Large Polarization Near 50 µC/cm2 in a Single Unit Cell Layer SrTiO3.

The generally nonpolar SrTiO3 has attracted more attention recently because of its possibly induced novel polar states and related paraelectric-ferroelectric phase transitions. By using controlled pulsed laser deposition, high-quality, ultrathin, and strained SrTiO3 layers were obtained. Here, transmission electron microscopy and theoretical simulations have unveiled highly polar states in SrTiO3 films even down to one unit cell at room temperature, which were stabilized in the PbTiO3/SrTiO3/PbTiO3 sandwich structures by in-plane tensile strain and interfacial coupling, as evidenced by large tetragonality (∼1.05), notable polar ion displacement (0.019 nm), and thus ultrahigh spontaneous polarization (up to ∼50 µC/cm2). These values are nearly comparable to those of the strong ferroelectrics as the PbZrxTi1-xO3 family. Our findings provide an effective and practical approach for integrating large strain states into oxide films and inducing polarization in nonpolar materials, which may broaden the functionality of nonpolar oxides and pave the way for the discovery of new electronic materials.

Atomic Insight into the Successive Antiferroelectric-Ferroelectric Phase Transition in Antiferroelectric Oxides.

Antiferroelectrics characterized by voltage-driven reversible transitions between antiparallel and parallel polarity are promising for cutting-edge electronic and electrical power applications. Wide-ranging explorations revealing the macroscopic performances and microstructural characteristics of typical antiferroelectric systems have been conducted. However, the underlying mechanism has not yet been fully unraveled, which depends largely on the atomistic processes. Herein, based on atomic-resolution transmission electron microscopy, the deterministic phase transition pathway along with the underlying lattice-by-lattice details in lead zirconate thin films was elucidated. Specifically, we identified a new type of ferrielectric-like dipole configuration with both angular and amplitude modulations, which plays the role of a precursor for a subsequent antiferroelectric to ferroelectric transformation. With the participation of the ferrielectric-like phase, the phase transition pathways driven by the phase boundary have been revealed. We provide new insights into the consecutive phase transformation in low-dimensional lead zirconate, which thus would promote potential antiferroelectric-based multifunctional devices.

Endoplasmic reticulum stress-related protein GRP78 and CHOP levels in synovial fluid correlate with disease progression of primary knee osteoarthritis: A cross-sectional study.

BACKGROUND: Endoplasmic reticulum (ER) stress has been shown to play an important role in osteoarthritis (OA). OBJECTIVE: This study was aimed at assessing the relationship of endoplasmic reticulum (ER) stress-related glucose-regulated protein 78 (GRP78) and CCAAT/enhancer-binding protein homologous protein (CHOP) concentrations in the serum/synovial fluid (SF) with disease severity of primary knee osteoarthritis (pkOA). METHODS: Patients with pkOA together with healthy individuals were consecutively recruited from our hospital. The levels of GRP78 and CHOP in serum / SF were detected using enzyme-linked immunosorbent assay. The levels of IL-6 and MMP-3 were also examined. Radiographic progression of pkOA was evaluated based on Kellgren-Lawrence (K-L) grades. Receiver Operating Characteristic (ROC) curves were used to assess the diagnostic value of GRP78/CHOP levels with regard to K-L grades. The assessment of clinical severity was conducted using the visual analogue scale (VAS), Oxford knee score (OKS), and Lequesne algofunctional index (LAI). RESULTS: A total of 140 pkOA patients and 140 healthy individuals were included. Serum GRP78 and CHOP levels in pkOA patients were not significantly different from those in healthy individuals. The SF GRP78 and CHOP levels in healthy controls were not detected due to ethical reasons. Compared to those with K-L grade 2 and 3, the pkOA patients with K-L grade 4 had higher GRP78 and CHOP levels in the SF with statistical significance. In addition, the pkOA patients with K-L grade 3 exhibited drastically upregulated GRP78 and CHOP concentrations in the SF compared to those with K-L grade 2. Positive correlations of GRP78 and CHOP levels with K-L grades, IL-6, and MMP-3 levels in the SF were observed. ROC curve analysis indicated that both GRP78 and CHOP levels may act as decent indicators with regard to OA. GRP78 and CHOP concentrations in the SF were positively correlated with VAS/LAI score and negatively associated with OKS score. CONCLUSION: The study indicated that GRP78 and CHOP levels in the SF but not the serum were positively correlated with disease severity of pkOA.

[Chrysin alleviates cerebral ischemia-reperfusion injury by inhibiting ferroptosis in rats].

The purpose of this study is to investigate whether chrysin reduces cerebral ischemia-reperfusion injury(CIRI) by inhi-biting ferroptosis in rats. Male SD rats were randomly divided into a sham group, a model group, high-, medium-, and low-dose chrysin groups(200, 100, and 50 mg·kg~(-1)), and a positive drug group(Ginaton, 21.6 mg·kg~(-1)). The CIRI model was induced in rats by transient middle cerebral artery occlusion(tMCAO). The indexes were evaluated and the samples were taken 24 h after the operation. The neurological deficit score was used to detect neurological function. The 2,3,5-triphenyl tetrazolium chloride(TTC) staining was used to detect the cerebral infarction area. Hematoxylin-eosin(HE) staining and Nissl staining were used to observe the morphological structure of brain tissues. Prussian blue staining was used to observe the iron accumulation in the brain. Total iron, lipid pero-xide, and malondialdehyde in serum and brain tissues were detected by biochemical reagents. Real-time quantitative polymerase chain reaction(RT-qPCR), immunohistochemistry, and Western blot were used to detect mRNA and protein expression of solute carrier fa-mily 7 member 11(SLC7A11), transferrin receptor 1(TFR1), glutathione peroxidase 4(GPX4), acyl-CoA synthetase long chain family member 4(ACSL4), and prostaglandin-endoperoxide synthase 2(PTGS2) in brain tissues. Compared with the model group, the groups with drug intervention showed restored neurological function, decreased cerebral infarction rate, and alleviated pathological changes. The low-dose chrysin group was selected as the optimal dosing group. Compared with the model group, the chrysin groups showed reduced content of total iron, lipid peroxide, and malondialdehyde in brain tissues and serum, increased mRNA and protein expression levels of SLC7A11 and GPX4, and decreased mRNA and protein expression levels of TFR1, PTGS2, and ACSL4. Chrysin may regulate iron metabolism via regulating the related targets of ferroptosis and inhibit neuronal ferroptosis induced by CIRI.

A celery transcriptional repressor AgERF8 negatively modulates abscisic acid and salt tolerance.

Ethylene response factors (ERFs) widely exist in plants and have been reported to be an important regulator of plant abiotic stress. Celery, a common economic vegetable of Apiaceae, contains lots of ERF transcription factors (TFs) with various functions. AP2/ERF TFs play positive or negative roles in plant growth and stress response. Here, AgERF8, a gene encoding EAR-type AP2/ERF TF, was identified. The AgERF8 mRNA accumulated in response to both abscisic acid (ABA) signaling and salt treatment. AgERF8 was proving to be a nucleus-located protein and could bind to GCC-box. The overexpression of AgERF8 in Arabidopsis repressed the transcription of downstream genes, AtBGL and AtBCH. Arabidopsis overexpressing AgERF8 gene showed inhibited root growth under ABA and NaCl treatments. AgERF8 transgenic lines showed low tolerance to ABA and salt stress than wild-type plants. Low increment in SOD and POD activities, increased accumulation of MDA, and significantly decreased plant fresh weights and chlorophyll levels were detected in AgERF8 hosting lines after treated with ABA and NaCl. Furthermore, the overexpression of AgERF8 also inhibited the levels of ascorbic acid and antioxidant-related genes (AtCAT1, AtSOD1, AtPOD, AtSOS1, AtAPX1, and AtP5CS1) expression in transgenic Arabidopsis. This finding indicated that AgERF8 negatively affected the resistance of transgenic Arabidopsis to ABA and salt stress through regulating downstream genes expression and relevant physiological changes. It will provide a potential sight to further understand the functions of ERF TFs in celery.

A comparative study on arsenic fractions in indoor/outdoor particulate matters: a case in Baoding, China.

The distribution and bioavailability of arsenic (As) in indoor/outdoor total suspended particulates (TSP), inhalable particulate matters (PM10), and fine particulate matters (PM2.5) in Baoding, China were investigated. The average I/O ratios for TSP, PM10, and PM2.5 were 0.52, 0.66, and 0.96, respectively. There was no significant correlation between indoor/outdoor TSP, PM10, and PM2.5. The indoor/outdoor concentrations of As surpassed the limited value of As. I/O ratios of arsenic in TSP, PM10, and PM2.5 were 0.52, 0.58, and 0.55, respectively. The contents of arsenic in different fractions were mainly affected by the total concentrations of arsenic in particulate matters (PM) rather than the particle sizes for TSP and PM10. Arsenic was mainly in non-specifically sorbed fraction (F1) in both indoor and outdoor PM2.5. The evaluated carcinogenic risk (CR) was within the safe level. The bioavailability of As increased with particle size decreasing for both indoor and outdoor PM. The potential bioavailability of As in outdoor particles was higher than that of indoor particles with the same size, especially PM2.5.

[Establishment of extraction method for Gardeniae Fructus extract and its application in evaluating different Gardeniae Fructus decoction pieces].

In this experiment,the gradation analysis method was used to evaluate the quality of different pieces of Gardeniae Fructus through the extraction rate difference and the difference analysis of the main components in the extract. In this experiment cold-dip and hot-dip methods were used to compare the yield of Gardeniae Fructus extract and the content of chemical constituents with water,25%,50%,75% and 95% ethanol fractions. By weighted calculation,the optimal extraction method of Gardeniae Fructus was determined,and this was verified by practical application. RESULTS:: showed that for the water-soluble extract,cold dip method was better than the hot dip method; and for alcohol-soluble extract,75% ethanol under cold dip method was best. The verification results showed that water-soluble extracts under cold dip methods could be used to significantly distinguish the raw Gardeniae Fructus( GF) and processed( stir-baked) GF( GFP) collected from the market. Meanwhile,this method could be also used to distinguish the same batch of GF,GFP and carbonized GF( GFC) with significant differences,respectively( P<0. 05). Ethanol-soluble extract can be used to clearly distinguish GFP and GFC pieces in the same batch( P<0. 05). The results of content determination showed that the variation coefficient of components in GF processed products was higher than that in extracts,and the content of hydroxygeniposide was the most significant component between GF and its processed products. It is suggested that the method of water-soluble extract of GF and the determination of the content of gardoside should be combined together to evaluate the quality of GF and its heat processed products.

[Study on quality standard of rice as excipients during rice stir-frying method].

Commercially available japonica rice and indica rice with different trade names were collected,and then based on the method of rice stir-frying,their many indexes were evaluated,for example the physical and chemical properties such as appearance color,grain type,broken kernel ratio,length-width ratio,1 000-grain weight,specific heat capacity,moisture content,amylose content,and protein content. The discriminant function analysis was used to determine the effective factors affecting the quality of rice as excipients. The results showed that two types of rice could be distinguished by rice color parameter a*,grain parameter circularity,1 000-grain weight and amylose content. These four effective factors can be used as the quality evaluation indexes for fried rice as excipients.Protein is one of the main components of rice,and its content affects the quality of rice. There is a significant difference in the protein content between japonica rice and indica rice. Therefore,protein content should be used as one of the evaluation indexes for rice quality. After comprehensive consideration,it is suggested that the red-green value a*shall not be less than 0. 50; the circularity not less than 53. 0,the 1 000-grain weight not less than 16. 0 g,the amylose content not less than 12. 0% and the protein content not less than4. 0% in the japonica rice; the red-green value a*shall not be lower than-1. 0,the circularity not less than 41. 0,the 1 000-grain weight not less than 13. 0 g,the amylose content not less than 9. 0% and the protein content not less than 3. 5% in the indica rice. In this study,the quality evaluation standards for rice as excipients( japonica rice,indica rice) were supplemented and improved,laying foundation for the development of quality standards for rice as excipients with the rice stir-frying method.

Local Enhancement of Polarization at PbTiO3/BiFeO3 Interfaces Mediated by Charge Transfer.

Ferroelectrics hold promise for sensors, transducers, and telecommunications. With the demand of electronic devices scaling down, they take the form of nanoscale films. However, the polarizations in ultrathin ferroelectric films are usually reduced dramatically due to the depolarization field caused by incomplete charge screening at interfaces, hampering the integrations of ferroelectrics into electric devices. Here, we design and fabricate a ferroelectric/multiferroic PbTiO3/BiFeO3 system, which exhibits discontinuities in both chemical valence and ferroelectric polarization across the interface. Aberration-corrected scanning transmission electron microscopic study reveals an 8% elongation of out-of-plane lattice spacing associated with 104%, 107%, and 39% increments of δTi, δO1, and δO2 in the PbTiO3 layer near the head-to-tail polarized interface, suggesting an over ∼70% enhancement of polarization compared with that of bulk PbTiO3. Besides that in PbTiO3, polarization in the BiFeO3 is also remarkably enhanced. Electron energy loss spectrum and X-ray photoelectron spectroscopy investigations demonstrate the oxygen vacancy accumulation as well as the transfer of Fe3+ to Fe2+ at the interface. On the basis of the polar catastrophe model, FeO2/PbO interface is determined. First-principles calculation manifests that the oxygen vacancy at the interface plays a predominate role in inducing the local polarization enhancement. We propose a charge transfer mechanism that leads to the remarkable polarization increment at the PbTiO3/BiFeO3 interface. This study may facilitate the development of nanoscale ferroelectric devices by tailing the coupling of charge and lattice in oxide heteroepitaxy.

Large Scale Two-Dimensional Flux-Closure Domain Arrays in Oxide Multilayers and Their Controlled Growth.

Ferroelectric flux-closures are very promising in high-density storage and other nanoscale electronic devices. To make the data bits addressable, the nanoscale flux-closures are required to be periodic via a controlled growth. Although flux-closure quadrant arrays with 180° domain walls perpendicular to the interfaces (V-closure) have been observed in strained ferroelectric PbTiO3 films, the flux-closure quadrants therein are rather asymmetric. In this work, we report not only a periodic array of the symmetric flux-closure quadrants with 180° domain walls parallel to the interfaces (H-closure) but also a large scale alternative stacking of the V- and H-closure arrays in PbTiO3/SrTiO3 multilayers. On the basis of a combination of aberration-corrected scanning transmission electron microscopic imaging and phase field modeling, we establish the phase diagram in the layer-by-layer two-dimensional arrays versus the thickness ratio of adjacent PbTiO3 films, in which energy competitions play dominant roles. The manipulation of these flux-closures may stimulate the design and development of novel nanoscale ferroelectric devices with exotic properties.

[DREAM: a multifunctional transcriptional regulator].

DREAM (downstream regulatory element antagonist modulator), Calsenilin and KChIP3 (potassium channel interacting protein 3) belong to the neuronal calcium sensor (NCS) superfamily, which transduces the intracellular calcium signaling into a variety of activities. They are encoded by the same gene locus, but have distinct subcellular locations. DREAM was first found to interact with DRE (downstream regulatory element) site in the vicinity of the promoter of prodynorphin gene to suppress gene transcription. Calcium can disassemble this interaction by binding reversibly to DREAM protein on its four EF-hand motifs. Apart from having calcium dependent DRE site binding, DREAM can also interact with other transcription factors, such as cAMP responsive element binding protein (CREB), CREB-binding protein (CBP) and cAMP responsive element modulator (CREM), by this concerted actions, DREAM extends the gene pool under its control. DREAM is predominantly expressed in central nervous system with its highest level in cerebellum, and accumulating evidence demonstrated that DREAM might play important roles in pain sensitivity. Novel findings have shown that DREAM is also involved in learning and memory processes, Alzheimer's disease and stroke. This mini-review provides a brief introduction of its discovery history and protein structure properties, focusing on the mechanism of DREAM nuclear translocation and gene transcription regulation functions.

[UPLC-Q-TOF/MS for rapid analysis of chemical constituents in Sanhuang tablets].

The qualitative analysis method of ultra performance liquid chromatography tandem quadrupole time of flight mass spectrometry (UPLC-Q-TOF-MS/MS) was established for the chemical constituents in Sanhuang tablets. Waters ACQUITY BEH C18 (2.1 mm×100 mm, 1.7 µm) column was used with 0.1% formic acid solution (A)-0.1% formic acid acetonitrile (B) as the mobile phase for gradient elution. The flow rate was 0.2 mL•min⁻¹; the sample volume was 1 µL and the column temperature was 30 ℃. The high-resolution quadrupole time-flight mass spectrometry was used as detector with electrospray ion source in both positive and negative models, and the dry gas temperature was 325 ℃. Based on the analysis of mass spectrometry and literature reports, 38 compounds were confirmed, including 1 alkaloid, 1 dianthrone compound, 6 tannins, 7 anthraquinone glycosides, 6 anthraquinones and 17 flavonoids. Liquid chromatography-mass spectrometry method is simple, reliable and rapid to identify the chemical compositions of Sanhuang tablets, and it is helpful to reveal its chemical constituents and pharmacodynamic substances.

[Development and innovation of traditional Chinese medicine processing discipline and Chinese herbal pieces industry].

To elucidate the key issues in the development and innovation of traditional Chinese medicine processing discipline and Chinese herbal pieces industry Chinese herbal pieces industry. According to the author's accumulated experience over years and demand of the development of the Chinese herbal pieces industry, the key issues in the development and innovation on the Chinese herbal pieces industry were summarized. According to the author, the traditional Chinese medicine processing discipline shall focus on a application basis research. The development of this discipline should be closely related to the development of Chinese herbal pieces. The traditional Chinese medicine processing discipline can be improved and its results can be transformed only if this discipline were correlated with the Chinese herbal pieces industry, matched with the development of the Chinese herbal pieces industry, and solved the problems in the development on the Chinese herbal pieces industry. The development of traditional Chinese medicine processing discipline and the Chinese herbal pieces industry also requires scientific researchers to make constant innovations, realize the specialty of the researches, and innovate based on inheritance.

Hepatitis B surface antigen in late hepatitis B infection.

Hepatitis B surface antigen (HBsAg) levels are used to evaluate and monitor clinical phases of chronic hepatitis B infection but their clinical significance is unclear in the late complications, cirrhosis of the liver and hepatocellular carcinoma. This study aimed to evaluate HBsAg levels across the whole natural history of hepatitis B virus infection, including late complications. This retrospective, cross-sectional study enrolled 838 treatment-naive patients diagnosed with chronic hepatitis B infection at First Affiliated Hospital of Fujian Medical University between 2009 and 2012. Patients were classified into six groups: immunotolerance, immunoclearance, low replicative, negative hepatitis e (HBeAg) phases, liver cirrhosis, and hepatocellular carcinoma. Main outcome measures were serum HBsAg, HBeAg, HBV DNA, total bilirubin, albumin, alanine and aspartate aminotransferase, and quantitative correlation of HBsAg with HBV DNA. HBsAg levels declined significantly between clinical phases of infection (all P < 0.001) and were significantly lower in decompensated than in compensated cirrhosis (2.90 vs. 3.30, P < 0.001) but not significantly different between early versus advanced hepatocellular carcinoma. Significant positive correlations were observed between serum HBsAg and HBV DNA at immunoclearance and HBeAg negative phases, compensated and decompensated liver cirrhosis and advanced but not early hepatocellular carcinoma (all P < 0.001). HBsAg and HBV DNA were significantly higher in HBeAg positive patients with advanced hepatocellular carcinoma (P < 0.001). HBsAg levels differ significantly between chronic hepatitis B infection phases, decreasing progressively from chronic infection to cirrhosis and hepatocellular carcinoma. Significant correlations are found between serum HBsAg and HBV DNA.

[The effective parts of liangxue tongyu prescription on cooling-blood and activating-blood and analysis of chemical constituents by HPLC-MS and GC-MS].

In order to clarify material basis of effective parts of liangxue tongyu prescription, blood-heat and blood-stasis rat model induced by dry yeast was established. The changes of rectal temperature, blood viscosity and plasma viscosity were used to evaluate the cooling-blood and activating-blood effects of liangxue tongyu prescription and its parts. Compared with the model group, the extract from liangxue tongyu prescription, its volatile oil and n-butanol part could significantly reduce rectal temperature (P<0.01), and also reduce blood viscosity and plasma viscosity to various degrees (P<0.01 or P<0.05). So volatile oil and n-butanol part were primarily identified as effective parts of liangxue tongyu prescription. By using GC-MS with normalization method of area to analyze volatile oil of liangxue tongyu prescription, 70 compounds were identified, accounting for about 92.54%, mainly as ß-asarone, paeonol, α-asarone and shyobunone. 42 compounds such as peony glycosides, tannins, and iridoid glycosides were identified by HPLC-MS techniques and standard comparison. The study determined the effective parts of liangxue tongyu prescription and clarified the chemical composition providing the foundation for further studies on material basis of liangxue tongyu prescription.

[Analysis of volatile ingredients in Gardeniae Fructus and its processed products by GC-MS].

Gardeniae Fructus contains volatile ingredients, however, the species and proportions in different processed products of Gardeniae Fructus are different. In this experiment, volatile ingredients were separated by steam distillation with content of 1.2, 1.0, 0.9, 0.7 µL · g(-1) in Gardeniae Fructus, fried Gardeniae Fructus, stir-baked Gardeniae Fructus, Gardeniae Fructus fried into carbon respectively. One hundred and twenty-four kinds of volatile components were identified by GC-MS. Fifty-three kinds of volatile ingredients consisted in Gardeniae Fructus accounting for 93.85%, 54 kinds in fried Cardeniae Fructus accounting for 92.01%, 32 kinds in stir-baked Cardeniae Fructus accounting for 91.59% and 43 kinds in Gardeniae Fructus fried into carbon accounting for 90.81%. In this paper, analysis of Gardeniae Fructus by GC-MS provides a scientific basis for elucidating the mechanism of different processed products.

[Research progress on processed Chinese medicine in vivo].

Processed Chinese medicine is the core of traditional Chinese medicine (TCM) industry chain,which directly affects the clinical efficacy and. safety of Chinese patent medicine and clinical formula Decoction pieces. Studied the variation of effective substance in vivo Chinese medicine processing before and after processed, clarifying the effective substance and processing principle is a top priority of the development of Chinese medicine processing. The traditional research method chiefly focus on the variation about chemicals in vitro of processed Chinese medicine, it cannot reveal that the integrity and complexity of processed Chinese medicine efficacy changes, so the change process is the focus of future research in vivo on the base of effective substance of TCM This paper described the research on the base of effective substance of TCM and Processed Chinese medicine research status in vitro, discussed the analytical methods (plasma chemistry, pharmacokinetics, metabonomics) of the dynamic process in vivo about processed Chinese medicine, and pointed out development and related problems in process in vivo on the base of effective substance of TCM, which could provided research ideas and methods for in-depth interpretation of Chinese medicine processing mechanism.

A LC-MS-based serum pharmacochemistry approach to reveal the compatibility features of mutual promotion/assistance herb pairs in Xijiao Dihuang decoction.

Xijiao Dihuang decoction (XDT), a famous formula, was usually used to improve the prognosis of patients with blood-heat and blood-stasis syndrome-related diseases. There were some mutual promotion and mutual assistance herb pairs in XDT. However, the exact functions of these herb pairs in the compatibility of XDT were not elucidated due to the lack of appropriate methodologies. Based on the theory of serum pharmacochemistry, a systematic method was established for the qualitative and quantitative analysis of characteristic components in the extracts and drug-containing plasma samples of XDT and its relational mutual promotion/assistance herb pairs. For qualitative analysis, 85 characteristic components were identified using the liquid chromatography with triple time-of-flight mass/mass spectrometry (LC-Triple QTOF-MS/MS) based on the mass defect filtering, product ion filtering, neutral loss filtering and isotope pattern filtering techniques. For quantitative detection, a relative quantitation assay using an extract ion chromatogram (EIC) of the full scan MS experiment was validated and employed to assess the quantity of the 85 identified compounds in the test samples of single herb, herb pairs and XDT. The results of multivariate statistical analyses indicated that both the assistant and guide herbs could improve the solubilization of active compounds from the sovereign and minister herbs in XDT in vitro, might change the trans-membrane transportation, and regulate metabolism in vivo. The methods used in present study might be also valuable for the investigation of multiple components from other classic TCM formulas for the purpose of compatibility feature study.

Whole-genome resequencing reveals the uniqueness of Subei yak.

Subei yak is an essential local yak in the Gansu Province, which genetic resource has recently been discovered. It is a meat-milk dual-purpose variety with high fecundity and relatively stable population genetic structure. However, its population genetic structure and genetic diversity are yet to be reported. Therefore, this study aimed to identify molecular markers of Subei yak genome by whole-genome resequencing, and to analyze the population structure and genetic diversity of Subei yak. This study screened 12,079,496 single nucleotide polymorphism (SNP) molecular markers in the 20 Subei yaks genome using whole-genome resequencing technology. Of these SNPs, 32.09% were located in the intronic region of the genome. Principal component analysis, phylogenetic analysis, and population structure analysis revealed that the Subei yak belonged to an independent group in the domestic yak population. A selective clearance analysis was carried out on Subei yak and other domestic yaks, and the genes under positive selection were annotated. The functional enrichment analysis showed that Subei yak possessed prominent selection characteristics in terms of external environment perception, hypoxia adaptation, and muscle development. Furthermore, Subei yak showed excellent muscle fat deposition and meat quality traits. Thus, this study will serve as a reference for discovering population structure, genetic evolution, and other unique traits of Subei yak and for expanding the genetic variation catalog of yaks.

Subei yak is an important local yak genetic resource newly discovered in Gansu Province. In this study, the molecular markers of Subei yak genome were identified by whole-genome resequencing. Principal component analysis, phylogenetic analysis, and population structure analysis showed that Subei yak belonged to an independent group in the domestic yak population. In addition, functional enrichment analysis showed that Subei yaks had prominent selection characteristics in external environment perception, hypoxia adaptation, and muscle development.

Moiré fringe imaging of heterostructures by scanning transmission electron microscopy.

A heterostructured crystalline bilayer specimen is known to produce moiré fringes (MFs) in the conventional transmission electron microscopy (TEM). However, the understanding of how these patterns form in scanning transmission electron microscopy (STEM) remains limited. Here, we extended the double-scattering model to establish the imaging theory of MFs in STEM for a bilayer sample and applied this theory to successfully explain both experimental and simulated STEM images of a perovskite PbZrO3/SrTiO3 system. Our findings demonstrated that the wave vectors of electrons exiting from Layer-1 and their relative positions with the atomic columns of Layer-2 should be taken into account. The atomic column misalignment leads to a faster reduction in the intensity of the secondary scattering beam compared to the single scattering beam as the scattering angle increases. Consequently, the intensity distribution of MFs in the bright field (BF)-STEM can be still described as the product of two single atomic images. However, in high angle annular dark field (HAADF)-STEM, it is approximately described as the superposition of the two images. Our work not only fills a knowledge gap of MFs in incoherent imaging, but also emphasizes the importance of the coherent scattering restricted by the real space when analyzing the HAADF-STEM imaging.