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A thermocell generates thermopower from a temperature difference (ΔT) between two electrodes. The converse process of thermocells is an electrochemical Peltier effect, which creates a ΔT on the electrodes by applying an external current. The Seebeck coefficient (Se ) of the electrochemical system is proportional to the entropy change of the redox reaction; therefore, a redox system having a significant entropy change is expected to increase the Se . In this study, a thermoresponsive polymer having a redox-active moiety, poly(N-isopropyl acrylamide-co-N-(2-acrylamide ethyl)-N'-n-propylviologen) (PNV), is used as the redox species of a thermocell. PNV2+ dication undergoes the coil-globule phase transition upon the reduction to PNV+ cation radical, and a large entropy change is introduced because water molecules are freed from the polymer chains. The Se of PNV thermocell drastically increased to +2.1 mV K-1 at the lower critical solution temperature (LCST) of PNV. The entropy change calculated from the increment of Se agrees with the value evaluated by differential scanning calorimetry. Moreover, the electrochemical Peltier effect is observed when the device temperature is increased above the LCST. This study shows that the large entropy change associated with the coil-globule phase transition can be used in electrochemical thermal management and refrigeration technologies.

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INTRODUCTION: Posterior internal fixation for unstable pelvic ring fractures is often associated with complications, including pelvic hemorrhage and gluteal necrosis. Pelvic ring fixation using the S2 alar iliac screw (SAIS) without fixation of the lumbosacral vertebrae may have potential as a novel, minimally invasive technique for treating unstable pelvic ring fractures. The present study compared clinical outcomes in patients who underwent SAIS fixation within the pelvic ring with a historical control group of patients who underwent conventional trans-iliac plate fixation for the treatment of unstable pelvic ring fractures. MATERIALS AND METHODS: Thirty-two patients diagnosed with unstable pelvic fractures with sacral fracture or sacroiliac joint fracture dislocation were retrospectively evaluated. Eight consecutive patients underwent trans-iliac plate fixation from April 2012 to March 2015, and 24 consecutive patients underwent SAIS fixation from April 2015 to February 2020. Rates of soft tissue complications, intraoperative blood loss, and intraoperative blood transfusion volume were compared in these two groups. RESULTS: Mean intraoperative blood loss was significantly lower in patients who underwent SAIS fixation than in those who underwent trans-iliac plate fixation (141.0 ml vs 315.0 ml; P = 0.027), although there were no between-group differences in intraoperative blood transfusion volume (0.0 ml vs 140 ml; P = 0.105), incidence rate of soft tissue complications (4.2% vs 0%; P = 1.000), and operation time (88.5 min vs 93.0 min; P = 0.862). Bone healing was confirmed in all patients who underwent SAIS fixation without dislocation of the fracture site, whereas one patient who underwent trans-iliac plate fixation experienced a dislocation of the fracture site during follow-up (0% vs 12.5%; P = 0.250). CONCLUSIONS: SAIS fixation reduces intraoperative blood loss and ensures bone healing without major complications, including dislocation of the fracture site. SAIS fixation may therefore be an alternative, minimally invasive method of treating unstable pelvic fractures.

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STUDY DESIGN: Retrospective study. OBJECTIVES: To investigate the risk factors associated with tracheostomy after traumatic cervical spinal cord injury (CSCI) and to identify factors associated with decannulation in an aging population. SETTING: Advanced critical care and emergency center in Yokohama, Japan. METHODS: Sixty-five patients over 60 years with traumatic CSCI treated between January 2010 and June 2017 were enrolled. The parameters analyzed were age, sex, American Spinal Injury Association impairment scale score (AIS) at admission and one year after injury, neurological level of injury (NLI), injury mechanism, Charlson's comorbidity index (CCI), smoking history, radiological findings, intubation at arrival, treatment choice, length of intensive care unit (ICU) stay, tracheostomy rate, improvement of AIS, decannulation rate, and mortality after one year. RESULTS: The study included 48 men (74%; mean age 72.8 ± 8.3 years). Twenty-two (34%), 10 (15%), 24 (37%), and 9 (14%) patients were classified as AIS A, B, C, and D, respectively. The tracheostomy group showed significantly more severe degree of paralysis, more patients with major fractures or dislocations, more operative treatment, longer ICU stay, poorer improvement in AIS score after one year and higher rate of intubation at arrival. AIS A at injury was the most significant risk factor for tracheostomy. The non-decannulation group had a significantly higher mortality. The risk factor for failure of decannulation was CCI. CONCLUSIONS: Risk factors for tracheostomy after traumatic CSCI were AIS A, operative treatment, major fracture/dislocation, and intubation at arrival. The only factor for failure of decannulation was CCI.

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OBJECTIVES: To investigate the mortality rate following cervical spinal cord injury (SCI) injury and analyze the associated risk factors. DESIGN: Retrospective cohort study. SETTING: One Level 1 trauma center. PATIENTS/PARTICIPANTS: A cohort of 76 patients with traumatic cervical SCI was reviewed between January 2010 and May 2015, of which 54 patients were selected for the present retrospective study. INTERVENTION: Operative or conservative treatment. MAIN OUTCOME MEASUREMENTS: The following patient parameters were analyzed; age, sex, American Spinal Injury Association (ASIA) impairment scale, neurological impairment level, injury mechanism, radiological findings, treatment, tracheostomy rate, and mortality. RESULTS: The mean age of the patient cohort was 65 ±â€Š17 years, with 11 females (20%) and 43 males (80%). A total of 16 (30%), 4 (7%), 22 (41%), and 12 patients (22%) were scored A, B, C, and D, respectively, on the ASIA impairment scale. Most of the injuries were at the C4 (30%) and C5 (33%) levels. Falls from standing (35%) and heights (39%) were the most common injury mechanisms. SCI in 40 patients (74%) occurred without major fracture or dislocation. Surgery was performed on 26 patients. The overall mortality was 19%. Patients in the deceased group were significantly older at the time of injury, compared with those who survived. Paralysis had been more severe in the deceased group. A significantly high number of patients in the deceased group received a tracheostomy. When analyzed using a multivariate logistic regression model, an ASIA impairment scale of A was a significant risk factor for mortality. CONCLUSIONS: The risk factors associated with mortality were age, tracheostomy, and an ASIA impairment scale of A, the latter had the highest risk. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

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BACKGROUND CONTEXT: Rapid diagnosis and accurate detection of etiological agents in pyogenic spinal infection (PSI) patients are important. PURPOSE: The purpose of this study was to evaluate the clinical usefulness of methicillin-resistant Staphylococcus-specific polymerase chain reaction (MRS-PCR) and broad-range universal PCR (U-PCR) for diagnosing PSI. STUDY DESIGN: A prospective diagnostic study. PATIENTS: Thirty-two clinically suspect PSI patients and six control patients who underwent computerized tomography-guided biopsy and/or surgical treatment were enrolled. METHODS: Tissue samples were examined by microbiological culture, histopathology, and real-time PCR (MRS-PCR and U-PCR). The diagnostic accuracy of real-time PCR was analyzed based on the definitive diagnosis of infection, defined as a positive result from microbiological culture or histopathology. RESULTS: All six control subjects were negative for PSI for all analyses. Twelve clinically suspect PSI subjects received definitive diagnoses (PSI group). The non-PSI group consisted of six control subjects plus the remaining 20 patients from the PSI clinically suspect group. MRS-PCR results were positive for all MRS-cultured PSI subjects. U-PCR was positive for all subjects in the PSI group with one discrepancy between real-time PCR and microbiological culture results in differentiation between gram-positive and gram-negative bacteria. In the non-PSI group, MRS-PCR and U-PCR were positive in three and seven cases, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of MRS-PCR for diagnosing MRS infection were 1.00, 0.91, 0.57, and 1.00, respectively; those for the diagnosis of bacterial infection with U-PCR were 1.00, 0.73, 0.63, and 1.00, respectively. CONCLUSION: Identification of MRS infection and ability to differentiate between gram-positive and gram-negative bacteria is rapidly achieved using MRS-PCR and U-PCR. Real-time PCR provides a sensitive molecular diagnosis of PSI and may contribute to antibiotic selection.

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