bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrogen Source Stabilization of Quorum Sensing in the Pseudomonas aeruginosa Bioaugmentation Strain SD-1
Authors: Wang Mei-Zhen , Lai Bai-Min , Dandekar Ajai A. , Yang Yu-Sheng , Li Na , Yin Jun , Shen Dong-Sheng
Published: June 2017

Pseudomonas aeruginosa
SD-1 is efficient at degrading aromatic compounds and can therefore contribute to the bioremediation of wastewater.
P. aeruginosa
uses quorum sensing (QS) to regulate the production of numerous secreted “public goods.” In wastewater bioaugmentation applications, there are myriad nitrogen sources, and we queried whether various nitrogen sources impact the stabilities of both QS and the bacterial populations. In a laboratory strain of
P. aeruginosa
, PAO1, the absence of a nitrogen source has been shown to destabilize these populations through the emergence of QS mutant “cheaters.” We tested the ability of SD-1 to grow in casein broth, a condition that requires QS for growth, when the nitrogen source with either NH
4
Cl, NaNO
3
, or NaNO
2
or with no added nitrogen source. There was great variability in susceptibility to invasion by QS mutant cheaters and, by extension, the stability of the SD-1 population. When grown with NH
4
Cl as an extra nitrogen source, no population collapse was observed; by contrast, two-thirds of cultures grown in the presence of NaNO
2
collapsed. In the populations that collapsed, the frequency of social cheaters exceeded 40%. NaNO
3
and NaNO
2
directly favor QS mutants of
P. aeruginosa
SD-1. Although the mechanism by which these nitrogen sources act is not clear, these data indicate that the metabolism of nitrogen can affect the stability of bacterial populations, an important observation for continuing industrial applications with this species.

IMPORTANCE
Bioaugmentation as a method to help remediate wastewater pollutant streams holds significant potential to enhance traditional methods of treatment. Addition of microbes that can catabolize organic pollutants can be an effective method to remove several toxic compounds. Such bioaugmented strains of bacteria have been shown to be susceptible to competition from the microbiota that are present in wastewater streams, limiting their potential effectiveness. Here, we show that bioaugmentation strains of bacteria might also be susceptible to invasion by social cheaters and that the nitrogen sources available in the wastewater might influence the ability of cheaters to overtake the bioaugmentation strains. Our results imply that control over the nitrogen sources in a wastewater stream or selective addition of certain nitrogen sources could help stabilize bioaugmentation strains of bacteria.
Laboratory Evolution of a Biotin-Requiring Saccharomyces cerevisiae Strain for Full Biotin Prototrophy and Identification of Causal Mutations
Authors: Bracher Jasmine M. , de Hulster Erik , Koster Charlotte C. , van den Broek Marcel , Daran Jean-Marc G. , van Maris Antonius J. A. , Pronk Jack T.
Published: June 2017

Biotin prototrophy is a rare, incompletely understood, and industrially relevant characteristic of
Saccharomyces cerevisiae
strains. The genome of the haploid laboratory strain CEN.PK113-7D contains a full complement of biotin biosynthesis genes, but its growth in biotin-free synthetic medium is extremely slow (specific growth rate [μ] ≈ 0.01 h
−1
). Four independent evolution experiments in repeated batch cultures and accelerostats yielded strains whose growth rates (μ ≤ 0.36 h
−1
) in biotin-free and biotin-supplemented media were similar. Whole-genome resequencing of these evolved strains revealed up to 40-fold amplification of
BIO1
, which encodes pimeloyl-coenzyme A (CoA) synthetase. The additional copies of
BIO1
were found on different chromosomes, and its amplification coincided with substantial chromosomal rearrangements. A key role of this gene amplification was confirmed by overexpression of
BIO1
in strain CEN.PK113-7D, which enabled growth in biotin-free medium (μ = 0.15 h
−1
). Mutations in the membrane transporter genes
TPO1
and/or
PDR12
were found in several of the evolved strains. Deletion of
TPO1
and
PDR12
in a
BIO1
-overexpressing strain increased its specific growth rate to 0.25 h
−1
. The effects of null mutations in these genes, which have not been previously associated with biotin metabolism, were nonadditive. This study demonstrates that
S. cerevisiae
strains that carry the basic genetic information for biotin synthesis can be evolved for full biotin prototrophy and identifies new targets for engineering biotin prototrophy into laboratory and industrial strains of this yeast.

IMPORTANCE
Although biotin (vitamin H) plays essential roles in all organisms, not all organisms can synthesize this vitamin. Many strains of baker's yeast, an important microorganism in industrial biotechnology, contain at least some of the genes required for biotin synthesis. However, most of these strains cannot synthesize biotin at all or do so at rates that are insufficient to sustain fast growth and product formation. Consequently, this expensive vitamin is routinely added to baker's yeast cultures. In this study, laboratory evolution in biotin-free growth medium yielded new strains that grew as fast in the absence of biotin as in its presence. By analyzing the DNA sequences of evolved biotin-independent strains, mutations were identified that contributed to this ability. This work demonstrates full biotin independence of an industrially relevant yeast and identifies mutations whose introduction into other yeast strains may reduce or eliminate their biotin requirements.
The Two-Component Signal Transduction System VxrAB Positively Regulates Vibrio cholerae Biofilm Formation
Authors: Teschler Jennifer K. , Cheng Andrew T. , Yildiz Fitnat H.
Published: June 2017

Two-component signal transduction systems (TCSs), typically composed of a sensor histidine kinase (HK) and a response regulator (RR), are the primary mechanism by which pathogenic bacteria sense and respond to extracellular signals. The pathogenic bacterium
Vibrio cholerae
is no exception and harbors 52 RR genes. Using in-frame deletion mutants of each RR gene, we performed a systematic analysis of their role in
V. cholerae
biofilm formation. We determined that 7 RRs impacted the expression of an essential biofilm gene and found that the recently characterized RR, VxrB, regulates the expression of key structural and regulatory biofilm genes in
V. cholerae
.
vxrB
is part of a 5-gene operon, which contains the cognate HK
vxrA
and three genes of unknown function. Strains carrying Δ
vxrA
and Δ
vxrB
mutations are deficient in biofilm formation, while the Δ
vxrC
mutation enhances biofilm formation. The overexpression of VxrB led to a decrease in motility. We also observed a small but reproducible effect of the absence of VxrB on the levels of cyclic di-GMP (c-di-GMP). Our work reveals a new function for the Vxr TCS as a regulator of biofilm formation and suggests that this regulation may act through key biofilm regulators and the modulation of cellular c-di-GMP levels.

IMPORTANCE
Biofilms play an important role in the
Vibrio cholerae
life cycle, providing protection from environmental stresses and contributing to the transmission of
V. cholerae
to the human host.
V. cholerae
can utilize two-component systems (TCS), composed of a histidine kinase (HK) and a response regulator (RR), to regulate biofilm formation in response to external cues. We performed a systematic analysis of
V. cholerae
RRs and identified a new regulator of biofilm formation, VxrB. We demonstrated that the VxrAB TCS is essential for robust biofilm formation and that this system may regulate biofilm formation via its regulation of key biofilm regulators and cyclic di-GMP levels. This research furthers our understanding of the role that TCSs play in the regulation of
V. cholerae
biofilm formation.
Ptosis as a complication of Kawasaki disease
Authors: Hameed Ammar , Alshara Hassan , Schleussinger Thomas
Published: June 2017

Kawasaki disease is an acute febrile exanthematous disease that affects children younger than 5 years of age. It is regarded as the most common cause of childhood acquired heart disease, but ocular and neurological problems are among the other important clinical findings. We present a 3-year-old boy who developed bilateral ptosis on day 21, 5 days after intravenous immunoglobulin. The ptosis was due to bilateral paralysis of the levator palpebrae superioris muscles and resolved spontaneously on day 25. There were no cardiac sequelae.
Features of optical coherence tomography predictive of choroidal neovascularisation treatment response in pathological myopia in association with fluorescein angiography
Authors: Lee Dong Hyun , Kang Hyun Goo , Lee Sung Chul , Kim Min
Published: June 2017

Background/Aims

The aim of this study was to evaluate the usefulness of several optical coherence tomography (OCT) findings to estimate choroidal neovascularisation (CNV) activity in pathological myopia using fluorescein angiography (FA) as a reference.

Methods

This was a single-centre, retrospective study. The medical records of patients with active myopic CNV who received intravitreal bevacizumab treatment were reviewed. Parameters to monitor CNV activity were morphological features of CNV on OCT, such as CNV height, central foveal thickness, intraretinal cysts, subretinal fluid, fuzziness of the CNV border, CNV network area on FA, and haemorrhage or exudation on fundus photo.

Results

There were 46 patients with active CNV enrolled in this study. After intravitreal bevacizumab treatment, all the previously mentioned parameters of CNV were significantly improved. Using logistic regression analyses with backward elimination, the fuzzy border seen on OCT showed the most significant correlation with improvement of leakage on FA, when compared with other variables such as intraretinal cysts, subretinal fluid or central foveal thickness (R2=0.324, p=0.009).

Conclusion

Our study showed that the fuzziness of the hyper-reflective CNV margin showed the most significant improvement and the strongest correlation with the improvement of CNV leakage on FA after intravitreal bevacizumab injections, suggesting its important role as an OCT parameter for the assessment of myopic CNV activity.
Use of Ruthenium-106 Brachytherapy for Iris Melanoma: The Scottish Experience
Authors: Agraval Umiya , Sobti Manvi , Russell Heather C , Lockington David , Ritchie Diana , Cauchi Paul , Kemp Ewan G , Chadha Vikas
Published: June 2017

Purpose

To analyse long-term outcomes of ruthenium-106 (106Ru) plaque brachytherapy for the treatment of iris melanoma.

Methods

We retrospectively reviewed medical records of 19 consecutive patients with pure iris melanoma treated with 106Ru plaque brachytherapy between 1998 and 2016 at the Scottish Ophthalmic Oncology Service, Glasgow. The iris melanoma was treated with a ruthenium plaque placed on the corneal surface to deliver a surface dose of 555 Gy. We analysed vision preservation, local tumour control, radiation-related complications, eye retention rates, symptomatic metastasis and melanoma-related mortality.

Results

The mean largest basal diameter of the lesions was 3.50±1.42 mm (range 1.6–6.5 mm), and the mean maximum height was 1.47±0.65 mm (range 0.7–2.8 mm). The tumour control and eye retention were 100% at a mean follow-up of 62 months (range 6–195 months). A 62% reduction in tumour height was observed on ultrasonography. Complications included cataract (68%), dry eye (47%), uveitis (37%) and scleral thinning (5%). At the final follow-up visit, the mean loss of Snellen visual acuity was 1.11±2.90 lines and vision of 6/9 or better was maintained in 53% of patients. None of the patients had evidence of symptomatic metastasis (non-imaged) or melanoma-related mortality.

Conclusions

106Ru plaque treatment for iris melanoma was highly effective a high tumour control, no tumour recurrences and a relatively a low complication rate.
Second primary malignancies in retinoblastoma patients treated with intra-arterial chemotherapy: the first 10 years
Authors: Habib Larissa A , Francis Jasmine H , Fabius Armida WM , Gobin Pierre Y , Dunkel Ira J , Abramson David H
Published: June 2017

Background/Aims

Survivors of retinoblastoma carry a lifetime risk of secondary malignancies. It is well established that external beam radiation increases this risk; however, the risk with ophthalmic artery chemosurgery (OAC) remains unknown. We report on 10 years of experience with OAC and the rate of second primary malignancy (SPM) development.

Methods

This is a single-centre retrospective review approved by the Memorial Sloan Kettering Cancer Center Institutional Review Board of all patients who received OAC over a 10-year period, from May 2006 to November 2016. The second tumour incidence and survival in patients with germline disease (bilateral and unilateral with family history or confirmed germline mutation) was estimated using the Kaplan-Meier method. Patients who received external beam radiotherapy were excluded from analyses.

Results

Two hundred and thirty-three patients with heritable retinoblastoma who received OAC were analysed. Nineteen patients were excluded for having received external beam radiation. The Kaplan-Meier estimate of the likelihood for SPM development was 2.7% at 5 years (95% CI 0 to 25). All of the SPMs were pineoblastomas and all patients had bilateral disease in this cohort.

Conclusions

In our 10-year experience, we have found that SPM development in patients with germline retinoblastoma treated with OAC alone is comparable to previously published rates. In the first 10 years, OAC did not increase the known incidence of SPMs. This cohort will continue to be followed to establish the rate of development with extended follow-up.
Optimal timing for elective caesarean delivery in a Chinese population: a large hospital-based retrospective cohort study in Shanghai
Authors: HU Yong , Shen Hong , Landon Mark B , Cheng Weiwei , Liu Xiaohua
Published: June 2017

Objective

To assess the relationship between the timing of antepartum elective caesarean delivery (CD) at term and perinatal outcomes in a Chinese population.

Methods

We conducted a retrospective cohort study of mode of delivery at a large obstetric centre in Shanghai, China between 2007 and 2014. Eligibility criteria included: term nulliparous women with a singleton gestation undergoing antepartum elective CD.

Results

There were 19 939 women delivered by antepartum CD without indications, with 5.9% performed at 37–37 6/7 weeks, 36.2% at 38–38 6/7 weeks, 38.4% at 39–39 6/7 weeks, 15.4% at 40–40 6/7 weeks, 4.0% at ≥41 weeks. As compared with births at 39–39 6/7 weeks, births at 37 weeks were associated with an increased odds of neonatal respiratory disease (adjusted odds ratian(aOR): 4.82; 95% CI 3.35 to 6.94), neonatal infection (aOR: 3.68; 95% CI 1.80 to 7.52), hypoglycaemia (aOR: 3.85; 95%CI 2.29 to 6.48), hyperbilirubinaemia (aOR: 3.50; 95%CI 2.12 to 5.68), neonatal intensive care admission (aOR: 3.73; 95% CI 2.84 to 4.89) and prolonged hospitalisation (aOR: 7.51; 95% CI 5.10 to 11.07). Births at 38 weeks, 40 weeks or ≥41 weeks were also associated with an increased odds of neonatal respiratory disease with corresponding aORs (95% CI) of 2.26 (1.71 to 3.00), 1.97 (1.33 to 2.94) and 2.91 (1.80 to 4.70), respectively.

Conclusion

For women undergoing elective CD, neonatal outcome data suggest that delivery at 39–39 6/7 complete weeks is optimal timing in a Chinese population.
Assessing the diagnostic accuracy of PCR-based detection ofStreptococcus pneumoniaefrom nasopharyngeal swabs collected for viral studies in Canadian adults hospitalised with community-acquired pneumonia: a Serious Outcomes Surveillance (SOS) Network of the Canadian Immunization Research (CIRN) study
Authors: Gillis Hayley D , Lang Amanda L S , ElSherif May , Martin Irene , Hatchette Todd F , McNeil Shelly A , LeBlanc Jason J
Published: June 2017

Study design

Detection and serotyping ofStreptococcus pneumoniae areimportant to assess the impact of pneumococcal vaccines. This study describes the diagnostic accuracy of PCR-based detection ofS. pneumoniaedirectly from nasopharyngeal (NP) swabs collected for respiratory virus studies.

Methods

Active surveillance for community-acquired pneumonia (CAP) in hospitalised adults was performed from December 2010 to 2013. Detection of pneumococcal CAP (CAPSpn) was performed by urine antigen detection (UAD), identification ofS. pneumoniaein sputum or blood cultures.S. pneumoniaewas detected in NP swabs usinglytAandcpsAreal-time PCR, and serotyping was performed using conventional and real-time multiplex PCRs. For serotyping, the Quellung reaction, PCR-based serotyping or a serotype-specific UAD was used.

Results

NP swab results were compared against CAP cases where all pneumococcal tests were performed (n=434), or where at least one test was performed (n=1616). CAPSpnwas identified in 22.1% (96/434) and 14.9% (240/1616), respectively. The sensitivity of NP swab PCR for the detection ofS. pneumoniaewas poor for CAPSpn(35.4% (34/96) and 34.17% (82/240)), but high specificity was observed (99.4% (336/338) and 97.89% (1347/1376)). Of the positive NP swabs, a serotype could be deduced by PCR in 88.2% (30/34) and 93.9% (77/82), respectively.

Conclusions

While further optimisation may be needed to increase the sensitivity of PCR-based detection, its high specificity suggests there is a value for pneumococcal surveillance. With many laboratories archiving specimens for influenza virus surveillance, this specimen type could provide a non-culture-based method for pneumococcal surveillance.
A mixed-methods evaluation of the Educational Supervision Agreement for Wales
Authors: Webb Katie Louise , Bullock Alison , Groves Caroline , Saayman Anton Gerhard
Published: June 2017

Objectives

In a bid to promote high-quality postgraduate education and training and support the General Medical Council’s (GMC) implementation plan for trainer recognition, the Wales Deanery developed the Educational Supervision Agreement (EdSA). This is a three-way agreement between Educational Supervisors, Local Education Providers and the Wales Deanery which clarifies roles, responsibilities and expectations for all. This paper reports on the formative evaluation of the EdSA after 1 year.

Design

Evaluation of pan-Wales EdSA roll-out (2013–2015) employed a mixed-methods approach: questionnaires (n=191), interviews (n=11) with educational supervisors and discussion with key stakeholders (GMC, All-Wales Trainer Recognition Group, Clinical Directors). Numerical data were analysed in SPSS V.20; open comments underwent thematic content analysis.

Participants

The study involved Educational Supervisors working in different specialties across Wales, UK.

Results

At the point of data collection, survey respondents represented 14% of signed agreements. Respondents believed the Agreement professionalises the Educational Supervisor role (85%, n=159 agreed), increases the accountability of Educational Supervisors (87%; n=160) and health boards (72%, n=131), provides leverage to negotiate supporting professional activities’ (SPA) time (76%, n=142) and continuing professional development (CPD) activities (71%, n=131). Factor analysis identified three principal factors: professionalisation of the educational supervisor role, supporting practice through training and feedback and implementation of the Agreement.

Conclusions

Our evidence suggests that respondents believed the Agreement would professionalise and support their Educational Supervisor role. Respondents showed enthusiasm for the Agreement and its role in maintaining high standards of training.
Evaluation of a physiatrist-directed prehabilitation intervention in frail patients with colorectal cancer: a randomised pilot study protocol
Authors: Wong Sherman G , Maida Eugene , Harvey David , Wagner Natalie , Sonnadara Ranil , Amin Nalin
Published: June 2017

Introduction

Prehabilitation interventions have shown efficacy in the orthopaedic and cardiothoracic surgical populations, but there has been limited evidence for general surgical patients. We present the protocol for a pilot trial of a novel prehabilitation intervention, consisting of a physiatrist-directed preoperative assessment and treatment programme.

Methods and analysis

This is a single-centre pilot randomised controlled trial investigating physiatrist-directed prehabilitation for a 4 to 6-week preoperative period. We will block randomise 40–50 participants awaiting surgery for colorectal cancer to prehabilitation versus control. Participants in the prehabilitation arm will undergo assessment by a physiatrist and enrol in a supervised exercise programme. The control group will not undergo any prehabilitation interventions in the preoperative period. Our primary outcome is feasibility, measured by examining recruitment, refusal, retention and adherence rates as well as participant satisfaction and feedback. Secondary outcomes include physical fitness, functional ability, health-related quality of life, postoperative complications, mortality, readmissions, length of stay, prehabilitation interventions performed and exercise complications.

Ethics and dissemination

This study has been approved by the Hamilton Integrated Research Ethics Board (HIREB reference number 2015–0090-GRA). The results of this pilot study will be used to design a full-scale study and published in peer-reviewed journals.

Trial registration number

NCT02531620; Pre-results.
Systematic review and meta-analysis of prevalence of, and risk factors for, pelvic floor disorders in community-dwelling women in low and middle-income countries: a protocol study
Authors: Islam Rakibul M , Oldroyd John , Karim Md Nazmul , Hossain Sultana Monira , Md Emdadul Hoque Dewan , Romero Lorena , Fisher Jane
Published: June 2017

Introduction

Pelvic floor disorders (PFDs) including urinary incontinence, faecal incontinence and pelvic organ prolapse are common debilitating conditions among women in high-income countries. However, PFDs in women in low/middle-income countries (LMICs) have not been studied extensively. We aim to conduct a systematic review and meta-analysis of the available literature to determine the prevalence of, and/or risk factors for, PFDs in women in LMIC.

Methods and analysis

We will search electronic databases including MEDLINE, EMBASE, PsycINFO, CINAHL, Maternity & Infant Care and Google Scholar for eligible studies. Inclusion criteria will be observational studies of healthy women, which have collected data using validated or non-validated tools, are published in English and were conducted in community women in LMICs, defined by the World Bank. A standardised data extraction form will be developed and piloted, based on the template of the Cochrane good practice data extraction form. All included studies will be assessed based on a risk-of-bias tool specifically developed for prevalence studies. Pooled prevalence estimates of PFDs will be generated using RevMan V.5.2.1 software. Forest plots will be generated to display the overall random-effects pooled estimates with CIs. A metaregression will be conducted to identify sources of between-study heterogeneity in the pooled prevalence estimates. We will quantify heterogeneity using the I2measure and its CI. We will use funnel plots to detect potential reporting biases and small-study effects. We will also conduct a sensitivity analysis to verify the robustness of the study conclusions, assessing the impact of methodological quality, study design, sample size and the effect of missing data.

Ethics and dissemination

Our review is entirely based on published data. Thus, an ethics committee approval or written informed consent will not be required for this study as primary data will not be collected. The results will be disseminated by publication of the manuscript in a peer-reviewed journal and/or will be presented at relevant conferences.

PROSPERO registration number

CRD42016043881.
Night work and prostate cancer in men: a Swedish prospective cohort study
Authors: Åkerstedt Torbjrn , Narusyte Jurgita , Svedberg Pia , Kecklund Göran , Alexanderson Kristina
Published: June 2017

Objectives

Prostate cancer is the most common cancer and the second leading cause of cancer-related deaths among men, but the contributing factors are unclear. One such may be night work because of the day/night alternation of work and the resulting disturbance of the circadian system. The purpose of the present study was to investigate the prospective relation between number of years with night work and prostate cancer in men.

Design

Cohort study comparing night and day working twins with respect to incident prostate cancer in 12 322 men.

Setting

Individuals in the Swedish Twin Registry.

Participants

12 322 male twins.

Outcome measures

Prostate cancer diagnoses obtained from the Swedish Cancer Registry with a follow-up time of 12 years, with a total number of cases=454.

Results

Multiple Cox proportional hazard regression analysis, adjusted for a number of covariates, showed no association between ever night work and prostate cancer, nor for duration of night work and prostate cancer. Analysis of twin pairs discordant for prostate cancer (n=332) showed no significant association between night work and prostate cancer.

Conclusions

The results, together with previous studies, suggest that night work does not seem to constitute a risk factor for prostate cancer.
Performance-based functional impairment and readmission and death: a prospective study
Authors: Aubert Carole E , Folly Antoine , Mancinetti Marco , Hayoz Daniel , Donzé Jacques D
Published: June 2017

Objectives

Readmission and death are frequent after a hospitalisation and difficult to predict. While many predictors have been identified, few studies have focused on functional status. We assessed whether performance-based functional impairment at discharge is associated with readmission and death after an acute medical hospitalisation.

Design, setting and participants

We prospectively included patients aged ≥50 years admitted to the Department of General Internal Medicine of a large community hospital. Functional status was assessed shortly before discharge using the Timed Up and Go test performed twice in a standard way by trained physiotherapists and was defined as a test duration ≥15 s. Sensitivity analyses using a cut-off at >10 and >20 s were performed.

Primary and secondary outcome measures

The primary and secondary outcome measures were unplanned readmission and death, respectively, within 6 months after discharge.

Results

Within 6 months after discharge, 107/338 (31.7%) patients had an unplanned readmission and 31/338 (9.2%) died. Functional impairment was associated with higher risk of death (OR 2.44, 95% CI 1.15 to 5.18), but not with unplanned readmission (OR 1.34, 95% CI 0.84 to 2.15). No significant association was found between functional impairment and the total number of unplanned readmissions (adjusted OR 1.59, 95% CI 0.95 to 2.67).

Conclusions

Functional impairment at discharge of an acute medical hospitalisation was associated with higher risk of death, but not of unplanned readmission within 6 months after discharge. Simple performance-based assessment may represent a better prognostic measure for mortality than for readmission.
Association between preoperative anaemia with length of hospital stay among patients undergoing primary total knee arthroplasty in Singapore: a single-centre retrospective study
Authors: Abdullah Hairil Rizal , Sim Yilin Eileen , Hao Ying , Lin Geng Yu , Liew Geoffrey Haw Chieh , Lamoureux Ecosse L , Tan Mann Hong
Published: June 2017

Objectives

Studies in western healthcare settings suggest that preoperative anaemia is associated with poor outcomes after elective orthopaedic surgery. We investigated the prevalence of preoperative anaemia among patients with primary unilateral total knee arthroplasty (TKA) in Singapore and its association with length of hospital stay (LOS), perioperative blood transfusion and hospital readmission rates.

Methods

Retrospective cohort study performed in a tertiary academic medical centre in Singapore, involving patients who underwent primary unilateral TKA between January 2013 and June 2014. Demographics, comorbidities, preoperative haemoglobin (Hb) level, LOS and 30-day readmission data were collected. Anaemia was classified according to WHO definition. Prolonged LOS was defined as more than 6 days, which corresponds to >75th centile LOS of the data.

Results

We analysed 2394 patients. The prevalence of anaemia was 23.7%. 403 patients (16.8%) had mild anaemia and 164 patients (6.8%) had moderate to severe anaemia. Overall mean LOS was 5.4±4.8 days. Based on multivariate logistic regression, preoperative anaemia significantly increased LOS (mild anaemia, adjusted OR (aOR) 1.71, p<0.001; moderate/severe anaemia, aOR 2.29, p<0.001). Similar effects were seen when preoperative anaemia was defined by Hb level below 13 g/dL, regardless of gender. Transfusion proportionately increased prolonged LOS (1 unit: aOR 2.12, p=0.006; 2 or more units: aOR 6.71, p<0.001). Repeat operation during hospital stay, previous cerebrovascular accidents, general anaesthesia and age >70 years were associated with prolonged LOS. Our 30-day related readmission rate was 1.7% (42) cases.

Conclusion

Anaemia is common among patients undergoing elective TKA in Singapore and is independently associated with prolonged LOS and increased perioperative blood transfusion. We suggest measures to correct anaemia prior to surgery, including the use of non-gender-based Hb cut-off for establishing diagnosis.
Practice patterns and outcomes associated with early sedation depth in mechanically ventilated patients: a systematic review protocol
Authors: Stephens Robert J , Dettmer Matthew R , Roberts Brian W , Fowler Susan A , Fuller Brian M
Published: June 2017

Introduction

Mechanical ventilation is a commonly performed intervention in critically ill patients. Frequently, these patients experience deep sedation early in their clinical course. Emerging data suggest that the practice of early deep sedation may negatively impact patient outcomes. The purpose of this review is to assess the world’s literature to describe and determine the impact of early deep sedation on the outcomes of mechanically ventilated patients.

Methods and analysis

Randomised controlled trials and non-randomised studies will be eligible for inclusion in this systematic review. With the assistance of a medical librarian, we will comprehensively search MEDLINE, Embase, Scopus, Cochrane Central Register of Controlled Trials, Database of Abstracts of Reviews and Effects, and Cochrane Database of Systematic Reviews for peer-reviewed literature. Grey literature from appropriate professional society conferences, held from 2010 to 2017, will be reviewed manually. Two authors will independently review all search results, and disagreements will be resolved through arbitration by a third author. If appropriate, meta-analysis will be used for quantitative analysis of the data. Heterogeneity between studies will be assessed using the I2statistic.

Ethics and dissemination

The proposed systematic review will not collect data that are associated with individual patients and does not require ethical approval. Results of this study will contribute to the understanding of early sedation, identify future research targets and guide early care in mechanically ventilated patients.

Trial registration number

This systematic review has been registered in the international prospective register of systematic reviews (PROSPERO #CRD42017057264).
The somatic mutation landscape of premalignant colorectal adenoma
Authors: Lin Shu-Hong , Raju Gottumukkala S , Huff Chad , Ye Yuanqing , Gu Jian , Chen Jiun-Sheng , Hildebrandt Michelle A T , Liang Han , Menter David G , Morris Jeffery , Hawk Ernest , Stroehlein John R , Futreal Andrew , Kopetz Scott , Mishra Lopa , Wu Xifeng
Published: June 2017

Objective

There are few studies which characterised the molecular alterations in premalignant colorectal adenomas. Our major goal was to establish colorectal adenoma genome atlas and identify molecular markers of progression from colorectal adenoma to adenocarcinoma.

Design

Whole-exome sequencing and targeted sequencing were carried out in 149 adenoma samples and paired blood from patients with conventional adenoma or sessile serrated adenoma to characterise the somatic mutation landscape for premalignant colorectal lesions. The identified somatic mutations were compared with those in colorectal cancer (CRC) samples from The Cancer Genome Atlas. A supervised random forest model was employed to identify gene panels differentiating adenoma from CRC.

Results

Similar somatic mutation frequencies, but distinctive driver mutations, were observed in sessile serrated adenomas and conventional adenomas. The final model included 20 genes and was able to separate the somatic mutation profile of colorectal adenoma and adenocarcinoma with an area under the curve of 0.941.

Conclusion

The findings of this project hold potential to better identify patients with adenoma who may be candidates for targeted surveillance programmes and preventive interventions to reduce the incidence of CRC.
Early proteinuria response: a valid real-life situation predictor of long-term lupus renal outcome in an ethnically diverse group with severe biopsy-proven nephritis?
Authors: Ugolini-Lopes Michelle R , Seguro Luciana Parente C , Castro Maitê Xavier F , Daffre Danielle , Lopes Alex C , Borba Eduardo F , Bonfá Eloisa
Published: June 2017

Objective

Two recent important lupus nephritis trials reported that proteinuria was a good predictor of renal outcome in Caucasians, but data on real-life situation, other races and severe nephritis are lacking to substantiate this finding as a simple test to guide clinical practice. The aim of this study was to validate proteinuria as a predictor of long-term renal outcome in real-life situation in a racially diverse group of patients with severe nephritis.

Methods

Proteinuria, serum creatinine (SCr) and urine red blood cells were assessed at baseline and after 3, 6 and 12 months, as early predictors of long-term renal outcome (SCr <1.5 mg/dL at 7 years), in 94 patients with biopsy-proven lupus nephritis. The parameter performance and cut-off values were computed by receiver operating characteristic curves. Kaplan-Meier curves were used to validate the parameter.

Results

A proteinuria <0.8 g/24 hours at 12 months was the best single predictor of long-term renal outcome (sensitivity 90%, specificity 78%, positive predictive value 67%, negative predictive value (NPV) 94% and area under the curve 0.86; p<0.001). Addition of other variables to proteinuria such as SCr and haematuria at 12 months did not improve its performance. The proteinuria cut-off value of 0.8 g/24 hours at 12 months was a good predictor of 7-year renal survival (years free of dialysis) for patients with pure membranous (p=0.005) and proliferative nephritis (p=0.043), as well as black (p=0.002) and white race (p=0.001), anti-dsDNA positive (p=0.001) and anti-dsDNA negative (p=0.04) and male (p=0.028) and female (p=0.003) patients.

Conclusion

We provided novel evidence that, in a real-life situation, proteinuria at 12 months of follow-up was the single best predictor of renal outcome at 7 years for an ethnically diverse group of patients with severe nephritis and a valid parameter for distinct histological classes, races, genders and anti-dsDNA profiles. The remarkably high NPV obtained reinforces its recommendation as the ideal predictor for clinical practice, since it is of low cost, easy to interpret, non-invasive and widely available.
A longitudinal and multicentre study of burnout and error in Irish junior doctors
Authors: O’Connor Paul , Lydon Sinéad , O’Dea Angela , Hehir Layla , Offiah Gozie , Vellinga Akke , Byrne Dara
Published: June 2017

Background

Junior doctors have been found to suffer from high levels of burnout.

Aims

To measure burnout in a population of junior doctors in Ireland and identify if: levels of burnout are similar to US medical residents; there is a change in the pattern of burnout during the first year of postgraduate clinical practice; and burnout is associated with self-reported error.

Methods

The Maslach Burnout Inventory—Human Services Survey was distributed to Irish junior doctors from five training networks in the last quarter of 2015 when they were approximately 4 months into their first year of clinical practice (time 1), and again 6 months later (time 2). The survey assessed burnout and whether they had made a medical error that had ‘played on (their) mind’.

Results

A total of 172 respondents out of 601 (28.6%) completed the questionnaire on both occasions. Irish junior doctors at time 2 were more burned out than a sample of US medical residents (72.6% and 60.3% burned out, respectively; p=0.001). There was a significant increase in emotional exhaustion from time 1 to time 2 (p=0.007). The association between burnout and error was significant at time 2 only (p=0.03). At time 2, of those respondents who were burned out, 81/122 (66.4%) reported making an error. A total of 22/46 (47.8%) of the junior doctors who were not burned out at time 2 reported an error.

Conclusion

Current levels of burnout are unsustainable and place the health of both junior doctors and their patients at risk.
Nondestructive health monitoring of soil nails using electromagnetic waves
Authors: Yu Jung-Doung , Kim Ki-Hong , Lee Jong-Sub
Published: June 2017

The installed length and grouted length of a soil nail should be evaluated to prevent construction disasters and landslides. The objective of this study is the development and application of a nondestructive method for evaluating the installed length and grouted length of soil nails using electromagnetic waves. Experiments are conducted on steel bars, partially grouted steel bars, fully grouted steel bars, and soil nails. Electromagnetic waves are generated and detected by a time-domain reflectometer. The experimental results show that the respective round-trip travel times increase with an increase in the length of the steel bar, grouted steel bar, and soil nail. The velocities are greatest and lowest for steel bars and soil nails installed in soil, respectively. For partially grouted steel bars, multiple reflections are detected at the interface between the nongrouted sections and grouted sections. The velocity decreases with an increase in the grouted ratio of the soil nail. This study demonstrates that electromagnetic waves can be effectively applied for the evaluation of the installed length and grouted length of the soil nail for health monitoring.
Hyperbiofilm phenotype of Pseudomonas aeruginosa defective for the PlcB and PlcN secreted phospholipases
Authors: Lewenza Shawn , Charron-Mazenod Laetitia , Afroj Shirin , van Tilburg Bernardes Erik
Published: June 2017

Biofilms are dense communities of bacteria enmeshed in a protective extracellular matrix composed mainly of exopolysaccharides, extracellular DNA, proteins, and outer membrane vesicles (OMVs). Given the role of biofilms in antibiotic-tolerant and chronic infections, novel strategies are needed to block, disperse, or degrade biofilms. Enzymes that degrade the biofilm matrix are a promising new therapy. We screened mutants in many of the enzymes secreted by the type II secretion system (T2SS) and determined that the T2SS, and specifically phospholipases, play a role in biofilm formation. Mutations in the xcp secretion system and in the plcB and plcN phospholipases all resulted in hyperbiofilm phenotypes. PlcB has activity against many phospholipids, including the common bacterial membrane lipid phosphatidylethanolamine, and may degrade cell membrane debris or OMVs in the biofilm matrix. Exogenous phospholipase was shown to reduce aggregation and biofilm formation, suggesting its potential role as a novel enzymatic treatment to dissolve biofilms.
Unpolarized and polarized densities based on a light-front quark–diquark model
Authors: Nikkhoo Negin Sattary , Shojaei Mohammad Reza
Published: June 2017

In this paper, we calculate the proton and neutron unpolarized and transversely polarized densities. We use the light-front wave function (LFWF), which at an initial scale is constrained by the soft-wall anti-de Sitter (AdS) QCD model, for calculating the Dirac and Pauli form factors which transverse densities are in terms of these form factors. Also, we use these form factors for calculating the flavor separated results for the proton and neutron electromagnetic form factors and calculate u and d quark unpolarized and transversely polarized densities. Finally, we compare our results with other previous parametrizations.
The inverse spin Hall effect in the lateral spin valve structure with dual injectors
Authors: Guo Zi-Zheng , Guo Z.-N.
Published: June 2017

The inverse spin Hall effect (ISHE) of a graphene-like material (GLM) in the lateral spin valve (LSV) structure with dual injectors is studied by the well-known spin-circuit method. We focus on the interactions among the ferromagnets, especially the effects of the relative orientations of these magnets on the ISHE. In addition, we discuss the possibility of graphene as the giant spin Hall effect (GSHE) material. In order to compare the results with more convenience, we calculate the ISHE signals of CuBi, CuIr and the GLM at the same time as the functions of the orientation angles of the magnets. Our calculations show that the structures with dual injectors help to improve the signal strength of the ISHE. However, the SHE of the GLM is not stronger than that of CuBi or CuIr.
Detection method of the LGP warpage degree based on edge detection evaluation function
Authors: Chen Gong , Zhu Xifang , Chu Lijuan , Cao Lihua , Lin Rong
Published: June 2017

Because of the shortage of rule gap measurement for light guide plate (LGP) warpage degree, image definition criterion of quality indexing is present based on single CCD camera. The detection paper and LGP are respectively arranged on the camera detection device platform, located by X- and Y-axes driving unit and focused by Z-axis driving unit firstly, different image definition criterion peaks of edge detection evaluation function are obtained in the middle surface of LGP bottom and surface. Finally, different edge detection algorithms are compared under different situations. Results show that the algorithm has good repetition and can meet the online, untouched detection needs.
Image system analysis of human eye wave-front aberration on the basis of HSS
Authors: Xu Ancheng
Published: June 2017

Hartmann–Shack sensor (HSS) has been used in objective measurement of human eye wave-front aberration, but the research on the effects of sampling point size on the accuracy of the result has not been reported. In this paper, point spread function (PSF) of the whole system mathematical model was obtained via measuring the optical imaging system structure of human eye wave-front aberration measurement. The impact of Airy spot size on the accuracy of system was analyzed. Statistics study show that the geometry of Airy spot size of the ideal light source sent from eye retina formed on the surface of HSS is far smaller than the size of the HSS sample point image used in the experiment. Therefore, the effect of Airy spot on the precision of the system can be ignored. This study theoretically and experimentally justifies the reliability and accuracy of human eye wave-front aberration measurement based on HSS.
Effects of coupled channels on cb̄ masses and decays in NRQM with OGEP
Authors: Bhat Manjunath , Monteiro Antony Prakash , Vijaya Kumar K. B.
Published: June 2017

The complete spectrum of [Formula: see text] states is obtained in a phenomenological nonrelativistic quark model (NRQM), which consists of a confinement potential and one gluon exchange potential (OGEP) as effective quark–antiquark potential with coupled channel effects. We make predictions for the radiative decay (E1 and M1) widths and weak decay widths of [Formula: see text] states in the framework of NRQM formalism.
Conformal scalar curvature equation on Sn: Functions with two close critical points (Twin Pseudo-Peaks)
Authors: Leung Man Chun , Zhou Feng
Published: June 2017

By using the Lyapunov–Schmidt reduction method without perturbation, we consider existence results for the conformal scalar curvature on [Formula: see text] ([Formula: see text]) when the prescribed function (after being projected to [Formula: see text]) has two close critical points, which have the same value (positive), equal “flatness” (“twin”; flatness [Formula: see text]), and exhibit maximal behavior in certain directions (“pseudo-peaks”). The proof relies on a balance between the two main contributions to the reduced functional — one from the critical points and the other from the interaction of the two bubbles.
Translation surfaces of some new types in 3-dimensional Minkowski space 𝔼13 satisfying Δri = λiri
Authors: Senoussi Bendehiba , Bekkar Mohammed
Published: June 2017

Following the publication online, it has been brought to the attention of the Editorial Board of Communications in Contemporary Mathematics (CCM) that the result of this paper was known since 1992 and appeared in the article by Luis Alías, Angel Ferrández and Pascual Lucas, Surfaces in the 3-dimensional Lorentz–Minkowski space satisfying [Formula: see text], Pacific J. Math. 156(2) (1992) 201–208.

The information has been verified, and therefore the Editors-in-Chief of CCM have decided to retract the acceptance of this paper.
Hamiltonian elliptic systems in dimension two with potentials which can vanish at infinity
Authors: Soares Sérgio H. Monari , Leuyacc Yony R. Santaria
Published: June 2017

We will focus on the existence of nontrivial solutions to the following Hamiltonian elliptic system [Formula: see text] where [Formula: see text] is a positive function which can vanish at infinity and be unbounded from above and [Formula: see text] and [Formula: see text] have exponential growth range. The proof involves a truncation argument combined with the linking theorem and a finite-dimensional approximation.
On 2-nil-good rings
Authors: Abdolyousefi Marjan Sheibani , Ashrafi Nahid , Chen Huanyin
Published: June 2017

A ring [Formula: see text] is defined to be 2-nil-good if every element in [Formula: see text] is the sum of two units and a nilpotent. Fundamental properties of such rings are obtained. We prove that every strongly [Formula: see text]-regular ring is 2-nil-good if and only if the identity is the sum of two units. One of the main result of this paper is that every square matrix ring over J-fine rings is 2-nil-good. We establish 2-nil-good property for Morita contexts. This implies, in particular, that every matrix ring over 2-nil-good rings is 2-nil-good. Furthermore, we prove that the ring [Formula: see text] of all lower triangular diagonal-finite matrices over a 2-good ring [Formula: see text] is 2-nil-good.
Chains of semidualizing modules
Authors: Amanzadeh Ensiyeh
Published: June 2017

Let [Formula: see text] be a commutative Noetherian local ring. We study the suitable chains of semidualizing [Formula: see text]-modules. We prove that when [Formula: see text] is Artinian, the existence of a suitable chain of semidualizing modules of length [Formula: see text] implies that the Poincar[Formula: see text] series of [Formula: see text] and the Bass series of [Formula: see text] have very specific forms. Also, in this case, we show that the Bass numbers of [Formula: see text] are strictly increasing. This gives an insight into the question of Huneke about the Bass numbers of [Formula: see text].