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We report on a photoluminescence observation of robust excitonic polarons due to resonant coupling of exciton and longitudinal optical (LO) phonon as well as Fano-type interference in high quality ZnO crystal. At low enough temperatures, resonant coupling of excitons and LO phonons leads to not only traditional Stokes lines (SLs) but also up to second-order anti-Stokes lines (ASLs) besides the zero-phonon line (ZPL). The SLs and ASLs are found to be not mirror symmetric with respect to the ZPL, strongly suggesting that they are from different coupling states of exciton and phonons. Besides these spectral features showing the quasiparticle properties of exciton-phonon coupling system, the first-order SL is found to exhibit characteristic Fano lineshape, caused by quantum interference between the LO components of excitonic polarons and the continuous phonon bath. These findings lead to a new insight into fundamental effects of exciton-phonon interactions. [ABSTRACT FROM AUTHOR]

Estimating the feed intake of grazing herbivores is critical for determining their nutrition, overall productivity and utilization of grassland resources. A 17-day indoor feeding experiment was conducted to evaluate the potential use of Medicago sativa as a natural supplement for estimating the total feed intake of sheep. A total of 16 sheep were randomly assigned to four diets (four sheep per diet) containing a known amount of M. sativa together with up to seven forages common to typical steppes. The diets were: diet 1, M. sativa + Leymus chinensis + Puccinellia distans ; diet 2, species in diet 1 + Phragmites australis ; diet 3, species in diet 2 + Chenopodium album + Elymus sibiricus ; and diet 4, species in diet 3 + Artemisia scoparia + Artemisia tanacetifolia. After faecal marker concentrations were corrected by individual sheep recovery, treatment mean recovery or overall recovery, the proportions of M. sativa and other dietary forages were estimated from a combination of alkanes and long-chain alcohols using a least-square procedure. Total intake was the ratio of the known intake of M. sativa to its estimated dietary proportion. Each dietary component intake was obtained using total intake and the corresponding dietary proportions. The estimated values were compared with actual values to assess the estimation accuracy. The results showed that M. sativa exhibited a distinguishable marker pattern in comparison to the other dietary forage species. The accuracy of the dietary composition estimates was significantly (P < 0.001) affected by both diet diversity and the faecal recovery method. The proportion of M. sativa and total intake across all diets could be accurately estimated using the individual sheep or the treatment mean recovery methods. The largest differences between the estimated and observed total intake were 2.6 g and 19.2 g, respectively, representing only 0.4% and 2.6% of the total intake. However, they were significantly (P < 0.05) biased for most diets when using the overall recovery method. Due to the difficulty in obtaining individual sheep recovery under field conditions, treatment mean recovery is recommended. This study suggests that M. sativa , a natural roughage instead of a labelled concentrate, can be utilized as a dietary supplement to accurately estimate the total feed intake of sheep indoors and further indicates that it has potential to be used in steppe grassland of northern China, where the marker patterns of M. sativa differ markedly from commonly occurring plant species. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Due to the increase in human life expectancy, a higher number of individuals are experiencing age-related cognitive impairments. Therefore, it is important to investigate the methods to tackle the effects of aging. MATERIALS AND METHODS: The mice were divided into the following groups: the aging mice (male, 20 months) and young mice (male, 2 months) were pairing-housed together in the same cage and lasted for at least one month (Aging-Young). The following tests were performed for the mice in different groups: Open field test, Morris water maze (MWM) test, Contextual fear conditioning test, Novel Object Recognition (NOR) test, Pain threshold test, Olfactory habituation/dishabituation test, T-maze test, Electrophysiological recordings. RESULTS: In this study, we housed aging and young mice together, and found that the paired housing for one-month improved the learning and memory of the aging mice. These mice exhibited better performance on the Morris water maze (MWM) test, a longer freezing duration in the contextual fear conditioning test, a higher alternation rate in the T-maze test, and an increased preference for novel objects in the novel object recognition (NOR) test. The paired housing with young mice also improved the impaired long-term potentiation (LTP) in aging mice. CONCLUSIONS: Our results suggest that the paired housing with young mice has beneficial effects on learning and memory of aging mice. The manipulation of the systemic environment may, therefore, provide a new strategy for aging rejuvenation. [ABSTRACT FROM AUTHOR]

Low-temperature photoluminescence spectroscopy has revealed a series of features labeled S1, S2, S3 in n-type 6H-SiC after neutron and electron irradiation. Thermal annealing studies showed that the defects S1, S2, S3 disappeared at 500 °C. However, the well-known D1 center was only detected for annealing temperatures over 700 °C. This experimental observation not only indicated that the defects S1, S2, S3 were a set of primary defects and the D1 center was a kind of secondary defect, but also showed that the D1 center and the E1, E2 observed using deep level transient spectroscopy might not be the same type of defects arising from the same physical origin. [ABSTRACT FROM AUTHOR]

Whole-crop wheat (Triticum aestivum L.) as forage has been extensively used in the world. In this study, the effects of N application rates on the yields, nutritive value and silage quality were investigated. The N application rates were 0, 75, 150, 225, and 300 kg/ha. The research results indicated that the dry matter yield of whole-crop wheat increased significantly with increasing N rate up to 150 kg/ha, and then leveled off. The crude protein content and in vitro dry matter digestibility of whole-crop wheat increased significantly with increasing N up to 225 kg/ha, while they no longer increased at N 300 kg/ha. On the contrary, the content of various fibers tended to decrease with the increase of N application. The content of lactic acid, acetic acid and propionic acid in silages increased with the increase of N rate (p<0.05). The ammonia-N content of silages with higher N application rates (≥225 kg/ha) was significantly higher than that with lower N application rates (≤150 kg/ha). Whole-crop wheat applied with high levels of N accumulated more nitrate- N. In conclusion, taking account of yields, nutritive value, silage quality and safety, the optimum N application to whole-crop wheat should be about 150 kg/ha at the present experiment conditions. [ABSTRACT FROM AUTHOR]

By using press-volume technique, this paper studied the seasonal changes of water potential at saturated point (Ψssat), water potential at turgor loss point (Psistlp), relative osmotic water content at turgor loss point (ROWCtlp), relative water content at turgor loss point (RWCtlp), relative content of apoplastic water (AWC), bound water/ free water (Va/Vo), and the difference between Ψssat and (Ψstlp(ΔP) of Reaumuria trigyna growing on heavy solonchack, non-salinized soil, and saline soil. The seasonal changes of Ψssat and Ψstlp were in order of May > July > September, while those of AWC, Va/Vo, and ΔP were in opposite sequence, indicating that the water deficit resistance ability of R. trigyna enhanced with season, being consistent with its growth rhythm. Comparing with other xerophytes, R. trigyna had very low Ψssat and Ψstlp, presenting its strong ability of maintaining high osmotic pressure and low water potential. Based on the water parameters measured in three months, and by using the subordination function of fuzzy mathematics, the water deficit resistance ability of R. trigyna was evaluated, which was the strongest on heavy solonchack, followed by on non-salinized soil, and on saline soil. [ABSTRACT FROM AUTHOR]

During the rice- and wheat-growing seasons we studied denitrification in the underground saturated soil within a rice paddy region. High concentrations of N2O were observed in the samples taken from observation wells of different depth, with a maximum of 225.4±12.3 μg N-N2O l−1 (n=6) for the rice season and 110.0±35.7 μg N-N2O l−1 (n=6) for wheat at 2.5 m depth, respectively. High δ15N values of NO3− were also observed in the samples collected from observation wells from 2.0 to 5.0 m in depth during the rice and wheat seasons, ranging from 38.0±3.32 (n=3) to 78.8±14.5 (n=3) and from 35.42±6.38 (n=3) to 77.18±2.66 (n=3), respectively. We also found that water from wells for domestic use, sampled at around 5 m in depth had high concentrations of N2O and high δ15NO3− values. In regions with high N input, denitrification in the underground saturated soil, on the one hand, mitigates NO3− load in the groundwater, and contributes N2O to atmosphere on the other. [Copyright &y& Elsevier]

Objective: To investigate the efficacy and clinical outcomes of intracytoplasmic sperm injection (ICSI) with micro amount frozen-thawed diagnostic sperm obtained by microdissection testicular sperm extraction (microTESE), percutaneous epididymal sperm as-piration (PESA) and testicularsperm extraction (TESA) in the treatment of azoospermia. Methods: A retrospective analysis was performed on 736 ICSI cycles of azoospermia patients.In Reprocluctive Medicine Center of the First Affiliated Hospital of Zhengzhou University from January 2018 to December 2019. Including 199 ICSI cycles (microTESE 47cycles, PESA 75cycles and TESA 77 cycles) with micro amount frozen-thawed diagnostic sperm and 537 ICSI cycles (microTESE 23 cycles, PESA 111 cycles and TESA 403 cycles) with fresh micro amount sperm. The general conditions, embryo development conditions and clinical outcomes of patients were compared between and within the two groups. Results: The recovery rate of PESA group was significantly lower than that of TESA group (89.3% vs 98.7%), P< 0.05. The rate of 2PN in the fresh control group was significantly higher than that in the experiment group (75.5% vs 71.3%) and the rate of 2PN in the fresh microTESE and PESA groups were also significantly higher than those of the frozen-thawed microTESE and PESA groups (74.2% vs 64.6%) and (78.5% vs 72.4%), P <0.05. Both the rate of D5 blastocyst formation and high quality blastocyst in the fresh group were significantly lower than that in the experiment group (26.9% vs 32.9%) and (15.1% vs 18.0%), P <0.05; both the rate of early cleavage and blastocyst formation in the fresh microTESE group were significantly lower than that in the frozen-thawed microTESE group (55.1% vs 68.3%) (27.3% vs 39.3%), P <0.05. Both the rate of 8 cells embryos and blastocyst formation in the fresh TESA group were significantly lower than those of the TESA frozen-thawed group (41.3% vs 46.0%) (26.5% vs 32.4%), P <0.05. There was no significant difference in pregnancy rate and planting rate between or within the groups( P> 0.05). The abortion rate in the frozen-thawed group was significantly higher than the fresh group (12.0% vs 4.0%), P <0.05, especially the abortion rate in the PESA frozen-thawed group was significantly higher than the fresh group (18.0% vs 1.7%), P <0.05. There was no significant difference in gender, weight and body length between the fresh group and the frozen-thawed group ( P> 0.05), but there were two malformed babies born in the frozen-thawed group. Conclusions: Frozen-thawed microinjection of diagnostic microspermatozoa is a feasible method for the treatment of asthenospermia.There was on significonty difference in pregnancy rate and planting rate between of with in the groups. However, significantly higher than the fresh PESA group of the influence on offspring needs to be further studied.

Objective: To investigate the effects of age and body mass index (BMI) on embryo development time kinetic parameters, embryo development potential and clinical pregnancy outcomes. Methods: A retrospective study was conducted to analyze the data of 6 294 embryos from 832 patients who underwent in vitro fertilization and embryo transfer (IVF-ET) in the Reproductive Medicine Center of the First Affiliated Hospital of Zhengzhou University from September 2016 to November 2018. According to the age, they were divided into two groups:<35-year-old group (655 cases, 5 076 embryos), ≥35-year-old group (177 cases, 1 218 embryos). According to the BMI, they were divided into three groups: low body mass group (BMI<18.5 kg/m(2), 47 cases, 355 embryos), normal body recombination (18.5-23.9 kg/m(2), 517 cases, 3 813 embryos), hyperrecombination (BMI>23.9 kg/m(2), 268 cases, 2 126 embryos). Embryo development time kinetic parameters, embryo development potential and clinical pregnancy outcomes in each group were compared. Results: Embryo development to 3 cells, 4 cells were faster in < 35-year-old group than in ≥35-year-old group. The blastocyst formation rate, high-quality blastocyst formation rate, pregnancy rate, implantation rate, delivery rate, live birth rate, and abortion rate were all statistically significant (all P< 0.05). There were no significant differences in normal fertilization rate, cleavage rate, embryo utilization rate, high quality embryo rate, pregnancy rate, implantation rate, abortion rate, delivery rate, live birth rate between the three BMI groups (all P> 0.05). Conclusions: The age has an effect on the partial embryo development time kinetic parameters, but BMI has a little effect on it.