[Progress and countermeasures of Dendrobium officinale breeding].

The standandized cultivation of Chinese medicinal materials is based on variety. With the rapid development of Dendrobium officinale industry and increasing demand of improved varieties, many studies have concentrated on the variety breeding of D. officinale and subsequently achieved remarkable success. This paper systematically expounds the research progress of D. officinale breeding, e. g. the collection and differentiated evaluation for germplasm, theory and practice for variety breeding, tissue culture and efficient production with low-carbon for germchit, and DNA molecular marker-assisted breeding, and then indicates the main problems of the current breeding of D. officinale. Furthermore, the priorities and keys for the further breeding of D. officinale have been pointed out.

Analysis method development and health risk assessment of pesticide and heavy metal residues in Dendrobium Candidum.

Herbal medicines that are widely used worldwide are easily contaminated by pesticides and heavy metals, threatening human health. In this study, a modified QuEChERS pre-treatment method combined with HPLC/GC-MS/MS was established for the determination of 24 pesticide residues in Dendrobium candidum. The average recoveries of 24 pesticides in D. candidum were 76.9-110.0% with the relative standard deviation (RSD) of 0.28-11.40%, and their limits of detection (LOD) and limits of quantitation (LOQ) were 0.005-10 and 0.011-22 µg kg-1, respectively. The results showed that 83.33% of all samples had detected pesticide residues with the concentrations of 0.06-312.83 µg kg-1. Meanwhile, microwave digestion combined with ICP-MS was used to detect the residues of 8 heavy metals in D. candidum. The average recoveries of 8 heavy metals were 82.7-108.1% with an RSD of 1.4-8.0%, and their LOD and LOQ were 0.0001-0.05 mg kg-1 and 0.0003-0.2 mg kg-1, respectively. The results indicated that 8 heavy metals were all detected in all samples, and the highest concentration of Zn was 11.97 mg kg-1. Furthermore, the health risk assessment showed that the risk of the detected pesticides and heavy metals in samples to humans, specifically to the general population including adults and children, was acceptable.

[Study on 11 metal [correction of mental] element contents in Dendrobium officinale].

OBJECTIVE: To find out the variation of 11 mental element contents in Dendrobium officinale with different germplasms and harvesting ages, the results can provide scientific basis for the quality evaluation and the breeding of D. officinale. METHOD: 32 samples with 1-3 ages were collected from cultivated fields of Zhejiang and 11 samples were collected from markets. The 11 mental element contents of samples were determined by ICP-MS or AAS. RESULT: The average contents of K, Ca, Mg, Mn, Zn, Cr, and Cu were 1,205.23, 766.82, 158.25, 31.06, 4.28, 8.28, and 0.97 mg x kg(-1), the contents of As, Hg, Pb, and Cd were all in limits except Cd content of one sample exceeded the standard limit 0.07 mg x kg(-1); germplasms and physiological ages impacted mental elements contents accumulation significantly. CONCLUSION: There were rich essential mental elements in D. officinale. D. officinale from Zhejiang province and medical materials from market were all safe; the breeding of D. officinale can increase the contents of essential mental elements and reduce contents of heavy mental elements; the effect of physiological age on metal elements contents was related to each element's physiological and biochemical function.

[Quantitive variation of polysaccharides content in cultivated Dendrobium candidum].

OBJECTIVE: To reveal the variation content of polysaccharides in cultivated Dendrobium candidum and the relationship between germplasms, harvesting and polysaccharides content for the breeding of quality of D. candidium. METHOD: The morphological characteristics were recorded when 33 samples were collected. The content of polysaccharides was determined by phenol-sulphuric acid method. RESULT: The average content of polysaccharides in 2-year-old samples was 34.47% (25.63%-41.65%). The polysaccharides content of samples were significantly different among germplasms and physiological ages. CONCLUSION: The polysaccharides content of cultivated D. candidum is higher than that of wild materials. Germplasms and physiological age impact on the polysaccharides content significantly. D. candidum breeding and the control of harvesting can increase polysaccharides content.

[Quantitative variation of total alkaloids contents in Dendrobium officinale].

OBJECTIVE: To investigate the total alkaloid content and find out the variation of total alkaloids content in Dendrobium officinale with different germplasms and harvesting ages with the aim of providing scientific basis for the authenticity identification and the breeding of D. officinale. METHOD: Forty one samples with 1-3 ages were collected from cultivated fields of Zhejiang and Yunnan provinces and 11 samples were collected from markets. The total alkaloid contents of samples were determined using acid-dye colorimetry method. RESULT: The determined total alkaloid contents in D. officinale ranged 0.0190%-0.0430%. The averages of total alkaloid contents were 0.0253%, 0.0270% and 0.0326% in 1-year-old, 2-year-old and 3-year-old samples of Zhejiang province, respectively. The average of total alkaloid content was 0.034 3% in 1-year-old samples of Yunnan province. CONCLUSION: The total alkaloid content of D. officinale with different germplasms and physiological ages existed significant discrepancy, and it increased with the growth of ages. The total alkaloid content of cultivated D. officinale in Yunnan province was higher than that in samples from Zhejiang province. But the authentic D. officinale had certain range of total alkaloid content. Samples whose total alkaloids content divagates from this range must be counterfeit; Samples whose total alkaloid content is in this range still need to combines with other active chemical groups like polysaccharides content to identify the authenticity and quality of medicinal materials.

EMG-Centered Multisensory Based Technologies for Pattern Recognition in Rehabilitation: State of the Art and Challenges.

In the field of rehabilitation, the electromyography (EMG) signal plays an important role in interpreting patients' intentions and physical conditions. Nevertheless, utilizing merely the EMG signal suffers from difficulty in recognizing slight body movements, and the detection accuracy is strongly influenced by environmental factors. To address the above issues, multisensory integration-based EMG pattern recognition (PR) techniques have been developed in recent years, and fruitful results have been demonstrated in diverse rehabilitation scenarios, such as achieving high locomotion detection and prosthesis control accuracy. Owing to the importance and rapid development of the EMG centered multisensory fusion technologies in rehabilitation, this paper reviews both theories and applications in this emerging field. The principle of EMG signal generation and the current pattern recognition process are explained in detail, including signal preprocessing, feature extraction, classification algorithms, etc. Mechanisms of collaborations between two important multisensory fusion strategies (kinetic and kinematics) and EMG information are thoroughly explained; corresponding applications are studied, and the pros and cons are discussed. Finally, the main challenges in EMG centered multisensory pattern recognition are discussed, and a future research direction of this area is prospected.