Development of a micro-combined heat and power powered by an opposed-piston engine in building applications.

Residential homes and light commercial buildings usually require substantial heat and electricity simultaneously. A combined heat and power system enables more efficient and environmentally friendly energy usage than that achieved when heat and electricity are produced in separate processes. However, due to financial and space constraints, residential and light commercial buildings often limit the use of traditional large-scale industrial equipment. Here we develop a micro-combined heat and power system powered by an opposed-piston engine to simultaneously generate electricity and provide heat to residential homes or light commercial buildings. The developed prototype attains the maximum AC electrical efficiency of 35.2%. The electrical efficiency breaks the typical upper boundary of 30% for micro-combined heat and power systems using small internal combustion engines (i.e., <10 kW). Moreover, the developed prototype enables maximum combined electrical and thermal efficiencies greater than 93%. The prototype is optimally designed for natural gas but can also run renewable biogas and hydrogen, supporting the transition from current conventional fossil fuels to zero carbon emissions in the future. The analysis of the unit's decarbonization and cost-saving potential indicate that, except for specific locations, the developed prototype might excel in achieving decarbonization and cost savings primarily in US northern and middle climate zones.

Potential of prehabilitation in hepatocellular carcinoma: a narrative review of available evidence.

BACKGROUND AND OBJECTIVE: Hepatocellular carcinoma (HCC) is a leading cause of cancer deaths. Patients with HCC are often significantly affected by sarcopenia and cancer cachexia. Prehabilitation, a multimodal pre-operative exercise and nutritional intervention, has been implemented with varying degrees of success in enhancing outcomes among other gastrointestinal (GI) malignancies. However, remarkably little is described how prehabilitation may be beneficial in improving outcomes among those with HCC. Thus, a narrative review is warranted to examine previously developed prehabilitation models and determine how interventions affected sarcopenia as a prognosticator in HCC and other GI malignancies. This article seeks to offer guidance on how prehabilitation may be implemented for those with HCC based on available data published on other GI malignancies and serve as a call for additional research specific to the value of prehabilitation in HCC. METHODS: Independent key-term searches were conducted by all authors of various databases (PubMed, ScienceDirect, Google Scholar) for relevant articles examining role, safety, and efficacy of prehabilitation in HCC and/or other GI malignancies. Relevant articles pertaining to sarcopenia, Enhanced Recovery After Surgery (ERAS) guidelines, and prehabilitation models were collected and analyzed. Review authors held multiple meetings to ensure coherence of narrative review process and final product. KEY CONTENT AND FINDINGS: Patients with HCC often suffer from sarcopenia and/or cachexia, which are known to be associated with poorer outcomes. The benefits of a prehab program in patients with HCC are not well described in current literature, but in referencing the benefits of prehab programs in other GI malignancies and ERAS protocols on patients undergoing liver resection and liver transplant, there is potential for a similar multimodal program to yield similar benefits and healthcare cost-savings. However, further investigation is needed as HCC has multiple etiologies and affects a wide variety of people. CONCLUSIONS: A multimodal prehabilitation program emphasizing regular aerobic and resistance exercise, nutritional optimization, lifestyle modifications, mental health and wellness practices, with a nurse and rehabilitation physician's oversight may improve outcomes in patients undergoing treatment for HCC. However further investigation into specific exercise models, optimal nutrition regimens and benefit/cost analysis of a multimodal prehabilitation program within this complex patient population is needed.

Dataset of ultralow temperature refrigeration for COVID 19 vaccine distribution solution.

Most COVID-19 vaccines require temperature control for transportation and storage. Two types of vaccine have been developed by manufacturers (Pfizer and Moderna). Both vaccines are based on mRNA and lipid nanoparticles requiring low temperature storage. The Pfizer vaccine requires ultra-low temperature storage (-80 °C to -60 °C), while the Moderna vaccine requires -30 °C storage. However, the last stage of distribution is quite challenging, especially for rural or suburban areas, where local towns, pharmacy chains and hospitals may not have the infrastructure required to store the vaccine at the required temperature. In addition, there is limited data available to address ancillary challenges of the distribution framework for both transportation and storage stages, including safety concerns due to human exposure to large amounts of CO2 from dry-ice sublimation, issues due to the pressure increase caused by dry-ice sublimation, and the potential issue caused by non-uniform cryogenic temperatures. As such, there is a need for test dataset to assist the development of a quick, effective, secure, and safe solution to mitigate the challenges faced by vaccine distribution logistics.

COVID 19 vaccine distribution solution to the last mile challenge: Experimental and simulation studies of ultra-low temperature refrigeration system.

Most COVID-19 vaccines require ambient temperature control for transportation and storage. Both Pfizer and Moderna vaccines are based on mRNA and lipid nanoparticles requiring low temperature storage. The Pfizer vaccine requires ultra-low temperature storage (between -80 °C and -60 °C), while the Moderna vaccine requires -30 °C storage. Pfizer has designed a reusable package for transportation and storage that can keep the vaccine at the target temperature for 10 days. However, the last stage of distribution is quite challenging, especially for rural or suburban areas, where local towns, pharmacy chains and hospitals may not have the infrastructure required to store the vaccine. Also, the need for a large amount of ultra-low temperature refrigeration equipment in a short time period creates tremendous pressure on the equipment suppliers. In addition, there is limited data available to address ancillary challenges of the distribution framework for both transportation and storage stages. As such, there is a need for a quick, effective, secure, and safe solution to mitigate the challenges faced by vaccine distribution logistics. The study proposes an effective, secure, and safe ultra-low temperature refrigeration solution to resolve the vaccine distribution last mile challenge. The approach is to utilize commercially available products, such as refrigeration container units, and retrofit them to meet the vaccine storage temperature requirement. Both experimental and simulation studies are conducted to evaluate the technical merits of this solution with the ability to control temperature at -30 °C or -70 °C as part of the last mile supply chain for vaccine candidates.

Analysis of Adherence to Acute Inpatient Rehabilitation in Patients with Cancer.

Importance: The need for cancer rehabilitation is expected to continue to dramatically increase with the aging population and increasing number of cancer survivors. These survivors experience a wide range of physical limitations and symptoms that negatively affect their health and quality of life. Research is needed to determine the rate of adherence, reasons for non-adherence, and interventions to improve adherence to acute inpatient rehabilitation among patients with cancer. Objective: To evaluate the rate of adherence and reasons for non-adherence to acute inpatient rehabilitation in patients with cancer. Design, Setting, and Participants: This was a secondary analysis of a retrospective study that assessed medical complications in 165 patients with cancer who had a median length of stay of 11 days (interquartile range of 8-14) in acute inpatient rehabilitation. We reviewed the records of all consecutive patients who underwent acute inpatient rehabilitation from September 1, 2017 through February 28, 2018 at a large academic, quaternary National Cancer Institute-designated Cancer Center. Main Outcomes and Measures: We calculated the rehabilitation session adherence rate and descriptively summarized the reasons for non-adherence. Results: There were 78/165 (47%) patients that had 1 or more incomplete rehabilitation sessions due to medical complications. These patients had a median of 2 (interquartile range of 1-4) incomplete rehabilitation sessions. We noted other reasons for incomplete rehabilitation sessions in 146/165 (89%) patients, who had a median of 3 (interquartile range of 2-4) incomplete rehabilitation sessions. The median total number of days with incomplete rehabilitation sessions in the entire cohort was 2 (interquartile range 1-3). Conclusion and Relevance: Among patients with cancer undergoing acute inpatient rehabilitation, the adherence rate to 1-hour long intensive rehabilitation sessions were low due to medical complications and other reasons. This in turn affected compliance with the 3 hours of rehabilitation a day requirement for acute inpatient rehabilitation. Patients with cancer undergoing acute inpatient rehabilitation are medically complex and further research at multiple institutions with larger cohorts may be beneficial in further assessing adherence rates and reasons for non-adherence to improve participation in acute inpatient rehabilitation.

Dataset of low global warming potential refrigerant refrigeration system for fault detection and diagnostics.

HVAC and refrigeration system fault detection and diagnostics (FDD) has attracted extensive studies for decades; however, FDD of supermarket refrigeration systems has not gained significant attention. Supermarkets consume around 50 kWh/ft2 of electricity annually. The biggest consumer of energy in a supermarket is its refrigeration system, which accounts for 40%-60% of its total electricity usage and is equivalent to about 2%-3% of the total energy consumed by commercial buildings in the United States. Also, the supermarket refrigeration system is one of the biggest consumers of refrigerants. Reducing refrigerant usage or using environmentally friendly alternatives can result in significant climate benefits. A challenge is the lack of publicly available data sets to benchmark the system performance and record the faulted performance. This paper identifies common faults of supermarket refrigeration systems and conducts an experimental study to collect the faulted performance data and analyze these faults. This work provides a foundation for future research on the development of FDD methods and field automated FDD implementation.

Medical Complications and Prognostic Factors for Medically Unstable Conditions During Acute Inpatient Cancer Rehabilitation.

PURPOSE: Acute inpatient rehabilitation provides concurrent medical care and intensive rehabilitation. We sought to describe the nature of types of medical complications and to identify the more frequent types of medical complications management in patients with cancer undergoing acute inpatient rehabilitation. METHODS: We reviewed the records of all consecutive patients admitted to acute inpatient rehabilitation from September 1, 2017, through February 28, 2018. Presenting problem noted to be a significant change in medical status using the Centers for Medicare & Medicaid Services' Evaluation and Management Service Guide was defined as a medical complication. We recorded demographic and clinical characteristics. Multivariable logistic regression analysis was performed to assess prognostic factors for returning to acute care. RESULTS: Among 165 evaluable patients, 158 (96%) had at least one medical complication, and 31 (19%) had an unplanned return to acute care. After excluding three patients who had planned return to acute care, there was a cohort of 162 patients and the most common medical complication categories were electrolyte abnormalities 81 (50%), musculoskeletal 70 (43%), genitourinary or renal 61 (38%), hematologic 58 (36%), and cardiovascular problems 46 (28%). Multivariable analysis showed that tachycardia (odds ratio [OR], 7.83; 95% CI, 2.23 to 27.54; P = .001) and weekly or more frequent RBC transfusions (OR, 5.23; 95% CI, 1.39 to 19.64; P = .014) were independently associated with unplanned return to acute care. CONCLUSION: A high frequency and wide range of medical complications and interventions occur in patients with cancer undergoing acute inpatient rehabilitation. Close monitoring and expertise are needed for this patient population.

Mechanical properties and surface characterization of beta titanium and stainless steel orthodontic wire following topical fluoride treatment.

OBJECTIVE: To study the effect of fluoride prophylactic agents on the loading and unloading mechanical properties and surface quality of beta titanium and stainless steel orthodontic wires. MATERIALS AND METHODS: Rectangular beta titanium and stainless steel wires were immersed in either an acidulated fluoride agent, a neutral fluoride agent, or distilled water (control) for 1.5 hours at 37 degrees C. After immersion, the loading and unloading elastic modulus and yield strength of the wires were measured using a 3-point bend test in a water bath at 37 degrees C. A one-way analysis of variance and Dunnett's post hoc, alpha = .05, were used to analyze the mechanical testing data. Scanning electron microscopy was also used to qualitatively evaluate the wire topography as a function of the fluoride treatments. RESULTS: Unloading mechanical properties of beta titanium and stainless steel wires were significantly decreased (P

Elastic anisotropy of bone and dentitional tissues.

The calculation of the scalar compressive and shear anisotropy factors developed for single crystal refractory compounds has been adapted to the anisotropic elastic stiffness coefficients determined by a number of ultrasonic measurements of bone based on transverse isotropic symmetry. Later, this work was extended to include the ultrasonic measurements of bone based on orthotropic symmetry. Recently, the five transverse isotropic elastic constants for both wet and dry human dentin were determined using resonant ultrasound spectroscopy. The five transverse isotropic elastic constants for wet bovine enamel and dentin had been calculated based on modeling of ultrasonic wave propagation measurements and related data in the literature. The scalar compressive and shear anisotropy factors have been calculated from both these sets of data and are compared with a representative set from those published previously for both human and bovine bone and both fluoro- and hydroxyl-apatites.