Molecular imprinting technology: challenges and prospects for the future

Molecular imprinting is a technique for the fabrication of biomimetic polymeric recognition sites or “plastic antibodies/receptors” which is attracting rapidly increasing interest. By this technology, recognition matrices can be prepared which possess high substrate selectivity and specificity. In the development of this technology, several applications have been foreseen in which imprinted materials may be exchanged for natural recognition elements. Thus, molecularly imprinted polymers have been used as antibody/receptor binding mimics in immunoassay-type analyses, as enzyme mimics in catalytic applications and as recognition matrices in biosensors. The best developed application area for imprinted materials, though, has been as stationary phases for chromatography, in general, and chiral chromatography, in particular. This review seeks to highlight some of the more intriguing advantages of the technique as well as pointing out some of the difficulties encountered. The prospects for future development will also be considered. Chirality 10:195–209, 1998. © 1998 Wiley-Liss, Inc.     

Bioinformatics challenges of new sequencing technology

New DNA sequencing technologies can sequence up to one billion bases in a single day at low cost, putting large-scale sequencing within the reach of many scientists. Many researchers are forging ahead with projects to sequence a range of species using the new technologies. However, these new technologies produce read lengths as short as 35-40 nucleotides, posing challenges for genome assembly and annotation. Here we review the challenges and describe some of the bioinformatics systems that are being proposed to solve them. We specifically address issues arising from using these technologies in assembly projects, both de novo and for resequencing purposes, as well as efforts to improve genome annotation in the fragmented assemblies produced by short read lengths.     

Combinatorial methods in molecular imprinting

Molecular imprinting is a general method for synthesizing robust, network polymers with highly specific binding sites for small molecules. Recently, combinatorial and computational approaches have been employed to select an optimal molecularly imprinted polymer (MIP) formulation for a targeted analyte. The use of MIPs in the combinatorial field, specifically their use for screening libraries of small molecules, has also been developed.     

粪便DNA分析技术在分子生态学研究中的机遇与挑战

随着粪便DNA分析技术的不断发展与完善,其越来越多地被应用于分子生态学研究中,特别是野生动物的遗传状况评估研究。粪便DNA的获取可以在不干扰,甚至无需观察到动物本身的情况下展开,因此避免了取样活动可能给野生动物带来的干扰或伤害,极大地促进了野生动物分子生态学的研究。虽然粪便DNA分析技术在其建立伊始因DNA质量问题而受到了一定的挑战,但自其建立至今,研究者发展了多种技术来克服这一问题。现已能获得较高质量的粪便DNA,并将基因分型错误率控制在较低水平。本文将结合我们在粪便DNA分析技术上所积累的经验,从粪便样品采集、保存、DNA提取、PCR扩增以及等位基因分型等各个环节对该技术进行详细探讨,以期阐明该技术在野生动物分子生态学研究中所面临的机遇与挑战,进一步推动其在我国野生动物保护研究中的应用与发展。     

Organizational responses to new ocean science and technology developments

Abstract

Rapid developments in ocean science and technology, together with the emerging new ocean regime, present considerable challenges to the international organizational structure. After indicating some recent ocean science and technology developments, the author examines the capacity for organizational response, both within and outside the UN system. Next, the paper identifies aspects of national ocean interests that tend to dictate policies of individual nations toward the responses of these international organizations to new advances. Finally, the author looks to prospects for the 1980s.     

Some recent developments in the molecular epidemiology of Epstein-Barr virus infections

We have applied two different recombinant DNA techniques to the study of the epidemiology of Epstein-Barr virus infections. In the first application, cloned subfragments of viral DNA were used as probes to detect EBV DNA in a variety of lymphoproliferative disorders and in lymphoid cell lines. Patients who are epidemiologically unrelated harbor EBV genotypes which can readily be distinguished from each other. Patients who are epidemiologically related (such as mothers and infants) have similar EBV genotypes. Some patients, especially those who are immunocompromised, are infected with two distinct genotypes. In the second application, we have examined the immune response to specific EBV antigens expressed from small cloned viral DNA subfragments. We have identified a group of patients with presumed chronic EBV infection who selectively fail to recognize one subcomponent of the EB nuclear antigen complex.     

Determination of phenformin hydrochloride using molecular imprinting technology coupled with flow-injection chemiluminescence

A novel method was developed using molecular imprinting technology (MIT) coupled with flow‐injection chemiluminescence (FI‐CL) for highly sensitive detection of phenformin hydrochloride (PH). The phenformin imprinted polymer was synthesized with methacrylic acid (MAA) as a functional monomer and ethylene glycol dimethacrylate (EGDMA) as a cross‐linker. Newly synthesized molecularly imprinted polymer (MIP) particles were packed into a column as a selective recognition element for determination of PH. A CL method for the determination of PH was developed based on the CL reaction of PH with N‐bromosuccinimide sensitized by eosin Y in basic media. The optimization of detection conditions was investigated. The CL intensity responded linearly to the concentration of PH in the range 0.09–2.0 µg/mL, with a correlation coefficient of 0.9920. The detection limit was 0.031 µg/mL. The relative standard deviation for the determination of 1.0 µg/mL PH solution was 1.0% (n = 11). The method was applied to the determination of PH in urine samples, with satisfactory results. Copyright © 2011 John Wiley & Sons, Ltd.     

Stoichiometric noncovalent interaction in molecular imprinting

In this review article the function of the binding site monomers in the molecular imprinting procedure is discussed. Especially, new developments towards stoichiometric noncovalent interactions are highlighted. In stoichiometric noncovalent interactions template and binding site monomer in an 1:1 molar ratio are nearly completely bound to each other. This is only possible if the association constants are considerably high (K _ass < 900 M^–1). Using this type of interaction in molecular imprinting no excess of binding sites is necessary and binding sites are only located inside the imprinted cavity. Since all cavities can be reloaded these polymers show high capacity (e.g., for preparative application) and are especially suited for the synthesis of catalytically active imprinted polymers. Discussed are binding site interactions based on amidines (and guanidines), multiple hydrogen bonding, charge-transfer interactions, and host–guest inclusion. The systematic investigation of the underlying binding reaction is described in detail. With low-molecular weight model substances the thermodynamics of the association can be conveniently investigated, e.g., by NMR spectroscopy.     

Genomic imprinting: developmental significance and molecular mechanism

Imprinting results in the preferential expression of either the maternal or the paternal allele of certain genes, and has a critical influence on the regulation of mammalian development. The identification of specific imprinted chromosomal regions and genes is being used to unravel the molecular mechanism of imprinting and the developmental significance of the non-random expression of parental alleles.     

New developments in microarray technology

Microarrays have emerged as indispensable research tools for gene expression profiling and mutation analysis. New classification of cancer subtypes, dissecting the yeast metabolism and large-scale genotyping of human single nucleotide polymorphisms are important results being obtained with this technique. Realizing the microsphere-based massively parallel signature sequencing technique as fluid microarrays, building new types of protein arrays and constructing miniaturized flow-through systems, which can potentially take this technology from the research bench into industrial, clinical and other routine applications, exemplify the intense developments that are now ongoing in this field.     

Simulation of algal photobioreactors: recent developments and challenges

Widespread cultivation of phototrophic microalgae for sustainable production of a variety of renewable products, for wastewater treatment, and for atmospheric carbon mitigation requires not only improved microorganisms but also significant improvements to process design and scaleup. The development of simulation tools capable of providing quantitative predictions for photobioreactor performance could contribute to improved reactor designs and it could also support process scaleup, as it has in the traditional petro-chemical industries. However, the complicated dependence of cell function on conditions in the microenvironment, such as light availability, temperature, nutrient concentration, and shear strain rate render simulation of photobioreactors much more difficult than chemical reactors. Although photobioreactor models with sufficient predictive ability suitable for reactor design and scaleup do not currently exist, progress towards this goal has occurred in recent years. The current status of algal photobioreactor simulations is reviewed here, with an emphasis on the integration of and interplay between sub-models describing hydrodynamics, radiation transport, and microalgal growth kinetics. Some limitations of widely used models and computational methods are identified, as well as current challenges and opportunities for the advancement of algal photobioreactor simulation.