| 1. |
- Beal, Jacob, et al.
(författare)
-
Robust estimation of bacterial cell count from optical density
- 2020
-
Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
-
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.
|
|
| 2. |
- Li, Wei, et al.
(författare)
-
Non-lab and semi-lab algorithms for screening undiagnosed diabetes : A cross-sectional study
- 2018
-
Ingår i: EBioMedicine. - : ELSEVIER SCIENCE BV. - 2352-3964. ; 35, s. 307-316
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The terrifying undiagnosed rate and high prevalence of diabetes have become a public emergency. A high efficiency and cost-effective early recognition method is urgently needed. We aimed to generate innovative, user-friendly nomograms that can be applied for diabetes screening in different ethnic groups in China using the non-lab or noninvasive semi-lab data. Methods: This multicenter, multi-ethnic, population-based, cross-sectional study was conducted in eight sites in China by enrolling subjects aged 20-70. Sociodemographic and anthropometric characteristics were collected. Blood and urine samples were obtained 2 h following a standard 75 g glucose solution. In the final analysis, 10,794 participants were included and randomized into model development (n - 8096) and model validation (n = 2698) group with a ratio of 3:1. Nomograms were developed by the stepwise binary logistic regression. The nomograms were validated internally by a bootstrap sampling method in the model development set and externally in the model validation set. The area under the receiver operating characteristic curve (AUC) was used to assess the screening performance of the nomograms. Decision curve analysis was applied to calculate the net benefit of the screening model. Results: The overall prevalence of undiagnosed diabetes was 9.8% (1059/10794) according to ADA criteria. The non-lab model revealed that gender, age, body mass index, waist circumference, hypertension, ethnicities, vegetable daily consumption and family history of diabetes were independent risk factors for diabetes. By adding 2 h post meal glycosuria qualitative to the non-lab model, the semi-lab model showed an improved Akaike information criterion (AIC: 4506 to 3580). The AUC of the semi-lab model was statistically larger than the non-lab model (0.868 vs 0.763, P < 0.001). The optimal cutoff probability in semi-lab and non-lab nomograms were 0.088 and 0.098, respectively. The sensitivity and specificity were 76.3% and 81.6%, respectively in semi-lab nomogram, and 72.1% and 673% in non-lab nomogram at the optimal cut off point. The decision curve analysis also revealed a bigger decrease of avoidable OGTT test (52 per 100 subjects) in the semi-lab model compared to the non-lab model (36 per 100 subjects) and the existed New Chinese Diabetes Risk Score (NCDRS, 35 per 100 subjects). Conclusion: The non-lab and semi-lab nomograms appear to be reliable tools for diabetes screening, especially in developing countries. However, the semi-lab model outperformed the non-lab model and NCDRS prediction systems and might be worth being adopted as decision support in diabetes screening in China.
|
|
| 3. |
- Albacete, Javier L., et al.
(författare)
-
Predictions for p + Pb Collisions at sN N = √5 TeV : Comparison with Data
- 2016
-
Ingår i: International Journal of Modern Physics E. - 0218-3013. ; 25:9
-
Forskningsöversikt (refereegranskat)abstract
- Predictions made in Albacete et al. [Int. J. Mod. Phys. E 22 (2013) 1330007] prior to the LHC p+Pb run at sNN = 5 TeV are compared to currently available data. Some predictions shown here have been updated by including the same experimental cuts as the data. Some additional predictions are also presented, especially for quarkonia, that were provided to the experiments before the data were made public but were too late for the original publication.
|
|
| 4. |
- Santangelo, James S., et al.
(författare)
-
Global urban environmental change drives adaptation in white clover
- 2022
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 375
-
Tidskriftsartikel (refereegranskat)abstract
- Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural dines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale.
|
|
| 5. |
- Sun, Xu, et al.
(författare)
-
Chinese Herbal Medicine as Adjunctive Therapy to Chemotherapy for Breast Cancer : A Systematic Review and Meta-Analysis
- 2016
-
Ingår i: Evidence-based Complementary and Alternative Medicine. - : Hindawi Limited. - 1741-427X .- 1741-4288.
-
Forskningsöversikt (refereegranskat)abstract
- Chinese herbal medicine (CHM) has been increasingly employed during therapy for breast cancer, but its efficacy remains a matter of debate. This systematic review examined randomized controlled trials to provide a critical evaluation of this treatment. The results demonstrated that the combined use of CHM with chemotherapy may improve the immediate tumor response and reduce chemotherapy-associated adverse events. Our findings highlight the poor quality of Chinese studies, and additional well-designed randomized controlled trials addressing the role of CHM are warranted. The lack of molecular-based evidence for CHM and Zheng has resulted in a limited understanding and acceptance of CHM and traditional Chinese medicine in Western countries. We believe that researchers should immediately explore a CHM-based cure, and CHM should be applied to routine care as soon as conclusive data are available.
|
|
| 6. |
- Tang, Ting-Ting, et al.
(författare)
-
Impaired thymic export and apoptosis contribute to regulatory T-cell defects in patients with chronic heart failure.
- 2011
-
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203 .- 1932-6203. ; 6:9, s. e24272-
-
Tidskriftsartikel (refereegranskat)abstract
- Animal studies suggest that regulatory T (T(reg)) cells play a beneficial role in ventricular remodeling and our previous data have demonstrated defects of T(reg) cells in patients with chronic heart failure (CHF). However, the mechanisms behind T(reg-)cell defects remained unknown. We here sought to elucidate the mechanism of T(reg-)cell defects in CHF patients.
|
|
| 7. |
- Chatzakis, Ioannis, et al.
(författare)
-
One- and two-dimensional photo-imprinted diffraction gratings for manipulating terahertz waves
- 2013
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 103:4, s. 043101-
-
Tidskriftsartikel (refereegranskat)abstract
- Emerging technology based on artificial materials containing metallic structures has raised the prospect for unprecedented control of terahertz waves. The functionality of these devices is static by the very nature of their metallic composition, although some degree of tunability can be achieved by incorporating electrically biased semiconductors. Here, we demonstrate a photonic structure by projecting the optical image of a metal mask onto a thin GaAs substrate using a femtosecond pulsed laser source. We show that the resulting high-contrast pattern of photo-excited carriers can create diffractive elements operating in transmission, potentially providing a route to terahertz components with reconfigurable functionality.
|
|
| 8. |
- Chen, Wei, et al.
(författare)
-
Colloidal PbS quantum dot stacking kinetics during deposition via printing
- 2020
-
Ingår i: Nanoscale Horizons. - : Royal Society of Chemistry (RSC). - 2055-6764 .- 2055-6756. ; 5:5, s. 880-885
-
Tidskriftsartikel (refereegranskat)abstract
- Colloidal PbS quantum dots (QDs) are attractive for solution-processed thin-film optoelectronic applications. In particular, directly achieving QD thin-films by printing is a very promising method for low-cost and large-scale fabrication. The kinetics of QD particles during the deposition process play an important role in the QD film quality and their respective optoelectronic performance. In this work, the particle self-organization behavior of small-sized QDs with an average diameter of 2.88 +/- 0.36 nm is investigated for the first time in situ during printing by grazing-incidence small-angle X-ray scattering (GISAXS). The time-dependent changes in peak intensities suggest that the structure formation and phase transition of QD films happen within 30 seconds. The stacking of QDs is initialized by a templating effect, and a face-centered cubic (FCC) film forms in which a superlattice distortion is also found. A body-centered cubic nested FCC stacking is the final QD assembly layout. The small size of the inorganic QDs and the ligand collapse during the solvent evaporation can well explain this stacking behavior. These results provide important fundamental understanding of structure formation of small-sized QD based films prepared via large-scale deposition with printing with a slot die coater.
|
|
| 9. |
- Chen, Wei, et al.
(författare)
-
In situ Grazing-Incidence Small-Angle X-ray Scattering Observation of Gold Sputter Deposition on a PbS Quantum Dot Solid
- 2020
-
Ingår i: ACS Applied Materials and Interfaces. - : NLM (Medline). - 1944-8244 .- 1944-8252. ; 12:41, s. 46942-46952
-
Tidskriftsartikel (refereegranskat)abstract
- For PbS quantum dot (QD)-based optoelectronic devices, gold is the most frequently used electrode material. In most device architectures, gold is in direct contact with the QD solid. To better understand the formation of the interface between gold and a close-packed QD layer at an early stage, in situ grazing-incidence small-angle X-ray scattering is used to observe the gold sputter deposition on a 1,2-ethanedithiol (EDT)-treated PbS QD solid. In the kinetics of gold layer growth, the forming and merging of small gold clusters (radius less than 1.6 nm) are observed at the early stages. The thereby formed medium gold clusters (radius between 1.9-2.4 nm) are influenced by the QDs' templating effect. Furthermore, simulations suggest that the medium gold clusters grow preferably along the QDs' boundaries rather than as a top coating of the QDs. When the thickness of the sputtered gold layer reaches 6.25 nm, larger gold clusters with a radius of 5.3 nm form. Simultaneously, a percolation layer with a thickness of 2.5 nm is established underneath the gold clusters. This fundamental understanding of the QD-gold interface formation will help to control the implementation of sputtered gold electrodes on close-packed QD solids in device manufacturing processes.
|
|
| 10. |
- Cheng, Hao-Wen, et al.
(författare)
-
Realizing Efficient Charge/Energy Transfer and Charge Extraction in Fullerene-Free Organic Photovoltaics via a Versatile Third Component
- 2019
-
Ingår i: Nano letters (Print). - : AMER CHEMICAL SOC. - 1530-6984 .- 1530-6992. ; 19:8, s. 5053-5061
-
Tidskriftsartikel (refereegranskat)abstract
- Solution-processed organic photovoltaics (OPVs) based on bulk-heterojunctions have gained significant attention to alleviate the increasing demend of fossil fuel in the past two decades. OPVs combined of a wide bandgap polymer donor and a narrow bandgap nonfullerene acceptor show potential to achieve high performance. However, there are still two reasons to limit the OPVs performance. One, although this combination can expand from the ultraviolet to the near-infrared region, the overall external quantum efficiency of the device suffers low values. The other one is the low open-circuit voltage (V-OC) of devices resulting from the relatively downshifted lowest unoccupied molecular orbital (LUMO) of the narrow bandgap. Herein, the approach to select and incorporate a versatile third component into the active layer is reported. A third component with a bandgap larger than that of the acceptor, and absorption spectra and LUMO levels lying within that of the donor and acceptor, is demonstrated to be effective to conquer these issues. As a result, the power conversion efficiencies (PCEs) are enhanced by the elevated short-circuit current and V-OC; the champion PCEs are 11.1% and 13.1% for PTB7-Th:IEICO-4F based and PBDB-T:Y1 based solar cells, respectively.
|
|
| 11. |
- Guo, Renjun, et al.
(författare)
-
Degradation mechanisms of perovskite solar cells under vacuum and one atmosphere of nitrogen
- 2021
-
Ingår i: Nature Energy. - : Springer Nature. - 2058-7546. ; 6:10, s. 977-
-
Tidskriftsartikel (refereegranskat)abstract
- Extensive studies have focused on improving the operational stability of perovskite solar cells, but few have surveyed the fundamental degradation mechanisms. One aspect overlooked in earlier works is the effect of the atmosphere on device performance during operation. Here we investigate the degradation mechanisms of perovskite solar cells operated under vacuum and under a nitrogen atmosphere using synchrotron radiation-based operando grazing-incidence X-ray scattering methods. Unlike the observations described in previous reports, we find that light-induced phase segregation, lattice shrinkage and morphology deformation occur under vacuum. Under nitrogen, only lattice shrinkage appears during the operation of solar cells, resulting in better device stability. The different behaviour under nitrogen is attributed to a larger energy barrier for lattice distortion and phase segregation. Finally, we find that the migration of excessive PbI2 to the interface between the perovskite and the hole transport layer degrades the performance of devices under vacuum or under nitrogen. Understanding degradation mechanisms in perovskite solar cells is key to their development. Now, Guo et al. show a greater degradation of the perovskite structure and morphology for devices operated under vacuum than under nitrogen.
|
|
| 12. |
- Han, Jing, et al.
(författare)
-
Selenium deficiency and selenium supplements : biological effects on fibrosisin chronic diseases, from animal to human studies
- 2019
-
Ingår i: Handbook of famine, starvation, and nutrient deprivation. - Cham : Springer. - 9783319400075 - 9783319553863 - 9783319553870 - 9783319553887 ; , s. 1911-1930
-
Bokkapitel (refereegranskat)abstract
- Selenium is a trace element, which is required for normal growth and development of animals and humans. It works by incorporating into proteins to make selenoproteins. These selenoproteins help to prevent free radicals from causing cellular damage, which may in turn lead to the development of various chronic diseases. Selenium deficiency, although is rare, can happen when the body does not have enough selenium. This chapter will review systematically the effects of selenium deficiency on fibrosis in various chronic diseases, such as cardiac fibrosis, liver fibrosis, kidney fibrosis, cystic fibrosis, thyroid fibrosis, oral submucous fibrosis, and pancreatic fibrosis in both animal and human studies. Moreover, their prevention and treatment with selenium supplement will be evaluated as well.
|
|
| 13. |
- Li, Y., et al.
(författare)
-
A life cycle analysis techno-economic assessment framework for evaluating future technology pathways – The residential air-conditioning example
- 2021
-
Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 291
-
Tidskriftsartikel (refereegranskat)abstract
- Clarity on cost and environmental benefits of individual technologies evaluated in a systemic and systematic manner is necessary in communicating the results at the policy level so as to enable effective decisions. Yet, the highly complex nature of many energy modelling tools makes it difficult for non-specialists to interpret and make sense of their results. An integrated life cycle analysis and techno-economic assessment framework is proposed in this study, as a first step towards developing an alternative and potentially more intuitive energy systems modelling tool. The residential air-conditioning sector in the Southeast Asian context is used as an example to demonstrate the advantages of the modelling methodology in profiling future technology pathways. The use of best available R32 technology can lead to cumulative savings of 2195 million tonnes of greenhouse gas emissions in the region by 2050; while the best available R407C technology has an average cost of $40.85 per tonne of greenhouse gas abatement. In addition, our modelling tool is capable of profiling energy outlooks for emerging economies and will be further integrated with hourly energy analysis frameworks in the next steps of development.
|
|
| 14. |
- Liu, Shengchun, et al.
(författare)
-
Alternative positions of internal heat exchanger for CO2 booster refrigeration system : Thermodynamic analysis and annual thermal performance evaluation
- 2021
-
Ingår i: International journal of refrigeration. - : ELSEVIER SCI LTD. - 0140-7007 .- 1879-2081. ; 131, s. 1016-1028
-
Tidskriftsartikel (refereegranskat)abstract
- Refrigeration systems running on transcritical CO2 cycle are considered an alternative to phase-down the use of hydrofluorocarbons (HFCs) in response to the Kigali Amendment. Responding to the need to improve the efficiency of CO2 booster systems and to identify optimum system designs, thermodynamic models of three booster systems are proposed with the use of an internal heat exchanger (IHX). Findings from this study suggest that placing the IHX with a low-temperature fluid side at the suction line of high pressure stage compressor and high-temperature fluid side at the outlet of gas cooler represents the most optimal approach in improving the coefficient of performance (COP) of the booster system. When operating in the transcritical conditions, the COP values can be improved by 6.35% at the IHX thermal effectiveness of 0.8 and by 6.48% at the ratio of medium temperature load to low temperature load of 6. Using IHX can significantly reduce the compressor discharge pressure, which can be reduced by 0.55 MPa at the ambient temperature of 40 degrees C. Furthermore, by adding IHX, the annual performance factor of CO2 system can be improved significantly by 1.68% and the annual total power consumption can be decreased by 6.48% in the tropical climate. It can be concluded that IHX can improve the COP values of a booster system when operating in the subtropical and tropical regions.
|
|
| 15. |
- Sun, Xu, et al.
(författare)
-
Elevated heparanase expression is associated with poor prognosis in breast cancer : a study based on systematic review and TCGA data
- 2017
-
Ingår i: Oncotarget. - : IMPACT JOURNALS LLC. - 1949-2553. ; 8:26, s. 43521-43535
-
Forskningsöversikt (refereegranskat)abstract
- Heparanase promotes tumorigenesis, angiogenesis, and metastasis. Here, we conducted a study based on systematic review and the Cancer Genome Atlas (TCGA) data that examined heparanase expression in clinical samples to determine its prognostic value. According to the meta-analysis and TCGA data, we found that heparanase expression was up-regulated in most breast cancer specimens, and elevated heparanase expression was associated with increased lymph node metastasis, larger tumor size, higher histological grade, and poor survival. These results suggest that targeting heparanase might improve treatments for breast cancer patients.
|
|
| 16. |
- Wan, Liyang, et al.
(författare)
-
Molecular Degradation of Iron Phthalocyanine during the Oxygen Reduction Reaction in Acidic Media
- 2022
-
Ingår i: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 12:18, s. 11097-11107
-
Tidskriftsartikel (refereegranskat)abstract
- Molecular iron phthalocyanine (FePc) possesses an FeN4 active site structure similar to practical pyrolyzed Fe/N/C catalysts for the acidic oxygen reduction reaction (ORR), making it an ideal model system to derive the degradation mechanism of such catalysts. However, the degradation mechanism of FePc during the acidic ORR has been largely unclear to date. Herein, five most likely degradation factors affecting FePc-based ORR activity are individually investigated and compared. The attack by free radicals is found to be the main reason for the instability of FePc. Assisted by the combination of several spectroscopic methods, we successfully identify the degradation products and then propose a full structural evolution of molecular FePc degradation. Finally, high similarity in the decay mechanism between molecular FePc and practical Fe/N/C catalysts was present. This study provides a clear picture of the currently missing degradation mechanism of molecular FePc during acidic ORR, which will assist future investigations on the performance degradation of practical Fe/N/C catalysts.
|
|
| 17. |
- Wang, F., et al.
(författare)
-
Do ‘green’ data centres really have zero CO2 emissions?
- 2022
-
Ingår i: Sustainable Energy Technologies and Assessments. - : Elsevier Ltd. - 2213-1388 .- 2213-1396. ; 53
-
Tidskriftsartikel (refereegranskat)abstract
- The claim of a green data centre is generally made based on a net-zero CO2 emission through a ‘balance-sheet’ approach, which considers renewable electricity through on-site installation or purchase agreement as abatement measures against the use of fossil electricity from the electric grid on an annual basis. However, when the hourly dynamic fuel mix is accounted for in the assessment, the annual net-zero energy approach does not lead to a true carbon neutral data centre. In response, two approaches based on net-zero energy and net-zero CO2 emission respectively are proposed and investigated regarding the goal of net-zero CO2 emission. A data centre in Singapore with typical load profiles is used as a case study, different scenarios considering climate change and projected future energy are defined to examine the impacts of dynamic energy mix on the net CO2 emission of the data centre. The net-zero energy approach is found to result in significant amount of annual CO2 emissions. In comparison, the net-zero CO2 emission approach can assure a true net-zero CO2 emission, but this approach will require an increase of PV capacity by 20% and 60% as compared to the net-zero energy approach based on assessment for the year 2030 and 2050, respectively.
|
|
| 18. |
- Wang, L., et al.
(författare)
-
Impacts of electric vehicle deployment on the electricity sector in a highly urbanised environment
- 2021
-
Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 95
-
Tidskriftsartikel (refereegranskat)abstract
- The developments in electric vehicles (EVs) are driven by the need for cleaner and more efficient road transport, but vehicle charging poses significant challenges to the electric grid and electricity sector planning. These challenges are further amplified in the case of a highly urbanised and densely populated small island state, like Singapore, with limited space and options for electricity sector planning. In response, this study aims to evaluate the impacts of a large-scale EV deployment on the electricity sector from a whole-system perspective with focus on investments in the power sector for EV adoption, assuming minimum deployment of advanced “smart-grid” and “vehicle-to-grid” technologies. Findings suggest that a small-scale deployment of EVs below 20% replacement can be economically manageable. A large-scale of deployment of EVs would inevitably bring a notable impact to the electricity sector regardless the state of advanced technology development. From the perspective of integrated planning, cities, especially those with high vehicle density, should continue to exercise caution with EV deployment. A large-scale deployment should be pursued after a “stress-test” of the power system infrastructure from both the technical and economic perspectives.
|
|
| 19. |
- Wang, Y., et al.
(författare)
-
Life cycle analysis of integrated gasification combined cycle power generation in the context of Southeast Asia
- 2018
-
Ingår i: Energies. - : MDPI AG. - 1996-1073. ; 11:6
-
Tidskriftsartikel (refereegranskat)abstract
- Coal remains a major source of electricity production even under the current state of developments in climate policies due to national energy priorities. Coal remains the most attractive option, especially to the developing economies in Southeast Asia, due to its abundance and affordability in the region, despite the heavily polluting nature of this energy source. Gasification of coal running on an integration gasification combined cycle (IGCC) power generation with carbon capture and storage (CCS) represents an option to reduce the environmental impacts of power generation from coal, but the decarbonization potential and suitability of IGCC in the context of Southeast Asia remain unclear. Using Singapore as an example, this paper presents a study on the life cycle analysis (LCA) of IGCC power generation with and without CCS based on a generic process-driven analysis method. We further evaluate the suitability of IGCC with and without CCS as an option to address the energy and climate objectives for the developing economies in Southeast Asia. Findings suggest that the current IGCC technology is a much less attractive option in the context of Southeast Asia when compared to other available power generation technologies, such as solar photovoltaic systems, coal with CCS, and potentially nuclear power technologies.
|
|
