Sensory Appeal and Routines Beat Health Messages and Visibility Enhancements: Mixed-Methods Analysis of a Choice-Architecture Intervention in a Workplace Cafeteria

Easier recognition and enhanced visibility of healthy options supposedly increase healthy choices, but real-world evidence remains scarce. Addressing this knowledge gap, we promoted nutritionally favourable foods in a workplace cafeteria with three choice-architectural strategies-priming posters, point-of-choice nutrition labels, and improved product placement-and assessed their effects on visual attention, food choices, and food consumption. Additionally, we developed a method for analysing real-world eye-tracking data. The study followed a pretest-posttest design whereby control and intervention condition lasted five days each. We monitored visual attention (i.e., total number and duration of fixations) and food choices with eye tracking, interviewed customers about perceived influences on food choices, and measured cafeteria-level food consumption (g). Individual-level data represents 22 control and 19 intervention participants recruited at the cafeteria entrance. Cafeteria-level data represents food consumption during the trial (556/589 meals sold). Results indicated that the posters and labels captured participants' visual attention (~13% of fixations on defined areas of interest before food choices), but the intervention had insignificant effects on visual attention to foods, on food choices, and on food consumption. Interviews revealed 17 perceived influences on food choices, the most common being sensory appeal, healthiness, and familiarity. To conclude, the intervention appeared capable of attracting visual attention, yet ineffective in increasing healthier eating. The developed method enabled a rigorous analysis of visual attention and food choices in a natural choice setting. We discuss ways to boost the impact of the intervention on behaviour, considering target groups' motives. The work contributes with a unique, mixed-methods approach and a real-world setting that enabled a multi-dimensional effects evaluation with high external validity.

Population-based assessment of contact tracing operations for COVID-19 in Pirkanmaa hospital district, Finland

Background

The coronavirus disease 2019 (COVID-19) epidemic overwhelmed local contact tracing (CT) efforts in many countries. In Finland, severe acute respiratory syndrome coronavirus 2 incidence and mortality were among the lowest in Europe during 2020–2021. We evaluated CT efficiency, effectiveness, and transmission settings.

Methods

Polymerase chain reaction (PCR) test–positive COVID-19 cases and high-risk contacts in the population-based CT database of Pirkanmaa Hospital District (population 540 000) during June 2020–May 2021 were interviewed.

Results

Altogether 353 926 PCR tests yielded 4739 (1.3%) confirmed cases (average 14-day case notification rate, 34 per 100 000 population); about 99% of confirmed cases and high-risk contacts were reached by a CT team. Of 26 881 high-risk contacts who were placed in quarantine, 2275 subsequently tested positive (48% of new cases), 825 (17%) had been in quarantine ≥48 hours before symptoms, and 3469 (77%) of locally acquired cases were part of transmission chains with an identified setting. The highest secondary attack rates were seen in households (31%), healthcare patients (18%), and private functions (10%). Among the 311 hospitalized patients, COVID-19 diagnosis or exposure was known in 273 (88%) before emergency room admission (identified patients). Healthcare workers had the highest proportion of work-related infections (159 cases [35%]). The source of infection was classifiable in 65% and was most commonly a coworker (64 cases [62%]).

Conclusions

Our data demonstrate the role of effective testing and CT implementation during the cluster phase of COVID-19 spread. Although half of newly diagnosed cases were already in quarantine, targeted public health measures were needed to control transmission. CT effectiveness during widespread community transmission should be assessed.

Tracing local and regional clusters of carbapenemase-producing Klebsiella pneumoniae ST512 with whole genome sequencing, Finland, 2013 to 2018

BackgroundTwo epidemiologically-unrelated clusters of Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae were detected among several healthcare facilities (HCF) in Finland by routine surveillance using whole genome sequencing (WGS).AimThe objective was to investigate transmission chains to stop further spread of the responsible strain.MethodsIn this observational retrospective study, cases were defined as patients with K. pneumoniae KPC-3 sequence type (ST)512 strain detected in Finland from August 2013 to May 2018. Environmental specimens were obtained from surfaces, sinks and toilets in affected wards. WGS was performed on K. pneumoniae cultures using Illumina MiSeq platform and data were analysed using Ridom SeqShere software K. pneumoniae core genome multilocus sequence typing (cgMLST) scheme. Epidemiological information of the cases was provided by HCFs.ResultsWe identified 20 cases in six HCFs: cluster 1 included 18 cases in five HCFs and cluster 2 two cases in one HCF. In cluster 1, a link with a foreign country was unclear, 6/18 cases without overlapping stay had occupied the same room in one of the five HCFs within > 3 years. In cluster 2, the index case was transferred from abroad, both cases occupied the same room 8 months apart. A strain identical to that of the two cases in cgMLST was isolated from the toilet of the room, suggesting a clonal origin.ConclusionsThe clusters were mostly related to case transfer between facilities and likely involved environmental transmission. We show that CPE surveillance using WGS and collaboration between hospitals are crucial to identify clusters and trace transmission chains.

Basal and cold-induced fatty acid uptake of human brown adipose tissue is impaired in obesity

Fatty acids (FA) are important substrates for brown adipose tissue (BAT) metabolism, however, it remains unclear whether there exists a difference in FA metabolism of BAT between lean and obese healthy humans. In this study we evaluated supraclavicular BAT fatty acid uptake (FAU) along with blood perfusion in lean and obese subjects during cold exposure and at room temperature using positron emission tomography (PET)/computed tomography (CT). Additionally, tissue samples were taken from supraclavicular region (typical BAT region) from a subset of subjects to evaluate histological presence of BAT. Non-shivering cold stress elevated FAU and perfusion of BAT in lean, but not in obese subjects. Lean subjects had greater FAU in BAT compared to obese subjects during cold exposure and interestingly also at room temperature. The higher BAT FAU was related to younger age and several indicators of superior systemic metabolic health. The subjects who manifested BAT histologically had several folds higher BAT FAU compared to subjects with no such histological manifestation. Together, obese subjects have less active tissue in supraclavicular region both in basal and cold-activated state and the FA metabolism of BAT is blunted in obesity.

MRI evaluation of the endolymphatic space in otosclerosis and correlation with clinical findings

PURPOSE

The purpose of this study was to investigate the clinical features of ears with otosclerosis and their correlation with endolymphatic hydrops and blood-labyrinth barrier (BLB) impairment on 3T magnetic resonance imaging (MRI).

MATERIALS AND METHODS

This was a single-center retrospective imaging study. Thirty-nine ears from 29 patients (17 men, 12 women; mean age 52±12 [SD] years; range 27-74 years) with non-operated otosclerosis were included. All patients underwent three-dimensional fluid attenuated inversion recovery (FLAIR) MRI sequences performed 4hours after the intravenous administration of a single dose of gadolinium-based contrast material. MRI examinations were analyzed by two radiologists for the presence of saccular hydrops (SH) and BLB impairment. Results of MRI examinations were compared with clinical findings, hearing levels and extent of otosclerotic lesions based on high-resolution computed tomography findings. BLB impairment was evaluated using the signal intensity ratio, ratio of intensities between the basal turn of the cochlea and the medulla.

RESULTS

SH was observed in 1/39 (3%) otosclerotic ears and BLB impairment in 8/39 (21%) while 8/29 patients with otosclerosis (28%) had vertigo. No significant associations were found between SH or BLB impairment on MRI, and the presence of vertigo or the degree of sensorineural hearing loss.

CONCLUSION

Clinical manifestations of otosclerosis (sensorineural hearing loss and rotatory vertigo) were not significantly associated with MRI findings such as BLB impairment and endolymphatic hydrops. SH was only observed in one patient with obstruction of the vestibular aqueduct by an otosclerotic focus.

Prosthetic Rehabilitation with Implant-Supported Mandibular Overdenture after Partial Glossectomy and Radiation Therapy: A Case Report

Implant-supported overdenture is a well-established treatment option for many patients who have functional problems with conventional dentures. It may be primary choice for patients with altered jaw anatomy, neuromuscular disorders, pronounced gag reflex, severe residual ridge resorption and oral tissue defects. In this article we describe a case report, where tongue cancer patients occlusion was rehabilitated with an implantretained overdenture. In 2001 patient was operated for squamous cell carcinoma on the left side of the tongue. Before preoperative radiation therapy, small residual mandibular dentition was removed because of its poor prognosis. Radiation dose on mandible was 57-66 Gy. After tumor surgery patient received conventional complete dentures. Ten years later, the patient was referred again to the Turku University Central Hospital due to constant ulceration under the mandibular denture. The residual ridge of the mandible was severely resorbed. Patient's existing lower complete denture was replaced with a milled bar-retained overdenture on four implants. Treatment turned out to be challenging due to severely restricted tongue movement and tissue defects.

A controlled survey of less typical long-term consequences after an extensive waterborne epidemic

Background

Extensive backflow of treated wastewater caused household water contamination in a Finnish town in 2007. The drinking water of 9 500 residents became heavily polluted with faecal microbes, resulting in a large gastroenteritis epidemic. Cases of reactive arthritis, milder joint symptoms and prolonged gastrointestinal symptoms were observed after the outbreak. A follow-up survey was performed to study less familiar long-term health consequences within a year from the outbreak.

Methods

The contaminated group comprised a sample of residents of the area with polluted water supply (N = 323) and the control group a sample of residents in a nearby municipality (N = 186). The presence of 20 general symptoms or complaints was inquired by a mail survey. Quarterly prevalence of each symptom or complaint was measured. Twelve of these proceeded to further analysis.

Results

The response rate was 53% (323/615) in the contaminated group and 54% (186/343) in the control group. Rash, eye irritation, heartburn and weight loss were more prevalent in the contaminated group during the first year quarter. In the last year quarter, only eye irritation was significantly more common in the contaminated group.

Conclusion

The excess prevalence of four complaints at the first year quarter can be explained by acute gastroenteritis or intensive water chlorination. The excess prevalence of eye irritation at the fourth year quarter cannot be explained by chlorination anymore but might be a sign of co-existing reactive joint disease. In general, long-term consequences of the outbreak can be considered minor in terms of the surveyed symptoms or complaints.

Trends in incidence and resistance patterns of Staphylococcus aureus bacteremia. Infect Dis (Lond) 2017;50:52-58. [PMID: 29161942 DOI: 10.1080/23744235.2017.1405276]

BACKGROUND

Staphylococcus aureus bacteremia (SAB) causes a significant burden on the population. Several infection control measures have been implemented in Pirkanmaa county to combat a local epidemic with methicillin-resistant Staphylococcus aureus (MRSA). We aimed to study the epidemiology of SAB and antibiotic resistance of S. aureus and the possible influence of improved infection control.

METHODS

Register data from 2005 to 2015 were retrospectively analysed to study the antimicrobial susceptibility, the incidence and mortality in SAB in a population-based setting.

RESULTS

The incidence of SAB increased during the study period from 21.6 to 35.8/100,000 population. The number of both health care-associated (HA) and community-associated (CA) cases has increased. The incidence of MSSA bacteremia increased from 19.9 to 35.2/100,000 population in Pirkanmaa in parallel to other parts of Finland. The incidence of MRSA bacteremia was 10-fold (4.5/100,000 population) higher in 2011 than in other parts of the country, but sank to the national level (0.59/100,000 population) in 2015. The fatality rate decreased from 22% to 17%. The proportion of penicillin-susceptible Staphylococcus aureus (PSSA) increased from 23.9% in 2008 to 43.1% in 2015.

CONCLUSION

The incidence of both HA and CA SAB has increased since 2005. Conversely, the proportion of MRSA and PRSA bacteremia has decreased. Promotion of infection control measures may have reduced the incidence of MRSA bacteremia but not the overall incidence of SAB. The rising proportion of PSSA enables the use of targeted, narrow spectrum antimicrobials.

Comparison of outcome and clinical characteristics of bacteremia caused by methicillin-resistant, penicillin-resistant and penicillin-susceptible Staphylococcus aureus strains

BACKGROUND

The aim of this study was to assess the association of methicillin resistance and penicillinase production with clinical characteristics and outcome of Staphylococcus aureus bacteremia.

METHODS

For 126 patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia, 378 age- and gender-matched controls with methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia were selected. Of controls, 126 had bacteremia caused by penicillin-susceptible strains (PSSA) and 252 by penicillinase-producing strains (PRSA). Underlying diseases, clinical course and mortality were retrospectively assessed.

RESULTS

Patients with MRSA bacteremia were more often smokers than patients with MSSA bacteremia (OR 2.34, 95% CI 1.27-4.32). MRSA bacteremia was more often healthcare-associated (OR 4.23, 95% CI 2.47-7.24), associated with central venous catheters (OR 2.09, 95% CI 1.27-3.47), glucocorticoid therapy (OR 1.82, 95% CI 1.12-2.93) and prior surgery (OR 2.32, 95% CI 1.43-3.76). Patients with MRSA bacteremia received appropriate empiric antibiotic (31%) less often than controls (98%). Mortality within 28 days was higher in MRSA bacteremia (26.8%) than in MSSA bacteremia (15.5%) (OR 2.00, 95% CI 1.20-3.34), PRSA bacteremia (17.0%) (OR 1.79 95% CI 1.04-3.09) or PSSA bacteremia (12.5%) (OR 2.56 95% CI 1.27-5.15). The difference remained after adjusting for underlying diseases and foci. There was no significant difference in clinical course between PRSA and PSSA bacteremias.

CONCLUSIONS

MRSA bacteremia was associated with poorer outcome than either PRSA or PSSA bacteremia. We corroborated several risk factors found in previous studies.

Degradation and Crystallization of Cellulose in Hydrogen Chloride Vapor for High-Yield Isolation of Cellulose Nanocrystals

Despite the structural, load-bearing role of cellulose in the plant kingdom, countless efforts have been devoted to degrading this recalcitrant polysaccharide, particularly in the context of biofuels and renewable nanomaterials. Herein, we show how the exposure of plant-based fibers to HCl vapor results in rapid degradation with simultaneous crystallization. Because of the unchanged sample texture and the lack of mass transfer out of the substrate in the gas/solid system, the changes in the crystallinity could be reliably monitored. Furthermore, we describe the preparation of cellulose nanocrystals in high yields and with minimal water consumption. The study serves as a starting point for the solid-state tuning of the supramolecular properties of morphologically heterogeneous biological materials.

Degradation and Crystallization of Cellulose in Hydrogen Chloride Vapor for High-Yield Isolation of Cellulose Nanocrystals

Despite the structural, load-bearing role of cellulose in the plant kingdom, countless efforts have been devoted to degrading this recalcitrant polysaccharide, particularly in the context of biofuels and renewable nanomaterials. Herein, we show how the exposure of plant-based fibers to HCl vapor results in rapid degradation with simultaneous crystallization. Because of the unchanged sample texture and the lack of mass transfer out of the substrate in the gas/solid system, the changes in the crystallinity could be reliably monitored. Furthermore, we describe the preparation of cellulose nanocrystals in high yields and with minimal water consumption. The study serves as a starting point for the solid-state tuning of the supramolecular properties of morphologically heterogeneous biological materials.

Electrical behaviour of native cellulose nanofibril/carbon nanotube hybrid aerogels under cyclic compression

Hybrid aerogels consisting of cellulose nanofibers (CNF) and modified few-walled carbon nanotubes (FWCNT) are investigated under cyclic mechanical compression to explore "electrical fatigue". For this purpose the FWCNTs were hydrophilized, thus promoting their aqueous dispersibility to allow FWCNT/CNF hybrid hydrogels, followed by freeze-drying to obtain hybrid aerogels. The optimized composition consisting of FWCNT/CNF 20/80 wt/wt showed conductivity of 10-5 S cm-1 as promoted due to double percolation, and showed only small changes in electrical and mechanical behaviour upon cycling 100 times. The electrical behaviour under cycled compression shows good stability and reversibility.

Rehabilitation referrals and outcomes in the early period after hematopoietic cell transplantation

In a cohort of inpatient hematopoietic cell transplantation (HCT) recipients, we assessed patterns of referral to rehabilitation treatment, functional performance and short-term outcomes in patients who received post-transplant rehabilitation in comparison with those who did not. Among 201 first-time HCT recipients, 53 (26%) were referred to an inpatient rehabilitation provider, had an assessment of functional performance using the Functional Independence Measure scale and underwent rehabilitation treatments to address functional needs. Patients who received rehabilitation therapy were more likely to be females (P=0.02), older than 60 years of age (P=0.0146), employed (P=0.01), have hypertension (P=0.02), peripheral vascular disease (P=0.01) and pre-transplant Karnofsky Performance Score (KPS) <90 (P=0.02). Mean functional performance scores for transfers and ambulation increased significantly in the group with rehabilitation interventions (P=0.0022 and P<0.0001, respectively). There was no difference between the groups that did and did not receive rehabilitation treatments in 30-day re-admission rates. Patients who are 60 years of age or older, with pre-transplant KPS<90, and pre-transplant hypertension were more likely to be referred for rehabilitation treatments in the early period after HCT. Future studies should be designed to determine the optimal timing and cost effectiveness of functional assessment and rehabilitation treatments in this high-risk population.

Combined interventions are effective in MRSA control

BACKGROUND

A large healthcare-associated epidemic mainly caused by one methicillin-resistant Staphylococcus aureus (MRSA) strain broke out in Pirkanmaa County, Finland, in 2001. This study describes the impact of infection control and screening practices on the epidemic.

METHODS

The number of hospital-acquired (HA)-MRSA findings obtained from clinical and screening samples during the epidemic was calculated. Strains were typed by pulsed-field electrophoresis (PFGE) or spa typing. Strain type distribution was studied in relation to sample type, year of the epidemic and site of transmission. Several infection control interventions were launched stepwise and screening protocols were expanded.

RESULTS

A total of 4118 cases were identified during 2001-2014, of which 3527 were classified as HA. One strain (spa t067) dominated in the epidemic. HA-MRSA cases decreased constantly from the year 2011. The number of new HA-MRSA cases was 57% less in the year 2014 (n = 171) as compared with the year 2011 (n = 399). The proportion of the epidemic strain declined significantly over the years. Screening samples comprised 71% (2439/3527) and clinical samples 29% (1034/3527) of HA-MRSA findings. The number of HA-MRSA cases found from clinical samples started to decrease when screening was expanded. An increase in hand-rub consumption was associated with a decrease in transmissions in Tampere University Hospital (TAUH).

CONCLUSION

Implementation of universal screening together with several other interventions is effective in containing an MRSA epidemic. The proportion of other than Pirkanmaa epidemic (PE)-MRSA strain findings increased throughout the period, indicating the changing epidemiology of MRSA.

Brown adipose tissue triglyceride content is associated with decreased insulin sensitivity, independently of age and obesity

The aim of the present study was to determine whether single-voxel proton magnetic resonance spectroscopy ((1)H-MRS) can non-invasively assess triglyceride content in both supraclavicular fat depots and subcutaneous white adipose tissue (WAT) to determine whether these measurements correlate to metabolic variables. A total of 25 healthy volunteers were studied using (18)F-fluorodeoxyglucose positron emission tomography (PET) and (15)O-H2O PET perfusion during cold exposure, and (1)H-MRS at ambient temperature. Image-guided biopsies were collected from nine volunteers. The supraclavicular triglyceride content determined by (1)H-MRS varied between 60 and 91% [mean ± standard deviation (s.d.) 77 ± 10%]. It correlated positively with body mass index, waist circumference, subcutaneous and visceral fat masses and 8-year diabetes risk based on the Framingham risk score and inversely with HDL cholesterol and insulin sensitivity (M-value; euglycaemic-hyperinsulinaemic clamp). Subcutaneous WAT had a significantly higher triglyceride content, 76-95% (mean ± s.d. 87 ± 5%; p = 0.0002). In conclusion, the triglyceride content in supraclavicular fat deposits measured by (1)H-MRS may be an independent marker of whole-body insulin sensitivity, independent of brown adipose tissue metabolic activation.

Hybrid supramolecular and colloidal hydrogels that bridge multiple length scales

Hybrid nanocomposites were constructed based on colloidal nanofibrillar hydrogels with interpenetrating supramolecular hydrogels, displaying enhanced rheological yield strain and a synergistic improvement in storage modulus. The supramolecular hydrogel consists of naphthyl-functionalized hydroxyethyl cellulose and a cationic polystyrene derivative decorated with methylviologen moieties, physically cross-linked with cucurbit[8]uril macrocyclic hosts. Fast exchange kinetics within the supramolecular system are enabled by reversible cross-linking through the binding of the naphthyl and viologen guests. The colloidal hydrogel consists of nanofibrillated cellulose that combines a mechanically strong nanofiber skeleton with a lateral fibrillar diameter of a few nanometers. The two networks interact through hydroxyethyl cellulose adsorption to the nanofibrillated cellulose surfaces. This work shows methods to bridge the length scales of molecular and colloidal hybrid hydrogels, resulting in synergy between reinforcement and dynamics.

Hybrid Supramolecular and Colloidal Hydrogels that Bridge Multiple Length Scales

Hybrid nanocomposites were constructed based on colloidal nanofibrillar hydrogels with interpenetrating supramolecular hydrogels, displaying enhanced rheological yield strain and a synergistic improvement in storage modulus. The supramolecular hydrogel consists of naphthyl-functionalized hydroxyethyl cellulose and a cationic polystyrene derivative decorated with methylviologen moieties, physically cross-linked with cucurbit[8]uril macrocyclic hosts. Fast exchange kinetics within the supramolecular system are enabled by reversible cross-linking through the binding of the naphthyl and viologen guests. The colloidal hydrogel consists of nanofibrillated cellulose that combines a mechanically strong nanofiber skeleton with a lateral fibrillar diameter of a few nanometers. The two networks interact through hydroxyethyl cellulose adsorption to the nanofibrillated cellulose surfaces. This work shows methods to bridge the length scales of molecular and colloidal hybrid hydrogels, resulting in synergy between reinforcement and dynamics.

Maternal diabetes induces changes in the umbilical cord gene expression

INTRODUCTION

Since maternal diabetes may affect fetal development and the umbilical cord provides an extension of the fetal vasculature, we decided to investigate cords' biological responses to maternal diabetic milieu.

METHODS

Using microarray analysis, we determined the gene expression profiles in the umbilical cords of six neonates born to type 1 diabetic mothers and in six control cords. Umbilical cord tissue was collected immediately after elective cesarean section. Expression data were confirmed by real-time polymerase chain reaction (11 genes). Additionally, the same umbilical cords were analyzed histologically.

RESULTS

Two hundred eighty six genes were differentially expressed in the umbilical cords from diabetic pregnancies compared to the controls (fold change ±1.5 and P < 0.01). Maternal diabetes had a major effect on the expression of genes involved in vascular development (Bone morphogenetic protein 4, Delta-like 1, and Notch homolog 4), vessel wall integrity (Collagen type VIII alpha 1, Myocyte enhancer factor 2C, and Matrix metalloproteinase 2), and vascular function (Natriuretic peptide precursor B, Endothelin 1, Endothelin receptor B, Cyclooxygenase 1, and Phosphodiesterase 5A). Maternal diabetes was associated with thicker umbilical vein intima-media layers and larger umbilical vein and artery intima-media areas compared to the controls.

DISCUSSION

Maternal diabetic environment seems to alter umbilical cord expression of genes involved in the regulation of vascular development and function with simultaneous umbilical vessel muscle layer thickening. These alterations suggest vascular phenotypic modifications, which in turn may lead to long-term vascular consequences in various tissues in infants of diabetic mothers.

An outbreak of human metapneumovirus in a rehabilitation center for alcoholics in Tampere, Finland

Reports of respiratory tract infections in a rehabilitation center for alcoholics triggered the epidemiological investigations in Tampere, Finland. Twenty-nine out of 40 residents (attack rate 73%) and four members of staff fulfilled the case criteria: cough; worsening of dyspnea; or rhinitis with or without fever. Ten cases were hospitalized, one needed treatment in the intensive care unit. All cases recovered. Serum hMPV antibody titer was high (10 240 or more) in 20 (69%) of the 29 tested cases and the difference was significant when compared with the titer measured from the voluntary laboratory personnel (n = 14, p < 0.001). The titers were rising in three out of the five cases from whom coupled samples could be obtained. Rt-PCR for hMPV was positive in three out of the eight tested cases. No other causative agent for the outbreak was detected. The outcome of hMPV infection among institutionalized smoking alcoholics was good with no mortality.

Effect of charge balance and dosage of polyelectrolyte complexes on the shear resistance of mineral floc strength and reversibility

We evaluated the effect of polyelectrolyte complexes (PEC) with varying balance of charges on the flocculation of precipitated calcium carbonate (PCC) particles. PECs composed of polyacrylamides carrying opposite charges (A-PAM and C-PAM) were investigated in terms of PCC floc shear resistance and re-flocculation effects. Light transmission was used in real time to monitor the dynamics of flocculation under shear fields. Compared to the single polyelectrolytes, PECs greatly enhanced particle re-flocculation while minor differences in shear resistance were observed. Shear resistance and re-flocculation depended strongly on the molecular weight and charge ratio of the PEC components. In order to achieve floc stability and re-flocculation conditions a minimum concentration of charge-asymmetric PEC should be applied.

Microemulsion systems for fiber deconstruction into cellulose nanofibrils

A new method to produce cellulose nanofibrils (CNF) is proposed to reduce the energy demand during deconstruction of precursor fibers suspended in aqueous media. Microemulsions were formulated with aqueous solutions of urea or ethylenediamine and applied to disrupt interfibril hydrogen bonding. Compared to typical fibrillation of lignin-containing and lignin-free fibers, pretreatment with microemulsion systems allowed energy savings during microfluidization of 55 and 32%, respectively. Moreover, microemulsion processing facilitated smaller-scale CNF structures (higher degrees of deconstruction), with higher water retention value (WRV) and surface area. Urea-containing microemulsions were found to be most effective in reducing energy consumption and in weakening the cellulosic matrix. Films prepared from CNF processed after pretreatment with urea-containing microemulsions presented a more uniform fiber network and produced films with smoother surfaces compared to those based on ethylenediamine. The lignin-containing CNF (LCNF) produced denser films than those obtained from lignin-free CNF. The mechanical properties of films obtained after application of microemulsion pretreatment were compared, and the benefits of the proposed approach were further confirmed. Overall, fiber deconstruction after microemulsion treatment is a step toward energy-efficient production of nanocellulose.

Effects of residual lignin and heteropolysaccharides on the bioconversion of softwood lignocellulose nanofibrils obtained by SO2-ethanol-water fractionation

The amount of residual lignin and hemicelluloses in softwood fibers was systematically varied by SO2-ethanol-water fractionation for integrated biorefinery with nanomaterial and biofuel production. On the basis of their low energy demand in mechanical processing, the fibers were deconstructed to lignocellulose nanofibrils (LCNF) and used as substrate for bioconversion. The effect of LCNF composition on saccharification via multicomponent enzymes was investigated at different loadings. LCNF digestibility was compared with the enzyme activity measured with a quartz crystal microbalance. LCNF hydrolysis rate gradually decreased with lignin and hemicellulose concentration, both of which limited enzyme accessibility. Enzyme inhibition resulted from non-productive binding of proteins onto lignin. Near complete LCNF hydrolysis was achieved, even at high lignin and hemicellulose content. Sugar yields for LCNF were higher than those for precursor SEW fibers, highlighting the benefits of high surface area in LCNF.

Thermoresponsive Nanocellulose Hydrogels with Tunable Mechanical Properties

Cellulose microfibrils physically bound together by soft hemicellulose chains form the scaffolding that makes plant cell walls strong. Inspired by this architecture, we designed biomimetic thermoreversible hydrogel networks based on reinforcing cellulose nanocrystals (CNC) and thermoresponsive methylcellulose (MC). Upon dissolving MC powder in CNC aqueous dispersions, viscoelastic dispersions were formed at 20 °C, where the storage modulus (G') is tunable from 1.0 to 75 Pa upon increasing the CNC concentration from 0 to 3.5 wt % with 1.0 wt % MC. By contrast, at 60 °C a distinct gel state is obtained with G' ≫ G″, G' ∼ ω⁰, with an order of magnitude larger G' values from 110 to 900 Pa upon increasing the CNC concentration from 0 to 3.5 wt % with constant 1.0 wt % MC, due to the physical cross-links between MC and CNCs. Therefore, simply mixing two sustainable components leads to the first all-cellulose thermoreversible and tunable nanocellulose-based hydrogels.

Affibody conjugation onto bacterial cellulose tubes and bioseparation of human serum albumin

We attached anti-human serum albumin (anti-HSA) affibody ligands on bacterial cellulose (BC) by EDC–NHS-mediated covalent conjugation and physical adsorption and demonstrate their application for tubular biofiltration of blood proteins.

Direct measurements of non-ionic attraction and nanoscaled lubrication in biomimetic composites from nanofibrillated cellulose and modified carboxymethylated cellulose

There is a growing interest to design biomimetic self-assembled composite films from renewable resources aimed at a combination of high toughness, strength and stiffness. However, the relationship between interfacial interactions of the components and the mechanical performance of the composite is still poorly understood. In this work we present evidence of the link between mechanical performance of carbohydrate-based composites with nanolubrication and with direct surface forces between the hard and soft domain in the system. Our approach was to use nanofibrillated cellulose (NFC) as the major reinforcing domain and to modify it by adsorption of a small amount of soft polyethylene glycol grafted carboxymethyl cellulose (CMC-g-PEG). The effect of the soft polymer on direct normal and friction forces in air between cellulose surfaces was evaluated using colloidal probe microscopy. The fibrillar structure of the NFC thin film affected the frictional behaviour; when decreasing load, the friction between pure cellulose surfaces increased, suggesting partial pull-out of fibrils, a phenomenon not observed for non-fibrillar cellulose substrates. Adsorption of CMC-g-PEG on both surfaces decreased the friction considerably but adhesion was still high. The symmetric system, having both cellulose substrates covered with the polymer, was compared to asymmetric systems where only one surface was covered with the polymer. Furthermore, a free standing composite film was prepared by non-ionic self-assembly of NFC and CMC-g-PEG with 99 : 1 weight-ratio; the mechanical properties of the macroscopic films were related to the nanoscaled interactions between the components. The composition studied showed excellent mechanical properties which do not follow the simple rule of mixture. Thus, a synergy in the direct surface forces and mechanical properties was found. This approach offers a robust path to aid in the efficient design of next generation biomimetic composites.

Adsorption of hydrophobically end-capped poly(ethylene glycol) on cellulose

Adsorption of poly(ethylene glycol), hydrophobically end-capped with octadecenylsuccinic anhydride (OSA-PEG-OSA), on an ultrathin film of cellulose has been studied by quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM). Normally, PEG does not adsorb on cellulosic surfaces, but the use of the telechelic hydrophobic modification was found to promote adsorption. The influence of the conformation of the polymer in solution prior to adsorption and the subsequent properties of the adsorbed layer were investigated. The adsorption experiments were done at concentrations below and above the critical association concentration. The adsorption of OSA-PEG-OSA on cellulose was observed to occur in four distinct stages. Because of the amphiphilic nature of cellulose, further adsorption experiments were performed on hydrophobic (polystyrene) and hydrophilic (silica) model substrates to illuminate the contribution of hydrophobic and hydrophilic factors in the adsorption phenomenon. As expected, the kinetics and the mechanism of adsorption were strongly dependent on the chemical composition of the substrate.

Controlled hydrophobic functionalization of natural fibers through self-assembly of amphiphilic diblock copolymer micelles

The functionalization of natural fibers is an important task that has recently received considerable attention. We investigated the formation of a hydrophobic layer from amphiphilic diblock copolymer micelles [polystyrene-block-poly(N-methyl-4-vinyl pyridinium iodide)] on natural fibers and on a model surface (mica). A series of micelles were prepared. The micelles were characterized by using cryoscopic TEM and light scattering, and their hydrophobization capability was studied through contact angle measurements, water adsorption, and Raman imaging. Mild heat treatment (130 °C) was used to increase the hydrophobization capability of the micelles. The results showed that the micelles could not hydrophobize a model surface, but could render the natural fibers water repellent both with and without heat treatment. This effect was systematically studied by varying the composition of the constituent blocks. The results showed that the micelle size (and the molecular weight of the constituent diblock copolymers) was the most important parameter, whereas the cationic (hydrophilic) part played only a minor role. We hypothesized that the hydrophobization effect could be attributed to a combination of the micelle size and the shrinkage of the natural fibers upon drying. The shrinking caused the roughness to increase on the fiber surface, which resulted in a rearrangement of the self- assembled layer in the wet state. Consequently, the fibers became hydrophobic through the roughness effects at multiple length scales. Mild heat treatment melted the micelle core and decreased the minimum size necessary for hydrophobization.

A fast method to produce strong NFC films as a platform for barrier and functional materials

In this study, we present a rapid method to prepare robust, solvent-resistant, nanofibrillated cellulose (NFC) films that can be further surface-modified for functionality. The oxygen, water vapor, and grease barrier properties of the films were measured, and in addition, mechanical properties in the dry and wet state and solvent resistance were evaluated. The pure unmodified NFC films were good barriers for oxygen gas and grease. At a relative humidity below 65%, oxygen permeability of the pure and unmodified NFC films was below 0.6 cm(3) μm m(-2) d(-1) kPa(-1), and no grease penetrated the film. However, the largest advantage of these films was their resistance to various solvents, such as water, methanol, toluene, and dimethylacetamide. Although they absorbed a substantial amount of solvent, the films could still be handled after 24 h of solvent soaking. Hot-pressing was introduced as a convenient method to not only increase the drying speed of the films but also enhance the robustness of the films. The wet strength of the films increased due to the pressing. Thus, they can be chemically or physically modified through adsorption or direct chemical reaction in both aqueous and organic solvents. Through these modifications, the properties of the film can be enhanced, introducing, for example, functionality, hydrophobicity, or bioactivity. Herein, a simple method using surface coating with wax to improve hydrophobicity and oxygen barrier properties at very high humidity is described. Through this modification, the oxygen permeability decreased further and was below 17 cm(3) μm m(-2) d(-1) kPa(-1) even at 97.4% RH, and the water vapor transmission rate decreased from 600 to 40 g/m(2) day. The wax treatment did not deteriorate the dry strength of the film. Possible reasons for the unique properties are discussed. The developed robust NFC films can be used as a generic, environmentally sustainable platform for functional materials.

Excess healthcare costs of a large waterborne outbreak in Finland

Background: The economic effects of waterborne outbreaks have rarely been reported. A large waterborne outbreak occurred in the town of Nokia in Finland in 2007 with half of the population in the contaminated area suffering from gastroenteritis. We studied the healthcare costs of this outbreak. Methods: Healthcare costs were studied using register data from the Nokia Health Care Centre, data collected in the regional university hospital, and data from laboratory register on stool samples. Results: Total excess healthcare costs were EUR 354,496, which is approximately EUR 10 per resident of Nokia. There were 2052 excess visits because of gastroenteritis in Nokia Health Care Centre, 403 excess episodes in the university hospital, and altogether over 2000 excess stool samples due to the outbreak. Care in the Nokia Health Care Centre accounted for 44% and care in the university hospital for 42% of the excess healthcare costs while stool samples accounted for only 10%. Conclusions: Despite the high morbidity, the total cost was low because most patients had a relatively mild illness. The situation would have been worse if the microbes involved had been more hazardous or if the financial situation of the community had been worse. Prevention of waterborne outbreaks is important, as there is a risk of severe short- and long-term health effects and substantial health-economic costs.

Main results of the European project NURESIM on the CFD-modelling of two-phase Pressurized Thermal Shock (PTS)

The European Platform for NUclear REactor SIMulations, (NURESIM project 2005 – 2008) addressed the creation of a Common European Standard Software Platform for modelling, recording, and recovering computer data for nuclear reactors simulations. One work package of the project was dedicated to the analysis and improvement of CFD capabilities for the simulation of two-phase PTS problems. Some SB-LOCA scenarios lead to a situation in which the cold leg is partially or totally uncovered when the Emergency Core Cooling injection is activated. The resulting complex two phase flow can be divided in characteristic flow regions: the jet flow with a free surface between steam and water, the zone of jet impingement, the horizontal two-phase flow and the flow in the downcomer. Many phenomena have to be reflected in a simulation of each separate region, but also when the simulations are coupled reflecting the integral process which is required to predict the thermal loads at the RPV wall. After analyzing the experimental database available for CFD model development and validation and identifying shortcomings of the models different activities were dedicated to the simulation of single flow regions as well as the integral flow. Based on these experiences recommendations for the CFD-simulation of the two-phase PTS problem were obtained.

Clostridium difficile contamination of public tap water distribution system during a waterborne outbreak in Finland

Aims: In November through December 2007, the drinking water distribution system in the town of Nokia, Finland, was contaminated with treated sewage effluent that resulted in a large gastroenteritis outbreak in the community. The aim of the present study was to investigate if the contaminated water in this outbreak was also a potential source of Clostridium difficile infections. Methods: Samples from the contaminated tap water and treated sewage effluent were collected. Stool samples from a portion of patients that fell ill during the outbreak were examined for C. difficile. PCR ribotyping was performed on toxin positive C. difficile isolates and the genetic profiles of the water and patient isolates were compared. Results: Twelve toxin-positive C. difficile isolates were found in water samples: five from contaminated tap water and seven from treated sewage effluent. Among these, four and five distinct PCR ribotype profiles were identified, respectively. Four PCR ribotype profiles were found among nine human faecal C. difficile isolates. Two isolates, one from tap water and one from a patient, had an indistinguishable PCR ribotype profile. Conclusions: Our findings demonstrate for the first time C. difficile contamination of a tap water distribution system and waterborne transmission of toxigenic C. difficile seems possible.

Protein-assisted 2D assembly of gold nanoparticles on a polysaccharide surface

Site-specific assembly of gold nanoparticles on a polysaccharide surface was accomplished via a straightforward method exploiting interfacial polymer blends, selective protein adsorption and electrostatic interaction. The method could be useful in further applications due to the universal nature of the utilized phenomena.

Valorization of residual Empty Palm Fruit Bunch Fibers (EPFBF) by microfluidization: production of nanofibrillated cellulose and EPFBF nanopaper

Different cellulose pulps were produced from sulfur-free chemical treatments of Empty Palm Fruit Bunch Fibers (EPFBF), a by-product from palm oil processing. The pulps were microfluidized for deconstruction into nanofibrillated cellulose (NFC) and nanopaper was manufactured by using an overpressure device. The morphological and structural features of the obtained NFCs were characterized via atomic force and scanning electron microscopies. The physical properties as well as the interactions with water of sheets from three different pulps were compared with those of nanopaper obtained from the corresponding NFC. Distinctive chemical and morphological characteristics and ensuing nanopaper properties were generated by the EPFBF fibers. The NFC grades obtained compared favorably with associated materials typically produced from bleached wood fibers. Lower water absorption, higher tensile strengths (107-137 MPa) and elastic modulus (12-18 GPa) were measured, which opens the possibility for valorization of such widely available bioresource.

Rapid and Complete Enzyme Hydrolysis of Lignocellulosic Nanofibrils

Rapid enzymatic saccharification of lignocellulosic nanofibrils (LCNF) was investigated by monitoring nanoscale changes in mass via quartz crystal microgravimetry and also by measuring reducing sugar yields. In only a few minutes LCNF thin films were completely hydrolyzed upon incubation in multicomponent enzyme systems. Conversion to sugars and oligosaccharides of LCNF dispersed in water occurred in about 4 h (50 °C, pH 5). In contrast, a conversion of only 57% was observed for partially crystalline cellulose (Avicel) after 9 h, under same experimental conditions. Under conditions of high enzyme loading the presence of residual lignin and other macromolecules in the cell wall of LCNF did not appear to affect negatively the recorded high hydrolysis rates. Overall, our findings suggest that deconstruction of the cell wall to nanofibrils is an effective pretreatment to facilitate rapid and complete cellulose bioconversion.

Methicillin-resistant Staphylococcus aureus epidemic restricted to one health district in Finland: a population-based descriptive study in Pirkanmaa, Finland, years 2001-2011

BACKGROUND

The incidence of methicillin-resistant Staphylococcus aureus (MRSA) has been low in the Scandinavian countries, including Finland.

METHODS

We report a population-based, prospective survey of an exceptionally large ongoing MRSA epidemic in a Finnish health district (HD), Pirkanmaa HD, during 2001-2011 caused by 1 strain, spa t067 (FIN-16).

RESULTS

The first FIN-16 case in the HD was identified in 2000. Ten years later, 2447 carriers had been found in 95 different institutions. MRSA in carriers was mostly health care-associated (98%). The epidemic emerged in long-term care facilities and gradually spread to acute hospitals. The majority of carriers were elderly people (median age 78 y). Fifty-two percent of new carriers had an infection with MRSA at the time of detection.

CONCLUSIONS

The incidence of MRSA in Pirkanmaa HD is substantially higher than the incidence for all of Finland. Temporary projects to control MRSA have not proved sufficient to contain this large epidemic.