Fe3+-induced luminescence quenching in carbon dots - mechanism unveiled.

Carbon dot (CD)-based fluorimetric sensors have attracted immense attention for the detection of metal ions. Among the available works in this direction, more than 70% of the studies reported the detection of Fe3+ through luminescence quenching. Ferric ions are significant species from environmental and biological point of view. Excited-state electron transfer from carbon dots to ferric ions is suggested as the reason for the luminescence quenching. However, to date, no solid proof was provided to demonstrate this electron transfer process. Herein, N-doped blue luminescent carbon dots prepared via hydrothermal carbonization are used to demonstrate the exact mechanism operating in the above-mentioned detection strategy. The carbon dots possessed an average size of 4.9 nm, and exhibited good aqueous solubility as well as an excitation wavelength-dependent emission. Fe3+-mediated luminescence quenching was quantitatively achieved at the micromolar level, with a detection limit of 1.426 µM. The CD-mediated reduction of ferric ions is confirmed by spectral analysis. Fe3+-induced luminescence quenching was partially restored in the presence of ascorbic acid, enabling the sub-micromolar level monitoring of this analyte, with the lowest detection amount of 276 nM. Turnbull's blue method is adopted for confirming the reducing role of ascorbic acid, which eventually increased the luminescence of the system, evoking a turn-on response.

Investigation on thermochemical co-gasification of rice husk and groundnut shell in open core gasifier for the generation of producer gas: An optimization by central composite design.

Several energy-related strategies and scenarios have been suggested to address concerns about rising global temperatures. In addition to using renewable energy, the improvement in energy efficiency of conventional systems is also in focus. Policies are already in place in many countries, including India, to address the energy needs of rural and small-scale enterprises by gasifying locally available, diverse agricultural leftovers. Although rice husk and groundnut shell are two commonly used agricultural leftovers in the southern part of India, their appropriate blending must be studied to improve their conversion efficiency in co-gasification. Therefore, the primary objective of this research is to construct a statistical model utilizing response surface methodology (RSM) to analyze the thermochemical co-gasification of the aforementioned biomass materials. Since RSM can predict optimum performance with limited experimental data, this could contribute to the identification of the performance and operating parameters of an open-core gasifier. The model predicts that the mixture containing 20% rice husk and working at an ER of 0.25 and a reduction zone inlet temperature of 879.9 °C will be CO-23.53%, H2-13.97%, and CH4-3.56%. In addition, the lower heating value and gas yield can be as high as 6.17 MJ/Nm3 and 2.369 m3/kg, respectively. This outcome can contribute to the effective utilization of biomass for energy supply in rural areas. However, the economic parameters must be analyzed to implement the same in any region.

A waste to energy technology for Enrichment of biomethane generation: A review on operating parameters, types of biodigesters, solar assisted heating systems, socio economic benefits and challenges.

Anaerobic Digestion (AD) is one of the promising wastestoenergy (WtE) technologies that convert organic wastes to useful gaseous fuel (biogas). In this process methane is produced in the presence of methanogens (bacteria). The survival and activities of methanogens are based on several parameters such as pH, temperature, organic loading rate, types of biodigester. Moreover, these parameters influence the production of biogas in terms of yield and composition. Maintaining an appropriate temperaturefor AD is highly critical and energy intensive. This study reviews the various hybrid technologies assistedbio gas production schemes particularly from renewable energy sources. Also discuss the direct and indirect solar assisted bio-digester impacts and recommendation to improve its performance. In addition, the performance analysis Solar Photovoltaic (PV) and thermal collector assisted bio gas plants; besides their impact on the performance of anaerobic digesters. Since opportunities of solar energy are attractive, the effective utilization of the same is selected for the discussion. Besides, the various constraints that affect the yield and composition of biogas are also evaluated along with the current biogas technologies and the biodigesters. The environmental benefits, challenges and socio-economic factors are also discussed for the successful implementation of various technologies.

Dynamic heart rate estimation using principal component analysis.

In this paper, facial images from various video sequences are used to obtain a heart rate reading. In this study, a video camera is used to capture the facial images of eight subjects whose heart rates vary dynamically, between 81 and 153 BPM. Principal component analysis (PCA) is used to recover the blood volume pulses (BVP) which can be used for the heart rate estimation. An important consideration for accuracy of the dynamic heart rate estimation is to determine the shortest video duration that realizes it. This video duration is chosen when the six principal components (PC) are least correlated amongst them. When this is achieved, the first PC is used to obtain the heart rate. The results obtained from the proposed method are compared to the readings obtained from the Polar heart rate monitor. Experimental results show the proposed method is able to estimate the dynamic heart rate readings using less computational requirements when compared to the existing method. The mean absolute error and the standard deviation of the absolute errors between experimental readings and actual readings are 2.18 BPM and 1.71 BPM respectively.

Dynamic heart rate measurements from video sequences.

This paper shows how dynamic heart rate measurements that are typically obtained from sensors mounted near to the heart can also be obtained from video sequences. In this study, two experiments are carried out where a video camera captures the facial images of the seven subjects. The first experiment involves the measurement of subjects' increasing heart rates (79 to 150 beats per minute (BPM)) while cycling whereas the second involves falling heart beats (153 to 88 BPM). In this study, independent component analysis (ICA) is combined with mutual information to ensure accuracy is not compromised in the use of short video duration. While both experiments are going on measures of heartbeat using the Polar heart rate monitor is also taken to compare with the findings of the proposed method. Overall experimental results show the proposed method can be used to measure dynamic heart rates where the root mean square error (RMSE) and the correlation coefficient are 1.88 BPM and 0.99 respectively.

Fish venom (Pterios volitans) peptide reduces tumor burden and ameliorates oxidative stress in Ehrlich's ascites carcinoma xenografted mice.

The present study was carried out to assess the effect of Pterios volitans venom (mixture of peptides) on Ehrlich's ascites carcinoma (EAC) and its influence on antioxidant status in the liver. Among six groups of albino mice, three were treated with sublethal doses of venom, along with the standard drug, 5-fluorouracil. In EAC-bearing mice, mean life span and antioxidants were significantly decreased, whereas, body weight, tumor volume, viable tumor cell count, lipid peroxidation and expression of proliferating cell nuclear antigen were significantly increased. These changes were brought back to near normal in treatment groups. The findings are further confirmed by histopathological observations.

Coronary angiography and angioplasty using the aberrant radial artery as an access site.

OBJECTIVE: To study the suitability of the aberrant radial artery (ARA) as an access site for coronary angiography and angioplasty. BACKGROUND: In certain situations, the radial artery operator finds that the right radial artery in its usual location is unsuitable for a transradial procedure (TRP). In such cases, the ARA should be considered as an alternate access site. METHODS: Between January 2002 and December 2004, all patients considered suitable for a TRP with a clinically absent radial artery, or a small radial artery and a palpable ARA, underwent a TRP using this vessel as an access site. We describe the technical aspects and the differences that this approach entails, in comparison to the standard radial artery approach to TRPs. RESULTS: Of the 3,610 patients considered suitable for a TRP, 22 patients underwent 29 procedures using the ARA as an access site [22 angiograms and 7 percutaneous transluminal coronary angioplasty procedures (PTCAs)]. The median age of the patients was 55 years, with 19 males and 3 females. All procedures using the aberrant radial artery were successful. None of the patients developed spasm or an access site complication. The mean fluoroscopy time for angiography in the right radial artery group was 4.6 minutes, and 4.8 minutes for the ARA group. The procedure timed were 24 minutes and 32 minutes, respectively. CONCLUSION: The aberrant radial artery can be used as a safe alternate access site for coronary angiography and angioplasty when the right radial artery at the usual site is not suitable.

Variable selection using genetic algorithm for analysis of near-infrared spectral data using partial least squares.

Genetic algorithm is used to perform variable selection to determine the ranges of wavelengths in NIR spectral data suitable to be used as predictors in multivariate calibration model via partial least squares. The NIR spectral data consists of three components of active substances, namely human serum albumin (HSA), γ-globulin and glucose. The wavelength selection is able to improve the calibration model by selecting the wavelengths that contains information or correlated with the concentration of substances, while others non-chosen wavelengths, which contribute no information or contain noises, are excluded from the calibration model.

Novel drug amooranin induces apoptosis through caspase activity in human breast carcinoma cell lines.

Amooranin (AMR) is a triterpene acid isolated from the stem bark of a tropical tree (Amoora rohituka) grown wild in India. A. rohituka stem bark is one of the components of a medicinal preparation used in the Indian Ayurvedic system of medicine for the treatment of human malignancies. We investigated the mechanism of cell death associated with AMR cytotoxicity in human mammary carcinoma MCF-7, multidrug resistant breast carcinoma MCF-7/TH and breast epithelial MCF-10A cell lines. AMR IC50 values ranged between 3.8-6.9 microg/ml among MCF-7, MCF-7/TH and MCF-10A cells. AMR induced oligonucleosome-sized DNA ladder formation characteristic of apoptosis when tumor cells were treated with 1-8 microg/ml AMR for 48 h. In situ cell death detection assay indicated that AMR caused 37.3-72.1% apoptotic cells in MCF-7, 32-48.7% in MCF-7/TH and 0-37.1% in MCF- 10A cells at 1-8 microg/ml concentrations. The induction of apoptosis in AMR treated cells was accompanied by the elevation of total caspase and caspase-8 activities. Flow cytometric analysis showed that AMR induced caspase-8 activation in 40.8-71% MCF-7, 28.5-43.2% MCF-7/TH and 4-32.8% MCF-10A cells at 1-8 microg/ml concentrations. Our results suggest that AMR is a novel drug having potential for clinical development against human malignancies.

VEP optimal channel selection using genetic algorithm for neural network classification of alcoholics.

In this letter, neural networks (NNs) classify alcoholics and nonalcoholics using features extracted from visual evoked potential (VEP). A genetic algorithm (GA) is used to select the minimum number of channels that maximize classification performance. GA population fitness is evaluated using fuzzy ARTMAP (FA) NN, instead of the widely used multilayer perceptron (MLP). MLP, despite its effective classification, requires long training time (on the order of 10(3) times compared to FA). This causes it to be unsuitable to be used with GA, especially for on-line training. It is shown empirically that the optimal channel configuration selected by the proposed method is unbiased, i.e., it is optimal not only for FA but also for MLP classification. Therefore, it is proposed that for future experiments, these optimal channels could be considered for applications that involve classification of alcoholics.

Hyperfractionation in advanced carcinoma of the uterine cervix: a preliminary report.

Experience with twice-a-day radiation therapy program for carcinoma of the uterine cervix (FIGO Stages IIB, IIIA & IIIB) is presented. The program consists of delivering 120 cGy per fraction, two fractions a day with 6 hours between fractions. A total of 6000 cGy was delivered in 50 fractions over 5 weeks. A control group was given conventional fractionation 5000 cGy in 25 fractions, 200 cGy per fraction over 5 weeks. This feasibility study enrolled 30 patients, 15 in each group. Normal tissue reactions in skin, mucosa and bowel were recorded. The acute normal tissue reactions were enhanced in the hyperfractionation group. This was significant with regard to the bowel complications. The tumor control rate did not show any significant difference between the two groups. A short follow-up period has revealed complete healing of all acute normal tissue reactions. This study shows that further dose escalation is feasible and a study with large sample size and longer follow-up is required to reach definite conclusions.

Responses of pre-implantation mouse embryos to thalidomide exposure in utero.

PIP: On Day 1 of pregnancy, a thalidomide suspension (.05 ml) in saline at concentrations of 5 and 10 mcg/ml was infused into the uterine horns via the cervical route of 2 1/2-3 month old Swiss albino mice. Another group was infused on Day 0 at the doses mentioned. Parallel experiments were conducted after intrauterine infusions of saline. Following infusion, the mice were sacrificed on Days 2, 3, and 4 of gestation. Zygote and 4- and 8-cell stages of embryogenesis were most sensitive to the teratogen in terms of the induction of morphological anomalies and cell death. Drug effect was also observed in the postmorula embryos as abnormalities of varying degrees. There was an overall increase in the incidence of mitotic cells.^ieng