Visible fluorescence induced by the metal semiconductor transition in composites of carbon nanotubes with noble metal nanoparticles

We show that single-walled carbon nanotube (SWNT) bundles emit visible fluorescence in the presence of noble metal nanoparticles and nanorods in the solid state. Conductivity measurements with metallic nanotubes, isolated from pristine SWNTs, show that they become semiconducting in the presence of the metal nanoparticles. Nanoparticle binding increases the defects in the nanotube structures which is evident in the Raman spectra. The metal-semiconductor transition removes the nonradiative decay channels of the excited states enabling visible fluorescence. Nanotube structures are imaged using this emission with resolution below the classical limits

A simulation of the application of SPARMOD in project cost control

A major task in project cost control and scheduling is the forecasting of time and cost to complete activities in the network. SPARMOD is a tool for accomplishing this task. An attempt has been made, in this thesis to supplement the limited actual project experience so far in the application of this tool by results of computer simulation studies. These studies,aimed at a better understanding of the behavior of certain parameters, have added further confirmation of the validity of the technique.Industrial Engineering, Department o

Oral cancer in the young with no tobacco exposure: A distinct epidemiological subset?

Objectives: To describe oral squamous cell carcinoma (OSCC) in the young (<45 years) with no tobacco exposure and identify the determinants of locoregional control and survival. Materials and Methods: This is a retrospective analysis of 82 young patients of OSCC with no tobacco exposure treated with surgery and adjuvant therapy. Survival analysis was performed, and determinants of control and survival were identified by Cox proportional hazards regression model. Results: Overall 67% were male, and the median age was 40 years. Survival was excellent: for Stages I, II, III, and IV, 5-year overall survival was 97%, 95%, 75%, and 64% and disease-free survival (DFS) was 84%, 79%, 57%, and 59%, respectively. On multivariable analysis, perineural invasion (PNI) predicted DFS and local and distant control. Conclusion: This cohort had excellent survival when treated appropriately with adjuvant therapy. PNI may represent the need for treatment escalation. Further study is required to identify if this is a biologically distinct cohort

Early Detection of Oral Potentially Malignant Disorders : A Review on Prospective Screening Methods with Regard to Global Challenges

Oral cancer is a cancer type that is widely prevalent in low-and middle-income countries with a high mortality rate, and poor quality of life for patients after treatment. Early treatment of cancer increases patient survival, improves quality of life and results in less morbidity and a better prognosis. To reach this goal, early detection of malignancies using technologies that can be used in remote and low resource areas is desirable. Such technologies should be affordable, accurate, and easy to use and interpret. This review surveys different technologies that have the potentials of implementation in primary health and general dental practice, considering global perspectives and with a focus on the population in India, where oral cancer is highly prevalent. The technologies reviewed include both sample-based methods, such as saliva and blood analysis and brush biopsy, and more direct screening of the oral cavity including fluorescence, Raman techniques, and optical coherence tomography. Digitalisation, followed by automated artificial intelligence based analysis, are key elements in facilitating wide access to these technologies, to non-specialist personnel and in rural areas, increasing quality and objectivity of the analysis while simultaneously reducing the labour and need for highly trained specialists.Funding: Linkoping University; Folktandvarden Stockholms la AB [7071]; Folktandvarden Region Dalarna, forskningsstiftelsen Folktandvarden Dalarna; VinnovaVinnova [2017-02447]; DBT-VINNOVA [2020-03611]</p

Outcomes following pharyngeal reconstruction in total laryngectomy – Institutional experience and review of literature

Background: Pharyngeal reconstruction is a challenging aspect of reconstruction after resections for head-and-neck cancer. The goals of reconstruction are to restore the continuity of the pharyngeal passage to enable oral alimentation and rehabilitation of speech wherever possible. This study was performed to determine the outcomes following pharyngeal reconstruction in total laryngectomy (TL) using different reconstructive options and to determine the predictors of pharyngocutaneous fistula (PCF) and swallowing dysfunction. Materials and Methods: Retrospective analysis of patient data between 2003 and 2010 of patients undergoing TL with partial or total pharyngectomy. Demographic and treatment details were collected and analysed. Univariate analysis was performed to determine predictors of PCF and swallowing dysfunction. Results: Fifty-seven patients underwent pharyngeal reconstruction following TL, 31 of whom had received prior treatment. Following tumour resection, 31 patients had circumferential defects and 26 patients had partial pharyngeal defects. The flaps used include pectoralis major myocutaneous flap (n = 29), anterolateral thigh flap (n = 8), gastric pull-up (n = 13) and free jejunal flap (n = 7). PCF was seen in 20 patients, of which 15 (75%) were managed conservatively and 5 required another surgery. At last follow-up, 99 patients (68%) were on full oral alimentation. Tracheo-oesophageal puncture and prosthesis insertion was done in 20 patients, of whom 17 (85%) developed satisfactory speech. Partial pharyngeal defects were associated with a higher risk of PCF on univariate analysis (P = 0.006) but were not significant on multivariate analysis. Post-operative swallowing dysfunction was significantly higher with hypopharyngeal involvement by tumour (P = 0.003). Conclusion: Pharyngeal reconstruction in TL is feasible with good results. Majority of the patients swallow and regain acceptable swallowing function within 3 months

Wide excision and microvascular reconstruction for maxillomandibular ameloblastomas: local control, functional, and esthetic outcomes

Introduction: Ameloblastomas are benign but aggressive odontogenic tumors with have a high propensity for bony destruction. They require to be excised completely to avoid local recurrence, and these resections involve significant functional and esthetic disturbances. With the advent of microvascular reconstruction, they can be excised, and defects are reconstructed with preservation of form and function. This paper presents our experience with wide excision and microvascular reconstruction for maxillomandibular ameloblastomas, and to describe the planning, resection, microvascular reconstruction, and rehabilitation of these patients. Materials and Methods: A retrospective review of records for patients treated with wide excision and microvascular reconstruction for maxillomandibular ameloblastomas at Amrita Institute of Medical Sciences Kochi between 2003 and 2015 was performed. Clinical and pathological features were described, and a literature review was performed. Results: A total of 48 patients were identified with equal sex distribution and mean age at presentation of 35 (range 16–71) years. Half of these patients had primary lesions, and the remaining half had the recurrent disease (range 1–4 previous surgeries). Forty patients (83%) had mandibular lesions and the remaining had the maxillary disease. All patients had wide excision with a gross bony margin of 1 cm and reconstruction with microvascular flaps (fibula free flap = 41, distal circumflex iliac artery flap = 3 and scapular free flap = 2, anterolateral thigh flap = 1 and radial forearm free flap = 1). Mean tumor size was 4.73 (2–14) cm. At a median follow-up of 21 months, all patients were free of recurrence. Successful dental rehabilitation was achieved in 40 patients (83%). Conclusion: This approach leads to results in excellent local control, functional, and esthetic outcomes. Although managing these patients is challenging, multidisciplinary expertise and planning are crucial for successful management