The Catalysis of Delayed Petroleum Coking

Due to the decreasing crude oil quality (heavier crudes and increasing contaminant concentrations) methods for upgrading residues from the refining process, such as coking, are becoming increasingly important. Delayed coking, a method by which residues are thermally cracked (large heavy molecules broken into smaller lighter molecules), produces liquid products and solid coke which can both be sold for further profit. In order to increase the amount of liquid products produced since they are the most value added product of the coking process catalysts (platinum on 0.5% alumina and nickel (skeletal),molybdenum promoted (1 wt%)) were tested to see how they would affect the process and products. Different ratios of vacuum residue, light gas oil, heavy gas oil, and catalyst were all loaded into a semi-batch reactor which operated under a nitrogen environment at 15 psi. Each ratio of components was tested at 450°C, 475°C, and 500°C. Gas chromatography based on ASTM D2887 was used to analyze gaseous products every 15 minutes during each test and the liquid products at the end. Testing is still ongoing and preliminary results have yet to be obtained. Due to the increased value of liquid products, catalysts and conditions which produce more of those are favored. Further research into these and other catalysts is recommended since residues from different crudes could interact differently with the catalysts

Catalysis in Petroleum Coking

The petroleum industry is challenged with the processing of present heavy crudes caused by high composition of sulfur and metals, which lead to a higher yield of unfavorable bottom product as vacuum residue. Vacuum residue is the least valuable fraction of four, such as saturates, aromatics, resins and asphaltenes. However, it can be upgraded to recover more valuable products such as light hydrocarbons. The Delayed Coking process is going to be used to transform the vacuum residue at different experimental conditions. First of all, the behavior of the vacuum residue needs to be analyzed with no additions in feedstock. Secondly, the vacuum residue can be mixed with unhydrogenated and hydrogenated light gas oil at different concentrations. Finally, the addition of different catalysts at various concentrations could be another method to achieve high yield of the desired product. Expected experimental conditions are 475oC for reactor temperature and bimetallic or trimetallic catalysts for the delayed coking process. In this research, 3 different catalysts will be tested in several proportions with respect to the weight of the feedstock material. The recommended feed concentration of light gas oil depends on the molecular structure of the vacuum residue and can be determined only by actual experiment. Based on these experimental conditions, a conclusion about the yield of the light hydrocarbons and ways to improving the process can be drawn

Intention to Inform Relatives, Rates of Cascade Testing, and Preference for Patient-Mediated Communication in Families Concerned with Hereditary Breast and Ovarian Cancer and Lynch Syndrome: The Swiss CASCADE Cohort.

Cascade screening for Tier 1 cancer genetic conditions is a significant public health intervention because it identifies untested relatives of individuals known to carry pathogenic variants associated with hereditary breast and ovarian cancer (HBOC) and Lynch syndrome (LS). The Swiss CASCADE is a family-based, open-ended cohort, including carriers of HBOC- and LS-associated pathogenic variants and their relatives. This paper describes rates of cascade screening in relatives from HBOC- and LS- harboring families, examines carriers' preferences for communication of testing results, and describes theory-based predictors of intention to invite relatives to a cascade screening program. Information has been provided by 304 index cases and 115 relatives recruited from September 2017 to December 2021. On average, 10 relatives per index case were potentially eligible for cascade screening. Approximately 65% of respondents wanted to invite relatives to the cohort, and approximately 50% indicated a preference for patient-mediated communication of testing results, possibly with the assistance of digital technology. Intention to invite relatives was higher for first- compared to second- and third-degree relatives, but was not different between syndromes or based on relatives' gender. The family environment and carrying pathogenic variants predicts intention to invite relatives. Information helps optimize delivery of tailored genetic services

Relatives from Hereditary Breast and Ovarian Cancer and Lynch Syndrome Families Forgoing Genetic Testing: Findings from the Swiss CASCADE Cohort.

Cascade genetic testing of relatives from families with pathogenic variants associated with hereditary breast and ovarian cancer (HBOC) or Lynch syndrome (LS) has important implications for cancer prevention. We compared the characteristics of relatives from HBOC or LS families who did not have genetic testing (GT (-) group) with those who had genetic testing (GT (+) group), regardless of the outcome. Self-administered surveys collected cross-sectional data between September 2017 and December 2021 from relatives participating in the CASCADE cohort. We used multivariable logistic regression with LASSO variable selection. Among n = 115 relatives who completed the baseline survey, 38% (n = 44) were in the GT (-) group. Being male (OR: 2.79, 95% CI: 1.10-7.10) and without a previous cancer diagnosis (OR: 4.47, 95% CI: 1.03-19.42) increased the odds of being untested by almost three times. Individuals from families with fewer tested relatives had 29% higher odds of being untested (OR: 0.71, 95% CI: 0.55-0.92). Reasons for forgoing cascade testing were: lack of provider recommendation, lack of time and interest in testing, being afraid of discrimination, and high out-of-pocket costs. Multilevel interventions designed to increase awareness about clinical implications of HBOC and LS in males, referrals from non-specialists, and support for testing multiple family members could improve the uptake of cascade testing

Finding Homogeneity in Heterogeneity—A New Approach to Quantifying Landscape Mosaics Developed for the Lao PDR

A key challenge for land change science in general and research on swidden agriculture in particular, is linking land cover information to human–environment interactions over larger spatial areas. In Lao PDR, a country facing rapid and multi-level land change processes, this hinders informed policy- and decision-making. Crucial information on land use types and people involved is still lacking. This article proposes an alternative approach for the description of landscape mosaics. Instead of analyzing local land use combinations, we studied land cover mosaics at a meso-level of spatial scale and interpreted these in terms of human–environmental interactions. These landscape mosaics were then overlaid with population census data. Results showed that swidden agricultural landscapes, involving 17% of the population, dominate 29% of the country, while permanent agricultural landscapes involve 74% of the population in 29% of the territory. Forests still form an important component of these landscape mosaics

MutSβ exceeds MutSα in dinucleotide loop repair

The target substrates of DNA mismatch recognising factors MutSalpha (MSH2+MSH6) and MutSbeta (MSH2+MSH3) have already been widely researched. However, the extent of their functional redundancy and clinical substance remains unclear. Mismatch repair (MMR)-deficient tumours are strongly associated with microsatellite instability (MSI) and the degree and type of MSI seem to be dependent on the MMR gene affected, and is linked to its substrate specificities. Deficiency in MSH2 and MSH6 is associated with both mononucleotide and dinucleotide repeat instability. Although no pathogenic MSH3 mutations have been reported, its deficiency is also suggested to cause low dinucleotide repeat instability

Screening for Microsatellite Instability Identifies Frequent 3′-Untranslated Region Mutation of the RB1-Inducible Coiled-Coil 1 Gene in Colon Tumors

BACKGROUND: Coding region microsatellite instability (MSI) results in loss of gene products and promotion of microsatellite-unstable (MSI-H) carcinogenesis. Recent studies have indicated that MSI within 3'-untranslated regions (3'UTRs) may post-transcriptionally dysregulate gene products. Within this context, we conducted a broad mutational survey of 42 short 3'UTR microsatellites (MSs) in 45 MSI-H colorectal tumors and their corresponding normal colonic mucosae. METHODOLOGY/PRINCIPAL FINDINGS: In order to estimate the overall susceptibility of MSs to MSI in MSI-H tumors, the observed MSI frequency of each MS was correlated with its length, interspecies sequence conservation level, and distance from some genetic elements (i.e., stop codon, polyA signal, and microRNA binding sites). All MSs were stable in normal colonic mucosae. The MSI frequency at each MS in MSI-H tumors was independent of sequence conservation level and distance from other genetic elements. In contrast, MS length correlated significantly with MSI frequency in MSI-H tumors (r=0.86, p=7.2x10(-13)). 3'UTR MSs demonstrated MSI frequencies in MSI-H tumors higher than the 99% upper limit predicted by MS length for RB1-inducible coiled-coil 1(RB1CC1, mutation frequency 68.4%), NUAK family SNF1-like kinase 1(NUAK1, 31.0%), and Rtf1, Paf1/RNA polymerase II complex component, homolog (RTF1, 25.0%). An in silico prediction of RNA structure alterations was conducted for these MSI events to gauge their likelihood of affecting post-transcriptional regulation. RB1CC1 mutant was predicted to lose a microRNA-accessible loop structure at a putative binding site for the tumor-suppressive microRNA, miR-138. In contrast, the predicted 3'UTR structural change was minimal for NUAK1- and RTF1 mutants. Notably, real-time quantitative RT-PCR analysis revealed significant RB1CC1 mRNA overexpression vs. normal colonic mucosae in MSI-H cancers manifesting RB1CC1 3'UTR MSI (9.0-fold; p = 3.6x10(-4)). CONCLUSIONS: This mutational survey of well-characterized short 3'UTR MSs confirms that MSI incidence in MSI-H colorectal tumors correlates with MS length, but not with sequence conservation level or distance from other genetic elements. This study also identifies RB1CC1 as a novel target of frequent mutation and aberrant upregulation in MSI-H colorectal tumors. The predicted loss of a microRNA-accessible structure in mutant RB1CC1 RNA fits the hypothesis that 3'UTR MSI involves in aberrant RB1CC1 posttranscriptional upregulation. Further direct assessments are indicated to investigate this possibility.Bogdan C. Paun, Yulan Cheng, Barbara A. Leggett, Joanne Young, Stephen J. Meltzer, Yuriko Mor

Dominantly inherited micro-satellite instable cancer - the four Lynch syndromes - an EHTG, PLSD position statement

The recognition of dominantly inherited micro-satellite instable (MSI) cancers caused by pathogenic variants in one of the four mismatch repair (MMR) genes MSH2, MLH1, MSH6 and PMS2 has modified our understanding of carcinogenesis. Inherited loss of function variants in each of these MMR genes cause four dominantly inherited cancer syndromes with different penetrance and expressivities: the four Lynch syndromes. No person has an "average sex "or a pathogenic variant in an "average Lynch syndrome gene" and results that are not stratified by gene and sex will be valid for no one. Carcinogenesis may be a linear process from increased cellular division to localized cancer to metastasis. In addition, in the Lynch syndromes (LS) we now recognize a dynamic balance between two stochastic processes: MSI producing abnormal cells, and the host's adaptive immune system's ability to remove them. The latter may explain why colonoscopy surveillance does not reduce the incidence of colorectal cancer in LS, while it may improve the prognosis. Most early onset colon, endometrial and ovarian cancers in LS are now cured and most cancer related deaths are after subsequent cancers in other organs. Aspirin reduces the incidence of colorectal and other cancers in LS. Immunotherapy increases the host immune system's capability to destroy MSI cancers. Colonoscopy surveillance, aspirin prevention and immunotherapy represent major steps forward in personalized precision medicine to prevent and cure inherited MSI cancer

In depth evaluation of the prognostic and predictive utility of PTEN immunohistochemistry in colorectal carcinomas: performance of three antibodies with emphasis on intracellular and intratumoral heterogeneity.

BACKGROUND: Phosphatase and tensin homolog deleted in chromosome 10 (PTEN) loss of function is frequently detected in advanced colorectal cancer. Its detection is thought to have prognostic significance and it is being considered to predict responsiveness to anti-EGFR therapy. Unfortunately, while immunohistochemical assessment of PTEN expression is widespread, it lacks standardization and the results are hardly comparable across the available publications. METHODS: Retrospectively collected, formalin-fixed and paraffin-embedded colorectal tumor tissue samples from 55 patients were combined into tissue microarray (TMA) blocks. We used three different PTEN antibodies to determine the frequency, intensity and intracellular pattern of PTEN immunohistochemical labeling: Neomarkers, Dako and CellSignaling. We evaluated the aforementioned parameters in selected regions of colorectal cancers and in their lymph node metastases by using three scoring methods that take into consideration both staining frequency and intensity (H1-H3-score). We also evaluated intracellular localization. RESULTS: The Dako and CellSignaling antibodies stained predominantly cytoplasms, while the Neomarkers antibody specifically stained cell nuclei. PTEN H-scores were significantly lower in all tumor areas as compared to the normal colonic mucosa based on staining with the DAKO and CellSignaling antibodies. Intratumoral regional differences or differences between matching tumors and metastases were not detected with any of the antibodies. Neither Dako, neither CellSignaling, nor the Neomarkers antibodies revealed a significant correlation between PTEN expression and pT, Dukes/MAC and clinical stage. KRAS status, histological grade correlated with PTEN H-scores based on staining with the Neomarkers antibody. PTEN H-scores did not correlate with MMR status. PTEN H-scores did not show any correlation with relapse-free survival based on staining with either antibody. CONCLUSIONS: While PTEN expression decreased in colorectal cancer according to two antibodies, neither of the three applied PTEN antibodies could justify significant correlation with clinicopathological data, nor had prognostic value. Thus, we might conclude that immunohistochemical PTEN investigation remains a challenge requiring more standardized evaluation on larger number of cases to clarify its utility as a prognostic and predictive tool in CRC. The standardization of immunohistochemical method is key in the evaluation process, which is further discussed