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- 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. |
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| 3. |
- Alexander, John H., et al.
(författare)
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Apixaban with Antiplatelet Therapy after Acute Coronary Syndrome
- 2011
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Ingår i: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 365:8, s. 699-708
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Tidskriftsartikel (refereegranskat)abstract
- Background: Apixaban, an oral, direct factor Xa inhibitor, may reduce the risk of recurrent ischemic events when added to antiplatelet therapy after an acute coronary syndrome.Methods: We conducted a randomized, double-blind, placebo-controlled clinical trial comparing apixaban, at a dose of 5 mg twice daily, with placebo, in addition to standard antiplatelet therapy, in patients with a recent acute coronary syndrome and at least two additional risk factors for recurrent ischemic events.Results: The trial was terminated prematurely after recruitment of 7392 patients because of an increase in major bleeding events with apixaban in the absence of a counterbalancing reduction in recurrent ischemic events. With a median follow-up of 241 days, the primary outcome of cardiovascular death, myocardial infarction, or ischemic stroke occurred in 279 of the 3705 patients (7.5%) assigned to apixaban (13.2 events per 100 patient-years) and in 293 of the 3687 patients (7.9%) assigned to placebo (14.0 events per 100 patient-years) (hazard ratio with apixaban, 0.95; 95% confidence interval [CI], 0.80 to 1.11; P = 0.51). The primary safety outcome of major bleeding according to the Thrombolysis in Myocardial Infarction (TIMI) definition occurred in 46 of the 3673 patients (1.3%) who received at least one dose of apixaban (2.4 events per 100 patient-years) and in 18 of the 3642 patients (0.5%) who received at least one dose of placebo (0.9 events per 100 patient-years) (hazard ratio with apixaban, 2.59; 95% CI, 1.50 to 4.46; P = 0.001). A greater number of intracranial and fatal bleeding events occurred with apixaban than with placebo.Conclusions: The addition of apixaban, at a dose of 5 mg twice daily, to antiplatelet therapy in high-risk patients after an acute coronary syndrome increased the number of major bleeding events without a significant reduction in recurrent ischemic events.
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| 4. |
- Yanlun, Zhu, et al.
(författare)
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An injectable continuous stratified structurally and functionally biomimetic construct for enhancing osteochondral regeneration
- 2019
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Ingår i: Biomaterials. - : Elsevier. - 0142-9612 .- 1878-5905. ; 192, s. 149-158
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Tidskriftsartikel (refereegranskat)abstract
- Osteochondral regeneration with the formation of hyaline cartilage and subchondral bone as well as the integration between the newly formed tissues with the host tissue still remains a great challenge. In this study, a construct containing an injectable continuous stratified scaffold and multiple cell systems was designed for enhancing osteochondral regeneration. Briefly, an injectable sodium alginate(SA)/bioglass (BG) composite hydrogel containing bone marrow stem cells (BMSCs) (SA/BG + BMSCs) was used for subchondral bone regeneration and an injectable thermosensitive SA/agarose (AG) composite hydrogel with co-culture of BMSCs and articular chondrocytes (ACs) (SA/AG + ACs/BMSCs) was applied for articular cartilage regeneration. The continuous SA phase and the stratified structure enable the scaffold to mimic the natural osteochondral structure. In addition, the SA/BG + BMSCs hydrogel could enhance the osteoblast differentiation of BMSCs by upregulating their alkaline phosphatase and collagen I gene expressions, and the SA/AG + ACs/BMSCs hydrogel could promote the chondrocyte differentiation of BMSCs by upregulating their Acan and collagen II gene expressions, which indicated that this stratified scaffold could mimic the natural osteochondral function. Furthermore, after the stratified construct was injected into a rat osteochondral defect model, obvious neonatal articular cartilage tissues and subchondral bone tissues with regular surface and highly integration with normal tissues could be observed. This structural and functional biomimetic construct, together with its proper swelling ratio, could not only stimulate the hyaline cartilage and subchondral bone regeneration in an entire osteochondral unit but also promote the integration between the newly formed tissues and the host tissue.
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