Investigation for conductance behavior of single walled carbon nanotubes decorated with UNCD and graphitic spherules using STM/STS

Carbon nanostructures were grown on single walled carbon nanotubes (SWCNTs) using hot filament chemical vapor deposition under diverse growth conditions. The difference in the morphological and structural properties of these deposits was confirmed mainly using transmission electron microscopy. These results depict the growth/decoration of ultrananocrystalline diamond (UNCD) and graphitic spherules i.e. dissimilar carbon phases onto the tube surface, further confirmed by estimating the ratio of sp2/sp3 carbon using X-ray photoelectron spectroscopy. The electronic properties of individual CNTs decorated with UNCD and graphitic spherules were investigated using scanning tunneling spectroscopy technique. Semiconducting behavior and the metallic behavior observed for the tubes decorated with UNCD and graphitic spherules respectively demonstrate the possibility to use these composites for various applications depending on the requirements

Trans-oral anterior fundoplication: 5-year follow-up of pilot study

Abstract Background This is a report of an IRB-approved pilot study of 13 patients who received a trans-oral anterior partial fundoplication for the treatment of GERD using an ultrasound-guided, flexible surgical stapler. All patients had a history of PPI use, objective evidence of GERD, and no significant comorbidity. Under general anesthesia, a flexible stapler was passed trans-orally into the stomach and placed two or three quintuplets of titanium staples approximately 3 cm above the gastroesophageal junction. The stapler contains an ultrasonic range finder, video camera, and illuminator. Methods Primary follow-up at 6 weeks included pH metrics, GERD-HRQL scores, and PPI use. The protocol allowed annual telephone interviews for the following 5 years to collect GERD-HRQL scores, PPI use, satisfaction with the procedure, and willingness to have the procedure again. Results At 6 weeks, mean total acid exposure was significantly reduced, and 12/13 patients reduced GERD-HRQL scores by C50 %. Twelve of 13 patients had stopped daily GERD medications, and nine of 13 had stopped all GERD medications. Each year, 11 of the 13 patients could be reached with all 13 patients having at least 4-year followup. Throughout the follow-up period, GERD-HRQL scores were normal (\10) in all but one patient. All patients would agree to do the procedure again. The median satisfaction score is 8 (range 6-10) on a scale of 1-10. None reported dysphagia. At 1 year, 54 % of respondents (6/11) had eliminated PPI use, with another 27 % (3/11) taking a reduced dose. Combining respondents at 4 and 5 years to account for all patients, 54 % (7/13) had eliminated and another 23 % (3/13) reduced PPI use C50 %. Conclusion At 5 years, the procedure remained effective as demonstrated by the improved quality of life and changes in PPI use. The results remained stable after the second year

Simple mathematical equation to predict distance to gastroesophageal junction through the submucosal tunnel during peroral endoscopic myotomy

Abstract Background and aim Accurate estimation of the distance to the gastroesophageal junction (GEJ) through a tunnel during per oral endoscopic myotomy (POEM) is technically challenging. The methods currently employed are often insufficient, and resultant errors may lead to incomplete myotomy and/or prolonged procedure times. Our hypothesis states that the additional distance while traversing the tunnel is directly proportional to the widest esophageal diameter; and is calculated by the formula X = Y + CZ (X = distance to the GEJ through the tunnel, Y = distance to the GEJ through the lumen, Z = widest esophageal diameter, C = arithmetic constant). This study evaluates the validity and accuracy of this hypothesis. Patients and methods This was a prospective single-center study with 80 patients, 12 in the pilot group and 68 in the study group. In the pilot group, Y was recorded during esophagogastroduodenoscopy (EGD) before POEM, Z on barium swallow/contrast enhanced computed tomography (CECT), and X was measured during POEM. Using the formula, mean C (SD) was calculated. In the study group, ‘C’ was substituted in the equation to predict the GEJ distance through the tunnel (Xp) before POEM. The operator was blinded to Xp and recorded the true Xt during POEM. The correlation between Xp and Xt was calculated. Results In the pilot group, the mean distances (cm, SD) for X, Y, and Z were 42.58 (3.33), 39.83 (3.08), and 4.39 (1.16), respectively. The calculated mean C was 0.63 (0.11). In the study group, the mean distances (cm, SD) for Y, Z, Xp, and Xt were 40.45 (2.58), 4.99 (1.43), 43.57 (2.68), and 43.54 (2.78), respectively. The Xp and Xt values demonstrated a high correlation (r = 0.97, P = 0.000). Conclusions Formula X = Y + CZ reliably predicts the GEJ distance through a tunnel during POEM. It is user friendly and requires no additional resources.</jats:p