Effects of antimicrobial and antioxidant activities of spice extracts on raw chicken meat quality

The antimicrobial and antioxidant effects of two spice extracts and their combination on raw chicken meat during storage for 15 days at 4◦C were studied.Raw chicken meat was treated with BHT(positive control),rosemary(RO),cloves(CL),and their combination,and the results were compared to those obtained for raw chicken meat without any additive(negative control).The antioxidant and antimicrobial activities of spice extracts were determined.The total phenolic and total flavonoid contents of rosemary was lower than those of cloves.Cloves exhibited a higher DPPH radical scavenging activity than that of rosemary.However,the ferrous ion-chelating effect of rosemary was significantly higher than that of cloves.The pH,instrumental colour(CIE L*,a*,b*),total viable counts(TVC),lactic acid bacteria(LAB)counts,Enterobacteriaceae counts,Pseudomonas spp.counts and 2-thiobarbituric acid reactive substances(TBARS)were determined at 3-day intervals over a period of 15 days.The bacterial counts of T-RO-CL samples were lower than those of control samples during storage.T-RO-CL samples maintained significantly(P<0.05)higher L*,a*and b*values during storage.The TBARS values of T-RO-CL samples were the lowest among the samples.These results demonstrate that spice extracts are highly effective against microbial growth and lipid oxidation and show potential as a natural antioxidant in raw chicken meats.

Dynamically controlled asymmetric transmission of linearly polarized waves in VO_(2)-integrated Dirac semimetal metamaterials

We numerically demonstrated a novel chiral metamaterial to achieve broadband asymmetric transmission(AT)of linearly polarized electromagnetic waves in terahertz(THz)band.The proposed metamaterial unit cell exhibits no rotational symmetry with vanadium dioxide(VO_(2)) inclusion embedded between Dirac semimetals(DSMs)pattern.The resonant frequency of AT can be dynamically tunable by varying the Fermi energy(EF)of the DSMs.The insulator-to-metal phase transition of VO_(2) enables the amplitude of the AT to be dynamically tailored.The transmission coefficient|T_(yx)|can be adjusted from 0.756 to nearly 0 by modifying the conductivity of VO_(2).Meanwhile,the AT parameter intensity of linearly polarized incidence can be actively controlled from 0.55 to almost 0,leading to a switch for AT.When VO_(2)is in its insulator state,the proposed device achieves broadband AT parameter greater than 0.5 from 1.21 THz to 1.80 THz with a bandwidth of 0.59 THz.When the incident wave propagates along the backward(-z)direction,the cross-polarized transmission|T_(yx)|reaches a peak value 0.756 at 1.32 THz,whereas the value of|T_(xy)|well below 0.157 in the concerned frequency.On the other hand,the co-polarized transmission|T_(xx)|and|T_(yy)|remained equal in the whole frequency range.This work provides a novel approach in developing broadband,tunable,as well as switchable AT electromagnetic devices.

Metabolic and Behavioral Patterns in a Pre-Menstrual Syndrome Animal Model with Liver-qi Invasion and Their Reversal by a Chinese Traditional Formula

This work successfully used model rats with Pre-Menstrual Syndrome (PMS) liver-qi invasion in the early de-velopment days to detect the Metabolic and Behavioral Patterns and their reversal by a Chinese traditional for-mula. Our aim is to verify the reliability of PMS liver-qi invasion rat model and explore some micro- mecha-nism of the syndrome of the liver failing to maintain the normal flow of qi. 30 rats with estrous cycles not in accepting time were selected and divided randomly into three groups: the normal control group, PMS liver-qi invasion model group and PMS liver-qi invasion medication-administered group. Emotional stimulation and multiple factors combination were used to prepare the PMS liver-qi invasion model. Baixiangdan Capsules (a Chinese traditional formula) were administered to rats to interfere with the PMS liver-qi invasion mode. Open-field test was used to explore behavioral aspects of the model. Urine samples, from the three groups, were collected and analyzed with UPLC-Q-TOF method to detect changes in metabolites related to liver func-tions. In the open-field experiment, the crossing scores, rearing scores and open-field experiment total scores of rats in the PMS liver-qi invasion model group increased remarkably (P < 0.05) compared with the scores of the normal control group, the tendency was retrieved remarkably after medications (P < 0.05). Metabolic finger-prints between the PMS liver-qi invasion model group and the normal control group had also distinguished changes through principal component analysis, and an evident restoration trend occurred after Baixiangdan Capsules administration. Taken together, behavioral and metabolic patterns can differentiate the PMS liver-qi invasion rat models from the normal rats. Our results identified potential biological markers that might reflect metabolic pathologies associated with PMS liver-qi invasion.

High-precision simulation and experimental verification of residual stress and surface topography of cylindrical surface shot peening

Shot peening is commonly employed for surface deformation strengthening of cylindrical surface part.Therefore,it is critical to understand the effects of shot peening on residual stress and surface topography.Compared to flat surface,cylindrical surface shot peening has two significant features:(i)the curvature of the cylindrical surface and the scattering of the shot stream cause dis-tributed impact velocities;(i)the rotation of the part results in a periodic variation of the impact velocity component.Therefore,it is a challenge to quickly and accurately predict the shot peening residual stress and surface topography of cylindrical surface.This paper developed a high-precision model which considers the more realistic shot peening process.Firstly,a kinematic analysis model was developed to simulate the relative movement of numerous shots and cylindrical surface.Then,the spatial distribution and time-varying impact information was calculated.Subsequently,the impact information was used for finite element modeling to predict residual stress and surface topography.The proposed kinematic analysis method was validated by comparison with the dis-crete element method.Meanwhile,9310 high strength steel rollers shot peening test verified the effectiveness of the model in predicting the residual stress and surface topography.In addition,the effects of air pressure and attack angle on the residual stress and surface topography were investigated.This work could provide a functional package for efficient prediction of the surface integrity and guide industrial application in cylindrical surface shot peening.

Anisotropy of the thermal and laser output properties in Yb,Nd:Sc_(2)SiO_(5) crystal

The anisotropy of thermal property in an Yb,Nd∶Sc_(2)SiO_(5) crystal is investigated from the temperature of 293 to 573 K. Based on the systematical study of thermal expansion, thermal diffusivity, and specific heat, the thermal conductivity in Yb,Nd∶Sc_(2)SiO_(5) crystals orientated at(100),(010),(001), and(406) is calculated to be 3.46, 2.60, 3.35, and 3.68 W=/(m·K),respectively. The laser output anisotropy of a continuous-wave(CW) and tunable laser is characterized, accordingly. A maximum output power of 6.09 W is achieved in the Yb,Nd∶Sc_(2)SiO_(5) crystal with(010) direction, corresponding to a slope efficiency of 48.56%. The tuning wavelength range in the Yb,Nd∶Sc_(2)SiO_(5) crystal orientated at(100),(010), and(001) is 68, 67,and 65 nm, separately. The effects of thermal properties on CW laser performance are discussed.

Widely tunable 2μm optical vortex from a Tm:YAP laser

In this paper,we report on a wide wavelength tuning optical vortex carrying orbital angular momentum(OAM)of±?,from a thulium-doped yttrium aluminum perovskite(YAP)laser employing a birefringent filter.The OAM is experimentally found to be well maintained during the whole wavelength tuning process.The Laguerre-Gaussian(LG_(0,+1))mode with a tuning range of 58 nm from 1934.8 to 1993.0 nm and LG0,-1mode with a range of 76 nm from 1920.4 to 1996.6 nm,are,respectively,obtained.This is,to the best of our knowledge,the first experimental implementation of wavelength tuning for a scalar vortex laser in the 2μm spectral range,as well as the broadest tuning range ever reported from the vortex laser cavity.Such a vortex laser with robust structure and straightforward wavelength tuning capability will be an ideal light source for potential applications in the field of optical communication with one additional degree of freedom.

High peak power 1.0 μm and tri-wavelength 1.3 μm Nd:ScYSiO5 crystal lasers

With a Nd:ScYSiO5 crystal, a high peak power electro-optically Q-switched 1.0 μm laser and tri-wavelength laser operations at the 1.3 μm band are both investigated. With a rubidium titanyle phosphate(RTP) electro-optical switcher and a polarization beam splitter, a high signal-to-noise ratio 1.0 μm laser is obtained, generating a shortest pulse width of 30 ns, a highest pulse energy of 0.765 mJ, and a maximum peak power of 25.5 kW,respectively. The laser mode at the highest laser energy level is the TEM200 mode with the Mvalue in the X and Y directions to be Mx2= 1.52 and My2= 1.54. A tri-wavelength Nd:ScYSiO5 crystal laser at 1.3 μm is also investigated. A maximum tri-wavelength output power is 1.03 W under the absorbed pump power of7 W, corresponding to a slope efficiency of 14.8%. The properties of the output wavelength are fully studied under different absorbed pump power.