Sterilization Time Research Articles

MODIFIKASI RUANG STERILISASI MEDIA TANAM JAMUR UNTUK MENGURANGI KEGAGALAN PRODUK JAMUR TIRAM


 
 
 
 Sterilization room of mushroomss baglog is.function to kill bacteria, or any type of life in the mushrooms baglog so when the planting of oyster mushrooms, not wild mushrooms are disturbitg. Most of the oyster mushroom farmers in Indonesia are still traditional mushroom farmers. They sterilize the baglog based only on experience – previous experience. Mushroom farmers during the sterilization process using sterilization room shaped pan with a total time of sterilization during the nine hours, to reach 90.7"C temperature baglog takes eight hours. Thus are requiring a lot of fuel which ultimately adds to the cost of production. By doing this modification, aiming to reduce the failure rate and save fuel in the process of sterilization. From the results of the modification and testing can reduce the failure rate on mushroom growing media up to 65,48% and can save fuel up to 66,67%.
 
 
 

Application of Central Composite Design to Optimize Spawns Propagation

Despite the increased recognition of the nutritional value of the Oyster mushroom, coupled with its ability to tolerate a wide range of climatic conditions, its production is still at infancy stage with low adoption rate in Kenya. The low uptake could be attributed to the cost of spawns or lack of skills for spawns preparations coupled with poor knowledge on oyster mushroom consumption benefits. The objective of this study was to optimize Pleurotus ostreatus (Oyster mushroom) spawns production. To achieve the objective, the spawns propagation was optimized by varying the temperature level, sterilization time and culture media concentration in order to establish the feasible levels which minimized the days of mycelium full development using central composite designs. Based on the study findings, 26.29˚C, 17.36 minutes and 60.95 g/L of temperature level, sterilization time and culture media concentration levels respectively minimized the days to full coverage of mycelium in a petri dish. Central composite designs for controlling temperature, sterilization time and culture media concentration were recommended for spawns maximum production. A further research on multiple response optimizations aimed at achieving resistance to bacterial diseases and yield by varying the strain in the culture were recommended.

Effects of Diluents, Saliva and Other Organics on the Microbicidal Activity of Cetylpyridinium Chloride and Povidone-iodine

Povidone-iodine (PVP-I) is used for infection control and preoperative sterilization of the oral and pharyngeal regions. Marketed preparations containing cetylpyridinium chloride (CPC) are used to inhibit growth of oral bacteria. We conducted an in vitro study of the sterilizing effects of these microbicides on 10 oral bacterial strains and fungi related to pneumonia and periodontal disease, after dilution with phosphate-buffered saline (PBS), saliva, and components in saliva. The CPC solution was evaluated at 50 mg/100 mL, which is the concentration used in products. CPC sterilized all strains within 1 minute. Prolongation of the sterilization time associated with dilution was more gradual in comparison to PVP-I solution. CPC sterilized 7 of 10 microbial strains within 3 minutes at 3 mg/100 mL. At 500 mg/100 mL, which is near the upper limit of the concentration that is actually used, PVP-I solution sterilized 7 microbial strains within 3 minutes. However, PVP-I had no sterilization effect when diluted to 100 mg/100 mL or lower. With addition of saliva, PVP-I sterilized 2 microbial strains within 3 minutes at 500 mg/100 mL, whereas CPC solution sterilized 9 microbial strains within 1 minute at 50 mg/100 mL. Our results show that in use influenced by dilution with saliva, CPC is likely to maintain a strong sterilization effect, whereas PVP-I may have a reduced effect.

Preparation of Sustained-Release Agent of Long-acting Chlorine Dioxide

In order to develop a sustained-release solid chlorine dioxide preservative with controlled concentration and effective sterilization time,the effects of different kinds of activators,gels and chloride salts on the concentration and slow release period of chlorine dioxide gas were investigated. The formulation was optimized by L9(34)orthogonal test design method. The optimized preservative by scanning electron microscopy was observed. The results showed that the use of EDTA as an activator made effective sterilize time over 20%. When sodium carboxymethyl cellulose(CMC)was used as the gel,the sustained-release rate of chlorine dioxide gas was the smallest and the effective sterilization time was longer. The using of NaCl as a chloride salt provided a micro-electric field environment while passivating the reactants. When the mass ratio of CMC,EDTA and NaCl was 14:1:5,the effective sterilization time(concentration of 1~50 mg/kg)of the sustained-release preservative reached 28 d. The internal structure of the preservative agent was observed under the electron microscope. After the formulation optimization,the internal structure of the sustained-release agent was a dense microporous network structure with a tight arrangement of particles and certain rules. The chlorine dioxide gas generated by the reaction was stored in the microporous structure of the sustained-release agent and released slowly.

Efecto de gas de formalina sobre el recuento de mesófilos en nailon comercial destinado a procedimientos quirúrgicos

La investigación se realizó a fin de evaluar el efecto del gas de formalina sobre el recuento de mesófilos en nailon comercial (poliamida) destinado a procedimientos quirúrgicos. En primer lugar, se evaluó la contaminación de una muestra del material comercial de 1 g expuesta al ambiente de quirófano por 72 horas, a través de la técnica de recuento en placa para mesófilos; se obtuvieron 850 UFC/g. Una vez comprobada la contaminación de la poliamida comercial, esta se sometió a gases de formalina en comprimidos. Se colocaron 5 muestras (n=5) de nailon de 1 g cada una en 5 recipientes herméticos de 1 litro con 1 gramo de formalina cada uno; estos recipientes se almacenaron en un mueble en sala de esterilización a un metro de altura del piso y posteriormente, fueron abiertos y cultivados a través de la técnica de recuento en placa para mesófilos, uno por día a lo largo de 5 días a intervalos de 24 horas. Los resultados obtenidos no registraron crecimientos de microorganismos a partir de las 24 horas y durante los 5 días posteriores y se encontraron diferencias estadísticamente significativas (p < 0,05). Se concluye que bajo las condiciones del presente estudio el tiempo de esterilización de la formalina sobre nailon comercial es de 24 horas.

Optimizing the sterilization process of canned yellowfin tuna through time and temperature combination

Differences in can dimension, filled volume and type of sterilization equipment affect the heat penetration rate, temperature and time required for sterilization process in canned food. Thus, careful calculation and decision for those factors are critical to determine the final product quality. Therefore, this research aimed to investigate the quality of canned yellowfin tuna in a specific can dimension using a 24 L pressure canner by applying different time and temperature combination i.e., sterilization at 121°C for 20 minutes and at 115°C for 50 minutes. Two type of mediums used were palm oil and brine. Heat penetration study and calculation of sterilization time (Fo value) were conducted using thermocouple data logger for both methods. The results showed that the protein content decreased slightly from 24.6% (fresh tuna) to 23,57% (canned tuna sterilized at 121°C for 20 min) and to 13,31% for canned tuna sterilized at 115°C for 50 min. There was a sharp increment obtained for fat content of canned tuna in palm oil (0.54% to 10.6%). Heat penetration study indicated that the Fo for canned tuna in brine were longer (30.13 minutes) than tuna in oil (20.09 minutes). This research suggests that sterilization of canned tuna is recommended to be done at 121°C for 20 minutes with regards to the nutritional content of the final product, particularly the protein content.

DEVELOPMENT OF INDICATION SYSTEM OF MOBILE ULTRASONIC SURGICAL INSTRUMENT

Prevalence of gunshot wounds in modern world is associated with criminalization of society, terrorist threats, increase of a number of local military conflicts and civil unrest. Search and development of methods for reducing blood loss, accelerating the healing of postoperative wounds and scars resorption is an important goal of modern surgery, the solution of which is facilitated by the use of ultrasound. The use of ultrasonic surgery in military medicine and the use of piezoelectric elements as the source of ultrasound are perspective. Primary surgical treatment of wounds is the main method of preventing the development of severe infectious complications of gunshot wounds. When using an ultrasonic surgical instrument, an urgent task is to disinfect it before and after the operation. The purpose of this work is to develop an indication system for a mobile ultrasonic surgical instrument. A monochrome OLED display is used to indicate the state and interaction with the user in a mobile ultrasonic surgical instrument. STM32 series microcontroller is used to work with the display. The indication system provides a display of the current value of power, time and battery charge. The following settings menu items are available: frequency, power, sterilization, clock, information. The power value is presented in percent as a scale from 0% to 100%. The sterilization time setting menu provides a maximum sterilization time of 99 minutes and 59 seconds. The handle of the surgical instrument has all basic control elements for ease of use and simplicity. Proposed surgical instrument is mobile and can be used in extreme conditions. It does not require the use of a power cord. Li-ion batteries are used to ensure the mobility of the instrument. This work was made within the framework of a state budgetary research topic “Development of mobile highly effective ultrasonic surgical instrument for military and civil medicine”.

Magnetic field enhanced cold plasma sterilization

Cold plasma sterilization offers an efficient way to sterilize medical components and instruments. This paper reports using a magnetized plasma to realize low-temperature sterilization. A radio frequency dielectric barrier discharge is created in a quartz tube using a mixture of argon and oxygen gas. A uniform amount of Escherichia coli is applied onto glass slides and exposed to the plasma afterglow at different pressures with and without a magnetic field. Optical emission spectroscopy is used to identify the plasma species present. The magnetic field significantly promotes the intensity of the plasma and the sterilization efficiency. A process gas pressure of 100 mTorr presents the most effective treatment with a sterilization time less than one minute and sample temperature below 32 °C.

Salpingectomy to reduce risk of ovarian cancer in women at average risk.

Ovarian cancer is a common gynecologic malignancy with a poor prognosis and a lack of screening for women at average risk. Focus has therefore shifted toward strategies for risk-reducing surgery to prevent the development of ovarian cancer. This Practice Pearl describes the evidence supporting opportunistic salpingectomy at the time of hysterectomy or tubal sterilization as a strategy to reduce the risk of ovarian cancer, the risks and benefits associated with the procedure, and the methods used.

Effect of sterilization methods on electrospun cellulose acetate butyrate nanofibers for SH-SY5Y cultivation

In the biomedical field, the sterilization of nanofibers is of particular importance because it can significantly affect their morphology, physicochemical properties and cytocompatibility. Here, we studied the effect of conventional sterilization with 70% ethanol or ultraviolet (UV) radiation on cellulose acetate butyrate (CAB) nanofibers. Scanning electron microscopy (SEM) revealed that short-term (30 min) UV sterilization had no influence on nanofiber morphology while 70% ethanol led to swelling and, thus, reduced porosity. Water contact angle (WCA) measurements confirmed an increase in wettability after sterilization with ethanol. Fourier transform spectroscopy (FTIR) and electrokinetic analyses indicated only slight changes in the chemical composition of the CAB nanofibers for both sterilization types. However, longer sterilization time (2 h) led to notable changes in the chemical structure of the scaffolds. In turn, X-ray photoelectron spectroscopy (XPS) revealed changes in the chemical composition, even after short-term sterilization. In combination with FTIR and XPS, differential scanning calorimetry (DSC) identified the hydrolysis of the ethanol-sterilized scaffold and degradation of UV-sterilized one. Human neuroblastoma cell (SH-SY5Y) cultivation on the CAB scaffolds demonstrated significant changes in cell morphology and viability depending on sterilization type. Sterilization of CAB with 70% ethanol was preferable for SH-SY5Y attachment, growth and migration.

Validating Autoclave Cycles for Carcass Disposal in Animal Biosafety Level 2/3 Containment Laboratories.

Animal carcasses differ in composition from other types of solid waste, and through prior testing it was determined that cycle parameters applied to general, solid biohazardous waste did not ensure proper sterilization of ferret carcasses. The goals of this study were to develop and validate an autoclave cycle that would ensure the decontamination of infectious animal carcasses before removal from an animal biosafety level 2/3 containment suite for downstream disposal and to test different ways to prepare and package animal carcasses for autoclaving. Intact ferret carcasses were implanted with biological indicators, and the carcasses were placed in biohazard bags, then into metal pans. To test the efficacy of the autoclave cycle on larger biomasses, 1, 2, or 4 ferret carcasses were placed in a biohazard bag. A total of 4 carcasses were placed in each pan. An autoclave cycle was created to begin the study. After initial tests, minor modifications to the initial test cycle parameters were made, and a new cycle was validated for ferret carcasses up to 2 kg each. Parameters for the validated cycle were as follows: sterilization time 240 minutes, temperature 125°C, 5 prevacuum pulses, and chamber pressure 15 psi. The results of this study indicate that an extended sterilization time is required to successfully decontaminate animal carcasses compared with regular, solid, and biohazardous waste. This study demonstrates that it is possible to sterilize multiple intact ferret carcasses per load under validated autoclave cycle conditions.

Comparison of heat stability of cow's milk subjected to ultra‐high temperature and in‐container sterilisation

Cow's milk of different fat contents with or without stabilising salts was sterilised by in‐container and UHT sterilisation. Heat stability decreased with increasing fat content following both UHT and in‐container sterilisation. Adding small amounts of stabilising salts (6.4 mM) increased heat stability in UHT‐treated milk, while excessive addition (12.8 mM) decreased heat stability. In contrast, increasing stabilising salts from 6.4 to 12.8 mM caused a decrease in heat stability after in‐container sterilisation. Increasing in‐container sterilisation time from 10 to 30 min caused a decrease in heat stability arising from an increase in particle size. This study confirmed discrepancies in heat stability for two sterilisation procedures.

Effect of steam sterilization and biocompatibility studies of hyaluronic acid hydrogel for viscosupplementation

Intra-articular injection of hyaluronic acid (HA) hydrogel is one of the treatment methods recommended for osteoarthritis (OA). Here HA hydrogel (2000 kDa) has been developed, sterilized by steam sterilization and the important properties required for viscosupplementation such as equilibrium swelling, enzymatic degradation, carbazole assay and rheology analysis has been compared before and after steam sterilization. The effect of steam sterilization was studied by varying the temperature and time of sterilization and a suitable temperature and time such as 118 ₀C for 5 min was optimized. It was found that the optimized sterilization condition does not affect the material properties of HA hydrogel except equilibrium swelling. The stability of the steam sterilized hydrogel was evaluated for 3 months at two different conditions (5 ₀C and 25 ₀C at 60% RH) and it was found that 5 ₀C at 60% RH is the suitable condition of storage. The safety profiles of the HA hydrogel was checked by cytotoxicity analysis, intracutaneous reactivity, acute toxicity studies and found to be biocompatible. Hence It was found the HA hydrogel developed is highly biocompatible, retain its properties after sterilization and is stable upto 3 months when stored at 5 ₀C at 60% RH.

Development of a microchip based on LIGA technology for bacterial inactivation

We designed and fabricated a new micro-needle-column discharge chip by Lithographie, Galvanoformung and Abformung technology to meet sterilization requirements. The dimensions of the chip are 11.6 mm × 11.7 mm × 3 mm. The micro-discharge structure is composed of a needle electrode and two cylinder electrodes. We employed a needle with a tip diameter of 20 [Formula: see text]m and a thickness of 20 [Formula: see text]m as the discharge cathode. We used a cylinder with a thickness of 1 mm and diameter of 0.4 mm as the anode. We carried out the gas discharge experiments in ambient air and at room temperature, without external air flow. In the experiments, a corona and glow discharge with applied voltages of −2.1 kV and −3.8 kV were realized. We carried out the sterilization experiments for six different discharge times (15, 30, 60, 90, 120 and 180 s) with an applied voltage of −3.8 kV. The inactivation efficiency of Escherichia coli and Staphylococcus aureus reached 100% for sterilization times of 120 s and 180 s. This indicates that the micro-needle-column discharge chip may be suitable as a portable sterilizer.

Calculating stochastic inactivation of individual cells in a bacterial population using variability in individual cell inactivation time and initial cell number

The traditional log-linear inactivation kinetics model considers microbial inactivation as a process that follows first-order kinetics. A basic concept of log reduction is decimal reduction time (D-value), which means time/dose required to kill 90% of the relevant microorganisms. D-value based on the first-order survival kinetics model is insufficient for reliable estimations of bacterial survivors following inactivation treatment. This is because the model does not consider the inactivation curvature and variability in bacterial inactivation. However, although the D-value has some limitations, it is widely used for risk assessment and sterilization time estimation. In this study, stochastic inactivation models are used in place of the conventional D-value to describe the probability of a population containing survivors. As representative bacterial inactivation normally follows a log-linear or log-Weibull model, we calculate the time required for a specific decrease in the number of cells and the number of survival cells as a probability distribution using the stochastic inactivation of individual cells in a population. We compare the probability of a population containing survivors calculated via the D-value, an inactivation kinetics model, and the stochastic formula. The stochastic calculation can be approximately estimated via a kinetic curvature model with less than 5% difference below the probability of a population containing survivors 0.1. This stochastic formula indicates that the D-value model would over- or under-estimate the probability of a population containing survivors when applied to inactivation kinetics with curvature. The results presented in this study show that stochastic analysis using mathematical models that account for variability in the individual cell inactivation time and initial cell number would lead to a realistic and probabilistic estimation of bacterial inactivation.

A Five–year review of female sterilization at the Lagos university teaching hospital, Lagos.

Background: Over the decades, female sterilization has become a highly effective, convenient, simple and safe method of long term contraception, attributable to technological and medical advances.Objective: This study aims at determining the uptake, indications, timing and surgical techniques of female sterilization in LUTH.Methodology: A retrospective study involving all female clients who had sterilization done at the Lagos University Teaching Hospital between January 2010 and December 2014. Clinical data were retrieved from the case files and analyzed with SPSS version 19. one hundred and eighteen clients were eligible, however only 115 case files could be located. Available case files had adequate information for the study.Results: There were 8,695 deliveries with 115 cases female sterilization, resulting in an incidence of 13 per 1000 births. The mean age at sterilization was 37.9 years. Completed family size was the main indication. Ninety percent of the clients had a postpartum procedure and Pomeroy's method was used in 76.5% of the clients.Conclusion: Female sterilization still has a role to play in family planning in our environment. Majority of the procedure were performed during planned caesarean section.Keywords: female sterilization, contraception, family planning, Pomeroy, tubal ligation.

Pilot study: Internally cooled orthopedic drills - standard sterilization is not enough?

SUMMARYBone drilling causes focal temperature rise due to metal-to-bone contact, which may result in thermal osteonecrosis. Newly constructed internally cooled medical drill of an open type decreases temperature rise at a point of metal-to-bone contact although standard sterilization of such a drill could be inadequate due to bacteria retention within the drill lumen. The aim of this pilot study was to examine the effectiveness of sterilization and to propose sterilization recommendations for internally cooled open type bone drills. Unused internally cooled medical steel bone drills were tested. Drills were contaminated with Pseudomonas aeruginosa, Bacillus sp., beta-hemolytic Streptococcus sp., Enterobacter sp. and methicillin-resistant Staphylococcus pseudintermedius and then incubated for 24 hours at 37 °C. Afterwards, drills were autoclaved for 15, 20 and 30 minutes at 132 °C and 2.6 bar. When 15-minute sterilization was used, one out of 16 drills was contaminated with Pseudomonas aeruginosa, while the other 15 drills were sterile. Extended cycle sterilization in autoclave lasting for 20 and 30 minutes resulted in 100% sterility of all drills tested. In conclusion, lumened drills should be exposed to extended sterilization times in autoclave. Minimal recommended time for sterilization of lumened drills is 20 minutes.

Stochastic simulation for death probability of bacterial population considering variability in individual cell inactivation time and initial number of cells

Decimal reduction time (D-value) based on the first-order survival kinetics model is not sufficient for reliable estimation of the bacterial survivors of inactivation treatment because the model does not consider inactivation curvature. However, even though doubt exists in the calculation of D-value, it is still widely used for risk assessment and sterilisation time estimation. This paper proposes an approach for estimating the time-to-inactivation and death probability of bacterial population that considers individual cell heterogeneity and initial number of cells via computer simulation. In the proposed approach, Weibull and Poisson distributions are respectively used to provide individual cell inactivation time variability and initial number of cells variability. Our simulation results show that the time-to-inactivation significantly depends on kinetics curvature and initial number of cells. For example, with increases in the initial number of cells, the respective variance of the time-to-inactivation of log-linear, concave downward curve, and concave upward curve remains constant, decreases, and increases, respectively. The death probability contour plot was successfully generated via our computer simulation approach without using D-value estimation. Further, the death probability calculated using our stochastic approach was virtually the same as that obtained using inactivation kinetics. We validated the simulation by using literature data for acid inactivation of Salmonella population. The results of this study indicate that inactivation curvature can replace D-value extrapolation to estimate the death probability of bacterial population. Further, our computer simulation facilitates realistic estimation of the time-to-inactivation of bacterial population. The R code used for the above stochastic calculation is outlined.

Establishment of Efficient Surface Sterilization Protocol on Different Types of Field Grown Strawberry Explants (Fragaria x ananassa Duch.)

The present study was conducted to develop the effective disinfection protocol for the in vitro micropropagation of strawberry (Fragaria x ananassa Duch) with the use of shoot tips, runner tips, nodal segments and leaf segments as explants. The explants used in this study were surface sterilized using antibiotics, fungicides and other sterilants for different time durations. Although using the same sterilants, the most effective and successive way of using sterilants is different upon the time duration for each sterilant. In this study, two sterilization protocols were used and each protocol included same fungicide and antibiotics concentrations for the same time durations but there were slightly different concentrations and time durations of other sterilants. The present investigation revealed that the most effective way of sterilization protocol which were observed on the nodal segments while treated with protocol II including (10ml/L) fungicide solution for 2 hours, (500mg/L) concentration of ciprofloxacin for 1 hour, (20%) chlorox solution with two drops of Tween 20 for 5 mins, (70%) ethanol solution for 5 mins and (0.1 %) mercuric chloride solution for 4mins. However the same sterilants using the same sterilization time did not give raise the survival rate for runner tip explants, because these treatments resulted in tissue necrosis and contamination and then finally the death of the explant materials. And also, the explants of shoot tips and leaf segments were not shown the effective result compared with using nodal segments. So, for the micropropagation of field grown strawberry, the sterilization protocol II was suite for the nodal segments used as explants for the culture initiation on MS basal medium.

베이킹 소다와 식초를 이용한 보육시설에서의 칫솔 살균 방법

This study was conducted to compare the effect of toothbrush sterilization using sodium bicarbonate and vinegar. The concentrations of the sodium bicarbonate were set to 1%, 3%, and 5% and the sterilization times were set to 10, 30, and 60 minutes. Additionally, the concentration of vinegar was set to 0.5%, 1%, and 2%, while the sterilization time was set to 5, 15, and 30 minutes. The test bacteria used were Streptococcus mutans, which cause cavities, and Staphylococcus aureus and Escherichia coli, which cause food poisoning and hygiene problems. The mean value and the significance of the number of bacteria remaining on the toothbrush were examined using the SPSS program and the optimal conditions were identified using Design expert. The results revealed that sodium bicarbonate effectively sterilized the samples when applied at 3% or 5% for 30 minutes, as did 1% or 2% vinegar applied for 30. However, the sterilization rate of sodium bicarbonate was 86–89%, which was more effective than the vinegar sterilization rate of 76–79%. In addition, considering the discomfort caused by the smell of vinegar, the most suitable method for application in child care facilities is sterilization in 3% or 5% solution of sodium bicarbonate for 30 minutes.