MOF-Derived Co/C and MXene co-Decorated Cellulose-Derived Hybrid Carbon Aerogel with a Multi-Interface Architecture toward Absorption-Dominated Ultra-Efficient Electromagnetic Interference Shielding.

Exploring electromagnetic interference (EMI) shielding materials with ultra-efficient EMI shielding effectiveness (SE) and an absorption-dominated mechanism is urgently required for fundamentally tackling EMI radiation pollution. Herein, zeolitic imidazolate framework-67 (ZIF-67)/MXene/cellulose aerogels were first prepared via a simple solution mixing-regeneration and freeze-drying process. Subsequently, they are converted into electric/magnetic hybrid carbon aerogels (Co/C/MXene/cellulose-derived carbon aerogels) through a facile pyrolysis strategy. ZIF-67-derived porous Co/C could provide the additional magnetic loss capacity. The resultant electric/magnetic hybrid carbon aerogels exhibit a hierarchically porous structure, complementary electromagnetic waves (EMWs) loss mechanisms, and abundant heterointerfaces. The construction of a porous architecture and the synergy of electric/magnetic loss could greatly alleviate the impedance mismatching at the air-specimen interface, which enables more EMWs to enter into the materials for consumption. Moreover, numerous heterointerfaces among Co/C, Ti3C2Tx MXene, and cellulose-derived carbon skeleton induce the generation of multiple polarization losses containing interfacial and dipole polarization, which further dissipate the EMWs. The resultant electric/magnetic hybrid carbon aerogel with a low density (85.6 mg/cm3) achieves an ultrahigh EMI SE of 86.7 dB and a superior absorption coefficient of 0.72 simultaneously. This work not only offers a novel approach to design high-performance EMI shielding materials entailing low reflection characteristic but also broadens the applicability of electric/magnetic hybrid carbon aerogels in aerospace, precision electronic devices, and military stealth instruments.

[Factors influencing induction and in vitro culture of hairy roots in Phytolacca americana L.]

To use hairy roots for producing medicinal ingredients of Phytolacca americana L. we studied the factors influencing the induction and in vitro culture. Hairy roots could be incited from the veins of cut surface (morphological lower) of P. americana L. leaf explants around 18 days after infection with the strain of Agrobacterium rhizogenes ATCC15834. The highest rooting rate, 70%, was obtained when leaf explants were pre-cultured for 1 day, infected for 20 min, and co-cultured for 4 days. The transformation was confirmed by PCR amplification of rolC of Ri plasmid and silica gel thin-layer chromatography of opines from P. americana L. hairy roots. All the hairy root lines could grow rapidly on solid exogenous phytohormone-free MS medium. Among the 9 hairy root lines, the hairy root line 2 had most rapid growth, most branched lateral roots and most intensive root hair; the root surface of some hairy root lines seemed purple or red, while that of the other hairy root line appeared white. Among liquid media MS, 1/2MS, B5 and 6,7-V tested, the best growth for hairy root lines was attained in liquid exogenous phytohormone-free MS medium. Compared with exogenous phytohormone-free MS medium, 6,7-V medium was better for synthesis and accumulation of esculento side A in hairy roots. The established optimal conditions for induction and in vitro culture of P. americana hairy roots had laid an experimental and technological foundation for production of medicinal constituents esculento side A from large scale culture of hairy roots.

Responses of the Hybrid between Sphagneticola trilobata and Sphagneticola calendulacea to Low Temperature and Weak Light Characteristic in South China.

Hybridization between exotic and native species is of great interest to evolutionary biologists and ecologists because it usually shows a quick evolution of species and invasiveness. It has been reported that such hybridization frequently increases the adaptation and aggressiveness of the new hybrids. A hybrid between invasive Sphagneticola trilobata and its native congener S. calendulacea was recently found in subtropical China. S. calendulacea has a significantly higher tolerance to low temperature and weak light stress than S. trilobata, and its range includes both tropical and temperate regions. This study examined how the tolerance of the new hybrid to low temperature and weak light conditions (LTWL), expanded its geographical range. All changes of phenotype, gas exchange parameters, chlorophyll fluorescence parameters, contents of malonaldehyde (MDA) and activity of superoxide dismutase (SOD) and peroxidase (POD) indicated that hybridization slightly catalyzed the tolerance of the hybrid to LTWL condition and the responses of the hybrid were more similar with their invasive parent. The results demonstrate that the current hybrid populations may not expand their geographical distribution ranges in a short period, but the distribution of the backcrossed generations is still uncertain. The threat of the hybrid to its native parent in subtropical region should be concerned.

[Induction and in vitro culture of hairy roots of Dianthus caryophyllus and its plant regeneration].

To use Agrobacterium rhizogenes-induced hairy roots to create new germplasm of Dianthus caryophyllus, we transformed D. caryophyllus with A. rhizogenes by leaf disc for plant regeneration from hairy roots. The white hairy roots could be induced from the basal surface of leaf explants of D. caryophyllus 12 days after inoculation with A. rhizogenes ATCC15834. The percentage of the rooting leaf explants was about 90% 21 days after inoculation. The hairy roots could grow rapidly and autonomously in liquid or solid phytohormone-free MS medium. The transformation was confirmed by PCR amplification of rol gene of Ri plasmid and silica gel thin-layer chromatography of opines from D. caryophyllus hairy roots. Hairy roots could form light green callus after cultured on MS+6-BA 1.0-3.0 mg/L + NAA 0.1-0.2 mg/L for 15 days. The optimum medium for adventitious shoots formation was MS + 6-BA 2.0 mg/L + NAA 0.02 mg/L, where the rate of adventitious shoot induction was 100% after cultured for 6 weeks. The mean number of adventitious shoot per callus was 30-40. The adventitious shoots can form roots when cultured on phytohormone-free 1/2 MS or 1/2 MS +0.5 mg/L NAA for 10 days. When the rooted plantlets transplanted in the substrate mixed with perlite sand and peat (volume ratio of 1:2), the survival rate was above 95%.