Final Water Rinse Research Articles

Transcorneal Vitrectomy in Eyes with Regressed Retinoblastoma

Purpose: Current treatments for retinoblastoma facilitate globe salvage but can result in vitreoretinal disorders that may require surgery. There is controversy on surgical approaches in eyes with retinoblastoma. Here we describe a transcorneal vitrectomy approach that avoids the use of chemotherapy or cryotherapy. Methods: Retrospective chart review was performed on five consecutive patients with regressed retinoblastoma for >12 months (Group D/ct2b) at Children’s Hospital Los Angeles who had vitrectomy between November 2022 and December 2023. Results: Five patients underwent 8 vitrectomies for various indications including IOL fibrosis, vitreous hemorrhage, cataract, retinal detachment, and silicone oil removal. Mean age at first vitrectomy was 6.2 years (range: 2-9 years); mean time from last retinoblastoma treatment was 50.4 months (range: 20-82 months). Radially oriented corneal incisions were made with the 23-gauge or 25-gauge trocar system and the Versa HD LenZ (Oculus) was utilized with the RESIGHT (Zeiss) for top-down visualization. Neither chemotherapy nor cryotherapy were utilized. Wounds were sutured parallel to the limbus with 10-0 polyglactin 910 suture (Vicryl, Ethicon), and a final water rinse was performed to lyse any potential retinoblastoma cells. Surgical objectives were achieved, vision remained stable, and no retinoblastoma spread was noted with a mean follow-up of 7.6 months (range: 3-12 months). Conclusions: This vitrectomy technique for eyes with regressed retinoblastoma permits top-down viewing with the Versa HD LenZ. Radial placement of corneal wounds avoids suturing through the uveal tract, and a postsurgical water rinse lyses any retinoblastoma cells. This approach may obviate the need for chemotherapeutics or cryotherapy.

Removal of Pseudomonas fluorescens biofilms from pilot-scale food processing equipment using ozone-assisted cleaning-in-place.

Biofilm formation in food processing environment and within equipment increases the risk of product spoilage and contamination with pathogens. Cleaning-in-place (CIP) operations are useful in removing soils and in sanitizing processing equipment, including eliminating biofilms. However, CIP is a resource-intensive process, particularly in the usage of chemical detergents, heat, and sanitizers. The current study was initiated to investigate the feasibility of integrating ozone into CIP operations to facilitate the elimination of Pseudomonas biofilm, with the long-term goal of decreasing the dependance on conventional cleaning and sanitizing reagents. To investigate integrating ozone into CIP, a robust biofilm of Pseudomonas fluorescens was developed on a pilot-scale food processing equipment after 2 days of incubation in 10% skim milk (skim milk-water mixture, 1:9 v/v) under stagnant conditions, followed by additional 5 days of circulation while feeding 10% fresh skim milk. CIP was applied using water prerinse at 22-25°C, alkaline cleaning with 0.2% potassium hydroxide at 50°C, and a final water rinse. These CIP operations reduced planktonic cell populations below the detection method's limit but did not fully remove P. fluorescens biofilm from either smooth or rough surfaces of the processing equipment. When the CIP process was followed by application of an aqueous ozone step (10 ppm for 10 min), the treatment reduced biofilm cell population, on smooth and rough surfaces, below the recovery method's detection limit (0.9 and 1.4 log CFU/ 100 cm2, respectively). These findings demonstrate the utility of ozone-assisted CIP in eliminating microbial biofilms on processing equipment, but further research is needed to optimize the use of cleaning agents and the application of ozone.

Nanoplasmonic Sensing and Capillary Electrophoresis for Fast Screening of Interactions between Phosphatidylcholine Biomembranes and Surfactants.

Nanoplasmonic sensing (NPS), based on localized surface plasmon resonance, with sensors composed of glass covered with golden nanodisks and overlaid with a SiO2 coating was applied in this study. Egg phosphatidylcholine (eggPC), being an easily accessible membrane-forming lipid, was used for preparation of biomimicking membranes. Small unilamellar vesicles with an approximate hydrodynamic diameter of 30 nm, formed by sonication in 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid buffer, were adsorbed within 10 min on the sensor surface either as intact vesicles or as a planar bilayer. The adsorbed biomembrane systems were further utilized for interaction studies with four different well-known surfactants (negatively and positively charged, zwitterionic, and nonionic) and each surfactant was tested at concentrations below and above the critical micelle concentration (CMC). Our results allowed the evaluation of different NPS patterns for every particular supported membrane system, surfactant, and its concentration. The most significant effect on the membrane was achieved upon the introduction of zwitterionic surfactant micelles, which in fact completely solubilized and removed the lipid membranes from the sensor surface. Other surfactant micelles interacted with the membranes and formed mixed structures remaining on the sensor surface. The studies performed at the concentrations below the CMCs of the surfactants showed that different mixed systems were formed. Depending on the supported membrane system and the type of surfactant, the mixed systems indicated different formation kinetics. Additionally, the final water rinse revealed the stability of the formed systems. To investigate the effect of the studied surfactants on the overall surface charge of the biomembrane, capillary electrophoresis (CE) experiments were carried out in parallel with the NPS analysis. The electroosmotic flow mobility of an eggPC-coated fused silica capillary was used to measure the total surface charge of the biomembrane after its treatment with the surfactants. Our results indicated in general good correlation between CE and NPS data. However, some discrepancies were seen while applying either zwitterionic or positively charged surfactants. This confirmed that CE analysis was able to provide additional data about the investigated systems. Taken together, the combination of NPS and CE proved to be an efficient way to describe the nature of interactions between biomimicking membranes and amphiphilic molecules.

The wash-off of dyeings using interstitial water part 2: Bis(aminochlorotriazine) reactive dyes on cotton

2% omf dyeings of three, bis(aminochlorotriazine) reactive dyes on cotton were washed-off using a five-stage process recommended by the dye maker and a novel method that utilised two water rinses and treatment with damp nylon beads. Whilst similar levels of fastness were obtained using four temperatures in the final water rinse stage (ie cold (ambient), 50 °C, 70 °C and 98 °C) of the bead wash-off processes, a final rinse in water at 98 °C imparted levels of staining that were similar to those achieved using the five-stage wash-off process. The depths of shade and colour of the dyeings achieved using the bead wash-off methods were very similar to those obtained for the recommended process. When 5% omf dyeings were washed-off using a bead process that employed a commercial wash-off auxiliary and a cold water final rinse stage, levels of staining and shade change were obtained that were comparable to those secured using a recommended, six-stage, recommended wash-off process. As the beads adsorbed a sizeable amount of vagrant dye that was removed during wash-off, the various bead wash-off processes generated either only one or two coloured rinse liquors compared to the five or six coloured rinse liquors that ensued from the standard wash-off process, thereby constituting a lower effluent load.

Elimination of Post Cu-CMP Watermark by Optimizing Post CMP Clean to Control Cu Dissolution

The continuous decrease of the effective dielectric constant of the dielectric stack forces Cu-CMP to either directly polish the low-k films or completely remove a higher-k protective cap layer on top of it. The exposure of hydrophobic low-k films to post CMP clean elicits the formation of watermarks on the inhomogeneous wetted patterned surface. In this study, we first confirm the benefit of IPA dryer vs. conventional spin dryer but also in improving the passivity of the Cu surface before the final water rinse by clean chemicals. The improvement in Cu passivity is correlated with lower Cu contamination on the dielectric surface.

Alkaline cleaning of PES membranes used in skimmed milk ultrafiltration: from reactor to spiral-wound module via a plate-and-frame module

This paper deals with an in-depth study of the physicochemistry of PES membrane cleaning when the membrane was fouled by skimmed milk ultrafiltration. The main target of the cleaning was protein removal from the active layer of the PES membrane as irreversible fouling was likely due to pore entrance blocking. Alkaline cleaning was restricted to pH and temperature that can be further used at industrial scale with a spiral membrane (pH 11.5–12.0, T = 50°C), limitations due to glue and seals but not to PES itself. By cleaning UF-fouled membranes in a stirred reactor, it was shown that an efficient cleaning solution might have an interfacial energy close to γL = 25 mJ m−2 and be mainly non-polar. Comparisons of the cleaning efficiency obtained in the stirred reactor on a plate-and frame-pilot and on a spiral-wound pilot were made for various UF conditions, and the same conclusions can be drawn. However, cleaning under UF conditions also highlighted the limiting role of hydrodynamic conditions (pressure, velocity) on cleaning efficiency. In spiral geometry, the final water rinse appeared crucial and needs further optimisation, as it is time and water consuming. This study underlines the need of an approach combining physicochemistry and hydrodynamics for the optimisation of the entire cleaning step.

Effect of adsorption of polyoxyethylene laurylether on electrodeposition of Pb-free Sn alloys

Three plating baths (Sn–Cu, Sn–Bi and Sn–Ag–Cu) containing a polyoxyethylene laurylether (POELE) additive were developed as Pb-free solder plating solutions. The addition of POELE afforded a smooth, homogeneous alloy upon deposition. A mechanism for the effect of POELE in the electrodeposition process is proposed in which POELE adsorbs on deposited Sn surfaces, suppressing subsequent deposition during electrolysis. The POELE remains on the surface of the deposited Sn as the plating layer grows, and is efficiently removed in the final water rinse.

Alkyltrichlorosilane-based self-assembled monolayer films for stiction reduction in silicon micromachines

We have investigated the potential of self-assembled monolayer (SAM) coatings for the purpose of adhesion reduction in microelectromechanical systems (MEMS). Two types of SAM coatings, derived from the precursor molecules octadecyltrichlorosilane [CH/sub 3/(CH/sub 2/)/sub 17/SiCl/sub 3/, OTS] and 1H,1H,2H,2H-perfluorodecyltrichlorosilane [CF/sub 3/(CF/sub 2/)/sub 7/(CH/sub 2/)/sub 2/SiCl/sub 3/, FDTS], were applied to polycrystalline silicon microstructures in a liquid-based process. Due to the hydrophobicity of these coatings, the water capillary forces responsible for the phenomenon known as release-related stiction are eliminated, and SAM-coated cantilever beams 2 /spl mu/m thick, 2 /spl mu/m above the substrate, and up to 2 mm in length emerge dry and free standing when removed from the final water rinse. The effects of SAM coating on adhesion encountered during device operation, termed in-use stiction, were characterized using arrays of cantilever beams of varying lengths. Structures made with a polycrystalline silicon of 3-nm rms roughness gave apparent works of adhesion of 30 and 8 /spl mu/J/m/sup 2/ for the OTS and FDTS SAM coatings, respectively, in comparison to 56 mJ/m/sup 2/ for standard oxide-coated structures. These results demonstrate that OTS coating reduces adhesion by more than three orders of magnitude over the conventional process and that the fluorinated SAM can lessen it further by four times. With regard to thermal stability, both SAM coatings can withstand heat treatment for 5 min at 450/spl deg/C in an N/sub 2/ ambient. In air, the OTS film begins to degrade at 150/spl deg/C while the fluorinated coating remains intact up to 400/spl deg/C. Therefore, both types of SAM coatings are compatible with several MEMS packaging techniques, with the FDTS monolayers exhibiting superior stiction and thermal stability properties to those derived from OTS. Furthermore, the FDTS formation does not require any chlorinated solvents such as carbon tetrachloride, which has been banned from industrial use, making the latter coating an industrially viable antistiction treatment.

Bacteriological Control of Food Equipment Surfaces by Cleaning Systems. II. Sanitizer Effects

A cleaning simulator was used to determine the changes in soil and bacterial numbers on stainless steel surfaces over 30 12-h soiling and washing cycles with four cleaning systems. The soiling milk was inoculated with 5 × 105Streptococcus faecalis and 5 × 105Enterobacter aerogenes organisms/ml. One system included a pre-milk rinse of water (20 C), soiling milk (30 C), wash with alkaline detergent (50 C) and two rinses with water (20 C). In the second system, an iodophor sanitizer (25 mg available iodine/L, 20 C) was substituted for the pre-milk water rinse, and in the third the iodophor was substituted for the final water rinse. In the fourth system, the iodophor was applied instead of the final water rinse, but was left for the 9.5-h intercycle period and drained immediately before the next milk soiling. Results showed that the sanitizer can be an important and, under some conditions, the most effective system component in controlling the bacterial population on surfaces. Of the short contact-time sanitizer applications, the post-wash sanitizer was more effective in reducing the bacterial count than the pre-milk sanitizer, but application of the sanitizer for the complete intercycle period completely eliminated all viable bacteria and was thus far more effective than either of the short contact-time methods. It was also shown that the sanitizer can play an important role in the detergency of the system. The organisms studied (S. faecalis and E. aerogenes) differed in their soiling characteristics and survival in intercycle conditions.

Bacteriological Control of Food Equipment Surfaces by Cleaning Systems. I. Detergent Effects

A cleaning simulator was used to determine the changes in soil and bacterial numbers on stainless steel surfaces over 36 soiling and washing cycles (each of 12 h) with four cleaning systems. The soiling milk contained 106Streptococcus faecalis colony forming units/ml. One system included a pre-milk iodophor rinse (20 C), milk soil (30 C), post-milk water rinse (20 C), alkaline detergent (50 C) and a final water rinse (20 C). The second system was similar, but without the final rinse. In the third system, the post-milk rinse was omitted. The fourth system was similar to the second, except that water at 20 C was substituted for the detergent. The simulator technique proved effective for determining changes in soil and bacterial numbers on surfaces over time. The detergent was the most important system component for controlling bacterial numbers, with the sanitizer contributing some control and the rinses very little. The numbers of S. faecalis on the surfaces were related to the amount of surface soil (detergent efficiency), and also to the inhibitory effect of solutions used before the intercycle rest period of 9.5 h between washing and the next soiling. S. faecalis did not grow during the intercycle period of 9.5 h at 30 C and a relative humidity of 80%, even on surfaces where a significant milk soil was present.