Chemical and Electronic Properties of Metal/Sb2Te3/CdTe Contacts for CdTe Thin Film Solar Cells Studied by Photoelectron Spectroscopy

Formation of low resistance back contacts in CdTe thin film solar cells has been a research issue for many years. Ohmic contacts to the absorber layer are typically prepared using the diffusion of dopant atoms from the back contact material into the CdTe forming a thin space charge layer that can be easily tunnelled. Stable CdTe solar cells with reasonable back contact characteristics have been prepared using metal/Sb2Te3 layer sequences. In this study the chemical and electronic properties of such layer systems have been investigated using photoelectron spectroscopy. The vacuum deposited Sb2Te3 layers do not react with the CdTe substrate. Band alignment does not indicate the formation of a good back contact. By subsequent deposition of metals a chemical reaction is induced forming metal-tellurides, a metal/Sb-alloy and elemental Sb. Although an Sb diffusion into the CdTe absorber is observed, no increase of p-doping in the surface region is evident.

Band Alignment at Oxide Semiconductor Interfaces

Transparent conductive oxides (TCOs) are important contact materials in thin film solar cells. It is thus important to understand their basic interface properties as the band alignment. We present results on the determination of interfacial properties of TCOs using photoelectron spectroscopy. Large interface dipole potentials are generally observed at interfaces between conducting oxides ZnO, SnO2, In2O3and TiO2and chalcogenide semiconductors CdS, CdTe and Cu2S, leading to small conduction band discontinuities in the case of ZnO, SnO2and In2O3and to large conduction band discontinuities for TiO2. In addition to the band alignment the Fermi level position at the interface determines the contact properties of TCOs in thin film solar cells.

Measurement of single- and double-spin asymmetries in deep inelastic pion electroproduction with a longitudinally polarized target

We report the first measurement of the transverse momentum dependence of double-spin asymmetries in semi-inclusive production of pions in deep-inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Jefferson Lab (JLab). Modulations of single spin asymmetries over the azimuthal angle between lepton scattering and hadron production planes ϕ have been measured over a wide kinematic range in Bjorken x and virtual photon squared four-momentum Q2. A significant nonzero sin2ϕ single spin asymmetry was observed for the first time indicating strong spin-orbit correlations for transversely polarized quarks in the longitudinally polarized proton.

Tensor correlations measured in 3He(e,e' pp)n

We have measured the 3He(e,e' pp)n reaction at an incident energy of 4.7 GeV over a wide kinematic range. We identified spectator correlated pp and pn nucleon pairs by using kinematic cuts and measured their relative and total momentum distributions. This is the first measurement of the ratio of pp to pn pairs as a function of pair total momentum p(tot). For pair relative momenta between 0.3 and 0.5  GeV/c, the ratio is very small at low p(tot) and rises to approximately 0.5 at large p(tot). This shows the dominance of tensor over central correlations at this relative momentum.

A first prospective randomized controlled trial on the efficacy and safety of synchronous balneophototherapy vs. narrow-band UVB monotherapy for atopic dermatitis

BACKGROUND

Data from an uncontrolled trial suggest synchronous balneophototherapy (sBPT), which simulates treatment conditions at the Dead Sea, to be effective in the management of atopic dermatitis (AD).

OBJECTIVES

The purpose of this prospective randomized controlled study was to compare the efficacy and safety of sBPT with narrow-band (NB) UVB monotherapy (PT) for AD.

METHODS

In this phase III multicentre trial, 180 patients with moderate-to-severe AD were allocated to two groups in a 1:1 ratio; group 1 received sBPT consisting of NB UVB treatment and synchronous bathing in 10% Dead Sea salt solution, group 2 monotherapy with UVB 311 nm. The confirmatory study design consisted of up to 35 treatment sessions. Primary endpoint, analysed on an intention-to-treat-basis (n=169), was the relative improvement of the severity SCORing of the Atopic Dermatitis Index (SCORAD) from baseline to the end of treatment (35 sessions or early cure). Sample-size calculation aimed at establishing at least 15% superiority.

RESULTS

SCORing of the Atopic Dermatitis Index at baseline was comparable between sBPT (61.8±14.1) and PT (61.5±12.4) group. At the end of therapy, a clinically relevant and statistically significant difference of 26.2% could be shown (P<0.001). Exploratory testing showed statistically significant superiority of sBPT after 6 months. Mild adverse events more frequently occurred in the sBPT group (n=46, PT: n=31), whereas more patients withdrew early because of adverse events in the PT group (n=6, sBPT: n=2).

CONCLUSIONS

A clear advantage of sBPT in comparison to PT was proven. Tolerability was comparable; both treatments showed to be safe.

Blockade of proteinase-activated receptor-4 inhibits the eosinophil recruitment induced by eotaxin-1 in the pleural cavity of mice

OBJECTIVE AND DESIGN

Although proteinase-activated receptor (PAR)-4 has been implicated in inflammation, its role in regulating eosinophil recruitment in response to chemoattractants has not yet been demonstrated. To investigate the contribution of proteinases and PAR-4 activation to eosinophil migration in response to eotaxin-1 or leukotriene B(4) (LTB(4)), the effects of aprotinin or PAR-4 antagonist trans-cinnamoyl-YPGKF-NH(2) (tcY-NH(2)) on eosinophil migration induced by these chemoattractants were investigated.

METHODS

BALB/c mice were pretreated with aprotinin or tcY-NH(2) (30 μg/mouse) prior to intrapleural injection of LTB(4) or eotaxin-1 and the number of infiltrating eosinophils was determined 48 h later.

RESULTS

Aprotinin (1 mg/kg) inhibited eosinophil recruitment induced by eotaxin-1 (p < 0.01), but not that induced by LTB(4). Moreover, tcY-NH(2) treatment inhibited eosinophil recruitment in response to eotaxin-1 (p < 0.01 by ANOVA/Tukey post-test).

CONCLUSION

These data suggest that aprotinin-inhibited proteinases participate in eosinophil migration induced by eotaxin-1 and that PAR-4 activation plays an important role in regulating this migration.

Absorption of the ω and ϕ mesons in nuclei

Because of their long lifetimes, the ω and ϕ mesons are the ideal candidates for the study of possible modifications of the in-medium meson-nucleon interaction through their absorption inside the nucleus. During the E01-112 experiment at the Thomas Jefferson National Accelerator Facility, the mesons were photoproduced from 2H, C, Ti, Fe, and Pb targets. This Letter reports the first measurement of the ratio of nuclear transparencies for the e+e- channel. The ratios indicate larger in-medium widths compared with what have been reported in other reaction channels. The absorption of the ω meson is stronger than that reported by the CBELSA-TAPS experiment and cannot be explained by recent theoretical models.

Probing quark-gluon interactions with transverse polarized scattering

We have extracted QCD matrix elements from our data on doubly polarized inelastic scattering of electrons on nuclei. We find the higher twist matrix element d˜2, which arises strictly from quark-gluon interactions, to be unambiguously nonzero. The data also reveal an isospin dependence of higher twist effects if we assume that the Burkhardt-Cottingham sum rule is valid. The fundamental Bjorken sum rule obtained from the a0 matrix element is satisfied at our low momentum transfer.

Immunocytochemical localization of component C of the methylreductase system in Methanococcus voltae and Methanobacterium thermoautotrophicum

Antibodies were raised against homogeneous preparations of component C of the methylreductase system from Methanococcus voltae and Methanobacterium thermoautotrophicum. Cells of these organisms were fixed with paraformaldehyde and/or glutaraldehyde, sectioned, and labeled with antibodies and colloidal gold-labeled protein A. In M. voltae the gold particles were predominantly located in the vicinity of the cytoplasmic membrane. In rare cases a similar result was obtained also with M. thermoautotrophicum. However, in all but a few of the ultrathin sections of this bacterium, the label was randomly distributed in the cell interior. If one assumes a reliable fixation of all cell components, these results would suggest that the two distantly related methanogens studied have distinctive patterns for the localization of component C. The results with M. voltae are in agreement with recent findings that the methylreductase system is involved in the generation of a proton-motive force at the membrane.

Insertional Mutations in the Hydrogenase vhc and frc Operons Encoding Selenium-Free Hydrogenases in Methanococcus voltae

Methanococcus voltae, which contains four different gene groups that encode [NiFe]-hydrogenases, was transformed with integration vectors to achieve polar inactivation of two of the four hydrogenase operons that encode the selenium-free enzymes Vhc and Frc. Transformants which were selected by their acquired puromycin resistance showed site-specific insertions in either the vhc or frc operon by single crossover events. Southern hybridization revealed tandem integrations of whole vectors in the vhc operon, whereas only one vector copy was found in the frc operon. Northern (RNA) hybridizations showed a pac transcript of defined size, indicating strong termination in front of the hydrogenase genes downstream. In spite of the apparent abolition of expression of selenium-free hydrogenases through these polar insertions, they were not lethal to cells upon growth in selenium-deprived minimal medium, which we had previously shown to strongly induce transcription of the respective operons in M. voltae. Instead, like wild-type control cultures, transformants responded to selenium deprivation only with a reduction in growth rate. We conclude that loss of the potential to express a selenium-free hydrogenase can nevertheless be balanced by very small amounts of selenium hydrogenases under laboratory conditions in which the hydrogen supply is not likely to be a limiting growth factor.

Challenges Facing Quantification of Rat Locomotion along Beams of Varying Widths

Optoelectronic motion capture systems have been widely used to investigate temporal gait parameters in humans and animals in order to understand function and behavioural attributes of different pathologies, e.g. Parkinson's disease (PD). The aim of the present paper was to investigate the practicality of utilising this system to investigate the effects of a unilateral 6-hydroxydopamine (6-OHDA) lesion on rat locomotion while walking on beams of varying widths (graduated, narrow, and wide). Temporal gait parameters of ten male Lister Hooded rats (five controls and five hemiparkinsonian) were observed using passive markers placed in locations that were representative of their four limbs and their body axis. The results demonstrate that marker-based motion capture can provide an effective and simple approach to quantifying temporal gait parameters for rat models of PD. They also reveal how the width of the path affects the locomotion in both experimental cohorts. Such measurements can be compared with human motion analysis to explore correlations between the animal model and human behaviour, which is an important step for translational medicine.

Expression plasmids are only useful for the investigation of co-receptor tropism and fusion capacity of short HIV-1 envelope domains

Expression vectors have been used widely to identify functionally important domains in HIV-1 glycoproteins. Env domains such as the V3 loop were amplified by polymerase chain reaction (PCR) and inserted into plasmids carrying the backbone of an HIV-1 reference strain like NL4-3. The hypothesis of the present approach was that cloning large domains of wild type envelopes yields constructs that are non-functional in co-receptor-expressing HeLaCD4 cells, in contrast to laboratory-adapted HIV-1 strains. The background for this assumption was that primary HIV-1 virions are frequently less infectious and lack fusion capacity in HeLaCD4 cells compared to laboratory-adapted (LA) viruses. To address this hypothesis, env domains of different length were amplified from a panel of X4-tropic HIV-1 clinical isolates cultured in peripheral blood lymphocytes (PBLs) and cloned into the backbone of NL4-3 env. Constructs bearing either the V3 loops or 312 nucleotides of the intracellular trunk (ICT) of gp41 led to a similar fusion capacity as NL4-3. In contrast, none of the plasmids carrying the 2322 N-terminal nucleotides of primary isolates led to similar syncytium formation. These results have an effect on studies that investigate pathogenic effects of Env regions with chimeric constructs in the backbone of HIV reference envelopes.

No significant effect of orally administered chemokine receptor 1 antagonist on intercellular adhesion molecule-3 expression in relapsing—remitting multiple sclerosis patients

We investigated the expression of intercellular adhesion molecules ICAM-1 and ICAM-3 on peripheral blood mononuclear cells in a subgroup of 34 patients with relapsing-remitting multiple sclerosis who were treated orally with the chemokine receptor 1 antagonist BX 471 in a 16-week, randomised, double-blind, placebo-controlled phase II study. ICAM-1 and ICAM-3 expression was measured by flow cytometry at different time points during and after therapy and compared using multivariate analysis of variance and non-parametric Mann Whitney test. ICAM-3 expression on CD14 + peripheral blood mononuclear cells was increased in the verum group under therapy, but did not differ significantly between the verum and placebo groups. Most likely, this trend represents a small epiphenomenon only mediated by receptor cross-talk and feedback mechanisms.

Representing Data Quality in Sensor Data Streaming Environments

Sensors in smart-item environments capture data about product conditions and usage to support business decisions as well as production automation processes. A challenging issue in this application area is the restricted quality of sensor data due to limited sensor precision and sensor failures. Moreover, data stream processing to meet resource constraints in streaming environments introduces additional noise and decreases the data quality. In order to avoid wrong business decisions due to dirty data, quality characteristics have to be captured, processed, and provided to the respective business task. However, the issue of how to efficiently provide applications with information about data quality is still an open research problem.

In this article, we address this problem by presenting a flexible model for the propagation and processing of data quality. The comprehensive analysis of common data stream processing operators and their impact on data quality allows a fruitful data evaluation and diminishes incorrect business decisions. Further, we propose the data quality model control to adapt the data quality granularity to the data stream interestingness.

Measurement of the differential cross section for the reaction gamman-->pi- p from deuterium

We report a measurement of the differential cross section for the gamman-->pi- p process from the CLAS detector at Jefferson Laboratory in Hall B for photon energies between 1.0 and 3.5 GeV and pion center-of-mass (c.m.) angles (thetac.m.) between 50 degrees and 115 degrees. We confirm a previous indication of a broad enhancement around a c.m. energy ([sqrt]s) of 2.1 GeV at thetac.m.=90 degrees in the scaled differential cross section s7dsigma/dt and a rapid falloff in a center-of-mass energy region of about 400 MeV following the enhancement. Our data show an angular dependence of this enhancement as the suggested scaling region is approached for thetac.m. from 70 degrees to 105 degrees.

Clinical benefit of catumaxomab in malignant ascites in patient subpopulations in a pivotal phase II/III trial

e14000

Background: Parsons et al. (ASCO 2008) reported the results of a pivotal phase II/III trial in patients with malignant ascites due to epithelial cancer. Treatment with the trifunctional antibody catumaxomab resulted in a clinically relevant prolongation of puncture-free survival, defined as the time to the next therapeutic puncture or the time to death, whichever occurred first. Malignant ascites is a typical late-stage manifestation of cancer associated with a poor prognosis and survival. Effective treatment options are limited. It is thus of special interest if all patient subgroups derive objective benefit from treatment. Methods: A post-hoc analysis was performed on the 258 patients with epithelial tumors treated with catumaxomab + paracentesis or paracentesis alone (control) in the pivotal trial to investigate any association between the primary endpoint (puncture-free survival) and the primary tumor, metastases, or other prognostic parameters. Results: Puncture-free survival was lower in patients with non-ovarian vs ovarian tumors and those with a poor prognosis (metastases vs no metastases, elderly vs younger, or low vs serum protein level). However, there was always a statistically significant treatment effect for catumaxomab compared with the respective control group (p≤0.0001, log rank test, for all comparisons) (see table). Conclusion: Catumaxomab demonstrated a significant clinical benefit in patients with malignant ascites independent of the primary tumor or other prognostic factors. Therefore, catumaxomab could be considered as a treatment option for patients with a poor prognosis.

[Table: see text]

[Table: see text]

Precise measurement of the neutron magnetic form factor G(M)n in the few-GeV2 region

The neutron elastic magnetic form factor was extracted from quasielastic electron scattering on deuterium over the range Q;{2}=1.0-4.8 GeV2 with the CLAS detector at Jefferson Lab. High precision was achieved with a ratio technique and a simultaneous in situ calibration of the neutron detection efficiency. Neutrons were detected with electromagnetic calorimeters and time-of-flight scintillators at two beam energies. The dipole parametrization gives a good description of the data.

Cacao extracts suppress tryptophan degradation of mitogen-stimulated peripheral blood mononuclear cells

ETHNOPHARMACOLOGICAL RELEVANCE

The fruits of Theobroma cacao L. (Sterculiaceae) have been used as food and a remedy for more than 4000 years. Today, about 100 therapeutic applications of cacao are described involving the gastrointestinal, nervous, cardiovascular and immune systems. Pro-inflammatory cytokine interferon-gamma and related biochemical pathways like tryptophan degradation by indoleamine 2,3-dioxygenase and neopterin formation are closely associated with the pathogenesis of such disorders.

AIM OF THE STUDY

To determine the anti-inflammatory effect of cacao extracts on interferon-gamma and biochemical consequences in immunocompetent cells.

MATERIALS AND METHODS

Effects of aqueous or ethanolic extracts of cacao were examined on mitogen-induced human peripheral blood mononuclear cells (PBMC) of healthy donors and on lipopolysaccharide-stimulated myelomonocytic THP-1 cells. Antioxidant activity of extracts was determined by oxygen radical absorption capacity (ORAC) assay.

RESULTS

In mitogen-stimulated PBMC, enhanced degradation of tryptophan, formation of neopterin and interferon-gamma were almost completely suppressed by the cacao extracts at doses of > or = 5 microg/mL. Cacao extracts had no effect on tryptophan degradation in lipopolysaccharide-stimulated THP-1 cells.

CONCLUSIONS

There is a significant suppressive effect of cacao extracts on pro-inflammatory pathways in activated T-cells. Particularly the influence on indoleamine 2,3-dioxygenase could relate to some of the beneficial health effects ascribed to cacao.

[Web-based electronic patient record as an instrument for quality assurance within an integrated care concept]

OBJECTIVE

A prerequisite for integrated care programmes is the implementation of a communication network meeting quality assurance standards. Against this background the main objective of the integrated care project between the University Eye Hospital Erlangen and the health insurance company AOK Bayern was to evaluate the potential and the acceptance of a web-based electronic patient record in the context of cataract and retinal surgery.

METHODS

Standardised modules for capturing pre-, intra- and post-operative data on the basis of clinical pathway guidelines for cataract- and retinal surgery have been developed. There are 6 data sets recorded per patient (1 pre-operative, 1 operative, 4-6 post-operative). For data collection, a web-based communication system (Soarian Integrated Care) has been chosen which meets the high requirements in data security, as well as being easy to handle. This teleconsultation system and the embedded electronic patient record are independent of the software used by respective offices and hospitals. Data transmission and storage were carried out in real-time.

RESULTS

At present, 101 private ophthalmologists are taking part in the IGV contract with the University Eye Hospital Erlangen. This corresponds to 52% of all private ophthalmologists in the region. During the period from January 1st 2006 to December 31st 2006, 1844 patients were entered. Complete documentation was achieved in 1390 (75%) of all surgical procedures. For evaluation of this data, a multidimensional report and analysis tool (Cognos) was used. The deviation from target refraction as one quality indicator was in the mean 0.09 diopter.

CONCLUSIONS

The web-based patient record used in this project was highly accepted by the private ophthalmologists. However there are still general concerns against the exchange of medical data via the internet. Nevertheless, the web-based patient record is an essential tool for a functional integration between the ambulatory and stationary health-care units. In addition to the telemedicine functions of the system, we achieved the export of the data to a data warehouse system in order to provide a flexible and powerful tool for quality assurance analysis and reporting.

Search for the photoexcitation of exotic mesons in the pi+pi+pi- system

A search for exotic mesons in the pi;{+}pi;{+}pi;{-} system photoproduced by the charge exchange reaction gammap-->pi;{+}pi;{+}pi;{-}(n) was carried out by the CLAS Collaboration at Jefferson Lab. A tagged-photon beam with energies in the 4.8 to 5.4 GeV range, produced through bremsstrahlung from a 5.744 GeV electron beam, was incident on a liquid-hydrogen target. A partial wave analysis was performed on a sample of 83 000 events, the highest such statistics to date in this reaction at these energies. The main objective of this study was to look for the photoproduction of an exotic J;{PC}=1;{-+} resonant state in the 1 to 2 GeV mass range. Our partial wave analysis shows production of the a_{2}(1320) and the pi_{2}(1670) mesons, but no evidence for the a_{1}(1260), nor the pi_{1}(1600) exotic state at the expected levels. An upper limit of 13.5 nb is determined for the exotic pi_{1}(1600) cross section, less than 2% of the a_{2}(1320) production.

Measurement of direct f0(980) photoproduction on the proton

We report on the results of the first measurement of exclusive f_{0}(980) meson photoproduction on protons for E_{gamma}=3.0-3.8 GeV and -t=0.4-1.0 GeV2. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The resonance was detected via its decay in the pi;{+}pi;{-} channel by performing a partial wave analysis of the reaction gammap-->ppi;{+}pi;{-}. Clear evidence of the f_{0}(980) meson was found in the interference between P and S waves at M_{pi;{+}pi;{-}} approximately 1 GeV. The S-wave differential cross section integrated in the mass range of the f_{0}(980) was found to be a factor of about 50 smaller than the cross section for the rho meson. This is the first time the f_{0}(980) meson has been measured in a photoproduction experiment.

Satellite cell dysfunction contributes to the progressive muscle atrophy in myotonic dystrophy type 1

AIMS

Myotonic dystrophy type 1 (DM1), one of the most common forms of inherited neuromuscular disorders in the adult, is characterized by progressive muscle weakness and wasting leading to distal muscle atrophy whereas proximal muscles of the same patients are spared during the early phase of the disease. In this report, the role of satellite cell dysfunction in the progressive muscular atrophy has been investigated.

METHODS

Biopsies were obtained from distal and proximal muscles of the same DM1 patients. Histological and immunohistological analyses were carried out and the past regenerative history of the muscle was evaluated. Satellite cell number was quantified in vivo and proliferative capacity was determined in vitro.

RESULTS

The size of the CTG expansion was positively correlated with the severity of the symptoms and the degree of muscle histopathology. Marked atrophy associated with typical DM1 features was observed in distal muscles of severely affected patients whereas proximal muscles were relatively spared. The number of satellite cells was significantly increased (twofold) in the distal muscles whereas very little regeneration was observed as confirmed by telomere analyses and developmental MyHC staining (0.3-3%). The satellite cells isolated from the DM1 distal muscles had a reduced proliferative capacity (36%) and stopped growing prematurely with telomeres longer than control cells (8.4 vs. 7.1 kb), indicating that the behaviour of these precursor cells was modified.

CONCLUSIONS

Our results indicate that alterations in the basic functions of the satellite cells progressively impair the muscle mass maintenance and/or regeneration resulting in gradual muscular atrophy.