Roles of the Narrow Electronic Band near the Fermi Level in 1T-TaS_{2}-Related Layered Materials.

Here we use low-temperature scanning tunneling microscopy and spectroscopy to reveal the roles of the narrow electronic band in two 1T-TaS_{2}-related materials (bulk 1T-TaS_{2} and 4H_{b}-TaS_{2}). 4H_{b}-TaS_{2} is a superconducting compound with alternating 1T-TaS_{2} and 1H-TaS_{2} layers, where the 1H-TaS_{2} layer has a weak charge density wave (CDW) pattern and reduces the CDW coupling between the adjacent 1T-TaS_{2} layers. In the 1T-TaS_{2} layer of 4H_{b}-TaS_{2}, we observe a narrow electronic band located near the Fermi level, and its spatial distribution is consistent with the tight-binding calculations for two-dimensional 1T-TaS_{2} layers. The weak electronic hybridization between the 1T-TaS_{2} and 1H-TaS_{2} layers in 4H_{b}-TaS_{2} shifts the narrow electronic band to be slightly above the Fermi level, which suppresses the electronic correlation-induced band splitting. In contrast, in bulk 1T-TaS_{2}, there is an interlayer CDW coupling-induced insulating gap. In comparison with the spatial distributions of the electronic states in bulk 1T-TaS_{2} and 4H_{b}-TaS_{2}, the insulating gap in bulk 1T-TaS_{2} results from the formation of a bonding band and an antibonding band due to the overlap of the narrow electronic bands in the dimerized 1T-TaS_{2} layers.

Theoretical study on the light-emitting mechanism of circularly polarized luminescence molecules with both thermally activated delayed fluorescence and aggregation-induced emission.

Circularly polarized luminescence molecules with both thermally activated delayed fluorescence (TADF) and aggregation-induced emission (AIE) have been reported recently and are thought as potential candidates for circular polarized organic light-emitting diodes. Since the study of these kinds of systems is quite limited, it is of great importance to reveal the relationship between the geometry and the light-emitting mechanism. In this paper, the TADF and AIE mechanisms were studied based on the study of a series of binaphthalene-containing luminogenic enantiomers in both toluene and solid phases. It was found that there was no influence on the light-emitting properties of enantiomers except for the electronic circular dichroism (ECD). The radiative rates for both molecules were enhanced in the solid phase, while the non-radiative rates were significantly suppressed. Both factors can induce the AIE phenomenon. Based on the calculation of the decay rates and adiabatic excitation energy of the excited states, we found that the TADF mechanisms of the two molecules were different. One is realized by the up-conversion process between S1 and T1, while a two-step process is involved for the other. Our theoretical research successfully elucidates the experimental measurement and illustrates the AIE and TADF mechanism, which could provide valuable insights for the design of highly efficient CPL emitters.

Tuning Phase Transitions in 1T-TaS2 via the Substrate.

Phase transitions in 2D materials can lead to massive changes in electronic properties that enable novel electronic devices. Tantalum disulfide (TaS2), specifically the "1T" phase (1T-TaS2), exhibits a phase transition based on the formation of commensurate charge density waves (CCDW) at 180 K. In this work, we investigate the impact of substrate choice on the phase transitions in ultrathin 1T-TaS2. Doping and charge transfer from the substrate has little impact on CDW phase transitions. On the contrary, we demonstrated that substrate surface roughness is a primary extrinsic factor in CCDW transition temperature and hysteresis, where higher roughness leads to smaller transition hysteresis. Such roughness can be simulated via surface texturing of SiO2/Si substrates, which controllably and reproducibly induces periodic strain in the 1T-TaS2 and thereby enables the potential for engineering CDW phase transitions.

Improvement of anti-nutritional effect resulting from ß-glucanase specific expression in the parotid gland of transgenic pigs.

ß-Glucan is the predominant anti-nutritional factors in monogastric animal feed. Although ß-glucanase supplementation in diet can help to eliminate the adverse effects, enzyme stability is substantially modified during the feed manufacturing process. To determine whether the expression of endogenous ß-glucanase gene (GLU) in vivo can improve digestibility of dietary ß-glucan and absorption of nutrients, we successfully produced transgenic pigs via nuclear transfer which express the GLU from Paenibacillus polymyxa CP7 in the parotid gland. In three live transgenic founders, ß-glucanase activities in the saliva were 3.2, 0.07 and 0.03 U/mL, respectively, and interestingly the enzyme activities increased in the pigs from 178 days old to 789 days old. From the feed the amount of gross energy, crude protein and crude fat absorbed by the transgenic pigs was significantly higher than the non-transgenic pigs. Meanwhile the moisture content of the feces was significantly reduced in transgenic pigs compared with the non-transgenic pigs. Furthermore, in all positive G1 pigs, ß-glucanase activity was detectable and the highest enzyme activity reached 3.5 U/mL in saliva. Also, crude protein digestion was significantly higher in G1 transgenic pigs than in control pigs. Taken together, our data showed that the transgenic ß-glucanase exerted its biological catalytic function in vivo in the saliva, and the improved performance of the transgenic pigs could be accurately passed on to the offspring, indicating a promising alternative approach to improving nutrient availability was established to improve utilization of livestock feed through transgenic animals.

Electrically driven reversible insulator-metal phase transition in 1T-TaS2.

In this work, we demonstrate abrupt, reversible switching of resistance in 1T-TaS2 using dc and pulsed sources, corresponding to an insulator-metal transition between the insulating Mott and equilibrium metallic states. This transition occurs at a constant critical resistivity of 7 mohm-cm regardless of temperature or bias conditions and the transition time is significantly smaller than abrupt transitions by avalanche breakdown in other small gap Mott insulating materials. Furthermore, this critical resistivity corresponds to a carrier density of 4.5 × 10(19) cm(-3), which compares well with the critical carrier density for the commensurate to nearly commensurate charge density wave transition. These results suggest that the transition is facilitated by a carrier driven collapse of the Mott gap in 1T-TaS2, which results in fast (3 ns) switching.

The aflatoxin-detoxifizyme specific expression in mouse parotid gland.

The aflatoxin-detoxifizyme (ADTZ) gene derived from Armillariella tabescens was cloned into parotid gland-specific expression vector (pPSPBGPneo) to construct the parotid gland-specific vector expressing ADTZ (pPSPBGPneo-ADTZ). Transgenic mice were generated by microinjection and identified by using PCR and Southern blotting analysis. PCR and Southern blotting analysis showed that total six transgenic mice carried the ADTZ gene were generated. RT-PCR analysis indicated that the expression of ADTZ mRNA could be detected only in parotid glands of the transgenic mice. The ADTZ activity in the saliva was found to be 3.72 ± 1.64 U/mL. After feeding a diet containing aflatoxin B1 (AFB1) for 14 days, the effect of ADTZ on serum biochemical indexes and AFB1 residues in serum and liver of mice were evaluated. The results showed that total protein and globulin contents in the test treatment (transgenic mice) produced ADTZ were significantly higher than that of the positive control, while alanine aminotransferase and aspartate aminotransferase activity in serum of the test treatment (transgenic mice) were remarkably lower compared to that of the positive control (P < 0.05). Moreover, AFB1 residues in serum and liver of the test treatment (transgenic mice) were significantly lower compared with that of the positive control (P < 0.05). These results in the study confirmed that ADTZ produced in transgenic mice could reduce, even eliminate the negative effects of AFB1 on mice.

Effect of Carvedilol on Serum Heart-type Fatty Acid-binding Protein, Brain Natriuretic Peptide, and Cardiac Function in Patients With Chronic Heart Failure.

OBJECTIVE: To observe the changes of serum heart-type fatty acid-binding protein (h-FABP) and brain natriuretic peptide (BNP) in children with chronic heart failure (CHF) and evaluate the effects of carvedilol. METHODS: A total of 36 patients with CHF, including 17 of endocardial fibroelastosis and 19 of dilated cardiomyopathy, were enrolled and were randomly divided into a carvedilol treatment group (group A) and a conventional treatment group (group B). Group A (n = 16) was treated with carvedilol and conventional treatment and group B (n = 20) was managed with conventional treatment only. Thirty healthy children were enrolled as controls. The concentrations of serum h-FABP and BNP were measured by enzyme-linked immunosorbent assay, and the left ventricular end-systolic diameter, left ventricular end-diastolic diameter, left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), and cardiac index (CI) were measured by echocardiography. RESULTS: The concentrations of serum h-FABP and BNP in patients with CHF were significantly higher than in the control group (21.7 ± 4.3 ng/mL vs. 6.3 ± 1.7 ng/mL, 582.4 ± 180.6 pg/mL vs.31.2 ± 9.8 pg/mL, all P < 0.01), positively correlated with the degree of heart failure (all P < 0.01), and were both higher in groups endocardial fibroelastosis and dilated cardiomyopathy than in the control group (all P < 0.01), but there was no statistically significant difference between the 2 groups (P > 0.05). h-FABP concentration in patients with CHF was positively correlated with BNP (r = 0.78, P < 0.01) but negatively correlated with LVEF, LVFS, and CI (r = -0.65, -0.64, and -0.71, respectively; all P < 0.01). BNP concentration was also negatively correlated with LVEF, LVFS, and CI (r = -0.75, -0.61, and -0.79, respectively; all P<0.01). After treatment with carvedilol, the serum concentrations of h-FABP and BNP in group A were lower than in group B, and the magnitude of heart rate reduction, improvement of LVEF, LVFS, and CI, and reduction of left ventricular end-systolic diameter and left ventricular end-diastolic diameter in group A were all greater than in group B (all P < 0.01). Treatment with carvedilol had no adverse events. CONCLUSIONS: Serum concentrations of h-FABP and BNP can be used as biomarkers to evaluate the severity of heart failure, and carvedilol can significantly improve heart function in children with CHF.

Association of apolipoprotein E (ApoE) polymorphisms with risk of primary hyperuricemia in Uygur men, Xinjiang, China.

BACKGROUND: Apolipoprotein E (ApoE) participates in lipoprotein metabolism and immune regulation. This study assessed association between ApoE polymorphisms with hyperuricemia and uric acid metabolism in Uygur men, Xinjiang, China. METHODS: A total of 474 hyperuricemia patients and 518 healthy male controls were recruited from the Health Screening Center, Uygur region of Xinjiang, China and subjected to ApoE genotyping using a multiplex amplification refractory mutation system PCR. RESULTS: Apolipoprotein E3/3 genotype was the predominant type with a frequency of 67.7%, while E2/2 was lower than E4/4 in Uygur males. The frequencies of ApoE2, E3, and E4 alleles were 8.5%, 80.1% and 11.4%, respectively. Distribution of ApoE genotypes was significantly different in hyperuricemia patients from the healthy controls (p<0.001). Particularly, the frequency of ApoE E3/3 was 71.7%, E2/3 9.3%, E3/4 9.3%, E4/4 3.2%, E2/4 2.3%, and E2/2 0.2% in patients vs. 68.1%, 4.6%, 2.9%, 12%, 0.6%, and 4.6% in controls, respectively. Moreover, frequency of ApoE E2 allele was greater in the healthy controls than in patients (p<0.001) and the highest level of uric acid occurred in those with ApoE2/4 and E3/4 genotypes, whereas the lowest uric acid level occurred in those with ApoE E2/2 genotype. In addition, the subjects with the ApoE2 allele had a lower uric acid and LDL-C level than those with the ApoE3 allele and ApoE4 allele (p<0.05). The risk of developing hyperuricemia in subjects without the ApoE2 allele was 1.7 fold higher than those subjects with the ApoE2 allele. CONCLUSIONS: This study revealed frequencies and distributions of ApoE alleles and genotypes in Uygur males, which are different from Han Chinese. ApoE E4 was associated with a slightly higher risk of primary hyperuricemia, whereas ApoE E2 was associated with reduced risk of primary hyperuricemia and LDL-C level.

The prevalence of nonalcoholic fatty liver disease and relationship with serum uric acid level in Uyghur population.

OBJECTIVE: To investigate the prevalence of nonalcoholic fatty liver disease (NAFLD) and the association of serum uric acid level with NAFLD in Uygur people, Xinjiang. METHODS: A total of 2241 Uyghur persons (1214 males and 1027 females) were interviewed for physical checkups from 2011 to 2012. The clinical data of questionnaire survey, body mass index (BMI), abdominal circumference, blood pressure, blood sugar, blood lipid, and serum uric acid level were collected for analysis. RESULTS: The prevalence rates of NAFLD determined by abdominal ultrasound examination and hyperuricemia were 43.9% and 8.4%, respectively. The persons with NAFLD had significantly higher serum uric acid levels than those without NAFLD (320 ± 88 versus 254 ± 80 µ mol/L; P < 0.001). The prevalence rate of NAFLD was significantly higher in subjects with hyperuricemia than that in those without hyperuricemia (78.19% versus 40.83%; P < 0.001), and the prevalence rate increased with progressively higher serum uric acid levels (P < 0.001). Multiple regression analysis showed that hyperuricemia was associated with an increased risk of NAFLD (odds ratio (OR): 2.628, 95% confidence interval (CI): 1.608-4.294, and P < 0.001). CONCLUSION: Serum uric acid level was significantly associated with NAFLD, and the prevalence rate of NAFLD increased with progressively higher serum uric acid levels.

ß-Glucanase specific expression in the parotid gland of transgenic mice.

The feasibility of using the pig parotid secretory protein promoter to drive the ß-glucanase transgene expression in mouse parotid glands was examined in this study. The parotid gland-specific vector expressing ß-glucanase gene (GLU, from Paenibacillus polymyxa CP7) was constructed. Transgenic mice were produced by the pronuclear microinjection. Both PCR and Southern blot analysis showed that the mice carried the ß-glucanase gene and the ß-glucanase gene could be stably inherited. Furthermore, RT-PCR and northern blot analysis indicated that it was specifically expressed in the parotid. The ß-glucanase activity in the saliva was found to be 0.18 U/mL. After feeding a diet containing 2 % ß-glucan, the average daily gain of transgenic was significantly higher than non-transgenic mice. The crude protein and crude fat concentration in faeces of transgenic mice were significantly reduced compared with that of the non-transgenic mice. These results suggest that the successful expression of foreign ß-glucanase in the animal parotid would offer a promising biological approach to reduce the anti-nutritional effect of ß-glucans in feed.