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Item type: Item , Access status: Open Access , Subsurface thermal energy recovery from depleted heavy oil reservoir after in-situ combustion operations and its implication on CO2 storage(2026-01-31) Yang, Min; Chai, Maojie; Yuan, Shibao; Xin, Lin; Niu, Maofei; Wang, Sen; Feng, Qihong; Chen, ZhangxinAbstract In-situ combustion (ISC) has a huge potential in recovering heavy oil resources with a low environmental footprint. At the end of the ISC operation, a huge amount of thermal energy is left in the reservoir. By appropriately recovering the thermal energy in the depleted reservoirs after ISC operation, it could extend the economic life of the heavy oil reservoirs. This work investigated the potential of extracting heat using the cold water and CO2 as the working fluids to advance the knowledge base regarding the thermal energy recovery and CO2 storage in depleted ISC reservoirs. The extracted fluids are fed to the surface binary cycle for power generation or district heating. Simulation of ISC was performed to estimate the temperature, energy, and fluids distributions after 20 years of the oil production. An assessment of the energy remaining in the reservoir is performed. It is estimated that a total of 3 × 1014 J thermal energy was left underground after ISC operation in the typical five-spot well pattern. Subsequently, an examination of the potentially recoverable energy from the post ISC operation is performed. Cold water and CO2 are recirculated into the reservoir for energy recovery. The results indicates that the heavy oil reservoir after ISC operation can be regarded as an artificial geothermal system for subsurface thermal energy extraction. As the water circulation rate increases from 200 m3/day and to 400 m3/day and 600 m3/day, the average reservoir temperature is declined to 95 ℃, 79 ℃, and 71 ℃, respectively. Meanwhile, the corresponding thermal energy recovery factors are 48%, 63%, and 77%, respectively. Larger water circulation rate can generate high energy output and high energy recovery in the post ISC operation. The thermal energy recovery could prolong the energy production to 15 to 20 years in a depleted reservoir. Except for thermal energy extraction, a total of 6100 tons of CO2 can be sequestrated underground by using the CO2 as the working fluids in the five spot well pattern. The numerical investigation in this study indicate that huge energy extraction potential and CO2 storage can be achieved at the full field scale. Utilization of subsurface thermal energy after the ISC operation is a beneficial choice to offset the operating costs, reduce the CO2 emission and extend the economic life of reservoir.Item type: Item , Access status: Open Access , Impaired systemic antibody response against gut microbiota pathobionts in critical illness and susceptibility to nosocomial infections(2026-01-27) Cho, Nicole A.; Schlechte, Jared; Yu, Ian-ling; Bains, Ish; Fahlman, Tanner; Mackenzie, Colin; McDonald, BraedonAbstract Background Critically ill patients in intensive care units (ICUs) experience high rates of hospital-acquired (nosocomial) infections, commonly caused by translocation and dissemination of pathogenic microorganisms that colonize the intestinal tract (pathobionts). Multiple immune barriers protect the host against commensal and pathogenic colonizers, including a repertoire of circulating anti-commensal antibodies. The integrity of this systemic antibody-mediated defense system, its relationship with gut microbiota dysbiosis, and its impact on nosocomial infections in the ICU have not been explored. Results We performed a longitudinal cohort study of 46 critically ill patients at day 1 and day 3 of their ICU admission compared to 28 healthy volunteer controls. Circulating IgM, IgG, and IgA responses against 10 common gut and extra-intestinal pathobionts were quantified by flow cytometry, together with high-dimensional analyses of circulating B cell populations, fecal microbiota composition, and clinical outcomes. We observed reduced plasma IgM and IgG reactivity against intestinal pathobionts such as Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis in ICU patients compared to healthy volunteers. Reduced gut pathobiont antibody responses in ICU patients was associated with B cell lymphopenia, and patients with gut microbiota dysbiosis had reduced levels of natural antibody producing B1-like B cells. Reduced IgG and IgM reactivity against gut Gram-negative pathobionts was associated with an increased risk of nosocomial infection or death. Conclusions These findings indicate that the systemic antibody barrier against microbiota pathobionts is compromised in critical illness and associated with increased risk of nosocomial infections.Item type: Item , Access status: Open Access , Conditioned media and extracellular vesicles derived from human Wharton’s jelly mesenchymal stem cells improve the in vitro maturation of immature oocytes in normal and PCOS mouse model(2025-12-27) Solati, Arezoo; Alaee, Sanaz; Zal, Fatemeh; Khodabandeh, Zahra; Dara, Mahintaj; Mehdinejadiani, Shayesteh; Bahmyari, SedighehAbstract Background The effects of conditioned medium (CM) and extracellular vesicles (EVs) derived from human Wharton’s jelly mesenchymal stem cells (hWJMSCs) on in vitro maturation (IVM) of immature oocytes in both normal and polycystic ovary syndrome (PCOS)-induced mice were investigated. PCOS was induced in adult female NMRI mice by administering letrozole (90 μg/kg/day) via gavage for one week. Germinal vesicle (GV) oocytes were collected from both PCOS-induced and normal mice, while mature oocytes (MII) were obtained from superovulated normal mice to serve as controls. The experimental groups included 7 groups: Control (MII oocytes), 3 IVM groups (in vitro maturation of GV oocytes): IVM (with simple IVM media), IVM + CM, and IVM + EVs (IVM media supplemented with CM and EVs, respectively), and three PCOS groups (in vitro maturation of GV oocytes from PCOS-induced mice): PCOS IVM (with simple IVM media), PCOS IVM + CM, and PCOS IVM + EVs (IVM media supplemented with CM and EVs, respectively). After IVM was conducted in all groups, mature oocytes were harvested and assessed for maturation rate, morphology, viability, and gene expression profiles of key regulators (CDK1, CCNB1, MAP2K). Developmentally competent oocytes were selected using Brilliant Cresyl Blue staining and then subjected to in vitro maturation with or without CM or EVs supplementation. Nuclear maturation was evaluated via orcein staining, while viability was assessed using Trypan Blue. Morphometric parameters were measured using ImageJ software. Real-time PCR was utilized for the evaluation of gene expression of targeted genes. Results Results demonstrated that in BCB + oocytes, CM and EVs improved the mature oocytes compared to IVM. Oocytes from PCOS-induced mice exhibited reduced maturation and increased degeneration, which were rescued by CM and EV treatment. Gene expression analysis revealed downregulation of MAP2K, CCNB1, and CDK1 in IVM and PCOS IVM groups compared to the control group, while CM supplementation restored their expression. Oocyte diameter and viability were significantly enhanced in IVM + CM compared to IVM (P < 0.05). Conclusions These findings suggest that hWJMSC-derived secretomes, particularly CM, enhance oocyte maturation and quality, offering potential therapeutic benefits for IVM in both normal and PCOS conditions.Item type: Item , Access status: Open Access , ‘We truly feel limited’: nurses and midwives’ perspectives on multi-level factors influencing women’s adherence to ANC in Rwanda: a qualitative study(2025-12-21) Tengera, Olive; Meharry, Pamela; Uwamahoro, Marie C.; Babenko-Mould, Yolanda; Rulisa, Stephen; Nyirazinyoye, LaetitiaAbstract Background Antenatal care (ANC) is essential for improving maternal and neonatal health outcomes, yet adherence to ANC services remains a challenge in many low-income settings, including Rwanda. Understanding nurses and midwives’ perspectives on factors influencing ANC adherence is crucial for developing targeted interventions to enhance service utilization and maternal health outcomes. Methods This study employed a qualitative descriptive design to explore the perspectives of nurses and midwives on ANC adherence in Rwanda. Fifteen in-depth interviews (IDIs) were conducted using a semi-structured interview guide in Kinyarwanda. The interviews were verbatim transcribed and then translated into English. Atlas.ti 7 software was used to organise the data and then thematically analysed. Results The perspectives of nurses and midwives were summarised in four themes. Participants mentioned facilitators of ANC engagement with ANC services such as community education, structural motivators, availability of diagnostic infrastructure like ultrasound, and nurses and midwives training and mentorship. The barriers to women’s ANC adherence noted by participants are cultural beliefs and community misconceptions, stigma and secrecy surrounding unintended pregnancies, cost-related delays in ANC seeking, gender dynamics and relationships. Nurses and midwives also highlighted health care system constraints, such as staffing shortages and infrastructure and equipment limitations. Recommended interventions to enhance ANC adherence included community engagement and support, increased staff and resources, and digitalization of records. Conclusion Nurses and midwives play a critical role in shaping ANC adherence through service delivery and patient education. Their consistent engagement and ability to build trust with pregnant women make them key influencers in promoting timely and sustained ANC attendance. Addressing systemic challenges, strengthening community-based support, and enhancing policy implementation are essential strategies for improving ANC adherence in Rwanda. These findings provide valuable insights for policymakers and healthcare stakeholders to develop targeted interventions aimed at increasing ANC adherence and improving maternal and neonatal health outcomes.Item type: Item , Access status: Open Access , The Layered Lives of Small School, Rural and Remote Teaching Principals in the Northwest Territories: Life Changing Work(2025-12-19) Lamoureux, Léa; Field, James Colin; Shanahan, Marie-Claire; Spencer, Brenda L.; Kowch, Eugene Gary; Scott, David Michael; Hauseman, CameronAlthough some research has been conducted on the experiences of remote teaching principals, a gap remains in the literature regarding the roles of small school, rural and remote teaching principals. This qualitative research study employed a broad interpretive approach to investigate the lived experience of small school teaching principals in the Northwest Territories, Canada. Data were generated through semistructured interviews with three participants who shared their meaningful experiences as small school teaching principals in the communities in which they were living, and a reflective journal. I also reflected on my own experiences as a small school teaching principal as I made connections with my participants’ experiences. This study contributes to the knowledge about the unique and life-changing experiences of participants as small school teaching principals in remote areas, with insight into their lived experiences, workload, and the effects of the job on them as people.
