| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- Ning, Yuping, et al.
(författare)
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Optical simulation and preparation of novel Mo/ZrSiN/ZrSiON/SiO2 solar selective absorbing coating
- 2017
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Ingår i: Solar Energy Materials and Solar Cells. - : Elsevier BV. - 0927-0248 .- 1879-3398. ; 167, s. 178-183
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Tidskriftsartikel (refereegranskat)abstract
- A novel Mo/ZrSiN/ZrSiON/SiO2 solar selective absorbing coating has been investigated, which was prepared by magnetron sputtering on stainless steel substrate. A high solar absorptance of 0.94 and a low thermal emittance of 0.06 at 25 degrees C were achieved. By proportionally decreasing the thicknesses of the ZrSiN, ZrSiON and SiO2 layers, the thermal emittance at 500 degrees C was decreased significantly from 0.19 to 0.12 (Delta epsilon = 0.07) while keeping the solar absorptance unchanged. The coating also showed high thermal stability at 500 degrees C in vacuum, implying that it is a promising candidate for high temperature concentrated solar power (CSP) applications.
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| 3. |
- Jin, Xinyi, et al.
(författare)
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Association of accelerometer-measured sleep duration and different intensities of physical activity with incident type 2 diabetes in a population-based cohort study.
- 2023
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Ingår i: Journal of Sport and Health Science. - : Elsevier BV. - 2095-2546 .- 2213-2961.
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of the current study was to investigate the association of accelerometer-measured sleep duration and different intensities of physical activity (PA) with the risk of incident type 2 diabetes in a population-based prospective cohort study.METHODS: Altogether, 88,000 participants (mean age = 62.2 ± 7.9 years, mean ± SD) were included from the UK Biobank. Sleep duration (short: <6 h/day; normal: 6-8 h/day; long: >8 h/day) and PA of different intensities were measured using a wrist-worn accelerometer over a 7-day period between 2013 and 2015. PA was classified according to the median or World Health Organization-recommendation: total volume of PA (high, low), moderate-to-vigorous PA (MVPA) (recommended, not recommended), and light-intensity PA (high, low). Incidence of type 2 diabetes was ascertained using hospital records or death registries.RESULTS: During a median follow-up of 7.0 years, 1615 incident type 2 diabetes cases were documented. Compared with normal sleep duration, short (hazard ratio (HR) = 1.21, 95% confidence interval (95%CI): 1.03-1.41) but not long sleep duration (HR = 1.01, 95%CI: 0.89-1.15) was associated with excessive type 2 diabetes risk. This increased risk among short sleepers seems to be protected against by PA. Compared with normal sleepers with high or recommended PA, short sleepers with low volume of PA (HR = 1.81, 95%CI: 1.46-2.25), not recommended (below the World Health Organization-recommended level of) moderate-to-vigorous PA (HR = 1.92, 95%CI: 1.55-2.36), or low light-intensity PA (HR = 1.49, 95%CI: 1.13-1.90) had a higher risk of type 2 diabetes, while short sleepers with a high volume of PA (HR = 1.14, 95%CI: 0.88-1.49), recommended moderate-to-vigorous PA (HR = 1.02, 95%CI: 0.71-1.48), or high light-intensity PA (HR = 1.14, 95%CI: 0.92-1.41) did not.CONCLUSION: Accelerometer-measured short but not long sleep duration was associated with a higher risk of incident type 2 diabetes. A higher level of PA, regardless of intensity, potentially ameliorates this excessive risk.
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| 4. |
- Liu, Bokai, et al.
(författare)
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Multiscale modeling of thermal properties in Polyurethane incorporated with phase change materials composites : a case study
- 2023
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Ingår i: Healthy buildings Europe 2023. - Red Hook, NY : Curran Associates, Inc.. - 9781713877158 ; , s. 923-929
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Konferensbidrag (refereegranskat)abstract
- Polyurethane (PU) is an ideal thermal insulation material due to its excellent thermal properties. The incorporation of Phase Change Materials (PCMs) capsules into Polyurethane (PU) has been shown to be effective in building envelopes. This design can significantly increase the stability of the indoor thermal environment and reduce the fluctuation of indoor air temperature. We develop a multiscale model of a PU-PCM foam composite and study the thermal conductivity of this material. Later, the design of materials can be optimized by obtaining thermal conductivity. We conduct a case study based on the performance of this optimized material to fully consider the thermal comfort of the occupants of a building envelope with the application of PU-PCMs composites in a single room. At the same time, we also predict the energy consumption of this case. All the outcomes show that this design is promising, enabling the passive design of building energy and significantly improving occupants' comfort.
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| 5. |
- Xu, Yilin, et al.
(författare)
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Analysis of Thermal Stress in a Solid Oxide Fuel Cell Due to the Sulfur Poisoning Interface of the Electrolyte and Cathode
- 2021
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Ingår i: Energy and Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 35:3, s. 2674-2682
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Tidskriftsartikel (refereegranskat)abstract
- The interface of an electrolyte and cathode strongly determines the oxygen reduction reaction and cell stability, but it is susceptible to sulfur impurities like SO2 in air. In this study, a 3D solid oxide fuel cell model is developed based on experimental characterization to reveal sulfur-deactivating active cathodes. The results indicate that both the average values for electric and ionic current densities drastically decrease after sulfur poisoning; meanwhile, their distributions are also changed, suggesting that the involved oxygen reduction reaction is detrimentally affected. Moreover, the temperature decreases after poisoning due to electrochemical reaction slowdown near the interface of the active cathode and electrolyte. The pronounced temperature changes together with differences in the thermal expansion coefficient of neighboring components, further resulting in uneven stress distributions at the active cathode, possibly bringing out cracks and bending. Thermal stresses are reduced after sulfur poisoning, especially for the third principal stress, which produces a decrement of 154 MPa. The visualized results of the current density, temperature, and stresses are helpful to understand the sulfur poisoning behavior and also to better understand the internal changes of some crucial electrochemical processes beneficial for further optimization of the microstructural stability.
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| 6. |
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| 7. |
- Zhang, Liangliang, et al.
(författare)
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Complete Range of the Universal mtDNA Gene Pool and High Genetic Diversity in the Thai Dog Population
- 2020
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Ingår i: Genes. - : MDPI. - 2073-4425. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- The dog population of Southern East Asia is unique in harboring virtually the full range of the universal mtDNA gene pool, and consequently, it has the highest genetic diversity worldwide. Despite this, limited research has been performed on dog genetics within this region. Here we present the first comprehensive study of a sub-region within Southern East Asia, analyzing 528 bp of mtDNA for 265 dogs from Thailand, in the context of dogs from across the Old World. We found that Thailand was the only region in the world that has the full range of the universal mtDNA gene pool, that is, all 10 sub-haplogroups. Consequently, the statistics for diversity are among the highest, especially in North Thailand, which had high values for haplotype diversity and the number of haplotypes, and the lowest proportion of individuals with a universal type-derived haplotype (UTd) among all regions. As previously observed, genetic diversity is distinctly lower outside Southern East Asia and it decreases following a cline to the lowest values in western Eurasia. Thus, the limited geographical region of Thailand harbors a distinctly higher genetic diversity than much larger regions in western Eurasia, for example, Southwest Asia and Europe which have only five and four of the 10 sub-haplogroups, respectively. Within Thailand, diversity statistics for all four sub-regions follow the general pattern of Southern East Asia, but North Thailand stands out with its high diversity compared to the other regions. These results show that a small part of Southern East Asia harbors the full range of the mtDNA gene pool, and they emphasize the exceptional genetic status of Southern East Asia. This indicates that today's dogs can trace a major part of their ancestry to Southern East Asia or closely situated regions, highlighting Thailand as a region of special interest. Considering the large genetic diversity found in Thailand and that many neighboring regions, e.g., Myanmar and Laos, have not been studied for dog genetics, it is possible that large parts of the dog gene pool remain undiscovered. It will be an important task for future studies to fill in these blanks on the phylogeographic map.
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| 8. |
- Zhang, Liangchen, et al.
(författare)
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Noncovalent Bile Acid Oligomers as Facial Amphiphilic Antimicrobials
- 2023
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 39:1, s. 495-506
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Tidskriftsartikel (refereegranskat)abstract
- New antimicrobial agents are needed to address the ever-growing risk of bacterial resistance, particularly for methicillin- and vancomycin-resistant Staphylococcus aureus (S. aureus). Here, we report a class of bile acid oligomers as facial amphiphilic antimicrobials, which are noncovalently fabricated by cholic acid (CA) and deoxycholic acid (DCA) with polyamines (e.g., diamines, diethylenetriamine, spermidine, and spermine). The antibacterial activities of these bile acid oligomers (CA/polyamines and DCA/polyamines) against S. aureus become stronger with increasing the amine group numbers of polyamines without obviously enhanced cytotoxicity and skin irritation. DCA/spermine, entirely composed of natural products, exhibits the best antibacterial activity but the lowest cytotoxicity and the weakest skin irritation. All CA/polyamines and DCA/polyamines form well-ordered ribbon-like aggregates, collecting numerous facial amphiphilic structures to significantly enhance the interactions with bacterial membranes. In particular, the biogenic polyamines with more than two amine groups provide extra positively charged sites, hence facilitating the binding of bile acid oligomers to the negatively charged outer membrane of the bacteria via electrostatic interaction. This in turn promotes more oligomeric bile acid units that can be inserted into the membrane through hydrophobic interaction between bile acids and lipid domains. The noncovalently constructed and separable amphiphilic antimicrobials can avoid the long-term coexistence of microorganisms and antibacterial molecules in different acting modes. Therefore, the noncovalent bile acid oligomers, especially those with higher oligomerization degrees, can be a potential approach to effectively enhance antibacterial activity, improve environmental friendliness, and reduce bacterial drug resistance.
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| 9. |
- Zhang, Yun, et al.
(författare)
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Reference-based cell type matching of in situ image-based spatial transcriptomics data on primary visual cortex of mouse brain
- 2023
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Ingår i: Scientific Reports. - 2045-2322. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- With the advent of multiplex fluorescence in situ hybridization (FISH) and in situ RNA sequencing technologies, spatial transcriptomics analysis is advancing rapidly, providing spatial location and gene expression information about cells in tissue sections at single cell resolution. Cell type classification of these spatially-resolved cells can be inferred by matching the spatial transcriptomics data to reference atlases derived from single cell RNA-sequencing (scRNA-seq) in which cell types are defined by differences in their gene expression profiles. However, robust cell type matching of the spatially-resolved cells to reference scRNA-seq atlases is challenging due to the intrinsic differences in resolution between the spatial and scRNA-seq data. In this study, we systematically evaluated six computational algorithms for cell type matching across four image-based spatial transcriptomics experimental protocols (MERFISH, smFISH, BaristaSeq, and ExSeq) conducted on the same mouse primary visual cortex (VISp) brain region. We find that many cells are assigned as the same type by multiple cell type matching algorithms and are present in spatial patterns previously reported from scRNA-seq studies in VISp. Furthermore, by combining the results of individual matching strategies into consensus cell type assignments, we see even greater alignment with biological expectations. We present two ensemble meta-analysis strategies used in this study and share the consensus cell type matching results in the Cytosplore Viewer (https://viewer.cytosplore.org) for interactive visualization and data exploration. The consensus matching can also guide spatial data analysis using SSAM, allowing segmentation-free cell type assignment.
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| 10. |
- Zhao, Qian, et al.
(författare)
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A flexible ammonia sensor based on MXene membrane with high sensitivity
- 2024
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Ingår i: Electroanalysis. - : WILEY-V C H VERLAG GMBH. - 1040-0397 .- 1521-4109.
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Tidskriftsartikel (refereegranskat)abstract
- Ammonia (NH3) of high concentration will pose a threat to ecological environment or human health, and exhaled NH3 is significant in disease monitoring and diagnosis. Thus, developing a highly sensitive gas sensor is significant to monitor NH3 concentration in complex environments. However, traditional NH3 sensors either need high working temperature, or face the challenge of poor conductivity/ sensitivity. In this work, NH3 sensors based on self-assembled MXene membrane have been fabricated. As-prepared sensors show a high sensitivity of 2.10 ppm-1 towards extremely low concentrations of NH3 (ppb level) at room temperature, attributed to large surface area and high conductivity. In addition, the sensors also display low detection limit (50 ppb), fast response time (41 s), good recoverability, long-term stability (15 days) and excellent flexibility (1000 bending cycles) towards NH3. The results provide insights into the development of highly sensitive NH3 sensors for industrial or biomedical applications. image
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