9 research outputs found

    Hepatitis C virus NS4B carboxy terminal domain is a membrane binding domain

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    <p>Abstract</p> <p>Background</p> <p>Hepatitis C virus (HCV) induces membrane rearrangements during replication. All HCV proteins are associated to membranes, pointing out the importance of membranes for HCV. Non structural protein 4B (NS4B) has been reported to induce cellular membrane alterations like the membranous web. Four transmembrane segments in the middle of the protein anchor NS4B to membranes. An amphipatic helix at the amino-terminus attaches to membranes as well. The carboxy-terminal domain (CTD) of NS4B is highly conserved in Hepaciviruses, though its function remains unknown.</p> <p>Results</p> <p>A cytosolic localization is predicted for the NS4B-CTD. However, using membrane floatation assays and immunofluorescence, we now show targeting of the NS4B-CTD to membranes. Furthermore, a profile-profile search, with an HCV NS4B-CTD multiple sequence alignment, indicates sequence similarity to the membrane binding domain of prokaryotic D-lactate dehydrogenase (d-LDH). The crystal structure of E. coli d-LDH suggests that the region similar to NS4B-CTD is located in the membrane binding domain (MBD) of d-LDH, implying analogy in membrane association. Targeting of d-LDH to membranes occurs via electrostatic interactions of positive residues on the outside of the protein with negative head groups of lipids. To verify that anchorage of d-LDH MBD and NS4B-CTD is analogous, NS4B-CTD mutants were designed to disrupt these electrostatic interactions. Membrane association was confirmed by swopping the membrane contacting helix of d-LDH with the corresponding domain of the 4B-CTD. Furthermore, the functionality of these residues was tested in the HCV replicon system.</p> <p>Conclusion</p> <p>Together these data show that NS4B-CTD is associated to membranes, similar to the prokaryotic d-LDH MBD, and is important for replication.</p

    Cholesteric color filter and method of manufacturing such

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    \u3cp\u3eThe invention pertains to a method of manufacturing a layer of a cholesterically ordered polymer material, in which the material is oriented in such a way that the axis of the molecular helix of the cholesterically ordered material extends transversely to the layer, wherein the method comprises the following steps: a) providing a layer comprising a cholesterically ordered material, which material comprises a quantity of a convertible compound, the conversion of said compound being inducible by radiation; b) irradiating the layer to convert at least a part of the convertible compound in the irradiated parts of the layer; c) optionally at least partially polymerizing and/or cross-linking the cholesterically ordered material to form a three-dimensional polymer; d) applying a diffusion agent onto the layer to transversely swell the layer as a function of the concentration variation of the diffusion agent; e) fixing the diffusion agent to the polymer to freeze in the formed structure.\u3c/p\u3

    GxxxG Motif of Severe Acute Respiratory Syndrome Coronavirus Spike Glycoprotein Transmembrane Domain Is Not Involved in Trimerization and Is Not Important for Entry▿

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    Recently, a paper was published in which it was proposed that the GxxxG motif of the severe acute respiratory syndrome (SARS) coronavirus spike (S) protein transmembrane domain plays a vital role in oligomerization of the protein (E. Arbely, Z. Granot, I. Kass, J. Orly, and I. T. Arkin, Biochemistry 45:11349-11356, 2006). Here, we show that the GxxxG motif is not involved in SARS S oligomerization by trimerization analysis of S GxxxG mutant proteins. In addition, the capability of S to mediate entry of SARS S-pseudotyped particles overall was affected moderately in the mutant proteins, also arguing for a nonvital role for the GxxxG motif in SARS coronavirus entry

    Predicting menopausal age with anti-Mullerian hormone: a cross-validation study of two existing models

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    Objective This study aimed to cross-validate two comparable Weibull models of prediction of age at natural menopause from two cohorts, the Scheffer, van Rooij, de Vet (SRV) cohort and the Tehran Lipid and Glucose Study (TLGS) cohort. It summarizes advantages and disadvantages of the models and underlines the need for achieving correct time dependency in dynamic variables like anti-Mullerian hormone. Methods Models were fitted in the original datasets and then applied to the cross-validation datasets. The discriminatory capacity of each model was assessed by calculating C-statistics for the models in their own data and in the cross-validation data. Calibration of the models on the cross-validation data was assessed by measuring the slope, intercept and Weibull shape parameter. Results The C-statistic for the SRV model on the SRV data was 0.7 (95% confidence interval (CI) 0.7-0.8) and on the TLGS data it was 0.8 (95% CI 0.8-0.9). For the TLGS model on the TLGS data, it was 0.9 (95% CI 0.8-0.9) and on the SRV data it was 0.7 (95% CI 0.6-0.8). After calibration of the SRV model on the TLGS data, the slope was 1, the intercept -0.3 and the shape parameter 1.1. The TLGS model on the SRV data had a slope of 0.3, an intercept of 12.7 and a shape parameter of 0.6. Conclusions Both models discriminate well between women that enter menopause early or late during follow-up. While the SRV model showed good agreement between the predicted risk of entering menopause and the observed proportion of women who entered menopause during follow-up (calibration) in the cross-validation dataset, the TLGS model showed poor calibration

    High aspect ratio surface relief structures by photoembossing

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    Photoembossing is a convenient and economical process to form complex surface relief structures in polymer thin films. We have improved the aspect ratio of photoembossed microstructures by adding t-butyl hydroquinone (TBHQ) to the polymerization mixture. The mechanism that is proposed is based on the radical transfer principle, where TBHQ converts acrylate radicals into stable phenol radicals that at elevated temperatures act as latent initiators, thereby controlling the kinetics without changing the number of polymerization active sites. As a result, the aspect ratio can be improved with a factor of 5–7 in comparison with previously proposed similar processe

    Anti-Mullerian Hormone Predicts Menopause: A Long-Term Follow-Up Study in Normoovulatory Women

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    Context: It has been hypothesized that a fixed interval exists between age at natural sterility and age at menopause. Both events show considerable individual variability, with a range of 20 yr. Correct prediction of age at menopause could open avenues of individualized prevention of age-related infertility and other menopause-related conditions, like cardiovascular disease and breast carcinoma. Objective: The aim of this study was to explore the ability of ovarian reserve tests to predict age at menopause. Design and Setting: We conducted a long-term follow-up study at an academic hospital. Participants: A total of 257 normoovulatory women (age, 21-46 yr) were derived from three cohorts with highly comparable selection criteria. Interventions: Anti-Mullerian hormone (AMH), antral follicle count, and FSH were assessed at time 1 (T1). At time 2 (T2), approximately 11 yr later, cycle status (strictly regular, menopausal transition, or postmenopause) and age at menopause were inventoried. Main Outcome Measures: Accuracy of the ovarian reserve tests in predicting time to menopause was assessed by Cox regression, and a nomogram was constructed for the relationship between age-specific AMH concentrations at T1 and age at menopause. Results: A total of 48 (19%) women had reached postmenopause at T2. Age, AMH, and antral follicle count at T1 were significantly related with time to menopause (P < 0.001) and showed a good percentage of correct predictions (C-statistic, 0.87, 0.86, and 0.84, respectively). After adjusting for age, only AMH added to this prediction (C-statistic, 0.90). From the constructed nomogram, it appeared that the normal distribution of age at menopause will shift considerably, depending on the individual Conclusions: AMH is highly predictive for timing of menopause. Using age and AMH, the age range in which menopause will subsequently occur can be individually calculated. (J Clin Endocrinol Metab 96: 2532-2539, 2011

    PALVELUTUOTTEEN HINNOITTELUN KEHITTÄMINEN

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    Tämän opinnäytetyön aiheena on palvelutuotteen hinnoittelun kehittäminen. Tutkimuksen kohteena on Tili- ja isännöitsijätoimisto Ky. Tili- ja isännöitsijätoimisto Ky on Vaasassa toimiva tili- ja isännöintitoimisto, joka tarjoaa taloushallinto- ja isännöintipalveluita yrityksille. Tutkimuksen tavoitteena on kehittää Tili- ja isännöitsijätoimisto Ky:n isännöitsijän palvelutuotteiden hinnoittelua. Hinnoittelumenetelmäksi valittiin toimintoperusteinen hinnoittelu, jonka lähtökohtana on selvittää asiakaskohtaisia välillisiä kustannuksia. Kysymys oli suorite-kohtaisten kustannusten laskemisesta, eli toimintoperusteisesta prosessilaskennasta. Toimintoperusteinen prosessilaskenta tukee hinnoittelun päätöstä. Toiminto-analyysin jälkeen selvitettiin resurssien kohdistumista yrityksen eri toiminnoille. Aluksi selvitettiin yrityksen kustannusajuri, jonka perusteella kustannukset on kohdistettu eri toiminnoille. Seuraavaksi selvitettiin toimintoajurin avulla toimintoihin liittyvät yksikkökustannukset. Tuotteiden hinnoittelussa myyntihinnan on tarkoituksena sisältää kaikkien kustannusten lisäksi voittotavoite. Tutkimuksen teoriaosuuden keskeisiä asioita ovat toimintoperusteisen kustannuslaskennan, sekä hinnoittelun perusteiden esittely. Niiden avulla voidaan perustella hinnoittelupäätöstä tukeva toimintolaskenta. Opinnäytetyössä esitellään lisäksi kustannusperusteista hinnoittelua sekä isännöintiä ja tilitoimistoa yleisesti. Tutkimusmenetelmänä käytettiin kvalitatiivista eli laadullista tutkimusta. Tutkimuksen teoriaosuuteen käytettiin toimintolaskennan, taloushallinnon alan sekä hinnoittelun teoriaan liittyvää kirjallisuutta. Aineistonkeruussa havainnoitiin yrityksen tilinpäätöstä vuodelta 2016 ja yrityksen toimintaa liittyviä ohjelmia sekä tietokantoja. Lisäksi haastateltiin Tili- ja isännöitsijätoimisto Ky:n omistajaa ja työntekijöitä.This research was designed to develop the used pricing method for the case firm Tili- ja isännöitsijätoimisto Ky. The main area of this research focused on the main service products in property management. The case firm offers financial accounting and management services to house companies and other customer companies. Activity based costing was selected as the new pricing method in order to identify the customer-specific indirect costs. The aim of activity-based costing was to support pricing decisions for the case firm. In the implementation steps, activities must be identified first, and then the process continues with an activity analysis. Once the costs of activity and its drivers have been identified and its costs have been determined, then the costs of activity is allocated to the service product. In the allocation process, when the activity driver has been determined, the cost per unit can then be determined. Once the product cost per unit has been determined then the case firm considers the generated value of its service product, so the pricing of all the service product sales cover the fixed expenses with any remaining contribution margin providing profits. The theoretical study of this thesis introduced activity based costing and pricing to support activity based cost implementation and pricing decisions. In addition, it introduced cost based pricing and property management business and accounting firms in general. This research was implemented using the qualitative research method. The research material consists of related activity based costing, financial management, management accounting and pricing literature. The theoretical information was gathered from scientific research, academic books and some material was collect-ed from the Internet. The empirical data in this research was gathered by observing the case company’s financial statement from the year 2016 together with some business activities related programs and databases. In addition, was collected by interviewing the case company owner and the other employers of the company

    Metabolomics reveals a link between homocysteine and lipid metabolism and leukocyte telomere length:the ENGAGE consortium

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    Telomere shortening has been associated with multiple age-related diseases such as cardiovascular disease, diabetes, and dementia. However, the biological mechanisms responsible for these associations remain largely unknown. In order to gain insight into the metabolic processes driving the association of leukocyte telomere length (LTL) with age-related diseases, we investigated the association between LTL and serum metabolite levels in 7,853 individuals from seven independent cohorts. LTL was determined by quantitative polymerase chain reaction and the levels of 131 serum metabolites were measured with mass spectrometry in biological samples from the same blood draw. With partial correlation analysis, we identified six metabolites that were significantly associated with LTL after adjustment for multiple testing: lysophosphatidylcholine acyl C17:0 (lysoPC a C17:0, p-value = 7.1 × 10-6), methionine (p-value = 9.2 × 10-5), tyrosine (p-value = 2.1 × 10-4), phosphatidylcholine diacyl C32:1 (PC aa C32:1, p-value = 2.4 × 10-4), hydroxypropionylcarnitine (C3-OH, p-value = 2.6 × 10-4), and phosphatidylcholine acyl-alkyl C38:4 (PC ae C38:4, p-value = 9.0 × 10-4). Pathway analysis showed that the three phosphatidylcholines and methionine are involved in homocysteine metabolism and we found supporting evidence for an association of lipid metabolism with LTL. In conclusion, we found longer LTL associated with higher levels of lysoPC a C17:0 and PC ae C38:4, and with lower levels of methionine, tyrosine, PC aa C32:1, and C3-OH. These metabolites have been implicated in inflammation, oxidative stress, homocysteine metabolism, and in cardiovascular disease and diabetes, two major drivers of morbidity and mortality
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