Air Injection for Enhanced Oil Recovery: <i>In Situ</i> Monitoring the Low-Temperature Oxidation of Oil through Thermogravimetry/Differential Scanning Calorimetry and Pressure Differential Scanning Calorimetry

Low-temperature oxidation (LTO) of oil plays an important role in air-injection based oil recovery processes. Systematic investigations on the regularities of LTO reactions, especially those decoupled with the influences of mass transfer, were highly expected to improve field application and even to develop new strategies for heavy oil recovery. In this contribution, both thermogravimetry/differential scanning calorimeter and pressure differential scanning calorimeter were employed as microreactors to <i>in situ</i> monitoring the heat release and mass loss performances of the LTO process under different oxygen partial pressures. The total amount of heat resulted from LTO reactions of oil was observed in a linear relationship with oxygen partial pressure. A one-step reaction model was proposed to simulate the low-temperature mass loss behavior. The kinetic parameters were calculated based on the Arrhenius expression and the assumption of distributed activation energy. These results indicated the feasibility of <i>in situ</i> generated heat during low-temperature oxidation by the promotion of oxygen partial pressure and the contact between oil and oxygen with little loss of deposited oil

Mechanistic Studies on the Metal-Free Activation of Dihydrogen by Antiaromatic Pentarylboroles

The perfluoro- and perprotiopentaphenylboroles <b>1</b> and <b>2</b> react with dihydrogen to effect H–H bond cleavage and formation of boracyclopentene products. The mechanism of this reaction has been studied experimentally through evaluation of the kinetic properties of the slower reaction between <b>2</b> and H₂. The reaction is first-order in both [borole] and [H₂] with activation parameters of Δ<i>H</i>^⧧ = 34(8) kJ/mol and Δ<i>S</i>^⧧ = −146(25) J mol^–1 K^–1. A minimal kinetic isotope effect of 1.10(5) was observed, suggesting an asynchronous geometry for H–H cleavage in the rate-limiting transition state. To explain the stereochemistry of the observed products, a ring-opening/ring-closing mechanism is proposed and supported by the separate synthesis of a proposed intermediate and its observed conversion to product. Furthermore, extensive DFT mapping of the reaction mechanism supports the plausibility of this proposal. The study illustrates a new mechanism for the activation of H₂ by a strong main group Lewis acid in the absence of an external base, a process driven in part by the antiaromaticity of the borole rings in <b>1</b> and <b>2</b>

Additional file 1: Table S1. of Response and survival of breast cancer intrinsic subtypes following multi-agent neoadjuvant chemotherapy

Cox model DRFS analyses including intrinsic subtype in all patients from the MDACC-based cohort (GSE25066). Table S2. Cox model DRFS analyses including ROR-P in all patients from the MDACC-based cohort (GSE25066). Table S3. Cox model DRFS analyses including intrinsic subtype in patients that achieved a pCR from the MDACC-based cohort (GSE25066). Table S4. Cox model DRFS analyses including ROR-P in patients that achieved a pCR from the MDACC-based cohort (GSE25066). Table S5. Cox model DRFS analyses including ROR-P in patients with residual disease from the MDACC-based cohort (GSE25066). Table S6. Distribution of the PAM50 subtypes within the TNBCtype groups and vice versa. Table S7. Association of the TNBCtype subtypes with chemotherapy response in triple-negative breast cancer. Figure S1. CONSORT diagram of the various cohorts evaluated in this study. Figure S2. Kaplan-Meier distant relapse-free survival analysis in MDACC-based (GSE25066 [13]) dataset set. (A) Survival outcomes of the ROR-P groups in all patients. (B) Survival outcomes of the ROR-P groups in patients with clinically node-negative disease. Figure S3. Levels of ESR1 across TNBCtype ESR1-low group, TNBCtype ESR1-high group and ER+ group. Median expression of ESR1 in the PAM50 training dataset reported in Parker et al. [24] has been set to zero. Figure S4. Distribution of the TNBCtype subtypes and ESR1-high group within the PAM50 subtypes in TNBC. Figure S5. Distribution of the TNBCtype subtypes and ESR1-high group within the PAM50 + Claudin-low subtypes in TNBC. Figure S6. Training and testing gene expression-based models predictive of pCR in all patients. Figure S7. Training and testing gene expression-based models predictive of pCR in patients with Basal-like disease. Figure S8. Training and testing gene expression-based models predictive of pCR in patients with luminal (A/B) disease. (DOCX 819 kb

Intrinsic subtypes and benefit from postmastectomy radiotherapy in node-positive premenopausal breast cancer patients who received adjuvant chemotherapy – results from two independent randomized trials

<p><b>Background:</b> The study of the intrinsic molecular subtypes of breast cancer has revealed differences among them in terms of prognosis and response to chemotherapy and endocrine therapy. However, the ability of intrinsic subtypes to predict benefit from adjuvant radiotherapy has only been examined in few studies.</p> <p><b>Methods:</b> Gene expression-based intrinsic subtyping was performed in 228 breast tumors collected from two independent post-mastectomy clinical trials (British Columbia and the Danish Breast Cancer Cooperative Group 82b trials), where pre-menopausal patients with node-positive disease were randomized to adjuvant radiotherapy or not. All patients received adjuvant chemotherapy and a subgroup of patients underwent ovarian ablation. Tumors were classified into intrinsic subtypes: Luminal A, Luminal B, HER2-enriched, Basal-like and Normal-like using the research-based PAM50 classifier.</p> <p><b>Results:</b> In the British Columbia study, patients treated with radiation had an overall significant lower incidence of locoregional recurrence compared to the controls. For Luminal A tumors the risk of loco-regional recurrence was low and was further lowered by adjuvant radiation. These findings were validated in the DBCG 82b study. The individual data from the two cohorts were merged, the hazard ratio (HR) for loco-regional recurrence associated with giving radiation was 0.34 (0.19 to 0.61) overall and 0.12 (0.03 to 0.52) for Luminal A tumors.</p> <p><b>Conclusions:</b> In both postmastectomy trials, patients with Luminal A tumors turned out to have a significant lower incidence of loco-regional recurrence when randomized to adjuvant radiotherapy, leaving no indication to omit postmastectomy adjuvant radiation in pre-menopausal high-risk patients with Luminal A tumors. It was not possible to evaluate the effect of radiotherapy among the other subtypes because of limited sample sizes.</p

IRS isoforms mediate distinct gene expression profiles, functional pathways, and breast cancer subtype association.

<p>(A) Venn diagrams depicting four distinct IRS isoform gene signatures were derived from overlapping and differential global gene expression patterns in response to IGF-I. (B) Target gene validation confirms both distinct and overlapping patterns of IRS-regulated gene expression. Gene expression was normalized to RPLP0 and is presented as fold-change of treatment (black bars) vs. serum-free (white bars) conditions. Error bars represent standard deviation and all results are representative of at least three independent replicates. (C) IRS gene signature enrichment in breast tumor subtypes in the UNC337 cohort. Median expression values are represented here in graphical format with p-values included for each of the IRS gene signatures.</p

IRS proteins regulate TGFβ2 mRNA expression and breast cancer cell motility.

<p>(A) Expression of TGFβ1 and TGFβ2 by qPCR in T47D-YA-IRS-1 (#10 and #20) and T47D-YA-IRS-2 (#1 and #6). (B) IGF-induced TGFβ2 expression in MCF10A, MCF-7L, MCF-7 ATCC, MDA-231 and F11 cells. For A & B, all cells were exposed to 5nm IGF-I for 4 hours prior to harvesting mRNA. Gene expression was normalized to RPLP0 and is presented as fold-change of treatment (black bars) vs. serum-free (white bars) conditions. (C) TGFβ2 expression was assessed by qPCR in an IRS-gene deletion mouse models (left) and IRS-overexpressing SH-EP neuroblastoma cells (right). (D) IRS-1, IRS-2 and TGFβ2 expression in a panel of patient breast tumors. Arrows indicate invasive breast carcinoma. Yellow bars signify high gene expression, blue bars signify low gene expression. E) pSMAD2 was examined by immunoblot at the indicated time points in MCF-7 cells. (F) Cell motility was examined by modified Boyden chamber assay. MCF-7 cells were incubated in the presence of neutralizing antibodies to either TGFβ1 or TGFβ2 and IGF-induced motility assessed. Error bars represent standard deviation and all results are representative of at least three independent replicates.</p

Gene set enrichment analysis for each IRS gene signature was performed using DAVID (Database of Annotation, Visualization and Integrated Discovery, v6.7).

<p>P-value indicates modified Fisher’s exact Probability Value and a high E-Scores (Enrichment Scores) indicates significant gene enrichment in the annotation cluster.</p

Multivariate Cox regression analysis of RFS & OS in Luminal B breast cancer tumors.

<p>Multivariate Cox regression analysis of RFS & OS in Luminal B breast cancer tumors.</p

IRS adaptor protein isoforms define tumor cell biology and regulate global gene expression profiles.

<p>(A) Monolayer growth and motility of T47D-YA (YA), T47D-YA-IRS-1 (#10 and #20) and T47D-YA-IRS-2 (#1 and #6) were measured by MTT assay and (B) scratch-wound healing assay in response to IGF-I treatment. The graphs are presented as fold-change response vs. non-treated control and error bars represent standard deviation. (C) IGF-induced gene expression is IRS-dependent. cDNA microarray analysis was performed on IRS-null YA, IRS-1, and IRS-2 clones. The graph represents IGF-regulated probes in comparison to untreated samples that met both fold (1.5) and p-value (0.05) cutoff values. Hierarchical clustering was carried out on log2-transformed using Gene Cluster 3.0 and visualized in Java TreeView.</p

Additional file 2: of Response and survival of breast cancer intrinsic subtypes following multi-agent neoadjuvant chemotherapy

Supplemental data. (XLSX 897 kb