| 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. |
- You, Xiaohu, et al.
(författare)
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Towards 6G wireless communication networks: vision, enabling technologies, and new paradigm shifts
- 2021
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Ingår i: Science China Information Sciences. - : Science Press. - 1674-733X .- 1869-1919. ; 64:1
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Forskningsöversikt (refereegranskat)abstract
- The fifth generation (5G) wireless communication networks are being deployed worldwide from 2020 and more capabilities are in the process of being standardized, such as mass connectivity, ultra-reliability, and guaranteed low latency. However, 5G will not meet all requirements of the future in 2030 and beyond, and sixth generation (6G) wireless communication networks are expected to provide global coverage, enhanced spectral/energy/cost efficiency, better intelligence level and security, etc. To meet these requirements, 6G networks will rely on new enabling technologies, i.e., air interface and transmission technologies and novel network architecture, such as waveform design, multiple access, channel coding schemes, multi-antenna technologies, network slicing, cell-free architecture, and cloud/fog/edge computing. Our vision on 6G is that it will have four new paradigm shifts. First, to satisfy the requirement of global coverage, 6G will not be limited to terrestrial communication networks, which will need to be complemented with non-terrestrial networks such as satellite and unmanned aerial vehicle (UAV) communication networks, thus achieving a space-air-ground-sea integrated communication network. Second, all spectra will be fully explored to further increase data rates and connection density, including the sub-6 GHz, millimeter wave (mmWave), terahertz (THz), and optical frequency bands. Third, facing the big datasets generated by the use of extremely heterogeneous networks, diverse communication scenarios, large numbers of antennas, wide bandwidths, and new service requirements, 6G networks will enable a new range of smart applications with the aid of artificial intelligence (AI) and big data technologies. Fourth, network security will have to be strengthened when developing 6G networks. This article provides a comprehensive survey of recent advances and future trends in these four aspects. Clearly, 6G with additional technical requirements beyond those of 5G will enable faster and further communications to the extent that the boundary between physical and cyber worlds disappears.
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| 3. |
- Liu, Claire, et al.
(författare)
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Multifunctional Materials Strategies for Enhanced Safety of Wireless, Skin-Interfaced Bioelectronic Devices
- 2023
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 33:34
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Tidskriftsartikel (refereegranskat)abstract
- Many recently developed classes of wireless, skin-interfaced bioelectronic devices rely on conventional thermoset silicone elastomer materials, such as poly(dimethylsiloxane) (PDMS), as soft encapsulating structures around collections of electronic components, radio frequency antennas and, commonly, rechargeable batteries. In optimized layouts and device designs, these materials provide attractive features, most prominently in their gentle, noninvasive interfaces to the skin even at regions of high curvature and large natural deformations. Past studies, however, overlook opportunities for developing variants of these materials for multimodal means to enhance the safety of the devices against failure modes that range from mechanical damage to thermal runaway. This study presents a self-healing PDMS dynamic covalent matrix embedded with chemistries that provide thermochromism, mechanochromism, strain-adaptive stiffening, and thermal insulation, as a collection of attributes relevant to safety. Demonstrations of this materials system and associated encapsulation strategy involve a wireless, skin-interfaced device that captures mechanoacoustic signatures of health status. The concepts introduced here can apply immediately to many other related bioelectronic devices.
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| 4. |
- Xu, An, et al.
(författare)
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Rewired m6A epitranscriptomic networks link mutant p53 to neoplastic transformation
- 2023
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- N6-methyladenosine (m6A), one of the most prevalent mRNA modifications in eukaryotes, plays a critical role in modulating both biological and pathological processes. However, it is unknown whether mutant p53 neomorphic oncogenic functions exploit dysregulation of m6A epitranscriptomic networks. Here, we investigate Li-Fraumeni syndrome (LFS)-associated neoplastic transformation driven by mutant p53 in iPSC-derived astrocytes, the cell-of-origin of gliomas. We find that mutant p53 but not wild-type (WT) p53 physically interacts with SVIL to recruit the H3K4me3 methyltransferase MLL1 to activate the expression of m6A reader YTHDF2, culminating in an oncogenic phenotype. Aberrant YTHDF2 upregulation markedly hampers expression of multiple m6A-marked tumor-suppressing transcripts, including CDKN2B and SPOCK2, and induces oncogenic reprogramming. Mutant p53 neoplastic behaviors are significantly impaired by genetic depletion of YTHDF2 or by pharmacological inhibition using MLL1 complex inhibitors. Our study reveals how mutant p53 hijacks epigenetic and epitranscriptomic machinery to initiate gliomagenesis and suggests potential treatment strategies for LFS gliomas.
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| 5. |
- Abbasi, Rasha, et al.
(författare)
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IceCube search for neutrinos from GRB 221009A
- 2023
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Ingår i: Proceedings of 38th International Cosmic Ray Conference (ICRC 2023). - : Sissa Medialab Srl.
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Konferensbidrag (refereegranskat)abstract
- GRB 221009A is the brightest Gamma Ray Burst (GRB) ever observed. The observed extremelyhigh flux of high and very-high-energy photons provide a unique opportunity to probe the predictedneutrino counterpart to the electromagnetic emission. We have used a variety of methods to searchfor neutrinos in coincidence with the GRB over several time windows during the precursor, promptand afterglow phases of the GRB. MeV scale neutrinos are studied using photo-multiplier ratescalers which are normally used to search for galactic core-collapse supernovae neutrinos. GeVneutrinos are searched starting with DeepCore triggers. These events don’t have directionallocalization, but instead can indicate an excess in the rate of events. 10 GeV - 1 TeV and >TeVneutrinos are searched using traditional neutrino point source methods which take into accountthe direction and time of events with DeepCore and the entire IceCube detector respectively. The>TeV results include both a fast-response analysis conducted by IceCube in real-time with timewindows of T0 − 1 to T0 + 2 hours and T0 ± 1 day around the time of GRB 221009A, as well asan offline analysis with 3 new time windows up to a time window of T0 − 1 to T0 + 14 days, thelongest time period we consider. The combination of observations by IceCube covers 9 ordersof magnitude in neutrino energy, from MeV to PeV, placing upper limits across the range forpredicted neutrino emission.
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| 6. |
- Abbott, Benjamin W., et al.
(författare)
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We Must Stop Fossil Fuel Emissions to Protect Permafrost Ecosystems
- 2022
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Ingår i: Frontiers in Environmental Science. - : Frontiers Media SA. - 2296-665X. ; 10
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Forskningsöversikt (refereegranskat)abstract
- Climate change is an existential threat to the vast global permafrost domain. The diverse human cultures, ecological communities, and biogeochemical cycles of this tenth of the planet depend on the persistence of frozen conditions. The complexity, immensity, and remoteness of permafrost ecosystems make it difficult to grasp how quickly things are changing and what can be done about it. Here, we summarize terrestrial and marine changes in the permafrost domain with an eye toward global policy. While many questions remain, we know that continued fossil fuel burning is incompatible with the continued existence of the permafrost domain as we know it. If we fail to protect permafrost ecosystems, the consequences for human rights, biosphere integrity, and global climate will be severe. The policy implications are clear: the faster we reduce human emissions and draw down atmospheric CO2, the more of the permafrost domain we can save. Emissions reduction targets must be strengthened and accompanied by support for local peoples to protect intact ecological communities and natural carbon sinks within the permafrost domain. Some proposed geoengineering interventions such as solar shading, surface albedo modification, and vegetation manipulations are unproven and may exacerbate environmental injustice without providing lasting protection. Conversely, astounding advances in renewable energy have reopened viable pathways to halve human greenhouse gas emissions by 2030 and effectively stop them well before 2050. We call on leaders, corporations, researchers, and citizens everywhere to acknowledge the global importance of the permafrost domain and work towards climate restoration and empowerment of Indigenous and immigrant communities in these regions.
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| 7. |
- Fu, Zhongjie, et al.
(författare)
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FGF21 via mitochondrial lipid oxidation promotes physiological vascularization in a mouse model of Phase I ROP
- 2023
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Ingår i: Angiogenesis. - : Springer Science and Business Media LLC. - 0969-6970 .- 1573-7209. ; 26:3, s. 409-21
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Tidskriftsartikel (refereegranskat)abstract
- Hyperglycemia in early postnatal life of preterm infants with incompletely vascularized retinas is associated with increased risk of potentially blinding neovascular retinopathy of prematurity (ROP). Neovascular ROP (Phase II ROP) is a compensatory but ultimately pathological response to the suppression of physiological postnatal retinal vascular development (Phase I ROP). Hyperglycemia in neonatal mice which suppresses physiological retinal vascular growth is associated with decreased expression of systemic and retinal fibroblast growth factor 21 (FGF21). FGF21 administration promoted and FGF21 deficiency suppressed the physiological retinal vessel growth. FGF21 increased serum adiponectin (APN) levels and loss of APN abolished FGF21 promotion of physiological retinal vascular development. Blocking mitochondrial fatty acid oxidation also abolished FGF21 protection against delayed physiological retinal vessel growth. Clinically, preterm infants developing severe neovascular ROP (versus non-severe ROP) had a lower total lipid intake with more parenteral and less enteral during the first 4weeks of life. Our data suggest that increasing FGF21 levels in the presence of adequate enteral lipids may help prevent Phase I retinopathy (and therefore prevent neovascular disease).
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| 8. |
- Ma, Xiaoping, et al.
(författare)
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Application of Ti Microalloying in a Thin-Slab-Cast Medium-Carbon Steel
- 2021
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Ingår i: Iron & Steel Technology. - : Association for Iron and Steel Technology. - 1547-0423. ; 18:7, s. 178-188
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Tidskriftsartikel (refereegranskat)abstract
- Addition of 0.035 wt.% Ti into a steel with 0.23 wt.% C and 1.3 wt.% Mn was designed to produce steels for axle housing application. The production of 11-mm-thick coils was carried out in a Direction Strip Production Complex strip mill. The present studies focus on structureproperties correlation of the steels as-rolled and after normalizing at 750°C. The precipitation, partial dissolution and re-precipitation behavior of TiC along with microstructure refinement in as-rolled steel and after normalizing are analyzed using electron microscopes. The results lay the foundation for application of Ti microalloying in heat-treated medium-carbon steels.
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| 9. |
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| 11. |
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| 12. |
- Yang, Bernard, et al.
(författare)
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A New Thermal Categorization of Ice-Covered Lakes
- 2021
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Ingår i: Geophysical Research Letters. - : American Geophysical Union (AGU). - 0094-8276 .- 1944-8007. ; 48:3
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Tidskriftsartikel (refereegranskat)abstract
- Lakes are traditionally classified based on their thermal regime and trophic status. While this classification adequately captures many lakes, it is not sufficient to understand seasonally ice‐covered lakes, the most common lake type on Earth. We describe the inverse thermal stratification in 19 highly varying lakes and derive a model that predicts the temperature profile as a function of wind stress, area, and depth. The results suggest an additional subdivision of seasonally ice‐covered lakes to differentiate underice stratification. When ice forms in smaller and deeper lakes, inverse stratification will form with a thin buoyant layer of cold water (near 0°C) below the ice, which remains above a deeper 4°C layer. In contrast, the entire water column can cool to ∼0°C in larger and shallower lakes. We suggest these alternative conditions for dimictic lakes be termed “cryostratified” and “cryomictic.”
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| 13. |
- Young, Nathalie, et al.
(författare)
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Graded operative autonomy in emergency appendectomy mirrors case-complexity : surgical training insights from the SnapAppy prospective observational study
- 2023
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Ingår i: European Journal of Trauma and Emergency Surgery. - : Urban und Vogel Medien und Medizin Verlagsgesellsc. - 1863-9933 .- 1863-9941. ; 49:1, s. 33-44
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Surgical skill, a summation of acquired wisdom, deliberate practice and experience, has been linked to improved patient outcomes. Graded mentored exposure to pathologies and operative techniques is a cornerstone of surgical training. Appendectomy is one of the first procedures surgical trainees perform independently. We hypothesize that, given the embedded training ethos in surgery, coupled with the steep learning curve required to achieve trainer-recognition of independent competency, 'real-world' clinical outcomes following appendectomy for the treatment of acute appendicitis are operator agnostic. The principle of graded autonomy matches trainees with clinical conditions that they can manage independently, and increased complexity drives attending input or assumption of the technical aspects of care, and therefore, one cannot detect an impact of operator experience on outcomes.MATERIALS AND METHODS: This study is a subgroup analysis of the SnapAppy international time-bound prospective observational cohort study (ClinicalTrials.gov Trial #NCT04365491), including all consecutive patients aged ≥ 15 who underwent appendectomy for appendicitis during a three-month period in 2020-2021. Patient- and surgeon-specific variables, as well as 90-day postoperative outcomes, were collected. Patients were grouped based on operating surgeon experience (trainee only, trainee with direct attending supervision, attending only). Poisson and quantile regression models were used to (adjusted for patient-associated confounders) assess the relationship between surgical experience and postoperative complications or hospital length of stay (hLOS), respectively, adjusted for patient-associated confounders. The primary outcome of interest was any complications within 90 days.RESULTS: A total of 4,347 patients from 71 centers in 14 countries were included. Patients operated on by trainees were younger (Median (IQR) 33 [24-46] vs 38 [26-55] years, p < 0.001), had lower ASA classifications (ASA ≥ 3: 6.6% vs 11.6%, p < 0.001) and fewer comorbidities compared to those operated on by attendings. Additionally, trainees operated alone on fewer patients with appendiceal perforation (AAST severity grade ≥ 3: 8.7% vs 15.6%, p < 0.001). Regression analyses revealed no association between operator experience and complications (IRR 1.03 95%CI 0.83-1.28 for trainee vs attending; IRR 1.13 95%CI 0.89-1.42 for supervised trainee vs attending) or hLOS.CONCLUSION: The linkage of case complexity with operator experience within the context of graduated autonomy is a central tenet of surgical training. Either subconsciously, or by design, patients operated on by trainees were younger, fitter and with earlier stage disease. At least in part, these explain why clinical outcomes following appendectomy do not differ depending on the experience of the operating surgeon.
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