Thermal Performance and Design Guidelines of Thermo-Active Foundations

A thermo-active foundation system can be a cost-effective technology to utilize ground thermal energy to heat and cool buildings. Indeed, thermo-active foundations, also known as thermal piles, integrate heat exchangers with the foundation elements and thus eliminate the need of drilling deep boreholes typically required by the conventional ground source heat pumps. In order to properly design thermo-active foundation systems, their thermal performance under various operating and climatic conditions are evaluated as part of this study using detailed modeling and simulation analyses. In particular, a transient three-dimensional finite difference numerical model has been developed and validated to analyze thermal performances of thermo-active foundations. The numerical model is then used to assess the impact of design parameters such as foundation depth, shank space, fluid flow rate, and the number of loops on the effectiveness of thermal piles to exchange heat between the building and the ground. Moreover, thermal response factors have been developed to integrate the performance of thermo-active foundations within detailed whole-building simulation programs. In this study, response factors specific to thermo-active foundations are implemented into EnergyPlus to investigate the impact of design and operating conditions. The results from the detailed simulation analysis are then used to develop a set of guidelines to properly design thermo-active foundation to meet heating and cooling loads of commercial buildings.This paper develops the design guide chart for TAF systems. The design guide chart provides the determination of required heat exchanger pipe length per water-to-water heat pump capacity for certain annual average ground temperature and for certain targeted maximum entering water temperature to a heat pump. Using an example application, this paper presents the usage of the design guide chart as well as shows the potential of the design guide chart for designing TAF system

Thermal Performance and Design Guidelines of Thermo-Active Foundations

A thermo-active foundation system can be a cost-effective technology to utilize ground thermal energy to heat and cool buildings. Indeed, thermo-active foundations, also known as thermal piles, integrate heat exchangers with the foundation elements and thus eliminate the need of drilling deep boreholes typically required by the conventional ground source heat pumps. In order to properly design thermo-active foundation systems, their thermal performance under various operating and climatic conditions are evaluated as part of this study using detailed modeling and simulation analyses. In particular, a transient three-dimensional finite difference numerical model has been developed and validated to analyze thermal performances of thermo-active foundations. The numerical model is then used to assess the impact of design parameters such as foundation depth, shank space, fluid flow rate, and the number of loops on the effectiveness of thermal piles to exchange heat between the building and the ground. Moreover, thermal response factors have been developed to integrate the performance of thermo-active foundations within detailed whole-building simulation programs. In this study, response factors specific to thermo-active foundations are implemented into EnergyPlus to investigate the impact of various design and operating conditions. The results from the detailed simulation analysis are then used to develop a set of guidelines to properly design thermo-active foundation to meet heating and cooling loads of commercial buildings.The design guidelines define the required number of thermal piles needed heating and cooling loads for prototypical office buildings in selected US climatic zones. In particular, charts have been developed to help determine the number of thermal piles needed depending on heating and cooling loads, heat pump size, foundation depth, and climate

Evaluation of Ground-Source Variable Refrigerant Flow System for US Office Buildings

This paper evaluates the energy performance of ground-source variable refrigerant flow (VRF) systems to condition office buildings located in various U.S. climates. Specifically, the performance of the ground-source VRF systems was determined and evaluated against that achieved by conventional space heating and cooling systems, including packaged terminal air-conditioners (PTACs), water-source heat pumps (WSHPs), ground-source heat pumps (GSHPs), and water-source VRF systems. A comparative analysis shows that ground-source VRF systems require significantly lower source energy uses than other heating and cooling systems in all U.S. climates, ranging from 21% to 50% for PTACs, from 36% to 52% for WSHPs, from 22% to 49% for GSHPs, and from 4% to 19% for water-source VRFs. These results indicate that ground-source VRFs can be suitable heating and cooling systems for all U.S. climates when designing high-energy-performance commercial buildings

Evaluation of Ground-Source Variable Refrigerant Flow System for U.S. Office Buildings

This paper evaluates the energy performance of ground-source variable refrigerant flow (VRF) systems to condition office buildings located in various U.S. climates. Specifically, the performance of the ground-source VRF systems was determined and evaluated against that achieved by conventional space heating and cooling systems, including packaged terminal air-conditioners (PTACs), water-source heat pumps (WSHPs), ground-source heat pumps (GSHPs), and water-source VRF systems. A comparative analysis shows that ground-source VRF systems require significantly lower source energy uses than other heating and cooling systems in all U.S. climates, ranging from 21% to 50% for PTACs, from 36% to 52% for WSHPs, from 22% to 49% for GSHPs, and from 4% to 19% for water-source VRFs. These results indicate that ground-source VRFs can be suitable heating and cooling systems for all U.S. climates when designing high-energy-performance commercial buildings

Evaluation of Effects of the Humidity Level-Based Auto-Controlled Centralized Exhaust Ventilation Systems on Thermal Comfort of Multi-Family Residential Buildings in South Korea

Building air-tightness has been increased to make energy efficient buildings. However, various indoor air quality issues can be caused by high building air-tightness because it allows low air and moisture transmission through building envelop. In order to solve and prevent these issues, mechanical ventilation systems can be used to control the indoor humidity level. The purpose of this paper is to evaluate the performances of the Relative Humidity (RH)-sensor based auto-controlled centralized exhaust ventilation systems to manage indoor air quality and thermal comfort of multi-family residential buildings in South Korea. A series of field tests were performed for different target zones and for various moisture source scenarios. As a result, it was found that the auto-controlled centralized exhaust ventilation systems were able to control indoor air quality and to maintain the zones thermal comfort faster than the baseline cases that did not operate exhaust vents. The results presented in this paper can show the potential and the feasibility of the auto-controlled centralized exhaust ventilation systems for multi-family residential buildings in South Korea. It is expected that the results presented in this paper would be useful for building owners, engineers, and architects when designing building systems

The salvage role of allogeneic hematopoietic stem-cell transplantation in relapsed/refractory diffuse large B cell lymphoma

Abstract To clarify the role of allogeneic hematopoietic stem-cell transplantation (allo-HSCT) in the chimeric antigen receptor T-cell therapy era, we analyzed the clinical characteristics and outcomes of 52 patients treated with allo-HSCT with relapsed/refractory diffuse large B cell lymphoma. Most enrolled patients had previously undergone intensive treatments, the median number of chemotherapy lines was 4, and the median time from diagnosis to allo-HSCT was 27.1 months. Patients were divided into remission-achieved (n = 30) and active-disease (n = 22) groups before allo-HSCT. Over a median follow-up period of 38.3 months, overall survival (OS) and event-free survival (EFS) rates were 38.4% and 30.6%, respectively. The cumulative incidence of relapse (CIR) and the non-relapsed mortality (NRM) were 36.7% and 32.7%, respectively. OS, EFS, and graft-versus-host disease-free, relapse-free survival (GRFS) outcomes were significantly superior in the remission-achieved group with lower CIR. In a multivariate analysis, a shorter interval from diagnosis to allo-HSCT reflected relatively rapid disease progression and showed significantly poor OS and EFS with higher CIR. Patients with active disease had significantly lower EFS, GRFS, and higher CIR. Previous autologous stem-cell transplantation was associated with better GRFS. Allo-HSCT is an established modality with a prominent group of cured patients and still has a role in the CAR T-cell era, particularly given its acceptable clinical outcomes in young patients with chemo-susceptible disease

Haploidentical versus Double-Cord Blood Stem Cells as a Second Transplantation for Relapsed Acute Myeloid Leukemia

There are limited data on second stem cell transplantation (SCT2) outcomes with alternative donors for relapsed AML after the first stem cell transplantation (SCT1). We analyzed the outcomes of 52 adult AML patients who received SCT2 from haploidentical donors (HIT, N = 32) and double-cord blood (dCBT, N = 20) between 2008 and 2021. The HIT group received T-cell-replete peripheral blood stem cells after reduced-toxicity conditioning with anti-thymocyte globulin (ATG), while the dCBT group received myeloablative conditioning. For a median follow-up of 64.9 months, the HIT group, compared to the dCBT group, had earlier engraftment, superior 2-year overall survival (OS), disease-free survival (DFS), and non-relapse mortality (NRM) with similar relapse. Multivariate analysis demonstrated that HIT was significantly associated with better OS, DFS, and lower NRM than dCBT. Both longer remission duration after SCT1 and complete remission at SCT2 were significantly associated with a lower relapse rate. In addition, bone marrow WT1 measurable residual disease (MRD) positivity was significantly associated with inferior OS and higher relapse. This study suggests that T-cell-replete HIT with ATG-based GVHD prophylaxis may be preferred over dCBT as SCT2 for relapsed AML and that WT1-MRD negativity may be warranted for better SCT2 outcomes

Depth of Response to Intensive Chemotherapy Has Significant Prognostic Value among Acute Myeloid Leukemia (AML) Patients Undergoing Allogeneic Hematopoietic Stem-Cell Transplantation with Intermediate or Adverse Risk at Diagnosis Compared to At-Risk Group According to European Leukemia Net 2017 Risk Stratification

We evaluated the prognostic efficiency of the European Leukemia Net (ELN) 2017 criteria on the post-transplant outcomes of 174 patients with intermediate (INT; n = 108, 62%) or adverse (ADV) risk (n = 66, 38%) of acute myeloid leukemia; these patients had received the first allogeneic hematopoietic stem-cell transplantation (HSCT) at remission. After a median follow-up period of 18 months, the 2 year OS, RFS, and CIR after HSCT were estimated to be 58.6% vs. 64.4% (p = 0.299), 50.5% vs. 53.7% (p = 0.533), and 26.9% vs. 36.9% (p = 0.060) in the INT and ADV risk groups, respectively. Compared to the ELN 2017 stratification, pre-HSCT WT1 levels (cutoff: 250 copies/104 ABL) more effectively segregated the post-HSCT outcomes of INT risk patients compared to ADV risk patients regarding their 2 year OS (64.2% vs. 51.5%, p = 0.099), RFS (59.4% vs. 32.4%, p = 0.003), and CIR (18.9% vs. 60.0% p WT1 levels were more prominent in INT risk patients than in ADV risk patients. Notably, FLT3-ITD had the greatest impact on post-HSCT outcomes among all the ELN 2017 criteria components; patients in the FLT3-ITD mutant subgroups exhibited the worst outcomes regardless of their allelic ratios or NPM1 status compared to the pre-HSCT WT1 level of other INT and ADV risk patients

Characterization of a novel anti-human TNF-α murine monoclonal antibody with high binding affinity and neutralizing activity

In order to develop an anti-human TNF-α mAb, mice were immunized with recombinant human TNF-α. A murine mAb, TSK114, which showed the highest binding activity for human TNF-α was selected and characterized. TSK114 specifically bound to human TNF-α without cross-reactivity with the homologous murine TNF-α and human TNF-β. TSK114 was found to be of IgG1 isotype with κ light chain. The nucleotide sequences of the variable regions of TSK114 heavy and light chains were determined and analyzed for the usage of gene families for the variable (V), diversity (D), and joining (J) segments. Kinetic analysis of TSK114 binding to human TNF-α by surface plasmon resonance technique revealed a binding affinity (KD) of ~5.3 pM, which is about 1,000- and 100-fold higher than those of clinically relevant infliximab (Remicade) and adalimumab (Humira) mAbs, espectively. TSK114 neutralized human TNF-α-mediated cytotoxicity in proportion to the concentration, exhibiting about 4-fold greater efficiency than those of infliximab and adalimumab in WEHI 164 cells used as an in vitro model system. These results suggest that TSK114 has the potential to be developed into a therapeutic TNF-α-neutralizing antibody with picomolar affinity