Molecular genetic identification of yeast strains isolated from egyptian soils for solubilization of inorganic phosphates and growth promotion of corn plants

Forty yeast strains isolated from soils taken from different locations in Egypt were tested for their P-solubilizing activities on the basis of analyzing the clear zone around colonies growing on a tricalcium phosphate medium after incubation for 5 days at 25degreesC, denoted as the solubilization index (SI). Nine isolates that exhibited P-solubilization potential with an SI ranging from 1.19 to 2.76 were genetically characterized as five yeasts belonging to the genus Saccharomyces cerevisiae and four non-Saccharomyces, based on a PCR analysis of the ITS1-26S region amplied by SC1/SC2 species-specific primers. The highest Psolubilization efficiency was demonstrated by isolate PSY- 4, which was identified as Saccharomyces cerevisiae by a sequence analysis of the variable D1/D2 domain of the 26S rDNA. The effects of single and mixed inoculations with yeast PSY-4 and Bacillus polymyxa on the P-uptake and growth of corn were tested in a greenhouse experiment using different levels of a phosphorus chemical fertilizer (50, 100, and 200 kg/ha super phosphate 15.5% P2O5). The results showed that inoculating the corn with yeast PSY-4 or B. polymyxa caused significant increases in the shoot and root dry weights and P-uptake in the shoots and roots. The P-fertilization level also had a significant influence on the shoot and root dry weights and P-uptake in the shoots and roots when increasing the P-level from 50 up to 200 kg/ha. Dual inoculation with yeast strain PSY-4 and B. polymyxa at a P-fertilization level of 200 kg/ha gave higher values for the shoot and root dry weights and P-uptake in the shoots and roots, yet these increases were nonsignificant when compared with dual inoculation with yeast strain PSY-4 and B. polymyxa at a P-fertilization level of 100 kg/ha. The best increases were obtained from dual inoculation with yeast strain PSY-4 and B. polymyxa at a P-fertilization level of 100 kg/ha, which induced the following percentage increases in the shoot and root dry weights, and P-uptake in the shoots and roots; 16.22%, 46.92%, 10.09%, and 31.07%, respectively, when compared with the uninoculated control (fertilized with 100 kg/ha).     

Au-Catalyzed Silicon Nanoneedles Synthesized from Pure Silane Gas at Various RF Powers on Silicon Substrate by VHF-PECVD

Silicon nanonowires (SiNWs) were synthesized with approximately 100 nm/min by very-high-frequency plasma-enhanced chemical vapor deposition method via a vapor–liquid–solid mechanism. Pure silane gas was deposited on Au-coated silicon substrates at various radio frequency (RF) powers varied from 5 to 20 W, keeping other deposition parameters constant. Synthesized SiNWs were needle-like shape with an ultra-sharp tip diameter of about 10 nm and a length about 3 μm, which differs from the standard cylindrical nanowire produced by similar techniques. Furthermore, it was shown that the average length of nanoneedles augmented with the increase of RF power. High-resolution transition electron microscopy displayed that the nanowires were composed of a crystalline Si core with an amorphous oxide shell. Raman spectroscopy also revealed the presence of crystalline Si in the grown Si nanoneedles.     

Chemotaxonomic significance of the essential oils of 18 Ferula species (Apiaceae) from Iran

To evaluate the chemotaxonomic significance of the essential oils of 23 populations of 18 Iranian Ferula species, the chemical composition of the oils was investigated by GC/FID and GC/MS. Altogether, 84 constituents, representing 81.3-99.7% of the total composition of the oils, have been identified. The composition of six species of the genus, i.e., F. oopoda, F. foetida, F. behboudiana, F. diversivittata, F. galbaniflua, and F. hezarlalehzarica, has been reported for the first time. The main constituents identified were α-terpinyl acetate (73.3%), 2,3,4-trimethylthiophene (2; 49.0%), sabinene (75.3%), verbenone (5; 69.4%), β-pinene (59.0-66.3%), and (Z)-β-ocimene (41.7%). Cluster analysis (CA) of the percentage content of the essential oil components of the Ferula species resulted in the characterization of four groups, i.e., taxa containing either i) monoterpene hydrocarbons, ii) oxygenated monoterpenes, iii) organosulfur compounds, or iv) monoterpene, sesquiterpene, and aliphatic hydrocarbons as the principal classes of compounds. Based on the results obtained, the chemical independence of F. hirtella from F. szowitsiana and of F. galbaniflua from F. gummosa at the specific level was concluded and their positions as distinct species were confirmed. The chemotaxonomic relationships among the representatives of the genus Ferula have been discussed in detail.     

Cellular and molecular response of human macrophages exposed to Aggregatibacter actinomycetemcomitans leukotoxin

Aggregatibacter (Actinobacillus) actinomycetemcomitans is a facultative anaerobic gram-negative bacterium associated with severe forms of periodontitis. A leukotoxin, which belongs to the repeats-in-toxin family, is believed to be one of its virulence factors and to have an important role in the bacterium''s pathogenicity. This toxin selectively kills human leukocytes by inducing apoptosis and lysis. Here, we report that leukotoxin-induced cell death of macrophages proceeded through a process that differs from the classical characteristics of apoptosis and necrosis. A. actinomycetemcomitans leukotoxin-induced several cellular and molecular mechanisms in human macrophages that led to a specific and excessive pro-inflammatory response with particular secretion of both interleukin (IL)-1β and IL-18. In addition, this pro-inflammatory cell death was inhibited by oxidized ATP, which indicates involvement of the purinergic receptor P2X₇ in this process. This novel virulence mechanism of the leukotoxin may have an important role in the pathogenic potential of this bacterium and can be a target for future therapeutic agents.     

Seasonality in the occurrence of two lepidopterous olive pests in Egypt

Abstract Prays oleae Bern, (OM) and Palpita unionalis Hüb., (JM) are two of the most important pests in olive groves in Egypt. A 3‐year monitoring study using sex pheromone traps in semi‐arid and arid olive groves was performed. In the semi‐arid grove, flight pattern of the OM was the same as in other Mediterranean countries, but in dates concordating plant phenology. The moth completes three generations annually: the first flight is in March to April, the second is in May to June and the third occurs in August to October. In the arid olive grove, an interesting flight pattern was observed. First flight was always very close or overlapped with the second one with no male catches during August to October. However, eggs were present most of the season, indicating unusually high female presence and oviposition activity of the OM during the absence of males in the traps. Generally, moth densities were significantly lower in low fruiting years than in higher ones and were also lower in the arid olive grove than in the semi‐arid one. In contrast, JM males were present all season, exhibiting six to seven and three to four overlapping flight peaks in arid and semi‐arid olive groves, respectively. Moth densities were significantly higher in the arid olive grove than those in the semi‐arid one. This study shows that trapping location and fruit bearing year are characteristics that strongly affect the grove‐specific information needed to estimate correctly adult emergence and thus the timing of control measures.     

Association of the metastatic phenotype with CCN family members among breast and oral cancer cells

The CCN family of proteins consists of six members with conserved structural features. These proteins play several roles in the physiology and pathology of cells. Among the pathological roles of the CCN family, one of the most important and controversial ones is their role in the expansion and metastasis of cancer. Up to now a number of reports have described the possible role of each CCN family member independently. In this study, we comprehensively analyzed the roles of all six CCN family members in cell growth, migration and invasion of breast cancer cells in vitro and in vivo. As a result, we found the CCN2/CCN3 ratio to be a parameter that is associated with the metastatic phenotype of breast cancer cells that are highly metastatic to the bone. The same analysis with cell lines from oral squamous carcinomas that are not metastatic to the bone further supported our notion. These results suggest the functional significance of the interplay between CCN family members in regulating the phenotype of cancer cells.     

Wettability of biomimetic thermally grown aluminum oxide coatings

In this paper, wettability behavior of a rough but intrinsically hydrophilic oxide ceramic, formed via simple thermal oxidation of a commercial metallic alloy in laboratory air, has been analyzed. Drop shape analysis (DSA) revealed static water contact angles for the rough ceramic surfaces up to 128° (greater than for Teflon?). We propose the high apparent contact angles to be a result of surface roughening via the morphological changes of the oxide scale with oxidation conditions. The surface morphological changes occurring during the growth of the oxide film resulted in the formation of vertical platelets that ably shifted the wetting behavior from a Wenzel to an unstable Cassie-Baxter state. The platelet morphology of the ceramic resembles the structure of epicuticular waxes on certain species of superhydrophobic leaves. Moreover, surface textures for very short oxidation times were also found to increase hydrophilicity in the scale and reduce the contact angle by imparting a Wenzel state. Various characterization techniques (XRD, XPS, and SEM) were performed in order to detect the crystallographic phases in the scales, analyze carbon content and determine the morphology of the oxide layer. Morphological features of the oxide platelets were quantified and platelet width, spacing and height were found to correlate well with the apparent contact angle trend as a function of oxidation time.     

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy presenting with severe keratopathy in an Egyptian patient with a homozygous R139X mutation

OBJECTIVE: To report a patient with an unusual presentation of autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) and severe keratopathy. CASE HISTORY: An Egyptian male sustained an injury to the left eye at 13 years of age and was found to have corneal damage which was attributed to the injury. Subsequently, however, he continued to have sore eyes with photophobia. A year later he became weak with pigmentation and episodes of collapse, and investigation showed that he had Addison's disease together with mucocutaneous candidiasis. At 15 years of age he developed carpo-pedal spasm and was found to have hypoparathyroidism with intracranial calcification. At 20 years of age the ophthalmic diagnosis was revised to keratopathy by which time the patient had corneal opacity and problems with visual acuity, especially in the right eye. Investigation at 22 years of age showed that he was homozygous for an R139X mutation in the gene encoding the AIRE protein, a mutation which to date has only been found in Sardinian patients. CONCLUSIONS: Keratopathy can be an early and severe manifestation of APECED, requiring expert ophthalmic care. Its presence should prompt a search for other components of APECED, some of which are life-threatening.     

Effect of microwave radiation on the biophysical properties of liposomes

Steadily growing use of electromagnetic fields, especially in conjunction with wireless communication systems, has led to increasing public concern about possible health effects of electromagnetic radiation. However, besides the well-known thermal effect of electromagnetic fields on biological tissue, there is no clear evidence of further athermal interaction mechanisms with biological systems. The present study was designed to determine the changes in bilayer permeability in egg lecithin multilamellar vesicles after exposure to 900 MHz microwave radiation for a period of 5 h. Specific absorption rate (SAR) of the radiation for the investigated liposome sample was found to be 12 +/- 1 W/kg. Liposomal changes in permeability were monitored using a light scattering technique. Optical anisotropy of the liposome sample decreased dramatically upon exposure to microwave radiation, indicating structural changes in acyl chain packing. IR and NMR ((1)H NMR) studies, which have been employed to reveal structural alterations in microwave, exposed vesicles showed an increased damage upon exposure to microwave. The changes observed in the (1)H NMR spectrum of the microwave exposed sample indicated hydrolysis of carboxylic and phosphoric esters. IR study showed conformational changes in the acyl chains of the lipids upon microwave exposure. However, both IR and (31)P NMR did not show any appreciable changes in the head group part of the lipids.