Laser applications in thin-film photovoltaics

We review laser applications in thin-film photovoltaics (thin-film Si, CdTe, and Cu(In,Ga)Se2 solar cells). Lasers are applied in this growing field to manufacture modules, to monitor Si deposition processes, and to characterize opto-electrical properties of thin films. Unlike traditional panels based on crystalline silicon wafers, the individual cells of a thin-film photovoltaic module can be serially interconnected by laser scribing during fabrication. Laser scribing applications are described in detail, while other laser-based fabrication processes, such as laser-induced crystallization and pulsed laser deposition, are briefly reviewed. Lasers are also integrated into various diagnostic tools to analyze the composition of chemical vapors during deposition of Si thin films. Silane (SiH4), silane radicals (SiH3, SiH2, SiH, Si), and Si nanoparticles have all been monitored inside chemical vapor deposition systems. Finally, we review various thin-film characterization methods, in which lasers are implemente

Lactation transcriptomics in the Australian marsupial, Macropus eugenii: transcript sequencing and quantification

<p>Abstract</p> <p>Background</p> <p>Lactation is an important aspect of mammalian biology and, amongst mammals, marsupials show one of the most complex lactation cycles. Marsupials, such as the tammar wallaby (<it>Macropus eugenii</it>) give birth to a relatively immature newborn and progressive changes in milk composition and milk production regulate early stage development of the young.</p> <p>Results</p> <p>In order to investigate gene expression in the marsupial mammary gland during lactation, a comprehensive set of cDNA libraries was derived from lactating tissues throughout the lactation cycle of the tammar wallaby. A total of 14,837 express sequence tags were produced by cDNA sequencing. Sequence analysis and sequence assembly were used to construct a comprehensive catalogue of mammary transcripts.</p> <p>Sequence data from pregnant and early or late lactating specific cDNA libraries and, data from early or late lactation massively parallel sequencing strategies were combined to analyse the variation of milk protein gene expression during the lactation cycle.</p> <p>Conclusion</p> <p>Results show a steady increase in expression of genes coding for secreted protein during the lactation cycle that is associated with high proportion of transcripts coding for milk proteins. In addition, genes involved in immune function, translation and energy or anabolic metabolism are expressed across the lactation cycle. A number of potential new milk proteins or mammary gland remodelling markers, including noncoding RNAs have been identified.</p

Optical emission spectroscopy to diagnose powder formation in SiH4-H2 discharges

Silane and hydrogen discharges are widely used for the deposition of silicon thin film solar cells in large area plasmaenhanced chemical vapor deposition reactors. In the case of microcrystalline silicon thin film solar cells, it is of crucial importance to increase the deposition rate in order to reduce the manufacturing costs. This can be performed by using high silane concentration, and usually high RF power and high pressure, all favorable to powder formation in the discharge that generally reduces the deposition rate as well as the deposited material quality. This work presents a study of powder formation using time-resolved optical emission spectroscopy. It is shown that this technique is suitable to detect different regimes in powder formation ranging from powder free discharge to discharge producing large dust particles. Intermediate powder formation regimes include the formation of small silicon clusters at plasma ignition as well as cycle of powder growth and ejection out of the discharge, and both are observable by this low-cost and experimentally simple technique

Laser applications in thin-film photovoltaics

We review laser applications in thin-film photovoltaics (thin-film Si, CdTe, and Cu(In,Ga)Se2 solar cells). Lasers are applied in this growing field to manufacture modules, to monitor Si deposition processes, and to characterize opto-electrical properties of thin films. Unlike traditional panels based on crystalline silicon wafers, the individual cells of a thin-film photovoltaic module can be serially interconnected by laser scribing during fabrication. Laser scribing applications are described in detail, while other laserbased fabrication processes, such as laser-induced crystallization and pulsed laser deposition, are briefly reviewed. Lasers are also integrated into various diagnostic tools to analyze the composition of chemical vapors during deposition of Si thin films. Silane (SiH4), silane radicals (SiH3, SiH2, SiH, Si), and Si nanoparticles have all been monitored inside chemical vapor deposition systems. Finally, we review various thin-film characterization methods, in which lasers are implemented

MammoSapiens: eResearch of the lactation program.

Delivering bioinformatics power to life science researchers inevitably runs into problems of limited computing resources in the context of exponentially increasing data sources, access time, costs, lack of skills and, rapidly evolving technology and software tools with poorly defined standards. In this context the development of e-facilities to best enable collaborative research often needs to be customized to specific project applications in close cooperation with the experimentalist users and, to be concerned with the storage and management of results to allow more consistency and traceability of e-results on a broad access data mining platform. Here we showcase an internet based eResearch platform using the PHP/MySQL paradigm for the collaborative, integrative and comparative analysis of lactation related gene sequences and gene expression experiments to support lactation research. We also illustrate how these resources are used, how they enable research by allowing meta-analysis of data and results and, how the bottom-up development of customized eResearch components can lead to the production of more generic functional software tools and eResearch environments for deployment to a larger number of biological research users working on other bio-systems.<br /

MammoSapiens: eResearch of the lactation program. Building online facilities for collaborative molecular and evolutionary analysis of lactation and other biological systems from gene sequences and gene expression data.

Delivering bioinformatics power to life science researchers inevitably runs into problems of limited computing resources in the context of exponentially increasing data sources, access time, costs, lack of skills and, rapidly evolving technology and software tools with poorly defined standards. In this context the development of online facilities to best enable collaborative research often needs to be customized to specific project applications in close cooperation with the experimentalist users and, to be concerned with the storage and management of results to allow more consistency and traceability of results on a broad access data mining platform. Here we showcase an Internet based research platform using the PHP/MySQL paradigm for the collaborative, integrative and comparative analysis of lactation related gene sequences and gene expression experiments to support lactation research. We also illustrate how these resources are used, how they enable research by allowing meta-analysis of data and results and, how the bottom-up development of customized eResearch components can lead to the production of more generic functional software tools and eResearch environments for deployment to a larger number of biological researchers working on other bio-systems

Impact of secondary gas-phase reactions on microcrystalline silicon solar cells deposited at high rate

The role of secondary gas-phase reactions during plasma-enhanced chemical vapor deposition of microcrystalline silicon is a controversial subject. In this paper, we show that the enhancement of such reactions is associated with the improvement of material properties of absorber layers deposited at high constant rate. We detect powder, a product of secondary gas-phase reactions, via infrared laser absorption spectroscopy, laser light scattering, and optical emission spectroscopy. As the powder formation is increased, we measure a systematic improvement of device performance. This demonstrates that secondary gas-phase reactions are not detrimental to the material quality of microcrystalline silicon deposited at high rate. © 2010 American Institute of Physics

Update of the Swiss guidelines on post-treatment Lyme disease syndrome.

Lyme borreliosis is caused by Borrelia burgdorferi sensu lato infection, which responds well to antibiotic therapy in the overwhelming majority of cases. However, despite adequate antibiotic treatment some patients report persisting symptoms which are commonly summarised as post-treatment Lyme disease syndrome (PTLDS). In 2005, the Swiss Society of Infectious Diseases published a case definition for PTLDS. We aimed to review the scientific literature with a special emphasis on the last 10 years, questioning whether the definitions from 2005 are still valid in the light of current knowledge. Furthermore, we describe the clinical history of infection with Borrelia burgdorferi sensu lato, the estimated prevalence of PTLDS, the possible pathogenesis of PTLDS, and treatment options with an emphasis on clinical studies. In summary, we were unable to find a scientific reason for modification of the PTLDS definitions published in 2005. Thus, the diagnostic criteria remain unchanged, namely documented clinical and laboratory evidence of previous infection with B. burgdorferi, a completed course of appropriate antibiotic therapy, symptoms including fatigue, arthralgia, myalgia, cognitive dysfunction or radicular pain persisting for &gt;6 months, a plausible timely association between documented B. burgdorferi infection and onset of symptoms (i.e., persistent or recurrent symptoms that began within 6 months of completion of a recommended antibiotic therapy for early or late Lyme borreliosis), and exclusion of other somatic or psychiatric causes of symptoms. The main therapeutic options remain cognitive behavioural therapy and low-impact aerobic exercise programmes. Growing and unequivocal evidence confirms that prolonged or repeated antibiotic therapy for PTLDS is not beneficial, but potentially harmful and therefore contraindicated. The Guidelines of the Swiss Society of Infectious Diseases offer an evidence based, diagnostic and therapeutic framework for physicians caring for patients suffering from presumptive PTLDS in Switzerland

Consensus of German Transplant Centers on Hematopoietic Stem Cell Transplantation in Fanconi Anemia

Allogeneic hematopoietic stem cell transplantation (HSCT) is currently the only curative therapy for the severe hematopoietic complications associated with Fanconi anemia (FA). In Germany, it is estimated that 10–15 transplants are performed annually for FA. However, because FA is a DNA repair disorder, standard conditioning regimens confer a high risk of excessive regimen-related toxicities and mortality, and reduced intensity regimens are linked with graft failure in some FA patients. Moreover, development of graft-versus-host disease is a major contributing factor for secondary solid tumors. The relative rarity of the disorder limits HSCT experience at any single center. Consensus meetings were convened to develop a national approach for HSCT in FA. This manuscript outlines current experience and knowledge about HSCT in FA and, based on this analysis, general recommendations reached at these meetings