Experience of an anatomic femoral stem in a UK orthopaedic centre beyond 20 years of follow-up.

INTRODUCTION: Increasing interest in the use of anatomical stems has developed as the prevalence of periprosthetic fractures (PPFs) continues to increase. The primary aim of this study was to determine the long-term survivorship and PPF rate of an anatomical femoral stem in a single UK centre. PATIENTS AND METHODS: Between 2000 and 2002, 94 consecutive THAs were performed using the 170 mm Lubinus SP II anatomical femoral stem in our institution. Patient demographics, operative details and clinical outcomes were collected prospectively in an arthroplasty database. Patient records and national radiographic archives were reviewed finally at a mean of 21.5 years (SD 0.7) following surgery to identify occurrence of subsequent revision surgery, dislocation or periprosthetic fracture. RESULTS: Mean patient age at surgery was 65.8 years (SD 12.5, 34-88 years). There were 48 women (51%). Osteoarthritis was the operative indication in 88 patients (94%). Analysis of all-cause THA failure demonstrated a survivorship of 98.5% (95% confidence interval [CI], 98.0-99.3%) at 10 years and 96.7% (94.5-98.9%) at 21 years. The 20-year stem survival for aseptic loosening was 100% with no cases of significant lysis found (lucent line > 2 mm) and no stems required revision. Patient demographics did not appear to influence risk of revision (p > 0.05). There were 2 revisions in total (2 for acetabular loosening with original stems retained). There were no PPFs identified at mean 21.5 year follow-up and 5 dislocations (5%). CONCLUSIONS: The Lubinus SP II 170 mm stem demonstrated excellent survivorship and negligible PPF rates over 20 years following primary THA.

Activity levels and return to work after revision total hip and knee arthroplasty in patients under 65 years of age.

Aims: The aim of this study was to identify predictors of return to work (RTW) after revision lower limb arthroplasty in patients of working age in the United Kingdom. Patients and Methods: We assessed 55 patients aged ≤ 65 years after revision total hip arthroplasty (THA). There were 43 women and 12 men with a mean age of 54 years (23 to 65). We also reviewed 30 patients after revision total knee arthroplasty (TKA). There were 14 women and 16 men with a mean age of 58 years (48 to 64). Preoperatively, age, gender, body mass index, social deprivation, mode of failure, length of primary implant survival, work status and nature, activity level (University of California, Los Angeles (UCLA) score), and Oxford Hip and Knee Scores were recorded. Postoperatively, RTW status, Oxford Hip and Knee Scores, EuroQol-5D (EQ-5D), UCLA score, and Work, Osteoarthritis and Joint-Replacement Questionnaire (WORQ) scores were obtained. Univariate and multivariate analysis was performed. Results: Overall, 95% (52/55) of patients were working before their revision THA. Afterwards, 33% (17/52) RTW by one year, 48% (25/52) had retired, and 19% (10/52) were receiving welfare benefit. RTW was associated with age, postoperative Oxford Hip Score, early THA failure (less than two years), mode of failure dislocation, and contralateral revision (p < 0.05). No patient returned to work after revision for dislocation. Only age remained a significant factor on multivariate analysis (p = 0.003), with 79% (11/14) of those less than 50 years of age returning to work, compared with 16% (6/38) of those aged fifty years or over. Before revision TKA, 93% (28/30) of patients were working. Postoperatively only 7% (2/28) returned to work by one year, 71% (20/28) had retired, and 21% (6/28) were receiving welfare benefits. UCLA scores improved after 43% of revision THAs and 44% of revision TKAs. Conclusion: After revision THA, age is the most significant predictor of RTW: only 16% of those over 50 years old return to work. Fewer patients return to work after early revision THA and none after revision for dislocation. After revision TKA, patients rarely return to work: none return to heavy or moderate manual work. Cite this article: Bone Joint J 2018;100-B:1043-53.

Transfer-printed micro-LED and polymer-based transceiver for visible light communications.

Visible light communications (VLC) is an emerging technology that uses LEDs, such as found in lighting fixtures and displays, to transmit data wirelessly. Research has so far focused on LED transmitters and on photoreceivers as separate, discrete components. Combining both types of devices into a single transceiver format will enable bi-directional VLC and offer flexibility for the development of future advanced VLC systems. Here, a proof of concept for an integrated optical transceiver is demonstrated by transfer printing a microsize LED, the transmitter, directly onto a fluorescent optical concentrator edge-coupled to a photodiode, the receiver. This integrated device can simultaneously receive (downlink) and transmit (uplink) data at rates of 416 Mbps and 165 Mbps, respectively. Its capability to operate in optical relay mode at 337 Mbps is experimentally demonstrated.

Green Perovskite Distributed Feedback Lasers.

A visible perovskite distributed feedback laser is fabricated for the first time. Through the use of nanocrystal pinning, highly luminescent methylammonium lead bromide films are used to produce stable lasers emitting at 550 nm, with a low threshold of 6 µJcm-2. The lasers were able to support multiple polarisations, and could be switched between transverse magnetic and transverse electric mode operation through simple tuning of the distributed feedback grating period.

Activity levels and return to work following total knee arthroplasty in patients under 65 years of age.

AIMS: Little is known about employment following total knee arthroplasty (TKA). This study aims to identify factors which predict return to work following TKA in patients of working age in the United Kingdom. PATIENTS & METHODS: We prospectively assessed 289 patients (289 TKAs) aged ≤ 65 years who underwent TKA between 2010 and 2013. There were 148 women. The following were recorded pre-operatively: age, gender, body mass index, social deprivation, comorbidities, indication for surgery, work status and nature of employment, activity level as assessed by the University of California, Los Angeles (UCLA) activity score and Oxford Knee Score (OKS). The intention of patients to return to work or to retire was not assessed pre-operatively. At a mean of 3.4 years (2 to 4) post-operatively, the return to work status, OKS, the EuroQol-5 dimensions (EQ-5D) score, UCLA activity score and Work, Osteoarthritis and joint-Replacement (WORQ) score were obtained. Univariate and multivariate analyses were performed. RESULTS: Of 261 patients (90%) who were working before TKA, 105 (40%) returned to any job, including 89 (34%) who returned to the same job at a mean of 13.5 weeks (2 to 104) post-operatively. A total of 108 (41%) retired following TKA and 18 remained on welfare. Patients not working before the operation did not return to work. Median UCLA scores improved in 125 patients (58%) from 4 (mild activity) to 6 (moderate activity) (p < 0.001). Significant (p < 0.05) factors which were predictive of return to any work included age, heavy or moderate manual work, better post-operative UCLA, OKS and EQ-5D general health scores. Significant predictive factors of return to the same work included age, heavy or moderate manual work and post-operative OKS. Multivariate analysis confirmed heavy or moderate manual work and age to independently predict a return to either any or the same work. All patients aged < 50 years who were working pre-operatively returned to any work as did 60% of those aged between 50 and 54 years, 50% of those aged between 55 and 59 years and 24% those aged between 60 and 65 years. CONCLUSION: If working pre-operatively, patients aged < 50 years invariably returned to work following TKA, but only half of those aged between 50 to 60 years returned. High post-operative activity levels and patient reported outcome measures do not predict return to work following TKA. Cite this article: Bone Joint J 2017;99-B:1037-46.

Probing the energy levels of perovskite solar cells via Kelvin probe and UV ambient pressure photoemission spectroscopy.

The field of organo-lead halide perovskite solar cells has been rapidly growing since their discovery in 2009. State of the art devices are now achieving efficiencies comparable to much older technologies like silicon, while utilising simple manufacturing processes and starting materials. A key parameter to consider when optimising solar cell devices or when designing new materials is the position and effects of the energy levels in the materials. We present here a comprehensive study of the energy levels present in a common structure of perovskite solar cell using an advanced macroscopic Kelvin probe and UV air photoemission setup. By constructing a detailed map of the energy levels in the system we are able to predict the importance of each layer to the open circuit voltage of the solar cell, which we then back up through measurements of the surface photovoltage of the cell under white illumination. Our results demonstrate the effectiveness of air photoemission and Kelvin probe contact potential difference measurements as a method of identifying the factors contributing to the open circuit voltage in a solar cell, as well as being an excellent way of probing the physics of new materials.

Return to work and sports after total hip replacement.

INTRODUCTION: Expectations of patients requiring total hip replacement have become higher than in the past and are often well beyond pain relief and improved mobility. Return to work and sporting activity are important factors to be considered when advising patients preoperatively. The objective of this study was to analyse the return to sports and work rates in patients still in employment and to analyse potential influencing factors. MATERIALS AND METHODS: Patients under the age of 65 who had a total hip replacement performed at a university teaching hospital were identified from the local arthroplasty database and contacted. Pre and postoperative levels of sporting activity and work were recorded. We also recorded the time point at which they returned to these activities. RESULTS: 285 total hip replacements were carried out on 239 patients. At the time of follow-up 170 of the patients were working. The mean length of time to return to work was 13.9 weeks (SD 7.7). 78 % returned to work without any restrictions, 18.6 % in heavy manual jobs. The mean time taken to return to sports or similar physical activities was 18.8 weeks (SD 8.8) weeks. Those with a lower body mass index returned to work and sporting activities faster. CONCLUSIONS: Our data show that the majority of patients undergoing total hip replacement can expect to return to work and sporting activities within 4-6 months. Activities at work are often initially limited and physical performance may not fully return to the expected level. Patients with a high body mass index take longer to return to work and sporting activities.

Fluidic fibre dye lasers.

We report the demonstration of compact fluidic fibre lasers based on capillary tubes and photonic crystal fibres, featuring single channel and multiple laterally integrated fluidic lasers respectively. Their preparation was based on capillary action and lasing occurred without the need for external mirrors or lithographically defined microstructures. The fibre lasers were found to be tunable by varying the chromophore density in the liquid core and a functional wavelength selectivity mechanism inherent in both types of lasers provided a long free spectral range that does not correspond to the length of the fibres. The enhanced mode spacing is attributed to a Vernier resonant effect.

Diode pumped distributed Bragg reflector lasers based on a dye-to-polymer energy transfer blend.

We report the demonstration of a compact, all-solid-state polymer laser system comprising of a Gallium Nitride (GaN) semiconductor diode laser as the pump source. The polymer laser was configured as a surface emitting, distributed Bragg reflector laser (DBR), based on a novel energy transfer blend of Coumarin 102 and the conjugated polymer poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene). In this configuration, diode pumping was possible both due to the improved quality of the resonators and the improved harvesting of the diode laser light.

Characterization of the metabolite produced by Mycosphaerella pinodes, the causal agent of mycosphaerella blight on field peas (Pisum sativum L.).

The metabolite produced by Mycosphaerella pinodes, the causal agent of mycosphaerella blight on field peas, was detected by thin layer chromatography (TLC) and was analyzed for its chemical and pathogenic characteristics. One blue dot was detected using 254nm UV light on TLC plate, and a spray of rho-anisaldehyde (110 degrees C, 30 min) also produced a blue dot. The solvent systems used for TLC analysis were ethyl acetate/water/acetone (5/2/5), chloroform/methanol/glacial acetic acid (19/10/2), toluene/ethyl acetate/90% formic acid (6/3/1), diethylether/methanol/water/90% formic acid (95/4/1/1), and bezene/methanol/acetic acid (24/2/1), with R(f) values (min-max) of 0.09-0.18, 0.88-0.95, 0.06-0.15, 0.39-0.47 and 0.05-0.12, respectively. The recovered metabolite from the TLC plate displayed UV absorption peaks at 212, 244, 250, 256 and 261 nm. The proposed formula of the main component of the metabolite was C16H12N3O6. The TLC-purified metabolite induced symptom of discoloration on detached pea leaves.

Anxiety and the schizophrenic process: clinical and epidemiological evidence.

BACKGROUND: The authors hypothesise that anxiety is an integral part of the development of schizophrenia in a significant sub-group of cases. This paper reviews the evidence for an epidemiological link between anxiety and schizophrenia, emphasising those studies that imply a temporal sequence. METHOD: An augmented systematic search of electronic databases was conducted, and the methods and results of the studies identified were reviewed. RESULTS: Panic disorder was identified in around 20% of cases of schizophrenia in clinical studies (range 5-33 %). Other anxiety disorders were less often studied, but were also frequent. Epidemiological studies from the Epidemiological Catchment Area Program confirm the strong association between anxiety disorders and schizophrenia. Finally, cohort studies identify anxiety as an early antecedent of schizophrenia. CONCLUSION: There is a significant link between anxiety and schizophrenia. This may represent a psychological process integral to an appreciable number of cases of schizophrenia. Focused psychological studies are needed to determine whether this is so.

The role of bacterial motility in the survival and spread of Pseudomonas fluorescens in soil and in the attachment and colonisation of wheat roots.

Motile and non-motile strains of Pseudomonas fluorescens SBW25 were constructed using different combinations of the lacZY, xylE and aph marker genes which allowed their detection and differentiation in soil, root and seed samples. The survival of motile and non-motile strains was investigated in both non-competitive and competitive assays in water and non-sterile soil. Although there was no difference between strains in water, the motile strain survived in significantly greater numbers than the non-motile strain after 21 days in soil. There was no significant difference between competitive assays, where motile and non-motile cells were co-inoculated into soil, and non-competitive assays where strains were inoculated separately. Bacterial survival decreased as matric potential increased from -224 to -17 kPa but matric potential had no significant effect on motile compared to non-motile strains. Vertical spread of both motile and non-motile strains was detected 6.4 mm from the inoculum zone after 14 days in the absence of percolating water. There was no significant difference, for either strain, in distance moved from the inoculum zone after 14, 26 or 40 days. The motile strain had a significant advantage in attachment to sterile wheat roots in both non-competitive and competitive studies. When the spatial colonisation of wheat root systems was assessed in non-sterile soil, there was no significant difference between the motile and non-motile strain from either seed or soil inoculum. However, when the whole root system was assessed as one sample unit, differences could be detected. Bacterial motility could contribute to survival in soil and the initial phase of colonisation, where attachment and movement onto the root surface are important.

Degradation of substituted phenylurea herbicides by Arthrobacter globiformis strain D47 and characterization of a plasmid-associated hydrolase gene, puhA.

Arthrobacter globiformis D47 was shown to degrade a range of substituted phenylurea herbicides in soil. This strain contained two plasmids of approximately 47 kb (pHRIM620) and 34 kb (pHRIM621). Plasmid-curing experiments produced plasmid-free strains as well as strains containing either the 47- or the 34-kb plasmid. The strains were tested for their ability to degrade diuron, which demonstrated that the degradative genes were located on the 47-kb plasmid. Studies on the growth of these strains indicated that the ability to degrade diuron did not offer a selective advantage to A. globiformis D47 on minimal medium designed to contain the herbicide as a sole carbon source. The location of the genes on a plasmid and a lack of selection would explain why the degradative phenotype, as with many other pesticide-degrading bacteria, can be lost on subculture. A 22-kb EcoRI fragment of plasmid pHRIM620 was expressed in Escherichia coli and enabled cells to degrade diuron. Transposon mutagenesis of this fragment identified one open reading frame that was essential for enzyme activity. A smaller subclone of this gene (2.5 kb) expressed in E. coli coded for the protein that degraded diuron. This gene and its predicted protein sequence showed only a low level of protein identity (25% over ca. 440 amino acids) to other database sequences and was named after the enzyme it encoded, phenylurea hydrolase (puhA gene).

The role of motility in the in vitro attachment of Pseudomonas putida PaW8 to wheat roots.

The attachment of motile and non-motile strains of Pseudomonas putida PaW8 to sterile wheat roots was assessed in both non-competitive and intra-specific competitive assays. The motile strain showed significantly greater attachment to wheat roots than non-motile strains in phosphate buffer. Overall, the motile strain attached better than the non-motile strain at 10(6), 10(7) and 10(8) cfu ml(-1) in competitive assays and at 10(6) and 10(7) cfu ml(-1) in non-competitive assays. When attachment was studied in Luria broth no significant difference between motile and non-motile strains was detected. P. putida PaW8 cells marked with the luxAB genes were used to compare direct detection of attached cells by luminometry with indirect detection by dilution plate counts following extraction from root material. Although direct detection permitted a rapid assessment (60 s) of attachment to surfaces, dilution plate counts provided a more sensitive method for quantification of bacteria. The detection limits were approximately 10 cfu root(-1) using dilution plate counts compared with 1000 cfu root(-1) using luminometry. All results highlighted the importance of motility for the attachment of P. putida to plant roots in simple model systems. To take this work further, studies to assess the role of motility using complex non-sterile systems are needed.

The evolution, current status, and regulation of ostomy products in the United States.

In today's rapidly evolving health care environment in which quality, cost-effectiveness, and outcomes are among the most valued health care products, significant issues must be addressed regarding ostomy products and how persons with stomas use them. The lack of evidence-based data has a direct impact on the pocketbooks of many patients with ostomies in the United States and their quality of life. Regulators, accrediting agencies, and payers look to WOC nurses and other providers to provide a sound scientific base upon which they can develop standards and regulations that will improve the life of Americans with stomas.