Expeditious assembly of biuret-guanidine derivatives via the catalyst-free transformation.

We disclose a mild and practical catalyst-free transformation for the expeditious construction of biuret-guanidine derivatives using aromatic isocyanates. This synthetic transformation is featured with mild reaction conditions and high efficiency.

Heat Balance Calculation and Energy Efficiency Analysis for Building Clusters Based on Psychrometric Chart.

How to perform accurate calculation of heat balance and quantitative analysis of energy efficiency for building clusters is an urgent problem to be solved to reduce building energy consumption and improve energy utilization efficiency. This article proposes a method for the heat balance calculation and energy efficiency analysis of building clusters based on enthalpy and humidity diagrams and applies it to the energy management of building clusters containing primary return air systems and heating pipe networks. Firstly, the basic structure and energy management principle of building clusters with a primary return air system and a heating pipe network were given, and the heat balance calculation and energy efficiency analysis method based on i-d diagram was proposed to realize the accurate calculation of heat load and the quantification of energy utilization. Secondly, the energy management model of the building cluster with a primary return air system and a heating pipe network was established to efficiently manage the indoor temperature and the heating schedule of ASHP, HN and HI. Finally, the proposed method was validated by calculation examples, and the results showed that the proposed method is beneficial for improving the energy economy and energy efficiency of building clusters.

Functional Characterization of the Stipa purpurea P5CS Gene under Drought Stress Conditions.

Free proline has multiple functions in plant cells, such as regulating osmotic potential and protecting both proteins and cell membranes. The expression of Δ1-Pyrroline-5-carboxylate synthase (P5CS), a key enzyme in the proline biosynthetic pathway, increases under drought, salt and cold stress conditions, causing plant cells to accumulate large amounts of proline. In this study, we cloned and identified the P5CS gene from Stipa purpurea, which has a full-length of 2196 bp and encodes 731 amino acids. A subcellular localization analysis indicated that SpP5CS localized to the cytoplasm. The ectopic overexpression of SpP5CS in Arabidopsis thaliana resulted in higher proline contents, longer roots, higher survival rates and less membrane damage under drought stress conditions compared with wild-type controls. SpP5CS-overexpressing A. thaliana was more resistant to drought stress than the wild type, whereas the deletion mutant sp5cs was less resistant to drought stress. Thus, SpP5CS may be a potential candidate target gene for increasing plant resistance to drought stress.

[Overview of quality standards of Eucommiae Cortex in China and overseas].

Eucommiae Cortex is an authentic medicinal material with broad growing areas( such as Hunan and Sichuan provinces in China. It is well-known for its efficacy in tonifying liver and kidney,strengthening muscles and bones,and stabilizing fetus. It has also been proven in pharmacology to possess the functions such as lowering blood pressure and lipids. Hence,Eucommiae Cortex has attracted increasing attention. The current quality standards of Eucommiae Cortex vary in different countries or regions. The quality of Eucommiae Cortex products on the market is affected by mix-ups of non-medicinal parts and insufficient growth years. In view of these problems,this paper summarizes the current quality standards and research progress of Eucommiae Cortex in China and overseas,aiming to provide a reference for the establishment of the quality standards of Eucommiae Cortex.

[Rapid detection of aflatoxin B_1 in Chinese herbal medicines by indirect and direct competitive enzyme-linked immunosorbent assays: a comparative analysis].

The indirect competitive enzyme-linked immunosorbent assay(ic-ELISA) and direct competitive enzyme-linked immunosorbent assay(dc-ELISA) were performed for the rapid detection of aflatoxin B_1(AFB_1) in Astragali Radix, Zingiberis Rhizoma Recens, Jujubae Fructus, and Nelumbinis Semen with self-made antigens and antibodies. Different extraction methods were investigated to reduce the matrix effects of different medicinal parts in Chinese herbal medicines. The sensitivity of dc-ELISA method was improved by optimizing the molar ratio of AFB_1 to horseradish peroxidase(HRP). In this study, the sensitivity(IC_(50)) of ic-ELISA and dc-ELISA was 0.046 and 0.023 ng·mL~(-1), with the limit of detection(LOD) of 0.007 and 0.004 ng·mL~(-1), respectively. The detection time was 3 h and 50 min for ic-ELISA and dc-ELISA, respectively. The recovery rates were within the range of 62.96%-104.4%, with RSDs of less than 10%. Confirmed by LC-MS/MS, three positive samples of Nelumbinis Semen were detected from 53 samples. Two ELISA methods established in this study were accurate, rapid and sensitive, and can be used for rapid screening of AFB_1 in Chinese herbal medicines such as Astragali Radix, Zingiberis Rhizoma Recens, Jujubae Fructus, and Nelumbinis Semen. In addition, the advantages and limitations of the two methods were compared and discussed, which can provide a reference for the testing institutions to choose the proper method.

Uncovering the role of a positive selection site of wax ester synthase/diacylglycerol acyltransferase in two closely related Stipa species in wax ester synthesis under drought stress.

Natural selection drives local adaptations of species to biotic or abiotic environmental stresses. As a result, adaptive phenotypic divergence can evolve among related species living in different habitats. However, the genetic foundation of this divergence process remains largely unknown. Two closely related alpine grass species, Stipa capillacea and Stipa purpurea, are distributed in different rainfall regions of northern Tibet. Here, we analyzed the drought tolerance of these two closely related Stipa species, and found that S. purpurea was more resistance to drought stress than S. capillacea. To further understand the genetic diversity behind their adaptation to drought environments, a comprehensive gene repertoire was generated using PacBio isoform and Illumina RNA sequencing technologies. Bioinformatics analyses revealed that differential transcripts were mainly enriched in the wax synthetic pathway, and a threonine residue at position 239 of WSD1 was identified as having undergone positive selection in S. purpurea. Using heterologous expression in the Saccharomyces cerevisiae mutant H1246, site-directed mutagenesis studies demonstrated that a positive selection site results in changes to the wax esters profile. This difference may play an important role in S. purpurea in response to drought conditions, indicating that S. purpurea has evolved specific strategies involving its wax biosynthetic pathway as part of its long-term adaptation to the Qinghai-Tibet Plateau.

[Cloning of AhWRKY33 from Asarum heterotropoides and its genetic transformation in Arabidopsis].

The WRKY family genes, which play an important role in plant morphogenesis and stress response, were selected based on the data of the full-length transcriptome of Asarum heterotropoides. Using AtWRKY33, which regulates the synthesis of the camalexin in the model plant Arabidopsis to compare homologous genes in A. heterotropoides, primers were designed to amplify the open reading frame(ORF) fragment of AhWRKY33 gene by RT-PCR using total RNA of A. heterotropoides leaves as template. Real-time PCR results showed that there was a significant difference between the aerial part and the underground part of A. heterotropoides, the toxic aristolochic acid content is highly expressed in the leaves higher than the root. After verification, the WRKY33 gene of A. heterotropoides is ORF long 1 686 bp, encoding 561 amino acids.AhWRKY33 had two conserved WRKYGQK domains. According to the classical classification, it belongs to group Ⅰ WRKY transcription factor. A. heterotropoides WRKY33 had some homology with amino acids of other species. The study successfully constructed the plant eukaryotic expression vector PHG-AhWRKY33 and transformed Arabidopsis thaliana, the transgenic Arabidopsis was obtained by PCR detection and hygromycin resistant plate screening. It found that the germination of transgenic Arabidopsis seeds was accelerated and the stress resistance was increased. It laid a foundation for further analysis of WRKY transcription factor in the growth and development of A. heterotropoides and the synthesis of secondary metabolites.

Impact of timing on in-patient outcomes of complete repair of tetralogy of Fallot in infancy: an analysis of the United States National Inpatient 2005-2011 database.

BACKGROUND: This study aimed to investigate whether age at complete repair of tetralogy of Fallot (TOF) impacts postoperative morbidity and length of hospital stay in infants less than 365 days of age. METHODS: The United States Nationwide Inpatient Sample was searched for infants 0-365 days of age that underwent complete repair of TOF between 2005 and 2011. Patients were categorized based on age at time of repair: 0-30 days; 31-90 days; 91-180 days; > 180 days. RESULTS: A total of 1112 infants were included in the study. Multivariate analysis showed the risk of postoperative complications was 40% lower in infants ≥91 days old at the time of repair as compared to those ≤30 days old. In addition, children > 30 days old at the time of repair had a significantly shorter length of hospital stay than those aged ≤30 days. In the subgroup with elective repair, older age was associated with a shorter length of hospital stay as compared to those ≤30 days old at repair, while association between age at complete repair of TOF and postoperative complication was not significant among the groups after adjusting for confounders. CONCLUSIONS: In children < 1 year old, postoperative complications and length of hospital stay are affected by the timing of complete repair of TOF.

Vanillic Acid Suppresses HIF-1α Expression via Inhibition of mTOR/p70S6K/4E-BP1 and Raf/MEK/ERK Pathways in Human Colon Cancer HCT116 Cells.

Hypoxia-inducible factor 1 (HIF-1) plays a pivotal role in tumor adaptation to microenvironmental hypoxia, and it also exerts important roles in angiogenesis and tumor development. Vanillic acid is a dietary phenolic compound reported to exhibit anticancer properties. However, the mechanisms by which vanillic acid inhibits tumor growth are not fully understood. Here, we investigated the effect of vanillic acid on HIF-1α activation. Vanillic acid significantly inhibits HIF-1α expression induced by hypoxia in various human cancer cell lines. Further analysis revealed that vanillic acid inhibited HIF-1α protein synthesis. Neither the HIF-1α protein degradation rate nor the steady-state HIF-1α mRNA levels were affected by vanillic acid. Moreover, vanillic acid inhibited HIF-1α expression by suppressing mammalian target of rapamycin/p70 ribosomal protein S6 kinase/eukaryotic initiation factor 4E-binding protein-1 and Raf/extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK pathways. We found that vanillic acid dose-dependently inhibited VEGF and EPO protein expressions and disrupted tube formation. The results suggest that vanillic acid effectively inhibits angiogenesis. Flow cytometry analysis demonstrated that vanillic acid significantly induced G1 phase arrest and inhibited the proliferation of human colon cancer HCT116 cells. In vivo experiments confirmed that vanillic acid treatment caused significant inhibition of tumor growth in a xenografted tumor model. These studies reveal that vanillic acid is an effective inhibitor of HIF-1α and provides new perspectives into the mechanism of its antitumor activity.

[Current situation of heavy metal pollution,detection and removal techniques in medicinal marine organisms in China].

As an important branch of traditional medicines,medicinal marine organisms have many advantages,including biological diversity,remarkable biological activity,especial for the treatment of anti-cancer,anti-virus,anti-coagulation,analgesia,anti-bacterial,cardiovascular and cerebrovascular diseases. In recent years,with the continuous exploration of marine organisms by human beings,many marine organisms with specific biological activities and medicinal prospects have been found,which have attracted great attention around the world and thus called " new hope" to solve human health problems. However,due to the rapid development of modern industry,heavy metal pollution not only poses a great threat to medicinal marine living resources,but also hinders the development of marine biomedical industry and threatens human health. In view of this,this paper introduced the development trend of medicinal marine organisms and the current situation of heavy metal pollution and focusing on the analysis technology and chemical removal technology of heavy metals in medicinal marine organisms,which is to provide reference for the heavy metals control in marine medicines and the development and utilization of marine medicines.

[Safety evaluation of heavy metals contaminated Xiaochaihu Tang using health risk assessment model].

In order to further improve the quality and safety evaluation standards of traditional Chinese medicine compound preparation,Xiaochaihu Tang compound preparations were selected to analyze the pollution level of heavy metals deeply,and the potential health risks were evaluated under taking such kind of compound preparations. In this study,the contents of copper( Cu),arsenic( As),cadmium( Cd),mercury( Hg),and lead( Pb) in different Xiaochaihu Tang compound preparations were determinated by the method of inductively coupled plasma mass spectrometry( ICP-MS). Moreover,combined with target hazard coefficient method and in vitro artificial system,the bioaccessibility and health risk level was investigated in three main consumption ways including powder,decoction and granule. The result was showed that,under the maximum residual limit set by International Standard Organization,only one batch of raw herb was eight times exceeded the Hg MRL,however,in water decoctions and granules,the heavy metal residue rate was reduced to 2. 02%( Hg in granules)-42. 85%( Cd in granules). So,the heavy metal pollutions and health risks can be reduced to safe region in spite of the serious pollution in raw herbs. Besides,the THQ and CR values of the three consumption methods were lower than the standard values of non-carcinogenic and carcinogenic risks of each heavy metal. It can be seen that even if the heavy metals in the raw herbs exceed the standard,the use of Xiaochaihu Tang decoction and granules can reduce the harm of heavy metals to the human body. Above all,the establishment of this health risk assessment model can be provided experimental basis and reference value for improving the safety evaluation standard of other heavy metals contained traditional Chinese medicine( TCM) compound preparations,and further improving the quality control methods of other different toxic compounds in clinical use.

[Simultaneous determination of aflatoxin B_1,B_2,G_1,G_2,M_1,M_2 in Eupolyphaga Steleophaga by immunoaffinity column clean-up and HPLC-FLD with post-column photochemical derivatization].

The contamination of aflatoxin B_1,B_2,G_1,G_2,M_1 and M_2 in Eupolyphaga Steleophaga was determined by immunoaffinity column clean-up and HPLC-FLD with post-column photochemical derivatization. Chromatographic separations were carried out using a Cloversil C_(18) column( 4. 6 mm×250 mm,5 µm) that were eluted in isocratic with methanol-acetonitrile-water( 20 ∶ 20 ∶ 60) as the mobile phase. The excitation wavelength and the emission wavelength of fluorescence detector were maintained at 360 nm and 450 nm,respectively. The flow rate was 0. 8 m L·min~(-1),and the column temperature was 30 ℃ ． The sample was prepared using the immunoaffinity column,then the recovery was measured with 75. 47%-101. 8% with RSD values lower than 6. 7%. A total of 20 batches of Eupolyphaga Steleophaga samples were assayed. According to the Chinese Pharmacopoeia( 2015 edition,part 1),the aflatoxin B_1 limit should be less than 5 µg·kg~(-1),and the sum of aflatoxins( AFB_1,AFB2,AFG_1,AFG_2) should be less than 10 µg·kg-1. Therefore,the positive rate of the 20 samples was 50. 0%,and 7 batches of samples exceeded the standard,and the over-standard rate was as high as 70. 0%. Among them,aflatoxins B_1,B_2,G_1,G_2,M_1,and M_2 were detected in three batches( SD-1,AH-1,AH-3),and aflatoxins B_1,B2,G1,G2,and M1 were detected in one batch( AH-7). The results showed that the newly developed method in this work is suitable for the simultaneous determination of six aflatoxins in Eupolyphaga Steleophaga,and also suggested that it should be of high values to take the contamination with aflatoxins into concerns.

[Survey on pesticide use in Crataegi Fructus and analysis of pesticide residues based on LC-ESI-MS/MS].

In order to study the pesticide residues of the medicinal Crataegi Fructus,this study aims to establish an analysis method for pesticide residues( mainly containing insecticides and fungicides) suitable for the actual situation of medicinal Crataegi Fructus based on the survey of the pesticides of the Crataegi Fructus base,combined with the blind screening results of the LC-ESI-MS/MS pesticide screening platform established by the research team in the early stage. Then,the pesticide residues in medicinal Crataegi Fructus from Shandong,Hebei,Henan,Shanxi,and Liaoning( main cultivation areas) were analyzed. The samples were pretreated by the modified Qu ECh ERS method,i.e.,extracted with acetonitrile-water( 9 ∶1),purified by PSA,C_(18),GCB,silica gel. The detection of pesticides was performed by LC-MS/MS. The ion source was ESI with positive scanning mode,and the linearity of 11 kinds of pesticides in the range of 5-300 µg·kg~(-1) was acceptable( R~2>0. 996 9). All the recoveries of pesticides were within 70. 02%~(-1)12. 0% in the low,medium and high levels,with RSD≤17%. The results showed that the detection rate of carbendazim,chlorpyrifos and difenoconazole is 79%,82%,56%,respectively. Besides,the prohibition pesticide carbofuran were detected in some of the batches,indicating the security risk. This study provides methodological references and basic data for risk assessment of Crataegi Fructus and government regulation.

[QuEchERS pretreatment coupled to gas chromatography and tandem mass spectrometry to fast determination of 34 pesticide residues in Glycyrrhizae Radix et Rhizoma].

This study proposed a quantitative method for 34 pesticides including organochlorine,organophosphorus and pyrethroids in Glycyrrhizae Radix et Rhizoma herbs and medicinal slices,and analyzed the pesticide residues of collected Glycyrrhizae Radix et Rhizoma samples from different regions. With acetonitrile extraction and optimized Qu Ech ERS purification,the 32 batches of Glycyrrhizae Radix et Rhizoma herbs and medicinal slices were analyzed by matrix matching standard curve quantitative analysis under GC-MS/MS multi-response monitoring( MRM) mode. This study investigated the pretreatment of Glycyrrhizae Radix et Rhizoma samples based on the Qu Ech ERS method of Chinese Pharmacopoeia( 2015 edition,4),and the result showed that the recoveries of some pesticide was low and pigment has a strong interference in analysis,which result in worse purification effect. Therefore,this paper further optimized the Qu Ech ERS method and corrected the matrix matching standard curve method,and compensated the qualitative and quantitative effects of matrix effects on the detected target compounds in Glycyrrhizae Radix et Rhizoma. The results showed that 34 kinds of pesticide had good linear( R~2 of 0. 996 4 or higher) within a covering 0. 01-0. 2 mg·kg~(-1) concentration range. The limits of quantitation are less than 0. 01 mg·kg~(-1). This method was further applied to the simultaneous determination of 34 pesticide residues of typical organochlorine,organophosphorus and pyrethroids in 32 batches of Glycyrrhizae Radix et Rhizoma herbs and medicinal slices. Six batches containing beta-endosulfan,thiosulphate,o,p'-DDD and thrta-cypermethrin were detected,but none of them exceeded the limit of pesticide residues stipulated in the Chinese Pharmacopoeia and the EU Pharmacopoeia. This study indicates that the established method is rapid,convenient,accurate,and sensitive,which provides a rapid and efficient method for the simultaneous determination of typical organochlorine,organophosphorus and pyrethroids in Glycyrrhizae Radix et Rhizoma.

[Recent research progress on natural medicines in treatment of cadmium toxicity].

Cadmium contamination of environment is a subject of serious international concern. Bioaccumulation of cadmium occurs primarily through ingestion of contaminated water and food. Cadmium poisoning came into prominence with the "itai-itai" disease event in Japan in the 1950s. It could also cause damages to liver, kidney, lung and other organs. Thus, the treatment of cadmium poisoning has become a research hotspot. Researchers are trying their best to explore prophylactic and therapeutic medicines for prevention and treatment of cadmium-induced poisoning. So far, chelation therapy, the conventional treatment for heavy metal toxicity, is reported to have a number of safety and efficacy issues. Natural medicines have a variety of advantages such as extensive sources, high safety, less adverse reactions, and thus have great potentials in treating cadmium poisoning. In this review, the progress in the antagonistic effects of natural drugs in cadmium poisoning and their therapeutic mechanisms were summarized in order to provide certain references for the future development and in-depth study of antagonistic substances.

[Identification and quality evaluation of Tripterygium wilfordii].

With the extensive clinical application of Tripterygium wilfordii, there are many counterfeit products on the market. Traditional technology can not effectively identify the authenticity of the traditional Chinese medicine. Therefore, a strategy of accurate identification and quality evaluation of Tripterygium based on DNA barcode and chemical fingerprint spectrum was established. Based on DNA barcode technology, HMMer annotation method of hidden Markov model and K2P model were used to analyze genetic distance.BLAST1, nearest distance and phylogenetic tree (NJ-tree) methods were used to assess the identification efficiency of the ITS2 barcode. The fingerprint of 27 T. wilfordii was established by UPLC-PDA method, and the similarity of the fingerprint of different sources was evaluated. The main components of T. wilfordii were determined by LC-MS/MS. The results revealed that the intraspecific genetic distances of T. wilfordii were lower than the interspecific genetic distances between T. wilfordii and its adulterants. The results of similarity search showed that ITS2 sequence was used to identify T. wilfordii and its adulterants. The clustering of T. wilfordii and its adulterants was clear in the tree of NJ cluster, and 12 of 27 samples were identified as true T. wilfordii.The chemical fingerprint spectrum research indicates that the feature one region can distinguish the false product of tripterygium glycosides more intuitively. The cluster analysis of HCA-thermal map showed that the contents of six active components of T. wilfordii from different habitats were significantly different, which could be used to evaluate the quality of T. wilfordii. This paper is of guiding significance for the accurate identification and quality evaluation of Tripterygium medicinal plants.

[Recent advances in analysis of endogenous toxic components in traditional Chinese medicines].

Endogenous toxic components have become an important topic in the field of traditional Chinese medicines (TCMs). Since the endogenous toxic components in TCMs are often used as clinical effective components, the safety and effectiveness of endogenous toxic substances has become an important part of the research of TCMs. In this paper, the classification and evaluation criteria of toxic Chinese medicinal materials are described, and the analytical methods of endogenous components in TCMs are summarized and expounded base on with the techniques of chromatography, spectroscopy, immunoassay, and so on. On this basis, the problems in terms of endogenous toxic components are analyzed and discussed. This paper could provide ideas and methods for the evaluation of the validity and safety of TCMs containing endogenous toxic components.

Activation of secondary cell wall biosynthesis by miR319-targeted TCP4 transcription factor.

The overexpression of miR319 in plants results in delayed senescence, and high levels of miR319-targeted TCP4 transcription factor cause premature onset of this process. However, the underlying mechanisms of this pathway remain elusive. Here, we found that miR319 overexpression results in a decrease in TCP4 abundance and secondary cell wall formation in the stem. Conversely, constitutive expression of miR319-resistant TCP4 promotes secondary cell wall formation, indicating that miR319-mediated TCP4 controls secondary cell wall formation during development. Further analysis revealed that TCP4 might directly bind the promoter of VND7 to activate its expression, which triggers the expression of a VND7 transcriptional network associated with secondary cell wall biosynthesis and programmed cell death and accelerates vessel formation. In addition, the development process gradually increased TCP4 expression. These results suggest that miR319 and its target TCP4 can act as switches that turn on secondary cell wall synthesis and programmed cell death.

[Application of natural plant pigments in enlarged health industry].

Natural plant pigment is rich in resources, with the features of natural color and environment friendly, which has a broad space for development and market prospects. In order to further develop and utilize of natural plant pigment, this paper mainly introduces the natural plant dyes in the domains of food, cosmetics and health care products on the historical development process and their application. In addition,this paper summarizes the application of representative natural plant pigment, dyes, and prospects the market of natural plant pigment, so as to provide reference for the development of natural plant pigment in the enlarged health industry of China.