Aegilops tauschii is the diploid progenitor of the D genome of hexaploid wheat (Triticum aestivum, genomes AABBDD) and an important genetic resource for wheat. The large size and highly repetitive ...nature of the Ae. tauschii genome has until now precluded the development of a reference-quality genome sequence. Here we use an array of advanced technologies, including ordered-clone genome sequencing, whole-genome shotgun sequencing, and BioNano optical genome mapping, to generate a reference-quality genome sequence for Ae. tauschii ssp. strangulata accession AL8/78, which is closely related to the wheat D genome. We show that compared to other sequenced plant genomes, including a much larger conifer genome, the Ae. tauschii genome contains unprecedented amounts of very similar repeated sequences. Our genome comparisons reveal that the Ae. tauschii genome has a greater number of dispersed duplicated genes than other sequenced genomes and its chromosomes have been structurally evolving an order of magnitude faster than those of other grass genomes. The decay of colinearity with other grass genomes correlates with recombination rates along chromosomes. We propose that the vast amounts of very similar repeated sequences cause frequent errors in recombination and lead to gene duplications and structural chromosome changes that drive fast genome evolution.
Two sediment cores recovered in the central part of Daihai Lake in north-central China were analysed at 2- to 4-cm intervals for grain-size distribution. Grain-size distributions of the lake ...sediments are inferred to be a proxy for past changes in East Asian monsoon precipitation, such that greater silt-size percentage and higher median grain size reflect increased monsoonal precipitation rates. The grain-size record of Daihai Lake sediments spanning the last ca 10,000 yr indicates that the monsoonal precipitation in the lake region can be divided into three stages: the Early, Middle and Late Holocene. During the Early Holocene before ca 7900 cal yr BP, the median grain size (Md) and the silt-fraction content were relatively low and constant, suggesting relatively low precipitation over the lake region. The Middle Holocene between ca 7900 and 3100 cal yr BP was marked by intensified and highly variable monsoonal precipitation, as indicated by high and variable Md values and silt contents of the lake sediments. During this period, average precipitation rate gradually increased from ca 7900 to 6900 cal yr BP, displayed intense oscillations between ca 6900 and 4400 cal yr BP, and exhibited a decreasing trend while fluctuating from ca 4400 to 3100 cal yr BP. Although generally high during the Middle Holocene, both the Md and the silt content assumed distinctly low values at the short intervals of ca 6500–6400, 6000–5900, 5700–5600, 4400–4200 cal yr BP, implying that monsoonal precipitation might have been significantly reduced during these intervals. During the Late Holocene since ca 3100 cal yr BP, grain-size values suggest that precipitation decreased. However, during the Late Holocene, relatively higher Md values and silt contents occurring between ca 1700 to 1000 cal yr BP may denote an intensification of hydrological cycles in the lake area. Changes in the East Asian monsoonal precipitation were not only directly linked with the changing seasonality of solar insolation resulting from progressive changes in the Earth's orbital parameters, but also may have been closely related to variations in the temperature and size of the Western Pacific Warm Pool, in the intensity of the El Nino–Southern Oscillation, and in the path and strength of the North Equatorial Current in the western Pacific.
Fracability evaluation of unconventional oil/gas reservoirs has become a general practice during the hydraulic fracturing job design to identify the best candidate pay zone. The brittleness of the ...reservoir rock was first used to characterize the capability of the reservoir rock to form a complex fracture network. Later, other factors like fracture toughness, in-situ stress, and natural fracture parameters were introduced in combination with brittleness to more comprehensively describe the fracability of the reservoir. However, most of the existing fracability evaluation has been performed for single wells. In contrast, the three-dimensional distribution of fracability within reservoirs was less pursued, though it might be beneficial for guiding the well placement. This study developed an integrated multi-scale fracability evaluation method for tight sandstone reservoirs based on three-dimensional geomechanical analysis. Factors like brittleness, fracture toughness, in-situ stress contrast that influence the hydraulic fracture initiation and propagation at different scales were first identified and analyzed. Then methods of deriving these quantities from well logs and three-dimensional seismic data were summarized. Finally, an integrated index incorporating these quantities was defined to differentiate the so-called engineering sweet-spot zones favorable for stimulation. A typical application of this method is the integrated multi-scale fracability evaluation method applied to a tight sandstone reservoir located in China’s south sea oil field, which demonstrated the effectiveness of the method. In addition, some implications for improving fracturing operations of tight sandstone reservoirs have been provided.
The association between aflatoxin B1 (AFB1) exposure and oxidative stress was extensively examined in 84 adolescents from an area at high risk for hepatocellular carcinoma in China. Plasma level of ...aflatoxin B1–albumin adducts (AAAs) was associated with AFB1 excretion in urine (r = 0.394, P < 0.001). Urinary AFB1 was also associated with both the urinary excretion of 8-hydroxydeoxyguanosine (8-OHdG) (r ≥ 0.479, P < 0.001) and 8-OHdG and hOGG1 levels in peripheral leukocytes (r ≥ 0.308, P ≤ 0.005). Similarly, AAA was significantly associated with both the urinary excretion of 8-OHdG (r ≥ 0.259, P ≤ 0.018) and the 8-OHdG and hOGG1 levels in peripheral leukocytes (r ≥ 0.313, P ≤ 0.004). In addition, urinary 8-OHdG was correlated with both the level of DNA 8-OHdG (r ≥ 0.24, P ≤ 0.05) and the expression of hOGG1 in peripheral leukocytes (r ≥ 0.429, P < 0.001). Protein carbonyl content (PCC) level was significantly associated with not only the level of DNA 8-OHdG (r ≥ 0.366, P < 0.001) and the urinary 8-OHdG (r ≥ 0.258, P ≤ 0.018) but also the expression of hOGG1 in peripheral leukocytes (r = 0.485, P < 0.001). A significant but weak association was found between high-performance liquid chromatograph–electrochemical detection (HPLC–ECD) and enzyme-linked immunosorbent assay (ELISA) for urinary 8-OHdG (r = 0.334, P = 0.002) and between HPLC–ECD and flow cytometry assays for 8-OHdG in leucocytes (r = 0.395, P < 0.001). Significant associations were observed between AAA and PCC and liver function indices (alanine aminotransferase and aspartate aminotransferase). These findings suggest significant contribution from AFB1 exposure to oxidative stress and subsequent repair among adolescents that may impose substantial risk for hepatocarcinogenesis in adulthood in this region.
Summary
Amplification of the human telomerase RNA component (TERC) gene was found in esophageal squamous cell carcinoma (ESCC). However, its roles in the progression and prognosis of ESCC have not ...been well understood. The amplification of TERC in normal mucosa, low‐grade and high‐grade intraepithelial neoplasia, and invasive ESCC samples were evaluated using a fluorescence in situ hybridization assay. The amplification of TERC invariably occurred in high‐grade intraepithelial neoplasia and invasive ESCC, partially occurred in low‐grade intraepithelial neoplasia specimens, and seldom occurred in normal mucosa. The average signal ratio of TERC to chromosome 3 centromere‐specific probe (TERC/CSP3) was 1.00 ± 0.01 (average ± standard deviation) in normal mucosas, 1.01 ± 0.08 in low‐grade intraepithelial neoplasias, 1.39 ± 0.26 in high‐grade intraepithelial neoplasias, and 1.56 ± 0.41 in invasive ESCC. High TERC/CSP3 ratio was positively associated with lymph node metastasis (P = 0.005) and advanced tumor stage (P = 0.045). Patients with high amplification of TERC had poor survival (P = 0.01). The amplification of TERC could be used as a new genomic marker for disease progression and prognosis of ESCC. The amplified TERC gene may be a potential therapeutic target for ESCC.
As an invasive cancer, breast cancer is the most common tumour in women and is with high mortality. To study the mechanisms of HER2-positive breast cancer, we analyzed microarray of GSE52194.
...GSE52194 was downloaded from Gene Expression Omnibus including 5 HER2-positive breast cancer samples and 3 normal breast samples. Using cuffdiff software, differentially expressed genes (DEGs) and differentially expressed long non-coding RNAs (DE-lncRNAs) were screened. Functions of the DEGs were analyzed by Gene Ontology (GO) and pathway enrichment analyses. Then, protein-protein interaction (PPI) network of the DEGs was constructed using Cytoscape and modules of the PPI network were screened by CFinder. Moreover, lncRNA-DEG pairs were screened.
Total 209 lncRNA transcriptions were predicted, and 996 differentially expressed transcriptions were screened. Besides, FOS had interaction relationships with EGR1 and SOD2 separately in module E and F of the PPI network for the DEGs. Moreover, there were many lncRNA-DEG pairs (e.g. TCONS_00003876-EGR1, TCONS_00003876-FOS, lnc-HOXC4-3:1-FOS, lnc-HOXC4-3:1-BCL6B, lnc-TEAD4-1:1-FOS and lnc-TEAD4-1:1-BCL6B), meanwhile, co-expressed DEGs of TCONS_00003876, lnc-HOXC4-3:1 and lnc-TEAD4-1:1 were enriched in p53 signaling pathway, MAPK signaling pathway and cancer-related pathways, respectively.
ANXA1, EGR1, BCL6, SOD2, FOS, TCONS_00003876, lnc-HOXC4-3:1 and lnc-TEAD4-1:1 might play a role in HER2-positive breast cancer.
The prevalence of wide-bandgap (WBG) semiconductors allows modern electronic devices to operate at much higher frequencies. However, development of soft magnetic materials with high-frequency ...properties matching the WBG-based devices remains challenging. Here we report a promising nanocrystalline-amorphous composite alloy with a normal composition Fe
Co
Mo
Cu
Nb
Si
B
in atomic percent, producible under industrial conditions, which shows an exceptionally high permeability at high frequencies up to 36000 at 100 kHz, an increase of 44% compared with commercial FeSiBCuNb nanocrystalline alloy (25000±2000 at 100 kHz), outperforming all existing nanocrystalline alloy systems and commercial soft magnetic materials. The alloy is obtained by a unique magnetic-heterogeneous nanocrystallization mechanism in an iron-based amorphous alloy, which is different from traditional strategy of nanocrystallization by doping non-magnetic elements (e.g., Cu and Nb). The induced magnetic inhomogeneity by adding Co atoms promotes locally the formation of highly ordered structures acting as the nuclei of nanocrystals, and Mo atoms agglomerate around the interfaces of nanocrystals, inhibiting nanocrystal growth, resulting in an ultrafine nanocrystalline-amorphous dual-phase structure in the alloy. The exceptional soft magnetic properties are shown to be closely related to the low magnetic anisotropy and the unique spin rotation mechanism under alternating magnetic fields. This article is protected by copyright. All rights reserved.
To explore the efficacy and technical features of fully endoscopic microvascular decompression(MVD) in primary trigeminal neuralgia(PTN) via keyhole approach.
The clinical data of 97 patients with ...PTN underwent fully endoscopic MVD via keyhole approach in the Department of Neurosurgery, Beijing Shijitan Hospital, Capital Medical University from December 2014 to February 2019 was collected. During fully endoscopic MVD in PTN via keyhole approach, performer use natural clearance without grinding except developed rock bone crest or excessive retraction of the brain tissue, visually and panoramically observe and evaluate the CPA area, accurately identify the responsible vessels, to avoid the omission of responsible vessels or insufficient decompression. And the use of preplaced technology, bridging technology and submersible technology, ensure the efficacy of surgery and reduce the surgical side injuries.Barrow Neurological Institute (BNI) pain score was used to evaluate the efficacy and identify the recurrence.
The purpose of this study is to use pulsed magnetron sputtering to deposit transparent conductive ZnO:Mo (MZO) film on a Corning 1737 glass substrate. Various process parameters, including power, ...work pressure, pulsed frequency, film thickness, and substrate temperature, were analyzed for their effects on the microstructure and optoelectronic characteristics of MZO thin film. Experimental results show that MZO film with a low resistivity of approximately 8.9
×
10
−
4
Ω cm and a visible light transitivity of greater than 80% can be obtained using a Mo content of 1.77
wt.%, sputtering power of 100
W, work pressure of 0.4
Pa, pulsed frequency of 10
kHz, and film thickness of 500
nm without heating. The value of optical band gap of MZO increased upon increasing the crystallinity of the MZO thin film, and the range of the optical band gap of MZO thin film is from 3.30 to 3.35
eV.
Genetic studies based on cohorts with rare and extreme bone phenotypes have shown that the LRP5 gene is an important genetic modulator of BMD. Using family‐based and case‐control approaches, this ...study examines the role of the LRP5 gene in determining normal population variation of BMD and describes significant association and suggestive linkage between LRP5 gene polymorphisms and BMD in >900 individuals with a broad range of BMD.
Introduction: Osteoporosis is a common, highly heritable condition determined by complex interactions of genetic and environmental etiologies. Genetic factors alone can account for 50–80% of the interindividual variation in BMD. Mutations in the LRP5 gene on chromosome 11q12–13 have been associated with rare syndromes characterized by extremely low or high BMD, but little is known about the contribution of this gene to the development of osteoporosis and determination of BMD in a normal population.
Materials and Methods: To examine the entire spectrum of low to high BMD, 152 osteoporotic probands, their families (597 individuals), and 160 women with elevated BMD (T score > 2.5) were recruited. BMD at the lumbar spine, femoral neck, and hip were measured in each subject using DXA.
Results: PAGE sequencing of the LRP5 gene revealed 10 single nucleotide polymorphisms (SNPs), 8 of which had allele frequencies of >5%, in exons 8, 9, 10, 15, and 18 and in introns 6, 7, and 21. Within families, a strong association was observed between an SNP at nucleotide C171346A in intron 21 and total hip BMD (p < 1 × 10−5 in men only, p = 0.0019 in both men and women). This association was also observed in comparisons of osteoporotic probands and unrelated elevated BMD in women (p = 0.03), along with associations with markers in exons 8 (C135242T, p = 0.007) and 9 (C141759T, p = 0.02). Haplotypes composed of two to three of the SNPs G121513A, C135242T, G138351A, and C141759T were strongly associated with BMD when comparing osteoporotic probands and high BMD cases (p < 0.003). An SNP at nucleotide C165215T in exon 18 was linked to BMD at the lumbar spine, femoral neck, and total hip (parametric LOD scores = 2.8, 2.5, and 2.2 and nonparametric LOD scores = 0.3, 1.1, and 2.2, respectively) but was not genetically associated with BMD variation.
Conclusion: These results show that common LRP5 polymorphisms contribute to the determination of BMD in the general population.
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