107 research outputs found

    Electrodeposition And Analysis Of Tin Selenide Films

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    Sn1±xSe films have been electrodeposited from aqueous solutions containing SnCl2 and ionically dissolved SeO2 or H2SeO3 and DMF solutions containing SnCl2 and molecularly dissolved selenium powder. The as-deposited films ranged from amorphous to polycrystalline and exhibited indirect or nondirect bandgaps from 0.85 to 0.95 eV. There was little difference between the appearance or material data of the films grown by the two techniques. Direct reaction between Sn++ and H2SeO3 or HSeO3_ in the aqueous solutions yielded a Se/SnxSe suspension/precipitate. Although this does not seem to have any serious effect on the deposition process, it does produce a decrease in the concentration and possibly a change in the composition of the ions in solution, as well as preventing in situ observation of the deposit and making the cleaning of the apparatus more difficult. Annealing slightly increased the Se/Sn ratio of microanalyzed layers near the substrate-deposit interface, and erased all x-ray diffraction structure. The bandgaps of the annealed films were shifted from approximately 0.9 eV to approximately 1.30 eV, consistent with the increased Se/Sn ratio. The films exhibited weak cathodic photocurents during deposition and photoconductance (ΔG/G⋍0.05) after deposition. The conductivity of Sample D (Sn0.91Se) was estimated to be on the order of 10 -4(Ω-cm)-1. Conductance-temperature plots indicated activation energies between 0.44 and 0.51 eV, probably indicative of deep acceptor levels and consistent with the p-type thermal voltage, millisecond photoconductance decay times, and the optical bandgaps. © 1986, The Electrochemical Society, Inc. All rights reserved

    Growth Of Tungsten Selenide Films Through Pyrolytic Conversion And Anodic Electrooxidation Of Ammonium Selenotungstate ((NH4)2WSe4)

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    WxSey thin films have been prepared by the spray pyrolysis and anodic electrodeposition of solutions of ammonium selenotungstate, (NH4)2WSe4, with y/x usually between two and three for the sprayed films and y x\u3e\u3e1 for the electrodeposited films. The sprayed films indicated regions of crystalline WSe2 and have optical absorbance spectra consistent with a mixture of WSe2, WSe3, and selenium. The electrodeposited films are totally amorphous, highly photoconductive, and have optical absorbance spectra typical of amorphous or vitreous selenium. The sprayed films transform into WO3 at temperatures greater than 350°C in the presence of oxygen wile the electrode-posited films tend to evaporate and/or decompose upon annealing. © 1985

    Systemic inflammatory response predicts outcome in patients undergoing resection for ductal adenocarcinoma head of pancreas

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    The aim of the present study was to examine the relationship between the clinicopathological status, the pre- and postoperative systemic inflammatory response and survival in patients undergoing potentially curative resection for ductal adenocarcinoma of the head of the pancreas. Patients (n=65) who underwent resection of ductal adenocarcinoma of the head of pancreas between 1993 and 2001, and had pre- and postoperative measurements of C-reactive protein, were included in the study. The majority of patients had stage III disease (International Union Against Cancer Criteria, IUCC), positive circumferential margin involvement (R1), tumour size greater than 25 mm with perineural and lymph node invasion and died within the follow-up period. On multivariate analysis, tumour size (hazard ratio (HR) 2.10, 95% confidence interval (CI) 1.20–3.68, P=0.009), vascular invasion (HR 2.58, 95% CI 1.48–4.50, P<0.001) and postoperative C-reactive protein (HR 2.00, 95% CI 1.14–3.52, P=0.015) retained independent significance. Those patients with a postoperative C-reactive protein ⩽10 mg l−1 had a median survival of 21.5 months compared with 8.4 months in those patients with a C-reactive protein >10 mg l−1 (P<0.001). The results of the present study indicate that, in patients who have undergone potentially curative resection for ductal adenocarcinoma of the head of pancreas, the presence of a systemic inflammatory response predicts poor outcome

    Factors Influencing Households’ Intention to Adopt Solar PV : A Systematic Review

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    Rising energy needs, concerns of energy security, mitigating greenhouse gas emissions, climate change phenomenon and a push to utilize indigenous sources for energy generation purposes has encouraged the use of solar photovoltaics (PV). The technological advancements of the recent past, improvement in technologies’ performance, reduction in the prices, policy and regulatory support, and its applicability at household level has made solar energy as a preferred form of energy generation. However, despite its rapid diffusion, it is widely believed that its current application is insignificant compared to its potential. This leads us to ask why solar PV has not been adopted to the level it should have. The existing literature has highlighted a number of factors affecting solar PV adoption. This paper systematically reviews the literature to identify the factors that have been instrumental to solar PV adoption. By exploring the Scopus database, this research identifies 39 articles matching the study objectives. Findings of this research will help academics, technology companies and policymakers in understanding the factors influencing the process and proposing solutions to address these.©2020 Springer. This is a post-peer-review, pre-copyedit version of an article published in Advances in Human Factors, Business Management and Leadership. AHFE 2020. The final authenticated version is available online at: http://dx.doi.org/10.1007/978-3-030-50791-6_36fi=vertaisarvioitu|en=peerReviewed

    Refining the role of laparoscopy and laparoscopic ultrasound in the staging of presumed pancreatic head and ampullary tumours

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    Laparoscopy and laparoscopic ultrasound have been validated previously as staging tools for pancreatic cancer. The aim of this study was to identify if assessment of vascular involvement with abdominal computed tomography (CT) would allow refinement of the selection criteria for laparoscopy and laparoscopic ultrasound (LUS). The details of patients staged with LUS and abdominal CT were obtained from the unit's pancreatic cancer database. A CT grade (O, A-F) of vascular involvement was recorded by a single radiologist. Of 152 patients, who underwent a LUS, 56 (37%) had unresectable disease. Three of 26 (12%) patients with CT grade O, 27 of 88 (31%) patients with CT grade A to D, 17 of 29 (59%) patients with CT grade E and all nine patients with CT grade F were found to have unresectable disease. In all, 24% of patients with tumours <3 cm were found to have unresectable disease. In those patients with tumours considered unresectable, local vascular involvement was found in 56% of patients and vascular involvement with metastatic disease in 17%, while 20% of patients had liver metastases alone and 5% had isolated peritoneal metastases. The remaining patient was deemed unfit for resection. Selective use of laparoscopic ultrasound is indicated in the staging of periampullary tumours with CT grades A to D

    The genome sequencing of an albino Western lowland gorilla reveals inbreeding in the wild

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    Background The only known albino gorilla, named Snowflake, was a male wild born individual from Equatorial Guinea who lived at the Barcelona Zoo for almost 40 years. He was diagnosed with non-syndromic oculocutaneous albinism, i.e. white hair, light eyes, pink skin, photophobia and reduced visual acuity. Despite previous efforts to explain the genetic cause, this is still unknown. Here, we study the genetic cause of his albinism and making use of whole genome sequencing data we find a higher inbreeding coefficient compared to other gorillas. Results We successfully identified the causal genetic variant for Snowflake¿s albinism, a non-synonymous single nucleotide variant located in a transmembrane region of SLC45A2. This transporter is known to be involved in oculocutaneous albinism type 4 (OCA4) in humans. We provide experimental evidence that shows that this amino acid replacement alters the membrane spanning capability of this transmembrane region. Finally, we provide a comprehensive study of genome-wide patterns of autozygogosity revealing that Snowflake¿s parents were related, being this the first report of inbreeding in a wild born Western lowland gorilla. Conclusions In this study we demonstrate how the use of whole genome sequencing can be extended to link genotype and phenotype in non-model organisms and it can be a powerful tool in conservation genetics (e.g., inbreeding and genetic diversity) with the expected decrease in sequencing cost. Keywords: Gorilla; Albinism; Inbreeding; Genome; Conservatio

    Diffuse idiopathic skeletal hyperostosis (DISH): relation to vertebral fractures and bone density

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    UnlabelledRadiographs and spinal bone mineral density (BMD) were evaluated from 342 elderly men regarding possible effects of diffuse idiopathic skeletal hyperostosis (DISH) on vertebral fractures and densitometry measurements. Prevalent vertebral fractures were more frequent among men with DISH compared to men with no DISH even after fracture prevalence was adjusted for BMD. Paravertebral calcifications should be considered in patients with DISH when interpreting BMD measurements because both dual X-ray absorptiometry (DXA) and quantitative CT (QCT) densitometry may not be reliable.IntroductionThe purpose of this study is to evaluate the prevalence of DISH in older men and its association with vertebral fractures and with BMD determined by DXA and QCT.MethodsLateral radiographs of the spine were analyzed in a sample of 342 men aged ≥ 65 years participating in the MrOS Study concerning the presence and grade of DISH and vertebral fractures. Lumbar BMD was measured by both DXA (areal, grams per square centimeter) and QCT (volumetric, grams per cubic centimeter). The association between DISH, BMD, and presence of fractures was studied using χ ( 2 ) and t tests.ResultsDISH was present in 52% (178/342) of the men. Men with DISH were older (mean, 75.1 vs 73.3, p &lt; 0.05) and more likely to have prevalent fractures (28% vs 20%, p &lt; p = 0.09). BMD assessed with DXA (1.08 vs 1.00 g/cm(2), p ≤ 0.0001), but not with QCT (0.11 vs 0.11 g/cm3, p = 0.65), was significantly higher in men with DISH compared to men without DISH. Significantly lower BMD of men with both DISH and fractures compared to men with DISH but without fractures was only detected by QCT (-25%, 0.09 vs 0.12, p &lt; 0.05). Both DXA BMD and QCT BMD were significantly higher in severe lumbar DISH (+22% and +31%, p &lt; 0.0001), respectively.ConclusionDISH was associated with a higher prevalence of vertebral fractures in elderly men. Lumbar ossifications related to DISH should be considered when interpreting BMD measurements to predict their fracture risk

    Testing the thrifty gene hypothesis: the Gly482Ser variant in PPARGC1A is associated with BMI in Tongans

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    <p>Abstract</p> <p>Background</p> <p>The thrifty gene hypothesis posits that, in populations that experienced periods of feast and famine, natural selection favoured individuals carrying thrifty alleles that promote the storage of fat and energy. Polynesians likely experienced long periods of cold stress and starvation during their settlement of the Pacific and today have high rates of obesity and type 2 diabetes (T2DM), possibly due to past positive selection for thrifty alleles. Alternatively, T2DM risk alleles may simply have drifted to high frequency in Polynesians. To identify thrifty alleles in Polynesians, we previously examined evidence of positive selection on T2DM-associated SNPs and identified a T2DM risk allele at unusually high frequency in Polynesians. We suggested that the risk allele of the Gly482Ser variant in the <it>PPARGC1A </it>gene was driven to high frequency in Polynesians by positive selection and therefore possibly represented a thrifty allele in the Pacific.</p> <p>Methods</p> <p>Here we examine whether <it>PPARGC1A </it>is a thrifty gene in Pacific populations by testing for an association between Gly482Ser genotypes and BMI in two Pacific populations (Maori and Tongans) and by evaluating the frequency of the risk allele of the Gly482Ser variant in a sample of worldwide populations.</p> <p>Results</p> <p>We find that the Gly482Ser variant is associated with BMI in Tongans but not in Maori. In a sample of 58 populations worldwide, we also show that the 482Ser risk allele reaches its highest frequency in the Pacific.</p> <p>Conclusion</p> <p>The association between Gly482Ser genotypes and BMI in Tongans together with the worldwide frequency distribution of the Gly482Ser risk allele suggests that <it>PPARGC1A </it>remains a candidate thrifty gene in Pacific populations.</p

    Evaluation of DNA ploidy in relation with established prognostic factors in patients with locally advanced (unresectable) or metastatic pancreatic adenocarcinoma: a retrospective analysis

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    <p>Abstract</p> <p>Background</p> <p>Most patients with ductal pancreatic adenocarcinoma are diagnosed with locally advanced (unresectable) or metastatic disease. The aim of this study was to evaluate the prognostic significance of DNA ploidy in relation with established clinical and laboratory variables in such patients.</p> <p>Methods</p> <p>Two hundred and twenty six patients were studied retrospectively. Twenty two potential prognostic variables (demographics, clinical parameters, biochemical markers, treatment modality) were examined.</p> <p>Results</p> <p>Mean survival time was 38.41 weeks (95% c.i.: 33.17–43.65), median survival 27.00 weeks (95% c.i.: 23.18–30.82). On multivariate analysis, 10 factors had an independent effect on survival: performance status, local extension of tumor, distant metastases, ploidy score, anemia under epoetin therapy, weight loss, pain, steatorrhoea, CEA, and palliative surgery and chemotherapy. Patients managed with palliative surgery and chemotherapy had 6.7 times lower probability of death in comparison with patients without any treatment. Patients with ploidy score > 3.6 had 5.0 times higher probability of death in comparison with patients with ploidy score < 2.2 and these with ploidy score 2.2–3.6 had 6.3 times higher probability of death in comparison with patients with ploidy score < 2.2.</p> <p>Conclusion</p> <p>According to the significance of the examined factor, survival was improved mainly by the combination of surgery and chemotherapy, and the presence of low DNA ploidy score.</p
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