Influence of cultivation substrate on antioxidant activities and triterpenoid profiles of the fruiting body of Ganoderma lucidum.

Introduction: The fruiting body of Ganoderma lucidum has been believed to possess a wide range of therapeutic effects. There are two main methods for artificial cultivation of G. lucidum to produce the fruiting body, namely wood log cultivation and substitute cultivation. The impact of cultivation substrates on the composition of bioactive compounds remains largely unexplored. This study aims to compare the antioxidant activities and triterpenoid profiles of the fruiting bodies of G. lucidum that cultivated through wood log cultivation (WGL) and substitute cultivation (SGL) methods. Methods: The antioxidant activities, including the DPPH radical scavenging, hydroxyl radical scavenging, superoxide radical scavenging, and total antioxidant activities, were assessed in both WGL and SGL samples. Furthermore, the UHPLC-Q-Orbitrap-MS technique was employed to compare their phytochemical profiles, with a specific emphasis on triterpenoid constituents. Results and discussion: It was found that WGL samples exhibited significantly higher total triterpenoid content, DPPH radical scavenging activity, and total antioxidant activity. Furthermore, an untargeted metabolomics approach employing UHPLC-Q-Orbitrap-MS tentatively identified a total of 96 triterpenoids. Distinguishingly different triterpenoid profiles between the two types of G. lucidum samples were revealed via the utilization of principal component analysis (PCA) and hierarchical cluster analysis (HCA). Specifically, 17 triterpenoids showed significant differences. Of these triterpenoids, 6 compounds, such as ganosporelactone B, ganoderol A, ganoderic acid A, ganoderic acid alpha, were significantly higher in SGL samples; 11 compounds, such as lucidenic acid A, lucidenic acid D1, lucidenic acid F, lucidenic acid G, lucidenic acid J, ganoderic acid E, and ganoderic acid O, were significantly higher in WGL samples. These findings expand our knowledge regarding the impact of cultivation substrate on the antioxidant activities and triterpenoid profiles of G. lucidum, and offer practical implications for its cultivation.

Millimeter-wave generation based on a monolithic dual-wavelength DFB laser with four phase-shifted sampled gratings and equivalent chirp technology.

A dual-wavelength DFB laser array based on four phase-shifted grating and equivalent chirp technology is first proposed, fabricated, and experimentally demonstrated. The dual-wavelength emitting is achieved by symmetrically introducing two π phase shifts into a chirped four phase-shifted sampled grating cavity. Meanwhile, the beating signal of the dual-wavelength output is stabilized by applying an electro-absorption modulator integrated at the rear of the cavity. Under different grating chirp rates, a series of RF signals from 66.8 GHz to 73.6 GHz with a linewidth of less than 210 kHz is obtained.

Sidewall grating slot waveguide microring resonator biochemical sensor.

Integrated microring resonator structures based on silicon-on-insulator (SOI) platforms are promising candidates for high-performance on-chip sensing. In this work, a novel sidewall grating slot microring resonator (SG-SMRR) with a compact size (5 µm center radius) based on the SOI platform is proposed and demonstrated experimentally. The experiment results show that the refractive index (RI) sensitivity and the limit of detection value are 620 nm/RIU and 1.4 × 10-4 RIU, respectively. The concentration sensitivity and minimum concentration detection limit are 1120 pm/% and 0.05%, respectively. Moreover, the sidewall grating structure makes this sensor free of free spectral range (FSR) limitation. The detection range is significantly enlarged to 84.5 nm in lab measurement, four times that of the FSR of conventional SMRRs. The measured Q-factor is 3.1 × 103, and the straight slot waveguide transmission loss is 24.2 dB/cm under sensing conditions. These results combined with the small form factor associated with a silicon photonics sensor open up applications where high sensitivity and large measurement range are essential.

Double slot micro ring resonators with inner wall angular gratings as ultra-sensitive biochemical sensors.

We simulate and demonstrate experimentally an inner-wall grating double slot micro ring resonator (IG-DSMRR) with a center slot ring radius of only 6.72 µm based on the silicon-on-insulator platform. This novel photonic-integrated sensor for optical label-free biochemical analysis boosts the measured refractive index (RI) sensitivity in glucose solutions to 563 nm/RIU with the limit of detection value being 3.7 × 10-6 RIU (refractive index units). The concentration sensitivity for sodium chloride solutions can reach 981 pm/%, with a minimum concentration detection limit of 0.02%. Using the combination of DSMRR and IG, the detection range is enlarged significantly to 72.62 nm, three times the free spectral range of conventional slot micro ring resonators. The measured Q-factor is 1.6 × 104, and the straight strip and double slot waveguide transmission losses are 0.9 dB/cm and 20.2 dB/cm, respectively. This IG-DSMRR combines the advantages of a micro ring resonator, slot waveguide, and angular grating and is highly desirable for biochemical sensing in liquids and gases offering an ultra-high sensitivity and ultra-large measurement range. This is the first report of a fabricated and measured double-slot micro ring resonator with an inner sidewall grating structure.

Asymmetric parameter enhancement in the split-ring cavity array for virus-like particle sensing.

Quantitative detection of virus-like particles under a low concentration is of vital importance for early infection diagnosis and water pollution analysis. In this paper, a novel virus detection method is proposed using indirect polarization parametric imaging method combined with a plasmonic split-ring nanocavity array coated with an Au film and a quantitative algorithm is implemented based on the extended Laplace operator. The attachment of viruses to the split-ring cavity breaks the structural symmetry, and such asymmetry can be enhanced by depositing a thin gold film on the sample, which allows an asymmetrical plasmon mode with a large shift of resonance peak generated under transverse polarization. Correspondingly, the far-field scattering state distribution encoded by the attached virus exhibits a specific asymmetric pattern that is highly correlated to the structural feature of the virus. By utilizing the parametric image sinδ to collect information on the spatial photon state distribution and far-field asymmetry with a sub-wavelength resolution, the appearance of viruses can be detected. To further reduce the background noise and enhance the asymmetric signals, an extended Laplace operator method which divides the detection area into topological units and then calculates the asymmetric parameter is applied, enabling easier determination of virus appearance. Experimental results show that the developed method can provide a detection limit as low as 56 vp/150µL on a large scale, which has great potential in early virus screening and other applications.

Stepped-height ridge waveguide MQW polarization mode converter monolithically integrated with sidewall grating DFB laser.

We report, to the best of our knowledge, the first demonstration of a 1555-nm stepped-height ridge waveguide polarization mode converter monolithically integrated with a sidewall grating distributed-feedback (DFB) laser using the identical epitaxial layer scheme. The device shows stable single longitudinal mode (SLM) operation with the output light converted from TE to TM polarization with an efficiency of >94% over a wide range of DFB injection currents (IDFB) from 140 mA to 190 mA. The highest TM mode purity of 98.2% was obtained at IDFB = 180 mA. A particular advantage of this device is that only a single step of metalorganic vapor-phase epitaxy and two steps of III-V material dry etching are required for the whole integrated device fabrication, significantly reducing complexity and cost.

UHPLC-Q-Orbitrap-MS-Based Metabolomics Reveals Chemical Variations of Two Types of Rhizomes of Polygonatum sibiricum.

The rhizomes of Polygonatum sibiricum are commonly consumed as food and also used as medicine. However, the metabolic profile of P. sibiricum has not been fully revealed yet. Recently, we developed a novel evergreen species of P. sibiricum. The objectives of this study were to compare the metabolic profiles of two types of P. sibiricum, i.e., the newly developed evergreen type (Gtype) and a wide-type (Wtype), by using UHPLC-Q-Orbitrap-MS-based untargeted metabolomics approach. A total of 263 and 258 compounds in the positive and negative modes of the mass spectra were tentatively identified. Distinctively different metabolomic profiles of these two types of P. sibiricum were also revealed by principal component analysis (PCA) and principal coordinates analysis (PCoA). Furthermore, by using partial least squares discriminant analysis (PLS-DA) modeling, it was found that, as compared with Wtype, Gtype samples had significantly higher content of oxyberberine, proliferin, alpinetin, and grandisin. On the other hand, 15 compounds, including herniarin, kaempferol 7-neohesperidoside, benzyl beta-primeveroside, vanillic acid, biochanin A, neoschaftoside, benzyl gentiobioside, cornuside, hydroxytyrosol-glucuronide, apigenin-pentosyl-glucoside, obacunone, 13-alpha-(21)-epoxyeurycomanone, vulgarin, digitonin, and 3-formylindole, were discovered to have higher abundance in Wtype samples. These distinguishing metabolites suggest the different beneficial health potentials and flavor attributes of the two types of P. sibiricum rhizomes.

DFB laser array based on four phase-shifted sampled Bragg gratings with precise wavelength control.

A four-laser array based on sampled Bragg grating distributed feedback (DFB) lasers in which each sampled period contains four phase-shift sections is proposed, fabricated, and experimentally demonstrated. The wavelength spacing between adjacent lasers is accurately controlled to 0.8 nm ± 0.026 nm and the lasers have single mode suppression ratios larger than 50 dB. Using an integrated semiconductor optical amplifier, the output power can reach 33 mW and the optical linewidth of the DFB lasers can be as narrow as 64 kHz. This laser array uses a ridge waveguide with sidewall gratings and needs only one metalorganic vapor-phase epitaxy (MOVPE) step and one III-V material etching process, simplifying the whole device fabrication process, and meeting the requirements of dense wavelength division multiplexing systems.

Determination of copper ions in herbal medicine based on click chemistry using an electronic balance as a readout.

The amount of copper affects the quality of herbal medicine greatly, it is necessary to develop some simple and sensitive methods to detect copper for the remote or resource-limited area. An electronic balance is one of the most familiar equipment that can be found nearly in all laboratories. The presence of Cu(i) can catalyze azide-alkyne cycloaddition reaction (called as click chemistry) with high efficiency. In this study, a simple method had been developed to detect copper ions in herbal medicine using an electronic balance as a readout device based on click chemistry. Cu(ii) is reduced to Cu(i) by sodium ascorbate in situ, which induces the "click" reaction between azido-DNA modified magnetic beads (MB-DNA) and alkynyl-DNA modified platinum nanoparticles (Pt NP-DNA) and results in the fixing of the platinum nanoparticles on the beads (called as MB-Pt NPs). MB-Pt NPs can be separated by a magnetic frame easily and transferred into a drainage reaction device containing hydrogen peroxide. Then, hydrogen peroxide can be decomposed by Pt NPs modified on MB to generate oxygen, which increases the pressure in the drainage reaction device and forces the water in the system to be discharged. The weight of the discharged water can be easily and accurately measured by an electronic balance. The weight of the water has a linear relationship with Cu(ii) in the range of 2.0-200 µM and a detection limit of 0.83 µM under 30 min of collected time. This method does not need complicated and expensive instruments, skilled technicians, and a complex data processing process. The proposed method had been applied to detect copper ions in herbal medicine with satisfactory results.

[Spectroscopic study on CdS nanoparticles prepared by microwave irradiation].

CdS nanoparticles capped by mercaptoacetic acid have been successfully synthesized by microwave method employing thioacetamide as sulfur source, which was proved to be a simple, rapid and specific mothod compared with traditional synthetical methods, such as precipitation, sol-gel, solvo-thermal method and so on. The concrete procedure synthesizing CdS nanoparticles was as follows: Cd(NO3)2 (40 mL, 5 mmol c L(-1)) was titrated with mercaptoacetic acid to pH 2.0, resulting in a turbid blue solution. NaOH (0.1 mol x L(-1)) was then added dropwise until the pH was 7 and the solution was again colorless. While quickly stirring the solution, 40 mL of 5 mmol x L(-1) CH3CSNH2 was added. Subsequently, the solution was adjusted to pH 9.0 and placed in a microwave oven for 25 min with power 30% (it means that if microwave works in a 30 s regime, it works 6 s, and does not work 24 s. This is some kind of pulse regime, but the totalpower is still 100%). This kind of nanoparticles were water-soluble and symmetrical. The diameter of CdS nanoparticles which have a spherical morphology was determined to be 12 nm by transmission electron microscopy(TEM), which posess perfect uniforminty. According to literatures report, there are two kinds of emission peak: one is edge-emission peak, and the other is surface blemish emission. In contrast to edge-emission peak, the surface blemish emission shows red shift on fluorescence spectra. In the present paper, the prominent peak of CdS QDs fluorescence spectrum was located at 490 nm, the humpbacked peak caused by surface blemish of CdS nanoparticles was located at 565 nm. However, the surface blemish emission was unconspicuous, thus we can conclude that the synthetical CdS QDs possesses excellent luminescence capability and favorable structure. The size and absorption and fluorescence spectra of CdS nanoparticles at different microwave power, pH value, reaction time and different sulfur source were investigated. The result showed that the better nanoparticles could be obtained in the condition of 30% microwave power, pH 9.0 at the beginning of reaction, and the time of microwave reaction of 25 min. The synthesized nanoparticles were compared with the nanoparticles with CH3 CSNH2, NH2CSNH2 and Na2S as sulfur source. The experiment indicated that CdS nanoparticles applying CH3CSNH2 as sulfur source showed strong edge-emission, and blemish emission was weak, so the fluorescence quality is excellent; but CdS nanoparticles applying NH2CSNH2 as sulfur source showed weak edge-emission; and CdS nanoparticles applying Na2S as sulfur source showed mainly fluorescence blemish emission. At the same time, the mercaptoacetic acid capped CdS nanoparticles were employed to study the quantitative analysis of Cu2+. According to the results of experiment, in a certain range of concentration(6.4-512 microg x L(-1)), Cu2+ quenched the fluorescence intensity of mercaptoacetic acid capped CdS nanoparticles with good linearity, which can be used in the determination of trace Cu2+ in samples. In conclusion, this kind of method supplied a new way to study synthesizing the CdS nanoparticles.

Determination of ciprofloxacin with functionalized cadmium sulfide nanoparticles as a fluorescence probe.

A novel assay of ciprofloxacin with a sensitivity at the microgram level is proposed based on the measurement of enhanced fluorescence intensity signals resulting from the interaction of functionalized nano-CdS with ciprofloxacin. The CdS nanoparticles was synthesized by thioacetamide (TAA) and cadmium nitrate (Cd(NO(3))(2)) in the alkaline solution. At pH 7.4, the fluorescence signals of functionalized nano-CdS were greatly enhanced by ciprofloxacin with the increase concentration of ciprofloxacin. Linear relationship can be established between the enhanced fluorescence intensity and ciprofloxacin concentration in the range of (1.25-8.75)x10(-4) mg mL(-1) ((3.77-26.4) x 10(-4)mmol L(-1)) or (8.75-1200) x 10(-4)mg mL(-1) ((26.4-3625) x 10(-4) mmol L(-1)). The limit of detection is 7.64 x 10(-6) mg mL(-1) (2.31 x 10(-5)mmol L(-1)). Based on this, a new direct quantitative determination method for ciprofloxacin in human serum samples without separation of foreign substances was established. The contents of ciprofloxacin in human serum samples were determined with recovery of 95-105% and relative standard deviation (R.S.D.) of 1.5-2.5%. This method was proved to be very sensitive, rapid, simple and tolerance of most interfering substances.

Surface-modified CdS quantum dots as luminescent probes for sulfadiazine determination.

A novel, sensitive and convenient determine technology based on the quenching of the fluorescence intensity of functionalized CdS quantum dots by sulfadiazine was proposed. Luminescent CdS semiconductor quantum dots (QDs) modified by thioglycollic acid (TGA) were synthesized with the microwave method. The modified CdS QDs are water-soluble, stable and highly luminescent. The possible mechanism for the reaction was also discussed. When sulfadiazine was added into the CdS QDs colloid solution, the surface of CdS QDs generates the electrostatic interaction in aqueous medium, which induces the quenching of fluorescence emission at 489 nm. Under optimum condition, the fluorescence intensity versus sulfadiazine concentration gave a linear response according Stern-Volmer equation with an excellent 0.9981 correlation coefficient. The linearity range of the calibration curve was 1.2 x 10(-5) to 2.13 x 10(-3) mol L(-1). The limit of detection (3delta) is 8.0 micromol L(-1). The relative standard deviation for five determinations of 0.13 x 10(-3)mol L(-1) sulfadiazine is 1.4%. The concentrations of sulfadiazine injections were determined by the proposed method with a satisfactory result.