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- 2019
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Xu, Chao-Qun, et al.
(författare)
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Genome sequence of Malania oleifera, a tree with great value for nervonic acid production
- 2019
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Ingår i: GigaScience. - : Oxford University Press. - 2047-217X. ; 8:2
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Tidskriftsartikel (refereegranskat)abstract
- Background Malania oleifera, a member of the Olacaceae family, is an IUCN red listed tree, endemic and restricted to the Karst region of southwest China. This tree's seed is valued for its high content of precious fatty acids (especially nervonic acid). However, studies on its genetic makeup and fatty acid biogenesis are severely hampered by a lack of molecular and genetic tools. Findings We generated 51 Gb and 135Gb of raw DNA sequences, using Pacific Biosciences (PacBio) single-molecule real-time and 10x Genomics sequencing, respectively. A final genome assembly, with a scaffold N50 size of 4.65 Mb and a total length of 1.51Gb, was obtained by primary assembly based on PacBio long reads plus scaffolding with 10x Genomics reads. Identified repeats constituted approximate to 82% of the genome, and 24,064 protein-coding genes were predicted with high support. The genome has low heterozygosity and shows no evidence for recent whole genome duplication. Metabolic pathway genes relating to the accumulation of long-chain fatty acid were identified and studied in detail. Conclusions Here, we provide the first genome assembly and gene annotation for M. oleifera. The availability of these resources will be of great importance for conservation biology and for the functional genomics of nervonic acid biosynthesis.
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| 3. |
- Riera-Galindo, Sergi, et al.
(författare)
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Impact of Singly Occupied Molecular Orbital Energy on the n-Doping Efficiency of Benzimidazole Derivatives
- 2019
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Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 11:41, s. 37981-37990
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the impact of singly occupied molecular orbital (SOMO) energy on the n-doping efficiency of benzimidazole derivatives. By designing and synthesizing a series of new air-stable benzimidazole-based dopants with different SOMO energy levels, we demonstrated that an increase of the dopant SOMO energy by only similar to 0.3 eV enhances the electrical conductivity of a benchmark electron-transporting naphthalenediimide-bithiophene polymer by more than 1 order of magnitude. By combining electrical, X-ray diffraction, and electron paramagnetic resonance measurements with density functional theory calculations and analytical transport simulations, we quantitatively characterized the conductivity, Seebeck coefficient, spin density, and crystallinity of the doped polymer as a function of the dopant SOMO energy. Our findings strongly indicate that charge and energy transport are dominated by the (relative) position of the SOMO level, whereas morphological differences appear to play a lesser role. These results set molecular-design guidelines for next-generation n-type dopants.
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| 4. |
- Wang, Huijiao, et al.
(författare)
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Oxidation of emerging biocides and antibiotics in wastewater by ozonation and the electro-peroxone process
- 2019
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Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 235, s. 575-585
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the abatement of a number of antimicrobials frequently detected in municipal wastewater by conventional ozonation and a recently developed ozone-based advanced oxidation process, the electro-peroxone (E-peroxone) process. A synthetic water and a real secondary wastewater effluent were spiked with fourteen antimicrobials, including antibiotics and biocides, and then treated by the two processes. The results show that most of the antibiotics investigated (e.g., ofloxacin, trimethoprim, norfloxacin, and ciprofloxacin) readily react with ozone (O3) and could therefore be efficiently eliminated from the water matrices by direct O3 oxidation during both processes. In contrast, most of the biocides tested in this study (e.g., clotrimazole, pentamidine, bixafen, propiconazole, and fluconazole) were only moderately reactive, or non-reactive, with O3. Therefore, these biocides were removed at considerably lower rate than the antibiotics during the two ozone-based processes, with hydroxyl radical (OH) oxidation playing an important role in their abatement mechanisms. When compared with conventional ozonation, the E-peroxone process is defined by the in situ electrogeneration of hydrogen peroxide, which considerably enhances the transformation of O3 to OH. As a result, the E-peroxone process significantly accelerated the abatement of biocides and required a considerably shorter treatment time to eliminate all of the tested compounds from the water matrices than conventional ozonation. In addition, the E-peroxone process enhanced the contributions of OH fractions to the abatement of moderately ozone reactive benzotriazoles. These results demonstrate that the E-peroxone process holds promise as an effective tertiary treatment option for enhancing the abatement of ozone-resistant antimicrobials in wastewater.
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| 5. |
- Xu, Shuang Feng, et al.
(författare)
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Lactoferrin ameliorates dopaminergic neurodegeneration and motor deficits in MPTP-treated mice
- 2019
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Ingår i: Redox Biology. - : Elsevier BV. - 2213-2317. ; 21
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Tidskriftsartikel (refereegranskat)abstract
- Brain iron accumulation is common in patients with Parkinson's disease (PD). Iron chelators have been investigated for their ability to prevent neurodegenerative diseases with features of iron overload. Given the non-trivial side effects of classical iron chelators, lactoferrin (Lf), a multifunctional iron-binding globular glycoprotein, was screened to identify novel neuroprotective pathways against dopaminergic neuronal impairment. We found that Lf substantially ameliorated PD-like motor dysfunction in the subacute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD. We further showed that Lf could alleviate MPTP-triggered apoptosis of DA neurons, neuroinflammation, and histological alterations. As expected, we also found that Lf suppressed MPTP-induced excessive iron accumulation and the upregulation of divalent metal transporter (DMT1) and transferrin receptor (TFR), which is the main intracellular iron regulation protein, and subsequently improved the activity of several antioxidant enzymes. We probed further and determined that the neuroprotection provided by Lf was involved in the upregulated levels of brain-derived neurotrophic factor (BDNF), hypoxia-inducible factor 1α (HIF-1α) and its downstream protein, accompanied by the activation of extracellular regulated protein kinases (ERK) and cAMP response element binding protein (CREB), as well as decreased phosphorylation of c-Jun N-terminal kinase (JNK) and mitogen activated protein kinase (MAPK)/P38 kinase in vitro and in vivo. Our findings suggest that Lf may be an alternative safe drug in ameliorating MPTP-induced brain abnormalities and movement disorder.
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| 6. |
- Chen, Gang, et al.
(författare)
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On the kinematic algebra for BCJ numerators beyond the MHV sector
- 2019
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Ingår i: Journal of High Energy Physics (JHEP). - : Springer. - 1126-6708 .- 1029-8479. ; :11
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Tidskriftsartikel (refereegranskat)abstract
- The duality between color and kinematics present in scattering amplitudes of Yang-Mills theory strongly suggests the existence of a hidden kinematic Lie algebra that controls the gauge theory. While associated BCJ numerators are known on closed forms to any multiplicity at tree level, the kinematic algebra has only been partially explored for the simplest of four-dimensional amplitudes: up to the MHV sector. In this paper we introduce a framework that allows us to characterize the algebra beyond the MHV sector. This allows us to both constrain some of the ambiguities of the kinematic algebra, and better control the generalized gauge freedom that is associated with the BCJ numerators. Specifically, in this paper, we work in dimension-agnostic notation and determine the kinematic algebra valid up to certain ? ((epsilon i .epsilon j )(2)) terms that in four dimensions compute the next-to-MHV sector involving two scalars. The kinematic algebra in this sector is simple, given that we introduce tensor currents that generalize standard Yang-Mills vector currents. These tensor currents control the generalized gauge freedom, allowing us to generate multiple different versions of BCJ numerators from the same kinematic algebra. The framework should generalize to other sectors in Yang-Mills theory.
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| 7. |
- Davidsson, Marcus, et al.
(författare)
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A systematic capsid evolution approach performed in vivo for the design of AAV vectors with tailored properties and tropism
- 2019
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 1091-6490. ; 116:52, s. 27053-27062
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Tidskriftsartikel (refereegranskat)abstract
- Adeno-associated virus (AAV) capsid modification enables the generation of recombinant vectors with tailored properties and tropism. Most approaches to date depend on random screening, enrichment, and serendipity. The approach explored here, called BRAVE (barcoded rational AAV vector evolution), enables efficient selection of engineered capsid structures on a large scale using only a single screening round in vivo. The approach stands in contrast to previous methods that require multiple generations of enrichment. With the BRAVE approach, each virus particle displays a peptide, derived from a protein, of known function on the AAV capsid surface, and a unique molecular barcode in the packaged genome. The sequencing of RNA-expressed barcodes from a single-generation in vivo screen allows the mapping of putative binding sequences from hundreds of proteins simultaneously. Using the BRAVE approach and hidden Markov model-based clustering, we present 25 synthetic capsid variants with refined properties, such as retrograde axonal transport in specific subtypes of neurons, as shown for both rodent and human dopaminergic neurons.
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| 8. |
- Hu, Zengyun, et al.
(författare)
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“Dry gets drier, wet gets wetter”: A case study over the arid regions of central Asia
- 2019
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Ingår i: International Journal of Climatology. - : Wiley. - 0899-8418 .- 1097-0088. ; 39:2, s. 1072-1091
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Tidskriftsartikel (refereegranskat)abstract
- © 2018 Royal Meteorological Society The “dry gets drier, wet gets wetter” (DGDWGW) paradigm well describes the pattern of precipitation changes over the oceans. However, it has also been usually considered as a simplified pattern of regional changes in wet/dry under global warming, although GCMs mostly do not agree this pattern over land. To examine the validity of this paradigm over land and evaluate how usage of drought indices estimated from different hydrological variables affects detection of regional wet/dry trends, we take the arid regions of central Asia as a case study area and estimate the drying and wetting trends during the period of 1950–2015 based on multiple drought indices. These indices include the standardized precipitation index (SPI), the standardized precipitation evapotranspiration index (SPEI), the Palmer drought severity index (PDSI) and self-calibrating PDSI (sc_PDSI) with both the Thornthwaite (th) and Penman–Monteith (pm) equations in PDSI calculation (namely, PDSI_th, PDSI_pm, sc_PDSI_th and sc_PDSI_pm). The results show that there is an overall agreement among the indices in terms of inter-annual variation, especially for the PDSIs. All drought indices except SPI show a drying trend over the five states of central Asia (CAS5: including Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan). The four PDSIs and SPEI reveal a wetting tendency over the northwestern China (NW; including Xinjiang Uygur Autonomous Region and Hexi Corridor). The contrasting trends between CAS5 and NW can also be revealed in soil moisture (SM) variations. The nonlinear wet and dry variations are dominated by the 3–7 years oscillations for the indices. Relationships between the six indices and climate variables show the major drought drivers have regional features: with mean temperature (TMP), precipitation total (PRE) and potential evapotranspiration (PET) for CAS5, and PRE and PET for NW. Finally, our analyses indicate that the dry and wet variations are strongly correlated with the El Niño/Southern Oscillation (ENSO).
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| 9. |
- Li, Gang, et al.
(författare)
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All-cause mortality in patients with treatment-resistant depression : a cohort study in the US population
- 2019
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Ingår i: Annals of General Psychiatry. - : BMC. - 1744-859X. ; 18:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Treatment-resistant depression (TRD) may represent a substantial proportion of major depressive disorder (MDD); however, the risk of mortality in TRD is still incompletely assessed. Methods Data were obtained from Optum Clinformatics (TM) Extended, a US claims database. Date of the first antidepressant (AD) dispensing was designated as the index date for study entry and 6 months prior to that was considered the baseline period. Patients with MDD aged >= 18 years, index date between January 1, 2008 and September 30, 2015, no AD claims during baseline, and continuous enrollment in the database during baseline were included. Patients who started a third AD regimen after two regimens of appropriate duration were included in the TRD cohort. All-cause mortality was compared between patients with TRD and non-TRD MDD using a proportional hazards model and Kaplan-Meier estimate with TRD status being treated as a time-varying covariate. The model was adjusted for study year, age, gender, depression diagnosis, substance use disorder, psychiatric comorbidities, and Charlson comorbidity index. Results Out of 355,942 patients with MDD, 34,176 (9.6%) met the criterion for TRD. TRD was associated with a significantly higher mortality compared with non-TRD MDD (adjusted HR: 1.29; 95% CI 1.22-1.38; p < 0.0001). Survival time was significantly shorter in the TRD cohort compared with the non-TRD MDD cohort (p < 0.0001). Conclusions Patients with TRD had a higher all-cause mortality compared with non-TRD MDD patients.
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| 10. |
- Li, Gang, et al.
(författare)
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Quantum Spin Hall States in 2D Bismuth-Based Materials
- 2019
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Ingår i: Springer Series in Materials Science. - Singapore : Springer Singapore. - 2196-2812 .- 0933-033X. ; 285, s. 351-379
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Berrys phase, an inherent constituent of the electronic wave functions, has revolutionarily enriched our understanding of the fundamental states of matter and has triggered the discovery of many interesting phenomena in condensed matter physics, such as quantum charge/spin pumping, polarization, topological insulating phase, etc. Among them, the discovery of the two-dimensional (2D) quantum spin Hall (QSH) states protected by time-reversal symmetry (TRS) boosts the wide interest in the study of topological materials in the past decade. These include the 2D quantum anomalous Hall states (QAH), three-dimensional topological insulators (TIs), Dirac semimetals (SM), and topological nodal-line SMs as well as Weyl SMs. This article by no means can cover everything of this rapidly developing field, we rather focus on the bismuth-based honeycomb materials hosting large-gap QSH/QAH states, which promise applications for room-temperature spintronic. We will explain their topological mechanisms in terms of Berrys phase and topological invariant. After introducing a concrete material example which has been successfully grown in experiment, e.g., Bi/SiC(0001), various theoretical proposals on atom substitution and functionalization based on bismuth honeycomb lattice will then be discussed, from which a general designing principle for achieving large topological gaps can be summarized. This article hopes to stimulate more experimental activities toward the examination of large-gap QSH/QAH theoretical proposals and the potential applications in spintronic devices.
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