Root Cultures for Secondary Products

Plants are source of many high-value secondary compounds used as drugs, food additives, flavors, pigments and pesticides. The production of these compounds in nature faces to many difficulties because of the dependence on weather, soil … Furthermore, these compounds are usually limited by species, periods of growth or stress. The utilization of plant cells in vitro for the secondary compounds has gained increasing attention over past decades. However, the yield is still low, probably due to the degree of cell differentiation. Therefore, root culture is focused on research as an alternative to cell cultures to produce secondary compounds because of high rate proliferation, great potential in the production with high and stable yields. Hairy roots and adventitious roots have a high ability to biosynthesize secondary compounds in vitro with high and fairly stable in yield in comparison with plant cell suspension cultures. Nowadays, it is feasible to expand the scale of root cultures in bioreactors, which makes it possible to produce secondary compounds on an industrial scale

Rosmarinic acid production in cell suspension cultures of Ehretia asperula Zollinger & Moritz

Plant cell cultures provide an alternative means for producing secondary compounds in food, cosmetic and pharmaceutical industries. Ehretia asperula Zollinger & Moritzi is used as a traditional medicine for the treatment of liver detoxification, ulcers, tumors, inflammation and enhancing the body's resistance in Vietnam. The study was carried out to select suitable callus line for cell suspension cultures of E. asperula Zollinger & Moritzi and investigate the effects of inoculum size, rotation speed and naphthalene acetic acid (NAA) on the proliferation of cell suspension cultures. In addition, the influence of light intensity on the growth and rosmarinic acid (RA) biosynthesis of cell suspension was also surveyed. After 4 weeks of culture, the white to pale yellow friable callus expanded significantly with a fresh weight (FW) of 0.788 g and a high RA content of 2.062 mg/g FW. An appropriate medium for cell proliferation was the liquid B5 medium, which contained 30 g/l glucose, 0.1 mg/l benzyl adenine (BA) and 0.4 mg/l NAA. The results also demonstrated that a 1:20 ratio (w/v) inoculum size, darkness and rotation speed of 90 rpm were the optimal conditions for the proliferation and RA accumulation to 188.217 mg/l in 4 weeks of culture. These findings showed that E. asperula Zollinger & Moritzi cell suspension cultures could be a potential alternative approach for RA production in vitro

Developing Rural Tourism with the Participation of Related Parties in Bac Kan Province

Tourism development policy will pay attention to stakeholders, especially the people, who play an important role. However, in reality, when people participate in rural tourism development, they are not equipped with basic knowledge and skills in managing and serving tourists. Because the benefits between stakeholders are still not clear, the participation of people in rural tourism development is currently only passive. Active participation need to be directed from the Government and local authorities because the concept that rural tourism development is not only about creating economic benefits but also associated with conservation and preservation, together with keeping and promoting cultural - historical values in rural areas

Optimal Sizing and Location of Shunt Capacitors in Medium Voltage Underground Power Cables: A Case of Minimum Cost

This paper introduces a method to determine optimal sizing and location of shunt capacitors in medium voltage Underground Power Cables or in distribution system. To execute this method, two models of standard branch and the Newton-Raphson method are also mentioned to analyze and determine values of bus voltage and currents going through lines in whole system. The EN 50160 standard is introduced to evaluate all operational parameters and propose solutions to reduce risks. In additionally, the cost function method is introduced basing on cost of purchasing compensative device, power loss in own compensators and whole system after compensating. By considering partial derivative of cost function with respect to variables, optimal sizing and location of shunt capacitors can be determined for all buses in the system. Analyzing the system by using the Newton-Raphson method in stable mode, all operational parameters are evaluated to see the benefit of placing capacitors in some criterions: reduce the current going through all lines and increase value of bus voltage in whole system. Theory research are verified by simulation results carried out in Matlab 2016 software

Morphodynamic modeling and causes of closure of My A inlet

Morphodynamics and sediment transport of the My A inlet in the low flow season are modeled using Delft3D. The simulation model takes into account the forcing of waves, tides and river flows. Model outputs of sediment transport and morphological changes of allow analysing the mechanism and cause of inlet closure. The analysis shows that longshore sediment is accreted on the northern side of the inlet both on the ebb tidal delta and along the north coast, but onshore sediment transport by wave reworking is the main process to close the inlet

Effect of molybdenum on growth and nitrogen metabolism of Brassica parachinensis L. and Brassica integrifolia L. under drought stress

Molybdenum (Mo) is an essential trace element that plays a critical role in various physiological processes of plants. Drought stress poses a significant threat to plant growth, making it imperative to study the effects of Mo in mitigating its impact on Brassica parachinensis L. and Brassica integrifolia L. This study aims to investigate the influence of molybdenum on the growth and nitrogen metabolism of Brassica species under drought-stress conditions. The study delves into the physiological and biochemical responses of these plants to Mo supplementation to comprehend the mechanisms by which Mo enhances drought tolerance and nitrogen assimilation. The results revealed that Mo supplementation (150 g ha-1) significantly improves the growth and nitrogen metabolism of Brassica species under drought-stress conditions. In particular, the application of Mo under drought stress leads to a notable increase in yield, as indicated by the improvement in productivity from 3.41 to 4.25 (kg m-2) and 3.89 to 4.97 (kg m-2) in Brassica parachinensis and Brassica integrifolia, respectively. Furthermore, Mo supplementation enhances chlorophyll levels, thereby promoting efficient photosynthesis. Additionally, it positively affects the accumulation of soluble sugars, starch, and proteins, indicating improved nutrient assimilation and utilization in the plants. These findings suggest that Mo supplementation plays a crucial role in enhancing drought tolerance and nitrogen assimilation in Brassica species. The study highlights the potential of Mo as a valuable tool for improving crop productivity and resilience under drought-stress condition

Calculation of Temperature-Dependent Thermal Expansion Coefficient of Metal Crystals Based on Anharmonic Correlated Debye Model

This study aims to calculate the anharmonic thermal expansion (TE) coefficient of metal crystals in the temperature dependence. The calculation model is derived from the anharmonic correlated Debye (ACD) model that is developed using the many-body perturbation approach and correlated Debye model based on the anharmonic effective potential. This potential has taken into account the influence on the absorbing and backscattering atoms of all their nearest neighbors in the crystal lattice. The numerical results for the crystalline zinc (Zn) and crystalline copper (Cu) are in agreement with those obtained by the other theoretical model and experiments at several temperatures. The analytical results show that the ACD model is useful and efficient in analyzing the TE of coefficient of metal crystals

Chemical composition and antibacterial activities of essential oils from fruits of Melicope pteleifolia (Champ. Ex Benth.) T.G. Hartley grown in Lam Dong Province, Vietnam

In the present study, chemical composition and antibacterial properties of essential oil obtained from the aerial parts of the Melicope pteleifolia (Champ. ex Benth.) T.G Hartley in Dalat were evaluated. Essential oil was isolated through hydro-distillation. Twenty-nine constituents comprising 100% of the essential oil were characterized by gas chromatography/mass spectrometry (GC-MS) techniques. The major compounds in the essential oil were (+)-Sabinene (34.73%), Cis-α-bergamotene (13.15%), Z-α-trans-bergamotol (5.28%), β-mycrene (4.98%), and 1,3,6-octatriene, 3,7-dimethyl-(4.71%). Antibacterial activities of Melicope pteleifolia essential oil were investigated against Gram-positive and-negative bacteria. Results showed significant activities against Streptococcus pyogenes and Escherichia coli using an agar well diffusion method. The application of this essential oil in preventing and eliminating bacteria could be useful in fields as medicine and cosmetics.