1,863 research outputs found
Optimization of Quercetin Extraction from Green Tea (Camellia sinensis) Using Central Composite Design, and the Pharmacological Activity of the Extract
The aim of this paper was to optimize an extraction procedure of quercetin from green tea using central composite design. Extraction time, ethanol concentration, and solid to liquid ratio were selected as the independent variables, while quercetin yield was defined as a response. The impact of factors and their interactions on the quercetin yield was studied based on the results of ANOVA test. The extraction time of 58.5 min, ethanol concentration of 94.7 % (v/v), and solid to liquid ratio of 1:19.4 (m/v) were found as the optimal conditions. The experimental confirmation of the proposed optimal conditions indicated that there was a good agreement between the experimental and predicted values. In addition to quercetin, the presence of 17 bioactive compounds was confirmed in the green tea extract using mass spectrometry method. Antioxidant, antimicrobial and antitumor activity of the optimal extract was determined using DPPH assay, disk diffusion method, and MTT assay, respectively
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High-resolution mapping of fluoroquinolones in TB rabbit lesions reveals specific distribution in immune cell types.
Understanding the distribution patterns of antibiotics at the site of infection is paramount to selecting adequate drug regimens and developing new antibiotics. Tuberculosis (TB) lung lesions are made of various immune cell types, some of which harbor persistent forms of the pathogen, Mycobacterium tuberculosis. By combining high resolution MALDI MSI with histology staining and quantitative image analysis in rabbits with active TB, we have mapped the distribution of a fluoroquinolone at high resolution, and identified the immune-pathological factors driving its heterogeneous penetration within TB lesions, in relation to where bacteria reside. We find that macrophage content, distance from lesion border and extent of necrosis drive the uneven fluoroquinolone penetration. Preferential uptake in macrophages and foamy macrophages, where persistent bacilli reside, compared to other immune cells present in TB granulomas, was recapitulated in vitro using primary human cells. A nonlinear modeling approach was developed to help predict the observed drug behavior in TB lesions. This work constitutes a methodological advance for the co-localization of drugs and infectious agents at high spatial resolution in diseased tissues, which can be applied to other diseases with complex immunopathology
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Results from a Phase 1 Study of Sodium Selenite in Combination with Palliative Radiation Therapy in Patients with Metastatic Cancer.
In preclinical studies, selenite had single agent activity and radiosensitized tumors in vivo. Here we report results from a Phase 1 trial in 15 patients with metastatic cancer treated with selenite (5.5 to 49.5 mg) orally as a single dose 2 hours before each radiation therapy (RT) treatment. Patients received RT regimens that were standard of care. The primary objective of the study was to assess the safety of this combination therapy. Secondary objectives included measurement of pharmacokinetics (PK) and evaluation of efficacy. Endpoints included assessment of PK, toxicity, tumor response, and pain before and after treatment. The half-life of selenite was 18.5 hours. There were no adverse events attributable to selenite until the 33 mg dose level, at which the primary toxicities were grade 1 GI side effects. One patient treated with 49.5 mg had grade 2 GI toxicity. Although this was not a DLT, it was felt that the highest acceptable dose in this patient population was 33 mg. Most patients had stabilization of disease within the RT fields, with some demonstrating objective evidence of tumor regression. Most patients had a marked improvement in pain and seven out of nine patients with prostate cancer had a decrease in PSA ranging from 11-78%. Doses up to 33 mg selenite were well tolerated in combination with RT. A randomized, well controlled study is needed at the 33 mg dose level to determine if selenite results in clinically meaningful improvements in the response to palliative RT
Comparison of three data-driven techniques in modelling the evapotranspiration process.
Evapotranspiration is one of the main components of the hydrological cycle as it accounts for more than two-thirds of the precipitation losses at the global scale. Reliable estimates of actual evapotranspiration are crucial for effective watershed modelling and water resource management, yet direct measurements of the evapotranspiration losses are difficult and expensive. This research explores the utility and effectiveness of data-driven techniques in modelling actual evapotranspiration measured by an eddy covariance system. The authors compare the Evolutionary Polynomial Regression (EPR) performance to Artificial Neural Networks (ANNs) and Genetic Programming (GP). Furthermore, this research investigates the effect of previous states (time lags) of the meteorological input variables on characterizing actual evapotranspiration. The models developed using the EPR, based on the two case studies at the Mildred Lake mine, AB, Canada provided comparable performance to the models of GP and ANNs. Moreover, the EPR provided simpler models than those developed by the other data-driven techniques, particularly in one of the case studies. The inclusion of the previous states of the input variables slightly enhanced the performance of the developed model, which in turn indicates the dynamic nature of the evapotranspiration process
Nexus assessment for water, food, and energy system and the implication on human development
This is the author accepted manuscriptWater, food, and energy are basic needs crucial to human survival but also pervade
many aspects of human development. Systemically, they are vastly interdependent.
In order to gain insight into the dynamics behaviour of water, food, and energy systems
and their interactions to human development, a system dynamics model has been
constructed. The model is structurally designed to generate behaviour of the system
of interest at a national level and on an annual basis. The model is generic but
purposely designed for Indonesia case, and hence it was subjected to behavioural test
against national historical data of Indonesia. Test results show that the simulated
behaviour of key elements of the model such as population size, income per capita,
life expectancy at birth, water demands, crops demands and productions, and energy
demands and productions, closely resemble behaviour of the actual data (i.e., pass
the set criteria of the behavioural test). Model experiment with two different scenarios
shows that our system model is sensitive to change in income per capita and energy
demand. As part of future work, we will use the model to assess the implications of a
range of policy scenarios on the
Water, food, energy nexus investigation for human development
This is the author accepted manuscriptWe are investigating the nexus among water, food, and energy systems and their
relationship(s) to human development. The aim is to gain a better understanding of the
interconnectedness among these sectors and human development in order to assess the potential
impacts and implications of a range of policy scenarios on the system. Considering the feedback
mechanism between elements in the system, we use system dynamics modelling and simulation
technique to represent system structure and capture the dynamics behavior of the system being
studied. Our system model comprises five modules, namely water, food, energy, human
development, and demographic. The model is purposely built to be implemented in Indonesia on
a national scale. The simulation is run on a yearly basis. The model is being built therefore we
present only preliminary results here. As part of the future work, once the model is fully
constructed, it will be applied to assess the impact of a range of policy scenarios and implications
on the water, food, and energy sectors and on human development in Indones
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