Investigation of the Effect of Cupric Chloride on Thermal Stabilization of Polyamide 6 as Carbon Fiber Precursor

An investigation on the role of cupric (Cu2+) ion incorporation during the thermal stabilization of polyamide 6 fibers was carried out using a combination of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) measurements. Cupric chloride pretreated and thermally stabilized polyamide 6 (PA6) fibers was characterized by a reduction in fiber diameter and linear density values together with color changes from light brown to black with increasing stabilization time. PA6 fibers were properly stabilized after 8 h of stabilization time prior to carbonization. The results obtained from DSC and TGA measurements indicated that there was an improvement in the thermal stability when cupric (Cu2+) ions were incorporated into the polymer structure. TGA thermograms showed the relative improvement in thermal stability as indicated by increasing char yield with progressing time. Char yield reached a maximum value of 33.6% at 1000 degrees C for the cupric chloride pretreated PA6 fibers stabilized for 12 h at 180 degrees C. Experimental results obtained from DSC and X-ray diffraction methods suggested the loss of crystallinity as a result of perturbation of hydrogen bonds with progressing time. The formation of cupric ion-amide coordination bonds improved the thermal stabilization by encouraging the development of ladder-like structures. The investigation resulted in a new method of evaluation of X-ray stabilization index specifically intended for the thermally stabilized PA6 fiber

Anesthetic Management of Children with Larsen Syndrome

Larsen Syndrome is the rare inherited disease of defect in collagen formation. It is characterized by facial and extremity abnormalities. Spine anomalies scoliosis, kyphosis, wedge vertebrae, and spondylosis also have been described in this syndrome. A 7 month old, male, 3750 gr. boy with a diagnosis of Larsen syndrome was scheduled for bilateral inguinal hernias operation under general anesthesia. The preoperative examination revealed knee joint dislocations, clubfoot and unusual face (flat faces, high palate). Long QT syndrome was detected and propranolol medication was started preoperatively. The patient had severe scoliosis, thorax deformities with pectus carinatus. Following standart monitors placement, anesthesia was induced sevoflurane/air, intubation facilitated with rocuronium (0.6 mg/kg) and then caudal analgesia was performed. The intraoperative course uneventful. The hemodynamic status and rhythm was stable during surgery and in the postoperative period. At the end of the surgery neuromuscular blockage was reversed with sugammadex. The child was totally awake without any respiratory difficulty except with minimal substernal retraction and there was no motor block. The patient was sent to the recovery room and he was discharged home following day without any complication. In conclusion, patients with Larsen syndrome have issues pertinent to anesthesiology relating to the musculoskeletal, respiratory, cardiac and neurological systems

Prevalence, etiology, and biopsychosocial risk factors of cervicogenic dizziness in patients with neck pain: A multi-center, cross-sectional study

Objectives: This study aims to investigate the prevalence, etiology, and risk factors of cervicogenic dizziness in patients with neck pain. Patients and methods: Between June 2016 and April 2018, a total of 2,361 patients (526 males, 1,835 females; mean age: 45.0 +/- 13.3 years; range, 18 to 75 years) who presented with the complaint of neck pain lasting for at least one month were included in this prospective, cross-sectional study. Data including concomitant dizziness, severity, and quality of life (QoL) impact of vertigo (via Numeric Dizziness Scale [NDS]), QoL (via Dizziness Handicap Inventory [DHI]), mobility (via Timed Up-and-Go [TUG] test), balance performance [via Berg Balance Scale [BBS]), and emotional status (via Hospital Anxiety Depression Scale [HADS]) were recorded. Results: Dizziness was evident in 40.1% of the patients. Myofascial pain syndrome (MPS) was the most common etiology for neck pain (58.5%) and accompanied with cervicogenic dizziness in 59.7% of the patients. Female versus male sex (odds ratio [OR]: 1.641, 95% CI: 1.241 to 2.171, p=0.001), housewifery versus other occupations (OR: 1.285, 95% CI: 1.006 to 1.642, p=0.045), and lower versus higher education (OR: 1.649-2.564, p<0.001) significantly predicted the increased risk of dizziness in neck pain patients. Patient with dizziness due to MPS had lower dizziness severity scores (p=0.034) and milder impact of dizziness on QoL (p=0.005), lower DHI scores (p=0.004), shorter time to complete the TUG test (p=0.001) and higher BBS scores (p=0.001). Conclusion: Our findings suggest a significant impact of biopsychosocial factors on the likelihood and severity of dizziness and association of dizziness due to MPS with better clinical status