Toolbox for atomic layer deposition process development on high surface area powders.

Atomic layer deposition (ALD) is an industrially applied technique for thin film deposition. The vast majority of processes target flat substrates rather than powders. For ALD on powders, new processes are needed, as different reaction conditions are required. Here, two setups are described in detail, which enhance the ALD process development for powders. The first setup described is capable of directly measuring the vapor pressure of a given precursor by a capacitance diaphragm gauge. Promising precursors can be pre-selected, and suitable precursor saturation temperatures can be determined. The second setup consists of four parallel reactors with individual temperature zones to screen the optimal ALD temperature window in a time efficient way. Identifying the precursor saturation temperature beforehand and subsequently performing the first ALD half cycle in the parallel setup at four different reactor temperatures simultaneously will drastically reduce process development times. Validation of both setups is shown for the well-known ALD precursors, trimethylaluminum to deposit aluminum oxide and diethyl zinc to deposit zinc oxide, both on amorphous silica powder.

Effects of rectilinear acceleration and optokinetic and caloric stimulations in space.

During the flight of Spacelab 1 the crew performed a number of experiments to explore changes in vestibular function and visual-vestibular interactions on exposure to microgravity. Measurements were made on the threshold for detection of linear oscillation, vestibulo-ocular reflexes elicited by angular and linear movements, oculomotor and posture responses to optokinetic stimulations, and responses to caloric stimulation. Tests were also conducted on the ground, during the 4 months before and on days 1 to 6 after flight. The most significant result was that caloric mystagmus of the same direction as on the earth could also be evoked in the weightless environment.

Concurrent expression of erythroid and renal aquaporin CHIP and appearance of water channel activity in perinatal rats.

Major phenotypic changes occur in red cell membranes during the perinatal period, but the underlying molecular explanations remain poorly defined. Aquaporin CHIP, the major erythroid and renal water channel, was studied in perinatal rats using affinity-purified anti-CHIP IgG for immunoblotting, flow cytometry, and immunofluorescence microscopy. CHIP was not detected in prenatal red cells but was first identified in circulating red cells on the third postnatal day. Most circulating red cells were positive for CHIP by the seventh postnatal day, and this proportion rose to nearly 100% by the 14th day. The ontogeny of red cell CHIP correlated directly with acquisition of osmotic water permeability and inversely with Arrhenius activation energy. Only minor alterations in the composition of red cell membrane lipids occurred at this time. Immunohistochemical analysis of perinatal kidneys demonstrated a major induction of CHIP in renal proximal tubules and descending thin limbs at birth, coincident with the development of renal concentration mechanisms. Therefore, water channels are unnecessary for oxygen delivery or survival in the prenatal circulation, however CHIP may confer red cells with the ability to rehydrate rapidly after traversing the renal medulla, which becomes hypertonic after birth.

Human red cell Aquaporin CHIP. II. Expression during normal fetal development and in a novel form of congenital dyserythropoietic anemia.

Channel-forming integral protein (CHIP) is the archetypal member of the Aquaporin family of water channels. Delayed CHIP expression was shown recently in perinatal rat (Smith, B. L., R. Baumgarten, S. Nielsen, D. Raben, M. L. Zeidel, and P. Agre. 1993. J. Clin. Invest. 92:2035-2041); here we delineate the human patterns. Compared with adult, second and third trimester human fetal red cells had lower CHIP/spectrin ratios (0.72 +/- 0.12, 0.94 +/- 0.22 vs 1.18 +/- 0.11) and reduced osmotic water permeability (0.029, 0.026 vs 0.037 cm/s); CHIP was already present in human renal tubules by the second trimester. A patient with a novel form of congenital dyserythropoietic anemia (CDA) with persistent embryonic and fetal globins and absent red cell CD44 protein was studied because of reduced CHIP-associated Colton antigens. Novel CDA red cells contained < 10% of the normal level of CHIP and had remarkably low osmotic water permeability (< 0.01 cm/s), but no mutation was identified in Aquaporin-1, the gene encoding CHIP. These studies demonstrate: (a) unlike rat, human CHIP expression occurs early in fetal development; (b) red cell water channels are greatly reduced in a rare phenotype; and (c) disrupted expression of red cell CHIP and CD44 suggests an approach to the molecular defect in a novel form of CDA.

Genomic organization of the translocations (8;14) and (14;18) in a new lymphoma cell line.

We generated a new lymphoma cell line carrying the translocations (8;14) and (14;18) and studied the genomic organization and expression of the BCL-2 and MYC genes. Polymerase chain reaction (PCR) and Southern analysis showed that the breakpoints of t(14;18) were located in the major breakpoint region (mbr) of the BCL-2 gene and just 5' of JH6 in the IgH locus. The breakpoints of the t(8;14) were located upstream of exon 2 in the non-coding region of the MYC gene and near the switch region of the IgH locus. Both IgH loci were involved in chromosomal translocations resulting in the absence of a functional B-cell receptor. Normal BCL-2 and truncated MYC transcripts were detected in these cells. The BCL-2 protein was expressed.

Interactions between oestradiol and the progesterone antagonist RU-486 in establishing and maintaining female rats' sexual responsiveness: central versus peripheral effects.

Progesterone is well known to contribute specifically to the emergence of the female rats' sexual behaviour by the establishment of 'proceptivity'. Analysis of the mechanism of progesterone action benefits from the availability of highly effective anti-progestagenic compounds. However, results obtained during the study of female rats' sexual behaviour, including such compounds into the experimental protocol, appear equivocal. The present experiments were designed to further examine the possible effects of the antiprogestagenic compound RU-486 (Mifepristone) on the female rats' sexual responsiveness as elicited through exposure of the animals to oestradiol alone. The experimental design aimed to distinguish between receptivity (defined as response to sexually active males) and proceptivity (defined as female-initiated sexual behaviour). Mifepristone advanced the onset of receptivity after the injection of oestradiol benzoate (OB). Upon further investigation a steady level of receptivity was reached during prolonged treatment with OB and this level appeared unaltered through concurrent treatment with Mifepristone. OB alone was insufficient to induce full proceptivity as revealed by observations of sexual behaviour with tethered males. Such defined proceptivity was significantly further inhibited by Mifepristone. It thus appears that, dependent upon the time and type of female sexual behavioural analysis, Mifepristone either enhances, inhibits, or does not affect sexual responsiveness. After the observation period, autopsy revealed the presence of copulatory plugs and infections in the uterus of OB + Mifepristone-treated rats. This unexpected finding could result from effects of the compound on the uterine cervical musculature. Uterine infections might result in painful, aversive, intra-abdominal sensations, especially during intravaginal penile intromissions.(ABSTRACT TRUNCATED AT 250 WORDS)

Copulatory stimuli in rats induce heat abbreviation through effects on genitalia but not through effects on central nervous mechanisms supporting the steroid hormone-induced sexual responsiveness.

Male copulatory stimuli in various animal species abbreviate the length of the period of their female conspecifics' heat. Such effect can be explained in some species as the result of copulation-induced alterations in ovarian hormone secretion (e.g. reflex ovulators). Other species require a different explanation: specifically, interactions in the hypothalamus between effects of steroid hormones and inhibitory neural afferents from the genital area have been hypothesized to play a role in some laboratory animals such as guinea pigs, hamsters and rats. However, the evidence in support of heat abbreviation through copulatory stimuli in rats is at best equivocal. There is obvious need for its unequivocal demonstration prior to any further analysis of the potential mechanism of action. The present study intended to find a model in support of the concept of 'centrally induced' heat abbreviation in rats. Virgin rats during 'natural heat' were examined with or without allowing them the opportunity to pace male copulatory activities. Ovariectomized, steroid hormone-treated rats were studied with minor or ample experience with sexual activities in prior tests and, also, with or without the opportunity to 'pace' male sexual acts. None of the experimental models revealed unequivocal support for detrimental effect of large numbers of intromittive copulations on 'central mechanisms' regulating heat duration. It rather seemed that frequent intromittive copulations and ejaculates affected the 'peripheral' genital tract (vulva, vagina, cervix) making further copulation of a highly aversive quality so that sexual encounters were avoided or prevented. This effect was noticed with great inter-individual variability. The conclusion is drawn that rats do not show the counterpart of heat abbreviation reportedly occurring rapidly and reliably in guinea pigs after a limited amount of vaginal/cervical stimulation through copulation or insertions of a glass-rod.

Pneumocystis carinii pneumonia in the Federal Republic of Germany in the era of changing antiretroviral therapy - IDKF 13 -. German AIDS Study Group (GASG/IdKF).

BACKGROUND: Pneumocystis carinii pneumonia (PCP) is one of the most common AIDS defining diagnoses. METHODS: In a prospective observational trial all cases of Pneumocystis carinii pneumonia (PCP) were evaluated. Patients with and without PCP-prophylaxis were compared for symptoms, efficacy, side effects and mortality at week 4 and 26. RESULTS: 293 patients developed a PCP episode. Patients with no prophylaxis had a significant lower CD4 cell count and a more severe clinical status at time of diagnosis. This was pronounced in the group with first positive HIV test at time of diagnosis. There was no difference in the rate of successful treatment between both groups. At week four a tendency to a better survival in the group with prophylaxis was observed, however this changed to a trend to a better survival at week 26 for the group without prophylaxis. CONCLUSION: Even in the era of highly active antiretroviral treatment many patients present with PCP. Nearly 60% of patients presented without antiretroviral treatment or PCP-prophylaxis. Nearly 25% of all patients had their first HIV-test at time of PCP diagnosis.

Correlation between disease and community: is drug addiction a problem of fringe groups?

Addiction, because of its associated psychological and physical diseases, is producing increasing expenses through social burden and influencing the epidemiological situation of the whole population via sexual or simple intimate social contacts. Outstanding infectious diseases with a high incidence in drug addicts are tuberculosis, hepatitis A, hepatitis B and the classical notifiable venereal diseases. Preventive measures are required, involving immunization and isolation. HIV infection is another increasing problem in drug addicts. The relatively long asymptomatic course in this population also raises the potential for the spread of AIDS to the general population. There is no ideal method for preventing this danger, but because the traditional abstinence paradigm has not been successful, methadone substitution is improving the medical compliance of this difficult clientele, reducing crime and prostitution and, at the same time, drug-associated risks for the general population.

Ocular counterrolling. Some practical considerations of a new evaluation method for diagnostic purposes.

Ocular counterrolling (OCR) data taken from the literature (12 publications) were used to test the best fit (least-square fit) of these measurements with respect to three mathematical models: a sine relation between OCR and the lateral tilt stimulus, a complex cosine-square relation, and a logarithmic relation between OCR gain and tilt. The latter proved to be the best fitting function. On the basis of this model, we attempted to define a physiological transfer function between OCR gain and tilt, which could serve as a reference of normal population, assuming healthy subjects for the investigations applied. Comparison of this physiological range with pathological data demonstrated marked differences between them. The mathematical simplicity of a logarithmic model permits rapid analysis of clinical OCR examinations, and a classification of the findings.

Effects of rectilinear acceleration, caloric and optokinetic stimulation of human subjects in the Spacelab D-1 mission.

A set of vestibular experiments was performed during the course of the German Spacelab D-1 mission from 30 October to 6 November 1985 by a consortium of experimenters from various european countries. Similar to the Spacelab SL-1 mission all of the scientific crew members were theoretically and practically trained for the experiments. Baseline measurements for all tests were collected 113, 86, 44, 30 and 18 days prior to the mission and compared with data taken inflight, on the landing day and the consecutive 7 to 14 days. The hardware comprised mainly a motordriven accelerating platform, the SPACE SLED, and the vestibular helmet, a multi-purpose instrument in support of a variety of vestibular experiments including air-calorisation of the ears, optokinetic stimulation pattern presentation and optical and nystagmographic recording of eye movements. Measurements of the threshold for the perception of detection of whole body movement did not reveal any dramatic changes in the 2 measured axes inflight when compared to preflight values. Early postflight values show a significantly elevated threshold for all axes in 3 out of 4 subjects. The caloric nystagmus, already found during the SL-1 mission, was confirmed on all three tested subjects during the D-1 mission. It's amplitude and in some instances it's direction were influenced by horizontal acceleration on the SLED. The amplitude of optokinetic nystagmus increased when subjects were allowed to free-float over that seen when subjects were fixed. Stimulation of the neck receptors by roll movements of the body against the fixated head resulted in illusory object motion to the contralateral side. Torsional movements of the eyes during such neck receptor stimulation was present inflight and postflight, while it had not been observed preflight. Most results point to a reduction of otolithic effects in favour of visual and proprioceptive influences for spatial orientation.

Influence of proprioceptive information on space orientation on the ground and in orbital weightlessness.

Conscious space orientation depends on afferent information from different sense organs including the labyrinth, the eyes, tactile cues from the skin, joint receptors, muscle spindles, tendon organs and possibly viscera. An important role is played by impulses from the cervical position receptors in interaction with concomitant information from the otolith system. In order to isolate the effect of cervical position receptors from that of the otolith system, space experiments in orbital weightlessness and in parabolic aircraft flight were performed. It was found that stimulation of the neck receptors in weightlessness markedly influences the perception of the subjective vertical and horizontal and in addition has a weak effect on ocular torsion.

Dorsal light response and changes of its responses under varying acceleration conditions.

In order to improve our understanding about functions of the gravity sensors, we have conducted four experiments in goldfish: 1) To define the effect of visual information influx on the static labyrinthine response, the dorsal light response (DLR) which had been proposed by von Holst as a model for postural adjustment in fish was reexamined with a newly designed, rotatory illumination device. The fish responded to illumination from the upper half of the visual field and a narrow range around 180 degrees of the lower half visual field. The maximal tilting angle of normal fish was about 40 degrees under horizontal illumination. 2) Under the changes of the gravito-inertial force level produced by a linear sled, the threshold of the gravity sensors was determined from postural adjustment responses. 3) Under hypogravic conditions during the parabolic flight of an airplane, the light-dependent behavior was investigated in intact and labyrinthectomized goldfish. 4) As one of the most likely candidates of the neural centers for the DLR, the valvula cerebelli, which receives its visual information not through the optic tectum but through the pretectal areas, is confirmed by the brain lesion experiments.

The European vestibular experiments in Spacelab-1.

A series of experiments were performed in the Spacelab-1 mission on November/December, 1983, pre-, in-, and postflight. These experiments covered various aspects of the functions of the vestibular system, the inflight tests comprising threshold measurements for linear movements in three orthogonal axes, optokinetic stimulation, vestibulo-ocular reflexes under linear and angular accelerations, caloric stimulation with and without linear accelerations; pre- and postflight tests repeated the inflight protocol with the addition of subjective vertical and eye counter-rotation measurements using a tilt table. One of the most surprising and significant results was the caloric test: strong caloric nystagmus on the two subjects tested was recorded inflight; this was contrary to what was expected from Barany's convection hypothesis for caloric nystagmus.

Physiological response to hyper- and hypogravity during rollercoaster flight.

Healthy male subjects--26--were flown in a Lear jet aircraft through rollercoaster and parabolic weightlessness flight. Eye movements, respiration, and blood volume pulse were recorded on magnetic tape. The same subjects underwent a battery of five vestibular tests in the laboratory on the ground. One subject in each flight was flown in an upright position, the other in a 90 degree foreward tilted head position. The foreward tilted subjects always reported motion sickness earlier and after fewer rollercoaster manoeuvres than the upright sitting subjects. It is concluded that the susceptibility to changes of X-axis acceleration is higher than to changes of Z-axis acceleration. Correlation was found between the ability to estimate the subjective vertical (modified Müller-Aubert-test), optokinetic nystagmus asymmetries, and susceptibility to rollercoaster flight sickness.

Evidence of sensory conflict and recovery in carp exposed to prolonged weightlessness.

BACKGROUND: Evidence in support of the sensory conflict hypothesis for space motion sickness (SMS) is still needed. HYPOTHESIS: We hypothesized that sensory conflict and recovery processes should be demonstrated in intact fish during initial days of microgravity exposure, as a disturbance and restoration of the dorsal light response (DLR; a functional model of visual-graviceptor interaction), respectively. We also expected that this would be true in an otolith-removed fish if it had been fully compensated for dysfunction before the exposure. METHODS: The DLR of carp (Cyprinus carpio) was examined intermittently during the 8-d mission of Spacelab-J. Two carp, normal and labyrinthectomized (LB), made the flight. RESULTS: In the normal carp, the DLR was unstable for the first 3 d inflight but gradually recovered thereafter. The recovery was characterized by gradual restoration of the DLR tilt speed. The LB fish whose otoliths had been removed 2 mo before the flight maintained DLR at the first inflight test session (22 h after launch), but DLR was disrupted at 2 d as in normal fish. The recovery process could not be evaluated in this fish, because the EEG cable which was attached to the fish for supplementary study became tightly twisted and thus immobilized the fish for the remainder of the experiment. CONCLUSION: These findings provided additional evidence in fish for sensory-motor disorder and readjustment during the early phase of microgravity, thus supporting the sensory conflict hypothesis for SMS.

Effects of prolonged weightlessness on the swimming pattern of fish aboard Skylab 3.

Two fingerling fish and 50 embryonated eggs of (Fundulus heteroclitus) were flown aboard Skylab 3 in a plastic bag aquarium. Videographic picutres were taken with the on-board color-TV camera on flight Days 3 and 22 and video tapes were made for later evaluation on the ground. When observed first after 3 d in orbital weightlessness, both fish swam in tight circles for a considerable fraction of the observed time resembling the "looping behavior" as observed in previous studies with goldfish in parabolic aircraft flight. The frequency of looping diminished slowly after the third day until normal swimming was prevalent. At flight Day 22, both fish swam normally with their backs turned toward the light source. Looping episodes could still be provoked at this time by gentle shaking of the bag aquarium. Of the fish eggs carried aboard, 96% hatched during the mission. The hatch fry displayed normal swimming behavior.

Effect of prehatching weightlessness on adult fish behavior in dynamic environments.

At 16-17 months of age, three groups of fish from the embryonated eggs in the ASTP killifish experiment were subjected to postflight tests consisting of rapidly changing environments. It was found that the group of fish with the least amount of development at orbital insertion (A-32) had a decreased rheotropism for both the moving background and the rotating water current tests when compared to ground control fish. Exposure to parabolic aircraft flight conditions revealed that the A-32 fish were less disoriented during zero gravity periods and were hypersensitive to high-gravity periods. These results suggested a modified vestibular competency due to a 9-d prehatching weightlessness exposure.

[HIV infection and long-term health: therapeutically attainable?]. / HIV-Infektion und langfristige Gesundheit: therapeutisch erreichbar?

New knowledges about the pathogenesis of HIV-induced immune deficiency syndrome suggest that a change of the natural history of HIV disease by support with antiviral medicaments will be possible. Most important insights are the non-existence of a viral latency phase and the existence of a strong correlation between active viral replication and loss of immunological capacity. Monitoring of HIV replication for detection of efficacy of antiviral therapies is necessary. Potent combinations of antiviral drugs seem to decrease the tendency for development of drug resistant viruses. It seems to be possible to remain healthy for a long time by effective drugs.

[Viral hepatitis: preventable illnesses]. / Virushepatitiden: Vermeidbare Erkrankungen.

The availability of vaccines had made on Hepatitis A as well as Hepatitis B an avoidable illnesses. However, there is a lack of knowledge referring to the epidemiological situation. This might be due to the physician's as well as the patient's underestimation of the risk of a new infection but also insufficient knowledge about indication, management of vaccination, adverse events and cost effectiveness might. Vaccination against Hepatitis A and B produce a longlasting immunisation which is indicated in every age. A combined vaccination for both infectious diseases are effective and support the compliance. The role of the family physician is decisive in the management of a sufficient vaccination strategy.