Molecular Interactions between Amino Silane Adhesion Promoter and Acrylic Polymer Adhesive at Buried Silica Interfaces.

In this study, the influence of an amino silane (3-(2-aminoethylamino)-propyldimethoxymethylsilane, AEAPS) on the interfacial structure and adhesion of butyl acrylate/methyl methacrylate copolymers (BAMMAs) to silica was investigated by sum frequency generation vibrational spectroscopy (SFG). Small amounts of methacrylic acid, MAA, were included in the BAMMA polymerizations to assess the impact of carboxylic acid functionality on the glass interface. SFG was used to probe the O-H and C═O groups of incorporated MAA, ester C═O groups of BAMMA, and CH groups from all species at the silica interfaces. The addition of AEAPS resulted in a significant change in the molecular structure of the polymer at the buried interface with silica due to specific interactions between the BAMMA polymers and silane. SFG results were consistent with the formation of ionic bonds between the primary and secondary amines of the AEAPS tail group and the MAA component of the polymer, as evidenced by the loss of the MAA O-H and C═O signals at the interface. It is extensively reported in the literature that methoxy head groups of an amino silane chemically bind to the silanols of glass, leaving the amine groups available to react with various chemical functionalities. Our results are consistent with this scenario and support an adhesion promotion mechanism of amino silane with various aspects: (1) the ionic bond formation between the tail amine group and acid functionality on BAMMA, (2) the chemical coupling between the silane head group and glass, (3) migration of more ester C═O groups to the interface with order, and (4) disordering or reduced levels of CH groups at the interface. These results are important for better understanding of the mechanisms and effect of amino silanes on the adhesion between acrylate polymers and glass substrates in a variety of applications.

Seroprevalence of SARS-CoV-2 antibodies in healthcare workers at a London NHS Trust.

Healthcare workers (HCWs) have a theoretically increased risk of contracting severe acute respiratory coronavirus virus 2 (SARS-CoV-2) given their occupational exposure. We tested 2,167 HCWs in a London Acute Integrated Care Organisation for antibodies to SARS-CoV-2 in May and June 2020 to evaluate seroprevalence. We found a seropositivity rate of 31.6% among HCWs.

Olfactory and taste dysfunction among mild-to-moderate symptomatic COVID-19 positive health care workers: An international survey.

OBJECTIVES: To determine the prevalence of olfactory and taste dysfunction (OD; TD) among COVID-19 positive health care workers (HCWs), their associated risk factors and prognosis. METHODS: Between May and June 2020, a longitudinal multicenter study was conducted on symptomatic COVID-19 PCR confirmed HCWs (COVID-19 positive) in London and Padua. RESULTS: Hundred and fourteen COVID-19 positive HCWs were surveyed with a response rate of 70.6% over a median follow-up period of 52 days. UK prevalence of OD and TD was 73.1% and 69.2%, respectively. There was a male to female ratio of 1:3 with 81.6% being white, 43.7% being nurses/health care assistants (HCAs), and 39.3% being doctors. In addition, 53.2% of them worked on COVID-19 wards. Complete recovery was reported in 31.8% for OD and 47.1% for TD with a 52 days follow-up. The job role of doctors and nurses negatively influenced smell (P = .04 and P = .02) and taste recovery (P = .02 and P = .01). Ethnicity (being white) showed to positively influence only taste recovery (P = .04). Sex (being female) negatively influenced OD and TD recovery only in Paduan HCWs (P = .02 and P = .011, respectively). Working on a COVID-19 ward did not influence prognosis. CONCLUSIONS: The prevalence of OD and TD was considerably higher in HCWs. The prognosis for OD and TD recovery was worse for nurses/HCAs and doctors but working on a COVID-19 ward did not influence prognosis. Sixty-eight percent of surveyed HCWs at 52 days continued to experience OD or TD requiring additional future medical management capacity. LEVEL OF EVIDENCE: 4.

Role of inflammasomes in the pathogenesis of periodontal disease and therapeutics.

Inflammasomes are a group of multimolecular intracellular complexes assembled around several innate immune proteins. Recognition of a diverse range of microbial, stress and damage signals by inflammasomes results in direct activation of caspase-1, which subsequently induces the only known form of secretion of active interleukin-1ß and interleukin-18. Although the importance of interleukin-1ß in the periodontium is not questioned, the impact of inflammasomes in periodontal disease and its potential for therapeutics in periodontology is still in its very early stages. Increasing evidence in preclinical models and human data strongly implicate the involvement of inflammasomes in a number of inflammatory, autoinflammatory and autoimmune disorders. Here we review: (a) the currently known inflammasome functions, (b) clinical/preclinical data supporting inflammasome involvement in the context of periodontal and comorbid diseases and (c) potential therapies targeting inflammasomes. To clarify further the inflammasome involvement in periodontitis, we present analyses of data from a large clinical study (n = 5809) that measured the gingival crevicular fluid-interleukin-1ß and grouped the participants based on current periodontal disease classifications. We review data on 4910 European-Americans that correlate 16 polymorphisms in the interleukin-1B region with high gingival crevicular fluid-interleukin-1ß levels. We show that inflammasome components are increased in diseased periodontal tissues and that the caspase-1 inhibitor, VX-765, inhibits ~50% of alveolar bone loss in experimental periodontitis. The literature review further supports that although patients clinically present with the same phenotype, the disease that develops probably has different underlying biological pathways. The current data indicate that inflammasomes have a role in periodontal disease pathogenesis. Understanding the contribution of different inflammasomes to disease development and distinct patient susceptibility will probably translate into improved, personalized therapies.

Probing the Transformation of Boron Nitride Catalysts under Oxidative Dehydrogenation Conditions.

Hexagonal boron nitride (h-BN) and boron nitride nanotubes (BNNT) were recently reported as highly selective catalysts for the oxidative dehydrogenation (ODH) of alkanes to olefins in the gas phase. Previous studies revealed a substantial increase in surface oxygen content after exposure to ODH conditions (heating to ca. 500 °C under a flow of alkane and oxygen); however, the complexity of these materials has thus far precluded an in-depth understanding of the oxygenated surface species. In this contribution, we combine advanced NMR spectroscopy experiments with scanning electron microscopy and soft X-ray absorption spectroscopy to characterize the molecular structure of the oxygen functionalized phase that arises on h-BN and BNNT following catalytic testing for ODH of propane. The pristine BN materials are readily oxidized and hydrolyzed under ODH reaction conditions to yield a phase consisting of three-coordinate boron sites with variable numbers of hydroxyl and bridging oxide groups which is denoted B(OH) xO3- x (where x = 0-3). Evidence for this robust oxide phase revises previous literature hypotheses of hydroxylated BN edges as the active component on h-BN.

Aerobic Oxidations of Light Alkanes over Solid Metal Oxide Catalysts.

Heterogeneous metal oxide catalysts are widely studied for the aerobic oxidations of C1-C4 alkanes to form olefins and oxygenates. In this review, we outline the properties of supported metal oxides, mixed-metal oxides, and zeolites and detail their most common applications as catalysts for partial oxidations of light alkanes. By doing this we establish similarities between different classes of metal oxides and identify common themes in reaction mechanisms and research strategies for catalyst improvement. For example, almost all partial alkane oxidations, regardless of the metal oxide, follow Mars-van Krevelen reaction kinetics, which utilize lattice oxygen atoms to reoxidize the reduced metal centers while the gaseous O2 reactant replenishes these lattice oxygen vacancies. Many of the most-promising metal oxide catalysts include V5+ surface species as a necessary constituent to convert the alkane. Transformations involving sequential oxidation steps (i.e., propane to acrylic acid) require specific reaction sites for each oxidation step and benefit from site isolation provided by spectator species. These themes, and others, are discussed in the text.

Addition of Pear Ester With Sex Pheromone Enhances Disruption of Mating by Female Codling Moth (Lepidoptera: Tortricidae) in Walnut Orchards Treated with Meso Dispensers.

We evaluated the low-density application of 50 dispensers per hectare, in contrast to the traditional >800 dispensers per hectare in apple orchards, to achieve disruption of communication of adult codling moth, Cydia pomonella (L.), in walnuts, Juglans regia (L.), using several methods. These methods included cumulative catches of male moths in traps baited with sex pheromone (Ph) or codlemone, (E,E)-8,10-dodecadien-1-ol, or a combination of codlemone, pear ester (PE), ethyl (E,Z)-2,4-decadienoate, and acetic acid, and by examining the mating status of females. These data were collected from 2011-2014 in nontreated plots and in similar plots treated with Meso dispensers loaded with codlemone (Ph Meso) or codlemone and PE (Ph + PE Meso). Male moth captures in both the Ph and combination lure traps reduced by 88-96% and 72 to 77%, respectively, compared with traps in the nontreated plots. A significantly higher proportion of female moths were nonmated in plots treated with Ph + PE Meso dispensers (33%) than in plots treated with Ph Meso (18-26%), or left nontreated (13%). In addition, significantly fewer multiple-mated females were trapped in the Ph + PE Meso-treated plots (6%) than in either Ph Meso-treated (13-18%) or nontreated plots (23%). These data suggest that the addition of PE can effectively improve Ph-based disruption of C. pomonella in walnut orchards. In addition, these data suggest that the use of low-density hand-applied dispensers can be an effective and lower-cost approach to manage this pest in the large canopy presented by walnut orchards.

Pain management using patient controlled anaesthesia in adults post Nuss procedure: an analysis with respect to patient satisfaction.

BACKGROUND: The Nuss procedure for correction of pectus excavatum is commonly associated with severe postoperative pain. The belief that thoracic epidural offers the best pain control has recently come under scrutiny after several studies have shown patient controlled anaesthesia (PCA) to be just as effective. Nevertheless, centres who have shifted to an exclusively PCA regime exist in the minority. We have conducted a retrospective survey of all patients who underwent the Nuss procedure at the Heart Hospital, London, where all patients are managed exclusively using PCA. The study aims to assess the efficacy and validity of our practice. METHODS: A retrospective survey was carried out on 149 patients (139 males and 10 females), with an average age of 28, after undergoing a Nuss bar insertion. The study was conducted between August and October, 2014. The PCA technique used a 1 mg bolus dose of morphine sulphate, administered through a 5-minute lockout. There was no background infusion and no maximum dose limit in a 4-hour period. The outcome of the study measured patient satisfaction with postoperative analgesia and medication prescribed for home usage. The pre-operative provision of information with regard to patient expectations of pain was also assessed. The study is approved by the institutional ethical committee and has obtained the informed consent from every patient. RESULTS: The majority of patients were either satisfied or extremely satisfied with the pain management received in hospital immediately following surgery. Additionally, a substantial number of patients strongly agreed that they were adequately warned about postoperative pain prior to the operation. None of the cohort specified that they experienced more pain than expected or thought that the medication prescribed for home usage was inadequate. Moreover, a small minority of patients reported postoperative long-term or chronic pain, with only one reporting that it lasted for longer than 6 months. CONCLUSIONS: Results obtained from retrospective patient satisfaction surveys indicate high efficacy for PCA as a pain management strategy. The large majority of patients did not seek more medication for pain alleviation and found in-hospital treatment sufficient. Further, all patients agreed that they were adequately informed of pain-risk prior to surgery.

Enhanced guest affinity and enantioselectivity through variation of the Gd3+ [15-metallacrown-5] side chain.

Supramolecular hosts that bind guests reversibly are investigated for potential catalysis and separations applications. Chiral Ln(3+)[15-Metallacrown-5] metallocavitands bind carboxylate guests in hydrophobic cavities generated by their ligand side chains. A thermodynamic study on Gd(3+)[15-metallacrown-5] hosts with ligands bearing phenyl side chains containing 0, 1, and 2 methylene spacers (1-pgHA, 1-pheHA, 1-hpheHA, respectively) is presented to quantitatively assess how guest affinity and chiral selectivity can be enhanced through changes to the ligand side chain. Guest binding affinity was measured with cyclic voltammetry using ferrocene carboxylate as a redox probe. K(a) values between ferrocene carboxylate and 1-pgHA and 1-pheHA were 4800 ± 400 M(-1) and 4400 ± 700 M(-1), respectively. Significantly stronger binding affinity of 12,100 ± 700 M(-1) was measured with 1-hpheHA, a result of the longer side-chains more completely encapsulating the guest. A similar trend was observed with benzoate. The side chain also influenced enantioselectivity, as K(S)/K(R) values of up to 2.2 ± 0.6 were measured. The side chain dependent guest binding supports the development of highly selective Ln(3+)[15-Metallacrown-5] hosts for use in catalysis and separations through careful ligand design.

Does use of pesticides known to harm natural enemies of spider mites (Acari: Tetranychidae) result in increased number of miticide applications? An examination of California walnut orchards.

Integrated pest management (IPM) offers guidelines to reduce spider mite (Acari: Tetranychidae) outbreaks by avoiding pesticides known to be harmful to the natural enemies of spider mites. However, in practice, these guidelines can be inconsistent in their effectiveness. The project examined whether California walnut (Juglans L.) growers, following IPM guidelines to avoid pesticides harmful to the natural enemies of spider mites, achieved lower miticide use. Significant statistical tests suggested that fields with harmful applications were 40% more likely to have a miticide application than fields without. Although the IPM guidelines achieved the goal of reducing miticide use, further analysis of other potential causal mechanisms behind outbreaks could strengthen the effectiveness of the guidelines, potentially increasing IPM adoption.

Developing Drosophila suzukii management programs for sweet cherry in the western United States.

BACKGROUND: The spotted wing drosophila, Drosophila suzukii Matsumura (Diptera: Drosophilidae), is a newly introduced pest of sweet cherry on the west coast of North America which produces about 97% of the value of the US sweet cherry crop. D. suzukii initially caused considerable economic loss to cherry growers, who were unaware of this new pest. Little control information was available at the time of initial infestation. Pest control studies were initiated to examine the materials, timings and application methods to control D. suzukii in three major cherry-producing states (California, Oregon and Washington). RESULTS: Three classes of registered insecticides, organophosphates, pyrethroids and spinosyns, have demonstrated good topical or residual activity against D. suzukii. Neonicotinoids and the systemic organophosphate dimethoate appear to be able to kill eggs or larvae in fruit. Preliminary timing studies indicate that at least two preharvest insecticide sprays are required to obtain control of D. suzukii in California cherry orchards. Aerially applied malathion ULV (ultra-low volume) appears to be a viable control tactic for this pest. CONCLUSION: The results presented here form the basis for developing D. suzukii management programs in the western United States. Additional studies are needed to refine management practices for the different growing regions and conventional versus organic production requirements. Cherry growers will likely need to apply broad-spectrum insecticides in a prophylactic manner until treatment thresholds and monitoring methods have been developed and validated.

The role of tyloses in crown hydraulic failure of mature walnut trees afflicted by apoplexy disorder.

In the Central Valley of California, mature walnut trees afflicted with apoplexy disorder exhibit rapid and complete crown defoliation within a few weeks of symptom initiation. Symptoms are typically found throughout the entire crown and are initially expressed as wilting and chlorosis followed by scorching of leaves. Since the cause of apoplexy disorder is unknown, we set out to elucidate the water relations physiology underlying this condition. Stem water potential (Psi(s)) of healthy, asymptomatic trees remained high throughout the 2007 growing season, while that of apoplexy-afflicted trees decreased significantly with the onset of symptoms for both healthy-appearing and symptomatic portions of these trees. Psi(s)s were significantly reduced by at least 0.7 MPa in the lower, middle and upper portions of the symptomatic canopies compared with those from asymptomatic trees. Heat pulse velocities measured in the main trunk at three radial depths consistently decreased prior to the onset of symptoms and eventually reached zero with complete crown defoliation. Comparison of sap flow with predicted water use based on walnut evapotranspiration suggests that stomata of symptomatic trees were closing at higher evaporative demand prior to symptom formation. Specific hydraulic conductivity (K(s)) of symptomatic stems was significantly lower than that of asymptomatic stems, and no detectable K(s) could be measured on several of the symptomatic stem samples. However, shallow root K(s) did not significantly differ between symptomatic and asymptomatic trees, suggesting that hydraulic failure was isolated to the crown of these grafted trees. Light and scanning electron microscopy of stem and trunk sapwood revealed extensive tylose development in vessels throughout the crown of symptomatic trees. Analysis of the formation of tyloses on multiple dates revealed rapid development of these vessel occlusions in conjunction with visual symptom formation and dramatic decreases in sap flow. In 2008, tylose development was associated with elevated ethylene production in the active sapwood of symptomatic trees. The cause of elevated ethylene associated with tylose production and symptom formation is yet to be determined.

Fluorescent-dye-doped sol-gel sensor for highly sensitive carbon dioxide gas detection below atmospheric concentrations.

Optical fluorescence sol-gel sensors have been developed for the detection of carbon dioxide gas in the 0.03-30% range with a detection limit of 0.008% (or 80 ppm) and a quantitation limit of 0.02% (or 200 ppm) CO(2). Sol-gels were spin-coated on glass slides to create an organically modified silica-doped matrix with the 1-hydroxypyrene-3,6,8-trisulfonate (HPTS) fluorescent indicator. The luminescence intensity of the HPTS indicator (513 nm) is quenched by CO(2), which protonates the anionic form of HPTS. An ion pair technique was used to incorporate the lipophilic dye into the hydrophilic sol-gel matrix. TiO(2) particles (<5 microm diameter) were added to induce Mie scattering and increase the incident light interaction with the sensing film, thus increasing the signal-to-noise ratio. Moisture-proof overcoatings have been used to maintain a constant level of water inside the sensor films. The optical sensors are inexpensive to prepare and can be easily coupled to fiber optics for remote sensing capabilities. A fiber-optic bundle was used for the gas detection and shown to work as part of a multianalyte platform for simultaneous detection of multiple analytes. The studies reported here resulted in the development of sol-gel optical fluorescent sensors for CO(2) gas with sensitivity below that in the atmosphere (ca. 387 ppm). These sensors are a complementary approach to current FT-IR measurements for real-time carbon dioxide detection in environmental applications.