Electron Storage in Electroactive Biofilms.

Microbial electrochemical technologies (METs) are promising for sustainable applications. Recently, electron storage during intermittent operation of electroactive biofilms (EABs) has been shown to play an important role in power output and electron efficiencies. Insights into electron storage mechanisms, and the conditions under which these occur, are essential to improve microbial electrochemical conversions and to optimize biotechnological processes. Here, we discuss the two main mechanisms for electron storage in EABs: storage in the form of reduced redox active components in the electron transport chain and in the form of polymers. We review electron storage in EABs and in other microorganisms and will discuss how the mechanisms of electron storage can be influenced.

Competition of electrogens with methanogens for hydrogen in bioanodes.

Bioelectrochemical systems (BES) can provide an energy efficient way to recover nutrients from wastewaters. However, the electron donors available in wastewater are often not sufficient to recover the total amount of nutrients. This work investigates hydrogen (H2) as an additional substrate for bioanodes. This hydrogen can be produced in the fermentation of complex organic waste or could be recycled from the cathode. Understanding how to influence the competition of electroactive microorganisms (EAM) with methanogens for H2 gas from different sources is key to successful application of H2 as additional electron donor in bioelectrochemical nutrient recovery. Ethanol (EtOH) was used as model compound for complex wastewaters since it is fermented into both acetate and H2. EtOH was efficiently converted into electricity (e-) by a syntrophic biofilm. Total recovered charge from 1 mM EtOH was 20% higher than for the same amount of acetate. This means that H2 from EtOH fermentation was converted by EAM into electricity. Low EtOH concentrations (1  mM) led to higher conversion efficiencies into electricity than higher concentrations (5 and 10  mM). Thermodynamic calculations show this correlates with a higher energy gain for electrogens compared to methanogens at low H2 concentrations. Cumulatively adding 1 mM EtOH without medium exchange (14 times in 14 days) resulted in stable conversion of H2 to e- (67%-77% e-) rather than methane. With H2 gas as electron donor, 68 ±â€¯2% H2 was converted into e- with no carbon source added, and still 53 ±â€¯5% to e- when 50  mM bicarbonate was provided. These results show that under the provided conditions, electrogens can outcompete methanogens for H2 as additional electron donor in MECs for nutrient recovery.

(Bio)electrochemical ammonia recovery: progress and perspectives.

In recent years, (bio)electrochemical systems (B)ES have emerged as an energy efficient alternative for the recovery of TAN (total ammonia nitrogen, including ammonia and ammonium) from wastewater. In these systems, TAN is removed or concentrated from the wastewater under the influence of an electrical current and transported to the cathode. Subsequently, it can be removed or recovered through stripping, chemisorption, or forward osmosis. A crucial parameter that determines the energy required to recover TAN is the load ratio: the ratio between TAN loading and applied current. For electrochemical TAN recovery, an energy input is required, while in bioelectrochemical recovery, electric energy can be recovered together with TAN. Bioelectrochemical recovery relies on the microbial oxidation of COD for the production of electrons, which drives TAN transport. Here, the state-of-the-art of (bio)electrochemical TAN recovery is described, the performance of (B)ES for TAN recovery is analyzed, the potential of different wastewaters for BES-based TAN recovery is evaluated, the microorganisms found on bioanodes that treat wastewater high in TAN are reported, and the toxic effect of the typical conditions in such systems (e.g., high pH, TAN, and salt concentrations) are described. For future application, toxicity effects for electrochemically active bacteria need better understanding, and the technologies need to be demonstrated on larger scale.

Substantial injuries influence ranking position in young elite athletes of athletics, cross-country skiing and orienteering.

The relationship between injury and performance in young athletes is scarcely studied. The aim of this study was therefore to explore the association between injury prevalence and ranking position among adolescent elite athletes. One hundred and sixty-two male and female adolescent elite athletes (age range 15-19), competing in athletics (n = 59), cross-country skiing (n = 66), and orienteering (n = 37), were monitored weekly over 22-47 weeks using a web-based injury questionnaire. Ranking lists were collected. A significant (P = .003) difference was found in the seasonal substantial injury prevalence across the ranked athletes over the season, where the top-ranked (median 3.6%, 25-75th percentiles 0%-14.3%) and middle-ranked athletes (median 2.3%, 25-75th percentiles 0%-10.0%) had a lower substantial injury prevalence compared to the low-ranked athletes (median 11.3%, 25-75th percentiles 2.5%-27.1%), during both preseason (P = .002) and competitive season (P = .031). Athletes who improved their ranking position (51%, n = 51) reported a lower substantial injury prevalence (median 0%, 25-75th percentiles 0%-10.0%) compared to those who decreased (49%, n = 49) their ranking position (md 6.7%, 25-75th percentiles 0%-22.5%). In the top-ranked group, no athlete reported substantial injury more than 40% of all data collection time points compared to 9.6% (n = 5) in the middle-ranked, and 17.3% (n = 9) in the low-ranked group. Our results provide supporting evidence that substantial injuries, such as acute and overuse injuries leading to moderate or severe reductions in training or sports performance, influence ranking position in adolescent elite athletes. The findings are crucial to stakeholders involved in adolescent elite sports and support the value of designing effective preventive interventions for substantial injuries.

Multiple factors explain injury risk in adolescent elite athletes: Applying a biopsychosocial perspective.

Many risk factors for injury are presented in the literature, few of those are however consistent and the majority is associated with adult and not adolescent elite athletes. The aim was to identify risk factors for injury in adolescent elite athletes, by applying a biopsychosocial approach. A total of 496 adolescent elite athletes (age range 15-19), participating in 16 different sports, were monitored repeatedly over 52 weeks using a valid questionnaire about injuries, training exposure, sleep, stress, nutrition, and competence-based self-esteem. Univariate and multiple Cox regression analyses were used to calculate hazard ratios (HR) for risk factors for first reported injury. The main finding was that an increase in training load, training intensity, and at the same time decreasing the sleep volume resulted in a higher risk for injury compared to no change in these variables (HR 2.25, 95% CI, 1.46-3.45, P<.01), which was the strongest risk factor identified. In addition, an increase by one score of competence-based self-esteem increased the hazard for injury with 1.02 (HR 95% CI, 1.00-1.04, P=.01). Based on the multiple Cox regression analysis, an athlete having the identified risk factors (Risk Index, competence-based self-esteem), with an average competence-based self-esteem score, had more than a threefold increased risk for injury (HR 3.35), compared to an athlete with a low competence-based self-esteem and no change in sleep or training volume. Our findings confirm injury occurrence as a result of multiple risk factors interacting in complex ways.

Timing of Antibiotic Prophylaxis for Preventing Surgical Site Infections in Foot and Ankle Surgery.

BACKGROUND: Surgical site infections (SSIs) are one of the most troublesome complications after foot and ankle surgery. Previous literature has emphasized the significance of appropriate timing of antibiotic prophylaxis. However, the optimal timing of antibiotic prophylaxis for SSI prevention is still inconclusive. Our study aimed to investigate the optimal timing of antibiotic administration and to elucidate the risk factors for SSIs in foot and ankle surgery. METHODS: A retrospective review of 1933 foot and ankle procedures in 1632 patients from January 1, 2011, through August 31, 2015, was performed. Demographic data; type, amount, and timing of antibiotic administration; incision; and closure time were recorded. Subsequent wound infection and incision and drainage procedure (I&D) within 30 days and 90 days were documented. Outcomes and demographic variables were compared between procedures in which antibiotics were administered less than 15 minutes and between 15 to 60 minutes prior to incision. A total of 1569 procedures met inclusion criteria. RESULTS: There were 17 cases (1.1%) of subsequent wound infection, of which 6 required a subsequent I&D within 30 days. There were 63 additional cases (4%) of wound complications, which did not meet SSI criteria. When comparing SSI and non-SSI groups, the only significant independent predictors were longer surgeries and nonambulatory surgeries (both P < .05). Stepwise multivariate logistic regression analysis demonstrated that 91.8% of the risk of an SSI could be predicted by ASA score and length of surgery alone. CONCLUSION: In foot and ankle surgeries, the timing of intravenous antibiotic prophylaxis did not appear to play a significant role in the risk of SSI. Host factors and duration of surgery appear to have played a much larger role in SSI than the timing of antibiotic prophylaxis. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Guidelines for the use of magnetic resonance imaging in diagnosing and monitoring the treatment of multiple sclerosis: recommendations of the Swedish Multiple Sclerosis Association and the Swedish Neuroradiological Society.

Multiple sclerosis (MS) is associated with inflammatory lesions in the brain and spinal cord. The detection of such inflammatory lesions using magnetic resonance imaging (MRI) is important in the consideration of the diagnosis and differential diagnoses of MS, as well as in the monitoring of disease activity and predicting treatment efficacy. Although there is strong evidence supporting the use of MRI for both the diagnosis and monitoring of disease activity, there is a lack of evidence regarding which MRI protocols to use, the frequency of examinations, and in what clinical situations to consider MRI examination. A national workshop to discuss these issues was held in Stockholm, Sweden, in August 2015, which resulted in a Swedish consensus statement regarding the use of MRI in the care of individuals with MS. The aim of this consensus statement is to provide practical advice for the use of MRI in this setting. The recommendations are based on a review of relevant literature and the clinical experience of workshop attendees. It is our hope that these recommendations will benefit individuals with MS and guide healthcare professionals responsible for their care.

Too little sleep and an unhealthy diet could increase the risk of sustaining a new injury in adolescent elite athletes.

Little is known about health variables and if these variables could increase the risk of injuries among adolescent elite athletes. The primary aim was to present overall data on self-perceived stress, nutrition intake, self-esteem, and sleep, as well as gender and age differences, on two occasions among adolescent elite athletes. A secondary aim was to study these health variables as potential risk factors on injury incidence. A questionnaire was e-mailed to 340 adolescent elite athletes on two occasions during a single school year: autumn semester and spring semester. The results show that during autumn semester, the recommended intake of fruits, vegetables, and fish was not met for 20%, 39%, and 43% of the adolescent elite athletes, respectively. The recommended amount of sleep during weekdays was not obtained by 19%. Multiple logistic regression showed that athletes sleeping more than 8 h of sleep during weekdays reduced the odds of injury with 61% (OR, 0.39; 95% CI, 0.16-0.99) and athletes reaching the recommended nutrition intake reduced the odds with 64% (OR, 0.36; 95% CI, 0.14-0.91). Our findings suggest that nutrition intake and sleep volume are of importance in understanding injury incidence.

Swedish translation and validation of a web-based questionnaire for registration of overuse problems.

The main aim of this study was to translate the Oslo Sport Trauma Research Center (OSTRC) Overuse Injury Questionnaire into Swedish. The validity and applicability of the questionnaire for studying overuse injuries among Swedish handball, volleyball, tennis, and orienteering top athletes were also examined. The back-translation method was used for translation. An expert committee further developed it for use in a study of injuries in handball, orienteering, tennis, and volleyball. A 10-week pretest was then conducted on 43 athletes, average age 21 (18-31) from these sports, during which time the athletes completed the modified OSTRC questionnaire on a weekly basis. In the 10th week, four additional questions were added in order to examine the questionnaire's content validity. No major disagreement was found in the translation. The athletes perceived the web-based questionnaire to be smooth and easy to complete, accurately capturing overuse injuries. However, suggestions were made to add questions relating to the hip for orienteerers and to the hand/fingers for handball players. The average prevalence of overuse injuries for all athletes, in any anatomical area was 22% (95% confidence interval 20-25). Construct validity appeared to be high, and we therefore suggest that the questionnaire may be used when studying overuse injuries in different sports.

Theory of ion transport with fast acid-base equilibrations in bioelectrochemical systems.

Bioelectrochemical systems recover valuable components and energy in the form of hydrogen or electricity from aqueous organic streams. We derive a one-dimensional steady-state model for ion transport in a bioelectrochemical system, with the ions subject to diffusional and electrical forces. Since most of the ionic species can undergo acid-base reactions, ion transport is combined in our model with infinitely fast ion acid-base equilibrations. The model describes the current-induced ammonia evaporation and recovery at the cathode side of a bioelectrochemical system that runs on an organic stream containing ammonium ions. We identify that the rate of ammonia evaporation depends not only on the current but also on the flow rate of gas in the cathode chamber, the diffusion of ammonia from the cathode back into the anode chamber, through the ion exchange membrane placed in between, and the membrane charge density.

A nine-test screening battery for athletes: a reliability study.

Studies have shown that reduced neuromuscular control or strength increases the risk of acute injuries. It is hypothesized that a non-functional movement pattern can predispose for injuries. In the present paper a detailed description of a test battery consisting of nine different tests to screen athletic movement pattern is provided. The aim was to evaluate the inter- and intra-rater reliability of the test battery on a group of male elite soccer players. Twenty-six healthy elite soccer players (17-28 years) were screened. Eighteen participated at a second occasion 7 days later. No significant difference (P=0.31) was found between test occasion 1 (LS means 18.3, 95% confidence interval 14.9-21.7) and test occasion 2 (18.0, 14.4-21.7) in the mean total score of the test battery. No significant difference in the inter-rater reliability was found between the eight physiotherapists at the two test occasions. The intra-class correlation coefficient was 0.80 and 0.81, respectively. The test battery showed good inter- and intra-rater reliability. The screening battery is easy to use for familiarized professionals and requires minimal equipment. However, further studies are needed to confirm the validity of the test battery in injury prevention, rehabilitation and performance enhancement.

Predictive factors for 12-month outcome after anterior cruciate ligament reconstruction.

There is a lack of knowledge regarding predictive factors for a successful clinical outcome after an anterior cruciate ligament (ACL) reconstruction. The aim was to investigate pre-operative factors that may predict good outcomes as measured with the subscales Function in sports and recreation and Quality of life in Knee injury Osteoarthrithis Outcome Score (QOL-KOOS), one-leg hop test and Tegner Activity Scale 12 months after ACL reconstruction. Sixty-four patients, operated with either patellar or hamstring tendon graft, were included. Demographics, range of motion, anterior knee laxity, pivot shift, muscle-torques, anterior knee pain (AKP) and knee function were registered pre-operatively and used in a multiple regression model. Results show less degree of AKP and low influence on knee function to be the most important predictors for good outcome in Sport/Rec-KOOS (explained 31% of variances). Less AKP was in addition the most important predictor for QOL-KOOS (14%). Patellar-tendon graft, in favor of hamstring tendon graft, explained 8% of the improvement in the Tegner Activity Scale. In conclusion, a low degree of AKP was found to be the most important predictor for good clinical outcome 12 months after ACL reconstruction. Future studies, including psychological parameters, should use analyses that have the potential to control for independency between variables.

Rehabilitation and recovery after anterior cruciate ligament reconstruction: patients' experiences.

The aim was to explore patients' experiences of the rehabilitation process after anterior cruciate ligament (ACL) reconstruction. Ten participants were enrolled in the study. Semi-structured interviews were performed, focusing on challenges during the post-operative rehabilitation to 1 year after ACL reconstruction. The participants perceived no real choice between operative and non-operative treatment. Only surgery symbolized a full return to the pre-injury level of sports, and surgery was understood as the only way to become a completely restored "functional human being." A major source of frustration was that the meaning of and progress during the rehabilitation did not match their expectations. Three different responses to the challenge of a prolonged rehabilitation were expressed: "going for it,""being ambivalent," and "giving in." Fear of re-injury was common; however, some participants decided not to return to their pre-injury level of sports due to reasons other than physical limitations or fear of re-injury. From a patient perspective, it seems important that the choice of operative or non-operative treatment should be discussed in terms of the meaning and extent of the post-operative rehabilitation and the expected outcomes. There also seems to be a need for more guidance in realistic goal setting and coaching throughout the rehabilitation process.

Acute spinal epidural abscess without concurrent spondylodiscitis. Successful closed treatment in 10 cases.

We performed a retrospective survey of the clinical records and radiological examinations of 10 patients with a diagnosis of spinal epidural abscess, without spondylodiscitis. All patients had an acute onset of fever and local or radiating back pain. 3 patients had mild, and 1 patient severe neurological symptoms. The diagnosis and subsequent regression of the abscess after treatment were verified by MRI. In all cases, the imaging findings included signs of septic arthritis in an adjoining facet joint. 7/10 abscesses were located in the lumbar region. Blood cultures showed Staphylococcus aureus as the etiological agent in 8/10 patients. In 2 cases, no agent was found, probably due to ongoing antibiotic therapy when the cultures were taken. All patients were treated successfully using antibiotics alone, with complete regression of the neurological symptoms.

Recurrent varicocele. Demonstration by 3D phase-contrast MR angiography.

This is a report on an initial experience with Gd-enhanced 3D phase-contrast MR angiography in 4 patients with recurrent varicocele. The examinations were performed with the patients prone, and a coronal imaging volume was used. The scrotal part of the varicocele was demonstrated in 3 cases and the spermatic vein in 2 cases. This technique could be an alternative to spermatic venography in the radiological mapping of dilated spermatic veins.