Air Bubble Technique Research Articles

Prevention of Argentinian flag sign in intumescent cataracts using anterior chamber air bubble and cortical fluid release techniques

BackgroundTo investigate the efficiency of a new method for the prevention of argentinian flag sign during the process of continuous, circular, and centered anterior capsulotomy (CCC) on the anterior capsule in cortically liquefied intumescent cataracts. This study was registered in an appropriate registry and the registration number of registration was xyy11[2022]-XJSFX-087; The date of of registration was 2022-04-29.MethodsPreoperative examinations including slit-lamp examination, ocular A-scan ultrasonography, and Ultrasound Biomicroscopy (UBM) UBM were conducted on 61 patients with intumescent cataracts. Cases with cortically liquefied intumescent cataracts were selected and after staining with indocyanine green, the anterior chamber air bubble technique was used to compress the anterior capsule, and liquefied cortex was aspirated using a puncture needle. Corrected Distance Visual Acuity (CDVA) and intraocular pressure were recorded on postoperative days 1, 1 week, 1 month, and 6 months. Intraoperative and postoperative complications were documented and analyzed.ResultsFifty eyes were identified as having cortically liquefied intumescent cataracts. No cases of the Argentinian flag sign occurred, and standard capsulorrhexis was achieved, facilitating smooth phacoemulsification. All patients achieved satisfactory outcomes at follow-ups of 1 day, 1 week, 1 month, and 6 months postoperatively. Mild corneal edema was observed in three cases on the first postoperative day, with no other complications noted.ConclusionsThe anterior chamber air bubble technique combined with cortical fluid release technique can prevent the occurrence of the Argentinian flag sign in cortically liquefied intumescent cataracts, this method is simple, convenient and economic for the clinical promotion.

The Role of Hysteroscopy in the Assessment of Fallopian Tubal Patency: A Comprehensive Review and Meta-analysis.

Hysteroscopy has been recognized as a reliable method for the evaluation of female infertility for several years. The outpatient setting is particularly convenient, as patients do not require general anesthesia and do not have to stay overnight. In recent years, more and more articles have dealt with the role of diagnostic hysteroscopy in tubal evaluation. Twenty-four articles were included in this comprehensive review and 14 of them were also included in a meta-analysis. This review provides an overview of the different techniques of hysteroscopic tubal evaluation, with a focus on perioperative changes in cul-de-sac volume, the air bubble technique ("Parryscope" technique), the Flow technique and selective hysteroscopic pertubation with methylene blue dye (SHPMBD). In pooled analyses, SHPMBD achieved the highest sensitivity for tubal patency (91.7%, 95% confidence interval, CI: 88.8-94.0), whereas the air bubble technique revealed the highest specificity of all methods (98.4, 95% CI: 95.3-99.6). Furthermore, in a meta-analysis of all methods on the assessment of single tubes, an overall sensitivity of 87.1% and an overall specificity of 79.8% (95% CI: 76.4-82.9) could be shown. In conclusion, the techniques of hysteroscopic tubal evaluation are well-tolerated, clinically relevant, and reliable.

Clinical outcomes of management of posterior capsule rupture with air bubble techniques.

To introduce a new surgical technique, air-bubble technique for the management of posterior capsule rupture (PCR) and to evaluate the safety and efficacy of the technique. A retrospective case series analysis of 24 eyes of 24 patients, in which the air bubble technique was used for the management of PCR, was performed. Once PCR occurred, a dispersive ophthalmic viscosurgical device (OVD) was injected into the tear. And small volumes (0.2-0.3 mL) of air bubbles were injected beneath the OVD. The air bubble served as a physical barrier and supported the posterior capsule. After surgery, none of the patients had serious complications during the follow-up period of 1y. Extension of the PCR size occurred in only 2 cases, and additional OVD injection was required only in 3 cases. Air bubbles imparted great stability to the nuclear pieces and the posterior capsule. The air-bubble technique may be considered a safe and effective procedure for managing a PCR. It may be of value to the inexperienced cataract surgeon.

Modified deep anterior lamellar dissection for corneal opacity during vitrectomy: case reports

BackgroundTo introduce a modified deep anterior lamellar dissection technique to improve visibility during surgery for vitreoretinal diseases with coexisting corneal opacity.Case presentationTwo patients with retinal detachment and coexisting corneal blood staining or corneal decompensation underwent modified deep anterior lamellar dissections followed by vitrectomy. The modified deep anterior lamellar dissection techniques, unlike the dissection and removal of corneal lamellar in a typical deep anterior lamellar keratoplasty, included the creation and preservation of a deep lamellar corneal flap, the retroillumination to visualize and easily remove the remaining opaque stroma on the Descemet membrane, and the big air bubble technique in the eye with endothelial decompensation. The patient’s own cornea flap was sutured back after vitrectomy was done. The modified dissection techniques provided adequate fundus view during vitrectomy while removing as less corneal tissue as possible and decreasing the surgical complications and the requirement of a fresh cornea. Postoperatively, in case 1, the corneal blood staining was gradually absorbed and the vision improved from light perception to counting fingers. In case 2, even though the cornea remained cloudy and the vision was poor, the cornea endothelial decompensation was stable and asymptomatic. Both retinas were attached after silicone oil removal at 6-month follow-up.ConclusionsThis modified and limited deep anterior lamellar corneal dissection procedure appears to be a useful alternative to penetrating keratoplasty, ophthalmic endoscope and temporary keratoprosthesis during the vitrectomy with coexisting corneal opacity.

Amphiphilic hydrolyzable polydimethylsiloxane-b-poly(ethyleneglycol methacrylate-co-trialkylsilyl methacrylate) block copolymers for marine coatings. II. Antifouling laboratory tests and field trials

Poly(dimethylsiloxane) (PDMS) elastomer coatings containing an amphiphilic hydrolyzable diblock copolymer additive were prepared and their potential as marine antifouling and antiadhesion materials was tested. The block copolymer additive consisted of a PDMS first block and a random poly(trialkylsilyl methacrylate (TRSiMA, R = butyl, isopropyl)-co-poly(ethyleneglycol) methacrylate (PEGMA) copolymer second block. PDMS-b-TRSiMA block copolymer additives without PEGMA units were also used as additives. The amphiphilic character of the coating surface was assessed in water using the captive air bubble technique for measurements of static and dynamic contact angles. The attachment of macro- and microorganisms on the coatings was evaluated by field tests and by performing adhesion tests to the barnacle Amphibalanus amphitrite and the green alga Ulva rigida. All the additive-based PDMS coatings showed better antiadhesion properties to A. amphitrite larvae than to U. rigida spores. Field tests provided meaningful information on the antifouling and fouling release activity of coatings over an immersion period of 23 months.

Closed-Chamber Anterior Capsulorhexis Under Air Tamponade In White Cataract.

PurposeTo evaluate the efficacy and safety of a closed-chamber air bubble capsulotomy technique to prevent the Argentinean flag sign (AFS) in patients with white and intumescent cataracts.SettingSohag University, Faculty of Medicine, Ophthalmology Department, Sohag, Egypt.DesignProspective interventional noncomparative case series.MethodsEighty-two eyes of 80 patients with white and intumescent cataracts were included. Eyes with any ocular pathology other than cataract or eyes subjected to previous intraocular surgery were excluded. Needle capsulorhexis was performed under a large air bubble tamponade without capsular staining. Efficacy of the technique was assessed intraoperatively by successful completion of capsulorhexis. Safety of the technique was assessed by the occurrence of intraoperative or postoperative complications.ResultsComplete capsulorhexis by the closed-chamber air bubble technique was successful in 75 eyes (91.5%), while capsulorhexis extension occurred in seven eyes. In four eyes with extension, the procedure was shifted to the standard technique of CCC (circular curvilinear capsulorhexis), using a viscoelastic device. A shift to extracapsular cataract extraction (ECCE) surgery occurred in the remaining three eyes, as the extension was so far-gone. No intraoperative or postoperative complications were observed.ConclusionThe closed anterior chamber air bubble technique for capsulorhexis is a novel, safe, and effective technique to prevent AFS in white and intumescent cataracts. It is also time-saving and cost-effective, with less likelihood of capsulorhexis extension. The technique is considered a valuable addition to previously described techniques.

CFD simulation of an oil-water skimmer tank

Water recovery from oil wells is an environmental necessity. In order to achieve this goal, an air bubble technique is used to separate water from oil. This technique is being developed for usage in oil fields, and computational fluid dynamic (CFD) simulation is helping to improve the cleaning efficiency of the process. In this paper, the separation of an oil-water mixture using an air bubble stream in an open tank, skimmer tank, is implemented. The simulation was performed using commercial computational fluid dynamics software, CFD, Star CCM®. The separation of liquid mixtures with different densities is performed in this equipment using flotation along with drag forces created by fine air bubbles. The models required to simulate the process were deeply researched to secure the quality and the accuracy of the solution while making sure the time required for solution was manageable. The results show that 100-micron air bubbles are able to efficiently separate oil from water, reducing the time required for the process as long as the bubbles do not coalesce. The oil concentration at the over flow is close to 70%, and 0.5 litres of water per kilogram of oil are required in the cleaning process. [Received: May 22, 2016; Accepted: January 28, 2017]

CFD simulation of an oil-water skimmer tank

Water recovery from oil wells is an environmental necessity. In order to achieve this goal, an air bubble technique is used to separate water from oil. This technique is being developed for usage in oil fields, and computational fluid dynamic (CFD) simulation is helping to improve the cleaning efficiency of the process. In this paper, the separation of an oil-water mixture using an air bubble stream in an open tank, skimmer tank, is implemented. The simulation was performed using commercial computational fluid dynamics software, CFD, Star CCM®. The separation of liquid mixtures with different densities is performed in this equipment using flotation along with drag forces created by fine air bubbles. The models required to simulate the process were deeply researched to secure the quality and the accuracy of the solution while making sure the time required for solution was manageable. The results show that 100-micron air bubbles are able to efficiently separate oil from water, reducing the time required for the process as long as the bubbles do not coalesce. The oil concentration at the over flow is close to 70%, and 0.5 litres of water per kilogram of oil are required in the cleaning process. [Received: May 22, 2016; Accepted: January 28, 2017]

Air Bubble Technique for Fundus Visualization during Vitrectomy in Aphakia.

Purpose To evaluate the efficacy and safety of air bubble technique for vitrectomy in aphakia. Study Design Prospective interventional uncontrolled case series. Methods This study included 53 eyes of 53 patients who are phakic and indicated for phacovitrectomy (7 eyes, group 1), aphakic and indicated for vitrectomy (22 eyes, group 2), or underwent unplanned vitrectomy for immediate management of a phacoemulsification surgery complicated by rupture posterior capsule with dropped nucleus, fragments, or IOL (24 eyes, group 3). Cases with complicated vitreoretinal pathology were not included in this study. All vitrectomy surgeries were conducted by the air bubble technique in the anterior chamber. Main outcomes included anatomical success, visual acuity, and intraoperative and postoperative complications. Results The surgical success was achieved in 50 eyes (94.3%). Conversion to BIOM viewing system was needed in the retinal detachment cases of groups 1 and 2. The mean overall LogMAR visual acuity was significantly improved from 1.29 ± 0.58 preoperatively to 0.56 ± 0.19 at the final visit, 6 months postoperatively (P < 0.001). Conclusion The air bubble technique as visualization method for vitrectomy in aphakia is an effective and cheap technique for immediate management of complications of phacoemulsification surgery. This trial is registered with Pan African Clinical Trial Registry PACTR201709002466296.

Comparing Pain of the First-generation Long-Acting Antipsychotic Injections among Three Different IM Techniques

Aim and objectives: To determine the optimal technique to prevent leakage and pain from LAIs, the study compared three types of intramuscular injection techniques: (a) Airbubble technique, (b) Z-track method, and (c) a combination of the air-bubble technique and Z-track method. Background: Long-acting antipsychotic injections (LAIs) are often injected through the muscle, allowing the medication to be slowly absorbed through it. Past literature yields inconclusive results in how to minimize the leakage and pain experienced at the injection site. Design: This experimental study had a within-subjects design. Methods: A total of 144 patients who received the firstgeneration LAIs were purposively sampled from a psychiatry hospital. All participants experienced the three types of injection methods over a 3-month period. They were all asked to rate their level of pain using the numerical rating scale, and after each injection, medical personnel rated the level of medication leakage at the injection site. Results: No significant differences were found in the leakage level between the air-bubble technique, Z-track method, and the combination of the two (F=0.53, p>0.05). Pain level also showed no significant difference between the three types of injection methods during pre-injection (F=0.68 p>.05), 5 minutes post-injection (F=0.87, p>0.05), and 30 minutes post-injection (F=0.97, p>0.05). Conclusion: During the injection of long-acting antipsychotic medication, we suggest consulting the guidance of a clinical injection expert. Choosing an injection method that is most familiar to the nursing staff would allow the minimization of medication leakage and pain at the injection site. Relevance to clinical practice: Nurses should make sure the guidance of a clinical injection expert and verify knowledge of the IM injection skill. Choosing correct injection site and process that can effectively experience of pain and leakage at the injection site.

A brief review on frictional pressure drop reduction studies for laminar and turbulent flow in helically coiled tubes

This review, summarises the pertinent literature on drag reduction (DR) in laminar and turbulent flow in coiled tubes. Due to their compact design, ease of manufacture and superior fluid mixing properties, helically coiled tubes are widely used in numerous industries. However, flow through coiled tubes yields enhanced frictional pressure drops and thus, drag reduction is desirable as it can: decrease the system energy consumption, increase the flow rate and reduce the pipe and pump size. The main findings and correlations for the friction factor are summarised for drag reduction with the: injection of air bubbles and addition of surfactant and polymer additives. The purpose of this study is to provide researchers in academia and industry with a concise and practical summary of the relevant correlations and supporting theory for the calculation of the frictional pressure drop with drag reducing additives in coiled tubes. A significant scope for future research has also been identified in the fields of: air bubble and polymer drag reduction techniques.

Subcutaneous Administration of Bortezomib: A Pilot Survey of Oncology Nurses.

Subcutaneous (SC) administration of the proteasome inhibitor bortezomib was approved in the United States and European Union in 2012. There is limited guidance regarding how to administer SC bortezomib and a general lack of clear direction on optimal techniques for administering SC chemotherapy injections. Nurses may be utilizing different techniques, and inconsistent techniques may result in injection-site reactions, causing patient discomfort and treatment cessatioin. This observational survey of oncology nurses in community oncology clinics aimed to identify techniques being used and explore nurses' opinions about SC bortezomib administration. A 44-question electronic survey was developed, based on the current literature regarding appropriate techniques for administering SC injections. A total of 43 nurses from 17 clinics in 12 states responded. The majority (74%) had been practicing oncology nursing for at more than 5 years. Respondents predominantly used and preferred the abdomen for injections (88%); 81% used a skin lift to ensure injection into adipose tissue. There was no relationship between the angle of insertion and the needle length; 51% used an air-bubble technique. Nurses took 3-5 (49%), 5-10 (35%), 10-30 (9%), or > 30 (7%) seconds to administer each mL of SC bortezomib injection. All nurses completely/somewhat agreed that practice guidelines would be important for standardizing SC bortezomib administration. Advanced practice registered nurses (APRNs) shared the responsibility for ordering SC bortezomib, according to 53% of respondents. These findings could help APRNs improve the quality of patient care, may help minimize adverse events and maximize effective therapy, and could help inform the development of practice guidelines.

Preparation, preservation, and morphological evaluation of the donor graft for descemet membrane endothelial keratoplasty: an experimental study

Background Though there have been various methods for harvesting and preserving descemet membrane (DM) and intact endothelium, there is no literature about the morphological evaluation of endothelium after graft preparation for descemet membrane endothelial keratoplasty (DMEK). The aim of this study was to establish and improve a simple method for preparing, preserving, and morphologically evaluating the donor graft for DMEK. Methods To obtain a donor graft, an air bubble was formed by injecting a 29 G needle with 1 ml sterile air into a small edge created outside the Schwalbe line. Another needle was inserted into the bubble through the stroma to aspirate the air or replace half the air with organ culture medium. Trypan blue was used to mark the location for small incision to improve the success rate. Frozen sections were stained with hematoxylin and eosin (HE). Based on the air bubble, DM grafts were divided into four groups: group A (normal control), graft without any operative technique; group B, graft with zero-pressure air bubble; group C, graft with full-pressure air bubble; group D, graft with half-pressure air bubble. The four groups of grafts were preserved for 24 hours to observe the effect of bubbles on cells. The gross and ultrastructure morphologies were evaluated using alizarin red and scanning electron microscopy (SEM), respectively. Results Donor grafts were harvested via the air bubble technique, facilitated by prior trypan blue staining. HE-stained sections revealed a pure graft without stroma. There were no significant changes under light microscope. In group A, SEM revealed a confluent layer of polygonal endothelium with distributed microvilli exhibiting characteristics of interdigitating junctions. In group B, intercellular borders became thinner. In group C, interdigitations were almost flat and microvilli were observed less frequently. In group D, other than less microvilli, there were minimal changes. Conclusions The donor graft preparation method appears to be effective and convenient. Properly decreasing the air pressure could protect and preserve the endothelium.

Subcutaneous (SC) Administration Of Bortezomib: A Pilot Survey Of Oncology Nurses

BackgroundThe SC route of administration for bortezomib was approved in the USA in January 2012 and the EU in September 2012, in addition to the intravenous (IV) route. Although there is limited guidance in the US Prescribing Information and EU SmPC regarding how to administer SC bortezomib, more broadly there is a lack of clear direction in the literature on administering SC injections. Studies in non-oncology fields suggest that injection site reactions, pain, and bruising can be reduced by using small, short needles, the air bubble rather than purge technique, and slower injections. Inconsistent or poor administration techniques may increase injection site reactions and could contribute to patients stopping effective treatment. Thus, it is important to identify how oncology nurses are administering SC bortezomib. This observational survey of oncology nurses practicing in US community oncology clinics (Cancer Clinics of Excellence) aimed to identify the techniques used and explore nurses' opinions about SC bortezomib administration. MethodsA 41-question electronic survey on SC bortezomib administration was developed, with all questions based on current literature regarding appropriate techniques for administering SC injections. The questions explored site of administration, needle length, angle of insertion, use of air purge or bubble technique, and duration of administration. Questions were also included regarding convenience of SC administration, nurses' opinions on patients' preferences for administration site, and correlation between facility layout and administration site. Nurses at 19 clinics who had administered SC bortezomib were invited to participate in the survey, with limitations imposed on respondent numbers to ensure country-wide input. ResultsA total of 43 nurses from 17 clinics responded to the survey. The majority (74%) had been practicing oncology nursing for >5 years, including 21% for >20 years. Most respondents (93%) indicated that oncologists were responsible for ordering bortezomib for SC administration. Nurse practitioners shared this responsibility according to 53% of respondents. 60% of nurses indicated that they always/sometimes provided input into the decision to use SC administration, with 40% always/sometimes responsible for bortezomib reconstitution. Nurses reported using the abdomen (98%), thigh (19%), and arm (53%) for SC bortezomib. Only the abdomen and thigh were used in the phase 3 study of SC vs IV bortezomib (Moreau et al, Lancet Oncol 2011). The abdomen (88%) and arm (12%) were nurses' preferred sites due to presence of more tissue, ease of access, less irritation, and patient preference. Nurses believed that patients preferred SC injections in the abdomen (72%) and arm (28%). Nurses' injection site preferences differed significantly according to facility layout. All respondents indicated a preference for abdominal injection in private/somewhat private facilities, while the abdomen (76%) and arm (24%) were preferred in non-private facilities (p=0.02). Nurses used 25 gauge 5/8 inch (42%) and 27–30 gauge ≤1/2 inch (56%) needles, with both 45º (61%, 42%) and 90º (39%, 58%) angles of insertion used with these respective needle sizes (p=0.21). The air purge technique was used by 49% of nurses, with 51% using an air bubble. Nurses took 3–5 (49%), 5–10 (35%), 10–30 (9%), and >30 seconds (7%) to administer each mL of SC bortezomib injection. All but 1 nurse (98%) indicated that SC administration was much more or somewhat more convenient than IV, with 95% indicating that SC administration took much less or somewhat less time than IV. Most nurses (86%) believed that patients preferred the SC route for reasons including less time spent at clinic, avoidance of IV access, and less toxicity. All nurses completely agreed (77%) or somewhat agreed (23%) that developing a practice guideline would be important, and all but 1 completely agreed (67%) or somewhat agreed (30%) that nurses would change their practice to be consistent with such a guideline. ConclusionsThese findings indicate the heterogeneity of techniques used for SC bortezomib administration, and will help inform the development of practice guidelines with the aim of achieving greater consistency among oncology nurses. Disclosures:Martin:ONS: Edge: Membership on an entity's Board of Directors or advisory committees; Millennium: The Takeda Oncology Company: Employment. Zhu:Millennium: The Takeda Oncology Company: Employment. Agretelis:Millennium: The Takeda Oncology Company: Employment; Takeda Pharmaceutical Company Limited: Equity Ownership.

Unintentional staining of the posterior lens capsule with trypan blue dye during phacoemulsification: case report

We report a complication related to the use of trypan blue during capsular staining of the anterior lens capsule during phacoemulsification surgery. In phacoemulsification surgery of the left eye, trypan blue was injected using an air bubble technique. Unintentionally, trypan blue was administered under high pressure, dispersing the dye through the zonules leading to staining of the posterior capsule. This caused a temporary disturbance of visual acuity during the postoperative period.

Amphiphilic block copolymer surface composition: Effects of spin coating versus spray coating

Spray coating is demonstrated to produce different surface compositions of block copolymer films than spin coating even after annealing above the glass transition temperatures of both blocks. An amphiphilic block copolymer derived by chemically modifying the polyisoprene block of a polystyrene-block-poly(ethylene-ran-butylene)-block-polyisoprene precursor with different molar ratios of 550 g/mol poly(ethylene glycol) monomethyl ether and a semifluorinated alcohol, 10-Perfluorodecyl-1-decanol, is used as a model system to investigate the effect. X-ray photoelectron spectroscopy demonstrated significantly higher amounts of CF2 and CF3 carbons at the surface for spray coated films while the overall concentration of C–O bonded carbons did not change. Near edge X-ray absorption fine structure spectroscopy shows a larger C1s → σC−F∗ transition partial electron yield peak for the spray coated films and a negligible amount of polystyrene populating the surface for both solution deposition techniques. Water contact angles measured by the captive air bubble technique are found to be higher for the spray coated samples upon immersion in water. Scanning force microscopy also shows significant differences in the surface morphology of both films. These results indicate that it should not be assumed that the surface composition of a spin coated polymer film is representative of the same polymer deposited by spray coating.

The air bubble technique for confirming the location of an image-guided biopsy – a technical note

We describe a technique for accurate localisation of the biopsy-site following image-guided biopsy of an intracranial lesion. The injection of 0.1 ml of air through the biopsy needle, allows the exact location of the biopsy to be visualised on post-operative CT scans performed within 24 hours of the procedure. Knowledge of the location of the biopsy can be useful in resolving ambiguous histological findings and the possibility of sampling error. Injection of 0.1 ml air is a safe and effective method for verifying the location of intracranial biopsies and is recommended as a routine part of image-guided biopsy procedures.

Impregnação inadvertida da cápsula posterior do cristalino com azul de tripano durante a facectomia extracapsular: relato de caso

Report of a complication related to the use of 0.1% trypan blue during capsular staining of the anterior crystalline lens capsule in an extracapsular cataract extraction with intraocular lens implantation. The capsular dye was injected using an air-bubble technique, inadvertently, it was done using high pressure dispersing the dye through the zonules leading to a complete lost of red reflex, the following steps of the procedure becoming more difficult after the cataract extraction and causing a temporary disturbance of visual acuity in the postoperative period. In order to avoid this complication, the authors also describe the use of "Modified air-bubble technique" where dispersive viscoelastic is placed into the iridolenticular space 360 degrees to create a protection barrier.

Determining the lowest trypan blue concentration that satisfactorily stains the anterior capsule

Purpose: To determine the lowest concentration of trypan blue that will stain the anterior capsule satisfactorily to perform a safe continuous curvilinear capsulorhexis and to describe a staining technique using a dispersive viscoelastic material. Setting: Cerrahpasa School of Medicine, University of Istanbul, Istanbul, Turkey. Methods: Trypan blue 0.1% (Vision Blue®) was diluted by half by adding an equal volume of balanced salt solution (BSS®) in a stepwise pattern continuously until the concentration failed to stain the anterior capsule satisfactorily. After the dilution, 4 concentrations of the dye were obtained: 0.050%, 0.025%, 0.0125%, and 0.00625%. The volume of dye used for staining was 0.1 cc at all concentrations. Each concentration of the dye was applied using a classic air-bubble technique or a technique in which the dye was injected under sodium hyaluronate 3.0%-chondroitin sulfate 4.0% (Viscoat®) onto the anterior lens surface without using an air bubble to reform the anterior chamber. Each diluted concentration was used in 10 eyes by the same surgeon, with 5 eyes having the air-bubble technique and 5 having the viscoelastic technique. The 0.1% concentration was used in 5 eyes, all having the viscoelastic technique. Results: Trypan blue in concentrations as low as 0.0125% stained the anterior capsule satisfactorily. In addition, staining was possible under the Viscoat. The viscoelastic technique was faster, safer, and easier to perform than the air-bubble technique. Conclusions: As trypan blue is a potentially carcinogenic vital dye and its possible long-term side effects are unknown, the lowest effective concentration should be used. A concentration lower than 0.1% was effective in staining the anterior capsule even under dispersive viscoelastic material.

Photoinduced grafting of ultrafiltration membranes: comparison of poly(ether sulfone) and poly(sulfone)

Using UV-assisted graft polymerization of three hydrophilic monomers, N-vinyl-2-pyrrolidinone (NVP), 2-acrylamidoglycolic acid monohydrate (AAG) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AAP), both poly(ether sulfone) (PES) and poly(sulfone) (PSf) 50 kDa ultrafiltration (UF) membranes were modified using the dip method with 300 nm wavelength lamps. The concentration of monomer and irradiation energy supplied to the membranes was varied. The modified membranes were characterized physicochemically by their degree of grafting using attenuated total reflection-Fourier transform infrared spectra (ATR-FTIR) and by their wettability using a captive air bubble technique. They were also characterized by their filtration performance with a 0.1 wt.% bovine serum albumin (BSA) solution in phosphate buffered saline (PBS) at 20±2°C and at pH 7.4. The filtration protocol gave several measures of performance including the initial water permeability, the protein solution permeability and the water permeability after flushing with DI water. Four different modification conditions were found that gave modified UF membranes with superior filtration performance than the base unmodified PES, the base unmodified PSf, or a regenerated cellulose (RC) control membrane. Slightly compromised protein solution permeabilities were compensated for with low fouling modified membranes that exhibited excellent cleaning characteristics. All the best cases were at the highest monomer concentrations (5 wt.%) and lowest irradiation energy (<65 mJ/cm 2 for PES and <130 mJ/cm 2 for PSf). This work also suggests that low degrees of grafting (DG<0.53) and intermediate wettabilities ( 0.74< cos θ<0.82 ) were sufficient to obtain attractive non-fouling membranes. Since BSA is strongly negatively charged at pH 7.4, it is not surprising that AAP was the monomer that exhibited best performance for two of the four best cases. An important finding was that PES is far more sensitive to UV-assisted graft polymerization and, thus, requires far less energy to attain a desired degree of grafting than PSf.