Collaboration and distances between German immunological institutes – a trend analysis

Background

The hypothesis that distance matters but that in recent years geographical proximity has become less important for research collaboration was tested. We have chosen a sample–authors at German immunological institutes–that is relatively homogeneous with regard to research field, language and culture, which beside distance are other possible factors influencing the willingness to co-operate. We analyse yearly distributions of co-authorship links between institutes and compare them with the yearly distributions of distances of all institutes producing papers in journals indexed in the Science Citation Index, editions 1992 till 2002. We weight both types of distributions properly with paper numbers.

Results

One interesting result is that place matters but if a researcher has to leave the home town to find a collaborator distance does not matter any longer. This result holds for all years considered, but is statistically most significant in 2002. The tendency to leave the own town for collaborators has slightly increased in the sample. In addition, yearly productivity distributions of institutes have been found to be lognormal.

Conclusion

The Internet did not change much the collaboration patterns between German immunological institutes.

     

Effects of silver content and morphology on the catalytic activity of silver-grafted titanium oxide nanostructure

As titanium oxide is a well-known photocatalyst, we investigated the effects of silver content and nanostructural morphology on the photocatalytic degradation of two dyes, methylene blue and rhodamine B. Two nano-formulations were utilized, including nanofibers and nanoparticles. Silver-grafted titanium oxide nanofibers were synthesized using the electrospinning of silver nitrate/titanium isopropoxide/poly(vinyl acetate) sol-gel. The nanoparticulate form was obtained by calcination of a ground powder prepared from the same electrospun sol-gel. The results affirmed the advantage of the silver-grafted titanium oxide nanostructures over the silver-free ones. Increasing the silver content in the nanofibers led to increases in their surface area, which is an important parameter in heterogeneous catalytic chemical reactions. Therefore, the results strongly suggest the use of silver-grafted titanium oxide in a nanofibrous form. These results further support utilizing Agloaded titanium oxide nanofibers as a photocatalyst.     

Union dyeing of the photografted PET/wool blend fabrics with dimethylaminopropyl methacrylamide

Dimethylaminopropyl methacrylamide (DMAPMA) was grafted onto PET/wool blend fabrics by continuous UV irradiation. Union dyeing of the photografted fabrics was investigated using three reactive dyes of α-bromoacrylamide reactive groups. The influence of grafting yield, DMAPMA concentration, NaCl amount, pH value, and dyeing temperature on the dyeability was evaluated. The dyeability of both PET and wool components was improved significantly by the DMAPMA photografting and successive reactive dyeing. Although the dyeability of the PET component in the blend substantially was improved with higher grafting, equal dyeability between PET and wool was difficult to achieve due to more facile grafting and higher reactivity of the wool component compared with the modified PET component. However, the color fastness of the PET/wool blend fabric was excellent for all three colors. This study may offer a way to achieve union dyeing of PET/wool blend fabrics.     

Antioxidant and Cytotoxic Activities of Aphanes arvensis Extracts

The objectives of this study were to examine the free radical scavenging activity and the protective effects against macromolecular oxidation as well as the cytotoxic activity of Aphanes arvensis aqueous and methanolic extracts. Free radical scavenging activity was determined by DPPH method. The methanolic extract showed a scavenging activity nearly equivalent to Trolox and Vitamin C and has an IC₅₀ value of 4.54 μg/mL. Total antioxidant capacity was determined by CUPRAC method. The antioxidant capacity of aqueous and methanolic extract was 0.792 and 1.550 mmol TE/g DWE, respectively. The protective effect of A. arvensis extracts against lipid peroxidation was evaluated using a liposome oxidation system. The methanolic extract was more active than the aqueous extract. The aqueous extract possessed protective effect against protein oxidation in a dose dependent manner. Both extracts showed inhibitory effect on DNA oxidation as measured by plasmid relaxation assay. Results presented here indicate that A. arvensis possess strong antioxidant activity and protective effects with very little cytotoxic effect, and they can therefore be used as a natural additive in food, cosmetic and pharmaceutical industries.     

Six Edible Wild Fruits as Potential Antioxidant Additives or Nutritional Supplements

Total antioxidant activity of six non-cultivated but traditionally collected fruits from the south of Europe was assessed by measuring their ability to reduce the hydroxyl radical ( OH^· ) \left( {{\hbox{O}}{{\hbox{H}}^\bullet }} \right) and hydrogen peroxide (H₂O₂), and their Trolox equivalent antioxidant capacity (TEAC). This antioxidant activity was compared with that shown by the synthetic antioxidants BHA (E-320), BHT (E-321) and propyl gallate (E-310). Total phenolics, ascorbic acid and the carotenoid content of the fruits were also analyzed. All fruits showed a high ability to scavenge the OH^· {\hbox{O}}{{\hbox{H}}^\bullet } radical, ranging from 60.61% to 81.04% inhibition for Rosa canina and Crataegus monogyna, respectively. The H₂O₂ scavenging capacity and the TEAC value varied widely, ranging between 3.63% and 87.26% inhibition of H₂O₂ and between 0.47 and 416.64 mM trolox g⁻¹ FW for Sorbus domestica and Rosa canina, respectively. The antioxidant activity of fruits was higher than that of the synthetic additives analyzed, except in the TEAC assay. The phenolic and carotenoid content of R. canina was much higher than that of the other fruits analyzed and its ascorbic acid concentration was also high, reflecting its higher efficacy towards ABTS ^·- {\hbox{ABT}}{{\hbox{S}}^{ \bullet - }} (TEAC assay) and H₂O₂ species_. In spite of these associations, the correlation coefficients between total antioxidant activity and the antioxidant compounds analyzed were not very significant; only phenolics and carotenoids showed a marginal correlation with the TEAC assay. The results support the possible use of R. canina as natural antioxidant to replace the synthetic additives, as well as their use in the production of functional foods with a high antioxidant activity.     

Effect of CIPC on Sprout Inhibition and Processing Quality of Potatoes Stored Under Traditional Storage Systems in India

Indigenous non-refrigerated methods like heaps and pits are used in India for short-term storage of potatoes (Solanum tuberosum L.) to avoid distress sale. Storing untreated potatoes generally results in high losses from sprouting, moisture loss and rotting. To reduce storage losses by inhibition of sprouting and to determine the suitability of stored potatoes for processing into crisps, a single spray application of a commercial formulation of 3-chlorophenyl carbamate (CIPC or chlorpropham) 50% a.i., (Oorja, United Phosphorus Limited, Mumbai, India) of CIPC (or chlorpropham) was tested on potatoes during storage from March to June under two traditional storage methods [heap (17–33 °C, 58–92% relative humidity (RH)) and pit (17–27 °C, 72–95% RH)] in 2 years [2005 up to 90 days of storage (DOS) and 2006 up to 105 DOS], using four cultivars and two rates of CIPC application (20 and 30 mg a.i. kg⁻¹ tubers). The two rates of application were comparably effective in reducing weight losses, sprouting and sprout growth in stored tubers, and the effect was more pronounced in pit storage than in heap storage. By contrast to untreated tubers, CIPC-treated potatoes remained turgid under the two storage methods and fetched market prices comparable to those for cold-stored (2–4 °C) potatoes after 105 days of storage. Reducing sugar concentrations in treated potatoes decreased during storage especially in 2006 when the initial reducing sugar concentration was higher than in 2005. Crisp colour improved only in 2005 after 90 DOS, but it deteriorated in 2006 during storage up to 105 DOS. Sucrose concentration increased tremendously during storage in 2 years. Only one cultivar (Kufri Chipsona-1) with low initial reducing sugar concentration and less sucrose accumulation during storage could produce acceptable colour crisps after storage in both years. The remaining three cultivars—with high initial reducing sugar concentration—were suitable for processing after storage in heap and pit in 2005, but not in 2006. Stored potatoes were safe for human consumption as the CIPC residue concentrations were far below the permissible level of 10 mg kg⁻¹ as prescribed by the European Union. Single spray application of CIPC (20 mg kg⁻¹ treatment) can effectively reduce storage losses in potatoes stored in traditional non-refrigerated methods of heap and pit and extend the storage life by 90 to 105 days.     

Iron Fortification of Whole Potato Using Vacuum Impregnation Technique with a Pulsed Electric Field Pretreatment

In this study, the effect of a vacuum impregnation (VI) process with pulsed electric field (PEF) pretreatment on fortification of whole potato with ferric pyrophosphate was investigated. The VI process and PEF pretreatment were optimized with respect to physicochemical attributes of PEF-VI-processed samples using response surface methodology (RSM). The results indicated that the iron content of VI-processed and PEF-VI-processed potatoes was increased about 126 and 457%, respectively, compared to unprocessed potatoes. A more intensive PEF pretreatment led to a higher cell disintegration, decrease in colour and textural parameters and also increase in components leakage from treated potato. Our study suggests that whole 180-g potatoes should be pretreated at 394 V/cm with 36 pulses and then treated at 3.5 kPa for 37 min in vacuum stage and 39 min restoration time in atmospheric stage to achieve the highest iron fortification and the lowest physicochemical changes during PEF-VI processing.     

Application of <Emphasis Type="Italic">Sterculia Foetida</Emphasis> Fruit Shell Waste Biomolecules on Silk for Aesthetic and Wellness Properties

There has been growing interest in the use of bioresource waste for natural dyeing and finishing. This paper discusses dye extraction from the novel source fruit shell waste of Sterculia foetida and its application on mulberry silk fabric to confer aesthetic coloration and wellness properties such as ultra-violet (UV) protection and antibacterial properties. Treated fabrics showed a substantial increase in color depth and adequate wash, light, and rubbing fastness properties for dyed silk fabrics with and without mordanting. Pre-and post-mordanting of silk fabrics were carried out using mordants such as alum, harda (myrobalan), and copper sulfate. UV-visible spectrophotometric analysis of fruit shell extract (FSE) at different pHs and FSE with three different mordants at neutral pH was used to understand the phenomena of dye-fiber interaction. The treated fabrics characterised by ATR-FTIR, SEM-EDS, and XRD analysis indicate the nature of dye fiber interaction justifying the multifunctional properties. The treated fabric also showed very good ultraviolet protection property and antibacterial properties both against S. aureus and E. coli bacteria even after ten washes. The results indicate that Sterculia foetida fruit shell extract offers an excellent potential as coloration, antibacterial, and ultraviolet protective agent for mulberry silk fabric.     

1-Aminoanthraquinone Diazonium Salt on the Coupling Modification Dyeing of Silk Fibroin with Enhanced Color Fastness

Chromophore incorporated into the protein chains through residue modification on silk fibroin will be an important way to get new dyeing technology with improved color fastness. Herein, 1-aminoanthraquinone diazonium salt was prepared and used for the modified dyeing on tyrosine of silk fibroin. The silk after modified dyeing was measured by UV-Vis, FTIR, MS, ¹H-NMR, Data color, and other testing techniques. Interestingly, the resulting silk showed excellent rub and wash fastness. The enhanced color fastness is contributed by an electrophilic substitution reaction between 1- aminoanthraquinone diazonium salt and the ortho position of phenolic hydroxyl in tyrosine molecular. Moreover, the mechanical property of silk was protected effectively by the mild coupling modified dyeing, better than the traditional acid dyeing under high temperature for a long time. This facile strategy provides an alternative approach to silk dyeing and benefits the silk applications.