Search

Direct Heating Equipment (DHE) is a type of space heating appliance that supplies warm air directly to the space where it is installed. It has been estimated that DHE is the primary and/or secondary source of space heating in 16% of households in California and that one-third of this fleet was installed more than 20 years ago. In addition, DHE is rarely maintained and is repaired only in extreme situations. Old DHE that is still in use has energy and emission implications. We evaluated 12 DHE units in the combustion laboratory at Lawrence Berkeley National Laboratory. Of those, eight were low-efficiency units removed from homes in California, and four were new, high-efficiency units. We found that, in most cases, the amount of natural gas used by a unit is consistent with the input rate of the model. We also found that, except for two high-efficiency models with ultra-low NOx burners, the NOx emissions from both the low- and high-efficiency models were very similar. Emissions of CO and CH4 are relatively uniform across models, except for two high-efficiency models that exhibit higher emissions of these gases. Additionally, many piloted units produced non-negligible amounts of CO and CH4 during stand-by periods, when only the pilot was lit. In general, our results are consistent with results from another study with similar scope.

Direct Heating Equipment (DHE) is a category of ductless space heating appliances that supply heat directly to the space where they are installed. While DHE is the primary or secondary heating source in a non-negligible proportion of California households, its performance, installation, and operational characteristics remain poorly understood, as do the main barriers to adopting efficient DHE in the state. Inefficient DHE increases household energy costs, greenhouse gas emissions, and safety and health risks to users. We surveyed households with DHE in California. Results demonstrate that both homeowners and tenants are willing to invest in a new DHE unit to improve their thermal comfort and indoor air quality and reduce fuel costs and environmental impacts. It further shows that the primary barrier to more efficient DHE is their additional cost compared to baseline models. Monetary incentives and building codes that are more stringent can contribute to increasing the adoption of high-efficiency DHE in the state, increasing safety, reducing energy costs for consumers, and reducing greenhouse gas emissions in California.

In this study, the thermal deformation behavior of Cu–Ti–Zr(-Mg) alloys were investigated by Gleeble-1500D. The two alloys were deformed at 700–900 °C with 0.003–10 s−1 strain rate. The intrinsic equations of the two alloys were constructed and calculated thermal activation energies, which indicates that it is improved from 325.67 kJ/mol to 344.03 kJ/mol after Mg addition. The result showed that the hot working area of Cu–Ti–Zr alloy is greatly extended after Mg addition, and rheological instability area is reduced. The morphology of the alloys was observed to analyze thermal behavior. It revealed that Mg elements inhibited the occurrence of dynamic recrystallization and shifted the texture types in the alloys by characterization of EBSD. TEM results showed that the phases during hot deformation in Cu–Ti–Zr–Mg are Cu4Ti and Cu10Zr7, which are in a semi-coherent relationship with the Cu matrix.

To investigate methods for enhancing the resistance of electrical contact materials to arc erosion, this study focuses on the preparation and properties of novel composites. Al2O3–Cu/30Cr and 0.3GO-0.3Ag/Al2O3–Cu/30Cr composites were fabricated using vacuum hot press sintering. The composites achieved high relative densities (99.82% and 99.6%), good electrical conductivities (47.8% IACS and 46.1% IACS), excellent hardness (142 HV and 158 HV), and superior thermal conductivities (124 W/(m·K) and 188 W/(m·K) at 150 °C), with compressive strengths of 693 MPa and 711 MPa. In addition, the addition of GO-Ag improved the resistance of the material to arc erosion, and the transfer and loss of the material were significantly reduced. Under the 30 V DC 30 A condition, the anode mass gain, cathode mass reduction and total mass loss decreasing from 3 mg, 3.73 mg, and 0.73 mg–1.97 mg, 2.30 mg, and 0.33 mg, respectively. Furthermore, the transmission electron microscopy (TEM) and energy dispersive spectrometer (EDS) results show that Cr3C2 compounds effectively pin the Cr–Cu interface. High thermal conductivity and good micro-interface improve the electrical contact properties of the composites and help to improve the compression properties.

To reveal the energy accumulation law of surrounding rock in coal thickness change area and the influence of mining direction on it, this study takes the 17# coal seam of Hegang Junde Coal Mine as the research background, and takes the combined rock strata as the object to discuss the stress transfer mechanism of coal thickness change area. The relationship between the original rock stress and the thickness ratio and elastic modulus ratio of coal rock in the coal thickness change area is revealed, and the influence of mining direction on the mining stress and energy accumulation law in the coal thickness change area is clarified. The following conclusions are obtained: due to the difference in strength (stiffness) between rock and coal, the principal stress distribution in the coal thickness change area is uneven. The peak stress appears in the coal thickness thinning area, and the valley stress appears in the thickening area. The larger the range of coal thickness change and the smaller the elastic modulus ratio of coal and rock, the greater the peak stress and the smaller the valley stress. Under the influence of mining stress, the advance abutment pressure and the abnormal stress of coal thickness change are superimposed in the area of coal thickness change, and the stress concentration of surrounding rock is high. From thin to thick mining, there is an impact danger zone due to the superposition of the advance abutment pressure zone and the stress anomaly zone in front of the working face, and there are two impact danger zones from thick to thin mining, so it is more reasonable to mine from thin to thick. In view of the mining stress and energy accumulation law in the coal thickness change area, the prevention and control ideas of regulating the surrounding rock structure, surrounding rock stress, and increasing impact resistance energy are put forward, the engineering application is carried out, and the application effect is good.

BackgroundRipretinib, a broad-spectrum tyrosine kinase inhibitor, has been approved for the treatment of advanced gastrointestinal stromal tumors in adult patients. Clinical studies have shown that higher in vivo exposure of ripretinib correlates with improved efficacy, highlighting the potential clinical significance of therapeutic drug monitoring. In this study, a simple and stable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was attempted to be established and validated for pharmacokinetic studies of ripretinib and its metabolite DP-5439 and therapeutic drug monitoring in human plasma.MethodRipretinib and DP-5439 were separated by chromatography using a Thermofisher Hypersil GOLDTM C18 HPLC column. The mobile phase for gradient elution is composed of 0.1% formic acid in water and acetonitrile. Multiple reaction monitoring was implemented along with electrospray ionization positive mode for detection. The ion pairs of ripretinib, DP-5439 and internal standard D8-ripretinib were m/z 510.1→m/z 417, m/z 496.11→m/z 402.9 and m/z 518.15→m/z 420, respectively. Plasma samples from ripretinib-treated patients of our hospital were collected for pharmacokinetic analysis.ResultsRipretinib and DP-5439 demonstrated a strong linear relationship over 10–5,000 μg/L (R2 > 0.99). Accuracy, precision, specificity, recoveries, matrix effect, stability, and dilution effect were all validated and found to meet the required criteria. Following validation, the method was utilized to determine plasma samples from patients treated with ripretinib. The median steady-state trough concentrations (Cmin, range) were 398.50 (66.98 ∼ 1,458.91) μg/L for ripretinib and 654.74 (30.71 ∼ 1,522.48) μg/L for DP-5439, with a total median concentration of 1,129.46 (140.95 ∼ 2,981.39) μg/L in patients receiving ripretinib at 150 mg once daily. Meanwhile, using the established methods, the study conducted pharmacokinetics studies on four patients with ripretinib and DP-5439.ConclusionThis study developed and validated a robust LC-MS/MS method for determining ripretinib and its metabolite DP-5439 in human plasma. Furthermore, the practicality of this method in clinical sample analysis was demonstrated. This approach can serve as an effective tool for the pharmacokinetics analysis and therapeutic drug monitoring in patients treated with ripretinib.

BackgroundTargeted next-generation sequencing (tNGS) has become a trending tool in the field of infection diagnosis, but concerns are also raising about its performance compared with metagenomic next-generation sequencing (mNGS). This study aims to explore the clinical feasibility of a tNGS panel for respiratory tract infection diagnosis and compare it with mNGS in the same cohort of inpatients.Methods180 bronchoalveolar lavage fluid samples were collected and sent to two centers for mNGS and tNGS blinded tests, respectively. The concordance between pathogen reports of both methods and the clinical significance among samples with/without known etiology was further evaluated.ResultsOverall, both methods displayed high agreement on pathogen reports, as the average percent agreement reached 95.29%. But tNGS presented a slightly higher detection rate per species than mNGS (PWilcoxon=1.212e-05; standard mean difference = 0.2887091), as detection rates for 32 out of 48 species were higher than those of mNGS. Due to limitations of panel coverage, tNGS identified 28 fewer species than mNGS, among which only 3 were considered clinically relevant. In reference to composite reference standard, accuracy, sensitivity, and specificity combining both tNGS and mNGS reached 95.61%, 96.71%, and 95.68%, respectively, while positive prediction value (PPV) was low at 48.13%, which was caused by low agreement regarding opportunistic pathogens. tNGS and mNGS improved the etiology identification in 30.6% (55/180) and 33.9% (61/180) cases, respectively.ConclusionCollectively, tNGS presented a similar overall performance in pathogen identification compared to mNGS, but outperformed in some pathogens. This study also demonstrated that deployment of tNGS significantly improves etiology identification in routine practice and provides hints for clinical decisions. The low agreement between clinical diagnosis and NGS reports towards opportunistic pathogens implies that adjudication is essential for report interpretation. Finally, We proposed tNGS as a diagnosis option in clinical practice due to its cost-efficiency.

Abstract Background In recent years, with benefits from the continuous improvement of clinical technology and the advantage of fertility preservation, the application of embryo cryopreservation has been growing rapidly worldwide. However, amidst this growth, concerns about its safety persist. Numerous studies have highlighted the elevated risk of perinatal complications linked to frozen embryo transfer (FET), such as large for gestational age (LGA) and hypertensive disorders during pregnancy. Thus, it is imperative to explore the potential risk of embryo cryopreservation and its related mechanisms. Methods Given the strict ethical constraints on clinical samples, we employed mouse models in this study. Three experimental groups were established: the naturally conceived (NC) group, the fresh embryo transfer (Fresh-ET) group, and the FET group. Blastocyst formation rates and implantation rates were calculated post-embryo cryopreservation. The impact of FET on fetal growth was evaluated upon fetal and placental weight. Placental RNA-seq was conducted, encompassing comprehensive analyses of various comparisons (Fresh-ET vs. NC, FET vs. NC, and FET vs. Fresh-ET). Results Reduced rates of blastocyst formation and implantation were observed post-embryo cryopreservation. Fresh-ET resulted in a significant decrease in fetal weight compared to NC group, whereas FET reversed this decline. RNA-seq analysis indicated that the majority of the expression changes in FET were inherited from Fresh-ET, and alterations solely attributed to embryo cryopreservation were moderate. Unexpectedly, certain genes that showed alterations in Fresh-ET tended to be restored in FET. Further analysis suggested that this regression may underlie the improvement of fetal growth restriction in FET. The expression of imprinted genes was disrupted in both FET and Fresh-ET groups. Conclusion Based on our experimental data on mouse models, the impact of embryo cryopreservation is less pronounced than other in vitro manipulations in Fresh-ET. However, the impairment of the embryonic developmental potential and the gene alterations in placenta still suggested it to be a risky operation.

Abstract Background Doxorubicin (Dox) is an effective chemotherapeutic drug for various cancers, but its clinical application is limited by severe cardiotoxicity. Dox treatment can transcriptionally activate multiple cardiotoxicity-associated genes in cardiomyocytes, the mechanisms underlying this global gene activation remain poorly understood. Methods and results Herein, we integrated data from animal models, CUT&Tag and RNA-seq after Dox treatment, and discovered that the level of H3K27ac (a histone modification associated with gene activation) significantly increased in cardiomyocytes following Dox treatment. C646, an inhibitor of histone acetyltransferase, reversed Dox-induced H3K27ac accumulation in cardiomyocytes, which subsequently prevented the increase of Dox-induced DNA damage and apoptosis. Furthermore, C646 alleviated cardiac dysfunction in Dox-treated mice by restoring ejection fraction and reversing fractional shortening percentages. Additionally, Dox treatment increased H3K27ac deposition at the promoters of multiple cardiotoxic genes including Bax, Fas and Bnip3, resulting in their up-regulation. Moreover, the deposition of H3K27ac at cardiotoxicity-related genes exhibited a broad feature across the genome. Based on the deposition of H3K27ac and mRNA expression levels, several potential genes that might contribute to Dox-induced cardiotoxicity were predicted. Finally, the up-regulation of H3K27ac-regulated cardiotoxic genes upon Dox treatment is conservative across species. Conclusions Taken together, Dox-induced epigenetic modification, specifically H3K27ac, acts as a molecular switch for the activation of robust cardiotoxicity-related genes, leading to cardiomyocyte death and cardiac dysfunction. These findings provide new insights into the relationship between Dox-induced cardiotoxicity and epigenetic regulation, and identify H3K27ac as a potential target for the prevention and treatment of Dox-induced cardiotoxicity.

Compression tests of the Cu-1.5Ti and Cu-1.5Ti-0.5Fe alloys were carried out using the Gleeble-1500D hot deformation simulator. The deformation temperature was 750–900 °C and the strain rate was 0.1–0.003 s−1. The Cu-1.5Ti-0.5Fe alloy clearly shows higher rheological stress and displays dynamic recovery and dynamic recrystallization characteristics under the same deformation conditions. The constitutive equations of the alloys were established. The activation energy of the Cu-1.5Ti alloy was 341.76 kJ/mol, which increased to 378.03 kJ/mol with the addition of 0.5 wt% Fe. After 750 °C and 0.003 s−1 deformation the Cu4Ti phase precipitated in Cu-1.5Ti alloy. Adding 0.5 wt% Fe caused dynamic recrystallization during hot deformation. The hot-deformed Cu-1.5Ti-0.5Fe alloy had more dislocations and finer grains with Cu4Ti and Fe2Ti precipitated phases.

In this study, Al2O3–Cu/35Mo composites were prepared by rapid hot-press sintering-internal oxidation method, and the materials were modified by adding trace amounts of graphene oxide (GO). The results show that the relative densities of the composites are above 99%, the γ-Al2O3 generated by internal oxidation is diffusely distributed on the copper matrix. The incorporation of GO produced a small number of hard MoC particles at the interface, which facilitated the interfacial bonding of the composites. In the 30 V DC, 10–30 A electrical contact test, the anode mass of the composites increases, while the cathode mass decreases. And GO reduces the total mass loss of the electric contact by 63.6%, 38.9%, 51.3% and 20.9%, respectively. A comparison of the electrical contact properties of the two materials showed that the addition of GO dispersed the concentrated erosion of the arc. At 10 A and 30 A, the arc energy is reduced by 75.5% and 12.5%, respectively. With the gradual increase in electric current, GO makes the Al2O3–Cu/35Mo composites more stable during the electric contact process, improves the anti-welding ability of the contact and reduces contact resistance.

Pecan Street’s field-metered data offer an opportunity to track actual appliance usage patterns and energy consumption over multiple years, and can supplement data from the US Energy Information Administration’s Residential Energy Consumption Survey (RECS). This report is based on dishwasher metering data collected from more than 500 households located in Texas, California, New York, and Colorado from 2012 to 2021. The historical dishwasher usage frequency, the COVID-19 period usage change, and the potential seasonal trend in usage were investigated. Dishwasher cycle features such as cycle duration, quick cycle usage frequency, and average per cycle dishwasher energy consumption were observed and characterized. Due to the sample size, the lack of demographic data, and the limited geographic locations of the participating households, the results are not nationally representative. However, when compared with the usage frequency reported by RECS, the field-obtained average annual cycle counts per household are 164 in 2015 and 197 in 2020 for selected households which are consistent with the RECS annual cycle counts of 181 and 191 respectively in 2015 and 2020 for the same geographic locations. Our findings support the use of RECS data to approximate field dishwasher usage. The field data usage frequency for households with infrequent dishwasher use could supplement the RECS information to better characterize the national usage distribution of different cycle selections.

Water and energy are two critical natural resources necessary for human activities and socioeconomic development. Water and energy systems are highly interdependent, and water efficiency and energy efficiency are two related indicators for the United Nations' Sustainable Development Goals. It is critical to improve energy–water use efficiency to sustain socioeconomic development while reducing adverse effects on natural resources, society and the environment. By using longitudinal energy–water use data for China over the past 21 years, this paper develops a temporo-spatial study to address key issues and introduce analytical approaches needed to understand the water–energy nexus and support integrated resource planning and management to achieve the Sustainable Development Goals. Decomposition analysis indicates that the production effect was the dominating factor contributing the increase in the country's energy–water use, while energy–water efficiency is the major factor slowing the growth of the country's energy–water use. Changes and trends analyses show that the country's energy intensity, water intensity, and water/energy ratio significantly decreased from 1999 to 2019, but the rate of decline has slowed. The disparities of the country's provincial energy intensities, water intensities, and water/energy ratios significantly decreased with economic growth. Results suggest that improving energy–water efficiency is critical for the country to curb increasing energy and water use and achieve resource and environmental protection targets with rapid economic development. The disparities between regional energy-water efficiencies can be reduced along with economic growth, while an overheated economy can widen the disparities and result in unsustainable and inefficient utilization of resources. Government coordination, targets and policy as part of the efficiency governance system are critical for continuous energy–water efficiency improvement and directly influence the implementation and effectiveness of energy–water efficiency policy.