Disposable Manner Research Articles

Disposable Attenuated Total Reflection-Infrared Crystals from Silicon Wafer: A Versatile Approach to Surface Infrared Spectroscopy

Attenuated total reflection-infrared (ATR-IR) spectroscopy is increasingly used to characterize solids and liquids as well as (catalytic) chemical conversion. Here we demonstrate that a piece of silicon wafer cut by a dicing machine or cleaved manually can be used as disposable internal reflection element (IRE) without the need for polishing and laborious edge preparation. Technical aspects, fundamental differences, and pros and cons of these novel disposable IREs and commercial IREs are discussed. The use of a crystal (the Si wafer) in a disposable manner enables simultaneous preparation and analysis of substrates and application of ATR spectroscopy in high temperature processes that may lead to irreversible interaction between the crystal and the substrate. As representative application examples, the disposable IREs were used to study high temperature thermal decomposition and chemical changes of polyvinyl alcohol (PVA) in a titania (TiO(2)) matrix and assemblies of 65-450 nm thick polystyrene (PS) films.

Engineering Natural Materials as Surface-Enhanced Raman Spectroscopy Substrates for In situ Molecular Sensing

Surface-enhanced Raman spectroscopy (SERS) is a powerful analytical tool. However, its applications for in situ detection of target molecules presented on diverse material surfaces have been hindered by difficulties in rapid fabricating SERS-active substrates on the surfaces of these materials through a simple, low-cost, and portable approach. Here, we demonstrate our attempt to address this issue by developing a facile and versatile method capable of in situ generating silver nanoparticle film (SNF) on the surfaces of both artificial and natural materials in a simple, cheap, practical, and disposable manner. Taking advantage of the high SERS enhancement ability of the prepared SNF, the proposed strategy can be used for in situ inspecting herbicide and pesticide residues on vegetables, as well as the abuse of antiseptic in aquaculture industry. Therefore, it opens new avenues for advancing the application prospects of SERS technique in the fields of food safety, drug security, as well as environment monitoring.

Growth, chemical composition and soil properties of Tipuana speciosa (Benth.) Kuntze seedlings irrigated with sewage effluent

This study was carried out at a greenhouse of Sabahia Horticulture Research Station, Alexandria, Egypt, to study the effect of sewage effluent on the growth and chemical composition of Tipuana speciosa (Benth.) Kuntze seedlings as well as on soil properties for three stages. The irrigation treatments were primary-treated wastewater and secondary-treated wastewater, in addition to tap water as control. Therefore, the treated wastewater was taken from oxidation ponds of New Borg El-Arab City. Results of these study revealed that the primary effluent treatment explored the highest significant values for vegetative growth and biomass, compared to the other treatments. In addition, the higher significant concentration and uptake of chemical composition in different plant parts were obtained from the primary effluent treatment during the three stages of irrigation. It was found that the concentration of heavy metals in either plant or soil was below as compared to the world-recommended levels. These findings suggested that the use of sewage effluent in irrigating T. speciosa seedlings grown in calcareous soil was beneficial for the improvement of soil properties and production of timber trees, and also important for the safe manner of disposal of wastewater.

Effect of fly ash on biochemical responses and DNA damage in earthworm, Dichogaster curgensis

Fly ash is receiving alarming attention due to its hazardous nature, widespread usage, and the manner of disposal; leading to environmental deterioration. We carried out bio-monitoring and risk assessment of fly ash in earthworms as a model system. Dichogaster curgensis were allowed to grow in presence or absence of fly ash (0–40%, w/w) for 1, 7, and 14 d. The biochemical markers viz. catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione S-transferase (GST), and malondialdehyde (MDA) level were measured. The comet and neutral red retention assays were performed on earthworm coelomocytes to assess genetic damages and lysosomal membrane stability. The results revealed increased activities of SOD, GPx, GST, and MDA level in a dose–response manner while GR activity was decreased with increasing concentrations of fly ash. No obvious trend was observed in the CAT activity and fly ash concentration. Lysosomal membrane destabilization was noted in the earthworms exposed to 5% and more fly ash concentration in a dose and time dependent manner. The comet assay demonstrated that the fly ash induced DNA damage and DNA–protein crosslinks in earthworm coelomocytes.

An Unusual Subtilisin-like Serine Protease Is Essential for Biogenesis of Quinohemoprotein Amine Dehydrogenase

Quinohemoprotein amine dehydrogenase (QHNDH), an αβγ heterotrimer present in the periplasm of several Gram-negative bacteria, catalyzes the oxidative deamination of various aliphatic amines such as n-butylamine for assimilation as carbon and energy sources. The γ subunit of mature QHNDH contains a protein-derived quinone cofactor, cysteine tryptophylquinone, and three intrapeptidyl thioether cross-links between Cys and Asp or Glu residues. In its cytoplasmic nascent form, the γ subunit has a 28-residue N-terminal leader peptide that is necessary for the production of active QHNDH but must be removed in the following maturation process. Here, we describe the role of a subtilisin-like serine protease encoded in the fifth ORF of the n-butylamine-utilizing operon of Paracoccus denitrificans (termed ORF5) in QHNDH biogenesis. ORF5 disruption caused bacterial cell growth inhibition in n-butylamine-containing medium and production of inactive QHNDH, in which the γ subunit retained the leader peptide. Supply of plasmid-encoded ORF5 restored the cell growth and production of active QHNDH, containing the correctly processed γ subunit. ORF5 expressed in Escherichia coli but not its catalytic triad mutant cleaved synthetic peptides surrogating for the γ subunit leader peptide, although extremely slowly. The cleaved leader peptide remained unstably bound to ORF5, most likely as an acyl enzyme intermediate attached to the active-site Ser residue. These results demonstrate that ORF5 is essential for QHNDH biogenesis, serving as a processing protease to cleave the γ subunit leader peptide nearly in a disposable manner.

Disposable thermo-pneumatic micropump for bio lab-on-a-chip application

We present a disposable thermo-pneumatic micropump with microscale check valves for easy incorporation in a fully integrated biochip. The microfluidic device is comprised of biocompatible materials: glass and polydimethylsiloxane (PDMS). The chip consists of a glass substrate and three PDMS layers. In the chip, a Cr/Au heater is fabricated by micromachining on a glass substrate, while the flow channel, pump chamber, and valves are made by replica molding using layers of PDMS. The glass-based heater chip and the PDMS-based micropump chip are assembled and clamped together to enable operation of the system, and then the components are separable such that the heater chip can be used repeatedly and the PDMS chip can be used in a disposable manner. The operation of the micropump was investigated experimentally, as well as through simulations using fluid dynamics software. Superior pumping performance was achieved when the duty ratio of the voltage applied to the heater was 33%.

Substrate Integrated Waveguide Cavity Resonators for Complex Permittivity Characterization of Materials

A novel planar substrate integrated waveguide cavity resonator technique for measurement of complex permittivity is described, which has applications for dielectric measurement systems in the pharmaceutical industry. The high-Q resonant structure is a modernization of well-known measurement cells where the dielectric constant is deduced by cavity perturbation from the shift in resonant frequency and the change in the Q factor. The method uses extremely small amounts of a broad range of materials for accurate characterization. The ease of fabrication, low cost, and potential for integration with many other components on the same substrate allows it to be used in a disposable manner.

A Simple and Low-Cost Measurement System for the Complex Permittivity Characterization of Materials

A microwave planar resonant sensor, its equivalent circuit, and the driving electronics for the measurement of the complex permittivity in compact areas of the material under test are presented. Compared to transmission or reflection sensors, the adoption of a scalar two-port measurement procedure reduces the cost of the system and improves its robustness. The measuring system requires only the calculation of two parameters, namely, the resonant frequency and the 3 dB bandwidth, thus achieving a substantial reduction of cost and computation time. Such a sensor can be adopted in moisture measurement systems, and its low cost is such as to allow its use even in a disposable manner.

Comparative Voltammetric Behavior of Indigo Carmine at Screen-Printed Carbon Electrodes

The redox activity of indigo carmine (IC) at two different commercial screen-printed carbon electrode strips (SPCE) was investigated in this work by different voltammetric techniques. Cyclic voltammograms of this molecule in 0.1 M HClO4 solutions show two well-defined diffusion-controlled signals, one reversible at a formal potential (E1/2) of −0.57 V vs. Pt pseudoreference electrode (−0.15 V vs. Ag), and a second anodic peak at a potential (Ep, a) of +0.13 V vs. Pt (+0.57 V vs. Ag). Both electrodes exhibit good analytical performance towards this analyte, if they were applied in a disposable manner. Their use in consecutive experiments offers substantial differences, since an oxidation wave due to adsorption of indigo carmine superimposed on the anodic peak of the redox pair at one of these SPCEs. In addition, this adsorption component appears to foul the electrode surface. This wave is greatly enhanced if the working electrode is previously activated by applying high positive potentials for a certain period of time. The other SPCE does not exhibit any fouling process, thus allowing the performance of several consecutive experiments with the same strip. With these electrodes, calibration plots were obtained by cyclic, differential pulse, square-wave and alternating current voltammetry. Wide linear ranges of more than two orders of magnitude and limits of the detection down to 10−7 M were achieved. Relative standard deviations of the peak current in a range of 0.9–7%, recorded in indigo carmine solutions of different concentrations, at one single electrode, give an estimation of the good precision of this data.

A review of the capital gains tax treatment of the disposal of existing trees by landholders

Summary This article provides a brief overview of the former and prevailing capital gains tax (CGT) treatment of the sale of timber harvested on freehold land. In particular the consequences of granting a profit à prendre will be discussed. The manner and timing of current disposal of pre-capital gains tax assets is critical to the tax implications for the taxpayer. The sale of trees (acquired pre-CGT) harvested by the landowner and disposed of will not attract CGT, whereas granting a profit à prendre to harvest the same timber may. Under current legislation the proportion of the original purchase price of post-CGT acquired land and trees that is attributable to the trees is included in the cost base of trees subsequently disposed of. This reduces the amount of any capital gains incurred upon the sale of the trees. Accordingly, an initial apportionment of the original purchase price between the land and standing timber may be well advised in order to avoid any future problems at the time of disposal.

The Treatment and Disposal of Wastewaters from Settlements and Tourist Resorts on the Mediterranean Coast–State of the Art Review

The Mediterranean Sea is in comparison to the Oceans a semi-enclosed sea and represents a concentration basin as the annual water mass brought in by rivers and rainfall is smaller than evaporation. Wastewaters from settlements and tourist resorts contribute comparatively little to the total pollution of the Mediterranean and thus cannot be considered as decisive sources of the waste matter in the sea. The harmful effect of wastewaters from settlements and tourist resorts is noticeable in special local conditions, especially in areas with a poor exchange of the sea water. The most frequent manner of wastewater disposal into the Mediterranean is through its coastal discharge without any previous treatment. In the reconstruction of the existing sewerage systems and in the construction of the new systems, marine outfalls with mechanical treatment as well as short outfalls with biological treatment are applied. In some cases land treatment is applied and wastewater is used for agricultural purposes. Although the sanitation of tne existing discharge and generally the control of the waste matter both require considerable financial means, all the Mediterranean countries are now making an effort to stop the further pollution of the coastal sea.

Solar Magnetic Fields and Convection: VII.A Review of the Primordial Field Theory

We review the primordial field theory of solar magnetic fields (Papers I–VI) whose three main features are, first, a permanent dipole-like magnetic field, second a mainly toroidal field formed by shearing and rolling into individual, helically twisted ropes as suggested by Babcock, and third a mechanism for reversing the toroidal field. The theory explains numerous observational effects where the dynamo theory fails.(i) An active region forms when a rope section emerges and expands layer by layer to form a rotating arch filament system and then spots. Only a rope model explains the radial inflow of magnetic elements to build up a spot, as well as the spiral structure and other features pointed out by Babcock. (ii) The model explains umbral and penumbral structures, the Wilson depression, Evershed flow, the sunspot energy deficit and the very slow loss of flux fragments by some sunspots. (iii) The model is then extended to background magnetic fields to show that surface magnetic fields are like the upppermost branches of a magnetic ‘tree’ whose trunk is a flux rope. This explains unipolar magnetic regions, ‘pepper and salt’, and ephemeral active regions. Tension in the submerged flux ropes accounts for the observed migrations of magnetic regions, active longitudes and magnetic longitudes. (iv) On a smaller scale spicules, mottles and other network elements are explained in terms of the tree structure. (v) The mechanism of reversal of the toroidal field system is explained and the manner of disposal of old toroidal fields. (vi) The basic error in the dynamo theory is discussed briefly. We point out that radical changes in dynamo theory have been suggested by Parker, but appear to have been ignored by others.

The Efficiency of Competition as an Allocator of Resources: II. External Economies of Consumption

Economists have long been aware of the interdependence of the consumption and the consumption plans of individuals. For the most part they have been interested in the implications of this interdependence for the theory of market behaviour rather than in its implications for welfare. The purpose of this article is to give a detailed diagrammatic treatment of the welfare implications of external economies and diseconomies of consumption. In particular, we shall discuss the fiscal measures which, in a competitive economy, would provide the incentives necessary to the attainment of an optimal allocation of resources.We shall distinguish from each other, and consider separately, three types of interdependence of consumption and consumption plans.(i) The consumption of a particular commodity X by a particular individual A may increase (decrease) the satisfactions of other individuals, that is, generate external economies (diseconomies).(ii) The consumption of a particular commodity X may change the satisfactions of other individuals independently of the identity of the consumer.(iii) The receipt of money income by a particular individual A may, independently of his manner of disposal of the income, change the satisfactions of other individuals.No doubt this classification is not exhaustive. Thus no place is found for various external repercussions of consumption which might be discussed in a dynamic model, that is, in a model permitting instability of preference maps. Even in static models a place could be found for types of interdependence not discussed here. Many of these excluded types, however, can be described as combinations of those already enumerated (for example, a particular act of consumption may lower the satisfaction of some, raise that of other individuals) and can be treated by the techniques to be developed for their analysis.

Effects of prolonged high dosage with ascorbic acid.

Results and ConclusionThe data for the 4 subjects were so concordant, they have been averaged together and treated as replicates. There is clearly no progressive change in either the serum or white cell level, tolerance curve, or urinary excretion (Table I). The averages obscure the fact that the individual tolerance curves differed a little in shape. However, the individual character of the curves remained essentially unchanged throughout. There seems, therefore, to be no reason to believe that the prolonged high dosage of ascorbic acid had any qualitative or quantitative effect on the manner of disposal of excess acid by the body. Furthermore, in these fourpersons, at least, no harmful effects whatever were observed during the 3 months with 1000 mg daily intake.

United States Merchant Marine Policy and Surplus Ships

IT is now five years since the conclusion of World War II and of the greatest shipbuilding program in history. It is nearly four years since the enactment of the Merchant Ship Sales Act of I946.' The American merchant marine now consists very largely of the war-built vessels. Of the privately owned, American flag, dry-cargo fleet on December 3I, I949, 654 ships, amounting to 6,873,700 deadweight tons, out of 727 ships of 7,367,i00 deadweight tons, had been built since I940.2 Of the vessels in the United States Maritime Commission Reserve Fleet anchorages on February 28, I950, 2,8i out of 2,229 were war-built.3 Clearly the manner of disposal of the great war-built fleet has been, and will continue to be, of great importance to the American shipping industry. Furthermore, both sold and unsold vessels are of great significance for the national defense. Hence it is worth while to examine the effects of American ship disposal policy (i) on development of the American merchant marine; (2) on national preparedness for defense; and (3) on world ocean traffic and foreign shipping. The origin of this problem lies in the very great shipbuilding achievement of World War II. Production reached a peak in I943, when I9,21iooo deadweight tons were delivered, a quantity in excess of all the tonnage delivered in the United States from I9I4 through I938 and equal to one-quarter of the 8o,6oo,ooo deadweight tons under all flags on September I) I939. The achievement may be summarized as in Table i.

Some Factors in the Defense Mechanism against Reinfection with Trypanosoma lewisi

Early in experimental studies on Trypanosoma lewisi it was discovered that rats having spontane ously recovered from an infection are refractory to reinfection (Kanthack, Durham and Blanford1). The immunity thus acquired lasts, with an occasional exception, for life of rat. The numerous immunological studies with T. lewisi have been chiefly centered on determining factors involved in recovery of rats from an initial infection (Taliaferro,2 Regendanz and Kikuth,3 and others). Our knowledge of defense mechanism against reinfection is at present meager and largely based on in vitro studies. Only a few observations have been made directly on parasite during course of reinfection. Laveran and Mesnil4 noted that when recovered or hyperimmunized rats are inoculated intraperitoneally with living T. lewisi parasites seldom appear in circulating blood. They be lieved that phagocytosis was chief mechanism involved in both active and passive immunity. Agglutination of parasites was observed by Laveran and Mesnil, but they did not consider it an important event in defense mechanism since parasites were apparently uninjured by reaction. Recent workers have generally failed to observe typical phagocytosis of trypanosomes. Taliaferro5 has noted trypanosomes attached to leucocytes under conditions similar to experiments of Laveran and Mesnil and when inactivated immuna rat serum was mixed with washed T. lewisi and washed guinea pig leucocytes. It would appear that, at present time, phagocytosis is not con sidered to be important or usual manner of destruction and disposal of T. lewisi in either initial infection or in reinfection. Taliaferro5 injected intravenously large quantities of washed adult trypanosomes into recovered rats? but otherwise normal?and also into recovered rats splenectomized during course of their initial infection. In first experiments, 27 rats were inoculated from 6 to 325 days after end of initial infection. There was no apparent correlation between length of time from recovery to second inoculation and duration of reinfec tion. No reproduction by parasites was noted in 8 rats whose reinfections lasted from 2 to 3 days. Dividing forms occurred in 6 rats whose reinfections lasted 2 to 13 days and, for others, trypano somes remained in blood too short a time to determine reproductive activity. In many of rats recovery was apparently rapid, since the parasites were swept from blood in 5 to 15 minutes. To what extent reproduction developed and whether a numerical increase of trypanosomes occurred is not stated. In splenectomized series, 10 rats were reinfected from 31 to 353 days after end of initial infection. The reinfec tions lasted from 1 to 40 days and in 2 rats slight variation of trypanosomes but no division was noted. It was concluded that, in most cases, trypanocidal antibody is so strong in recovered rats that it is largely effective before ablastin (repro duction-inhibiting antibody) has time to play any particular r?le. The nature of trypanocidal antibody has not been determined, but according to Taliaferro,6 it is a lytic antibody which may act as an opsonin in vivo. In vivo studies, thus far, have failed to indicate specific character of this antibody. From a review of literature it would appear that in most attempts to establish reinfection experimental animal was injected intraperitoneally with a dilute suspension of infective blood. Since trypanosomes injected into peritoneal cavity must traverse one or more lymph nodes before they can enter blood stream, possibility was early considered that in spontaneous recovery lymph nodes might become sensitized and thus produc? an effective barrier against parasites entering circulation. In present study, experiments designed to gain information on this question clearly demon strated that trypanosomes pass without hindrance