Polyethylene glycol hydrogel coatings for protection of electroactive bacteria against chemical shocks.

Loss of bioelectrochemical activity in low resource environments or from chemical toxin exposure is a significant limitation in microbial electrochemical cells (MxCs), necessitating the development of materials that can stabilize and protect electroactive biofilms. Here, polyethylene glycol (PEG) hydrogels were designed as protective coatings over anodic biofilms, and the effect of the hydrogel coatings on biofilm viability under oligotrophic conditions and ammonia-N (NH4+-N) shocks was investigated. Hydrogel deposition occurred through polymerization of PEG divinyl sulfone and PEG tetrathiol precursor molecules, generating crosslinked PEG coatings with long-term hydrolytic stability between pH values of 3 and 10. Simultaneous monitoring of coated and uncoated electrodes co-located within the same MxC anode chamber confirmed that the hydrogel did not compromise biofilm viability, while the coated anode sustained nearly a 4 × higher current density (0.44 A/m2) compared to the uncoated anode (0.12 A/m2) under oligotrophic conditions. Chemical interactions between NH4+-N and PEG hydrogels revealed that the hydrogels provided a diffusive barrier to NH4+-N transport. This enabled PEG-coated biofilms to generate higher current densities during NH4+-N shocks and faster recovery afterwards. These results indicate that PEG-based coatings can expand the non-ideal chemical environments that electroactive biofilms can reliably operate in.

Renewed call for lifestyle interventions to address obesity among individuals with serious mental illness in the COVID-19 era and beyond.

Behavioral health has the opportunity to lead the way in using lifestyle interventions to address obesity and health disparities in people with serious mental illness (SMI) in the COVID-19 era. Evidence-based interventions for weight loss in individuals with SMI exist, and the field has developed strategies for implementing these interventions in real-world mental health care settings. In addition to promoting weight loss, lifestyle interventions have the potential to address social isolation and loneliness and other patient-centered outcomes among individuals with SMI, which will be especially valuable for mitigating the growing concerns about loneliness attributed to the COVID-19 pandemic restrictions on in-person encounters. In this commentary, we discuss practice, policy, and research implications related to using evidence-based lifestyle interventions for individuals with SMI during the COVID-19 pandemic and sustaining these programs in the long-term.

Is medial elbow pain correlated with cubital tunnel syndrome? An electrodiagnostic study.

INTRODUCTION: Medial elbow pain is often considered to be a symptom associated with ulnar neuropathy at the elbow (UNE). We examined the relationship between medial elbow pain and a positive electrodiagnostic (EDx) test result for UNE. METHODS: We performed a retrospective review of 884 patients referred for EDx evaluation of UNE. Regression models were used to determine the odds ratios between clinical findings and a positive EDx result for UNE. RESULTS: Patients reported medial elbow pain in 44.3% of cases. Clinical factors that correlated with a positive EDx study result for UNE included male gender, small and ring finger numbness, ulnar intrinsic weakness, and age. Medial elbow pain was negatively correlated with a positive EDx result. CONCLUSIONS: This study demonstrates a negative correlation between medial elbow pain and a positive EDx result for UNE. Medial elbow pain should not be considered a clear diagnostic symptom of UNE.

The time-course of cortico-limbic neural responses to air hunger.

Several studies have mapped brain regions associated with acute dyspnea perception. However, the time-course of brain activity during sustained dyspnea is unknown. Our objective was to determine the time-course of neural activity when dyspnea is sustained. Eight healthy subjects underwent brain blood oxygen level dependent functional magnetic imaging (BOLD-fMRI) during mechanical ventilation with constant mild hypercapnia (∼ 45 mm Hg). Subjects rated dyspnea (air hunger) via visual analog scale (VAS). Tidal volume (V(T)) was alternated every 90 s between high VT (0.96 ± 0.23 L) that provided respiratory comfort (12 ± 6% full scale) and low V(T) (0.48 ± 0.08 L) which evoked air hunger (56 ± 11% full scale). BOLD signal was extracted from a priori brain regions and combined with VAS data to determine air hunger related neural time-course. Air hunger onset was associated with BOLD signal increases that followed two distinct temporal profiles within sub-regions of the anterior insula, anterior cingulate and prefrontal cortices (cortico-limbic circuitry): (1) fast, BOLD signal peak <30s and (2) slow, BOLD signal peak >40s. BOLD signal during air hunger offset followed fast and slow temporal profiles symmetrical, but inverse (signal decreases) to the time-courses of air hunger onset. We conclude that differential cortico-limbic circuit elements have unique contributions to dyspnea sensation over time. We suggest that previously unidentified sub-regions are responsible for either the acute awareness or maintenance of dyspnea. These data enhance interpretation of previous studies and inform hypotheses for future dyspnea research.

The Effect of Pulley Reconstruction on Maximum Flexion, Bowstringing, and Gliding Coefficient in the Setting of Zone II Repair of FDS and FDP: a Cadaveric Investigation.

PURPOSE: The purpose of this experiment was to determine the effect of A2 pulley reconstruction on gliding coefficient (GC), bowstringing, and proximal interphalangeal (PIP) joint maximum flexion angle after zone II repair of flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) lacerations. METHODS: Fresh frozen cadaver forearms were mounted, and the wrist and MCP joints fixed. FDS and FDP tendons were dissected free, and sequential loads were applied while digital images were captured. The dissected digit with intact native A2 pulley, FDS, and FDP tendons was used as the control (group 1). Zone II lacerations followed by four-stranded repair of FDP plus epitendinous suture and repair of FDS were then performed, and the data recorded (group 2). A2 pulley excision and reconstruction with a loop of palmaris longus autograft was then completed and the specimens sequentially loaded and photographed (group 3). Using the digital images, GC, bowstringing, and maximum flexion angle were calculated. RESULTS: No difference in maximum flexion angle was observed across the three testing conditions. Zone II laceration and subsequent FDS and FDP tendon repair significantly increased the GC for group 2 specimens; however, pulley reconstruction alleviated some of this increase for group 3. Bowstringing was significantly greater after pulley reconstruction, with a mean increase of 1.9 mm at maximum flexion for group 3 specimens relative to group 1 controls. DISCUSSION: Strong flexor tendon repairs are needed to prevent gap formation and subsequent triggering; however, the increased bulk from these large repairs can itself produce deleterious triggering, as well as tendon abrasion. Pulley reconstruction, in the setting FDP and FDS repair (group 3), significantly reduced the GC relative to tendon repair alone (group 2). While bowstringing was significantly greater after pulley reconstruction (group 3), it averaged only 1.9 mm over group 1 specimens and did not compromise maximum flexion angle compared to the uninjured controls (group 1) or the isolated tendon repair digits (group 2).

Composite bone models in orthopaedic surgery research and education.

Composite bone models are increasingly used in orthopaedic biomechanics research and surgical education-applications that traditionally relied on cadavers. Cadaver bones are suboptimal for many reasons, including issues of cost, availability, preservation, and inconsistency between specimens. Further, cadaver samples disproportionately represent the elderly, whose bone quality may not be representative of the greater orthopaedic population. The current fourth-generation composite bone models provide an accurate reproduction of the biomechanical properties of human bone when placed under bending, axial, and torsional loads. The combination of glass fiber and epoxy resin components into a single phase has enabled manufacturing by injection molding. The high level of anatomic fidelity of the cadaver-based molds and negligible shrinkage properties of the epoxy resin results in a process that allows for excellent definition of anatomic detail in the cortical wall and optimized consistency of features between models. Recent biomechanical studies of composites have validated their use as a suitable substitute for cadaver specimens.

Imageless computer-assisted versus conventional total hip arthroplasty: one surgeon's initial experience.

Computer-assisted surgery (CAS) systems are advocated to improve component positioning in THA, though potential operative risks and costs of CAS have fueled debate. The present study examines the radiographic outcomes, operative efficiency, cost, and midterm functional outcomes for patients who underwent THA, either with CAS or conventional instrumentation. Patient baseline characteristics were recorded for 126 lower-extremities in the CAS series, and 215 in the conventional series. There was no difference in Harris Hip Score or leg length discrepancy between series. Inclination angle, blood loss, and operating room times were increased for CAS. These results suggest that CAS confers no advantage over conventional methods regarding accuracy of THA component placement, drives unreimbursed increases in procedure costs, may expose patients to additional operative risk, and produces no functional benefit at midterm follow-up.

PLANNING AND RESPONSE IN THE AFTERMATH OF A LARGE CRISIS: AN AGENT-BASED INFORMATICS FRAMEWORK*

We present a synthetic information and modeling environment that can allow policy makers to study various counter-factual experiments in the event of a large human-initiated crisis. The specific scenario we consider is a ground detonation caused by an improvised nuclear device in a large urban region. In contrast to earlier work in this area that focuses largely on the prompt effects on human health and injury, we focus on co-evolution of individual and collective behavior and its interaction with the differentially damaged infrastructure. This allows us to study short term secondary and tertiary effects. The present environment is suitable for studying the dynamical outcomes over a two week period after the initial blast. A novel computing and data processing architecture is described; the architecture allows us to represent multiple co-evolving infrastructures and social networks at a highly resolved temporal, spatial, and individual scale. The representation allows us to study the emergent behavior of individuals as well as specific strategies to reduce casualties and injuries that exploit the spatial and temporal nature of the secondary and tertiary effects. A number of important conclusions are obtained using the modeling environment. For example, the studies decisively show that deploying ad hoc communication networks to reach individuals in the affected area is likely to have a significant impact on the overall casualties and injuries.

Chronic ethanol intake alters circadian phase shifting and free-running period in mice.

Chronic alcohol intake is associated with widespread disruptions in sleep and circadian rhythms in both human alcoholics and in experimental animals. Recent studies have demonstrated that chronic and acute ethanol treatments alter fundamental properties of the circadian pacemaker--including free-running period and responsiveness to photic and nonphotic phase-shifting stimuli--in rats and hamsters. In the present work, the authors extend these observations to the C57BL/6J mouse, an inbred strain characterized by very high levels of voluntary ethanol intake and by reliable and stable free-running circadian activity rhythms. Mice were housed individually in running-wheel cages under conditions of either voluntary or forced ethanol intake, whereas controls were maintained on plain water. Forced ethanol intake significantly attenuated photic phase delays (but not phase advances) and shortened free-running period in constant darkness, but voluntary ethanol intake failed to affect either of these parameters. Thus, high levels of chronic ethanol intake, beyond those normally achieved under voluntary drinking conditions, are required to alter fundamental circadian pacemaker properties in C57BL/6J mice. These observations may be related to the relative ethanol insensitivity displayed by this strain in several other phenotypic domains, including ethanol-induced sedation, ataxia, and withdrawal. Additional experiments will investigate chronobiological sensitivity to ethanol in a range of inbred strains showing diverse ethanol-related phenotypes.

Circadian activity rhythms in selectively bred ethanol-preferring and nonpreferring rats.

Chronic alcohol intake is associated with dramatic disruptions in sleep and other circadian biological rhythms in both humans and experimental animals. In human alcoholics, these disruptions persist during extended abstinence and appear to promote relapse to drinking. Whereas chronic ethanol intake alters fundamental properties of the circadian pacemaker in unselected rats, nothing is known concerning circadian pacemaker function in selectively bred ethanol-preferring and nonpreferring rats, which are the most widely accepted animal models of genetic predisposition to alcoholism. The present experiments were designed to characterize free-running circadian activity (wheel-running) rhythms under both constant darkness and constant light in selectively bred ethanol-preferring (P, HAD2) and nonpreferring (NP, LAD2) rats. Differences in circadian organization between ethanol-preferring and nonpreferring animals were seen for both pairs of selected lines (P vs. NP; HAD2 vs. LAD2), but these differences were not identical in the two line pairs. For example, although P rats showed shorter free-running periods than NP rats only in constant light, HAD2 rats showed shorter free-running periods than LAD2 rats only in constant darkness. In addition, ethanol-preferring HAD2 rats showed a high rate of rhythm "splitting" that was not seen in any of the other three lines. Taken together, these results suggest that the circadian pacemakers of P and NP rats differ mainly in light sensitivity, whereas those of HAD2 and LAD2 rats differ in their intrinsic period.

Psychological factors in pelvic/urogenital pain: the influence of site of pain versus sex.

Chronic pelvic pain (CPP), a fairly common gynecological complaint in women, has been associated with multiple psychological sequelae, including depression and somatization. Previous work has compared these patients to gynecological controls and women with headache, but has failed to include male comparison groups with a comparable site of chronic pain. In order to test possible sex and pain site differences, the present study compared 22 women with CPP, 22 men with either penile or testicular pain, 22 women with low back pain and 28 men with low back pain referred for a psychological evaluation as part of multidisciplinary pain treatment. Depression, coping, pain intensity and interference were assessed. Two-way analyses of variance (sex by pain site) were conducted to determine if there were group differences on demographic variables and medical history. Pain duration, age, and pain severity differed among the groups and were entered as covariates in hierarchical regression analyses designed to identify predictors of adjustment and pain coping. Sex and pain site did not contribute independently to the prediction of depressive symptoms. Pain site predicted physical functioning with low back pain patients reporting greater pain-related interference. Similar findings were demonstrated for coping. A variety of pain-coping strategies, including catastrophizing, were more frequently utilized by low back pain patients, regardless of sex. In the present study, pain severity and pain site explained more variance in depressive symptoms, physical functioning, and pain-coping than sex.

Body image dissatisfaction among women with scleroderma: extent and relationship to psychosocial function.

Body image dissatisfaction and its relationship to psychosocial function were investigated in 127 women with scleroderma Results indicated elevated body image dissatisfaction, with participants reporting higher levels than a sample of patients with severe burn injuries. Age, skin tightening above the elbows, and functional disability were related to heightened body image dissatisfaction, suggesting that younger patients with more severe disease may be at greatest risk for developing body image concerns. Path analysis revealed that depression mediated the relationship between body image dissatisfaction and psychosocial function. Results suggest that body image dissatisfaction is a significant concern in women with scleroderma and should be assessed routinely. Early identification and treatment of body image dissatisfaction may help prevent the development of depression and psychosocial impairment in this population.

The impact of pain and symptoms of depression in scleroderma.

Systemic sclerosis (scleroderma) is a rare connective tissue disease that can affect multiple organ systems. Case reports and small treatment studies suggest that pain is significant in scleroderma, but few data speak of the frequency or impact of pain. This study sought to determine the frequency and impact of pain, symptoms of depression, and social network characteristics on physical functioning and social adjustment in patients with scleroderma. One hundred and forty-two scleroderma patients completed measures of pain, depressive symptoms, social network characteristics, physical functioning, and social adjustment. Sixty-three percent reported at least mild pain and 50% reported at least mild levels of depressive symptomatology. Hierarchical regression analyses revealed that pain, depressive symptoms, and employment status (disabled/unemployed vs. not) were significant, independent predictors of physical functioning, together accounting for 37% of the total variance. Pain was the single strongest predictor of physical function, accounting for 20% of the variance. Depressive symptoms, physical functioning, diversity of social network, and employment status were significant independent predictors of social adjustment, together accounting for 63% of the variance. Depressive symptoms were the single strongest predictor of social adjustment, accounting for 26% of the variance. The effects of pain and physical function on social adjustment became non-significant when depressive symptoms were entered into the model, suggesting that symptoms of depression mediate the effect of pain and physical function on social adjustment. These findings indicate that pain is common in scleroderma and that pain and depressive symptoms are significant determinants of physical functioning and social adjustment, two important components of health-related quality of life. Increased attention to effective management of pain and symptoms of depression in scleroderma will likely lead to improved functioning and quality of life.