85 research outputs found

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

    Get PDF
    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

    Get PDF
    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

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

    Get PDF
    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

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

    Get PDF
    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

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

    Get PDF
    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

    Taxonomic distribution and origins of the extended LHC (light-harvesting complex) antenna protein superfamily

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The extended light-harvesting complex (LHC) protein superfamily is a centerpiece of eukaryotic photosynthesis, comprising the LHC family and several families involved in photoprotection, like the LHC-like and the photosystem II subunit S (PSBS). The evolution of this complex superfamily has long remained elusive, partially due to previously missing families.</p> <p>Results</p> <p>In this study we present a meticulous search for LHC-like sequences in public genome and expressed sequence tag databases covering twelve representative photosynthetic eukaryotes from the three primary lineages of plants (Plantae): glaucophytes, red algae and green plants (Viridiplantae). By introducing a coherent classification of the different protein families based on both, hidden Markov model analyses and structural predictions, numerous new LHC-like sequences were identified and several new families were described, including the red lineage chlorophyll <it>a/b</it>-binding-like protein (RedCAP) family from red algae and diatoms. The test of alternative topologies of sequences of the highly conserved chlorophyll-binding core structure of LHC and PSBS proteins significantly supports the independent origins of LHC and PSBS families via two unrelated internal gene duplication events. This result was confirmed by the application of cluster likelihood mapping.</p> <p>Conclusions</p> <p>The independent evolution of LHC and PSBS families is supported by strong phylogenetic evidence. In addition, a possible origin of LHC and PSBS families from different homologous members of the stress-enhanced protein subfamily, a diverse and anciently paralogous group of two-helix proteins, seems likely. The new hypothesis for the evolution of the extended LHC protein superfamily proposed here is in agreement with the character evolution analysis that incorporates the distribution of families and subfamilies across taxonomic lineages. Intriguingly, stress-enhanced proteins, which are universally found in the genomes of green plants, red algae, glaucophytes and in diatoms with complex plastids, could represent an important and previously missing link in the evolution of the extended LHC protein superfamily.</p

    Modelling prognostic factors in advanced pancreatic cancer

    Get PDF
    Pancreatic cancer is the fifth most common cause of cancer death. Identification of defined patient groups based on a prognostic index may improve the prediction of survival and selection of therapy. Many prognostic factors have been identified often based on retrospective, underpowered studies with unclear analyses. Data from 653 patients were analysed. Continuous variables are often simplified assuming a linear relationship with log hazard or introducing a step function (dichotomising). Misspecification may lead to inappropriate conclusions but has not been previously investigated in pancreatic cancer studies. Models based on standard assumptions were compared with a novel approach using nonlinear fractional polynomial (FP) transformations. The model based on FP-transformed covariates was most appropriate and confirmed five previously reported prognostic factors: albumin, CA19-9, alkaline phosphatase, LDH and metastases, and identified three additional factors not previously reported: WBC, AST and BUN. The effects of CA19-9, alkaline phosphatase, AST and BUN may go unrecognised due to simplistic assumptions made in statistical modelling. We advocate a multivariable approach that uses information contained within continuous variables appropriately. The functional form of the relationship between continuous covariates and survival should always be assessed. Our model should aid individual patient risk stratification and the design and analysis of future trials in pancreatic cancer

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

    Get PDF
    <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
    corecore