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This method originated due to the need to quickly and sensitively detect Avocado sunblotch viroid (ASBVd) in nursery and field trees in California. Optimum sampling protocols were developed for leaf collection from different sized trees based on size and branching as well as for fruit. An ethanol containing buffered extract from 1 g of ground leaf tissue was used as the source of RNA. The extract was absorbed onto small pieces (disks) of Whatman No. 1 filter paper which were then washed and dried. RNA was eluted from the filter paper using sterile water and used as a template in a standard single-tube RT-PCR reaction. The RNA adsorbed on the filter paper disks was quite stable, and the disks could be stored for over 1 year and shipped worldwide at ambient temperature with no noticeable decline in the quality or quantity of the resulting RT-PCR products. The filter paper capture method was expanded to the detection of other viroids including Potato spindle tuber viroid, Peach latent mosaic viroid, and Chrysanthemum stunt viroid and was tested with some viruses as well with minor modifications of the standard protocol.

The pulp and paper industry is one of the major consumers of water. Pulp and paper industrial wastewaters usually contain halogenated organic materials, because general use is made of chlorine-containing compounds as bleaching agents during pulp and paper manufacture. Kraft pulping is the most common commercial chemical delignification procedure. Chlorination is generally the first stage in kraft pulping and during this treatment phase, chlorinated organic compounds are produced. The chlorinated substances are extracted with dilute alkali from the pulp in the subsequent extraction phase. Chloro-organic compounds tend to persist in nature because of their inherent recalcitrance; they are often toxic to aquatic live; many are genotoxic and have the potential to migrate widely throughout the ecosystem, ultimately accumulating in the fatty tissues of organisms. Legislation has been introduced to limit the levels of these toxic compounds in effluents. Additionally, during bleaching treatments chromophoric, highly oxidized, polymeric lignin/chlorolignin derivatives are formed that give rise to a dark color in the effluent. The color poses an aesthetic problem and contributes to the biological oxygen demand. Several methods have been attempted for decolorization and detoxification of bleached kraft effluents. These include physicochemical and biotechnological methods. The problems underlying the physicochemical treatments are those associated with cost and reliability. Biotechnological methods have the potential to eliminate/ reduce the problems associated with physicochemical methods. This article reviews the research on the use of Biotechnological methods for treatment of pulp and paper mill effluents. The progress made and the further scope are also discussed.

The paper manufacturing process has several stages - Raw material preparation and handling, Pulp manufacturing, Pulp Washing and Screening, Chemical recovery, Bleaching, Stock Preparation, and Papermaking. Paper production is basically a two-step process in which a fibrous raw material is first converted into pulp, and then the pulp is converted into paper. The harvested wood is first processed so that the fibers are separated from the unusable fraction of the wood, the lignin. Pulp making can be done mechanically or chemically. The pulp is then bleached and further processed, depending on the type and grade of paper that is to be produced. In the paper factory, the pulp is dried and pressed to produce paper sheets. Post-use, an increasing fraction of paper and paper products is recycled. Nonrecycled paper is either landfilled or incinerated.

Dried blood spots (DBS) on paper as a sampling technique in newborn screening has been widely adopted by bioanalytical chemists for preclinical and clinical sample collection. DBS is based on the assumption that single size punch of DBS absorbs the same volume of blood regardless of physiological differences derived from test subject genders, disease states, nutrition, or hydration affecting blood viscosity, although it is well known that such differences have a fundamental impact on the quantitation accuracy of DBS as a sampling technique. There are multiple types of sampling media in either plain filter paper or chemically treated paper/cards available for DBS applications. Pretreated paper/cards contain chemicals such as denaturants, surfactants, and/or chelating agents to deactivate pathogens, enzymes and prevent the growth of biological organisms. In this chapter, the chemical constituents of various paper/cards are explored. The impact of paper/card type on analytical interference, evenness of DBS spots, and radial distribution of analyte are evaluated. The paper/card impact on the matrix effect was studied. It was found that the impregnated chemicals on the pretreated DBS paper/cards could be more than 50 % of the total paper/card weight. These water-soluble chemicals make the analyte distribution unpredictable across the dried blood spots and can interfere with LC-MS. Six compounds across a large Log D range were used to evaluate different types of paper/cards for understanding the impact of the sampling paper/cards on DBS quantitation accuracy. The results indicate that the impact is significant and an evaluation of sampling paper/card impact is necessary for most compounds.

Enhanced production and efficient utilization of lignocellulosic products are issues of critical importance to both industry and society. Benefits from the manufacture of mechanical wood pulp include high yield and low cost. During the past decade, mechanical pulping processes have been developed that can produce high-performance pulps at significantly lower capital and operating costs compared with kraft pulping. Although the production of mechanical pulp is environmentally benign, the use of mechanical pulps is restricted severely by their tendency to undergo color reversion (yellowing) upon exposure to daylight and/or long-term storage at ambient temperatures. This discoloration is cited as the principal reason for limited commercial applications of mechanical wood pulps in high-quality printing papers (Cockram, 1989; Ford and Sharman, 1996).

The manufacture of pulp and paper from wood is an important industry; worldwide annual production is about 125 million metric tons. Paper products are used for printing and writing, packaging, and a wide variety of special purposes (Nordman, 1989).

Column chromatography was used only occasionally until 1931, when it was found that cis- and trans-isomers of organic compounds could be separated by this technique. From 1931 until 1944 there was a rapid development in theory and applications, but no one really challenged the basic idea of using a column.

In paper coating, the pigment volume content of the coated layer is over critical pigment volume concentration (CPVC) and latex polymer used as main binder forms a discontinuous film. It is known that the coated layer has a porous structure. This feature of the coated layer has significant influence on printing performance parameters. In addition, printing is a dynamic process. Due to difficulty in measuring the dynamic mechanical properties of such a thin and composite layer, dynamic mechanical analysis of the coated layer has not been studied in the paper coating processes. Results based on DMTA studies indicate that three transitions of dynamic viscoelastic properties are observed in the coated layer. The first transition corresponds to polymer Tg and frequency dependent, while second and third transitions show independence on frequency and seem to be related to the packing state of the coated layer.The effect of these transitions related to the printability influenced by latex properties is discussed.

The purpose of this paper is to summarise the state of Coronavirus epitope research, with an emphasis laid on the most recent achievements, i.e. the correlation between antigenicity and polypeptide primary structure. The antigenic properties of coronaviruses reside mainly in their envelope glycoproteins: the S (spike) protein, a high molecular weight polypeptide which constitutes the petal-shaped peplomers and the M (membrane) protein, a smaller integral membrane polypeptide. Some coronaviruses possess an additional surface glycoprotein, the haemagglutinin-esterase (HE) protein.

Enveloped viruses carry in their membranes one or more surface glycoproteins. In coronaviruses three such proteins have been identified: a small integral membrane protein (M), a large glycoprotein constituting the characteristic viral spikes (S), and an intermediate-sized glycoprotein (HE). This paper will summarize published knowledge on the properties and function of the small and the intermediate-sized membrane proteins. They will be referred to as M and HE, respectively.

Hydrogels are water-swollen polymer networks. They are of great interest both medically and commerically. Conventional hydrogels change little in swelling with environmental conditions while stimuli-responsive hydrogels may swell or deswell sharply with relatively small changes of temperature or pH. A general review of the principles and applications of these interesting materials is presented here.

For coronaviruses, the glycoproteins have both historical and biological significance (1,2). Because some coronaviruses were difficult to isolate and propagate, their characteristic large, petal-shaped spikes first allowed coronaviruses to be identified as related agents in a common family. Viral glycoproteins play important roles throughout the life cycle of coronaviruses. Viral glycoproteins interact with receptors on the host cell membrane and are required for penetration of the viral genome into cells by fusion of the viral envelope with the plasma membrane or endosomal membranes. In virus-infected cells, Coronavirus glycoproteins may be glycosylated, acylated, oligomerized, cleaved into subunits by proteases, and transported to specific membrane compartments. The viral glycoproteins participate in assembly of virions, and the intracellular location of viral glycoproteins may determine the location of Coronavirus budding. Viral glycoproteins on the surface of infected cells may permit fusion with adjacent cells, and may make the cell susceptible to immune cytolysis or cell-mediated cytotoxicity, or permit hemadsorption. Epitopes of viral glycoproteins may be recognized by neutralizing, non-neutralizing or hemagglutination-inhibiting antibodies. Thus, elucidation of the structure and functions of Coronavirus glycoproteins is of central importance in understanding the replicative cycle and pathogenesis of coronaviruses.

In 1962 Caspar and Klug conjectured that self-assembly of equivalent or quasi-equivalent protein subunits and viral nucleic acid produces either icosahedral or helical structures according to the biological functions required (1). Some 15 years later Wengler introduced the terms “transcription helices” and “translation helices” to describe the relationship between helical ribonucleoprotein (RNP) structure and genome function for animal viruses containing single-stranded RNA (2). In transcription helices the RNA genome is transcribed into complementary nucleic acid, without permanent disassembly of the RNP. In translation helices the RNA is liberated from the RNP and translated into protein. To account for the fact that no examples of enveloped viruses containing translation helices had been described, Wengler speculated that “the forces exerted on the viral RNP during budding necessitate the design of a helical RNP of such high stability that RNA cannot be released for translation in vivo. Therefore, translation helices will not be present in viruses which obtain a viral membrane by budding”.

During the last decade recombinant DNA technology has been successfully applied to the development of ‘new’ vaccines. Although there are many examples of successful vaccines which have been developed using the ‘classical approach’ e.g. inactivated, attenuated and subunit vaccines, the demand for a new generation of vaccines is evident. The risk of the escape of a pathogen from a vaccine production facility, the difficulties associated with the production of viral subunits, the high mutation frequency observed in many RNA viruses and the possibility of genetic reassortment and recombination have stimulated researchers to explore new avenues of vaccine biotechnology.

Pulp and paper mill effluents are complex mixtures of dissolved lignin and cellulose degradation products and other substances extracted during the pulping process. The toxicity of these effluents to fish has been documented (Howard and Walden, 1971; Wande, 1976; Walden and Howard, 1977). A number of investigators have shown that effluents and process streams from pulp and paper mills are mutagenic in Salmonella (Ander et al., 1977; Eriksson et al., 1979; Douglas et al., 1980) and cause chromosome damage in mammalian cells (Douglas et al., 1980). Over 300 compounds have been identified in studies on various pulp and paper mill effluents (reviewed in CPAR, 1978). Because of the extensive use of chlorine in the bleaching process, many of these compounds contain chlorine substitutions. Since first chlorination-stage liquors are consistently among the most mutagenic by-products of the pulping process, it has been suggested that chlorinated substances are responsible for a major portion of the mutagenicity found (Bjorseth et al., 1979; Nestmann et al., 1979; Nestmann et al., 1980; McKague et al., 1981; Rapson et al., 1980).

Various types of simple separation on paper have been described as fore-runners of paper chromatography, among them a method of Runge in 1850, and the process called ‘capillary analysis’ (Goppelsroder, 1909). Such methods were really more like adsorption chromatography, and paper chromatography as it is now understood was a development of the partition system introduced by Martin and Synge in 1941 (see Chapter 2). One of the solids which can be used to support the stationary phase is cellulose powder (p. 38). Consden, Gordon and Martin[l] in 1944 separated the amino-acids and peptides in wool protein hydrolysates by a method in which the powder column was replaced by a sheet or strip of paper, freely suspended in a vapour-tight vessel.

Radioactive tracer techniques, coupled with chemical analysis by paper chromatography, became important in biochemical research in the late 1940’s, and today many investigations into intermediary and other aspects of metabolism rely on these methods. Soon after the marriage of chromatography to the use of tracers, various instruments were constructed which were able simultaneously to locate the positions of radioactive compounds on paper chromatograms and to determine the amount of radioactivity in each separated compound. Such devices are now available commercially in many different designs, and are intended for the scanning and counting of one-dimensional chromatograms only.

Assay of C14-labeled compounds isolated from metabolic experiments has been greatly aided by the high counting efficiency of liquid scintillation spectrometers and the ease of preparing samples for such assay. Difficulties arise, however, in liquid scintillation assay of (A) compounds isolated on paper chromatograms and (B) protein, because it is not easily soluble in most scintillation mixtures. The present report deals with improved methods for liquid scintillation assay of C14-compounds isolated by paper chromatography and of C14-labeled protein.

It is now common to analyze a concentration profile obtained by electrophoresis or gas chromatography using Gaussian distribution properties. The theory of chromatography [1] suggested that a similar type of analysis might also be valid for paper chromatography. The present study indicated the validity of this analytical method in the particular case of paper chromatography, provided that certain precautions are taken [2]. We propose here to point out its essential features.

Mass screening for congenital hypothyroidism in newborns has been developed because the irreversible mental retardation caused by this disorder can be prevented by early treatment. These programs include measurement of thyrotropin or total thyroxine (T4), or both, in dried blood samples. Measurement of total T4 is useful for detecting primary, secondary, and tertiary hypothyroidism, but gives false-positive results for subjects with abnormal concentrations of thyroxine-binding globulin (TBG), who do not need to be treated. Hence, we developed an enzyme immunoassay (EIA) and a radioimmunoassay (RIA) for measuring free T4 (FT4) in dried blood samples on filter paper.

Determining the type and amount of organophosphate pesticide residue in food products is a complex problem, and one which concerns both the companies which manufacture the pesticides and the Governmental agencies which enforce their proper use.

DNA methylation serves to mark DNA as either a directed epigenetic signaling modification or in response to DNA lesions. Methods for detecting DNA methylation have become increasingly more specific and sensitive over time. Conventional methods for detecting DNA methylation, ranging from paper chromatography to differential restriction enzyme digestion preference to dot blots, have more recently been supplemented by ultrahigh performance liquid chromatography coupled with mass spectrometry (UHPLC-MS/MS) to accurately quantify specific DNA methylation. Methylated DNA can also be sequenced by either methylated DNA immunoprecipitation followed by sequencing (MeDIP-seq) or single-molecule real-time sequencing (SMRTseq) for identifying genomic locations of DNA methylation. Here we describe a protocol for the detection and quantification of epigenetic signaling DNA methylation modifications including, N6-methyladenine (6mA), N4-methylcytosine (4mC) and C5-methylcytosine (5mC) in genomic DNA by triple quadrupole liquid chromatography coupled with tandem mass spectrometry (QQQ-LC-MS/MS). The high sensitivity of the UHPLC-MS/MS methodology and the use of calibration standards of pure nucleosides allow for the accurate quantification of DNA methylation.

A Strain of cellulose-decomposing bacterium 372–24D together with a saprophytic bacterium 372–24M were isolated from soil. On the basis of morphology, physiological properties and cellulolytic activity of these isolates, strain 372–24M was identified as Cellulomonas flavigena and strain 372–24M as Pseudomonas putida. They grew syntrophically in a liquid medium containing basal salts with paper pulp (73.3% cellulose) as sole carbon source. The cellulose was decomposed to the extent of 98% after 5-day culture. The cell protein yield was about 0,17 Kg per Kg of paper pulp used. The cell protein was rich in lysine, arginine, leucine and valine. After adjusting the pH of the culture broth to 10 and temperature to 60°C, one half of the cell RNAs could be degraded to mononucleotides by cell RNAase within 20 min. The products were isolated from the culture broth, purified and crystallized. They were identified at 5’-AMP, 5’-GMP, 5′-CMP and 5′-UMP. A complex process for the production of SCP and mononucleotides was developed.

In this study paper is modelled as a homogeneous structure where the cell wall layer of the fiber constitutes the main building unit. By this approach the macroscopic properties of paper are related to the properties of the constituent polymers cellulose and hemicelluloses. The effects of fiber orientation and the influence of moisture content on the elastic moduli and hygroexpansivity of paper is examined and compared to experimental data. It is advocated that the mechanical properties of paper are dependent on a mixture of transverse and longitudinal cell wall layer properties and not only on the proportion of fibers in any direction.

The sizing treatment of printing papers to make them resistant to penetration by liquids, for example, water or printing inks, also weakens the bond strength between the polymer and the paper in printing processes in which solid polymers create the image on plain, bond-type papers. The adhesion characteristics of a series of business papers treated with either rosin sizes or synthetic, cellulose-reactive sizing agents are described. It is demonstrated that the decrease in bond strength correlates with a decrease in paper wettability, as measured by capillary penetration of organic liquids of suitable surface tension, or as defined by surface energetics using the elution-gas-chromatography technique. Examples are presented, which show that these analytical techniques are effective in specifying paper performance in nonimpact printing technologies (for example, electrophotographic printing and resistive-ribbon, thermal-transfer imaging).

As the consequences of climate change become apparent, metabolic engineers and synthetic biologists are exploring sustainable sources for transportation fuels. The design and engineering of microorganisms to produce bio-gasoline and other biofuels from renewable feedstocks can significantly reduce dependence on fossil fuels as well as lower the emissions of greenhouse gases. A significant amount of research over the past two decades has led to the development of microbial strains for the production of advanced fuel compounds. Crucial to these efforts are robust methods to quantify the amount of the biofuel compound being produced as well as the other metabolites that might be present during fermentation. Here, we provide a protocol for the quantification of branched-chain alcohols, specifically isobutanol and isopropanol, using high-performance liquid chromatography (HPLC).

Bioreactors are manufactured apparatuses that allow the generation of a specific environment for the highly controlled cultivation of living cells. Originally used for microbial production systems, they have found widespread applications in fields as diverse as vaccine production, plant cell cultivation, and the growth of human brain organoids and exist in equally diverse designs (Chu and Robinson, Curr Opin Biotechnol 12(2):180-187, 2001; Qian et al., Nat Protoc 13:565-580, 2018). Manufacturing of biologics is currently mostly performed using a stirred tank bioreactor and CHO host cells and represents the most "classical" bioreactor production process. In this chapter, we will therefore use the cultivation of suspension Chinese hamster ovary (CHO) cells for recombinant protein production in a stirred tank bioreactor as an example. However, general guidelines provided in this chapter are transferable to different bioreactor types and host cells (Li et al., MAbs 2(5):466-479, 2010).The preparation and operation of a bioreactor (also referred to as upstream process in a biotechnological/industrial setting) is comprised of three main steps: expansion (generation of biomass), production (batch, fed-batch, or continuous process), and harvest. The expansion of cells can last from few days to weeks depending on the number of cells at the start, the cellular doubling time, and the required biomass to inoculate the production bioreactor. The production phase lasts a few weeks and is a highly sensitive phase as the concentration of different chemicals and physical parameters need to be tightly controlled. Finally, the harvest will allow the separation of the product of interest from large particles and then the desired material (cell culture supernatant or cells) is transferred to the downstream process.The raw materials used during the upstream phase (all three steps) need to be aligned with the final purpose of the manufactured product, as the presence of residual impurities may have an impact on suitability of the final product for a desired purpose.

There are three essential steps involved in bioethanol production from lignocellulosic biomass feedstocks. They are pretreatment, hydrolysis, and fermentation process. Among them, biomass pretreatment is an expensive and energy-intensive process used to remove the lignin and make the feedstock amenable for bioethanol production. The hydrodynamic cavitation can also be used for biomass pretreatment process. In order to improve the effectiveness of biomass pretreatment, a combination of any two methods of physical, chemical, and biological pretreatment can be used. A combination of the hydrodynamic cavitation pretreatment of biomass with the chemical or biochemical catalyst can be performed better than the individual pretreatment method. In this chapter, a protocol is describes the biomass pretreatment via a combined hydrodynamic cavitation with biocatalyst process.

Yarrowia lipolytica produces a range of valuable biotechnological products from natural metabolites and enzymes to heterologous proteins. The production of these products is affected by medium composition and various environmental factors. Here we describe bioprocess development for a recombinant laccase production by Y. lipolytica. At first, response surface methodology (RSM), as a statistical technique for design of experiment (DOE), is used for the optimization of medium composition in flask level. Then, results of RSM are applied to increase laccase production in controlled conditions of the bioreactor.

Rare earth metals, in the range of 0 to 250 micrograms, have been extracted quantitatively from perchloric, nitric or hydrochloric acid solutions by strong acid ion exchange paper disks in the sodium ion form. After the exchange is completed, the ion exchange paper disk is placed in a rotating sample holder and the amount of rare earth metals exchanged is determined by x-ray emission spectrography. At the 10 microgram level, the accuracy has a mean error of 2% with a precision of 1.5% relative standard deviation. The procedure has been applied to Sc+3, Y+3, Ce+4, Pr+3, Nd+3, Sm+3, Eu+3, Gd+3, Tb+3, Dy+3, Ho+3, Er+3, Tm+3, Yb+3 and Lu+3.

Hypoxanthine-guanine phosphoribosyltransferase (HGPRT; E.2.4.2.8.) and adenine phosphoribosyltransferase (APRT; E.2.4.2.7.) function in the metabolic salvage of purines. Complete absence of the activity of HGPRT leads to the Lesch-Nyhan Syndrome, characterised by severe developmental, neurological and behavioural abnormalities and gout.1, 2 Partial deficiencies of the enzyme cause hyperuricaemia and severe gout.3 On the other hand, complete deficiency of the enzyme APRT is associated with urinary stones composed of 2, 8-dihydroxyadenine (2, 8-DHA).4 Although these enzyme deficiencies are extremely rare, an early diagnosis is required to prevent the renal damage.5, 6 Among patients with urolithiasis, an increased incidence of APRT deficiency is proposed.7

All alcoholics drink excessive amounts of alcohol. Surely, those interested in the many aspects of alcoholism, regardless of viewpoint, would agree on this simple but general proposition. Researchers who wish to understand the conditions which lead to excessive alcohol intake are often interested in producing such intake in animals so that hypotheses of alcohol abuse can be evaluated with greater freedom than they can be in humans. Efforts taken over the last decade and a half have shown greater promise in producing excessive alcohol Intake in animals than did the early pioneering efforts. Until recently, for example, it was difficult to arrange conditions so that animals would voluntarily consume enough alcohol to produce intoxication as defined behaviorally or biochemically (e.g., Lester, 1966). It is now possible, however, to induce sustained intoxication in animals using a variety of techniques, and to examine analytically the conditions that induce the effects and the sequalae of this sustained intoxication, such as alcohol tolerance and dependence.

A gridded ionization chamber has been used to study the maximum energy resolution achievable with liquid argon and liquid xenon. With its high density and atomic number, liquid xenon is a particularly interesting filling for a high resolution detector to be used in many different applications. Our specific interest is to develop a large volume high resolution imaging liquid xenon instrument for high energy gamma-ray astrophysics as well as to search for nuclear double beta decay of Xe-136 with much better sensitivity than existing instruments. The energy resolution of liquid argon or xenon ionization detectors is expected to be close to that achievable with Ge (Li) spectrometers, given the measured W values and the small Fano factors calculated by Doke. However, the best experimental results so far are nearly an order of magnitude worse than the theoretical values. In order to understand the reasons for this discrepancy, we have carried out several measurements with both liquids. The electric field dependence of conversion electrons has been measured up to 11 kV/cm with optimized grid geometry and liquid purity. In liquid argon, we obtain 2.7% fwhm for the resolution of the dominant 976 keV electron line in the Bi-207 spectrum. This value, the best reported so far in the literature, is still a factor of seven worse than the Fano limit. We find that our results can be explained if we take into account the additional statistical fluctuations associated with incomplete charge collection from delta-electron tracks produced in large number along the path of the primary ionizing particle. The strong recombination rate on these heavily ionizing delta-electrons is the limiting process to the ultimate energy resolution of noble liquid detectors, unless very high fields are used. Alternatively, one can increase the electron mobility.

I am a member of a club which argues that one can get from high energy spectroscopy surprisingly good values for the (Hubbard) correlation energy of narrow band electrons, for the strength of hybridization energy of the narrow band states, and for the degrees of occupation of these levels. Working in this area can have its frustrations. On the one hand, if one is honest, one must admit that we are normally working with models in order to interpret the results. One thus wishes to discuss not only possible refinements of the models but also their limitations. On the other hand it is always difficult to live with the fact that many people do not seem to be aware about the possibilities of the high energy spectroscopies, or do not want to know. And if you talk about the problems in front of the people who do not know (or do not want to know) you do not make them very enthusiastic about what you are trying to do.

F. De Martini’s contribution was a description of the first results from his laboratory of the experiments in the title. He set up a laser interferometer by splitting the laser beam into two arms which were then recombined; a photon counter was placed so as to count photons in the recombined beam. One of the interferometer arms had a transparent, but translucent plastic disc placed in it, through which the light in that arm passed. Photon counting was then carried on when the original unsplit beam was attenuated throughout a range of intensities. The final photon counter readings varied from more than several thousand photons per second to the lowest levels of less than ten photons per second. Each of these readings was taken with the plastic disc stationary, and each such reading was considered as the standard or reference level for the particular setting of attenuation of the unsplit beam.

The availability of oxygen throughout the brain is far from homogeneous, oxygen tensions varying 30 or 40 mm Hg within a distance of a few microns (1–4). However, the pO2 at a given micro-area of cerebral tissue is remarkably constant, and can be changed only through major alterations in blood supply or the composition of respiratory gases (1,4,10). We have defined the different processes arrived at maintaining the constant brain cell oxygen micro-environment as “oxygen autoregulatory mechanisms.”

Karachay Ayran is a product of mixed fermentation that contains low levels of alcohol and carbon dioxide. Karachay Ayran has been reported to have antimicrobial, anticancer, and other health promoting properties.

The primary components of wood, the main raw material used for papermaking in North America, are the fibrous, hydrophilic carbohydrates (cellulose and hemicelluloses) and the three-dimensional, hydrophobic lignin. For the purpose of making papers, wood, either in the form of wood chips or sawmill residues, must first be reduced to pulps (discrete fibres) by a chemical or mechanical pulping process.1 In chemical pulping, pulps are produced in a yield of 45–55% through the dissolution of lignin by the pulping chemicals at an elevated temperature (≥ 160 °C). In mechanical pulping, pulps are formed in a yield of 90-98% through the action of mechanical forces that separate the fibres but retain lignin. From 1980 to 1999, the world mechanical pulp production has increased steadily from 27.6 to 35.1 million tonnes, accounting for ~ 23% of the total world wood pulp production.2 Such a steady increase is expected to continue because of the low cost and high efficiency in material usage involved in the production of mechanical pulps. Indeed, as far as the pulp and paper industry is concerned, one of the most profitable uses of lignin is to use it as a component of pulps and papers.3

Recent intensive research and development of organic field-effect transistors (FETs) [1–6] have been motivated by a new class of applications that cannot be easily realized by conventional electronics based on inorganic semiconductors. Organic transistors are mechanically flexible, thin, lightweight, and shock-resistant, because organic devices are manufactured on plastic films at low (ambient) temperature. Furthermore, manufacturing costs of organic transistor circuits would be inexpensive, even for large areas, when they are fabricated using printing technologies and/or roll-to-roll processes. There are two major applications for organic transistors. The first one is a flexible display. This new display includes a paper-like display or an electronic paper, where electric inks, electroluminescent (EL) devices, and liquid crystals or other mediums are powered by organic transistor active matrices [4, 7]. The second one is a radio frequency identification (RFID) tag [8, 9]. An organic transistor-based RFID tag may be printed on packages of products, resulting in an inexpensive and robust electronics. As another application of organic transistors, we demonstrated large-area flexible sensors. The first organic transistor-based large-area sensors are flexible pressure sensor matrices; organic transistor active matrices are used to read out pressure distributions over a large area from a 2-D array of pressure sensor cells. The new pressure sensor can be ideal for electronic artificial skin (e-skin) applications for future generations of robots. The mobility of pentacene that is known as a high-mobility low-molecular weight semiconductor is typically 1 cm2/Vs. This value is about two or three orders of magnitude lower than that of polyor single-crystalline silicon, respectively. Although flexible displays and/or RFID tags require usually high-electronic performance, the

In the present paper, the results are reported of an investigation on the biodegradability of poly(vinyl alcohol) (PVA) based systems containing poly(s-hydroxybutyrate) (PHB) of both microbial and synthetic source, as attained by polymerization of racemic s-butyrolactone. These materials, in the form of graft copolymers and blends, were submitted to the biological attack of natural soil and specific PVA-degrading microorganisms in respirometric tests. Significant levels of mineralization were recorded under soil burial conditions, though still lower than the biodegradation extent recorded by a filter paper sample utilized as biodegradable reference material. High levels of mineralization of PVA based blend and graft copolymer with atactic PHB occurred in a aqueous medium inoculated with PVA-degrading microorganisms. These results confirmed that amorphous PHB oligomers can be bioassimilated by non-PHB-degrading bacteria, also evidencing that high molecular weight atactic PHB can be degraded by the same selected microbial strains when blended with PVA.