Mass Treatment of Flooded Archival Materials by Gamma Radiation

Author(s):  
Matteo Montanari ◽  
Sara Pipponzi ◽  
Pietro Livi ◽  
Antonio Prodi

Abstract This work describes mass recovery processes of flooded archival materials at industrial scale. The presence of fungi on paper represents a threat to the integrity of the document because they degrade cellulose, one of the main components of paper. Gamma radiation treatments are investigated as mass disinfection agents for their high penetrating power, speed of treatment, and absence of risk due to chemical residuals. We compared two different recovery processes: thermal drying followed by gamma irradiation and gamma irradiation followed by thermal drying. Both these processes were conducted simultaneously on naturally contaminated archival items and on paper specimens artificially contaminated with species test. Efficacy was assessed by culture method and ATP assay, right after the treatments and after four years of storage at room temperature. Coupling gamma irradiation with a drying step with dry heat at 55–60 °C reduces the fungal loads on natural items up to levels close to the detection limits, and the reduction is maintained after four years. On artificial specimens, spore germination is completely inhibited, mycelia growth is also highly affected, but the melanised test species appear to be more resistant. A synergistic effect between gamma irradiation, water content, and thermal drying is highlighted in this paper.

Author(s):  
Vachira Jiravatana ◽  
José Cuevas-Ruiz ◽  
Horace D. Graham

Shelf-life extension (measured as ripening delay) and the retention of nutrients in irradiated P. R. 965 papayas have been investigated at constant storage temperature and relative humidity. The major findings were: 1. The ripening process in irradiated papayas was delayed up to 7 days by the use of gamma radiation treatments. The maximum delay in ripening was achieved by 25 to 50 Krads treatments, while the 100 Krad treatment showed a slight stimulation of ripening in storage. 2. Some destruction of vitamin C (ascorbic acid) seemed to have been effected by the gamma irradiation, although there were only slight differences between dose levels. 3. The level of total carotenoids was not affected by gamma radiation. During storage, there was a marked increase in these pigments as the papayas ripened. 4. Gamma irradiation inhibited fungal proliferation on papaya fruit even at dosages of 25 Krad. 5. There was no effect observed at the dosages studied on the skin of the fruit which developed its characteristic bright yellow color when ripe.


2018 ◽  
pp. 37-40
Author(s):  
Phuong Thao Tien Nguyen ◽  
Anh Hung Tran ◽  
Van Tam Le ◽  
Huu Thao Phung ◽  
Phan Quynh Anh Nguyen

Objective: To evaluate the effect of gamma sterilization and its effect on microscopic structure of deeply frozen dog skull. Subjects and methods: 50 pairs of dog skull fragments have the same size,which were taken symmetrically through the midline of the skull, were divided into two lots. Evident lot consisting of 50 pieces are just deeply frozen, not irradicated. Experimental lot which was composed of 50 pieces were deeply frozen and exposed to 25kGy of gamma radiation. Afterwards, to evaluate the effect of gamma sterilization and compare the alter of bone matrix between lot groups. Results: After gamma irradiation, all dog skull fragments were negative with bacteriological examination. In microscopic scale, no difference was found between the two lots and there was no structural change in the irradiated fragments of all dog skull. Conclusion: Gamma irradiation with 25 kGy: (i) It has the ability to kill bacteria completely in the type of bacteria commonly infected tissue. (ii) It does not alter the structure of dog skull in microstructures. Key words: dog skull, gamma, sterilize


1964 ◽  
Vol 44 (2) ◽  
pp. 188-194 ◽  
Author(s):  
H. B. Heeney ◽  
W. M. Rutherford ◽  
K. F. MacQueen

The effects of gamma radiation doses of 110,000, 220,000, and 330,000 rad on the storage life and quality of two varieties of strawberries stored at 40°, 55°, and 70° F were studied. Results indicated that a dose of 330,000 rad prevented fungal development of the Redcoat variety stored for 26 days at 40° F. The fungal-free period was sharply reduced at lower radiation doses or at higher storage temperatures. Under the conditions of this trial there was no apparent effect of radiation on appearance or texture of fruit.In organoleptic tests in the first two weeks of storage observers were not able to differentiate between radiation treatments. There was some preference for treated berries as the storage period increased. After 20 days the flavor of the fruit deteriorated very rapidly and it soon became commercially unacceptable.


Author(s):  
S. Kostyuk ◽  
A. Busenko

It is found that gamma radiation leads to a significant decrease in the skin of rabbits content of these fatty acids, as meristinіс, pantadekanovaya, palmitic, palmitoleic, linoleic, arachidonic, and at the end issledvany, ie 76 Tide day, the concentration of fatty acids increased, and meristinіс palmitoleic and close to the physiological norm.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
H. Wang ◽  
R. Chandra Segaran ◽  
L. Y. Chan ◽  
Aref A. M. Aladresi ◽  
A. Chinnathambi ◽  
...  

Ionizing radiation-induced cardiovascular diseases (CVDs) have been well documented. However, the mechanisms of CVD genesis are still not fully understood. In this study, human umbilical vein endothelial cells (HUVECs) were exposed to gamma irradiation at different doses ranging from 0.2 Gy to 5 Gy. Cell viability, migration ability, permeability, oxidative and nitrosative stresses, inflammation, and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) pathway activation were evaluated postirradiation. It was found that gamma irradiation at doses ranging from 0.5 Gy to 5 Gy inhibited the migration ability of HUVECs without any significant effects on cell viability at 6 h and 24 h postirradiation. The decreased transendothelial electrical resistance (TEER), increased permeability, and disruption of cellular junctions were observed in HUVECs after gamma irradiation accompanied by the lower levels of junction-related proteins such as ZO-1, occludin, vascular endothelial- (VE-) cadherin, and connexin 40. The enhanced oxidative and nitrosative stresses, e.g., ROS and NO2- levels and inflammatory cytokines IL-6 and TNF-α were demonstrated in HUVECs after gamma irradiation. Western blot results showed that protein levels of mitogen-activated protein kinase (MAPK) pathway molecules p38, p53, p21, and p27 increased after gamma irradiation, which further induced the activation of the NF-κB pathway. BAY 11-7085, an inhibitor of NF-κB activation, was demonstrated to partially block the effects of gamma radiation in HUVECs examined by TEER and FITC-dextran permeability assay. We therefore concluded that the gamma irradiation-induced disruption of cellular junctions in HUVECs was through the inflammatory MAPK/NF-κB signaling pathway.


1969 ◽  
Vol 52 (4) ◽  
pp. 805-811
Author(s):  
D L Grant ◽  
C R Sherwood ◽  
K A Mccully

Abstract Disulfoton and phorate were subjected to gamma radiation from 60Co at dose levels of 0, 0.1, 0.5, 1, 2, and 4 Mrad. The inhibition of beef liver carboxylesterases by disulfoton and phorate in vitro was greater with increasing doses of radiation. The degradation of these organophosphorus pesticides was monitored by GLC with electron capture and phosphorus detectors, by TLC with detection by Brilliant green, and by enzyme inhibition with 5-bromoindoxyl acetate as substrate. The pesticides were degraded to the greatest extent in hexane or acetone solution. Less decomposition occurred at low temperatures. The sulfoxide and oxygen analog were present in most irradiated samples. The sulfone, oxygen analog sulfone, and oxygen analog sulfoxide were present in some of the disulfoton and phorate samples which were irradiated with 4 Mrad.


2011 ◽  
Vol 15 (3) ◽  
pp. 107-114 ◽  
Author(s):  
Iram Batool ◽  
Ijaz Ahmad Bhatti ◽  
Shahid Adeel ◽  
Muhammad Abbas

The effect of gamma radiation on the dyeing of cotton with Reactive Blue 13 dye powder has been investigated. The cotton and dye powder are irradiated to absorb doses of 100, 200, 300, 400 and 500 Gy by using a Co-60 gamma irradiator. Dyeing is performed by using irradiated and un-irradiated cotton with irradiated and un-irradiated dye powder, in order to observe the effect of radiation treatment on the colour strength of the reactive dye on cotton. Different dyeing parameters such as temperature, time and p H are optimized using irradiated cotton and dye powder. The effect of gamma irradiation on the colour strength and Lab values has been observed through optimized conditions of dyeing. The colour strength and Lab values are obtained by spectra flash spectrophotometer (SF650). ISO standard methods are employed to study the effect of gamma radiation on the Colourfastness properties of fabric. It can be demonstrated that gamma irradiation not only improves the colour strength of the dye in irradiated cotton, but also enhances the Colourfastness properties.


1988 ◽  
Vol 28 (6) ◽  
pp. 809 ◽  
Author(s):  
BP Oldroyd ◽  
C Reinganum

Honeybee (Apis mellifera) colonies hived in beehive materials that had been sterilised by gamma irradiation had an average weight gain of 29.3 kg while those housed in untreated hives had an average gain of 27.1 kg.Bees sampled from both the treated and untreated colonies were examined for the presence of Nosema apis and virus, causitive organisms of stress related diseases, at the end of the season. No significant differences were found. The slight increase in weight (2.2 kg) of the sterilised colonies was not sufficient to justify the cost of prophylactic sterilisation of beehive equipment.


2000 ◽  
Vol 57 (3) ◽  
pp. 389-394 ◽  
Author(s):  
Marta Helena Filet Spoto ◽  
Cláudio Rosa Gallo ◽  
André Ricardo Alcarde ◽  
Maria Sílvia do Amaral Gurgel ◽  
Lucimara Blumer ◽  
...  

This work evaluated the effect of gamma radiation on reducting the population of Staphylococcus aureus, Escherichia coli and Salmonella typhimurium in ground chicken breast stored under refrigeration. The experiment included a control and 4 doses of gamma radiation (2.0, 4.0, 6.0 and 8.0 kGy) along with 5 periods of storage under refrigeration (1, 7, 14, 21 and 28 days). Samples of ground chicken breast were inoculated with Staphylococcus aureus (ATCC 14458), Escherichia coli (ATCC 11105) and Salmonella typhimurium (ATCC 0626), irradiated at temperatures between 4 and 8°C and stored under refrigeration (5°C) for 28 days. The increased radiation dose and period of storage under refrigeration caused a reduction of Staphylococcus aureus, Escherichia coli and Salmonella typhimurium populations in the ground chicken breast. Mean radiation D values determined for Staphylococcus aureus and Escherichia coli were 0.41 and 0.72 kGy, respectively. Gamma irradiation was an effective treatment for chicken meat conservation because the radiation dose of 6.0 kGy kept the ground chicken breast within the microbiological limits established by the Brazilian legislation, for up to 28 days under refrigeration.


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