Nanofibers fabricated using triaxial electrospinning as zero order drug delivery systems

A new strategy for creating functional trilayer nanofibers through triaxial electrospinning is demonstrated. Ethyl cellulose (EC) was used as the filament-forming matrix in the outer, middle, and inner working solutions and was combined with varied contents of the model active ingredient ketoprofen (KET) in the three fluids. Triaxial electrospinning was successfully carried out to generate medicated nanofibers. The resultant nanofibers had diameters of 0.74 ± 0.06 μm, linear morphologies, smooth surfaces, and clear trilayer nanostructures. The KET concentration in each layer gradually increased from the outer to the inner layer. In vitro dissolution tests demonstrated that the nanofibers could provide linear release of KET over 20 h. The protocol reported in this study thus provides a facile approach to creating functional nanofibers with sophisticated structural features.

Synthesis and characterization of thermally stable second-order nonlinear optical side-chain polyimides containing thiazole and benzothiazole push-pull chromophores

Push-pull nonlinear optical (NLO) chromophores containing thiazole and benzothiazole acceptors were synthesized and characterized. Using these chromophores a series of second-order NLO polyimides were Successfully prepared from 4,4'-(hexafluoroisopropylidene) diphthalic anhydride (6FDA), pyromellitic dianhydride (PMDA) and 3,3'4,4'-benzophenone tetracarboxylic dianhydride (BTDA) by a standard condensation polymerization technique. These polyimides exhibit high glass transition temperatures ranging from 160 to 188 degrees C. UV-vis spectrum of polyimide exhibited a slight blue shift and decreases in absorption due to birefringence. From the order parameters, it was found that chromophores were aligned effectively. Using in situ poling and temperature ramping technique, the optical temperatures for corona poling were obtained. It was found that the optimal temperatures of polyimides approach their glass transition temperatures. These polyimides demonstrate relatively large d(33) values range between 35.15 and 45.20 pm/V at 532 nm. (C) 2008 Elsevier B.V. All rights reserved.

Exploring context-awareness in the construction logistics services delivery

Managing a construction project supply chain effectively and efficiently is extremely difficult due to involvement of numerous sectors that are supported by ineffective communication system. An efficient construction supply chain system ensures the delivery of materials and other services to construction site while minimising costs and rewarding all sectors based on value added to the supply chain. The advancement of information, communication and wireless technologies is driving construction companies to deploy supply chain management strategies to seek better outputs. As part of the emerging wireless technologies, contextaware computing capability represents the next generation of ICT to the construction services. Conceptually, context-awareness could be integrated with Web Services in order to ensure the delivery of pertinent information to construction site and enhance construction supply chain collaboration. An initial study has indicated that this integrated system has the potential of serving and improving the construction services delivery through access to context-specific data, information and services on as-needed basis.

The human side of project management - an investigation of critical chain concepts in the Argentinean Project Environment

The global marketplace is rapidly intensifying. Longer product sales lives, greater profit margins or simply survival, is dependent on management¿s ability to create and lead change. Project Management has become an important competency, combined with other business practices to adapt to the trend of changing conditions. Critical Chain is a relatively new project methodology, elaborated by Eliyahu Goldratt in order to complete projects faster, make more efficient use of resources and securing the project deliverables. The methodology is based on the assumption that traditional project techniques such as CPM and PERT, do not recognize critical human behavior. The methodology claims that many project failures are a direct result of how safety is built into the task delivery times, and then wasted by human behavior such as Student Syndrome, Parkinson Law and Multitasking. However, there has been little or no previous research regarding this topic in the Argentine marketplace. This study intended to investigate to what extent the human behavior concepts of critical chain project management are present, by performing in-depth interviews with Argentine project stakeholders. It appears that the four human behavior concepts are present in Argentina and that the majority of Argentine companies are yet to apply project management techniques.

Tissue distribution of a plasmid DNA encoding Hsp65 gene is dependent on the dose administered through intramuscular delivery

In order to assess a new strategy of DNA vaccine for a more complete understanding of its action in immune response, it is important to determine the in vivo biodistribution fate and antigen expression. In previous studies, our group focused on the prophylactic and therapeutic use of a plasmid DNA encoding the Mycobacterium leprae 65-kDa heat shock protein (Hsp65) and achieved an efficient immune response induction as well as protection against virulent M. tuberculosis challenge. In the present study, we examined in vivo tissue distribution of naked DNA-Hsp65 vaccine, the Hsp65 message, genome integration and methylation status of plasmid DNA. The DNA-Hsp65 was detectable in several tissue types, indicating that DNA-Hsp65 disseminates widely throughout the body. The biodistribution was dose-dependent. In contrast, RT-PCR detected the Hsp65 message for at least 15 days in muscle or liver tissue from immunized mice. We also analyzed the methylation status and integration of the injected plasmid DNA into the host cellular genome. The bacterial methylation pattern persisted for at least 6 months, indicating that the plasmid DNA-Hsp65 does not replicate in mammalian tissue, and Southern blot analysis showed that plasmid DNA was not integrated. These results have important implications for the use of DNA-Hsp65 vaccine in a clinical setting and open new perspectives for DNA vaccines and new considerations about the inoculation site and delivery system. © 2006 Coelho-Castelo et al; licensee BioMed Central Ltd.

Development of a recombinant fusion protein based on the dynein light chain LC8 for non-viral gene delivery

The low efficiency of gene transfer is a recurrent problem in DNA vaccine development and gene therapy studies using non-viral vectors such as plasmid DNA (pDNA). This is mainly due to the fact that during their traffic to the target cell's nuclei, plasmid vectors must overcome a series of physical, enzymatic and diffusional barriers. The main objective of this work is the development of recombinant proteins specifically designed for pDNA delivery, which take advantage of molecular motors like dynein, for the transport of cargos from the periphery to the centrosome of mammalian cells. A DNA binding sequence was fused to the N-terminus of the recombinant human dynein light chain LC8. Expression studies indicated that the fusion protein was correctly expressed in soluble form using E. coli BL21(DE3) strain. As expected, gel permeation assays found the purified protein mainly present as dimers, the functional oligomeric state of LC8. Gel retardation assays and atomic force microscopy proved the ability of the fusion protein to interact and condense pDNA. Zeta potential measurements indicated that LC8 with DNA binding domain (LD4) has an enhanced capacity to interact and condense pDNA, generating positively charged complexes. Transfection of cultured HeLa cells confirmed the ability of the LD4 to facilitate pDNA uptake and indicate the involvement of the retrograde transport in the intracellular trafficking of pDNA: LD4 complexes. Finally, cytotoxicity studies demonstrated a very low toxicity of the fusion protein vector, indicating the potential for in vivo applications. The study presented here is part of an effort to develop new modular shuttle proteins able to take advantage of strategies used by viruses to infect mammalian cells, aiming to provide new tools for gene therapy and DNA vaccination studies. (C) 2012 Elsevier B.V. All rights reserved.

Development of a supplier and purchase order management product/service under the 4PL logistics concept: a case study

Supply chain starts with a demand arisen and ends with material transport and delivery at its final destination. With this in mind, most of manufacturing, processors or distribution companies of consumer goods, spare parts and components for production, processing and finished goods, within national or international markets, may not have information and control over its supply chain performance. This article presents concept and logistics models evolution, purchase order and international supplier management, control tower and its logistics information systems. This also presents a real process implementation for a global high tech manufacturer company.

The relationship of maternal low birthweight and infant low birthweight among African-American women at term delivery: Findings from the 1988 National Maternal and Infant Health Survey

A cohort study study design was used to study the relationship of maternal low birthweight and infant low birthweight among African American women delivering full term infants. The cohort consisted of 3,157 mother-infant pairs drawn from the 1988 National Maternal and Infant Health Survey conducted by the National Center for Health Statistics. The objectives of the study were (1) to determine if low birthweight, African American mothers delivering term infants experienced higher rates of infant low birthweight and (2) to examine the role of selected contributory variables in the relationship of maternal low birthweight and infant low birthweight. Contributory risk factors examined included maternal marital status, maternal age, maternal education, maternal height, maternal prepregnant weight, birth order, history of a prior low birthweight delivery, timing of prenatal care, number of prenatal visits, gestational length, infant gender, and behavioral factors of smoking, alcohol, and illicit drug use during pregnancy.^ Using logistic regression analysis, risk of infant low birthweight among maternal low birthweight mothers increased after controlling for less than a high school education, less than 20 years of age, prepregnant weight less than 100 lbs, history of a prior low birthweight delivery, birth order, smoking during pregnancy, and use of alcohol and illicit drugs during pregnancy, but was not statistically significant. Loss of statistical significance was attributed to a large reduction in cases available for analysis after including illicit drug use in the model.^ This study demonstrated a consistent pattern of increased rates of infant low birthweight among low birthweight mothers. The force of history remains, hence women with this trait should be carefully monitored and advised during pregnancy to decrease risk of a low birthweight infant, in order to decrease the chain of events leading to future generations of low birthweight mothers. ^

Supply chain collaboration and responsiveness : a comparison between Thai automotive and electronics industries

This paper examines factors that promote firms to develop supply chain collaborations (SCC) with their partners and relationships between SCC and supply chain operational performances (SCOP), using a questionnaire survey on Thai automotive and electronics industries in 2012. This paper also carries out a comparative study on these questions between the electronics and automotive industries. Two-stage least squares (2SLS) regressions verifY that supplier evaluation and audit is a foundation for firms to share information and synchronize decision makings with their partners, and that such SCC are significantly related to SCOP indictors such as on-time delivery, fast procurement, and flexibility to customer need irrespective of industry type. On the other hand, competitive pressure motivates only electronics firms to develop sec in order to be more innovative.

Auto component supply chain: a path to global India

Supply chain management works to bring the supplier, the distributor, and the customer into one cohesive process. The Supply Chain Council defined supply chain as ‘Supply Chain: The flow and transformation of raw materials into products from suppliers through production and distribution facilities to the ultimate consumer., and then Sunil Chopra and Meindl, (2001) have define Supply chain management as ‘Supply Chain Management involves the flows between and among stages in a supply chain to maximize total profitability.’ After 1950, supply chain management got a boost with the production and manufacturing sector getting highest attention. The inventory became the responsibility of the marketing, accounting and production areas. Order processing was part of accounting and sales. Supply chain management became one of the most powerful engines of business transformation. It is the one area where operational efficiency can be gained. It reduces organizations costs and enhances customer service. With the liberalization of world trade, globalization, and emergence of the new markets, many organizations have customers and competitions throughout the world, either directly or indirectly. Business communities are aware that global competitiveness is the key to the success of a business. Competitiveness is ability to produce, distribute and provide products and services for the open market in competition with others. The supply chain, a critical link between supplier, producer and customer is emerged now as an essential business process and a strategic lever, potential value contributor a differentiator for the success of any business. Supply chain management is the management of all internal and external processes or functions to satisfy a customer’s order (from raw materials through conversion and manufacture through logistics delivery.). Goods-either in raw form or processed, whole sale or retailed distribution, business or technology services, in everyday life- in the business or household- directly or indirectly supply chain is ubiquitously associated in expanding socio-economic development. Supply chain growth competitive performance and supporting strong growth impulse at micro as well as micro economic levels. Keeping the India vision at the core of the objective, the role of supply chain is to take up social economic challenges, improve competitive advantages, develop strategies, built capabilities, enhance value propositions, adapt right technology, collaborate with stakeholders and deliver environmentally sustainable outcomes with minimum resources.

Transition-state structure as a unifying basis in protein-folding mechanisms: Contact order, chain topology, stability, and the extended nucleus mechanism

I attempt to reconcile apparently conflicting factors and mechanisms that have been proposed to determine the rate constant for two-state folding of small proteins, on the basis of general features of the structures of transition states. Φ-Value analysis implies a transition state for folding that resembles an expanded and distorted native structure, which is built around an extended nucleus. The nucleus is composed predominantly of elements of partly or well-formed native secondary structure that are stabilized by local and long-range tertiary interactions. These long-range interactions give rise to connecting loops, frequently containing the native loops that are poorly structured. I derive an equation that relates differences in the contact order of a protein to changes in the length of linking loops, which, in turn, is directly related to the unfavorable free energy of the loops in the transition state. Kinetic data on loop extension mutants of CI2 and α-spectrin SH3 domain fit the equation qualitatively. The rate of folding depends primarily on the interactions that directly stabilize the nucleus, especially those in native-like secondary structure and those resulting from the entropy loss from the connecting loops, which vary with contact order. This partitioning of energy accounts for the success of some algorithms that predict folding rates, because they use these principles either explicitly or implicitly. The extended nucleus model thus unifies the observations of rate depending on both stability and topology.