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. |
- Maurya, Naresh Chandra, et al.
(författare)
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Exciton many-body interactions and charge transfer in CsPbBr3/graphene derivatives
- 2023
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Ingår i: Physical Review B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 108:15
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Tidskriftsartikel (refereegranskat)abstract
- Charge separation and many-body interactions at the interface of the light-absorbing semiconductor and contact layer are of crucial importance to the photophysical properties and optoelectronic device performance. Here, we report the exciton many-body interactions and charge transfer dynamics at the interface of metal halide perovskite nanocrystals and graphene derivatives [graphene oxide (GO) and reduced GO (RGO)] using ultrafast transient absorption (TA) and time-resolved photoluminescence (PL) measurements. At the early timescales, the TA spectra of CsPbBr3/GO and CsPbBr3/RGO show an asymmetric derivative feature originating from the exciton many-body interactions. The band gap renormalization and binding energies of exciton and biexciton of CsPbBr3 nanocrystals are significantly reduced in CsPbBr3/GO(RGO) due to the charge transfer and change in the dielectric environment, respectively. More specifically, the exciton (biexciton) binding energy of CsPbBr3 nanocrystals, originally 38 +/- 2 (34 +/- 1) meV, decreases to 27 +/- 1 (22 +/- 1) meV in CsPbBr3/RGO and 17 +/- 1 (15 +/- 1) meV in CsPbBr3/GO. Furthermore, we observe a reduction in the Auger recombination rate and exciton PL quenching in CsPbBr3/GO and CsPbBr3/RGO, corroborating the charge transfer mechanism. Our systematic studies successfully describe photoexcited charge transfer from CsPbBr3 nanocrystals to GO (RGO) in 7.0 +/- 0.4 (4.2 +/- 0.1) ps, which is one order of magnitude faster than the charge transfer for other acceptor materials such as metal oxide, fullerene, anthraquinone, 1-aminopyrene, and phenothiazine. Our results offer insights and guidance for perovskite-based high-performance optoelectronic devices.
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3. |
- Kapur, P.K., et al.
(författare)
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Optimal price and warranty length
- 2012
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Ingår i: Communications in Dependability and Quality Management. - 1450-7196. ; 15:1, s. 5-13
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Tidskriftsartikel (refereegranskat)abstract
- With rapid advancement in technologies in the last few decades organizations today have shifted their focus from being product centric to customer/market driven. With post sales services like providing warranty playing an influential role in the purchase of new product, manufacturers today are leaning towards optimizing warranty length & price of their products in order to ensure profitability. In this paper treating optimal warranty length and price of goods as decision variables, we intend to maximize overall profit for producers under the influence of a combination of free replacement and pro-rata warranty policies. Two-dimensional innovation diffusion model incorporating both price and warranty length is employed to demonstrate product sales cycle. Exponential distribution is used to represent the lifetime of a product. To elucidate application of the model real data set is presented as illustration.
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4. |
- Meilia, P.D.I., et al.
(författare)
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The PERFORM-P (Principles of Evidence-based Reporting in FORensic Medicine-Pathology version)
- 2021
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Ingår i: Forensic Science International. - : Elsevier. - 0379-0738 .- 1872-6283. ; 327
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Most findings of forensic pathology examinations are presented as written reports. There are currently no internationally accepted recommendations for writing forensic pathology reports. Existing recommendations are also varied and reflect the differences in the scope and role of forensic medical services and local settings in which they are to be implemented. The legal fact-finder thus faces wide variation in the quality of forensic pathology reports, which poses a threat to the reliability of legal decision-making. To address this issue, the development of the “PERFORM-P (Principles of Evidence-based Reporting in FORensic Medicine-Pathology version)” was undertaken. The goal of the PERFORM-P is to provide common practice recommendations adaptable to local requirements to promote evidence-based practice (EBP) in forensic pathology. Methods: An international consensus study was conducted in three phases by (1) developing a long-list of items to be considered in the reporting recommendations, (2) conducting a Delphi process (an iterative survey method to transform individual opinions into group consensus) with international forensic pathologists, and (3) designing the PERFORM-P prototype and its accompanying manual. Results: With assistance from 106 forensic pathologists/forensic medical practitioners from 41 countries, the PERFORM-P was developed. The PERFORM-P consists of a list of 61 items to be included in a forensic pathology report, which is accompanied by its Explanation and Elaboration (E&E) document. Discussion: To prepare forensic pathology (postmortem) reports that incorporate principles of evidence-based practice, internationally accepted recommendations might be helpful. The PERFORM-P identifies recommendations for necessary elements to include in a forensic pathology report. PERFORM-P can be applied to a wide range of matters requiring forensic pathological analysis, acceptable to forensic pathologists from a representative selection of jurisdictions and medico-legal systems.
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5. |
- Mortensen, Svend A, et al.
(författare)
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The effect of coenzyme Q10 on morbidity and mortality in chronic heart failure: results from Q-SYMBIO : a randomized double-blind trial.
- 2014
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Ingår i: JACC. Heart failure. - : Elsevier BV. - 2213-1787 .- 2213-1779. ; 2:6, s. 641-649
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: This randomized controlled multicenter trial evaluated coenzyme Q10 (CoQ10) as adjunctive treatment in chronic heart failure (HF).BACKGROUND: CoQ10 is an essential cofactor for energy production and is also a powerful antioxidant. A low level of myocardial CoQ10 is related to the severity of HF. Previous randomized controlled trials of CoQ10 in HF were underpowered to address major clinical endpoints.METHODS: Patients with moderate to severe HF were randomly assigned in a 2-year prospective trial to either CoQ10 100 mg 3 times daily or placebo, in addition to standard therapy. The primary short-term endpoints at 16 weeks were changes in New York Heart Association (NYHA) functional classification, 6-min walk test, and levels of N-terminal pro-B type natriuretic peptide. The primary long-term endpoint at 2 years was composite major adverse cardiovascular events as determined by a time to first event analysis.RESULTS: A total of 420 patients were enrolled. There were no significant changes in short-term endpoints. The primary long-term endpoint was reached by 15% of the patients in the CoQ10 group versus 26% in the placebo group (hazard ratio: 0.50; 95% confidence interval: 0.32 to 0.80; p = 0.003) by intention-to-treat analysis. The following secondary endpoints were significantly lower in the CoQ10 group compared with the placebo group: cardiovascular mortality (9% vs. 16%, p = 0.026), all-cause mortality (10% vs. 18%, p = 0.018), and incidence of hospital stays for HF (p = 0.033). In addition, a significant improvement of NYHA class was found in the CoQ10 group after 2 years (p = 0.028).CONCLUSIONS: Long-term CoQ10 treatment of patients with chronic HF is safe, improves symptoms, and reduces major adverse cardiovascular events. (Coenzyme Q10 as adjunctive treatment of chronic heart failure: a randomised, double-blind, multicentre trial with focus on SYMptoms, BIomarker status [Brain-Natriuretic Peptide (BNP)], and long-term Outcome [hospitalisations/mortality]; ISRCTN94506234).
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