193 research outputs found

    Long-term survival from gastrocolic fistula secondary to adenocarcinoma of the transverse colon

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    BACKGROUND: Gastrocolic fistula is a rare presentation of both benign and malignant diseases of the gastrointestinal tract. Malignant gastrocolic fistula is most commonly associated with adenocarcinoma of the transverse colon in the Western World. Despite radical approaches to treatment, long-term survival is rarely documented. CASE PRESENTATION: We report a case of a 24-year-old woman who presented with the classic triad of symptoms associated with gastrocolic fistula. Radical en-bloc surgery and adjuvant chemotherapy were performed. She is still alive ten years after treatment. CONCLUSIONS: Gastrocolic fistula is an uncommon presentation of adenocarcinoma of the transverse colon. Radical en-bloc surgery with adjuvant chemotherapy may occasionally produce long-term survival

    Mechanistic insights to drive catalytic hydrogenation of formamide intermediates to methanol via deaminative hydrogenation

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    Amine-promoted hydrogenation of CO2 to methanol typically proceeds via a formamide intermediate when amines are used as additives or if the hydrogenation is performed in carbon capture solvents. The catalysts used for the hydrogenation of the formamide intermediate dictate the selectivity of the products formed: 1) Deoxygenative hydrogenation (C–O bond cleavage) resulting in N-methylation of amine and deactivation of the solvent, 2) Deaminative hydrogenation (C–N bond cleavage) resulting in formation of methanol and regeneration of the solvent. To date, catalytic reductions of CO2 with amine promoters suffer from poor selectively for methanol which we attribute to the limiting formamide intermediate, though to date, the conditions that favor C–N cleavage have yet to be fully understood. To better understand the reactivity of the formamide intermediates, a range of heterogenous catalysts were used to study the hydrogenation of formamide. Well-known gas phase CO2 hydrogenation catalysts catalyze the hydrogenation of formamide to N-methyl product via C–O bond cleavage. However, the selectivity can be readily shifted to selective C–N bond cleavage by addition of an additive with sufficient basicity for both homogenous and heterogeneous catalytic systems. The base additive shifts the selectivity by deprotonating a hemiaminal intermediate formed in situ during the formamide hydrogenation. This prevents dehydration process leading to N-methylated product, which is a key capture solvent deactivation pathway that hinders amine use in carbon capture, utilization, and storage (CCUS). The findings from this study provide a roadmap on how to improve the selectivity of known heterogenous catalysts, enabling catalytic reduction of captured CO2 to methanol

    Process simulation and analysis of carbon capture with an aqueous mixture of ionic liquid and monoethanolamine solvent

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    This study investigated the prospect of using aqueous mixture of 1-butylpyridinium tetrafluoroborate ([Bpy][BF4]) ionic liquid (IL) and monoethanolamine (MEA) as solvent in post-combustion CO2 capture (PCC) process. This is done by analysis of the process through modelling and simulation. In literature, reported PCC models with a mixture of IL and MEA solvent were developed using equilibrium-based mass transfer approach. In contrast, the model in this study is developed using rate-based mass transfer approach in Aspen Plus®. From the results, the mixed aqueous solvent with 5–30 wt% IL and 30 wt% MEA showed 7%–9% and 12%–27% less specific regeneration energy and solvent circulation rate respectively compared to commonly used 30 wt% MEA solvent. It is concluded that the IL concentration (wt%) in the solvent blend have significant impact on specific regeneration energy and solvent circulation rate. This study is a starting point for further research on technical and economic analysis of PCC process with aqueous blend of IL and MEA as solvent

    Integrative multi-omics database (iMOMdb) of Asian pregnant women

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    Asians are underrepresented across many omics databases, thereby limiting the potential of precision medicine in nearly 60% of the global population. As such, there is a pressing need for multi-omics derived quantitative trait loci (QTLs) to fill the knowledge gap of complex traits in populations of Asian ancestry. Here, we provide the first blood-based multi-omics analysis of Asian pregnant women, constituting high-resolution genotyping (N= 1079), DNA methylation (N=915) and transcriptome profiling (N=238). Integrative omics analysis identified 219 154 CpGs associated with cis-DNA methylation QTLs (meQTLs) and 3703 RNAs associated with cis-RNA expression QTLs (eQTLs). Ethnicity was the largest contributor of inter-individual variation across all omics datasets, with 2561 genes identified as hotspots of this variation; 395 of these hotspot genes also contained both ethnicity-specific eQTLs and meQTLs. Gene set enrichment analysis of these ethnicity QTL hotspots showed pathways involved in lipid metabolism, adaptive immune system and carbohydrate metabolism. Pathway validation by profiling the lipidome (similar to 480 lipids) of antenatal plasma (N = 752) and placenta (N = 1042) in the same cohort showed significant lipid differences among Chinese, Malay and Indian women, validating ethnicity-QTL gene effects across different tissue types. To develop deeper insights into the complex traits and benefit future precision medicine research in Asian pregnant women, we developed iMOMdb, an open-access database.Peer reviewe

    Population-based plasma lipidomics reveals developmental changes in metabolism and signatures of obesity risk : a mother-offspring cohort study

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    Publisher Copyright: © 2022, The Author(s).Background: Lipids play a vital role in health and disease, but changes to their circulating levels and the link with obesity remain poorly characterized in expecting mothers and their offspring in early childhood. Methods: LC-MS/MS-based quantitation of 480 lipid species was performed on 2491 plasma samples collected at 4 time points in the mother-offspring Asian cohort GUSTO (Growing Up in Singapore Towards healthy Outcomes). These 4 time points constituted samples collected from mothers at 26–28 weeks of gestation (n=752) and 4–5 years postpartum (n=650), and their offspring at birth (n=751) and 6 years of age (n=338). Linear regression models were used to identify the pregnancy and developmental age-specific variations in the plasma lipidomic profiles, and their association with obesity risk. An independent birth cohort (n=1935), the Barwon Infant Study (BIS), comprising mother-offspring dyads of Caucasian origin was used for validation. Results: Levels of 36% of the profiled lipids were significantly higher (absolute fold change > 1.5 and Padj < 0.05) in antenatal maternal circulation as compared to the postnatal phase, with phosphatidylethanolamine levels changing the most. Compared to antenatal maternal lipids, cord blood showed lower concentrations of most lipid species (79%) except lysophospholipids and acylcarnitines. Changes in lipid concentrations from birth to 6 years of age were much higher in magnitude (log2FC=−2.10 to 6.25) than the changes observed between a 6-year-old child and an adult (postnatal mother) (log2FC=−0.68 to 1.18). Associations of cord blood lipidomic profiles with birth weight displayed distinct trends compared to the lipidomic profiles associated with child BMI at 6 years. Comparison of the results between the child and adult BMI identified similarities in association with consistent trends (R2=0.75). However, large number of lipids were associated with BMI in adults (67%) compared to the children (29%). Pre-pregnancy BMI was specifically associated with decrease in the levels of phospholipids, sphingomyelin, and several triacylglycerol species in pregnancy. Conclusions: In summary, our study provides a detailed landscape of the in utero lipid environment provided by the gestating mother to the growing fetus, and the magnitude of changes in plasma lipidomic profiles from birth to early childhood. We identified the effects of adiposity on the circulating lipid levels in pregnant and non-pregnant women as well as offspring at birth and at 6 years of age. Additionally, the pediatric vs maternal overlap of the circulating lipid phenotype of obesity risk provides intergenerational insights and early opportunities to track and intervene the onset of metabolic adversities. Clinical trial registration: This birth cohort is a prospective observational study, which was registered on 1 July 2010 under the identifier NCT01174875.Peer reviewe

    E2F5 status significantly improves malignancy diagnosis of epithelial ovarian cancer

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    <p>Abstract</p> <p>Background</p> <p>Ovarian epithelial cancer (OEC) usually presents in the later stages of the disease. Factors, especially those associated with cell-cycle genes, affecting the genesis and tumour progression for ovarian cancer are largely unknown. We hypothesized that over-expressed transcription factors (TFs), as well as those that are driving the expression of the OEC over-expressed genes, could be the key for OEC genesis and potentially useful tissue and serum markers for malignancy associated with OEC.</p> <p>Methods</p> <p>Using a combination of computational (selection of candidate TF markers and malignancy prediction) and experimental approaches (tissue microarray and western blotting on patient samples) we identified and evaluated E2F5 transcription factor involved in cell proliferation, as a promising candidate regulatory target in early stage disease. Our hypothesis was supported by our tissue array experiments that showed E2F5 expression only in OEC samples but not in normal and benign tissues, and by significantly positively biased expression in serum samples done using western blotting studies.</p> <p>Results</p> <p>Analysis of clinical cases shows that of the E2F5 status is characteristic for a different population group than one covered by CA125, a conventional OEC biomarker. E2F5 used in different combinations with CA125 for distinguishing malignant cyst from benign cyst shows that the presence of CA125 or E2F5 increases sensitivity of OEC detection to 97.9% (an increase from 87.5% if only CA125 is used) and, more importantly, the presence of both CA125 and E2F5 increases specificity of OEC to 72.5% (an increase from 55% if only CA125 is used). This significantly improved accuracy suggests possibility of an improved diagnostics of OEC. Furthermore, detection of malignancy status in 86 cases (38 benign, 48 early and late OEC) shows that the use of E2F5 status in combination with other clinical characteristics allows for an improved detection of malignant cases with sensitivity, specificity, F-measure and accuracy of 97.92%, 97.37%, 97.92% and 97.67%, respectively.</p> <p>Conclusions</p> <p>Overall, our findings, in addition to opening a realistic possibility for improved OEC diagnosis, provide an indirect evidence that a cell-cycle regulatory protein E2F5 might play a significant role in OEC pathogenesis.</p

    High Performance Flexible All Perovskite Tandem Solar Cells with Reduced Voc Deficit in Wide Bandgap Subcell

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    Among various types of perovskite based tandem solar cells TSCs , all perovskite TSCs are of particular attractiveness for building and vehicle integrated photovoltaics, or space energy areas as they can be fabricated on flexible and lightweight substrates with a very high power to weight ratio. However, the efficiency of flexible all perovskite tandems is lagging far behind their rigid counterparts primarily due to the challenges in developing efficient wide bandgap WBG perovskite solar cells on the flexible substrates as well as their low open circuit voltage VOC . Here, it is reported that the use of self assembled monolayers as hole selective contact effectively suppresses the interfacial recombination and allows the subsequent uniform growth of a 1.77 eV WBG perovskite with superior optoelectronic quality. In addition, a postdeposition treatment with 2 thiopheneethylammonium chloride is employed to further suppress the bulk and interfacial recombination, boosting the VOC of the WBG top cell to 1.29 V. Based on this, the first proof of concept four terminal all perovskite flexible TSC with a power conversion efficiency of 22.6 is presented. When integrating into two terminal flexible tandems, 23.8 flexible all perovskite TSCs with a superior VOC of 2.1 V is achieved, which is on par with the VOC reported on the 28 all perovskite tandems grown on the rigid substrat

    Co-limitation towards lower latitudes shapes global forest diversity gradients

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    The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers

    Designing Value-Oriented Service Systems by Value Map

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    In this paper, we introduce a problem structuring method (PSM) called “Value Map”. Value Map is an extension to the Supplier Adopter Relationship Diagram in the Systemic Enterprise Architecture Method (SEAM). Value Map assists in understanding, analysis and design of value creation and capture in service systems. We illustrate the applicability of the Value Map by modeling value creation and capture in the service system of a social networking company called Webdoc. To validate the usefulness of the Value Map, we conducted an empirical study in which we also compared the Value Map to Business Model Canvas, one of the most established methods in business model design. The results of the study show that the Value Map helps business practitioners in understanding and analyzing customer value, customer value creation, and the value capture processes. We conducted an empirical study in which we assessed the usefulness of Value Map and compared it with Business Model Canvas, one of the most established methods in business model design. The results of the study show that the Value Map helps business practitioners to understand and analyze customer value, customer value creation, and the value capture processes
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