Genomic relationships of Triticum searsii to other S-genome diploid Triticum species

Genome ◽  
1990 ◽  
Vol 33 (3) ◽  
pp. 369-373 ◽  
Author(s):  
Yang Yen ◽  
Gordon Kimber
Keyword(s):  
Biological Species ◽  
Phylogenetic Distance ◽  
Natural Logarithm ◽  
Triticum Species ◽  
Relative Affinity ◽  
Genomic Relationships

Interspecific triploid hybrids of Triticum searsii (2x) (= Aegilops searsii) with T. longissimum (4x), T. speltoides (4x), and T. bicorne (4x) were made and cytologically studied. Optimization analyses of the meiotic configurations allow the calculation of a numerical measure (the natural logarithm of the ratio of the relative affinity of the most closely related chromosomes to the most distantly) of phylogenetic distance and showed that T. searsii was almost equally but distantly related to the three other species. The validity of T. searsii being a biological species is therefore confirmed.Key words: triploid, wheat, meiosis, phylogenesis, hybrid.

THE ANALYSIS OF MEIOSIS IN HYBRIDS. II. TRIPLOID HYBRIDS

1981 ◽  
Vol 23 (2) ◽  
pp. 221-234 ◽  
Author(s):  
L. C. Alonso ◽  
G. Kimber
Keyword(s):  
Quantitative Determination ◽  
Relative Affinity ◽  
Genomic Relationships ◽  
Meiotic Analyses

Methods are developed that allow a quantitative determination of relative affinity in triploid hybrids. This results in new insights into the analysis of meiosis in hybrids, genomic relationships and the assignment of genome symbols. The separate recording of open and closed chromosome figures in meiotic analyses is shown to be essential.

Genomic relationships of N-genome Triticum species

Genome ◽  
1992 ◽  
Vol 35 (6) ◽  
pp. 962-966 ◽  
Author(s):  
Yang Yen ◽  
Gordon Kimber
Keyword(s):  
Genome Analysis ◽  
Polyploid Species ◽  
D Genome ◽  
The Third ◽  
Triticum Species ◽  
Genomic Relationships ◽  
M Genome

Induced autotetraploids of Triticum uniaristatum, T. tauschii, and T. umbellulatum were used to study the genomes of the polyploid species T. ventricosum, T. neglecta, and T. recta. The N genome in T. ventricosum is homologous to the N genome in the putative diploid donor T. uniaristatum and has undergone little modification. The D genome in T. ventricosum is also essentially unmodified. The U genome of T. neglecta appears to be unchanged from the U genome of T. umbellulatum. Two of the genomes of T. recta are the same as the genomes in T. neglecta (U and a presumed modified M genome). The presence of a U genome in T. recta has also been independently confirmed. The origin of the third genome in T. recta has not been confirmed.Key words: chromosomes, meiosis, genome analysis, wheat.

A TEM study of electron tunneling in biological macromolecules

1987 ◽  
Vol 45 ◽  
pp. 140-141
Author(s):  
J. A. Panitz
Keyword(s):  
Stark Effect ◽  
Electron Tunneling ◽  
Imaging Modality ◽  
Tunneling Current ◽  
Biological Species ◽  
Scanning Tunneling ◽  
Biological Macromolecules ◽  
Flat Surfaces ◽  
Virus Particles ◽  
Stm Images

Tunneling is a ubiquitous phenomenon. Alpha particle disintegration, the Stark effect, superconductivity in thin films, field-emission, and field-ionization are examples of electron tunneling phenomena. In the scanning tunneling microscope (STM) electron tunneling is used as an imaging modality. STM images of flat surfaces show structure at the atomic level. However, STM images of large biological species deposited onto flat surfaces are disappointing. For example, unstained virus particles imaged in the STM do not resemble their TEM counterparts.It is not clear how an STM image of a biological species is formed. Most biological species are large compared to the nominal electrode separation of ∼ 1nm that is required for electron tunneling. To form an image of a biological species, the tunneling electrodes must be separated by a distance that would normally be too large for a tunneling current to be observed.

Graphene and Graphene Oxide Applications for SERS Sensing and Imaging

2019 ◽  
Vol 26 (38) ◽  
pp. 6878-6895 ◽  
Author(s):  
Anna Jabłońska ◽  
Aleksandra Jaworska ◽  
Mateusz Kasztelan ◽  
Sylwia Berbeć ◽  
Barbara Pałys
Keyword(s):  
Graphene Oxide ◽  
Surface Enhanced Raman Spectroscopy ◽  
Biological Species ◽  
Chemical Mechanism ◽  
Aromatic Molecules ◽  
Sers Enhancement ◽  
Reduced Graphene ◽  
Surface Enhanced Raman ◽  
Active Nanoparticles ◽  
Fluorescence Quencher

: Surface Enhanced Raman Spectroscopy (SERS) has a long history as an ultrasensitive platform for the detection of biological species from small aromatic molecules to complex biological systems as circulating tumor cells. Thanks to unique properties of graphene, the range of SERS applications has largely expanded. Graphene is efficient fluorescence quencher improving quality of Raman spectra. It contributes also to the SERS enhancement factor through the chemical mechanism. In turn, the chemical flexibility of Reduced Graphene Oxide (RGO) enables tunable adsorption of molecules or cells on SERS active surfaces. Graphene oxide composites with SERS active nanoparticles have been also applied for Raman imaging of cells. This review presents a survey of SERS assays employing graphene or RGO emphasizing the improvement of SERS enhancement brought by graphene or RGO. The structure and physical properties of graphene and RGO will be discussed too.

Serum Thyroid Peroxidase Antibody Level and Incident Hypertension in Iranian Men: A Suggestion for the Role of Thyroid Autoimmunity

2020 ◽  
Vol 20 (10) ◽  
pp. 1711-1718
Author(s):  
Maryam Tohidi ◽  
Aidin Baghbani-Oskouei ◽  
Atieh Amouzegar ◽  
Ladan Mehran ◽  
Fereidoun Azizi ◽  
...  
Keyword(s):  
Total Population ◽  
Thyroid Autoimmunity ◽  
Elevated Serum ◽  
Thyroid Peroxidase ◽  
Incident Hypertension ◽  
Natural Logarithm ◽  
Hazard Ratios ◽  
Thyroid Peroxidase Antibody ◽  
Unit Increase

Background: Dysfunction of the thyroid gland has profound effects on the cardiovascular system. Objective: We aimed to explore the relation of serum thyroid peroxidase antibody (TPO-Ab), as a marker of thyroid autoimmunity with incident hypertension among a euthyroid population. Methods: A total of 3681 participants (1647 men) entered the study. Multivariate Cox proportional hazard models were conducted to estimate the association between TPO-Ab and incident hypertension. Results: The mean age (standard deviation) of the participants was 37.5 (12.8) years. During a median follow-up of 12.2 years, 511 men and 519 women developed hypertension. The multivariable hazard ratios (HRs) and related 95% confidence intervals (CIs) of 1-unit increase in natural logarithm (ln) of TPO-Ab for incident hypertension were 1.09 (1.00-1.19), 1.03 (0.97-1.10), and 1.05 (1.00-1.11) for men, women, and total population, respectively. Moreover, considering the TPO-Ab status as a categorical variable (i.e. TPO-Ab positive or TPO-Ab negative), the multivariate-adjusted HRs (95% CIs) of TPO-Ab positivity for incident hypertension, were 1.33 (0.95-1.85), 1.12 (0.86-1.45) and 1.19 (0.97- 1.46) for men, women, and total population, respectively. Conclusion: Elevated serum TPO-Ab level can contribute to the development of hypertension among euthyroid men during a long follow-up; suggesting a role for thyroid autoimmunity.

Simulation for enhancement in sensitivity of chalcogenide glasses-based fibre optic evanescent absorption sensor for malignant tissue detection

2020 ◽  
Vol 12 ◽  
Author(s):  
Ritesh Kumar Singh ◽  
Adarsh Chandra Mishra ◽  
Pooja Lohia ◽  
D.K. Dwivedi
Keyword(s):  
Evanescent Wave ◽  
Chalcogenide Glasses ◽  
Biological Tissues ◽  
Biological Species ◽  
Primary Objective ◽  
Effect Of Temperature ◽  
Refractive Indices ◽  
Core Radius ◽  
Source Illumination ◽  
Study Results

Background: Refractive index determination of biological tissues is a challenging issue. Many biological species also show vibrational signature in infrared domain. The chalcogenide-based glasses can be used to make the fiber optic evanescent wave sensors for detection of analyte. Objectives: The primary objective is to study the effect of various parameters on the sensitivity of chalcogenide glass-based evanescent wave sensor for biological tissue detection. Methods: An evanescent wave sensor has been proposed with collimated source illumination and uniform tapering. The chalcogenide materials are chosen such that the weakly guiding approximation could be followed. Complex refractive indices of liver tissue samples have been taken for the analysis of sensitivity via method of evanescent absorption coefficient. Equations for sensitivity have been solved analytically using MATLAB software. Results: The simplification of the formula for sensitivity leads to the inference that the sensitivity is a function of core radius, refractive indices of sample tissues and wavelength used. Moreover, since the refractive indices of the materials are also a function of temperature, therefore a change in temperature results into change in the profile of guiding mode. Hence the effect of temperature must also be observed. The initial simulation parameters are taken; core radius 100 µm, sensing length 4 cm and wavelength 1.0 µm. In the NIR region we have a better sensitivity of detection for all the tissues samples and the risk of photodamage of the biosamples is reduced to a good extent. It has been found that sensitivity decreases with wavelength and core radius whereas increases with temperature. It has also been shown that sensitivity is found to be better with collimated in comparison with diffused source. Conclusion: The comparative study results that one should operate at shorter NIR region of wavelength for higher sensitivity. The collimated source illumination should be preferred over diffused one for launching the light within the fiber to have high sensitivity. Further, length of sensing region should be larger but the fiber core radius should be smaller. The proposed biosensor is robust and can also be used many times if the probe (sensing region) is cleaned properly. Moreover, a small amount of analyte is enough for the detection. Thus, the proposed sensor is very useful for bio-medical applications with its high performance, accuracy and robustness.

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