.Bimatoprost is a structural analog of PGF2α-ethanolamide (prostamide F2α), which is formed from the endocannabinoid anandamide by a biosynthetic pathway involving cyclooxygenase-2 (COX-2). Their pharmacology is remarkably similar, such that bimatoprost may be regarded as a prostamide mimetic. The target receptor for bimatoprost and the prostamides appears unique and unrelated to PG- and endocannabinoid-sensitive receptors. Extensive ocular distribution/metabolism studies in non-human primates demonstrate that bimatoprost is not a prodrug, it remains essentially intact. Its profound ocular hypotensive effects may, therefore, be attributed to its prostamide-mimetic properties.

Notes: This paper presents new findings on ultrasonic spray pyrolysis of zirconium hydroxyl acetate precursor drops whose sizes were precisely measured using laser light diffraction technique. Precursor concentration plays a predominant role in determination of product particle size. At 0.01 wt% precursor concentration, conventional spray pyrolysis at 750°C using precursor drops 5–8 μm in diameter, generated by an ultrasonic nebulizer at 2.66 MHz, yielded uniform spherical yttria-stabilized zirconia (YSZ) particles 73 nm in diameter measured by scanning electron microscopy. The YSZ particle diameters were much smaller than those predicted by the one-particle-per-drop mechanism. Under similar reaction conditions, the high-throughput ultrasound-modulated two-fluid (UMTF) spray pyrolysis of larger precursor drops (28-μm peak diameter) also yielded spherical dense particles; they were significantly smaller in size than those produced by the low-throughput conventional ultrasonic spray pyrolysis of smaller drops (6.8-μm peak diameter).

Notes: Haplotype associations of the major histocompatibility complex (MHC) with psoriasis vulgaris (PV) have been demonstrated in different racial or ethnic populations. The objective of this study was to demonstrate the different haplotype associations of the MHC in Chinese patients with psoriasis according to the type of onset and their sex. One hundred and thirty-eight patients with PV and 149 normal control subjects without psoriasis were typed for HLA-A, -B, -C, -DQA1, -DQB1 and -DRB1 by using the PCR with sequence-specific primers. The results showed: (i) HLA-A*26 (26.1% vs. 12.1%, Pc 〈 1 × 10−5), -B*27 (17.03% vs. 1.01%, Pc 〈 1 × 10−7), -Cw*0602 (15.58% vs. 5.03%, Pc 〈 1 × 10−2), -DQA1*0104 (19.93% vs. 9.40%, Pc 〈 1 × 10−3), -DQA1*0201 (22.40% vs. 10.74%, Pc 〈 1 × 10−3), -DQB1*0303 (18.12% vs. 9.73%, Pc 〈 1 × 10−7), and -DRB1*0701/02 (26.09% vs. 9.73%, Pc 〈 1 × 10−7) were significantly increased in PV patients, while HLA-B*57, -DQB1*0201 were slightly increased in PV patients. HLA-Cw*0304 (5.07% vs. 14.43%, Pc 〈 1 × 10−3), -DQA1*0501 (5.79% vs. 14.09%, Pc 〈 0.05) were found to be negatively associated with PV, but HLA-A*2 (2.54% vs. 6.38%, Pc 〈 0.5) was decreased in PV patients without statistical significance. (ii) HLA-A*26-B*27 [P 〈 0.0001, odds ratio (OR) = 48.38], -A*26-Cw*0602 (P 〈 0.0001, OR = 11.84), -B*27-Cw*0602 (P 〈 0.0001, OR = undefined), -DRB1*0701/02-B*27 (P 〈 0.0001, OR = 22.62), -DRB1*0701/02-DQA1*0104 (P 〈 0.0002, OR = 3.59), -DRB1*0701/02-DQB1*0303 (P 〈 0.0001, OR = 5.63), -DQA1*0201-DQB1*0303 (P 〈 0.0002, OR = 7.77), -A*26-B*27-Cw*0602 (P 〈 0.0004, OR = undefined), -A*26-DRB1*0701/02-DQA1*0201-DQB1*0303 (P 〈 0.01, OR = undefined) were identified as risk haplotypes for patients with PV in China. (iii) HLA-A*26 -B*27 (P 〈 0.0001, OR = 58.47), -DQA1*0201-DQB1*0303 (P 〈 0.0001, OR = 8.62), -DRB1*0701/02 -DQA1*0104 (P 〈 0.0002, OR = 4.13), -DRB1*0701/02-DQB1*0303 (P 〈 0.0001, OR = 6.68) and -A*26-DRB1*0701-DQA1*0201 -DQB1*0303 (P 〈 0.006, OR = undefined) were only significantly associated with type I psoriasis compared with controls, while others showed no differences in either type I or type II psoriasis. (iv) These associated haplotypes with PV were not different by sex, except that the frequency of DRB1*0701/02-DQB1*0303 (P 〈 0.0001, OR = 10.14) was higher in male patients with psoriasis. To summarize, this study demonstrated a differential association of HLA and identified some special risk haplotypes in Chinese patients with PV compared with other ethnic or racial populations.

Notes: A melt-annealing method has been developed to deposit highly textured superconducting thick films on different substrates in the Bi-Sr-Ca-Cu-O system. As opposed to previous techniques, this method uses powder made from an extremely dense glass sample to yield very uniform and dense thick films. The x-ray diffraction and scanning electron microscopy results indicate that the superconducting phase is strongly oriented along the c axis perpendicular to the substrate and the films are chemically uniform. Electrical transport measurements consistently show a Tc near 80 K for all samples.

Notes: Hot-electron transistors fabricated using a 600-A(ring) InGaAs base and a 500-A(ring) InAlAs barrier have shown a peak ballistic common base current gain of 0.82 at 77 K despite the large injection energies. Reduction of injection energies by lowering the emitter and collector barriers should lead to an even higher ballistic transport ratio due to the reduced Γ-L scattering.

Notes: Kinetics of the 110 K superconducting phase formation has been studied in the Bi-Sr-Ca-Cu-O system with and without the addition of small amounts of lead. The kinetics of the phase transformation has been greatly affected by lead doping. The time required for the maximum formation of the 110 K phase is substantially reduced by the addition of lead. This phenomenon has been shown to be associated with the lead enhancing the nucleation and growth process of the 110 K phase and the diffusivity of calcium and copper.

Notes: The base-collector junction of GaAs/AlGaAs single heterojunction bipolar transistors has been observed to emit light at avalanche breakdown. The spectral distribution curve exhibits broad peaks at 2.03 and 1.43 eV, with the intensities dependent upon the reverse current. These observations suggest that electrons, excited to the upper conduction band by the field, lose their energy by impact ionizing electron-hole pairs and producing the 2.03 eV light, which corresponds to the threshold energy for electron impact ionization. The band-edge emission is the result of direct-gap free-carrier recombination and self-absorption of the high-energy transition.

Notes: Infrared photodiodes fabricated with HgCdTe epilayers grown on GaAs substrates by molecular beam epitaxy (MBE) are reported here for the first time. Growth was carried out on the (211)B orientation of GaAs, and the as-grown epilayer (x=0.24) was p type. The n-p junction was formed by Be ion implantation, the resistance-area product (R0 A) at zero bias was 1.4×103 Ω cm2 , the wavelength cutoff was 8.0 μm, and the quantum efficiency was 22%; all were measured at 77 K. We show that in the diffusion regime diodes fabricated with MBE HgCdTe/GaAs have comparable R0 A product values to those made with HgCdTe grown by bulk techniques. This result discloses new possibilities for advanced monolithic HgCdTe devices based on GaAs integrated circuit technology.