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Pressure induced densification in a molecular arsenic sulfide glass is studied at ambient temperature using x-ray scattering, absorption and Raman spectroscopic techniques in situ in a diamond anvil cell. The relatively abrupt changes in the position of the first sharp diffraction peak, FSDP, and the pressure-volume equation of state near ∼2 GPa suggest a phase transition between low- and high-density amorphous phases characterized by different densification mechanisms and rates. Raman spectroscopic results provide clear evidence that the phase transition corresponds to a topological transformation between a low-density molecular structure and a high-density network structure via opening of the constituent As4S3 cage molecules and bond switching. Pressure induced mode softening of the high density phase suggests a low dimensional nature of the network. The phase transformation is hysteretically reversible, and therefore, reminiscent of a first-order phase transition. [ABSTRACT FROM AUTHOR]

This case study was the first of its kind, where neutron computed tomography (CT) was applied to a wrapped mummified animal. Conventional X‐ray CT was also used to allow for meaningful comparison, and complementary data for a comprehensive investigation. Previous applications of both techniques are limited to metallic objects, such as bronze Buddhas. The mummy used in this study (IA.2402) is dated between the Third Intermediate Period (1069–664 bce) to Late Period (664–332 bce) according to the wrapping style, and was originally believed to contain a complete skeleton of a feline. However, precise date and provenance were unknown. Our results prove the presence of only partial juvenile feline remains, and provide a date range for artefact creation (900–804 bce ± 30) and alteration (367–204 bce ± 30). Therefore, this study implements an established imaging technique (neutron CT) in a novel way, while preserving and conserving the intrinsic value of the artefact through non‐destructive investigation. [ABSTRACT FROM AUTHOR]

High-resolution x-ray diffraction with diamond-anvil cells, using argon as a quasi-hydrostatic pressure medium, documents the crystal structure and equation of state of osmium to over 60 GPa at room temperature. We find the zero-pressure bulk modulus in fair agreement with other experiments as well as with relativistic electronic band-structure calculations: Osmium is the densest but not the most incompressible element at ambient conditions. We also find no evidence for anomalies in the ratio of unit-cell parameters, c/a, or in the compressibility of osmium as a function of pressure. This is in agreement with other experiments and quantum mechanical calculations but disagrees with recent claims that the electronic structure and equation of state of osmium exhibit anomalies at pressures of ∼15-25 GPa; the discrepancies are may be due to the effects of texturing. [ABSTRACT FROM AUTHOR]

The thermodynamic nature of phase stabilities and transformations are investigated in crystalline and amorphous Ge1Sb2Te4 (GST124) phase change materials as a function of pressure and temperature using high-resolution synchrotron x-ray diffraction in a diamond anvil cell. The phase transformation sequences upon compression, for cubic and hexagonal GST124 phases are found to be: cubic → amorphous → orthorhombic → bcc and hexagonal → orthorhombic → bcc. The Clapeyron slopes for melting of the hexagonal and bcc phases are negative and positive, respectively, resulting in a pressure dependent minimum in the liquidus. When taken together, the phase equilibria relations are consistent with the presence of polyamorphism in this system with the as-deposited amorphous GST phase being the low entropy low-density amorphous phase and the laser melt-quenched and high-pressure amorphized GST being the high entropy high-density amorphous phase. The metastable phase boundary between these two polyamorphic phases is expected to have a negative Clapeyron slope. [ABSTRACT FROM AUTHOR]

We studied the compressibility of monolithic fully dense electrodeposited nanocrystalline Ni (∼29 nm grain size) under both quasihydrostatic and nonhydrostatic conditions up to a nominal pressure of 50 GPa using angle-dispersive x-ray diffraction. We obtained an equation of state consistently and unambiguously from each measured reflection. The apparent bulk modulus measured under nonhydrostatic conditions is larger than that of the corresponding coarse-grained material under either type of compression, but is nearly the same when measured under quasihydrostatic conditions. These results may be consistent with a strength, but not necessarily a bulk modulus, that is enhanced in the nanomaterial relative to its coarse-grained counterparts. [ABSTRACT FROM AUTHOR]

The article presents a case study of an 11-month-old baby boy was presented with rashes on the face and arms. Also discusses the diagnosis of variegated pigmentation, telangiectases and erosions on the skin after light microscopy, and identifying frameshift mutation in exons and introns through Sanger sequencing.

Objectives: Increasing multidrug resistance amongst canine pathogenic staphylococci has renewed interest in topical antibacterial therapy for skin infections in the context of responsible veterinary prescribing. We therefore determined the activity in vitro of three clinically relevant topical agents and synergism between two of them against Staphylococcus pseudintermedius and Staphylococcus aureus. Methods: The MICs of fusidic acid (n=199), chlorhexidine (n=198), miconazole (n=198) and a 1:1 combination of miconazole/chlorhexidine (n=198) were determined for canine isolates [50 MRSA and 49 methicillin-resistant S. pseudintermedius (MRSP), 50 MSSA and 50 methicillin-susceptible S. pseudintermedius (MSSP)] collected from the UK and Germany using an agar dilution method (CLSI VET01-A4). Fractional inhibitory concentration (FIC) indices were calculated to assess the interaction of miconazole with chlorhexidine. Results: MICs of each drug/combination were significantly (P<0.0005) higher for S. aureus when compared with S. pseudintermedius. Most strains (n=172) had an MIC of fusidic acid of ≤0.03 mg/L (MIC ≥64 mg/L, n=5 MRSA). All strains had MICs of chlorhexidine of 0.5-4 mg/L, except for one MRSA (MIC=8 mg/L). All but four strains had MICs of miconazole of 1-4 mg/L (MIC=16 mg/L, n=3; MIC=256 mg/L, n=1). Miconazole/chlorhexidine (1:1 ratio) had a synergistic effect against 49/50 MRSA, 31/50 MSSA, 12/49 MRSP and 23/49 MSSP. Conclusions: Since the majority of these staphylococci, including methicillin-resistant isolates, had MICs that should be readily exceeded by topical skin application of these agents, their therapeutic efficacy for canine superficial pyoderma should be assessed. The synergistic interaction shown in vitro supports further clinical evaluation of miconazole/chlorhexidine combination therapy for staphylococcal infection. [ABSTRACT FROM AUTHOR]

Because the deep Earth is not directly accessible, geoscientists rely on laboratory experiments and computer models in order to understand the properties of minerals at the extreme pressure and temperature conditions of deep crust, the mantle and the core. In the field of high-pressure mineral physics and chemistry, we use our understanding of mineral properties, stress–strain relationships in multiphase rocks, and processes such as partial melting at high pressures and temperatures, to interpret geophysical observations of the deep Earth. Studies have constrained the pressure sensitivity of deformation of minerals such as olivine under subduction zone conditions, and the effect of pressure on slip systems in high-pressure minerals such as wadsleyite and perovskite. These results have important implications for the variation of mantle viscosity with depth, the geodynamic interpretation of seismic anisotropy, and changes in mantle rheology as a function of composition. However, the rheology and dynamics of the deep Earth are still poorly understood. Fortunately, technical development has been undertaken over the past 10 years in the USA, and scientific advances have been helped by the development of high-P–T deformation apparatus, such as the large volume multi-anvil deformation apparatus known as the D-DIA. This has opened up the possibility of determining physical and chemical processes in the upper mantle, and into the mantle transition zone. To participate in this exciting new area of research, we are now developing a high-pressure facility at the Australian Synchrotron. In this overview paper, we describe the background and current research that is being conducted in other synchrotron high-pressure facilities and what will now be possible for the Australian Synchrotron. [ABSTRACT FROM PUBLISHER]

Quantum entanglement is the central resource behind quantum information science, from quantum computation and simulation to enhanced metrology and secure communication. These applications require the quantum control of large networks of qubits to realize gains and speed increases over conventional devices. However, propagating entanglement becomes difficult or impossible as the system grows in size. Here, we demonstrate the first step in a modular approach to scaling entanglement by using complementary quantum buses on a collection of three atomic ion qubits stored in two remote ion trap modules. Entanglement within a module is achieved with deterministic near-field interactions through phonons, and remote entanglement between modules is achieved with a probabilistic interaction through photons. This minimal system allows us to address generic issues in the synchronization of entanglement with multiple buses. It points the way towards a modular large-scale quantum information architecture that promises less spectral crowding and thus potentially less decoherence as the number of qubits increases. We generate this modular entanglement faster than the observed remotely entangled qubit-decoherence rate, showing that entanglement can be scaled simply by adding more modules. [ABSTRACT FROM AUTHOR]

Experiments at 20–97 GPa and 2000 K in the system CaO–MgO–TiO2–SiO2 constrain phase relations involving Mg-rich and Ca-rich perovskite solid solutions at conditions relevant to the Earth's deep Transition Zone and lower mantle. Bulk compositions were investigated with molar Ti/(Ti + Si) up to 0·5 within the quasi-ternary ‘perovskite plane’, which is defined by a reciprocal solution among the components MgSiO3, MgTiO3, CaSiO3, and CaTiO3. Multi-anvil experiments at 20 GPa and 2000 K on bulk compositions within the plane produce akimotoite coexisting with Ca-perovskites that lie close to the CaSiO3–CaTiO3 join. Higher-pressure experiments using a laser-heated diamond anvil cell constrain the position of a two-perovskite field that extends into the perovskite plane from the solvus along the MgSiO3–CaSiO3 binary join, where limited mutual solubility exists between MgSiO3 and CaSiO3 perovskites. On the join MgSiO3–MgTiO3, MgTiO3 solubility in MgSiO3 perovskite increases with pressure, with MgSi0·8Ti0·2O3 perovskite stable at ∼50 GPa. Limited reciprocal solution at ∼25 GPa results in an expansive two-perovskite field that occupies much of the Si-rich portion of the perovskite plane. Solution of Ti into Mg-rich and Ca-rich perovskites enhances the solubility of reciprocal Ca and Mg components, respectively. Increase in pressure promotes reciprocal solution, and the two-phase field collapses rapidly with pressure toward the MgSiO3–CaSiO3 join. We find that a single-phase, orthorhombic perovskite with near equimolar Ca and Mg is stable in a composition with Ti/(Ti + Si) of only 0·05 at 97 GPa, requiring that by this pressure the two-phase field occupies a small area close to the MgSiO3–CaSiO3 join. On the basis of experiments at∼1500 K, temperature has only a mild effect on the position of the Ca-rich limb of the solvus. Ca(Ti,Si)O3 mineral inclusions in deep sublithospheric diamonds could not have formed in equilibrium with Mg-perovskite owing to their virtual lack of MgSiO3 component at pressures of Mg-perovskite stability, but may have equilibrated with Transition Zone MgSiO3-rich phases at lower pressures; this observation can be extended generally to near-endmember CaSiO3 inclusions. On an iron-free basis, the average bulk compositions of clinopyroxene–ilmenite and orthopyroxene–ilmenite megacrysts from kimberlites plot in single-perovskite fields at pressures greater than about 45 and 65 GPa, respectively, when projected onto the perovskite plane. We predict that the effect of iron will not be large, and estimate that single-phase perovskites may form at somewhat lower pressures than in the iron-free system. Thus, the origin of pyroxene–ilmenite megacrysts from single-phase perovskite solutions in the lower mantle is plausible on the basis of phase relations, although a lower pressure magmatic origin appears more likely. Deeply subducted Ti-rich lithologies such as ocean-island basalt will crystallize a single perovskite rather than a two-perovskite assemblage beginning at pressures of ∼80 GPa. Normal mid-ocean ridge basalt and primitive mantle peridotite are expected to remain within a two-phase perovskite field until Mg-perovskite transforms to post-perovskite. [ABSTRACT FROM PUBLISHER]

Tenascin-X is a large extracellular matrix glycoprotein that is widely distributed within connective tissues and is associated with an autosomal recessive type of Ehlers-Danlos syndrome (EDS). Tenascin-X represents the first EDS susceptibility gene that does not code for a fibrillar collagen or collagen-processing enzyme. We describe a paediatric case of tenascin-X deficiency and review the literature. [ABSTRACT FROM AUTHOR]

We present isothermal volume compression behavior of two polycrystalline (Mg,Fe)O samples with FeO = 39 and 78 mol% up to ~90 GPa at 300 K using synchrotron X-ray diffraction and neon as a pressure-transmitting medium. For the iron-rich (Mg0.22Fe0.78)O sample, a structural transition from the B1 structure to a rhombohedral structure was observed at 41.6 GPa, with no further indication of changes in structural or compression behavior changes up to 93 GPa. In contrast, a change in the compression behavior of (Mg0.61Fe0.39)O was observed during compression at P ≥ 71 GPa and is indicative of a spin crossover occurring in the Fe2+ component of (Mg0.61Fe0.39)O. The low-spin state exhibited a volume collapse of ~3.5%, which is a larger value than what was observed for a similar composition in a laser-heated NaCl medium. Upon decompression, the volume of the high-spin state was recovered at approximately 65 GPa. We therefore bracket the spin crossover at 65 ≤ P (GPa) ≤ 77 at 300 K (Mg0.61Fe0.39)O. We observed no deviation from the B1 structure in (Mg0.61Fe0.39)O throughout the pressure range investigated. [ABSTRACT FROM AUTHOR]

Partial melting in the Earth’s mantle plays an important part in generating the geochemical and isotopic diversity observed in volcanic rocks at the surface. Identifying the composition of these primary melts in the mantle is crucial for establishing links between mantle geochemical ‘reservoirs’ and fundamental geodynamic processes. Mineral inclusions in natural diamonds have provided a unique window into such deep mantle processes. Here we provide experimental and geochemical evidence that silicate mineral inclusions in diamonds from Juina, Brazil, crystallized from primary and evolved carbonatite melts in the mantle transition zone and deep upper mantle. The incompatible trace element abundances calculated for a melt coexisting with a calcium-titanium-silicate perovskite inclusion indicate deep melting of carbonated oceanic crust, probably at transition-zone depths. Further to perovskite, calcic-majorite garnet inclusions record crystallization in the deep upper mantle from an evolved melt that closely resembles estimates of primitive carbonatite on the basis of volcanic rocks. Small-degree melts of subducted crust can be viewed as agents of chemical mass-transfer in the upper mantle and transition zone, leaving a chemical imprint of ocean crust that can possibly endure for billions of years. [ABSTRACT FROM AUTHOR]

X-ray diffraction measurements of natural talc plus water at combined pressures and temperatures of 0-15 GPa and 23-400 °C reveal the presence of a structural change that could be interpreted as a new high-pressure phase at 4.0 (±0.5) GPa, and raise the possibility that the newly inferred phase transition takes place in cold subducting slabs as a precursor to appearance of the 10 Å phase of talc. [ABSTRACT FROM AUTHOR]

A tensonometer for stretching metal foils has been constructed for the study of strain broadening in X-ray diffraction line profiles. This device, which is designed for use on powder diffractometers and was tested on Station 2.3 at Daresbury Laboratory, allows in situ measurements to be performed on samples under stress. It can be used for data collection in either transmission or reflection modes using either symmetric or asymmetric diffraction geometries. As a test case, measurements were carried out on an 18 µm-thick copper foil experiencing strain levels of up to 5% using both symmetric reflection and symmetric transmission diffraction. All the diffraction profiles displayed peak broadening and asymmetry which increased with strain. The measured profiles were analysed by the fundamental-parameters approach using the TOPAS peak-fitting software. All the observed broadened profiles were modelled by convoluting a refineable diffraction profile, representing the dislocation and crystallite size broadening, with a fixed instrumental profile predetermined using high-quality LaB6 reference powder. The deconvolution process yielded `pure' sample integral breadths and asymmetry results which displayed a strong dependence on applied strain and increased almost linearly with applied strain. Assuming crystallite size broadening in combination with dislocation broadening arising from f.c.c. a/2〈110〉{111} dislocations, the variation of mechanical property with strain has been extracted. The observation of both peak asymmetry and broadening has been interpreted as a manifestation of a cellular structure with cell walls and cell interiors possessing high and low dislocation densities. [ABSTRACT FROM AUTHOR]

Background It is generally accepted that the onset of sebum secretion occurs before puberty in boys and girls as a result of increasing androgen output during the adrenarche. Propionibacteria are part of the commensal skin flora and, in adults, are found in highest numbers in sebum-rich areas of skin such as the face and upper trunk. Previous studies investigating the association between sebum output and propionibacterial population densities have been cross-sectional and have been carried out mainly in adults. Objectives The purpose of this study was to examine the association between the onset of sebum secretion and expansion of the propionibacterial flora in a population of early adolescent children aged between 5.5 and 12 years, and to evaluate the temporal relation between the two factors longitudinally. In addition, the study aimed to evaluate the change with age in sebaceous gland activity and propionibacterial colonization on the skin and in the nares between children who developed acne and those who did not. Methods Biannual examinations of volunteers included age, pubertal (Tanner) stage, weight and height, lesion counting on the face, propionibacterial colonization on the skin surface and in the nares and sebum secretion. A longitudinal analysis based on all observations of each subject throughout the study was applied to examine the change of sebaceous gland activity and propionibacterial colonization with age and pubertal stage. A generalized estimating equation was used with a 0.05 level of significance. Results The commencement of sebum production was asynchronous, with only a small number of follicles initially starting to secrete sebum onto the skin surface. The number of secreting follicles and the area of sebum increased with age and pubertal stage (P < 0.0001, P < 0.05, respectively). Numbers of propionibacteria on the skin tended to increase after the age of 9 years, but not significantly so. In contrast, numbers of propionibacteria in the nares increased significantly with age (P < 0.0001) but not with pubertal maturation. Children who developed acne had higher sebum output and propionibacterial densities with increasing age than children who did not develop acne. This effect was significant for the increase of total sebum area with age in pubertal children (P = 0.0023), the increase in number of secreting follicles with age (P = 0.020) in prepubertal children, and the increase in propionibacteria densities in the nares with age (P = 0.0005) in pubertal children. Sebaceous gland activity and propionibacterial numbers on the skin surface remained unchanged with increasing age in children who did not develop acne. Propionibacterial population densities in the nares increased with age regardless of the development of acne. Conclusions Onset of sebum secretion and consequently expansion of the propionibacterial skin flora occur earlier in children who develop acne than in children of the same age and pubertal status who do not develop acne. These observations suggest that postponing the onset of sebum production or the expansion of the propionibacterial skin flora until after puberty may represent ways of preventing the disease or minimizing its severity. Determinants of propionibacterial colonization on the skin and in the nares may be different. [ABSTRACT FROM AUTHOR]

Background. There is a lack of data regarding the use of narrowband ultraviolet B (NB-UVB) phototherapy in children with atopic dermatitis (AD). Many centres use this mode of treatment for children with AD; however, there have only been two previous studies observing the effect of NB-UVB in children with AD. Aim. We undertook a retrospective review of children with severe eczema who had undergone NB-UVB consecutively in our department between 1999 and 2005. Methods. All children with AD who had undergone NB-UVB consecutively in our department between 1999 and 2005 were identified from the phototherapy database. Their clinical notes were reviewed for information on age, sex, skin type, minimal erythema dose (MED), adjuvant therapy, previous therapy, adverse effects, number of exposures, cumulative dose, response to treatment and length of remission. Results. In total, 50 children (83%) completed more than 10 exposures of NB-UVB. Complete clearance or minimal residual activity was achieved in 20 children (40%). A good improvement was achieved in a further 10 children (23%), and a moderate improvement in 13 (26%). Children with MEDs > 390 mJ/cm2 were more likely to clear, and this was found to be statistically significant ( P = 0.02). Overall, the treatment was well tolerated and the median length of remission was 3 months. Conclusion. NB-UVB is an effective treatment for children with severe AD. Children with MEDs > 390 mJ/cm2 are more likely to clear. Further studies are needed to evaluate the efficacy of NB-UVB and long-term safety in treating children with severe AD. [ABSTRACT FROM AUTHOR]

Background The hygiene hypothesis is often proposed to explain the high prevalence of atopy in the western world. Dysregulation of the immune system may result from inadequate exposure to micro-organisms such as mycobacteria. A small trial suggested that a killed extract of Mycobacterium vaccae ameliorates atopic dermatitis (AD). Objectives To confirm in a large clinical trial whether killed M. vaccae ameliorates AD in 5–16-year-old children. Methods This was a randomized, placebo-controlled, double-blind, multi-centre study of the effect of intradermal injection of killed M. vaccae (0.1 or 1 mg) on patients, aged 5–16, with moderate-to-severe AD. Patients were followed up for 24 weeks. The primary end point was the change in severity of AD at 12 weeks, assessed using the six area, six-sign, atopic dermatitis (SASSAD) score. Secondary end points included changes in disease extent, patient's global assessment and children's dermatology life quality index. Results There were 166 patients randomized. The mean SASSAD score fell to a similar degree at week 12 in all treatment arms: from 33 to 24, (26%) in the high-dose group, from 30 to 23 (25%) in the low-dose group and from 36 to 27 (24%) in the placebo group ( P>0.05). Secondary end points followed the same trend. Adverse events were generally those expected to occur in this population. Injection site reactions occurred in 32 patients at week 4. Conclusions M. vaccae was no more effective than the placebo in ameliorating the severity of AD. [ABSTRACT FROM AUTHOR]

Crisp expanded wafers were produced from extruded pellets containing specialty starches and flours derived from peas, lentils, corn and blends of lentils and corn. The density, hardness and consumer acceptability of the wafers varied with the different ingredients. The most acceptable products were produced from corn, lentils and blends of these two ingredients. The weight, density, stiffness and hardness of the wafers increased with the proportion of lentil flour used to make them. Sensory analysis suggested that consumer acceptability was optimal for blends containing between 40 and 80% of lentil flour. Stiffness and fracture force measured by texture profile analysis were correlated with the sensory attributes of hardness and toughness. The glycemic potential measured by in vitro digestion of the wafers was lower for the 100% lentil wafers compared with the 100% corn wafers because of the amount of starch in the grain. For combinations of corn and lentils, the carbohydrate digestion rate, and hence the glycemic potential, was lower than for either 100% corn or 100% lentil wafers. Blending of selected cereal flour ingredients should be a useful method for reducing the glycemic impact of cooked starchy snacks. [ABSTRACT FROM AUTHOR]

Background Allergic contact dermatitis (ACD) increases with age, and a prevalence of between 13·3% and 24·5% has been reported. Patch testing infants may be particularly difficult, and false-positive reactions may occur. Objectives The purpose of this retrospective study was to determine whether the site of primary dermatitis in children could predict a diagnosis of ACD. The current frequency of sensitization in children was also evaluated and the main sensitizing substances among children were verified. Methods Between 1995 and 2004, 500 children were patch tested and entered on to the patch test database at Leeds General Infirmary. Analysis of the database included identifying the presenting patterns of eczema and reviewing the patch test results for each child. Results Of the children, 133 (27%) had one or more positive patch test result. The effect of age on the likelihood of a positive patch test was highly significant ( P < 0·001). Girls were significantly more likely to have a positive patch test compared with boys: odds ratio for a positive test 0·62 (95% confidence interval 0·41–0·95; P = 0·029). Type IV allergy to nickel (33%) was the most frequent finding. Reactions to fragrance mix (18%), cobalt (11%), mercapto chemicals, Myroxylon pereirae and p-phenylenediamine (each 8%) were the next most common. No statistical significance was found in the relationship between the site of primary dermatosis and a positive patch test result. Conclusions The pattern of presenting dermatitis in children should not determine referral for patch testing. Any child with persistent eczema should be referred for patch testing. [ABSTRACT FROM AUTHOR]

The possibility of using X-ray diffraction to precisely monitor crystal structure at the extremes of pressure and temperature produced by shock-wave loading is explored. A summary of the advantages of using various X-ray sources for this work and an outline of the necessary experimental layout is given. [ABSTRACT FROM AUTHOR]

Examines equation of state measurements of chlorite, pyrophyllite and talc. Room temperature compressibility of chlorite; Thermal expansivity of chlorite; Implications of data for phase stabilities in the earth.

A host of fascinating and useful magnetic phenomena are found in composites containing magnetizable particles in viscoelastic solids. Embedding magnetically soft iron particles in natural rubber produces a class of magnetostrictive composites sometimes termed magnetorheological (MR) elastomers. We have previously shown that these materials can exhibit viscoelastic moduli that increase substantially in an applied magnetic field. In this paper, we incorporate MR elastomers in a simple resonant structure called a tuned vibration absorber to measure the complex dynamic shear moduli of these materials at high frequencies. We find that the field-induced modulus increase in MR elastomers is substantial even at kilohertz mechanical frequencies. As in previous measurements at low frequencies, the moduli are generally found to decrease with strain amplitude. We also report preliminary measurements of the relatively large elongation of these materials in applied magnetic fields. [ABSTRACT FROM AUTHOR]

BACKGROUND: Few therapies are currently available to treat keratosis pilaris atrophicans (KPA), a spectrum of disorders which includes ulerythema ophryogenes and atrophoderma vermiculata. OBJECTIVE: To evaluate the response of KPA to treatment with the pulsed dye laser (PDL) with regard to improvements in erythema and skin roughness, treatment tolerability, and side effects. METHODS: Treatment of all facial areas involved with KPA with the PDL at 585 nm was evaluated in 12 patients. Prior to and after each treatment skin erythema was estimated using an erythema meter, and skin roughness was analysed using micrometer evaluation of a skin surface biopsy taken from the same mapped area and anaysed by computer to calculate the roughness profile. RESULTS: Patients received 2 to 8 treatments with the PDL with energies ranging from 6.0 to 7.5 J/cm[sup 2]. Clinical improvement was noted in all patients with significant reduction in erythema scores. Pre-treatment scores ranged from 4 to 13 (mean 8.3) and post-treatment 0 to 8 (mean 3.1) (P < 0.05). Improvements in skin roughness were clinically apparent in all but two patients, but these were not significant on evaluation of skin surface biopsies. Treatment was generally well tolerated, and side effects other than local pain during treatment were very few. CONCLUSION: PDL treatment appears to be a safe and effective treatment for the erythema associated with KPA but does not give significant improvement in associated skin roughness. [ABSTRACT FROM AUTHOR]

Acne is usually recognized as a disorder of adolescence. However, the referral of patients over the age of 25 years with acne has significantly increased over the past 10 years. The clinical features of 200 patients over the age of 25 years, referred to our department for treatment of acne, were evaluated with a view to establishing possible aetiological factors. There were 152 (76%) women and 48 (24%) men. The mean age of the patients was 35.5 years (range 25-55 years). The acne was mild or moderate in severity, consisting principally of inflammatory lesions, with mean total acne grade (Leeds Grading Scale) of 1.125 for men and 0.75 for women. Most patients had persistent acne: but true late-onset acne (onset after the age of 25 years) was seen in 28 (18.4%) of women and four (8.3%) of men. Thirty-seven per cent of women had features of hyperandrogenicity. One hundred and sixty-four patients (82%) had failed to respond to multiple courses of antibiotics, and 64 (32%) had relapsed after treatment with one or more courses of isotretinoin. External factors, such as cosmetics, drugs and occupation, were not found to be significant aetiological factors. A family history revealed that 100 (50%) of patients had a first-degree relative with post-adolescent acne. Patients with post-adolescent acne appear to represent an increasingly important population of acne sufferers. External factors do not seem to have a significant aetiological role. Two main clinical groups were identified: those with persistent acne and those with late-onset acne. A minority of women also had features of hyperandrogenicity. These patients, and those with late-onset acne, may represent a subgroup who have underlying abnormalities of ovarian, adrenal or local androgen metabolism, and require separate investigation. [ABSTRACT FROM AUTHOR]

Accidental hypothermia and heatstroke are more common in aged populations. While peripheral factors are undoubtedly important to the high incidence of dysthermia in the aged, alterations in central temperature controls associated with aging may be primarily responsible. It has been shown that the sensitivity of the hypothalamus to neurotransmitters is changed in aged animals, and it may be that similar alterations in central temperature controls underlie the increased susceptibility to dysthermia. As a first step in testing this hypothesis the responsiveness of central temperature controls of aged squirrel monkeys to taurine, a putative inhibitory neurotransmitter or neuromodulator, was tested. Intracerebroventricular (i.c.v.) administration of this sulfonated amino acid (0.5-4.0 mg) produced dose-related hypothermia in squirrel monkeys over nine years of age in a thermoneutral environment (23°C). Younger animals had significantly smaller hypothermias. In a hot environment (30°C) there were no significant differences between the temperature decreases of the two age groups after any dose. However, in a cold environment (17°C), in which young animals developed slightly larger hypothermias than in the thermoneutral environment, core temperature of the aged squirrel monkeys dropped so rapidly in response to even the lowest dose that they had to be removed and warmed to prevent death by hypothermia. The temperature controls of the aged squirrel monkey appear to be extrememly sensitive to taurine. The findings indicate that a rise in central taurine concentration in old primates can, in a cold environment, produce an effect very much like accidental hypothermia in aged man. [ABSTRACT FROM PUBLISHER]

This paper demonstrates how remote sensing can be used to aid the general approach of landscape archaeology. The methodology and results of a project attempting to elucidate links and controls between environmental change and long-term social change in southern Madagascar are outlined. Multi-seasonal Landsat TM images, SPOT panchromatic and ERS-1 SAR images are used to produce a number of outputs. These include a general landcover map, a detailed map of forest extent and type (split into primary, secondary, and regenerative), field pattern maps, and predictions of archaeological site locations based on spectral properties of known sites. From these maps it has been possible to predict possible former settlements, archaeological sites, and forests of sacred significance. [ABSTRACT FROM AUTHOR]

A novel sample chamber has been developed for the study of chemical reactions involving air sensitive samples using energy-dispersive powder diffraction. The apparatus consists of a reaction vessel, automatic reactant dispensing system, heating jacket, stirrer, and gas purge system. The use of this apparatus is illustrated with data collected on station 9.7 of the UK Synchrotron Radiation Source during a study on the intercalation of cobaltocene into tin disulfide. [ABSTRACT FROM AUTHOR]

The design and implementation of a flexible and modular digital control and data acquisition system for scanned probe microscopes (SPMs) is presented. The measured performance of the system shows it to be capable of 14-bit data acquisition at a 100-kHz rate and a full 18-bit output resolution resulting in less than 0.02-Å rms position noise while maintaining a scan range in excess of 1 µm in both the X and Y dimensions. This level of performance achieves the goal of making the noise of the microscope control system an insignificant factor for most experiments. The adaptation of the system to various types of SPM experiments is discussed. Advances in audio electronics and digital signal processors have made the construction of such high performance systems possible at low cost. [ABSTRACT FROM AUTHOR]

X-ray powder diffraction measurements using synchrotron radiation are currently being carried out on three experimental stations on the SRS at Daresbury Laboratory. Station 9.1 contains a general purpose powder diffractometer for angular dispersive measurements. The instrument is sited on the wiggler beamline, which provides radiation with a critical energy of 12 keV. A Si ( 111 ) water-cooled, channel-cut monochromator gives useful flux over an energy range from 6 to 30 keV. A cryostat and furnace are available for experiments requiring special environments, while a curved position sensitive detector can be used for time-resolved measurements. The wiggler white beam is employed on Station 9.7 for energy dispersive powder diffraction experiments. Various sample stages for kinetic experiments are in use on this station, and examples are shown of recent high-pressure work. A new high resolution powder diffractometer has been built and commissioned on Station 8.3, using bending magnet radiation. The diffractometer is based on the Parrish and Hart design, in which long, parallel foils are used to define the angular divergence accepted by the detector. In this way, large synchrotron beam cross sections can be employed while maintaining high angular resolution. [ABSTRACT FROM AUTHOR]

We report on the optical investigation of single electron spins bound to fluorine donor impurities in ZnSe. Measurements of photon antibunching confirm the presence of single, isolated optical emitters, and magneto-optical studies are consistent with the presence of an exciton bound to the spin-impurity complex. The isolation of this single-donor-bound-exciton complex and its potential homogeneity offer promising prospects for a scalable semiconductor qubit with an optical interface. [ABSTRACT FROM AUTHOR]

The article provides information on the case of a 32-month Pakistani girl diagnosed with Griscelli's syndrome characterized by partial albinism and immunodeficiency. The girl suffers from developmental delay, abdominal pain, and lethargy. She was also diagnosed with acute meningitis and hydrocephalus. The patient's histological examination shows that she has histiocytic tumour with a degree of erythrophagocytosis and lymphophagocytosis. Details about Griscelli's syndrome are also presented.