Induction and establishment of adventitious and hairy root cultures of Plumbago zeylanica L.

This study was investigated to develop efficient protocols for adventitious and hairy root cultures of Plumbago zeylanica. Adventitious roots were initiated from leaf and stem explants cultured on MS medium with different concentrations and combinations of auxins. The highest number of roots was obtained when the explants was cultured on MS medium with 1.0 mg·L-1 IBA and 0.5 mg·L-1 NAA. Hairy root culture of P. zeylanica was obtained by infecting leaf explants cultured in vitro with Agrobacteriumrhizogenes MTCC 532. The highest frequency of explant transformation was about 93%. The developed culture exhibited fast growth and high lateral branching on growth regulator free MS medium. The rootcultures obtained were inoculated into B5, MS and SH media supplemented with different carbon sources with or without auxins and were placed on a rotary shaker 80 rpm for 35 days under dark or light conditions. Of the three media tested, MS medium sustained better root growth than others and sucrose proved to be the best carbon source. The biomass in hairy root culture was higher than in nontransformed root culture

Adventitious shoot regeneration from leaf explants of miniature paprika (Capsicum annuum) ‘Hivita Red’ and ‘Hivita Yellow’

A simple and efficient protocol was developed for in vitro propagation of two miniature paprika cultivars. Seeds of miniature paprika (Capsicum annuum) ‘Hivita Red’ and ‘Hivita Yellow’ were decontaminated and placed in a petri dish containing a half-strength MS medium and then wereincubated in the dark for 7 10 days for germination. Leaf explants excised from one month-old aseptic seedlings were cultured on a MS medium supplemented with TDZ (0.1, 0.5, 1.0, 2.0, or 3.0 mgL-1) alone or in a combination with NAA (0.1 or 0.01 mgL-1) for four weeks. The highest number of regenerated shoot buds was obtained when leaf explants were cultured on a MS medium supplemented with 2.0 mgL-1 TDZ and 0.1 mgL-1 NAA with an average shoots per explant of 8.0 in ‘Hivita Red’ and 5.6 in ‘Hivita Yellow’. Regenerated shoot buds were separated and transferred onto a MS medium without growth regulators for shoot growth and rooting. Plantlets were successfully acclimatized in a greenhouse andcultivated for three months. After about two months, they started to produce flowers and continuously produced fruits. Morphology and fruit shape of regenerated plants were normal and plants set seeds asthe same as to the seed-raised plants

Effect of soaking of seeds in potassium silicate and uniconazole on germination and seedling growth of tomato cultivars, Seogeon and Seokwang

Experiments were conducted to investigate the effects of soaking seeds in potassium silicate and uniconazole on seed germination and seedling growth of two tomato cultivars. Tomato (Lycopersicum esculentum Mill. ‘Seogeon and Seokwang’) seeds were put in a Petri dish filled with 15 ml of a solutions containing either 50 or 100 mg L-1 potassium silicate or uniconazole and were placed in an environment controlled chamber (25°C, 80% RH, dark) for 12 or 24 h. After the soaking treatment, seeds were washed in distilled water and were dried in a growth chamber (25°C, 80% RH, and in the dark) for 4 h. Seeds were sown in 288-cell (11 cc) plug trays containing a Tosilee medium and trays were layed out in a randomized complete block design on beds in a glasshouse. A nutrient solution was supplied uniformly for all treatments once a day through a sub-irrigation system. Soaking seeds in potassium silicate or uniconazole solution reduced germination percentage in both cultivars when compared to the control. In both cultivars, soaking treatment of uniconazole significantly reduced length of stem, hypocotyls, internode, leaf area and dry weight of stem and root, as compared to the control and other treatments. Root length increased significantly in all treatments when compared with the control. Hypocotyl length and plant height of 'Seogeon' seedlings were suppressed in the 100 mg L-1 potassium silicate treatment as compared to the control and water soaking. In contrast, height of ‘Seokwang’ seedlings increased by potassium silicate treatment. The chlorophyll fluorescence ratio (Fv/Fm) increased by low concentration of uniconazole treatment as compared to the control and other treatments. The growth of tomato seedlings was efficiently regulated by uniconazole 50 mg L-1 (12 h soaking) treatment.Key words: Chlorophyll fluorescence, plant growth retardants, plug plants, potassium silicate, seed treatment, silicon, uniconazole

Perpendicular Magnetic Anisotropy in FePt Patterned Media Employing a CrV Seed Layer

A thin FePt film was deposited onto a CrV seed layer at 400°C and showed a high coercivity (~3,400 Oe) and high magnetization (900–1,000 emu/cm3) characteristic of L10 phase. However, the magnetic properties of patterned media fabricated from the film stack were degraded due to the Ar-ion bombardment. We employed a deposition-last process, in which FePt film deposited at room temperature underwent lift-off and post-annealing processes, to avoid the exposure of FePt to Ar plasma. A patterned medium with 100-nm nano-columns showed an out-of-plane coercivity fivefold larger than its in-plane counterpart and a remanent magnetization comparable to saturation magnetization in the out-of-plane direction, indicating a high perpendicular anisotropy. These results demonstrate the high perpendicular anisotropy in FePt patterned media using a Cr-based compound seed layer for the first time and suggest that ultra-high-density magnetic recording media can be achieved using this optimized top-down approach

Analytical expression of Kondo temperature in quantum dot embedded in Aharonov-Bohm ring

We theoretically study the Kondo effect in a quantum dot embedded in an Aharonov-Bohm ring, using the "poor man's" scaling method. Analytical expressions of the Kondo temperature TK are given as a function of magnetic flux Φ penetrating the ring. In this Kondo problem, there are two characteristic lengths, Lc=ℏvF∕|ε˜0| and LK = ħvF = TK, where vF is the Fermi velocity and ε˜0 is the renormalized energy level in the quantum dot. The former is the screening length of the charge fluctuation and the latter is that of the spin fluctuation, i.e., size of Kondo screening cloud. We obtain diferent expressions of TK(Φ) for (i) Lc ≪ LK ≪ L, (ii) Lc ≪ L ≪ LK, and (iii) L ≪ Lc ≪ LK, where L is the size of the ring. TK is remarkably modulated by Φ in cases (ii) and (iii), whereas it hardly depends on Φ in case (i)

Disulfide-Based Poly(amido amine)s for siRNA Delivery: Effects of Structure on siRNA Complexation, Cellular Uptake, Gene Silencing and Toxicity

Purpose\ud \ud RNA interference (RNAi) is a process by which small interfering RNAs (siRNA) induce sequence-specific gene silencing. Therefore, siRNA is an emerging promise as a novel therapeutic. In order to realize the high expectations for therapeutic applications, efficient delivery systems for siRNA are necessary.\ud \ud Methods\ud \ud In this study, a new series of biodegradable poly(amido amine)s with disulfide linkages in the backbone was synthesized out of N,N′-cystaminebisacrylamide (CBA), 4-amino-1-butanol (ABOL) and ethylene diamine (EDA). Effects of different percentages of butanolic side chains and protonatable fragments in the main chain on siRNA complexation, cellular uptake, gene silencing and toxicity were investigated.\ud \ud Results\ud \ud Incorporation of EDA in the polymer resulted in increased siRNA condensation. Efficient siRNA condensation was shown to be necessary for cellular uptake; however, excess of polymer decreased siRNA uptake for polymers with high amounts of EDA. Silencing efficiency did not correlate with uptake, since silencing increased with increasing w/w ratio for all polymers. More than 80% knockdown was found for polyplexes formed with polymers containing 25% or 50% EDA, which was combined with low cytotoxicity.\ud \ud Conclusions\ud \ud Poly(amido amine)s with minor fractions of protonatable fragments in the main chain are promising carriers for delivery of siRNA\u

Identification of a novel angiogenic peptide from periostin

Angiogenic peptides have therapeutic potential for the treatment of chronic ischemic diseases. Periostin, an extracellular matrix protein expressed in injured tissues, promotes angiogenesis and tissue repair. We previously reported that in vivo administration of both recombinant full-length protein and the first FAS I domain of periostin alleviated peripheral artery occlusive disease by stimulating the migration of humane endothelial colony forming cells (ECFCs) and subsequent angiogenesis. In the present study, we ascertained the peptide sequence responsible for the periostin-induced angiogenesis. By serial deletion mapping of the first FAS I domain, we identified a peptide sequence (amino acids 142-151) of periostin for stimulation of chemotactic migration, adhesion, proliferation and endothelial tube formation of human ECFCs in vitro. Chemotactic migration of ECFCs induced by the periostin peptide was blocked by pre-incubation with an anti-??5 integrin neutralizing antibody. Treatment of ECFCs with the periostin peptide led to phosphorylation of both AKT and ERK, and pretreatment of ECFCs with the MEK-ERK pathway inhibitor U0126 or the PI3K-AKT pathway inhibitors, LY294002 or Wortmannin, blocked the periostin peptide-stimulated migration of ECFCs. These results suggest that the synthetic periostin peptide can be applied for stimulating angiogenic and therapeutic potentials of ECFCs

Aptamers as molecular recognition elements for electrical nanobiosensors

Recent advances in nanotechnology have enabled the development of nanoscale sensors that outperform conventional biosensors. This review summarizes the nanoscale biosensors that use aptamers as molecular recognition elements. The advantages of aptamers over antibodies as sensors are highlighted. These advantages are especially apparent with electrical sensors such as electrochemical sensors or those using field-effect transistors

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO