Dielectric, Ultrasonic and Viscoelastic Properties of Rubber Wood

Dielectric, ultrasonic and viscoelastic properties of rubber wood were studied with various physical parameters, such as moisture contents (MC), grain directions and temperatures. Three anisotropic directions, namely longitudinal, radial and tangential to the growth ring were considered for the measurement of these properties. Dielectric properties were measured at low frequencies from 10⁻² to 10⁻⁵ Hz and at microwave frequencies from 1 to 18 GHz. Ultrasonic properties were determined with a commercial ultrasonic tester at 45 kHz. Viscoelastic properties were carried out with the Dynamic Mechanical Thermal Analyzer at frequency ranging ,from 0.01 to 1 00 Hz. At low frequencies, five types of dielectric mechanism were observed for different MC such as 1) less than 5%, 2) 5-10%, 3) 11 - 17%, 4) 18-25% and 5) more than 25%. Dielectric constant increased with temperature for these frequencies while dielectric loss factor showed minimum value in oven-dry condition. Dielectric constant and dielectric loss factor varied in the order of longitudinal> radial 2:. tangential directions. Dielectric data at low frequency are in well agreement with those calculated from equivalent circuit using the concept of universal capacitor. Three equivalent circuits fitted well for data at very low MC or for oven-dried wood, MC below fiber saturation point and MC above fiber saturation point. Activation energies were 0.27eV, 0.34eV and 0.41eV for longitudinal, radial and tangential directions respectively. At microwave frequencies, dielectric constant and dielectric loss factor were found to increase with MC ranging from oven-dry up to saturation point. Dielectric constant also decreased with temperature and dielectric loss factor exhibited peaks at 10 GHz. Dielectric constants are predicted well by Winner, Lichteneker and generalized equations with lower value of the exponents. Above 3 G Hz, dielectric loss factor fitted well with the predicted values using Winner, Kraszewski, Looyenga or with generalized equations with lower values of the exponents. Below 3 GHz, dielectric loss factor are unpredictable by these mixture equations

An overview of Triple infection with Hepatitis B, C and D viruses

Viral hepatitis is one of the major health problems worldwide, particularly in South East Asian countries including Pakistan where hepatitis C virus (HCV) and hepatitis B virus (HBV) infections are highly endemic. Hepatitis delta virus (HDV) is also not uncommon world-wide. HCV, HBV, and HDV share parallel routes of transmission due to which dual or triple viral infection can occur in a proportion of patients at the same time. HBV and HCV are important factors in the development of liver cirrhosis (LC) and hepatocellular carcinoma (HCC). In addition to LC and HCC, chronic HDV infection also plays an important role in liver damage with oncogenic potential

Temperature Dependence of the Dielectric Properties of Rubber Wood

The effect of temperature on the dielectric properties of rubber wood were investigated in three anisotropic directions-longitudinal, radial, and tangential, and at different measurement frequencies. Low frequency measurements were conducted with a dielectric spectrometer, and high frequencies used microwave applied with open-ended coaxial probe sensors. Dielectric constants and dielectric loss factors were measured at temperatures from 25 to 100°C. A large dielectric dispersion occurred at frequencies less than 10 Hz and at temperatures more than 60°C. The minimum peak value of the dielectric loss factors shifted towards higher frequencies at higher temperatures in all three grain directions. The tangential direction showed the highest activation energy. The dielectric constant decreased as frequency increased from 1 to 10 GHz, and thereafter remained unchanged with additional frequency increases. The dielectric constant exhibited higher values at higher temperatures. The dielectric loss factor showed a peak value at around 10 GHz at 25°C

Dielectric properties of rubber wood at microwave frequencies measured with an open-ended coaxial line

Dielectric properties of rubber wood were studied at different microwave frequencies, structural directions, and moisture contents using an open-ended coaxial probe. Frequencies used for this study were 1.00, 2.45, 6.0, 8.0, 10.0, 14.0, and 17.0 GHz; and the measurements were carried out at a room temperature of 22-24°C. The dielectric constant and dielectric loss factor were found to increase continuously as the moisture content increased. A sharp rise in the dielectric constant and dielectric loss factor was obtained at high moisture content, and the trends became concave upward. As the frequency increased, the dielectric constant decreased, whereas the dielectric loss factor increased. The dielectric loss factor remained almost constant above the frequency of 6 GHz for all structural directions. Fourth-order polynomial equations were found suitable for the best fit curve. Dielectric constant and dielectric loss factor of oven-dry wood were higher in the longitudinal direction than in the radial and tangential directions. With respect to frequency, the dielectric loss factor exhibited a peak value around 10 GHz. The dielectric anisotropy of wood may be attributed to the microscopic and macroscopic molecular structures as well as to chemical constituents of wood

Effect of moisture content and grain direction on the dielectric properties of rubber wood at low frequencies

Dielectric constant and dielectric loss factor of rubber wood have been studied at different moisture content, grain direction and frequency. Different dielectric dispersion mechanisms are also observed at different ranges of moisture content. The moisture content above the fiber saturation point does not contribute much to the dielectric properties following a single dielectric mechanism. But the moisture content below the fiber saturation point shows considerable effect on the variations of dielectric properties having different dispersion processes at different moisture content ranges. Based on the shape of the curves, five different moisture content ranges have been identified such as 1) 25% and above, 2) 18-25%, 3) 11-17%, 4) 5-10% and 5) below 5%. It may be possible to explain all these dispersion processes by means of dielectric mechanism for dipole, quasi-dc and diffusive processes. Longitudinal direction shows a higher dielectric constant when compared to radial and tangential directions in ovendry condition. This dielectric anisotropy may be attributed to the microscopic, macroscopic and molecular structures of wood

In Vitro Propagation of Eggplant through Meristem Culture

Meristem culture was done for developing an efficient protocol of production of eggplant clones. Shoot tips of 30-35 days old field grown eggplants were used for meristem isolation. Three cultivars viz. ‘Islampuri’, ‘Khatkhatia’ and ‘Katabegun’ were used in the present investigation as explants source. Surface sterilization of shoot tips was found to be the best in 0.1% HgCl2 solution for 3 minutes. For primary establishment of isolated apical meristem in MS liquid medium containing 2.0 mg l-1 BAP was found the best in cv Islampuri. BAP was also proved to be best for the primary establishment of isolated apical meristem in all the cultivars. Subsequent development of meristem derived shoot was achieved in MS semisolid medium containing either 2.0 mg l-1 BAP and 1.0 mg l-1 NAA or 1.0 mg l-1 BAP. For root development from meristem derived shoots, 1.0 mg l-1 IBA was found most responsive in cv. ‘Islampuri’ and ‘Khatkhatia’. Aft er transplantation, the in vitro plants showed normal growth

Identification of novel transcripts and peptides in developing murine lens.

We previously investigated the transcriptome and proteome profiles of the murine ocular lens at six developmental time points including two embryonic (E15 and E18) and four postnatal time points (P0, P3, P6, and P9). Here, we extend our analyses to identify novel transcripts and peptides in developing  mouse lens. We identified a total of 9,707 novel transcripts and 325 novel fusion genes in developing mouse lens. Additionally, we identified 13,281 novel alternative splicing (AS) events in mouse lens including 6,990 exon skipping (ES), 2,447 alternative 3' splice site (A3SS), 1,900 alternative 5' splice site (A5SS), 1,771 mutually exclusive exons (MXE), and 173 intron retention (IR). Finally, we integrated our OMIC (Transcriptome and Proteome) datasets identifying 20 novel peptides in mouse lens. All 20 peptides were validated through matching MS/MS spectra of synthetic peptides. To the best of our knowledge, this is the first report integrating OMIC datasets to identify novel peptides in developing murine lens

Mutations in phosphodiesterase 6 identified in familial cases of retinitis pigmentosa.

To delineate the genetic determinants associated with retinitis pigmentosa (RP), a hereditary retinal disorder, we recruited four large families manifesting cardinal symptoms of RP. We localized these families to regions on the human genome harboring the α and β subunits of phosphodiesterase 6 and identified mutations that were absent in control chromosomes. Our data suggest that mutations in PDE6A and PDE6B are responsible for the retinal phenotype in these families

Loss of function mutations in RP1 are responsible for retinitis pigmentosa in consanguineous familial cases.

PurposeThis study was undertaken to identify causal mutations responsible for autosomal recessive retinitis pigmentosa (arRP) in consanguineous families.MethodsLarge consanguineous families were ascertained from the Punjab province of Pakistan. An ophthalmic examination consisting of a fundus evaluation and electroretinography (ERG) was completed, and small aliquots of blood were collected from all participating individuals. Genomic DNA was extracted from white blood cells, and a genome-wide linkage or a locus-specific exclusion analysis was completed with polymorphic short tandem repeats (STRs). Two-point logarithm of odds (LOD) scores were calculated, and all coding exons and exon-intron boundaries of RP1 were sequenced to identify the causal mutation.ResultsThe ophthalmic examination showed that affected individuals in all families manifest cardinal symptoms of RP. Genome-wide scans localized the disease phenotype to chromosome 8q, a region harboring RP1, a gene previously implicated in the pathogenesis of RP. Sanger sequencing identified a homozygous single base deletion in exon 4: c.3697delT (p.S1233Pfs22*), a single base substitution in intron 3: c.787+1G>A (p.I263Nfs8*), a 2 bp duplication in exon 2: c.551_552dupTA (p.Q185Yfs4*) and an 11,117 bp deletion that removes all three coding exons of RP1. These variations segregated with the disease phenotype within the respective families and were not present in ethnically matched control samples.ConclusionsThese results strongly suggest that these mutations in RP1 are responsible for the retinal phenotype in affected individuals of all four consanguineous families

Pathogenic mutations in TULP1 responsible for retinitis pigmentosa identified in consanguineous familial cases.

PurposeTo identify pathogenic mutations responsible for autosomal recessive retinitis pigmentosa (arRP) in consanguineous familial cases.MethodsSeven large familial cases with multiple individuals diagnosed with retinitis pigmentosa were included in the study. Affected individuals in these families underwent ophthalmic examinations to document the symptoms and confirm the initial diagnosis. Blood samples were collected from all participating members, and genomic DNA was extracted. An exclusion analysis with microsatellite markers spanning the TULP1 locus on chromosome 6p was performed, and two-point logarithm of odds (LOD) scores were calculated. All coding exons along with the exon-intron boundaries of TULP1 were sequenced bidirectionally. We constructed a single nucleotide polymorphism (SNP) haplotype for the four familial cases harboring the K489R allele and estimated the likelihood of a founder effect.ResultsThe ophthalmic examinations of the affected individuals in these familial cases were suggestive of RP. Exclusion analyses confirmed linkage to chromosome 6p harboring TULP1 with positive two-point LOD scores. Subsequent Sanger sequencing identified the single base pair substitution in exon14, c.1466A>G (p.K489R), in four families. Additionally, we identified a two-base deletion in exon 4, c.286_287delGA (p.E96Gfs77*); a homozygous splice site variant in intron 14, c.1495+4A>C; and a novel missense variation in exon 15, c.1561C>T (p.P521S). All mutations segregated with the disease phenotype in the respective families and were absent in ethnically matched control chromosomes. Haplotype analysis suggested (p<10(-6)) that affected individuals inherited the causal mutation from a common ancestor.ConclusionsPathogenic mutations in TULP1 are responsible for the RP phenotype in seven familial cases with a common ancestral mutation responsible for the disease phenotype in four of the seven families