Internal Jugular Vein Cannulation Using a 3-Dimensional Ultrasound Probe in Patients Undergoing Cardiac Surgery: Comparison Between Biplane View and Short-Axis View.

OBJECTIVE: To compare the clinical performance in terms of procedure time, success rate, and cannulation attempts between ultrasound biplane view (BPX) and short-axis (SAX) view for internal jugular vein cannulation (IJV) in patients undergoing cardiac surgery. DESIGN: Prospective, observational pilot study. SETTING: University level tertiary referral hospital. PATIENTS: The study comprised 100 patients between ages 18 and 75 years undergoing elective cardiac surgery. INTERVENTIONS: One hundred patients were divided into 2 groups of 50 (BPX group and SAX group) by assigning the study participants alternatively to each group. IJV cannulation was performed using a 3-dimensional ultrasound probe in all patients with either BPX view (BPX group, n = 50) or the SAX view (SAX group, n = 50) by an experienced anesthesiologist. MEASUREMENTS AND MAIN RESULTS: Time required for imaging, time for IJV puncture, time for guidewire confirmation, number of needle punctures and needle redirections, and incidence of posterior wall puncture were noted in both groups. In addition, the quality of needle visualization and the incidence of complications were recorded. The time taken for imaging was significantly greater in the BPX group than in the SAX group (9.52 ± 2.69 s v 7.94 ± 2.55 s; p = 0.0034), whereas the time taken for IJV puncture (10.39 ± 2.33 s v 23.7 ± 2.46 s; p < 0.0001), time taken for confirmation of guidewire (32.94 ± 4.50 s v 57.64 ± 7.14 s; p < 0.0001), and the incidence of posterior wall puncture (4% v 26%; p = 0.0022) were significantly less in the BPX group than in the SAX group. The total number of attempts taken to puncture the IJV was fewer in the BPX group than in the SAX group (55 v 78). Successful puncture of the IJV occurred on the first attempt in 90% of patients in the BPX group, whereas it was only 50% in the SAX group (p < 0.0001). The quality of needle visualization was good in 90% of patients in the BPX group, whereas it was only 6% in the SAX group. The number of needle redirections for IJV puncture was less in the BPX group than in the SAX group (48 v 116). The incidence of complications was not significant between the 2 groups. CONCLUSION: The results suggested that the BPX view may be a safer, feasible and more reliable method than the SAX view for IJV cannulation in cardiac surgical patients.

Outcomes of Mitral Valve Replacement after Closed Mitral Valvotomy: A Retrospective Cohort Study.

BACKGROUND: The incidence of rheumatic fever and rheumatic heart disease still remains high in the developing countries. Mitral stenosis is predominantly due to rheumatic origin and affects females more than males. Historically, closed mitral valvotomy (CMV) was the first effective intervention for mitral stenosis. We studied the immediate and early surgical outcomes of MVR in patients with history of CMV to see whether their disease behaves differently, when compared with patients without prior CMV undergoing MVR. METHODS: This single center retrospective cohort study was conducted in Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India. Patients who underwent MVR from January 2008 to December 2012 at our institute were studied. The hospital records of 90 patients were analyzed both in the CMV cohort and also in the non-CMV cohort. Preoperative details, intraoperative parameters, immediate postsurgery echocardiography parameters, and follow-up echocardiography details at 1 year and 5 years were studied. RESULTS: Both the cohorts were similar in age, height, weight, and BSA. In the CMV cohort, 67% were females and in the non-CMV cohort 48% were females. Most of the patients in both the cohorts presented with functional classes 2 and 3. The mean duration between onset of symptoms and MVR in the CMV cohort and the non-CMV cohort was 24.6 years and 6.25 years, respectively. Fifty-nine patients in the CMV cohort had preoperative atrial fibrillation, whereas 47 patients in the non-CMV cohort presented with atrial fibrillation. The mean left atrial (LA) size of patients with sinus rhythm and atrial fibrillation was 46.34 (SE, 0.852) and 55.21(SE, 0.808), respectively. Preoperative echocardiographic assessment revealed a mean ejection fraction of 62% and 63%, mean mitral stenosis gradient of 13 mm Hg and 14.7 mm Hg, mean LA size of 53.2 mm and 50.5 mm, and mean right ventricular systolic pressure of 47.5 mm Hg and 43.6 mm Hg in the post-CMV cohort and in the non-CMV cohort, respectively. The CMV cohort had a longer cardiopulmonary bypass time (111.5 minutes) in comparison with the non-CMV cohort (97 minutes). The aortic cross-clamp time remained similar in both the cohorts. Thirty-six percent of the post-CMV cohort patients had a valve size of 25, and 48% of patients belonging to the non-CMV cohort had a valve size of 27. The percent of moderate-to-severe subvalvar pathology was 88 in both the cohorts. Patients belonging to the post-CMV cohort had a median ventilation time of 16.35 hours, and the patients of the non-CMV cohort had a median ventilation time of 13.75 hours. The duration of ICU stay was 4.41 (SE, 0.188) days and 4.13 (SE, 0.153) days, and length of hospital stay was 8.93 (SE, 0.230) days and 9.13 (SE, 0.313) days in the CMV and the non-CMV cohorts, respectively. Inotropic requirement, measured by the vasoactive inotropic score, was higher in the post-CMV group (11.9), when compared to the other cohort (9.7). Right ventricular (RV) function and pulmonary arterial hypertension assessed in the immediate postoperative period, at 1 year, and at 5 years did not show any significant difference. CONCLUSION: The percentage of females in the CMV cohort is higher. Delaying the valve replacement by performing a surgical palliative procedure like CMV, is beneficial in female patients in the child-bearing age group so that they can complete the families. The disease process started earlier in the CMV cohort, and they had a longer duration of illness before undergoing MVR. Even with the longer duration of disease, the RV function, LA size, PA pressures, and mitral stenosis gradients were comparable. Therefore, CMV prevented progression of the disease in the CMV group. The mean LA size is significantly higher in patients with atrial fibrillation. The CMV cohort had a longer cardiopulmonary bypass time. The duration of ventilation, ICU stay, and hospital stay were similar in both cohorts. Inotrope requirement was higher in the post-CMV group. RV function and pulmonary arterial hypertension assessed in the immediate postoperative period, at 1 year, and at 5 years did not show any significant difference.

Intraoperative Transesophageal and Postoperative Transthoracic Echocardiographic Evaluation of a Mechanical Heart Valve Prosthesis Implanted at Aortic Position.

OBJECTIVE: The aims of this study were to evaluate the intraoperative transesophageal echocardiographic (iTEE) characteristics and Doppler flow profile of aortic Chitra heart valve prosthesis (CHVP) under stable hemodynamic and loading conditions, and to compare and correlate the iTEE data with the postoperative transthoracic echocardiography (TTE) data obtained at 48 hours (TTE1) and 3 months (TTE2) after the surgery. DESIGN: Prospective, observational study. SETTING: University-level tertiary referral hospital. PARTICIPANTS: Forty patients between 18 years and 65 years of age undergoing elective aortic valve replacement (AVR) using CHVP during the period January 2015 to August 2016. INTERVENTIONS: After obtaining permission from institutional ethics committee, 40 patients undergoing elective AVR were studied prospectively. The iTEE examination was performed in the pre-cardiopulmonary bypass (CPB) and post-CPB period in all the study subjects. CHVP was subjected to iTEE two-dimensional (2D) echo, color Doppler, and spectral Doppler evaluation under stable hemodynamic and loading condition in the post-CPB period after the administration of protamine. The CHVP were re-evaluated using TTE in all the patients 48 hours after the surgery (TTE1) and 3 months after the surgery (TTE2). The iTEE and postoperative TTE Doppler values were compared and correlated. MEASUREMENTS AND MAIN RESULTS: The CHVP could be imaged adequately and interrogated with Doppler in all the patients. None of the patients had restriction of occluder mobility or unstable seating of the valve. The intraoperative flow dependent (peak velocity [PV] and mean pressure gradient [MPG]) and less flow dependent (Doppler velocity index, acceleration time, acceleration time/ejection time, effective orifice area [EOA] and indexed EOA) Doppler parameters of CHVP were measured as per the American Society of Echocardiography recommendations. The PV and MPG of CHVP measured by iTEE showed no statistical difference (p > 0.05) and were in limits of agreement when compared with TTE1 and TTE2 data. CONCLUSION: The iTEE features of CHVP were found compliant with the criteria set by the ASE defining normal functioning of an aortic valve prosthesis. The iTEE Doppler parameters obtained under stable loading conditions strongly predicted the postoperative values of Doppler parameters on TTE examination. The iTEE Doppler values can be used as the reference values for the postoperative follow up studies.

OfftargetFinder: a web tool for species-specific RNAi design.

MOTIVATION: RNA interference (RNAi) technology is being developed as a weapon for pest insect control. To maximize the specificity that such an approach affords we have developed a bioinformatic web tool that searches the ever-growing arthropod transcriptome databases so that pest-specific RNAi sequences can be identified. This will help technology developers finesse the design of RNAi sequences and suggests which non-target species should be assessed in the risk assessment process. AVAILABILITY AND IMPLEMENTATION: http://rnai.specifly.org CONTACT: crobin@unimelb.edu.au.

Improved Correlation of Strain Indices with Cognitive Dysfunction with Inclusion of Adventitial Layer with Carotid Plaque.

Plaque instability may lead to chronic embolization, which in turn may contribute to progressive cognitive decline. Accumulated strain tensor indices over a cardiac cycle within a pulsating carotid plaque may be viable biomarkers for the diagnosis of plaque instability. Using plaque-only carotid artery segmentations, we recently demonstrated that impaired cognitive function correlated significantly with maximum axial and lateral strain indices within a localized region of interest in plaque. Inclusion of the adventitial layer focuses our strain or instability measures on the vessel wall-plaque interface hypothesized to be a region with increased shearing forces and measureable instability. A hierarchical block-matching motion tracking algorithm developed in our laboratory was used to estimate accumulated axial, lateral, and shear strain distribution in plaques identified with the plaque-with-adventitia segmentation. Correlations of strain indices to the Repeatable Battery for the Assessment of Neuropsychological Status Total score were performed and compared with previous results. Overall, correlation coefficients (r) and significance (p) values improved for axial, lateral, and shear strain indices. Shear strain indices, however, demonstrated the largest improvement. The Pearson correlation coefficients for maximum shear strain and cognition improved from the previous plaque-only analyses of -0.432 and -0.345 to -0.795 and -0.717 with the plaque-with-adventitia segmentation for the symptomatic group and for all patients combined, respectively. Our results demonstrate the advantage of including adventitia for ultrasound carotid strain imaging providing improved association to parameters assessing cognitive impairment in patients. This supports theories of the importance of the vessel wall plaque interface in the pathophysiology of embolic disease.

Marine Actinomycetes as potential source for histone deacetylase inhibitors and epigenetic modulation.

UNLABELLED: In the light of important detrimental role of aberrant histone deacetylases (HDAC) production during various clinical complications, development of therapeutically effective and specific inhibitors of HDAC is critically important. This study deals with the screening for HDAC inhibitors from marine Actinomycetes. The isolation of Actinomycetes from 22 sediment samples along the Southern Coast of India yielded 186 strains including Streptomyces, Nocardipsis, evaluated for HDAC inhibition using HeLa cells. Among the 186 isolates, 10 strains have shown moderate to strong inhibition. The maximum inhibition (61%) was seen with strain VITKSM06 and least inhibition (31%) was seen with strain VITSJT03. The MTT cell proliferation assay using HeLa cell line showed significant cytotoxicity with an IC50 of 5·9 µg ml(-1) by VITKSM06-derived metabolite and 26·2 µg ml(-1) by VITSJT03. The compound treated HeLa cells displayed an altered morphology and condensed chromatin which may be due to HDAC inhibition. Based on the phylogenetic analysis, the potential strains were identified as Nocardiopsis sp VITKSM06, Streptomyces sp VITAKS1 and Streptomyces sp VITRSM02. This study reveals the importance of screening marine Actinomycetes for the discovery of potential novel HDAC inhibitors of therapeutic importance. SIGNIFICANCE AND IMPACT OF THE STUDY: Histone deacetylases (HDAC) are epigenetic enzymes that regulate the deacetylation in lysine group on a histone, and thus regulate the gene expression. The HDAC inhibitors are reported to promote apoptosis on tumour cells, thus become clinically important drug target. Several studies have addressed the identification of putative HDAC inhibitors as therapeutic agents for cancer and until now those cleared phase III human trials are very limited. This study attempts to investigate the chemical diversity found in marine Actinomycetes towards negative HDAC modulation, which could be used individually or in combination as anti-cancerous and other therapeutic measure.

Preoperative mitral annulus size - Can we get it right?

Objective: We looked for a correlation between the surgically measured mitral valve size and the cardiac dimensions (left ventricle internal diameter, left atrial size, aorta size, and body surface area) measured by preoperative and intraoperative echocardiography. We also assessed to see if we could predict the mitral prosthesis size based on the correlation data obtained. Methods: The hospital records of 180 patients who underwent mitral valve replacement (MVR) with TTK Chitra valve between January 2008 and December 2012 at our hospital, were studied. The correlation between surgically measured mitral annulus size to left ventricular internal diameter systolic (LVIDS) and diastolic (LVIDD), left atrial size (linear measurement), and aorta size on echocardiography and body surface area was calculated using Pearson correlation coefficient. Mean LVIDS was calculated for each valve prosthesis size separately and the correlation was studied. Results: The correlation between mitral valve prosthesis size and left ventricular internal diameter (systolic) showed a Pearson coefficient of 3.3 with significance at the level 0.01. Mitral valve size and left atrial size showed a correlation coefficient of 2.7 with significance at the level 0.01. The correlation coefficient for mitral valve size with left ventricular internal diameter diastolic, aorta and body surface area were 2.5, 1.9, and 1.8, respectively. There was a gradual increase in the mean LVIDS with increase in the prosthetic valve size. Box plot and scatter plot showed linear correlation between valve size and mean LVIDS.

Electrode displacement strain imaging of thermally-ablated liver tissue in an in vivo animal model.

PURPOSE: Percutaneous thermal ablation is increasingly being used to destroy hepatic tumors in situ. The success of ablative techniques is highly dependent on adequate ablation zone monitoring, and ultrasound-based strain imaging could become a convenient and cost-effective means to delineate ablation zone boundaries. This study investigates in vivo electrode displacement-based strain imaging for monitoring hepatic ablation procedures that are difficult to perform with conventional elastography. METHODS: a In our method, minute displacements (less than a millimeter) are applied to the unconstrained end of the ablation electrode, resulting in localized tissue deformation within the ablation zone that provides the mechanical stimuli required for strain imaging. This article presents electrode displacement strain images of radiofrequency ablation zones created in porcine liver in vivo (n = 13). RESULTS: Cross-sectional area measurements from strain images of these ablation zones were obtained using manual and automated segmentation. Area measurements from strain images were highly correlated with areas measured on histopathology images, quantitated using linear regression (R = 0.894, P < 0.001 and R = 0.828, P < 0.001, respectively). CONCLUSIONS: This study further demonstrates that electrode displacement elastography is capable of providing high-contrast images using widely available commercial ultrasound systems which may potentially be used to assess the extent of thermal ablation zones.

In vivo carotid strain imaging using principal strains in longitudinal view.

Carotid plaque rupture can result in stroke or transient ischemic attack that can be devastating for patients. Ultrasound strain imaging provides a noninvasive method to identify unstable plaque likely to rupture. Axial, lateral and shear strains in carotid plaque have been shown to be linked to carotid plaque instability. Recently, there has been interest in using principal strains, which do not depend on angle of insonification of the carotid artery for quantifying instability in plaque along the longitudinal view. In this work relationships between angle dependent axial, lateral and shear strain along with axis independent principal strains are compared. Three strain indices were defined, 1) Average Mean Strain (AMS), 2) Maximum Mean Strain (MMS) and 3) Mean Standard Deviation (MSD) to identify relationships between these five strain image types in a group of 76 in vivo patients. The maximum principal strain demonstrated the highest strain values when compared to axial strain for all patients with a linear regression slope of 1.6 and a y intercept of 2.4 percent strain for AMS. The maximum shear strain when compared to shear strain had a slope of 1.15 and a y intercept of 0.21 percent for AMS. Next, the effect of insonification angle, which is the angle subtended by the artery at the location of plaque was studied. Patients were divided into three sub groups, i.e. less than 5 degrees (n = 31), between 5 and 10 degrees (n = 24) and above 10 degrees (n = 21). The angle of insonification did not make a significant difference between the three angle groups when comparing the relationship between the angle dependent and independent strain values.

A Cross-Sectional Investigation of Cognition and Ultrasound-Based Vascular Strain Indices.

OBJECTIVE: We examine the relationship between variability in the plaque strain distribution estimated using ultrasound with multiple cognitive domains including executive, language, visuospatial reasoning, and memory function. METHOD: Asymptomatic (n = 42) and symptomatic (n = 34) patients with significant (>60%) carotid artery stenosis were studied for plaque instability using ultrasound strain imaging and multiple cognitive domains including executive, language, visuospatial reasoning, and memory function. Correlation and ROC analyses were performed between ultrasound strain indices and cognitive function. Strain indices and cognition scores were also compared between symptomatic and asymptomatic patients to determine whether there are significant group differences. RESULTS: Association of high-strain distributions with dysexecutive function was observed in both asymptomatic and symptomatic patients. For memory, visuospatial, and language functions, the correlations between strain and cognition were weaker for the asymptomatic compared to symptomatic group. CONCLUSIONS: Both asymptomatic and symptomatic patients demonstrate a relationship between vessel strain indices and executive function indicating that silent strokes and micro-emboli could initially contribute to a decline in executive function, whereas strokes and transient ischemic attacks may cause the further decline in other cognitive functions.

Acoustic backscatter and effective scatterer size estimates using a 2D CMUT transducer.

Compared to conventional piezoelectric transducers, new capacitive microfabricated ultrasonic transducer (CMUT) technology is expected to offer a broader bandwidth, higher resolution and advanced 3D/4D imaging inherent in a 2D array. For ultrasound scatterer size imaging, a broader frequency range provides more information on frequency-dependent backscatter, and therefore, generally more accurate size estimates. Elevational compounding, which can significantly reduce the large statistical fluctuations associated with parametric imaging, becomes readily available with a 2D array. In this work, we show phantom and in vivo breast tumor scatterer size image results using a prototype 2D CMUT transducer (9 MHz center frequency) attached to a clinical scanner. A uniform phantom with two 1 cm diameter spherical inclusions of slightly smaller scatterer size was submerged in oil and scanned by both the 2D CMUT and a conventional piezoelectric linear array transducer. The attenuation and scatterer sizes of the sample were estimated using a reference phantom method. RF correlation analysis was performed using the data acquired by both transducers. The 2D CMUT results indicate that at a 2 cm depth (near the transmit focus for both transducers) the correlation coefficient reduced to less than 1/e for 0.2 mm lateral or 0.25 mm elevational separation between acoustic scanlines. For the conventional array this level of decorrelation requires a 0.3 mm lateral or 0.75 mm elevational translation. Angular and/or elevational compounding is used to reduce the variance of scatterer size estimates. The 2D array transducer acquired RF signals from 140 planes over a 2.8 cm elevational direction. If no elevational compounding is used, the fractional standard deviation of the size estimates is about 12% of the mean size estimate for both the spherical inclusion and the background. Elevational compounding of 11 adjacent planes reduces it to 7% for both media. Using an experimentally estimated attenuation of 0.6 dB cm(-1) MHz(-1), scatterer size estimates for an in vivo breast tumor also demonstrate improvements using elevational compounding with data from the 2D CMUT transducer.

Estimation of ultrasound attenuation from broadband echo-signals using bandpass filtering.

A problem with video signal analysis for estimating frequency-dependent ultrasonic attenuation is that relative echogenicity versus depth curves are distorted when broadband pulses are used. In this correspondence, we present results that demonstrate improved accuracy of attenuation estimates computed from B-mode or envelope data derived after narrowband (1 MHz BW) filtering at different frequencies around the center frequency of the broadband echo signal. Based on the premise that transducer center frequencies are selected in part on penetration or imaging depth requirements, simulation and experimental results for a typical ultrasound imaging system show that narrowband video signal analysis for frequencies lower than or at the center frequency of the broadband pulse provide unbiased attenuation estimation over this depth. Filtered signals above the center frequency of the pulse yield accurate results only at shallow depths.

Polylactic acid/chitosan films for packaging of Indian white prawn (Fenneropenaeus indicus).

Composite films were developed by embedding nanochitosan (0.5%, 1% and 2%) in a polylactic acid (PLA) matrix using polyethylene glycol as a cross linking agent and polyvinyl alcohol as plasticizer. The mixture was casted into films via solvent casting. The interaction between the polylactic acid/nanochitosan (PLA/NCS) and polyethylene glycol had a significant effect on the tensile strength and the heat sealing properties. Antimicrobial properties of PLA/NCS films have been confirmed against aerobic microorganisms. PLA/NCS solvent casted films were used to pack prawn meat (Fenneropeneaus indicus) which was further stored in chilled condition for 18 days. The study proved that microbial and biochemical quality indices of prawn samples packed in different PLA/NCS film were retained and concluded that PLA/NCS composite films can be used for packing of fresh prawn to increase its shelf life.

Risk Factors for Post-operative Complications in Primary Oral Cancer Surgery-a Prospective Study.

The surgical treatment of oral cavity cancers can be influenced by post-operative complications. Identification of risk factors based on clinical characteristics may assist in therapeutic planning and thereby helps in reducing complications. Here, an attempt is made to identify the factors associated with post-operative complications (complications developing within 1 month of surgery) in patients undergoing primary oral cancer surgery. Six hundred seventy-six consecutive patients who underwent primary surgery for oral cancer from December 2007 to May 2010 were prospectively evaluated. The risk factors that predict for post-operative complications were analyzed. There was one mortality and 15% (103 patients) had post-operative complications. The complications included metabolic complications, primary site problems, donor site problems, and systemic complications. Fifteen factors were found statistically significant for the development of post-operative complications by univariate analysis. On multivariate analysis, three of the 15 factors, i.e., presence of COPD, full thickness wide excision, and increased duration of surgery were found to be independently associated with the development of post-operative complications. Presence of COPD, full thickness wide excision, and increased duration of surgery were identified as independent risk factors for post-operative complications in primary oral cancer surgery. The development of complications invariably resulted in increased hospital stay. Hence, the prompt recognition of risk factors for complications based on pre-operative clinical characteristics plus the identification of the risks associated with the surgical procedure can help in determining the appropriate therapeutic planning to prevent complications and in achieving cost effectiveness.

Non-invasive ultrasound-based temperature imaging for monitoring radiofrequency heating-phantom results.

Minimally invasive therapies (such as radiofrequency ablation) are becoming more commonly used in the United States for the treatment of hepatocellular carcinomas and liver metastases. Unfortunately, these procedures suffer from high recurrence rates of hepatocellular carcinoma ( approximately 34-55%) or metastases following ablation therapy. The ability to perform real-time temperature imaging while a patient is undergoing radiofrequency ablation could provide a significant reduction in these recurrence rates. In this paper, we demonstrate the feasibility of ultrasound-based temperature imaging on a tissue-mimicking phantom undergoing radiofrequency heating. Ultrasound echo signals undergo time shifts with increasing temperature, which are tracked using 2D correlation-based speckle tracking methods. Time shifts or displacements in the echo signal are accumulated, and the gradient of these time shifts are related to changes in the temperature of the tissue-mimicking phantom material using a calibration curve generated from experimental data. A tissue-mimicking phantom was developed that can undergo repeated radiofrequency heating procedures. Both sound speed and thermal expansion changes of the tissue-mimicking material were measured experimentally and utilized to generate the calibration curve relating temperature to the displacement gradient. Temperature maps were obtained, and specific regions-of-interest on the temperature maps were compared to invasive temperatures obtained using fiber-optic temperature probes at the same location. Temperature elevation during a radiofrequency ablation procedure on the phantom was successfully tracked to within +/-0.5 degrees C.

Normal and shear strain estimation using beam steering on linear-array transducers.

In current ultrasound elastography, only the axial component of the displacement vector is estimated and used to produce strain images. A method was recently proposed by our group to estimate both the axial and lateral components of a displacement vector following a uniaxial compression. Previous work evaluated the technique using both simulations and a mechanically translated phased array transducer. In this paper, we present initial results using beam steering on a linear array transducer attached to a commercial scanner to acquire echo signals for estimating 2-D displacement vectors. Single-inclusion and anthropomorphic breast phantoms with different boundary properties between the inclusion and background material are imaged by acquiring echo data along beam lines ranging from -15 degrees to 15 degrees relative to the compression direction. 1-D cross-correlation is used to calculate "angular displacements" in each acquisition direction, yielding axial and lateral components of the displacement vector. Strain tensor components are estimated from these displacements. Features on shear strain images generated for the inclusion phantom agree with those predicted using FEA analysis. Experimental results demonstrate the utility of this technique on clinical scanners. Shear strain tensors obtained using this method may provide useful information for the differentiation of benign from malignant tumors. For the linear array transducer used in this study, the optimum angular increment is around 3 degrees. However, more work is required for the selection of an appropriate value for the maximum beam angle for optimal performance of this technique.

UV protective poly(lactic acid)/rosin films for sustainable packaging.

Recently, biopolymer based plastic materials are regarded as potential alternative for conventional plastics of fossil fuel origin in order to compensate depleting petroleum resources and address environmental pollution issues. Poly(lactic acid) (PLA) is one among the biopolymers which is rapidly commercialized for food packaging application. However, the demerits accompanied with PLA like brittle nature, slower crystallization rate, poor gas barrier and high ultraviolet radiation transmission properties confines its commercial application in food packaging sector. Studies on the improvement of ductility, crystallization rate and gas barrier properties are markedly reported. Much emphasis is not given in the literature on improving UV shielding properties which plays important role in preventing oxidation degradation of PLA. Therefore, the current work is focused on fabrication of eco-friendly poly(lactic acid)/rosin (RS) based biocomposite films with improved UV shielding along with ductility and oxygen barrier properties. The PLA-RS biocomposite films containing different loadings (1, 3, 5, 10 and 20wt%) of RS with an average thickness of 50µm are fabricated via solution casting technique. The PLA-RS film demonstrated noteworthy light barrier feature by shielding the passage of ∼98%, 92% and 53% in UV-B, UV-A and visible light regime, respectively. In case of UV-C region, complete blockage of UV transmission through the PLA-RS biocomposite film is noticed. In addition to this, the presence of RS in the PLA matrix brought considerable improvement in terms of ductility and oxygen barrier characteristics. This in turn indicates PLA-RS biocomposite films hold significant potential for sustainable food packaging application.

Assessment of Iron Deposition in the Brain in Frontotemporal Dementia and Its Correlation with Behavioral Traits.

BACKGROUND AND PURPOSE: Brain iron deposition has been implicated as a major culprit in the pathophysiology of neurodegeneration. However, the quantitative assessment of iron in behavioral variant frontotemporal dementia and primary progressive aphasia brains has not been performed, to our knowledge. The aim of our study was to investigate the characteristic iron levels in the frontotemporal dementia subtypes using susceptibility-weighted imaging and report its association with behavioral profiles. MATERIALS AND METHODS: This prospective study included 46 patients with frontotemporal dementia (34 with behavioral variant frontotemporal dementia and 12 with primary progressive aphasia) and 34 age-matched healthy controls. We performed behavioral and neuropsychological assessment in all the subjects. The quantitative iron load was determined on SWI in the superior frontal gyrus and temporal pole, precentral gyrus, basal ganglia, anterior cingulate, frontal white matter, head and body of the hippocampus, red nucleus, substantia nigra, insula, and dentate nucleus. A linear regression analysis was performed to correlate iron content and behavioral scores in patients. RESULTS: The iron content of the bilateral superior frontal and temporal gyri, anterior cingulate, putamen, right hemispheric precentral gyrus, insula, hippocampus, and red nucleus was higher in patients with behavioral variant frontotemporal dementia than in controls. Patients with primary progressive aphasia had increased iron levels in the left superior temporal gyrus. In addition, right superior frontal gyrus iron deposition discriminated behavioral variant frontotemporal dementia from primary progressive aphasia. A strong positive association was found between apathy and iron content in the superior frontal gyrus and disinhibition and iron content in the putamen. CONCLUSIONS: Quantitative assessment of iron deposition with SWI may serve as a new biomarker in the diagnostic work-up of frontotemporal dementia and help distinguish frontotemporal dementia subtypes.