SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Construction

172

Lentiviral vectors (LVs) are powerful tools for transgene expression in vivo and in vitro. However, the construction of LVs is of low efficiency, due to the large sizes and lack of proper clone sites. Therefore, it is critical to develop efficient strategies for cloning LVs. Here, we reported a combinatorial strategy to efficiently construct LVs using EGFP, hPlk2 wild type (WT) and mutant genes as inserts. Firstly, site-directed mutagenesis (SDM) was performed to create BamH I site for the inserts; secondly, pWPI LV was dephosphorylated after BamH I digestion; finally, the amounts and ratios of the insert and vector DNA were optimized to increase monomeric ligation. Our results showed that the total percentage of positive clones was approximately 48%±7.6%. Using this method, almost all the vectors could be constructed through two or three minipreps. Therefore, our study provided an efficient method for constructing large-size vectors.

Concepts: Gene, Mutation, Viral vector, In vivo, In vitro, Cloning, Construction, Clone

165

Home fires account for 85% of fire deaths in the United States, the majority in 1- or 2-family homes lacking fire sprinklers. Since 1978, however, a grassroots movement has successfully promoted more than 360 local ordinances mandating sprinklers in all new residential construction, including 1- and 2-family homes. The homebuilding industry has responded by seeking state preemption of local authority, a strategy previously used by other industries concerned about protecting their profits. From 2009 through 2011, 13 states adopted laws eliminating or limiting local authority over residential fire sprinklers. This study of the residential sprinkler movement adds to our understanding of grassroots public health movements and provides additional evidence that preemption can have a negative impact on public health and safety. (Am J Public Health. Published online ahead of print August 15, 2013: e1-e8. doi:10.2105/AJPH.2013.301317).

Concepts: United States, U.S. state, Occupational safety and health, Massachusetts, American football, Construction, Local government, Fire sprinkler

42

Calcium silicate hydrate (C-S-H) is the binder in concrete, the most used synthetic material in the world. The main weakness of concrete is the lack of elasticity and poor flexural strength considerably limiting its potential, making reinforcing steel constructions necessary. Although the properties of C-S-H could be significantly improved in organic hybrids, the full potential of this approach could not be reached because of the random C-S-H nanoplatelet structure. Taking inspiration from a sea urchin spine with highly ordered nanoparticles in the biomineral mesocrystal, we report a bioinspired route toward a C-S-H mesocrystal with highly aligned C-S-H nanoplatelets interspaced with a polymeric binder. A material with a bending strength similar to nacre is obtained, outperforming all C-S-H-based materials known to date. This strategy could greatly benefit future construction processes because fracture toughness and elasticity of brittle cementitious materials can be largely enhanced on the nanoscale.

Concepts: Materials science, Construction, Sea urchin, Concrete, Reinforced concrete, Rebar, Fireproofing, Prestressed concrete

28

The construction industry is one of the biggest and most active sectors of the European Union (EU), consuming more raw materials and energy than any other economic activity. Furthermore, construction waste is the commonest waste produced in the EU. Current EU legislation sets out to implement construction and demolition waste (CDW) prevention and recycling measures. However it lacks tools to accelerate the development of a sector as bound by tradition as the building industry. The main objective of the present study was to determine indicators to estimate the amount of CDW generated on site both globally and by waste stream. CDW generation was estimated for six specific sectors: new residential construction, new non-residential construction, residential demolition, non-residential demolition, residential refurbishment, and non-residential refurbishment. The data needed to develop the indicators was collected through an exhaustive survey of previous international studies. The indicators determined suggest that the average composition of waste generated on site is mostly concrete and ceramic materials. Specifically for new residential and new non-residential construction the production of concrete waste in buildings with a reinforced concrete structure lies between 17.8 and 32.9 kg m(-2) and between 18.3 and 40.1 kg m(-2), respectively. For the residential and non-residential demolition sectors the production of this waste stream in buildings with a reinforced concrete structure varies from 492 to 840 kg m(-2) and from 401 to 768 kg/m(-2), respectively. For the residential and non-residential refurbishment sectors the production of concrete waste in buildings lies between 18.9 and 45.9 kg/m(-2) and between 18.9 and 191.2 kg/m(-2), respectively.

Concepts: European Union, Construction, Building, Waste, Fire protection, Occupancy, Reinforced concrete, Demolition waste

27

A presentation of acoustical terminology and concepts that relate directly to the design and construction of an architectural space, non-technical explanations, descriptions, and examples. Architectural acoustics can be defined as the study and application of acoustic principles as they are applied to the inside of a building or structure. Usually, these are buildings that will be used for a live performance or the presentation of other useful information. This paper is written with the architect in mind; to help define and explain some of the most basic concepts relating to architectural acoustics. In today’s pro/commercial audio marketplace, architectural acoustics must play a significant role in the design process for any programmed meeting or entertainment space. This work puts essential terms and concepts into the hands of the architect, owner, or anyone else who would like to have a better understanding of this topic. Contents: What is Sound? Sound Propagation Three Acoustical Tools Where Does All the Unused Sound Go After it’s Been Heard? Audio Volume Changes-What Do the Numbers Mean? The Inverse Square Law Room Geometry-The Good, Bad, and Ugly Reverberation and Echo Speech Intelligibility Noise Internal vs External Noise Room Modes Variable Acoustics Psychoacoustics Conclusion.

Concepts: Acoustics, Sound, Sound pressure, Construction, Psychoacoustics, Architectural engineering, Architect, Inverse-square law

27

Falls from heights account for 64% of residential construction worker fatalities and 20% of missed work days. We hypothesized that worker safety would improve with foremen training in fall prevention and safety communication.

Concepts: Autumn, Project management, Occupational safety and health, Construction, Construction worker

27

The stereoselective total synthesis of garsubellin A is described. The total synthesis was achieved through the stereoselective construction of a bicyclo[3.3.1]nonane derivative via a three-step sequence: intramolecular cyclopropanation, formation of a germinal dimethyl group, and regioselective ring opening of cyclopropane. To complete the total synthesis of garsubellin A, chemo- and stereoselective hydrogenation to generate the C8 stereogenic center is followed by the formation of the fused tetrahydrofuran ring by a regioselective epoxide-opening reaction with C3 ketone, and finally cross metathesis to construct two prenyl groups.The Journal of Antibiotics advance online publication, 6 February 2013; doi:10.1038/ja.2012.125.

Concepts: Stereochemistry, Total synthesis, Mathematical analysis, Vector space, Alkane, Stereocenter, Construction, Cyclopropane

26

Early retirement is an increasing problem in the construction industry. There is limited information about causes leading employees to leave working life early. We have compared construction workers present situation with their perception of future demands at work to avoid early retirement.

Concepts: Cognition, Perception, Information, Employment, Project management, Construction, Bricklayer, Construction worker

24

Theranostic nanoplatforms with integrated diagnostic and therapeutic functions, aiming at imaging-guided therapy to improve treatment planning, as well as combination therapy to enhance treatment efficacy, have received tremendous attention in recent years. Among numerous types of functional nanomaterials explored in this field, protein-based nanocarriers with inherent biocompatibility have also been selected as building blocks to construct multifunctional theranostic platforms. In particular, albumin, which has been extensively used as drug-delivery carriers for decades, has shown great new promise in the construction of novel imaging and therapeutic nanoagents, as demonstrated by a number of recent studies. IHere, the motivations of using albumins to build up nanoscale theranostics are discussed, and the latest progress/future perspectives in this direction are summarized.

Concepts: Therapy, Albumin, Efficacy, Construction, Building, Fire protection, Theranostics, Computing platform

24

A photo-click reaction was used as an efficient method to construct two-photon fluorescent probes bearing two functional peptides for targeting and for protease cleavage respectively. The activatable two-photon probe constructed by this method was applied to two-photon imaging of caspase-3 both in cellular apoptosis and in tumor tissue.

Concepts: Cancer, Developmental biology, Apoptosis, Caspase 3, Construction, XIAP, Space probe, The Proteolysis Map