Experimental realization of ultrasonic retroreflection tweezing via metagratings.

Acoustic tweezing and contactless object manipulation are significant and has become a research hotspot. Here, we present a prototype of retroreflection tweezer based on the metagratings, which can be used for implementing particle levitation and contactless movement. Different from previous tweezers, where the standing wave was typically generated from normal incidence, the retroreflection tweezer proposed here operates for the oblique incidence case that provides more degrees of freedom for real-time observation. We also give the exact relation between the metagrating geometries and retroreflection angles in a wide range based on the grating theory and optimization algorithm. Experiments are conducted to show the retroreflection at a preset angle on the designed metagrating, where levitation and contactless movement of particles are demonstrated.

Extremely Asymmetrical Acoustic Metasurface Mirror at the Exceptional Point.

Previous research has attempted to minimize the influence of loss in reflection- and transmission-type acoustic metasurfaces. This Letter shows that, by treating the acoustic metasurface as a non-Hermitian system and by harnessing loss, unconventional wave behaviors that do not exist in lossless metasurfaces can be uncovered. Specifically, we theoretically and experimentally demonstrate a non-Hermitian acoustic metasurface mirror featuring extremely asymmetrical reflection at the exception point. As an example, the metasurface mirror is designed to have high-efficiency retroreflection when the wave comes from one side and near-perfect absorption when the wave comes from the opposite side. This work marries conventional gradient index metasurfaces with the exceptional point from non-Hermitian systems, and it paves the way for identifying new mechanisms and functionalities for wave manipulation.

Acoustic perfect absorbers via Helmholtz resonators with embedded apertures.

Acoustic perfect absorption via a structure with deep subwavelength thickness is of great and continuing interest in research and engineering. This study analytically and experimentally investigates acoustic systems based on Helmholtz resonators which have embedded-apertures. The strategy of embedding apertures greatly improves the ability to manipulate the impedance of the systems. Based on the inverted configuration, perfect absorption has been realized (reaching 0.999 in experiments) via a design whose thickness is only ∼1/50th of the operating wavelength. Moreover, a tunable resonant frequency (137-300 Hz) and tunable absorption frequency bandwidth (22%-46%) can be achieved while preserving the perfect absorption performance and constant external shape. In tuning the perfect absorbers having a constant thickness, a conservation factor is revealed experimentally and then verified analytically, which could guide absorbers' design and facilitate the tuning. In addition, the distinct features of the proposed design were evaluated and validated and were compared with those of a related structure, a metasurface with a coiled backing cavity. The results have the potential to help with the design of highly efficient, thin, and tunable acoustic absorbers.

Conformally Mapped Multifunctional Acoustic Metamaterial Lens for Spectral Sound Guiding and Talbot Effect.

We demonstrate a conformally mapped multifunctional acoustic metamaterial Mikaelian lens. Mikaelian lens is a gradient medium with a hyperbolic secant refractive index profile that can realize functions like beam self-focusing. Unlike the conventional design approaches, with a conformal transformation method, only isotropic material parameters with gradient refractive index profiles are required for the construction of such lens. To realize desired gradient index distribution, we carefully design a new type of cross-channel-shaped acoustic metamaterial, whose refractive index can be effectively modulated by simply changing the slit opening size. The distinct capabilities of the metamaterial Mikaelian lens in manipulating acoustic waves are experimentally verified with the fabricated sample. Simultaneous sound guiding and Talbot effects, which normally require respective geometrical and wave acoustic approximations, are observed in simulations and experiments. Furthermore, those effects of shaping acoustic wave propagations were validated within a relatively wide frequency range. Our study reveals how the conformal transformation method can help to bridge the ray acoustics with wave acoustics. It offers opportunities to the development of novel multifunctional acoustic devices for various applications, such as sound and particle manipulations.

[Directing construction of CRISPR/Cas9 vector of SmPAL1 in Salvia miltiorrhiza by target efficiency detection in vitro].

To construct CRISPR/Cas9 vectors for the editing of SmPAL1 in the phenylpropane metabolic pathway of Salvia miltiorrhiza, CIRSPR/Cas9 target sites of SmPAL1 were designed by online software. Its target efficiencies were detected in vitro by enzyme digestion and sequences with highly efficiency were constructed into CRISPR/Cas9 vectors. Three possible CRISPR target sequences (SmPAL1-g1, SmPAL1-g2, SmPAL1-g3) were designed and the enzyme digestion efficiencies were 53.3%, 76.6% and 10.0%. SmPAL1-g1 and SmPAL1-g2 were constructed into vector VK005-03 named as VK005-03-g1 and VK005-03-g2. The results of sequencing showed that the two CRISPR/Cas target sequences were all constructed into VK005-03. Here we first laid the foundation for the study of SmPAL1 and provided an effective strategy for the screening of sgRNA.

Simultaneous Observation of a Topological Edge State and Exceptional Point in an Open and Non-Hermitian Acoustic System.

This Letter reports on the experimental observation of a topologically protected edge state and exceptional point in an open and non-Hermitian (lossy) acoustic system. Although the theoretical underpinning is generic to wave physics, the simulations and experiments are performed for an acoustic system. It has nontrivial topological properties that can be characterized by the Chern number provided that a synthetic dimension is introduced. Unidirectional reflectionless propagation, a hallmark of exceptional points, is unambiguously observed in both simulations and experiments.

Optimization of Ultrasonic-Assisted Simultaneous Extraction of Three Active Compounds from the Fruits of Forsythia suspensa and Comparison with Conventional Extraction Methods.

An efficient ultrasonic-assisted extraction (UAE) method was developed for simultaneous extraction of three active compounds, forsythiaside A (FSA), phillyrin (PHI) and rutin (RT), from the fruits of Forsythia suspensa. The effects of various factors including a binary mixed solvent of methanol/water and ethanol/water, the pH of the solvent, particle size, temperature, solvent to material ratio, ultrasonic input power and extraction time on UAE were investigated in detail. The mass transfer mechanism of UAE using different mixed solvents was further explained by comparison with the maceration extraction method. The response surface methodology was used to optimize the experimental variables including ethanol concentration, solvent to material ratio and extraction time. The optimized conditions for the simultaneous extraction of RT, FSA and PHI were: particle size 60⁻80 mesh, temperature 30 °C, ultrasonic power 200 W, ethanol concentration 50%, solvent to material ratio 32 mL/g and extraction time 37 min. Compared to conventional extraction methods, UAE provided the highest extraction efficiency and offered many advantages including the reduction of solvent, temperature and time for extraction.

Effect of Genotype and Environment on Salvia miltiorrhiza Roots Using LC/MS-Based Metabolomics.

Salvia miltiorrhiza (S. miltiorrhiza) Bunge is broadly used as herbal medicine for the clinical treatments of cardiovascular and cerebrovascular diseases. Despite its commercial and medicinal values, few systematic studies on the metabolome of S. miltiorrhiza roots have been carried out so far. We systematically described the metabolic profiles of S. miltiorrhiza using high pressure liquid chromatography mass spectrometry (LC/MS) in conjunction with multivariate statistical analyses, aimed at monitoring their biological variations of secondary metabolites related to three locations and four S. miltiorrhiza genotypes. A total of 40 bioactive constituents were putatively annotated in S. miltiorrhiza root samples. This study found that both the same S. miltiorrhiza genotype growing at three different locations and four S. miltiorrhiza genotypes growing at the same location had significant metabonomic differences identified by the principal component analysis (PCA) approach. By using orthogonal projection to latent structure with discriminant analysis (OPLS-DA), 16 and 14 secondary metabolites can be used as potential location-specific and genotype-specific markers in S. miltiorrhiza, respectively. The specificity of LC/MS profiles offered a powerful tool to discriminate S. miltiorrhiza samples according to genotypes or locations.

Simultaneous extraction, identification and quantification of phenolic compounds in Eclipta prostrata using microwave-assisted extraction combined with HPLC-DAD-ESI-MS/MS.

A simple and rapid method was developed using microwave-assisted extraction (MAE) combined with HPLC-DAD-ESI-MS/MS for the simultaneous extraction, identification, and quantification of phenolic compounds in Eclipta prostrata, a common herb and vegetable in China. The optimized parameters of MAE were: employing 50% ethanol as solvent, microwave power 400 W, temperature 70 °C, ratio of liquid/solid 30 mL/g and extraction time 2 min. Compared to conventional extraction methods, the optimized MAE can avoid the degradation of the phenolic compounds and simultaneously obtained the highest yields of all components faster with less consumption of solvent and energy. Six phenolic acids, six flavonoid glycosides and one coumarin were firstly identified. The phenolic compounds were quantified by HPLC-DAD with good linearity, precision, and accuracy. The extract obtained by MAE showed significant antioxidant activity. The proposed method provides a valuable and green analytical methodology for the investigation of phenolic components in natural plants.

[Study on physiological trait changes in growth process of different varieties of Lonicera japonica].

OBJECTIVE: To study the physiological trait changes in the growth process of different varieties of Lonicera japonica, and to explore the growth regularity. METHODS: Length, color, flowering rate and drying rate in the growth and development process of different varieties of Lonicera japonica were observed. Nonlinear regression analysis was used to conclude the growth simulation curve equation. RESULTS: Among different varieties and different sections of the same branch, the growth showed a similar law, the drying rates of the 'sanqing' period got the maximum value in all of the three varieties, the weight of the flower in 'erbai' period was the highest, and no differences between varieties. The R2 of the two curve equations was 0.996 and 0.995, respectively. CONCLUSION: Both of two curve equations can reply the growth regularity of Lonicera japonica flower very well. Study on the growth process systematically can guide the agricultural production very well.

Microwave-assisted extraction followed by RP-HPLC for the simultaneous extraction and determination of forsythiaside A, rutin, and phillyrin in the fruits of Forsythia suspensa.

An optimized microwave-assisted extraction (MAE) method and RP-HPLC method were developed for the simultaneous extraction and determination of rutin, forsythiaside A, and phillyrin in the fruits of Forsythia suspensa. The key parameters of the open-vessel MAE process were optimized. A mixed solvent of methanol and water (70:30, v/v) was most suitable for the simultaneous extraction of the three components. The sample was soaked for 10 min before extraction. The optimized conditions were: microwave power 400 W, temperature 70°C, solvent-to-material ratio 30 mL/g, and extraction time 1 min. Compared to conventional extraction methods, the proposed method can simultaneously extract the three components in high yields and was proved to be a more rapid method with a lower solvent consumption. The optimized HPLC-photodiode array detection analysis was validated to have good linearity, precision, accuracy, and sensitivity. The developed MAE followed by RP-HPLC is a fast and appropriate method for the simultaneous extraction and determination of rutin, forsythiaside A, and phillyrin in the fruits of F. suspensa.

Effect of Kushen (Radix Sophorae flavescentis) extract on laryngeal neoplasm Hep2 cells.

OBJECTIVE: To evaluate the effect of fermented extract of Kushen (Radix Sophorae Flavescentis) or non-fermented ESF on laryngeal neoplasms Hep2 cells. METHODS: Use 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay to explore the effect of fermented ESF and non-fermented ESF on Hep2 cells, and detect the mRNA and protein expression level of Bcl-2, Bax and Caspase-3 with reverse transcription polymerase chain reaction (RT-PCR) and Western blot. RESULTS: Both fermented ESF and non-fermented ESF could inhibit laryngeal neoplasm's Hep2 cells, but and the cells did not response to the dilution 1: 320 of fermented ESF, nor to the 1:1280 dilution of non-fermented ESF. As time progressed, the dilution 1:80 of fermented ESF and 1:320 dilution of non-fermented ESF could significantly reduce Bcl-2 mRNA and protein expression and down-regulate Caspase-3 mRNA and protein expression. Bax mRNA and protein were not expressed in Hep2 cells. CONCLUSIONS: Both fermented ESF and non-fermented ESF could inhibit the proliferation of Hep2 cells, and the effect of non-fermented ESF was significantly better than that of the fermented.

Development and optimization of solid lipid nanoparticle formulation for ophthalmic delivery of chloramphenicol using a Box-Behnken design.

The purpose of the present study was to optimize a solid lipid nanoparticle (SLN) of chloramphenicol by investigating the relationship between design factors and experimental data using response surface methodology. A Box-Behnken design was constructed using solid lipid (X(1)), surfactant (X(2)), and drug/lipid ratio (X(3)) level as independent factors. SLN was successfully prepared by a modified method of melt-emulsion ultrasonication and low temperature-solidification technique using glyceryl monostearate as the solid lipid, and poloxamer 188 as the surfactant. The dependent variables were entrapment efficiency (EE), drug loading (DL), and turbidity. Properties of SLN such as the morphology, particle size, zeta potential, EE, DL, and drug release behavior were investigated, respectively. As a result, the nanoparticle designed showed nearly spherical particles with a mean particle size of 248 nm. The polydispersity index of particle size was 0.277 ± 0.058 and zeta potential was -8.74 mV. The EE (%) and DL (%) could reach up to 83.29% ± 1.23% and 10.11% ± 2.02%, respectively. In vitro release studies showed a burst release at the initial stage followed by a prolonged release of chloramphenicol from SLN up to 48 hours. The release kinetics of the optimized formulation best fitted the Peppas-Korsmeyer model. These results indicated that the chloramphenicol-loaded SLN could potentially be exploited as a delivery system with improved drug entrapment efficiency and controlled drug release.

Optimization of microwave-assisted extraction followed by RP-HPLC for the simultaneous determination of oleanolic acid and ursolic acid in the fruits of Chaenomeles sinensis.

An optimized microwave-assisted extraction (MAE) method and an efficient HPLC analysis method were developed for fast extraction and simultaneous determination of oleanolic acid and ursolic acid in the fruit of Chaenomeles sinensis. The open vessel MAE process was optimized by using a central composite experimental design. The optimal conditions identified were microwave power 600 W, temperature 52 degrees C, solvent to material ratio 32 mL/g and extraction time 7 min. The results showed that MAE is a more rapid extraction method with higher yield and lower solvent consumption. The HPLC-photodiode array detection analysis method was validated to have good linearity, precision, reproduction and accuracy. Compared with conventional extraction and analysis methods, MAE-HPLC-photodiode array detection is a faster, convenient and appropriate method for determination of oleanolic acid and ursolic acid in the fruits of C. sinensis.

[Effect of seed soaking with aluminum on seed germination and seedling physiology of Platycodon grandiflorum].

In order to study the effect of seed soaking with different aluminum solution on seed germination and seedling physiological characteristics of Platycondon grandiflorum, two P. grandiflorum varieties'seed (the white flower and the purple flower) were soaked in Al3+ solution with different concentrations (0, 10, 100, 250, 500, 750 and 1000 mg x L) for 24 h, then germinated in illumination incubator. Results showed that the aluminum toxicity on the trends of the germination rate, germination index and vigor index was positive associated with its concentration, and the Al tolerance of the purple was slightly greater than that of the white. There were some relationships between the physiological indices, which were the leakage rate of electrolyte, the malonaldehyde (MDA) content, the activities of peroxidase (POD) and superoxide dismutase (SOD) , the free praline(Pro) and the soluble sugar contents, with the concentrations of Al. It was suggested that there was Al tolerance difference between the two P. grandiflorum varieties: the purple flower was greater than the white.

Microwave-assisted extraction with water for fast extraction and simultaneous RP-HPLC determination of phenolic acids in radix Salviae Miltiorrhizae.

An optimized microwave-assisted extraction method using water (MAE-W) as the extractant and an efficient HPLC analysis method were first developed for the fast extraction and simultaneous determination of D(+)-(3,4-dihydroxyphenyl) lactic acid (Dla), salvianolic acid B (SaB), and lithospermic acid (La) in radix Salviae Miltiorrhizae. The key parameters of MAE-W were optimized. It was found that the degradation of SaB was inhibited when using the optimized MAE-W and the stable content of Dla, La, and SaB in danshen was obtained. Furthermore, compared to the conventional extraction methods, the proposed MAE-W is a more rapid method with higher yield and lower solvent consumption with a reproducibility (RSD <6%). In addition, using water as extractant is safe and helpful for environment protection, which could be referred to as green extraction. The separation and quantitative determination of the three compounds was carried out by a developed reverse-phase high-performance liquid chromatographic (RP-HPLC) method with UV detection. Highly efficient separation was obtained using gradient solvent system. The optimized HPLC analysis method was validated to have specificity, linearity, precision, and accuracy. The results indicated that MAE-W followed by HPLC-UV determination is an appropriate alternative to previously proposed method for quality control of radix Salviae Miltiorrhizae.

Facilitating effects of berberine on rat pancreatic islets through modulating hepatic nuclear factor 4 alpha expression and glucokinase activity.

AIM: To observe the effect of berberine on insulin secretion in rat pancreatic islets and to explore its possible molecular mechanism. METHODS: Primary rat islets were isolated from male Sprague-Dawley rats by collagenase digestion and treated with different concentrations (1, 3, 10 and 30 micromol/L) of berberine or 1 micromol/L Glibenclamide (GB) for 24 h. Glucose-stimulated insulin secretion (GSIS) assay was conducted and insulin was determined by radioimmunoassay. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to evaluate cytotoxicity. The mRNA level of hepatic nuclear factor 4 alpha (HNF4alpha) was determined by reverse transcription polymerase chain reaction (RT-PCR). Indirect immunofluorescence staining and Western blot analysis were employed to detect protein expression of HNF4alpha in the islets. Glucokinase (GK) activity was measured by spectrophotometric method. RESULTS: Berberine enhanced GSIS rather than basal insulin secretion dose-dependently in rat islets and showed no significant cytotoxicity on islet cells at the concentration of 10 mumol/L. Both mRNA and protein expressions of HNF4alpha were up-regulated by berberine in a dose-dependent manner, and GK activity was also increased accordingly. However, GB demonstrated no regulatory effects on HNF4alpha expression or GK activity. CONCLUSION: Berberine can enhance GSIS in rat islets, and probably exerts the insulinotropic effect via a pathway involving HNF4alpha and GK, which is distinct from sulphonylureas (SUs).

[Relationship between photosynthetic characteristics and environmental factors in leaves of Pueraria lobata].

OBJECTIVE: To study the relationship between photosynthetic characteristics and environmental factors in leaves of P. lobata. METHOD: Photosynthetic characteristics and environmental factors were measured by using CIRAS-2 portable photosynthesis system. RESULT: The apparent quantum yield in leaves was 0.0173 micromol CO2 x micromol(-1) photon. The dark respiration rate was 2.9333 micromol x m(-2) x s(-1). The light compensation point of photosynthesis was 180 micromol x m(-2) x s(-1). The light saturation point was 1600 micromol x m(-2) x s(-1). The carboxylation efficiency was 0.0338 micromol x m(-2) x s(-1). The light respiration rate was 2.5 micromol x m(-2) x s(-1). The CO2 compensation point was 100 micromol x mol(-1), The CO2 saturation point was 1 600 micromol x mol(-1). CONCLUSION: Photo flux density and air temperature are major environmental factors influencing diumal changes of net photosynthetic rate.

[The qualitative analysis and quantitative analysis of purification of salvianolic acids by macroreticular resin].

OBJECTIVE: To purify salvianolic acids by macroreticular resin,then mensurate the contents of salvianolic acids and analyse the chromatogram with HPLC. METHOD: Make salvianolic acids with macroreticular resin; mensurate the content of Salvianolic acids with UV spestrophotometry: the control compound is protocaechuic aldehyde, and the wavelength is 281 nm. Analysis the chromatogram with HPLC, and compare the chromatogram in different technics: zorbax ODS column (4.6 mm x 250 mm, 5 microm), mobilephase: 1% aceticacid-water and methanol in different proportions, the wavelength is 281 nm. RESULT: The contents of salvianolic acids is 53.8%; HPLC chromatogram indicate that the method is reasonable to make salvianolic acids. CONCLUSION: Determination of contents and HPLC chromatogram can control the quality of Salvianolic acids more accurately.