A Digital Core Analysis Approach to the Non-Archie Behaviour Mechanisms of Sedimentary Rocks

The interpretation of electrical measurements in reservoir rocks for the purpose of hydrocarbon reservoir characterisation is complicated by non-Archie behaviour. Effective stress during production of a reservoir may change and monitoring fluid saturations requires understanding of non-Archie behaviour as a function of confining pressure. Mechanistically, non-Archie behaviour may be caused by micro-structural features like grain contacts, micro-porosity or vugular porosity, all of which react differently to applied confining pressure due to different levels of compliance. Digital rock physics based calculation of electrical responses from high-resolution micro Xray-CT is a developing technique when faced with complex multi-scale rock micro-structure or the application of confining pressure. This thesis explores the utility of digital rock physics towards the modelling and mechanistic understanding of the zero-frequency resistivity response as a function of confining pressure using direct voxel-based numerical simulation based on micro-tomographic images with parameters further constrained by scanning electron microscopy measurements of grain contact aperture. Fluid saturations are calculated in a morphological approximation for strongly water-wet conditions. Three different non-Archie rocks are chosen based on their micro-structural complexity. These are low-porosity Fontainebleau sandstone where grain contacts are considered the main compliant porosity element, Indiana limestone where non-Archie behaviour is considered a result of the presence of multi-modal porosity (micro-porosity), and Winterset limestone where grain contacts and vuggy porosity are both present. For Fontainebleau sandstone, the main mechanism of returning to Archie behaviour was the closing of grain contacts with increasing confining pressure. To match the dependence of porosity on confining pressure it was necessary to model the compaction of non-compliant porosity. For Indiana limestone numerical simulations of FF and RI, the non-Archie behaviour can be explained by considering micro-porosity types with different saturation behaviour. Partial volume effects on RI behaviour are also found and evaluated in the simulations. Different types of non-Archie behaviours are displayed in two types of Winterset limestone samples. Vuggy porosity controls the non-Archie behaviour over much of the saturation range, with grain contacts playing a significant role. Overall RI experiments can be matched with single-resolution models, but accurately predicting the low-saturation range requires significant advances in multi-scale modelling

A digital rock physics approach to effective and total porosity for complex carbonates: pore-typing and applications to electrical conductivity

Recent advances in micro-CT techniques allow imaging heterogeneous carbonates at multiple scales and including voxel-wise registration of images at different resolution or in different saturation states. This enables characterising such carbonates at the pore-scale targeting the optimizing of hydrocarbon recovery in the face of structural heterogeneity, resulting in complex spatial fluid distributions. Here we determine effective and total porosity for different pore-types in a complex carbonate and apply this knowledge to improve our understanding of electrical properties by integrating experiment and simulation in a consistent manner via integrated core analysis. We consider Indiana Limestone as a surrogate for complex carbonate rock and type porosity in terms of macro- and micro-porosity using micro-CT images recorded at different resolution. Effective and total porosity fields are derived and partitioned into regions of macro-porosity, micro-porosity belonging to oolithes, and micro-porosity excluding oolithes’ rims. In a second step we use the partitioning of the micro-porosity to model the electrical conductivity of the limestone, matching experimental measurements by finding appropriate cementation exponents for the two different micro-porosity regions. We compare these calculations with calculations using a single cementation exponent for the full micro-porosity range. The comparison is extended to resistivity index at partial saturation, further testing the assignment of Archie parameters, providing insights into the regional connectivity of the different pore types

Serum APE1 as a predictive marker for platinum-based chemotherapy of non-small cell lung cancer patients

Purpose: To define the role of the DNA repair protein apurinic/apyrimidinic endonuclease 1 (APE1) in predicting the prognosis and chemotherapeutic response of non-small cell lung cancer patients receiving platinum-containing chemotherapy. Results: Our investigations found that serum APE1 level was significantly elevated in 229 of 412 NSCLC patients and correlated with its level in tissue (r2 = 0.639, p < 0.001). The elevated APE1 level in both tissue and serum of patients prior to chemotherapy was associated with worse progression-free survival (HR: 2.165, p < 0.001, HR: 1.421, p = 0.012), but not with overall survival. After 6 cycles of chemotherapy, a low APE1 serum level was associated with better overall survival (HR: 0.497, p = 0.010). Experimental Design: We measured APE1 protein levels in biopsy tissue from 172 NSCLC patients and sera of 412 NSCLC patients receiving platinum-based chemotherapy by immunohistochemistry and a newly established sensitive and specific enzyme-linked immunosorbent assay, respectively. APE1 levels in sera of 523 healthy donors were also determined as control. Conclusions: Our studies indicate that APE1 is a biomarker for predicting prognosis and therapeutic efficacy in NSCLC. The chemotherapy-na\uefve serum APE1 level, which correlated with its tissue level inversely associated with progressionfree survival of platinum-containing doublet chemotherapy, whereas post-treatment serum APE1 level was inversely associated with overall survival

Fabrication of High-Performance Thin-Film Composite Nanofiltration Membrane by Dynamic Calcium-Carboxyl Intra-Bridging during Post-Treatment

Widespread applications of nanofiltration (NF) and reverse osmosis (RO)-based processes for water purification and desalination call for high-performance thin-film composite (TFC) membranes. In this work, a novel and facile modification method was proposed to fabricate high-performance thin-film composite nanofiltration membrane by introducing Ca2+ in the heat post-treatment. The introduction of Ca2+ induced in situ Ca2+-carboxyl intra-bridging, leading to the embedment of Ca2+ in the polyamide (PA) layer. This post modification enhanced the hydrophilicity and surface charge of NF membranes compared to the pristine membrane. More interestingly, the modified membrane had more nodules and exhibited rougher morphology. Such changes brought by the addition of Ca2+ enabled the significant increase of water permeability (increasing from 17.9 L&middot;m&minus;2&middot;h&minus;1&middot;bar&minus;1 to 29.8 L&middot;m&minus;2&middot;h&minus;1&middot;bar&minus;1) while maintaining a high selectivity (Na2SO4 rejection rate of 98.0%). Furthermore, the intra-bridging between calcium and carboxyl imparted the NF membranes with evident antifouling properties, exhibiting milder permeability decline of 4.2% (compared to 16.7% of NF-control) during filtration of sodium alginate solution. The results highlight the potential of using Ca2+-carboxyl intra-bridging post-treatment to fabricate high-performance TFC membranes for water purification and desalination

Sentinel Lymph Node Biopsy Is Feasible in Cervical Cancer Laparoscopic Surgery: A Single-Center Retrospective Cohort Study

Background and Objective. Sentinel lymph node (SLN) biopsy efficiency has been confirmed in various solid tumors. This study aimed to assess SLN biopsy feasibility in clinical application and explore how to improve its detection rates and diagnostic accuracy in cervical cancer laparoscopic surgery. Methods. A total of 100 cervical cancer patients undergoing laparoscopic surgery with SLN biopsy were included. Indocyanine green, carbon nanoparticles (CNPs), and a combination of both were used during surgeries. Detection rates, sensitivity, negative predictive value (NPV) of SLN biopsy, and related factors were analyzed. Results. The overall and bilateral SLN detection rates were 92% (92/100) and 74% (74/100), respectively. Combined tracers had higher bilateral SLN detection rates than CNPs alone (p=0.005). Menopause and lymph node metastasis were associated with lower overall and bilateral SLN detection rates (p<0.05). SLN biopsy sensitivity and NPV for lymph node metastasis in patients with at least one detected SLN were 81.8% (9/11) and 97.3% (72/74), respectively. Among those with bilateral detected SLNs, higher sensitivity and NPV of 87.5% (7/8) and 98.3% (57/58) were observed, respectively. SLN algorithm can ensure that all patients with lymph node metastasis are detected by SLN biopsy. Conclusion. SLN biopsy appears to be safe and effective for specific cervical cancer patients with high detection rates and NPV in laparoscopic surgery, especially for those with detected bilateral SLNs and undergoing the SLN algorithm. Selecting suitable patients for SLN mapping has prospects for clinical application

Nanocrystallization of Anthocyanin Extract from Red-Fleshed Apple ′QN-5′ Improved Its Antioxidant Effect through Enhanced Stability and Activity under Stressful Conditions

Red-flesh apples are known as functional fruits because of their rich anthocyanin. The anthocyanin content of the red flesh apple cultivar &#8242;QN-5&#8242; we bred can reach 361 mg&#183;kg&#8722;1 (FW), and showed higher scavenging capacity to DPPH radicals, hydroxyl radicals, and superoxide anion radicals, with scavenging rates of 80.0%, 54.0%, and 43.3%, respectively. We used this particular anthocyanin-rich &#8242;QN-5&#8242; apple as material to examine how nanocrystallization affects the antixodiant effect of anthocyanin. The anthocyanin extract was encapsulated with biocompatible zein to form zein-anthocyanin nanoparticles (ZANPs). Transmission electron microscopy (TEM) scanning showed that ZANPs had a regular spherical shape with an average diameter size of 50&#8211;60nm. When the ratio of the zein and the anthocyanin was 1:0.5, the results suggested that the encapsulation efficiency (EE) of the ZANPs could reach as high as 92.8%, and that scavenging rate for DPPH radicals was increased from 87.1% to 97.2% compared to the non-nanocrystallized anthocyanin extract. Interestingly, treatment under alkaline conditions (pH 9.0), high temperature (90 &#176;C), and a storage time of 7 days could decrease the scavenging capacity of the ZANPs for DPPH radicals, but this scavenging capacity loss for ZANPs was significantly lower than that observed in the non-nanocrystallized anthocyanin, suggesting the higher stability of ZANPs is caused by encapsulation. These results would provide a theoretical basis for the application of the anthocyanin in scavenging free radicals under stress conditions