Thermoelectric Properties of Cu2Te Nanoparticle Incorporated N-Type Bi2Te2.7Se0.3.

To develop highly efficient thermoelectric materials, the generation of homogeneous heterostructures in a matrix is considered to mitigate the interdependency of the thermoelectric compartments. In this study, Cu2Te nanoparticles were introduced onto Bi2Te2.7Se0.3 n-type materials and their thermoelectric properties were investigated in terms of the amount of Cu2Te nanoparticles. A homogeneous dispersion of Cu2Te nanoparticles was obtained up to 0.4 wt.% Cu2Te, whereas the Cu2Te nanoparticles tended to agglomerate with each other at greater than 0.6 wt.% Cu2Te. The highest power factor was obtained under the optimal dispersion conditions (0.4 wt.% Cu2Te incorporation), which was considered to originate from the potential barrier on the interface between Cu2Te and Bi2Te2.7Se0.3. The Cu2Te incorporation also reduced the lattice thermal conductivity, and the dimensionless figure of merit ZT was increased to 0.75 at 374 K for 0.4 wt.% Cu2Te incorporation compared with that of 0.65 at 425 K for pristine Bi2Te2.7Se0.3. This approach could also be an effective means of controlling the temperature dependence of ZT, which could be modulated against target applications.

Bacterial meningitis and cauda equina syndrome after trans-sacral epiduroscopic laser decompression: A case report.

RATIONALE: Trans-sacral epiduroscopic laser decompression (SELD) is a noninvasive pain-relieving procedure for treatment of herniated lumbar disc (HLD), and is known to have positive effects in alleviating lower back pain or radicular leg pain after HLD. However, little is known about the possible complications of SELD. PATIENT CONCERNS: A 51-year-old woman received SELD with a holmium:yttrium-aluminum-garnet laser for controlling radicular pain due to HLD on L5-S1. However, 5 days after SELD, she complained of headache, and 9 days after the SELD, cauda equine syndrome (CES) symptoms, including motor weakness of both lower extremities (manual muscle testing-left: 3, right: 4), voiding and defecation difficulties, and neuropathic pain, were manifested. DIAGNOSES: Cerebrospinal fluid (CSF) analysis performed 15 days after the SELD revealed elevated white blood cell count 7560 cells/µL. Staphylococcus hominis sensitive to vancomycin was cultured from CSF. The gadolinium-enhanced magnetic resonance imaging showed diffuse leptomeningeal enhancement along the distal cord and cauda equina. The latency of electrically induced bulbocavernosus reflex (BCR) was delayed in the right side and no response of BCR was presented in the left side. Based on the patient's symptoms and the results of the clinical evaluation, we diagnosed the patient as having a bacterial meningitis and CES. INTERVENTIONS: The patient received 2 g per day of intravenous vancomycin for 2 months. OUTCOMES: After treatment with intravenous vancomycin for 2 months, all the CES symptoms were completely resolved. LESSONS: In this study, we described a patient who had bacterial meningitis after SELD. During SELD, clinicians should keep in mind the possibility of infection.

Effect of intradiscal monopolar pulsed radiofrequency on chronic discogenic back pain diagnosed by pressure-controlled provocative discography: a one year prospective study.

OBJECTIVE: To investigate the efficacy and safety of percutaneous intradiscal monopolar pulsed radiofrequency (PRF) in patients with chronic disabling discogenic back pain. METHOD: Twenty-six subjects (7 males; mean age 43.2 years) with chronic back pain refractory to active rehabilitative management were recruited. All subjects underwent MRI for evaluation of Modic changes, and monopolar PRF (20 min at 60 V) at the center of target lumbar intervertebral disc confirmed by pressure-controlled provocative discography. Clinical outcomes were measured by the visual analogue scale (VAS), Oswestry disability index (ODI), and sitting tolerance time (ST) for 12 months after treatment. Successful clinical outcome was described as a minimum of 2 point reduction in VAS compared with the baseline at each follow-up period. RESULTS: The mean VAS for low back pain reduced significantly from 6.4±1.1 at pre-treatment to 4.4±1.9 at 12 months (p<0.05). The mean ODI score was 47.3±15.4 points at pre-treatment and 36.7±19.5 at 12 months (p<0.001). The ST was 27.8±20.4 minutes at pre-treatment and 71.5±42.2 at 12 months (p<0.001). However, successful clinical outcome was achieved at 58%, 50%, and 42%, measured at 3, 6, and 12 months post-treatment. There were no significant relationship between the clinical outcome and Modic changes; no adverse events were recorded. CONCLUSION: The results demonstrated that the application of intradiscal monopolar PRF might be relatively effective but limited; successful intervention for chronic refractory discogenic back pain is needed. To achieve the optimal outcome through intradiscal PRF, we suggested further studies about stimulation duration, mode, and intensity of PRF.

Medial lemniscus lesion in pediatric hemiplegic patients without corticospinal tract and posterior thalamic radiation lesion.

OBJECTIVES: Using diffusion tensor imaging (DTI), we investigated the state of medial lemniscus (ML), corticospinal tract (CST), and posterior thalamic radiation (PTR), which were expected as probable reasons for clinical hemiplegia in pediatric patients, especially those who showed impaired fine motor control and proprioception, but no definite motor weakness or spasticity. METHODS: We recruited 13 hemiplegic patients and 8 age-matched healthy control subjects. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) for the bilateral ML, CST, and PTR were calculated and compared between the affected hemisphere of the patient (AP), the unaffected hemisphere of the patient (UP), and the mean value of the bilateral hemispheres in control subjects (MC). RESULTS: FA and ADC values for the CST and PTR did not differ significantly between the AP, UP, and MC subgroups (p > 0.05). However, the FA value for the ML in AP showed a significant decrease, compared with that in UP (p = 0.012) and MC (p = 0.047). DTT for the CST and PTR showed preserved integrity and ML in the UP also had continuity to the cortex; however, ML in AP showed disruption. CONCLUSIONS: Using DTI, we demonstrated that the ML lesion might be related to clinical hemiplegia in pediatric patients.

The effect of a stretching device on hand spasticity in chronic hemiparetic stroke patients.

We attempted to evaluate the effect of a stretching device for treatment of hand spasticity in chronic stroke patients. We recruited 21 chronic hemiplegic stroke patients with severe finger flexor spasticity and randomly assigned them to the intervention group (10 patients) and control group (11 patients). The stretching device consisted of a resting hand splint, finger stretcher, and frame. The stretching state was maintained for 30 seconds and relaxed for the next 30 seconds. This stretching and relaxation were repeated for 20 minutes (one session). The stretching program was practiced 2 sessions/day and 6 days/week for 3 weeks for the patients of the intervention group. The effect of this stretching device was assessed using the modified Ashworth scale (MAS) score of finger flexor muscles. Patients in both groups were assessed six times within an interval of one week and patients in the intervention group were assessed two times before starting the stretching program. The two-way repeated measures analysis of variance (ANOVA) test for evaluation of the effect of intervention across all time-points between the two groups showed a significant interaction between time and effect of intervention (P < 0.001). Within the intervention group, the average of mean MAS score at Pre-1 and Pre-2 were 2.83 and 2.93, respectively (the difference between Pre-1 and Pre-2 was not significant (P> 0.05)), and this improved significantly to 1.97 at Inter-1, 1.55 at Inter-2, 1.20 at Inter-3, and 1.97 at Post-1 (P < 0.001) using the one-way repeated measures ANOVA test for evaluation of the effect of intervention across all time-points. We found that our stretching device was effective in relieving hand spasticity in chronic stroke patients.

Changes in expression of mRNA for interleukin-8 and effects of interleukin-8 receptor inhibitor in the spinal dorsal horn in a rat model of lumbar disc herniation.

STUDY DESIGN: Autologous nucleus pulposus obtained from coccygeal intervertebral discs was grafted on the proximal of L5 dorsal root ganglion. Pain behavior, mRNA expression of Interleukin-8 (IL-8), and immunohistochemical changes were assessed. OBJECTIVE: The purpose of this study is to investigate temporal changes of IL-8 expression in the spinal cord and dorsal root ganglion and the pain-related behaviors with time course and to elucidate whether repertaxin (IL-8 receptor inhibitor) attenuates pain-related behaviors in a rat model of lumbar disc herniation. SUMMARY OF BACKGROUND DATA: Inflammatory mediators like cytokines and chemokines have been implicated in radicular pain because of disc herniation. IL-8, known as CXCL8, is a chemokine, which has been reported to be associated with painful degenerative disc disorders and chronic inflammatory pain states. METHODS: Lumbar disc herniated rat model was made by implantation of the autologous nucleus pulposus, harvested from the coccygeal vertebra of each tail, on the left L5 nerve root just proximal to the dorsal root ganglion. Rats were tested for mechanical allodynia and thermal hyperalgesia at 2 days before surgery, and on days 1, 5, 10, 20, 30, 40, 50, and 60 postoperatively. Experimental group was intrathecally injected with the IL-8 receptor inhibitor at L5 level on postoperative day 10. Mechanical allodynia of the plantar surface of both hindpaw was tested on 30 minutes, 1, 3 hours, 1, 3, 5, and 10 days after administration. For the staining of astrocytes and microglia, immunohistochemical study was done 20 days after surgery. RESULTS: Mechanical allodynia in ipsilateral hindpaw developed 1 day after surgery and lasted until 60 days and thermal withdrawal latency decreased significantly on the ipsilateral side 10 days after surgery and gradually increased through day 60. The IL-8 receptor inhibitor attenuated the mechanical allodynia caused by nucleus pulposus when it was administered on postoperative day 10 and reduced microglial activation and phosphorylated form of mitogen-activated protein kinase (pERK) expression in the spinal dorsal horn. CONCLUSION: IL-8 might be a potential therapeutic target in chronic radicular neuropathic pain because of disc herniation, CXCL8 inhibitor could be one of its promising therapeutic agents.