A new approach to the medicinally-important natural product triptolide is significantly shorter than previous syntheses, highly convergent and avoids the use of protecting groups; key features include two Diels-Alder reactions and a new deoxygenative aromatisation process.

The amphiphilic graft copolymer using chitosan (CS) as hydrophilic segment and poly (L-lactic acid) (PLLA) as hydrophobic segment, was prepared through a protection-graft-de protection route. Chitosan is a polysaccharide comprising of copolymers of glucosamine and N-acetyl glucosamine. Chitosan is the deacetylated derivative of chitin, which is one of the most abundant natural polysaccharides c...

The study was conducted to measure bird species diversity at Taunsa Barrage Wildlife Sanctuary from 2009 to 2011. The objective of the study was to identify avian diversity and main threats to them in the sanctuary. Data were collected by direct census method. In total, 58,598 bird species belonging to 53 families and 171 species were recorded. Density of the birds was 6.9 birds per hectare. Sh...

The present review synthesizes lines of emerging evidence showing how several samples of children populations living in large cities around the world suffer to some degree neural, behavioral and cognitive changes associated with air pollution exposure. The breakdown of natural barriers warding against the entry of toxic particles, including the nasal, gut and lung epithelial barriers, as well a...

A/Goose/Guangdong/1/96-like H5N1 influenza viruses now circulating in southeastern China differ genetically from the H5N1 viruses transmitted to humans in 1997 but were their precursors. Here we show that the currently circulating H9N2 influenza viruses provide chickens with cross-reactive protective immunity against the currently circulating H5N1 influenza viruses and that this protective immu...

This paper describes the results of some experiments using a new approach to information access that combines techniques from natural language processing and knowledge representation with a penalty based technique for relevance estimation and passage retrieval. Unlike many attempts to combine natural language processing with information retrieval, these results show substantial benefit from usi...

In this paper, we consider the problem of machine reading task when the questions are in the form of keywords, rather than natural language. In recent years, researchers have achieved signi€cant success on machine reading comprehension tasks, such as S‹AD and TriviaQA. Œese datasets provide a natural language question sentence and a pre-selected passage, and the goal is to answer the question a...

The present study applies the model of American Meteorological Society-Environmental Protection Agency Regulatory Model (AERMOD) to investigate NO2 emissions from Besat thermal power plant, which is fuelled by natural gas to function. Results indicate that the simulated concentration of NO2 based on AERMOD, does not exceed NO2 concentration limit, set by the Iranian Ambient Air Quality Standard...

Information retrieval systems can attempt to answer the user’s query directly, by extracting an appropriate passage of text from a corpus and presenting it on the results page. However, sometimes the passage of text contains extraneous information, or multiple passages are needed to form an answer. In cases like these, some sort of answer distillation system could be useful, taking as input the...

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