INVESTIGATION OF HORMETIC STIMULATION IN STRAWBERRY PLANTS USING IONIZING RADIATION

1987 ◽  
Vol 67 (4) ◽  
pp. 1181-1192 ◽  
Author(s):  
S. C. SHEPPARD ◽  
C. L. GIBB ◽  
J. L. HAWKINS ◽  
W. R. REMPHREY
Keyword(s):  
Ionizing Radiation ◽  
Field Trials ◽  
Early Growth ◽  
Dominant Factor ◽  
X Rays ◽  
X Ray ◽  
Significant Stimulation ◽  
Low Levels ◽  
The Individual ◽  
Stimulation Of

Hormesis is the stimulation of growth by very low levels of inhibitors or stressors. This phenomenon may be useful in crops where the usual cultural factors have been optimized. The literature indicates that substantial stimulation of early growth of strawberries (Fragaria × ananassa) could be achieved by exposing transplants to low doses of ionizing radiation. Experiments were conducted to test the effectiveness and reliability of X rays as a hormetic agent. Plants of a day-neutral cultivar Hecker and of a June-bearing cultivar Glooscap were irradiated at 0.5–16 Gy and planted in pots. The plants were grown outdoors and growth was recorded each week. Significant stimulation above the controls in the number of trifoliate leaves occurred in the day-neutral cultivar. This effect persisted until the first phase of fruiting. No significant stimulatory effects were observed at any time in the June-bearing cultivar. Two field trials with a June-bearing cultivar Redcoat, irradiated at doses of 0.5 and 2 Gy, also revealed no significant stimulation. The dominant factor regulating early growth was the size of the individual transplants. Therefore, although hormetic stimulation may occur, it will be difficult to quantify and optimize and it will not likely be useful for practical application.Key words: X ray, transplant, day-neutral, June-bearing

scholarly journals Physical and chemical imaging of adhesive interfaces with soft X-rays

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Hiroyuki Yamane ◽  
Masaki Oura ◽  
Osamu Takahashi ◽  
Tomoko Ishihara ◽  
Noriko Yamazaki ◽  
...  
Keyword(s):  
Molecular Level ◽  
Covalent Bond ◽  
Chemical Imaging ◽  
Diglycidyl Ether ◽  
X Rays ◽  
X Ray ◽  
Covalent Bond Formation ◽  
Chemical States ◽  
The Individual ◽  
Physical And Chemical

AbstractAdhesion is an interfacial phenomenon that is critical for assembling carbon structural composites for next-generation aircraft and automobiles. However, there is limited understanding of adhesion on the molecular level because of the difficulty in revealing the individual bonding factors. Here, using soft X-ray spectromicroscopy we show the physical and chemical states of an adhesive interface composed of a thermosetting polymer of 4,4’-diaminodiphenylsulfone-cured bisphenol A diglycidyl ether adhered to a thermoplastic polymer of plasma-treated polyetheretherketone. We observe multiscale phenomena in the adhesion mechanisms, including sub-mm complex interface structure, sub-μm distribution of the functional groups, and molecular-level covalent-bond formation. These results provide a benchmark for further research to examine how physical and chemical states correlate with adhesion, and demonstrate that soft X-ray imaging is a promising approach for visualizing the physical and chemical states at adhesive interfaces from the sub-mm level to the molecular level.

scholarly journals The effect of low LET (Linear Energy Transfer) ionizing radiation to catalase activity of wistar’s submandibular gland

2016 ◽  
Vol 1 (3) ◽  
pp. 145
Author(s):  
Nevy T. Putri ◽  
Sarianoferni Sarianoferni ◽  
Endah Wahjuningsih
Keyword(s):  
Energy Transfer ◽  
Ionizing Radiation ◽  
Submandibular Gland ◽  
Rattus Norvegicus ◽  
Catalase Activity ◽  
Linear Energy Transfer ◽  
Submandibular Salivary Gland ◽  
X Rays ◽  
X Ray ◽  
Bonferroni Test

Intraoral periapical radiograph examination is the additional examination which is the most widely used in Dentistry. This radiograph examination using an x-ray ionizing radiation with low LET (Linear Energy Transfer), and may affect submandibular salivary gland. Ionizing radiation exposure can cause damage by inducing a series of changes at the molecular and cellular level. This study aimed to prove the effects of x-ray ionizing radiation with low LET towards the catalase activity of Rattus norvegicus strain Wistar’s submandibular gland. The subjects were 28 male Wistar rats and divided into 4 groups (n=7). Three groups were exposed 4, 8 and 14 times to radiation with 0.002 µSv for each exposure. The catalase activity of each rat was examined by a spectrophotometer. Data were analyzed using one-way ANOVA followed by Bonferroni test. The results showed the average of catalase activity on Wistar rat’s submandibular gland, respectively for: 0.150±0.0895 (KK), 0.1405±0.0607 (K1), 0.1228±0.0290 (K2), 0.1227±0.0556 (K3). Data showed significant differences of catalase activity between test groups, but showed not significant differences of catalase activity between each groups of Rattus norvegicus strain Wistar’s submandibular gland. In this study concluded decreased catalase activity of Rattus norvegicus strain Wistar’s submandibular gland resulting from x-rays ionizing radiation by 4 times, 8 times and 14 times exposures.

scholarly journals Evaluation the Safety and Security Procedures used In X-ray Clinics in Al-Harthiya-Baghdad

2021 ◽  
Vol 2114 (1) ◽  
pp. 012009
Author(s):  
Thuraya A. Abdul Hussian ◽  
Anwar kh. Farman
Keyword(s):  
Ionizing Radiation ◽  
X Rays ◽  
X Ray ◽  
Beta Particles ◽  
Medical Clinics ◽  
Γ Rays ◽  
Health Laws ◽  
Different Sources ◽  
Α Particles ◽  
Security Procedures

Abstract Radiation is a form of energy, its emitted either in the form of particles such as α-particles and β-particles (beta particles including the electron and the positron) or waves such as sunlight, X-rays and γ-rays. Radiation found everywhere around us and it comes from many different sources naturally or man-made sources. In this study a questionnaire was distributed to people working in the field of X-rays that used for a medical imaging (X-ray and CT-scan) to evaluate the extent of awareness and knowledge in estimate the damage of ionizing radiation as a result of wrong use. The questionnaire was distributed to medical clinics in Al-Harithiya in Baghdad, which it’s considered as one of the important areas in Iraq to attract and treat patients. It’s found that most of the commitment of radiography clinics by safety and security procedures. Most of the radiology clinics abide by most of the Iraqi Ministry of Health laws. However, some clinics did not implement some of the security and safety conditions

scholarly journals Patient Knowledge Regarding Radiation Exposure from Orthopaedic Foot and Ankle Imaging

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0015
Author(s):  
Daniel Bohl ◽  
Blaine Manning ◽  
George Holmes ◽  
Simon Lee ◽  
Johnny Lin ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Ct Scan ◽  
Radiation Exposure ◽  
Cone Beam Ct ◽  
Plain Film ◽  
Ct Scans ◽  
Cone Beam ◽  
X Rays ◽  
Foot And Ankle ◽  
X Ray

Category: Other Introduction/Purpose: Foot and ankle surgeons routinely prescribe diagnostic imaging that exposes patients to potentially harmful ionizing radiation. The purpose of this study is to characterize patients’ knowledge regarding radiation exposure associated with common forms of foot and ankle imaging. Methods: A survey was administered to all new patients prior to their first foot and ankle clinic appointments. Patients were asked to compare the amount of harmful radiation associated with chest x-rays to that associated with various types of foot and ankle imaging. Results were tabulated and compared to actual values of radiation exposure from the published literature. Results: A total of 890 patients were invited to participate, of whom 791 (88.9%) completed the survey. The majority of patients believed that a foot x-ray, an ankle x-ray, a “low dose” CT scan of the foot and ankle (alluding to cone-beam CT), and a traditional CT scan of the foot and ankle all contain similar amounts of harmful ionizing radiation to a chest x-ray (Table 1). This is in contrast to the published literature, which suggests that foot x-rays, ankle x-rays, cone beam CT scans of the foot and ankle, and traditional CT scans of the foot and ankle expose patients to 0.006, 0.006, 0.127, and 0.833 chest x-rays worth of radiation. Conclusion: The results of the present study suggest that patients greatly over-estimate the amount of harmful ionizing radiation associated with plain film and cone-beam CT scans of the foot and ankle. Interestingly, their estimates of radiation associated with traditional CT scans of the foot and ankle were relatively accurate. Results suggest that patients may benefit from increased counseling by surgeons regarding the relatively low risk of radiation exposure associated with plain film and cone-beam CT imaging of the foot and ankle.

scholarly journals Hard X-Ray Imaging Observations by Yohkoh of the 15 November, 1991 Flare

1993 ◽  
Vol 141 ◽  
pp. 258-262
Author(s):  
Taro Sakao
Keyword(s):  
Magnetic Fields ◽  
Energy Release ◽  
Impulsive Phase ◽  
Time Profile ◽  
X Rays ◽  
X Ray ◽  
Precipitation Model ◽  
X Ray Imaging ◽  
Coronal Magnetic Fields ◽  
The Individual

AbstractWe present hard X-ray imaging observations by Yohkoh of the 15 November, 1991 flare. The pre-impulsive and the impulsive phase observations are summarized as follows: (1) Hard X-ray sources in the precursor (or pre–impulsive) phase appear in a much wider area compared with the impulsive phase sources and they show clear evolution just before the onset of the impulsive phase. This suggests that some global re-structuring of coronal magnetic fields led to the impulsive energy release. (2) In the impulsive phase, at the peaks of the individual spikes of the time profile, the bulk of the hard X-ray emission (above 20 keV) originates from the footpoints of the flaring loop. At the valleys between the spikes, X-rays below 30 keV are emitted from near the loop top, while higher energy ones (above 30 keV) are still emitted from the footpoints. Such behavior of hard X-ray sources can be explained by the partial precipitation model.

scholarly journals Differences in the directions of ejection of x-ray photo-electrons from various atomic levels

1929 ◽  
Vol 126 (800) ◽  
pp. 138-143 ◽  
Keyword(s):  
Resolving Power ◽  
X Rays ◽  
Expansion Chamber ◽  
X Ray ◽  
Chamber Method ◽  
Heavy Atoms ◽  
Intensity Measurements ◽  
The Individual ◽  
Radio Corporation Of America ◽  
Slow Electrons

Very valuable studies of the directions in which photo-electrons are ejected by X-rays have been made recently by Williams, Auger, and Anderson. All of these observers, however, used the C. T. R. Wilson expansion-chamber method which, in spite of its power in working with the individual electron, suffers from the disadvantage that the particular energy level in the atom from which the electron is ejected in general cannot be determined. It is true that in the case of heavy atoms such as xenon and bromine, Auger and Anderson succeeded, through the use of X-rays of particular energies, in distinguishing the electrons thrown out of the K level from those thrown out of the L levels, but to go much further in this direction by the expansion-chamber method (and, for example, to distinguish the L I from the L II or L III electrons) seems hopeless. Consequently, the magnetic spectrograph developed by one of us for studying the velocity of the X-ray electrons as a function of the angle of emission was applied to the problem with the results which it is the purpose of this paper to describe. We, as yet, have not succeeded in determining the actual directions of ejection with the precision which has been attained in the expansion-chamber method, but the resolving power of the apparatus for velocities is so large that the particular level in which each electron group originates is in general quite unambiguous. A description of the apparatus used and the procedure followed has been given in the paper referred to above and need not be repeated here. Ballast lamps of the sort developed at the General Electric Company and sold by the Radio Corporation of America (radiotron UV-886) have proved very useful in holding the current through the solenoid which produces the magnetic field constant during the long exposures (100-200 hours) which are necessary. Eastman X-ray plates were used throughout, as they have been found to be the most sensitive of any so far tried (except Schumann plates which are much too irregular for intensity measurements). The work has been seriously handicapped by the lack of sensibility of the photographic plates for slow electrons and by their rapid falling off in sensibility for electrons of velocities below about 12,000 volts. X-ray tubes with silver, molybdenum and copper anticathodes were used. The characteristic radiation from copper is, however, in spite of its intrinsic intensity, too soft to eject electrons with sufficient velocity to give photographic results in a reasonable length of time with the apparatus used. All the results shown below consequently were obtained with the characteristic rays of either silver or molybdenum.

Determination of the Mechanical Response of Thin Films with X-Rays

1993 ◽  
Vol 308 ◽  
Author(s):  
I. C. Noyan ◽  
G. Sheikh
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mechanical Response ◽  
Strain Analysis ◽  
Local Strain ◽  
X Rays ◽  
Stress Strain ◽  
X Ray ◽  
The Individual

ABSTRACTThe mechanical response of a specimen incorporating thin films is dictated by a combination of fundamental mechanical parameters such as Young's moduli of the individual layers, and by configurational parameters such as adhesion strength at the interface(s), residual stress distribution and other process dependent factors. In most systems, the overall response will be dominated by the properties of the (much thicker) substrate. Failure within the individual layers, on the other hand, is dependent on the local strain distributions and can not be predicted from the substrate values alone. To better understand the mechanical response of these systems, the strain within the individual layers of the thin film system must be measured and correlated with applied stresses. Phase selectivity of X-ray stress/strain analysis techniques is well suited for this purpose. In this paper, we will review the use of the traditional x-ray stress/strain analysis methods for the determination of the mechanical properties of thin film systems.

Optical and Dimensional Changes Which Accompany the Freezing and Melting of Hevea Rubber

1939 ◽  
Vol 12 (1) ◽  
pp. 18-30 ◽  
Author(s):  
W. Harold Smith ◽  
Charles Proffer Saylor
Keyword(s):  
Optical Properties ◽  
Low Temperatures ◽  
Heat Content ◽  
Uniaxial Crystal ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dimensional Changes ◽  
Ether Yield ◽  
The Individual

Abstract At suitable, low temperatures, unvulcanized rubber loses its elasticity and becomes hard and opaque. Similar changes frequently occur in baled rubber which has been tightly compressed before shipment. It is said to be frozen or “boardy.” The phenomenon has been studied by many investigators who have determined changes of volume, softening temperatures, the effects of increasing time of storage at low temperatures, the influence of pressure during freezing, and changes in heat capacity and entropy. These effects have generally been ascribed to a form of crystallization, and x-ray diffraction powder patterns indicate that crystals are present in frozen rubber. When total rubber is stretched, there are changes of volume and of heat content such as attend crystallization. With x-rays a crystal fiber pattern is obtained. It and the powder pattern obtained with frozen, compact rubber have been shown to indicate similar spacings and are assumed to be caused by the same type of crystal, the differences being ascribed to conditions of orientation. Dilute solutions of rubber hydrocarbon in ethyl ether yield small crystals of the hydrocarbon when they are subjected to temperatures between −35° and − 60° C. for several hours. The optical properties and melting points of these crystals and their x-ray diffraction patterns indicate their identity with the crystals in stretched and frozen rubber. Under the best conditions the crystals appear in spherulitic groupings, the individual needles in each spherulite having optical properties that closely approach those of a uniaxial crystal with negative elongation. The crystals of sol rubber which we obtained, melted between 9.5° and 11.0° C. Crystals of gel rubber melted between −2° and 14° C., but the melting ranges within this interval were not the same for all samples. Numerous observations have repeatedly confirmed the data. About 90 per cent of the rubber in solution may be obtained as birefringent material at −65° C. Temperatures between −40° and −50° C. have been preferred, however, because better crystals are obtained in that range.

scholarly journals Can Smartphones Measure Radiation Exposures?

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Lawrence Y. Pang
Keyword(s):  
Ionizing Radiation ◽  
Incident Angle ◽  
Normal Incidence ◽  
Radiation Detectors ◽  
Calibration Factor ◽  
Radiation Absorption ◽  
X Rays ◽  
X Ray ◽  
The Public ◽  
Standard Detector

Ionizing radiation, such as X-rays, is potentially harmful to humans. Ionizing radiation can be detected by radiation detectors, which are not easily available to the public. Thus, the feasibility of using smartphones to detect and measure X-ray exposures was investigated in this work. Two sets of experiments were conducted using an Apple iPhone 4 smartphone. For one experiment, the smartphone was used as an X-ray source, while the second experiment tested the use of the iPhone as an exposure meter. Using the iPhone 4, it was found that when videos were taken during X-ray exposures, white tracks appeared in the videos, which indicated a radiation absorption event. By counting the total number of tracks in the videos (using image processing software), X-ray exposures could be determined using a calibration factor obtained from the first set of experiments. It was found that the calibration factor was strongly dependent on the video settings, but weakly dependent on the incident angle of X-rays on the phone as long as the incident angle was within ±45 degrees from the normal incidence. It was observed that, as an exposure meter, the iPhone 4 was ±20% accurate compared to a standard detector used by hospitals. The results of this work suggest that it is feasible to use an iPhone 4 to measure radiation exposures.Les rayonnements ionisants comme les rayons X, peuvent être nuisible sans être sensiblement distingués par des humains. La faisabilité de l’utilisation des smartphones qui peuvent détecter des rayons X, et ce, en mesurant l’exposition à de tels rayons faisait l’objet de cet étude. Deux séries d’expériences ont été fait avec un iPhone4. Une série portait sur le calibrage de l’iPhone avec une source de rayon X. L’autre série portait sur l’utilisation de l’iPhone comme dispositif de photométrie. L’expérience a révélé que lors de la prise de vidéo pendant une exposition aux rayons X, des brillantes traces blanches se sont apparues dans les vidéos dont chacune a indiqué un événement d’absorption de radiation. En comptant le nombre total de traces dans les vidéos (utilisant un logiciel de traitement d’image), des expositions radiographiques pourraient être déterminées en utilisant un facteur de calibrage obtenu de la première série d’expériences. Les paramètres de vidéo ont eu une importante influence sur le facteur de calibrage, tandis que l’influence de l’angle d’incident de radiographies au téléphone leur signifiait moins tant que l’angle d’incident était d’environ ±45 degrés de l’incidence normale. L’iPhone comme dispositif de photométrie révélait être d’environ ±20 % précis par rapport à un détecteur standard utilisé dans des hôpitaux.

scholarly journals Chest X-ray image analysis and classification for COVID-19 pneumonia detection using Deep CNN

2020 ◽  
Author(s):  
Terry Gao ◽  
Grace Wang
Keyword(s):  
Training Dataset ◽  
X Rays ◽  
X Ray ◽  
Speed Up ◽  
Chest X Ray ◽  
Coronavirus Infection ◽  
Deep Cnn ◽  
Detection And Diagnosis ◽  
The Individual ◽  
New Diagnosis

Abstract To speed up the discovery of COVID-19 disease mechanisms, this research developed a new diagnosis platform using a deep convolutional neural network (CNN) that is able to assist radiologists with diagnosis by distinguishing COVID-19 pneumonia from non-COVID-19 pneumonia in patients at Middlemore Hospital based on chest X-ray classification and analysis. Such a tool can save time in interpreting chest X-rays and increase the accuracy and thereby enhance our medical capacity for the detection and diagnosis of COVID-19. The research idea is that a set of X-ray medical lung images (which include normal, infected by bacteria, infected by virus including COVID-19) were used to train a deep CNN that can distinguish between the noise and the useful information and then uses this training to interpret new images by recognizing patterns that indicate certain diseases such as coronavirus infection in the individual images. The supervised learning method is used as the process of learning from the training dataset and can be thought of as a doctor supervising the learning process. It becomes more accurate as the number of analyzed images grows. In this way, it imitates the training for a doctor, but the theory is that since it is capable of learning from a far larger set of images than any human, it can have the potential of being more accurate.

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