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We have developed indirectly heated hollow cathode electrodes and a cascade arc discharge apparatus with different channel diameters to realize plasma windows (PWs) as virtual vacuum interfaces. A compact arc discharge source with a channel diameter of 3 mm is fabricated to realize windowless vacuum–atmosphere separation. An atmospheric high-density Ar thermal plasma is generated, and a PW that produces 100 kPa and 81 Pa separation is demonstrated. An 8 mm channel diameter arc device is also constructed for application as an alternative differential pump with the separation of low- and high-pressure vacuum chambers, and the production of a high-density He plasma. Pressure differences of 2.5 kPa and 16 Pa between PWs are realized. Moreover, vacuum UV and visible emission spectroscopy reveal the characteristics of expanding plasmas and the plasma parameters.

The aims of this descriptive study were to confirm the high incidence of subacute sclerosing panencephalitis (SSPE) previously reported from Papua New Guinea (PNG) and to relate SSPE to previous measles vaccination and measles illness. From February 1997 to April 1999 we diagnosed a total of 55 patients with SSPE at Goroka Base General Hospital in Eastern Highlands Province (EHP) of PNG. The diagnosis was based on high cerebrospinal fluid and serum measles virus antibody titres with progressive neurological disorder and myoclonic jerks. Of these 55 patients 42 were from EHP, including 32 whose onset was in the 2-year period 1997–1998. The annual incidence of SSPE in EHP in these 2 years was 98 per million population under 20 years of age, the highest ever reported. This incidence was more than ten times higher than the highest incidence in the prevaccine era reported from elsewhere. The mean age of onset of SSPE was 7·7 years (range 2·8–14·8 years) and the interval between measles and the onset of SSPE, where known, had a mean of 5·9 years and a range of 2·5–11·1 years. Among the SSPE patients 19 had a documented history of measles vaccination. Eight of these 19 also had documentation of previous measles illness; of these, seven were vaccinated after the development of measles and one was vaccinated 20 days before measles illness. Two non-SSPE children received vaccination twice which was documented and subsequently developed measles which was also substantiated by documentation. Two patients with SSPE yielded amplified nucleotide sequences of measles virus that were different from any of the vaccine strains. We found no evidence to implicate measles vaccination in the development of SSPE.

We present a theory for the electronic and optical properties of n- and p-type In1−xMnxAs in ultra-high magnetic fields. An eight-band effective mass model based on the Pidgeon–Brown model and including the wavevector dependence of the electronic states as well as the s–dand p–dexchange interactions with Mn d-electrons is used to determine the electronic states. The optical properties such as cyclotron resonance are computed using Fermi's golden rule. Comparison of the theory with ultra-high magnetic field (>50 T) cyclotron resonance experiments shows that the electron cyclotron resonance peak shifts with Mn doping and that the shift allows one to extract the Mn-electron/hole exchange parameters, α and β. The hole cyclotron resonance shows multiple resonance peaks, which we attribute a heavy to heavy and light to light hole transitions.

We have performed a two-color time-resolved magneto-optical Kerr effect (MOKE) study of a ferromagnetic InMnAs/GaSb heterostructure. We observed ultrafast photoinduced changes in the MOKE signal induced by a large density of spin-polarized transient carriers created only within the InMnAs layer using intense 140 fs mid-infrared pulses. Our data clearly demonstrates that magnetic properties, e.g., remanence and coercivity, can be strongly modified. The dependence of these changes on the time delay, pump polarization, pump intensity, and sample temperature is discussed.

We have studied the cyclotron resonance of electrons and holes in various types of InMnAs-based structures at ultrahigh magnetic fields. Our observations, in conjunction with an eight-band effective mass model including the s–d and p–d exchange interactions with Mn d-electrons, unambiguously suggest the existence of s-like and p-like delocalized carriers in all samples studied. The samples studied include Paramagnetic n-type In1−xMnxAs films (x ∼ 0.12) grown on GaAs, ferromagnetic p-type In1−xMnxAs films (x ∼ 0.025) grown on GaAs with Curie temperatures (TC) > 5 K, paramagnetic n-type In1−xMnxAs/InAs superlattices, ferromagnetic p-type In1−xMnxAs/GaSb heterostructures (x ∼ 0.09) with TC= 30-60 K, and ferromagnetic (In0.53Ga0.47)1−xMnxAs/In0.53Ga0.47As heterostructures (x ∼ 0.05) grown on InP with TCup to 120 K.

We have investigated the terahertz photoresponse of quantum wires in high magnetic fields, employing intense far-infrared (FIR) radiation from the UCSB Free-Electron Lasers. Both GaAs-based and InAs-based quantum wires, with widths ranging from 50 nm to 1 μm, were studied. At high FIR power we observed Shubnikov–de Haas type oscillations in photoresponse versus magnetic field,B, resulting from non-resonant electronic heating the oscillations were much more pronounced than those in resistance versusB. At low FIR power we observed resonant peaks due to magnetoplasmon excitations, whose strength shows strong polarization-dependence and whose energy extrapolates to a finite value at zeroB. These results provide a powerful tool for characterizing 1D electronic states in quantum wires.

We have probed the linear and nonlinear terahertz (THz) properties of magnetoexcitons in GaAs/AlGaAs quantum wells. By monitoring photoluminescence from the quantum wells that were simultaneously driven by THz fields, we have directly observed internal transitions of excitons. In the nonlinear, high-THz-excitation regime, we observed mixing of optical and THz radiation, which resulted in THz optical sidebands. By monitoring the sidebands, we observed one- and two-THz-photon nonlinear internal transitions in excitons. These results provide new and accurate information on the energy structure and internal dynamics of excitons.

Saturation of the D01s-2p^+transition, the D−-singlet transition and CR has been studied in donor (Si)-doped GaAs/AlGaAs multiple-quantum-well samples by magneto-transmission and magneto-photoconductivity measurements with the UCSB free electron laser. Effective lifetimes of the D01s-2p+transition were found to vary systematically with laser frequency, decreasing from 62 ns at 84≈cm−1to 3 ns at 124 cm−1. The absorption coefficient of the D–-singlet transition initially increased by up to 40% and showed complete quenching at higher laser powers.

South-east Asian ovalocytosis status was determined in 1629 individuals originating from 12 different geographical areas of Papua New Guinea, representing different ethnic groups and degrees of malaria endemicity. This was achieved by using polymerase chain reaction amplification to demonstrate a 27 base pair deletion in the erythrocyte band 3 (AE1) gene. By using this method, the prevalence of erythrocyte band 3 gene deletion was determined to range from zero in both the lowland inland area of Wosera, East Sepik Province and the highland region of Goroka, Eastern Highlands Province to 35% on the north coast of Madang Province. In general, the prevalence correlated well with altitude, being highest on the coast where malaria transmission is high, intermediate in the lowlands, and lowest in the non-malarious highlands. However, Wosera, a lowland area in the Sepik River Plains, which is hyperendemic for malaria, was an exception in that no ovalocytosis was detected. These results largely confirm the prevalence rates that have been reported in the past using microscopy. In keeping with the autosomal dominant mode of inheritance, the male:female ratio was 1.02 and no homozygote was detected, indicating that homozygosity for the ovalocytosis band 3 gene deletion is lethal.

Wir berichten über einen bisher weitgehend asymptomatischen bisexuellen Patienten mit beidseitiger luesindizierter Optikusperineuritis als Frühmanifestation einer HIV-Infektion. Ein 29-jähriger Mann stellte sich aufgrund subjektiver Sehverschlechterung beim Augenarzt vor. Es bestanden sonst keine weiteren Beschwerden. Der Visus lag rechts bei 0,4 und links bei 0,6. Pigmentierte Endothelbeschläge und eine unscharf begrenzte prominente Papilla nervi optici fielen an beiden Augen auf. Das Gesichtsfeld zeigte einen vergrößerten blinden Fleck. Das VEP ergab links eine normale Ableitung, rechts eine im Seitenvergleich reproduzierbare Amplitudenminderung bei dezenter Latenzverzögerung. Serologisch waren die Untersuchungen für Lues (TPHA 1:655360, Lues-IgM-FTA-Test und Lues-IgMELISA, Cardiolipin > 1:640) und HIV (starke Antikörperreaktion mit allen diagnostisch relevanten HIV-1-Proteinen) positiv. Nach i.v. und i.m. Penicillin-Therapie kam es zu einer deutlichen Besserung der Symptome. Eine Optikusperineuritis kann als Erstmanifestation einer Syphilis bei human-immunodeficiencyvirus-positiven Patienten vorkommen. Die syphilisinduzierte Optikusperineuritis kann sogar als initiale Manifestation einer HIV-Infektion auftreten. We report on an asymptomatic bisexual patient with bilateral lues induced papillitis as early manifestation of HIV infection. A 29-year old man presented with a reduced visual acuity without any other complaints. Visual acuity was 5/20 (OD) and 12/20 (OS). Pigmented corneal precipitates and prominent optic disc with indistinct margins were formed. The visual field showed an enlargement of blind spot. VEP was normal at the left side and a comparative marginal reduction of amplitude right. Serological examination showed positive results for lues (TPHA 1:655360, Lues-IgMFTA-Test and Lues IgM ELISA, Cardiolipin > 1:640) and HIV (reactive with all diagnostic relevant HIV-1-proteines). Clinical symptoms and morphological findings improved after i.v. and i.m. penicillin therapy. Optic perineuritis may be the first manifestation of syphilis in HIV-positive patients. Syphilitic optic perineuritis may even be an early manifestation of HIV disease.

We observe the linear and non-linear optical properties of a semiconductor multiple quantum well under intense terahertz irradiation to reveal a Dynamical Franz-Keldysh Effect. It is characterized by increased sub-gap absorption and oscillations in the absorption above the gap which vary with applied THz field and frequency. We also observe non-linear mixing of near-bandgap light of frequency ΩNIR with a strong Terahertz field of frequency ωTHz to produce optical sidebands at frequencies ΩNIR ± 2nωTHz. We discuss our results as a function of THz field and frequency, and compare them to our theoretical model.

We examined the effects of the intravenous anaesthetic agents, thiamylal and ketamine, on the phagocytic function of polymorphonuclear leukocytes (PMN) in heparinized peripheral blood from healthy individuals using the phagocytic plaque method. Subclinical doses of thiamylal caused enhancement of the phagocytic activity of PMN and super-clinical doses of thiamylal inhibited phagocytic activity of PMN. Ketamine did not adversely affect phagocytic function at relevant therapeutic concentrations. The results presented in this manuscript indicate the phagocytic plaque method can provide a quantitative assessment of the phagocytic function of leukocytes. This method may prove useful in determining whether anaesthetic agents and other drugs adversely affect leukocyte function and hence help prevent the increased susceptibility to infection which can occur in anaesthetized patients. Conversely, the phagocytic plaque method may prove useful in the search for immune-enhancing drugs.

We present a theoretical and experimental study on electronic and magneto-optical properties of p-type paramagnetic InMnAsdilute magnetic semiconductor (DMS) alloys in ultrahigh (> 100 T) external magnetic fields (B). Theoretical calculations are based on an 8-band Pidgeon–Brown model which is generalized to include the wavevector dependence of the electronic states along Bas well as s–dand p–dexchange interactions with localized Mnd-electrons. The spin-dependent electronic structure as a function of Mndoping is computed and the dependence of the valence band structure on parameters such as the sp–dexchange interaction strength and effective masses in paramagnetic p-InMnAsalloys are examined. The cyclotron resonance (CR) and magneto-optical properties of InMnAsare calculated using Fermi's golden rule. Two strong CR peaks are observed in p-type InMnAsalloys which correspond to the transitions within either heavy-hole (HH) or light-hole (LH) Landau levels. Furthermore, we also observed strong resonance absorption for electron-active polarization which can occur in p-type semiconductors originating from transitions between the light and heavy hole Landau levels.