Effect of ion beam irradiation on the corrosion behavior of the melt-spun ribbon Ti60Ni40

Potentiodynamic polarization studies were carried out on unirradiated and irradiated Ti₆₀Ni₄₀ specimens in 1 M HNO₃ aqueous medium at room temperature. The irradiation was carried out using N⁺ 150 keV ions at a fluence of 1 × 10¹⁶ ions/cm². Polarization results revealed that the irradiated specimen exhibits less corrosion current density as compared to the unirradiated Ti₆₀Ni₄₀ specimen. X-ray photoelectron spectroscopy (XPS) studies were also carried out on the irradiated and unirradiated specimens after corrosion test. It was observed that the absence of Ti³⁺ species in the oxide film of the irradiated specimen as compared to the unirradiated specimen results in the improvement of the corrosion resistance. Polarization results are also corroborated by weight loss data.     

Computerized classification of intraductal breast lesions using histopathological images

In the diagnosis of preinvasive breast cancer, some of the intraductal proliferations pose a special challenge. The continuum of intraductal breast lesions includes the usual ductal hyperplasia (UDH), atypical ductal hyperplasia (ADH), and ductal carcinoma in situ (DCIS). The current standard of care is to perform percutaneous needle biopsies for diagnosis of palpable and image-detected breast abnormalities. UDH is considered benign and patients diagnosed UDH undergo routine follow-up, whereas ADH and DCIS are considered actionable and patients diagnosed with these two subtypes get additional surgical procedures. About 250,000 new cases of intraductal breast lesions are diagnosed every year. A conservative estimate would suggest that at least 50% of these patients are needlessly undergoing unnecessary surgeries. Thus, improvement in the diagnostic reproducibility and accuracy is critically important for effective clinical management of these patients. In this study, a prototype system for automatically classifying breast microscopic tissues to distinguish between UDH and actionable subtypes (ADH and DCIS) is introduced. This system automatically evaluates digitized slides of tissues for certain cytological criteria and classifies the tissues based on the quantitative features derived from the images. The system is trained using a total of 327 regions of interest (ROIs) collected across 62 patient cases and tested with a sequestered set of 149 ROIs collected across 33 patient cases. An overall accuracy of 87.9% is achieved on the entire test data. The test accuracy of 84.6% is obtained with borderline cases (26 of the 33 test cases) only, when compared against the diagnostic accuracies of nine pathologists on the same set (81.2% average), indicates that the system is highly competitive with the expert pathologists as a stand-alone diagnostic tool and has a great potential in improving diagnostic accuracy and reproducibility when used as a "second reader" in conjunction with the pathologists.     

Parameter estimation,data compression and stochastic noise elimination in robotics: a wavelet domain-based integrated approach

Accurate parameter estimation in presence of stochastic noise is the essential part of almost all control hardware of the plants. However, the optimal design of the control hardware depends on processing power and installed memory. The proposed research investigation focuses on precise parameter estimation from compressed temporal data of error dynamics with exiguous susceptibility to the robot’s controllability. Instead of using Maximum Likelihood estimation (MLE) and Least Squares (LS) estimation in the time domain, the proposed method exploits the recursive wavelet domain’s properties to selectively store the error data coefficients negating the data related to noise. As a result, data compression is achieved. The proposed algorithm may be directly implemented on any scalable “Very Large Scale Integration” (VLSI) circuit due to the recursive implementation. For the evaluation of robustness, dynamic parameter variation is considered. The variation in scalar & vector-valued error is considered to evaluate the performance of the stochastic system. The proposed algorithm implementation is demonstrated experimentally on commercially available Omni Bundle robot.

     

Correlation between quantum charge fluctuations and magnetic ordering in multiferroic LuFe<Subscript>2</Subscript>O<Subscript>4</Subscript>

We examine the interplay between quantum charge fluctuations and magnetic ordering in multiferroic LuFe₂O₄ and show that this can couple spin and charge degrees of freedom in a LuFe₂O₄ bilayer below the Neel temperature T _N . Our analysis supports the idea that the double exchange mechanism normally used in metallic systems can be applied to charge-ordered insulators. This causes ferrimagnetic spin order to reduce the transfer integrals between Fe²⁺ and Fe³⁺ in LuFe₂O₄, decreasing charge fluctuations and increasing the polarization in this system below T _N . This work thus provides a more detailed understanding of the mechanism for spin-charge coupling in LuFe₂O₄.     

Combined blockade of HER2 and VEGF exerts greater growth inhibition of HER2-overexpressing gastric cancer xenografts than individual blockade

Gastric cancer overexpressing the human epidermal growth factor 2 (HER2) protein has a poor outcome, although a combination of chemotherapy and the anti-HER2 antibody trastuzumab has been approved for the treatment of advanced gastric cancer. Vascular endothelial growth factor (VEGF) expression in gastric cancer is correlated with recurrence and poor prognosis; however, the anti-VEGF antibody bevacizumab has shown limited efficacy against gastric cancer in clinical trials. In this study, we evaluated the antitumor effects of trastuzumab; VEGF-Trap binding to VEGF-A, VEGF-B and placental growth factor (PlGF); and a combination of trastuzumab and VEGF-Trap in a gastric cancer xenograft model. Although trastuzumab and VEGF-Trap each moderately inhibited tumor growth, the combination of these agents exerted greater inhibition compared with either agent alone. Immunohistochemical analyses indicated that the reduction in tumor growth was associated with decreased proliferation and increased apoptosis of tumor cells and decreased tumor vascular density. The combined treatment resulted in fewer proliferating tumor cells, more apoptotic cells and reduced tumor vascular density compared with treatment with trastuzumab or VEGF-Trap alone, indicating that trastuzumab and VEGF-Trap had additive inhibitory effects on the tumor growth and angiogenesis of the gastric cancer xenografts. These data suggest that trastuzumab in combination with VEGF-Trap may represent an effective approach to treating HER2-overexpressing gastric cancer.     

Low Cost Time Efficient Multi-tone Test Signal Generation Using OFDM Technique

In this paper, we present a new multi-tone test signal generation method with different frequency tones uniformly distributed across a wideband spectrum. It employs OFDM (orthogonal frequency-division multiplexing) spread spectrum technique to allow users to define signal parameters with a great flexibility as per the test requirements. This OFDM method essentially starts from the frequency sampling and then conversion to generate time domain signals, which can significantly reduce the number of data points in the signal generation. Response of such test signals from the device under test (DUT) can be captured and analyzed so as to characterize frequency response associated with each frequency tone. For validation, simulations with Matlab Simulink tool and hardware implementation on a Xilinx Virtex5 FPGA board are developed.     

Low Complexity On-Line Adaptation Techniques in Context of Assamese Spoken Query System

In this work, we present the development of an Assamese spoken query (SQ) system for accessing the price of agricultural commodities. The developed system intends to make the cultivators aware of the recent market trends. The SQ system enables the user to access the latest price of the commodity by calling the system using a landline/mobile phone. The spoken query input by the user is processed and then current price of the desired commodity in the given district is played back by the system. Features that make the system user friendly are incorporated into the design after taking feedbacks from local farmers. In other words, the system is tuned as per the needs of the users. Furthermore, the issues of adapting such query systems to the end user are also explored in this work. In case of the developed SQ system, the typical user responses are of extremely small duration (1–2 seconds due to isolated word response from the user). Moreover, the employed adaptation approach must keep the system latency low since these systems are meant for real-time applications. Consequently, adapting such systems to the end user becomes an extremely challenging task. In this regard, acoustic model interpolation based adaptation techniques are proposed that employ interpolation weights derived in an approximate fashion. The proposed approaches try to minimize the latency in the system response by avoiding the iterative weight estimation procedure used in the earlier reported works. Even with extremely small amount of adaptation data, the proposed approaches are found to result in a relative improvement of 12 % over the baseline ASR system.     

In situ bioconversion of compactin to pravastatin by Actinomadura species in fermentation broth of Penicillium citrinum

The biocatalytic production of pravastatin from compactin by hydroxylation has found many applications in health care and pharmaceuticals. Actinomadura macra, Actinomadura madurae, and Actinomadura livida can efficiently bioconvert compactin to pravastatin. The fermentation broth (Penicillium citrinum fermented media) harvested on the eighth day contained 388.90 mg L^?1 of compactin and an undetectable level of mycotoxin (citrinin). Bioconversion by A. macra was highest (87 %) in the yeast extract-amended medium. The anti-actinomadura effects of citrinin reduce the bioconversion capacity of Actinomadura. The in situ hydroxylation of compactin produced by P. citrinum represents a preferable alternative for the use of purified compactin, as a way to reduce cost and time processing.     

4-Mercaptophenylacetic acid functionalized Mn2+-doped ZnS nanoparticles fluorescence quenching caused by the addition of Cu2+

This paper reports that 4-mercaptophenylacetic acid functionalized Mn²⁺-doped ZnS nanoparticles (4-MPAA-ZnS-Mn²⁺ NPs) as fluorescent probes for the detection of copper ions in solution. The fluorescence quenching was due to the aggregation of copper ions with 4-MPAA-ZnS-Mn²⁺ NPs. These aggregations were confirmed by using UV lamp, UV–visible spectroscopy and dynamic light scattering (DLS). These 4-MPAA-ZnS-Mn²⁺ NPs were applied as fluorescent probes to detect copper ions in aqueous solution.