Search

Metrics are a useful way to assess biocatalyst performance and, when compared to techno-economic targets, can help set goals for further enzyme and bioprocess research and development. Here, we outline some of the remaining challenges to ensure wider acceptance of this approach, both in industry and in academia.

Background Malaria in pregnancy remains a significant cause of morbidity and mortality, affecting the highly endemic countries of sub-Saharan Africa (SSA). Insecticide-treated nets (ITNs) are effective for malaria prevention. However, poor adherence in SSA remains a challenge. Methods We conducted a standard questionnaire survey among 710 pregnant women from 37 primary care clinics in the Upper West Region of Ghana from January through May 2019. Using a sequential explanatory design, we integrated the survey data from six focus group discussions with pregnant women. Results While 67% of women had some general knowledge about malaria prevention, only 19% knew the specific risks in pregnancy. Determinants of ITN use included ITN ownership (odds ratio [OR] 2.4 [95% confidence interval {CI} 1.3 to 4.4]), good maternal knowledge of the risks of malaria in pregnancy (OR 2.4 [95% CI 1.3 to 4.3]) and more antenatal care (ANC) contacts (OR 1.3 [95% CI 1.0 to 1.5)]. Focus group discussions showed that non-use of ITNs resulted from inappropriate hanging infrastructure, a preference for other malaria prevention alternatives, allergy and heat. Conclusions Specific maternal knowledge of malaria risks in pregnancy was low and influenced the regular use of ITNs. Community and ANC-based malaria interventions should prioritize increasing knowledge of the specific risks of malaria.

Mercury telluride colloidal quantum dots (CQD) hold potential for the fabrication of IR devices that operate in the range of near IR, through short-, mid-, and long wavelength (NIR, SWIR, MWIR, and LWIR, respectively). We synthesized a variety of colloidal HgTe QDs using the wet technique in a non-coordinating environment. Both a standard synthesis technique (mixing Hg and Te precursors and letting the nanocrystals grow and develop) and a more complex technique involving the controlled intermittent addition of precursors were applied. CQDs with sizes up to 20–30 nm were grown, although materials with sizes well above 10 nm did not show a distinct excitonic absorption peak. Our synthesized CQDs were used to fabricate photoconductive devices and measure their photoresponse. We present the synthesis techniques used in this work, photoconductive device fabrication and characterization. Devices with quantum efficiency of about 12.5% at a 4 V bias were obtained.

Search strategy. (DOCX 12 kb)

A list of all the records screened after duplicates were removed (N = 474). (PDF 329 kb)

Globally child mortality is one of the major health-related problem areas particularly in developing countries. In 2000 the United Nations (UN) pledged to reduce child mortality by 66 % until 2015. Targeted interventions have ameliorated the health situation of children to a large extent. Vaccines improved quality of care for common diseases in childhood and improved social determinants of health are essential elements. Adolescent health is a newly recognized problem area. Local action and global initiatives will be further needed to assure healthy survival of children and adolescents and to promote their development on a long-term basis.

There is an abundance of evidence for short intervals of cold climatic conditions during the Early Cretaceous. However, the lack of a high-resolution, long-term Early Cretaceous paleotemperature record hampers a full-scale synthesis of these putative “cold snap” episodes, as well as a more holistic approach to Early Cretaceous climate changes. We present an extended compilation of belemnite-based oxygen, carbon and strontium isotope records covering the Berriasian–middle Albian from the Vocontian Basin (SE France). This dataset clearly demonstrates three intervals of cold climatic conditions during the Early Cretaceous (late Valanginian–earliest Hauterivian, late early Aptian, latest Aptian–earliest Albian). Each of these intervals is associated with rapid and high amplitude sea-level fluctuations, supporting the hypothesis of transient growth of polar ice caps during the Early Cretaceous. As evidenced by positive carbon isotope excursions, each cold episode is associated with enhanced burial of organic matter on a global scale. Moreover, there is a relatively good match between the timing and size of large igneous province eruptions and the amplitude of Early Cretaceous warming episodes. Altogether, these observations confirm the instrumental role of atmospheric CO2 variations in driving Early Cretaceous climate change. From a long-term perspective, the coupling of global paleotemperature and seawater strontium isotopic ratio during the Early Cretaceous is best explained by temperature-controlled changes of continental crust weathering rates.

We present the first detailed stable isotope record (δ13C, δ18O) for the Valanginian (Lower Cretaceous) of the southern Boreal Realm. The observations are based on the geochemical analysis of 286 belemnite rostra from stratigraphically well-dated sections in northwest Germany. A major positive carbon isotope excursion (CIE) of ~ 2‰ in the early late Valanginian documents a perturbation of the carbon cycle. This positive CIE, which is well known as the ‘Weissert Event’ in the Tethys, is also displayed in composite carbon isotope records based on published and own data from three different palaeolatitudes (35°, 39°, 65° North). These findings suggest that the environmental changes indicated by the CIE in the early late Valanginian are synchronous, thereby pointing to a global control. The combined oxygen isotope data sets show long-term fluctuations of up to 7 °C with a cooling in the late Valanginian for both the southern and the arctic part of the Boreal Realm, whilst Tethyan data document only a ca. 1 °C cooling. Based on a reliable bio- and chemostratigraphic correlation between the different realms this study highlights the amplitude of the environmental perturbations in the Valanginian and supports the idea that a combination of regional and global factors caused such shifts.

The Institute of Mineral Processing at the Montanuniversitaet Leoben in cooperation with the company CEMTEC has developed a pilot scale, 200 mm table diameter, vertical roller mill for energy controlled laboratory tests. The mill provides the technical options to vary process parameters like air-flow, mass flow, grinding force and classifier speed in a wide range and is equipped to analyze the internal circulating load. In order to address grinding efficiency (defined as the increase in mass specific surface vs. net specific energy input) the energy consumption of two pilot scale vertical roller mills (200 mm and 670 mm table diameter) was compared to that of a sequence of laboratory comminution equipment covering the same size range. The sequence consisting of a laboratory jaw crusher and three laboratory tumbling mills of differing grinding media was operated following the principles of energy optimized comminution according to the OCS-method. With respect to the grinding energy only all the results for marble, siderite and hematite ore show energy savings when using the vertical roller mill at optimized settings. The methods used are outlined including the special features of the equipment.

HgTe and PbS colloidal quantum dots (CQD) with first excitonic absorption peak of about 2 μm and shorter (down to about 1 μm) have been synthesized and characterized. The synthesized CQDs were characterized using FTIR spectroscopy and TEM technique. The nanomaterials were tested for photo-electrical properties with photoconductive (PC) devices. The devices were fabricated by drop-casting a suspension of the CQDs on the fanout, followed by solid state ligand exchange (SSLE) process, and then spectral and electrical photoresponse of the device were measured. The SSLE process was evaluated thru absorption spectra of test samples. The device fabrication parameters were the number of deposited layers, the thickness of individual layers, the type of the substituting ligand, and the ligand exchange duration. For selected devices external quantum efficiency (EQE) was also determined.

Chapter 3 addresses challenges in radio link and system design in indoor scenarios. Given the fact that most human activities take place in indoor environments, the need for supporting ubiquitous indoor data connectivity and location/tracking service becomes even more important than in the previous decades. Specific technical challenges addressed in this section are(i), modelling complex indoor radio channels for effective antenna deployment, (ii), potential of millimeter-wave (mm-wave) radios for supporting higher data rates, and (iii), feasible indoor localisation and tracking techniques, which are summarised in three dedicated sections of this chapter.

Weichselian cryogenic calcites collected in what is referred to as the Rätselhalle of the Herbstlabyrinth-Advent Cave system are structurally classified as rhombohedral crystals and spherulitic aggregates. The carbon and oxygen isotopic composition of these precipitates (δ13C = +0.6 to −7.3‰ δ18O = −6.9 to −18.0‰) corresponds to those of known slowly precipitated cryogenic cave calcites under conditions of isotopic equilibrium between water and ice of Central European caves. The carbon and oxygen isotopic composition varies between different caves which is attributed to the effects of cave air ventilation before the freezing started. By petrographic and geochemical comparisons of Weichselian cryogenic calcite with recent to sub-recent precipitates as well as Weichselian non-cryogenic calcites of the same locality, a model for the precipitation of these calcites is proposed. While the recent and sub-recent pool-calcites isotopically match the composition of interglacial speleothems (stalagmites, etc.), isotope ratios of Weichselian non-cryogenic pool-calcites reflect cooler conditions. Weichselian cryogenic calcites show a trend towards low δ18O values with higher carbon isotope ratios reflecting slow freezing of the precipitating solution. In essence, the isotope geochemistry of the Weichselian calcites reflects the climate history changing from overall initial permafrost conditions to permafrost-free and subsequently to renewed permafrost conditions. Judging from the data compiled here, the last permafrost stage in the Rätselhalle is followed by a warm period (interstadial and/or Holocene). During this warmer period, the cave ice melted and cryogenic and non-cryogenic Weichselian calcite precipitates were deposited on the cave ground or on fallen blocks, respectively.

Using transient expression, high amounts (>20 mg/mL) of secreted anti-human Rhesus-D IgG1 were produced in a suspension-adapted HEK293 EBNA cell line (Meissner et al., Biotechnol Bioeng 75: 197-203, 2001). Time of harvest was 3 days after transfection. For the estimation of transfection efficiencies, we routinely co-transfected EGFP reporter DNA. At higher reporter plasmid concentrations, >2% of total transfecting plasmid DNA, a substantial reduction of recombinant antibody synthesis, was observed. This phenomenon was investigated in detail by co-expressing various green fluorescent protein (GFP) reporter constructs, which were targeted at different subcellular locations. Enhanced and humanized GFPs targeted to either the endoplasmic reticulum, the cytosol, or the nucleus reduced recombinant antibody production by 30 to 40% when present at higher concentrations in the transfection solution. The most severe effects were observed when the co-transfected EGFP was targeted to the endoplasmic reticulum, leading to a reduction of up to 80% in the presence of only 5% of reporter DNA. Interestingly, one nuclear-targeted GFP variant that was not codon optimized for expression in human cell lines could be added, to up to almost half of the total amount of transfecting DNA, without adverse effect on antibody production. Although the minimum amount of this reporter DNA needed for fluorescence reading was 10 times higher than for the other variants, it provided a much broader quantity range within which the transfection process could be studied without being negatively affected.

The fast neutron beam, used for fast neutron therapy in Essen, is produced by the nuclear reaction of a 14 MeV cyclotron-based deuteron beam on a thick beryllium target. The resulting neutron beam has a continuous energy spectrum with a mean and a maximum energy equal to 5.5 and 18 MeV, respectively. The dose delivered to the patient is computed by a treatment planning system (TPS) based on an empirical model, in which the dose components (neutron and photon) are described by analytical functions. In order to improve the dose calculation, and thus to use the fast neutron beam for other applications (e.g., Boron Neutron Capture Enhancement of Fast Neutron Therapy), in this work we aim to develop a new TPS. For this purpose, a model based on pencil beams of mono-energetic neutrons has been created. The neutron energy ranged from 0.25 MeV up to 17.25 MeV by steps of 0.5 MeV in order to cover the energy range of the Essen facility. The Monte Carlo method was then used to simulate the transport of neutrons within such pencil beams in a homogeneous water phantom. By using Monte Carlo techniques, it is possible to distinguish the energy deposition due to a primary collision in water to that due to scattered neutrons. The energy deposition due to pencil beams of 2.224 MeV photons, coming from hydrogen neutron capture reaction in the phantom or in the collimator, was also determined. In order to complete this work, air filled cylinders have been introduced in the water phantom. It is shown that the resulting depth dose curves for primary neutrons can be easily derived using the homogeneous phantom, and that the description of the effect on scattered neutron dose distribution is more complex. In this work we demonstrate the relevance of Monte Carlo simulations of mono-energetic neutron pencil beams for purposes of neutron treatment planning. Some additional work is still required to describe a clinical situation (continuous energy neutron spectrum) as well as to experimentally validate the method described here.

188 Elongation of the small intestine (without histological changes) in young pigs with experimentally induced exocrine pancreatic insufficiency (EPI) − used as a model for children with EPI A. Moseler1, T. Schwarzmaier1, P.C. Gregory2, J. Kamphues3. 1University of Veterinary Medicine, Hannover, Institute for Animal Nutrition, Hannover, Germany; 2Abbott Laboratories (GmbH), Hannover, Germany; 3University of Veterinary Medicine, Hannover, Hannover, Germany

In this work we report on micromechanically tunable Fabry–Perot filter concepts for wavelength division multiplexing (WDM) systems. The optical resonator is designed for a cavity length around 30 μm in order to increase the filter selectivity while relaxing the demands on the required mirror reflectance. The introduction of micromechanical actuators, utilizing electrothermal and electrostatic principles, allows wavelength tuning of the filter over a range of more than 40 nm in the 1.55 μm wavelength regime. The movable Bragg mirror, designed as suspended membrane and fabricated with an InP bulk-micromachining technology, consists of a molecular beam epitaxy-grown InAlGaAs quarter-wavelength multilayer stack. The influence of micromechanical actuation and the effect of intrinsic mechanical stress on the mirror deformation has been investigated systematically to optimize the optical filter performance. Filter losses induced by the light absorption within the epitaxial Bragg mirror have been minimized using a highly doped InGaAs/InAlAs composition. Furthermore, low-loss Fabry–Perot filters have been fabricated using InAlGaAs/InAlAs Bragg mirrors. The measured full-width at half-maximum (FWHM) is 0.24 nm and a filter insertion loss of 2.8 dB has been observed. The FWHM is kept below 0.35 nm over an entire tuning range of 40 nm for an actuation power of 1.3 mW. The bulk-micromachining technology presented here is open for the future development of WDM components, e.g. tunable receivers or laser diodes.

We present, for what is believed to be the first time, a direct comparison of two basically differently working polarization mode dispersion compensation techniques, the first-order compensator working in optical domain and an adjustable transversal filter working in electrical domain. Based on numerical simulations we show the efficiency of both equalizers in presence of first- and higher order PMD applying a transmission at 10 Gbit/s. Furthermore we show the applicability of spectral filtering for penalty signal extraction in presence of higher order PMD and give an overview of adaptive blind channel equalization.

An accurate modeling of very high bit-rate transmission systems over standard-fiber using mid-span spectral inversion (MSSI) is reported. As for the pulsewidth, comparison of simulations with experimental data in an 80-Gb/s transmission system over 106 km shows that second-order group velocity dispersion (GVD) is the limiting factor in this transmission scheme. Additionally, it is shown that even though first-order GVD can be compensated easily second-order GVD, is still remaining. It is pointed out that the performance of the system is very sensitive to the length of the different fiber spans.

Summary We irrigated 36 species and provenances of mainly Australian native trees with saline drainage water (EC 2 dS/m and boron 2.4 mg/L) in a trial sited at Loxton, in semi-arid south eastern Australia. Twelve months after planting, the survival rates amongst species were similar with a site mean of 96%. Three years after planting, the tallest trees were E. gomphocephala and the provenances/clones of E. occidentalis and E. camaldulensis, with heights ranging from 5.3 to 6.7 m; these trees also had the greatest girth with basal areas (measured at 0.3 m above ground level) ranging from 16 m2/ha to 24 m2/ha. The basal area and height of E. camaldulensis was highly variable ranging from 1 m2/ha and 2.1 m for the CML42 clone, to 16 m2/ha and 6.2 m for the Alcoa clone 20. Provenance also had a significant effect on the values of these parameters in E. occidentalis. In the third year, water use rates were determined for 12 of the better growing species. Over summer, the mean daily water use rates ranged from ...

We present an accurate model for the evaluation of the performance of a direct detection system with frequency selective Fabry-Perot (FP) filter and optical preamplification. The model includes the Poisson statistics of photodetection, a realistic model of the polarization behavior of the amplified spontaneous emission and the degradation of the system due to intersymbol interference (ISI). The influence of filtered white noise is taken into account by the expansion in a set of orthonormal functions. We discuss the implementation of a polarization filter for the rigorous model as well as the optimum bandwidth-bit duration (BT) product. The results confirm that the optimum bandwidth-bit duration product has a value of 6 for the discussed system.

A novel broadside coupled stripline coupler with a uniplanar compact photonic bandgap (UC-PBG) structure is presented. Construction of the coupler is based on a stripline with two-dimensional periodically etched ground plane. The slow-wave phenomenon has been predicted and observed. Numerical and experimental investigations show an enhanced backward coupling effect. The usefulness of both phenomena in the coupler construction has been verified experimentally.

Anti-oxidant treatment has been shown to prevent nerve dysfunction in experimental diabetes mellitus, thus providing a rationale of potential therapeutic value for diabetic patients. The effects of the anti-oxidant alpha-lipoic acid (thioctic acid) were studied in a 3-week multicentre, randomized, double-blind placebo-controlled trial (Alpha-Lipoic Acid in Diabetic Neuropathy; ALADIN) in 328 non-insulin-dependent diabetic patients with symptomatic peripheral neuropathy who were randomly assigned to treatment with intravenous infusion of alpha-lipoic acid using three doses (1200, 600, or 100 mg ALA) or placebo (PLAC). Neuropathic symptoms (pain, burning, paraesthesiae, and numbness) were scored at baseline and at each visit (days 2-5, 8-12, and 15-19) prior to infusion. In addition, the Hamburg Pain Adjective List, a multidimensional specific pain questionnaire, and the Neuropathy Symptom and Disability Scores were assessed at baseline and day 19. According to the protocol 260 (65/63/66/66) patients completed the study. The total symptom score in the feet decreased from baseline to day 19 by -4.5 +/- 3.7 (-58.6%) points (mean +/- SD) in ALA 1200, -5.0 +/- 4.1 (-63.5%) points in ALA 600, -3.3 +/- 2.8 (-43.2%) points in ALA 100, and -2.6 +/- 3.2 (-38.4%) points in PLAC (ALA 1200 vs PLAC: p = 0.003; ALA 600 vs PLAC: p < 0.001). The response rates after 19 days, defined as an improvement in the total symptom score of at least 30%, were 70.8% in ALA 1200, 82.5% in ALA 600, 65.2% in ALA 100, and 57.6% in PLAC (ALA 600 vs PLAC; p = 0.002). The total scale of the Pain Adjective List was significantly reduced in ALA 1200 and ALA 600 as compared with PLAC after 19 days (both p < 0.01). The rates of adverse events were 32.6% in ALA 1200, 18.2% in ALA 600, 13.6% in ALA 100, and 20.7% in PLAC. These findings substantiate that intravenous treatment with alpha-lipoic acid using a dose of 600 mg/day over 3 weeks is superior to placebo in reducing symptoms of diabetic peripheral neuropathy, without causing significant adverse reactions.

We present the performance of a unipolar barrier long-wave type-II InAs/GaSb superlattice (SLS) photodetector with a 50% cut-off wavelength of approximately 8.7 microns. In this study, the ability to lower dark current densities over traditional PIN diodes is presented by way of hetero-structure engineering of a pBiBn structure utilizing superlattice Ptype (P) and N-type (N) contacts, Intrinsic (I) superlattice active (absorber) region, and unipolar superlattice electron and hole blocking (b) layers. The spectral response of this pBiBn detector structure was determined using a Fourier Transform Infrared (FTIR) Spectrometer and the quantum efficiency (QE) was determined using a narrow 6250 nm narrow band filter and a 500K blackbody source. A diode structure designed, grown, and fabricated in this study yielded a dark current density of less than one (1) mA/cm 2 at a reverse bias of 150 mV and a specific detectivity value of greater than 10 11 Jones at 77K. In addition to single point temperature measurements, a variable temperature study (80K-300K) of the dark current is presented for a diode demonstrating diffusion limited dark current from 160K down to 80K.

We have investigated for the first time the electrical properties of metal-semiconductor-metal (MSM) photodectors fabricated using black silicon-germanium on silicon substrate (Si1-xGex/Si) for I-V, optical response, external quantum efficiency (EQE), internal quantum efficiency (IQE), and responsivity and reflectivity. Silicon-germanium (Si1-xGex)/Si with variations of Ge were blackened by metal enhanced chemical etching (MECE) using nanometer-scale gold particles as catalyst and HF:H2O2:CH3COOH solution as etchant. The etched surface was black, textured, and showed strong suppression of reflectivity. These properties are consistent with Si1?xGex becoming highly micro-structured due to metal catalysis and wet etching. Using the blackened SiGe/Si, MSM photodiodes were fabricated and tested. The lowering of reflection using a U.S. Army Research Laboratory (ARL)-developed technique has helped the enhancement of absorption in Si1-xGex to provide increased optical response, which is an important milestone towards practical, extended wavelength (2 microns) electro-optical applications.

Resonant-tunnelling-diodes (RTD) with heavily doped collectors are investigated. Within this work an oscillation frequency of 1.1 THz has been achieved. Our RTD oscillators are extremely compact room-temperature sources of coherent CW THz radiation.

This work explores the influence of the post-transfer anneal temperature and the substrate on transferred graphene and its Raman properties. Graphene grown by low pressure chemical vapor deposition on copper foils was transferred to SiO2/Si, fused silica, and silicon substrates via a process that involves coating the graphene with PMMA as a protective handling layer during the wet chemical etching of the copper and then placing the PMMA/graphene onto the substrate. The PMMA layer was then removed by heating in a hydrogen/argon atmosphere at temperatures ranging from 350 to 550 °C or by exposing the PMMA to heated acetone vapor/liquid. Raman spectroscopy measurements, taken before and after PMMA removal, reveal differences in the prominent Raman features, the G and G’ peaks, upon annealing. These changes include (1) a shift in the average G and G’ peak positions when comparing Raman spectra before and after PMMA removal and (2) a decrease in the G’:G peak intensity ratio (IG’/IG), which is typically used as a measure of the number of graphene layers. For both the as-transferred graphene and graphene removed by the heated acetone, the IG’/IG peak ratio was approximately 2, indicating single layer graphene. However, when the graphene was annealed at temperatures above 350 °C, the IG’/IG intensity ratio varied from 0.5 to 1.5. These changes in the Raman spectra are similar to those observed in exfoliated single layer graphene supported on SiO2/Si substrates and are indicative of graphene-substrate interaction effects that lead to hole doping of the graphene [1,2]. These trends were observed for graphene transferred to all three substrates, regardless of the substrate surface roughness and/or composition.

We describe the establishment of two permanent Simian virus 40- transformed human stromal cell lines, designated L87/4 and L88/5, derived from the bone marrow of a hematologically normal male patient. Both cell lines show a fibroblastoid morphology and do not express hematopoietic cell markers. L87/4 but not L88/5 expresses the macrophage marker CD68. The most remarkable feature of these new stromal cell lines is their ability to persist as growth-arrested adherent feeder cells after ionizing-irradiation at doses up to, and exceeding 20 Gy (L87/4). This renders them particularly useful for studying aspects of feeder dependence of hematopoietic cell development in long-term culture. Both cell lines are able to function as feeder cells, supporting the long-term proliferation of CD34+ human cord blood cells as well as the clonogenic growth of the human Burkitt lymphoma B- cell line BL70.

For the first time a vertical-cavity surface-emitting laser (VCSEL) with a single-mode wavelength-tuning over 102 nm in the range of 1550 nm is demonstrated. The fiber-coupled optical output power has a maximum of 3.5 mW and is > 2 mW over the entire tuning range. The sidemode suppression ratios are > 45 dB. The wavelength tuning is achieved with the micro-electro mechanical actuation of a mirror membrane fabricated with surface micro-machining for on-wafer mass production. The mirror membrane consists of low cost dielectric materials (SiOx/SiNy) deposited with low temperature (< 100°C) Plasma Enhanced Chemical Vapor Deposition (PECVD).

The structural quality of graphene films is of immense importance both in improving growth procedures and understanding the resulting films' electronic properties. The graphene film needs to be atomically smooth with low defects, low roughness, and high electronic mobility for high performance Field Effect Transistor (FET) devices. Because of graphene's high optical transmittance and conductivity, it is also being considered as a transparent conductive electrode [1]. Multilayer graphene prepared by diluted methane-based CVD at 1 atm on nickel (Ni) films deposited over Si/SiO 2 wafers has been shown in various colours, sizes, and shapes [2]. Their preferred nucleation sites in relation to the Ni grain boundaries are not well understood. In this study, we prepared a variety of Ni templates having grain structures ranging from small to large and with mixed distribution across the surface. This was achieved through evaporation and sputter deposition methods. We found the greatest variety of Ni grains was achieved by changing the sputter deposition temperature (100 and 250 °C), and pressure (2 and 20 mT). The ability to grow single- and few-layer graphene on top of the Ni catalyst depended on the highly diluted methane gas in CVD, as confirmed by micro-Raman spectroscopy. Methane ratios from 0.5 vol.% to 0.41 vol.% exhibited a strong presence of graphene, 0.36 vol. % produced mixed results, and 0.24 vol.% or less produced no evidence of graphene on a Ni template after the anneal and CVD. Annealing temperatures with as small as a 25 °C difference had a great influence on final size of graphene. The grains grew almost double in size when annealed at 975 °C as compared to 950 °C. So it is advantageous to perform annealing followed by growth at the highest possible temperature and then combine it with an optimized cooling rate.

We have investigated for the first time the reflectivity and absorbance of black silicon-germanium (Si1-xGex). Black Si1-xGex was produced by metal enhanced chemical etching using nanometer-scale gold particles as catalyst and HF:H2O2:CH3COOH etchant. The etched surface was black, textured, and showed strong suppression of reflectivity and enhancement of absorption in the near-infrared region. These properties are consistent with Si1-xGex becoming highly micro-structured due to metal catalysis and wet etching. The lowering of reflection and enhancement of absorption in Si1-xGex is an important milestone towards practical, extended wavelength (~2 micrometers) electro-optical applications.

The interband cascade (IC) technology is uniquely suited for fabrication of high-density 2-dimensional arrays of MWIR and LWIR emitters. In this talk, we briefly overview the fabrication and performance of MWIR Interband Cascade LED arrays and discuss the design, fabrication, and performance characteristics of vertically-emitting resonant cavity structures. We will assess the current performance of these structures for meeting the requirements of IR scene projection systems.

Alcohol consumption habits and the clinical consequences of intake of alcoholic beverages were examined in 254 individuals with a diagnosis of acute intermittent porphyria or variegate porphyria, using a questionnaire. The study failed to demonstrate a connection between the amount of ethanol consumed, or the frequency of ingestion, and the development of symptoms of acute porphyria, other than in extreme consumption patterns. It was concluded that agents in alcoholic beverages other than ethanol play important roles in precipitating the porphyric symptoms. A majority of the individuals were able to identify alcoholic beverages that were less well tolerated and those that were better tolerated. The results suggest that polyphenolic compounds and 3 to 5 carbon chain hydrophobic alcohols may be responsible for the induction of clinical symptoms in acute porphyria by some alcoholic beverages. On the basis of these findings advice is proposed on alcohol counseling in inducible porphyria.

A new and simple two-chip concept for microcavities with application in dense wavelength-division-multiplexed systems as tunable optical filters is presented. The Fabry-Perot cavity is created without any costly distance holder or sacrificial layer by simply utilizing the stress of the dielectric Bragg-mirrors against the semiconductor substrate. Electrostatic tunability is achieved by making use of the high capacitance of the metallized cantilevers holding the actuable membrane.