Water-soluble chitosan salt as ecofriendly corrosion inhibitor for N80 pipeline steel in artificial sea water: Experimental and theoretical approach

Chitosan, as a proficient biopolymer, has enormous potential as an ecofriendly corrosion inhibitor (CI), but their limited solubility restricts practical applications. Herein, an eco-friendly and water-soluble chitosan salt (CS) was utilized as a green CI on N80 pipeline steel in artificial sea water. Several structural and surface analytical tools were engaged in describing the characteristics of novel CS polymer. The corrosion inhibition efficiencies of CS on steel at different concentrations were investigated through gravimetric, conventional and advanced electrochemical techniques along with the surface analyses. Tafel polarization tests specified that CS performed as mixed-type CI with prevalent anodic inhibition characteristics. At a concentration of 1000 ppm, CS provided an inhibition efficiency (IE) of 96.68 %, following physiochemical adsorptions of CS on N80 surface validated by fitting Langmuir adsorption isotherm. However, the reductions in the values of IE at high temperature specified that the CS is the temperature dependent CIs. Scanning electrochemical microscopic evaluation confirmed the formation of thin CS inhibitors films with high electrochemical stability on N80 steel in saline. The performed surface characterizations on inhibited surfaces validated the adsorption of CS on the N80 surface by forming thin inhibitor film to obstruct metal corrosion. The theoretical simulation studies using molecular dynamics and density functional theory corroborated the experimentally obtained results.

Hybrid algorithm for retinal blood vessel segmentation using different pattern recognition techniques

Blood vessel segmentation of the retina has become a necessary step in automatic disease identification and planning treatment in the field of Ophthalmology. To identify the disease properly, both thick and thin blood vessels should be distinguished clearly. Diagnosis of disease would be simple and easier only when the blood vessels are segmented accurately. Existing blood vessel segmentation methods are not supporting well to overcome the poor accuracy and low generalization problems because of the complex blood vessel structure of the retina. In this study, a hybrid algorithm is proposed using binarization, exclusively for segmenting the vessels from a retina image to enhance the exactness and specificity of segmentation of an image. The proposed algorithm extracts the advantages of pattern recognition techniques, such as Matched Filter (MF), Matched Filter with First-order Derivation of Gaussian (MF-FDOG), Multi-Scale Line Detector (MSLD) algorithms and developed as a hybrid algorithm. This algorithm is authenticated with the openly accessible dataset DRIVE. Using Python with OpenCV, the algorithm simulation results had attained an accurateness of 0.9602, a sensitivity of 0.6246, and a specificity of 0.9815 for the dataset. Simulation outcomes proved that the proposed hybrid algorithm accurately segments the blood vessels of the retina compared to the existing methodologies.

Relationship between personality traits and facebook addiction: A meta-analysis

Personality traits are important factors in determining online behaviors. Especially personality traits are linked with users’ behavior on Facebook. Despite the substantial quantity of studies conducted on the relationship between personality factors and Facebook addiction, researchers have yet to reach an agreement. This study sought to examine the relationship between personality traits and Facebook addiction. In this meta-analysis study, agreeableness, openness to experience and conscientiousness were negatively related to Facebook addiction. Loneliness, narcissism, impulsivity and shyness were significantly correlated with Facebook addiction. Meta analysis also found that geographical location, personality scales, Facebook addiction scales, publication status moderated the link between personality variables and Facebook addiction. The limitations and future directions are discussed.

A novel hybrid 3D dose reconstruction approach for pre-treatment verification of intensity modulated proton therapy plans

AIM

A novel hybrid three-dimensional (3D) dose reconstruction method, based on planar dose measured at a single shallower depth, was developed for use as patient-specific quality assurance (PSQA) of intensity modulated proton therapy (IMPT) plans. The accuracy, robustness and sensitivity of the presented method were validated for multiple IMPT plans of varying complexities.

METHODS AND MATERIALS

An in-house MATLAB program was developed to reconstruct 3D dose distribution from the planar dose (GyRBE) measured at 3 g cm^-2 depth in water or solid phantom using a MatriXX PT ion chamber array. The presented method was validated extensively for 11 single-field optimization (SFO) and multi-field optimization (MFO) plans on Proteus Plus. A total of 47 reconstructed planar doses at different depths were compared against the corresponding RayStation treatment planning system (TPS) and MatriXX PT measurement using a gamma passing rate (γ%) evaluated for 3%/3 mm. The robustness of the reconstruction method with respect to depth, energy layers, field dimensions and complexities in the spot intensity map (SIM) were analysed and compared against the standard PSQA. The sensitivity of the reconstruction method was tested for plans with intentional errors.

RESULTS

The presented reconstruction method showed excellent agreement (mean γ% > 98%) and robustness with both TPS-calculated and measured dose planes at all depths (2.97-30 g cm^-2), energy layers (82.1-225.5 MeV), field dimensions, target volume (17.7-1000 cm³) and SIMs from both SFO and MFO plans. In comparison to the overall mean ± SD γ% from standard PSQA, the reconstruction method showed reductions in mean γ% within 1% for both standard cubes and clinical plans. The reconstruction method was sensitive enough to detect intentional spot positional errors in a selected energy layer of a plan.

CONCLUSION

The presented hybrid reconstruction method is sufficiently accurate, robust and sensitive to estimate planar dose at any user-defined depth. It simplifies the measurement setup and eliminates multiple depth measurements.

Characterization and Performance Evaluation of the First-Proton Therapy Facility in India

Purpose:

The purpose of this study is to evaluate the performance characteristic of volumetric image-guided dedicated-nozzle pencil beam-scanning proton therapy (PT) system.

Materials and Methods:

PT system was characterized for electromechanical, image quality, and registration accuracy. Proton beam of 70.2–226.2 MeV was characterized for short- and long-term reproducibility in integrated depth dose; spot profile characteristics at different air gap and gantry angle; positioning accuracy of single and pattern of spot; dose linearity, reproducibility and consistency. All measurements were carried out using various X-ray and proton-beam specific detectors following standard protocols.

Results:

All electro-mechanical, imaging, and safety parameters performed well within the specified tolerance limit. The image registration errors along three translation and three rotational axes were ≤0.5 mm and ≤0.2° for both point-based and intensity-based auto-registration. Distal range (R₉₀) and distal dose fall-off (DDF) of 70.2–226.2 MeV proton beams were within 1 mm of calculated values based on the international commission on radiation units and measurements 49 and 0.0156× R₉₀, respectively. The R₉₀ and DDF were reproducible within a standard deviation of 0.05 g/cm² during the first 8 months. Dose were linear from 18.5 (0.011 MU/spot) to 8405 (5 MU/spot) MU, reproducible within 0.5% in 5 consecutive days and consistent within 0.8% for full rotation. The cGy/MU for 70.2–226.2MeV was consistent within 0.5%. In-air X(Y) spot-sigma at isocenter varies from 2.96 (3.00) mm to 6.68 (6.52) mm for 70.2–226.2 MeV. Maximum variation of spot-sigma with air-gap of ±20 cm was ±0.36 mm (5.28%) and ±0.82 mm (±12.5%) along X- and Y-direction and 3.56% for full rotation. Relative spot positions were accurate within ±0.6 mm. The planned and delivered spot pattern of known complex geometry agreed with (γ%≤1) for 1% @ 1 mm >98% for representative five-proton energies at four gantry angle.

Conclusion:

The PT-system performed well within the expected accuracy level and consistent over a period of 8 months. The methodology and data presented here may help upcoming modern PT center during their crucial phase of commissioning.

Facebook addiction and personality

This study explored the associations between Facebook addiction and personality factors. A total of 114 participants (age range of participants is 18-30 and males were 68.4% and females were 31.6 %) have participated through an online survey. The results showed that 14.91 % of the participants had reached the critical polythetic cutoff score, and 1.75 % has reached the monothetic cutoff score. The personality traits, such as extraversion, openness to experience, neuroticism, agreeableness, conscientiousness, and narcissism, are not related to Facebook addiction and Facebook intensity. Loneliness was positively related to Facebook addiction, and it significantly predicted Facebook addiction by accounting to 14% of the variation in Facebook addiction. The limitations and suggestions for further research have been discussed.

Climate change impacts on plant diseases

The change in Global climate is due to increasing concentration of greenhouse gases (GHG) in the atmosphere. The earths’ observed climatic changes over the past 50 years are primarily caused by various human activities. The increasing global temperature over the past century by about 0.8°C and expected to rise between 0.9 and 3.5°C by 2100. Such changes will not only have a great effect on the growth and cultivation of different crops but also affect the reproduction, spread and severity of many plant pathogens. Various plant disease models have been developed to incorporate more sophisticated climate predictions at various levels. At the level, the adaptive potential of plant and pathogen populations may prove to be one of the most important predictors of the magnitude of climate change effects. This review highlights various influences of climate change on plant diseases and their effects with suitable examples.SAARC J. Agri., 14(2): 200-209 (2016)

A quantitative comparison of gross tumour volumes delineated on [18F]-FDG PET-CT scan and CECT scan in head and neck cancers

Purpose:

To compare quantitatively Gross tumor volume (GTV), both primary and nodal areas of head and neck cancers, delineated on [18F]-2fluoro, 2deoxy d-glucose-positron emission tomography/computed tomography ([18F]-FDG-PET-CT) scan to those delineated on Contrast-enhanced CT scan (CECT scan).

Methods:

A total of 26 consecutive patients with squamous cell cancers of head and neck were included in this study. The primary sites were oropharynx (n = 7), hypopharynx (n = 6), paranasal sinus (n = 6), nasopharynx (n = 4), oral cavity (n = 2), and one with unknown primary and secondary neck node. All patients underwent routine staging work-up. FDG-PET and CECT scans were performed with dedicated PET-CT scanner in single session as a part of the radiotherapy treatment planning for Intensity modulated radiotherapy/Image-guided radiotherapy.

Results:

All patients had abnormal increased uptake in PET-CT scans. PET-CT resulted in changes of CT-based staging in 8 of 26 patients (up-staged in 7 and down-staged in 1). The mean primary and nodal GTV volumes on PET-CT and CT were significantly different (primary: PET-GTV: 48.43 ± 53.21 cc vs. CT 54.78 ± 64.47 cc, P < 0.001; nodes: PET-GTV: 12.72 ± 15.46 cc vs. 11.04 ± 14.87 cc, P < 0.001). The mismatch between two target volumes was statistically significant (P = 0.03 for GTV primary, P = 0.04 for GTV node).

Conclusion:

Accuracy of delineation of GTV can be improved along with functional imaging using [18F]-FDG. These metabolically active volumes are significantly smaller than CT-based volumes and could be missed during conventional CT-based target delineations of GTVs.

Morphometry and CT measurements of useful bony landmarks of skull base

OBJECTIVE

Aim of this study was to determine the distance between Henle's spine (HS) on the temporal bone to the clinically important bony landmarks on the dry skulls that will act as a guide in various surgical procedures on skull base. Distances from the head of malleus (HOM) to surgically relevant landmarks were also studied on CT images.

MATERIALS AND METHODS

Thirty-nine adult preserved dry skulls were studied bilaterally. The parapetrosal triangle bounded by spinopterygoidal, bispinal and the midsagittal lines was identified. The location of the HS and its distance from the various important anatomical structures were measured. In addition, five CT images, where distances from the HOM to various anatomical landmarks were measured.

RESULTS

The mean and range of distances from the HS to various important anatomical landmarks on the spinopterygoidal line, bispinal line and in the parapetrosal triangle were tabulated. The mean and range of CT-based measurements of distances from HOM to other anatomical landmarks were also noted.

CONCLUSIONS

The knowledge of unvarying relationship of the HS and the HOM to the various structures of the skull would assume significance while planning surgeries around the temporal bone by guiding the direction and degree of bone removal. Statistical differences between the two genders showed significant difference only in the distance between the HS to the medial margin of the external orifice of carotid canal. Therefore, these landmarks can also be applied as references for various surgeries of middle cranial fossa, as well as transpetrosal and transmastoid approaches.

Strongyloidosis hyperinfection in a neutropenic host diagnosed by bronchoalveolar lavage

Opportunistic disseminated strongyloidosis is an important cause of morbidity and mortality in immunocompromised patients. In addition to a high index of clinical suspicion, alerting the microbiologist will help in diagnosing this condition early and institute therapy. We report a 51-year-old male who developed pulmonary infiltrates during the period of chemotherapy-induced neutropenia. Strongyloidosis larvae were found on bronchoalveolar lavage fluid and stool specimens. The patient responded to treatment with albendazole.

Fibrinolysis of loculated pleural effusion in malignant mesothelioma

Surgical resection is not feasible in most cases of malignant mesothelioma and palliation of symptoms remains the mainstay of treatment. When a pleural effusion is loculated, the standard treatment methods of intercostal tube drainage and pleurodesis may not be helpful. We report a 49-year-old man with malignant mesothelioma in whom intrapleural fibrinolysis was performed using streptokinase. It was successful in breaking the locules and draining the effusion. Intrapleural fibrinolysis should be considered in cases of loculated pleural effusion due to malignant mesothelioma, as it may provide symptom relief and palliation.

Intra-arterial thrombolysis for left middle cerebral artery embolic stroke during percutaneous mitral commissurotomy

Cerebral thromboembolism is a serious complication. Early recognition and rapid reperfusion can prevent long-term neurological morbidity. We report a case of successful intra-arterial thrombolysis for middle cerebral artery embolic stroke during percutaneous mitral commissurotomy, which resulted in complete neurological recovery.

Fracture of cutting balloon microsurgical blade inside coronary artery during angioplasty of tough restenotic lesion: a case report

We report a rare complication due to fracture of the blade of a cutting balloon in the setting of a tough nondilatable restenotic lesion. This resulted in a mural hematoma as a result of dissection of coronary artery.

Percutaneous transluminal angioplasty with cutting balloon and stenting for isolated bilateral aorto-coronary ostial stenosis in a young female

Coronary artery disease involving both coronary ostia (left main and right coronary) is extremely rare in a premenopausal female, without pre-existing coronary risk factors. We report a case of tight bilateral coronary ostial disease which presented in unusual clinical circumstances in a young female, which was successfully revascularized by single-stage aorto-ostial cutting balloon angioplasty and stenting.