Micro-solid oxide fuel cells: status, challenges, and chances

Abstract: Micro-solid oxide fuel cells (micro-SOFC) are predicted to be of high energy density and are potential power sources for portable electronic devices. A micro-SOFC system consists of a fuel cell comprising a positive electrode-electrolyte-negative electrode (i.e. PEN) element, a gas-processing unit, and a thermal system where processing is based on micro-electro-mechanical-systems fabrication techniques. A possible system approach is presented. The critical properties of the thin film materials used in the PEN membrane are discussed, and the unsolved subtasks related to micro-SOFC membrane development are pointed out. Such a micro-SOFC system approach seems feasible and offers a promising alternative to state-of-the-art batteries in portable electronics. Graphical abstract: Graphical Abstract tex

Isolation and characterization of new Puumala orthohantavirus strains from Germany

Orthohantaviruses are re-emerging rodent-borne pathogens distributed all over the world. Here, we report the isolation of a Puumala orthohantavirus (PUUV) strain from bank voles caught in a highly endemic region around the city Osnabrück, north-west Germany. Coding and non-coding sequences of all three segments (S, M, and L) were determined from original lung tissue, after isolation and after additional passaging in VeroE6 cells and a bank vole-derived kidney cell line. Different single amino acid substitutions were observed in the RNA-dependent RNA polymerase (RdRP) of the two stable PUUV isolates. The PUUV strain from VeroE6 cells showed a lower titer when propagated on bank vole cells compared to VeroE6 cells. Additionally, glycoprotein precursor (GPC)-derived virus-like particles of a German PUUV sequence allowed the generation of monoclonal antibodies that allowed the reliable detection of the isolated PUUV strain in the immunofluorescence assay. In conclusion, this is the first isolation of a PUUV strain from Central Europe and the generation of glycoprotein-specific monoclonal antibodies for this PUUV isolate. The obtained virus isolate and GPC-specific antibodies are instrumental tools for future reservoir host studies

A broadly cross-reactive monoclonal antibody against hepatitis E virus capsid antigen

To generate a hepatitis E virus (HEV) genotype 3 (HEV-3)–specific monoclonal antibody (mAb), the Escherichia coli–expressed carboxy-terminal part of its capsid protein was used to immunise BALB/c mice. The immunisation resulted in the induction of HEV-specific antibodies of high titre. The mAb G117-AA4 of IgG1 isotype was obtained showing a strong reactivity with the homologous E. coli, but also yeast-expressed capsid protein of HEV-3. The mAb strongly cross-reacted with ratHEV capsid protein derivatives produced in both expression systems and weaker with an E. coli–expressed batHEV capsid protein fragment. In addition, the mAb reacted with capsid protein derivatives of genotypes HEV-2 and HEV-4 and common vole hepatitis E virus (cvHEV), produced by the cell-free synthesis in Chinese hamster ovary (CHO) and Spodoptera frugiperda (Sf21) cell lysates. Western blot and line blot reactivity of the mAb with capsid protein derivatives of HEV-1 to HEV-4, cvHEV, ratHEV and batHEV suggested a linear epitope. Use of truncated derivatives of ratHEV capsid protein in ELISA, Western blot, and a Pepscan analysis allowed to map the epitope within a partially surface-exposed region with the amino acid sequence LYTSV. The mAb was also shown to bind to human patient–derived HEV-3 from infected cell culture and to hare HEV-3 and camel HEV-7 capsid proteins from transfected cells by immunofluorescence assay. The novel mAb may serve as a useful tool for further investigations on the pathogenesis of HEV infections and might be used for diagnostic purposes. Key points • The antibody showed cross-reactivity with capsid proteins of different hepeviruses. • The linear epitope of the antibody was mapped in a partially surface-exposed region. • The antibody detected native HEV-3 antigen in infected mammalian cells

Micro-solid oxide fuel cells as power supply for small portable electronic equipment

Micro-solid oxide fuel cell (SOFC) systems are anticipated for powering small, portable electronic devices, such as laptop, personal digital assistant (PDA), medical and industrial accessories. It is predicted that micro-SOFC systems have a 2-4 higher energy density than Li-ion batteries [1]. However, literature mainly focuses on the fabrication and characterization of thin films and membranes for micro-SOFC systems [2-12]; the entire system approach is not yet studied in detail. We will therefore discuss in this paper the entire approach from the fabrication of thin films and membranes up to the complete system, including fuel processing, thermal management and integration

Identification and molecular characterization of small mammal-associated hepeviruses for the development of novel animal models

Hepeviruses are small viruses with a RNA-genome of positive polarity that form the family Hepeviridae. The family includes two genera: members of the genus Piscihepevirus were detected in fish species and members of the genus Orthohepevirus were found in different mammal and bird species. The genus Orthohepevirus contains four different species, namely Orthohepevirus A, B, C and D. The species Orthohepevirus A contains five human pathogenic genotypes, with three of them being zoonotic. The species Orthohepevirus C contains mammal-associated pathogens, which were identified in rats and carnivores. The human pathogenic genotypes are responsible for a self-limiting acute hepatitis in humans, which could become chronically in immunocompromised individuals. The main route of transmission is the consumption of undercooked meat and direct contact with HEV-positive excreta or blood. In Germany, hepatitis E is a notifiable disease since 2001 with an increased number of cases per year. Rats are the reservoir of rat-associated HEV (ratHEV), but also the zoonotic HEV-3 genotype was detected in rats. The European rabbit (Oryctolagus cuniculus) was identified as a reservoir host of a subgenotype of human pathogenic HEV-3 (HEV-3ra). For the development of small mammal animal models, the objective of this study was to evaluate different small mammal populations for novel hepeviruses and to study the presence of HEV and sequence divergence of ratHEV and rabbitHEV in rat and rabbit populations from Europe. Approximately 3000 rodents from Germany and the Czech Republic were screened by broad spectrum HEV-RT-PCR. As a result, 13 common voles (Microtus arvalis) and one bank vole (Myodes glareolus) were detected to be HEV-RNA positive. Comparison of the obtained sequences, complete genome determination and phylogenetic analysis indicated the finding of a novel common vole-associated HEV (cvHEV), which shows a high sequence divergence towards other members of the species Orthohepevirus C, but shares a high sequence similarity to a HEV-genome derived from a kestrel (Falco tinnunculus). The finding of cvHEV-RNA in a bank vole might be caused by a spillover infection. The cvHEV genome shares the hepevirus-typical open reading frames, but also has unique cvHEV-specific attributes in its genome. The investigation of 420 Norway rats (Rattus norvegicus) and 88 Black rats (Rattus rattus) identified HEV-RNA in Norway rats from eight of nine and Black rats from two of four European countries. In a single Norway rat from Belgium, a HEV-3-strain with high sequence similarities to rabbitHEV (HEV-3ra), was detected. The investigation of zoo animals revealed a ratHEV spillover infection in a Syrian brown bear (Ursus arctos syriacus). This infection was most likely caused by ratHEV-infected free-living, wild rats from the same zoo. Investigation of wild rabbit populations trapped in and around Frankfurt am Main, Germany, showed anti-HEV antibodies (34.7%) and rabbitHEV-RNA (25%). A high sequence similarity of rabbitHEV in the animals trapped at the urban site was observed, whereas a high sequence divergence was seen for the animals trapped at the rural trapping sites. In conclusion, hepeviruses are widespread among different small mammal populations in Europe. The broad geographical distribution of these hepeviruses should be taken into account in further public health risk assessments. Further investigations are needed to characterize the presence of cvHEV in more detail, especially by taking the population dynamics of common voles into account. The detected HEV-strains could be taken as basis for the establishment of novel HEV-animal models, which might replace the so far used swine and non-human primate models.Hepeviren sind kleine Viren mit einem einzelsträngigen RNA-Genom positiver Polarität und bilden die Familie Hepeviridae. Die Familie beinhaltet zwei Gattungen: Zur Gattung Piscihepevirus gehört ein bei Fischen gefundenes Virus, während Vertreter der Gattung Orthohepevirus in Säugetieren und Vögeln nachgewiesen wurden. Die Gattung Orthohepevirus enthält die Arten Orthohepevirus A, B, C und D. Die Spezies Orthohepevirus A beinhaltet fünf humanpathogene Genotypen, von denen drei zoonotische Erreger sind (HEV-3, HEV-4, HEV -7). Die Spezies Orthohepevirus C beinhaltet ebenfalls Säugetier-assoziierte Viren, die bei Ratten und Karnivoren identifiziert worden sind. Die humanpathogenen Genotypen sind für eine akute selbstlimitierende Hepatitis beim Menschen, die bei immungeschwächten Individuen chronisch werden kann, verantwortlich. Als Hauptübertragungsweg wird der Verzehr von rohem oder ungenügend gegartem Fleisch sowie der direkte Kontakt mit HEV-positiven Ausscheidungen oder Blut angenommen. In Deutschland ist die Hepatitis E seit 2001 eine meldepflichtige Krankheit mit einer jährlich steigenden Zahl von gemeldeten Fällen. Ratten stellen das Reservoir des Ratten-Hepatitis E-Virus (ratHEV) dar, dessen zoonotisches Potenzial kontrovers diskutiert wird. Darüber hinaus wurde in Wanderratten (Rattus norvegicus) der humanpathogene Genotyp HEV-3 nachgewiesen. Kaninchen (Oryctolagus cuniculus) wurden als Reservoir eines Subgenotyps des humanpathogenen Genotyp HEV-3 (Kaninchen-assoziiertes HEV, rabbitHEV, HEV-3ra) identifiziert. Im Rahmen der Entwicklung von Kleinsäuger-Tiermodellen für HEV sollte in der vorliegenden Studie in Kleinsäugerpopulationen nach neuen Hepeviren gesucht werden und das Vorkommen und die Sequenzvariation von ratHEV und rabbitHEV in Ratten- und Kaninchenpopulationen in Europa genauer charakterisiert werden. Bei der Suche nach neuen Hepeviren wurden ca. 3000 Kleinsäuger aus Deutschland und der Tschechischen Republik mittels einer Breitspektrum HEV-RT-PCR untersucht. Dabei wurde in 13 Feldmäusen (Microtus arvalis) und einer Rötelmaus (Myodes glareolus) HEV-RNA nachgewiesen. Sequenzvergleiche und phylogenetische Untersuchungen anhand von partiellen und Komplettgenomen zeigten, dass es sich dabei um ein neues Feldmaus-assoziiertes HEV handelt (common vole HEV, cvHEV), das sich deutlich von den bisher bekannten Genotypen der Spezies Orthohepevirus C unterscheidet, aber eine große Ähnlichkeit zu einem bei einem Falken (Falco tinnunculus) gefundenen Virusgenom zeigte. Der Nachweis von cvHEV-RNA in einer Rötelmaus könnte auf eine Spilloverinfektion zurückzuführen sein. Das cvHEV-Genom besitzt die für alle Hepeviren typischen offenen Leserahmen, zeigt aber auch einige cvHEV-spezifische Besonderheiten im Genom. Im Rahmen der Untersuchungen wurden insgesamt 420 Wanderratten und 88 Hausratten (Rattus rattus) aus zwölf europäischen Ländern auf das Vorhandensein von HEV-RNA untersucht. In Wanderratten aus acht europäischen Ländern und Hausratten aus zwei Ländern konnte ratHEV-RNA nachgewiesen werden. In einer Wanderratte aus Belgien wurde ein HEV-3-Stamm mit großer Sequenzähnlichkeit zum rabbitHEV (HEV-3ra) identifiziert. Bei der Untersuchung von Zootieren wurde eine ratHEV-Spilloverinfektion in einem syrischen Braunbären (Ursus arctos syriacus) nachgewiesen, welche vermutlich durch Schadratten im gleichen Zoo verursacht worden ist. Die Untersuchung von Wildkaninchenpopulationen aus der Stadt Frankfurt am Main und deren Umgebung zeigte das Vorkommen von anti-HEV Antikörpern (34.7%) und rabbitHEV-RNA (25%). Die rabbitHEV-Stämme der urbanen Population zeigten eine sehr große Sequenzähnlichkeit, während bei den Tieren aus der ländlichen Population eine starke Sequenzdivergenz des rabbitHEV beobachtet wurde. Die hier vorgestellten Ergebnisse belegen das gleichzeitige Vorkommen verschiedener Hepeviren in Kleinsäugerpopulationen in Europa. Die weite geografische Verbreitung der Erreger sollte zukünftig bei einer Gefährdungsbeurteilung für die Bevölkerung berücksichtigt werden. Weitere Untersuchungen sollten das Vorkommen des cvHEV genauer charakterisieren, insbesondere auch im Zusammenhang mit Populationsveränderungen bei der Feldmaus. Auf der Basis der hier nachgewiesenen Erreger können zukünftig neue HEV-Tiermodelle entwickelt werden, die die bisher verwendeten Schweine- und Primatenmodelle möglicher Weise ersetzen könnten

Spatial and Temporal Evolutionary Patterns in Puumala Orthohantavirus (PUUV) S Segment

The S segment of bank vole (Clethrionomys glareolus)-associated Puumala orthohantavirus (PUUV) contains two overlapping open reading frames coding for the nucleocapsid (N) and a non-structural (NSs) protein. To identify the influence of bank vole population dynamics on PUUV S segment sequence evolution and test for spillover infections in sympatric rodent species, during 2010–2014, 883 bank voles, 357 yellow-necked mice (Apodemus flavicollis), 62 wood mice (A. sylvaticus), 149 common voles (Microtus arvalis) and 8 field voles (M. agrestis) were collected in Baden-Wuerttemberg and North Rhine-Westphalia, Germany. In total, 27.9% and 22.3% of bank voles were positive for PUUV-reactive antibodies and PUUV-specific RNA, respectively. One of eight field voles was PUUV RNA-positive, indicating a spillover infection, but none of the other species showed evidence of PUUV infection. Phylogenetic and isolation-by-distance analyses demonstrated a spatial clustering of PUUV S segment sequences. In the hantavirus outbreak years 2010 and 2012, PUUV RNA prevalence was higher in our study regions compared to non-outbreak years 2011, 2013 and 2014. NSs amino acid and nucleotide sequence types showed temporal and/or local variation, whereas the N protein was highly conserved in the NSs overlapping region and, to a lower rate, in the N alone coding part

Micro-solid oxide fuel cells: Status, challenges, and chances

ISSN:0026-9247ISSN:1434-447

Indigenous house mice dominate small mammal communities in northern Afghan military bases

Background: Small mammals are important reservoirs for pathogens in military conflicts and peacekeeping operations all over the world. This study investigates the rodent communities in three military bases in Northern Afghanistan. Small mammals were collected in this conflict zone as part of Army pest control measures from 2009 to 2012 and identified phenotypically as well as by molecular biological methods. Results: The analysis of the collected small mammals showed that their communities are heavily dominated by the house mouse Mus musculus and to a lesser extent Cricetulus migratorius and Meriones libycus. The origin of M. musculus specimens was analyzed by DNA sequencing of the mitochondrial cytochrome b gene and D-loop sequences. All animals tested belonged to the Mus musculus musculus subspecies indigenous to Afghanistan. The results were supported by detection of two nucleotide exchanges in the DNA polymerase gene of Mus musculus Rhadinovirus 1 (MmusRHV1), a herpesvirus, which is specific for all gene sequences from Afghan house mice, but absent in the MmusRHV1 sequences of German and British house mice. Studies of astrovirus RNA polymerase gene sequences did not yield sufficient resolution power for a similarly conclusive result. Conclusions: House mouse populations in military camps in Northern Afghanistan are indigenous and have not been imported from Europe. Nucleotide sequence polymorphisms in MmusRHV1 DNA polymerase gene might be used as an additional phylogeographic marker for house mice

Field vole‑associated Traemmersee hantavirus from Germany represents a novel hantavirus species

Vole-associated hantaviruses occur in the Old and New World. Tula orthohantavirus (TULV) is widely distributed throughout the European continent in its reservoir, the common vole (Microtus arvalis), but the virus was also frequently detected in field voles (Microtus agrestis) and other vole species. TULV and common voles are absent from Great Britain. However, field voles there harbor Tatenale and Kielder hantaviruses. Here we screened 126 field voles and 13 common voles from Brandenburg, Germany, for hantavirus infections. One common vole and four field voles were anti-TULV antibody and/or TULV RNA positive. In one additional, seropositive field vole a novel hantavirus sequence was detected. The partial S and L segment nucleotide sequences were only 61.1% and 75.6% identical to sympatrically occurring TULV sequences, but showed highest similarity of approximately 80% to British Tatenale and Kielder hantaviruses. Subsequent determination of the entire nucleocapsid (N), glycoprotein (GPC), and RNA-dependent RNA polymerase encoding sequences and determination of the pairwise evolutionary distance (PED) value for the concatenated N and GPC amino acid sequences confirmed a novel orthohantavirus species, tentatively named Traemmersee orthohantavirus. The identification of this novel hantavirus in a field vole from eastern Germany underlines the necessity of a large-scale, broad geographical hantavirus screening of voles to understand evolutionary processes of virus–host associations and host switches

Identification of a novel hantavirus strain in the root vole (Microtus oeconomus) in Lithuania, Eastern Europe

Hantaviruses are zoonotic pathogens that can cause subclinical to lethal infections in humans. In Europe, five orthohantaviruses are present in rodents: Myodes-associated Puumala orthohantavirus (PUUV), Microtus-associated Tula orthohantavirus, Traemmersee hantavirus (TRAV)/ Tatenale hantavirus (TATV)/ Kielder hantavirus, rat-borne Seoul orthohantavirus, and Apodemus-associated Dobrava-Belgrade orthohantavirus (DOBV). Human PUUV and DOBV infections were detected previously in Lithuania, but the presence of Microtus-associated hantaviruses is not known. For this study we screened 234 Microtus voles, including root voles (Microtus oeconomus), field voles (Microtus agrestis) and common voles (Microtus arvalis) from Lithuania for hantavirus infections. This initial screening was based on reverse transcription-polymerase chain reaction (RT-PCR) targeting the S segment and serological analysis. A novel hantavirus was detected in eight of 79 root voles tentatively named “Rusne virus” according to the capture location and complete genome sequences were determined. In the coding regions of all three genome segments, Rusne virus showed high sequence similarity to TRAV and TATV and clustered with Kielder hantavirus in phylogenetic analyses of partial S and L segment sequences. Pairwise evolutionary distance analysis confirmed Rusne virus as a strain of the species TRAV/TATV. Moreover, we synthesized the entire nucleocapsid (N) protein of Rusne virus in Saccharomyces cerevisiae. We observed cross-reactivity of antibodies raised against other hantaviruses, including PUUV, with this new N protein. ELISA investigation of all 234 voles detected Rusne virus-reactive antibodies exclusively in four of 79 root voles, all being also RNA positive, but not in any other vole species. In conclusion, the detection of Rusne virus RNA in multiple root voles at the same trapping site during three years and its absence in sympatric field voles suggests root voles as the reservoir host of this novel virus. Future investigations should evaluate host association of TRAV, TATV, Kielder virus and the novel Rusne virus and their evolutionary relationships