Seconds Of Contact Research Articles

Inactivation kinetics of benzalkonium chloride and ethanol-based hand sanitizers against a betacoronavirus and an alphacoronavirus

Hand hygiene is critical to lower the potential for the spread of SARS-CoV-2 and other infectious agents by direct contact. When running water and soap are not available for hand hygiene, ethanol-based hand sanitizers are currently the recommended standard of care [1-3]. Though recently published data showed comparable invitro effectiveness of benzalkonium chloride (BAK)-based and ethanol-based hand sanitizers against SARS-CoV-2 virus, a paucity of peer-reviewed data on the effectiveness of these formulations against other types of infective coronaviruses remains. This work assessed human coronavirus HCoV-229E (genus Alphacoronavirus) concurrently with SARS-CoV-2, Isolate USA-WA1/2020 (genus Betacoronavirus) to fill this gap. The test was conducted according to EN14476:2013-A2:2019 [EN14476] Quantitative Suspension Test for the Evaluation of Virucidal Activity in the Medical Area [4]. Two BAK-based hand sanitizers, five ethanol-based hand sanitizers, and an 80% ethanol reference formulation were tested for antiviral activity against SARS-CoV-2 and HCoV-229E at 15- and 30- second contact times. Both SARS-CoV-2 and HCoV-229E were reduced by greater than 4.00-log10 within 15 seconds of contact. Virus decay constants (k) following first-order kinetics were similar for BAK and ethanol-based formulations against both test viruses. The SARS-CoV-2 results reported herein mirrored previous data reported by Herdt etal. (2021). BAK and ethanol hand sanitizer formulations inactivate SARS-CoV-2 and HCoV-229E at similar rates. This data supports previously published effectiveness data for both chemistries and indicates that additional coronavirus strains and variants would demonstrate similar inactivation trends.

Biomechanics of a Plant-Derived Sealant for Corneal Injuries.

The corneal epithelium has a glycocalyx composed of membrane-associated glycoproteins, mucins, and galactin-3. Similar to the glycocalyx in visceral tissues, the corneal glycocalyx functions to limit fluid loss and minimize frictional forces. Recently, the plant-derived heteropolysaccharide pectin has been shown to physically entangle with the visceral organ glycocalyx. The ability of pectin to entangle with the corneal epithelium is unknown. To explore the potential role of pectin as a corneal bioadhesive, we assessed the adhesive characteristics of pectin films in a bovine globe model. Pectin film was flexible, translucent, and low profile (80 µm thick). Molded in tape form, pectin films were significantly more adherent to the bovine cornea than control biopolymers of nanocellulose fibers, sodium hyaluronate, and carboxymethyl cellulose (P < 0.05). Adhesion strength was near maximal within seconds of contact. Compatible with wound closure under tension, the relative adhesion strength was greatest at a peel angle less than 45 degrees. The corneal incisions sealed with pectin film were resistant to anterior chamber pressure fluctuations ranging from negative 51.3 ± 8.9 mm Hg to positive 214 ± 68.6 mm Hg. Consistent with these findings, scanning electron microscopy demonstrated a low-profile film densely adherent to the bovine cornea. Finally, the adhesion of the pectin films facilitated the en face harvest of the corneal epithelium without physical dissection or enzymatic digestion. We conclude that pectin films strongly adhere to the corneal glycocalyx. The plant-derived pectin biopolymer provides potential utility for corneal wound healing as well as targeted drug delivery.

Comparing the antibacterial efficacy and functionality of different commercial alcohol-based sanitizers.

The use of alcohol-based sanitizers has been recommended as an effective alternative to clean hands, especially in the case when hand washing is not doable. This is especially critical with the COVID-19 pandemic, where personal hygiene is an important factor to deter the spread of the virus. This study assesses and evaluates the differences in antibacterial efficacy and functionalities of five different commercial alcohol-based sanitizers with different formulations. All sanitizers were able to provide instant sanitization functionality, effectively killing 5x105 CFU/mL of inoculated bacteria. However, comparing pure alcohol-based sanitizers against alcohol-based sanitizers with a secondary active ingredient demonstrated that the addition of a secondary active ingredient enhanced the effectiveness and functionalities of the sanitizers. Alcohol-based sanitizers with secondary active ingredients demonstrated a more rapid antimicrobial mode of action, eradicating all 106 CFU/mL of bacteria within 15 seconds of contact, in contrast to the 30 min for purely alcohol-based sanitizers. The secondary active ingredient also provided additional anti-biofilm functionality to prevent opportunistic microbes from attaching and proliferating on the treated surface, leading to serious biofilm formation. On top of that, treatment of surfaces with alcohol-based sanitizers with secondary active ingredients also imparted prolonged antimicrobial protection to the surface lasting up to 24 h. On the other hand, purely alcohol-based sanitizers do not seem to possess such quality with the treated surface being vulnerable to microbial contamination within minutes after application. These results highlighted the benefits of adding a secondary active ingredient in sanitizer formulation. However, care needs to be taken to evaluate the type and concentration of antimicrobial agents chosen as the secondary active ingredient.

Multilayer In Vitro Human Skin Tissue Platforms for Quantitative Burn Injury Investigation.

This study presents a multilayer in vitro human skin platform to quantitatively relate predicted spatial time-temperature history with measured tissue injury response. This information is needed to elucidate high-temperature, short-duration burn injury kinetics and enables determination of relevant input parameters for computational models to facilitate treatment planning. Multilayer in vitro skin platforms were constructed using human dermal keratinocytes and fibroblasts embedded in collagen I hydrogels. After three seconds of contact with a 50-100 °C burn tip, ablation, cell death, apoptosis, and HSP70 expression were spatially measured using immunofluorescence confocal microscopy. Finite element modeling was performed using the measured thermal characteristics of skin platforms to determine the temperature distribution within platforms over time. The process coefficients for the Arrhenius thermal injury model describing tissue ablation and cell death were determined such that the predictions calculated from the time-temperature histories fit the experimental burn results. The activation energy for thermal collagen ablation and cell death was found to be significantly lower for short-duration, high-temperature burns than those found for long-duration, low-temperature burns. Analysis of results suggests that different injury mechanisms dominate at higher temperatures, necessitating burn research in the temperature ranges of interest and demonstrating the practicality of the proposed skin platform for this purpose.

SG-APSIC1050: Personal care formulations prove effective against evolving variants of SARS-CoV-2: Implications for public health and hygiene

Objectives: Early in the COVID-19 pandemic, global health authorities identified and emphasized the importance of practicing proper hand hygiene to reduce the transmission of SARS-CoV-2 and to diminish the chances of becoming infected. It is well established in the scientific literature that surfactants and alcohols are capable of inactivating enveloped viruses such as SARS-CoV-2. However, given the novel nature of the virus, Unilever adopted an evidence-based approach to demonstrate virucidal efficacy of marketed bar soaps, liquid handwashes, and alcohol-based hand sanitizers against the original and selected variants of SARS-CoV-2. Methods: High titers of clinically isolated and laboratory-propagated SARS-CoV-2 strains were subjected to a range of selected proprietary formulations from Unilever at end-user–relevant dilutions, temperature, and contact duration, and were tested according to the internationally recognized ASTM E-1052 test protocol. Results: All tested personal-care formulations were effective against the parental SARS-CoV-2 strain as well as the β (beta) and δ (delta) variants of concern. More specifically, bar soaps with a varying concentration of total fatty matter content and liquid handwashes with varying levels of total surfactants reduced the viral titer by &gt;99.9% within 20 seconds. Alcohol-based hand sanitizers demonstrated &gt;99.99% reduction of input viral load within 15 seconds of contact with the viral inoculum. Conclusions: In conclusion, we have provided empirical proof that well-designed personal-care formulations that act through generic physicochemical mechanism against the basic structure of the virus particle have high virucidal efficacy against the original and evolved SARS-CoV-2 variants. Furthermore, we argue that due to the broad-spectrum mode of action of these tested formulations, the continued practice of good hand hygiene practices with everyday products holds significant promise as an easily accessible, economic, and effective nontherapeutic public health intervention toward reducing the transmission of present and future variants of SARS-CoV-2 across communities and populations.

Prevalence and Disinfection of Bacteria Associated with Various Types of Wristbands

The potential role of personal items in the transmission of pathogens is poorly understood. In this study, we cultured bacteria of public health importance found on wristbands, determined whether there is a correlation between wristband material and prevalence, and tested three household disinfectants for efficacy in reducing bacteria on wristbands made of plastic, rubber, metal, and cloth, using standard microbiological assays. Total cultivable bacteria, Staphylococci, Enterobacteria (Escherichia coli), and Pseudomonas on 20 smartwatch wristbands were cultured from randomly recruited subjects. Nearly all wristbands (95%) were contaminated, with the highest average numbers of 3.46E+4 cfu/cm2 and 1.52E+4 cfu/cm2 on rubber and plastic bands respectively. Metallic gold and silver wristbands had zero to 18 cfu/cm2. While the high prevalence of Staphylococcus spp (85% of wristbands)—skin microbiota; was not unexpected, the occurrence of Pseudomonas spp (30%), and enteric bacteria (60%), even at relatively low numbers is of public health significance. Bacterial load on individual subjects varied remarkably with males and females harboring average total bacteria of 4.045 and 3.42 log10cfu/cm2 of wristband, respectively. The most important predictor of wristband bacteria load was the texture of wristband material and activity (hygiene) of the subject at sampling time. Potential pathogens—Staphylococcus aureus (8143 cfu/cm2) and Pseudomonas spp. (1126 cfu/cm2) were most abundant on cloth and rubber wristbands, respectively, while the presence of the E. coli group was associated with animal handling activity by a veterinarian. Lysol Disinfectant Spray and 70% Ethanol were highly effective regardless of wristband material with >99.99% kill rate and a log cfu/cm2 reduction of 3 - 4.0 and 3 - 4.5 respectively within 30 seconds. Apple Cider Vinegar (ACV) was not as potent. Only 2 - 3.5 log cfu/cm2 drop was obtained after 120 seconds of exposure. Further susceptibility assays with standard reference bacteria showed that Lysol and 70% alcohol effectively killed > 99.99% (>8 log CFU drop) of Escherichia coli strain 7001, Staphylococcus aureus strain 6538, and Pseudomonas aeruginosa strain 10662 within 30 seconds of contact. Vinegar had a similar efficacy on the gram negatives but little or no effect on Staph aureus (only a 2-log CFU/ml reduction in 5 minutes!) The high prevalence of potential pathogens, some of which could be reservoirs of antibiotic resistance reveals a weak link in infection control and underscores the need for regular cleaning of personal and hand-held accessories with adequate considerations of their texture.

Highly active nanoparticle enhanced rapid adsorption-killing mechanism to combat multidrug-resistant bacteria.

Contact-killing surfaces with the ability to rapidly adsorb and kill microorganisms are desperately needed since the rapid outbreak of multidrug-resistant (MDR) bacteria poses a serious threat to human health. Therefore, a series of amphiphilic nanoengineered polyquaterniums (ANPQs) were synthesized, and immobilizing ANPQs onto equipment surfaces provided a simple method for preventing microbial infections. The strong charge-positive property of ANPQ offered the possibility of rapid adsorption and efficient killing, such that all bacteria are adsorbed after 10 seconds of contact with ANPQ-treated fabrics, and more than 99.99% of pathogens are killed within 30 seconds. Surprisingly, the adsorption-killing mechanism made it difficult for bacteria to develop resistance to ANPQ coating, even after long-term repeated treatment. Importantly, in a Methicillin-resistant Staphylococcus aureus infection model, ANPQ-treated fabrics exhibited a potent anti-infectious performance while remaining nontoxic. It is envisaged that the strategy of using ANPQ coating undoubtedly provides a promising candidate for fighting MDR strains.

Decarbonisation of calcium carbonate in sodium hydroxide solutions under ambient conditions: effect of residence time and mixing rates.

The decarbonisation of CaCO3 is essential for the production of lime (Ca(OH)2 and CaO), which is a commodity required in several large industries and the main precursor for cement production. CaCO3 is usually decarbonised at high temperatures, generating gaseous CO2 which will require post-process capture to minimise its release into the environment. We have developed a new process that can decarbonise CaCO3 under ambient conditions, while sequestering the CO2 as Na2CO3·H2O or Na2CO3 in the same stage. Here, the effects of increasing stirring rates and residence times on reaction efficiency of the key reaction occurring between CaCO3 and NaOH solution are studied. It is shown that the reaction is enhanced at lower stirring rates and longer residence times up to 300 seconds of contact between the reactants. The mass balance performed for Ca and CO2 revealed that up to the 95% of the process CO2 embodied in CaCO3 was sequestered, with maximum capture rate assessed at nn moles CO2 captured per second of reaction progress. A deeper insight into the precipitation of Na2CO3·H2O or Na2CO3 under different reaction conditions was gained, and SEM-EDX analysis enabled the observation of the reaction front by detection of Na migrating towards inner regions of partially-reacted limestone chalk particles.

In Vitro Efficacy of a Povidone-Iodine Nasal Antiseptic for Rapid Inactivation of SARS-CoV-2

Research is needed to demonstrate the efficacy of nasal povidone-iodine (PVP-I) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To evaluate the in vitro efficacy of PVP-I nasal antiseptic for the inactivation of SARS-CoV-2 at clinically significant contact times of 15 and 30 seconds. The SARS-CoV-2, USA-WA1/2020 strain, virus stock was tested against nasal antiseptic solutions consisting of aqueous PVP-I as the sole active ingredient. Povidone-iodine was tested at diluted concentrations of 0.5%, 1.25%, and 2.5% and compared with controls. The test solutions and virus were incubated at mean (SD) room temperature of 22 (2) °C for time periods of 15 and 30 seconds. This controlled in vitro laboratory research study used 3 different concentrations of study solution and ethanol, 70%, as a positive control on test media infected with SARS-CoV-2. Test media without virus were added to 2 tubes of the compounds to serve as toxicity and neutralization controls. Ethanol, 70%, was tested in parallel as a positive control and water only as a negative control. The primary study outcome measurement was the log reduction value after 15 seconds and 30 seconds of given treatment. Surviving virus from each sample was quantified by standard end point dilution assay, and the log reduction value of each compound was compared with the negative (water) control. Povidone-iodine nasal antiseptics at concentrations (0.5%, 1.25%, and 2.5%) completely inactivated SARS-CoV-2 within 15 seconds of contact as measured by log reduction value of greater than 3 log10 of the 50% cell culture infectious dose of the virus. The ethanol, 70%, positive control did not completely inactivate SARS-CoV-2 after 15 seconds of contact. The nasal antiseptics tested performed better than the standard positive control routinely used for in vitro assessment of anti-SARS-CoV-2 agents at a contact time of 15 seconds. No cytotoxic effects on cells were observed after contact with each of the nasal antiseptics tested. Povidone-iodine nasal antiseptic solutions at concentrations as low as 0.5% rapidly inactivate SARS-CoV-2 at contact times as short as 15 seconds. Intranasal use of PVP-I has demonstrated safety at concentrations of 1.25% and below and may play an adjunctive role in mitigating viral transmission beyond personal protective equipment.

Comparison of In Vitro Inactivation of SARS CoV-2 with Hydrogen Peroxide and Povidone-Iodine Oral Antiseptic Rinses.

PurposeTo evaluate the in vitro inactivation of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) with hydrogen peroxide (H2O2) and povidone‐iodine (PVP‐I) oral antiseptic rinses at clinically recommended concentrations and contact times.Materials and MethodsSARS‐CoV‐2, USA‐WA1/2020 strain virus stock was prepared prior to testing by growing in Vero 76 cells. The culture media for prepared virus stock was minimum essential medium (MEM) with 2% fetal bovine serum (FBS) and 50 µg/mL gentamicin. Test compounds consisting of PVP‐I oral rinse solutions and H2O2 aqueous solutions were mixed directly with the virus solution so that the final concentration was 50% of the test compound and 50% of the virus solution. Thus PVP‐I was tested at concentrations of 0.5%, 1.25%, and 1.5%, and H2O2 was tested at 3% and 1.5% concentrations to represent clinically recommended concentrations. Ethanol and water were evaluated in parallel as standard positive and negative controls. All samples were tested at contact periods of 15 seconds and 30 seconds. Surviving virus from each sample was then quantified by standard end‐point dilution assay and the log reduction value of each compound compared to the negative control was calculated.ResultsAfter the 15‐second and 30‐second contact times, PVP‐I oral antiseptic rinse at all 3 concentrations of 0.5%, 1.25%, and 1.5% completely inactivated SARS‐CoV‐2. The H2O2 solutions at concentrations of 1.5% and 3.0% showed minimal viricidal activity after 15 seconds and 30 seconds of contact time.ConclusionsSARS‐CoV‐2 virus was completely inactivated by PVP‐I oral antiseptic rinse in vitro, at the lowest concentration of 0.5 % and at the lowest contact time of 15 seconds. Hydrogen peroxide at the recommended oral rinse concentrations of 1.5% and 3.0% was minimally effective as a viricidal agent after contact times as long as 30 seconds. Therefore, preprocedural rinsing with diluted PVP‐I in the range of 0.5% to 1.5% may be preferred over hydrogen peroxide during the COVID‐19 pandemic.

Rapid In-Vitro Inactivation of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Using Povidone-Iodine Oral Antiseptic Rinse.

PurposeTo investigate the optimal contact time and concentration for viricidal activity of oral preparation of povidone‐iodine (PVP‐I) against SARS‐CoV‐2 (‘corona virus’) to mitigate the risk and transmission of the virus in the dental practice.Materials and MethodsThe severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) USA‐WA1/2020 strain, virus stock was tested against oral antiseptic solutions consisting of aqueous povidone‐iodine (PVP‐I) as the sole active ingredient. The PVP‐I was tested at diluted concentrations of 0.5%, 1%, and 1.5%. Test media without any virus was added to 2 tubes of the compounds to serve as toxicity and neutralization controls. Ethanol (70%) was tested in parallel as a positive control, and water only as a negative control. The test solutions and virus were incubated at room temperature (22 ± 2 °C) for time periods of 15 and 30 seconds. The solution was then neutralized by a 1/10 dilution in minimum essential medium (MEM) 2% fetal bovine serum (FBS), 50 µg/mL gentamicin. Surviving virus from each sample was quantified by standard end‐point dilution assay and the log reduction value (LRV) of each compound compared to the negative (water) control was calculated.ResultsPVP‐I oral antiseptics at all tested concentrations of 0.5%, 1%, and 1.5%, completely inactivated SARS‐CoV‐2 within 15 seconds of contact. The 70% ethanol control group was unable to completely inactivate SARS‐CoV‐2 after 15 seconds of contact, but was able to inactivate the virus at 30 seconds of contact.ConclusionsPVP‐I oral antiseptic preparations rapidly inactivated SARS‐CoV‐2 virus in vitro. The viricidal activity was present at the lowest concentration of 0.5 % PVP‐I and at the lowest contact time of 15 seconds. This important finding can justify the use of preprocedural oral rinsing with PVP‐I (for patients and health care providers) may be useful as an adjunct to personal protective equipment, for dental and surgical specialties during the COVID‐19 pandemic.

Treatment of oropharyngeal candidiasis in immunocompetent and immunocompromised patients

Treatment of oropharyngeal candidiasis in immunocompetent and immunocompromised patients

Anodized Aluminum with Nanoholes Impregnated with Quaternary Ammonium Compounds Can Kill Pathogenic Bacteria within Seconds of Contact.

Bacterial contamination of surfaces results in the spread of pathogens in public spaces such as hospitals and public transport. The development of antibacterial surfaces that rapidly kill bacteria is therefore highly desirable. Here, we investigate the antibacterial efficacy of a novel anodized aluminum surface featuring nanoholes impregnated with quaternary ammonium compounds, referred to as A3S. The antimicrobial activity of A3S was assessed using both Gram-positive and Gram-negative bacteria in a novel assay which simulates pathogen transfer from a contaminated "finger" to a clean finger in a real-world scenario. Enumeration of colony-forming units shows that the number of viable bacteria on the second "finger" contacting A3S is significantly reduced compared to a control surface. Furthermore, bacterial contact with the A3S material results in compromised cell membranes in less than 1 min, and a kill zone assay shows that an exposure time as short as 5 s is sufficient to kill pathogenic bacteria. The rapid antimicrobial action of A3S was particularly evident against Gram-positive bacteria, that account for more than 70% of nosocomial infections. Taken together, these findings demonstrate that A3S is a promising candidate for the fabrication of antibacterial surfaces that can be used in a wide range of clinical and commercial applications to stop the spread of harmful bacteria.

Plasma membrane is the target of rapid antibacterial action of silver nanoparticles in Escherichia coli and Pseudomonas aeruginosa.

IntroductionSilver nanoparticles (AgNP) are widely used in consumer products and in medicine, mostly due to their excellent antimicrobial properties. One of the generally accepted antibacterial mechanisms of AgNP is their efficient contact with cells and dissolution in the close vicinity of bacterial cell envelope. Yet, the primary mechanism of cell wall damage and the events essential for bactericidal action of AgNP are not elucidated.Materials and methodsIn this study we used a combination of various assays to differentiate the adverse effects of AgNP on bacterial cell envelope: outer membrane (OM) and plasma membrane (PM).ResultsWe showed that PM was the main target of AgNP in gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa: AgNP depolarized PM, induced the leakage of the intracellular K+, and inhibited cellular respiration. The results of bacterial bioluminescence inhibition assay in combination with AgNP dissolution and oxidation assays demonstrated that the adverse effects of AgNP occurred at concentrations 7–160 µM. These toxic effects occurred already within the first few seconds of contact of bacteria and AgNP and were driven by dissolved Ag+ ions targeting bacterial PM. However, the irreversible inhibition of bacterial growth detected after 1-hour exposure occurred at 40 µM AgNP for P. aeruginosa and at 320 µM AgNP for E. coli. In contrast to effects on PM, AgNP and Ag+ ions had no significant effect on the permeability and integrity of bacterial OM, implying that AgNP indeed targeted mainly PM via dissolved Ag+ ions.ConclusionAgNP exhibited antibacterial properties via rapid release of Ag+ ions targeting the PM and not the OM of gram-negative bacteria.

Adhesion forces and mechanics in mannose-mediated acanthamoeba interactions.

The human pathogenic amoeba Acanthamoeba castellanii (A. castellanii) causes severe diseases, including acanthamoeba keratitis and encephalitis. Pathogenicity arises from the killing of target-cells by an extracellular killing mechanism, where the crucial first step is the formation of a close contact between A. castellanii and the target-cell. This process is mediated by the glycocalix of the target-cell and mannose has been identified as key mediator. The aim of the present study was to carry out a detailed biophysical investigation of mannose-mediated adhesion of A. castellanii using force spectroscopy on single trophozoites. In detail, we studied the interaction of a mannose-coated cantilever with an A. castellanii trophozoite, as mannose is the decisive part of the cellular glycocalix in mediating pathogenicity. We observed a clear increase of the force to initiate cantilever detachment from the trophozoite with increasing contact time. This increase is also associated with an increase in the work of detachment. Furthermore, we also analyzed single rupture events during the detachment process and found that single rupture processes are associated with membrane tether formation, suggesting that the cytoskeleton is not involved in mannose binding events during the first few seconds of contact. Our study provides an experimental and conceptual basis for measuring interactions between pathogens and target-cells at different levels of complexity and as a function of interaction time, thus leading to new insights into the biophysical mechanisms of parasite pathogenicity.

Cambios morfológicos en gametos del barbo tigre Puntius tetrazona (Cypriniformes: Cyprinidae) e implementación de la fertilización in vitro

The production of ornamental fishes represents an economic activity of a growing number of Mexican families. Nevertheless, the reproduction of fish in captivity is one of the complications faced by farmers. This study was set up to: (i) evaluate the morphological and functional changes induced by hydration in the gametes of fish tiger barb (Puntius tetrazona; 240 samples) at tree times after hydration (10, 20 and 30s) with classic spermograms (volume, sperm concentration, viability, motility, and normal morphology); and (ii) evaluate the implementation of in vitro fertilization based on the ovulation rate, the percentage of fertilization and hatching; and the larval numbers obtained after 72 hours. The average volume of milt was 3.0 ± 0.7 μL, and the minimum, maximum and average concentration of sperm was 44.4 x 10(6) spz/mL, 52.3 x 10(6) spz/mL, and 48.1 ± 5.9 x 10(6) spz/mL, respectively. The viability and motility of the sperm was 84.6 ± 3.2% and 81.5 ± 2.2%, respectively. The diameter of the sperm with/without water contact was 2.10 ± 6 μm and 3.8 ± 1.0 μm (p < 0.05); the largest diameter was recorded 30 seconds after the contact with water. For oocytes, the smaller and larger diameters were recorded at 10 and 30s, respectively (both with/without water contact); the oocytes diameters after 10 and 30 seconds of contact with water were 1.11 and 1.55 mm, respectively. A higher ovulation rate was recorded using the in vitro fertilization: 250 ± 50 oocytes versus 28 ± 09 oocytes (during natural fertilization; p < 0.05). Nevertheless, fertilization and hatching rates were higher for the natural fertilization (80 and 60%, respectively). Considering the number of larvae obtained after 72 hours, our results showed a higher value for the in vitro fertilization (75 ± 18 compared to 13.4 ± 12 of the natural fertilization; p < 0.05). We propose this fish as a model for other ornamental fishes of commercial interest. Our results demonstrate that the in vitro fertilization is a very high viable option to optimize and maximize resources; besides, the reproduction management optimization under controlled conditions may enhance wild fish stocks preservation.

Bulk Manufacture of Concentrated Oxygen Gas‐Filled Microparticles for Intravenous Oxygen Delivery

Self-assembling, concentrated, lipid-based oxygen microparticles (LOMs) have been developed to administer oxygen gas when injected intravenously, preventing organ injury and death from systemic hypoxemia in animal models. Distinct from blood substitutes, LOMs are a one-way oxygen carrier designed to rescue patients who experience life-threatening hypoxemia, as caused by airway obstruction or severe lung injury. Here, we describe methods to manufacture large quantities of LOMs using an in-line, recycling, high-shear homogenizer, which can create up to 4 liters of microparticle emulsion in 10 minutes, with particles containing a median diameter of 0.93 microns and 60 volume% of gas phase. Using this process, we screen 30 combinations of commonly used excipients for their ability to form stable LOMs. LOMs composed of DSPC and cholesterol in a 1:1 molar ratio are stable for a 100 day observation period, and the number of particles exceeding 10 microns in diameter does not increase over time. When mixed with blood in vitro, LOMs fully oxygenate blood within 3.95 seconds of contact, and do not cause hemolysis or complement activation. LOMs can be manufactured in bulk by high shear homogenization, and appear to have a stability and size profile which merit further testing.

Histologic Impact of Dual-modality Intracorporeal Lithotripters to the Renal Pelvis

To test the hypothesis that dual-modality intracorporeal lithotripters used during percutaneous nephrolithotomy create a degree of tissue trauma in the dual-modality mode (ballistic and ultrasonic) similar to that in the single-modality mode (ultrasonic). The lithotripter devices tested were the Cyberwand and Swiss LithoClast Select. The activated probes, in both single- and dual-modality modes, were applied directly to the renal pelvis of 11 fresh nephrectomy specimens. The treated tissue sites were then processed for light microscopy and reviewed by a single genitourinary pathologist. Microscopic examination of the renal pelvis after 2 seconds of direct contact showed minimal denudation of the urothelium, with no changes noted in the subepithelial or muscle layers for the 2 devices evaluated. Direct contact for 4 seconds showed urothelial denudation and subepithelial changes (n= 13 of 23). Muscle injury was observed in some dual-modality specimens (n= 6 of 12). Increasing the contact time to 8 seconds resulted in fragmentation of the muscle layers more frequently with both settings (n= 15 of 22), except for when the Cyberwand was used at the small stone setting (n= 0 of 7). In the exvivo setting, minimal differences were noted in the degree of histologic trauma between the Cyberwand and Swiss LithoClast Select at 2 seconds. However, both dual-modality devices resulted in muscle damage at 4 and 8 seconds of contact time. Care should be taken during clinical procedures to avoid prolonged contact with the renal pelvis to minimize the potential for tissue trauma.

Early onset of zooplanktivory in equatorial reef coral recruits

Scleractinian coral recruits face multiple challenges as theyattempt to meet the metabolic demands for growth anddevelopment post-settlement. Although coral recruits ofsome scleractinian species can obtain zooxanthellae fromtheir parent colonies to enable autotrophy (Richmond 1997),the development of tentacles is essential for the capture ofparticulate matter to supplement the nutrient and energysupply of the growing juvenile coral. However, studiesexamining the onset of zooplanktivory in coral recruits arelimited (Cumbo et al. 2012).In April 2011, gravid colonies of the broadcasting coralAcropora hyacinthus were harvested from the reef off KusuIsland, Singapore (1°13′25′′N, 103°51′38′′E) for ex situspawning and establishment of larval culture (following Tohet al. 2012). The larvae were settled on tiles (2.3 cm×2.3 cm)and the recruits were tagged to determine their age. Using astereomicroscope (Nikon) with a camera setup (Canon), weobservedthat2-day-oldA.hyacinthusazooxanthellaterecruits(n=7) immobilized live 1-day-old Artemia salina naupliiwithin seconds of contact with their tentacles (Fig. 1a). The

Kinetics of the non-isothermal fusion-welding of unlike ethylene copolymers over a wide crystallinity range

The non-isothermal fusion-welding of unlike polyethylene materials has been studied using three linear ethylene copolymers covering the crystallinity range 16–77% and displaying partial miscibility of the binary blends. Welding was carried out by putting into intimate contact under slight pressure the molten surfaces of two flat beams quickly heated up far above the melting point by means of infrared radiations. Particular attention was paid to the wetting of the beams using ultrasonic measurements. The interface adhesion strength was determined by means of double cantilever beam method. Homo- as well as hetero-welding proved to be highly efficient for only a few seconds of contact of the two beams in the molten state. The critical strain energy release rate of the interface reached values G1C ≥ 6 kJ/m2 for contact time less than 10 s. The time window of efficient welding proved to be intermediate between the number-average and weight-average values of the terminal relaxation time according to melt rheology. This is consistent with Wool's criterion assuming that perfect self-welding of amorphous polymer requires reptation of chains over their whole length through the interface. The longer chains yet seemed not to be able to achieve complete tube renewal during the experimental time window of efficient welding. It is suggested that the reptation of the shortest chains contributes to the restoration of the entanglement network of the longest chains within a time scale much shorter than the reptation time of the latter ones. The surprising efficiency of hetero-welding in agreement with Wool's criterion is attributed to the interfacial miscibility of the unlike copolymers. The concomitant role of cocrystallization in the process is pointed out for such semi-crystalline polymers.