Multifunctional Textiles from New Zealand Wool Coloured with Silver or Silver Halide Nanoparticles

Significant opportunities exist for the development of innovative multifunctional textiles for high value market applications. Composites that combine the inherent properties of their all precursor components in a synergistic manner in particular are sought after. Thus the unique chemical and physical properties of silver or silver halide nanoparticles are combined with the traditional properties of wool, thereby producing an innovative multifunctional composite. The prepared wool - silver or - silver halide nanoparticle composites retain the elasticity, thermal insulation and softness of the wool, whilst the colour, conductivity and antimicrobial properties owing to the nanoparticles are also incorporated. Due to the multi functions of silver the resulting high quality, high value product has numerous applications within the fashion and interior furnishings industries. The wools employed for the preparation of wool - silver or - silver chloride nanoparticle composites are merino wool and crossbred wool. Merino wool provides the main focus of the research. The experimental approach for the colouring of merino by silver or silver halide nanoparticles follows a novel and proprietary approach. The preparation of wool - silver nanoparticle composites includes two different procedures: 1) the synthesis of nanoparticles in the presence of wool fibres, using an external reducing agent/stabilising agent (trisodium citrate (TSC)), with the in situ binding of nanoparticles to the surface of the fibre; and 2) the synthesis of nanoparticles in the presence of the merino wool substrate, using the reducing nature of wool, with the in situ binding of nanoparticles within the fibre. Merino wool - silver nanoparticle composites range in colour from very pale yellow, through gold to tan and brown. The successful preparation of wool - silver halide nanoparticle composites includes the in situ precipitation of nanoparticles within the wool fibre. This is accomplished by doping the wool, with one of the halides, Cl⁻, Br⁻ or I⁻, prior to treatment with a silver containing solution. The colour of merino wool - silver halide nanoparticle composites can be tuned from pink to peach to purple. The colour of the wool - silver or - silver halide nanoparticle composites is due to surface plasmon resonances, i.e. the interaction of electromagnetic radiation of visible light with the nanoparticles. The reflected colour is dependent upon the size and shape of the nanoparticle, in addition to the refractive index of the stabilising agent surround the particle. The refractive index of silver chloride or silver bromide differs to that of the reducing/stabilising agent implemented, TSC, or merino, and thus the reflected colour is altered. The colour of silver iodide nanoparticles appears to be due to the interaction of light with the formed nanoparticles themselves and not due to the formation of silver nanoparticles within the silver iodide nanoparticles. In addition to the colour being measured by UV-vis in reflectance mode, the characterisation of the hues of the prepared composites were monitored by obtaining CIE L*, a*, b* values via the HunterLab Colourquest. The morphological characterisation of merino wool coloured by silver or silver chloride nanoparticles was undertaken using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). When merino wool - silver nanoparticle composites are prepared using an external reducing agent, the formed nanoparticles predominantly bind to the wool fibres surfaces only. When the reducing nature of wool is used for composite preparation, nanoparticles are formed within the fibre and are dispersed throughout the fibres core, with few being present on the surface. Comparable studies of merino wool - silver halide nanoparticle composites showed that silver halide nanoparticles are formed and stabilised just below the fibres surface. The confirmation of silver or silver halide species within the prepared composites was undertaken using energy dispersive spectroscopy (EDS), scanning transmission spectroscopy (STEM), x-ray diffraction (XRD) and x-ray absorption near edge spectroscopy (XANES). Colourfastness tests to washing, rubbing and exposure to chlorinated swimming pool water were undertaken to assess the robustness of the prepared composites in terms of their colour. These tests indicate that the colours of both merino wool - silver and - silver chloride nanoparticle composites are very stable. The leaching of silver during the washing process was noted to be insignificant, suggesting a strong and stable bond between the fibre substrate and the nanoparticles. X-ray photoelectron spectroscopy (XPS) was used to elucidate the chemical bonding between the wool fibre substrate and the silver or silver halide nanoparticles. The colourfastness of merino wool - silver or - silver halide nanoparticle composites to light however, was not observed. When exposed to UV light for extended periods, a distinct change in colour occurs. Silver nanoparticle composites lighten considerably, whereas their silver chloride nanoparticle counterparts are noted to become grey in their colour. XPS was used in an attempt to determine what leads to the discolouration of the composites. Further research is required however, in order to reduce or halt the colour degradation of merino wool - silver or - silver chloride nanoparticle composites. Silver iodide nanoparticles, on the other hand, show great potential as colourants for wool, exhibiting stable colours over a long time period to light. A range of desirable colours are obtained through the colouring of wool by silver or silver halide nanoparticles. These nanoparticles are strongly bound to the fibres and thus the colours are stable to washing and rubbing, exhibiting insignificant leaching of silver during such processes. Additionally, the prepared silver and silver halide nanoparticle composites tested positive for their antistatic properties, and their antimicrobial activity, providing a high value multifunctional material. Numerous applications within fashion and interior furnishing industries are therefore apparent. However, the evident setback for applications in these fields is the colour instability to light of silver, silver chloride and silver bromide nanoparticles, and thus further studies are required to eliminate this problem. Alternative options exist for the exploitation of the photosensitivity of silver halide nanoparticles within the merino wool composites, or the possibility of using silver or silver halide nanoparticles in combination with other strong dyes for the production of coloured woollen fabrics

Point-of-Care Tests to Strengthen Health Systems and Save Newborn Lives: The Case of Syphilis

Rosanna Peeling and colleagues describe their experience of introducing point-of-care testing to screen for syphilis in pregnant women living in low- and middle-income countries

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND: The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting. METHODS: Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups. RESULTS: Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005). CONCLUSION: Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery

Strange Particle Production in pp Collisions at sqrt(s) = 0.9 and 7 TeV

Peer reviewe

Search for three-jet resonances in pp collisions at √s=7 TeV

This is a Pre-Print version of the Article - Copyright @ 2011 APSA model-independent search for three-jet hadronic resonance production in pp collisions at a center-of-mass energy of 7 TeV has been conducted by the CMS Collaboration at the LHC, using a data sample corresponding to an integrated luminosity of 35 inverse picobarns. Events with high jet multiplicity and a large scalar sum of jet transverse momenta are analyzed. The number of expected standard model background events is found to be in good agreement with the observed events. Limits are set on a model describing the production of R-parity-violating supersymmetric gluino pairs, and gluino masses in the range of 200 to 280 GeV/c^2 are excluded at a 95% confidence level for the first time.This work is supported by the FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF andWCU (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTD (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)

Measurement of the charge ratio of atmospheric muons with the CMS detector

This is the pre-print version of this Article. The official published version can be accessed from the link below - Copyright @ 2010 ElsevierWe present a measurement of the ratio of positive to negative muon fluxes from cosmic ray interactions in the atmosphere, using data collected by the CMS detector both at ground level and in the underground experimental cavern at the CERN LHC. Muons were detected in the momentum range from 5 GeV/c to 1 TeV/c. The surface flux ratio is measured to be 1.2766 \pm 0.0032(stat.) \pm 0.0032 (syst.), independent of the muon momentum, below 100 GeV/c. This is the most precise measurement to date. At higher momenta the data are consistent with an increase of the charge ratio, in agreement with cosmic ray shower models and compatible with previous measurements by deep-underground experiments

Observation of a new Xi(b) baryon

The first observation of a new b baryon via its strong decay into Xi(b)^- pi^+ (plus charge conjugates) is reported. The measurement uses a data sample of pp collisions at sqrt(s) = 7 TeV collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 5.3 inverse femtobarns. The known Xi(b)^- baryon is reconstructed via the decay chain Xi(b)^- to J/psi Xi^- to mu^+ mu^- Lambda^0 pi^-, with Lambda^0 to p pi^-. A peak is observed in the distribution of the difference between the mass of the Xi(b)^- pi^+ system and the sum of the masses of the Xi(b)^- and pi^+, with a significance exceeding five standard deviations. The mass difference of the peak is 14.84 +/- 0.74 (stat.) +/- 0.28 (syst.) MeV. The new state most likely corresponds to the J^P=3/2^+ companion of the Xi(b).Comment: Submitted to Physical Review Letter

Measurements of inclusive W and Z cross sections in pp collisions at root s=7 TeV

This is the pre-print version of the Published Article, which can be accessed from the link below - Copyright @ 2011 Springer VerlagMeasurements of inclusive W and Z boson production cross sections in pp collisions at sqrt(s)=7 TeV are presented, based on 2.9 inverse picobarns of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are combined to give sigma(pp to WX) times B(W to muon or electron + neutrino) = 9.95 \pm 0.07(stat.) \pm 0.28(syst.) \pm 1.09(lumi.) nb and sigma(pp to ZX) times B(Z to oppositely charged muon or electron pairs) = 0.931 \pm 0.026(stat.) \pm 0.023(syst.) \pm 0.102(lumi.) nb. Theoretical predictions, calculated at the next-to-next-to-leading order in QCD using recent parton distribution functions, are in agreement with the measured cross sections. Ratios of cross sections, which incur an experimental systematic uncertainty of less than 4%, are also reported

Cost-effectiveness of easy-access, risk-informed oral pre-exposure prophylaxis in HIV epidemics in sub-Saharan Africa: a modelling study.

BACKGROUND: Approaches that allow easy access to pre-exposure prophylaxis (PrEP), such as over-the-counter provision at pharmacies, could facilitate risk-informed PrEP use and lead to lower HIV incidence, but their cost-effectiveness is unknown. We aimed to evaluate conditions under which risk-informed PrEP use is cost-effective. METHODS: We applied a mathematical model of HIV transmission to simulate 3000 setting-scenarios reflecting a range of epidemiological characteristics of communities in sub-Saharan Africa. The prevalence of HIV viral load greater than 1000 copies per mL among all adults (HIV positive and negative) varied from 1·1% to 7·4% (90% range). We hypothesised that if PrEP was made easily available without restriction and with education regarding its use, women and men would use PrEP, with sufficient daily adherence, during so-called seasons of risk (ie, periods in which individuals are at risk of acquiring infection). We refer to this as risk-informed PrEP. For each setting-scenario, we considered the situation in mid-2021 and performed a pairwise comparison of the outcomes of two policies: immediate PrEP scale-up and then continuation for 50 years, and no PrEP. We estimated the relationship between epidemic and programme characteristics and cost-effectiveness of PrEP availability to all during seasons of risk. For our base-case analysis, we assumed a 3-monthly PrEP cost of US$29 (drug$11, HIV test $4, and$14 for additional costs necessary to facilitate education and access), a cost-effectiveness threshold of $500 per disability-adjusted life-year (DALY) averted, an annual discount rate of 3$100 per DALY averted, a discount rate of 7% per annum, the use of PrEP outside of seasons of risk, and reduced uptake of risk-informed PrEP. FINDINGS: In the context of PrEP scale-up such that 66% (90% range across setting-scenarios 46-81) of HIV-negative people with at least one non-primary condomless sex partner take PrEP in any given period, resulting in 2·6% (0·9-6·0) of all HIV negative adults taking PrEP at any given time, risk-informed PrEP was predicted to reduce HIV incidence by 49% (23-78) over 50 years compared with no PrEP. PrEP was cost-effective in 71% of all setting-scenarios, and cost-effective in 76% of setting-scenarios with prevalence of HIV viral load greater than 1000 copies per mL among all adults higher than 2%. In sensitivity analyses with a $100 per DALY averted cost-effectiveness threshold, a 7% per year discount rate, or with PrEP use that was less well risk-informed than in our base case, PrEP was less likely to be cost-effective, but generally remained cost-effective if the prevalence of HIV viral load greater than 1000 copies per mL among all adults was higher than 3%. In sensitivity analyses based on additional setting-scenarios in which risk-informed PrEP was less extensively used, the HIV incidence reduction was smaller, but the cost-effectiveness of risk-informed PrEP was undiminished. INTERPRETATION: Under the assumption that making PrEP easily accessible for all adults in sub-Saharan Africa in the context of community education leads to risk-informed use, PrEP is likely to be cost-effective in settings with prevalence of HIV viral load greater than 1000 copies per mL among all adults higher than 2%, suggesting the need for implementation of such approaches, with ongoing evaluation. FUNDING: US Agency for International Development, US President's Emergency Plan for AIDS Relief, and Bill & Melinda Gates Foundation