Search results for "medium"
showing 10 items of 3746 documents
Preliminary approach to elucidate the role of pigment as a binding site for drugs and chemicals in anagen hairs: pigments as carriers for 3 H-haloper…
2002
In view of the melanin-binding characteristics of haloperidol and its differential uptake by pigment- and non-pigment-producing cells, a co-culture of HaCaT with Sk-Mel-1 cell lines was performed to investigate whether melanosomes act as carriers for drug molecules associated with the pigments. Initially, HaCaT and Sk-Mel-1 cells were separately cultivated in the presence of 3H-haloperidol (400 pmol/ml medium ) for 28 days followed by subsequent co-cultivation in the absence of 3H-haloperidol for 5 days. The transfer of pigments into the keratinocytes during co-culture was confirmed by transmission electron microscopy. After the co-culture experiments a striking increase (or = 50%) of 3H-ha…
Colon-specific drug delivery: Influence of solution reticulation properties upon pectin beads performance.
2006
In this study, pectinate gel beads were produced by ionotropic gelation method with different solutions of cross-linking agents and ketoprofen was entrapped as model drug. The influence of these formulation parameters was investigated upon bead properties and upon their performance to target the colon. Zinc pectinate beads obtained with 10% of counter-ions solution at pH 1.6 exhibited the strongest gel network due to "egg-box" dimmer formation helped by hydrogen bonding. Furthermore the gel network formed at low pH was arranged in a compact three-fold conformation. Thus, this matrix structure in enteric capsules induced the lowest drug release in the upper gastro-intestinal tract (pH 1.2 fo…
Kontrastmittel-Kurzinfusion oder -Bolusinjektion bei der i.v. Urographie
1993
The rate of contrast injection during i.v. urography may vary considerably (bolus injection or drip infusion). The effect of 5 rates of injection (6, 12, 18, 36 and 72 ml/min) on the contrast density in the renal collecting system was examined over a period of 30 minutes. Measurements showed an inter-individual difference of more than 200% in each group. The intra-individual variations for different rates of injection were very slight; individual concentration in the kidney for a given dose depends only slightly on the rate of injection. There is no statistically significant improvement in contrast values as a result of a bolus injection. The reduced incidence of side effects justifies the …
Oxidation of niobium sheets at high temperature
1997
Abstract This work shows the role of oxygen pressure on growth kinetics, morphology, phase composition and texture of oxide scale in the oxidation of niobium sheets at 900 °C. The particular morphology observed at low pressure shows the existence of competition between edge and surface growth mechanisms. Pressure and conversion rate influence the nature of preferential orientations of the Nb2O5 oxide layer: a [110] fibre axis is stabilized at high pressure but, at low pressure, the higher is the conversion rate, the more evident is this fibre axis. This behaviour is observed not only after cooling but also in situ. At high pressure, the evolution is not only temporal but also spatial: with …
The requisite match between internal resources and network ties to cope with knowledge scarcity
2020
PurposeThis paper aims to investigate the internationalization strategies of small and medium enterprises (SMEs), focusing on the interaction between network ties and “soft” internal resources at the foundation of knowledge management (KM). Specifically, it identifies the firms’ internal capabilities that affect KM strategies, and their collective influence on the degree of internationalization; verifies the influence of network ties on the internationalization process itself; and develops a conceptual “preliminary theoretical framework of SME internationalization capabilities and networks.”Design/methodology/approachThe primary research and analysis are based on a proportional stratified s…
Barriers in organizing the Romanian firms in responsibility centers
2017
In the current turbulent business environment, the big and medium enterprises must organize their activity in order to face new challenges. One of the organizational forms that can stimulate the performances of the firms is the one in responsibility centers. This paper addresses the issue of the responsibility centers starting from the possibility of using benchmarking before and after the implementation of this organizational form. After highlighting the advantages of the responsibility centers, we presented a study made in Romanian big and medium organizations, regarding the barriers in the design and implementation of this organizational form. The main causes that determine Romanian mana…
Successful SME web design through consumer focus groups
2011
Purpose – The purpose of this research is to pursue two major objectives. First, to identify the key design variables for building successful transactional SME (Small Medium Enterprises) websites. Second, the transactional relevance of each key design variable is tested in order to establish priorities.Design/methodology/approach – The present paper is developed through seven consumer focus groups. Two approaches were used: an ethnographic summary of each focus group (qualitative approach) and a systematic coding procedure (quantitative approach).Findings – The findings indicate that a transactional website should have three main strong points: it must be secure; price information should be…
ERP System Implementation in Make-to-Order SMEs: An Exploratory Case Study
2011
The purpose of this paper is to investigate the issue of Enterprise Resource Planning (ERP) system implementation in the context of Make-To-Order (MTO) Small and Medium-size Enterprises (SMEs). No prior study has investigated the whole ERP implementation process in MTO SMEs. Because of the special requirements of both the SME and the MTO context, ERP implementations under these conditions are challenging. We investigate how these organizational characteristics influence the implementation of an ERP system. This study is part of a larger research project to investigate ERP implementation issue in SMEs. We present the empirical findings from an exploratory case study of an ERP implementation …
Hydrological consequences of natural rubber plantations in Southeast Asia
2020
Since the turn of the century, rubber plantations have been expanding their footprint across Southeast Asia in response to an increasing global demand for rubber products. Between 2000 and 2014, the area cultivated with rubber more than doubled. It is not clear how this major change in the agricultural landscape of Southeast Asia, the main area of rubber production in the world, is affecting land‐use patterns and water resources in the region. Here we use maps of rubber plantations and other croplands in conjunction with a hydrological model and remote sensing analyses to assess land‐use patterns and water resources affected by natural rubber plantations. Results show water requirements of …
Effect of EDTA on divalent metal adsorption onto grape stalk and exhausted coffee wastes
2007
In the present work, two industrial vegetable wastes, grape stalk, coming from a wine producer, and exhausted coffee, coming from a soluble coffee manufacturer, have been investigated for the removal of Cu(II) and Ni(II) from aqueous solutions in presence and in absence of the strongly complexing agent EDTA. Effects of pH and metal-EDTA molar ratio, kinetics as a function of sorbent concentration, and sorption equilibrium for both metals onto both sorbents were evaluated in batch experiments. Metal uptake was dependent of pH, reaching a maximum from pH around 5.5. EDTA was found to dramatically reduce metal adsorption, reaching total uptake inhibition for both metals onto both sorbents at e…