[Problems and strategy of further development of Chinese medicinal materials with edible values].

"Medicine and food homology" is a precious health care concept rooted in the culture of Chinese medicine and plays an important role in the development of the national health industry. It is consistent with the current global trend that food and medicine are mutually penetrating. Accordingly, the Chinese medicinal materials with edible values have an increasing production scale. Especially, in the context that the development of Chinese medicinal materials is switching from pursuing quantity to quality, the food field has become the main market for the new production capacity of Chinese medicinal materials, which has presented a broad prospect. However, the quality standards of raw materials, production methods, and administration ways vary between the materials for edible and medicinal purposes. Specifically, the food for medicinal use on the market cannot meet the quality standards of medicinal mate-rials, while the medicinal materials fail to meet the taste requirements as food. As a result, these problems cause difficulties in market circulation and supervision. In this paper, we analyzed the formation of Chinese medicinal materials with edible values, compared the food with medicinal value, common food, and functional food, and analyzed the different quality requirements of Chinese medicinal materials used in different scenarios. Further, we advised the differential development of Chinese medicinal materials in different directions(edible or medicinal use) from production to supervision. Including:(1) In the variety registration of Chinese medicinal materials with edible values, the variety breeding direction should be announced according to the requirements that medicinal materials care more about the content of active ingredients and food use materials preferentially need to meet the requirements of edible palatability.(2) Differentiation can be reflected in the selection of cultivation mode and planting and processing technology of medicinal materials, The differential production technical specification of medicinal materials with edible values should be developed. Such as the "simulated cultivation" mode is encouraged in the plant of medicinal materials to ensure its quality and the strict management of inputs and sufficient cultivation years should be guaranteed. While for edible medicinal materials, more kinds of cultivation techniques can be selected according to their processing methods.(3) The market supervision of medicinal materials with edible values should be guided by the purpose of their sales and use, which depends on the accurately recognize of the relationship between the properties of medicinal materials with edible values and the situation of pharmacopeia collection.(4) During publicity, when used as ordinary food and health food medi-cinal materials, it should be noticed that the publicity of the product's efficacy must meet the requirements of corresponding regulations.

TLR3 polymorphisms are associated with the severity of hand, foot, and mouth disease caused by enterovirus A71 in a Chinese children population.

Hand, foot, and mouth disease (HFMD) caused by enterovirus A71 (EV-A71) is a contagious viral disease, and toll-like receptors (TLRs) play essential roles in resisting the pathogen. The aim of this study was to assess the potential relationship between several TLRs polymorphisms and the HFMD severity in a Chinese children population. A total of 328 Chinese children with HFMD were included in the present study. The polymorphisms of TLR3 (rs3775290, rs3775291, rs3775296, rs1879026, rs5743312, rs5743313, rs5743303, rs13126816, and rs3775292), TLR4 (rs4986790, rs4986791, rs2149356, rs11536889, and rs41426344), TLR7 (rs179009, rs179010, rs179016, rs3853839, rs2302267, rs1634323, and rs5741880), and TLR8 (rs3764880, rs2159377, rs2407992, rs5744080, rs3747414, rs3764879, and rs5744069) genes were selected. The study indicated that individuals with the GG genotype of TLR3 single-nucleotide polymorphism rs1879026 had a higher risk of developing severe cases (GG vs. GT: OR = 1.875; 95% CI, 1.183-2.971; p = .007). Meanwhile, TLR3 rs3775290 CC genotype and C allele were associated with lower disease severity in females (CC vs. CT: OR = 0.350; 95% CI, 0.163-0.751; p = .006; C vs. T: OR = 0.566; 95% CI, 0.332-0.965; p = .036). TLR3 rs3775291 CC genotype showed 2.537 folds higher risk of developing severe cases in females (CC vs. CT: OR = 2.537; 95% CI, 1.108-5.806; p = .026). Moreover, TLR3 rs1879026 GG genotype was found to be related to increased risk of severe cases in males (GG vs. GT: OR = 2.076; 95% CI, 1.144-3.768; p = .016). The current findings show that the genetic variants of TLR3 rs1879026, rs3775290, and rs3775291 are associated with the severity of EV-A71-associated HFMD in a Chinese children population.

[Cloning and functional verification of carboxyl CoA ligases(AeCCLs) in Arnebia euchroma].

Carboxyl CoA ligases(CCLs) is an important branch of adenylate synthetase gene family, which mainly has two-step catalytic reactions. Firstly, in the presence of adenosine triphosphate, it can catalyze the pyrophosphorylation of carboxylateswith diffe-rent structures to form corresponding acyl adenosine monophosphate intermediates. Secondly, adenosine monophosphate was replaced by free electrons in the mercaptan group of enzyme A or other acyl receptors by nucleophilic attack to form thioesters. In this study, on the basis of the transcriptome database of Arnebia euchroma, two genes were selected, named AeCCL5(XP_019237476.1) and AeCCL7(XP_019237476.1). Bioinformatics analysis showed that their relative molecular weights were 60.569 kDa and 60.928 kDa, theoretical PI were 8.59 and 8.92, respectively. They both have transmembrane domains but without signal peptide. By multiple sequence alignment and phylogenetic tree analysis, we found that the similarity between AeCCLs and other plant homologous proteins was not high, and the substrate binding sites of AeCCLs were not highly conserved. The reasons might be that the sequence and structure need to adapt to the changes of new substrates in the process of evolution. In this study, the full-length of AeCCL5 and AecCCL7 were cloned into the expression vector pCDFDuet-1. The proteins of AeCCL5 and AeCCL7 with His-tag were expressed in Escherichia coli. The proteins of AeCCL5 and AeCCL7 were purified by nickel column. In vitro enzymatic reactions proved that both AeCCL5 and AeCCL7 can participate in the upstream phenylpropane pathway of shikonin biosynthesisby catalyzing 4-coumaric acid to produce 4-coumarin-CoA, and then to synthesis p-hydroxybenzoic acid, which is an important precursor of shikonin biosynthesis in A. euchroma.

[Analysis of economic benefits of Chinese medicine eco-agriculture based on multiple stakeholders].

As the most advanced environment-friendly production model in the international society, ecological agriculture of Chinese materia medica(CMM) is the only way for the development of modern agriculture. With the proposal of the declaration on ecolo-gical agriculture of CMM, "Don't grab land from farmland, don't be enemies of grass and insects, don't be afraid of barren slopes and forests, and live up to the green and green mountains", the ecological planting of CMM has blossomed all over the country, and formed a scientific theory, technology and model. Based on the theory and method of economics, this paper expounds the comprehensive benefits and development advantages of ecological agriculture of CMM from the perspectives of farmers(producers), patients(consumers) and the country. From the perspective of medicinal farmers, the input and output income of conventional agriculture and ecological agriculture of CMM such as Panax ginseng, Astragalus propinquus, Atractylodes lancea, and Bupleurum chinense were compared, and it was found that ecological agriculture of CMM had obvious advantages in net income, average annual income and input-output ratio, which could better promote farmers' income. From the perspective of patients, according to the same dose, the content of active ingredients in ecologically planted CMMs is significantly higher than that in conventionally-planted herbs, and the amount of effective substances taken by patients is also higher, so as to achieve better therapeutic effect. At the national level, ecological planting of CMM is the key to ensuring the high-quality development of CMM industry, increasing farmers' income, ensuring the safety of people's drug use and promoting the sustainable development of agriculture. It is also an important part of realizing the harmonious development of economy, society and environment and promoting ecological civilization. In general, the declaration on ecological agriculture of CMM embo-dies the core characteristics and goals of ecological agriculture, and also points of the path and vision of ecological agriculture of CMM in the future. The declaration will guide production practice, promote the benefit of farmers, and lay the foundation for the sustainable development of CMM industry.

[Effect of combined application of inorganic and organic fertilizers on growth and quality of Salvia miltiorrhiza].

The study is aimed through field experiments to study the effect of combined application of organic and chemical fertilizers on the growth and quality of Salvia miltiorrhiza, provide ideas for reducing fertilization while increasing the efficiency as well as improving the quality of produces. The experiment included 6 treatments viz., no fertilization(CK), full application of chemical fertilizer(F), 25% orga-nic fertilizer with 75% chemical fertilizer(M25), 50% organic fertilizer with 50% chemical fertilizer(M50), 75% organic fertilizer with 25% chemical fertilizer(M75), and fully apply organic fertilizer(M100). The results showed that:(1)from the perspective of yield and economic benefits, M75 was the best and M100 second;(2)for effective components, the combined application of organic and chemical fertilizers increased the content of main water-soluble components and the total content of effective components, among which M25 and M50 were better.

[Cloning and functional analysis of caffeic acid and rosmarinic acid glycosyltransferases from Arnebia euchroma].

Caffeic acid and its oligomers are the main water-soluble active constituents of the traditional Chinese medicine(TCM) Arnebiae Radix. These compounds possess multiple biological activities such as antimicrobial, antioxidant, cardiovascular protective, liver protective, anti-liver fibrosis, antiviral and anticancer activities. The phenylpropanoid pathway in plants is responsible for the biosynthesis of caffeic acid and its oligomers. Glycosylation can change phenylpropanoid solubility, stability and toxic potential, as well as influencing compartmentalization and biological activity. In view of the important role played by de-glycosylation in the regulation of phenylpropanoid homeostasis, the biosynthesis of caffeic acid and its oligomers are supposed to be under the control of relative UDP-glycosyltransferases(UGTs). Through the data mining of Arnebia euchroma transcriptome, we cloned 15 full-length putative UGT genes. After recombinant expression using the prokaryotic system, the crude enzyme solution of the putative UGTs was examined for the glycosylation activities towards caffeic acid and rosmarinic acid in vitro. AeUGT_01, AeUGT_02, AeUGT_03, AeUGT_04 and AeUGT_10 were able to glycosylate caffeic acid and/or rosmarinic acid resulting in different mono-and/or di-glycosylated products in the UPLC-MS analyses. The characterized UGTs were distantly related to each other and divided into different clades of the phylogenetic tree. Based on the observation that each characterized UGT exhibited substrate or catalytic similarity with the members in their own clade, we supposed the glycosylation abilities towards caffeic acid and/or rosmarinic acid were evolved independently in different clades. The identification of caffeic acid and rosmarinic acid UGTs from A. euchroma could lead to deeper understanding of the caffeic acid oligomers biosynthesis and its regulation. Furthermore, these UGTs might be used for regiospecific glycosylation of caffeic acid and rosmarinic acid to produce bioactive compounds for potential therapeutic applications.

Identification of new susceptibility loci associated with rheumatoid arthritis.

OBJECTIVES: The present study aimed to discover novel susceptibility loci associated with risk of rheumatoid arthritis (RA). METHODS: We performed a new genome-wide association study (GWAS) in Chinese subjects (1027 RA cases and 2879 controls) and further conducted an expanded meta-analysis with previous GWAS summary data and replication studies. The functional roles of the associated loci were interrogated using publicly available databases. Dual-luciferase reporter and cytokine assay were also used for exploring variant function. RESULTS: We identified five new susceptibility loci (IL12RB2, BOLL-PLCL1, CCR2, TCF7 and IQGAP1; pmeta <5.00E-08) with same effect direction in each study cohort. The sensitivity analyses showed that the genetic association of at least three loci was reliable and robust. All these lead variants are expression quantitative trait loci and overlapped with epigenetic marks in immune cells. Furthermore, genes within the five loci are genetically associated with risk of other autoimmune diseases, and genes within four loci are known functional players in autoimmunity, which supports the validity of our findings. The reporter assay showed that the risk allele of rs8030390 in IQGAP1 have significantly increased reporter activity in HEK293T cells. In addition, the cytokine assay found that the risk allele of rs244672 in TCF7 was most significantly associated with increased plasma IL-17A levels in healthy controls. Finally, identified likely causal genes in these loci significantly interacted with RA drug targets. CONCLUSION: This study identified novel RA risk loci and highlighted that comprehensive genetic study can provide important information for RA pathogenesis and drug therapy.

Hypoglycemic cardiac arrest and rapid return-of-spontaneous circulation (ROSC) with dextrose.

Hypoglycemia was part of the "H's and T's" in the 2005 American Heart Association ACLS guidelines for reversible causes of cardiac arrest but was removed in subsequent editions. We present a case of return of spontaneous circulation in a patient with cardiac arrest after administration of dextrose for hypoglycemia. Routine administration of dextrose to patients in cardiac arrest has been shown to be associated with increased mortality and worse neurological outcomes. However, this case reminds the clinician to consider hypoglycemia in patients with cardiac arrest, and to attempt correcting a low blood glucose if noted.

[Establishment of RNA interfered hairy root system of two CYP450 genes in Arnebia euchroma and its influence].

In this study, based on the transcriptome database of suspension cells of Arnebia euchroma, we explored two candidate cytochrome P450 enzyme genes that might relate to the shikonin biosynthesis downstream pathway when CYP76B74 sequence was referenced. We constructed interference-type hairy roots of candidate genes and cultured them. We measured the fresh weight, dry weight, total naphthoquinone content, shikonin and its derivatives content and expression levels of key enzyme genes involved in shikonin biosynthesis pathway. The effects of candidate genes on the growth and shikonin production of A. euchroma hairy roots were discussed, and the possible regulatory mechanisms that candidate genes affected shikonin synthesis were discussed. Through local Blast and phylogenetic analysis, two candidate CYP450 genes(CYP76B75 and CYP76B100) with high homology to CYP76B74 in A. euchroma were screened, and corresponding interference hairy roots were constructed. Compared with the control(RNAi-control), the fresh weight of CYP76B75 interfered hairy root(RNAi-CYP76B75) and CYP76B100 interfered hairy root(RNAi-CYP76B100) were significantly reduced, while dry weight were not affected, so the dry rate increased significantly. Except for ß-acetoxyisovalerylalkannin, which is high in three groups of hairy roots, the contents of shikonin, deoxyshikonin, acetylshikonin, ß,ß'-dimethacrylicalkannin, ß-hydroxyisovalerylshikonin,ß-hydroxyisovalerylshikonin, isobutyrylshikonin and total naphthoquinones showed a consistent pattern: RNAi-CYP76B75>RNAi-CYP76B100>RNAi-control. Among them, the synthesis of ß-hydroxyisovalerylshikonin was most significantly promoted by interfering with the expression of CYP76B75. The content of ß-hydroxyisovalerylshikonin in RNAi-CYP76B75 was 11.7 times that of RNAi-control. RESULTS:: of real-time qPCR analysis showed that compared to RNAi-control, the expression levels of AePGT gene in RNAi-CYP76B75 and RNAi-CYP76B100 were not changed significantly, and the expression levels of CYP76B74 and AeHMGR were up-regulated. In addition, the expression level of CYP76B100 in RNAi-CYP76B75 was down-regulated, whereas in RNAi-CYP76B100, the expression of CYP76B75 was significantly up-regulated. Therefore, this study confirmed that when the expression of CYP76B75 and CYP76B100 were interrupted, the growth of hairy roots were suppressed, but the synthesis of shikonin were promoted. They might increase the shikonin biosynthesis by up-regulating the expression of CYP76B74 in the hairy roots of A. euchroma.

[Strategies for medicinal plants adapting environmental stress and "simulative habitat cultivation" of Dao-di herbs].

This paper analyzed life form, habitats and environmental stresses of medicinal plants and algal fungi collected in Chinese Pharmacopoeia(2015). ①It was found that only 0.94% of the medicinal plants mainly cultivated in field. The most common habitats of medicinal plants are divided into two types: those whose natural habitats are forest margins/undergrowth(about 42.53%) and those whose natural habitats are roadside, hillside, wasteland/sand(about 43.78%). The former mainly faces environmental stresses such as weak light, pests and diseases; the latter often faces the main environmental stresses of drought, strong light, ultraviolet radiation, high temperature, low temperature(day and night or annual temperature difference is large), nutrient deficiency, pests and so on. ②Based on analyzing the strategies of medicinal plants to adapt to environmental stresses, it is pointed out that the synthesis and accumulation of secondary metabolites are the most important strategies of medicinal plants to protect against environmental stresses. In the process of long-term adaptation to specific stress, the accumulation of relevant genetic variation and epigenetic inheritance has become an important condition for the formation of quality of medicinal plants. ③It is proposed that "simulative habitat cultivation" has obvious advantages in balancing growth and secondary metabolism and guaranting the quality of traditional Chinese medicinal materials.

[Pattern and matching technology of ecological planting for Chinese materia medica based on system level].

The ecological agriculture of Chinese materia medica(CMM) has become the most dynamic and promising new field in the global ecological agriculture. The development of ecological planting of CMM has become the national strategy of Chinese traditional medicine agriculture. It has been highly valued and has flourished throughout the country, and has formed some more mature ecological planting models of CMM. Based on the system level, this paper sorts out the common ecological cultivation patterns of CMM, and obtains five basic patterns: landscape pattern at the ecological landscape level, circulation pattern at the ecosystem level, stereo model at the bio-community level, biodiversity patterns at the level of biological populations and well-established models at the level of biological individuals. On this basis, eight common ecological planting techniques of CMM were obtained, includingwild tending techniques, fine agricultural farming techniques, directional cultivation techniques, soil improvement techniques, soil testing and fertilization techniques, mycorrhizal cultivation techniques, green control technology for pests and diseases and facility cultivation techniques.This paper aims to provide theoretical basis for scientific research and popularization and application of CMM ecological planting.

[Pattern of ecological planting for Chinese materia medica based on regional distribution].

As an environment-friendly agriculture, ecological agriculture of Chinese materia medica(CMM) is being implemented in all parts of the country. Due to the stronger dependence on natural environmental conditions, ecological agriculture of CMM shows obvious regional differences in production practice. More mature CMM ecological planting patterns representative of each region were collected. It was found that common types of patterns in various regions of the country mainly included intercropping,intercropping,rotation planting mode, undergrowth planting mode, wild tending planting mode and landscape ecological planting mode. Based on the Construction Plan of National Dao-di Herbs Production Base(2018-2025) and Chinese Medicine Division, this paper systematically sorts out the pattern of ecological planting of CMM in the 8-avenue medicinal materials production areas according to the varieties and regions. The specific pattern of ecological planting of CMM included the ginseng undergrowth planting pattern in northeastern China, the bionics wild ecological planting of the Forsythia suspensa in northern China, the Fritillaria thunbergii-rice rotation in eastern China, the imitation wild planting pattern under the Polygonatum cyrtonema in central China, the planting pattern of the Fructus amomi under forest in southern China, the Ligusticum chuanxiong-rice rotation pattern in the Southwest, wild tending of Glycyrrhiza uralensis in the Northwest, and rhubarb imitation wild planting pattern in Qinghai-Tibet area. Finally, it is expected to provide reference for the screening and popularization of ecological planting patterns of other CMMs in various distribution areas.

[Cultivation strategy on cluster brand of ecological agriculture of Dao-di herbs].

The cluster brand is the embodiment of the core competitiveness of an industry. Developing and cultivating cluster brand of ecological agriculture of Dao-di herbs not only helps to optimize the value chain of the Chinese medicinal materials(CMMs) industry cluster, realize the value-added of the CMMs industry cluster, but also enhance the visibility and influence of the industrial cluster, enhance the core competitiveness of the industrial cluster. This has important practical significance for promoting the "orderly" "safe" and "effective" development of the Dao-di herbs. Based on the industry development status of CMMs, this article introduces several concepts related to cluster brands and their relationships, and focuses on the cultivation models and strategies of cluster brand in the CMMs industry. Based on the current status of the development of the CMMs industry, this article introduces several concepts related to cluster brands and their interrelationships. It discusses the cultivation models and strategies of cluster brands in the CMMs industry, industry associations, Chinese medicine companies and individual growers as the support, insists on the ecological cultivation of authentic medicinal materials and the cultivation of cluster brands. Finally, it points out the direction for the high-quality development of the ecological agriculture of CMMs.

[Core position of secondary metabolism of medicinal plants in ecological planting of Chinese materia medica and its utilization].

This paper summarized the effects of ecological planting on secondary metabolism firstly and pointed out that ecological planting can increase the content of secondary metabolites in plants, especially the content of defensive secondary metabolites. The possible mechanism was analyzed subsequently. Then, we reviewed the induction and utilization of secondary metabolism in the ecological planting of Chinese materia medica from the perspectives of biological control of pests and diseases, promotion of beneficial microorganism accumulation, optimization of mixed planting, regulation of no-tillage and straw cover. In this article, we pointed out that paying close attention to secondary metabolism is the most important feature of ecological planting of Chinese materia medica. Ecological planting can promote the accumulation of secondary metabolites of Chinese materia medica which means can improve the quality of Chinese materia medica, beneficial to the prevention and control of diseases, insects and weeds. Furthermore, lacking of systemic researches,the extensive verifications and systematic in-depth researches on the ecological planting of Chinese materia medica should be carry out urgently.

Germline mutations in 40 cancer susceptibility genes among Chinese patients with high hereditary risk breast cancer.

Multigene panel testing of breast cancer predisposition genes have been extensively conducted in Europe and America, which is relatively rare in Asia however. In this study, we assessed the frequency of germline mutations in 40 cancer predisposition genes, including BRCA1 and BRCA2, among a large cohort of Chinese patients with high hereditary risk of BC. From 2015 to 2016, consecutive BC patients from 26 centers of China with high hereditary risk were recruited (n = 937). Clinical information was collected and next-generation sequencing (NGS) was performed using blood samples of participants to identify germline mutations. In total, we acquired 223 patients with putative germline mutations, including 159 in BRCA1/2, 61 in 15 other BC susceptibility genes and 3 in both BRCA1/2 and non-BRCA1/2 gene. Major mutant non-BRCA1/2 genes were TP53 (n = 18), PALB2 (n = 11), CHEK2 (n = 6), ATM (n = 6) and BARD1 (n = 5). No factors predicted pathologic mutations in non-BRCA1/2 genes when treated as a whole. TP53 mutations were associated with HER-2 positive BC and younger age at diagnosis; and CHEK2 and PALB2 mutations were enriched in patients with luminal BC. Among high hereditary risk Chinese BC patients, 23.8% contained germline mutations, including 6.8% in non-BRCA1/2 genes. TP53 and PALB2 had a relatively high mutation rate (1.9 and 1.2%). Although no factors predicted for detrimental mutations in non-BRCA1/2 genes, some clinical features were associated with mutations of several particular genes.

Quantum Dynamics Calculations of Na (32S, 32P) + HF → NaF + H Reactions.

The dynamics of the reactive scatterings of the ground (Na(3S)) and first excited (Na(3P)) state sodium atoms from hydrogen fluoride (HF) molecules is investigated by performing comprehensive Coriolis-coupled quantum wave packet calculations on the recent ab initio potential energy surface (PES). In the Na(3S) + HF reaction, the nonadiabatic effect is found to be negligibly small, and the reactivity is significantly promoted by the initial vibrational excitations being in line with the available experimental result. Excellent quantitative agreement between theory and experiment is also achieved for the initial state specified integral cross sections and rate constants for v ≥ 3 vibrational states. However, the calculated rate constant for v = 2 significantly underestimates the experimental result. The possible cause for the disagreement is discussed in detail. For the Na(3P) + HF scattering, which can lead to the formation of either the ground state NaF + H product or Na(3S) + HF reactant via the harpooning process, the calculated result for the integral cross section shows excellent agreement with the available experimental result indicating the reasonable accuracy of the interstate coupling term of the employed PES.

[Research progress in modern clinical application and mechanism of Guizhi decoction].

Guizhi decoction come from Typhoid Theory written by Zhang Zhongjing, a famous physician in the Han dynasty. It is called "the leading group of the group" by later doctors. At present, Guizhi decoction is widely used in treatment of many diseases of internal, external, gynecologic and other diseases. This article discusses the clinical application and mechanism of Guizhi decoction in two aspects. This article expounds that Guizhi decoction is widely used in colds, febrile diseases, various perspiration, digestive system diseases and respiratory diseases, Some diseases, such as ear, nose and throat disease, nervous system disease, cardiac autonomic neuropathy, and bone and joint disease. The mechanism of Guizhi decoction in the treatment of diseases may be related to the mechanism of biaxial regulation of body temperature and gastrointestinal motility, mucosal immune intervention, secretion of sweat glands, inflammation immune function and myocardial protective effect and so on.

Experimental Demonstration of Spontaneous Chirality in a Nonlinear Microresonator.

Chirality is an asymmetric property widely found in nature. Here, we propose and demonstrate experimentally the spontaneous emergence of chirality in an on-chip ultrahigh-Q whispering-gallery microresonator, without broken parity or time-reversal symmetry. This counterintuitive effect arises due to the inherent Kerr-nonlinearity-modulated coupling between clockwise and counterclockwise propagating waves. Above an input threshold of a few hundred microwatts, the initial chiral symmetry is broken spontaneously, and the counterpropagating output ratio exceeds 20∶1 with bidirectional inputs. The spontaneous chirality in an on-chip microresonator holds great potential in studies of fundamental physics and applied photonic devices.

A new ab initio potential energy surface of LiClH (1A') system and quantum dynamics calculation for Li + HCl (v = 0, j = 0-2) → LiCl + H reaction.

A new ab initio potential energy surface (PES) for the ground state of Li + HCl reactive system has been constructed by three-dimensional cubic spline interpolation of 36 654 ab initio points computed at the MRCI+Q/aug-cc-pV5Z level of theory. The title reaction is found to be exothermic by 5.63 kcal/mol (9 kcal/mol with zero point energy corrections), which is very close to the experimental data. The barrier height, which is 2.99 kcal/mol (0.93 kcal/mol for the vibrationally adiabatic barrier height), and the depth of van der Waals minimum located near the entrance channel are also in excellent agreement with the experimental findings. This study also identified two more van der Waals minima. The integral cross sections, rate constants, and their dependence on initial rotational states are calculated using an exact quantum wave packet method on the new PES. They are also in excellent agreement with the experimental measurements.

Quantum and classical dynamics of H + CaCl(X (2)Σ(+)) → HCl + Ca((1)S) reaction and vibrational energy levels of the HCaCl complex.

We carried out accurate quantum wave packet as well as quasi-classical trajectory (QCT) calculations for H + CaCl (νi = 0, ji = 0) reaction occurring on an adiabatic ground state using the recent ab initio potential energy surface to obtain the quantum and QCT reaction probabilities for several partial waves (J = 0, 10, and 20) as well as state resolved QCT integral and differential cross sections. The complete list of vibrational energy levels supported by the intermediate HCaCl complex is also obtained using the Lanczos algorithm. The QCT reaction probabilities show excellent agreement with the quantum ones except for the failure in reproducing the highly oscillatory resonance structure. Despite the fact that the reaction is exothermic and the existence of a barrier that is energetically lower than the bottom of the reactant valley, the reaction probability for J = 0 shows threshold-like behavior and the reactivity all through the energies is very low (<0.1). The dynamical features at two different energy regions (<0.35 eV and >0.35 eV) are found to be different drastically from each other. The analyses of these results suggest that the reaction is governed by one of the two different types of reaction mechanism, one is the direct mechanism at the high energy region and the other is the indirect mechanism at the low energy region by which the reaction proceeds through the long-lived intermediate complex followed by a statistical dissociation into asymptotic channels.