Apparatus For Sterilization Research Articles

A 120-kV, 5-kA Multipurpose Pulsed-Power Generator Using a Semiconductor Switch and Magnetic Pulse Compression

This paper describes a high-frequency pulsed-power generator for various industrial applications such as water treatment, food and medical apparatus for sterilization, or polluted gas treatment. The system is made of silicon-controlled rectifier as a main trigger switch, capacitors, two-stage magnetic pulse compression stages, and a linear transformer to generate a maximum of 120-kV, 5-kA pulse. The parameters obtained through the development are: output voltage: 120 kV (maximum), pulse repetition ration: 300 pulse per second, pulsewidth: 0.25 μs, and mean power: 30 kW. The designed pulsed-power generator is confirmed to be used effectively for many high-voltage pulsed-power applications related to environmental industry by simulation and experiments.

Investigation of a sterilization system using active oxygen species generated by ultraviolet irradiation.

We have been investigating an advanced sterilization system that employs active oxygen species (AOS). We designed the sterilization equipment, including an evacuation system, which generates AOS from pure oxygen gas using ultraviolet irradiation, in order to study the conditions necessary for sterilization in the system's chamber. Using Geobachillus stearothermophilus spores (10(6) CFU) in a sterile bag as a biological indicator (BI) in the chamber of the AOS sterilization apparatus, we examined the viability of the BI as a function of exposure time, assessing the role of the decompression level in the sterilization performance. We found that the survival curves showed exponential reduction, and that the decompression level did not exert a significant influence on the survival curve. Subsequently, we investigated the sterilization effect as influenced by the spatial and environmental temperature variation throughout the chamber, and found that the sterilization effect varied with position, due to the varying environmental temperature in the respective areas. We confirmed that temperature is one of the most important factors influencing sterilization in the chamber, and estimated the temperature effect on the distribution of atomic oxygen concentration, using the quartz crystal microbalance (QCM) method with fluorocarbon thin film prepared by radio frequency sputtering.

Triboelectrification induced UV emission from plasmon discharge

UV is a high-energy electromagnetic radiation that has been widely used in industrial production and the scientific research domain. In this work, a deep UV light emission was obtained using triboelectrification induced plasma discharge without any extra power supply. By a mechanical friction between polymer and quartz glass, the triboelectric charges cause a changing electric field, which may bring plasma discharge of low pressure gas (Ar-Hg) and give out 253.7 nm irradiation. The UV light caused by continuous friction can excite a trichromatic phosphor and afford a bright white light emission. A UV sterilization experiment shows that ∼98% of Escherichia coli can be killed in 30 min by UV irradiation, which reveals that a self-powered sterilization apparatus with good sterilization effect was fabricated. This work provides a novel design to fabricate a self-powered UV light emitting device using low-frequency mechanical friction and realizes the coupling of triboelectrification and plasma luminescence, which may further expand the application of UV light in special circumstances.

Solar-Powered Sanitation

Almost 20% of the world’s population has no access to electricity, according to the International Energy Agency. Without electricity, people in developing regions can’t run modern-day sanitation and sterilization devices needed to prevent the spread of infectious diseases. To address this problem, a research team led by Naomi J. Halas of Rice University has engineered a portable sterilization apparatus—an autoclave—that generates steam by using sunlight and metallic nanoparticles (Proc. Natl. Acad. USA 2013, DOI: 10.1073/pnas.1310131110). The autoclave makes enough steam to raise the temperature and keep it at 132 °C for at least five minutes. That’s enough time to make water drinkable, sterilize a physician’s surgical equipment, or sanitize the contents of a portable toilet. Last year, the Rice University researchers demonstrated how gold-coated silica nanoparticles dispersed in water can directly convert solar energy into steam ( C&EN, Nov. 26, 2012, page 9). When focused sunlight hits the particles, th...

E123 エンジン式超高圧パルス殺菌試験装置の水圧発生特性(一般講演(6))

Ultra high pressure underwater shock waves were applied to the sterilization of microbes. We used the imploding detonation of propane-oxygen to occur the ultra high pressure underwater shock waves. We investigated the imploding detonation using an engine type liquid sterilization apparatus having a precombustion chamber and two sample holders with inner volume of 5L. This apparatus can work 60〜90 rpm continuously and sterilize the water of 20m^3/h. We investigated the pressure of underwater shock waves relation with engine speed and supplied pressure. We found that we could generate about 40〜60 MPa underwater shock waves in the sample holders.

Ultraviolet radiation as disinfection for fish surgical tools

BackgroundTransmitters used in telemetry studies are typically surgically implanted into the coelom of fish. When large numbers of fish are implanted consecutively, as in large telemetry studies, it is common for surgical tools (such as scalpels, forceps, needle holders and sutures) to be sterilized or, at minimum, disinfected between each use to minimize the transfer of pathogens. Chemicals are commonly used for disinfection but they can potentially harm fish and surgeons. UV radiation could provide a safe and more effective means for disinfection. The efficacy of UV radiation was determined for disinfecting surgical tools exposed to one of four aquatic organisms that typically lead to negative health issues for salmonids. The organisms include Aeromonas salmonicida, Flavobacterium psychrophilum, Renibacterium salmoninarum, and Saprolegnia parasitica, the causative agents of ulcer disease, coldwater disease, bacterial kidney disease, and saprolegniasis (water mold), respectively.ResultsIn the first experiment, forceps were exposed to three species of bacteria at three varying concentrations. After exposure, tools were placed into a mobile Millipore UV sterilization apparatus. The tools were then radiated for three different time periods – 2, 5 or 15 minutes. UV radiation exposures at all durations were effective at killing all three species of bacteria on forceps at the highest bacteria concentrations. In the second experiment, stab scalpels, sutures and needle holders were exposed to A. salmonicida using the same methodology as used in Experiment 1. UV radiation exposure at 5 and 15 minutes was effective at killing A. salmonicida on stab scalpels and sutures but not needle holders. In the third experiment, S. parasitica, a water mold, was tested using an agar plate-method and forceps-pinch method. UV radiation was effective at killing the water mold at all three exposure durations.ConclusionsCollectively, this study shows that UV radiation appears to be an effective disinfection method for some surgical tools. However, we do not recommend using this method for tools that have overlapping parts, such as needle holders, or other structures that cannot be exposed directly to UV radiation.

Sterilization of medical equipment and contaminated articles by making use of a resistive barrier discharge

Presented here is an apparatus consisting of an atmospheric resistive-barrier discharge for the sterilization of medical tools wrapped in typical hospital cloths, for the sterilization of manufactured drugs in typical packaging materials, and for the sterilization of biologically-contaminated articles. The sterilization apparatus consists of layers of the resistive-barrier discharge device operating at room temperature, a sterilization chamber, and an ozone destruction device. An electrical discharge in the resistive-barrier discharge system generates an atmospheric plasma in oxygen gas, generating ozone, which in turn efficiently sterilizes medical tools and biologically contaminated articles at room temperature. A sterilization experiment was carried out at an apparatus volume of 100 liters, with a sterilization chamber volume of 60 liters, and a discharge device volume of 40 liters. The sterilization in this experiment required 60 W of power for 5 hours of residence time. For a given sterilization time, the required electrical power was proportional to the apparatus volume. Ozone in the sterilization chamber was destroyed safely after sterilization.

Simple technique of talc delivery for video-assisted talc pleurodesis

It has been proven that talc is the sclerosant of choice for pleurodesis, especially for malignant effusions. Uniform talc deposition on the visceral pleura is often difficult, resulting in clump deposition with the use of an atomizer or bladder syringe delivery apparatus. We have devised a simple sterile apparatus that allows the operator to retain full control over the talc delivery rate and coat the lung uniformly under direct vision using a pressurized system.

Dispensing and Administration of Radiopharmaceuticals for Dacryoscintigraphy

Dacryoscintigraphy was first introduced in 1972 as a method to detect and localize obstructions of lacrimal drainage under physiologic conditions.1 It has since become commonly used in the evaluation of epiphora.2–7 Briefly, about 50–100 μCi of Technetium Tc-99m sodium pertechnetate or Tc-99m sulfur colloid in a volume of about 10–15 μL is placed on the surface of the eye.3,5 The transport of the radioactive tracer from the conjunctiva into the lacrimal drainage system and flow through the drainage duct to the nasal cavity can then be followed through images obtained using a gamma camera. This radiopharmaceutical dose has customarily been administered onto the surface of the eye using a micropipette.2–6,8–12 Although feasible for administration, dispensing of the radioactive dose in this manner is problematic, especially related to issues of sterility and radioactive contamination. Using a micropipette necessarily requires withdrawal of the radiopharmaceutical solution from an open container into an unsealed pipette tip, which makes sterility difficult to maintain. Leakage of radiopharmaceutical solution from the unsealed pipette tip, resulting in radioactive contamination of the immediate surroundings, may be difficult to avoid. Because these sterility and radioactive contamination issues preclude transportation of the loaded micropipette, it must be filled with the radiopharmaceutical at the immediate location of use. Hence, dispensing (and administration) of the radiopharmaceutical dose in a closed, sterile apparatus taken from a sealed, sterile source would be desirable. The purpose of this study was to evaluate alternative devices for dispensing and administration of radiopharmaceuticals for dacryoscintigraphy.

5350562 Method and apparatus for sterilization and separation of plastic and non-plastic medical wastes

Medical waste products including plastic and non-plastic elements are placed in a metal container which includes a raised insert element for supporting the waste above the bottom of the container. The container and used medical waste products are subjected to dry heat treatment at temperatures below the waste material flash points but of sufficient temperature and for a sufficient time to melt the plastic elements as well as to sterilize the contents. During the heating process the metal, rubber and other non-plastic elements remain on the raised insert; whereas, the molten plastic flows through or over the side of the insert to the bottom of the container. Upon cooling the plastic and non-plastic components of the medical waste products are separated as well as being sterile such that the container can be opened and the contents separately handled for appropriate recycling. The dry heat generator conveniently may be placed in a medical office or the like and is microprocessor controlled to obtain the desired end products. The processor additionally controls an electrical interlock system whereby the heat generator unit may not be opened until an entire heat cycle has been completed, and the waste products have cooled to a safe temperature.

Microwave sterilization in school microbiology

For a long time the standard procedure for ensuring total sterilization of equipment and culture media for microbiological investigations has been to autoclave; this method destroys even the most resistant bacterial spores by a combination of heat and pressure, using steam (typically 120°C and 100 kPA for 15–20 minutes). Most biology teachers are familiar with the noise, smell, condensation, and time involved with the use of the autoclave. However, there is no other effective, efficient way of preparing class-size quantities of materials. Microbiology in both research and industry is a much wider and more important field than its coverage in many biology courses might suggest. There is now an increasing trend to incorporate more microbiology into the Biology and Science syllabuses, especially in relation to Biotechnology and areas such as Food Science. While autoclaving is likely to remain the recommended method of producing large amounts of sterile apparatus and media, a typical school situation could require the quick sterilization of relatively small quantities of materials. In such circumstances the autoclave is slow and uneconomical. The use of the microwave oven could provide a suitable alternative to the familiar autoclave or the pressure cooker. This article describes an investigation carried out in a school Biology department, using a domestic microwave oven, to compare the relative attributes of the autoclave and microwave oven in school use.

A Contribution Toward Lichen Synthesis

The synthesis of lichens in the laboratory, beginning with the isolated algal and fungal symbionts, has long been the dream of lichenologists. Despite numerous attempts (a good history is given by Werner 1927) and a few reported successes (Bonnier 1889, Thomas 1939), the problem still remains unsolved and is as enigmatic today as it was some 90 years ago when the true nature of lichens was discovered. The experiments described in this paper have resulted in some interesting observations regarding the initial stages of lichen synthesis. Several of the results obtained deviate quite markedly from those published by earlier workers, notably those of Gaston Bonnier, who has claimed to have achieved many true lichen syntheses. Bonnier described synthetic culture in which 5 days after germination the clasping hyphae had laid hold of the algae and symbiotic growth had begun, a small lichen thallus being formed some 50 days later, with subsequent apothecial formation. In the light of my experiments this is indeed a remarkable feat. Bonnier's experiments contain numerous inconsistencies and unexplained points (Thomas 1939, p. 187); these, coupled with the fact that no one has been able to duplicate his experiments, make one hesitant in accepting his results. The lichen used for our experiments was Lecanora dispersa (Pers.) Rohl., an urban, saxicolous form growing quite conveniently on the concrete ledge of the basement window of the Farlow Herbarium. The procedure, carried out under sterile conditions and using sterile apparatus and cultures, may be outlined as follows: A non-nutrient agar (Noble's Agar) containing Knop's mineralsolution medium (pH 7.3) was employed. Immediately after autoclaving, this medium was pipetted into a van Tieghem cell and a carefully washed cover-slip was then placed over this filled cell and lifted off again

Cystometry: an apparatus and a method.

SUMMARY A simple apparatus which allows cystometry to be performed easily in any hospital ward with minimal delay in the provision of sterile apparatus is described. The use of a finger-cot to separate blood from an aneroid sphygmomanometer is depicted in an article on intra-arterial transfusion by Robertson, Trincher, and Dennis (1948). The aneroid pressure-gauge described above was obtained from the Genito- Urinary Manufacturing Company, London.

An apparatus for sterilization by filtration.

An apparatus for sterilization by filtration.