126 research outputs found

    Using and Developing Database and Analysing Tools for Production Testers of Printed Circuit Boards in Order to Improve the Process

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    Piirikorttien valmistuksen ja testauksen laadun seurannassa on monenlaisia haasteita. Piirikorttien toiminnalliset testerit keräävät eriäviä tietoja ja tätä aineistoa ei myöskään analysoida samoilla menetelmillä. Alihankkijoiden eli piirikorttivalmistajien sijainti ympäri maailmaa ei myöskään osaltaan helpota tilannetta, jolloin tietoa valmistus- ja testausprosesseista on vaikea saada. Tilannetta voidaan helpottaa pyrkimällä yhtenäiseen datamuotoon, jotta aineisto piirikorttien välillä olisi yhtenevää, mikä helpottaisi prosessien analysointia. Myös analysointimenetelmien yhtenäistäminen olisi toivottavaa, jotta eri piirikorttien laatua voitaisiin helpommin vertailla. Testeriaineiston saaminen reaaliaikaisesti analysoitavaksi tehostaisi myös toimintaa merkittävästi. Käyttämällä prosessien tilastolliseen analysointiin tarkoitettua Minitab-ohjelmaa ja tämän valmiita tilastotyökaluja voidaan testaustuloksia analysoida hyvinkin tehokkaasti. Data-aineiston varastointiin ja hallintaan kannattaa käyttää tietokantaohjelmaa, jollainen on esim. Microsoft Access. Access voi myös käyttää suoraan testeritietokoneessa olevaa aineistoa, jos piirikorttivalmistajan kanssa ollaan luotu VPN-yhteys. Näin dataa voidaan seurata ja käsitellä reaaliaikaisesti.There are plenty of problems that aggravate quality analysis of the manufacturing and the testing process of printed circuit boards. Nowadays the suppliers, printed circuit boards' manufacturers, locate far away and in different locations than the factory which uses the PCBs. It means that the mentioned processes are quite difficult to survey and analyse when the test data isn't always available. Every PCB tester also uses different kind of data form which means that the analysing tools must be modified greatly for each PCB type. If homogenous data form and analysing tools are used the quality analysis and comparison between different PCB types is much easier. When the test data is available in a real time the problems of the manufacturing and testing processes can also be handled immediately. When a dedicated statistical analyse program Minitab is used the quality analysis can be done very efficiently because Minitab contains a wide range of tools for statistical process control. The huge amount of test data is better to be stored into databases which can be managed by e.g. Microsoft Access. Access can also link straight into the databases, which are located in PCB manufacturers' testers if VPN access is established between these two locations

    Detection of Low-Copy Human Virus DNA upon Prolonged Formalin Fixation

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    Formalin fixation, albeit an outstanding method for morphological and molecular preservation, induces DNA damage and cross-linking, which can hinder nucleic acid screening. This is of particular concern in the detection of low-abundance targets, such as persistent DNA viruses. In the present study, we evaluated the analytical sensitivity of viral detection in lung, liver, and kidney specimens from four deceased individuals. The samples were either frozen or incubated in formalin (±paraffin embedding) for up to 10 days. We tested two DNA extraction protocols for the control of efficient yields and viral detections. We used short-amplicon qPCRs (63–159 nucleotides) to detect 11 DNA viruses, as well as hybridization capture of these plus 27 additional ones, followed by deep sequencing. We observed marginally higher ratios of amplifiable DNA and scantly higher viral genoprevalences in the samples extracted with the FFPE dedicated protocol. Based on the findings in the frozen samples, most viruses were detected regardless of the extended fixation times. False-negative calls, particularly by qPCR, correlated with low levels of viral DNA (150 base pairs). Our data suggest that low-copy viral DNAs can be satisfactorily investigated from FFPE specimens, and encourages further examination of historical materials

    Detection of Low-Copy Human Virus DNA upon Prolonged Formalin Fixation

    Get PDF
    Formalin fixation, albeit an outstanding method for morphological and molecular preservation, induces DNA damage and cross-linking, which can hinder nucleic acid screening. This is of particular concern in the detection of low-abundance targets, such as persistent DNA viruses. In the present study, we evaluated the analytical sensitivity of viral detection in lung, liver, and kidney specimens from four deceased individuals. The samples were either frozen or incubated in formalin (±paraffin embedding) for up to 10 days. We tested two DNA extraction protocols for the control of efficient yields and viral detections. We used short-amplicon qPCRs (63–159 nucleotides) to detect 11 DNA viruses, as well as hybridization capture of these plus 27 additional ones, followed by deep sequencing. We observed marginally higher ratios of amplifiable DNA and scantly higher viral genoprevalences in the samples extracted with the FFPE dedicated protocol. Based on the findings in the frozen samples, most viruses were detected regardless of the extended fixation times. False-negative calls, particularly by qPCR, correlated with low levels of viral DNA (150 base pairs). Our data suggest that low-copy viral DNAs can be satisfactorily investigated from FFPE specimens, and encourages further examination of historical materials

    A hybrid pipeline for reconstruction and analysis of viral genomes at multi-organ level

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    Background: Advances in sequencing technologies have enabled the characterization of multiple microbial and host genomes, opening new frontiers of knowledge while kindling novel applications and research perspectives. Among these is the investigation of the viral communities residing in the human body and their impact on health and disease. To this end, the study of samples from multiple tissues is critical, yet, the complexity of such analysis calls for a dedicated pipeline. We provide an automatic and efficient pipeline for identification, assembly, and analysis of viral genomes that combines the DNA sequence data from multiple organs. TRACESPipe relies on cooperation among 3 modalities: compression-based prediction, sequence alignment, and de novo assembly. The pipeline is ultra-fast and provides, additionally, secure transmission and storage of sensitive data. Findings: TRACESPipe performed outstandingly when tested on synthetic and ex vivo datasets, identifying and reconstructing all the viral genomes, including those with high levels of single-nucleotide polymorphisms. It also detected minimal levels of genomic variation between different organs. Conclusions: TRACESPipe's unique ability to simultaneously process and analyze samples from different sources enables the evaluation of within-host variability. This opens up the possibility to investigate viral tissue tropism, evolution, fitness, and disease associations. Moreover, additional features such as DNA damage estimation and mitochondrial DNA reconstruction and analysis, as well as exogenous-source controls, expand the utility of this pipeline to other fields such as forensics and ancient DNA studies. TRACESPipe is released under GPLv3 and is available for free download at https://github.com/viromelab/tracespipe.Peer reviewe

    The landscape of persistent human DNA viruses in femoral bone

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    The imprints left by persistent DNA viruses in the tissues can testify to the changes driving virus evolution as well as provide clues on the provenance of modern and ancient humans. However, the history hidden in skeletal remains is practically unknown, as only parvovirus B19 and hepatitis B virus DNA have been detected in hard tissues so far. Here, we investigated the DNA prevalences of 38 viruses in femoral bone of recently deceased individuals. To this end, we used quantitative PCRs and a custom viral targeted enrichment followed by next generation sequencing. The data was analyzed with a tailor-made bioinformatics pipeline. Our findings revealed bone to be a much richer source of persistent DNA viruses than earlier perceived, discovering ten additional ones, including several members of the herpesand polyomavirus families, as well as human papillomavirus 31 and torque teno virus. Remarkably, many of the viruses found have oncogenic potential and/or may reactivate in the elderly and immunosuppressed individuals. Thus, their persistence warrants careful evaluation of their clinical significance and impact on bone biology. Our findings open new frontiers for the study of virus evolution from ancient relics as well as provide new tools for the investigation of human skeletal remains in forensic and archaeological contexts.Peer reviewe

    Urine and Free Immunoglobulin Light Chains as Analytes for Serodiagnosis of Hantavirus Infection

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    Rapid point-of-care testing is a megatrend in infectious disease diagnosis. We have introduced a homogeneous immunoassay concept, which is based on the simultaneous binding of antigen and protein L to a given immunoglobulin molecule. The complex formation is detected utilizing time-resolved Förster resonance energy transfer between antigen-attached donor and acceptor-labeled protein L, hence the name LFRET. Here, we demonstrate that urine can be used as a sample matrix in LFRET-based serodiagnostics. We studied urine samples collected during the hospitalization and recovery of patients with acute Puumala orthohantavirus (PUUV) infection. We compared PUUV antibody-specific LFRET signals in urine to those in plasma, and found excellent correlation in the test outcomes The LFRET test from urine was positive in 40/40 patients with acute PUUV infection. PUUV causes a mild form of hemorrhagic fever with renal syndrome, characterized by acute kidney injury and proteinuria. Immunofluorescence and western blotting demonstrated PUUV-IgG and -IgA in urine, however, the presence of intact immunoglobulins did not fully explain the LFRET signals. We purified free light chains (FLCs) from both urine and serum of healthy volunteers and patients with acute PUUV infection, and verified the presence of antigen-specific FLCs. Antigen-specific FLCs provide a new means for non-invasive antibody detection and disease diagnosis

    Newly detected DNA viruses in juvenile nasopharyngeal angiofibroma (JNA) and oral and oropharyngeal squamous cell carcinoma (OSCC/OPSCC)

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    PurposeApproximately 20% of cancers are estimated to have a viral etiology. We aimed to investigate whether DNA of 8 human parvoviruses [bocavirus 1-4 (HBoV1-4), parvovirus B19 (B19V), protoparvoviruses (bufa-, tusa-, and cutavirus)] and 13 human polyomaviruses (HPyV) can be detected in oropharyngeal and oral cavity squamous cell carcinoma (OPSCC/OSCC), and in juvenile nasopharyngeal angiofibroma (JNA) tissue samples.MethodsFresh samples of seven JNA tissues and ten paired tissues of OSCC/OPSCC tumor and adjacent healthy tissues were collected. DNA extraction and real-time PCRs were performed to detect HBoV1-4, B19V, bufa- tusa- and cutavirus, and HPyV genomes.ResultsJNA specimens were negative for all parvoviruses tested, whereas one JNA sample was Merkel cell polyomavirus (MCPyV) DNA positive. The OSCC/OPSCC samples were negative for the human protoparvoviruses, HBoV1-4, and all human polyomaviruses, except for one patient that was MCPyV DNA positive in both healthy and tumor tissues. Seven OSCC/OPSCC patients were positive for B19V DNA, three of them in both healthy and cancerous tissues and three in only healthy tissues. Three of the B19V DNA-positive patients harbored viral genotype 1, three genotype 2, and one genotype 3B.ConclusionsThese are the first reports of MCPyV and B19V DNA being detected in JNA and OPSCC. The significance of viral DNA positivity is unclear. B19V DNA is known to remain in the tissues lifelong, however, it is of interest that there are some patients with B19 DNA in healthy tissue, but not in the corresponding cancer tissue.Peer reviewe

    Factors affecting the STR amplification success in poorly preserved bone samples

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    Background Factors affecting the success of short tandem repeat (STR) amplification of poorly preserved samples are generally known, but as of yet, they have seldom been systematically assessed. Using two different maximum likelihood-based methods, the relative importance of DNA quantity, degradation and inhibition in STR genotyping was studied with DNA extracts from a set of old bone samples. First, the effects of different factors related to PCR amplification were estimated with a generalized linear mixed model. Second, error rates of allelic drop-out and drop-in were estimated on the basis of the frequency and nature of mismatches between replicates. Results In autosomal STR analyses, the most important factor was the DNA quantity, followed by the degradation, whereas in Y-chromosomal STR analysis, the most important factor was the degradation. Inhibition was a minor concern in STR analyses of poorly preserved bones. Conclusions The success of PCR amplification depends largely on the template DNA quality (amount and degradation), but these problems can be partly compensated for by different primer design and amplification chemistry. Consequently, the relative roles of the compromising factors differ according to the kit used.Peer reviewe
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