Extended C-band tunable multi-channel InP-based coherent receiver PICs.

Fully integrated monolithic, multi-channel InP-based coherent receiver PICs and transceiver modules with extended C-band tunability are described. These PICs operate at 33 and 44 Gbaud per channel under dual polarization (DP) 16-QAM modulation. Fourteen-channel monolithic InP receiver PICs show integration and data rate scaling capability to operate at 44 Gbaud under DP 16-QAM modulation for combined 4.9 Tb/s total capacity. Six channel simultaneous operation of a commercial transceiver module at 33 Gbaud is demonstrated for a variety of modulation formats including DP 16-QAM for >1.2Tbit/s aggregate data capacity.

Lithium diffusion in congruent LiNbO3 single crystals at low temperatures probed by neutron reflectometry.

The self-diffusion of lithium in congruent LiNbO3 single crystals was investigated at low temperatures between 379 and 523 K by neutron reflectometry. From measurements on (6)LiNbO3 (amorphous film)/(nat)LiNbO3 (single crystal) samples, Li self-diffusivities were determined in single crystals down to extremely low values of 1 × 10(-25) m(2) s(-1) on small length scales of 1-10 nm. The measured diffusivities are in excellent agreement with (extrapolated) literature data obtained by experiments based on Secondary Ion Mass Spectrometry and Impedance Spectroscopy. The tracer diffusivities can be described by a single Arrhenius line over ten orders of magnitude with an activation enthalpy of 1.33 eV, which corresponds to the migration energy of a single Li vacancy. A deviation from the Arrhenius behaviour at low temperatures, e.g., due to defect cluster formation is not observed.

Li self-diffusion in lithium niobate single crystals at low temperatures.

Li self-diffusion in Li(2)O-deficient LiNbO(3) single crystals is investigated in the temperature range between 423 and 773 K (150-500 °C) by secondary ion mass spectrometry. A thin layer of ion-beam sputtered isotope enriched (6)LiNbO(3) was used as a tracer source, which allows one to study pure isotope interdiffusion. The diffusivities can be described by the Arrhenius law with an activation enthalpy of (1.33 ± 0.03) eV, which is in acceptable agreement with the migration energy of a single Li vacancy as determined by ab initio calculations given in the literature. Charge diffusivities as derived from impedance spectroscopy measurements on the same type of samples are identical to the tracer diffusivities within error limits. No indication of the formation of defect-complexes at low temperatures could be found in the diffusion behaviour.

1.12 Tb/s superchannel coherent PM-QPSK InP transmitter photonic integrated circuit (PIC).

In this work, a 10-wavelength, polarization-multiplexed, monolithically integrated InP coherent QPSK transmitter PIC is demonstrated to operate at 112 Gb/sec per wavelength and total chip superchannel bandwidth of 1.12 Tb/s. This demonstration suggests that increasing data capacity to multi-Tb/s per chip is possible and likely in the future.

Dual-mode optical projection tomography microscope using gold nanorods and hematoxylin-stained cancer cells.

An optical projection tomography microscope (OPTM) can improve axial resolution by viewing a sample from different perspectives. Here, we report a dual-mode OPTM that can generate 3D images of single cancer cells in both absorption mode and polarization mode. Cancer cells were labeled with hematoxylin for absorption imaging and nanorods for polarization imaging. Absorption images can provide morphologic information, and polarization images can provide molecular information. The combination of molecular detection and 3D cytological cell analysis may help with early cancer diagnosis.

Development of a microbial test suite and data integration method for assessing microbial health of contaminated soil.

There is no standard methodology or guideline for assessing soil microbial health for the purposes of contaminant risk assessments. Here we propose a laboratory-based test suite and novel data integration method for evaluating soil microbial health using site-specific contaminated and reference soil. The test suite encompasses experiments for evaluating microbial biomass, activity, and diversity. The results from the tests are then integrated so that a Soil Microbial Health Score (SMHS) may be assigned. This test suite and data integration method was tested on soils from 3 different contaminated sites in Canada. The soil microbial health of a petroleum hydrocarbon (PHC) contaminated site was found to be 'Mildly Impacted' and 'Moderately Impacted' for two soil horizons at a boreal forest site. The soil microbial health of the mixed metal/PHC and mixed metal sites were both found to be 'Not Impacted'. Continued use of this test suite and data integration method will help create guidelines for assessing soil microbial health in ecological risk assessments.

Glioma invasion mediated by the p75 neurotrophin receptor (p75(NTR)/CD271) requires regulated interaction with PDLIM1.

The invasive nature of glioblastoma renders them incurable by current therapeutic interventions. Using a novel invasive human glioma model, we previously identified the neurotrophin receptor p75(NTR) (aka CD271) as a mediator of glioma invasion. Herein, we provide evidence that preventing phosphorylation of p75(NTR) on S303 by pharmacological inhibition of PKA, or by a mutational strategy (S303G), cripples p75(NTR)-mediated glioma invasion resulting in serine phosphorylation within the C-terminal PDZ-binding motif (SPV) of p75(NTR). Consistent with this, deletion (ΔSPV) or mutation (SPM) of the PDZ motif results in abrogation of p75(NTR)-mediated invasion. Using a peptide-based strategy, we identified PDLIM1 as a novel signaling adaptor for p75(NTR) and provide the first evidence for a regulated interaction via S425 phosphorylation. Importantly, PDLIM1 was shown to interact with p75(NTR) in highly invasive patient-derived glioma stem cells/tumor-initiating cells and shRNA knockdown of PDLIM1 in vitro and in vivo results in complete ablation of p75(NTR)-mediated invasion. Collectively, these data demonstrate a requirement for a regulated interaction of p75(NTR) with PDLIM1 and suggest that targeting either the PDZ domain interactions and/or the phosphorylation of p75(NTR) by PKA could provide therapeutic strategies for patients with glioblastoma.

Three-dimensional imaging of single isolated cell nuclei using optical projection tomography.

A method is presented for imaging single isolated cell nuclei in 3D, employing computed tomographic image reconstruction. The system uses a scanning objective lens to create an extended depth-of-field (DOF) image similar to a projection or shadowgram. A microfabricated inverted v-groove allows a microcapillary tube to be rotated with sub-micron precision, and refractive index matching within 0.02 both inside and outside the tube keeps optical distortion low. Cells or bare cell nuclei are injected into the tube and imaged in 250 angular increments from 0 to 180 degrees to collect 250 extended DOF images. After these images are further aligned, the filtered backprojection algorithm is applied to compute the 3D image. To estimate the cutoff spatial frequency in the projection image, a spatial frequency ratio function is calculated by comparing the extended depth-of-field image of a typical cell nucleus to the fixed focus image. To assess loss of resolution from fixed focus image to extended DOF image to 3D reconstructed image, the 10-90% rise distance is measured for a dyed microsphere. The resolution is found to be 0.9 microm for both extended DOF images and 3D reconstructed images. Surface and translucent volume renderings and cross-sectional slices of the 3D images are shown of a stained nucleus from fibroblast and cancer cell cultures with added color histogram mapping to highlight 3D chromatin structure.

Vaccines against influenza A viruses in poultry and swine: Status and future developments.

Influenza A viruses are important pathogens with a very broad host spectrum including domestic poultry and swine. For preventing clinical disease and controlling the spread, vaccination is one of the most efficient tools. Classical influenza vaccines for domestic poultry and swine are conventional inactivated preparations. However, a very broad range of novel vaccine types ranging from (i) nucleic acid-based vaccines, (ii) replicon particles, (iii) subunits and virus-like particles, (iv) vectored vaccines, or (v) live-attenuated vaccines has been described, and some of them are now also used in the field. The different novel approaches for vaccines against avian and swine influenza virus infections are reviewed, and additional features like universal vaccines, novel application approaches and the "differentiating infected from vaccinated animals" (DIVA)-strategy are summarized.

Inducible synthesis of the mitomycin C resistance gene product (MCRA) from Streptomyces lavendulae.

The mcr locus from Streptomyces lavendulae confers high level resistance (> 100 micrograms/ml) to mitomycin C (MC) and related mitomycins when cloned into Streptomyces lividans. Production of the mcrA gene product (MCRA) was shown to be MC-inducible by identification of MCRA (M(r) of 54 kDa) using Western blot analysis and enzyme linked immunosorbent assay (ELISA). The magnitude of MCRA production was dependent on MC concentration, with primary induction starting at 0.1 microgram/ml and maximum induction at 10 micrograms/ml of the drug. Different levels of MCRA production were observed when other mitomycin metabolites were used as inducers, and the level of induction related directly to aziridine ring substitution on the individual molecules. Moreover, inducible synthesis of the mcr A gene product was unique to this structural class since production of MCRA did not occur as a general response to DNA damaging agents. The time profile of intracellular MCRA synthesis correlated with MC production in S. lavendulae, suggesting coordinated regulation of MC resistance and biosynthetic genes.

Prospective evaluation of the effects of stress on exercise adherence in community-residing women.

The effects of stress on exercise behavior in community-residing women exercising on their own were assessed. Participants (N = 82) completed a background questionnaire and kept exercise diaries and Weekly Stress Inventories (P. J. Brantley, G. N. Jones, E. Boudreax, & S. L. Catz, 1997) for 8 consecutive weeks. During weeks with a high frequency of stressful events, participants exercised for less time and reported lower self-efficacy for meeting upcoming exercise goals. During weeks of high perceived stress, participants exercised significantly fewer days, omitted more planned exercise sessions, were less satisfied with their exercise, and had lower self-efficacy for meeting exercise goals. Findings suggest that perceptions of stressful events and cognitive reactions to missed exercise may play a significant role in mediating exercise behavior and support the view of exercise relapse as an ongoing process.

Direct 99mTc-labeling of antibodies by sodium dithionite reduction, and role of ascorbate as a stabilizer in cysteine challenge.

A method for the direct 99mTc-labeling of antibodies by dithionite reduction was developed. Among three murine monoclonal IgG1 and one human polyclonal IgG (hIgG) antibodies tested, hIgG was the most quickly reduced by dithionite. These differences may reflect the reactivities of antibody disulfide bonds toward the oxidation products of dithionite. By optimizing reduction conditions to generate enough free sulfhydryl groups, it was possible to radiolabel human IgG and monoclonal antibody 170 with 99mTc with a 90% monomeric antibody efficiency. The process avoided colloid formation. In contrast, about 0.1 sulfhydryl groups per antibody molecule, less than 1% of the possible 36, were detected after treatment with ascorbate (up to 35,000:1 molar ratio) at room temperature for 1 h for the antibodies tested. Sulfhydryl groups generated in antibodies were estimated using a new method: 5-iodoacetamidofluorescein-labeled antibodies quantitated by size exclusion HPLC. Ascorbate was found to prevent antibody aggregate formation in cysteine-challenged samples.

Comparison of the efficacy of three premedicants administered to cats.

Healthy cats (n = 90), anesthetized for minor procedures, were included in a study designed to evaluate the efficacy of three premedicant mixtures. The drug combination was assigned randomly and the evaluations were made by individuals unaware of the treatment used. The mixtures and their final concentrations were as follows: acepromazine (1.0 mg/mL) and atropine (0.25 mg/mL) with either meperidine (20.0 mg/mL), ketamine (25.0 mg/mL), or oxymorphone (0.2 mg/mL). The dose used was 0.2 mL/kg(0.75). There was no significant difference (p< 0.05) among drug combinations in the degree of sedation achieved, difficulty of handling for IV catheter placement, induction dose of thiopental, or heart or respiratory rate following induction. All combinations were considered satisfactory for premedication of healthy cats. The ketamine combination had a tendency for more consistent sedation (0.05 < p < 0.01).

Novel Vitamin K analogs suppress seizures in zebrafish and mouse models of epilepsy.

Epilepsy is a debilitating disease affecting 1-2% of the world's population. Despite this high prevalence, 30% of patients suffering from epilepsy are not successfully managed by current medication suggesting a critical need for new anti-epileptic drugs (AEDs). In an effort to discover new therapeutics for the management of epilepsy, we began our study by screening drugs that, like some currently used AEDs, inhibit histone deacetylases (HDACs) using a well-established larval zebrafish model. In this model, 7-day post fertilization (dpf) larvae are treated with the widely used seizure-inducing compound pentylenetetrazol (PTZ) which stimulates a rapid increase in swimming behavior previously determined to be a measurable manifestation of seizures. In our first screen, we tested a number of different HDAC inhibitors and found that one, 2-benzamido-1 4-naphthoquinone (NQN1), significantly decreased swim activity to levels equal to that of valproic acid, 2-n-propylpentanoic acid (VPA). We continued to screen structurally related compounds including Vitamin K3 (VK3) and a number of novel Vitamin K (VK) analogs. We found that VK3 was a robust inhibitor of the PTZ-induced swim activity, as were several of our novel compounds. Three of these compounds were subsequently tested on mouse seizure models at the National Institute of Neurological Disorders and Stroke (NINDS) Anticonvulsant Screening Program. Compound 2h reduced seizures particularly well in the minimal clonic seizure (6Hz) and corneal-kindled mouse models of epilepsy, with no observable toxicity. As VK3 affects mitochondrial function, we tested the effects of our compounds on mitochondrial respiration and ATP production in a mouse hippocampal cell line. We demonstrate that these compounds affect ATP metabolism and increase total cellular ATP. Our data indicate the potential utility of these and other VK analogs for the prevention of seizures and suggest the potential mechanism for this protection may lie in the ability of these compounds to affect energy production.

Dual-modal three-dimensional imaging of single cells with isometric high resolution using an optical projection tomography microscope.

The practice of clinical cytology relies on bright-field microscopy using absorption dyes like hematoxylin and eosin in the transmission mode, while the practice of research microscopy relies on fluorescence microscopy in the epi-illumination mode. The optical projection tomography microscope is an optical microscope that can generate 3-D images of single cells with isometric high resolution both in absorption and fluorescence mode. Although the depth of field of the microscope objective is in the submicron range, it can be extended by scanning the objective's focal plane. The extended depth of field image is similar to a projection in a conventional x-ray computed tomography. Cells suspended in optical gel flow through a custom-designed microcapillary. Multiple pseudoprojection images are taken by rotating the microcapillary. After these pseudoprojection images are further aligned, computed tomography methods are applied to create 3-D reconstruction. 3-D reconstructed images of single cells are shown in both absorption and fluorescence mode. Fluorescence spatial resolution is measured at 0.35 microm in both axial and lateral dimensions. Since fluorescence and absorption images are taken in two different rotations, mechanical error may cause misalignment of 3-D images. This mechanical error is estimated to be within the resolution of the system.

Simultaneous 3D imaging of morphology and nanoparticle distribution in single cells with the Cell-CT technology.

The Cell-CT is an optical projection tomography microscope (OPTM) developed for high resolution 3D imaging of single cells based on absorption stains and brightfield microscopy. In this study we demonstrate the use of the Cell-CT in multi-color mode for simultaneous imaging of cellular 3D morphology and the 3D distribution of nanoparticle clusters in the cytoplasm. The ability to image cellular processes in relation to cellular compartments with a non-fluorescence 3D technology opens new perspectives for molecular research.

Light scattering from multilayer optics: comparison of theory and experiment.

Measurements of angular scattering due to surface roughness were taken from a 24-layer dielectric mirror and compared to theory. In addition, the top surface roughness of the multilayer stack is analyzed from Talystep profilometer measurements. These roughness data are used to obtain a roughness spectral density function to be used in a vector multilayer scattering theory. The theory uses three multilayer stack models to incorporate possible effects of different degrees of correlation between interfaces of the stack. It was found that the angular scattering calculated using the experimentally obtained roughness spectral density function agreed remarkably well with the measured angular scattering data. This is especially true if care is taken to differentiate between particulate and roughness scattering. For the sake of comparison, the angular scattering from an aluminum film is also given, and differences from scattering from the multilayer mirror are noted.

Production of a polyhydroxyalkanoate biopolymer in insect cells with a modified eucaryotic fatty acid synthase.

A novel pathway for the synthesis of poly-3-hydroxybutyrate has been engineered by simultaneous delivery of two genes into insect cells (Spodoptera frugiperda) by use of individual baculovirus vectors. This system includes expression of a dehydrase-domain mutant rat fatty acid synthase cDNA and the phbC gene encoding polyhydroxyalkanoate synthase from Alcaligenes eutrophus. The dehydrase-deficient fatty acid synthase provides de novo synthesis of R-(-)-3-hydroxybutyryl-coenzyme A as a premature termination product rather than palmityl-coenzyme A, the normal product of wild-type rat fatty acid synthase. High levels of this mutant multifunctional protein provide a suitable precursor pool of R-(-)-3-hydroxybutyryl-coenzyme A for conversion to poly-3-hydroxybutyrate in insect cells coexpressing the phbC gene product. This strategy for redesigning a poly-3-hydroxybutyrate biosynthetic pathway suggests a new method for generating structurally diverse polyhydroxyalkanoates by metabolic engineering.

The importance of MUC1 cellular localization in patients with breast carcinoma: an immunohistologic study of 71 patients and review of the literature.

BACKGROUND: The MUC1 mucin is present on the apical surface of normal secretory epithelia. In breast carcinoma, MUC1 expression is variable in amount and cellular localization, the significance of which is controversial. The authors undertook a detailed analysis of staining pattern combined with a comprehensive literature review to better understand the role of MUC1 in breast carcinoma. METHODS: Seventy-one patients with breast carcinoma were examined for MUC1, beta-catenin, and E-cadherin staining patterns. These data were compared with data from 25 articles from the literature examining the expression of MUC1 in breast carcinoma. RESULTS: All invasive carcinomas showed some MUC1 staining. In invasive ductal carcinomas, MUC1 was detected in the apical membrane (15%), cytoplasm (93%), or circumferential membrane (13%), with 81% of tumors showing a mixture of patterns. Tumors with low overall MUC1 expression (< or = 50% positive tumor cells) had a higher nuclear grade than tumors with high overall MUC1 expression (> 50%; P = 0.01). Tumors with high and low cytoplasmic expression had no difference in nuclear grade (P > 0.3). Circumferential membrane staining was correlated with positive lymph node status (P = 0.011). CONCLUSIONS: In the literature, similar findings prevailed in which overall MUC1 expression was increased in lower grade (10 of 14 studies), estrogen receptor positive (8 of 13 studies) tumors and was associated with a better prognosis (8 of 13 studies). High cytoplasmic staining was associated with a worse prognosis, an association that was not explained by differences in histologic grade. Thus, the presence of MUC1 in the majority of tumor cells is associated with better differentiated tumors and with an improved prognosis. However, aberrantly localized MUC1 in the tumor cell cytoplasm or nonapical membrane is associated with a worse prognosis.