Polygonati Rhizoma (PR), for which rapid geographical origin identification is crucial to ensure its efficacy and product authenticity, is a traditional Chinese medicine with multiple pharmacological effects such as hypoglycemic and antitumor effects. This study presents a rapid identification method of sliced PR geographical origin based on auto-focus laser-induced breakdown spectroscopy (LIBS) combined with interpretable machine learning. The spectral data of sliced PR samples from 8 producing areas were obtained by using the self-built auto-focus LIBS system without further sample processing. Various data preprocessing methods, feature variable selection methods, and classification algorithms were evaluated. The results showed that the combination of wavelet transform (WT), Model-Free (MF) algorithm, and area normalization (AN) outperformed each method used individually. Among the feature selection methods, iteratively retaining informative variables (IRIV), variable iterative space shrinkage approach (VISSA), and the successive projection algorithm (SPA), the fewest feature variables were selected by SPA. However, by combining with Linear discriminant analysis (LDA), K-nearest neighbors (KNN), Multilayer perceptron (MLP), and Support vector machine (SVM), a good prediction accuracy of 95.00% was still achieved by SPA-SVM. Furthermore, according to the importance analysis by the SHapley Additive exPlanations (SHAP) algorithm, Ca was the most essential element to distinguish sliced PR samples from different geographical origins, followed by other elements in the order of Fe, Ti, Sr, C, Mn, Mg, Li, Ba, K, H, Si, and Na. This study provides a simple, rapid, and reliable analytical approach for PR authentication, which has broader applications in medicinal material and food product verification.

Dear Editor, Biomacromolecules aggregate to form membraneless organelles(MLOs)via phase separation has been observed in a variety of physiological processes over the last decade.1 However,the molecular basis of biomacromolecule phase separation in cells and assembly modes of this process remain largely unknown due to a lack of available experimental methods.The dynamics of different MLOs vary widely.For example,in the nucleus of eukaryotic cells,nuclear speckles have been shown to form membraneless organelles by phase separation,and it is mainly involved in the highly dynamic biological process of pre-mRNA splicing.2 In contrast,the structure of heterochromatin regions is relatively stable.3 In this study,we investigated whether heterochromatin protein HP1α and nuclear speckle protein SRSF2,two classical phase separation proteins with different dynamics,share the same basic unit and similar assembly mode during the formation of MLOs.

Piezotronic devices have attracted a great deal of attention due to their potential applications in self-powered tactile sensing, nano-device memory, human-electronic interface, etc. As the size of piezotronic devices shrinks, some interesting quantum effects begin to appear. In this paper, we establish a theory oriented to the engineering application of piezoelectric semiconductors, called quantum-corrected phenomenological (QCP) theory, by coupling the density-gradient theory and the linear piezoelectricity theory through Gauss's law. For numerical verification, we specifically studied the electromechanical behaviors in GaN/AlGaN heterostructure quantum wells (QWs) with both infinite and finite barrier height. The results of electron density, electric potential, and quantum potential are provided, and their dependence on the doping density, the applied stress, and the Al mole fraction is investigated. Some interesting quantum effects are revealed, and their influencing mechanisms are well investigated from a macroscopic perspective. Not only do the conclusions drawn in this paper enrich the fundamental understanding of the piezotronic effect in a QW structure, but also the proposed QCP theory can serve as a valuable tool for future device engineering.

As an important branch of laser-induced breakdown spectroscopy (LIBS), calibration-free LIBS (CF-LIBS) is a famous element quantitative analysis method without standards. This method has many advantages such as real-time, in-situ, on-site, single-point, and multi-elemental analysis, with excellent potential for geology, archaeology, industrial and environmental monitoring, and biomedicine. In this review, we summarized the development of CF-LIBS. It covered a brief description of the basic theory of CF-LIBS, several modified methods and variants, proposed to overcome the non-stoichiometric ablation, self-absorption effect, and high algorithmic complexity. Furthermore, the applications of CF-LIBS in a variety of fields were reviewed. Finally, the existing problems of CF-LIBS and its potential were discussed.

As a popular food, Chinese yam (CY) powder is widely used for healthy and commercial purposes. Detecting adulteration of CY powder has become essential. In this work, chemometric methods combined with laser-induced breakdown spectroscopy (LIBS) were developed for identification and quantification of CY powder adulteration. Pure powders (CY, rhizome of winged yam (RY) and cassava (CS)) and adulterated powders (CY adulterated with CS) were pressed into pellets to obtain LIBS spectra for identification and quantification experiments, respectively. After variable number optimization by principal component analysis and random forest (RF), the best model random forest-support vector machine (RF-SVM) decreased 48.57% of the input variables and improved the accuracy to 100% in identification. Following the better feature extraction method RF, the Gaussian process regression (GPR) method performed the best in the prediction of the adulteration rate, with a correlation coefficient of prediction (Rp2) of 0.9570 and a root-mean-square error of prediction (RMSEP) of 7.6243%. Besides, the variable importance of metal elements analyzed by RF revealed that Na and K were significant due to the high metabolic activity and maximum metal content of CY powder, respectively. These results demonstrated that chemometric methods combined with LIBS can identify and quantify CY powder adulteration accurately.

Sea salt aerosols significantly impact marine ecosystems and climate change; however, self-absorption effects unavoidably occur in the detection of sea salt aerosols via laser-induced breakdown spectroscopy (LIBS).This work illustrates the application of a renowned replica plasma method for self-absorption correction in the detection of sea salt aerosols via LIBS.Two sets of spectral data were obtained by adding a duplicating mirror behind the plasma, and the self-absorption correction factor was calculated using a previously described method.Consequently, the experimental results show a marked improvement in the linearity of the calibration curve.The determination coefficients of linear fitting were above 0.99, and the root mean square error of the cross-validation RMSECV was negligible.The duplicating mirror method for self-absorption correction in the detection of sea salt aerosols via LIBS can thus achieve high accuracy and stability within a certain range and therefore can prove useful for sea salt aerosol, aerosol, and gas detection.

Novel amorphous Ni-Co-S/ZACN-O self-supporting nanohybrid electrodes were fabricated by a facile two-step electrochemical method. ZrAlCoNi-O (ZACN-O) nanotubes were obtained by anodization of Zr56Al16Co23Ni5 amorphous alloy precursor. Then, amorphous Ni-Co-S nanospheres were electrochemical deposited on ZACN-O NTs by using cyclic voltammetry. Coral-like Ni-Co-S nanosphere clusters in the scale of several hundred nanometers were homogeneously distributed on ZACN-O amorphous nanotubes. The amorphous Ni-Co-S/ZACN-O nanohybrid electrode with unique nanoarchitecture exhibited excellent catalytic activity toward glucose oxidation with an ultrahigh sensitivity of 2603 μA mM-1 cm-2, a wide detection range, as well as a low detection limit. Moreover, the amorphous Ni-Co-S/ZACN-O nanohybrid electrodes exhibited superior selectivity and long-term stability. The excellent electrochemical performance of the amorphous hybrid electrode was attributed to special hybrid architecture with abundantly active sites, high electron transfer ability, as well as synergistic effect of multiple valences of Ni, Co and S element. The Ni-Co-S nanospheres and nanotubes substrate both in amorphous state also play an important role in high catalytic activity due to abundant of microdefects and long-range disorder microstructure. The amorphous Ni-Co-S nanospheres modified ZACN-O NTs electrode sets up a new strategy for the application of amorphous compounds in non-enzyme electrochemical sensors.

Buckwheat is one of the five main allergenic foods (eggs, milk, wheat, buckwheat, and peanuts). Oleosin is an important type of allergen in some allergic foods. However, although most diagnostic nut and seed extracts are defatted, some patients with food allergies may have false negative diagnostic results of oleosin in vitro. Recently, we found that the serum of buckwheat allergic patients responded strongly to an 18 kDa protein. Mass spectrometry analysis showed it is the oleosin protein family. We further purified and evaluated the allergenicity of this buckwheat oleosin-type allergen, which is involved in the formation of buckwheat oil bodies. The tartary buckwheat oleosin allergen was named Fag t 6, according to the WHO/IUIS Allergen Nomenclature Subcommittee criteria. The DNA sequence of tartary buckwheat oleosin was cloned. Dot blot and enzyme-linked immunosorbent assay (ELISA) showed half of the 20 buckwheat allergic patients' serum had strong reactivity with purified buckwheat Fag t 6. Circular dichroism experiment analysis of its thermal stability showed a Tm of 64.65 ± 0.65 °C. A buckwheat allergy showed possible cross-reaction with a wheat allergy. In summary, this study not only increases our understanding of buckwheat allergies and oil-soluble allergens in general, it may also be used to improve diagnostic tests for buckwheat allergies in the future.

The matrix effect is one of the main bottlenecks for the laser-induced breakdown spectroscopy (LIBS) technique. In this work, image-assisted, laser-induced breakdown spectroscopy (IA-LIBS) based on the Lomakin-Scherbe formula was put forward as a correction to the matrix effect. The brightness and area information in the plasma image was extracted to correct the spectral line intensities among which the brightness information characterizes the plasma temperature, and the area information characterizes the ablative mass. To verify the feasibility of this method, the experiment was conducted on metal samples and pressed samples. The method was applied for quantitative analysis of copper (Cu), magnesium (Mg) in metal samples and chromium (Cr), manganese (Mn) in pressed samples. For the metal samples, after correcting the matrix effect by IA-LIBS, the determination coefficient R squared (R2) of Cu I 510.55 nm and Mg I 518.36 nm calibration curves were increased from 0.726 to 0.942 to 0.992 and 0.988, respectively. The root-mean-square-error of cross-validation (RMSECV) and the average relative error (ARE) decreased by 75.10% and 77.18%, respectively. For the pressed samples, R2 of Cr I 520.84 nm and Mn I 403.07 nm calibration curves corrected by IA-LIBS increased from 0.364 to 0.098 to 0.975 and 0.980; and RMSECV and ARE decreased by 77.88% and 83.83%, respectively. The experimental results showed that IA-LIBS had an obvious improvement on elimination of the matrix effect for the different samples and the different elements. Therefore, IA-LIBS will become a promising technology and will greatly promote the development of LIBS in various fields.

Heavy metal pollution is one of the main problems in water pollution, which is harmful to humans. Surface-enhanced laser-induced breakdown spectroscopy (SENLIBS) has been applied to detect trace amounts of heavy metal elements in aqueous solution; however, it is still a big challenge to explore the relationship between the LIBS detection sensitivity and the substrate's physical properties. In this work, four typical substrates, zinc (Zn), magnesium alloy (Mg), nickel (Ni), and silicon (Si), were compared; and the mechanism of spectral enhancement by different substrates in SENLIBS was investigated. The results indicated that the limit of detection (LoD) of heavy metal elements on different substrates is positively proportional to the boiling of the substrate. That is mainly because a higher plasma excitation temperature and electron density are obtained, leading to more intense collision between particles. The signal enhancement is associated with the lower boiling point of the substrate (corresponding to a lower ablation threshold and higher ablation quantity from the substrate). As a result, the best LoD was 0.0011 mg/L for chromium (Cr) and 0.004 mg/L for lead (Pb) on an optimal Zn substrate, respectively. The LoDs were sufficiently low to meet the drinking water sanitation standard. These results showed that the detection sensitivity of heavy metal elements in aqueous solution can be improved by choosing a substrate with a lower boiling point in SENLIBS.

Fish play important roles in human nutrition and health, but also trigger allergic reactions in some population. Parvalbumin (PV) represents the major allergen of fish. While IgE cross-reactivity to PV in various bony fish species has been well characterized, little information is available about allergens in cartilaginous fish. In this study, two shark PV isoforms (named as SPV-I and SPV-II) from Mustelus griseus were purified. Their identities were further confirmed by mass spectroscopic analysis. IgE immunoblot analysis showed that sera from fish-allergic patients reacted to both SPV-I and SPV-II, but the majority of sera reacted more intensely to SPV-I than SPV-II. Thermal denaturation monitored by CD spectrum showed that both of the SPV allergens are highly thermostable. SPV-I maintained its IgE-binding capability after heat denaturation, while the IgE-binding capability of SPV-II was reduced. The results of crystal structure showed that SPV-I and SPV-II were similar in their overall tertiary structure, but their amino acid sequences shared lower similarities, indicating that the differences in the IgE-binding capabilities of SPV-I and SPV-II might be due to differential antigen epitopes in these two isoforms.

Objective To study the chemical constituents from the roots and rhizomes of Acorus tatarinowii. Methods Using different chromatographic methods to isolate and purify the constituents of A. tatarinowii, and their structures were identified by physicochemical properties and spectroscopic technology. Results Thirteen compounds were isolated and identified as fumaric acid (1), nicotinic acid (2), p-hydroxybenzonic acid (3), uracil (4), N-trans-feruloyltyramine (5), thymine (6), variecolorquinone A (7), butanedioic acid (8), tatarol (9), tataroside-12-β-D-glucoside (10), β-sitosterol (11), 2, 5-dimethoxy benzoquinone (12), and 5-hydroxymethyl-2-furaldehyde (13). Conclusion Compounds 1—7 are isolated from the plants in Acorus L. for the first time.

To study the chemical constituents of Cinamomum Camphora leaves,they were extracted isolated and purified by normal-phase and reverse-phase silica gel chromatography and semi-preparative high performance liquid chromatography and their structures were elucidated by spectral analysis.5 compounds included 1 lignans and 4 flavonoid glycosides were obtained.They are(8R,8'R)-3,3',4,4'-tetramethoxy-9-oxo-8-8',9-O-9'-lignans(I),Quercitin-3-O-α-L-rhamnoside(II),Kaempferol-3-Ο-β-D-glucose(6→1)-α-L-rhamnoside(III),rutin(IV),Quercitin 3-Ο-β-D-glucoside(V) respectively.

Acorus is a commonly used traditional Chinese medicine with a variety of pharmacological and physiological role.Acorus contains a lot of compositions such as monoterpenes,sesquiterpenes,phenylpropanoids,quinones,alkaloids,organic acids,amino acids,sugars and etc.In this paper,chemical compositions and pharmacological actions of Acorus plants were discussed to provide proof for further research and development of Acorus.

The chemical constituents in the rhizome of Acorus tatarinowii Schott were systematically investigated,five compounds were isolated by solvent extraction,silica gel,and reversed-phase silica gel column chromatography and semi-preparative high performance liquid chromatography.Their structures were determined by NMR spectroscopy.The five compounds were isolated and identified as cis-methylisoeugenol(Ⅰ),asarylaldehyde(Ⅱ),benzoic-acid(Ⅲ),stigmasterol(Ⅳ),calamenone(Ⅴ).Compoud Ⅲ were obtained from the plant for the first time.The study provides a theoretical basis for the further study on Acorus tatarinowii.

Salvinorin A (1), the main active ingredient of Salvia divinorum, is a potent and selective kappa-opioid receptor (KOPR) agonist. A series of C-12 triazole analogs and the oxadiazole (4) analog of 1 are synthesized and screened for binding affinity at kappa, mu (MOPR), or delta (DOPR). Surprisingly, all triazole analogs have shown negligible binding affinity at opioid receptors and the oxadiazole 4, a reported MOPR and KOPR antagonist, exhibits very low affinities to opioid receptors and no antagonism in our binding assays. These results suggest that electronic factors that may affect either the electron density of hydrogen bond acceptor at C-12 or hydrophobic interactions between C-12 moiety and KOPR are critical to C-12 analog's affinity for KOPR.

OBJECTIVE:To investigate the safe use of 10% difenoconazole in planting Gentiana scabra.METHOD:The degradation dynamics of 10% ifenoconazole in the stems and leaves of G. scabra collecting in different time were determined by GC with ECD detection, and the half life of difenoconazole in the plant was calculated, and then the safe use method of 10% difenoconazole was formulated.RESULT:Under the local climatic conditions, the half life of 10% difenoconazole was 6.84-6.90 days.CONCLUSION:In the good agricultural practice (GAP) of G. scabra, the maximal concentration of 10% difenoconazole is 400 g x ha(-1), the safety interval of using 10% difenoconazole is 40 days.

The management system of Chinese medicines plays a decisive role in the formulation and implementation of the technological standards and the enhancement of international competitiveness of the products of Chinese medicines. Their study includes the following three parts: (1) the history and status quo of the management system in the technological standards of Chinese medicines in China; (2) the study of management system in the technological standards of plant medicines related to Chinese medicines abroad; (3) problems and countermeasures in the management system of the technological standards of Chinese medicines in China. In the study the organization departments for the management of Chinese medicines in the country and the laws and regulations they have made are analyzed, systems and laws and regulations in the management of plant medicines related to Chinese medicines in some major countries (regions) of the world are studied and compared, and measures and strategies which should be taken in the formulation and implementation of the technological standards of Chinese medicines in the country and relevant technical barriers which should be set up in the international trade of medicines are put forward. As the first part of the study this article historically reviews the management system of the technological standards of Chinese medicines and analyzes the status quo of the management of the technological standards of Chinese medicines in China at various levels, thus laying a foundation of comparative study in this field.

为制定我国中药行业的技术标准战略,受国家科技部委托,我们负责中药技术标准管理体制的战略研究部分.中药管理体制在国家制定和实施中药国家技术标准,提高中药产品国际竞争力等方面具有举足轻重的作用.研究分三个部分:1.我国中药技术标准管理体制的历史与现状;2.与中药有关的国际植物药技术标准管理体制研究;3.我国中药技术标准管理体制的问题与对策.研究通过分析我国中药管理的组织机构和所制定的法律法规,研究比较了国际主要国家(地区)与中药相关的植物药管理体制和法律法规状况,提出在制定和实施我国中药国家技术标准时,采取的措施和策略,以及在国际贸易中应设置的相关技术壁垒.本文作为研究的第一部分历史性地回顾了我国中药技术标准的管理体制,从不同层次分析了我国中药技术标准管理的现状,为比较研究提供了基础.