| 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. |
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| 3. |
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| 4. |
- Cheng, LT, et al.
(författare)
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Sex difference in the prevalence of left ventricular hypertrophy in dialysis patients
- 2009
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Ingår i: American journal of nephrology. - : S. Karger AG. - 1421-9670 .- 0250-8095. ; 29:5, s. 398-405
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Tidskriftsartikel (refereegranskat)abstract
- <i>Background:</i> Left ventricular hypertrophy (LVH) is an important, independent negative predictor of cardiovascular morbidity and mortality in the general population and in dialysis patients. Previous studies suggest a sex dimorphism in the prevalence of LVH; however, this issue has never been approached in dialysis patients. <i>Methods:</i> This study enrolled 237 prevalent dialysis patients: 49 on hemodialysis (HD) and 188 on peritoneal dialysis (PD) from a single center. LVH was defined by echocardiography measurements, which were normalized to body surface area (BSA) and height<sup>2.7</sup>, respectively. <i>Results:</i> The mean ages in HD and PD patients were 60 ± 14 and 60 ± 13 years, with a median dialysis vintage of 43 and 20 months, respectively. Although there was no significant difference in age, diabetes, proportion of uncontrolled hypertension, antihypertensive medication and blood pressure between male and female patients within each dialysis modality, the prevalence of LVH (whether indexed to BSA or height<sup>2.7</sup>) was consistently higher in females than in males. When these patients were divided into LVH or non-LVH groups, a significant difference in sex distribution was observed between the two groups (62.0% vs. 41.0% when the BSA-indexed standard was used, p < 0.01; 62.8% vs. 37.1% when the height<sup>2.7</sup>-indexed standard was used, p < 0.001). In logistic regression analysis, female sex was identified as a risk factor of LVH (odds ratio, OR = 2.48, 95% confidence interval, CI = 1.33–4.59; when BSA-indexed LVH was treated as dependent variable, and OR = 4.05, 95% CI = 1.96–8.38, when height<sup>2.7</sup>-indexed LVH was treated as dependent variable) even after adjustment for age, diabetes, blood pressure and antihypertensive medication. <i>Conclusion:</i> This study showed that the prevalence of LVH determined by echocardiography was significantly higher in female dialysis patients than in male dialysis patients. Compared with males, female patients had a 2.5- to 4-fold higher risk to develop LVH even after adjustment for other potential confounding factors, which may indicate that elderly females in the uremic scenario are more prone to develop LVH than elderly males.
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| 5. |
- Feng, Dawei, et al.
(författare)
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Stable metal-organic frameworks containing single-molecule traps for enzyme encapsulation
- 2015
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 6, s. 5979-
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Tidskriftsartikel (refereegranskat)abstract
- Enzymatic catalytic processes possess great potential in chemical manufacturing, including pharmaceuticals, fuel production and food processing. However, the engineering of enzymes is severely hampered due to their low operational stability and difficulty of reuse. Here, we develop a series of stable metal-organic frameworks with rationally designed ultra-large mesoporous cages as single-molecule traps (SMTs) for enzyme encapsulation. With a high concentration of mesoporous cages as SMTs, PCN-333(Al) encapsulates three enzymes with record-high loadings and recyclability. Immobilized enzymes that most likely undergo single-enzyme encapsulation (SEE) show smaller Km than free enzymes while maintaining comparable catalytic efficiency. Under harsh conditions, the enzyme in SEE exhibits better performance than free enzyme, showing the effectiveness of SEE in preventing enzyme aggregation or denaturation. With extraordinarily large pore size and excellent chemical stability, PCN-333 may be of interest not only for enzyme encapsulation, but also for entrapment of other nanoscaled functional moieties.
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| 6. |
- Gao, Xindi, et al.
(författare)
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Cryptococcal Hsf3 controls intramitochondrial ROS homeostasis by regulating the respiratory process
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Mitochondrial quality control prevents accumulation of intramitochondrial-derived reactive oxygen species (mtROS), thereby protecting cells against DNA damage, genome instability, and programmed cell death. However, underlying mechanisms are incompletely understood, particularly in fungal species. Here, we show that Cryptococcus neoformans heat shock factor 3 (CnHsf3) exhibits an atypical function in regulating mtROS independent of the unfolded protein response. CnHsf3 acts in nuclei and mitochondria, and nuclear- and mitochondrial-targeting signals are required for its organelle-specific functions. It represses the expression of genes involved in the tricarboxylic acid cycle while promoting expression of genes involved in electron transfer chain. In addition, CnHsf3 responds to multiple intramitochondrial stresses; this response is mediated by oxidation of the cysteine residue on its DNA binding domain, which enhances DNA binding. Our results reveal a function of HSF proteins in regulating mtROS homeostasis that is independent of the unfolded protein response.
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| 7. |
- Gu, Enyao, et al.
(författare)
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A real-time Raman spectroscopy study of the dynamics of laser-thinning of MoS2 flakes to monolayers
- 2017
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Ingår i: AIP Advances. - : AIP Publishing. - 2158-3226. ; 7:12
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Tidskriftsartikel (refereegranskat)abstract
- Transition metal dichalcogenides (TMDCs) in monolayer form have attracted a great deal of attention for electronic and optical applications. Compared to mechanical exfoliation and chemical synthesis, laser thinning is a novel and unique “on-demand” approach to fabricate monolayers or pattern desired shapes with high controllability and reproducibility. Its successful demonstration motivates a further exploration of the dynamic behaviour of this local thinning process. Here, we present an in-situ study of void formation by laser irradiation with the assistance of temporal Raman evolution. In the analysis of time-dependent Raman intensity, an empirical formula relating void size to laser power and exposure time is established. Void in thinner MoS2 flakes grows faster than in thicker ones as a result of reduced sublimation temperature in the two-dimensional (2D) materials. Our study provides useful insights into the laser-thinning dynamics of 2D TMDCs and guidelines for an effective control over the void formation.
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| 8. |
- Gu, Tian, et al.
(författare)
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Hybrid Integrated Photonic Platforms : feature issue introduction
- 2021
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Ingår i: Optical Materials Express. - : The Optical Society. - 2159-3930 .- 2159-3930. ; 11:12, s. 4095-4096
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Hybrid photonic integration and interfaces allow different optical materials and components to be combined on a single platform and thus are crucial to future integrated photonic systems. This feature issue covers frontier research, technologies, and perspectives in this rapidly-evolving area and aims to address the key challenges and requirements across a broad range of photonic technologies.
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| 9. |
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| 10. |
- Gu, Z. J., et al.
(författare)
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Optimizing transformation-induced plasticity in CoCrNi alloys by combined grain refinement and chemical tuning
- 2022
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Ingår i: Scripta Materialia. - : Elsevier BV. - 1359-6462 .- 1872-8456. ; 214, s. 114658-
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Tidskriftsartikel (refereegranskat)abstract
- Grain refinement increases yield strength, but usually at the cost of ductility reduction. In the present work, we explored the strategy of grain refinement and composition tuning in CoCrNi alloys to optimize mechanical properties. Grain refinement was found to strongly suppress deformation-induced martensitic transformation in metastable CoCrNi alloys, which was utilized to modulate the transformation-induced plasticity (TRIP) effect in combination with composition tuning guided by theoretical calculations. We demonstrated in a non-equiatomic CoCrNi TRIP medium-entropy alloy (MEA) that our approach resulted in an excellent combination of strength and ductility. The proposed strategy is expected to be useful in exploring superior mechanical properties of MEAs and high-entropy alloys in varying systems.
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| 11. |
- Huang, Zi-Nan, et al.
(författare)
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Analysis of the stress field in the reactor vessel of the China Initiative Accelerator Driven System during postulated ULOF and UTOP transients
- 2023
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Ingår i: Annals of Nuclear Energy. - : Elsevier BV. - 0306-4549 .- 1873-2100. ; 194
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Tidskriftsartikel (refereegranskat)abstract
- The China Initiative Accelerator Driven System (CiADS) was proposed by China Academy of Science since 2015. The subcritical reactor in CiADS is a liquid Lead Bismuth Eutectic (LBE) cooled fast reactor. When the reactor core is in operation, the LBE coolant will directly contact and corrode the inner surface of reactor vessel. Due to the high temperature, the corrosion will be more severe. If the stress on the reactor vessel exceeds the limit, the plastic deformation will occur, leading to the generation and expansion of defects and cracks, and the safety of the reactor will be affected. Therefore, evaluating the stress field of the reactor vessel under different operating conditions is a very important research project. In this paper, the finite element analysis software ADINA was applied to analyze the reactor vessel in CiADS, and the ASME Code was used as stress assessment standards. We can preliminarily prove that the stress assessments of the vessel during the postulated Unprotected Loss of Flow (ULOF) accidents satisfy the requirements of ASME Code. The limit reactivity insertion to protect the vessel from plastic deformation is 0.58$ in the postulated Unprotected Transient over Power (UTOP) accidents based on our current results. Therefore, we can preliminarily conclude that the current material selection and structural design of the reactor vessel in CiADS could survive most of the postulated transient accidents considering the stress effect.
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| 12. |
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| 13. |
- Joshi, Peter K, et al.
(författare)
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Directional dominance on stature and cognition in diverse human populations
- 2015
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 523:7561, s. 459-462
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Tidskriftsartikel (refereegranskat)abstract
- Homozygosity has long been associated with rare, often devastating, Mendelian disorders, and Darwin was one of the first to recognize that inbreeding reduces evolutionary fitness. However, the effect of the more distant parental relatedness that is common in modern human populations is less well understood. Genomic data now allow us to investigate the effects of homozygosity on traits of public health importance by observing contiguous homozygous segments (runs of homozygosity), which are inferred to be homozygous along their complete length. Given the low levels of genome-wide homozygosity prevalent in most human populations, information is required on very large numbers of people to provide sufficient power. Here we use runs of homozygosity to study 16 health-related quantitative traits in 354,224 individuals from 102 cohorts, and find statistically significant associations between summed runs of homozygosity and four complex traits: height, forced expiratory lung volume in one second, general cognitive ability and educational attainment (P < 1 × 10(-300), 2.1 × 10(-6), 2.5 × 10(-10) and 1.8 × 10(-10), respectively). In each case, increased homozygosity was associated with decreased trait value, equivalent to the offspring of first cousins being 1.2 cm shorter and having 10 months' less education. Similar effect sizes were found across four continental groups and populations with different degrees of genome-wide homozygosity, providing evidence that homozygosity, rather than confounding, directly contributes to phenotypic variance. Contrary to earlier reports in substantially smaller samples, no evidence was seen of an influence of genome-wide homozygosity on blood pressure and low density lipoprotein cholesterol, or ten other cardio-metabolic traits. Since directional dominance is predicted for traits under directional evolutionary selection, this study provides evidence that increased stature and cognitive function have been positively selected in human evolution, whereas many important risk factors for late-onset complex diseases may not have been.
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| 14. |
- Kristanl, Matej, et al.
(författare)
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The Seventh Visual Object Tracking VOT2019 Challenge Results
- 2019
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Ingår i: 2019 IEEE/CVF INTERNATIONAL CONFERENCE ON COMPUTER VISION WORKSHOPS (ICCVW). - : IEEE COMPUTER SOC. - 9781728150239 ; , s. 2206-2241
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Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge VOT2019 is the seventh annual tracker benchmarking activity organized by the VOT initiative. Results of 81 trackers are presented; many are state-of-the-art trackers published at major computer vision conferences or in journals in the recent years. The evaluation included the standard VOT and other popular methodologies for short-term tracking analysis as well as the standard VOT methodology for long-term tracking analysis. The VOT2019 challenge was composed of five challenges focusing on different tracking domains: (i) VOT-ST2019 challenge focused on short-term tracking in RGB, (ii) VOT-RT2019 challenge focused on "real-time" short-term tracking in RGB, (iii) VOT-LT2019 focused on long-term tracking namely coping with target disappearance and reappearance. Two new challenges have been introduced: (iv) VOT-RGBT2019 challenge focused on short-term tracking in RGB and thermal imagery and (v) VOT-RGBD2019 challenge focused on long-term tracking in RGB and depth imagery. The VOT-ST2019, VOT-RT2019 and VOT-LT2019 datasets were refreshed while new datasets were introduced for VOT-RGBT2019 and VOT-RGBD2019. The VOT toolkit has been updated to support both standard short-term, long-term tracking and tracking with multi-channel imagery. Performance of the tested trackers typically by far exceeds standard baselines. The source code for most of the trackers is publicly available from the VOT page. The dataset, the evaluation kit and the results are publicly available at the challenge website(1).
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| 15. |
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| 16. |
- Li, Liyuan, et al.
(författare)
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An Efficient Sequential Approach to Tracking Multiple Objects through Crowds for Real-Time Intelligent CCTV Systems
- 2008
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Ingår i: IEEE Transactions on Systems, Man and Cybernetics Part B: Cybernetics. - 1083-4419. ; 38:5, s. 1254-1269
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Tidskriftsartikel (refereegranskat)abstract
- Efficiency and robustness are the two most important issues for multi-object tracking algorithms in real-time intelligent video surveillance systems. We propose a novel2 1/2 D approach to real time multi-object tracking in crowds, which is formulated as a MAP estimation problem and is approximated through an “assignment” step and a “location” step. Observing that the occluding object is usually less affected by the occluded objects, sequential solutions for the assignment and the location are derived. A novel dominant color histogram (DCH) is proposed as an efficient object model. The DCH can be regarded as a generalized color histogram, where dominant colors are selected based on a given distance measure. Comparing with conventional color histograms, DCH only requires a few color components (31 in average). Further, our theoretical analysis and evaluation on real data have shown that DCHs are robust to illumination changes. Using DCH, efficient implementations of sequential solutions for the assignment and the location steps are proposed. The "Assignment" step includes the estimation of depth order for the objects in a dispersing group, one-by-one assignment, and feature exclusion from the group representation. The "Location" step includes the depth order estimation for the objects in a new group, two-phase mean-shift location, and the exclusion of tracked objects from the new position in the group. Multi-object tracking results and evaluation from public datasets are presented. Experiments on image sequences captured from crowded public environments have shown good tracking results, where about 90% of objects have been successfully tracked with the correct identification numbers by the proposed method. Our results and evaluation have indicated that the method is efficient and robust for tracking multiple objects (large than or equal to 3) in complex occlusions for real world surveillance scenarios.
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| 24. |
- Meng, Wen-Jian, et al.
(författare)
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Microsatellite instability did not predict individual survival in sporadic stage II and III rectal cancer patients
- 2007
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Ingår i: Oncology. - : S. Karger AG. - 0890-9091 .- 0030-2414 .- 1423-0232. ; 72:1-2, s. 82-88
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Tumors with high-frequency microsatellite instability (MSI-H) have unique biological behavior and the predictive role of microsatellite instability (MSI) status on survival of colorectal cancer is still debated. The prognostic significance of MSI status in sporadic stage II and III rectal cancer patients needs to be more precisely defined. So we investigated the relationship between MSI status and clinicopathological features and prognosis in these patients. Methods: DNAs from fresh-frozen paired samples of tumors and corresponding normal tissue from 128 stage II and III rectal cancer patients were analyzed for MSI by PCR amplification using markers recommended by a National Cancer Institute workshop on MSI. To assess prognostic significance, Cox proportional hazards modeling was used. Results: Twelve (9.3%) tumors in our study were MSI-H, 28 (21.9%) were low-frequency MSI (MSI-L) and 88 (68.8%) were microsatellite stable (MSS). Most of the MSI-H tumors compared with MSI-L and MSS tumors were found in female patients (p = 0.031), had mucinous histology (p = 0.023), high grade of differentiation (p = 0.002) and high level of preoperative serum carcinoembryonic antigen (p = 0.005). Rectal cancer patients with MSI-H did not show a better clinical outcome than those with MSI-L/MSS, neither in all cases (p = 0.986) nor in stage II and stage III disease analyzed separately (p = 0.705 and p = 0.664, respectively). Conclusions: Data provided here demonstrated there was high incidence of MSI-H and MSI was not a prognostic factor in sporadic stage II and III rectal cancers from the Chinese Han population included in this study. Tumor stage is more suitable than MSI status for prediction of individual survival in sporadic stage II and III rectal cancer patients. Copyright © 2007 S. Karger AG.
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| 25. |
- Meng, Wen-Jian, et al.
(författare)
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Novel mutations and sequence variants in exons 3-9 of human T Cell Factor-4 gene in sporadic rectal cancer patients stratified by microsatellite instability
- 2007
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Ingår i: World Journal of Gastroenterology. - 1007-9327 .- 2219-2840. ; 13:27, s. 3747-3751
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To establish the role of human T Cell Factor-4 (hTCF-4) gene exons 3-9 mutation status in association with sporadic rectal cancer with microsatellite instability (MSI). Methods: Microsatellite markers were genotyped in 93 sporadic rectal cancer patients. Eleven cases were found to be high-frequency MSI (MSI-H). Sequence analysis of the coding region of the exons 3-9 of hTCF-4 gene was carried out for the 11 MSI-H cases and 10 controls (5 microsatellite stability (MSS) cases and 5 cases with normal mucosa). The sequencing and MSI identification were used. Results: Several novel mutations and variants were revealed. In exon 4, one is a 4-position continuous alteration which caused amino acid change from Q131T and S132I (391insA, 392 G > A, 393 A > G and 395delC) and another nucleotide deletion (395delC) is present in MSI-H cases (5/10 and 4/10, respectively) but completely absent in the controls. Conclusion: Novel mutations in exon 4 of hTCF-4 gene were revealed in this study, which might be of importance in the pathogenesis of sporadic rectal cancer patients with MSI-H. © 2007 WJG. All rights reserved.
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