Nonthermal Laser-Induced Formation of Crystalline Ge Quantum Dots on Si(100)

The effects of laser-induced electronic excitations on the self-assembly of Ge quantum dots on Si (100) - (2×1) grown by pulsed laser deposition are studied. Electronic excitations due to laser irradiation of the Si substrate and the Ge film during growth are shown to decrease the roughness of films grown at a substrate temperature of ∼120 °C. At this temperature, the grown films are nonepitaxial. Electronic excitation results in the formation of an epitaxial wetting layer and crystalline Ge quantum dots at ∼260 °C, a temperature at which no crystalline quantum dots form without excitation under the same deposition conditions.© 2008 American Institute of Physics. [DOI: 10.1063/1.3041493

Molecular Role of Nitric Oxide in Secondary Products Production in Ginkgo biloba Cell Suspension Culture

Effects of sodium nitroprusside (SNP; nitric oxide donor) treatment on the enhancement of secondary metabolites production, oxidative stress mediators (O2-.) accumulation and antioxidant defense enzymes of Ginkgo biloba callus culture was investigated. On one hand, the obtained data showed a highly metabolic modification of chemical constituents, PAL activity and various antioxidant defense enzymes (APX, SOD), which gradually increased in response to SNP treatments. On the other hands the high NO levels significantly increased the accumulation of various oxidative burst of O2-.. MS basal medium supplemented with casein hydrolase (500 mg/L), NAA and BA at equal concentration (0.5 mg/L) recorded the highest number of regenerated shoots (4.81 cm) and shoot height (4.96 cm) as well as root number (2.25 cm) and root length (4.5 cm). The highest survival (40 %) was shown in acclimatization on the mixture containing sand, peat moss and vermiculite (1: 1: 1, v/v/v), which significantly confirmed and reflected the variation in survival percentage. Meanwhile, higher treatment (500 μM) of NO positively enhanced secondary products accumulation of total tannins, saponins, phenols and total flavonoids in G. biloba callus culture

Randomized ancillary qubit overcomes detector-control and intercept-resend hacking of quantum key distribution

Practical implementations of quantum key distribution (QKD) have been shown to be subject to various detector side-channel attacks that compromise the promised unconditional security. Most notable is a general class of attacks adopting the use of faked-state photons as in the detector-control and, more broadly, the intercept-resend attacks. In this paper, we present a simple scheme to overcome such class of attacks: A legitimate user, Bob, uses a polarization randomizer at his gateway to distort an ancillary polarization of a phase-encoded photon in a bidirectional QKD configuration. Passing through the randomizer once on the way to his partner, Alice, and again in the opposite direction, the polarization qubit of the genuine photon is immune to randomization. However, the polarization state of a photon from an intruder, Eve, to Bob is randomized and hence directed to a detector in a different path, whereupon it triggers an alert. We demonstrate theoretically and experimentally that, using commercial off-the-shelf detectors, it can be made impossible for Eve to avoid triggering the alert, no matter what faked-state of light she uses.Comment: Quantum encryption, bidirectional quantum key distribution, detector control, intercept and resend attacks, faked state photon

Interleukin 6 (IL6) as a predictor outcome in patients with compensated cirrhosis and symptomatic gall stones after cholecystectomy

Compensated cirrhosis means that the liver is heavily scarred but can still perform many important functions; many peoples with compensated cirrhosis have gall bladder stones. The advantages of laparoscopic cholecystectomy (LC) for most patients have been extensively published. However its benefits and successful use in patients with cirrhosis are less documented. The study compromised 50 patients with symptomatic gallstone in compensated liver disease and undergone either open cholecystectomy (OC) or laparoscopic cholecystectomy. These patients were randomized into two groups: Group I included 24 patients who underwent OC, and group II included 26 patients who underwent LC. Patient’s age, sex, clinical presentation and Child-Turcotte-Pugh (CTP) class were documented. No patients in this study had CTP class c cirrhosis. IL-6 was measured by ELISA, postoperative pain (measured by Visual analog scale), hospital stay, blood loss, recovery time (return to work), and liver function tests were documented. IL-6 was significantly lowered at 6th hour and 12th hour post operative in LC group. Mean surgical time was significantly longer in OC than LC group, (mean ±SD, 96.6 ±32 vs 58.7 ± 23.8 min, P = 0.037). No patients in group II required any blood replacement in contrast to 9 patients (37.5%) in group I. Intraoperative bleeding remained significantly higher in group I (P = 0.043). No patients in group II had wound complications compared with 5 patients (29.14%) in group I. Group I had significantly longer hospital stay than group II, mean 9.0+ 1.3 days (median 7) vs 2.3 days + 1.9 (median 2.5); P = 0.001. Our results were demonstrated that laparoscopic cholecystectomy can be performed safely in patients with CTP class A and B cirrhosis. IL-6 was more significantly, increased post operatively in open cholecystectomy than laparoscopic one and it correlated well with intensity of operative trauma. Keywords: Interleukin 6; Liver cirrhosis; Cholecystectom

HYDROCHEMICAL CHARACTERISTICS AND WATER QUALITY ASSESSMENT IN ABU-ZAABAL AREA, EASTERN NILE DELTA, EGYPT

Objective: The study presents simple tools for water resources quality classification based on its chemical compositions in Abu Zaabal area, eastern Nile Delta, Egypt and assess the water quality for different uses. Methods: 31 water samples were collected from different water resources in the study area and analyzed for physicochemical parameters. Hydrochemical relations, contour maps and statistical methods were used to estimate the contamination indices and evaluate the water resources for different purposes. Results: 83.3% of groundwater samples is fresh water and 16.7% are brackish water. 85.7% of surface water samples are fresh and 14.3% is saline. 92% of groundwater samples and 71.5% of surface water samples are very hard water. According to HPI values, 8% of the quaternary groundwater samples are good, 4% are poor, 4% are very poor and 84% of the samples are unsuitable. All groundwater samples and 71% of surface water samples are contaminated with respect to ammonia. Conclusion: Higher concentrations of TDS and heavy metal may be due to the clay nature of the soil, the marine sediments in the aquifer matrix together with the dissolution and leaching of minerals from agricultural, anthropogenic and industrial activities. The groundwater in the polluted zones is considered unsuitable for human drinking