Effect of Self-Healing by Dicyclopentadiene Microcapsules on Tensile and Fatigue Properties of Epoxy Composites.

Microcapsules of urea-formaldehyde (UF) containing dicyclopentadiene (DCPD) were synthesized by the in situ polymerization technique for self-healing of epoxy. The dispersion of microcapsules in the epoxy matrix was achieved using ultrasonication. Composites of epoxy, having 0.5, 1.0, 1.5, and 2.0 wt.% of microcapsules capable of self-healing, were prepared. The shape and size of the microcapsules were determined by field emission electron microscopy. Spherical capsules of DCPD, with an average diameter of 172 nm, were obtained. Investigation of tensile properties indicated a decrease in the tensile modulus with an increase in wt.% of microcapsules. There was a reduction of 22%, 27%, 39%, and 30% in the elastic modulus of composites for 0.5, 1.0, 1.5, and 2.0 wt.% of microcapsules, respectively. Tensile strength was found to increase with an increase in wt.% of microcapsules. The tensile strength of the composites increased by 33%, 20%, 8%, and 21% for 0.5, 1.0, 1.5, and 2.0 wt.% of microcapsules, respectively, in comparison with that of neat epoxy. The fatigue life of composites was investigated by conducting uniaxial tension-tension fatigue tests at constant stress amplitudes of 20, 25, 30, and 35 MPa, at a constant stress ratio (R = 0.1) and a frequency of 3 Hz. The fatigue life of composites increased with an increase in wt.% of microcapsules in comparison with that of neat epoxy. It was found that the fatigue life of the composites decreased with 1.5 and 2.0 wt.% of microcapsules in comparison with composites with 0.5 and 1.0 wt.% of microcapsules. The fracture surfaces of the tested samples were examined with the help of scanning electron microscopy (SEM) to understand the various mechanisms responsible for the change in modulus, strength, failure strain, and fatigue life of composites.

Genetic diversity & drug sensitivity profiles of Mycobacterium tuberculosis isolates from two slums of Jaipur city, Rajasthan, India.

BACKGROUND & OBJECTIVES: Slums are considered as hotspots of tuberculosis (TB). The study of genetic diversity and drug susceptibility profile of Mycobacterium tuberculosis (MTB) will help understand the transmission dynamics and can be used for better prevention and control of the disease. The aim of this study was to determine the drug susceptibility profiles and genetic diversity using the random amplified polymorphic DNA (RAPD) and mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU VNTR) of MTB isolates from sputum samples of pulmonary TB patients residing in the two slums of Jaipur city in Rajasthan, India. METHODS: Sputum samples collected from pulmonary TB patients, their contacts and suspects during 2010-2012 were processed for microscopy and mycobacterial culture. Drug susceptibility testing was done by one per cent indirect proportion method on Lowenstein-Jensen medium for first-line anti-TB drugs rifampicin, isoniazid, ethambutol and streptomycin. MTB DNA was extracted by physicochemical method, and DNA fingerprinting was done by RAPD and MIRU VNTR analysis. RESULTS: Among 175 sputum samples collected, 75 were positive (43.8%) for acid-fast bacilli, 83 for MTB culture and four were contaminated. Fifty two isolates (62.7%) were fully sensitive to four drugs, and five (6%) were multidrug resistant (MDR). RAPD analysis of 81 isolates revealed six clusters containing 23 (28.4%) isolates, and 58 (71.6%) were unique. MIRU VNTR analysis clustered 20 (24.7%) isolates, and 61 (75.3%) were unique. INTERPRETATION & CONCLUSIONS: About 62.7 per cent isolates from the sputum samples from slum areas were sensitive to four drugs; six per cent of isolates were MDR. Poly-resistance other than MDR was high (16%). About one-fourth isolates were clustered by either method. RAPD was rapid, less expensive but had low reproducibility. MIRU VNTR analysis could identify to greater extent the epidemiological link in the population studied.

Carcinoma of the cervix in elderly patients treated with radiotherapy: patterns of care and treatment outcomes / 부인종양

OBJECTIVE: The aim of this analysis was to examine the management of cervix cancer in elderly patients referred for radiotherapy and the results of treatment in terms of overall survival (OS), relapse-free survival (RFS), and treatment-related toxicities. METHODS: Patients were eligible if they were aged ≥75 years, newly diagnosed with cervix cancer and referred for radiotherapy as part of their treatment. Patient details were retrieved from the gynaecology service database where clinical, histopathological treatment and follow-up data were prospectively collected. RESULTS: From 1998 to 2010, 126 patients aged ≥75 years, met selection criteria. Median age was 81.5 years. Eighty-one patients had definitive radiotherapy, 10 received adjuvant radiotherapy and 35 had palliative radiotherapy. Seventy-one percent of patients had the International Federation of Gynecology and Obstetrics stage 1b–2b disease. Median follow-up was 37 months. OS and RFS at 3 years among those treated with curative intent were 66.6% and 75.9% respectively with majority of patients dying without any evidence of cervix cancer. Grade 2 or more late toxicities were: bladder 5%, bowel 11%, and vagina 27%. Eastern Cooperative Oncology Group (ECOG) status was a significant predictor of OS and RFS with each unit increment in ECOG score increased the risk of death by 1.69 times (p<0.001). CONCLUSION: Following appropriate patient selection, elderly patients treated curatively with radiotherapy for cervix cancer have good disease control. Palliative hypofractionated regimens are well tolerated in patients unsuitable for radical treatment.

Surgical staging of para-aortic LN in patients with locally advanced cervix cancer and no evidence of metastases in preoperative PET/CT imaging / 부인종양

No abstract available.

The survival outcome and patterns of failure in node positive endometrial cancer patients treated with surgery and adjuvant radiotherapy with curative intent / 부인종양

OBJECTIVE: The purpose of this study was to evaluate the patterns of failure, overall survival (OS), disease-free survival (DFS) and factors influencing outcome in endometrial cancer patients who presented with metastatic lymph nodes and were treated with curative intent. METHODS: One hundred and twenty-six patients treated between January 1996 to December 2008 with surgery and adjuvant radiotherapy were identified from our service's prospective database. Radiotherapy consisted of 45 Gy in 1.8 Gy fractions to the whole pelvis. The involved nodal sites were boosted to a total dose of 50.4 to 54 Gy. RESULTS: The 5-year OS rate was 61% and the 5-year DFS rate was 59%. Grade 3 endometrioid, serous, and clear cell histologies and involvement of upper para-aortic nodes had lower OS and DFS. The number of positive nodes did not influence survival. Among the histological groups, serous histology had the worst survival. Among the 54 patients relapsed, only three (6%) failed exclusively in the pelvis and the rest of the 94% failed in extrapelvic nodal or distant sites. Patients with grade 3 endometrioid, serous and clear cell histologies did not influence pelvic failure but had significant extrapelvic failures (p<0.001). CONCLUSION: Majority of node positive endometrial cancer patients fail at extrapelvic sites. The most important factors influencing survival and extrapelvic failure are grade 3 endometrioid, clear cell and serous histologies and involvement of upper para-aortic nodes.

We should not settle for low-level evidence but should always use the best available evidence / 부인종양

No abstract available.

Ultrasound guided conformal brachytherapy of cervix cancer: survival, patterns of failure, and late complications / 부인종양

OBJECTIVE: The aim of this study was to report on the long-term results of transabdominal ultrasound guided conformal brachytherapy in patients with cervical cancer with respect to patterns of failures, treatment related toxicities and survival. METHODS: Three hundred and nine patients with cervical cancer who presented to Institute between January 1999 and December 2008 were staged with magnetic resonance imaging and positron emission tomography and treated with external beam radiotherapy and high dose rate conformal image guided brachytherapy with curative intent. Follow-up data relating to sites of failure and toxicity was recorded prospectively. RESULTS: Two hundred and ninety-two patients were available for analyses. The median (interquantile range) follow-up time was 4.1 years (range, 2.4 to 6.1 years). Five-year failure free survival and overall survival (OS) were 66% and 65%, respectively. Primary, pelvic, para-aortic, and distant failure were observed in 12.5%, 16.4%, 22%, and 23% of patients, respectively. In multivariate analysis, tumor volume and nodal disease related to survival, whereas local disease control and point A dose did not. CONCLUSION: Ultrasound guided conformal brachytherapy of cervix cancer has led to optimal local control and OS. The Melbourne protocol compares favorably to the more technically elaborate and expensive GEC-ESTRO recommendations. The Melbourne protocol's technical simplicity with real-time imaging and treatment planning makes this a method of choice for treating patients with cervical cancer.