Diblock bottlebrush polymer in a non-polar medium: Self-assembly, surface forces, and superlubricity

Whilst bottlebrush polymers have been studied in aqueous media for their conjectured role in biolubrication, surface forces and friction mediated by bottlebrush polymers in non-polar media have not been previously reported. Here, small-angle neutron scattering (SANS) showed that a diblock bottlebrush copolymer (oligoethyleneglycol acrylate/ethylhexyl acrylate; OEGA/EHA) formed spherical core-shell aggregates in n-dodecane (a model oil) in the polymer concentration range 0.1-2.0 wt%, with a radius of gyration Rg ∼ 7 nm, comprising 40-65 polymer molecules per aggregate. The surface force apparatus (SFA) measurements revealed purely repulsive forces between surfaces bearing inhomogeneous polymer layers of thickness L ∼ 13-23 nm, attributed to adsorption of a mixture of polymer chains and surface-deformed micelles. Despite the surface inhomogeneity, the polymer layers could mediate effective lubrication, demonstrating superlubricity with the friction coefficient as low as µ ∼ 0.003. The analysis of velocity-dependence of friction using the Eyring model shed light on the mechanism of the frictional process. That is, the friction mediation was consistent with the presence of nanoscopic surface aggregates, with possible contributions from a gel-like network formed by the polymer chains on the surface. These unprecedented results, correlating self-assembled polymer micelle structure with the surface forces and friction the polymer layers mediate, highlight the potential of polymers with the diblock bottlebrush architecture widespread in biological living systems, in tailoring desired surface interactions in non-polar media.

Analysis of Germin-like protein genes family in Vitis vinifera (VvGLPs) using various in silico approaches

Abstract Germin-like proteins (GLPs) play an important role against various stresses. Vitis vinifera L. genome contains 7 GLPs; many of them are functionally unexplored. However, the computational analysis may provide important new insight into their function. Currently, physicochemical properties, subcellular localization, domain architectures, 3D structures, N-glycosylation & phosphorylation sites, and phylogeney of the VvGLPs were investigated using the latest computational tools. Their functions were predicted using the Search tool for the retrieval of interacting genes/proteins (STRING) and Blast2Go servers. Most of the VvGLPs were extracellular (43%) in nature but also showed periplasmic (29%), plasma membrane (14%), and mitochondrial- or chloroplast-specific (14%) expression. The functional analysis predicted unique enzymatic activities for these proteins including terpene synthase, isoprenoid synthase, lipoxygenase, phosphate permease, receptor kinase, and hydrolases generally mediated by Mn+ cation. VvGLPs showed similarity in the overall structure, shape, and position of the cupin domain. Functionally, VvGLPs control and regulate the production of secondary metabolites to cope with various stresses. Phylogenetically VvGLP1, -3, -4, -5, and VvGLP7 showed greater similarity due to duplication while VvGLP2 and VvGLP6 revealed a distant relationship. Promoter analysis revealed the presence of diverse cis-regulatory elements among which CAAT box, MYB, MYC, unnamed-4 were common to all of them. The analysis will help to utilize VvGLPs and their promoters in future food programs by developing resistant cultivars against various biotic (Erysiphe necator and in Powdery Mildew etc.) and abiotic (Salt, drought, heat, dehydration, etc.) stresses.

Does F4TCNQ Adsorption on Cu(111) Form a 2D-MOF?

The results of a quantitative experimental structural investigation of the adsorption phases formed by 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinodimethane (F4TCNQ) on Cu(111) are reported. A particular objective was to establish whether Cu adatoms are incorporated into the molecular overlayer. A combination of normal incidence X-ray standing waves, low-energy electron diffraction, scanning tunneling microscopy, and X-ray photoelectron spectroscopy measurements, complemented by dispersion-inclusive density functional theory calculations, demonstrates that F4TCNQ on Cu(111) does cause Cu adatoms to be incorporated into the overlayer to form a two-dimensional metal-organic framework (2D-MOF). This conclusion is shown to be consistent with the behavior of F4TCNQ adsorption on other coinage metal surfaces, despite an earlier report concluding that the adsorption structure on Cu(111) is consistent with the absence of any substrate reconstruction.

Effect of Anionic Lipids on Mammalian Plasma Cell Membrane Properties

The effect of lipid composition on models of the inner leaflet of mammalian cell membranes has been investigated. Grazing incidence X-ray diffraction and X-ray and neutron reflectivity have been used to characterize lipid packing and solvation, while electrochemical and infrared spectroscopic methods have been employed to probe phase behavior in an applied electric field. Introducing a small quantity of the anionic lipid dimyristoylphosphatidylserine (DMPS) into bilayers of zwitterionic dimyristoylphosphatidylethanolamine (DMPE) results in a significant change in the bilayer response to an applied field: the tilt of the hydrocarbon chains increases before returning to the original tilt angle on detachment of the bilayer. Equimolar mixtures, with slightly closer chain packing, exhibit a similar but weaker response. The latter also tend to incorporate more solvent during this electrochemical phase transition, at levels similar to those of pure DMPS. Reflectivity measurements reveal greater solvation of lipid layers for DMPS > 30 mol %, matching the greater propensity for DMPS-rich bilayers to incorporate water. Taken together, the data indicate that the range of 10-35 mol % DMPS provides optimum bilayer properties (in flexibility and function as a barrier), which may explain why the DMPS content of cell membranes tends to be found within this range.

Implementing 3HP vs. IPT as TB preventive treatment in Pakistan

BACKGROUND: We assessed treatment uptake and completion for 6 months of isoniazid (6H) and 3 months of isoniazid plus rifapentine weekly (3HP) in a programmatic setting in Pakistan.METHODS: All household contacts were clinically evaluated to rule out TB disease. 6H was used for TB preventive treatment (TPT) from October 2016 to April 2017; from May to September 2017, 3HP was used for contacts aged ≥2 years. We compared clinical evaluation, TPT uptake and completion rates between contacts aged ≥2 years in the 6H period and in the 3HP period.RESULTS: We identified 3,442 contacts for the 6H regimen. After clinical evaluation, 744/1,036 (72%) started treatment, while 46% completed treatment. In contrast, 3,722 contacts were identified for 3HP. After clinical evaluation, 990/1,366 (72%) started treatment, while 67% completed treatment. Uptake of TPT did not differ significantly between the 6H and 3HP groups (OR 1.03, 95%CI 0.86-1.24). However, people who initiated 3HP had 2.3 times greater odds (95% CI 1.9-2.8) of completing treatment than those who initiated 6H after adjusting for age and sex.CONCLUSION: In programmatic settings in a high-burden country, household contacts of all ages were more likely to complete TPT with shorter weekly regimens, although treatment uptake rate for the two regimens was similar.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Direct Experimental Evidence for Substrate Adatom Incorporation into a Molecular Overlayer

While the phenomenon of metal substrate adatom incorporation into molecular overlayers is generally believed to occur in several systems, the experimental evidence for this relies on the interpretation of scanning tunneling microscopy (STM) images, which can be ambiguous and provides no quantitative structural information. We show that surface X-ray diffraction (SXRD) uniquely provides unambiguous identification of these metal adatoms. We present the results of a detailed structural study of the Au(111)-F₄TCNQ system, combining surface characterization by STM, low-energy electron diffraction, and soft X-ray photoelectron spectroscopy with quantitative experimental structural information from normal incidence X-ray standing wave (NIXSW) and SXRD, together with dispersion-corrected density functional theory (DFT) calculations. Excellent agreement is found between the NIXSW data and the DFT calculations regarding the height and conformation of the adsorbed molecule, which has a twisted geometry rather than the previously supposed inverted bowl shape. SXRD measurements provide unequivocal evidence for the presence and location of Au adatoms, while the DFT calculations show this reconstruction to be strongly energetically favored.

A smart and responsive crystalline porous organic cage membrane with switchable pore apertures for graded molecular sieving

Membranes with high selectivity offer an attractive route to molecular separations, where technologies such as distillation and chromatography are energy intensive. However, it remains challenging to fine tune the structure and porosity in membranes, particularly to separate molecules of similar size. Here, we report a process for producing composite membranes that comprise crystalline porous organic cage films fabricated by interfacial synthesis on a polyacrylonitrile support. These membranes exhibit ultrafast solvent permeance and high rejection of organic dyes with molecular weights over 600 g mol^-1. The crystalline cage film is dynamic, and its pore aperture can be switched in methanol to generate larger pores that provide increased methanol permeance and higher molecular weight cut-offs (1,400 g mol^-1). By varying the water/methanol ratio, the film can be switched between two phases that have different selectivities, such that a single, 'smart' crystalline membrane can perform graded molecular sieving. We exemplify this by separating three organic dyes in a single-stage, single-membrane process.

Green synthesis of gold nanaoparticles using Delphinium Chitralense tuber extracts, their characterization and enzyme inhibitory potential

Green synthesis has been introduced as an alternative to chemical synthesis due to the serious consequences. Metal nanoparticles synthesized through green approach have different pharmaceutical, medical and agricultural applications. The present study followed a green and simple route for the preparation of potentially bioactive gold nanoparticles (Au NPs). Au NPs were prepared via green synthesis approach using crude basic alkaloidal portion of the tuber of Delphinium chitralense. The green synthesized Au NPs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) fourier transform infrared (FTIR), and UV-Visible spectrophotometer. Morphological analysis shows that Au NPs have cubic geometry with different sizes. UV-Vis spectroscopic analysis confirmed the synthesis of Au NPs while XRD proved their pure crystalline phase. The Au NPs showed promising dose dependent inhibition of both AChE and BChE as compared to the crude as well as standard drug.

A keyhole approach gives a sound repair for ileal conduit parastomal hernia

PURPOSE

The purpose of this study was to report and evaluate a laparoscopic surgical technique for the treatment of parastomal hernia (PSH) after ileal conduit urinary diversion aiming to minimize PSH recurrence and perioperative complications.

METHODS

We retrospectively evaluated all patients who underwent a PSH (after ileal conduit urinary diversion) repair at Addenbrookes Hospital, Cambridge. As a surgical approach, a laparoscopic repair with mesh was utilized in all cases. Subsequently, we performed a voluntary follow-up of the patients to evaluate long-term recurrence and complication rates. In addition, we conducted a reassessment of the cross-sectional imaging available.

RESULTS

Between November 2008 and December 2019, 27 patients underwent hernia repair due to a clinically significant hernia. Out of those patients, one suffered from a post-operative wound infection. In total 23 patients participated in the follow-up with a median follow-up period of 91 months. Follow-up examination revealed two cases of recurrent PSH (8.7% of patients followed up), four patients suffered from minor complications (14.8%).

CONCLUSION

Repair of PSH associated with ileal conduit is particularly scarce. Our surgical approach presents the only laparoscopic case series of an effective method for treating a PSH from an ileal conduit with a low complication and recurrence rate.

Glycogen synthase kinase-3 (GSK-3) a magic enzyme: it's role in diabetes mellitus and glucose homeostasis, interactions with fluroquionlones. A mini-review

Diabetes mellitus (DM) is a non-communicable disease throughout the world in which there is persistently high blood glucose level from the normal range. The diabetes and insulin resistance are mainly responsible for the morbidities and mortalities of humans in the world. This disease is mainly regulated by various enzymes and hormones among which Glycogen synthase kinase-3 (GSK-3) is a principle enzyme and insulin is the key hormone regulating it. The GSK-3, that is the key enzyme is normally showing its actions by various mechanisms that include its phosphorylation, formation of protein complexes, and other cellular distribution and thus it control and directly affects cellular morphology, its growth, mobility and apoptosis of the cell. Disturbances in the action of GSK-3 enzyme may leads to various disease conditions that include insulin resistance leading to diabetes, neurological disease like Alzheimer's disease and cancer. Fluoroquinolones are the most common class of drugs that shows dysglycemic effects via interacting with GSK-3 enzyme. Therefore, it is the need of the day to properly understand functions and mechanisms of GSK-3, especially its role in glucose homeostasis via effects on glycogen synthase.

Structure, Nanomechanical Properties, and Wettability of Organized Erucamide Layers on a Polypropylene Surface

Understanding the nanostructure and nanomechanical properties of surface layers of erucamide, in particular the molecular orientation of the outermost layer, is important to its widespread use as a slip additive in polymer materials. Extending our recent observations of nanomorphologies of erucamide layers on a hydrophilic silica substrate, here we evaluate its nanostructure on a more hydrophobic polypropylene surface. Atomic force microscopy (AFM) imaging revealed the molecular packing, thickness, and surface coverage of the erucamide layers, while peak force quantitative nanomechanical mapping (QNM) showed that erucamide reduced the adhesive response on polypropylene. Synchrotron X-ray reflectivity (XRR) was used to probe the out-of-plane structure of the surface layers. Static contact angle measurements further corroborated on the resulting wettability, also demonstrating the efficacy of erucamide physisorption in facilitating control over polypropylene surface wetting. The results show the formation of erucamide monolayers, bilayers and multilayers, depending on the concentration in the spin-cast solution. Correlation of AFM, XRR and wettability results consistently points to the molecular orientation in the outermost layer, i.e. with the erucamide tails pointing outward for the surface nanostructures with different morphologies (i.e., bilayers and multilayers). Rare occurrence of monolayers with exposed hydrophilic head groups were observed only at the lowest erucamide concentration. Compared with our previous observations on the hydrophilic surface, the erucamide surface coverage was much higher on the more hydrophobic propylene surface at similar erucamide concentrations in the spin-cast solution. Furthermore, the structure, molecular orientation and nanomechanical properties of the spin-cast erucamide multilayers atop polypropylene were also similar to those on industrially relevant polypropylene fibers coated with erucamide via blooming. These findings shed light on the nanostructural features of the erucamide surface layer underpinning its nanomechanical properties, relevant to many applications in which erucamide is commonly used as a slip additive.

Incidence, patterns, risk factors, and histopathological findings of liver injury in coronavirus disease 2019 (COVID-19): a scoping review

BACKGROUND

Coronavirus disease 2019 (COVID-19) exhibits many extrapulmonary manifestations, including liver injury. This scoping review aimed to provide insight into the incidence, patterns, risk factors, histopathological findings, and relationship with disease severity of COVID-19-associated liver injury. Furthermore, we identified existing gaps in the research on the hepatic manifestations of COVID-19 and highlighted areas for future investigations.

METHODS

A scoping review was conducted following the methodological framework suggested by Arksey and O'Mallay. Five online databases, along with grey literature, were searched for articles published until 22 May 2020, and we included 62 articles in the review. The research domains, methodological characteristics, and key conclusions were included in the analysis.

RESULTS

Retrospective observational studies comprised more than one third (41.9%) of the included publications, and 77.8% were conducted on living patients. The incidence of liver injury varied widely across the studies (4.8%-78%), and liver injury was frequently associated with severe COVID-19. We identified the following risk factors for liver injury: male sex, lymphopoenia, gastrointestinal involvement, old age, increased neutrophil count, and the use of hepatotoxic drugs. Histopathological findings indicate that COVID-19 has direct cytopathic effects and causes liver function test derangements secondary to inflammation, hypoxia, and vascular insult.

CONCLUSIONS

Liver injury following COVID-19 infection is common and primarily hepatocellular, with a greater elevation of aspartate aminotransferase tahn of alanine aminotransferase. However, the evidence regarding hepatic failure secondary to COVID-19 is insufficient. Standardised criteria to diagnose liver injury need to be devised. Current use of hepatotoxic drugs necessitates close monitoring of liver function.

Synthesis of CuO-NPS by simple wet chemical method using various dicarboxylic acid salts as precursors: Spectral characterization and in-vitro biological evaluation

In this study, a simple chemical reduction method was employed to synthesize CuO-NPs.  Various dicarboxylic acids were converted into Cu(II) salt of dicarboxylic acid which were used as precursors. NPs were produced by reducing precursors with NaBH4. Characteristics of synthesized NPs were investigated by using important analytical techniques including Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM). Developed NPs were investigated for their antibacterial activity against a range of bacterial strains by employing agar well diffusion method. CuO-NPs exhibited good to moderate activity against E-Coli, B. Subtilis and poor activity against K. pneumonia and Methicillin-resistant Staphylococcus aureus (MRSA). It was found that amongst all experienced compounds sample 2 showed good activity with minimum inhibition concentration (MIC) 10 µg/mL (zone of inhibition: 22± 0.12 mm) while sample 3 showed poor activity with MIC 40 µg/mL (zone of inhibition: 8.0 ± 0.18 mm).                     KEY WORDS: CuO-NPs, Dicarboxylic acids, Sodium borohydride, Antibacterial study   Bull. Chem. Soc. Ethiop. 2020, 34(2), 323-334 DOI: https://dx.doi.org/10.4314/bcse.v34i2.10

Growth and electronic properties of bi- and trilayer graphene on Ir(111)

Interesting electronic properties arise in vertically stacked graphene sheets, some of which can be controlled by mutual orientation of the adjacent layers. In this study, we investigate the MBE grown multilayer graphene on Ir(111) by means of STM, LEED and XPS and we examine the influence of the substrate on the geometric and electronic properties of bilayer graphene by employing XSW and ARPES measurements. We find that the MBE method does not limit the growth to two graphene layers and that the wrinkles, which arise through extended carbon deposition, play a crucial role in the multilayer growth. We also find that the bilayer and trilayer graphene sheets have graphitic-like properties in terms of the separation between the two layers and their stacking. The presence of the iridium substrate imposes a periodic potential induced by the moiré pattern that was found to lead to the formation of replica bands and minigaps in bilayer graphene. From tight-binding fits to our ARPES data we find that band renormalization takes place in multilayer graphene due to a weaker coupling of the upper-most graphene layer to the iridium substrate.

Barriers to implementing a national health screening program for men in Malaysia: An online survey of healthcare providers

INTRODUCTION

This study aimed to determine the views and practices of healthcare providers and barriers they encountered when implementing the national health screening program for men in a public primary care setting in Malaysia.

METHODS

An online survey was conducted among healthcare providers across public health clinics in Malaysia. All family medicine specialists, medical officers, nurses and assistant medical officers involved in the screening program for adult men were invited to answer a 51-item questionnaire via email or WhatsApp. The questionnaire comprised five sections: participants' socio-demographic information, current screening practices, barriers and facilitators to using the screening tool, and views on the content and format of the screening tool.

RESULTS

A total of 231 healthcare providers from 129 health clinics participated in this survey. Among them, 37.44% perceived the implementation of the screening program as a "top-down decision." Although 37.44% found the screening tool for adult men "useful," some felt that it was "time consuming" to fill out (38.2%) and "lengthy" (28.3%). In addition, 'adult men refuse to answer' (24.1%) was cited as the most common patient-related barrier.

CONCLUSIONS

This study provided useful insights into the challenges encountered by the public healthcare providers when implementing a national screening program for men. The screening tool for adult men should be revised to make it more user-friendly. Further studies should explore the reasons why men were reluctant to participate in health screenings, thus enhancing the implementation of screening programs in primary care.

P2804Initial experience with the novel BioMime Morph 40–60 mm long sirolimus-eluting tapered stent in long coronary lesions

Aims

Aims: Long lesions treated with overlapping stents has been reported to be associated with healing problems and/or adverse events. The novel BioMime Morph is a 40, 50 and 60 mm long sirolimus-eluting cobalt chromium stent (65 μm strut thickness, biodegradable polymer) with a tapered design (0.5 mm taper from proximal to distal end) and is available in the following proximal and distal diameters (2.75–2.2 5mm, 3–2.5 mm and 3.5–3 mm). It can be a novel alternative for treatment of long coronary lesions, overcoming the limitations of overlapping stents.

Methods and results

Methods: Data was evaluated from our centre's prospective BioMime Morph database from August 2016 - January 2019. Primary endpoint was device oriented composite endpoint (DOCE: cardiac death, TV-MI, TLR and TVR). Secondary endpoints were technical (successful Morph implantation) and procedural success (successful procedure with Morph without in-hospital MACE).

Results

103 patients had BioMime Morph stents implanted, with mean follow up of 411 (±214) days and a mean age of 66 (±11) years. Co-morbidities included hypertension (58%), hypercholesterolemia (38%), diabetes mellitus (28%), PVD (2%), CVD (5%), CKD (12%), previous MI (17%), smoking (40%) and positive family history (20%). There was history of previous PCI in 18% and CABG in 4%. Indication for PCI was predominantly ACS (78% including 13% STEMI), 15% were CTOs. 80% of the procedures were performed via radial access using 5–6F sheath in 73%. Vessels treated included LAD (43%), Cx (12%) and RCA (45%). Pre-dilatation was performed in 96% including use of non-complaint balloons in 51%, scoring balloons in 12% and rotablation in 4%. Post-dilatation was performed in 99%. Buddy wire was used in 41% while a guideliner used in 13%. Technical success (secondary endpoint) was achieved in 100 whilst procedural success was achieved in 96% (4 cases of contrast induced nephropathy). Cumulative DOCE (primary endpoint) was % (cardiac death 1%, TV-MI 1%, definitive ST 0%, possible ST 1%, TLR 2% and TVR 2%). OCT follow up at 1 month, 3 month and 6 months in 2 patients showed endothelialisation even at 1 month.

Conclusions

Our initial experience of the use of the novel BioMime Morph tapered DES for treatment of long coronary lesions exhibit promising results in short to medium follow-up. Elution of the drug in 1 month along with biodegradable polymer and ultra thin struts potentially helps early healing and raises the possibility of short DAPT even in these complex long lesions. BioMime Morph stents can potentially be an alternative to overlapping conventional stents for treating long coronary lesions.

Interaction of a tripeptide with titania surfaces: RGD adsorption on rutile TiO2(110) and model dental implant surfaces

The adsorption of peptides on metal oxides is an area of significant interest, both fundamentally and in a number of technologically important areas. These range from the integration of biomaterials in the body, to denaturation of protein therapeutics and the use of biomolecules and bioinspired materials in synthesis and stabilization of novel nanomaterials. Here we present a study of the tripeptide arginylglycylaspartic acid (RGD) on the surfaces of vacuum-prepared single crystalline TiO₂(110), pyrocatechol-capped TiO₂(110), and model SLA and SLActive dental implant samples. X-ray Photoelectron Spectroscopy and Scanning Tunneling Microscopy show that the RGD adsorption mode on the single crystal is consistent with bonding through the deprotonated carboxylate groups of the peptide to surface Ti atoms of the substrate. Despite the increased hydrophobicity of the pyrocatechol-capped TiO₂(110) surface RGD adsorption from solution increases following this surface treatment. RGD adsorption on SLA and SLActive surfaces shows that the SLActive surface has a greater uptake of RGD. The RGD uptake on the pyrocatechol capped single crystal and the model implant surfaces suggest that the ease with which surface contaminant hydrocarbons are removed from the surface has a greater influence on peptide adsorption than hydrophobicity/hydrophilicity of the surface.

Improving childhood tuberculosis detection and treatment through facility-based screening in rural Pakistan

SETTING

Many children with tuberculosis (TB) remain undiagnosed due to the absence of services, lack of child-friendly diagnostics and underappreciation of TB as a common cause of childhood illness.

OBJECTIVE

To show the impact of systematic verbal screening and contact tracing with appropriate management services on TB case finding in pediatric populations.

DESIGN

Between October 2014 and March 2016, children were verbally screened at the pediatric out-patient departments of four public hospitals in Jamshoro District, Pakistan. Children with symptoms or risk of TB were referred for clinical evaluation and free chest X-ray and bacteriological tests. Children with TB were started on treatment and their care givers asked to bring household members to the hospital for screening.

RESULTS

Over 105 000 children were verbally screened and 5880 presumptive childhood TB patients were identified; 1417 children (prevalence 1.3%) were diagnosed with TB; 43% were female. The median age was 5 years; 82% had pulmonary TB. An additional 390 children with TB were diagnosed through contact tracing. These activities resulted in a three-fold increase in pediatric TB case notifications.

CONCLUSION

Systematic verbal screening with clinical evaluation and free diagnostics can identify children with TB who may otherwise be missed in rural health settings.

Water-Induced Reversal of the TiO2(011)-(2 × 1) Surface Reconstruction: Observed with in Situ Surface X-ray Diffraction

The (011) termination of rutile TiO₂ is reported to be particularly effective for photocatalysis. Here, the structure of the interface formed between this substrate and water is revealed using surface X-ray diffraction. While the TiO₂(011) surface exhibits a (2 × 1) reconstruction in ultra-high vacuum (UHV), this is lifted in the presence of a multilayer of water at room temperature. This change is driven by the formation of Ti-OH at the interface, which has a bond distance of 1.93 ± 0.02 Å. The experimental solution is in good agreement with density functional theory and first-principles molecular dynamics calculations. These results point to the important differences that can arise between the structure of oxide surfaces in UHV and technical environments and will ultimately lead to an atomistic understanding of the photocatalytic process of water splitting on TiO₂ surfaces.

Phenotype and Variant Spectrum in the LAMB3 Form of Amelogenesis Imperfecta

Amelogenesis imperfecta (AI) is a heterogeneous group of inherited disorders characterized by abnormal formation of dental enamel, either in isolation or as part of a syndrome. Heterozygous variants in laminin subunit beta 3 ( LAMB3) cause AI with dominant inheritance in the absence of other cosegregating clinical features. In contrast, biallelic loss-of-function variants in LAMB3 cause recessive junctional epidermolysis bullosa, characterized by life-threatening skin fragility. We identified 2 families segregating autosomal dominant AI with variable degrees of a distinctive hypoplastic phenotype due to pathogenic variants in LAMB3. Whole exome sequencing revealed a nonsense variant (c.3340G>T, p.E1114*) within the final exon in family 1, while Sanger sequencing in family 2 revealed a variant (c.3383-1G>A) in the canonical splice acceptor site of the final exon. Analysis of cDNA from family 2 revealed retention of the final intron leading to a premature termination codon. Two unerupted third molar teeth from individual IV:5 in family 2 were subject to computerized tomography and scanning electron microscopy. LAMB3 molar teeth have a multitude of cusps versus matched controls. LAMB3 enamel was well mineralized but pitted. The architecture of the initially secreted enamel was abnormal, with cervical enamel appearing much less severely affected than coronal enamel. This study further defines the variations in phenotype-genotype correlation for AI due to variants in LAMB3, underlines the clustering of nonsense and frameshift variants causing AI in the absence of junctional epidermolysis bullosa, and highlights the shared AI phenotype arising from variants in genes coding for hemidesmosome proteins.

Studies of the Corneocytary Pathway Across the Stratum Corneum. Part I: Diffusion of Amino Acids Into the Isolated Corneocytes

Amino acids (AAs), important constituents of natural moisturizing factors (NMFs) of the skin are decreased in diseased conditions such as psoriasis and atopic dermatitis. No study so far investigated the uptake of AAs into isolated corneocytes (COR). The present study was performed using 19 AAs, including taurine (TAU), to measure their amount diffused into the COR and binding of these AAs to keratin. Incubation of alanine, aspartic acid, asparagine, glutamine, glutamic acid, histidine, proline, serine and TAU with the isolated COR showed uptake after 24 h of 51.6, 95.4, 98.6, 94.1, 95.6, 90.1, 94.6, 72.9 and 57.8 %, respectively, into the COR but no binding with keratin. Uptake of TAU was validated by time dependent in-vitro diffusion models 'without COR and 'with COR'. The time dependent curve fitting showed that in in-vitro diffusion model 'without COR' there was no change in the total concentration of TAU until 72 hours, while in diffusion model 'with COR' the total conc. decreased to 37.8 % after 72 hours. The Pearson's correlation coefficient 'r' between the conc. curves of both in-vitro diffusion models was -0.54 that was an evidence of significant amount of TAU uptake by the COR. AAs as part of the NMFs have a great potential to be diffused into the COR. This property of the AAs can be employed in further dermatological research on diseased or aged skin conditions with NMFs deficiency.

Therapeutic Radiographers' perceptions of the barriers and enablers to effective smoking cessation support

INTRODUCTION

Tobacco smoking during and post radiotherapy is associated with increased treatment toxicity and increased cancer related mortality. Routine delivery of smoking cessation advice is inconsistent in practice. This study identifies the key barriers and facilitators to the provision of effective smoking cessation conversations in radiotherapy practice.

METHODS

A baseline questionnaire (n = 43) was used to identify current practice, barriers and facilitators to smoking cessation in radiotherapy and to inform a topic guide for follow up focus groups (n = 5). Ethical approval was obtained through the 4 NHS trusts and the Health Research Authority. Focus group transcription was coded by two researchers.

RESULTS

Therapeutic Radiographers initiate health behaviour conversations with patients; there are a number of factors that facilitate the likelihood of a health behaviour conversation; indication that a patient smokes anatomical site and presence of acute effects. Key barriers to smoking cessation provision include; lack of training, limited knowledge, limitations as a result of poor clinical infrastructure, local culture and perceptions that patients do not prioritise smoking cessation during treatment.

CONCLUSION

Therapeutic Radiographers have the motivation to provide smoking cessation advice, however they require further training to develop knowledge and skills in relation to benefits of smoking cessation and cessation strategies. Therapeutic Radiographers also expect that patients will respond negatively to smoking cessation advice, and that this might be damaging to the therapeutic relationship. Departmental culture and trust infrastructure can also significantly inhibit the provision of smoking cessation in radiotherapy practice and further support to implement NICE guidance is required.

Structure of a Superhydrophilic Surface: Wet Chemically Prepared Rutile-TiO2(110)(1 × 1)

Surface X-ray diffraction has been employed to quantitatively determine the geometric structure of an X-ray-induced superhydrophilic rutile-TiO₂(110)(1 × 1) surface. A scatterer, assumed to be oxygen, is found at a distance of 1.90 ± 0.02 Å above the five-fold-coordinated surface Ti atom, indicating surface hydroxylation. Two more oxygen atoms, situated further from the substrate, are also included to achieve the optimal agreement between experimental and simulated diffraction data. It is concluded that these latter scatterers are from water molecules, surface-localized through hydrogen bonding. Comparing this interfacial structure with previous studies suggests that the superhydophilicity of titania is most likely to be a result of the depletion of surface carbon contamination coupled to extensive surface hydroxylation.

Tuberculosis in Canada: 2017

BACKGROUND

Tuberculosis (TB) is a major global health problem that affected an estimated 10 million people worldwide in 2017. The Public Health Agency of Canada monitors active TB disease through a national surveillance system, which is a collaborative effort with the provinces and territories.

OBJECTIVE

To present an epidemiological summary of active TB cases reported in 2017. Results are discussed in the context of the previous year's data. Treatment outcomes for cases diagnosed in 2016 are also presented.

METHODS

The Canadian Tuberculosis Reporting System is a case-based surveillance system that maintains non-nominal data on people diagnosed with active TB disease in Canada. Data are collected annually from the provinces and territories, analyzed by the Public Health Agency of Canada and validated by each province and territory.

RESULTS

There were 1,796 cases of active TB reported in Canada in 2017 compared with 1,750 cases in 2016, representing a 2.6% increase. There was a corresponding increase in the incidence rate from 4.8 to 4.9 per 100,000 population. Foreign born individuals continued to make up the majority of cases (71.8%) and the incidence rate remained highest among Canadian born Indigenous people (21.5 per 100,000 population), in particular, among the Inuit population (205.8 per 100,000 population). Consistent with the previous decade, TB incidence rates in 2017 continued to be higher among males (5.5 per 100,000) compared with females (4.3 per 100,000), and the majority of cases (45.6%) were between the ages of 15 and 44 years. The incidence rate was highest among adults over 75 years of age (13.8 cases per 100,000 for males and 7.2 for females). Of the TB cases diagnosed in 2016 where outcomes were reported, 80.4% were treated successfully.

CONCLUSION

Although the incidence rate of TB in Canada in 2017 remained low in the global context and has been relatively stable over the last decade, both the case count and rate have been gradually increasing since 2014. Indigenous and foreign born Canadians continued to be disproportionately represented among TB cases. Canadian TB surveillance data are an important source of information for monitoring progress and informing public health action related to reducing the burden of TB in Canada, with the ultimate goal of TB elimination.

Water Dissociates at the Aqueous Interface with Reduced Anatase TiO2 (101)

Elucidating the structure of the interface between natural (reduced) anatase TiO2 (101) and water is an essential step toward understanding the associated photoassisted water splitting mechanism. Here we present surface X-ray diffraction results for the room temperature interface with ultrathin and bulk water, which we explain by reference to density functional theory calculations. We find that both interfaces contain a 25:75 mixture of molecular H2O and terminal OH bound to titanium atoms along with bridging OH species in the contact layer. This is in complete contrast to the inert character of room temperature anatase TiO2 (101) in ultrahigh vacuum. A key difference between the ultrathin and bulk water interfaces is that in the latter water in the second layer is also ordered. These molecules are hydrogen bonded to the contact layer, modifying the bond angles.

Abstract P3-07-05: Potential of breast tumour kinase (Brk) as a therapeutic target: Brk modulates drug responses in breast cancer cell lines

Background: Breast tumour kinase (Brk/PTK6) is over-expressed in up to 86% of all breast cancers and has shown to be involved in the processes regulating tumour development and progression. A few Brk inhibitors are in development and our studies indicate potential for a Brk inhibitor to be used in combination with current breast cancer therapies. Furthermore the effect of common breast cancer therapies and Brk inhibition on the expression of ptk6 as well as it's alternatively spliced isoform (ALT-PTK6) have not been previously been shown. Using qPCR we have determined gene expression of both genes before and after treatment.

Methods: Breast cancer cell lines T47D, GI101, BT474, SKBR3, MDA-MB 231, and MDA-MB 436 were treated with Brk inhibitor, Compound 4f (Mahmoud et al, 2012) and common breast cancer therapies (Taxol, Doxorubicin, Lapatinib and Tamoxifen) at concentrations ranging from 0µM to 10µM. Western blotting was carried out to determine levels of Brk and activation of Brk substrate; STAT3 after treatment with Brk inhibitor. RNA was extracted using Qiagen Mini RNeasy prep kit, cDNA synthesized using Invitrogen Superscript II Reverse Transcriptase and qPCR carried out using primers specific for PTK6 or primers that recognized both transcripts (PTK6 and ALT-PTK6) for total expression.

Results: In all cell lines tested there was a moderate reduction in cell proliferation following treatment with the Brk inhibitor (4f). However a greater effect was observed in combination therapy. Triple negative breast cancer cell lines MDA-MB 231 and MDA-MB 436 were treated with Compound 4f and Taxol or Doxorubicin (n=3) resulting in modest but statistically significant reduction in cell numbers. Cell responses to Taxol in both cell lines were significantly greater in the presence of 4f over a range of doses (P between 0.05 and 0.007). Responses to Doxorubicin were also significantly improved in the presence of 4f (P<0.03 for MDA-MB-231 and P=0.03 for MDA-MB-436). Co-treatment of HER2 positive breast cancer cell lines BT474 and Sk-Br-3 with Lapatinib and 4f showed significant increase in responses over a range of doses between 0.31 and 5µM (n=3, P<0.05 for BT474 and P between 0.03 and 0.0004 for Sk-Br-3). In comparison to untreated cells, there was statistically significant reduction in ptk6 and Total gene expression observed at various time points within multiple breast cancer cell lines in response to Compound 4f treatment. Significant differences between untreated and treated cells for T47D cell line were at 8 hours post treatment (p=0.02), 2 and 4 hours post treatment in GI101 cell line (p=0.04 and p=0.02 respectively), 8 and 24 hours post treatment in Sk-Br-3 (p=0.001 and p=0.017 respectively) and 8 hours post treatment in MDA-MB 231 cell lines (p=0.03).

Conclusion: Inhibition of Brk led to a decrease in ptk6 gene expression. Expression ratios of ptk6 and the short isoform ALT-PTK6 were determined and a reduction of ptk6 gene correlated with elevation of ALT-PTK6 and vice versa. Inhibition of Brk also indicated an increase in breast cancer cell sensitivity to current breast cancer therapies. Our studies thus indicate potential for inhibition of Brk kinase activity in combination with current breast cancer treatments.

Citation Format: Hussain H, Harvey A. Potential of breast tumour kinase (Brk) as a therapeutic target: Brk modulates drug responses in breast cancer cell lines [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-07-05.

Structure of a model TiO2 photocatalytic interface

The interaction of water with TiO₂ is crucial to many of its practical applications, including photocatalytic water splitting. Following the first demonstration of this phenomenon 40 years ago there have been numerous studies of the rutile single-crystal TiO₂(110) interface with water. This has provided an atomic-level understanding of the water-TiO₂ interaction. However, nearly all of the previous studies of water/TiO₂ interfaces involve water in the vapour phase. Here, we explore the interfacial structure between liquid water and a rutile TiO₂(110) surface pre-characterized at the atomic level. Scanning tunnelling microscopy and surface X-ray diffraction are used to determine the structure, which is comprised of an ordered array of hydroxyl molecules with molecular water in the second layer. Static and dynamic density functional theory calculations suggest that a possible mechanism for formation of the hydroxyl overlayer involves the mixed adsorption of O₂ and H₂O on a partially defected surface. The quantitative structural properties derived here provide a basis with which to explore the atomistic properties and hence mechanisms involved in TiO₂ photocatalysis.

Quantitative Structure of an Acetate Dye Molecule Analogue at the TiO2-Acetic Acid Interface

The positions of atoms in and around acetate molecules at the rutile TiO₂(110) interface with 0.1 M acetic acid have been determined with a precision of ±0.05 Å. Acetate is used as a surrogate for the carboxylate groups typically employed to anchor monocarboxylate dye molecules to TiO₂ in dye-sensitized solar cells (DSSC). Structural analysis reveals small domains of ordered (2 × 1) acetate molecules, with substrate atoms closer to their bulk terminated positions compared to the clean UHV surface. Acetate is found in a bidentate bridge position, binding through both oxygen atoms to two 5-fold titanium atoms such that the molecular plane is along the [001] azimuth. Density functional theory calculations provide adsorption geometries in excellent agreement with experiment. The availability of these structural data will improve the accuracy of charge transport models for DSSC.

Development of new UV-vis spectroscopic microwave-assisted method for determination of glucose in pharmaceutical samples

A new UV-Visible spectroscopic method assisted with microwave for the determination of glucose in pharmaceutical formulations was developed. In this study glucose solutions were oxidized by ammonium molybdate in the presence of microwave energy and reacted with aniline to produce a colored solution. Optimum conditions of the reaction including wavelength, temperature, and pH of the medium and relative concentration ratio of the reactants were investigated. It was found that the optimal wavelength for the reaction is 610 nm, the optimal reaction time is 80s, the optimal reaction temperature is 160°C, the optimal reaction pH is 4, and the optimal concentration ratio aniline/ammonium molybdate solution was found to be 1:1. The limits of detection and quantification of the method are 0.82 and 2.75 ppm for glucose solution, respectively. The use of microwaves improved the speed of the method while the use of aniline improved the sensitivity of the method by shifting the wavelength.

Effectiveness of pictorial health warning on cigarette packages: A cross-sectional study in Sarawak, Malaysia

INTRODUCTION

Specific health warning placed on the tobacco product packages is considered as an effective and low-cost method for increasing the knowledge and awareness among the community. Thus, a study was conducted to assess the perception of pictorial health warnings (PHWs) against smoking among the adult rural population of Sarawak.

METHODS

Cross-sectional data were collected from 10 villages in Kota Samarahan and Kuching Division by face to face interview using modified Global Adult Tobacco Survey questionnaire. Nonprobability sampling method was adopted to select the villages. All the households of the selected villages were visited and an adult member was selected randomly from each house irrespective of the sex. After missing value imputation, 1000 data were analysed using statistical software IBM SPSS 20.0 version.

RESULTS

Analysis showed that 28.8% of the respondents were current smokers, 7.8% were past smokers and the rest were non-smokers. Six items of pictorial health warnings were evaluated with five point Likert's scales for attractiveness, fearfulness and adequacy of the information. Analysis revealed that the majority of the respondents had perceived awareness on PHWs, but the smokers believed that this was not adequate to make them quit smoking. Only one-fifth (19.7%) of them reported that current pictorial health warnings were sufficient to motivate people to quit smoking.

CONCLUSION

Though the PHWs on cigarette packages are appealing, it is not sufficient as a reason to stop smoking. Thus, an approach using an integrated anti-tobacco public health programme should be focused into the specific targeted community.