Laminar Air Flow Research Articles

Air contamination inside an actual operating room due to ultrafine particles: An experimental-numerical thermo-fluid dynamic study

Hospital Operating Rooms (ORs) are working spaces which demand an utmost clean air environment for enhancing both the safety and the comfort conditions of medical staff and patients, in order to reduce the risk of post-operative complications. In this context, an integrated experimental-numerical thermo-fluid dynamic study has been carried out in the present work, to investigate air contamination due to UltraFine Particles (UFPs) inside an actual, but unoccupied, OR, equipped with a laminar air flow system, located near Milan in Northern Italy. The UFPs considered in the present study are geometrically representative of surgical smoke and SARS-CoV, SARS-CoV-2 (COVID-19) virus particles. The flow and thermal fields in the OR have been calculated by using the Realizable k-ε turbulence model. A transient passive scalar species transport equation, based on the drift flux model, has been implemented along with the particle deposition boundary conditions at the OR walls, to analyze the UFPs concentration within the OR. The numerical model has been used, after validation against experimental data, to reproduce the quantities of interest in the OR. Moreover, type A and type B uncertainties have been associated to the experimental measurements. The velocity and temperature fields in the OR, obtained from both the numerical and experimental analysis, are compliant to the technical standards. A good agreement is observed between experimental and numerical results, in terms of velocity, temperature and UFPs concentration. A time of 19 min to completely evacuate UFPs from the OR has been obtained from both experimental and numerical analysis, with a deviation smaller than 2% between the results.

Impact du type d’incubateur (atmosphère humidifiée versus sec) sur l’osmolalité des milieux de culture embryonnaire

IntroductionBenchtop incubators with small individual chambers have been developed in order to improve the stability of embryo culture conditions reducing the environmental stress during the embryo development. These new dry incubators were designed without any air humidification system in order to prevent bacterial proliferation and to enable the use of time-lapse system. However, an elevated evaporation of the culture media could occur in these conditions. The main objective of the study is to analyse the impact of the used incubator type on the embryo culture media osmolality. Materials and methodsMicrodrops of 50μL of culture media were placed in 60mm diameter culture dishes, and quickly covered with either 7 or 8mL of mineral oil in an IVF workstation with laminar airflow. Two series of culture dishes have been randomly placed either in a humidified incubator or in a dry benchtop incubator. The microdrops of each culture dishes were sampled at D0, D1, D2, D3, and D5 respectively to measure the osmolality in triplicate using a cryoscopic osmometer. The mean values of osmolality in each incubator have been compared respectively on D0, D1, D2, D3 and D5 with appropriate statistical tests, and considered statistically significant when P<0.05. ResultsThe osmolality of the microdrops placed in the dry benchtop incubator differed significantly after the third day of culture, regardless of the level of mineral oil in the culture dishes. Indeed, using Petri dishes covered respectively with 7 or 8mL of mineral oil, osmolality values of samples from the dry incubator were significantly higher than those from the humidified one, at D3 and D5 (D3/7mL: 273±2.1 vs. 268±1.0mOsm/kg; P=0.02; D3/8mL: 282±8.0 vs. 270±0.7mOsm/kg; P=0.04) and D5 (D5/7mL: 283±1.5 vs. 270±3.6mOsm/kg; P=0.004; D5/8mL: 287±5.6 vs. 268±2.3mOsm/kg; P=0.005). Furthermore, the analysis on paired samples showed that the osmolality in the dry benchtop incubator at D5 using 7mL of oil (283±1.5mOsm/kg; P=0.003) and at D3 (273±2.1mOsm/kg; P=0.016) and D5 (287±5.6mOsm/kg; P=0.009) using 8mL of oil was significantly higher than that measured at D0 (265±1.9mOsm/kg). ConclusionA significant increase of the embryo culture media osmolality was observed in the dry benchtop incubator with ambient hygrometry in our standard conditions. Adding 1mL of oil was not sufficient to reduce the evaporation of the media. Although maintained at a physiological level, the impact of the osmolality changes on the in vitro embryo development has to be further determined.

The effect of type of ventilation used in the operating room and surgical site infection: A meta-analysis.

The relation between type of ventilation used in the operating room and surgical site infection has drawn considerable attention with its conflicting results. A possible relationship between the type of ventilation used in the operating room and surgical site infection has been reported. This meta-analysis was performed to evaluate this relationship. A systematic literature search up to May 2020 identified 14 studies with 590,121 operations, 328,183 operations of which were performed under laminar airflow ventilation and 261,938 of which were performed operations under conventional ventilation. These articles reported relationships between type of operating-room ventilation with its different categories and surgical site infection: 10 studies were related to surgical site infection in the total hip replacement; 7 studies in total knee arthroplasties; and 3 studies in different abdominal and open vascular surgery. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated comparing surgical site infection prevalence and type of operating room ventilation using the dichotomous method with a random-effects or fixed-effects model. No significant difference was found between operation performed under laminar airflow ventilation and conventional ventilation in total hip replacement (OR, 1.23; 95% CI, 0.97-1.56, P = .09), in total knee arthroplasties (OR, 1.14; 95% CI, 0.62-2.09; P = .67), and in different abdominal and open vascular surgery (OR, 0.75; 95% CI, 0.43-1.33; P = .33). The impact of the type of operating room ventilation may have no influence on surgical site infection as a tool for decreasing its occurrence. Based on this meta-analysis, operating under laminar airflow or conventional ventilation may have no independent relationship with the risk of surgical site infection. This relationship forces us not to recommend the use of laminar airflow ventilation because it has a much higher cost compared to conventional ventilation.

Aerosol generation during phacoemulsification in live patient cataract surgery environment.

To investigate whether phacoemulsification is an aerosol-generating procedure in a live patient environment. New Hayesbank Ophthalmology Services, Kent, United Kingdom. In vivo experimental human eyes study. Aerosol particle counts sized 0.3 μm or lesser, more than 0.3 to 0.5 μm or lesser, more than 0.5 to 1 μm or lesser, more than 1 to 2.5 μm or lesser, more than 2.5 to 5 μm or lesser, and more than 5 to 10 μm or lesser were measured during elective phacoemulsification surgery of 25 eyes. The baseline particle count in the operating theater was measured on 2 separate days to assess for fluctuation. Then, 5 readings each during prephacoemulsification and phacoemulsification of all eyes were measured. The difference in aerosol generation during prephacoemulsification and phacoemulsification was also measured with the use of the mobile laminar air flow (LAF) machine. Finally, aerosol generation during phacoemulsification was measured using 2% hydroxypropyl methylcellulose (HPMC). There was no statistically significant difference in measurement of aerosol between the baseline measurements on both days and between each patient's prephacoemulsification and phacoemulsification stages of surgery. The LAF system showed statistically significant reduction in particles size of 0.3 μm or lesser, more than 0.3 to 0.5 μm or lesser, more than 0.5 to 1 μm or lesser, more than 1 to 2.5 μm or lesser, more than 2.5 to 5 μm or lesser, and more than 5 to 10 μm during phacoemulsification compared with that during prephacoemulsification (P value .00 for all particle sizes, t test). The use of 2% HPMC did not show any statistically significant reduction in particle measurements. Aerosol particles sized less than 10 μm are not produced during phacoemulsification of human crystalline lens in a live patient setting. The use of a mobile LAF machine significantly reduced the number of particles sized 10 μm or lesser within the surgical field.

Mechanochemical Synthesis of High Purity Anhydrous Binary Alkali and Alkaline Earth Chloride Mixtures

A direct synthesis route for high purity anhydrous binary and ternary salt mixtures has been developed. This atom efficient, solvent free process is easily scalable with potential to produce salt eutectics with purity standards required to meet the needs of industrial heat transfer and nuclear applications. The methodology involves mechanochemical mixing of alkali and alkaline earth chloride salts followed by subsequent drying under dry air laminar flow. Each salt mixture was then analyzed for waters of hydration, purity, and oxide content through subsequent thermogravimetric analysis, X-ray diffraction, and strong acid titration. This process is proposed to provide a cost effective, single pot synthesis for both fuel and coolant chloride salt compositions for use in generation IV molten salt reactor systems. This work was supported as part of the Molten Salts in Extreme Environments Energy Frontier Research Center, funded by the U.S. Department of Energy Office of Science.

Laminar air flow reduces particle load in TKA\u2014even outside the LAF panel: a prospective, randomized cohort study

PurposeReleased particles are a major risk of airborne contamination during surgery. The present prospective study investigated the quantitative and qualitative particle load in the operating room (OR) depending on location, time of surgery and use of laminar air flow (LAF) system.MethodsThe particle load/m3 was measured during the implantation of 12 total knee arthroplasties (6 × LAF, 6 × Non-LAF) by using the Met One HHPC 6 + device (Beckmann Coulter GmbH, Germany). Measurement was based on the absorption and scattering of (laser) light by particles and was performed at three different time-points [empty OR, setting up, ongoing operation) at 3 fixed measurement points [OR table (central LAF area), anaesthesia tower (marginal LAF area), surgical image amplifier (outside LAF area)].ResultsIndependent of time and location, all measurements showed a significantly higher particle load in the Non-LAF group (p < 0.01). With ongoing surgical procedure both groups showed increasing particle load. While there was a major increase of fine particles (size < 1 µm) with advancing activity in the LAF group, the Non-LAF group showed higher particle gain with increasing particle size. The lowest particle load in the LAF group was measured at the operating column, increasing with greater distance from the operating table. The Non-LAF group presented a significantly higher particle load than the LAF group at all locations.ConclusionThe use of a LAF system significantly reduces the particle load and therefore potential bacterial contamination regardless of the time or place of measurement and therefore seems to be a useful tool for infection prevention. As LAF leads to a significant decrease of respirable particles, it appears to be a protective factor for the health of the surgical team regardless of its use in infection prevention.Level of evidenceI.

Heat and mass transfer during water film evaporation in a horizontal channel with a cocurrent flow of moist air

In this paper, we consider the issues of modeling of joint processes of heat and mass transfer during evaporative cooling of a laminar flow of moist air in a flat horizontal channel, taking into account the finite thickness of the water film. Numerical simulation of processes is based on solving the system of differential equations in boundary layer approximation and in two-dimensional formulation. The research is conducted in the range of input parameters: temperature T 0 = 10 ÷ 50 °C, relative humidity φ0 = 0 ÷ 100 %, and Reynolds number Re = 50 ÷ 1000 at atmospheric pressure. The influence of the Reynolds number and relative humidity on the change of local and average thermodynamic and thermohydraulic parameters of flows along the channel length is shown.

Physical compatibility of alprostadil with selected drugs commonly used in the neonatal intensive care units.

This study aimed to determine the physical compatibility of alprostadil with 17 continuous infusion drugs commonly administered in neonatal intensive care units. Test samples were prepared in a laminar airflow hood. Alprostadil 20 mcg/ml was mixed with each drug in a 1:1 ratio, in two orders of mixing. Physical stability of the admixtures was assessed by visual examination and by measuring turbidity. Visual examination was conducted by two observers by two methods: visual examination against a black and white background under normal fluorescent light and using a high-intensity monodirectional light. pH was measured as chemical stability predictor. Evaluations were performed immediately and 4 h after mixing. An additional visual control was performed at 24 h. Visual examination was positive or doubtful for the four drug combinations not considered compatible. Turbidity values were under 0.5 NTU throughout the study in all samples. No modifications of one pH unit or more was detected in any drug pair over time.Conclusion: Alprostadil was considered physical compatible with 13 drugs (adrenalin, amiodarone, calcium gluconate, dobutamine, dopamine, fentanyl, flecainide, furosemide, heparin, ketamine, midazolam, milrinone and morphine). Incompatibility could not be ruled out for 3 drugs (cisatracurium, dexmedetomidine and noradrenalin), and insulin was considered incompatible with alprostadil. What is Known: • Y-site administration is common in neonatal intensive care units, and volume of diluents and rate of infusions in newborns were lower than in adults which might result in high concentrations and prolonged contact time at Y-site administration. • Available data about compatibility of alprostadil with other drugs was scarce. What is New: • Alprostadil was compatible with 13 drugs commonly used in neonatal intensive care units. • Insulin was considered incompatible with alprostadil, and incompatibility cannot be ruled out for cisatracurium, dexmedetomidine and noradrenalin with alprostadil.

Comprehensive assessment of bioactive glass and glass-ceramic scaffold permeability: experimental measurements by pressure wave drop, modelling and computed tomography-based analysis

Proper microstructural and transport properties are fundamental requirements for a suitable scaffold design and realization in tissue engineering applications. Scaffold microstructure (i.e. pore size, shape and distribution) and transport properties (i.e. intrinsic permeability), are commonly recognized as the key parameters related to the biological performance, such as cell attachment, penetration depth and tissue vascularization. While pore characteristics are relatively easy to asses, accurate and reliable evaluation of permeability still remains a challenge.In the present study, the microstructural properties of foam-replicated bioactive glass-derived scaffolds (basic composition 47.5SiO2–2.5P2O5–20CaO–10MgO–10Na2O–10K2O mol.%) were determined as function of the sintering temperature within the range 600-850°C, identified on the basis of thermal analyses that were previously performed on the material.Scaffolds with total porosity between 55 and 84 vol.% and trabecular-like architecture were obtained, with pore morphological features varying according to the sintering temperature. Mathematical modelling, supported by micro-computed tomography (μ-CT) imaging, was implemented to selectively investigate the effect of different pore features on intrinsic permeability, which was determined by laminar airflow alternating pressure wave drop measurements and found to be within 0.051-2.811·10−10 m2. The calculated effective porosity of the scaffolds was in the range of 46 to 66 vol.%, while the average pore diameter assessed by μ-CT varied between 220 and 780 μm, where the values in the lower range were observed for higher sintering temperatures (750-850°C). Experimental results were critically discussed by means of a robust statistical analysis. Finally, the complete microstructural characterization of the scaffolds was achieved by applying the general constitutive equation based on Forchheimer's theory.

Association of Laminar Airflow During Primary Total Joint Arthroplasty With Periprosthetic Joint Infection

Whether laminar airflow (LAF) in the operating room is effective for decreasing periprosthetic joint infection (PJI) after total joint arthroplasty remains a clinically important yet controversial issue. To investigate the association between operating room LAF ventilation systems and the risk of PJI in patients undergoing total joint arthroplasty. A retrospective cohort study was conducted of 6972 consecutive patients undergoing primary total knee arthroplasty or total hip arthroplasty at 2 surgical facilities within a single institution from January 1, 2013, to September 15, 2017, with a minimum of 1 year of follow-up. All procedures were performed by 5 board-certified arthroplasty surgeons. Statistical analysis was performed from January 1, 2014, to September 15, 2018. Patients underwent total joint arthroplasty in operating rooms equipped with either LAF or turbulent airflow. Patient characteristics were extracted from clinical records. Periprosthetic joint infection was defined according to Musculoskeletal Infection Society criteria within 1 year of the index arthroplasty. A multivariable logistic regression model was performed to explore the potential association between LAF and risk of PJI at 1 year, and then a sensitivity analysis using propensity score matching was performed to further validate the findings. A total of 6972 patients (2797 who underwent total knee arthroplasty and 4175 who underwent total hip arthroplasty; 3690 women [52.9%]; mean [SD] age, 63.9 [10.7] years) were included. The incidence of PJI within 1 year for patients from the facility without LAF was similar to that of patients from the facility with LAF (0.4% [12 of 3027] vs 0.5% [21 of 3945]). In the multivariable logistic regression analysis, after all confounding factors were taken into account, the use of LAF was not associated with a reduction of the risk of PJI (adjusted odds ratio, 0.94; 95% CI, 0.40-2.19; P = .89). After propensity score matching, there was no significant difference in the incidence of PJI within 1 year for patients who underwent total joint arthroplasty at these 2 sites. This study suggests that the use of LAF in the operating room was not associated with a reduced incidence of PJI after primary total joint arthroplasty. With an appropriate perioperative protocol for infection prevention, LAF does not seem to play a protective role in PJI prevention.

Effect of Cylinder Arrangement on Fluid Flow and Heat Transfer Characteristics past Four Elliptic Cylinders

Fluid flow and heat transfer characteristics past four elliptic cylinders arranged in square configuration are numerically investigated in this study. An in-house finite element method code based on streamline upwind Petrov - Galerkin algorithm has been used for simulations of two-dimensional, incompressible and laminar flow of air. Analyses are carried out by changing geometric parameters such as spacing ratio, axis ratio and incident angle. Results in terms of vorticity and temperature contours, Strouhal number, drag and lift coefficients and Nusselt number are studied for all cases. These results show that fluid flow patterns are strongly influenced by geometric parameters, based on which flow can be categorized into different types. A critical spacing ratio is found for some of the configurations, where a steep increase in drag coefficient is encountered. From this study, it is observed that incident angle 22.5 degree gives a higher heat transfer rate compared to the other two configurations (0 and 45 degree). Also, elliptic cylinders (axis ratio of 0.8 and 0.5) have similar Nusselt number value with less drag force compared to circular cylinders (axis ratio of 1.0) which justifies the utilization of elliptic cylinders as an alternative for circular ones.

Effects of thermophoresis on dust accumulation on solar panels

The dust accumulation on a solar panel may be one of the most serious losses in the energy yield of photovoltaic systems, especially in the desert environment. The transport of airborne dust particles onto solar panels is governed by various physical processes and described by particle dynamics in a fluid. Here we investigate how the temperature gradient between the solar panel and the ambient air affects the dust accumulation. This so-called thermophoresis, which drives particles moving from the hot solar panel to the cold air, is examined using the boundary layer approximation for non-isothermal laminar airflow along the solar panel. We find that a strong thermophoretic force is built up at the entry region of the solar panel. With the velocity and temperature profiles of non-isothermal laminar airflow, we simulate Lagrangian particle trajectories. We demonstrate that for submicrometer-size particles, the thermophoresis builds a region free of the dust accumulation on the solar panel. It is shown that the thermophoretic effect may decrease the accumulation of submicrometer-size particles on the solar panel whose temperature is a few tens of degrees higher than the ambient air in the daytime.

Opening Doors in the Operating Rooms: An Intervention and Outcome Study

Background: Surgical site infections (SSIs) are a major cause of morbidity and mortality with an estimated cost of $3–10 billion annually in the United States. Laminar air flow in the operating room (OR) is 1 factor in reducing SSIs. Opening the OR door results in interruption of laminar air flow. As a part of annual infection prevention evaluation of our facility, we observed cases in the OR in which we identified excessive unnecessary door openings during surgical cases. We report an intervention in door openings in the OR and the effect on infection rate after surgery. Methods: We conducted an observational analytical study using prospective audit and feedback. Door-opening counters were placed on 4 OR doors. Each day, they were reset and the number was logged for each case by the circulating nurse. A baseline number of door openings was established between April 18, 2019, and May 2, 2019. Subsequently, daily feedback sheets were provided to all persons involved in the previous day’s procedures detailing the rationale to limit unnecessary door openings and the number of door openings that had occurred during the case(s) in which they were specifically involved from May 3, 2019, to June 4, 2019. Analyses of postoperative infection rates compared with historical controls were conducted. Using Stata version 15 statistical software, independent sample t tests were performed to see the difference between control and intervention groups. A CI 95% was set for significance. Results: There were no differences between control and intervention groups with the number of procedures (71 vs 80), OR, duration of procedure, or type of case. Outliers due to vibration of doors triggering the counters were removed, and door stabilizations were performed throughout the study. After removing outliers, there were no differences in control groups and interventions groups (39 vs 43). An independent sample t test showed a significant difference in the mean number of door openings between the control and intervention groups: 32.13 versus 24.84 (P &lt; .05 and P = .0072). There have been no postoperative infections in any of the cases in the study to date compared to an overall annual rate of 1.5% in 2018 at our facility. Conclusions: Prospective audit and feedback to OR staff can reduce the number of unnecessary door openings during operating procedures. The baseline number of door openings from this study was 25 per case. No postoperative infections occurred in the patients receiving surgery in this study.Funding: NoneDisclosures: None

A localized laminar flow device decreases airborne particulates during shoulder arthroplasty: a randomized controlled trial

Although the rate of periprosthetic joint infection following shoulder arthroplasty is low, it is a morbid and costly complication. Airborne particulates have long been recognized as a potential source of wound contamination, and operating room-mounted and smaller localized laminar airflow devices have been developed to minimize airborne particulates. This randomized controlled trial evaluated the effectiveness of a localized laminar flow device in reducing the intrusion of ambient airborne particles and bacteria into the surgery site during shoulder arthroplasty as measured by overall particle counts and colony-forming units (CFUs). Patients undergoing primary anatomic or reverse shoulder arthroplasty were eligible for participation. After providing informed consent, patients were randomly assigned to the Air Barrier System (ABS) group or control group. For all patients, the ABS was placed on the surgical field; however, it was only turned on by the technician for those randomized to the ABS. Study participants, surgeons, and surgical staff were blinded to group assignment. Bacterial CFUs were collected from within 5 cm of the surgical wound every 10 minutes, whereas airborne particulates were collected every minute. Poisson regression models were used to determine whether differences existed in CFUs and particulate counts between the ABS and control groups. A total of 43 patients were randomized into the ABS (n = 21) or control (n = 22) group. Surgical time (P = .53) and the average staff count (P = .16) in the operating room did not differ between groups. Poisson regression showed that the ABS group had significantly lower CFUs (β = -0.583, P < .001) along with surgical time and particulates with a diameter ≥ 5 μm. Staff count and particulates with a diameter < 5 μm were not significant predictors of CFUs. Infection was not a primary outcome; however, no postoperative infections have been reported in either study group with a minimum of 1-year follow-up for all patients. This double-blinded, randomized trial demonstrated that a localized laminar flow device dramatically reduced the count of CFUs in the air directly above the wound and beneath the ABS (adjusted for the number of operating room personnel and surgical time). The use of the device was not associated with a longer case duration; however, some additional setup time was required prior to surgical incision to place the device. Further study is required to determine the clinical implications of this finding-specifically, whether such devices result in lower rates of periprosthetic joint infection after shoulder arthroplasty.

Effect of laminar airflow unit diffuser size on pathogen particle distribution in an operating room

Operating room ventilation is quite important to protect patients from infection risk inside a surgical field. The laminar flow units (LAF) used in these applications contribute to removal of pathogen particles from the operation area by creating a protection zone on the surgical field. In this study, effect of LAF diffuse size on airflow and particle distribution in an operating room is investigated using computational fluid dynamics (CFD). Three different diffuser sizes (1.8 m x 2.4 m, 2.4 m x 2.4 m, 3.2 m x 3.2 m) and three different particle diameters (5 µm, 10 µm, 20 µm) are examined. In the modeling of airflow and particle motion, the Realizable k-ε turbulence model and Lagrangian approach are used, respectively. The distributions of airflow and particles originated from the surgical team are analysed. Also, the air change efficiency is predicted as for the entire operating room and for the breathing zone. The results reveal that the LAF diffuser size has a decisive role in air velocity and contaminant distribution in the operating room. It is seen that the amount of particles deposited on the operating table could be reduced up to 73% by increasing the diffuser size.

Aerosol Exposure During Surgical Tracheotomy in SARS-CoV-2 Positive Patients.

Since December 2019, the novel coronavirus SARS-CoV-2 has been spreading worldwide. Since the main route of infection with SARS-CoV-2 is probably via contact with virus-containing droplets of the exhaled air, any method of securing the airway is of extremely high risk for the health care professionals involved. We evaluated the aerosol exposure to the interventional team during a tracheotomy in a semiquantitative fashion. In addition, we present novel protective measures. To visualize the air movements occurring during a tracheotomy, we used a breathing simulator filled with artificial fog. Normal breathing and coughing were simulated under surgery. The speed of aerosol propagation and particle density in the direct visual field of the surgeon were evaluated. Laminar air flow (LAF) in the OR reduced significantly the aerosol exposure during tracheostomy. Only 4.8 ± 3.4% of the aerosol was in contact with the surgeon. Without LAF, however, the aerosol density in the inspiratory area of the surgeon is 10 times higher (47.9 ± 10.8%, P < 0.01). Coughing through the opened trachea exposed the surgeon within 400 ms with 76.0 ± 8.0% of the aerosol-independent of the function of the LAF. Only when a blocked tube was inserted into the airway, no aerosol leakage could be detected. Coughing and expiration during a surgical tracheotomy expose the surgical team considerably to airway aerosols. This is potentially associated with an increased risk for employees being infected by airborne-transmitted pathogens. Laminar airflow in an operating room leads to a significant reduction in the aerosol exposure of the surgeon and is therefore preferable to a bedside tracheotomy in terms of infection prevention. Ideal protection of medical staff is achieved when the procedure is performed under endotracheal intubation and muscle relaxation.

Application of cryobanking for Platycodon grandiflorum in vitro axillary buds using cryo-plate methods

The application of the V cryo-plate method using either PVS2 or PVS3 and the D cryo-plate method to Platycodon grandiflorum in vitro axillary buds was investigated. Precultured buds (1 mm) were attached to cryo-plates using calcium alginate gel. Then, osmoprotection treatment (2 M glycerol and 1 M sucrose) was performed by immersing the cryo-plates for 30 min at 25°C. The procedures for each cryogenic method were as follows: in the V cryo-plate method, the buds on cryo-plates were exposed to PVS2 for 40 min (highest regrowth 71.1%) or PVS3 for 50 min (highest regrowth 82.2%). In the D cryo-plate method, the buds on the cryo-plates were dehydrated under the air current of a laminar air flow cabinet for 60 min (highest regrowth 80.0%) at 25°C. Then, the cryo-plates were plunged directly into liquid nitrogen. After cryopreservation, buds on the cryo-plates were rewarmed and unloaded by immersion in 1 M sucrose solution for 15 min at 25°C for subsequent plant regeneration. The average regrowth seen on the V cryo-plates exposed to PVS3 and in the D cryo-plate method was higher than that of the V cryo-plates exposed to PVS2. The regrowth after cryopreservation in the V cryo-plate method with PVS2 was not stable. Thus, the V cryo-plate method with PVS3 and the D cryo-plate method are considered to be practical cryopreservation methods for P. grandiflorum germplasm.

Microbiological monitoring during aseptic handling: Methods, limits and interpretation of results

Aseptic handling is the procedure to enable sterile products to be made ready to administer using closed systems (EU Resolution CM/Res(2016)2). Microbiological monitoring (MM) and media fills are used for environmental and process control.In this study, the application of MM methods during aseptic handling inside, or related to working in, a laminar airflow cabinet or safety cabinet in hospital pharmacies is described and evaluated. Results are expressed as colony forming units (cfu) and Contamination Recovery Rate (CRR; the rate at which MM samples contain any level of contamination -USP<1116>-). For trend analysis, a rolling CRR is developed (a rolling CRR calculates a CRR using a predetermined number of most recent samples).Of all MM methods, glove print is the most informative. The added value of air sampling is doubtful. Because of microbiological as well as statistical considerations, the use of CRR for assessing MM results is advised. Glove prints, in general, give the highest CRR. A CRR < 10% is a realistic limit for MM during aseptic handling in hospital pharmacies. A rolling CRR, calculated using the last 100 samples, is a good compromise between reliability of the CRR value and timely prediction of process changes.

Smoke-mediated visualization of airflow from the outside of the negative pressure booth with a stair-cut front curtain. A laminar air flow was shown to be sucked into the booth smoothly, while a dummy doctor was sitting outside and a man was sitting inside the booth

Smoke-mediated visualization of airflow from the outside of the negative pressure booth with a stair-cut front curtain. A laminar air flow was shown to be sucked into the booth smoothly, while a dummy doctor was sitting outside and a man was sitting inside the booth

INFECTIVITY OF BEAUVERIA BASSIANA (BALSAMO) AGAINST TRIBOLIUM CASTANEUM (COLEOPTERA: TENEBRIONIDAE)

Tribolium castaneum is a major pest in wheat flour but can attack other processed foodstuffs. Control of these pests can be done in various ways, one of them by biological control using entomopathogenic fungus Beauveria bassiana. This study aims to determine the infectivity of B. bassiana entomopathogenic fungus against T. castaneum populations in the laboratory. The experiment was completed with random preparations, each preparation was repeated three times. Imago T. castaneum was sprayed with a conidia suspension of B. bassiana at a density of 106 and 107 conidia/mL on three different storage media namely PDA, rice, and corn media. Mortality was calculated based on the percentage of imago that died of B. bassiana fungi. One week observation showed the mortality of T. castaneum after the application of B. bassiana fungus was 55.33% with 107 conidia/mL in corn media. The highest spore density was found in rice media with an average of 10.53 x 106 conidia/mL. Meanwhile, the value of the results showed LC50 of 2.11 x 107 conidia/mL and the fastest LT50 in corn media was 5.31 days