Strawberry plants showing symptoms of leaf spots and petiole lesions were collected from El Qalubya governorate, which is one of the most famous areas that extensively grows strawberry in Egypt. The objectives of this study were to isolate and characterize the causal pathogen of the disease. The isolated pathogen was identified as Paramyrothecium roridum (formerly known as Myrothecium roridum) based on its morphological characteristics and sequencing the partial rDNA internal transcribed spacer (ITS). A pathogenicity test using detached leaf assay revealed that P. roridum is a potential pathogen of strawberry. Symptoms started as small necrotic areas which expanded rapidly to macerate whole leaflets and petioles. In advanced stages of infection, dark olive green sporodochia were clearly distinguished on the infected tissues. Six strawberry cultivars showed different levels of susceptibility to P. roridum. Florida was the most resistant cultivar while Beauty, Camarosa, Fortuna and Sweet Charlie were susceptible. Festival showed a moderate level of susceptibility. An in vitro assay on the effect of the liquid culture filtrate of P. roridum on strawberry leaves showed that the filtrate caused damage to tissues and clear necrotic symptoms were developed. High performance liquid chromatograph (HPLC) analysis on the filtrate of 10 day old P. roridum culture revealed the presence of various mycotoxins. The two major toxins detected were 8-alpha-hydroxyroridin H and myrothecin A in addition to other trichothecenes. Data also revealed the capability of P. roridum to produce polygalacturonase (PG) and cellulase (Cx) enzymes in liquid cultures. The activity of PG was found to be significantly correlated with the age of the growth culture. This is the first record of P. roridum on strawberry in Egypt.
In order to enhance bioactive properties of titanium 99.2 used in implantology and various biomedical applications, numerous methods to form tight oxide coatings are being investigated. Some of these interesting techniques for generating TiO2 coatings include: electrochemical methods with anodizing, electric discharge treatment, plasma methods (PVD) and diffusive methods (i.e. oxidation in a fluidized bed). Each method aims to create a thin homogenous oxide coating characterized with thermal stability and repassivation ability in the presence of body fluid environment. However, new methods are still sought for increasing the biocompatibility of the substrate following a change in the intensity of depositing on the oxide coating compounds with high biocompatibility with body tissues, including hydroxyapatite, which constitutes the basis for subsequent osseointegration processes. The article presents investigation of HAp formation on titanium substrate surface after hybrid oxidation process. Hybrid surface treatments combine methods of fluidized bed atmospheric diffusive treatment FADT with the PVD surface treatment realized with different parameters (FADT – 640°C / 8h and PVD – magnetron sputtering with TiO2 target). In order to investigate the effects of hybrid oxidation and the formation of HAp molecules, SEM-EDS, SEM-EBSD, STEM-EDS, RS, nanoindentation and Kokubo bioactivity tests (c-SBF2) were carried out. The hybrid method of titanium oxidation, proposed by the Author, presents a new outlook on the modification and development of the properties of oxide coatings in the area of biomedical applications. Combining the ways of Ti Grade 2 oxidation in the hybrid method highly improves the formation of hydroxyapatite compounds and shows the potential of applying such a technique in implantology, where the intensive growth of bone tissues is crucial.
Scanning electron microscopy (SEM) is a perfect technique for micro-/nano-object imaging [1] and movement measurement [2, 3] both in high and environmental vacuum conditions and at various temperatures ranging from elevated to low temperatures. In our view, the magnetic field expanding from the pole-piece makes it possible to characterize the behaviour of electromagnetic micro- and nano electromechanical systems (MEMS/NEMS) in which the deflection of the movable part is controlled by the electromagnetic force. What must be determined, however, is the magnetic field expanding from the e-beam column, which is a function of many factors, like working distance (WD), magnification and position of the device in relation to the e-beam column. There are only a few experimental methods for determination of the magnetic field in a scanning electron microscope. In this paper we present a method of the magnetic field determination under the scanning electron column by application of a silicon cantilever magnetometer. The micro-cantilever magnetometer is a silicon micro-fabricated MEMS electromagnetic device integrating a current loop of lithographically defined dimensions. Its stiffness can be calibrated with a precision of 5% by the method described by Majstrzyk et al. [4]. The deflection of the magnetometer cantilever is measured with a scanning electron microscope and thus, through knowing the bias current, it is possible to determine the magnetic field generated by the e-beam column in a defined position and at a defined magnification.