| 1. |
- Rasmussen, Morten, et al.
(author)
-
Ancient human genome sequence of an extinct Palaeo-Eskimo
- 2010
-
In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 463:7282, s. 757-762
-
Journal article (peer-reviewed)abstract
- We report here the genome sequence of an ancient human. Obtained from ∼4,000-year-old permafrost-preserved hair, the genome represents a male individual from the first known culture to settle in Greenland. Sequenced to an average depth of 20×, we recover 79% of the diploid genome, an amount close to the practical limit of current sequencing technologies. We identify 353,151 high-confidence single-nucleotide polymorphisms (SNPs), of which 6.8% have not been reported previously. We estimate raw read contamination to be no higher than 0.8%. We use functional SNP assessment to assign possible phenotypic characteristics of the individual that belonged to a culture whose location has yielded only trace human remains. We compare the high-confidence SNPs to those of contemporary populations to find the populations most closely related to the individual. This provides evidence for a migration from Siberia into the New World some 5,500 years ago, independent of that giving rise to the modern Native Americans and Inuit.
|
|
| 2. |
- Wan, Lu Ming, et al.
(author)
-
Heparanase Facilitates PMA-Induced Megakaryocytic Differentiation in K562 Cells via Interleukin 6/STAT3 Pathway
- 2020
-
In: Thrombosis and Haemostasis. - : GEORG THIEME VERLAG KG. - 0340-6245 .- 2567-689X. ; 120:4, s. 647-657
-
Journal article (peer-reviewed)abstract
- Heparanase (HPSE) is an endo-beta-D-glucuronidase that cleaves heparan sulfate and hence participates in remodeling of the extracellular matrix, leading to release of cytokines that are immobilized by binding to heparan sulfate proteoglycans (HSPGs), and consequently activating signaling pathways. This function of HPSE is correlated to its expression level that is normally very low in majority of the tissues. Exceptionally, human platelets express high level of HPSE, suggesting a unique physiological role in this cell. Using K562 cell line, we found a progressive increase of HPSE during the megakaryocytic differentiation. Analysis of a series of megakaryocytic differentiation-related heparin-binding proteins (HBPs) in the cell culture medium revealed an exclusive positive correlation between the level of interleukin 6 (IL-6) and HPSE expression. IL-6 modulated megakaryocytic differentiation through activation of STAT3. Further, we demonstrated that overexpression of HPSE potentiates megakaryocytic differentiation, whereas elimination of HPSE led to a delayed differentiation. This function of HPSE is associated with its activity, as overexpression of inactive HPSE had no effect on IL-6 production and megakaryocytic differentiation. The role of HPSE is further supported by the observation in an umbilical cord blood CD34+ cells megakaryocytic differentiation model. Our data propose a novel role for HPSE in platelets production by a HPSE/IL-6/STAT3 positive feedback loop that specifically regulates megakaryocytes maturation.
|
|
| 3. |
- Zhang, Fengjiao, et al.
(author)
-
Passive seismic interferometry imaging : An example from the Ketzin pilot CO2 geological storage site
- 2022
-
In: Journal of Applied Geophysics. - : Elsevier. - 0926-9851 .- 1879-1859. ; 205
-
Journal article (peer-reviewed)abstract
- Ketzin is a well-known onshore CO2 geological storage test site. Injection started in June 2008 and ended in August 2013. About 67 kt of CO2 was injected into a saline aquifer reservoir. Numerous geophysical surveys have been conducted at the site, including passive seismic ones. Passive seismic interferometry can be applied in many seismic exploration investigations to image the underground structures. This study compares several passive seismic interferometry imaging methods to a data set acquired at Ketzin. The passive data set consist of 5 lines with 20 h of recordings in total. First, we apply the autocorrelation method to obtain zero offset stacked sections directly. Secondly, we test different interferometry methods to generate virtual shot gathers. These virtual shot gathers are then processed to obtain CDP stacked sections. Results from these methods are compared with an active data set recorded at the site. The processed passive sections have relatively less coherent reflections compared with the active stacked sections. However, the passive sections obtained by autocorrelation show good agreement with the active stacked sections. The stacked sections obtained by processing virtual shot gathers using crosscorrelation show similar features to the active stacked sections, but with poorer coherence in the reflections and are noisier than the autocorrelation sections.
|
|
| 4. |
- Zhang, Zhuo-Zhi, et al.
(author)
-
A suspended silicon single-hole transistor as an extremely scaled gigahertz nanoelectromechanical beam resonator
- 2020
-
In: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 32:52
-
Journal article (peer-reviewed)abstract
- Suspended single-hole transistors (SHTs) can also serve as nanoelectromechanical resonators, providing an ideal platform for investigating interactions between mechanical vibrations and charge carriers. Demonstrating such a device in silicon (Si) is of particular interest, due to the strong piezoresistive effect of Si and potential applications in Si-based quantum computation. Here, a suspended Si SHT also acting as a nanoelectromechanical beam resonator is demonstrated. The resonant frequency and zero-point motion of the device are approximate to 3 GHz and 0.2 pm, respectively, reaching the best level among similar devices demonstrated with Si-containing materials. The mechanical vibration is transduced to electrical readout by the SHT. The signal transduction mechanism is dominated by the piezoresistive effect. A giant apparent effective piezoresistive gauge factor with strong correlation to single-hole tunneling is extracted in this device. The results show the great potential of the device in interfacing charge carriers with mechanical vibrations, as well as investigating potential quantum behavior of the vibration phonon mode.
|
|
| 5. |
- Zheng, Fenglian, et al.
(author)
-
Structural and functional hippocampal alterations in Multiple sclerosis and neuromyelitis optica spectrum disorder
- 2022
-
In: Multiple Sclerosis Journal. - : SAGE Publications. - 1352-4585 .- 1477-0970. ; 28:5, s. 707-717
-
Journal article (peer-reviewed)abstract
- Background: Hippocampal involvement may differ between multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). Objective: To investigate the morphometric, diffusion and functional alterations in hippocampus in MS and NMOSD and the clinical significance. Methods: A total of 752 participants including 236 MS, 236 NMOSD and 280 healthy controls (HC) were included in this retrospective multi-center study. The hippocampus and subfield volumes, fractional anisotropy (FA) and mean diffusivity (MD), amplitude of low frequency fluctuation (ALFF) and degree centrality (DC) were analyzed, and their associations with clinical variables were investigated. Results: The hippocampus showed significantly lower volume, FA and greater MD in MS compared to NMOSD and HC (p < 0.05), while no abnormal ALFF or DC was identified in any group. Hippocampal subfields were affected in both diseases, though subiculum, presubiculum and fimbria showed significantly lower volume only in MS (p < 0.05). Significant correlations between diffusion alterations, several subfield volumes and clinical variables were observed in both diseases, especially in MS (R = -0.444 to 0.498, p < 0.05). FA and MD showed fair discriminative power between MS and HC, NMOSD and HC (AUC > 0.7). Conclusions: Hippocampal atrophy and diffusion abnormalities were identified in MS and NMOSD, partly explaining how clinical disability and cognitive impairment are differentially affected.
|
|
| 6. |
- Janknecht, Rebecca, et al.
(author)
-
A Strategy to Enhance the B-Solubility and Mechanical Properties of Ti-B-N Thin Films
- 2024
-
In: Acta Materialia. - : Elsevier. - 1359-6454 .- 1873-2453. ; 271
-
Journal article (peer-reviewed)abstract
- The Ti–B–N system offers a wide range of possible meta(stable) phases, making it interesting for science and industry. However, the solubility for B within the face-centered cubic (fcc)-TiN lattice is rather limited and less studied, especially without forming B-rich phases. Therefore, we address how chemistries along the TiN–TiB2 or TiN–TiB tie-line influence this B-solubility. The variation between these two tie-lines is realized through non-reactive co-sputtering of a TiN, TiB2, and Ti target. We show that for variations along the TiN–TiB tie-line, even 8.9 at.% B (equivalent to 19.3 at.% non-metal fractions) can fully be incorporated into the fcc-TiNy lattice without forming other B-containing phases. The combination of detailed microstructural characterization through X-ray diffraction and transmission electron microscopy with ab initio calculations of fcc-Ti1-xNBx, fcc-TiN1-xBx, and fcc-TiN1-2xBx solid solutions indicates that B essentially substitutes N.The single-phase fcc-TiB0.17N0.69 (the highest B-containing sample along the TiN–TiB tie-line studied) exhibits the highest hardness H of 37.1±1.9 GPa combined with the highest fracture toughness KIC of 3.0±0.2 MPa·m1/2 among the samples studied. These are markedly above those of B-free TiN0.87 having H = 29.2±2.1 GPa and KIC = 2.7±<0.1 MPa·m1/2.
|
|
| 7. |
- Jin, Ying, et al.
(author)
-
"Soap bubble" sign as an imaging marker for posterior fossa ependymoma Group B
- 2023
-
In: Neuroradiology. - : Springer. - 0028-3940 .- 1432-1920. ; 65, s. 1707-1714
-
Journal article (peer-reviewed)abstract
- Purpose: To investigate the predictive value of the "soap bubble" sign on molecular subtypes (Group A [PFA] and Group B [PFB]) of posterior fossa ependymomas (PF-EPNs).Methods: MRI scans of 227 PF-EPNs (internal retrospective discovery set) were evaluated by two independent neuroradiologists to assess the "soap bubble" sign, which was defined as clusters of cysts of various sizes that look like "soap bubbles" on T2-weighted images. Two independent cohorts (external validation set [n = 31] and prospective validation set [n = 27]) were collected to validate the "soap bubble" sign.Results: Across three datasets, the "soap bubble" sign was observed in 21 PFB cases (7.4% [21/285] of PF-EPNs and 12.9% [21/163] of PFB); none in PFA. Analysis of the internal retrospective discovery set demonstrated substantial interrater agreement (1st Rating: kappa = 0.71 [0.53-0.90], 2nd Rating: kappa = 0.83 [0.68-0.98]) and intrarater agreement (Rater 1: kappa = 0.73 [0.55-0.91], Rater 2: kappa = 0.74 [0.55-0.92]) for the "soap bubble" sign; all 13 cases positive for the "soap bubble" sign were PFB (p = 0.002; positive predictive value [PPV] = 100%, negative predictive value [NPV] = 44%, sensitivity = 10%, specificity = 100%). The findings from the external validation set and the prospective validation set were similar, all cases positive for the "soap bubble" sign were PFB (p < 0.001; PPV = 100%).Conclusion: The "soap bubble" sign represents a highly specific imaging marker for the PFB molecular subtype of PF-EPNs.
|
|
| 8. |
- Li, Biao, et al.
(author)
-
Decoupling the roles of Ni and Co in anionic redox activity of Li-rich NMC cathodes
- 2023
-
In: Nature Materials. - : Springer Nature. - 1476-1122 .- 1476-4660. ; 22:11, s. 1370-1379
-
Journal article (peer-reviewed)abstract
- Li[LixNiyMnzCo1−x−y−z]O2 (lithium-rich NMCs) are benchmark cathode materials receiving considerable attention due to the abnormally high capacities resulting from their anionic redox chemistry. Although their anionic redox mechanisms have been much investigated, the roles of cationic redox processes remain underexplored, hindering further performance improvement. Here we decoupled the effects of nickel and cobalt in lithium-rich NMCs via a comprehensive study of two typical compounds, Li1.2Ni0.2Mn0.6O2 and Li1.2Co0.4Mn0.4O2. We discovered that both Ni3+/4+ and Co4+, generated during cationic redox processes, are actually intermediate species for triggering oxygen redox through a ligand-to-metal charge-transfer process. However, cobalt is better than nickel in mediating the kinetics of ligand-to-metal charge transfer by favouring more transition metal migration, leading to less cationic redox but more oxygen redox, more O2 release, poorer cycling performance and more severe voltage decay. Our work highlights a compositional optimization pathway for lithium-rich NMCs by deviating from using cobalt to using nickel, providing valuable guidelines for future high-capacity cathode design.
|
|
| 9. |
- Ma, Tao, et al.
(author)
-
Genomic insights into salt adaptation in a desert poplar
- 2013
-
In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 4, s. 2797-
-
Journal article (peer-reviewed)abstract
- Despite the high economic and ecological importance of forests, our knowledge of the genomic evolution of trees under salt stress remains very limited. Here we report the genome sequence of the desert poplar, Populus euphratica, which exhibits high tolerance to salt stress. Its genome is very similar and collinear to that of the closely related mesophytic congener, P. trichocarpa. However, we find that several gene families likely to be involved in tolerance to salt stress contain significantly more gene copies within the P. euphratica lineage. Furthermore, genes showing evidence of positive selection are significantly enriched in functional categories related to salt stress. Some of these genes, and others within the same categories, are significantly upregulated under salt stress relative to their expression in another salt-sensitive poplar. Our results provide an important background for understanding tree adaptation to salt stress and facilitating the genetic improvement of cultivated poplars for saline soils.
|
|
| 10. |
- Xu, Zhuo, et al.
(author)
-
Extrapolated supervirtual refraction interferometry
- 2021
-
In: Geophysical Journal International. - : Oxford University Press. - 0956-540X .- 1365-246X. ; 227:2, s. 1439-1463
-
Journal article (peer-reviewed)abstract
- Accurate picking of head-wave arrival times is an important component of first-arrival traveltime tomography. Far-offset traces in particular have low signal-to-noise ratio (SNR), but picking on these traces is necessary in order to obtain velocity information at depth. Furthermore, there is often an insufficient number of far-offset traces for obtaining reliable models at depth. We present here an extrapolation method for increasing the number of first arrivals beyond the maximum recorded offset, thereby extending the supervirtual refraction interferometry (SVI) method. We refer to the method as extrapolated SVI (ESVI). It is a novel attempt to extrapolate first arrivals using a fully data-driven method. We first test the methodology on synthetic data sets, and we then apply ESVI to two published real data sets over the Parvie fault system in northern Sweden. These data sets were acquired along the same profile at different times with different acquisition parameters and noise levels. The results show that ESVI enhances the SNR of head waves when the noise level is high. That is the same as the conventional SVI. ESVI also increases the number of pickable first arrivals by extrapolating head waves past the original maximum offset of each shot. We also show that the significant increase in first-arrival traveltime picks is beneficial for improving resolution and penetration depth in the tomographic imaging and, consequently, better revealing the subsurface velocity distribution. The tomographic images show higher velocities in the hanging walls of the main Parvie fault and another subsidiary fault, as interpreted relative to migrated images from previous seismic reflection processing.
|
|
