Static vs dynamic settlement and adhesion of diatoms to ship hull coatings

Many experiments utilize static immersion tests to evaluate the performance of ship hull coatings. These provide valuable data; however, they do not accurately represent the conditions both the hull and fouling organisms encounter while a ship is underway. This study investigated the effect of static and dynamic immersion on the adhesion and settlement of diatoms to one antifouling coating (BRA 640), four fouling-release coatings (Intersleek^® 700, Intersleek^® 900, Hempasil X3, and Dow Corning 3140) and one standard surface (Intergard^® 240 Epoxy). Differences in community composition were observed between the static and dynamic treatments. Achnanthes longipes was present on all coatings under static immersion, but was not present under dynamic immersion. This was also found for diatoms in the genera Bacillaria and Gyrosigma. Melosira moniformis was the only diatom present under dynamic conditions, but not static conditions. Several common fouling diatom genera were present on panels regardless of treatment: Amphora, Cocconeis, Entomoneis Cylindrotheca, Licmophora, Navicula, Nitzschia, Plagiotropis, and Synedra. Biofilm adhesion, diatom abundance and diatom diversity were found to be significantly different between static and dynamic treatments; however, the difference was dependent on coating and sampling date. Several coatings (Epoxy, DC 3140 and IS 700) had significantly higher biofilm adhesion on dynamically treated panels on at least one of the four sampling dates, while all coatings had significantly higher diatom abundance on at least one sampling date. Diversity was significantly greater on static panels than dynamic panels for Epoxy, IS 700 and HX3 at least once during the sampling period. The results demonstrate how hydrodynamic stress will significantly influence the microfouling community. Dynamic immersion testing is required to fully understand how antifouling surfaces will respond to biofilm formation when subjected to the stresses experienced by a ship underway.     

The use of aeration as a simple and environmentally sound means to prevent biofouling

Biofouling is a major problem faced by marine industries. Physical and chemical treatments are available to control fouling, but most are costly, time consuming or negatively affect the environment. The use of aeration (ie continuous streams of air bubbles) to prevent fouling was examined. Experiments were conducted at three sites with different benthic communities. Experimental panels (10 cm × 10 cm; PVC and concrete) were deployed with or without aeration. Aeration flowed continuously from spigots 0.5 m below the panels at a rate of ～3.3 to 5.0 l min^?1. After 1 and 4 weeks, aerated PVC panels from all sites had significantly less fouling than non-aerated controls. Aeration reduced fouling on both the PVC and concrete surfaces. Fouling was reduced on panels directly in bubble streams while panels 30 cm and 5 m away had significantly more fouling. Thus, under the conditions used in this study, aeration appears to be an effective and simple way to prevent fouling.     

Prediction of membrane fouling in MBR systems using empirically estimated specific cake resistance

The focus of this study was to empirically estimate the specific cake resistance (SCR) by the variation in shear intensity (G) in four laboratory-scale MBRs. The control reactor (MBR₀) was operated with aeration only while other MBRs (MBR₁₅₀, MBR₃₀₀ and MBR₄₅₀) were operated with aeration and mechanical mixing intensities of 150, 300 and 450 rpm, respectively. It was found that the SCR was strongly correlated (R² = 0.99) with the fouling rates in the MBRs. Moreover, the contribution of cake resistance (R_c) to the total hydraulic resistance (R_t) was predominant compared to the irreversible fouling resistance (R_f). On this basis, the cake filtration model was selected as a predictive tool for membrane fouling. This model was modified by replacing the SCR with its empirical shear intensity relationship. The modified model can predict the fouling rate for a given shear intensity (G) within 80 and 250 s⁻¹ in a MBR system.     

Modulation of hybridoma cell growth and antibody production by coating cell culture material with extracellular matrix proteins

The influence of coating polystyrene tissue culture plates with different proteins on murine hybridoma cell growth and antibody production was investigated. Fibronectin, collagen I, bovine serum albumin and laminin were used to coat NUNC^® and COSTAR^® cell culture plates. Cell number and antibody concentration in culture fluids were quantified as indicators for cell viability, proliferation and productivity. Adhesive behaviour, morphology, expression of surface receptors of hybridoma cells and the presence of tyrosine-phosphorylated proteins in cell lysates were characterized by cell adhesion experiments, microscopy, flow cytometry and Western Blot analysis.It was shown that coatings with fibronectin (0.2 μg/ml) lead to a substantial improvement of cell growth by 50–70% and an increase of monoclonal antibody production by 100–120%.Collagen I coatings showed an improvement in cell growth by 30–70% and by 60% for the production of monoclonal antibodies. Coatings with BSA and laminin had minor effects on these parameters. It was found that the hybridoma cell lines used in this study did not express the α₂-chain of the α₂β₁-integrin, which is responsible for binding to collagen and laminin.However, the presence of β₁-integrin on the cell surface was shown, which should enable hybridoma cells to bind fibronectin. We propose, therefore, that fibronectin adsorption to cell culture materials may be a promising approach to enhance the production of monoclonal antibodies by cultivated hybridoma cells.     

A simple and sensitive fluorescence method for the determination of trace ozone in air using acridine red as a probe

The ozone in an air sample was trapped by H₃BO₃‐LK solution to produce iodine (I₂) that interacted with excess I^– to form I₃^–. In pH 4.0 acetate buffer solutions, the I₃^– reacted with acridine red to form acridine red–I₃ ion association particles that resulted in the fluorescence peak decreased at 553 nm. The decreased value ΔF_{553 nm} is linear to the O₃ concentration in the range 0.08–53.3 × 10^–6 mol/L, with a detection limit of 4 × 10^–8 mol/L. This fluorescence method was used to determine ozone in air samples, and the results were in agreement with that of indigo carmine spectrophotometry. Copyright © 2014 John Wiley & Sons, Ltd.     

Comparison of the effects of prostaglandin I2 and prostaglandin E2 stimulation of the rat kidney adenylate cyclase-cyclic AMP systems

Prostacyclin (Prostaglandin I₂) effects on the rat kidney adenylate cyclase-cyclic AMP system were examined. Prostaglandin I₂ and prostaglandin E₂, from 8 · 10^?4 to 8 · ^?7 M stimulated adenylate cyclase to a similar extent in cortex and outer medulla. In inner medulla, prostaglandin I₂ was more effective than prostaglandin E₂ at all concentrations tested. Both prostaglandin I₂ and prostaglandin E₂ were additive with antidiuretic hormone in outer and inner medulla. Prostaglandin I₂ and prostaglandin E₂ were not additive in any area of the kidney, indicating both were working by similar mechanisms. Prostaglandin I₂ stimulation of adenylate cyclase correlated with its ability to increase renal slice cyclic AMP content. Prostaglandin I₂ and prostaglandin E₂ (1.5 · 10^?4 M) elevated cyclic AMP content in cortex and outer medulla slices. In inner medulla, with Santoquin® (0.1 mM) present to suppress endogenous prostaglandin synthesis, prostaglandin I₂ and prostaglandin E₂ increased cyclic AMP content. 6-Ketoprostaglandin F_1α, the stable metabolite of prostaglandin I₂, did not increase adenylate cyclase activity or tissue cyclic AMP content. Thus, prostaglandin I₂ activates renal adenylate cyclase. This suggests that the physiological actions of prostaglandin I₂ may be mediated through the adenylate cyclase-cyclic AMP system.     

A realistic in silico model for structure/function studies of molybdenum–copper CO dehydrogenase

CO dehydrogenase (CODH) is an environmentally crucial bacterial enzyme that oxidizes CO to CO₂ at a Mo–Cu active site. Despite the close to atomic resolution structure (1.1 Å), significant uncertainties have remained with regard to the protonation state of the water-derived equatorial ligand coordinated at the Mo-center, as well as the nature of intermediates formed during the catalytic cycle. To address the protonation state of the equatorial ligand, we have developed a realistic in silico QM model (~179 atoms) containing structurally essential residues surrounding the active site. Using our QM model, we examined each plausible combination of redox states (Mo^VI–Cu^I, Mo^V–Cu^II, Mo^V–Cu^I, and Mo^IV–Cu^I) and Mo-coordinated equatorial ligands (O^2?, OH^?, H₂O), as well as the effects of second-sphere residues surrounding the active site. Herein, we present a refined computational model for the Mo(VI) state in which Glu763 acts as an active site base, leading to a MoO₂-like core and a protonated Glu763. Calculated structural and spectroscopic data (hyperfine couplings) are in support of a MoO₂-like core in agreement with XRD data. The calculated two-electron reduction potential (E = ?467 mV vs. SHE) is in reasonable agreement with the experimental value (E = ?558 mV vs. SHE) for the redox couple comprising an equatorial oxo ligand and protonated Glu763 in the Mo^VI–Cu^I state and an equatorial water in the Mo^IV–Cu^I state. We also suggest a potential role of second-sphere residues (e.g., Glu763, Phe390) based on geometric changes observed upon exclusion of these residues in the most plausible oxidized states.     

Bacteria and diatom resistance of silicones modified with PEO-silane amphiphiles

Silicone coatings with enhanced antifouling behavior towards bacteria, diatoms, and a diatom dominated slime were prepared by incorporating PEO-silane amphiphiles with varied siloxane tether lengths (a–c): α-(EtO)₃Si(CH₂)₂-oligodimethylsiloxane_n-block-poly(ethylene oxide)₈-OCH₃ [n = 0 (a), 4 (b), and 13 (c)]. Three modified silicone coatings (A–C) were prepared by the acid-catalyzed sol–gel cross-linking of a–c, respectively, each with a stoichiometric 2:3 M ratio of α, ω-bis(Si–OH)polydimethylsiloxane (M_n = 3,000 g mol^?1). The coatings were exposed to the marine bacterium Bacillus sp.416 and the diatom (microalga) Cylindrotheca closterium, as well as a mixed community of Bacillus sp. and C. closterium. In addition, in situ microfouling was assessed by maintaining the coatings in the Atlantic Ocean. Under all test conditions, biofouling was reduced to the highest extent on coating C which was prepared with the PEO-silane amphiphile having the longest siloxane tether length (c).     

Highly sensitive fluorescence detection of glycoprotein based on energy transfer between CuInS2 QDs and rhodamine B

A highly sensitive fluorescence method for glycoprotein detection has been established based on fluorescence resonance energy transfer (FRET) between CuInS₂ quantum dots (QDs) and rhodamine B (RB). Lectins comprise a group of proteins with unique affinities toward carbohydrate structures, so the process of FRET can occur between lectin‐coated QDs (CuInS₂ QDs–Con A conjugates, acceptors) and carbohydrate‐coated RB (RB–NH₂‐glu conjugates, donors). The fluorescence of lectin‐coated QDs was recovered in the presence of a glycoprotein such as glucose oxidase (GOx) and transferrin (TRF), which significantly reduced the FRET efficiency between the donor and the acceptor. Under optimal conditions, a linear correlation was established between the fluorescence intensity ratio I₆₅₄/I₅₇₇ and the TRF concentration over the range of 6.90 × 10^‐10 to 3.45 × 10^‐8 mol/L, with a detection limit of 2.5 × 10^‐10 mol/L. The linear range for GOx is 3.35 × 10^‐10 to 6.70 × 10^‐8 mol/L, with a detection limit of 1.5 × 10^‐10 mol/L. The proposed method was applied to the determination of glycoprotein in human serum and cell‐extract samples with satisfactory results. Furthermore, CuInS₂ QDs–Con A conjugates are used as safe and efficient optical nanoprobes in HepG2 cell imaging. Copyright © 2015 John Wiley & Sons, Ltd.     

The effects of nitric oxide in settlement and adhesion of zoospores of the green alga Ulva

Previous studies have shown that elevated nitric oxide (NO) reduces adhesion in diatom, bacterial and animal cells. This article reports experiments designed to investigate whether elevated NO reduces the adhesion of zoospores of the green alga Ulva, an important fouling species. Surface-normalised values of NO were measured using the fluorescent indicator DAF-FM DA and parallel hydrodynamic measurements of adhesion strength were made. Elevated levels of NO caused by the addition of the exogenous NO donor SNAP reduced spore settlement by 20% and resulted in lower adhesion strength. Addition of the NO scavenger cPTIO abolished the effects of SNAP on adhesion. The strength of attachment and NO production by spores in response to four coatings (Silastic® T2; Intersleek® 700; Intersleek® 900 and polyurethane) shows that reduced adhesion is correlated with an increase in NO production. It is proposed that in spores of Ulva, NO is used as an intracellular signalling molecule to detect how conducive a surface is for settlement and adhesion. The effect of NO on the adhesion of a range of organisms suggests that NO-releasing coatings could have the potential to control fouling.     

Effects of negative air ions,noise, sex and age on maze learning in rats

An equal number of male and female rats of the King-Holtzman hybrid breed, divided into two age groups (group A₁ : 21–30 days old and group A₂ : 90–100 days old), were exposed to two levels of noise: N₀ = 30 db and N₁ = 90 db, (Ref. 0.0002μ bar), and three levels of negative air ions: I_O = no measurable ion concentration, I₁ = 7 × 10⁶ ions/cm³ and I₂ = 7 × 10⁷ ions/cm³. Time and error scores of 240 rats running a modified Lashley left-right maze with an escape-from-water motive served as criteria. A randomized complete blocks design with replications (2×3×2×2×10) was selected for treatment by analysis of variance. The results indicate that (a) the males show significantly lower error score in negatively ionized air; and (b) the females swim significantly faster than males under all investigated conditions with no apparent effect of noise or ions on their performance.

---

Zusammenfassung Eine gleiche Anzahl m?nnlicher und weiblicher Ratten (n = 120) des King-Holtzman Stammes, unterteilt in 2 Altersgruppen (21–30 und 90–100 Tage) wurden zwei Ger?uschintensit?ten (30 db und 90 db) und 3 Konzentrationen negativer Luftionen I₀: nicht messbar niedrig, I₁:7×10⁶, I₂:7×10⁷ Ionen/cm³ ausgesetzt. Die Wirkung wurde geprüft an der Schwimmzeit und der Anzahl Fehler der Tiere im Lasley-Links-Rechts-Labyrinth. Das Motiv zum Schwimmen war, aus dem Wasser zu entkommen. Die Auswertung durch Varianzanalyse erfolgte unter Nachbildung randomisierter kompletter Blockentwürfe. Die Ergebnisse zeigen, dass (a) die M?nnchen bei negativ ionisierter Luft signifikant weniger Fehler machten und (b) die Weibchen unter allen Bedingungen schneller schwammen als die M?nnchen, ohne dass das L?rmniveau oder die Luftionisation darauf einen Einfluss hatten.

---

Resume Un nombre égal de rats males et femelles (120 de chaque) de la race King-Holtzman futdivisé en deux groupes d'age (21 à 30 jours et 90 à 100 jours). Ils furent exposés à 2 intensités auditives (30 et 90 db) et à 3 concentrations d'ions négatifs: I₀ non mesurables (faible), I₁ : 7 × 10⁶ et I₂: 7 × 10⁷ ions/cm³. Les effets d'un tel traitement furent examinés au moyen de deux critères: le temps pris pour sortir de l'eau et le nombre de fautes commises dans un labyrinthe droitegauche de Laslay. Pour l'analyse des variances, on a adopté une répartition due au hasard avec répétitions (2×3×2×2×10). On peut en conclure que: (a) les males font moins d'erreurs dans l'air ionisé négativement et cela de fa?on significative et (b) les femelles ont nagé plus vite que les males dans toutes les conditions de l'essai. Ni le bruit ni le degré d'ionisation ne semblent avoir d'influence sur leur comportement.

---

---

This study was supported in part by a grant from the Faculty Research Fund of the University of Oklahoma.     

Photochemistry of Co(EDTA)−-I− System in Aqueous Solutions

The Co(EDTA)⁻ complex in aqueous solution gives rise to a specific interaction with I⁻ ions as evidenced by a new, relatively intense band formed at 290–300 nm. This specific interaction is attributed to the formation of an ion-pair between Co(EDTA)⁻ and I⁻, even though they are like charged ions. Irradiation of this ion-pair in air- equilibrated solutions with 313 nm light, causes the reduction of the Co(EDTA)⁻ to Co(EDTA)²⁻ and the oxidation of the I⁻ ion to I₃⁻. The results obtained are interpreted on the basis of a mechanism in which Co(EDTA)²⁻ and I^· are the primary photoproducts. The I^· radical is then scavenged by I⁻ to yield I₂⁻, which subsequently disproportionates to I₃⁻ and I⁻ and reoxidizes Co(EDTA)²⁻ to Co(EDTA)⁻. At the beginning of the photoreaction, the I₂⁻ decay is equally distributed on the two reaction pathways. It was possible to determine a value of 0.2 ± 0.05 for the photoreaction quantum yield and an efficiency of the primary photochemical step almost unitary. A schematic representation of the energetics of the overall reaction is reported.     

Riluzole suppresses postinhibitory rebound in an excitatory motor neuron of the medicinal leech

Postinhibitory rebound (PIR) is an intrinsic property often exhibited by neurons involved in generating rhythmic motor behaviors. Cell DE-3, a dorsal excitatory motor neuron in the medicinal leech exhibits PIR responses that persist for several seconds following the offset of hyperpolarizing stimuli and are suppressed in reduced Na⁺ solutions or by Ca²⁺ channel blockers. The long duration and Na⁺ dependence of PIR suggest a possible role for persistent Na⁺ current (I _NaP). In vertebrate neurons, the neuroprotective agent riluzole can produce a selective block of I _NaP. This study demonstrates that riluzole inhibits cell DE-3 PIR in a concentration- and Ca²⁺-dependent manner. In 1.8 mM Ca²⁺ solution, 50–100 µM riluzole selectively blocked the late phase of PIR, an effect similar to that of the neuromodulator serotonin. However, 200 µM riluzole blocked both the early and late phases of PIR. Increasing extracellular Ca²⁺ to 10 mM strengthened PIR, but high riluzole concentrations continued to suppress both phases of PIR. These results indicate that riluzole may suppress PIR via a nonspecific inhibition of Ca²⁺ conductances and suggest that a Ca²⁺-activated nonspecific current (I _CAN), rather than I _NaP, may underlie the Na⁺-dependent component of PIR.     

Rapid treatment of vessels fouled with an invasive polychaete,Sabella spallanzanii,using a floating dock and chlorine as a biocide

Chlorine solution was added to the water encapsulated within a proprietary ‘floating dock’ to treat a vessel infested with the invasive polychaete Sabella spallanzanii. The chlorine was added as sodium dichloroisocyanurate (‘dichlor’) at an initial concentration of 200 mg l^?1 of free available chlorine (FAC). This concentration killed 99% of S. spallanzanii in their tubes during a 4-h exposure in laboratory tests (EC₉₉ 160 mg FAC l^?1). The concentration of FAC in the floating dock declined to ~50 mg l^?1 after 4 h and < 10 mg l^–1 after 16 h. Residual FAC was neutralised with thiosulphate at completion of exposure. A sample of 30 S. spallanzanii individuals collected from the hull after treatment all showed morphological damage and 28 showed no response to touch. Re-examination of the hull after 6 d found no live worms or other fouling organisms. This method provides a cost-effective, rapid means of treating hull fouling.     

Theoretical investigation of the mechanism for the reductive dehalogenation of methyl halides mediated by the Co<Superscript>I</Superscript>-based compounds cobalamin and cobaloxime

Theoretical calculations focusing on the cleavage of the C–X bond in methyl halides (CH₃X; X?=?Cl, Br, I) as mediated by Co^I-based systems have been carried out using the hybrid functional ωB97-XD together with the basis set 6–311++G(2d,2p). A total of seven Co^I-based compounds were evaluated: cob[I]alamin (Co^ICbl) in its base-on form and cobaloxime (Co^ICbx) with either no ligand or different ligands (either pyridine (PYR), tributylphosphine (TBP), dimethyl sulfide (DMS), cyclohexylisocyanide (CI), or 5,6-dimethylbenzimidazole (DMB)) at the lower axial position. For the large Co^ICbl system, an ONIOM scheme was employed, where the high layer was described at the DFT level and the low layer was computed using the semi-empirical method PM6. A full DFT model was employed for the Co^ICbx cases. An S_N2-like mechanism was evaluated in all cases. The intrinsic reaction coordinate profiles suggested early transition states with activation energies of ≈ 12 kcal/mol, ≈ 10 kcal/mol, and ≈ 5 kcal/mol for C–Cl, C–Br, and C–I cleavage, respectively, which is consistent with the leaving group abilities of these halides. The evolutions of the atomic charges in and the bond orders of Co–C and C–X were computed, and the results confirmed the existence of early transition states (δB_av≈ 40%), where the polarization C^δ+–X^δ? (%E_v?≈?43%) is the determining factor in the reaction process. Finally, a comparison of all the determined parameters showed that the reaction in the DMB–Co^ICbx system resembles the process that occurs in the larger Co^ICbl, suggesting that the former system could be a reliable model for the study of reductive dehalogenation mediated by vitamin B₁₂, which is key to the anaerobic microbiological treatment of halocarbon contaminants.     

Bumetanide Hyperpolarizes Madin–Darby Canine Kidney Cells and Enhances Cellular Gentamicin Uptake by Elevating Cytosolic Ca2+ Thus Facilitating Intermediate Conductance Ca2+-Activated Potassium Channels

Loop diuretics such as bumetanide and furosemide enhance aminoglycoside ototoxicity when co-administered to patients and animal models. The underlying mechanism(s) is poorly understood. We investigated the effect of these diuretics on cellular uptake of aminoglycosides, using Texas Red-tagged gentamicin (GTTR), and intracellular/whole-cell recordings of Madin–Darby canine kidney (MDCK) cells. We found that bumetanide and furosemide dose-dependently enhanced cytoplasmic GTTR fluorescence by ~60 %. This enhancement was suppressed by La³⁺, a non-selective cation channel (NSCC) blocker, and by K⁺ channel blockers Ba²⁺ and clotrimazole, but not by tetraethylammonium (TEA), 4-aminopyridine (4-AP) or glipizide, nor by Cl^? channel blockers diphenylamine-2-carboxylic acid (DPC), niflumic acid (NFA), and CFTR_inh-172. Bumetanide and furosemide hyperpolarized MDCK cells by ~14 mV, increased whole-cell I/V slope conductance; the bumetanide-induced net current I/V showed a reversal potential (V _r) ~?80 mV. Bumetanide-induced hyperpolarization and I/V change was suppressed by Ba²⁺ or clotrimazole, and absent in elevated [Ca²⁺]_i, but was not affected by apamin, 4-AP, TEA, glipizide, DPC, NFA, or CFTR_inh-172. Bumetanide and furosemide stimulated a surge of Fluo-4-indicated cytosolic Ca²⁺. Ba²⁺ and clotrimazole alone depolarized cells by ~18 mV and reduced I/V slope with a net current V _r near ?85 mV, and reduced GTTR uptake by ~20 %. La³⁺ alone hyperpolarized the cells by ~?14 mV, reduced the I/V slope with a net current V _r near ?10 mV, and inhibited GTTR uptake by ~50 %. In the presence of La³⁺, bumetanide-caused negligible change in potential or I/V. We conclude that NSCCs constitute a major cell entry pathway for cationic aminoglycosides; bumetanide enhances aminoglycoside uptake by hyperpolarizing cells that increases the cation influx driving force; and bumetanide-induced hyperpolarization is caused by elevating intracellular Ca²⁺ and thus facilitating activation of the intermediate conductance Ca²⁺-activated K⁺ channels.     

Microevolutionary trends in the dentition of the Red fox (Vulpes vulpes)

Microevolutionary trends in dental traits were studied in a Polish population of the Red fox, Vulpes vulpes (Linnaeus, 1758). Changes in qualitative and quantitative traits over a 70‐year interval were analysed in 1453 museum specimens collected between 1927 and 1996. Over that period, there were qualitative trends towards increasing complication of occlusal crown surface in posterior premolars (i.e. P⁴, P₃, P₄) and I³. Other cheek teeth did not undergo directional change. Changes in trait correlations were assessed using samples from the 1960s and 1990s. The correlations between C¹–C₁ and M¹–M² increased, while correlation values in the incisor region (I₁–I₂, I¹–I₁, I¹–I₂, I³–I₂), carnassial region (P₄–M₁, P⁴–M₁ and M₁–M₁) and in P²–P₁ decreased. These changes may be related to increasing dietary opportunism of the Red fox during the 20th century.     

Clinical radiotherapy application of N-vinylpyrrolidone-containing 3D polymer gel dosimeters with remote external MR-reading

PurposeAdvanced 3D dosimetry is required for verifications of complex dose distributions in modern radiotherapy. Two 3D polymer gel dosimeters, coupled with magnetic resonance (MR) imaging (3 T MRI) readout and data processing with polyGeVero® software, were tested for the verification of calculated 3D dose distributions by a treatment planning system (TPS) and ArcCHECK®–3DVH®, related to eradication of a lung tumour.MethodsN-vinylpyrrolidone-containing 3D polymer gel dosimeters were used: VIC (containing ascorbic acid and copper sulfate pentahydrate) and VIC-T (containing tetrakis(hydroxymethyl)phosphonium chloride). Three remote centers were involved in the dosimeters preparation and irradiation (Poland), and MRI (Austria). Cross beam calibration of the dosimeters and verification of a 3D dose distribution calculated with an Eclipse External Beam TPS and ArcCHECK®–3DVH® were performed. The 3D-to-3D comparisons of the VIC and VIC-T with TPS and ArcCHECK®–3DVH® along with ArcCHECK®–3DVH® versus TPS dose matrixes were performed with the aid of the polyGeVero® by analyzing dose profiles, isodoses lines, gamma index, gamma angle, dose difference, and related histograms.ResultsThe measured MR-relaxation rate (R₂ = 1/T₂) for the dosimeters relates to the dose, as follows: R₂ = 0.0928 ± 0.0008 [Gy⁻¹ s⁻¹] × D [Gy] + 2.985 ± 0.012 [s⁻¹] (VIC) and 0.1839 ± 0.0044 [Gy⁻¹ s⁻¹] × D [Gy] + 2.519 ± 0.053 [s⁻¹] (VIC-T). The 3D-to-3D comparisons revealed a good agreement between the measured and calculated 3D dose distributions.ConclusionsVIC and VIC-T with 3T MRI readout and polyGeVero® showed potential for verifications of calculated irradiation plans. The results obtained suggest the implementation of the irradiation plan for eradication of the lung tumour.     

Colonisation and succession of marine biofilm-dwelling ciliate assemblages on biocidal antifouling and fouling-release coatings in temperate Australia

Ciliate assemblages are often overlooked, but ubiquitous components of microbial biofilms which require a better understanding. Ciliate, diatom and bacterial colonisation were evaluated on two fouling-release (FR) coatings, viz. Intersleek 970 and Hempasil X3, and two biocidal antifouling (AF) coatings, viz. Intersmooth 360 and Interspeed 5640, in Port Phillip Bay, Australia. A total of 15 genera were identified during the 10 week deployment. Intersleek 970 displayed the most rapid fouling by ciliates, reaching 63.3(± 5.9) cells cm^?2. After 10 weeks, all four coatings were extensively fouled. However, the toxicity of the AF coatings still significantly inhibited microbial fouling compared to the FR coatings. On all treatments, colonies of sessile peritrichs dominated the ciliate assemblage in the early stage of succession, but as the biofilm matured, vagile ciliates exerted more influence on the assemblage structure. The AF coatings showed selective toxic effects, causing significant differences in the ciliate species assemblages among the treatments.