Light regulation of horticultural crop nutrient uptake and utilization

Plants demonstrate dynamic changes in molecular structures under fluctuating light conditions.Accumulating evidence suggests that light plays a vital role in plant growth and morphogenesis.In particular,light has a role in the absorption and utilization of nutrients in plants.Despite significant progress in understanding the mechanism of nutrient acquisition and assimilation,how light affects and regulates ion uptake remains a question.Studies in model plants,Arabidopsis thaliana,suggest that light affects the nutrient utilization in roots through a complex regulatory network;nonetheless,the molecular mechanisms underlying the various effects of light on these processes in crop plants remain fragmentary.In this review,we discuss the light effects(light quality,light intensity,and photoperiod)on nutrient uptake and utilization in horticultural crops for optimizing crop productivity and increasing fertilizer use efficiency.

The Safety and Tolerance of Herbal Anti-Angina Drug Compound Danshen Droplet Pill in Healthy Volunteers

Background: Compound Salvia Pellet (T89), consisting of Danshen (salvia miltiorrhiza), Sanqi (panax notoginseng), and Borneol (Cinnamomum camphora), has been used worldwide for 14 years for chronic angina treatment. Purpose: A dose escalation study to determine the maximum tolerance dose (MTD) in Chinese population to support a proposed dose regimen change. Methods: Forty-six participants (age 18 to 45 yrs, male to female ratio = 1:1) were divided into a series of 6 patients cohorts, and sequentially assigned into one of the escalating dose groups, starting from 540 mg, the clinical doses, until 4 out of 6 subjects experience clinical Adverse Events (AEs) or when the pre-defined 3510 mg dose level is reached and completed. All doses were given orally as a single dose 2 hours after breakfast. Adverse events, vital signs, 12-lead ECG, clinical and laboratory parameters and medical evaluation were conducted as outcome measures. Results: Study completed at the highest pre-defined dose level of 3510 mg dose as never had 4/6 of subject experience AEs in any dose levels studied. All participants completed the study and data were included in the safety analysis. The only moderate AE observation (muscle damage) was observed at 2970 mg dose and was recovered without any medical treatment, and all other AEs (ECG, dizziness, muscle damage) were mild and may (5 cases) or may not (9 cases) be related to testing drug and were all self-resolved within 30 min after dose. Conclusion: Given as single oral dose, Compound Salvia Pellet is safe and well-tolerated up to the 3510 mg studied. The MTD value of Compound Salvia Pellet is unknown from this trial and must be higher than 3510 mg, 13 times higher than its current clinical dose.

Shade responses of prostrate and upright turf-type bermudagrasses

Bermudagrass(Cynodon dactylon)shade tolerance is a trait of immense importance to the turfgrass industry.However,little is known about shade tolerance of turf-type bermudagrass native to China.Additional knowledge of the mechanism of shade tolerance in bermudagrass is required to identify specific plant features that promote shade tolerance and assist breeding efforts worldwide.This study examines shade tolerance of two different bermudagrass cultivars,Yangjiang(prostrate form)and Guanzhong(upright form),which were developed in China.Each cultivar was subjected to 0,30.4,61.2,and 90.6%shade levels during growth and assessed for turf quality,turfgrass color intensity,biomass allocation,growth rate,antioxidant enzyme activity,leaf anatomy,and photochemical properties.Results generally demonstrated that turf quality and turf color intensity were lower in Guanzhong compared with Yangjiang on the 90.6%shade testing days.Yangjiang exhibited a less severe reduction of growth rate,leaf thickness,root to shoot ratio,and chlorophyll a to chlorophyll b ratio(Chla/b)under 90.6%shade compared with Guanzhong.Both cultivars exhibited a decrease in photochemical efficiency as determined by reduced qP,ETR,and Fv/Fm values.Photochemical efficiency was impacted less in Yangjian,and superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT)enzymes activities were greater than in Guanzhong when exposed to severe shade.When exposed to 90.6%shade level,Yangjiang had better turf quality than Guanzhong as determined by morphological,anatomical,and physiological features.Breeding efforts focused on these shade tolerance features will lead to improved bermudagrass germplasm and aid turf management in shade environments.

Ultra-low thermal conductivity of two-dimensional phononic crystals in the incoherent regime

Two-dimensional silicon phononic crystals have attracted extensive research interest for thermoelectric applications due to their reproducible low thermal conductivity and sufficiently good electrical properties.For thermoelectric devices in high-temperature environment,the coherent phonon interference is strongly suppressed;therefore phonon transport in the incoherent regime is critically important for manipulating their thermal conductivity.On the basis of perturbation theory,we present herein a novel phonon scattering process from the perspective of bond order imperfections in the surface skin of nanostructures.We incorporate this strongly frequency-dependent scattering rate into the phonon Boltzmann transport equation and reproduce the ultra low thermal conductivity of holey silicon nanostructures.We reveal that the remarkable reduction of thermal conductivity originates not only from the impediment of low-frequency phonons by normal boundary scattering,but also from the severe suppression of high-frequency phonons by surface bond order imperfections scattering.Our theory not only reveals the role of the holey surface on the phonon transport,but also provide a computation tool for thermal conductivity modification in nanostructures through surface engineering.

Organic modification of carbon nanotubes

The organic modification of carbon nanotubes is a novel research field being developed recently. In this article, the history and newest progress of organic modification of carbon nanotubes are reviewed from two aspects: organic covalent modification and organic noncovalent modification of carbon nanotubes. The preparation and properties of organic modified carbon nanotubes are discussed in detail. In addition, the prospective development of organic modification of carbon nanotubes is suggested.