An economical synthesis of D- and L-pyrimidine arabino- and ribonucleosides

The one-step synthesis of several β-D/L-arabino- and ribonucleosides was performed in good yields under reflux or microwave-assisted fusion method. A comparison of the two methods showed that better yields were obtained using the reflux conditions.     

An economical mobile intensive care unit.

A mobile intensive care unit is an important extension of a regional intensive treatment service. The treatment and monitoring of critically ill patients can be maintained during transfer for specialist investigation or treatment. Such units can be brought into service with low construction and running costs.     

An economical method for cell-free protein synthesis using glucose and nucleoside monophosphates

Cell-free protein synthesis reactions have not been seriously considered as a viable method for commercial protein production mainly because of high reagent costs and a lack of scalable technologies. Here we address the first issue by presenting a cell-free protein synthesis system with comparable protein yields that removes the most expensive substrates and lowers the cell-free reagent cost by over 75% (excluding extract, polymerase, and plasmid) while maintaining high energy levels. This system uses glucose as the energy source and nucleoside monophosphates (NMPs) in place of nucleoside triphosphates (NTPs) as the nucleotide source. High levels of nucleoside triphosphates are generated from the monophosphates within 20 min, and the subsequent energy charge is similar in reactions beginning with either NTPs or NMPs. Furthermore, significant levels (>0.2 mM) of all NTPs are still available at the end of a 3-h incubation, and the total nucleotide pool is stable throughout the reaction. The glucose/NMP reaction was scaled up to milliliter scale using a thin film approach. Significant yields of active protein were observed for two proteins of vastly different size: chloramphenicol acetyl transferase (CAT, 25 kDa) and beta-galactosidase (472 kDa). The glucose/NMP cell-free reaction system dramatically reduces reagent costs while supplying high protein yields.     

An economical wireless cavity-nest viewer

ABSTRACT.   Inspection of cavity nests and nest boxes is often required during studies of cavity-nesting birds, and fiberscopes and pole-mounted video cameras are sometimes used for such inspection. However, the cost of these systems may be prohibitive for some potential users. We describe a user-built, wireless cavity viewer that can be used to access cavities as high as 15 m and with entrance diameters as small as 2.5 cm. System components include a wireless camera, boom with near-infrared lighting system, hand-held television, and telescoping pole. The unit can be assembled in about one day with commonly available tools, and the total cost was about $850 (US). Our cavity-viewing system was used to monitor the nests of Western Bluebirds ( Sialia mexicana ) and proved to be reliable and effective. During two field seasons, we attempted to check the status of nests 928 times and were able to determine the nesting stage 901 times (97%). For those willing to assemble their own units, our cavity viewer permits safe, direct examination of cavity nests or open nests for investigators with limited budgets.     

An economical 20 litre bench-top fermenter

We describe an economical 20 litre bench-top fermenter suitable for production of recombinant antibody fragments in bacterial expression systems. The bacterial culture contained within a polycarbonate carboy is mixed (400-600 rpm) and aerated (1 vessel vol./min) by a high-shear radial flow impeller mounted on a hollow stainless steel shaft, through which pressurised air is pumped. Air is dispersed as fine bubbles into the culture medium by the turbine impeller, without the need for a porous sparger. A stainless steel baffle stabilised by a gliding counterweight increases mixing. The components can easily be disassembled for cleaning and sterilisation. Temperature (range 20-37 degrees C) and pH (range 7.0-7.5) are controlled manually. Using the apparatus, it proved possible to achieve Escherichia coli cell culture densities equivalent to an optical density at 600 nm (OD(600)) of 30-32, compared with OD(600) 4-6 in shake flasks. A yield of 40 mg/litre/day of a recombinant antibody fragment was obtained with the fermenter, which was 15-fold more than the yield of 2.5mg/litre/day achieved in shake flasks. The fermenter may be particularly suited for research purposes.     

An economical minichamber for immunohistochemical incubation

A simple and economical "slide-minichamber" method for incubating tissue sections with antisera in immunohistochemical (peroxidase-antiperoxidase) staining procedures is described. The technique requires only materials routinely used in the laboratory. The method permits prolonged incubation of tissue sections with antiserum at 4 degrees C or at room temperature, use of small quantities of antiserum, and simultaneous incubation of two tissue sections with the same small quantity of antiserum, thereby allowing use of very dilute antisera and conservation of antisera when availability is limited.     

An economical system for liquid scintillation counting

Small glass shell vials (12 × 35 mm minivials), containing 2.0 ml of a dioxane-based scintillation solution plus a ¹⁴C-labeled sample, were placed in a conventional glass, 20-ml count vial and assayed in a scintillation spectrometer. Statistical comparison of counts recorded from ¹⁴C samples prepared both in the minivial system and conventional 20-ml count vials indicated that the two systems were equivalent with sample volumes of 10 and 100 μliters (1600-cpm solution) and 10 μliters (60-cpm solution). Conventional 20-ml glass or plastic count vials were both acceptable as containers for the minivials.There were no significant differences in the counts from samples in minivials placed on-center and off-center in the container vial. Cost per sample was reduced from 24.8 cents (conventional glass vials) to 4.7 cents (minivial system).     

An economical and highly productive cell-free protein synthesis system utilizing fructose-1,6-bisphosphate as an energy source

In this study, we describe the development of a cost effective and highly productive cell-free protein synthesis system derived from Escherichia coli. Through the use of an optimal energy source and cell extract, approximately 1.3 mg/mL of protein was generated from a single batch reaction at greatly reduced reagent costs. Compared to previously reported systems, the described method yields approximately 14-fold higher productivity per unit reagent cost making this cell-free synthesis technique a promising alternative for more efficient protein production.     

The novel economical synthesis and antimicrobial activity of a trithiocarbonate derivative

The compound diethyl 2,2′-(thiocarbonyl-bis(sulfanediyl))-diacetate 4 belongs to the trithiocarbonate class containing a trithiocarbonate function group flanked by ethyl acetate. In this procedure, a novel economic synthesis route to obtain compound 4 is described. This compound proved to possess broad-spectrum antimicrobial activity both in vitro and in vivo, and could be used as a lead compound. It is worth mentioning that this compound has been patented [No. US 9,988,348 B1; date of patent: June 5, 2018].     

An improved synthesis of tert-butyloxycarbonyl-L-histidine.

In our investigations on the effect of replacement of histidine by homohistidine (1) on the biological activity of some peptide-hormones, relatively large quantities of Boc-homohistidine were required. Homohistidine being difficult to synthesize, it was essential to find an effective way of introducing the Boc-group. In the past, many syntheses of Boc-histidine were reported (2-6), none of which proved to be quite satisfactory. However, by modifying the procedure of Flouret et al. (6) a convenient method resulting in a high yield of Boc-histidine and Boc-homohistidine was found.     

Biscoumarin: new class of urease inhibitors; economical synthesis and activity

A variety of biscoumarins (1-21) with variable substituents at C-11 were synthesized with an improved method and evaluated as urease inhibitors. The synthesized compounds showed varying degree of urease inhibitory activity ranging from 15.06-91.35 microM. The size and electron donating or withdrawing effects of substituents influenced the activity, which lead to the urease inhibitors.     

An economical canopy model for use in urban climatology

A multi-layered canopy leaf energy budget model (CANOPY) has been developed for the purpose of systematically examining the building-vegetation cause and effect structure in urban landscapes. At great computer savings, this simple, parametric model compared favorably with a much more complex canopy model (SPAM). The economic operation of this model makes it possible to investigate the spatial diversity of canopy budget characteristics on a microclimatic, geographical scale.     

An economical bioreactor for evaluating biogas potential of particulate biomass

An economical bioreactor designed for evaluating the biogas potential of particulate biomass is described. The bioreactor uses a simple stirring apparatus, called the Bordeaux stirrer, to enable gas-tight mixing of fermentation cultures. The apparatus consists of a low-rpm motor connected to a bent steel stir rod, which is placed in a length of flexible plastic tubing inserted through a rubber stopper in a gas-tight manner. This stirrer is suitable for providing intermittent or continuous mixing in bench-scale anaerobic cultures containing particulate biomass. The reactor system may be operated as a batch-fed or semi-continuously fed digester. This communication documents the advantages of the stirring apparatus, describes the details of reactor fabrication and operation, and outlines the type of experimental work for which the bioreactor is suitable.     

Streamlining Escherichia coli S30 extract preparation for economical cell-free protein synthesis

Escherichia coli extracts activate cell-free protein synthesis systems by providing the catalysts for translation and other supporting reactions. Recent results suggest that high-density fermentations can be used to provide the source cells, but the subsequent cell extract preparation procedure requires multiple centrifugation and dialysis steps as well as an expensive runoff reaction. In the work reported here, the extract preparation protocol duration was reduced by nearly 50% by significantly shortening several steps. In addition, by optimizing the runoff incubation, overall reagent costs were reduced by 70%. Nonetheless, extracts produced from the shorter, less expensive procedure were equally active. Crucial steps were further examined to indicate minimal ribosome loss during the standard 30,000g centrifugations. Furthermore, sucrose density centrifugation analysis indicated that although an incubation step significantly activates the extract, ribosome/polysome dissociation is not required. These insights suggest that consistent cell extract can be produced more quickly and with considerably less expense for large-scale cell-free protein production, especially when combined with high-density fermentation protocols.     

An economical device for carbon supplement in large-scale micro-algae production

One simple but efficient carbon-supplying device was designed and developed, and the correlative carbon-supplying technology was described. The absorbing characterization of this device was studied. The carbon-supplying system proved to be economical for large-scale cultivation of Spirulina sp. in an outdoor raceway pond, and the gaseous carbon dioxide absorptivity was enhanced above 78%, which could reduce the production cost greatly.     

TMEDA-derived biscationic amphiphiles: An economical preparation of potent antibacterial agents

Bis-alkylated derivatives of N,N,N′,N′-tetramethylethylenediamine (TMEDA) represent a well-known class of versatile biscationic amphiphiles, owing to their low cost and ease of preparation. Asymmetric TMEDA derivatives, however, have been studied significantly less, particularly in regards to their antimicrobial properties. We have thus prepared a series of 36 mono- and bis-alkylated TMEDA derivatives to evaluate their inhibition of bacterial growth. This series of compounds showed low micromolar activity against a panel of four bacteria. Optimal inhibition was observed when the biscationic amphiphiles possessed modest asymmetry and were composed of between 20 and 24 total carbon atoms in the side chains. These amphiphiles were prepared in a simple two-step procedure, utilizing inexpensive materials and atom-economical reactions, making them practical for further development.