Electrostatic Removal of Loose Particulate Surface Contamination from Historical Photographs / Elektrostatische Abnahme lose aufliegender partikulärer Verunreinigungen von historischen Photographien / Dissolution électrostatique des particules libres contaminant la surface de photographies historiques

Author(s):  
Marie-Louise Frank ◽  
Ernst Becker ◽  
Julia Schultz ◽  
Ulrike Hähner ◽  
Irene Brückle ◽  
...  

AbstractThis article discusses the use of electrostatic cleaning technology to remove loose particulate surface contamination - which here includes microbial contaminants such as spores, conidia and hyphal fragments - from two 19th century albumen photographs mounted on cardboard. The results of this study, obtained using light microscopy, SEM/EDX and microbiological methods, as well as conservators' visual evaluation, show that the technology is fundamentally suitable for removing microbial contamination from photographic prints and their cardboard mounts. Cleaning the surface four times with electrostatically charged foils reduced the microbial contamination by up to 70%. The surface of the albumen print, which is sensitive to abrasion, was not harmed, and its characteristic features were not changed. The photographs, which were partly delaminated from the cardboard support and the mechanically weakened cardboard, could be treated without creating any additional damage.

2010 ◽  
Vol 14 (5) ◽  
pp. 245-248 ◽  
Author(s):  
Iman Hemmati ◽  
W. Alastair McLeod ◽  
Richard I. Crawford

Background: Progressive mucinous histiocytosis (PMH) is a benign, non-Langerhans cell histiocytosis with characteristic ultrastructural features that can be used for diagnosis. Once an important tool in dermatologic diagnosis, electron microscopy has been largely replaced by immunohistochemistry and immunofluorescence techniques today. However, electron microscopy occasionally still plays a crucial role in the diagnosis of dermatologic conditions. We report a case of PMH as an example of a dermatologic disorder that requires electron microscopy for its diagnosis. Methods: A 60-year-old woman presented to our clinic with a history of small, sharply demarcated, skin-colored papules ranging from 2 to 5 mm in diameter distributed over the arms, forearms, and dorsal hands. The results of light microscopy, immunohistochemical studies, and clinical examination were inconclusive. Another biopsy for electron microscopy showed the characteristic features of PMH. Conclusion: This case demonstrates that a dermatopathology service still needs to have access to electron microscopy for diagnostic purposes to successfully diagnose a small number of rare conditions.


1991 ◽  
pp. 249-256
Author(s):  
Philip C. D. Hobbs ◽  
J. Samuel Batchelder ◽  
Vaughn P. Gross ◽  
Kenneth D. Murray

2020 ◽  
Author(s):  
Juliet Kyayesimira ◽  
Wangalwa Rapheal ◽  
Grace Kagoro Rugunda ◽  
Lejju Julius Bunny ◽  
Morgan Andama ◽  
...  

Abstract Background If hygiene practices along the beef processing nodes at small and medium enterprise (SME) slaughter houses and butcheries are not observed, they may pose a health risk due to microbial contamination. In SME slaughterhouses and butcheries, the risk may be higher due to transmission of foodborne pathogens. This study determined the hygienic practices and microbial quality risk among meat handlers (MH) in SME slaughterhouses and butcheries. Methods Assessment of microbiological quality of beef was carried out at slaughter houses and butcher shops in the districts of Western, Central and Eastern regions of Uganda. A cross sectional study was conducted from June 2017 to January 2018 using observation checklists to record unhygienic practices among the various actors. Microbial load at slaughter and butchery was determined from a total of 317 swab samples collected from carcass, tools, protective clothing and hands of meat handlers. The microbiological quality of beef was evaluated using standard microbiological methods. The samples were inoculated into differential and selective media. Results Butcheries had the highest microbial load on beef carcass ranging from 4.76 log 10 cfu/cm 2 to 7.90 log 10 cfu/cm 2 Total Viable Counts (TVC) while Total Coliform Counts (TCC) ranged from 1.42 log 10 cfu/cm 2 to 3.05 log 10 cfu/cm 2 , E. coli ranged from 0.68 log 10 cfu/cm 2 to 1.06 log 10 cfu/cm 2 and Staphylococcus aureus ranged from 3.25 log 10 cfu/cm 2 to 4.84 log 10 cfu/cm 2 . Salmonella was absent in all the samples analysed. Results of overall microbial quality of beef in Uganda indicated that only TCC (1.60±0.26 log 10 cfu/cm 2 ) of the beef carcass samples at slaughter houses was not significantly above the safe level (p = 0.693). Overall microbial load (TVC, TCC, E. coli and S. aureus ) at butcheries were significantly (p < 0.05) above the safe level. Butcheries of Mbale district had the highest percentage (70%) of beef carcass samples above the TCC safe levels whereas butcheries of Mbarara district had the highest percentage (40%) of beef carcass samples above the E. coli safe levels. TVC from hands and clothes at butchery across the three study districts varied significantly (p=0.007) with the highest counts (7.23 log 10 cfu/cm 2 ) recorded from personnel clothes and lowest (5.46 log 10 cfu/cm 2 ) recorded from hands. On the other hand, swab samples picked from chopping board and working table at the butchery did not show significant variation in TVC, TCC, E. coli and S. aureus microbial loads across the three study districts. Conclusion Hygienic handling of carcasses after slaughter is critical in preventing contamination and ensuring meat safety in informal meat trading sectors in Uganda. Handling practices of beef at Ugandan slaughterhouses and butcheries are not hygienic hence not up to standard and they contribute to microbial contamination of beef posing a risk to consumers. The distribution stage is the most critical period, during which the quality of meat can easily be compromised.


Author(s):  
Lisa Were ◽  
Gertrude Were ◽  
Kevin Omondi Aduol

Street-vended foods are a major threat to public health because of their microbial contamination. This study investigated hygiene practices and microbial contamination of street foods in Kenyatta University’s environs. Both cross-sectional and experimental designs were adopted. Four (4) major vending stalls at the main entrance to Kenyatta University, gate (A) and at the hind gate at KM shopping center were identified for this study. Twelve (12) food samples were collected from these stalls; sausages, samosas and kachumbari. The foods were collected and transported in cooler boxes to the Microbiology Laboratory at Kenyatta University within 3 hours for analyses. Standard microbiological methods were used for enumeration of Salmonella, coliforms and Escherichia coli. No Salmonella was detected per 25g in all food samples tested. Fifty percent (50%) of kachumbari samples tested positive for E.coli whereas samosas and sausages tested negative. Kachumbari, from all vending stalls, had total coliform levels 4.12 log10 cfu/g, 4.26 log10 cfu/g and 4.21 log10 cfu/g, that did not meet the quality standards (4.00 log10 cfu/g) for ready-to-eat foods. Total coliform counts were below detection limits in samosas and sausages. All (100%) the stalls were exposed to potential contaminants: 75% of the vendors did not wear protective clothing, they handled money and sold food simultaneously, and polythene bags exposed to open air, were used for packaging take away rations. All the foods evaluated were safe for human consumption except kachumbari. Policies on safe street food to be enforced and education and training of vendors on environmental and personal hygiene to be strengthened.


2006 ◽  
Vol 3 (1) ◽  
pp. 37-42
Author(s):  
Daiva Paškevičienė ◽  
Algimantas Paškevičius

The article presents methodological recommendations for the implementation of the project of a microbiological nature. The urgency of the project is undoubted, as it has been noticed that school classes were overcrowded with pupils and almost not ventilated in winter, thus, schoolchildren often suffered from respiratory illnesses. Besides, secondary school programs include many themes in which the concept of microorganisms is used, however, pupils usually lack practical knowledge about isolation of microorganisms in a laboratory and their distribution in the air. The main aim of this work was to evaluate microbial contamination of school premises as well as to provide pupils with knowledge about biological peculiarities of various systematic groups (bacteria, micromycetes and yeast-like fungi) and their macro- and micro-morphological peculiarities. To achieve the aim, the following tasks were set: 1) to develop pupils’ abilities to make experiments and develop their initial skills in research; 2) to form their cognitive experience of the surrounding world while performing team tasks; 3) to develop pupils’ creative-organizational abilities as an integral process of theoretical and practical actions. Due to lack of equipment and conditions, it is not easy to perform microbiological projects in schools. Furthermore, a teacher should have competence, though due to this, in the article much attention is paid to the methods of project performance. Necessary labware and nutritive media for project implementation are indicated. Possible variants of an experiment scheme are discussed and the stages of the experiment are presented coherently. Preparation of microscopical mounts and microscopy methods are described in detail. It is pointed out that the identification of microorganisms is a very hard work, so teachers should be trained in microbiological methods. Handbooks, which can be used for the identification of some microorganisms, are indicated. Much attention is paid to the presentation of experiment results, as pupils participating in the project get much information about microorganisms. Participants get familiarized with the size and shape of bacterial cells and fungal macro-morphological (colony colour, shape, size and colour of colony reverse) and micro-morphological (a shape of conidia and mycelium) peculiarities. Pupils observe reproduction ways of yeast-like fungi (budding and binary fission) and determine yeast cell shape, size and other characteristic properties. While describing microorganisms isolated from school indoor air, pupils indicate a systematic group to which a microorganism (a bacterium, micromycete and yeast-like fungus) belongs. When the opportunities to identify microorganisms exist, pupils point out a genus and a species to which a microorganism is ascribed. Possible variants of systematizing the obtained results (tables and pictures, etc.) are discussed. The implementation of the project in schools has undoubted theoretic and practical significance, because pursuing the project the pupil’s abilities to make an experiment are developed and initial skills in research and cognitive experience of the surrounding invisible world are formed. Execution of the project induces pupils’ creative-organizational abilities as an integral process of theoretical and practical actions. Later the pupils willingly participate in competitions and conferences of young researchers – naturalists, write papers, prepare a wall newspaper about microbial contamination of school indoor air and give recommendations about improvement of school sanitation. While performing team tasks, participants get knowledge about microorganisms of various systematic groups (bacteria, micromycetes and yeast-like fungi), their isolation under laboratory conditions and distribution in the indoor air. Pupils can use obtained knowledge in the lessons of the course “A Man and his Health” (9th grade) as well as in ecology and general biology (11th – 12th grades) lessons. Key words: microorganisms, distribution, air of school premises.


2020 ◽  
Vol 20 (06) ◽  
pp. 16669-16688
Author(s):  
Nii Korley Kortei ◽  
◽  
T Annan ◽  
L Quansah ◽  
G Aboagye ◽  
...  

One serious threat to public health in both developed and developing countries is the microbial contamination of food. This problem poses a great challenge and consequently has economic implications. Causes of microbial contamination are diverse and these may be natural, environmental, or technological. The microbiological quality of most ready-to-eat foods is of great significance to human health because they require minimal or no processing when consumed.The aim of this research was to investigate the microbiological quality of some ready-to-eat mixed vegetable salad foods, ingredients as well as the wash water samples of an urban restaurant located in Accra, Ghana. A total of thirty (30) samples categorized into mixed vegetable salads, foods and water obtained from an urban restaurant in the national capital of Ghana, Accra. They were analyzed at the microbiology laboratory and food microbiology laboratories of School of Allied Health Sciences(UHAS)and Council for Scientific and Industrial Research-Food Research Institute (CSIR-FRI), Ghana,respectively. Standard microbiological methods that are per International Organization for Standardization(ISO) Methods and Nordic Committee on Food Analysis Methods (NMKL) were used in determining the presence and levels of bacteria and fungi.Data obtained were transformed from standard to logarithmic forms and reported as mean+standard deviations. The aerobic plate count samples ranged from 0-4.73 log 10CFU/g. E-coli counts also ranged between 0-2.53 log 10CFU, while Bacillus cereus counts were very low at0-<10log 10CFU/g. Clostridium perfringens and Staphylococcus aureus counts were also very low ranging from0-1.0log10CFU/g.Enterobacteriaceae counts also ranged from 0-1.90 log10CFU/g. Molds and yeasts counts were generally low and ranged from 0-2.48 log 10CFU/g and 0-1.0 log10CFU/g,respectively. None of the samples tested contained Listeria monocytogenes and Salmonella spp. Fungal microbial loads were minimal given the quantities, and were deleterious to the health of consumers. The study revealed that the bacterial loads on mixed vegetable salads, ingredients and water samples used and served by an urban restaurant in Accra were within safe limits according to American Public Health Association (APHA) and International Commission for Microbiological Specifications for Foods (ICMSF) guidelines and,therefore,good for human consumption.


2019 ◽  
Vol 366 (23) ◽  
Author(s):  
Edward Cunningham-Oakes ◽  
Rebecca Weiser ◽  
Tom Pointon ◽  
Eshwar Mahenthiralingam

ABSTRACT Preventing microbial contamination of non-food products is a major area of industrial microbiology where preservatives are used to stop microbial growth. However, microorganisms occasionally overcome product preservation, causing recalls and the implementation of multiple procedures to prevent further contamination. Correct reporting of microbial contamination in non-food industrial products is vital, especially if spoilage organisms are antimicrobial resistant and pose a health threat. Gram-negative bacteria such as Pseudomonas, Burkholderia and Enterobacteriaceae are frequently reported as non-food product contaminants, including species that overlap current antimicrobial resistance priorities. Historical analysis of recall databases highlighted that for greater than 15% of contamination incidents, the causative microbial agents are reported as unidentified. Here we review the current antimicrobial resistant bacterial species associated with non-food product contamination and evaluate recall reporting in Europe from 2005 to 2018. Our review shows that 49% of microbial contaminants are reported as unidentified despite frequent detection of antimicrobial resistant pathogens; in contrast, 98% of food-related microbial contaminants are classified. Recommendations to fill this microbial identification gap in non-food product recalls are made. Overall, reporting standards for microbial contamination in non-food products must be improved to enable surveillance and for understanding the risks associated with antimicrobial resistant microorganisms


2015 ◽  
Vol 15 (1) ◽  
pp. 41-46
Author(s):  
M. Maj ◽  
K. Pietrzak

Abstract This study discloses the characteristic features of the modified low-cycle fatigue test used for the determination of the mechanical properties of two types of cast iron, i.e. EN-GJL-250 and EN-GJS-600-3. For selected materials, metallographic studies were also conducted in the range of light microscopy and scanning microscopy.


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