Search

The mammalianYchromosome plays a critical role in spermatogenesis. However, the exact functions of each gene on the Y chromosome have not been completely elucidated, due, in part, to difficulties in gene targeting analysis of the Y chromosome. The zinc finger protein, Y-linked (ZFY) gene was first proposed to be a sex determination factor, although its function in spermatogenesis has recently been elucidated. Nevertheless, ZFY gene targeting analysis has not been performed to date. In the present study, RNA interference (RNAi) was used to generate ZFY-interrupted Hu sheep by injecting short hairpin RNA (shRNA) into round spermatids. The resulting spermatozoa exhibited abnormal sperm morphology, including spermatozoa without tails and others with head and tail abnormalities. Quantitative real-time polymerase chain reaction analysis showed that ZFY mRNA expression was decreased significantly in Hu sheep with interrupted ZFY compared with wild-type Hu sheep. The sex ratio of lambs also exhibited a bias towards females. Together, the experimental strategy and findings of the present study reveal that ZFY also functions in spermatogenesis in Hu sheep and facilitate the use of RNAi in the control of sex in Hu sheep. [ABSTRACT FROM AUTHOR]

Co epitaxial thin films with 2.5nm thickness were prepared on single-crystal MgO(001) substrates and annealed at different temperatures. The contribution of each interface of the MgO/Co/Cu trilayer to the in-plane magnetic anisotropy (IMA) was studied by changing interfacial coupling through annealing. The structure was measured by low energy electron diffraction (LEED), and the magnetic properties were measured using the anisotropic magnetoresistance (AMR) measurements and the longitudinal Magneto-optical Kerr effect magnetometer (MOKE). We found that the magnetic anisotropy of the as-deposited one shows superposition of a two-fold symmetry with a weak four-fold contribution caused by the stress of the interface between Co/Cu, which is along the easy axis [-110]. After annealing at 200°C, the symmetry of magnetic anisotropy was changed from uniaxial magnetic anisotropy (UMA) into four-fold symmetry due to the significant increasing of four-fold magnetocrystalline anisotropy. When the films were annealed above 300°C, the damage of the MgO/Co interface additionally decreased the IMA to isotropy. Meanwhile, the coercivity raised from 45Oe (without annealing) to 1200Oe (annealed at 400°C) along the easy axis direction. Our experimental results prove that the Co/Cu interface and the MmO/Co interface play an essential role in manipulating the four-fold and the UMA in the system. [ABSTRACT FROM AUTHOR]

Identifying the plants aphids have fed on can increase our understanding of their roles in food webs, and help in improving management and implementation control strategies in agricultural systems. Field sampling and laboratory experiments were carried out to determine the stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) in three different varieties of cotton and the aphids (Aphis gossypii) that fed on these varieties. The results were used to test the hypothesis that stable isotope signatures of aphids that have fed on different varieties of cotton differ. Two-dimensional plots of stable isotope signatures for aphids and the cotton varieties they fed on displayed a non-overlapping pattern, indicating that stable isotope signatures of the three cotton varieties and the aphids that fed on them differed. The results indicate that stable isotope analysis can potentially be used to identify aphids that have fed on different varieties of cotton. When the stable isotope signatures of diets clearly differ then it is highly likely the consumers will be distinguishable. [ABSTRACT FROM AUTHOR]

The controllable synthesis of 3-methylene-2,3-dihydrobenzofurans 2 and 3-methylene-2,3-dihydroindoles 5 has been developed through Rh-catalyzed intramolecular annulation of aromatic rings with azavinyl carbenes. [ABSTRACT FROM AUTHOR]

Rh(II)-catalyzed novel tandem intramolecular cycloisomerizations of aldehydes or ketones with 1-sulfonyl 1,2,3-triazoles have been disclosed, providing a facile protocol to access a series of functionalized aza-bridged benzodioxepine heterocycles. [ABSTRACT FROM AUTHOR]

We construct a Parrondo's game using discrete-time quantum walks (DTQWs). Two losing games are represented by two different coin operators. By mixing the two coin operators UA(αA,βA,γA) and UB(αB,βB,γB)), we may win the game. Here, we mix the two games in position instead of time. With a number of selections of the parameters, we can win the game with sequences ABB, ABBB, etc. If we set βA = 45°,γA = 0,αB = 0, ⓰B = 88°, we find game 1 with UAS = US(-51°,45°,0), = UBS(0,88°,-16°) will win and get the most profit. If we set αA = 0,⓰A = 45°, αB = 0,βB = 88° and game 2 with UAS = US(0,45°, -51°), UBS = US(0,88°, -67°) will win most. Game 1 is equivalent to game 2 with changes in sequences and steps. But at large enough steps, the game will lose at last. Parrondo's paradox does not exist in classical situation with our model. [ABSTRACT FROM AUTHOR]

We investigate the discrete-time quantum random walks on a line in periodic potential. The probability distribution with periodic potential is more complex compared to the normal quantum walks, and the standard deviation σ has interesting behaviors for different period q and parameter θ. We study the behavior of standard deviation with variation in walk steps, period, and θ. The standard deviation increases approximately linearly with θ and decreases with 1/q for θ ∈ (0, π/4), and increases approximately linearly with 1/q for θ ∈ [π/4, π/2). For θ ∈ (π/4, 3π/4), the transmission is larger than the reflection, with sensibility the diffussion will be accelerated. However, when q = 2, the standard deviations are nearly the same, and when q > 2, the standard deviation will decrease. [ABSTRACT FROM AUTHOR]

Celastrol, a quinone methide triterpene isolated from Tripterygium wilfordii Hook F., has various biochemical and pharmacological activities, and is now being developed as a promising anti-tumor agent. Inhibitory activity of compounds towards UDP-glucuronosyltransferase (UGT) is an important cause of clinical drug-drug interactions and herb-drug interactions. The aim of the present study is to investigate the inhibition of celastrol towards two important UDP-glucuronosyltransferase (UGT) isoforms UGT1A6 and UGT2B7. Recombinant UGT isoforms and non-specific substrate 4-methylumbelliferone (4-MU) were used. The results showed that celastrol strongly inhibited the UGT1A6 and 2B7-mediated 4-MU glucuronidation reaction, with 0.9 ± 0.1% and 1.8 ± 0.2% residual 4-MU glucuronidation activity at 100 μM of celastrol, respectively. Furthermore, inhibition kinetic study (Dixon plot and Lineweaver-Burk plot) demonstrated that celastrol noncompetitively inhibited the UGT1A1-mediated 4-MU glucuronidation, and competitively inhibited UGT2B7-catalyzed 4-MU glucuronidation. The inhibition kinetic parameters (Ki) were calculated to be 0.49 μM and 0.045 μM for UGT1A6 and UGT2B7, respectively. At the therapeutic concentration of celastrol for anti-tumor utilization, the possibility of celastrol-drug interaction and celastrol-containing herbs-drug interaction were strongly indicated. However, given the complicated nature of herbs, these results should be viewed with more caution. [ABSTRACT FROM AUTHOR]

Gossypol, the polyphenolic constituent isolated from cottonseeds, has been used as a male antifertility drug for a long time, and has been demonstrated to exhibit excellent anti-tumor activity towards multiple cancer types. The toxic effects of gossypol limit its clinical utilization, and enzyme inhibition is an important facet of this. In the present study, in vitro human liver microsomal incubation system supplemented with UDPGA was used to investigate the inhibition of gossypol towards UGT1A1, 1A9 and 2B7-mediated metabolism of xenobiotics and endogenous substances. Estradiol, the probe substrate of UGT1A1, was selected as representative endogenous substance. Propofol (a probe substrate of UGT1A9) and 3'-azido-3'-deoxythimidine (AZT, a probe substrate of UGT2B7) were employed as representative xenobiotics. The results showed that gossypol noncompetitively inhibits UGT-mediated estradiol-3-glucuronidation and propofol O-glucuronidation, and the inhibition Kinetic parameters (Ki) were calculated to be 34.2 and 16.4 μM, respectively. Gossypol was demonstrated to exhibit competitive inhibition towards UGT-mediated AZT glucuronidation, and the inhibition Kinetic parameter (Ki) was determined to be 14.0 μM. All these results indicated that gossypol might induce metabolic disorders of endogenous substances and alteration of metabolic behaviour of co-administered xenobiotics through inhibition of UGTs' activity. [ABSTRACT FROM AUTHOR]

Engineering the surface morphology of magnetic film is one of the important methods to tune the magnetic anisotropy of ultrathin magnetic material. However, the influence of competing shape effects on magnetic anisotropy of ultrathin film is still not clearly demonstrated. Here, we investigated the magnetic anisotropy of obliquely deposited Fe films on vicinal Si(111) substrate by using in-situ and ex-situ surface magneto-optical Kerr effect (MOKE). Thickness-induced in-plane spin-reorientation transition, i.e. magnetization easy axis gradually rotates away from the step direction, was observed. MOKE measurements and micromagnetic simulation demonstrate this spin-reorientation transition process largely originated from the competition between step-induced magnetic shape anisotropy and oblique-deposition-induced magnetic shape anisotropy. Our study indicates the possibility of tuning magnetic spin order orientation by the competing magnetic shape anisotropies. [ABSTRACT FROM AUTHOR]

Cobalt thin films with 5 nm thickness were prepared on single-crystal MgO (001) substrates with different thickness Cu buffer (0 nm, 5 nm, 10 nm, 20 nm). The structure, magnetic properties and transport behaviors were investigated by employing low-energy-electron-diffraction (LEED), magneto-optical Kerr effect (MOKE) and anisotropic magnetoresistance (AMR). By comparing the magnetic properties of the sample as-deposited (without Cu buffer layer) one with those having the buffer Cu, we found that the magnetic anisotropy was extremely affected by the Cu buffer layer. The magnetic anisotropy of the as-deposited, without buffer layer, sample shows the uniaxial magnetic anisotropy (UMA). We found that the symmetry of the magnetic anisotropy is changed from UMA to four-fold when the thickness of the Cu buffer layer reaches to 20 nm. Meanwhile, the coercivity increased from 49 Oe (without buffer layer) to 300 Oe (with 20 nm Cu buffer), in the easy axis direction, as the thickness of the buffer layer increases. Moreover, the magnitudes of various magnetic anisotropy constants were determined from torque curves on the basis of AMR results. These results support the phenomenon shown in the MOKE. [ABSTRACT FROM AUTHOR]

A novel rhodium(II)-catalyzed tandem cycloisomerization of methylenecyclopropanes (MCPs) with N-sulfonyl 1,2,3-triazoles is disclosed. The reaction produces a series of highly functionalized polycyclic N heterocycles via a rhodium imino carbene intermediate. A distinct feature of this divergent synthesis is that different types of substrates control the reaction pathways. Moreover, several interesting transformations of these products to construct diazabicyclo[3.2.1]octane derivatives are also reported. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the clinical benefits and underlying mechanisms of action of betulin in the treatment of cancer using a neuroblastoma (NB) cell model. Method: Cell viability assay (MTT assay) was applied to investigate the effects of betulin on proliferation and apoptosis of SK-N-SH cell. The expression or translocation of apoptosis-related biomarkers, which include protein kinase C (PKC) family members, were analyzed and quantified by Western blotting, caspase activity assay or enzyme-linked immunosorbent assay (ELISA). Results: Betulin treatment significantly inhibited the growth of SK-N-SH cells (p < 0.001), with halfmaximal inhibition concentration (IC50) of 8 μmol/mL. Furthermore, betulin treatment increased the activity of PKC-δ, which subsequently activated caspases 3, 8 and 9, thus initiating mitochondriamediated endogenous apoptotic pathways in SK-N-SH cells Conclusion: Data generated in this study suggest that betulin inhibits cell proliferation and promotes apoptosis via PKC-δ activation, which may provide new insights into NB treatment from the perspective of adjuvant chemotherapy and prevention of tumor recurrence. [ABSTRACT FROM AUTHOR]

The present study evaluated the protective effect of selenium against cisplatin-induced nasopharyngeal cancer in the cardiac tissue of adult rats. Male Wistar rats were divided into 4 groups of 6 rats each. Different combinations of selenium and cisplatin were administered for 45 days, following which the animals were sacrificed and the nasopharyngeal tissue was surgically removed. Lipid peroxidation, reduced glutathione, and the antioxidant enzymes superoxide dismutase (SOD), catalase and lactate dehydrogenase (LDH) were measured. Apoptotic-related gene (p53, bax and caspase 3) mRNA expression was determined using quantitative polymerase chain reaction. Caspase 3 activity was also measured in all the groups. The results demonstrated that selenium significantly reduced the levels of malondialdehyde. The levels of glutathione, SOD, LDH and catalase significantly increased following selenium treatment. Relative mRNA expression (p53, bax and caspase 3) was significantly reduced in the cisplatin-treated rats, but it significantly increased following selenium treatment. The anticancer activity of selenium was also investigated in HK1cells. Fluorescence and confocal microscopy were used to analyze apoptosis and reactive oxygen species. The protective effect of selenium was also evident through caspase 3 activity, which significantly increased following selenium treatment. Taken together, these results indicate that selenium may be beneficial against cisplatin-induced nasopharyngeal cancer. [ABSTRACT FROM AUTHOR]

Postoperative early enteral nutrition (EEN) is useful for the effective recovery of patients that have undergone surgery. However, the feasibility and efficacy of EEN in patients with digestive tract surgery remain inconclusive. In the present meta-analysis, the PubMed, EMBASE, Web of Science, The Cochrane Library, China National Knowledge Infrastructure and VIP databases were searched to identify controlled trials of patients with and without EEN following digestive tract surgery between October, 1966 and December, 2014. Methodological quality assessment was carried out for each of the included studies. For estimation of the analysis indexes, relative risk (RR) was used as the effect size of the the categorical variable, while the weighted mean difference (MD) was used as the effect size of the continuous variable. The meta-analysis was conducted using RevMan 5.2 software. Eleven randomized controlled trials involving 1,095 patients were included in the meta-analysis. The results revealed that, EEN in patients with digestive tract surgery was more effective in decreasing the incidence of infectious [RR=0.50, 95% confidence interval (CI): 0.38, 0.67; P<0.01] and non-infectious complications (RR=0.72, 95% CI: 0.43, 1.22; P<0.05) and shortening the length of first bowel action (MD=-4.10, 95% CI: -5.38, -2.82; P<0.05). It also had a significant influence on increasing the serum albumin (MD=2.87, 95% CI: 1.03, 4.71; P<0.05) and serum prealbumin (MD=0.04, 95% CI: 0.02, 0.05; P<0.05) levels. In conclusion, the results of the study have shown that EEN in patients with digestive tract surgery improved the nutritional status, reduced the risk of postoperative complications, shortened the length of hospital stay and promoted the functional recovery of the digestive system. [ABSTRACT FROM AUTHOR]

Although the spin-reorientation transition from out-of-plane to in-plane in Fe/Si film is widely reported, the tuning of in-plane spin orientation is not yet well developed. Here, we report the thickness-, temperature- and Cu-adsorption- induced in-plane spin-reorientation transition processes in Fe/Si (557) film, which can be attributed to the coexistence of two competing step-induced uniaxial magnetic anisotropies, i.e., surface magnetic anisotropy with magnetization easy axis perpendicular to the step and volume magnetic anisotropy with magnetization easy axis parallel to the step. For Fe film thickness smaller than 32 monolayer (ML), the magnitudes of two effects under various temperatures are extracted from the thickness dependence of uniaxial magnetic anisotropy. For Fe film thickness larger than 32 ML, the deviation of experimental results from fitting results is understood by the strain-relief-induced reduction of volume magnetic anisotropy. Additionally, the surface and volume magnetic anisotropies are both greatly reduced after covering Cu capping layer on Fe/Si (557) film while no significant influence of NaCl capping layer on step-induced magnetic anisotropies is observed. The experimental results reported here provide various practical methods for manipulating in-plane spin orientation of Fe/Si films and improve the understanding of step-induced magnetic anisotropies. [ABSTRACT FROM AUTHOR]

The battery state-of-charge estimation was one of core issues in the development of electric vehicles battery management system, and higher accurate model was needed in state-of-charge estimation correctly. Therefore, accurate battery modeling and simulation was researched here. The Thevenin equivalent circuit model of NiMH battery was established for the poor accuracy of traditional model. Based on the data which were brought from the 6V 6Ah NiMH battery hybrid pulse cycling test experiments, Thevenin model parameters were identified by means of the linear regression analysis method. Then, the battery equivalent circuit simulating model was built in the MATLAB/Simulink environment. The simulation and experimental results showed that the model has better accuracy and can be used to guide the battery state-of-charge estimation. [ABSTRACT FROM AUTHOR]

The famous Kibble-Zurek mechanism offers us a significant clue to study quantum phase transitions out of equilibrium. Here, we investigate an intriguing phenomenon of a spin-orbit coupled Bose-Einstein condensate by quenching the Raman coupling strength from a high-symmetry phase (nonmagnetic phase) to a low-symmetry phase (magnetic phase). When crossing the critical point, the fluctuation of momentum distribution leads to delayed bifurcation structures. Simultaneously, the domain information emerges in momentum space. Moreover, the universal scalings of spatiotemporal dynamics are extracted from the fluctuations and domains, which manifests homogeneous and inhomogeneous Kibble-Zurek power laws at different timescales. Our work demonstrates a paradigmatic study on the inhomogeneous Kibble-Zurek mechanism. [ABSTRACT FROM AUTHOR]

The study on photon counting statistics is of fundamental importance in quantum optics. We theoretically analyzed the imperfect detection of an arbitrary quantum state. We derived photon counting formulae for six typical quantum states (i.e., Fock, coherent, squeeze-vacuum, thermal, odd and even coherent states) with finite quantum efficiencies and dark counts based on multiple on/off detector arrays. We applied the formulae to the simulation of multiphoton number detections and obtained both the simulated and ideal photon number distributions of each state. A comparison between the results by using the fidelity and relative entropy was carried out to evaluate the detection scheme and help select detectors for different quantum states. [ABSTRACT FROM AUTHOR]

We present a systematic investigation of magnetic anisotropy induced by oblique deposition of Co thin films on MgO (001) substrates by molecular beam epitaxy at different deposition angles, i.e., 0°, 30°, 45°, 60°, and 75° with respect to the surface normal. Low energy electron diffraction (LEED), surface magneto–optical Kerr effect (SMOKE), and anisotropic magnetoresistance (AMR) setups were employed to investigate the magnetic properties of cobalt films. The values of in-plane uniaxial magnetic anisotropy (UMA) constant Ku and four-fold magnetocrystalline anisotropy constant K1 were derived from magnetic torque curves on the base of AMR results. It was found that the value of Ku increases with increasing deposition angle with respect to the surface normal, while the value of K1 remains almost constant for all the samples. Furthermore, by using MOKE results, the Ku values of the films deposited obliquely were also derived from the magnetization curves along hard axis. The results of AMR method were then compared with that of hard axis fitting method (coherent rotation) and found that both methods have almost identical values of UMA constant for each sample. [ABSTRACT FROM AUTHOR]