scholarly journals FIBROUS DYSPLASIA OF BONES.

2020 ◽  
pp. 1-3
Author(s):  
M. Darrsana ◽  
Venkatachalam. K ◽  
Ampalaya Manu R ◽  
Haemanath P
Keyword(s):  
Fibrous Dysplasia ◽  
Bone Remodelling ◽  
X Rays ◽  
Endocrine Dysfunction ◽  
X Ray ◽  
The Past ◽  
Café Au Lait Spots ◽  
Gs Alpha ◽  
Topping Off ◽  
Made In

Fibrous dysplasia is an ailment , that can include , one or a few bones and is portrayed by bone deformations, pain and fractures, arising due to bone weakening. A few patients can also present with endocrine dysfunction ( precocious puberty) and cutaneous cafe '- au - lait spots.[1] Determination depends on X-ray assessment. Anticipation is to be surveyed with X-rays and markers of bone remodelling. A few newer comprehensions , of the patho - physiology have been made in the past I0 years. It is presently perceived that fibrous dysplasia is brought about , by a physical initiating transformation of the Gs alpha subunits , of the protein G, bringing about an expanded cAMP fixation and in this way, brings about anomalies of osteoblasts separation, and then subsequently these osteoblasts, creates abnormal bone. There is also an expansion in interleukin-6-initiated osteoclastic bone resorption, which forms the basis of reasoning, for treating these patients with bisphosphonates. In the previous 10 years, the bisphosphonate pamidronate has been utilized by imbuement for fibrous dysplasia (two courses for each year), with great outcomes regarding pain and, in about half of patients, the topping off of osteolytic sores.[2]

scholarly journals The thermal expansion of quartz by x-ray measurements

1933 ◽  
Vol 142 (846) ◽  
pp. 237-247 ◽  
Keyword(s):  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Optical Measurements ◽  
Optical Methods ◽  
X Rays ◽  
Atomic Lattice ◽  
X Ray ◽  
The Past ◽  
Theoretical Considerations ◽  
Made In

The study of the coefficients of thermal expansion of substances has in the past, for the most part, been confined to direct measurement by optical methods. At the present time X-rays are being used for determining the expansion of the atomic lattice as distinct from the specimen block. A question has arisen as to tire relation between the coefficient of expansion as measured visually and that measured by X-rays. From theoretical considerations Zwicky* has predicted that the two are not identical. X -ray measurements on the thermal expansion of single crystals of bismuth by Goetz and Hergenrothers have shown that there is a difference between the values obtained by the two methods of measurement. On the other hand Y. Tu finds no evidence in his experiments on rock salt of the secondary structure described by Zwicky. The question to be answered is thus one of great importance. the present paper gives evidence to shown that for silver and quarts there is no difference between the coefficients of expansion as measured by X-rays and those from optical measurements. The work described in this paper was carried out to measure the thermal expansion of quartz by X-rays and by comparing the results with those from optical measurements to test the validity of the assumption, made in previous papers, that the coefficient of thermal expansion of silver is the same whether measured by X-rays or optical methods.

scholarly journals Glimpses of the past activity of Sgr A★ inferred from X-ray echoes in Sgr C

2018 ◽  
Vol 610 ◽  
pp. A34 ◽  
Author(s):  
D. Chuard ◽  
R. Terrier ◽  
A. Goldwurm ◽  
M. Clavel ◽  
S. Soldi ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Black Hole ◽  
Monte Carlo Model ◽  
Line Of Sight ◽  
X Rays ◽  
X Ray ◽  
Supermassive Black Hole ◽  
The Past ◽  
Sgr A ◽  
Past Activity

Context. For a decade now, evidence has accumulated that giant molecular clouds located within the central molecular zone of our Galaxy reflect X-rays coming from past outbursts of the Galactic supermassive black hole. However, the number of illuminating events as well as their ages and durations are still unresolved questions. Aims. We aim to reconstruct parts of the history of the supermassive black hole Sgr A★ by studying this reflection phenomenon in the molecular complex Sgr C and by determining the line-of-sight positions of its main bright substructures. Methods. Using observations made with the X-ray observatories XMM-Newton and Chandra and between 2000 and 2014, we investigated the variability of the reflected emission, which consists of a Fe Kα line at 6.4 keV and a Compton continuum. We carried out an imaging and a spectral analysis. We also used a Monte Carlo model of the reflected spectra to constrain the line-of-sight positions of the brightest clumps, and hence to assign an approximate date to the associated illuminating events. Results. We show that the Fe Kα emission from Sgr C exhibits significant variability in both space and time, which confirms its reflection origin. The most likely illuminating source is Sgr A★. On the one hand, we report two distinct variability timescales, as one clump undergoes a sudden rise and fall in about 2005, while two others vary smoothly throughout the whole 2000–2014 period. On the other hand, by fitting the Monte Carlo model to the data, we are able to place tight constraints on the 3D positions of the clumps. These two independent approaches provide a consistent picture of the past activity of Sgr A★, since the two slowly varying clumps are located on the same wavefront, while the third (rapidly varying) clump corresponds to a different wavefront, that is, to a different illuminating event. Conclusions. This work shows that Sgr A★ experienced at least two powerful outbursts in the past 300 yrs, and for the first time, we provide an estimation of their age. Extending this approach to other molecular complexes, such as Sgr A, will allow this two-event scenario to be tested further.

Sky survey of high-energy cosmic X-rays and spectral information on sources in the Crab nebula, Cygnus, and Scorpius

1968 ◽  
Vol 46 (10) ◽  
pp. S409-S413 ◽  
Author(s):  
Walter H. G. Lewin ◽  
George W. Clark ◽  
William B. Smith
Keyword(s):  
Crab Nebula ◽  
High Energy ◽  
X Rays ◽  
Coma Cluster ◽  
X Ray ◽  
Sky Survey ◽  
Upper Limits ◽  
Intensity Ratios ◽  
The Crab Nebula ◽  
Made In

A complete X-ray survey of the northern sky has been made in the energy range 20–100 keV. Spectra are given for Cyg X-1 and Tau X-1. Intensity ratios (Cyg X-1/Tau X-1) of 0.84 ± 0.10 and 1.30 ± 0.25 were derived in the 20–70 keV range from data obtained on July 19, 1966 and February 13, 1967, respectively. Observations on Sco X-1 and the Coma cluster show upper limits which are quite different from results reported by other groups.

scholarly journals Atomic constants deduced from secondary cathode ray measurements

1933 ◽  
Vol 143 (848) ◽  
pp. 48-60 ◽  
Keyword(s):  
Magnetic Fields ◽  
X Rays ◽  
X Ray ◽  
The Past ◽  
Wide Range

1. It is well known that the accurate measurement of the energies of the secondary cathode rays excited by homogeneous X-rays can yield results capable of supplementing our knowledge of the most probable values of the fundamental atomic constants. this application of the "magnetic spectrograph" has already been discussed by one of us in some detail, and kretschmar has published an account of accurate measurements on X-ray electrons, from which he has deduced very consistent values of e / m 0 . In this work Kretschmar used molybdenum K radiations, and produced his magnetic fields by a large solenoid. 2. We have during the past fifteen months photographed a large number of secondary cathode-ray spectra, using cooper K as primary X radiation. For a few elements, for which the results will be detailed later in this paper, we have made very careful measurements of the energies, cross-checking the observations by working in a wide range magnetic fields.

scholarly journals A Morphological and Histological Investigation of Imperfect Lungfish Fin Regeneration

2021 ◽  
Vol 9 ◽  
Author(s):  
Vivien Bothe ◽  
Igor Schneider ◽  
Nadia B. Fröbisch
Keyword(s):  
Tissue Regeneration ◽  
Molecular Mechanisms ◽  
Limb Regeneration ◽  
Body Parts ◽  
Serial Sections ◽  
Fin Regeneration ◽  
X Ray ◽  
The Past ◽  
Great Progress ◽  
Made In

Regeneration, the replacement of body parts in a living animal, has excited scientists for centuries and our knowledge of vertebrate appendage regeneration has increased significantly over the past decades. While the ability of amniotes to regenerate body parts is very limited, members of other vertebrate clades have been shown to have rather high regenerative capacities. Among tetrapods (four-limbed vertebrates), only salamanders show unparalleled capacities of epimorphic tissue regeneration including replacement of organ and body parts in an apparently perfect fashion. The closest living relatives of Tetrapoda, the lungfish, show regenerative abilities that are comparable to those of salamanders and recent studies suggest that these high regenerative capacities may indeed be ancestral for bony fish (osteichthyans) including tetrapods. While great progress has been made in recent years in understanding the cellular and molecular mechanisms deployed during appendage regeneration, comparatively few studies have investigated gross morphological and histological features of regenerated fins and limbs. Likewise, rather little is known about how fin regeneration compares morphologically to salamander limb regeneration. In this study, we investigated the morphology and histology of regenerated fins in all three modern lungfish families. Data from histological serial sections, 3D reconstructions, and x-ray microtomography scans were analyzed to assess morphological features, quality and pathologies in lungfish fin regenerates. We found several anomalies resulting from imperfect regeneration in regenerated fins in all investigated lungfish species, including fusion of skeletal elements, additional or fewer elements, and distal branching. The similarity of patterns in regeneration abnormalities compared to salamander limb regeneration lends further support to the hypothesis that high regenerative capacities are plesiomorphic for sarcopterygians.

scholarly journals Prevention of pathological fracture in fibrous dysplasia of proximal femur in a 24-year-old female a rare presentation - a case report

2021 ◽  
Vol 7 (6) ◽  
pp. 1238
Author(s):  
Amit Supe ◽  
Jayesh Mhatre ◽  
Nihar Modi
Keyword(s):  
Case Report ◽  
Fibrous Dysplasia ◽  
Pathological Fracture ◽  
Medical Literature ◽  
Favourable Outcome ◽  
Endocrine Dysfunction ◽  
Rare Presentation ◽  
Café Au Lait Spots ◽  
Hip Screw

<p class="abstract">Fibrous dysplasia (FD) was historically mentioned in the medical literature in 1938 by Dr. Lichtenstein and in 1942 by Dr. Lichtenstein and Jaffe. The term Jaffe-Lichtenstein syndrome is sometimes used synonymously with monostotic FD or to denote cases of polyostotic FD with café au lait spots, but no endocrine dysfunction. Our case is a 24-year-old female, housewife presented to our hospital with a complaints of right hip pain and backache with difficulty in walking of 6 months duration. She had dull aching pain which increased in intensity with the course of time, there was no radiation, but was aggravated by movements. She was managed with dynamic hip screw along with curettage of the lesion and bone graft, after 9 months of follow up, she had no pain over her hip and there was calcification over the previous lesion, our patient had a very favourable outcome.</p>

scholarly journals Binary Stucture of Accreting Neutron Stars

1998 ◽  
Vol 188 ◽  
pp. 105-106
Author(s):  
D.A. Leahy
Keyword(s):  
Neutron Stars ◽  
Spectral Resolution ◽  
Relevant Literature ◽  
Short Paper ◽  
X Rays ◽  
X Ray ◽  
The Past ◽  
Great Progress ◽  
Satellite Missions ◽  
X Ray Binaries

The study of X-ray binaries has made great progress with the advent in the past few years of a number of very capable X-ray astronomy missions. These are reviewed, for example, by Bradt et al 1992, and a set of recent relevant papers in Makino and Mitsuda, 1997. For example, ASCA has allowed a significant increase in sensitivity and spectral resolution in 0.5-10 keV X-rays (Tanaka et al 1994). Many recent Compton/GRO results on X-ray binaries are reviewed in the proceedings of the Second Compton Symposium (Fichtel et al 1994). Another source of recent results from analysis of data from several satellite missions is the proceedings of the Evolution of X-ray Binaries (Holt & Day, 1994). In this short paper, the emphasis is on guiding the reader to some relevant literature.

scholarly journals Tracking the year-to-year variation in the spectral energy distribution of the narrow-line Seyfert 1 galaxy Mrk 335

2020 ◽  
Vol 499 (1) ◽  
pp. 1266-1286 ◽  
Author(s):  
S Tripathi ◽  
K M McGrath ◽  
L C Gallo ◽  
D Grupe ◽  
S Komossa ◽  
...  
Keyword(s):  
Spectral Energy Distribution ◽  
Principal Component ◽  
Accretion Disc ◽  
Spectral Energy ◽  
X Rays ◽  
Physical Processes ◽  
Energy Distributions ◽  
X Ray ◽  
The Past ◽  
Over Time

ABSTRACT Multiwavelength monitoring of Mrk 335 with Swift between 2007 and 2019 are used to construct annual spectral energy distributions (SEDs) and track year-to-year changes. Non-contemporaneous archival data prior to 2007 are used to build a bright state SED. In this work, the changes are examined and quantified to build the foundation for future SED modelling. The yearly SEDs trace a downward trend on the average, with the X-ray portion varying significantly and acquiring further lower values in the past two years when compared to the optical/UV portion of SED. The bolometric Eddington ratios derived using optical/UV to X-ray SEDs and the calculated X-ray luminosities show a gradual decrease over the monitoring period. Changes in the parameters over time are examined. Principal component analysis suggests that the primary variability is in the X-ray properties of Mrk 335. When looking at the broader picture of Mrk 335 and its behaviour, the X-rays, accounting most of the variability in the 13-yr data, are possibly driven by physical processes related to the corona or absorption whereas the modest optical–UV variations suggest their origin within the accretion disc. These results are consistent with the previous interpretation of Mrk 335 using the timing analyses on the monitoring data and spectral modelling of deep observations.

scholarly journals Recent Advances in X-Ray Astronomy

1995 ◽  
Vol 10 ◽  
pp. 3-16
Author(s):  
Yasuo Tanaka
Keyword(s):  
Wide Temperature Range ◽  
X Rays ◽  
New Era ◽  
X Ray ◽  
Temperature Range ◽  
Rocket Flight ◽  
Recent Advances ◽  
Multi Wavelength ◽  
The Universe ◽  
Made In

X-ray astronomy was born in June 1962 with a totally unexpected discovery of a bright X-ray source (presently known as Sco X-1) in a historic rocket flight conducted by Riccardo Giacconi, Herb Gursky, Frank Paolini and late Bruno Rossi. In the last 30 years, astronomy through the newly opened window has made a dramatic expansion.The universe contains enormously rich varieties which had been left unexplored until recent times. From 40’s through 60’s, new wavelength windows, radio, infrared and X-rays successively opened. As a result, the presence of objects and regions distributed over an extremely wide temperature range from a few Kelvin through hundreds of millions of Kelvin were discovered. A burst of surprising discoveries made in 60’s marked the opening of a whole new era of multi-wavelength astronomy.

Hitachi Model XMA-5 Electron Probe Microanalyzer

1968 ◽  
Vol 26 ◽  
pp. 308-309
Author(s):  
Tomura ◽  
Okano ◽  
Hara
Keyword(s):  
Electron Probe ◽  
High Performance ◽  
List Type ◽  
X Rays ◽  
Type Number ◽  
Fluorescence Excitation ◽  
X Ray ◽  
Electron Probe Microanalyzer ◽  
Scientific Instrumentation ◽  
Made In

The recent advancement in scientific instrumentation has been phenomenal. This is particularity true in the electron probe microanalyzer field. This paper describes the improvements made in the Hitachi Model XMA-5 Electron Probe Microanalyzer to achieve high performance.1.X-ray spectroscopy1-1.It is now possible to analyze a wide variety of elements including ultra light elements in minute concentrations with the advent of an increasing number of dispersing elements and high detectability.1-2.A linear crystal drive and direct wavelength read-out (with respect to the crystal) is employed in the spectrometer to assure simultaneous analyses of up to three elements by using three of the six crystals provided. For correction of absorbed X-rays and fluorescence excitation and with due consideration of the angular distribution of the characteristic X-rays, an X-ray take off angle of 38° (electron probe is incident vertically on the specimen surface) was adopted.

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